Hecht studies

The methodology discussed previously can be applied to the study of colloidal suspensions where a number of different molecular forces and hydrodynamic effects come into play to determine the dynamics. As an illustration, we briefly describe one example of an MPC simulation of a colloidal suspension of claylike particles where comparisons between simulation and experiment have been made [42, 60]. Experiments were carried out on a suspension of AI2O3 particles. For this system electrostatic repulsive and van der Waals attractive forces are important, as are lubrication and contact forces. All of these forces were included in the simulations. A mapping of the MPC simulation parameters onto the space and time scales of the real system is given in Hecht et al. [42], The calculations were carried out with an imposed shear field. 

In summary, the relationship between TER and solute permeability shown here and by Madara and Hecht (1989) emphasizes that these two measures of paracellular leakage are related but not directly correlated. The most obvious feature is that permeability as a function of TER is dependent upon the solute characteristics, primarily molecular size but also charge. The degree of correlation becomes worse as the molecular size of the solute increases. Consequently, the interrelationship between TER and solute permeability must be measured for each cell model before a minimum TER value can be selected as a prerequisite for flux studies. 

Miehthling, R. Hecht, V., and Deckwer, W. D., Microbial Degradation of Quinoline, Kinetic Studies with Comamonas Acidovorans DSM 6426. Biotech. Bioeng, 1993. 42 pp. 589-95. 

Johnston, T.S. and Hecht, H.G. 1965. An automatic fitting procedure for the determination of anisotropic g-tensors from EPR studies of powder samples. Journal of Molecular Spectroscopy 17 98-107. 

Hatsukami DK, Hecht SS, Hennrikus DJ, Joseph AM, Pentel PR (2003) Biomarkers of tobacco exposure or harm application to clinical and epidemiological studies. 25-26 October 2001, Minneapolis, Minnesota. Nicotine Tob Res 5(3) 387-396 Hecht SS (2003) Tobacco carcinogens, their biomarkers and tobacco-induced cancer. Nat Rev Cancer 3(10) 733-744... 

Reynolds, S. D., M.-K. Liu, T. A. Hecht, P. M. Roth, and J. H. Sdnfeld. Urban Air Shed Photochemical Simulation Model Study. Vol. 1. Development and Evaluation. EPA-R4-73-030a. (Prepared for the Environmental Protection Agency) Beverly Hills, Calif. Systems Applications, Inc., 1973. 151 pp. 

Vikram B, Malamud S, Silverman P, Hecht H, Grabstald H. A pilot study of chemotherapy alternating with twice-a-day accelerated radiation therapy as an alternative to cystectomy in muscle infiltrating (stages T2 and T3) cancer of the bladder preliminary results. J Urol 1994 151 602-604. 

Penultimate effects have been observed for many comonomer pairs. Among these are the radical copolymerizations of styrene-fumaronitrile, styrene-diethyl fumarate, ethyl methacrylate-styrene, methyl methacrylate l-vinylpyridine, methyl acrylate-1,3-butadiene, methyl methacrylate-methyl acrylate, styrene-dimethyl itaconate, hexafluoroisobutylene-vinyl acetate, 2,4-dicyano-l-butene-isoprene, and other comonomer pairs [Barb, 1953 Brown and Fujimori, 1987 Buback et al., 2001 Burke et al., 1994a,b, 1995 Cowie et al., 1990 Davis et al., 1990 Fordyce and Ham, 1951 Fukuda et al., 2002 Guyot and Guillot, 1967 Hecht and Ojha, 1969 Hill et al., 1982, 1985 Ma et al., 2001 Motoc et al., 1978 Natansohn et al., 1978 Prementine and Tirrell, 1987 Rounsefell and Pittman, 1979 Van Der Meer et al., 1979 Wu et al., 1990 Yee et al., 2001 Zetterlund et al., 2002]. Although ionic copolymerizations have not been as extensively studied, penultimate effects have been found in some cases. Thus in the anionic polymerization of styrene t-vinylpyri-dine, 4-vinylpyridine adds faster to chains ending in 4-vinylpyridine if the penultimate unit is styrene [Lee et al., 1963]. 

NTl 71 Hecht, S. S., S. Carmella, H. Mori, and D. Hoffmann. A study of tobacco carcinogenesis. XX. Role of catechol as a major cocarcinogen in the weakly acidic fraction of smoke condensate. J Natl Cancer Inst 1981 66(1) 163-169. 

This study was supported by the National Cancer Institute Grant No. l-CP-55666 and CA-21393. Stephen S. Hecht is recipient of National Cancer Institute Research Career Development Award No. 5K04CA00124. 

Hoagland, M. B., M. L. Stephenson, J. F. Scott, L. I. Hecht, and P. Zamecnik, A soluble ribonucleic acid intermediate in protein synthesis. J. Biol. Chem. 231 241-257, 1958. Describes the pioneering tracer studies that chart the course of amino acid into polypeptide chain. 

Bell AF, Barron LD, Hecht L. Vibrational Raman optical activity study of D-Glucose. Carbohydrate Research 1994, 257, 11-24. 

Recently, Barron and Hecht (1993) wrote a review of the latest ROA studies on biomolecules. They summarized the work published in this field to date and emphasized the point that ROA should provide more insight into protein structure than VCD. This conclusion is drawn on the fact that it is easily possible to replace N-H by N-D and to note the spectral changes, thereby often simplifying the spectrum by the reduction of overlap. VCD is not that easily possible in H2O solution as normal water tends to obscure important parts of the IR spectrum, and there only the D2O results are more readily available. 

Fyfe, P. K., McAuley-Hecht, K. E., Ridge, J. P., Prince, S. M., Fritzsch, G., Isaacs, N. W., Cogdell, R. J., and Jones, M. R., 1998b, Crystallographic studies of mutant reaction centres from Rhodobacter sphaeroides. Photosynth. Res., 55 1339140. 

Although the sampling methodology of Falesi s chronosequence study has been criticized (see Hecht 1982), other studies considering the dynamics of soil fertility in pasture areas in the Amazon basin found similar results (Diez et al. 1991, Hecht 1982,... 

Hecht, S. B, 1982. "Deforestation in the Amazon Basin Magnitude, dynamics and soil resource effects." Studies in Third World Societies 13 61-101. 

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