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51.
52.
Oxidative cleavage of the C-20/C-21 bond in apoptolidin (1) provides two fragments of similar complexity, facilitating a divide-and-diversify strategy for the determination of the structural basis for apoptolidin's biological activity, the remarkably selective induction of apoptosis in sensitive cell lines. The ability of compounds derived from this cleavage to inhibit mitochondrial F(0)F(1)-ATPase is reported. [structure: see text] 相似文献
53.
[reaction: see text] Vinylsilanes are formed in high yields in the reaction of representative acyl(trimethyl)silanes with anions generated from Kocienski's sulfones. 相似文献
54.
The method of quasilinearization is a procedure for obtaining approximate solutions of differential equations. In this paper, this technique is applied to a differential-algebraic problem. Under some natural assumptions, monotone sequences converge quadratically to a unique solution of our problem. 相似文献
55.
We have performed the direct measurements of 13C magnetic shielding for pure liquid TMS, solution of 1% TMS in CDCl3 and solid fullerene. The measurements were carried out in spherical ampoules exploring the relation between the resonance frequencies, shielding constants and magnetic moments of 13C and 3He nuclei. Next the 13C shielding constants of glycine, hexamethylbenzene and adamantane were established on the basis of appropriate chemical shifts measured in the solid state. All the new results are free from susceptibility effects and can be recommended as the reference standards of 13C shielding scale in the magic angle spinning NMR experiments. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
56.
Krzysztof Jankowski Anna Jerzak Anna Sernicka-Poluchowicz Ludwik Synoradzki 《Analytica chimica acta》2001,440(2):67-221
A method for multielement determination of major elements in polymer additives by microwave induced plasma atomic emission spectrometry (MIP-AES) has been elaborated. Microwave digestion with nitric acid was selected for sample preparation because of its speed and versatility. Sodium nitrate was added to the digestion mixture in order to reduce phosphorus losses. The precision obtained varied between 2 and 4.5% depending on the element determined. The accuracy of the method was studied by analyzing the Spex 5-element oil standard. The method was applied to a variety of commercial and in-house prepared compositions. 相似文献
57.
Zuzana Cibulková Andrea Černá Peter Šimon Ján Uhlár Karol Kosár Peter Lehocký 《Journal of Thermal Analysis and Calorimetry》2012,108(2):415-419
The type of cooperation between antioxidants in the binary mixtures of four substituted diphenylamines and phenotiazine in
the stabilization of styrene-butadiene rubber has been tested. Thermooxidation of the samples has been studied by differential
scanning calorimetry under non-isothermal conditions. The protection factors of the individual stabilizers and their mixtures
were determined. The synergy factors were applied to asses the type of cooperation of antioxidants in the mixtures. From their
values it can be concluded that the type of cooperation depends on temperature. The highest synergistic effect has been observed
for the mixture of phenotiazine and [4-(1-methyl-1-phenyl-ethyl)-phenyl]-phenylamine. 相似文献
58.
59.
Karol Michalak 《Tetrahedron letters》2008,49(48):6807-6809
A functionalized hydroazulene derivative has been synthesized efficiently from 2-methylcyclopent-2-en-1-one as a part of a study oriented toward the total synthesis of diterpenoids of biological significance, guanacastepenes, and heptemerones. 相似文献
60.
W. D. Jankowski 《Fresenius' Journal of Analytical Chemistry》1935,100(5-6):211
Ohne Zusammenfassung 相似文献