Current Efforts

a British company, developed a two-step process while Fare, an Italian company, pursued a one-step method. Both processes produced high-strength polypropylene filaments with a highly oriented a-monoclinic crystalline structure, an elongation of 16-20% and breaking strength of 75 and 65 cN/tex, respectively. 

In the two-step process, polypropylene resin of typically MFR = 35 g/min and isotacticity above 90% is spun at 280°C at a low speed of 200 m/min. The spun fiber, which has a structure of low-oriented hexagonal crystallinity, is drawn at a low temperature of 60°C over seven rolls. The drawn fiber, still having a paracrystalline structure, is drawn again at a higher temperature of 110°C 140°C to change the paracrystallinity into a highly oriented 

Tensile Strength of Experimental HSHM Polypropylene Fiber 

PP resin no. Melt flow rate Extension rate Strength (cN/tex) 

Ube-Nitto Chemical Products, Japan, has also developed a high-strength (HS) polypropylene fiber under the brand name Simtex. The technology is principally to optimize the crystallization of fiber by a new orientation technique. The HS fiber exhibits strength up to 88-115 cN/tex versus 40 60 cN/tex for the conventional polypropylene fiber. The heat shrinkage rate is below 50%. It also has high chemical resistance, especially to organic 

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The first dynamical simulation of a protein based on a detailed atomic model was reported in 1977. Since then, the uses of various theoretical and computational approaches have contributed tremendously to our understanding of complex biomolecular systems such as proteins, nucleic acids, and bilayer membranes. By providing detailed information on biomolecular systems that is often experimentally inaccessible, computational approaches based on detailed atomic models can help in the current efforts to understand the relationship of the strucmre of biomolecules to their function. For that reason, they are now considered to be an integrated and essential component of research in modern biology, biochemistry, and biophysics. 

In a similar scheme, acylation of 2-methoxynaphthalene gives ketone, 15. This is then converted to the acetic acid by the Wilgerodt reaction. Esterification, alkylation of the carbanion (sodium hydride methyl iodide), and finally saponification affords naproxen (17). The intense current effort on nonsteroid antiinflammatory agents and acrylacetic acids in particular make... 

Increased computational resources allow the widespread application of fundamental kinetic models. Relumped single-event microkinetics constitute a subtle methodology matching present day s analytical techniques with the computational resources. The singleevent kinetic parameters are feedstock invariant. Current efforts are aimed at mapping catal) t properties such as acidity and shape selectivity. The use of fundamental kinetic models increases the reliability of extrapolations from laboratory or pilot plant data to industrial reactor simulation. 

Section 2 mainly focuses on the current efforts to improve the accuracy of quantum calculations using simplified empirical model forms. McNamara and Hillier, in Chapter 5, summary their work on improving the description of the interactions in biological systems via their optimized semiempirical molecular models. Piquemal and co-workers present recent advances in the classical molecular methods, aiming at better reproduction of high-level quantum descriptions of the electtostatic interactions in Chapter 6. In Chatper 7, Cui and Elstner describe a different semiempir-... 

The use of multiple otherwise incompatible catalysts allows multistep reactions to proceed in one reaction vessel, providing many potential benefits. In this chapter, literature examples of nanoencapsulation for the purpose of process intensification have been discussed comprehensively. Current efforts in the literature are mostly concentrated in the areas of LbL template-based nanoencapsulation and sol-gel immobilization. Other cascade reactions (without the use of nanoencapsulation) that allow the use of incompatible catalysts were also examined and showcased as potential targets for nanoencapsulation approaches. Finally, different methods for nanoencapsulation were investigated, thereby suggesting potential ways forward for cascade reactions that use incompatible catalysts, solvent systems, or simply incompatible reaction conditions. 

Several current efforts are focusing on the portability of enzymatic heterocyclization. For example, novel chiral heterocyclic carboxylic acids were produced by using hybrid enzymes [62] (Figure 13.21). Stimulated by biosynthesis pathways, biomimetic heterocyclization methods have also been developed with high efficiency [63]. 

Very thin films exhibit special structure because of their confined geometry between substrate and surface. Their structure cannot be studied in a normal setup. In order to obtain enough photons on the detector, the X-ray beam must impinge on them under grazing incidence (Cf. Sects. 7.6.3.1,1.63.2, 8.8). This technique is suitably combined with microbeams. Current effort is focusing both on progress of the instrumentation and on the development of adapted analysis methods. 

Although some nanostructured carbons are able to store reversibly higher amounts of lithium than graphite [2], they generally demonstrate a high hysteresis (see for example Figure 2) that still precludes their use in lithium-ion batteries. In order to improve their electrochemical properties as electrode materials, a current effort is made to better understand the... 

One of these, MOOM, is especially intriguing and is the focus of current efforts to detect and characterize it via surface-analysis techniques. 

Aiming to construct explicit dynamic models, Eqs. (5) and (6) provide the basic relationships of all metabolic modeling. All current efforts to construct large-scale kinetic models are based on an specification of the elements of Eq (5), usually involving several rounds of iterative refinement For a schematic workflow, see again Fig. 4. In the following sections, we provide a brief summary of the properties of the stoichiometric matrix (Section III.B) and discuss the most common functional form of enzyme-kinetic rate equations (Section III.C). A selection of explicit kinetic models is provided in Table I. TABLE I Selected Examples of Explicit Kinetic Models of Metabolisin 1 ... 

Formation of dihydrotropylium ions is a key feature of the C H9+ hypersurface. Currently, efforts in our laboratory276 have concentrated on the presence of different C H9+ isomers by probing their bimolecular reactivity. Thus, gas-phase titration in the FT-ICR mass spectrometer has revealed that mixtures of C7H9+ ions are formed by protonation of 1,3,5-cycloheptatriene, 6-methylfulvene and norbomadiene as the neutral precursors but that, in contrast to the results obtained by CS mass spectrometry, fragmentation of the radical cations of limonene yields almost exclusively toluenium ions275. 

In apoptosis a series of events takes place in an orderly sequence involving the activation of various proteases which are called caspases, for cysteine and aspartate proteases. Several distinct caspases act in a cascade vaguely reminiscent of the blood-clotting cascade of complement proteins. If one wishes to interfere with the apoptotic process, then one strategy would be to develop drugs that inhibit various caspases, a current effort underway in the pharmaceutical industry. 

The rather time- and cost-expensive preparation of primary brain microvessel endothelial cells, as well as the limited number of experiments which can be performed with intact brain capillaries, has led to an attempt to predict the blood-brain barrier permeability of new chemical entities in silico. Artificial neural networks have been developed to predict the ratios of the steady-state concentrations of drugs in the brain to those of the blood from their structural parameters [117, 118]. A summary of the current efforts is given in Chap. 25. Quantitative structure-property relationship models based on in vivo blood-brain permeation data and systematic variable selection methods led to success rates of prediction of over 80% for barrier permeant and nonper-meant compounds, thus offering a tool for virtual screening of substances of interest [119]. 

Current efforts in vaccine development have predominantly utilized clade B isolates, which represent the subtype in North America and Western Europe. There is also an increased interest in the development of clade A and C vaccines for the expanding pandemic in Asia and sub-Saharan Africa. A concern in fhe clade-specific vaccine strategy is the potential inability to produce large amounts of vaccine specific for distinct clades. This leaves open the question of specific vs. cross-clade effectiveness. Choice of immunogen(s), adjuvant, dose, and mode of administration are also additional variables that must be addressed in candidate vaccine research. 

Although current efforts are focused on global ocean paleoredox, the Mo stable isotope system should also prove useful in other oceanographic and environmental applications and in geobiological research. Such possibilities, while as yet unexplored, are previewed hriefiy below. 

It should be emphasized at this point that the use of physicochemical methods is so far the only way to demonstrate the import of transgene DNA into the mitochondrial matrix in living mammalian cells. The unavailability of a mitochondria-specific reporter plasmid designed for mitochondrial expression severely hampers current efforts toward the development of effective mitochondrial expression vectors. Although any new nonviral transfection system (i.e., cationic lipids, polymers, and others) aimed at the nuclear-cytosolic expression of proteins can be systematically tested and subsequently improved by utilizing anyone of many commercially available reporter gene systems, such a methodical approach to develop mitochondrial transfection systems is currently impossible. 

Glycoproteins play an important role in, for example, immunology and the elucidation of the functions of the carbohydrate residues are therefore the focus of great current efforts. The protein-bound carbohydrates perform an array of functions ranging from protection against proteolysis to the complex interplay with receptors and the discrimination of these functions in simple model systems can perhaps aid in a more detailed understanding of protein-carbohydrate interactions. 

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