Remark

Concluding remarks. - From the above it is clear that neither the problem of the structure of supported vanadium oxide nor that of the special role of Ti02 as a support have definitively been solved. Further work on these and related problems is certainly necessary. As suggested above a more widespread use of some of the experimental methods by different research groups, allowing a comparison of the results, offers important advantages in this respect. 

Meteniowski and S. Zielinski, React. Kinet. Catal. Lett., 1980, 14, 233. 

A review3 with 69 references was published in 1979 by Katzer and Sivasubramanian where the industrial aspect from a North American economic point of view has been emphasized. Shah and Cronauer4 and Gavin68d have reviewed the O, N, and S removal reactions in coal liquefaction, where the part concerning N removal was elegantly summarized. However a more fundamental examination emphasizing the mechanistic and kinetic aspects of the reaction seems necessary, because much work on these aspects has been described in the literature since 1979. Economic and industrial aspects will however also be reviewed. 

Comparison of the estimated figures for demand and production shows a deficit of about 1 x 1091, a value which however depends upon the state of the economies of the developing countries. This deficit will however only be filled by synthetic petroleum originating either from liquefied coal, heavy oils, sand oils and/or shale oils. Proven reserves and their locations are reported in Table 1. 

Two of the great industrial nations, Japan and France, are absent from this concert. The alternative solutions are not clearly foreseen for Japan. France has opted for the nuclear solution. In 2000 the electric capacity from nuclear power stations will be 108kW, which is 1.75 kW per inhabitant this compares with 1.05 kW per inhabitant for Sweden, 1.00 for Finland, 0.94 for Belgium, 0.91 for Canada, 0.7 for the USA and West Germany and only 0.48 for the UK. Italy is absent from both tables. 

Conventions and remarks are advanced for the sake of a sound analysis of steady reactions based on the concept of the stoichiometric number. 

The stoichiometric number of a constituent step may be negative as determined by the procedure described above for its arbitrarily prescribed forward direction. The prescribed forward direction of a step may, however, be reversed without any loss of generality. The a , of the step reverses its sign by inverting its prescribed forward direction and in consequence its stoichiometric number as well. By thus prescribing the directions of the constituent steps properly, we have exclusively positive stoichiometric numbers throughout the constituent steps of the single route to be dealt with here. 

The direction of every constituent step is taken, in what follows, as so prescribed that its stoichiometric number is positive, if not zero. 

It follows readily from Eq. (III.7) that a steady reaction of a single route, i.e., of unique solution N, has a unique stoichiometric equation, although the converse is not necessarily true. Consider for instance a 

Let F be the rate of a steady reaction, which is the net rate of the set of reactants on the left side of the stoichiometric equation converted into the set of products on its right side per unit time and by definition always positive. We have by definition of stoichiometric number, 

It is valuable to make some concluding remarks (written in 1982), which attempt to bring together some general perception of the developing subject of the quantum theory applied to the rate phenomena of interfacial systems. 

Levich, in Physical Chemistry An Advanced Treatise, Vol. 9B, H. Eyring, D. Henderson, and W. lost, eds.. Academic Press, New York (1970), Chap. 12. 

Dogonadze, in Reactions of Molecules at Electrodes, N. S. Hush, ed., Wiley-Interscience, New York (1971), Chap. 3. 

Bockris and S. U. M. Khan, in Proceedings of the Third Symposium on Electrode Processes, Vol. 80-3, Electrochemical Society, Princeton, New Jersey (1980), p. 34. 

There is a tendency for PMs to be discipline specific. Physicists, for example, often use PMs based on information theoretic and entropy concepts. These metrics appear to have seen limited use in chemistry, and the interested reader is referred to Ref. 246 for an application example, and Chapters 5 and 6 of Ref. 13 for a theoretical discussion. 

The discussion of the experimental results in Section in.2 shows that a fundamental understanding of pattern formation in electrochemical systems has been achieved. However, it also demonstrates that the present state represents just a first step toward a complete picture of possible dynamic behaviors. There are many observations that cannot yet be explained, for example, the spatiotemporal period-doubling bifurcation detected during the electrodissolution of iron, the occurrence of antiphase oscillations during Ni electrodissolution, or the emergence of modulated waves during the electrodissolution of Co. Nevertheless, these phenomena seem to be understandable through an extension of the models introduced in Section III.l. 

However, the reader should be aware that there are many other systems in which different types of patterns have been observed that result from a qualitatively different kind of coupling. Hence they also require fundamentally different models from that considered in this chapter. This first includes convection-induced patterns. These might arise from large concentration gradients in the solutions or different sinface tensions as found, for example, under certain conditions for anodic metal dissolu-or for some inhibited charge-transfer processes at Hg elec- 

The simplest manifestation of self-organization in a reacting system is the occurrence of bistability, that is, the coexistence of two locally stable homogeneous states. In all electrical models, bistable behavior results from the interaction of an N-shaped stationary polarization curve with a sufficiently large ohmic resistor in the external circuit. These two features also represent the backbone for all more complex forms of self-organization where, owing to exactly these two properties of the system, the double-layer potential takes on the role of the autocatalytic variable. 

In HNDR oscillators, the feedback loop contains a slow, potential-de-pendent process that acts on the rate of the main charge-transfer reaction. Oscillations occur around a branch of the stationary polarization curve with a positive slope, under potentiostatic conditions in the presence of a sufficiently large series ohmic resistor, as well as under galvanostatic conditions. The destabilization is again due to a fast negative impedance process. However, the negative slope is hidden in the stationary current-potential curve. This is because the slope of the polarization curve is 

Typical wave velocities arising from the spatial coupling through the electric field are on the order of cm s to ms , and characteristic wavelengths are on the order of centimeters. Hence, in most experiments, one wave train at a time propagates across the surface. 

The major components of the phase structure of semi-crystalline polymers and the most common techniques of characterization of the crystalline, amorphous 

The two goals of this chapter were to provide a critical review of the current state of the art in the field of two-phase flow with heat transfer and to provide procedures which can be used for the design of tubular fluid-fluid systems. Both heat transfer without phase change and with phase change were discussed in detail. In each case the analysis was based on an understanding of the flow patterns and the hydrodynamics of the system. 

It was shown that in heat transfer with phase change it is necessary to understand the phase-change phenomenon on the molecular level to model effectively the mass- and heat-transfer processes. An analytical expression for the rates of vaporization and condensation was developed. It was also shown that the assumption of a saturated vapor phase greatly simplified the calculation without a significant loss in accuracy for given examples. However, experimental verification of this simplified assumption is currently lacking. 

The analysis of tubular contactors for heat transfer with phase changes in fluid-fluid systems was shown to be heavily dependent on a proper understanding of two-phase hydrodynamics. It was shown that three basic flow patterns exist within a tube, each with a different heat-transfer mechanism. The formulation of the proper mass and energy models pinpointed three key 

The design of two-phase contactors with heat transfer requires a firm understanding of two-phase hydrodynamics in order to model effectively the heat- and mass-transfer processes. In this chapter we have pointed out areas where further theoretical and experimental research is critically needed. It is hoped that design engineers will be motivated to test the procedures presented, in combination with their use of the details from the original references, in the solution of pragmatic problems. 

Cross-sectional area of the ft , Wall heat transfer coefficient 

This chapter provides an overview of spedroscopic investigations into the photophysics of luminescent mono- and polynuclear gold(I) and -(III) complexes. 

New York, pp. 195-229 (b) Gade, L.H. (1997) Hyt was of Gold, and Shon so Bryghte..Luminescent Gold(I) Compormds. Angewandte Chemie (International Edition in English), 36, 1171-1173. 

and Fackler, J.P. Jr (1989) Luminescence and metal-metal interactions in binuclear gold(I) compounds. Inorganic Chemistry, 28, 2145-2149. 

and Cho, K.-C. (1989) Spectroscopic properties and redox chemistry of the phosphorescent excited state of [Au2(dppm)2] [dppm = bis (diphenylphosphino)methane]. Journal of the Chemical Society, Chemical Communications, 885-886. 

Omary M.A., Mohamed, A.A., Rawashdeh-Omary, M.A. and Fackler, J.P. Jr (2005) Photophysics of supramolecular binary stacks consisting of electron-rich trinuclear Au(I) complexes and organic electrophiles. Coordination Chemistry Reviews, 249, 1372-1381. 

Reviews see (a) Wasserscheid, P. Welton, T. (Eds). Ionic Liquids in Synthesis Wiley-VCH Weinheim, 2003. (b) Rogers, R. D. Seddon, K. R. (Eds). Ionic Liquids as Green Solvents, ACS Symposium Series 856 American Chemical Society Washington, DC, 2002. (c) Park, S. Kazlauskas, R. J. Curr. Opin. Biotechnol. 2003,14, 432. (d) Kragl, U. Eckstein, M. Kaftzik, N. 

Reviews see (a) Wong, C.-H. Whitesides, G. M. Enzymes in Synthetic Organic Chemistry, Pergamon Oxford, 1994. (b) Bornscheuer, U. T. Kazlauskas, R. J. Hydrolases in Organic Synthesis Regio- and Stereoselective Biotransformations Wiley Chichester, 1999. 

Recent other examples of stabilization of enzyme using IL as co-solvent in SCCO2 solvent system Reetz, M. T. Wiesenhofer, W. Francio, G. Leitner, W. Adv. Synth. Catal. 2003, 345, 1221. 

Okrasa, K. Guibe-Jampel, E. Therisod, M. Tetrahedron Asymm. 2003, 14, 2487. 

The most favorable coordination sites in thiophenes are the C2C3 and C4C5 double bonds ( -coordination, 38). This type of coordination greatly enhances the nucleophilic power of the sulfur atom, which then gives rise to two new modes of binding the metal atoms, as in the V, S-p.2-, 42, and V, S-p.3-species, 43. 

A limited number of non-transition-metal derivatives of thiophene will be considered in this subsection. There are no short-range contacts between the lithium atoms originating from the (LiO)6 cores and the sulfur atoms in [Li—O—EMc2 (2-C4H3S)]6 (E = C, Si) (97OM5032), and evidence for Tr-interactions can be found in the X-ray crystal structures of these compounds. Theoretical computations show that a- (S ) Li interactions are weak, whereas Tr-Li contributions are considerable, in accord with the general reasoning on the electronic characteristics of uncomplexed thiophene. 

The weakness of the ri -coordination follows from the general stmcture determination of tetrakis(2-thienyl)borate, 44 (96IC7095). Counterions of potassium are ri -coordinated, one cation per two thienyl substituents belonging to the neighboring anions. 

Thermolysis of the t]-coordinated zirconium complex of thiophene Cp2Zr(SiMc3) (C4H3S) is a thienyl ring cleavage reaction (920M1646). 

The concept of intramolecular coordination by the use of C, Y-chelating ligands of aryl units has been well established. However, the analogous chemistry of its cousin, the three-dimensional carborane, remains relatively unexplored. Recently, o-carborane has attracted much interest due to its ease of preparation and derivati-zation, thermal stability, and steric bulk. The easy preparation of o-carborane can be utilized for preparing useful compounds similar to the C, Y-chelating ligands of 

Thanks are due to the excellent practical work of a large number of graduate students in our research project. The X-ray crystallographers, Drs. S. W. Lee and S. Cho, are thanked for their continued interest in our studies. The BK-21 project (J. Ko), administered by the Ministry of Education, Korea, is thanked for financial support. 

Department of Chemistry Massachusetts Institute of Technology Cambridge, Massachusetts 02139 

Copyright 2001 by Academic Press. All rights of reproduction in any form reserved. 

As recently as 1965, Thoma and Stewart predicted that alterations in reaction rates [in the presence of the cycloamyloses] should be anticipated whose magnitude and sign will fluctuate with the reaction type, and added that at the present juncture, it is impossible to sort out confidently. . . which factors may contribute importantly to raising or lowering the activation energy of the reaction. In the short interval between 1965 and the present, a wide variety of cycloamylose-induced rate accelerations and decelerations have, indeed, been revealed. More importantly, rate alterations imposed by the cycloamyloses can now be explained with substantially more confidence. The reactions of derivatives of carboxylic acids and organo-phosphorus compounds with the cycloamyloses, for example, proceed to form covalent intermediates. Other types of reactions appear to be influenced by the dielectric properties of the microscopic cycloamylose cavity. Still other reactions may be affected by the geometrical requirements of the inclusion process. 

The catalytic specificity of the cycloamyloses has led to their utilization as a model for understanding enzymatic catalysis. It is the authors expectation that the cycloamyloses will continue to serve as an enzyme model as well as a model for designing more efficient catalytic systems. Toward this end, it would seem profitable to pursue the idea that the cycloamyloses may lower the activation energy of a chemical reaction by inducing strain into the substrate. 

The reactions of the cycloamyloses may also be useful in achieving stereoselective organic synthesis or they may serve as models for hydrophobic interactions in aqueous solution. As the scope of cycloamylose catalysis is extended to include other reaction types and other cycloamylose derivatives, additional applications will undoubtedly be revealed for the cycloamyloses as catalysts. 

We gratefully acknowledge financial support from the National Science Foundation during preparation of this manuscript. We also wish to express our appreciation to Dr. T. S. Straub, Dr. H. J. Brass, and Dr. W. B. Gruhn for their helpful criticisms. 

Bender, M. L. (1971). Mechanisms of Homogeneous Catalysis from Protons to Proteins. Wiley (Interscience), New York. 

Already a considerable number of transient organometallic species have been characterized by IR kinetic spectroscopy (see Table I). Like most other sporting techniques for structure determination, IR kinetic spectroscopy will not always provide a complete solution to every problem. What it can do is to provide more structural information, about metal carbonyl species at least, than conventional uv-visible flash photolysis. This structural information is obtained without loss of kinetic data, which can even be more precise than data from the corresponding uv-visible 

Metal Carbonyl Intermediates Detected by IR Kinetic Spectroscopy 

The development of IR kinetic spectroscopy has been challenging. Organometallic chemists have had to learn about lasers and electronics, while chemical physicists have learned about organometallic chemistry. However the final apparatus has turned out to be relatively uncomplicated and not difficult to use. We therefore anticipate that such equipment will become more widely available in the near future. 

Braterman, Metal Carbonyl Spectra. Academic Press, London, (1975). 

Pieter C.A. Bruijnincx thanks the Netherlands Organization for Scientific Research (NWO) for financial support through a Rubicon Scholarship. We thank the EPSRC, BBSRC, Royal Society, Wellcome Trust, EC (Marie Curie and COST), Scottish Enterprise, and Oncosense Ltd. for support of our recent research on therapeutic metal complexes. 

The University of Edinburgh (former employer of Peter J. Sadler) has filed patent applications relating to the ruthenium-arene, and platinum diazido complexes and University of Warwick for osmium-arene complexes under study in the Peter J. Sadler laboratory. 

Krogsgaard-Larsen, P. Liljefors, T. Madsen, U. (Eds.) Textbook of Drug Design and Discovery -, Taylor Francis London, 2002. 

Mascharak, P. K. Curr. Opin. Chem. Biol. 2008,12, 238-244. 

Kasparkova, JMackay, F. SBrabec, V. Sadler, P. J. J. Biol. Inorg. Chem. 2003, 8, 741-745. 

The complex vanadate(V), molybdate(VI), and tungstate(VI) systems have been clarified to such an extent that the identity of practi- 

The research also revealed new complexities and some questions are still to be answered. The molybdate(VI) system in particular needs further clarification regarding the existence of some polyions. More kinetic and thermodynamic data would also help to improve our understanding of these systems and perhaps lead to a general inclusive explanation of the mechanism of polyoxoanion formation. In this respect the new information about some structural preferences of the different metals in mixed polyoxoanions is of interest and a useful addition to known facts regarding polyoxometalate structures (181). 

The author thanks Elisabeth Rohwer for technical assistance in the preparation of graphs and figures for this chapter. 

Mesmer, R. E. The Hydrolysis of Cations Wiley-Interscience New York, 1976. 

Heteropoly and Isopoly Oxometalates Springer-Verlag Berlin, 1983. 

The enzyme was examined by Fischer following earlier studies by Bour-quelot (39) in France. Bourquelot (39) reported that he had made known in 1883 that an extract from a culture of A. niger hydrolyzed maltose. He now provided evidence that the solution also caused hydrolysis of trehalose. However, since this activity was lost on heating to 63 °C but that responsible for the hydrolysis of maltose was maintained up to 75 °C, he concluded that the fungus produced two different ferments —one a maltase, the other a trehalase. 

The turning of the key once the complex has formed is a separate issue. In this regard, Lemieux (47) has pointed out that rotation about the glycosidic bond must weaken the exo-anomeric effect and thereby importantly activate the anomeric carbon to nucleophilic attack. Therefore, it seems likely that the role of the key hydroxyl group of the aglycon is to accommodate the rotation prior to the attack by water to form / -D-glucopyranose, which is the first product of the reaction. 

It appears that the overall mechanism for the hydrolysis of maltose by glucoamylase will soon be delineated. A brief summary of how this is being accomplished deserves comment. 

The Three Key Hydroxyl Groups (Bold Letters) Necessary for Efficient Hydrolysis of an a-D-Glucopyranoside by the GlucoamyJase of Aspergillus niger 

Aleshin and coworkers (49) have reported the X-ray crystal structure at 2.2-A resolution of a G2-type variant produced by Aspergillus awamori. Meanwhile, an attempt was made to determine the amino acid residues that participate in the substrate binding and catalysis provided by G2 of A. niger (52). The results of the chemical approach indicated that the Asp-176, Glu-179, and Glu-180 form an acidic cluster crucial to the functioning of the enzyme. This conclusion was then tested by site-specific mutagenesis of these amino acid residues, which were replaced, one at a time, with Asn, Gin, and Gin, respectively (53). The substitution at Glu-179 provided an inactive protein. The other two substitutions affected the kinetic parameters but were not of crucial importance to the maintenance of activity. The crystal structure (49) supports the conclusion that Glu-179 functions as the catalytic acid but Asp-17 6 does not appear to be a good candidate for provision of catalytic base. Thus, there still exists considerable uncertainty as to how the disaccharide is accepted into the combining site for hydrolysis. Nevertheless, the kind of scheme presented by Svensson and coworkers (52) almost surely prevails. 

Financial support from the Natural Sciences and Engineering Research Council of Canada and SHARCnet (Ontario) is gratefully acknowledged. 

Bhushan, Ed., CRC Press, Boca Raton, FL, 1999, pp. 525—597. Atomic-Scale Simulations of Tribological and Related Phenomena. 

Boca Raton, FL, 2001, pp. 717—770. Computer Simulations of Friction, Lubrication, 

Miiser, M. Urbakh, andM. O. Robbins, Adv. Cbem. Phys., 126,187 (2003). Statistical 

in Reviews in Computational Chemistry, K. B. Lipkowitz and D. B. Boyd, Eds., Wiley, New York, 2000, pp. 291—397. Nonequilibrium Molecular Dynamics. 

The authors are grateful to Professor Weitschies for permission to use his data on MRI (Weitschies et al., Pharm Res 2003 In press.) 

Washington N, Washington C, Wilson CG. Physiological Pharmaceutics Barriers to Drug Absorption. Taylor Francis, 2001. 

Perkins AC, Wilson CG, Frier M, Blackshaw PE, Danserau RJ, Vincent RM, Wenderoth D, Hathaway S, Li Z, Spiller RC. The use of scintigraphy to demonstrate the rapid esophageal transit of the oval film-coated placebo risedronate tablet compared to a round uncoated placebo tablet when administered with minimal volumes of water. Int J Pharm 2001 222 295—303. 

Perkins AC, Wilson CG, Blackshaw PE, Vincent RM, Danserau RJ, Juhlin KD, Bekker PJ, Spiller RC. Impaired oesophageal transit of capsule versus tablet formulations in the elderly. Gut 1994 35 1363-1367. 

Was a common principle found in protein sorting Schatz and Dob-berstein (1996) discussed some similarity in import/export systems between various organelles. It is most interesting to know why apparently vague sequence patterns can be so specific. One key seems to lie in the fact that we have seen several different phenomena as a whole (as in the case of signal peptides). The next 10 years will also be exciting for sequence analysts. 

Aizawa, S. I. (1996). Flagellar assembly in Salmonella typhimurium. Mol. Microbiol. 19, 1-5. Alfano, J., and Collmer, A. (1997). The type III (Hrp) secretion pathway of plant pathogenic bacteria trafficking hairpins, Avr proteins, and death./. Bacteriol. 179, 5655- 

and Balch, W. (1999). Protein sorting by directed maturation of Golgi compartments. Science 285, 63-66. 

Anderson, D., and Schneewind, O. (1997). A mRNA signal for the type III secretion of yop proteins by Yersinia enterocolitica. Science 278, 1140-1143. 

Andersson, H., Bakker, E., and von Heijne, G. (1992). Different positively charged amino acids have similar effects on the topology of a polytopic transmembrane protein in Escherichia coli. J. Biol. Chem. 267, 1491-1495. 

G3 theory based on multiplicative scaling of the energy terms (G3S) instead of the additive higher-level correction has a mean absolute deviation of 1.08 for the G3/99 test set, an increase from 0.99 for the G2/97 test set. As in the case of G3 theory, the increase is largely due to the new non-hydrogen species in the test set. However, systems such as the highly strained P4 molecule perform poorly with the scaled methods. 

The density functional methods assessed in this study (B3LYP, BLYP, and LDA) all perform much worse for the enthalpies of formation of the larger molecules in the G3/99 set. This is due to a cumulative effect in the errors for the larger molecules in this test set. The errors are found to be approximately proportional to the number of pairs of electrons in the molecules but the methods are not improved significantly when a higher-level correction such as that used in G2 or G3 theory is added the DFT methods. Further correction schemes may be necessary to improve the performance of density functional methods for large molecules. 

Langhoff (Ed.) Quantum Mechanical Electronic Structure Calculations with Chemical Accuracy, Kluwer Academic Publishers, Dordrecht (1995). 

Yarkony (Ed.) Modern Electronic Structure Theory, Parts I and II. World Scientific, Singapore (1995). 

Raghavachari, G. W. Trucks, J. A. Pople, and M. Head-Gordon, Chem. Phys. Lett. 157, 479 (1989). 

It is to be hoped that this chapter will have given readers a better understanding of the basic principles of ion recognition detected by changes in photophysical properties of a fluorophore coupled to an ionophore. Examples have been chosen to illustrate the immense variety of structures that have been already designed and the inexhaustible possibilities of creating new systems. 

At the present time, there is a striking contrast between the extensive development of fluorescent probes for cation recognition and the limited number of available probes for anions notwithstanding the great need for the latter. This is due to the difficulty of the design of selective anion receptors progress made in the relevant field of supra-molecular chemistry will certainly lead in the future to new selective fluorescent signaling receptors of anions. 

In biomedical applications, the ranges of ion concentration are higher by several orders of magnitude. For instance, the abovementioned calcium probes for living cells cannot be used because the dissociation constant is so low that they would be saturated. Special attention is thus to be paid to the ionophore moiety to achieve proper selectivity and efficiency of binding. For instance, at present there is a need for a selective fluorescent probe for the determination of calcium in blood which could work in the millimolar range in aqueous solutions so that optodes with immobilized probes on the tip could be made for continuous monitoring calcium in blood vessels. 

In analytical chemistry, detection of metal ions is of major importance. In particular, the development of simple and reliable methods for continuous control in situ of metal ions in the environment is the object of much attention. For instance, the detection of lead, mercury, cadmium, and iron ions in sea water will be performed in the near future by optodes associated with suitable fluoroionophores, thus allowing continuous monitoring by instruments on ships. 

It should be emphasized that best design (each application corresponding to a particular design), proper choice, and correct use of fluorescent probes require a thorough knowledge of the basic phenomena involved in ion recognition medium effect on complexation equilibrium, fundamental photophysical processes, and possible changes from other causes than complexation. 

The vibrational frequencies of isotopic isotopomers obey certain combining rules (such as the Teller-Redlich product rule which states that the ratio of the products of the frequencies of two isotopic isotopomers depends only on molecular geometry and atomic masses). As a consequence not all of the 2(3N — 6) normal mode frequencies in a given isotopomer pair provide independent information. Even for a simple case like water with only three frequencies and four force constants, it is better to know the frequencies for three or more isotopic isotopomers in order to deduce values of the harmonic force constants. One of the difficulties is that the exact normal mode (harmonic) frequencies need to be determined from spectroscopic information and this process involves some uncertainty. Thus, in the end, there is no isotope independent force field that leads to perfect agreement with experimental results. One looks for a best fit of all the data. At the end of this chapter reference will be made to the extensive literature on the use of vibrational isotope effects to deduce isotope independent harmonic force constants from spectroscopic measurements. 

It is important to point out here, in an early chapter, that the Born-Oppenheimer approximation leads to several of the major applications of isotope effect theory. For example the measurement of isotope effects on vapor pressures of isotopomers leads to an understanding of the differences in the isotope independent force fields of liquids (or solids) and the corresponding vapor molecules with which they are in equilibrium through use of statistical mechanical theories which involve vibrational motions on isotope independent potential functions. Similarly, when one goes on to the consideration of isotope effects on rate constants, one can obtain information about the isotope independent force constants which characterize the transition state, and how they compare with those of the reactants. 

As will be shown further on, the most interesting isotope effects are quantum effects. Since the most important quantized motions in molecules are vibrations it makes sense that isotope effects yield information about the isotope independent surface (the vibrational force field) on which these quantized motions take place. 

Of the activation volumes given in Table II, 70 values are either zero or positive and 31 values are negative. This indicates that 

Many of the investigations are carried out at low temperatures and/or at pH values deviating somewhat from neutrality. It has earlier been emphasized that the influence from factors such as temperature, pressure, pH, concentrations, ionic strength, and salt effects must be considered when pressure effects are discussed. This is because conditions that are optimal to one enzyme may be intolerable to another. After all, we are dealing with enzymes from microorganisms, cold-blooded, and warm-blooded animals. Such complications make comparison of pressure effects on enzymes nearly meaningless. 

Perhaps it would be most informative to study the enzymes at their respective physiological conditions, at least for the purpose of predicting the effect of pressure on a living organism. Nevertheless, deliberate changes of conditions may be valuable when pressure is used to probe structure and mechanism. As we learn to understand the role of protein structure in the determination of pressure effects, we may be able to predict the effects on one enzyme from knowledge of the effect on another. Then, we may be able to gain information about pressure effects on human enzymes. 

I thank professors A. Ben-Naim, T. Brun, W. Kauzmann, W. J. le Noble, R. C. Neumann, Jr., G. N. Somero, and A. A. Yayanos for stimulating discussions and their hospitality during my stay in the United States. 

Berger, L. R. (1974. Proc. Int. Conf. High Pressure, 4th, 1974, Kyoto, p. 639. Borrowman, S. R. (1950). Ph.D. Thesis, University of Utah, Salt Lake City. 

It is likely that combined CMT and EC measurements can contribute to further information about the basic details of several other corrosion processes and provide more reliable data for corrosion rates than EC measurements alone. Concerning the possible use of CMT measurements as a routine test of technical products, some of the limitations (it can t be used with iron and steel in aerated solutions or with other metals in bicarbonate solutions) are rather serious. However, there are still many applications where the fast and quantitative results obtained by CMT measurements would seem advantageous. 

Scintigraphic techniques have proven to be useful when investigating the in vivo behavior of liposomes. The major advantage of scintigraphy is the ability to obtain noninvasive quantifiable images at many time points in either humans or animals. This rapidly provides the in vivo behavior of the liposomes. 

Laverman P, Boerman OC, Oyen WJ, Dams ET, Storm G, Corstens FH. Liposomes for scintigraphic detection of infection and inflammation. Adv Drug Deliv Rev 1999 37 225. 

Phillips WT. Delivery of gamma-imaging agents by liposomes. Adv Drug Deliv Rev 1999 37 13. 

Goins B, Phillips WT. Radiolabelled liposomes for imaging and biodistribution studies. In Torchilin VP, Weissig V, eds. Liposomes A Practical Approach. Oxford, U.K. Oxford University Press, 2003 319. 

Awasthi VD, Goins B, Klipper R, Phillips WT. Dual radiolabeled liposomes biodistribution studies and localization of focal sites of infection in rats. Nucl Med Biol 1998 25 155. 

Solid-phase synthesis has unique advantages in accommodating purification at each individual reaction step without losing compound mass. However, to ensure reaction completion is a challenging task. Our capability to monitor reactions on 

Although the field of histone methyltransferase inhibitors is still in its infancy in terms of drug discovery, a lot of kno vledge in terms of their biological roles has been acquired. Test systems for in vitro and in vivo evaluation are available and model approaches have been presented already that led to inhibitors of these enzymes with promising cellular activity. Therefore, a dynamic development of the field can be expected vhich hopefully vill lead to clinical candidates in the upcoming years. 

1 Schafer, S. and lung, M. (2005) Chromatin modifications as targets for new anticancer drugs. Archives ofFharmarcy Chemistry and Life Sciences, 338, 347-357. 

3 Yang, X.J. and Seto, E. (2007) HATs and HDACs from structure, function and regulation to novel strategies for therapy and prevention. Oncogene, 26, 5310-5318. 

4 Minucd, S. and Pelicd, P.G. (2006) Histone deacetylase inhibitors and the promise of epigenetic (and more) treatments for cancer. Nature Reviews. Cancer, 6, 38—51. 

5 Herranz, M. and Esteller, M. (2006) New therapeutic targets in cancer the epigenetic connection. Clinical Transplants and Oncology, 8, 242—249. 

The chemistry of curved, polynuclear aromatic hydrocarbons holds great promise due, in part, to the rampant interests in fullerenes. Of special interest, of course, is their relationship to the fullerenes, and these compounds should serve as good models in many ways since the curvature of the systems already known matches that of buckminsterfullerene, at least at the point of maximum curvature. 

Research on plasma lipoproteins has entered a highly productive period during which major advances have been made from both the conceptual and technological standpoints. The information gained on lipoprotein apoproteins has particular relevance, especially in terms of pri- 

Akanuma, Y., and Glomset, J., In vitro incorporation of cholesterol- C into very low density lipoprotein cholesteryl esters. J. Lipid Res. 9, 620-626 (1968). 

Alaupovic, P., Seidel, D., McConathy, W. J., and Furman, R. H., Identification of the protein moiety of an abnormal human plasma low-density lipoprotein in obstructive jaundice. FEBS Fed. Eur. Biochem. Soc.), Lett. 4, 113-116 (1969). 

Albers, J. J., and Aladjem, F., Precipitation of I-labeled lipoproteins with specific polypeptide antisera. Evidence for two populations with differing polypeptide compositions in human density lipoproteins. Biochemistry 10, 3436-3442 (1971). 

Wadsley, A.D., Nonstoichiometric Compounds, ed. L. Mandelcorn (1964) Academic Press. 

Domenges, B., Hervieu, M. and Raveau, B , Solid State Comm. 68 303 (1988). 

Raveau, B., Reviews on Silicon, Germanium, Tin and Lead Compounds 6 287 (1982). 

This chapter has attempted to give some flavor of the historical development of nonlinear methods. Early investigators of these methods expended great effort in overcoming the popular notion that bandwidth extrapolation was not possible or practical. It was, for example, believed that the Rayleigh limit of resolution was a limit of the most fundamental kind—unassailable by mathematical means. To be sure, the popular notion was reinforced by a long history of misfortune with linear techniques and hypersensitivity to noise. Anyone who still needs to be convinced of the virtues of the nonlinear methods would benefit from reading the paper by Wells (1980) the nonlinear point of view is nowhere else more clearly stated. 

Now that the efficacy and potential of the nonlinear methods have gained substantial acceptance, we need not fear that a few cautionary notes will spoil the sensible trend in their direction. 

First let us deal with deconvolution in general. We have a few admonitions to the reader of a literature report on a new method. They should ask, does the writer deal fairly with noise Even the most volatile of the linear methods can produce a reasonable restoration when noise is limited to roundoff error in the seventh significant figure of the data. A method s capability of yielding acceptable restorations in the presence of realistic noise is critical to its practicality. 

An amplitude bound has the added virtue of producing solutions having reduced noise sensitivity, fewer artifacts, superior resolution, and possible bandwidth extrapolation. In contrast, methods having an output that is linear in the irradiance data i(x) either produce artifacts or trade off resolution to suppress artifacts. If a bound makes physical sense and can be computationally afforded, use it. Simple clipping of unphysical parts does not always work well, however. Subtle techniques may be more desirable. 

In spite of authors usual claims, the newest algorithm is not necessarily the best. Nevertheless, a new algorithm, even if it performs poorly, may contain the seed of an idea that can be adapted and improved. Such an algorithm, however, is not for the reader who needs a proved effective method. It is material for the deconvolution researcher. 

The following general points may be made about the catalytic activity of metals for the exchange of hydrocarbons  

Metal films are usually more active than bulk metal catalysts. 

The reaction which has been studied over the greatest range of metals is the exchange of ethane and the order of activity of the different metals (Table VIII) is 

Nickel shows some activity at low temperatures approximately equivalent to the activity of rhodium, but normal catalytic behavior with a constant activation energy is observed only at substantially higher temperatures similar to those necessary for activity with palladium. 

The pattern of activity of the metals for the exchange of other hydrocarbons appears to be similar to that established for the exchange of ethane. For the exchange of methane (Table V), nickel behaves like palladium, but for the exchange of the cyclic hydrocarbons (Table X), nickel exhibits activity similar to that of rhodium. 

Let us close by noting that starting with the papers of Saltzman [117] and Lorentz [118], the problem of turbulent transport has been amenable to analysis on the basis of the unsteady-state transport equations without any additional assumptions. While this extremely meaningful procedure is outside the scope of the present contribution, at least a few [117-125] from a very large number of references need mention. 

Landau, L. D., and Lifshitz, E. M., Fluid Mechanics. Pergamon, Oxford, 1959. 

and Crawford, M. E., Convective Heat and Mass Transfer, 2nd Ed. McGraw-Hill, New York, 1980. 

Levich, V. G., Physicochemical Hydrodynamics. Prentice Hall, New York, 1962. 

Not only does this example show that solvent effects should be taken seriously, it also provides a clear message of the prospects involved. Eventually, the authors developed a scaled-up process (63 kg ), corroborating the consistency of the small-scale results. 

In a similar approach, Kasture and coworkers describe the use of neat substrate (ethyl acetate both as alcohol donor and as the reaction medium) in the preparation of chirally pure S-(-)-l,4-benzodioxan-2-carboxylate, an important drug intermediate used in the synthesis of doxazosin mesylate, from racemic l,4-benzodioxan-2-carboxylic acid [138]. Again, CaLB catalyzed the transesterification reaction with good enanhoselectivity (E = 160) and acceptable enantiomeric excess ( 95%) and chemical yield (50%). 

Finally, Sanfilippo and coworkers describe the enzymatic kinetic resolution of atropisomeric ( )-3,3 -bis(hydroxymethyl)-2,2 -bipyridine N,N-dioxide by enantioselective esterifcation in an unusual medium of 2-propanol/vinyl acetate (20 80) [139]. Lipase from Mucor miehei (immobilized lipase preparation, Lipozyme ) was found to give good enantioselectivity with an (aS)-enantiopreference in the axial recognition and allowed efficient preparation of both enantioforms with 98%. Despite the fact that the propanol reacts with the acyl donor, this did not diminish its positive effects on the solubility of the bipyridyl substrate. 

Considering the beneficial effect of the use of neat substrates on the reduction of the environmental impact of industrial solvents, it might seem that further examples of this approach in kinetic resolution processes may be expected in the near future. 

Despite the large number of reports of successful efforts to increase the E-value of enzymes by managing the medium composition, proper understanding of the 

Carbonate has proved to be a versatile ligand. Its coordination mode expands from 1 to 6, the last one is visualized when each atom binds two metal ions simultaneously. In recent years, significant progress has been made in the synthesis, structure, and magnetic properties of polynuclear carbonato complexes of transition metal ions. Such studies have also been extended to lanthanides and actinides. The speciation studies of these metal ions in aquatic environments in the presence of carbonate have resulted in significant 

SHA svp Schaffer Horn Aldrich split valence polarization constant 

(a) Halman, M. M. Chemical Fixation of Carbon Dioxide -, CRC Press Boca Raton, FL, 1993 (b) Catalytic Activation of Carbon Dioxide -, Ed. Ayers, W. M. ACS Symposium Series 363 American Chemical Society Washington DC, 1988  

Bazzicalupi, C. Bencini, A. Bianchi, A. Corana, F. Fusi, V. Giorgi, P. Paoli, P. Paoletti, P. Valtancoli, B. Zanchini, C. Inorg. Chem. 1996, 35, 5540. 

Escuer, A. Penalba, E. Vicente, R. Solans, X. Font-Bardia, M. J. Chem. Soc. Dalton Trans. 1997, 2315. 

In addition to the synthetic advances, the study of the optical properties of these species is a growing field. Many complexes which exhibit these interactions are luminescent. Other interesting points are the induction of rotator phases or the modulation of magnetic properties by designing the appropriate heterometallic complexes. Gold-gold interactions are still a hot topic in gold chemistry. This is evidenced in the observation that some complexes which exhibit these interactions, characterized some years ago, are revisited and modified in order to study their properties. 

4 Gimeno, M.C. and Laguna, A. (2003) Comprehensive Coordination Chemistry II, 5 (eds S. Pataiand Z. Rappoport), Elsevier, New York, p. 911. 

Schmidbaur, H., Schier, A. (2007) in Comprehensive Organometallic Chemistry III, 2 (eds R. Crabtree, M. Mingos and K. Meyer) Elsevier, New York, p. 251. Pyykko, P. (2004) Angewandte Chemie (International Edition in English), 43, 4412. 

10 Schmidbaur, H. (ed.) (1999) Gold Progress in Chemistry, Biochemistry and Technology, John Wiley sons. 

An increasing number of crystal structures of metalloenzymes have been reported, with more molecular structures of the metal active centers. We believe, however, that this is only the beginning of a new bioinorganic chemistry. The structural data provide more questions 

(a) Kimura, E. Koike, T. In Comprehensive Supramolecular Chemistry Elsevier Science Oxford in press (b) Kimura, E. In Progress in Inorganic Chemistry Karkin, K. D., Ed. John Wiley Sons New York, 1994 Vol. 41, p. 443 (c) Kimura, 

Shionoya, M. In Transition Metals in Supramolecular Chemistry Fabbrizzi, 

Kimura, E. Nakamura, I. Koike, T. Shionoya, M. Kodama, Y. Ikeda, T. Shiro, 

ACTIVATION OF DIOXYGEN BY COBALT GROUP METAL COMPLEXES 

Accumulation of fucosylated derivatives in pathological cases, and excessive excretion of similar compounds in the urine, generally reflects deficiency of a-L-fucosidase or depression of its activity, and study of these compounds can serve as a diagnostic tool. 

In the biochemistry of D-fucose and its derivatives, there are larger lacunae in our knowledge. The biosynthesis of D-fucose has not been examined, so that it is not yet known how this sugar is produced in the organisms that contain it (mainly plants and some micro-organisms). In plants, it occurs especially in the form of steroid glycosides, whereas, in micro-organisms, it has been particularly located in antibiotic substances. It has not been identified in animals. 

The metabolic degradation of D-fucose has been investigated in bacteria, and oxidative steps elucidated that closely resemble those undergone by the L enantiomer in the animal body. 

The magnitude of the piezoelectric response owing to applications of stress or strain transverse to the chain axis is much greater than the response owing to application of stress or strain parallel to the chain axis. This anisotropy in electrical response reflects the mechanical anisotropy of extended chain polymer 

The total pyroelectric response at constant pressure (or stress) is the sum of two contributions. Primary pyroelectricity, which is due to changes in the magnitude of the dipole oscillation with temperature, accounts for only about 9% of the total response of the crystal at 300 K. The remaining overwhelming contribution is due to secondary pyroelectricity—the coupling of the piezoelectric response and thermal expansion. 

Acknowledgments The authors are grateful to the National Science Foundation (CTS 9457111) and the AT T foundation for financial support of this work, and to D. J. Lacks of Tulane University for his contribution to the development of the lattice dynamics code. 

Herbert, and A. M. Glass, The Applications of Ferroelectric Polymers, Blackie, Glasgow (1988). 

Bom and K. Huang, Dyanamical Theory of Crystal Lattices. Oxford University Press, Oxford, (1954). 

To summarize, a compensation effect may be caused by several reasons. 

In some cases the statistical mechanical concept of entropy changes makes it conceivable that relations exist between A/f° and AS° or between A2/ and A S for a number of reactions. As a special case, reactions involving the tunneling of electrons between ions of different valence states may serve as an example for the possibility that a tunnel effect may account for the occurrence of compensation effects. 

In many cases a compensation effect is indicated on comparison of the rates of the same reaction at the same type of catalyst after the latter has undergone special pretreatments or has been changed in its composition. In such cases the occurrence of a compensation effect may be expected if different kinds of active surface centers act simultaneously as sites of the catalytic reaction and if the proportions of these different active centers (involving different activation energies) are shifted by means of special pretreatments of the catalyst or by changes in its composition. 

An apparent compensation effect can result from errors in the experimental data used for an Arrhenium plot. Besides trivial errors, there may also occur errors in the calculation of rate constants, for instance when a homogeneous and a heterogeneous reaction occur simultaneously or when a heterogeneous reaction undergoes a change from a certain reaction order to another order. A temperature dependence of the activation energy, and the variability of the effective surface of the catalyst with temperature, especially caused by diffusion processes, may also account for apparent compensation effects. 

Constable, F. H., Proc. Roy. Soc. London) A108, 355 (1923), and later papers. 

Palladium-catalyzed transformations greatly enhance the scope of solid-phase synthetic chemistry. A number of fundamental pharmacophores are accessible through a variety of reliable manipulations that may be performed in high yield under mild conditions. This area continues to grow, as solution-phase chemistry is adapted to provide better methods for carbon-carbon bond formation in combinatorial chemistry. We view these advances as central to the field and look forward to future developments. 

Beletskaya, I. P. Palladium Catalysed C-C and C-heteroatom Bond Formation Reactions, Pure Appl. Chem. 1997, 69, 471-476. 

Sonogashira, K. Tohda, Y. Hagihara, N. A Convenient Synthesis of Acetylenes Catalytic Substitutions of Acetylenic Hydrogen with Bromoalkenes, Iodoarenes and Bromopyridines, Tetrahedron Lett. 1975, 50, 4467-4470. 

Bailey, D. C. Langer, S. H. Immobilised Transition-Metal Carbonyls and Related Catalysts, Chem. Rev. 1981, 81, 109-148. 

Andersson, C.-M. Karabelas, K. Hallberg, A. Andersson, C. Palla-dium/Phosphinated Polystyrene as a Catalyst in the Heck Arylation. A Comparative Study, J. Org. Chem. 1985, 50, 3891-3895. 

By the end of this century, the supply of petroleum will reach a maximum and then decline slowly. On the other hand, the worldwide demand for liquid fuels will remain at present levels or even increase because of rapidly growing demands of developing countries. Thus, both saving energy and finding new supplies of liquid fuels are major tasks to be developed within these 10 years. 

Coal liquefaction that can provide liquid fuels at the price of current petroleum (not cost but price) is one of the most important technologies that needs to be developed. The catalyst and control of its operating conditions are still key to technology for advanced coal liquefaction. The creative design of catalyst materials and reaction schemes is an important and challenging goal for the future. 

The authors are grateful to Dr. Paul B. Weisz lor the invitation to review the topic of the present article. They also acknowledge Drs. O. Okhuma, Y. Mitarai, S. Ueda, the Ministry of Education, the Ministry of International Trade and Industry, and New Energy and Industrial Technology Development Organization for their long term support of our coal liquefaction research. The authors also express special thanks to Dr. D. D. Whitehurst and Dr. F. J. Derbyshire for their valuable comments on the manuscript. 

Lummus Co., The C-E Lummus Clean Fuel From Coal Process, 1975. 

Derbyshire, F. J., Mitchell, G. D., and Schobert, H. H., Enhanced Coal Liquefaction by Low-Severity Catalytic Reactions, Report to U. S. Dept, of Energy, DOE-PC-90910-F1, p. 175. 1989. 

In the past the study of polymer networks has been undertaken along three separate lines, viz. from the point of view of network formation, the structure, and the elastic behaviour. 

Without any proof it has often been assumed that C equals C so that an estimate of rcl could be obtained which could be compared with the number of chemically crosslinked units, vc. Any differences were subsequently interpreted in terms of various network defects, as e.g. entanglements, closed loops, or unreacted functionalities. 

In the preceding chapters we have endeavoured to stress the point of view that, in order to understand the network behaviour, it is necessary 

The accumulation of structural information regarding a network is not an easy task. Direct measurements through optical techniques are often open to various interpretations. Also, their resolving power with respect to factors, important in elasticity, (as, for example, network chain length distribution) is often insufficient. It is, therefore, necessary to obtain structural information through studies of the network formation processes (Chapter II). 

The classical approach to crosslinking statistics, as especially developed by Flory and Stockmayer, is capable of treating the simpler type of network formation processes, but becomes mathematically intractable in the more complicated cases (unequal reactivities, cyclization). Of the various recently proposed alternatives, the link probability generating function approach of Gordon et al., which is based upon the theory of 

It would appear that the study of the diffusion equation subject to a phase change at one boundary is in a relatively satisfactory state, provided simple boundary conditions of the first, second, or third kind are specified. From a mathematical point of view, the interesting features of the problem arise from the nonlinearity, exhibited for all but a few particular boundary motions. A wide variety of approximate and numerical methods have been employed, and it has frequently been difficult for workers in one specialized field of activity to become conversant with similar approaches made by investigators in other areas. It is hoped that the present work will, to some extent, alleviate this problem. 

From a practical point of view, much remains to be learned. For 

Finally, the subject of bubble dynamics, in which the pressure equation is coupled to the convective diffusion equation, offers a number of unsolved problems which will be considered in a succeeding volume of this series. 

The author wishes to acknowledge, with appreciation, the invaluable assistance of his student, Mr. V. K. Pai, in assembling and editing this manuscript. The work was supported in part by a grant from the National Science Foundation. 

The four types of nickel-containing enzymes are quite distinct in the coordination sites and catalytic function of the nickel centers. In urease, the nickel appears to be bound to oxygen and nitrogen ligands and appears to remain as Ni(II), a state which favors octahedral or square-planar coordination. The function of nickel in this unique case may be analogous to that of zinc in other hydrolases such as carboxypeptidase. 

Electron paramagnetic resonance ESEEM, Electron spin-echo envelope modulation EXAFS, Extended X-ray absorption fine structure 

Cammack, R., Fernandez, V. M., and Schneider, K., In Bioinorganic Chemistry of Nickel (J. R. Lancaster, Jr., ed.) VCH Publ., Deerfield Beach, Florida, 1988 (in press). 

Sunderman, F. W., Jr. et al. (eds.), Nickel in the Human Environment. Scientific Publications, Lyon, France, 1984. 

Although the number of valence electrons present on an atom places definite restrictions on the maximum formal oxidation state possible for a given transition element in chemical combination, in condensed phases, at least, there seem to be no a priori restrictions on minimum formal oxidation states. In future studies we hope to arrive at some definitive conclusions on how much negative charge can be added to a metal center before reduction and/or loss of coordinated ligands occur. Answers to these questions will ultimately define the boundaries of superreduced transition metal chemistry and also provide insight on the relative susceptibility of coordinated ligands to reduction, an area that has attracted substantial interest (98,117-119). 

I wish to express gratitude and appreciation to all of my co-workers who are listed as joint authors in the references, to the Petroleum Research Fund, administered by the American Chemical Society, and to the National Science Foundation for continuing generous support of this research on highly reduced organometallics. Special thanks are due to Kelly V. Beamer for expert assistance with the manuscript. 

Hieber, W. Beck, and G. Braun, Angevv. Chem. 72, 795 (1960), and references cited therein. 

Fischer and R. Boucher, Z. Naturforsch. B Anorg. Chem., Org. Chem., Biochem., Biophys., Biol. 10B, 600 (1955). 

In this review we have attempted to cover the very recent literature relevant to the coordination chemistry of carbon dioxide and its use as a source of chemical carbon. We have omitted similar investigations involving the more reactive substrates, carbon disulfide and carbonyl sulfide. The reader is referred to a recent review by Ibers (722) which has contrasted the behavior of these sulfides to carbon dioxide. Likewise we have, as stated at the onset, elected to neglect heterogeneous processes involving the reduction 

It should be apparent from our coverage that we have just begun to understand the chemistry associated with the activation of carbon dioxide. However, efforts are presently being intensified in this area and it appears safe to predict that major advances in this field will occur during this decade. Clearly, one of the greatest challenges for the organometallic chemist will be to find potential catalysts which activate C02 and H2 simultaneously. 

The authors are most grateful to the National Science Foundation, whose support has made possible their contributions to the research described herein. They are likewise appreciative to all their colleagues mentioned in the references, whose many original contributions have made this such an interesting and stimulating area of research to be involved in. Finally, we are thankful to Mrs. Melanie Gray for preparing this manuscript for publication. 

Dixneuf and R. D. Adams, Report on the International Seminor of the Activation of Carbon Dioxide and Related Heteroallenes on Metal Centers, Rennes, France, 1981. 

Gambarotta, M. Pasquali, C. Floriani, A. Chiesi-Villa, and C. Guastini, Jnorg. Chem. 20, 1173(1981). 

We describe herein our recent achievement of total syntheses of (-)-strychnine and fostriecin. The key stereocenters were constructed using catalytic asymmetric reactions developed in our group. Catalytic asymmetric reactions that can produce versatile chiral building blocks with high practicality should ensure further efficient total synthesis of complex molecules in future. 

The research described in this paper was possible through the dedication of coworkers, whose names are acknowledged on the publications from our laboratory cited here. 

Altenbach, C., Cai, K., Khorana, H. G., and Hubbell, W. L. (1999a). Structural features and light-dependent changes in the sequence 306-322 extending from helix VII to the palmitoylation sites in rhodopsin A site-directed spin-labeling study. Biochemistry 38, 7931-7937. 

Angers, S., Salahpour, A., and Bouvier, M. (2002). Dimerization An emerging concept for G protein-coupled receptor ontogeny and function. Annu. Rev. Pharmacol. Toxicol. 42, 409—135. 

Archer, E., Maigret, B., Escrieut, C., Pradayrol, L., and Fourmy, D. (2003). Rhodopsin crystal New template yielding realistic models of G-protein-coupled receptors Trends Pharmacol. Sci. 24, 36—40. 

Simple calculations of heat and water balance indicate that for successful self-cold start from — 30°C, heat release corresponding to approximately 1 mg/cm2 of product water from ORR reaction is required. Therefore, the key challenge is the removal or storage of 1 mg/cm2 water. The cathode catalyst layer of common design can store 0.5 mg/cm2 water, at most. The vapor phase removal of water from the catalyst layer to the gas channel is negligibly small at this temperature. Hence, it is necessary to store some water in the electrolyte membrane. 

Detailed investigation of ORR kinetics under subzero temperature showed that the fundamental ORR kinetic mechanism remains unchanged over a wide temperature range down to -40°C. The low-temperature CV detected the loss of cathode catalyst electrochemical active area during cold start, part of which was recovered at room temperature, while others were not recovered until higher temperature ( 70°C) operation. 

Tabuchi, F. Kagami, Handbook of fuel cells fundamentals, technology, and application, vol. 6 (Wiley, New York, NY, 2009) 

Kagami, T. Ogawa, Y. Hishinuma, T. Chikahisa, in Fuel cell seminar (Palm Springs, CA, 2002) 

COMPARISON OF AQUEOUS SOIL EXTRACTS WITH CARBOHYDRATE GELS 

As described above, gas sensors as HTS tools in catalysis have been applied in several reactions due to their small size, easy parallelization and high sensitivity. We expect the importance of gas sensors to increase for HTS in catalysis. Recently, Simon et al. reported the development of gas sensors with a combinatorial approach [35]. Developing tailor-made gas sensors for specific reactions, this technology will become increasingly important for catalysis researchers. 

Snively, J. Lauterbach, in Combinatorial Catalysis and Highthroughput Catalyst Design and Testing, NATO Science Series, C560, 1999, 311 pp. 

Dehestani, R. Doolen, D.M. Giaquinta, S. Guan, V. Marcov, D. Poojary, K. Self, H. Turner, W. H. Weinberg, Proc. Natl. Acad. Sci. USA 1999, 96, 11077. 

Takada, in Chemical Sensors IV (Eds. M. Butler, N. Yamazoe, P. Vanysek, 

Joaquin J. Jimenez, Wenche Jy, Lucia M. Mauro, Laurence L. Horstman, Carlos J. Bidot, and Yeon S. Ahn 

Department of Medicine, Division of Hematology Oncology, Wallace H. Coulter Platelet Laboratory, University of Miami School of Medicine, Miami, Florida 33136 

Endothelial cells (ECs) have long been implicated in the pathogenesis and pathophysiology of a myriad of vascular, thrombotic, and inflammatory disorders [1-3]. The prevalence of endothelial perturbation in vascular disease has underscored the need for noninvasive sensitive and specific markers 

The thermochemistry of molecules is of major importance in the chemical sciences and is essential to many technologies. Recent advances in theoretical methodology, computer algorithms, and computer power now allow us to compute reliable thermochemical data for a fairly wide variety of molecules. In this chapter we have reviewed the current state of the art in computational thermochemistry. 

Despite the successes, much remains to be done in the future to further develop capabilities for accurate prediction of thermochemical data. Among the challenges will be extension of the accurate methods to larger molecules, ob- 

Chase Jr., C. A. Davies, J. R. Downey Jr., D. J. Frurip, R. A. McDonald, and A. N. Syverud, J. Phys. Chem. Ref. Data, 14 Suppl. 1 (1985). JANAF Thermochemical Tables, Third Edition. 

Curtiss, K. Raghavachari, P. C. Redfern, and J. A. Pople,/. Chem. Phys., 106, 1063 (1997). Assessment of Gaussian-2 and Density Functional Methods for the Computation of Enthalpies of Formation. 

Without doubt, the gas-continuous impinging streams (GIS) method has been proved by a number of investigations to significantly enhance transfer between phases [58-60, etc. ]. This feature gives it good application potential. 

Only solid particles residence time and its distribution are discussed in the present chapter although, because of the similarities of movements of the dispersed phases in impinging streams, the results described above are also of referential significance for gas-liquid impinging streams. The differences between the properties of liquids and solids and their influences will be discussed in detail in the relevant chapters. 

Another problem arising from the results of the investigation on residence time distribution is the strong mixing of the materials in dispersed phase in the impingement zone. The fact that the model of RTD derived above fits well the concentration of the tracer in the out stream of the device indicates that the assumption of perfect mixing of 

Leffler, E. Grunwald, Rates and Equilibria of Organic Reactions, Wiley, New York, N. Y., 1963. 

Shinkai, T. Ogawa, T. Nakajima, Y. Kusano, O. Manabe, Tetrahedron Lett. 1979, 20, 4569. 

Desvergne, H. Bouas-Laurent,/. Chem. Soc., Chem. Commun. 1978, 403. 

Bouas-Laurent, A. Castellan, J-P. Desvergne, PureAppl Chem. 1980, 52, 2633. 

Yamashita, M. Fujii, T. Kaneda, S. Misumi, T. Otsubo, Tetrahedron Lett. 1980, 21, 541. 

Measurement of electron density by X-ray diffraction cannot distinguish each electron in different orbitals however, it provides overall information on the asphericity of the d electron distribution in a molecule as well as on the redistribution of electrons upon chemical bond formation. At the present stage, experimental charge distributions can be compared only qualitatively with theoretical calculations. The method, however, will be of considerable value in clarifying poorly understood bonding situations. If the electron-density distribution and the geometrical arrangement of the atomic nuclei in a complex are known, it is possible, at least in principle, to predict all its physical and chemical properties on the basis of quantum mechanics. 

The authors would like to thank Dr. Kazuo Kitaura for his valuable suggestions concerning molecular orbital interpretations. The authors are, however, entirely responsible for the content of this article. 

International Tables for X-ray Crystallography, Vol. Ill, Kynoch Press, Birmingham, 1962. 

Kijima, N., Tanaka, K., and Marumo, F., Acta Crystallogr. Sect. B 39 (in press). 

Pauling, L., The Nature of Chemical Bond, 3rd ed., Cornell Univ. Press, Ithaca, New York, 1960. 

Part of the work reported in this chapter was supported by research grants from the National Science Council (NSC90-2320-B010-078 and NSC90-2320-B010-079) and the National Health Research Institutes (NHRI-EX91-9120BN) of the Republic of China. 

Fujimura, H., Nishikawa, Y., Yorifuji, S., Mezaki, T., Hirono, N., Nishitani, N., and Kameyama, M., Marked reduction in CSF lactate and pyruvate levels after CoQ therapy in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Acta Neurol. Scand. 83, 356-359 (1991). 

Matsuo, Y., Kadekawa, J., Inoue, S., and Yanagihara, T., Effect of coenzyme Q10 in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) Evaluation by noninvasive tissue oximetry. J. Neurol. Sci. 162, 65-68 (1999). 

Nakagawa, M., Miyata, M., Higuchi, I., Nakao, S., Suehara, M., Osame, M., and Tanaka, H., Cardiac involvement in mitochondrial diseases. A study on 17 patients with documented mitochondrial DNA defects. Circulation 91, 955-961 (1995). 

Angelini, C., Melacini, P., Valente, M. L., Reichmann, H., Carrozzo, R., Fanin, M., Vergani, L., Boffa, G. M., Martinuzzi, A., and Fasoli, G., Hypertrophic mitochondrial myopathy with mitochondrial myopathy. A new phenotype of Complex II defect. Jpn. Heart J. 34, 63-77 (1993). 

The fundamental theme for this review was the attempt to illustrate the flavor of current research in this area. If one were to summarize (62, 146) the present status of our knowledge of these remarkable systems, it might be that most of the properties of excess electrons in solution can be interpreted in terms of models that are (qualitatively) easily understood, but quantitatively evaluated only with considerable effort. This is, indeed, an observation pertinent not only to metal solutions, but to inorganic chemistry in general  

We conclude this review as we have started it—with a brief reference to unpublished work by Sir Humphry Davy  

During the course of many laborious experiments (1808-1809) on the action of dry gaseous ammonia with molten potassium (Fig. 1), Davy speculated briefly on the possible reaction at the metal interface, questioning whether any substances can be formed which will not absorb Ammonia. Unfortunately, Davy s intense activity during this period led to considerable fatigue, and (136) a most severe fit of illness, which for a time caused an awful pause in his researches, broke the thread of his pursuits, and turned his reflections into different channels.  

The purpose of this section, added in proof, is to include certain work published since the review was completed. 

The first observation of the NMR spectrum of Na- in a metal solution without added cation-complexing agents has recently been reported (65a). The rationale behind this observation was that the solvent HMPA by itself appeared to fulfill many of the requirements generally sought from macrocyclic complexing agents high solubility via cation complexation, stability to electron reduction, weak anion solvation, etc. The NMR spectrum of Na- in fluid Na-HMPA solutions, shown in Fig. 26, exhibits precisely the same chemical shift as that observed for Na-in solutions of Na in anhydrous methylamine and ethylamine in the presence of 2,2,2-cryptand. The metal anion here is truly gas-like in 

Prince JA, Feuk L, Howell WM, Jobs M, Emahazion T, Blennow K, Brookes AJ. Robust and accurate single nucleotide polymorphism genotyping by dynamic allele-specific hybridization (DASH) design criteria and assay validation. Genome Res 2001 11 152-162. 

Jobs M, Howell WM, Stromqvist L, Mayr T, Brookes AJ. DASH-2 flexible, low-cost, and high-throughput SNP genotyping by dynamic allele-specific hybridization on membrane arrays. Genome Res 2003 13 916-924. 

Fakhrai-Rad H, Pourmand N, Ronaghi M. Pyrosequencing an accurate detection platform for single nucleotide polymorphisms. Hum Mutat2002 19 479-485. 

Suomalainen A, Syvanen AC. Analysis of nucleotide sequence variations by solid-phase minisequencing. Methods Mol Biol 2003 226 361-366. 

Kanazin Y, Talbert H, Blake T. Electrophoretic detection of singlenucleotide polymorphisms. Biotechniques 2000 28 710-714, 716. 

Radiobiological Implications op the Reactions op Hydrated Electrons with Organic Compounds 

The great effort invested in the investigation of the radioly tic behaviour of organic compounds in aqueous solutions has been justified by the assumption that the major part of the radiobiological damage to the living cell at the molecular level may be described by the radiolytic behaviour of organic solutes in aqueous solution. Ultimately, this effort led to the discovery of the hydrated electron and its reactions. 

There has been a tendency among radiation chemists to use the information on the kinetic and stoicheiometric behaviour of dilute aqueous solutions containing biochemical solutes for interpreting mechanisms of molecular radiobiology. Such a comparison may possibly be justified for the reactions of OH radicals and H atoms. The analogous treatment of hydrated-electron reactions seems, however, to be a gross oversimplification that might easily result in erroneous conclusions. 

It is suggested, therefore, that hydrated electrons are not likely to be formed in the intracellular fluid and that the formation of solvated electrons is also of low probability in the presence of solutes that are capable of accommodating electrons. On the other hand, it should be remembered that electrons are being formed in radiolysed living systems and are finally incorporated in certain functional groups of the molecules involved. A qualitative, and perhaps a semiquantitative, correspondence is expected between the tendency of the constituents of the living cell to incorporate an electron and their reactivity towards hydrated electrons in dilute solutions. From this standpoint only, it may be beneficial to acquire qualitative as well as quantitative information on the reactions of biopolymers and their functional groups with hydrated electrons. 

In the following paragraphs, we shall describe the known information on the reactivity of different constituents of the living cell with hydrated electrons, bearing in mind that the information described does not represent part of the mechanism of radiobiological damage. Hydrated-electron reactions may, therefore, be used in molecular radiobiology, with appropriate caution, merely as model processes for electron-transfer reactions which undoubtedly take place in the radiolysed cell. 

In this section, we have shown how the first-principle calculations can be performed to analyze steady state and time-resolved spectra to obtain the rate constants of the processes involved in the experiments and how to employ the ab initio potential surfaces and the interactions between these surfaces to calculate these rate constants. 

Developments in the density matrix method still remain to be done, in both the fundamental aspect and the technical aspect. For example, the properties of the damping operator T are yet poorly known. Usually, only very simple parameters are input by hands. Such approach can help us simplify the process of model setup. However, there might be artifacts in the computation, as will be explained below. 

The energy difference between two states ha ab — Ea — Eb follows the simple addition rule  

Technically, the density matrix for a molecular system can be very large, especially when many nuclear degrees of freedom are taken into account, or when more than two electronic levels are involved. In the future, to make the density matrix method a realistic tool for large scale problem, computational techniques have to be further developed. 

The previous sections of this chapter have been written with more emphasis on the definitions and the mathematical derivations rather than providing a lot of physical discussions. In the following, a few questions are given to guide the readers to think more into the physical meanings of what have been presented  

The reasons of the discrepancy between the failure of cultured neonatal astrocytes to release exocytotically glutamate by depolarization, reported in the 

Araque, A., Parpura, V., Sanzgiri, R. P., and Haydon, P. G. (1999). Tripartite synapses Glia, the unacknowledged partner. Trends Neurosci. 22, 208—215. 

Barres, B. A., Koroshetz, W. J., Chun, L. L., and Corey, D. P. (1990). Ion channel expression by white matter glia The type-1 astrocyte. Neuron 5, 527—544. 

Bergles, D. E., andjahr, C. E. (1997). Synaptic activation of glutamate transporters in hippocampal astrocytes. Neuron 19, 1297-1308. 

In this chapter, we introduced the reader to some basic principles of solution chemistry with emphasis on the C02-carbonate acid system. An array of equations necessary for making calculations in this system was developed, which emphasized the relationships between concentrations and activity and the bridging concept of activity coefficients. Because most carbonate sediments and rocks are initially deposited in the marine environment and are bathed by seawater or modified seawater solutions for some or much of their history, the carbonic acid system in seawater was discussed in more detail. An example calculation for seawater saturation state was provided to illustrate how such calculations are made, and to prepare the reader, in particular, for material in Chapter 4. We now investigate the relationships between solutions and sedimentary carbonate minerals in Chapters 2 and 3. 

Ligands such as alkynes, and diphenyldiazoalkanes can act as 7r-donor ligands (as well as -acceptors). The 1 1 adducts of these derivatives are relatively stable compared with those of allenes, which, like olefins, are not generally viewed as rc-acceptor and rc-donor ligands. 

Certain features of the W2C3 core of the alkyne insertion products bear striking resemblance to Schrock s 14,15) L3W( /2-C3R3) metallacyclo- 

Several questions remain. In particular, why is it that only one alkylidyne ligand appears to be susceptible to attack (addition/insertion). Perhaps the answer to this question lies in a combination of steric and electronic factors associated with the initial insertion/addition products. In some cases these lack any formal W—W bond, the tungsten atoms being in a formal +6 oxidation state, whereas in others the nature of the W—W bond and its accessibility toward entering 7t-acid ligands is at present not well understood. Further studies are clearly warranted. 

We thank the National Science Foundation, the donors of the Petroleum Research Fund administered by the American Chemical Society, and the Wrubel Computing Center for financial support. We are also indebted to Drs. John Huffman, Kirsten Folting, and William Streib at the Molecular Structure Center for single-crystal X-ray studies, to Mr. David L. Clark for assistance with the Fenske-Hall calculations, and to Drs. Dennis Lichtenberger and Edward Kober for obtaining photoelectron spectra. 

For a theoretical treatment of the relationship between metallacyclopentanes and bis(olefin) metal complexes see A. Stockis and R. Hoffmann, J. Am. Chem. Soc. 102, 2952 (1980). 

We have mentioned only in passing other cluster complexes in which a tetrahedral core of 1 carbon and 3 metal atoms is present. Such complexes in which the metal atoms are nickel, ruthenium, and osmium have been prepared XIII (81), XIV (82, 83), and XV (66, 82). Their chemistry remains largely unexplored, except for the transformations of compound XV in strong acid medium which we mentioned in the previous section. 

Related structurally to the RCCo3(CO)9 complexes are the acetylenedi-cobalt hexacarbonyls which have the structure with a pseudotetrahedral 

The acetylenedicobalt hexacarbonyls have been described in terms of 

From the discussion of the organic chemistry of the alkylidynetricobalt nonacarbonyl complexes given in this review, it is apparent that this has been a fruitful area of research. We think that it shall continue to be so. Admittedly, the sensitivity of these cluster complexes to diverse bases, nucleophiles, and oxidizing agents will seriously limit the chemistry that can be carried out, but even with these limitations it should be possible to continue a broad development of the organo-functional interconversions of these complexes. 

We were first drawn into studies on alkylidynetricobalt nonacarbonyl complexes because in these one is dealing with a carbon atom in a most unusual environment. We felt that this novel class of complexes would show some rather interesting organic and organometallic chemistry and we 

The calculations made and the conclusions drawn concerning DADNE are based on DFT methodology. While there are errors to be expected in applying DFT calculations to the various steps in the reaction path studied, 

The structural parameters that we have calculated for DADNE are consistent with the experimental crystallographic structure [2,3], and also with the previous calculations of Politzer et al [8]. Additionally, we have obtained the structural parameters for the initial transition state, as well as for each subsequent step along the decomposition pathway. Thus, the unimolecular decomposition of DADNE appears to be well characterized. 

We mention here certain interesting calculation results obtained by other groups, subsequent to our work, which added important additional 

al [35]., study DADNE structure and properties using ab intio calculations. Most interestingly, they study the relative stability of three different isomers of DADNE, and established their relative order of stability. They also calculate the vibration spectra of the molecule and find it compares favorably to the corresponding experimental results. 

While there is considerably more work required, to complete the study of DADNE, in the short time since its synthesis, quantum theory and its computational implementation have done much to clarify our understanding of the molecule. 

The research work described above that was carried out by us was supported by the Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences Division. 

Recent Advances in Hydride Chemistry, Eds. Peruzzini, M. Poli, R. Elsevier Science B.V. Amsterdam, 2001. 

Metal Dihydrogen and a-Bond Complexes, Kubas, G. J. Kluwer Academic/Plenum Publishers New York, NY, 2001. 

For a retrospective account of homogenous catalytic hydrogenation, see Halpern, J. J. Organomet. Chem. 1980, 200,133. 

Huhmann-Vincent, J. Scott, B. L. Kubas, G. J. Inorg. Chim. Acta. 1999, 294, 240. 

X-ray diffraction measurements can give direct structural information on complexes in solution, which cannot be obtained by other methods. Although the complete structure of a solution cannot be derived from the limited information in a single one-dimensional diffraction curve, a separation of the distinct contributions given by intramolecular interactions can often be made. This makes it possible to determine structures of complexes even in solutions with chemically complicated compositions. Comparison of diffraction curves for different solutions can give information on structural changes caused by changes in concentration of a particular atomic species. 

For a dominant complex in a solution precise determinations of the intramolecular distances can usually be made. Derivations of coordination numbers and geometries will depend on the specific characteristics of the system investigated. Although solution X-ray diffraction measurements have been primarily concerned with the structures of metal aqua ions, other ligands and nonaqueous solutions often offer more favorable conditions for structure determinations of complexes. 

Palinkas, and E. Kalman, in Diffraction Studies on Non-Crystalline Substances (I. Hargittai and W. J. Orville-Thomas, eds.), p. 293. Elsevier, Amsterdam, 1981. 

Johansson, Solution Diffraction Data Handling Programs. Stockholm, 1988. 

Compounds containing E-E single bonds between the heavier elements of Group 13 received considerable interest in the last decades and developed to a broad field in current organoelement chemistry with a multitude of different formulas and types of structures. The first synthesis of a tetraalkyldielement(4) derivative in 1988 marked the starting point for many aspects of that chemistry and influenced the further development of organoelement chemistry with aluminum, gallium, indium, and thallium in unusual oxidation states to a considerable extent. Some of the first cluster 

Organisch-Chemisches Institut der Universitat Munster, Corrensstrasse 40, 

The Unique (,v-tra ,v-q4-Conjugatcd Diene)Metal Complex Family. Ill 

Coupling Reactions with Selected Main Group Element Reagents. . . 137 

The (Butadiene)zirconocene Route to Active Ziegler-Natta 

Microcompartmentation of metabolic enzymes has been shown to be a powerful way to control energy production in living cells. PSD is an excellent example for the ATP utilized by ion channels or protein kinases involved in signal trans- 

This work was supported by FP6-2003-LIFESCIHEALTH-I Bio-Sim and Hungarian National Scientific Research Fund Grants OTKA T-046071 (to J.O.) and T-049247 (to F.O.), and NKFP-MediChem2 l/A/005/2004 (to J.O.). 

1 Chih, C. P., Lipton, P., Roberts, E. L ). Do 7 active cerebral neurons really use lactate rather than glucose Trends Neurosci. 2001, 24 573-578. 

2 Pellerin, L., Magistretti, P. J. Glutamate uptake into astrocytes stimulates aero- 8 bic glycolysis a mechanism coupling neuronal activity to glucose utilization. 

3 Pellerin, L., Pellegri, G., Bittar, P. G., Char-nay, Y., Bouras, C., Martin, J. L., Stella, 9 N., Magistretti, P. J. Evidence supporting the existence of an activity-dependent astrocyte-neuron lactate shuttle. Dev. Neu- 10 rosci. 1998, 20 291-299. 

Spontaneous monolayer dispersion of compounds on supports is a widespread phenomenon and displays many unique effects. The principles involved have applications not only to heterogeneous catalysis, but also to materials science and other related fields. The theoretical and practical aspects of this phenomenon appear to offer prospects that should not be overlooked. Studies in connection with this phenomenon are continuing in our laboratory. 

The authors acknowledge China s National Natural Science Foundation for generous support of this work, which is a part of the major project Structural Chemistry and Molecular Design. We are grateful to all our colleagues who have contributed toward a better understanding of the phenomenon of spontaneous monolayer dispersion. Thankful acknowledg- 

Structural Inorganic Chemistry, 4th Ed., p. 259. Oxford Univ. Press, London and New York, 1975. 

Thewlis, J., Encyclopaedic Dictionary of Physics, Vol. 7. p. 171. Pergamon, Oxford, 1962. 

in Surface Properties and Catalysis by NonMetafs (J. P. Bonnelle, B. Delmon, and E. Derouane, eds.), p. 1. Reidel, Dordrecht, Netherlands, 1983. 

1 Halevi, E.A. (1992) Orbital Symmetry and Reaction Mechanism, Springer-Verlag, Berlin. 

Electronic Aspects of Organic Photochemistry, Wiley-Interscience, New York. 

3 (a) Weir, D. and Scaiano, J.C. (1985) Lifetimes of the biradicals produced in the Norrish type I reaction of cycloalkanones. Chemical Physics Letters, 118, 526-529  

4 Garcia-Garibay, M.A. and Campos, L.M. (2004) Photochemical decarbonylation of ketones recent advances and reactions in crystalline solids, in CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn (eds W. Horspool and F. Lenci) CRC Press, Boca Raton, pp. 48/1—48/41. 

5 Cram, D.J., Tanner, M.E., and Thomas, R. (1991) The taming of cydobutadiene. Angewandtc Chemie, International Edition, 30, 1024-1027. 

We would like to thank the Editors Kenny Lipkowitz and Don Boyd for carefully editing the manuscript. Also, we would like to thank Thomas Lengauer (GMD) and Martin Stahl (F. Hoffmann-La Roche AG, Basel) for helpful suggestions and discussions. 

Subbiah, Science, 252,128 (1991). Low-Resolution Real Space Envelopes An Approach to 

Briinger, Nature (London), 355,472 (1992). A Novel Statistical Quantity for Assessing 

Markley, Methods Enzymol., 176, 12 (1989). Two-Dimensional Nuclear Magnetic 

Clore and A. M. Gronenborn, Science, 252,1390 (1991). Structures of Larger Proteins 

We thank Lori Giver, Seran Kim, and Phil Patten for critical input and Mark Welch for the bubble plot of subtilisins. 

and Youvan, D. C. (1992). Optimizing nucleotide mixtures to encode specific subsets of amino acids for semi-random mutagenesis. Bio/technology, 10, 297-300. 

Arnold, F. (1998a). Design by directed evolution. Acc. Ghent. Res., 31, 125-131. 

Arnold, F. H. (1998b). When blind is better protein design by evolution. Nature 

Arnold, G. E., and Ornstein, R. L. (1997). Molecular dynamics study of time-correlated protein domain motions and molecular flexibility cytochrome P450BM-3. Biophys J., 73, 1147-1159. 

The detailed study of electron distribution rearrangements in a chemical reaction needs a multiconfiguration ab initio method, because one determinantal wavefunctions are unreliable away from equilibrium geometries. By means of the CASSCF method it is possible to focus attention on the electrons more directly involved in the reaction, allowing the calculation to be done with a relatively limited number of Slater determinants. Moreover, CASSCF uses orthogonal orbitals which are simpler than non-orthogonal orbitals in the development of computer codes. Nowadays CASSCF is, in fact, efficiently included in practically all distributed packages for molecular quantum calculations. 

The calculations presented in this chapter have been done using the MCSCF code of the package GAMESS [36] which contains also the more recent developments, made in our laboratory, on the solvent dielectric model for the study of solvation (see for example [37]). Our solvation model implemented in GAMESS allows a CASSCF calculation with the inclusion of all the basic solute-solvent interactions. 

The interpretation of reactions can be made at this point by analyzing the weights of VB structures, calculated according to Eq. (3), along the reaction path. This type of study shows immediately how the electronic wavefunction changes with nuclear configuration within the adiabatic approximation. 

The energy profile in terms of the reaction coordinate is taken instead from the CASSCF calculation. The importance of this diagram is related to the shape of the curve. The presence of a barrier is relevant to the reaction kinetics it is well known in fact that the higher is such a barrier, the smaller is the conversion rate constant. Forbidden thermochemical 

The examples treated in this chapter have shown that only the Coulom-bic polarization of the solvent, represented as a continuum medium, is responsible for significant changes of the behaviour of reacting systems in passing from the gas phase to the solution. Dispersion, Pauli repulsion and cavitation do not lead to significant effects. 

This work has benefited from discussions with P. A. Dowben, A. Kashyap, R, D. Kirby, A. Y. Istomin, A. F. Starace, D. Leslie-Pelecky, S.-H. Liou, J.-P. Liu, K. D. Sorge, and D. J. Sellmyer. The underlying research is supported by NSF MRSEC, DARPA/ARO, DOE, ONR, AFOSR, the W. M. Keck oundation, and CMRA. 

Authors gratefully acknowledge the work of two anonymous referees for their helpful review of the manuscript. 

Wilson, M. J., and McHardy, W. J. (1996). Chemical and mineralogical forms of Cu and Ni in contaminated soils from the Sudbury mining and smelting region, Canada. Environ. Pollut. 91, 11-19. 

Arienzo, M., Bianco, M. R., and Violante, P. (2002a). Heavy metal contamination of the soils devoted to stocking raw materials in the former ILVA iron-steel industrial plant of Bagnoli (south Italy). Set. Total Environ. 295, 17-34. 

Wilson, M. J., andMcHardy, W. J. (2002b). Distribution of trace elements in soils from the Sudbury smelting area (Ontario, Canada). Water Air Soil Pollut. 135, 95—116. 

Denaix, L., Terribile, F., and Zampella, M. (2003). Characterization of heavy metals in contaminated volcanic soils of the Solofrana river valley (southern Italy). Geoderma 117, 347—366. 

For the models derived herein, the program was able to converge on the absolute minima—the correct coefficients. For 

The utility of the algorithm remains, however, even if confidence in the values of simplex-determined individual coefficients is not high. The routine never fails to find a visually correct fit of the model to the data, which allows good estimates of hidden onset temperatures and individual peak areas (which correspond to the latent heats of transformation). 

I would like to thank Dr. W. Butler for formatting figures of crystal structures and Drs. O. Mundt and H. J. Breunig for providing preprints of papers prior to publication. I also thank the donors of the Petroleum Research Fund administered by the American Chemical Society and the AFOSR (Grant 81-094) for partial support of our research. 

Bickelhaupt, R. Lourens, H. Vermeer, and R. J. M. Weustink, Recent Trav. Chim. Pays-Bas 98, 3 (1979). 

Though stoichiometric equations are not kinetic models of reactions in the true sense of the word, they are of prime importance for the kinetic analysis of a complex reaction in order to build up kinetic models of a reaction. 

Some authors recommended the use of a unique stoichiometric equation 

The interaction between the dispersed-phase elements at high volume fractions has an impact on breakup and aggregation, which is not well understood. For example, Elemans et al. (1997) found that when closely spaced stationary threads break by the growth of capillary instabilities, the disturbances on adjacent threads are half a wavelength out of phase (Fig. 43), and the rate of growth of the instability is smaller. Such interaction effects may have practical applications, for example, in the formation of monodisperse emulsions (Mason and Bibette, 1996). 

The research presented here has been supported over the past decade or so by grants to JMO awarded by the National Science Foundation, the Department of Energy—Basic Energy Sciences, and 3M. 

Acrivos, A., The breakup of small drops and bubbles in shear flows. 4th International Conference on Physicochemical Hydrodynamics, Ann. N. Y. Acad Sci., 404, 1-11 (1983). 

and Mills, P. M., Motion and rupture of a porous sphere in a linear flow field. J. Rheol. 23, 25-37 (1979). 

Stirring by chaotic advection. J. Fluid Mech. 143,1-21 (1984). 

We have in the present paper investigated two fundamentally different, yet complementary, routes to computational studies of radical hyperfine structures. On the one hand, we have the highly accurate MRCI - based approaches, which are able to predict hyperfine structures of small systems to very high accuracy. The role and importance of higher than double excitations in the configuration expansions has been elucidated by means of detailed case studies on a number of first row atoms, as well some selected molecular systems. We have also demonstrated how a newly developed method, the MRD-CI/Bk method, by means of a perturbative method is able to incorporate the effects 

In the second part of the paper, we have explored an alternative route to the calculation of radical hfs, namely the DFT-based approaches. In this case, we trade in the extremely high accuracy of the MRCI approaches for applicability to systems up to a few hundred atoms in size. As shown in the above examples, the accuracy of the DFT based approaches is still well beyond conventional single determinant CIS or CISD data, provided an appropriate functional is used. 

Future applications of the DFT based hfcc calculations will involve extending the sets of systems into areas such as surface chemistry, biophysics, and large transition metal complexes, where MRCI approaches again will serve as an extremely important tool for calibrating the calculations of the larger systems, to reveal possible pitfalls and explain deviations when these occur. 

Langhoff and E.R. Davidson. It has been substantially modified by D. Feller, R. Cave, D. Rawlings, R. Frey, R. Daasch, L. Nitzche, P. Phillips, K. Iberle, C. Jackels and E.R. Davidson. 

Uppsala Quantum Chemistry Group, Box 518, S-75120, Uppsala, Sweden. Quantum Theory Project, 362 Williamson Hall University of Florida, Gainesville, FL 32611-8435 

Compounds are arranged by metal and also in order of their B-NMR downfield chemical shift. A shift to lower field is an indication of an increased degree of direct metal to boron bonding (8). nB- and H-NMR chemical shifts are with respect to BF3 OEt2 and tetramethylsilane (TMS), respectively, with downfield positive S. For anionic metalloboranes and borides, H data are provided for the anion only. 

Ouster chemical shift chemical shift4 solvent structure Ref. 

Cluster B-NMR chemical shift H-NMR chemical shift21 NMR solvent X-ray structure Ref. 

Housecraft, Boranes and Metalloboranes Structure, Bonding and Reactivity. Ellis Horwood Limited, Chichester, 1990. 

Fehlner, in Comments in Inorganic Chemistry, p. 326. Gordon Breach Science Publishers, London, 1988. 

The author is indebted to PPG Industries and Transitions Optical for providing the resources and the opportunity to write this chapter. 

Laarhoven, in Photochromism Molecules and Systems (H. Durr and H. Bouas-Laurent, eds.), Chap. 7, pp. 270-309, Elsevier, Amsterdam (1990). 

Wizinger and H. Wenning, Intramolecular ionization, Helv. Chim.Acta, 23, 247-271 (1940). 

Livingston, D. Miller, and S. Morris, 2-Methoxy-2,4-diphenylchroman Mid 5,6-dihydro-6-methoxy-4,6-diphenyl-4 H- and 6,6-diphenyl-6/7 -naphtho(2, r 2,3)pyran, J. Chem. Soc., 1960, 5148-5152. 

Hirshberg and E. Fischer, Photochromism and reversible multiple internal transitions in some spiropyrans at low temperatures, J. Chem. Soc., 1954, 3129-3137. 

In summarizing the results obtained so far relating to the chemistry of the binuclear complexes of general composition Ms0 -X)(/ -Y)L2, two general statements can be made  

Most of the compounds are remarkably stable. Although the oxidation state of M is +1 (which is very unusual for palladium and platinum), the complexes generally react rather slowly with oxygen and tend to disproportionate to form M(0) and M(II) compounds only in those cases where steric hindrance between the bridging groups X or Y and the terminal lig- 

The presence of simple ir-allyl and ir-cyclopentadienyl ligands symmetrically coordinated to an M3 unit seems to be unique. Bridging allyl groups are found in [C3H5Pt(acac)]2 (42) and in the tetrameric [C3H5PtCl]4 (43), but they are linked differently to the platinum atoms, namely mono-hapto to one platinum and dihapto to the other. There is also no metal-metal bond formed in these complexes. 

It is a great pleasure for me to acknowledge the contribution of my co-workers cited in the references, in particular A. Kuhn and H. J. Kraus. I would also like to thank Dr. P. Hofmann of the Universitat Erlangen-Niimberg for valuable discussions, and the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie for financial support. 

Werner, V. Harder, and E. Deckelmann, Helv. Chim. Acta 52, 1081 (1969) V. Harder, Ph.D. Dissertation, Universitat Zurich (1973). 

The authors thank W.Kutzelnigg, I.Lindgren, U.Kaldor, R.J.Bartlett and S.Koch for many stimulating 

Lindgren and J.Morrison, Atomic Many Body Theory (Springer Verlag, Heidelberg, 1981). 

Linderberg and Y.Ohrn, Propagators In Quantum Chemistry (Acad. Press,N.Y., 1973). 

W von Niessen, L.S.Cederbaum, W.Domcke and J. Schirmer, in Computational Methods In Chemistry (Ed J.Bargon, Plenum Press, N.Y., 1980). 

Paldus, in New Horizons Of Quantum Chemistey (Ed P.Lowdin and B.Pullman, Reidel, Dordrecht, 1983) 

The author thanks H. Michel and the late A. Kroger for support and the coauthors of his cited publications for their contributions. Support by DFG Sonderforschungsbereich 472 ( Molecular Bioenergetics, P19) is gratefully acknowledged. 

Dutton, P. L., Chen, X., Page, C. C., Huang, S., Ohnishi, T., and Moser, C. C. (1998). In Biological Electron Transfer Chains Genetics, Composition and Mode of Operation (G. W. Canters and E. Vijgenboom, Eds.), pp. 3-8. Kluwer Academic, Dordrecht. Esnouf, R. M. (1997)./ Mol. Graphics Mod. 15, 132-134. 

Geisler, V., Ullmann, R., and Kroger, A. (1994). Biochim. Biophys. Acta Bioenerget. 1184, 219-226. 

Lancaster, C. R. D. (2001b). In Handbook of Metalloproteins (A. Messerschmidt, R. Huber, T. Poulos, and K. Wieghardt, Eds.), vol. 1, pp. 379-401. Wiley, Chichester, UK. Lancaster, C. R. D., Ed. (2002a). Biochim. Biophys. Acta Bioenerget. 1553, 1-176. (Special issue on fumarate reductases and succinate dehydrogenases) 

Besides filling in the missing links, it would be desirable to consider in addition the phosphorus oxide selenides. With their inclusion, the tendencies already detected in the oxides and oxide sulfides should become much more pronounced. Furthermore, one would introduce an additional probe atom (77Se) for NMR, a powerful analytical technique in this context. 

Financial support by the DFG (SFB 334 and Gottfried Wilhelm Leibniz-Programm) and the Fonds der Chemischen Industrie is gratefully acknowledged. 

Ullmann s Enzyklopadie der Technischen Chemie, Vol. XVIII, p. 303f. Verlag Chemie, Weinheim, 1979. 

Gillespie, R. J., in Molekiilgeometrie, Elektronenpaar-Abstofiung und molekulare Struktur. Verlag Chemie, Weinheim, 1975. 

Engels, B., Miihlhauser, M., Peyerimhoff, S. D., and Jansen, M., unpublished results. 

Although it is impossible to formulate a definition of molecular geometry that is fully quanturn-mechanical in nature and at the same time universally applicable to all chemical species, topological analysis of the electron density leads to a rigorous statement of the dominant molecular structure for any state, spectroscopic or localized, stationary or time dependent, with zero angular momentum. In this sense, unlike geometry or shape, structure is an observable property of an isolated molecule. 

It is highly unlikely that the conventional view of molecules will relinquish its dominance in the near future. As long as chemists stay aware of the fact that such a view constitutes modeling of reality rather than objective truth, the description of chemical species in terms of intuitively appealing entities remains beneficial to the scientific progress. In a 

Deumens, Y. Ohrn, L. Lathouwers, and P. Van Leuven, J. Chem. Phys. 

We have attempted to survey both the current status of studies attempting to elucidate the nature of higher oxidation Mn biomolecules, and the efforts directed toward the synthesis of satisfactory inorganic models. As we noted in Section I, this is consequently by no means an exhaustive account of all the work reported, and references to more detailed reviews of specific systems have been cited in the text. Nor have all Mn-containing or Mn-dependent biological systems been included again, more detailed and exhaustive reviews are available elsewhere (327). 

Nakada, Y., and Nakazawa-Tomizawa, K., Biochim. Biophys. Acta 912,178 (1987). 

Fujimoto, S., Nakagawa, T., Ishimitsu, S., and Ohara, A., Chem. Pharm. Bull. 25,1459 

Mn(III)-biphenoxide complexes do however contain infrared bands in this region. Schake, A., Vincent, J. B., and Christou, G., unpublished results. 

The potential that HNCC offer is beginning to be realized. It is clear that they have properties and exhibit reaction patterns that differ markedly from their mononuclear counterparts and even low-nuclearity clusters. It is also apparent that their reactivity patterns may be rationalized in simplistic terms and thereby extended to other systems. However, much work remains to be done, particularly in designed synthesis and studies of reaction mechanisms. The ability of these clusters to combine with important small substrates such as CO and Hj need also to be explored in much more detail. The study of the reactivity of large mixed-metal systems, which, as expected, exhibit enhanced and modified reactivities, equally requires more detailed investigation. In fact it would be useful to have available HNCC, which contain early and late transition metal elements, in order to combine both Lewis basic and Lewis 

In summary, despite the enormous effort that has been devoted to the synthesis and characterization of HNCC, there is a serious deficit in data related to their reactivity. Given the remarkable reactions that they are known to exhibit, efforts in this area are still needed and desirable. 

Longoni, G., Manassero, M., and Sansoni, M., Abstr. Eighth Meet. Ital. Assoc. Grystallogr., Ferrara, Gommun. 34 (1977). 

Barbier, J. P., Braunstein, P., Fischer, J., and Ricard, L., Inorg. Chim. Acta 31, L361 (1978). 

Fumagalli, A., Martinengo, S., Chini, P., Albinati, A., and Bruckner, S., Proc. All XIII Congr. Naz. Chim. Inorg., Camerino, Italy, 1980, Soc. Chim. Ital., 1980. 

The author would like to thank past and present members of the Walter lab for their hard work to elucidate many of the concepts presented in this chapter, Mike Carson for use of his Ribbons package, and the support from the National Institutes of Health (AI47300). 

Abdel-Meguid, S. S., Shieh, H. S., Smith, W. W., Dayringer, H. E., Violand, B. N., and Bende, L. A. (1987). Three-dimensional structure of a genetically engineered variant of porcine growth hormone. Proc. Natl. Acad. Sci. USA 84, 6434-6437. 

Adzhubei, A. A., and Sternberg, M. J. (1993). Left-handed polyproline II helices commonly occur in globular proteins. J. Mol. Biol. 229, 472-493. 

and Schreiber, R. D. (1997). The IFN gamma receptor A paradigm for cytokine receptor signaling. Annu. Rev. Immunol. 15, 563-591. 

Ashkenazi, A., Aguet, M., Murphy, K. M., and Schreiber, R. D. (1995). Ligand-induced autoregulation of IFN-gamma receptor beta chain expression in T helper cell subsets. Science 270, 1215—1218. 

It is to be hoped that syntheses of larger polynucleotides having defined sequences will serve the welfare of mankind in the near future. 

Department of Chemistry, University of Aberdeen, Old Aberdeen AB9 2UE, Scotland 

There have been many articles on the hemicelluloses,1-17 and this one, on the hemicelluloses of the Gramineae (grasses and cereals), is written in the knowledge that, when it is completed, Norman s state- 

The term hemicellulose is also often extended to include certain carbohydrates in cereal endosperms, namely, non-starch polysac- 

The author has been fortunate to work with Regenesys during the period of ownership change. A present-day author would find the path to the author s sources difficult to identify, because of the demise of significant UK organisations, and their web sites, along with the dispersion of their personnel. 

In a climate where intermittent power sources from wind, wave and tide are being built, power storage will be important to the economics of grid systems. The enforced intermittent operation of nominally base 

The most famous blues singer of them all had a void to fill. In the fuel cell industry the author finds all fuel cells to be incomplete and imperfect, with only the power storage system of the last chapter being an approach to completeness. This chapter goes into detail on the shortfalls of present-day fuel cell systems. 

A consistent stereochemical structure-activity pattern may be built up on the basis of the 4-phenylpiperidine ligands associating with the opioid receptor in the form of equatorial 4-phenyl chair conformations. Other conformations (i.e., axial 4-phenyl chairs or flexible boat forms) could have been employed as the basic active species but greatest adherence to probable conformations is possible by the approach adopted furthermore, no need arises to assume a major difference in the binding modes of the few examples of esters in which axial 4-phenyl chair conformations may be favored. 

Early attempts to account for the analgesic properties of pethidine and its reversed ester(68) involved the assumption that the active conformations of 4-phenylpiperidines mimic rigid analgesics of the morphine, morphinan, and 

Further studies of phenolic analogs of 4-phenylpiperidine analgesics— especially those with preferred axial 4-phenyl chair conformations—are therefore clearly important for the elucidation of the ligand-receptor binding modes of derivatives based on pethidine. 

Despite a considerable effort during the last two decades, relatively slow progress has been made in physicochemical aspects of the metal carboxylate extraction. The stoichiometry proposed for the extracted species still appears quite unlikely in some cases. 

The formation of heteropolynuclear carboxylates is a common phenomenon, which must be taken into account particularly in the separation of metal ions. 

It is encouraging to see that regular solution theory has been utilized with success in understanding the effect of solvent and extractant on the metal carboxylate extraction. 

To conclude, it may be said at present that problems of fundamental importance still await careful study from different points of view. 

Grzegrzolka, E., Chodowska, Z., and Maciejko, G., Chem. Anal. (Warsaw) 24, 1019 

As discussed above, the reactions of OH with oxygenated compounds seem to proceed via formation of complexes thaf involve one or two hydrogen bonds. Several theoretical studies on these complexes show binding energies large enough to overcome any inaccuracy of the calculation method (Table 12.8). 

TABLE 12.8 Binding energies (kcal/mol) of oxygenated VOCs -I- OH radical complexes, obtained from electronic energies -t- ZPE corrections 

FIGURE 12.11 Comparison between recommended, experimental, and calculated rate 

In summary, the utility of quantum chemical calculations to elucidate the detailed mechanisms of OH radical reactions with oxygenated VOCs has been proven. The importance of including reactant complexes in such modeling, to obtain accurate values of the rate coefficients, has also been shown. The best results are those obtained when it is assumed that such complexes are in their vibrational ground state. The relative site reactivity of the studied compounds towards OH radicals has been shown to be strongly influenced by intramolecular hydrogen-bond-like interactions that arise in the transition states. 

Since the main tropospheric sink of oxygenated VOCs seems to be their reactions with OH radicals, at least at daytimes, the mechanistic and kinetic information discussed in this work is relevant to fully understand the tropospheric chemistry of such compounds, as well as their subsequent fate. Hopefully, the large amount of experimental and theoretical work that has been revisited here, which has been devoted to chemical reactions of environmental significance, could contribute in some extent to act in the right directions and prevent more damage to our atmosphere. 

The microorganism Microhacterium imperiale CBS 498-74, used as resting cells, is able to hydrate nitriles via two steps by nitrile hydratase and amidase catalysed reactions. Both aliphatic (acrylonitrile, propionitrile) and aromatic (benzonitriie, 

3-cyanopyridine) nitriles were converted to the corresponding amide or acid. 

The use of a CSMR allowed to investigate the dependence of reaction rate on key parameters, such as temperature, substrate concentration and cell loading. 

This was performed for each enzyme independently, feeding the reactor with the appropriate substrate (nitrile for the cascade reaction, amide for the sole amidase). The activation energies of both catalysed reactions were evaluated together with those of the inactivation process that inevitably takes place even under the most suitable operational conditions. In the nitrile hydratase/amidase cascade system nitrile hydratase is the more labile enzyme that imposes process temperature choice. These findings make accessible the complete kinetic expression of the dependence from temperature of reaction rate, allowing accurate prediction on reactor performances for process scale-up. 

The continuous reactor proved to be very flexible, in that varying the operational parameters one can get a wide spectrum of product stream quahty, that is high productivity or high concentration. 

Finally, the recent development of suitable expression systems for recombinant molybdenum enzymes makes possible the use of site-directed mutagenesis to incisively probe the roles of specific active site residues in catalysis. Although these systems have been somewhat slow in development, presumably due to the intricacies of assembling and inserting the molybdenum center into the overexpressed apoenzyme, at least two such systems have now been developed and more can be expected in the immediate future. Future work can be expected to critically evaluate the involvement of specific amino acid residues in each step of a given catalytic sequence. 

Acknowledgments. The author wishes to thank Dr. Ortwin Meyer for his generous communication of data prior to publication. Work in the authoris laboratory is supported by grants from the National Institutes of Health 

Bailey, S., McEwan, A. G., and Bray, R. C., 1999, Reactions of dimethyl-sulfoxide reductase from Rhodobacter capsulatus with dimethylsulfide and with dimethyl-sulfoxide complexities revealed by conventional and stopped-flow spectrophotometry. 

Yamazaki, X., Sato, M., Noda, K., Nishino, T., and Nishino, T., 1990, Proteolytic conversion of xanthine dehydrogenase from the NAD-dependent type to the Oi-dependent 

Athwal, G. S., Huber, J. L., and Huber, S. C., 1998, Phosphorylated nitrate reductase and 14-3-3 proteins. Plant Physiol. 118 1041nl048. 

The rapid 3 4 equilibrium makes the coordinatively unsaturated mono(olefin)zirconocene (-hafnocene) complex 4 an easily accessible organometallic synthon even at extremely low temperatures, a fact that certainly will make its readily available precursor 3 a good starting material for the preparation of many novel organometallic compounds in the future. 

10 (1963) P. W. JoUy and G. Wilke, The Organic Chemistry of Nickel, Vol. 1. Academic Press, New York, 1974 Vol. 2 (1975) P. Heimbach and R. TraunmtUler, Chemie der Metall-Olefin-Komplexe, Verlag Chemie, Weinheim, 1970, and references cited therein. 

Collmann and L. S. Hegedus, Principles and Applications of Organotransition Metal Chemistry. University Science Books, Mill Valley, California, 1980 E. A. Koemer von Gustorf, F. W. Grevels, and I. Fischler, The Organic Chemistry of Iron. Academic Press, New York, 1978. 

Several examples of s-trans-butadiene bridging two transition metal centers have previously been described M. J. Grogan and K. Nakamoto, Inorg. Chim. Acta 1, 228 (1%7) M. Tachikawa, J. R. Shapley, R. C. Haltiwanger, and C. G. Pierpont, J. Am. Chem. Soc. 98,4651 (1976) C. G. Pierpont, Inorg. Chem. 17,1976 (1978) M. Ziegler, 

Yasuda, Y. Kajihara, K. Nagasuna, K. Mashima, and A. Nakamura, Chem. Lett. p. 719 (1981) Y. Kai, N. Kanehisa, K. Miki, N. Kasai, K. Mashima, K. Nagasuna, H. Yasuda, and A. Nakamura, ibid. p. 1979 (1982) the less substituted isoprene 0=C double bond is exclusively complexed by a nickel complex to form (3,4-n -isoprene) Ni (CH3)Cp H. Lehmkuhl, F. Danowski, R. Bcnn, A. Rufinska, G. Schroth, and R. Mynott, J. Organomei. Chem. 254, Cll (1983). 

Gel filtration in its various forms is an efficient tool for preparations in protein chemistry. It can also be used to test the supposed homogeneity of a protein or peptide preparation. A gel column calibrated with respect to its molecular-sieving properties may also be used to estimate the molecular size of biologically active or otherwise labeled substances before their isolation has been accomplished. Needless to say, the result of such an estimation must be cautiously interpreted. 

Dextran gels and other gel substances mentioned can be used as support in electrophoresis. It should be of great value to find out if similar separations can be obtained with gel filtration supplemented with pure zone electrophoresis as with starch-gel electrophoresis according to Smithies (1955). 

This survey of the present stage of gel-filtration methods as applied to proteins and peptides has been confined mainly to the dextran gels. It should be realized that the methods outlined should be applicable also to other gels with similar sieving properties. 

FjellstrSm, K. E. (1962). Acta Pathol. Microbiol. Scand. In press. 

Flodin, P. (1962). Dextran Gels and Their Application in Gel Filtration. Thesis, University of Uppsala. (Available from AB Pharmacia, Uppsala, Sweden.) 

The surface proteins of enveloped viruses perform three m or tasks for the virus shielding of the virus from the immune system, recognition of an appropriate host cell by binding to a cell surface receptor, and the subsequent fusion of the viral and cellular membranes. The first task is somewhat at odds with the last two. Escape from the immune system is aided by rapid evolution of the sequences of the surface proteins, whereas the need to maintain not one but two distinct functions requires that a core structure or structures be maintained. 

Enveloped viruses have a number of tricks to balance these conflicting constraints. In keeping with the economy of virus genomes and structures, some of these tricks even serve multiple purposes. Eirst, critical functions 

Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, and Division of Biology, California Institute of Technology, Pasadena, 

In this chapter we have tried to summarize the current status of the chemistry of quadruply bridged dimetal complexes of the group 10 elements. The area is closely related to that involving similar compounds of the group 9 elements and also the doubly bridged di- and polynuclear complexes of platinum and related metals, which are not included here. We have been able to include the latest developments in this subject area. We have not attempted to be comprehensive, and some omissions may have resulted. 

We are grateful to Professor S. Ooi and Dr. I. Kinoshita of Osaka City University, Japan, and Professor T. G. Appleton, University of Queensland, Australia, for providing us with their results prior to publication. Financial support by a Grant-in-Aid for Scientific Research on Priority Area (No, 03231105) from the Ministry of Education, Science, and Culture, Japan, is gratefully acknowledged. 

Cotton, F. A., and Walton, R. A., Multiple Bonds between Metal Atoms, 2nd ed. Oxford, New York, 1993. 

Umakoshi, K., Kinoshita, I., Ichimura,A., andOoi,S.,Inorg. Chem. 26,3551(1987). 

The title of this chapter may lead some to the conclusion that we intend to present all, or the majority, of the methods employed in modern synthetic practice. In fact, we have neither the intention nor the opportunity within the scope of this text. Such a comprehensive review can be found in excellent monographs mentioned in the list of references. Our goals are entirely different and more modest. We are going to present merely a step-by-step exposure of the basic guidelines that govern the elaboration and utilization of synthetic methods as tools for the solution of organic synthesis problems. 

Functional group transformations represent another extremely important component of the synthetic arsenal. In fact, this material constitutes the main content of every organic chemistry course. For this reason, we limit our discussion to the main features of those reactions which govern their application to the solution of organic synthesis problems. 

For the otherwise efficient synthetic transformations, the lack of selectivity represents a roadblock and so our next topic deals with the most general aspects of selectivity problems and the fairly diverse approaches elaborated to secure realiable control over the regio- and stereochemical course of the reaction, 

Organic synthesis has undergone the transformation from a purely heuristic discipline into a solid branch of science with its own logistics and technology based on the principles of retrosynthetic analysis. An essential part of retro-synthetic analysis involves the sequential disconnection of the target molecule 

The concepts mentioned above can equally well be applied to the synthesis of acyclic and cyclic compounds. Yet owing to the geometrical peculiarities of the cyclic structures, one may expect to find a number of additional, and at times extremely troublesome, challenges to be encountered in this area. For this reason, the problems inherent to the preparation of cyclic compounds of various ring sizes and a set of specific methods elaborated for this purpose are thoroughly discussed in separate sections. 

We have not yet specified if the operator to be handled is Hermitian (real eigenvalues) or whether it is a relaxation operator (eigenvalues either real or in the lower half of the complex plane). Uie moment problem related to a Hermitian operator is addressed as the classical moment problem, while by relaxation moment problem we mean the treatment of relaxation operators. 

Consider a Hermitian or relaxation operator H and a state /g). The moments of H with respect to the state of interest j/g) are defined as the diagonal matrix elements of H  

When H is Hermitian, the power moments ju are real quantities, and even moments are positive both properties are lost in the case of a general relaxation operator. 

We wish now, having only moments as ingredients, to express the Green s function or resolvent 

The possibility of expressing diagonal matrix elements Ggg( ) of the resolvent as a continued fraction of type (5.3) is quaranteed by the following physical argument.  

Computer simulations have become a powerful tool for understanding the structure and properties of polymers. The simulation results not only lead to a greater understanding of experimental data, but they also serve as a way to examine and extend analytic theories. In this chapter, we have tried to give first an introduction of the computational techniques currently available and, second, examples of applications from the current literature. Nonatomistic computational methods are also useful in the study of polymers, especially when one wishes to determine qualitative differences within a series of homologous compounds. 

Block copolymers, polymer blends, polymers at interfaces, liquid crystalline polymers, polymers with novel optical and electronic properties, cross-linked polymers (including elastomers and thermosets), and biocompatible polymers are all areas of active research that are beyond the scope of this chapter. 

It is the author s belief that advances in computer hardware, especially as described by Kendall et al. in this volume, will greatly enhance polymer modeling and make possible the study of realistic systems in a reasonable period of time. 

The author thanks Dr. J. G. Curro for supplying preprints of his work in the PRISM theory. The author is indebted to BIOSYM Technologies, Inc., Kumho Tire Company, Lord Corporation, Owens-Corning Fiberglas Corporation, and Raychem Corporation for continuing financial support. 

Kendall, R. J. Harrison, R. J. Littlefield, and M. F. Guest, this volume. High Performance Computing in Computational Chemistry Methods and Machines. 

Adhikary, S. P., and Sahu, J. (1992). Studies on the Trkhodesmium bloom of Chilka Lake, east coast of India. Phykos 30, 101—107. 

Agjiihotri, R., Bhattacharya, S. K., Sarin, M. M., and Somayajulu, B. L. K. (2003). Changes in surface productivity and subsurface denitrification during the Holocene A multiproxy study from the eastern Arabian Sea. Holocene 13, 701—713. 

Altabet, M. A. (1989). A time-series study of the vertical structure of nitrogen and particle dynamics in the Sar sso Sea. Limnol. Oceanogr. 34, 1185—1201. 

Altabet, M. A. (2007) Constraints on oceanic N balance/imbalance from sedimentary records. Biogeosciences 4, 75—86. 

Altabet, M. A., and Francois, R. (1994). Sedimentary nitrogen isotopic ratio as a recorder for surface nitrate utilization. Global Biogeochem. Cycles S, 103—116. 

To study the variety of structural transformation processes that occur simultaneously in the combustion wave, it is necessary to utilize a wide range of methods. The evolution and morphological features of the microstructure during com- 

For example, four microstmctural models of the product formation process in solid-solid systems can be distinguished based on the results of the experimental methods discussed in this chapter. Brief descriptions of the models are presented in Fig. 76. 

The first mechanism, reaction-diffusion, is based on the assumption that a layer of the solid product (or products) appears on the boundary between the two 

D issolution-cry suJlt/a lit n diuohitton of rcitctant f into melt f A) with ituckfllion of wild i ins buih in the tncli vutumo iind ai rcfwiory 

RoictiulioiMlekcnGci fusion of both molicn Kjcuiits, wiih nudcoiKin of ihc wild piodiict pniiu 

This chapter has been concerned with the effect of structural properties of cobalt(III) hexaamines on their other properties. Included in this review have been complexes ranging from cobalt hexaammine, to complexes composed of three secondary and three tertiary amine donors 

This section shows the structures of various compounds discussed in this chapter. 

Niketic, S. R., and Rasmussen, K., The Consistent Force Field. Springer-Verlag, Berlin, 1977. 

and Huber, F., Z. Anorg. Allg. Chem. 442,31 (1978). In this paper it is claimed that both crystallographically independent cations are in the lel2ob conformation. The cation shown in Fig. 3 of this paper however, has the lels conformation. Thus both conformations are observed in the one crystal structure. 

Kojima, M., Yoshikawa, Y., and Yamasaki, K., Inorg. Nucl. Chem. Lett. 9, 689 (1973). 

Becker, G. Hartmann, H. M. Hengge, E. Schrank, F. Z. Anorg. Allg. Chem. 

Allred, A. L. Smart, R. T. Beek, D. A. V., Jr. Organometallics 1992, 11, 4225. Hengge, E. Spielberger, A. Gspaltl, P. 10th International Symposium on Oigano-silicon Chemistry, 1993, Pozn6n, Poland Abstracts, p. 265. 

Kumada, M. Sakamoto, S. Ishikawa, M. J. Organomet. Chem. 1969, 17, 231. Hatanaka, Y. Hiyama, T. 40th Symposium on Organometallic Chemistry, 1993, Sapporo, Japan Abstracts, p. 136. 

Colvin, E. W. Silicon Reagents in Organic Synthesis Academic Press San Diego, 1988 pp. 27, 60. 

Fleming, I. J. Chem. Soc., Perkin Trans. 1,1992, 3363, and references cited therein. Fleming, I. Sanderson, P. E. J. Tetrahedron Lett. 1987, 28, 4229. 

We began our discourse on uncertainty in the physical sciences with the observation that complete certainty about anything in our world is an 

Russell, Our Knowledge of the External World, p. 75. Allen Unwin, London, 1914. 

Haldane and G. R. T. Ross (transl.), The Philosophical Works of Descartes, Vol. 1, p. 91. Cambridge Univ. Press, Cambridge, UK, 1911. 

The chemistry of metal-carbon triple bonds has developed considerably during the late 1980s. The synthetic basis was broadened, the utility of high-valent metal alkylidynes in metathesis reactions was further developed and refined, and the potential of low-valent carbyne complexes for applications in organic synthesis has become more apparent. The discovery of novel iridium alkylidyne complexes indicates that the full range of metal-carbon triple bonds is not yet known. We can therefore expect that future work in this area of organometallic chemistry will lead to new discoveries with fundamental implications and practical applications. 

We would like to thank Cecilia M. Bastos and Kimberly A. Belsky for helpful discussions during the preparation of the manuscript. Support for the work in our laboratory by the National Science Foundation, the Petroleum Research Fund, administered by the American Chemical Society, and by the Research Corporation is gratefully acknowledged. H.H. is grateful for support from the Degussa AG, Germany. 

Fischer, P. Hofmann, F. R. KreissI, R. R. Schrock, U. Schubert, and K. Weiss, Carbyne Complexes. VCH Publishers, Weinheim, Germany, 1988. 

Department of Chemistry University of Iowa Iowa City, Iowa 52242 

Historical Interest in the Role of Cationic Species in Ziegler-Natta Olefin 

The operation of conjugate base pathways, known for many years with Au(III) compounds, is now recognized as operating at a number of Pd(II) and Pt(II) complexes. These also appear to proceed by A or la mechanisms and probably have similar reaction profiles to the normal nucleophilic ligand replacements, though there are yet too few examples to be certain. 

Only for nickel(II) does the prospect of prereaction geometry change pose a potential complication and since more examples of faster associative nucleophilic ligand exchange at square-planar complexes (rather than their tetrahedral, 5-coordinate, or octahedral alterna- 

Ligand exchange by dissociative activation now appears to be well established for some 16-electron square-planar compounds, though examples are not common. The detail of the intimate mechanism is crude by comparison with associative reactions, but all the evidence indicates the involvement of T-shaped intermediates. 

The picture regarding solvation of square-planar molecules remains obscure. From the associative reactions, there is no evidence that solvation at the metal is important, though entering group solvation is clearly indicated. The dissociative reactions show the relative importance of solvation of the leaving groups and substrates, and solvent interaction with the substrate elsewhere than at the metal ion is probably common. 

Examples of electrophilic interactions at the metal ions (as well as at the leaving and entering groups) have been demonstrated. These represent a formal oxidation of the metal and can lead to oxidative additions to the metal or, by transfer to a ligand, to a dissociation. On the other hand, at least some concerted oxidative additions, often described as electrophilic interactions, are seen in reality to resemble nucleophilic attack in their early stages and some of the two-step oxidative additions (most of which do conform to electrophilic attack) probably resemble the concerted mechanism in their initial interactions, the boundary being indistinct. Nucleophilic attack can, in some cases, precede electrophilic attack. 

One typical argument for necessity in diversity of the family is that each cell type possesses a unique metabolism and that a specialized binding protein is necessary to facilitate such metabolism (Matarese and Bern-lohr, 1988). However, one must keep in mind that many of the compounds that hydrophobic ligand-binding proteins associate with are biochemically inert. They must be activated for further utilization. For example, the two common cellular enzymes that esterify fatty acids, the microsomal ATP-dependent acyl-CoA synthetase (or fatty acid CoA li-gase) and the GTP-dependent organellar synthetase, both produce an acyl-CoA (Bar-Tana et ai, 1975). Therefore, virtually all cells utilize fatty acids in the same fashion—they esterify them with CoA. 

The authors would like to thank the members of the Banaszak, Bernlohr, and Jones laboratories for their helpful comments during the preparation of this manuscript. In addition, we would like to thank our colleagues who allowed us to include unpublished and in press information as part of this review. Last, the authors acknowledge support from the National Institutes of Health (GM13925 to L.J.B.), the National Science Foundation (DMB9118658 to D.A.B. and L.J.B.), and the Swedish Natural Science Research Council and Uppsala University (to T.A.J.). 

Branden, C., and Tooze,J. (1991). Introduction to Protein Structure. Garland Publ., New York. 

Braunitzer, G., Chen, R., Schrank, B., and Stangl, A. (1973). Hoppe-Seyler s Z. Physiol. Chem. 354, 867-878. 

McKenzie, H. A. (1971). In Milk Proteins Chemistry and Molecular Biology (H. A. 

The direct electrochemistry of redox proteins has developed significantly in the past few years. Conditions now exist that permit the electrochemistry of all the proteins to be expressed at a range of electrodes, and important information about thermodynamic and kinetic properties of these proteins can be obtained. More recently, direct electron transfer between redox enzymes and electrodes has been achieved due to the more careful control of electrode surfaces. The need for biocompatible surfaces in bioelectrochemistry has stimulated the development of electrode surface engineering techniques, and protein electrochemistry has been reported at conducting polymer electrodes 82) and in membranes 83, 84). Furthermore, combination of direct protein electrochemistry with spectroscopic methods may offer 85) a novel way of investigating structure-function relationships in electron transport proteins. 

We thank our colleagues, most of whom are named in the references, for their help and hard work. We are also grateful to the financial support provided by the Science and 

Eddowes, M. J., and Hill, H. A. O., in Electrochemical and Spectroelectrochemical Studies of Biological Redox Components (K. M. Radish, ed.), pp. 173-197. American Chemical Society, Washington, D.C., 1982. 

ACTIVE-SITE PROPERTIES OF THE BLUE COPPER PROTEINS 

Department of Chemistry, The University, Newcastie upon Tyne NE1 7RU, Engiand 

A wide variety of alkyl derivatives of manganese- and rheniumpenta-carbonyl have now been prepared, many of them as recently as the early 1990s. This can partly be attributed to the instability of [MniC HsKCOfs], which may have deterred researchers from investigating this field any further. The synthetic routes to these alkyl derivatives vary, but the most widely used pathways involve treating Na[M(CO)5] (M = Mn, Re) with the appropriate alkyl halide, or, in cases where the metalpentacarbonyl anion will not react with the alkyl halide in question, thermal decarbon-ylation of the acyl derivative. 

(T-Carbene, Ciirbyne/7r-Alkene, Allyl. and Alkyne Complexes. . . 266 

The activation of simple organic molecules by more than one transition metal constitutes an area of research which has grown in interest since the mid 1970s. Transition metal clusters, homonuclear and later heteronu-clear compounds, have been widely studied because of the potential for application in catalysis. The chemistry of such complexes has been the topic of many review articles, some of which appeared in this series (1-5). The concept of utilizing binuclear complexes with metal-metal bonds for ligand activation has been recognized (6-8), and, as stated by Casey and Audett, there is some hope that a smooth transition from the chemistry of mononuclear compounds to dinuclear compounds to metal clusters to metal surfaces may be found (9). 

Parallel to the development of the chemistry of dinuclear transition metal complexes with metal-metal bonds, studies related to bimetallic complexes, hetero- and homonuclear, without metal-metal bonds are appearing in the literature at ever increasing frequency (10-13). In these complexes, two or more metals are separated by a common ligand which acts as a bridge between them. Two metal centers acting in a joint fashion could enhance the activation of an organic substrate considerably and in 

The following survey was compiled to facilitate searching for specific questions concerning the Ektachem system  

Enzymes, general E313, ESOO, ES68, ES82. 

Calibration E227, E387, E647, EN49, EN61, EN73, EN129. 

Comparison with other analyzers (Ektachem as comparative instrument).  

Abbott Vision E348, E3S0, E4S4, E643. 

This review of necessity brings together disparate information not always recognized as part of the /-amino effect principle. Consequently, some examples in the literature may have been overlooked. I apologize to those whose work I have not acknowledged and would be glad to hear from them for the next update. 

68JCS(C)1722 O. Meth-Cohn, H, Suschitzky, and M. E. Sutton, J. Chem. Soc. 

69CI(L)443 O. Meth-Cohn and H. Suschitzky, Chem. Ind. (London), 443 

73JCS(P1)696 R. Fielden, O. Meth-Cohn, and H. Suschitzky, J.C.S. Perkin 1, 696 

We have reviewed in this chapter the electronic structure and properties of semiconducting nanocrystals, materials that can be used in the field of nanoelectronics in the near future. Some of these materials already show very interesting properties that can be utilized to make devices and, therefore, it is necessary to have proper experimental and theoretical tools to probe and understand the electronic properties quantitatively. 

UV-Vis absorption spectroscopy is the easiest tool available to characterize semi- 

Viswanatha, J. Nanda et al., in Recent Advances in Inorganic Materials, ed. D. Bahadur, Narosa Publishers, New Delhi, 2003. 

Herron, K. Moller et al.. Solid State Commun., 77, 33, 1991. 

Gaponenko, Optical Properties of Semiconductor Nanocrystals, Cambridge University Press, Cambridge 1998. 

The work described above constitutes the beginning of a new area in which the faradaic electrochemistry of discrete, electroactive nanoparticles is explored, both from a 

This effort was supported by the National Science Foundation under Grant No. 0313661. 

1 Raimondi, F., Scherer, G.G., Koetz, R. and Wokaun, A. (2005) Angewandte Chemie-International Edition, 44, 2190. 

4 Riley, D.J. (2002) Current Opinion in Colloid el Interface Science, 7, 186. 

6 Bard, A.J., Ding, Z. and Myung, N. (2005) Structure and Bonding Springer (Berlin, Germany), Semiconductor Nanocrystals and Silicate Nanoparticles, vol. 118, 1. 

The authors would like to express their gratitude to Prof. Auro Atsushi Tanaka, Department of Chemistry, Federal University of Maranhao, Sao Luis (City) -Maranhao (State), Brazil for making available some of the data in Section 3.4 in 

6 McKeown, N.B. (1998) Phthalocyanine Materials Synthesis, Structure, and Function, Cambridge University Press, Cambridge, UK, New York. 

7 Cotton, F.A., Wilkinson, G., Murillo, C.A., and Bochmann, M. (1999) Advanced Inorganic Chemistry, 6th edn, Wiley, 

8 Falk, J.E. (1975) Porphyrins and metalloporphyrins a new edition based on the original volume (ed. KM. Smith), Elsevier Scientific, Amsterdam, New York. 

33 Forshey, P.A., Kuwana, T., Kobayashi, N. and Osa, T. (1982) Electrochemical and Spectrochemical Studies of Biological Redox 

As the reader can appreciate, extremely low concentrations of metal ions are able to orchestrate a multitude of activities in the brain, controlling the opening of various ion channels as well as activating various neurotransmitter receptors. Clearly, changes in the concentrations of such metal ions will induce adverse effects and induce the demise of neurons and other cell types. This will be considered in the next chapter. 

Abbott, N. J., Patabendige, A. A., Dolman, D. E., Yusof, S. R., Begley, D. J. (2009). Stmcture and function of the blood-brain barrier. 

Wenzel, H. J., Kafer, K. E., Schwartzkroin, P. A., Palmiter, R. D. (1999). Elimination of zinc from the synaptic vesicles in the intact mouse brain by dismption of the ZnT3 gene. Proceedings of the National Academy of Sciences of the United States of America, 96, 1716-1721. 

Cousins, R. J., Liuzzi, J. R, Litchten, L. A. (2006). Mammalian zinc transporters, trafficking and signals. Journal of Biological Chemistry, 281, 24085-24089. 

Deisseroth, K., Mermelstein, P. G., Xia, H., Tsien, R. W. (2003). Signalling from synapse to nucleus the logic behind the mechanisms. Current Opinion in Neurobiology, 13, 354—365. 

The ability to retain anisotropic spin interactions and the power to selectively suppress unwanted interactions using pulse sequences such as PISEMA in aligned solids have played a significant role in the applications of solid-state NMR spectroscopy. In addition, the excellent control over the order parameter (ranging from isotropic to rigid solids) of a system and creation of model biological systems obviously invited, simplified, created, and amplified the applications of solid-state NMR techniques. Although solid-state NMR 

Williams, Bioinorganic Pharmacy , in Introduction to the Principles of Drug Design , ed. H.J. Smith, Wiley, New York, 2nd Edition, 1989. 

Department of Health, Dietary Reference Values for Food Energy and Nutrients for the United Kingdom , Department of Health Report No. 41, HMSO, London, 1991. 

Duffield, S.B. Hall, D.R. Williams, and M.L Barnett, Safer Total Parenteral Nutrition based on Speciation Analysis , in Progress in Medical Chemistry , eds. G.P. Ellis and G.B. West, Elsevier, Amsterdam, 1991, p. 28. 

Coultate, Food - The Chemistry of Its Components , The Royal Society of Chemistry, Cambridge, 2nd Edition, 1988. 

Thomas, Wound Management and Dressings , The Pharmaceutical Press, London, 1990. 

It is pointed out above that metal deposition is different from outer-sphere charge-transfer reactions in that charge is carried across the metal/solution interface by the ions, not by electrons. Although this has been acknowledged by several noted electrochemists, a theory of charge transfer by ions, comparable in detail and depth to the theories of electron transfer, has yet to be developed. So far, 

The analysis of the kinetics of alloy deposition is complicated by the fact that at least two reactions occur in parallel. Consequently, the current-potential relation observed represents a combination of the contributions of two processes, each having its own overpotential, rate constant and potential dependence of the current density. Thus, any information obtained from the current-potential relation observed is of questionable value in evaluating the mechanism of the formation of the alloy. 

It should not be surprising that an ion such as WO4 cannot be reduced readily all the way to metallic tungsten. Indeed, it is surprising that there are certain conditions under which it can be reduced. Moreover, alloy deposition is often a complex, and quite unpredictable, process. In what is called anomalous deposition we classify processes that behave imexpectedly - the composition of the alloy cannot be predicted from the current-potential relation of the alloying elements studied each by itself. When forming a Ni-Fe alloy it seems that Fe + ions in solution inhibit the rate of deposition of nickel, while NP ions accelerate the rate of deposition of iron. In the deposition of a Ni-Zn alloy the situation is somewhat different. Here, one finds a complete synergistic effect adding either ion to the solution enhances the rate of deposition of the other metal. 

Anomalous alloy deposition is common in electroplating. Actually, it is so common that it is the rule rather than the exception. What could be the cause of this phenomenon In general, it is postulated that one of the alloying elements forms a hydroxide on the surface, which inhibits the deposition of the other. This could explain the inhibiting effect, but it is much more difficult to explain the enhancement. Another explanation is that the two ions form a mixed-metal complex that, for some reason, is more readily reduced at the surface than each of the metal ions separately. Naturally, such complexes can only be expected to exist in solution 

If the mixed-metal complex is the precursor for deposition of the alloy, then it can be seen that adding either of the two ions would increase the rate of deposition of the other. This simplistic interpretation could lead only to alloys having equal concentrations of the two elements. However, if the concentration of the two elements in solution is not equal, one could have a parallel reaction, in which one of the metals would also be deposited in parallel from its complex with citrate, giving rise to a whole range of alloy compositions. 

Atalla, IRE Solid-State Device Research Conference, Carnegie Institute of Technology, Pittsburgh, Pa. I960. 

Rodherick, R.H. Williams, Metal-Semiconductor Contacts. Oxford University Press. New York 1988. 

Physics of Semiconductor Devices, John Wiley, New York 1981. 

Physics of semiconductor devices, Prentice-Hall, Englewood Cliffs 1990. 

The development of radical additions to C=N bonds is a field with great promise for applications in the synthesis of multifunctional compounds the functional group compatibility of radical chemistry complements that of carbanion reagents to expand 

Entry Halide Hydrazone (R ) Catalyst load % Yield (% ee° ) 

Which of the following pairs of reactants would be expected to give synthetically useful yields in the Sn mediated addition reaction shown in Table 2.3 Explain. 

For the Mn mediated coupling of ethyl iodide with N acylhydrazone 8a (Table 2.6, entry 1), propose a source of the N H hydrogen. 

Design a synthesis of halosaline, using a Mn mediated coupling reaction as a C C bond construction step. 

In addition, the cathodic PCT technique offers an exceptionally powerful tool for understanding the kinetics of the cathode reaction, in the case where electrochemical reactions are self-enhanced over long periods of time ( 4 h) under the cathodic polarization. In contrast to the cathodic potentiodynamic polarization curves with a short measuring time ( 10 min), the cathodic PCTs allow observation of variations in the steady-state current with polarization time, which may provide valuable information when analyzing the reaction rate under cathodic polarization [120]. 

In this chapter we have summarized the fundamentals and recent advances in thermodynamic and kinetic approaches to lithium intercalation into, and deintercalation from, transition metals oxides and carbonaceous materials, and have also provided an overview of the major experimental techniques. First, the thermodynamics oflithium intercalation/deintercalation based on the lattice gas model with various approximations was analyzed. Lithium intercalation/deintercalation involving phase transformations, such as order-disorder transition or two-phase coexistence caused by strong interaction oflithium ions in the solid electrode, was clearly explained based on the lattice gas model, with the aid of computational methods. 

The chapter then detailed the kinetics of lithium intercalation/deintercalation 

Finally, a brief overview was presented of important experimental approaches, including GITT, EMF-temperature measurement, EIS and PCT, for investigating lithium intercalation/deintercalation. In this way, it is possible to determine - on an experimental basis - thermodynamic properties such as electrode potential, chemical potential, enthalpy and entropy, as well as kinetic parameters such as the diffusion coefficients of lithium ion in the solid electrode. The PCT technique, when aided by computational methods, represents the most powerful tool for determining the kinetics of lithium intercalation/deintercalation when lithium transport cannot be simply explained based on a conventional, diffusion-controlled model. 

1 Budnikov, P.P. andGinstling, A.M. (1968) Principles of Solid State Chemistry-Reactions in Solids, Gordon and Breach Science Publishers, New York. 

The past few years have seen many major advances in the understanding of insulinlike growth factor action, culminating in direct demonstrations of growth effects in laboratory animals. Inevitably, however, some of the most important questions are still unanswered. Remaining areas of controversy span all facets of somatomedin research, among which the following may be included. 

What forms do the peptides take Although the existence of a separate fetal form of somatomedin has been postulated, only SM-C/IGF-I and IGF-II, both of which are found in the fetus as well as postnatally, have been characterized to date. 

Where are they made IGF-II is 3 times more abundant in the adult human circulation than SM-C/IGF-I, yet its origin is entirely unknown. 

How are they delivered to cells Free somatomedins are not detectable in the circulation, but the extreme sensitivity of some cells to small amounts of the peptides leaves open the possibility that very low concentrations of unbound peptide might be responsible for major biological eflfects. If this is not the case, how does the binding protein complex release the growth factors at their target cells Where is the 150,000-molecular-mass complex produced, and what is its relationship to the various 40-60,000 molecular mass species  

Do somatomedins principally act locally, or at a location distant from their site of synthesis The evidence for local action is indirect, being based largely on observations of growth factor production by many different cells and tissue explants in culture. Is the secretion of growth fectors an adapta- 

It has not been possible in the present review to cover all the diversity of new ideas and approaches that have been developed in the electrochemistry of semiconductors. Therefore, in conclusion we would like to note those directions which seem to us the most interesting and promising (though some of them have not so far been developed extensively because of one reason or another which 

Quite promising may be the study of photoelectrochemical properties of microheterogeneous semiconductor systems (porous electrodes, suspensions of different degrees of dispersion up to colloidal solutions), in which photosensitivity inherent in semiconductors is combined with high electrocatalytic activity typical of systems with a developed surface. 

Modification of the surface of semiconductor electrodes by catalysts (mediators) attached to it also deserves intensive investigation. 

Finally, in recent years there has been a new surge of development in the field of thin-film electrochemistry, especially in view of practical applications. The thickness of films in such systems ranges from several angstroms to hundreds of angstroms in the latter case, the films often posess semiconducting properties. 

New methods of investigation. It may be expected that fresh important information will be gained with the aid of new methods, both developed directly within the framework of the electrochemistry of semiconductors and metals and borrowed from other fields, foremost of which is the physics of surfaces the latter methods are usually called nontraditional. 

This chapter has presented a summary of the important features of research on catalytic materials. It is a changing world and new data will be forthcoming. Nothing has been said about exciting new materials such as metal sulfates, phosphates/ metal-graphite intercalation compounds/ superbasic materials/ and carbides or nitrides/ all of which await industrial exploitation. 

Designing catalysts to satisfy process needs is like writing prescriptions to cure illnesses. We hope that the procedure is accurate and successful and try to base it on scientific method. Yet in practice, it is the skill of the practitioner, whose background, knowledge, experience, and awareness of what has worked in the past usually prevails. Nevertheless, in catalysis as well as medicine, we continually strive to improve the precision of the design process beyond mere copying of recipes. 

The procedure is attractive as a teaching vehicle. It has proven successful in many practical applications. As a training device, students progress 

A target reaction is essential. This is easiest with chemical processes since the critical reaction i easily identified. With petroleum and other fuel processes, so many reactions exist that some degree of lumping into reaction types, perhaps with model compounds. Is necessary. 

We now follow the original strategy of Dowden. The distinct steps in the method are shown in Fig. 5.1. These are as follows  

Andersen, M. E., Cfeweff, H. J., Ill, and Frederick, C. B. (1995). Appfying simulation modeling to problems in toxicology and risk assessment—A short perspective. Toxicol Appl Pharmacol 133, 181-187. 

Andersen, M. E., Clewell, H. J. I., Gargas, M. L., Smith, F. A., and Reitz, R. H. (1987). Physiologically-based pharmacokinetics and risk assessment process for methylene chloride. Toxicol Appl Pharmacol 87, 185-205. 

Andersen, M. E., and Dennison, J. E. (2001). Mode of action and tissue dosimetry in current and future risk assessments. Sci Total Environ 21 A, 3-14. 

Andersen, M. E., Krewski, D., and Withey, J. R. (1993). Physiological pharmacokinetics and cancer risk assessment. Cancer Lett 69, 1-14. 

While the synthesis of dendrimers requires the use of a series of time-consuming and elaborate steps, the synthesis of hyperbranched polymers can be simplified to a one-pot procedure based on classical condensation reactions. These reactions are made either in bulk or in solution where AxB monomers are condensed by themselves or in combination with a By core monomer. The use of a By core monomer affords better control over the molecular weight and polydispersity of a hyperbranched polymer. 

Hyperbranched polymers differ greatly from linear or moderately branched polymers. For example, the solubility is much higher for hyperbranched polymers but not as high as for dendrimers. Hyperbranched polymers normally exhibit an amorphous, nonentangled behavior, i.e., a Newtonian behavior in the melt. The nonentangled state also makes hyperbranched polymers rather brittle. Several thermoset resin materials have been described where the hyperbranched polymer exhibits a low resin viscosity, thereby reducing the need for solvents to attain the application viscosity. At the same time. 

Principles of Polymer Chemistry, Cornell University Press, Ithaca, N.Y. (1953). 

Solomon, Polyesterification, Chap. 1 in Step-Growth Polymerizations (D. H. Solomon, ed.), Marcel Dekker, New York (1972). 

Saunders and F. Dobinson, The Kinetics of Polycondensation Reactions, Chap. 7 in Comprehensive Chemical Kinetics, vol. 15, (C. H. Bamford and C. F. H. Tipper, eds.), American Elsevier, New York (1976). 

In conclusion, although the large-scale total synthesis of (2 R,4 R,8 R)-a-tocopher-ol (RRR-3) is (so far) not a success story within the area of industrial total syntheses of natural products, the incontestably high potential and usefulness of catalytic methods again became evident. If there ever will be a chemical solution, the key technology contributing decisively to this would very probably have to be labeled as the tide of this book asymmetric catalysis on industrial scale. 

Protein folding can be extremely fast, and some proteins fold to their native state within a few milliseconds. Trans cis peptide bond isomer-izations complicate the folding process and decelerate it, sometimes by more than 1000-fold. Nevertheless, cis peptide bonds occur frequently in folded proteins, mainly before proline and occassionally before other amino acid residues. Prolyl isomerization and conformational folding are coupled Incorrect prolines lower the stability of folding intermediates and partial folding can modulate isomerization rates. Prolyl iso-merases catalyze prolyl isomerizations in protein folding, provided the prolines are accessible. 

Cis prolines are very well suited to introduce tight turns (such as type VIft turns) into proteins, but this cannot be the sole reason for their widespread occurrence. Evidence increases that cis/trans heterogeneity at prolyl bonds exists not only in the course of protein folding, but also 

First evidence for a regulatory function of native-state prolyl isomerization comes from the parvulins Pinl and Essl, which are specific for pSer/pThr-Pro sequences and possibly link regulation by prolyl isomerization to regulation by phosphorylation/dephosphorylation. Similarly, the correlation between prolyl isomerization and Ca2+ binding in the mammalian lectins might indicate that prolyl isomerization could also be connected with Ca2+ signaling. 

In the future we need to elucidate which of the many interactions between prolyl isomerases and target proteins are functionally important in the cell and how prolyl isomerase domains of large proteins contribute to the overall functions of these proteins. At the molecular level the kinetic and structural consequences of native-state prolyl isomerization must be elucidated at high resolution to understand how these isomerizations can contribute to cellular regulation, and how they are modulated by prolyl isomerases and by other processes, such as phosphorylation. 

I thankj. Balbach, M.Jacob, A. Martin, R. Maier, D. Perl, M. Zeeb, and T. Oas for many discussions and their critical reading of the manuscript. This paper is dedicated to Prof. Rainer Jaenicke on the occasion of his seventieth birthday. I thank him for his continuing support and encouragement. 

Our approach has been pragmatic. Those terms that enter the ESR 

In their present stage of development, these new tools are appropriate for a very wide range of systems. The applications presented here, in the references, and in the publications that will appear in the coming months should reasonably define their current domain of application. While they are very powerful even now, further understanding and development is 

In closing, we would like to emphasize that this is a very dynamic and still growing field. The possibilities for applications seem endless and we are hopeful that, as the results provide a better-and-better picture of its strengths and limitations, the SOS- DFPT approach and its offspring will become even more powerful and general tools for analysing and interpreting ESR and NMR spectra. 

Financial support from the Swedish Natural Science Research Council 

Grimmer, in Nuclear Magnetic Shieldings and Molecular Structure, J. A. Tossell (ed.), Kluwer Academic Publishers, Dordrecht, 1993, p. 191. 

The electron-topological method describes molecules with emphasis on electronic parameters that can be related to biological activity. This approach is justified because the results allow one, in many cases, to predict unambiguously the features affecting activity and to work out better methods of designing biologically active compounds. This statement has been illustrated here by several examples of applications of the ET method to concrete QSAR problems. 

Unfortunately, the results of application of the more sophisticated versions of the ET method with m 1, i.e., when more than one set of electronic parameters describing the properties of atoms and bonds is tried [m ETMC forming TDETMC), cannot yet be presented. Work on this topic is now in progress. As mentioned earlier, the TDETMC method allows one to single out the best choice of electronic parameters that are most informative with respect to the biological activity under consideration. Such a choice would reveal the ETSA that gives the best separation of the active compounds from the inactive ones. 

Further improvements of the method are also possible. In particular, at the stage processing ETMC for active and inactive compounds in order to reveal the ETSA, one can introduce in the algorithm the requirement that only the steri-cally accessible active elements of the ETMC of molecules have to be compared with their activity. In the version of the ET method presented in this review, the effect of shielding groups is taken into account visually in addition to the predictions of the ETSA. 

Other parameters that are informative for the biological activity of molecules (solubility, volatility, lipophilicity, membrane permeability, stability in biological fluids, kinetic parameters, etc.), can, in principle, also be 

Fujita, in Drug Design Fact or Fantasy. G. Jolles and K. R. H. Wooldrigc, Eds., Academic Press, London, 1984. The Role of QSAR in Drug Design. 

The Pacific Gas Electric (PG E) system is also unique in that the PM250 was a prototype, power-management system and, perhaps, the forerunner of the PQ2000. PG E was also a test site for the subsequent PQ2000 prototype. 

The PREPA BESS can be viewed as a transitional system because it was selected by a utility to circumvent several system problems and funded without any outside incentive funds. The applications were characteristic of isolated or island utilities (note the similarities with BEWAG) and do not include peak shaving or load levelling. Its benefits were seemingly valued by PREPA. It will be interesting to see whether or not PREPA replaces the failed battery and returns the BESS to service. 

Metlakatla is another small, island utility in need of rapid reserve for utility stabilization and power-quality purposes. There are also environmental issues involved, i.e., fuel delivery and the stand-down of a diesel generator that would otherwise operate under difficult, inadvisable circumstances. 

The PQ2000 is a commercially available BESS. Following its commercial introduction at Homerville, GA, additional units have been sold and placed in service. This is evidence of commercial maturity and economic viability. Note that its primary application is standby power (rapid reserve) for interventions in the interest of assuring power quality. In one sense, it is an industrial-scale UPS. 

The cost data presented in Table 10.2 are interesting, but comparisons are difficult. Most of these systems are one-of-kind systems built for demonstration purposes and, in some instances, costs may have been a secondary issue. Chino and PREPA were large systems assembled from individual components. PREPA is the more expensive but was built six years later. The costs on a dollar per kW or kWh basis reflect the differences of their respective capacities. The BoP costs of the PREPA facility were much higher. Taking capacities into consideration, the SDG feE BESS was very expensive, perhaps unnecessarily so. The Metlakatla and Vernon systems differ in capacities, but are similar in many ways, e.g., similar components and built by the same entity. The costs of the Metlakatla BESS may reflect an economy based on experience and familiarity. The PQ2000 differs dramatically from the others its future costs will likely reflect its growing market and commercial status. 

A first step —a major step—in understanding initiation at a molecular level is to determine what unimolecular step(s) lead to large translational energy release. If certain key steps could be identified, one could in principle make a material less sensitive by some chemical modification that raises the (activation) energy barriers for those key steps. 

Another important issue is that large-scale molecular dynamics simulations are not poised to get this energy partitioning right without being taught the dynamical information that comes from the kinds of calculations discussed here. 

That is, for the molecular dynamics simulations that include energy release chemistry steps to be realistic, these chemical steps must have two features. They must have an endothermic component such that initial chemical events remove rather than release energy, and they must have exothermic steps that release a fraction rather that all the chemical energy into product translation. That fraction must come from calculations such as those discussed in this chapter. These two features are the MD-simulation equivalent of chemical induction times in fluid dynamics simulations. 

The dynamical methods presented in this chapter may be used in conjunction with electronic structure methods such as Density Functional Theory that can be used on various RDX fragments as well as on RDX itself. A key feature of the reaction path based methods is that the calculation does not scale unfavorably with the number of atoms, making the prospect of performing these calculations to get valuable dynamical information for larger systems tractable. 

Potential Energy Surfaces, Advances in Molecular Electronic Structure Theory, JAI press, Greenwich, CT, 1990, p. 129-173. 

My work has been supported by ongoing grants from the Namral Sciences and Engineering Research Council of Canada. I thank Professor J. R. Knowles and Professor C. O. Poulter for preprints of their papers, and I thank Dr. Zheng Huang for critical comments. 

(1978). Enzymatic Reaction Mechanisms. Freeman, San Francisco, California. 

(1965). Fundamentals of Carbanion Chemistry. Academic Press, New York. 

Kinetic Isotope Studies with Normal Substrates. 324 

Search for Radical Intermediates 2 -Azido Substrate Analogs. 331 

PrP-res can induce its own formation (Kocisko et al, 1994), an essential prerequisite for a protein-only infectious agent. This replication is clearly influenced by PrP primary sequence and conformation. Supporting data are now available for how, in the absence of any nucleic acid component, these variations in PrP sequence and conformation could account for TSE species and strain characteristics. It is important to remember, however, that the link between these properties of PrP-res at the molecular level and the in vivo events in TSE disease remains 

Bolton, D.C., and Bendheim, RE. (1988). In Novel Infectious Agents and the Central Nervous System (G., Bock, andj.. Marsh, eds.) pp. 164-181, John Wiley c Sons, Chichester. 

Madlung, A., Manson, J., Strome, R., Fraser, RE., Kruck, T., von Bohlens, A., Schulz-Schaeffer, W., Giese, A., Westaway, D., and Kret-zschmar, H. (1997a). Nature399, 684-687. 

(1996). In Methods in Molecular Medicine Prion Diseases (H., Baker, and R.M., Ridley, eds.) pp. 223-236, Humana Press, Totowa. 

Forloni, G., Angeretti, N., Ghiesa, R., Monzani, E., Salmona, M., Bugiani, O., and Tagli-avini, F. (1993). NatureS62, 543-546. 

Above we have presented some of the considerations and practical difficulties that must be taken into account in the derivation of 4-component basis sets for relativistic calculations. The ultimate validation of any basis set will have to take place through applications. Despite the availability of programs for 4-component calculations for more than 10 years, the field is still quite unexplored, compared to the wealth of information and experience that exists with regard to non-relativistic basis sets. Such experience will eventually accumulate also for relativistic work, but the size and cost of most calculations where relativity is of interest, indicates that this will be a slower process than what it has been for non-relativistic basis sets. 

apart from the compilation of dual family basis sets for the series potassium to element (118) [30], and the Universal Gaussian Basis of Malli et al. [26], there are few extensive series for the heavier elements which can be explored for systematic investigations. Among the tasks that need to be undertaken is a more complete derivation of higher quality basis sets, including polarization and correlation functions, and a systematic investigation of even-tempered basis sets. 

The authors are grateful to Dr. H. M. Quiney for helpful discussions and suggestions. The work has been partially supported by a grant from the Norwegian Research Council to KF. KF acknowledges the hospitality and support of the Laboratoire de Physique Quantique, Universite Paul Sabatier. 

Schaefer III (ed.), New York, pg.l (1977) E.R.Davidson, D. Feller, Chem. Rev. 86 (1986) 681 J. Almlof, T. Helgaker, P. R. Taylor, J. Phys. Chem. 92 (1988) 3029 T. Helgaker and P. R. Taylor, Gaussian basis sets and molecular integrals, in D. R. Yarkony (ed.). Modern Electronic Structure Theory, World Scientific, p. 725 (1995). 

Grant in G. W. F. Drake (ed.) Atomic, Molecular and Optical Physics Handbook, AIP Press, Woodbiuy New York, 1996. 

In this article we have advocated the use of a systematic, structured approach to reactor selection. The reactor selection exercise is conveniently split into three, separate, sequential decisions on the following subsets, or attributes  

Subset I Volume-to-surface area of each phase Subset II Contacting flow pattern of the phases Subset III Multiphase flow regimes. 

Reactor Sub Set 1 (Volume/Surface area) - effectiveness factor - influence of intra-particle transport on selectivity - thermal stability - gas-liquid reaction regime (slow, fast pseudo first order or instantaneous) 

The systems approach presented here has been mainly developed for application within the petroleum and petrochemical industries and, therefore. is restricted to continuous steady-state processing on a large scale. It is worthwhile examining the extension of these concepts to unsteady-state processing and batch operations. Also, there may be other ways to structure the reactor selection problem to suit one s own work environment and technology culture. 

The structural chemistry of coordination compounds continues to pose challenging problems, but a combination of physical methods and revolutionized synthetic techniques should clarify the picture and provide a real opportunity for those involved in this research. It should be encouraging. Such a prospect provides a major impetus to discover other coordination polymers with unexpected frameworks. 

Comprehensive Supramolecular Chemistry Lehn, J.-M., Ed. Pergamon Press Oxford, 1995 Vol. 9. 

Transitional Metals in Supramolecular Chemistry Fabbrizzi, L., and Poggi, A., Eds. Kluwer Holland, 1994. 

Farraro, J. R. Williams, J. M. Introduction to Synthetic Electrical Conductors Academic Press New York, 1987. 

A part of this work was carried out under the Visiting Researcher s Program of the IMR, Tohoku University of Japan. This work was partially supported by Foundation for Promotion of Material Science and Technology of Japan (MST Foundation), and a Grant-in-Aide for Scientific Research of Japan Society for the Promotion of Science (JSPS). 

French, and N.M. Short), Mono Book Corp, Baltimore, pp. 159-168 (1968). 

In Supramolecular Architecture Bein, T., Ed. American Chemical Society Washington, DC, 1992 Chapter 19 p. 256, 

A number of new macrolide antibiotics with interesting bioactivity have been isolated, and the unique and complex structures have been determined. Toward the total synthesis of such attractive macrolide antibiotics, very efficient synthetic strategies and useful methodologies have been developed. Recent advances in macrolide synthesis based on newly developed strategies and methodologies are remarkable various complex macrolides having many chiral centers have been efficiently synthesized with excellent stereoselectivity. Recently, combinatorial 

L-Selectride lithium tri-s-butylborohydride MCPBA m-chloroperoxybenzoic acid 

Suzuki, A. (1982). Acc. Chem. Res. 15, 178-184. (b) Suzuki, A. (1991). PureAppl. Chem. 63, 419-422. (c) Suzuki, A. (1992). In Organic Synthesis in Japan, Past, Present, and Future pp. 411 23. Tokyo Kagaku Dozin, Tokyo. 

The author is indebted to Dr. Warren J. Close, Head of the Organic Chemistry Department of this laboratory for the critical editing of this study and for the opportunity of discussing some of the reactions. We are particularly grateful to Dr. John Tadanier, also of this laboratory, for some of the ideas gained from him on reviewing possible mechanisms of action. 

Adkins, H., Reactions of Hydrogen, p. 64. Univ. of Wisconsin Press, Madison, Wisconsin, 1937. 

Ratusky, J., and Sorm, F., Collection Czechoslov. Chem. Commune. 19, 340 (1954). 

Of particular interest are recent developments linking the damaging activity of metals to the genetic mechanisms of processes involved in carcinogenesis and cancer progression, and these should increase our knowledge on the genetic activity of metals and their compounds. 

Adler ID and El-Tarhas A (1989) Clastogenic eflfcts of cis-diamminecUoroplatinum. I) Induction of 

Akiyama M, Oshima H and Nakamura M (2001) Genotoxicity of mercury used in chromosome aberration test. Toxicol In Vitro 25 463-467. 

Amorim MIM, Mergler D, Bahia MO, Dubeau H, Miranda D, Lebel J, Burbano RR and Lucotte M (1999) Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon. An Acad Bras Ci 72 497-507. 

Anastassopoulou J and Theophanides T (2002) Magnesium-DNA interactions and the possible relation of magnesium to carcinogenesis. Irradiation and free radicals. Grit Rev Oncol Hematol 42 79-91. 

Some information has been presented about the known P450s. Because the genome is nearly completed, no more human P450s are likely to be added unless our views of marker sequences change. 

There is considerable opportunity to improve screening and predictability for use with new chemical entities in the pharmaceutical industry. Another open issue is whether large-scale SNP analysis can be practical in drug development. 

Another area is understanding the relevance of variations in P450s (both SNPs and expression levels) to diseases, not only drug therapies. For instance, one can ask if some of the minor sterol products produced by P450 3A4 have any impact on cardiovascular disease. How important are some of the P450s that oxidize arachidonic acid to various products (in humans) Does a P450 2D6 deficit have any relevance to long-term health  

Research in the author s laboratory has been supported in part by USPHS grants ROl CA90426 and P30 ES00267. Thanks are extended to the many individuals who provided unpublished results, to Drs. E.M.J. Gillam, F.F. Kadlubar, and 

Waterman for comments, and to present and past members of the author s laboratory for their involvement in some of the original research. This chapter is dedicated to Dr. Tsutomu Shimada, my long-term collaborator, on the occasion of his retirement from the Osaka Prefectural Institute of Public Health (March 2003), and to my postdoctoral mentor. Prof. M.J. Coon, who introduced me to these enzymes 30 years ago. 

K Interfacial area of entrained / Bubble departure frequency 

Three isozymes of NOS have been identified, and their protein, cDNA, and genomic DNA structures have been elucidated. In humans NOSs I, II, 

Gaston, B., Lilly, C. M., Gerard, C., Drazen, J. M., and Stamler, J. S. (1994). Constitutive and inducible nitric oxide synthase gene expression, regulation, and activity in human lung epithelial cells. Proc. Natl. Acad. Set. U.S.A. 91, 10089-10093. 

Bandaletova, T., Brouet, I., Bartsch, H., Sugimura, T., Esumi, H., and Ohshima, H. (1993). Immunohistochemical localization of an inducible form of nitric oxide synthase in various organs of rats treated with Propionibacteriumacnes and lipopolysaccharide. Apmis 101, 330-336. 

Bigdeli, N., Niemann, A., Sandler, S., and Eizirik, D. L. (1994). Dissociation between interleukin-1 3-induced expression of mRNA for superoxide disrautase and nitric oxide synthase in insulin-producing cells. Biochem. Biophys. Res. Commun. 203, 1542-1547. 

Bogdan, C., Vodovotz, Y., Paik, J., Xie, Q. W., and Nathan, C. (1994). Mechanism of suppression of nitric oxide synthase expression by interleukin-4 in primary mouse macrophages. J. Leukocyte Biol. 55, 227-233. 

The overall analysis presented in this work shows that through the use of the density functional theory framework one may establish a simple unified approach to bond energies, activation energies, and reaction energies, in terms of hardness differences. 

According to the analysis, and the results presented here, one may conclude that Eq. (33) for the energy changes, accounts for the main contributions that are involved in the interaction between different chemical species, and therefore it may be used to study trends and to rationalize the behavior of molecules under different circumstances. 

On the other hand, it seems that the additivity of softness assumption may provide important information about the transition state structure, and about the reaction mechanism, because if the experimental activation energy is known, one can determine the looseness of the transition state, and also, among several possibilities, one may select the molecular fragments that provide the best description. 

In particular, 1 believe that the present approach may be very useful in organic reactions, because the differences in the chemical potential (electronegativity) of many organic compounds are very small. This situation implies that, in general, one may expect that the chemical potential difference term will be negligible, in comparison with the hardness difference term, and therefore, Eq. (33) may be particularly appropriate to understand the chemical reactivity of organic molecules. 

Acknowledgments. I would like to thank A. Vela and L.I. Rangel for many valuable discussions. 

In this paper, a detailed description of the state-of-the-art of catalyst preparation by the microemulsion technique has been given. It has been shown that one of the major advantages of the microemulsion technique is that it allows the preparation of metal-based catalysts displaying a narrow particle size distribution in the nanosize range. 

This feature is of a great importance since these materials may have a wide range of applications. Nanoparticles can possess unique properties, quite different from those of relatively larger particles of the same material. 

In some cases the performance of the microemulsion-based catalysts was superior to that of the traditional catalysts regarding both activity and selectivity. However, for the use of the microemulsion technique in catalyst preparation, the nature of the catalytic process itself should be taken into account. For processes in which the particle size does not play an important role, the election of other techniques for catalyst preparation might be more appropriate. 

The special properties of the catalysts prepared from microemulsion systems include in addition to a small and uniform particle size also unique features related to the special environment in which particle formation takes place. However, further studies are still required in order to understand the relation between the mode of preparation and the properties of the particles. 

It is expected that nanotechnology in catalysis manufacturing will become a remarkable challenge for catalysis science . 

The dynamic method for selection of active conformers appears to be useful in this venture. Its first step is a procedure for generation of 3D isomers, representing the conformational space of molecules. Although the 3DGEN algorithm is used in the OASIS system, most of the other algorithms for conformational space search (after minor modifications) could be used for that purpose. Next, a method for conformer screening is nsed, based on a hierarchical set ofmles, in an attempt to find the active conformers. 

Pasteur, Researches in Molecular Asymmetry of Natural Organic Products (1860) Alembic Club Reprint No. 14, Edinburgh, 1905. Note the erroneous translation from Recherches sur la Dissymetrie Moleculaire... ] 

Verbalis, and T. Dyott, Three-dimensional interactive model building, presented at the 162nd National Meeting of the American Chemical Society, Los Angeles (1972). 

DeClercq, Tetrahedron 40, 3717 (1981). [A program limited to joining ring templates] 

Quite similarly to modern relativistic electronic structure methods, whose application might be considered as almost inevitable for the description at least of molecular systems involving heavy elements, maybe in future a proper description of chiral molecular systems will be inconceivable without electroweak quantum chemistry . 

I am deeply indebted to Martin Quack for his stimulus, for sharing ideas and insight as well as for his support and help in various ways. Therefore, this chapter is dedicated to him on the occasion of his 55th birthday. I thank Jurgen Stohner for his comments on the manuscript and for stimulating discussions on various aspects of molecular parity violation. And last but not least I thank my student Guido Laubender for his dedicated work. 

For brevity I have used in section 3.1 the system of natural units, in which the numerical value of the speed of light c and the numerical value of h = /i/(27t), with h being the Planck constant, are equal to 1. The Einstein convention of summing over repeated indices, of which one is covariant and one is contravariant, has been employed. 

The contravariant space-time four-vector is given by 

The metric tensor g i, in four-dimensional Minkowski space reads in Cartesian coordinates as 

Istituto per lo Studio della Stereochimica ed Energetica del Compost dl Coordinazlone. Consigllo Nazlonale delle Ricerche, 50132 Firenze, Italy 

A further hurdle that must be overcome is the incorporation of a better representation of the solvent contributions, including those of specific interactions with water molecules and counterions. As shown in this chapter, these latter types of interactions play a crucial role in specific protein-DNA recognition, and as the repertoire of known 3D structures of protein complexes grows, we may well And them commonly mediating protein-protein association as well. 

Analysis has shown the potential interest in organic farming labeling as a means of generating market driven incentives to support Italian marine-fish aquaculture. On the demand side, the consumer survey carried out during the promotion sale of experimental organically farmed marine fish has shown  

At the marine fish farm managerial level, the following are of note  

Bremnes, H., and Wessel, C.R., 1999, Product Aggregation, Market kitegration and World Salmon Prices, American Journal of Agricultural Economics, 81(3) 568—581. 

Atkinson, A. A., Banker, R.D., Kaplan, R.S., and Young, S.M., 1998, Management Accounting, ISEDI, Torino. 

Bishop, R.C., and Romano, D. (eds.), 1998, Environmental Resource Valuation Applications of the Contingent Valuation in Italy, Kluwer Academic Publishers, Boston. 

The act of depositing records into a database and seeing these records made public has always been an exercise of pride on the part of submitters, a segment of the scientihc activity from their laboratory that they present to the scientific commimity. It is also a mandatory step that has been imposed by publishers as part of the publication process. In this process, submitters always hope to provide information in the most complete and useful fashion, allowing maximum use of their data by the scientihc commimity. 

CONTACT POINTS FOR SUBMISSION OF SEQUENCE DATA TO DDBJ/EMBL/GenBank 

Submissions Updates Information World Wide Web Home page Submissions 

EMBL (Emopean Bioinformatics Institutes, EMBL Outstation) 

Dunsmore SE, Rannels DE. Extracellular matrix biology in the lung. Am J Physiol 1996 270 L3-L27. 

McAnulty RJ, Laurent GJ. Pathogenesis of lung fibrosis and potential new therapeutic strategies. Exp Nephrol 1995 3 96-107. 

Cantor JO, Bray BA, Ryan SF, Mandl I, Turino GM. Glycosaminoglycan and collagen synthesis in N-nitroso-N-methylurethane induced pulmonary fibrosis. Proc Soc Exp Biol Med 1980 164 1-8. 

Kumar N, Bentolila A, Domb AJ. Structure and biological activity of hepari-noid. Mini Rev Med Chem 2005 5 441-447. 

26)—was now indeed split into a pair of helicene-like atropisomers, with a remarkable atropisomer excess (3 1) favouring 124a, the ancistrocladine type, which is predominant also in the plants. Using the procedure elaborated for the triphyophylline synthesis (see Section V.D.), the lactones 124a and 124b were separately transformed into ancistrocladine (1) and its natural atropisomer hamatine (10). 

Naphthyl isoquinoline alkaloids have proved to be a novel group of structurally intriguing natural products. Their extraordinary substitution pattern seems to correspond to an unprecedented biosynthesis of isoquinolines from acetate units via P-polycarbonyl precursors. 

This unusual biosynthetic pathway—the synthesis and regio-controlled cyclization of p-polyketones, optionally leading to tetrahydro-, dihydro-, or fully conjugated isoquinolines, or to naphthalenes and respective naphthoquinones— could be imitated effieiently in vitro. The smooth course of these chemical model reaetions underlines the chemieal plausibility of the proposed biogenetie scheme and simultaneously provides the basis for a first and variable total synthesis of naphthyl isoquinoline alkaloids. 

A broad and systematic synthetic elaboration of this fascinating class of natural products seems urgent not only for a confirmation (or disproval) of several uncertain alkaloid structures but also for an intensive investigation of their biological activity. Though, for instance, the roots of A.tectorius have been used to 

I wish to express my thanks to the Deutsche Forschungsgemeinschaft (DFG) and to the Fonds der Chemischen Industrie for the financial support of our work in this field. 

We have presented a unified formulation of dissipative dynamics based on the quantum theory of resonances. The reversible and dissipative confri-bufions fo fhe dynamics are gafhered in small-dimensional non-Hermifian effective Hamiltonians and effecfive Liouvillians wifh well-defined fheoref-ical sfafus. The formulation fends fo fill the gap between the dynamics and the thermodynamics. It has many advantages  

Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 

Furthermore, a multisubunit TAF complex was purified from yeast extracts using GST-TBP as a ligand for affinity chromatography (Reese et al., 1994). The use of epitope tag and immunoprecipitation also led to the isolation of TBP-TAFs complex from yeast extract (Poon et al., 

Similar to the higher eukaryotic TAFs, yeast TAFs do not support transcription on their own, but can function as coactivators. 

TFIID and its individual subunits have been subjected to intense study. As will be discussed below, complementary information from biochemical, genetic, and structural studies has shown, and will continue to give, a clearer picture of the forms and functions of this crucial component of the transcription machinery. 

It is now clear that when one considers the photoelectrochemical kinetics at semiconductor/electrolyte interface, at least light absorp- 

Solid curves are without and dashed curves are with space charge region recombination. The approximate relation tp = 5.21 x 10 6d 177 was assumed to simulate grain boundary recombination effects. 

We would like to thank Professor J. O M. Bockris for stimulating discussions. The correspondence with Professor S. Trasatti was very helpful to clarify the problem presented in Section II. We are also thankful to Miss M. Yoshida for typing this manuscript in a most expert and efficient manner. 

Myamlin and Yu. V. Pleskov, Electrochemistry of Semiconductors, Plenum Press, New York, 1967. 

and Powles, S.B. (2008) Pest Manage. ScL, 64, 319-325 and references cited therein. 

Besson, M, Gallezot, P, Perrard, A., and Pinel, C. (2005) CataL Today, 102-103, 160-165 and references cited therein. 

See for a nice overview on the catalytic properties of nitrogen-containing carbons Boehm, H.-P. (2009) in Carbon Materials for Catalysis (eds P, Serp and J.L. Figueiredo), John Wiley Sons Inc., Hoboken, NJ, pp, 219-265, 

Mirza-Aghayan, M, Kashef-Azar, E, and Boukherroub, R. (2012) Tetrahedron Lett, 53, 4962—4965. 

Liquid Phase Aerobic Oxidation Catalysis Industrial Applications and Academic Perspectives, 

This section summarizes the recent progress in supported ionic hquid catalysis, demonstrating synthetic apphcations where the ionic liquid can play its role as either iimocent solvent (SILP) or the catalyst itsdf (SILC), depending on the specific cation/anion combination and the reaction under investigation. 

Applied Homogeneous Catalysis with OrganometcdUc Compounds, 1st edn., B. Cornils, W. A. Herrmann (Eds.), VCH-Wiley, Weinheim, Germany. 1996. 

Cammarata, S. G. Kazarian, P. A. Salter, T. Welton, Phys. Chem. Chem. Phys. 2001, 3, 5192-5200. 

Swiss Patent, CH71 326 1914, BASF, Germany. 

Topsoe, A. Nielsen, Trans. Danish Acad. Tech. Sci. 1948, 2, 3-17. 

Klingbeil MM, Drew ME, Liu Y et al. Unlocking the secrets of trypanosome kinetoplast DNA network replication. Ptotist 2001 132(4) 255-62. 

Lukes J, Guilbride DL, Votypka J et al. Kinetoplast DNA network Evolution of an improbable structure. Eukaryot Cell 2002 l(4) 495-502. 

Lukes J, Hashimi H, Zikova A. Unexplained complexity of the mitochondrial genome and transcriptome in kinetoplastid flagellates. Curr Genet 2005 48(5) 277-99. 

Simpson L, Aphasizhev R, Gao G et al. Mitochondrial proteins and complexes in Leishmania and Trypanosoma involved in U-insertion/deletion RNA editing. RNA 2004 10(2) 159-70. 

Stuart KD, Schnaufer A Ernst NL et al. Complex management RNA editing in trypanosomes. Trends Biochem Sci 2005 30(2) 97-105. 

HEMA dextran derivatized with HEMA-lactate 

LPLG-PEO- block copolymer of poly(L-lactic-co-glycolic acid) 

PELA poly-DL-lactide-poly(ethylene glycol) 

SEC-HPIjC size-exclusion chromatography/high-pressure 

Crommelin DJA, Sindelar RD. Pharmaceutical Biotechnology. The Netherlands Harwood Academic Publishers, Amsterdam, 2002. 

However, as has been seen in simulations of the St, 2 reaction in wa-ter,33,99,io2,io3,io5 (hg dynamics of solution reactions do not necessarily follow the free energy surface. The full mechanism of the reaction must take into 

In this review, almost all of the simulations we have described use only classical mechanics to describe the nuclear motion of the reaction system. However, a more accurate analysis of many reactions, including some of the ones that have already been simulated via purely classical mechanics, will ultimately require some infusion of quantum mechanical methods. This infusion has already taken place in several different types of reaction dynamics electron transfer in solution, i 2 HI photodissociation in rare gas clusters and solids,i i 22 2 ° I2 photodissociation in Ar fluid,and the dynamics of electron solvation.22-24 Since calculation of the quantum dynamics of a full solvent is at present too time-consuming, all of these calculations involve a quantum solute in a classical solvent. (For a system where the solvent is treated quantum mechanically, see the quantum Monte Carlo treatment of an electron transfer reaction in water by Bader et al. O) As more complex reaaions are investigated, the techniques used in these studies will need to be extended to take into account effects involving electron dynamics such as curve crossing, the interaction of multiple electronic surfaces and other breakdowns of the Born-Oppenheimer approximation, the effect of solvent and solute polarization, and ultimately the actual detailed dynamics of the time evolution of the electronic degrees of freedom. 

This need for quantum mechanical techniques also arises in the connection between dynamics simulation and experiment when the detailed nature of light-matter interaction is important. An example is the initiation and probing of solution dynamics by ultrafast light pulses, in which the detailed time-frequency nature of the light interacts with the detailed time-frequency nature of the solution, and quantum aspects can become important. 1 At this level, the quantum dynamics of how the excitation and probe laser pulses interact with the sample must be considered in addition to all the other dynamics of the reaction process, 

Such effort will produce rewards not only in the further understanding on the microscopic level of how chemical reactions in solution happen, but also in providing feedback to the experimentalist by describing at a very detailed level (e.g., the specific nature of optimal laser pulses) what kind of experiments provide the most information. But mapping out the reaction dynamics is only a first step. A further frontier is to determine how to alter the reaction dynamics 

Emmacin has been reported as a new stmctural subclass that exhibits activity against methicilMn-resistant bacteria. Another class of antibiotics being screened is based on the pyridopyrimidine ring. These are just a few examples of new classes of antibiotics. As is shown, heterocycles play a critical role. 

Other molecules are being built with multiple functions to target cancerous cells. The compound shown next uses the crown ether functionality to detect sodium cations and the pyridine for protons. When both Na and H+ are at high levels, as in cancerous cells, the molecule acts as a photosensitizer to form singlet oxygen to kill cancer cells. 

There is eveiy reason to believe that most newly discovered pharmaceutically active compounds will continue to be based on heterocycles. As researchers develop new leads, an understanding of the physical properties and syntheses of heterocycles will be even more critical in the future. 

Gerster, R. H. Maren, M. H. Silverman, D. N. Proc. Int. Conf. Stable Isot. Chem. Biol. Med., 1st 1973,219. 

The description of thermomechanical and thermoelectrical measurements in a modest chapter such as this is an ambitious exercise. The author has attempted to cover a wide range of methods and applications with the intention of illustrating the diversity of this field whilst emphasising the relationships between the static techniques (such as TMA and TSCA) and the dynamic techniques (dynamic force TMA, DMA and DETA). With the exception of TMA, these methods are often promoted as some of the more advanced thermal analysis techniques. It is hoped that the preceding pages help to dispel this myth without belittling their ability to measure useful properties. 

In conclusion, it is fascinating to see the development that began with George Levitt s pioneering work at Du Pont over 30 years ago. In Gulliver s Travels Voyage to Brobdingnag, Ch. 6), the Irish author Jonathan Swift (1667-1745) wrote that 

Whoever could make two ears of com or two blades of grass grow upon a spot of ground where only one grew before, would deserve better of mankind, and do more essential service to his country than the whole race of politicians put together. 

It is against this background that the achievements of George Levitt and all other colleagues involved in the world s agrochemical industry should be viewed. 

The author is pleased to acknowledge Drs. Darren Mansfield, Klaus-Helmut Mueller, Graham Holmwood, Amo Schulz and Shinichi Shirakura for their critical review of the manuscript and many helpful suggestions, and Mrs. Tong Lin and Mr. Tetsuya Murata for translations of Chinese and Japanese publications. 

Chaleff, C. J. Mauvais, Acetolactate synthase is the site of action of two sulfonylurea herbicides in plants. Science, 224, 1443-1444 (1984). 

Archut A, Azzellini GC, Balzani V, Cola LD, Vogtle F. 1998. Toward photoswitchable dendritic hosts interation between azobenzene functionalized dendrimers and eosin. J Am Chem Soc 120 12187 12191. 

Astrand PO, Ramanujam PS, Hvilsted S, Bak KL, Sauer SPA. 2000. Ab initio calculation of the electronic spectrum of azobenzene dyes and its impact on the design of optical data storage materials. J Am Chem Soc 122 3482 3487. 

Balsara NP, Tirrell M, Lodge TP. 1991. Micelle formation of BAB triblock copolymers in solvents that preferentially dissolve the A block. Macromolecules 24 1975 1986. 

Biswas N, Abraham B, Umapathy S. 2002. Investigation of short time isomerization dynamics in p nitroazobenzene from resonance Raman intensity analysis. J Phys Chem A 106 9397 9406. 

Cantor R. 1981. Nonionic diblock copolymer as surfactants between immiscible solvents. Macromolecules 14 1186 1193. 

The previous sections have documented the fact that binuclear complexes can be obtained with a variety of novel structural features and that these undergo, in some cases, unprecedented chemical reactions. We can expect that work along these lines will continue to point out new structural types and new classes of reactions. Progress so far can be said to have laid a foundation for the basic coordination chemistry of the most readily obtained binuclear systems. It remains to be seen whether these reaction types can be clearly utilized in the design of new catalysts or whether unusual forms of catalytic activity for binuclear complexes will be discovered serendipitously. 

Several areas for future development can be easily identified. Strategies for the incorporation of two different metal ions into the same complex have only recently begun to be considered. The range of 

I thank Rich Eisenberg, Alan Sanger, and George Stanely for sharing unpublished data, and the NSF for the support of those aspects of original research done at the University of California, Davis. 

Chisholm, ed., Reactivity of Metal-Metal bonds, ACS Symposium Series 155, Washington, D.C., 1981. 

Whyman, Transition Metal Clusters, edited by B. F. G. Johnson (John Wiley and Sons, New York, 1980), p. 545. 

This chapter has described the potential applicability of NMR in combination with fluorinated haems for the detailed characterisation of structural properties of the haem active sites in b-type haemoproteins. By virtue of F NMR in studying biological macromolecules, molecular and electronic structures of haem active sites in the proteins can be readily characterised from the analysis of the NMR parameters of well-resolved signals. Furthermore, F NMR also allows quantitative characterization of the dynamic processes occurring at the haem active site in Mb. The present method provides a new means of studying in detail, structural 

Jardetzky and G. C. K. Roberts, NMR in Molecular Biology, Chap. Ill, Academic Press, New York, 1981. 

Bertini and C. Luchinat, NMR of Paramagnetic Molecules in Biological Systems, Benjamin/ Cummings Publishing, Menlo Park, CA, 1986. 

Bertini, C. Luchinat and G. Parigi, Solution NMR of Paramagnetic Molecules, Elsevier, Amsterdam, 2001. 

Shulman, in ESR and NMR of Paramagnetic Species in Biological and Related systems, 

The present review summarizes the work of the last fifty years in the field of the synthesis of Erythrina alkaloids and structurally related compounds. Their unique structure has attracted the attention of the synthesis chemists over a period of more than half a century until now. The numerous efforts devoted to the construction of the tetracyclic spiroamine framework have certainly led to original and impressive results, but with regard to today s standard and especially to an adequate supply of the promising compounds for a systematic pharmacological examination the total efficiency of their preparation yet leaves wishes in many cases. 

Not only because of their attractive structure, but also of their pharmacological potential, mainly that of the pure compounds, the synthesis of the Erythrina alkaloids will remain an important goal challenging the synthesis chemists in the forthcoming years. It is hoped, that this review along with the powerful arsenal of modem synthesis methods can stimulate the development of new efficient strategies to the Erythrina alkaloids and possibly to related new active agents. 

Rey P (1883) Note sur les proprietes therapeutiques de I Erythrina corallodendron. Le Journal de Therapeutique 10 843 

Altamirano F (1888) Nuevos Apuntes para el Estudio del Colorin, Erytrina cor-alloides. Gaceta Medica de Mexico 23 369 

Greshoff M (1890) Mitteilungen aus dem chemisch-pharmakologischen Laborato-rium des Botanischen Gartens zu Buitenzorg (Java). Chem Ber 23 3537 

In this chapter, we have tried to emphasize general aspects of main-group chemical bonding, with particular emphasis on periodic trends. The periodic table remains the most important classification tool in chemistry, and it is crucial to understand even subtle secondary periodicities if one is to make efficient use of the various elements for different chemical applications. The radial nodal structure of the valence orbitals has been pointed out to account for more of the known trends than most practitioners of chemistry are aware of. For example, the inversion barriers of phosphines or silyl anions, the dependence of the inert-pair effect on the electronegativity of the substituents, the stability of carbene- or carbyne-type species or of multiple bonds between heavy main-group elements are aU intricately linked to hybridization defects of s- and p-valence orbitals of disparate sizes. Even the question of hypervalency is closely connected to the effects of primogenic repulsion . 

Further important influences on the periodic trends arise from partial screening of nuclear charge (including lanthanide/actinide contraction, scandide contraction, and even a 2p-contraction) and from the effects of special relativity. Various aspects of main-group bonding are covered in more detail elsewhere in this book. 

(2012) in Huheey-Keiter-Keiter Anorganische Chemie - Prinzipien von Struktur und Reaktivitdt (ed. R. Steudel), 4th German Ed, Chapter 18, de Gruyter, Berlin, pp. 1043-1097. 

Klapotke, T.M. and Tornieporth-Oetting, I.G. (1994) Nicht-metallchemie, Verlag Ghemie, Weinheim. 

Although there is at present no convincing evidence of a natural function of lipoic acid other than that of a prosthetic group in a-keto acid dehydrogenation complexes, it is conceivable that lipoic acid may function in other enzyme systems as an acyl or electron carrier. 

2-Acetylthiamine pjrrophosphate appears to be yet another form of active acetate. It has been assigned a key role in the lipoic acid-Unked oxidative decarboxylation of pyruvate as the primary product of the oxidation of active acetaldehyde, i.e., 2-hydroxyethylthiamine pyrophosphate. It has been proposed that 2-acetylthiamine pyrophosphate is an intermediate in all oxidative transformations of pyruvate and that 2-succinylthiamine pyrophosphate plays a similar role in oxidation of a-ketoglutarate. Further evaluation of this proposal is anticipated in the near future. 

Guirard, B. M., Snell, E. E., and Williams, R. J. 1946. Arch. Biochem. 9, 381-386. Gunsalus, I. C. 1954a. In The Mechanism of Enzyme Action (W. D. McElroy and B. Glass, eds.), pp. 545-580. Johns Hopkins Press, Baltimore, Maryland. Gunsalus, I. C. 1954b. Federation Proc. 13, 715-722. 

Gunsalus, I. C., and Smith, R. A. 1958. In Proceedings of the International Symposium on Enzyme Chemistry, Tokyo-Kyoto, 1957 (K. Ichihara, ed.) pp. 77-85. Academic Press, New York. 

Holzer, H., and Crawford, R. M. JVI. 19fi(). Nature IM, 410-411. llolzer, II., and Kohlhaw, G. 1961. Biochem. Biophys. Research Commune. 6, 452-456. Holzer, H., Goedde, H. W., Goggel, K. H., and Ulrich, B. 1960. Biochem. Biophys. Research Communs. 3, 599-602. 

For the sake of synthesis, what must be noted is the relevance of the variable represented by pubhc information which-although indirectly-seems to be perceived as the key aspect for a broadly accepted development of a biorefinery at local level. Another relevant role is felt to be played by subsides, which are perceived to transmit a positive feedback directly to the development of a biorefinery, although it is also clear that it is capable of generating negative effects on markets distortion since it may destabilize the equihbrium of the whole local economic system. 

As it is clear that we are dealing with a complex system, whose observation is not straightforward because of the lack of quantitative data and/or any other 

Certainly, the results arising from the use of cognitive maps are strictly based on the perceptions of the interviewed people. This means that the apphcation of this same method to another place or country is unlikely to give the same results. For this reason, an extension of this application to other rural areas in the EU may provide a comprehensive view of the most-relevant aspects (determinants, influential conditions, and final effects), which can be helpful to address the EU policy in the domain of rural development, bioenergy, and agriculture. 

The authors are grateful for the constractive comments and suggestions provided by the editor and the anonymous referee. 

European Environment Agency (2007) Estimating the environmentally compatible bioenergy potential from agriculmre. EEA Technical report, n.12/2007. 

Cavitation generates conditions of high temperature and pressure along with the release of active radicals, which results in intensification of many of the physical and chemical transformations. The magnitudes of pressure and temperature and number of free radicals can be easily manipulated by adjusting the operating and 

In the case of acoustic cavitation, selection of suitable operating parameters such as the intensity and the frequency of ultrasound and the vapor pressure of the cavitating media is essential as the bubble behavior, and hence the yields of sonochemical transformation, is significantly altered due to these parameters. 

For the quantitative relationship of the effects, the work of Gogate and Pandit (2000a) is recommended. They have given a correlation for the estimation of collapse pressure as a function of different operating conditions, which clearly gives a quantitative idea about the optimum parameters. It is necessary that both the frequency and intensity of irradiation should not be increased beyond an optimum value, which is also a function of the type of application and the equipment under consideration. The liquid-phase physicochemical properties should be adjusted in such a way that generation of cavitation events is eased and also large number of smaller-size cavities are formed in the system. 

The design of sonochemical reactors is a very important parameter in deciding the net cavitational effects. The use of multiple transducers and multiple frequencies with possibility of variable power dissipation is recommended. Mapping studies using different techniques as described earlier are recommended to identify the cavitational-activity distribution. Use of process-intensifying parameters at zones with minimum cavitational intensity should help in enhancing the net cavitational effects. 

Pandit, Characterization of flow phenomena induced by ultrasonic horn, Chem. Eng. Sci., In Press (2005a). 

One of the main objectives of research in proteomics is the automation of all procedures from sample acquisition to protein identification. The role of bioinformatics is to treat all available data to obtain unique identification of proteins without human intervention. The recent generation of mass spectrometers are producing more accurate data, with precise mass values using MS where n are successive stages of mass spectrometry [176, 177]. 

Preliminary studies towards the development of efficient spectra modelling tools have been pubhshed. These include, for example, the analysis of the distribution of peptide masses generated by in silica digestion tools from protein sequence databases [182, 154] and the influence of a sequence on spectra intensity [143]. 

Bioinformatics tools should be easily adaptable to integrate all the new data generated by their analyses. We should envisage that one day an automatic system would integrate the experimental data (such as a LIMS), all kinds of mass specinim values (MS, MS/MS) and algorithms (PMF, ions search, de novo sequencing) to produce reliable and automatic protein identifications. 

Brandon C. and Wu J -Y. (1977) Electrophoretic and immunochemical characterization of choline acetyltransferase from Torpedo Soc Neurosa Abs 3, 404 

Brandon C, Lam K. M K, and Wu J.-Y (1979) The y-aminobutyric acid system in rabbit retina Localization by immunocytochemistry and autoradiography Proc Natl Acad Set USA 76, 3557-3561 

Brandon C, Lam D M, K, Su Y Y T, and Wu J.-Y (1980) Immunocytochemical localization of GABA neurons in the rabbit and frog retina, Bram Res Bull 5 (Suppl 2), 21-29 

Chan-Palay V., Palay S. L and Wu J -Y (1979) Gamma-aminobutyric acid pathways in the cerebellum studied by retrograde and anterograde transport of glutamic acid decarboxylase antibody after in vivo injections Anat Embryol 157, 1-14. 

Roux E, Yersin A. Contribution a I etude de la diphtheric. Annalcs de I lnscituc Pasteur 1888 2 629-661. 

Stanley JL, Smith H. Purification of factor I and recognition of a third factor of the anthrax toxin. J Gen Microbiol 1961 26 49-63. 

Smith H, Stoner HB. Anthrax toxic complex. Fed Proc 1967 26(5) 1554-1557. 

Singh Y, Klimpel KR, Quinn CP et al. The carboxyl-terminal end of protective antigen is required for receptor binding and anthrax toxin activity. J Biol Chem 1991 266(23) 15493-15497. 

Leppla SH. Anthrax toxin edema factor A bacterial adenylate cyclase that increases cyclic AMP concentrations of eukaryotic cells. Proc Natl Acad Sci USA 1982 79(10) 3162-3166. 

The central idea of this review is that the technique of topological reduction is a powerful one for the formal manipulation of cluster series and for generating useful approximate theoretical expressions for the thermodynamic properties and pair correlation functions of fluids. We have described just enough of the theory of graphs to have a meaningful discussion of topological reduction and have then discussed a number of types of theories in which topological reductions are applied. A detailed discussion of the approximate theories that result is outside the scope of this article, and the reader is referred to the literature cited in the text. 

There are many other interesting uses of cluster theory and many graph-theoretic techniques that we have not discussed. We will close this article by listing some of them and mentioning some of the relevant references. 

in The Equilibrium Theory of Classical Fluids (H. L. Frisch and J. L. Lebowitz, eds.), pp. II171-II266, Benjamin, New York (1964). 

We have considered here some of the physical factors involved in ion, electron, and proton transport in membrane structures, as well as the electric fields and electrical double layers that are intimately associated with these transport processes. In considering the membrane potential, which more accurately should be termed the transmembrane potential drop, it can be seen that the presence of membrane surface charges may be significant and could produce effects not expected from a consideration of Nernstian diffussion processes alone. For example, from Eq. (3) and the 

In considering the theoretical modeling of the electrical double layer at the cell surface, it may be useful to consider the way in which the value of the relative permittivity of the electrolyte varies with distance from the membrane surface. Usually the permittivity is assumed to be constant up to the surface and to have a value equivalent to that of normal bulk water. By comparing the value obtained for the zeta potential from electrophoresis measurements with the surface potential obtained from free radical quenching studies, more detailed information concerning the structure of the electrical double layer may be forthcoming. 

Hasselbach and H. Oetliker, Energetics and Electrogenicity of the Sarcoplasmic Reticulum Calcium Pump, Ann. Rev. Physiol. 45, 325-339 (1983). 

Tanford, Mechanism of Free Energy Coupling in Active Transport, Ann. Rev. Biochem. 52, 379-409 (1983). 

Mitchell, Coupling of Phosphorylation to Electron and Hydrogen Transfer by a Chemi-osmotic Type of Mechanism, Nature 191, 144-148 (1961). 

Gerhardt, E. Gulari, C. Manke,/. Polym. Sci. Polym. Phys. 1997, 35, 523-538. 

Janssen, Twin Screw Extrusion, Elsevier, Amsterdam, 1978. 

Rauwendaal, Polymer Extrusion, 3rd revised edition. Hanser Publishers, New York, 1994. 

Kazarian, N.H. Brantley, B.L. West, M.F. Vincent, C.A. Eckert, Appl. Sped. 

In the presence of redox couples confined to the hydrophobic liquid phase, photoinduced heterogeneous electron transfer can be effectively monitored by photoelectrochemical techniques under potentiostatic conditions. The photocurrent responses are uniquely related to specifically adsorbed porphyrins, as demonstrated by the photocurrent anisotropy to the angle of polarisation of the incident illumination (Section 4.3). Systematic studies of the photocurrent intensity as a function of the formal potential of the redox couple and the Galvani potential difference revealed that the dynamics of electron transfer are determined by the distance separating the redox species at the interface. Other processes including decay of the electronically excited state, back electron transfer, porphyrin regeneration and coupled ion transfer play important role on the dynamics of the photocurrent responses. 

Another important consideration is that all results reported here are based on the calculation of zero- and first-order connectivity indexes only. It is possible that the inclusion of higher-order indexes, which in turn means more detailed 

Atomistic simulations, even though more time-consuming will also yield valuable information on the dependence of e on chemical structure. One of the advantages of these simulations is that they can, in principle, predict frequency dependence. Work along these lines is in progress. 

Acknowledgments The authors would like to thank Molecular Simulations Inc., for partial support. 

Bicerano, Prediction of Polymer Properties, Marcel Dekker, New York (1993). 

This brief review is limited to consideration of platinum group metals in aqueous solutions. Thermodynamic approaches should work in other protic solvents. However these solvents are always of organic nature, and the experimental measurements of any thermodynamic quantities are complicated by irreversible dissociative adsorption of organic species. Another interesting field, still separated, is platinum electrochemistry in aptotic media. 

Surface thermodynamics of perfectly polarizable electrodes forms a basis for various amphyfunctional approaches being of interest for electrochemistry of oxides and functionally modified electrodes. Beyond platinum metals electrochemistry, this approach is also important for gold, silver and copper when OH adsorption with charge transfer takes place at these surfaces. 

The links between our knowledge about ideally and perfectly polarizable electrodes should be thoroughly maintained as water and ions adsorption are common phenomena for these types of systems. For ideally plarizable mercury-like) electrodes, pzc (pzfc) data are available for much higher number of metals, and the roles of electron woik function and water adsorption are more apparenL  

The electrons in a orbitals are localized in the a bonds, whereas it is possible for electrons in the tt orbitals to delocalize (or conjugate) throughout the molecule. Molecules composed of sp or sp hybridized orbitals are therefore known as wn-saturatedj while molecules composed of sp hybrids are known as saturated. Conjugated polymers are typically sp hybridized with one 7r-orbital per CH group. (An exception is polydiacetylene which has both sp and sp hybridization.) The four valence electrons are shared amongst the four hybrid orbitals. 

In TT-electron models the a and core electrons play the static role of screening the Coulomb interactions between the remaining degrees of freedom. In particular, they screen the nuclear-nuclear interactions, the interactions between the TT-electrons and the nuclei, and the mutual interactions between the Tr-electrons. This screening is often modelled by a static dielectric constant, and by the reduction of the effective charge of the nucleus to +Q at large distances. We now define Vp r R ) as the pseudopotential which models the effective interaction between the TT-electrons and the nuclei, while Vg g(r — r ) models the effective electron-electron interaction. 

the second quantization representation of the Born-Oppenheimer Hamiltonian, eqn (2.19), is valid for an orthonormal basis. Since the atomic orbitals are not automatically orthonormal, they must first be orthogonalized before they 

The four-centre integrals, Vijj-i, are dominated by the diagonal terms  

These terms are smaller than the diagonal ones, as they are determined by the wave function overlap, 4 r)(pj r). Moreover, since in practice 7r-electron models are parametrized to fit experiment, these terms are generally neglected, and this will be the approach largely adopted in this book.  

The approach taken in the research described here is characterized by a very simple model construction phase, followed by an extensive series of tests involving information from ab initio electronic structure theory, mineralogy, aqueous chemistry, and high vacuum surface science. As of the time of this review, classical models are the only models simple enough to perform the necessary benchmarking calculations in all these areas and also are the only models that can be extended to 10,000 atom/nanosecond timescale simulations of interfacial phenomena. 

Considerable improvement has been achieved in the design of functional nanocomposites based on aerogel dielectric matrices, in terms of range of accessible compositions, control over nanoparticle size, distribution and loading, and tailored porous texture. 

Since every preparation route has specific advantages and drawbacks, it is not possible to define a general strategy for obtaining nanocomposite aerogels. Nevertheless, metal and metal oxide nanoparticles supported on aerogel matrices with given compositional and microstructural features have been effectively prepared. 

The flexibility of the sol-gel route in the chemical design of materials opens up possibilities for new applications for aerogels in very diverse fields ranging from thermal and acoustic insulation to catalysis to magnetism. 

The authors are very grateful to D. Loche, A. Falqui, D. Carta, G. Navarra, and G. Mountjoy for discussion and proof reading. 

Ko I (1998) Aerogels, Kirk-Othmer Encyclopedia of Chemical Technology John Wiley Sons, 1-3 

and Brown, D. A., 1975, Actions of 7-aminobutyric acid on sympathetic ganglion cells,/. Physiol. 250 85-120. 

and Nicoll, R. A., 1979, GABA-mediated biphasic inhibitory responses in hippocampus. Nature 281 315-317. 

and Teyler, T. J., 1976, Long-term and short-term plasticity in the CAl, CA3, and dentate regions of the rat hippocampal slice. Brain Res. 110 463-480. 

This work has been supported by grants from the Leukemia and Lymphoma Society, the American Cancer Society ( IRG-58-006-44), the United States Department of Agriculture (IND73077AH), and the Leukemia Research Foundation. 

Springer, T., and Gutierrez-Ramos, J. C. (1997). The chemokine SDF-1 is a chemoattractant for human CD34-I- hematopoietic progenitor cells and provides a new mechanism to explain the mobilization of CD34+ progenitors to peripheral blood. J. Exp. Med. 185, 111-120. 

Andrew, D. P., Chang, M. S., McNinch, J., Wathen, S. T., Rihanek, M., Tseng, J., Spellberg, J. P., and Elias, C. G., Ill (1998). STCP-1 (MDC) CC chemokine acts specifically on chronically activated Th2 lymphocytes and is produced by monocytes on stimulation with Th2 cytokines IL-4 and IL-13. J. Immunol. 161, 5027-5038. 

Annunziato, F., Galli, G., Cosmi, L., Romagnani, P., Manetti, R., Maggi, E., and Romagnani, S. (1998). Molecules associated with human Thl or Th2 cells. Eur. Cytokine Netw. 9,12-16. 

McHeyzer-Williams, L. J., Ngo, V. N., McHeyzer-Williams, M. G., and Cyster, J. G. (1999). In vivo-activated CD4 T cells upregulate CXC chemokine receptor 5 and reprogram their response to lymphoid chemokines. J. Exp. Med. 190, 1123-1134. 

In this supplement, some of the most important formulas and definitions of dasses of single coronoids from Chapters 4-6 are summarized. In a condusion, this material is placed in a broader context. 

Spectroscopy utilizing tunable laser and microwave sources has been applied widely in exploring atoms, molecules, and condensed matter. Besides the classical areas of optical double resonance and optical pumping the extension of these or related methods to difference frequency measurements in the optical range seems to be of increasing importance. This includes heterodyne techniques. Laser microwave schemes can also play an essential role for the generation of modem frequen( standards. Last but not least, there will be many technical applications like infrared detectors, wavemeters, magnetometers, etc. 

Cohen-Tannoudji and A. Kastler, Progress in Optics (edited by E. Wolf), Vol. V, p. 1, North-Holland, Amsterdam (1966). 

Trambarulo, Microwave Spectroscopy, Wiley, New York, Chapman and Hall, London (1953). 

Chantry, Ed., Modem Aspects of Microwave Spectroscopy, Academic, New York (1979). 

Usually some of the distances are treated as dependent parameters, and the results will be slightly different whether shrinkage has been included or neglected. An example where the effect is large (hexafiuorobut-2-yne), is given in Table 8. A refinement where aU the distances are treated as 

At present, systematic errors tend to limit the accuracy of electron-dififraction studies more than do random errors. The probability of introducing a serious error by accident seems higher than in other methods for structure determination. Particularly it has too often happened that the scale error has been considerable. To keep the effect of systematic errors under control, it is necessary to study well-known standard compounds rather frequently. If this is done, and especially if the electron-diffraction investigation is combined with spectroscopic data as discussed in Chapter 4, standard deviations well below 0.001 A are obtainable for many compounds with photographic recording. It is possible that counting techniques may reduce the errors still further and also make the method more useful for electron density and energy determinations than it is today. 

The author is grateful to all the members of the electron-diffraction group in Oslo for helpful discussions. Cand. real. R. Stolevik should be thanked especially for his valuable suggestions during the work on the accuracy section, and Professor O. Bastiansen for his critical reading of the manuscript. Many helpful comments from Professor K. Kuchitsu are also gratefully acknowledged. 

Molecular Structure Understanding Steric and Electronic Effects from Molecular Mechanics. 

There are a number of miscellaneous items that are of interest and importance with regards to molecular structure that are mentioned but not really discussed elsewhere in this book. They are more or less well known to those working in this field. Since not all of them are well known to everyone, however, we have accumulated some of those topics here and will briefly describe them, giving some leading references for the convenience of the reader. 

The Mathematics of Diffusion, Oxford University Press, p. 2. 

Rousar, I., Micka, K., and Kimla, A., 1986, Electrochemical Engineering I, Elsevier Scientific Publishing Co., New York, parts A-C, p. 27. 

and Wragg, A. A., 1965, Electrochemical mass transfer studies in annuli, Electrochim. Acta, 10 1093-1106. 

Ascorbic acid is an important essential nutrient for the health maintenance of the population. Nevertheless, its importance must not be overestimated. The status assessment of the vitamin in well-nourished populations showed only a small percentage of subjects with an insufficient plasma ascorbic acid concentration. It has been documented that risk factors for the development of an ascorbic acid deficiency exist (e.g., smoking, alcohol use, pregnancy, certain pathophysiological conditions). These deficiencies can, however, be overcome without any problems when the current recommendations on vitamin C intake are fulfilled by the intake of either 

Bartens, C., Gotz, R., Urbanek, I., and Elmadfa, L, 1994, Antioxidant status and generation of super-oxide anion and H2O2 in granulocytes of patients with cystic fibrosis, FASEB J. 8 Abstract. 

Benedict, W. F., Wheatley, W. L., and Jones, P. A., 1982, Difference in anchorage dependent growth and tumorigenicities between transformed C3H/10T1/2 cells with morphologies that are or are not reverted to a normal phenotype by ascorbic acid. Cancer Res. 42 1041-1045. 

Simon-Schnass, 1., Rokitzki, L., and Keul, J., 1987, Die Bedeutung des Vitamin E fur den Sportier, Dtsch. Z. Sportmed. 38 416-424. 

and Nebioglu, S., 1992, Vitamin C aspirin interactions in laboratory animals, J. Clin. Pharm. Ther. 17 343-346. 

The chemistry of BH3 is an active area so the arrangement of this section has been changed (as compared to Boron Compounds 3rd Suppl. Vol. 1, 1987) to reflect this interest. Section 

The second important requirement is to maintain constant key dimensionless groups that control the important granulation rate process of most interest during scale. This is somewhat easier to do in fluidized beds than in high-shear mixers. 

Very small-scale tests, which have no geometric similarity to pilot-and full-scale tests should be used to focus on formulation design and measurement of key formulation properties that influence the granulation rate processes. 

Insightful understanding of the granulation processes is essential for the identification of key variables and parameters for the dimensional analysis and scale-up considerations. While development of definitive mathematical models for the granulation processes is incomplete, the scaling approaches recommended in this chapter help reduce uncertainty during new product development and transfer to industrial sites. 

The extent of this type of testing is limited to the abovementioned characterization criteria. Test conditions should not exceed a device s potential as provided by the manufacturer. The evaluation protocol is intended to provide an abbreviated and yet sufficient characterization of candidate devices to assess CWA detection capabilities to aid authorities in selecting equipment for CWA detection. 

The scope of this type of test program suggests that statistical analysis is not necessary because each test point will be conducted with repetitions using multiple units. The comparative data collected will provide insight on device performance. 

Of primary importance is the ability to detect the target CWA within acceptable time and concentration limits to protect the users such as first responders. The alarm threshold must be able to provide sufficient time for responders to don protective gear before they become casualties. Failure to meet this criterion is grounds for termination of further testing. 

Also important is the ability to resist false alarms. False alarms could be expected in high-sensitivity detectors no matter what technologies are used. The key is to assess false alarm rates and the materials that caused the false alarms. If the device responds with false alarms too frequently when exposed to common substances, its usefulness is greatly diminished. Equally if not more important is the ability of a device to function properly while under the influence of interferent vapors. If a relatively large number of interferent vapors affect a device s ability to detect the target chemicals, its usefulness is also limited. 

The tested device must be easy to operate and require minimal recalibration to produce reliable results after a period of storage. The ability to achieve operational stability within a short time after setup is an important criterion for usefulness to first responders in emergency situations. 

Mn(n) EPR spectra provide information about the environment of the Mn(II) ion in amorphous materials, which is reflected in the values of parameters g, D, and E and tire linewidth. As for proteins wifli Mn(II) complexes, signal broadening due to motional effect or by structural variations diminishes as the composition of the complex approaches that of the fiilly functional state of the protein. Hence, the improvement in the resolution of the spectrum provides some insight into the fidelity of the structure under investigation. The interpretation of the structure is facilitated by studying the various glassy spectra provided in this article, since a close parallel of biological systems exists with analysis of other amorphous materials in the solid state. 

Al tshuler SA, Kozyrev BM. 1974. Electron paramagnetic resonance in compounds of transition ions. New York John Wiley. 

Belford RL, Nilges MJ. 1979. Computer simulation of powder spectra. Paper presented at EPR Symposium, 21st Rocky Mountain Conference, Denver, Colorado. 

Bleaney B, Rubins RS. 1961. Prac Phys Soc (London) 77 33 corrigendum, 1961, 78 78. Blumberg WE, Peisach J. 1987. Life Chem Rep 5 5. 

Boas JF. 1984. In Copper proteins and copper enzymes, Ed R Lontie. Boca Raton, FL CRC Press, Boca Raton. 

Models related to spin-forbidden reactions are discussed in this chapter. Coupling between two surfaces of different spin and symmetry is given by various levels of approximation for spin-orbit operators from the reduction of relativistic quantum mechanics. Well-established methods such as the Breit-Pauli Hamiltonian exist, but new relativistic methods such as the Douglas-Kroll Hamiltonian and other new transformation schemes are also being investigated and implemented today. 

The nonadiabatic coupling matrix element is a consequence of the Born-Oppenheimer 

Approach, b) H. B. Schlegel, in Modem Electronic Structure Theory, D. R. Yarkony, Ed., World Scientific, Singapore, 1995, Part 1, Chapter 8, p. 459. Geometry Optimization on 

Spectroscopic Properties and Electronic Structure of Low-Spin Fe(lll)-Alkylperoxo Complexes Homolytic Cleavage of the 0—0 Bond. 

Harvey, in Computational Organometallic Chemistry, Thomas R. Cundari, Ed., Marcel 

One of the advantages of organic and polymeric materials is the possibility of unlimited structural variation. This also implies the availability of a huge array of synthetic possibilities to obtain those materials, lb some extent, there are two main approaches to the synthesis of conducting polymers the direct approach and the precursor methods. 

Precursor methods have been developed for polyacetylene and poly(p-phenylene). The precursor approach has been intensively stimulated by developments in the field of poly(p-phenylene viny-lene) and the use of this polymer in light-emitting devices. The Wessling precursor route is one of the most used procedures to prepare this material. The precursor route of Louwet and Van-derzande has overcome many of the limitations inherent in the Wessling precursor route and will most probably allow further interesting developments for the application of poly(p-phenylene vinylene) in polymer electronics. 

In theoretical modeling, it was assumed that single-polymer chains are not interacting with each other, as in the gas phase. To make the models and calculations more realistic, however, three-dimensional packing effects in solid-state systems should be taken into account, and this can play an important role in the desired properties of conjugated polymers. Usually, the three-dimensional packing effects enhance the interchain interaction, giving rise to a complex set of vibrational modes. This eventually 

At the next level of modeling, design, and synthesis of low-bandgap materials, intermolecular and interpolymer chain interactions, as well as supramolecular structure formation, etc., should be taken into account. Furthermore, in real systems several other factors, for example, liquid crystallinity, van der Waals interactions, hydrogen bonds, hydrophilic and lipophylic interactions, etc., should be given adequate importance in specific situations. 

In the last two decades, the field of conjugated polymers has evolved from one-dimensional linear chains to two-dimensional polymer network structures. Although many research groups are active in the field of supramolecular chemistry and nanotechnology, the ultimate challenge, yet to be resolved, is the secret behind the control of the third supramolecular dimension in ir-electron systems. 

Much remains to be done, however. One of the most challenging areas is to incorporate catalyst properties in kinetic models. For crystalline catalysts with well-characterized structures (e.g., zeolites), some limited progress has been made, but this is far from being the case for structurally complex catalysts such as highly amorphous metal sulfides. 

The tradeoff between kinetics and hydrodynamics for hydrodynamically complex systems continue to be a big challenge. For instance, to address problems of fluid maldistribution in trickle bed reactors or the feed injection zone at the base of a FCC riser, one is compelled to sacrifice chemistry. The same is true when one needs to solve control and optimization problems. 

Upgrading Petroleum Resids and Heavy Oils, Marcel Dekker, 1994. 

Kinetic Modeling at Mobil A Histroical Perspective, In Chemical Reactions in Complex Mixtures, Sapre, A.V. Krambeck, F. J. (Eds.), Van Nostrand Reinhold, 1991. 

Helfferich, F. G., Kinetics of Homogeneous Multistep Reactions, Elsevier, 2001. 

Weckhuysen, B. (ed.) (2010). Chem. Soc. Rev., 39, In-Situ Characterization of Heterogeneous Catalysts Themed Issue, pp. 4541-5072. 

) (2002). In-Situ Spectroscopy in Heterogeneous Catalysts, Wiley-VCH, Weinheim. 

Meitzner, G. (2002). In Situ XAS Characterization of Heterogeneous Catalysts, in J. Haw (ed.), In-Situ Spectroscopy in Heterogeneous Catalysts, Wiley-VCH, Weinheim, pp. 179-194. 

de Groot, F., Knop-Gericke, A. and Ressler, T. (2004). X-Ray Absorption Near Edge Spectroscopy, in B. Weckhuysen (ed.), In-Situ Spectroscopy of Catalysts, American Scientific Publishers, Stevenson Ranch, CA, pp. 107-122. 

I thank the current and former members of my research group at the University of Mississippi for their assistance and input during the preparation of this review, and I would also acknowledge the National Science Foundation for financial support (CHE-0517067, EPS-0132618). 

Vinogradov and R. H. Linnell, Hydrogen Bonding, Van Nostrand Reinhold, New York, 

Jeffrey and W. Saenger, Hydrogen Bonding in Biological Structures, Springer, Berlin, 1991. 

Despite of some misunderstandings in the discussion about a proper definition of photocatalysis, photocatalytic reactions have captured the interest of chemists for a long time. Furtheron, photocatalysis has preserved its fascination as a method that not only provides a real alternative of usual chemical synthetic pathways [37]. Other promising fields of application of photocatalysis are the conversion of solar energy into chemical energy [38], information recording [39], and environmental problems like waste water decontamination [40]. 

In our understanding of photocatalysis with respect to its more extensive application it seems to be useful to address definitorial points of view to practical aspects. Therefore, it is indicated to define the term photocatalysis 

In the majority of photocatalytic reactions both transition metal complexes and organometallic compounds play an important role in the light-induced conversion of inorganic as well as organic substrates. 

The convenient photochemical generation of catalytically active species like coordinatively unsaturated species, electron-rich metallo-fragments, as well as free ligands and ligand redox products, respectively, provides definite advantages when compared with the usual thermal activation in the homogeneous complex catalysis, for example. 

Depending on the wave-length of irradiation diverse electronically excited states of both transition metal complexes and organometallic compounds are accessible. Under certain circumstances one may switch between homolytic and heterolytic reaction pathways. 

Three types of SRMs are produced by NIST. Neat reagent SRMs and solution SRMs are intended primarily for instrument calibration whereas complex matrix SRMs are better suited for use as control materials. The amoimt of substance present for relevant constituents(s) is usually reported as a mass fraction with stated uncertainty. Values are usually assigned based on measurements from two or more independent methods. This approach is used to help assure the accuracy of the measurements by identifying potential method biases. A list of complex matrix and solution SRMs available from NIST is provided in Table 13.4. Levels of one or more persistent organic pollutant compoimds are reported for each of these environmental SRMs. A listing of CRMs available from other national metrology institutes has also been compiled [206]. 

The selection of methods used in the determination of persistent organic contaminants depends on the physical and chemical properties of the analytes imder study. Liquid chromatography is often well suited to applications that are not compatible with gas chromatography, and LC is the preferred method for the determination of POPs that are polar, thermally labile, or isomeric. Mass spectrometric detection is essential to achieve sufficient specificity and sensitivity for trace level analysis of complex matrix environmental samples. CRMs and SRMs serve as useful tools in the development and validation of new methods, as control materials in quality assurance, and in instrument calibration. Proper use of reference materials can also support claims of measurement traceability. 

TABLE 13.4 Standard Reference Materials with Relevance to Persistent Organic Pollutants 

SRM 1597a Complex Mixture of Polycyclic Aromatic Hydrocarbons From Coal Tar X  

SRM 1991 Mixed Coal Tar / Petroleum Extract in Methylene Chloride X  

The grand challenge of PEM modeling is to establish predictive relations between the chemical structure of the ionomer, membrane structure, and physicochemical properties. Addressing these objectives involves a hierarchy of phenomena. Major challenges and approaches along this path were discussed in this chapter. Applied topics in membrane research will be picked up again in Chapter 5. 

Self-Organization of Phase-Segregated Membrane Morphology 

Ionomer molecules aggregate and phase-segregate into hydrophobic polymer domains and hydrophilic water-filled pathways at the nanometer scale. These phenomena are understood on the basis of scattering data (SANS, SAXS, USAXS). However, the interpretation of such data is still controversial. Structural pictures of the membrane morphology, focusing on sizes, distribution, and connectivity of water-filled nanochannels, are still going through revisions. Relatively well established is 

Free hydrated protons produced by acid dissociation move inside of porous domains, relative to the interfacial layer of anionic surface groups. Self-consistent theories and coarse-grained molecular simulations can help to rationalize this structural picture. After demonstrating consistency with existing data on structure and transport, these modeling approaches could be employed as predictive tools in polymer design. 

Molecular simulations yield unrealistic morphologies (pore sizes, shapes, connectivity) if they employ insufficient representations of ionomer molecules. Results of simulations depend on interaction parameters that are provided as input. Parameters have to be acquired from fundamental modeling studies (DFT-based calculations) and experimental studies (e.g., adsorption studies). CGMD simulations offer a sound trade-off of computational efficiency and adequate structural representation. The coarse-grained treatment implies simplification in interactions, which can be systematically improved with advanced force-matching procedures, but it allows simulations of systems with sufficient size and sufficient statistical sampling. Structural correlations, thermodynamic properties and transport parameters of PEMs can be studied. 

There is increasing interest in the relativistic treatment of atoms/ molecules/ and solids. A relativistic Hartree-Fock scheme [Hartree-Fock-Dirac (HFD) method] based on the variation in the total energy obtained with a single Slater determinant (in which the one-electron orbitals are four-component Dirac spinors), using a Dirac-type Hamiltonian for each electron and including Coulomb interaction, was developed some time ago. For the remaining interaction terms the first-order perturbation of the Breit interaction operato reduced to large components (Pauli approximation) is usually taken into account (see, however, the work of Mann and Johnson ). 

In the case of atoms and molecules with central symmetry, in which case a one-center expansion is feasible, these equations are solved numerically. In the case of molecules with no central symmetry and in the case of crystals, this procedure is not possible and one must expand the molecular orbitals (MOs) or crystal orbitals (COs) as a linear combination of some basis functions (LCAO expansion). This was first conducted for molecules by Malli and Oreg and applications can be found for diatomic or linear molecules, the only exception being the HjCO molecule, which was treated by Aoyama et 

Derivation of the Relativistic Hartree-Fock-Roothaan Equations for Molecules and Crystals 

We shall assume here that we have a crystal of 2N + 1 unit cells in each direction and m orbitals in the unit cell, and further that we have four basis sets (t = 1, 2, 3,4) With their help any four-component relativistic crystal (Bloch) orbital can be expressed in the form 

1 Hartree-Fock Crystal-Orbital Theory of Periodic Polymers 

Enmirical Correlations with the Types of Interaction Present 

We have seen that 3D-QSAR techniques use mathematical tools to compare three-dimensional representations of molecules with their biological properties. Most of the methods, except those relying on the 3D structure of the ligand-macromolecule complex, require that the molecules be aligned. Sometimes the alignment and the choice of the conformation are automated by the method, but usually these crucial details are left to the scientist. Because the methods are quantitative, they all rely on statistical validation of the model. Usually this is done by leave-one-out cross-validation, but data scrambling and true predictions are also used by many workers. 

The 3D-QSARS also differ in their 3D molecular representations. Again, the modeler must ask Is one number sufficient or will many be used Will these be based on potential energy calculations or something simpler Where will the differences be measured On a lattice, a surface, or other points Will the 3D molecular representation account for all aspects of intermolecular inter- 

Is 3D-QSAR best left to experts, or can less skilled scientists apply the methods The discussions above may indmidate a nonexpert who had contemplated trying 3D-QSAR methods. In fact, the common approaches such as CoMFA are easily learned and hard to misuse. A little time spent learning how to interpret PLS statistics is all that is needed to supplement the individual s molecular modeling experience. If problems in alignment, choice of conformation, calculation of properties, or suspected nonlinearities arise, an expert collaborator should be sought. In our experience, most data sets fairly easily yield predictive CoMFA models, and those that do not often fail to improve with additional changing of parameters. 

Role of 3D-QSAR in 3D Database Searching, Combinatorial Library Design, and Computer De Novo Design 

The authors own contributions to the studies described in this article are supported by the Wellcome Trust, the British Heart Foundation, and the Medical Research Council. 

Lopez-Bameo J, Lopez-Lopez JR, Urena J, Gonzalez C. Chemotransduction in the carotid body current modulated by PO2 in type I ehemoreeeptor cells. Science 

Weir EK, Archer SL. The mechanism of acute hypoxic pulmonary vasoconstriction the tale of two channels. FASEB J 1995 9 183-189. 

Youngson C, Nurse CA, Yeger H, Cutz E. Oxygen sensing in airway chemoreeeptors. Nature 1993 365 153-155. 

Marcel Dekker, Inc. 270 Madison Avenue, New York, NewYoik 10016 

In this chapter, we have set forth a formal mathematical description of mutation-induction kinetics on the basis of certain simplifying assumptions. The resulting equations are sufficient for the analysis of many dose-response relationships found for radiations and chemicals. From this base, more elaborate mathematical methods could be developed to deal with more complex experimental situations or macromolecular processes than we have considered here. 

Real cell populations are often heterogeneous and may consist of two or more subpopulations that differ in mutability and sensitivity. The formal expressions presented here could be applied to each subpopulation and computer methods then used to work out the possible total population responses. Clearly, it would be desirable to obtain data in synchronized systems (which should eliminate one prominent source of population heterogeneity that exists in many systems), and also in populations deliberately rendered heterogeneous by mixing strains with different sensitivities to mutation and killing. 

Mutation-induction data in unicellular systems can be described mathematically within the framework of single-event Poisson statistics. This formal description can be linked to various mechanistic models for mutation and killing. Such mathematical links between formalism and mechanism enable one to make use of the quantitative details of the dose-response relationships in drawing general inferences regarding the macromolecular processes involved in mutation and killing. 

Mutation yields, and in particular the position and magnitude of maximum yields, should be measured as carefully as possible as a means of verifying the apparent pattern of mutation-induction kinetics revealed in mutation-frequency curves. For purely linear mutation induction and exponential survival, the maximum mutant yield occurs at the LD37 dose for other nonlinear kinetic patterns, the position and magnitude of the maximum yield shift in mathematically predictable ways. For any given kinetic pattern of killing and mutation, the ratio of the maximum mutant yields plotted over lethal 

x is the solution of equation (21). The left-hand side of this equation can be rearranged and written as the function 

The best studied case of viral inhibition of host cell protein synthesis is poliovirus infection of HeLa cells. Infected cells, and extracts prepared from these cells, are impaired in their ability to bind capped mRNAs to ribosomes, and thus fail to initiate translation. At least one multisubunit initiation factor (eIF-4F) which contains a documented cap-binding protein, and which is required for translation of most mRNAs, is functionally inactive and structurally disrupted following infection. The biochemical lesion underlying the dissociation of this factor is not yet understood, nor has its precise mechanism of action in uninfected cells been determined. Expression, but not extensive replication, of the infecting viral genome is required for inhibition to occur, but the molecular mediator of the inactivation remains to be identified. The fact that viral protein synthesis occurs under conditions of inhibition of cellular protein synthesis demands that viral mRNA initiate translation differently from its host cell. The discrimination apparently involves a lack of dependence on the cap structure, but additionally requires other sequence and/or structural features which permit initiation by a cap-independent mechanism (Brown et ai, 1982). Virtually nothing is known about how viral mRNA associates with ribosomes to enable it to bypass those steps in the usual initiation process which are inhibited following infection. 

Although the biochemistry of translational initiation is steadily being unraveled, and the block imposed by poliovirus in HeLa cells is simultaneously becoming clarified, other picornaviruses may interact with other cell types in different ways. Infection of at least some cells with the cardioviruses, EMC or mengovirus, does not appear to produce the same initiation factor inactivation as does poliovirus in HeLa cells, and the regulation of protein synthesis in such cells is not well understood. The majority of picornaviruses, in natural host tissue or in cultured cells, have not been studied at all. Thus, despite a long-standing interest in the phenomenon of virus-induced interference with host cell protein synthesis, many questions remain to be answered. 

and Lucas-Lenard, J., 1976, Cellular protein synthesis shut-off by mengo virus Translation of nonviral and viral mRNAs in extracts from uninfected and infected Ehrlich ascites tumor cells, J. Virol. 18 182. 

Alonso, M. A., and Carrasco, L., 1981, Reversion by hypotonic medium of the shutoff of protein synthesis induced by encephalomyocarditis virus, J. Virol. 37 535. 

Bablanian, R., 1972, Depression of macromolecular synthesis in cells infected with guanidine-dependent poliovirus under restrictive conditions, Virology 47 255. 

A Brief Introduction to Ball Grid Array Technologies, in Ball Grid Array Technology, J. Lau, Ed., McGraw-Hill, 1995 

Performance Test Methods and Qualification Requirements for Surface Mount Solder Attachments, IPC-9701, IPC, 2002 

Lau and Y. Pao, Solder Joint Reliability of BGA, CSP, Flip Chip, and Fine Pitch SMT Assemblies, McGraw-Hill, 1997, Chap. 6 

ANSYS is a product of Ansys, Inc., Can-onsburg, PA. Version 7.1 was used in this study. 

Madenci, I. Guven, and B. Kilic, Fatigue Life Prediction of Solder Joints in Electronic Packages with ANSYS, Kluwer, 2003 

The above discussion of the continuum theory of liquid crystals is by no means complete. There exist many more effects that can be described by the continuum theory, either in its present or modified form. In view of the diverse applications of the theory, the selection 

In this appendix we show the steps leading from Eq. [30] to Eq. [31]. From Eqs. [28a] and [30] we have 

Wojtowicz, Generalized Mean Field Theory of Nematic Liquid Crystals, Chapter 4. 

Zocher, The Effect of a Magnetic Field on the Nematic State, Trans. Faraday Soc., 29, p. 945 (1933). 

Freedericksz and A. Repiewa, Theoretisches und Experimentelles zur Frage nach der Natur der Anisotropen Flussigkeiten, Z Physik. 42, p. 532 (1927). 

De Winter, Die Makromol. Chem., Macromolecular Symposia No. 57, 253 (1992). Anon., Plastics Bulletin, 174, 6 (Jan-1992). 

in Plastics Recycling as a Future Business Opportunity, Technomic Publishing Co, Pennsylvania, USA, (1986). 

Ludewig, Polyester Fibers, Chemistry and Technology, Wiley Int. Publ., 1971. 

Randall Curlee, The Economic Feasibility of Recycling, Praeger Publishers, 

The Importance and Practicability of Co-Injected, Recycled Poly(ethylene terephthalate)/Virgin Poly(ethylene terephthalate) Containers 

It is most important—but outside the scope of this article—that such comparisons of spontaneous and induced mutation rates both in vitro and in vivo (e.g., Russell s, 1951, specific-locus system in mice) be extended. In this manner, one of the chasms separating in vitro mutagen assays and mutagenic effects in man (namely, the differences between the mutagen response of mammalian somatic cells in vitro and that of the whole mammal) can be bridged. 

A final procedural point might be noted here. With a 2 hr exposure to 10-2 M EMS, a 17,000-fold stimulation of the spontaneous mutation rate is observed. A single such treatment of a culture would yield 

We have tried to indicate the utility of the thymidine kinase locus in mouse lymphoma cells and the advantages it holds over the more widely employed HGPRT locus. As indicated in this chapter, the amount of labor involved for the utilization of the TK locus is approximately one-tenth that for its X-linked counterpart. This advantage can be exploited to delineate slight increases in the mutation rate above the spontaneous 

Donald Glive W. Gary Flamm, and James B. Patterson 

Advances in mutation research, insofar as they concern problems to human health, have been greatly increased in the past few years, and it is evident that further progress is dependent on the continuing development of mutational assay systems having a high degree of relevance. It is hoped that this chapter will contribute to this necessary and urgent task. 

This chapter presents a phenomenological description of viscoelastic properties of polymer solutions. While aspects of the description will appear familiar, this chapter is fundamentally unlike other chapters in this book. In Chapter 2 we discussed sedimentation. Much of the literature appeared before younger readers were born, but the sedimentation coefficient s is the coefficient familiar to everyone who has ever been interested in the method. In Chapter 3 we discussed capillary electrophoresis in polymer solutions. The notion that this method gives information about the polymer solutions being used as support media is nearly novel, but the electrophoretic mobility jx is the coefficient familiar to everyone who uses the technique. Similar statements apply to each of the other chapters. The perspective in prior chapters on a solution property may not be the same as seen elsewhere, but the parameters used to characterize the property have been familiar. 

The classical viscoelastic properties are the dynamic shear moduli, written in the frequency domain as the storage modulus G ( y) and the loss modulus G a ), the shear stress relaxation function G t), and the shear-dependent viscosity j (k). Optical flow birefringence and analogous methods determine related solution properties. Nonlinear viscoelastic phenomena are treated briefly in Chapter 14. 

Solution properties depend on polymer concentration and molecular weight, originally leading to the hope that one could apply reduction schemes and transform measurements of the shear moduli at different c and M to a few master curves. This hope was not met. Writing in 1980, Ferry observed It is evident... that the concentration reduction scheme for the transition zone described... above cannot be applied in the plateau zone, and indeed that no simple method for combining data at different concentrations can exist . ..the shapes of the viscoelastic functions change significantly with dilution. ) Pearson s 1987 review concluded The results 

This chapter removes the hmitations described by Ferry and Pearson. Section 13.2 supplies an ansatz that correctly predicts the shapes of major viscoelastic functions. Comparison with experiment shows that the ansatz describes experiment well. Material-dependent viscoelastic parameters determined from actual measurements have simple concentration and molecular weight dependences, as is reasonably expected for rational physical properties, leading to a description for the c and M dependences of the viscoelastic functions, and thus to a coherent description of the variations in the shapes of the viscoelastic functions when polymer concentration and molecular weight are changed. 

In order to make satisfactory predictions, it was necessary to take a step that prior chapters did not. Rather than using the classical storage and loss moduli G co) and G co), a novel pair of viscoelastic moduli are here introduced. The ansatz makes predictions for the novel functions. The new functions are actually not very radical indeed, there is a sense in which they are more consistent with prior chapters than are G (co) and G (co). The previous chapter described the zero-shear viscosity as the low-shear limit t](c, M) of the experimentally accessible viscosity. To describe shear thinning, rj is extended to the shear-dependent For oscillatory motion, one might by analogy have expected rj to become r cd) with complications arising because at nonzero co the displacement and applied force shift in relative phase. The orthodox loss function is G , with 

The nonfaradaic activation of heterogeneous catalytic reactions via the NEMCA effect is a novel and promising application of electrochemistry. There is a lot of new surface chemistry to be explored with several promising technological possibilities, primarily in product selectivity modification. At the very least, the new phenomenon or electrochemical promotion will allow for a systematic study and enhanced understanding of the role of promoters in heterogeneous catalysis. 

We thank the EEC JOULE and STRIDE-HELLAS programs for financial support during the last years. The first author is also grateful to the Ecole Polytechnique F6derale de Lausanne (EPFL), Lausanne, for an invited Professorship which enabled him to concentrate on the writing of this chapter. 

Politova, V. A. Sobyanin, and V. D. Belyaev, React. Kinet. Catal Lett. 41 (1990) 321. 

Vayenas, in Elementary Reaction Steps in Heterogeneous Catalysis, Ed. by R. W. Joyner and R. A. van Santen, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1993, pp. 73-92. 

Vayenas, S. Bebelis, I. V. Yentekakis, Ch. Karavasilis, and Y. Jiang, Solid State Ionics 72(1994) 321. 

Following the pioneering work of Gavach et al., electrochemistry at liquid-liquid interfaces has developed very quickly 

Our lack of theoretical knowledge of ion transfer reactions simply reflects the general lack of understanding of the molecular mechanisms involved in ionic motion in liquids. Conversely, the study of electron transfer reactions at liquid-liquid interfaces benefits from the detailed knowledge we have of homogeneous electron transfer reactions. 

Marecek, and D. Homolka, Faraday Discuss. Chem. Soc. 77 (1984) 277. 

Osakai, T. Kakutani, and M. Senda, Bull Chem. Soc. Jpn. 57 (i984) 370. 

Homolka, L. Q. Hung, A. Hofmanova, M. W. Khalil, J. Koryta, V. Marecek, 

One problem that has stymied comparison of NLO merit of complexes is that data are frequently reported at one wavelength only. The first wavelength-dependence study of both nonlinear refraction and nonlinear absorption of an organometallic complex appeared recently. Although these data were collected point-by-point, the complete spectrum requiring over a week of data collection, the recent development of techniques such as white light continuum Z-scan that permit rapid acquisition of an NLO spectrum should ensure that wavelength dependence studies become much more common in the near future. 

The excimple in this chapter showed the use of a recent development in toxicology, the benchmark dose (chapter 10), as a key component in developing a workplace 

We also incorporated several of the key points from chapter 6 (e.g., toxicokinetics) in our discussion of the approach used for determining the need for a specific uncertainty factor, and needed to extrapolate data from animal studies to humans, which was the focus of chapter 7. Finally, we had to relate the results of this work to the people working with the chemiccd, and the companies involved in its production and sale, in addition to the regulatory agencies and the general public. 

The nPB case study provides a good example of the twists and turns a relatively simple toxicological study can take, and how these bends in the road turn out to affect us all. Our job as risk assessors is to ensure that we can safely use our chemicals and other products, but our job as toxicologists requires that the best science be used in the process. Sometimes it does prevail in the end. 

ClinTrials BioResearch (ClinTrials). 1997a. A 28-Day Inhalation Toxicity Study of a Vapor Formulation of ALBTAl in the Albino Rat. Project No. 91189. Bio-Research Laboratories Ltd., Senneville, Quebec, Canada. Sponsored by Albemarle Corporation, Baton Rouge, LA. May 15. 

Directorates-General Environment and Enterprise, and the European Chemicals Bureau (ECB), 2003. Joint Views Concerning the Work of the Working Groups on Classification and Labelling. Brussels, September 5. 

American chemistry has grown tremendously over the past century as occupation, profession, and discipline. From a fledgling field in the 1870s, lacking cohesive institutional forms or a strong social identity, chemistry 

Lx)ng-run trends in aspects of American chemistry - the aggregate series on which much of this report is based - provide a background against which short-run variations in different indicators may be evaluated. Careful scrutiny of contemporary pronouncements by chemists and other observers of the enterprise may also suggest implicit indicators of the state of American chemistry at a given time. It is unwise to interpret a given indicator in isolation one should look instead to the conjuncture of several indicators over a limited period for the context in which chemists and others reacted to events. 

The sections contain information about ground and excited states, half-life, isotopic abundance, modes of decay as well as energies and intensities of the emitted radiation. Each of the properties is identified by a special code. Missing codes mean that they are not applicable for that nuclide or that no data for these properties are available. For nuclear masses, systematics on Q values for the different modes of decay, p+Zs ratios, half-lives, conversion coefficients, and X rays, see Chapter 1.2.1, p. 6. 

The information given refers always to the nuclide mentioned in the heading of the section. Sometimes the decay of this nuclide leads to a nuclide which itself is radioactive. Information about the radiation emitted in the decay of these daughter nuclides (and other following members of the decay chain) is not included in this compilation. 

Data The values given were selected according to their apparent reliability, taking into account the stated uncertainty, the experimental method used, and the detailed description of it, as well as the time of publication. In general, those data which where obtained by critical evaluations of published values were preferred. These eval data are marked with eval. If no experimental measurements or only unreliable measurements are available, data can in some cases either be deduced from other ded facts, like level and decay schemes, or be obtained with reasonable accuracy from syst systematic trends or calculations. These values are marked by ded, syst, or calc, calc respectively. 

In many cases, quite differing values for a given property have been published. In general, the apparently most reliable one was selected. However, if the available arguments did not warrant such a selection, two or more representative values are given. 

Uncertainties The given uncertainties are always as stated in the publications or evaluations. They in general mean the standard deviations, which are, however, unfortunately not always evaluated in the same manner and with the same objectivity. The uncertainties are given directly after the data. They always refer to the last digits of the numbers. For example, 349.3(15) means 349.3 + 1.5, 0.039(7) means 0.039 + 0.007, and 1.34(2) xIO means (1.34 + 0.02) X10 . Sometimes the given uncertainties are not symmetric this is denoted in the sections below as 3.4( + 15, —9) meaning 3.41J3. 

Storey, in The Biochemistry of Plants. A Comprehensive Treatise, Vol 2, Metabolism and Respiration (D. D. Davies, ed.), p. 125, Academic Press, New York (1980). 

Corbett, K. Wright, and A. C. Baillie, The Biochemical Mode of Action of Pesticides, 2nd ed.. Academic Press, London (1984). 

Belbachir, M. Matringe, D. Chevallier, and M. Tissut Pestic. Biochem. Physiol. 14, 309 (1980). 

It will be a challenge to introduce the application of starter cultures in cocoa bean fermentation practices, either to speed up and better control the fermentation process or to target the fermentation process towards predefined end-products. However, to scale up the initiation of cocoa bean fomentation processes with a defined inoculum to the farm level, whether applied to small farm holdings or laige estates, will be an even greater challenge, especially as it relates to starter culture production and maintenance, inoculation and fermentation method, and last but not least farmers training and extra costs. 

Aculey, P.C., Snitkjaer, R, Owusu, M., et al. (2010) Ghanaian cocoa bean fermentation characterized by spectroscopic and chromatographic methods and chemometrics. J Food Sci 75, S300-S307. 

Adeyeye, E.I., Akinyeye, R.O., Ogunlade, 1., et al. (2010) Effect of farm and industrial processing on the amino acid profile of cocoa beans. Food Chem 118, 357-363. 

Bolten, C.J., Dohnt, K., et al. (2013) Core fluxome and metafluxome of lactic acid bacteria under simulated cocoa pulp fermentation conditions. Appl Environ Microbiol 79, 5670-5681. 

Berger, A., et al. (2014) The key to acetate metaboUc fluxes of acetic acid acteria under cocoa pulp fermentation simulating conditions. Appl Environ Microbiol 80, 4702-A716. 

Throughout this chapter, we have focused our attention on defensive flexibihty strategies, that is, strategies that mitigate the negative impaet of nndesirable events. This focus should not be allowed to obscure the fact that flexibility can also be used as a proactive mechanism that enables firms to eompete more 

AMR (2006) AMR Research Report on Managing Supply Chain Risk. AMR Research, Inc. 

BiUington C (2002) HP Cuts Risk with Portfolio Approach. Purchasing Magazine Online, February 21. 

Brown D (2004) How U.S. Got Down to Two Makers of Flu Vaccine. Washington Post, October 16. 

Boyabatli O, Tokay B (2004) Operational Hedging A Review with Discussion. INSEAD working paper. 

Transition-metal coordination complexes that are susceptible to showing facile electron transfer through red-ox reactions are generally good catalysts for organic transformations of industrial importance. Flowever, the major drawback in using these coordination complexes as catalysts is the loss of catalyst in each run because the soluble metal coordination complex (catalyst) cannot be 

These simulations suggest that the collisional activation of protonated amino acids and peptides may directly drive the ion to a dissociation transition state structure, resulting in nonstatistical fragmentation dynamics. To consider the generality of this proposition, it will be important to study additional amino acids and larger peptides in the future. It is also important to compare the current AMI direct dynamics with direct dynamics simulations at higher levels of theory, such as B3LYP and MP2. 

The general Gaussian wavefunction for a N-dimensional system at time t with spatial coordinates q is 

Ohrn and co-workers have developed a direct dynamics approach which incorporates both the electrons and nuclei dynamics (END). The complete electron-nuclear coupling terms are retained in the calculation and, as a result, the dynamics is not constrained to a single Born-Oppenheimer potential energy surface i.e., electronic non-adiabaticity is explicitly included. A complication in this approach is the computational demand in propagating an electronic wavefunction which is an accurate representation of the ground electronic state as well as multiple excited electronic states. This approach will become more widely used as computation becomes more powerful. In its initial development, Deumens et al. used END and treated the dynamics of the nuclei purely classical as in the above classical direct dynamics. More recently, a semiclassical description of the nuclear motion has been implemented by incorporating Heller s Gaussian wave packet dynamics.  

Hase would like to acknowledge financial support from the National Science Foundation for his research in direct dynamics simulations. Animations of the direct dynamics trajectories described in the section on applications of Born-Oppenheimer direct dynamics are available at the Website http //octopus.chem. wayne.edu/hase. 

Transition state theory is based on the assumption of a dynamical bottleneck. The dynamical bottleneck assumption would be perfect, at least in classical mechanics, if the reaction coordinate were separable. Then one could find a dividing surface separating reactants from products that is not recrossed by any trajectories in phase space. Conventional transition state theory assumes that the unbound normal mode of the saddle point provides such a separable reaction coordinate, but dividing surfaces defined with this assumption often have significant recrossing corrections. Variational transition state theory corrects this problem, eliminating most of the recrossing. 

It is not sufficient to merely treat tunneling consistently with overbarrier processes it must be treated accurately. For overbarrier processes. 

Tmhlar, A. D. Isaacson, and B. C. Garrett, in Theory of Chemical Reaction Dynamics, Vol. 3, M. Baer, ed., CRC Press, Boca Raton, FL, 1985, pp. 65-137. Generalized Transition State Theory. 

Redmon, Comput. Phys. Commun., 47, 91 (1987). POLYRATE A General Computer Program for Variational Transition State Theory and Semiclassical Tunneling Calculations of Chemical Reaction Rates. 

Isaacson, S. N. Rai, G. C. Hancock, J. G. Lauderdale, T. Joseph, and D. G. Tmhlar, Comput. Phys. Commun., 71,235 (1992). POLYRATE 4 A New Version of a Computer Program for the Calculation of Chemical Reaction Rates for Polyatomics. 

Nonlinear approaches to image restoration have proven to be far superior to classical linear approaches. The maximum entropy approach, in particular, has proven to be very flexible in allowing a wide and complex variety of data and constraints to be used in the restoration process. The maximum entropy method, however, is not without 

Ideally an image restoration technique will deliver an image that is consistent with available data and constraints (e.g., positivity), and which is free of obvious artifacts. Any technique that achieves this should be taken seriously, regardless of whether it is based on an ad hoc procedure or justified by a formalism such as maximum entropy. It is the data, ultimately, that must drive a restoration process. In analyzing the solution to any ill-posed problem, it is important to differentiate between those characteristics dicatated by the data, and those that are dependent on the solution technique. Any physically implausible feature that is not required by the data should be ignored. 

Sommerfeld and H. Bethe, Electronentheorie der Metalle, Springer, Berlin, 1967. 

Trasatti, in Comprehensive Treatise of Electrochemistry, Vol. 1, Ed. by J. O M. Bockris, B. E. Conway, and E. Yeager, Plenum Press, New York, 1980, pp. 45-81. C. Kittel, Elementary Solid State Physics, Wiley, New York, 1962. 

Milnes and D. L. Feucht, Heterojunctions and Metal-Semiconductor Junctions, Academic, New York, 1972. 

Since the manuscript of this chapter was completed, the only patient reported as a case of lactosylceramidosis has been conclusively disproven (Wenger, D. A., Sattler, M., Clark, C., Tanaka, H., Suzuki, K., and Dawson, G., 1975, Lactosylceramidosis Normal activity for two lactosylceramide )8-galactosidases. Science 188 1310-1312). Therefore, there is no evidence at present for a )8-galactosidase specific for lactosylceramide hydrolysis. 

Apffel, C. A., and Peters, J. H., 1970, Regulation of antigenic expression, 7. Theor. Biol. 26 47-59. 

Aronson, N. N., and de Duve, C., 1968, Digestive activity of lysosomes. II. The digestion of macromolecular carbohydrates by extracts of rat liver lysosomes, J. Biol. Chem. 243 4564-4573. 

Norden, N. E., Ockerman, P. A., Riekkinen, P., Rapola, J., and Louhimo, T., 1973, Mannosidosis Clinical, fine structural and biochemical findings in three cases, Acta Paediat. Scand. 62 555-565. 

and Suzuki, K., 1975, Heterogeneity of human hepatic N-acetyl-/8-D-hexosa-minidase A activity toward natural glycosphingolipid substrates, J. Biol. Chem. 250 1328-1332. 

The origin of the ESR experiment lies in the spin possessed by an electron. Chemists will know that an electron has a spin of one-half. By this we mean that the component of spin angular momentum, S, in a direction specified by an applied magnetic field (conventionally labeled the z-direction) can take on only two values— + and - fi. The vector describing the spin angular momentum has a magnitude [5(2+ and this vector is perceived as 

FIGURE 3. The precession of the spin angular momentum vector about a magnetic field applied in the z-direction. The vector has a magnitude [5(2+ and the size of its component in the 

The existence of spin angular momentum, together with the electrons electrostatic charge, confers a magnetic moment, (ji, on the electron which is proportional to the magnitude of the spin vector (S)  

The ideas embodied in Eq. (1) were well established long before magnetic resonance experiments were carried out, from the famous Stern-Gerlach experiment, in which a beam of silver atoms was found to split into two separate beams upon passage through an inhomogeneous magnetic field. This was a direct reflection of the two only possible spin states of the unpaired electron within the atom. The existence of fine structure in atomic spectra provided further evidence for electron spin. 

If we apply a steady magnetic field, B, to the electron, then the energy of the interaction with the magnetic moment of the electron is represented by  

The results discussed before indicated that asphaltenes are the main fraction that forms coke. The coke yield for asphaltenes was 43.1 wt% and it is to be expected that asphaltenes were transformed into gases, oils, and resins during cracking reactions. Resins and aromatics exhibited similar amount of coke but the activation energy for resins was higher than that of aromatics, whereas saturates volatilized almost completely. Atmospheric residue showed an increase in activation energy as 

The discussion of concentrated solution models has indicated that, while the transport flux equations in their rigorous form (5) may be intractable, the use of the binary electrolyte approximation allows the convenient implementation of concentrated solution theory in pitting corrosion models. Engelhard et al. have shown that this approximation is valid over a surprisingly wide range of 

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N,N,N, N -tetramethyl-l,8,-naph-thalenediamiDe M.P. 51 C. A remarkably strong mono-acidic base (pKg 12-3) which is almost completely non-nucleophilic and valuable for promoting organic elimination reactions (e.g. of alkyl halides to alkenes) without substitution. 

It is manufactured by heating dicyandiamide, H2N C(NH) NH CN, either alone or in the presence of ammonia or other alkalis, in various organic solvents. Melamine is an important material in the plastics industry. Condensed with melhanal and other substances it gives thermosetting resins that are remarkably stable to heat and light. U.S. production 1980 80 000 tonnes. 

The phthalocyanine molecule is remarkably stable to heat and chemical reagents. The metal-free and heavy metal compounds sublime practically unchanged at 550-580 C. 

A remarkable survey covering all the major writers from Homer to Plutarch, with brilliant translations by the author, one of the leading poets of today. 

There have been several equations of state proposed to express the compressibility factor. Remarkable accuracy has been obtained when specific equations for certain components are used however, the multitude of their coefficients makes their extension to mixtures complicated. 

In 1972, Soave published a method of calculating fugacities based on a modification of the Redlich and Kwong equation of state which completely changed the customary habits and became the industry standard. In spite of numerous attempts to improve it, the original method is the most widespread. For hydrocarbon mixtures, its accuracy is remarkable. For a mixture, the equation of state is ... 

Aluminum complex greases, obtained by the reaction of aluminum isopropylate with a mixture of benzoic acid and fatty acids. These greases have a remarkable resistance to water, very good adhesion to metallic surfaces, good mechanical stability properties and resistance to temperature. They are less common than the first two types. 

The most remarkable defects, which have been detected and reported to the custumer, are cracks, casting defects (e g. wrinkles) and inside corrosion.(picture 1)... 

It is obvious the pitting origin remarkably showed in all mentiotmed levels, while run-in stage is not registered in levels 4 and 6 and very slightly in level 3. Similar courses may be seen even in the 3D projection. 

According to some remarks concerning the physical interaction between the incident ultrasonic wavelet and the defects [4-6], we consider that an Ascan signal, may be described as a weighted sum of few delayed and phase-shifted replicas of the ultrasonic incident wavelet j(r). We can express this mathematically as ... 

It is very important, from one hand, to accept a hypothesis about the material fracture properties before physical model building because general view of TF is going to change depending on mechanical model (brittle, elasto-plastic, visco-elasto-plastic, ete.) of the material. From the other hand, it is necessary to keep in mind that the material response to loads or actions is different depending on the accepted mechanical model because rheological properties of the material determine type of response in time. The most remarkable difference can be observed between brittle materials and materials with explicit plastic properties. 

The results are illustrated by figure 5 B-Scan, C-Scan and D-Scan representations show that there are two types of defects. On the left part of the weld, we remark a lack of fusion, while on the right part, we observe a nest of blow hole. 

Very many types of eddy current instruments available tend to look remarkably similar in much the same way as automobiles tend to look alike. This may be an inevitable trend since developments are converging on users needs, plus PC platforms are being used more and these too are tending to look more and more alike. In the way that the DSP has changed the inside of the instrument, the PC. is changing the outside. 

With this technology even boreholes, up to 2mm underneath the surface, can be identified, A remarkable borehole is represented in illustration 10, For the elucidation of the temperature contrast, a three-dimensional temperature distribution of the entire blade is shown beside the infrared picture (the similarity of the temperature distribution with the actual blade airfoil is purely coincidental). 

The large temperature difference of the remarkable borehole, opposite other boreholes and their environment is significant. This high temperature difference is a typical feature for a small wall thickness between borehole and blade surface. For technical reasons, precise eroding of the boreholes is difficult. Due to this, the remaining wallthickness between the boreholes and the blade surface has to be determined, in order to prevent an early failure, Siemens/Kwu developed a new method to determine the wallthickness with Impulse-Video-Thermography [5],... 

The automatic acquisition and analysis system we developed within the scope of the Super-Phenix steam generator tube inspection by ultrasonic arrays is a remarkable example of an exhaustive acoustic verification system. It works for every type of probe for tube inspection. 

Fig. 5, also an A-scan, shows the possibility of the echo-technique for concrete. The interface and backwall-echo of a 20 cm thick concrete specimen are displayed (RF-display). A HILL-SCAN 3041NF board and a broadband transducer (40mm element 0) are used which enable optimal pulse parameters in a range of 50 to 150 kHz. Remarkable for concrete inspections is the high signal-to-noise ratio of about 18 dB. 

The method is a very old one, remarks on it having been made by Tate in 1864 (33), and a simple expression for the weight W of a drop is given by what... 

One remarkably simple yet seemingly robust outcome of Turnbull s experiments was his empirical finding that the solid-liquid interfacial free energy was... 

Klein and co-workers have documented the remarkable lubricating attributes of polymer brushes tethered to surfaces by one end only [56], Studying zwitterionic polystyrene-X attached to mica by the zwitterion end group in a surface forces apparatus, they found /i < 0.001 for loads of 100 and speeds of 15-450 nm/sec. They attributed the low friction to strong repulsions existing between such polymer layers. At higher compression, stick-slip motion was observed. In a related study, they compared the friction between polymer brushes in toluene (ji < 0.005) to that of mica in pure toluene /t = 0.7 [57]. 

Remarkable chiral patterns, such as those in Figs. IV-15 and XV-8, are found in mixtures of cholesterol and 5-dipalmitoyl PC (DPPC) on compression to the plateau region (as in Fig. XV-6). As discussed in Section IV-4F, this behavior has been modeled in terms of an anisotropic line tension arising from molecular symmetry [46-49]. 

On the other hand, as applied to the submonolayer region, the same comment can be made as for the localized model. That is, the two-dimensional non-ideal-gas equation of state is a perfectly acceptable concept, but one that, in practice, is remarkably difficult to distinguish from the localized adsorption picture. If there can be even a small amount of surface heterogeneity the distinction becomes virtually impossible (see Section XVll-14). Even the cases of phase change are susceptible to explanation on either basis. 

Starting with the quantum-mechanical postulate regarding a one-to-one correspondence between system properties and Hemiitian operators, and the mathematical result that only operators which conmuite have a connnon set of eigenfiinctions, a rather remarkable property of nature can be demonstrated. Suppose that one desires to detennine the values of the two quantities A and B, and that tire corresponding quantum-mechanical operators do not commute. In addition, the properties are to be measured simultaneously so that both reflect the same quantum-mechanical state of the system. If the wavefiinction is neither an eigenfiinction of dnor W, then there is necessarily some uncertainty associated with the measurement. To see this, simply expand the wavefiinction i in temis of the eigenfiinctions of the relevant operators... 

In classical mechanics, it is certainly possible for a system subject to dissipative forces such as friction to come to rest. For example, a marble rolling in a parabola lined with sandpaper will eventually lose its kinetic energy and come to rest at the bottom. Rather remarkably, making a measurement of E that coincides with... 

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