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Bernd M. Rode Michael G. Schwendinger Sirirat U. Kokpol Supot V. Hannongbua Supa Polman 《Monatshefte für Chemie / Chemical Monthly》1989,120(11):913-921
Summary Linear models for the relation between electronic structure and antimalarial activity of chloroquine drugs have been investigated, based on CNDO/2 molecular orbital calculations. The results indicate that changes in electron density on the atoms N1, N2, C4, C9, and C10 have the strongest influence on the pharmacological activity, so that these atoms can be assumed to form the main active center of these drugs. Correlations improve, if substitution on the nucleus of chloroquine and side chain variations are treated separately. The models found seem to be a useful tool for designing new drugs within the chloroquine series.
Quantenchemisch-pharmakologische Untersuchungen von Antimalaria-Wirkstoffen
Zusammenfassung Auf der Basis von CNDO/2-Rechnungen wurden lineare Modelle für die Relation zwischen Elektronenverteilung und der Antimalaria-Aktivität von Chlorochinen untersucht. Es zeigte sich, daß Veränderungen in den Elektronendichten der Atome N1, N2, C4, C9 und C10 den stärksten Einfluß auf die pharmakologische Wirkung haben. Es kann somit angenommen werden, daß diese Atome die hauptsächlich aktiven Zentren der Verbindung sind. Die Korrelation wird verbessert, wenn die Substitution am Chlorochin-Kern und Variationen der Seitenketten separat behandelt werden. Die aufgefundenen Modellvorstellungen sollten ein nützliches Werkzeug zur gezielten Synthese neuer Wirkstoffe innerhalb der Chlorochin-Reihe darstellen.相似文献
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Uses of the numerical radius in the analysis of basic iterative solution methods, of the SOR method for quasi-Hermitian positive definite matrices (not being consistently ordered) and of maximal eigenvalues of symmetric positive definite matrices using incomplete block-matrix factorizations are presented. 相似文献
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Isoperimetric inequalities are applied to a moving-boundaryproblem for doubly-connected domains. This problem occurs forexample in electrochemistry, in which case the domains in questionare the electrolyte of an electrolytic cell. The two electrodessurrounding the electrolyte are assumed to grow or dissolve,at different rates in general, by electrochemical reaction.We obtain optimal estimates showing, for example, that the leastchange in volume of each electrode always occurs in sphericalsymmetry. 相似文献
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S. Coffa S. Lombardo F. Priolo G. Franzó S. U. Campisano A. Polman G. N. van den Hoven 《Il Nuovo Cimento D》1996,18(10):1131-1148
Summary In this work we demonstrate that efficient light emission at 1.54 μm can be achieved when Er ions are incorporated into crystalline
Si or in heavily oxygen-doped amorphous and polycrystalline Si films (SIPOS). We have found that temperature quenching of
photo- and electroluminescence, which is the major limitation towards the achievement of room temperature luminescence, can
be strongly reduced by codoping these films with oxygen. This impurity is already present in as-prepared SIPOS and it is introduced
by ion-implantation in crystalline Si. Er luminescence is obtained under both optical and electrical excitation and we demonstrate
that excitation occurs through a carrier-mediated process. Electrical excitation is obtained by incorporating Er in properly
designed device structures. It is found that this excitation can occur both through the recombination of hole-electron pairs
and through impact excitation of the Er ions by hot electrons. These two mechanisms have different efficiencies and impact
excitation is shown to prevail at room temperature. These data are presented and possible future developments are discussed.
Paper presented at the III INSEL (Incontro Nazionale sul Silicio Emettitore di Luce), Torino, 12–13 October 1995. 相似文献
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A van der Horst P N de Goede H A van Diemen C H Polman H J Martens 《Journal of chromatography. A》1992,574(1):166-169
An assay for the determination of 4-aminopyridine in serum has been developed using 3,4-diaminopyridine as internal standard and reversed-phase high-performance liquid chromatography with detection at 244 nm. A mobile phase of acetonitrile-methanol-ethanol-1% ammonium carbonate (75:10:10:5) provided excellent separation of both compounds. Samples were extracted on solid-phase columns. The linearity, precision, recovery and the limit of detection were all sufficient for the routine use of this assay in clinical studies of patients treated with 4-aminopyridine. 相似文献
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Polman James K. Breckenridge Cynthia R. Dugan Patrick R. Quigley David R. 《Applied biochemistry and biotechnology》1991,(1):487-494
Applied Biochemistry and Biotechnology - 相似文献