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21.
22.
Была высказана гипотеза, что биосинтез гризеофульвине, цитромицетина, фульвиновой кислоты, фусаeубине, руброфусарина и родствеооых им вешеств протекаеР не путем конденсации линейнон цепочки, а из двух более коротких цепочек, которые возникают конденсацией 4 и 3 ацетатных единп. реакции, осушествляющиеся на уровне этих цапочек (илн прнмежувочных структур) метиляция, редукция, и, возможно, последующая дегидратация или только эноэизация— определяют направление дальнeйшeй кондeнсации в такой стeпeни, что конeчныe продуктыотдичаются своeй структурой. 相似文献
23.
International Journal of Biometeorology - 相似文献
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I Grys M Dudziak W Piechota W Rózański M Su?ek M Adamczyk-Szymańska 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1990,45(49-50):984-986
The study involved 126 patients with cholelithiasis. Set of biochemical, radiological, endoscopic, and ultrasound examinations was carried out in these patients. Potential coincidence of clinical symptoms and causes of so-called postcholecystectomy syndrome was the purpose of a 1-year follow-up studies. The significance of the results are discussed. 相似文献
26.
Variability of entrainment of cohesive sediments in freshwater 总被引:6,自引:0,他引:6
Estimates of sediment entrainment are required for models of particle transport in lakes and estuaries but are difficult to make because of the multiplicity of factors affecting cohesiveness of surficial sediments. We present results of sediment resuspension studies performed in an annular flume calibrated with laser-Doppler velocimetry. In our experiments, using sediments collected from two sites in the R. Raisin which flows into L. Erie and from one site in the western basin of L. Erie near the mouth of the R. Raisin, we applied shear stresses at the sediment-water interface in steps from 2 to 12 dyne/cm2. Percent water content at the surface of the sediments was either 77 or 74%, and trials were run with and without oxygenating the water overlying the sediments. Entrainment rates as a function of shear stress at the sediment-water interface were best described by a power-law relationship. All but 14% of the variability in the power law expression was due to shear stress and percent water content; the variability not accounted for was due to differences in particle size distributions, chemical properties, and biological activity in the sediments. 相似文献
27.
Three fluorescent probes, tetramethyl rhodamine ethyl ester (TMRE), 3,3′-dipropylthiacarbocyanine iodide (diS-C3(3)) and 3,3′-dipropyloxacarbocyanine iodide (diO-C3(3)), were tested for their suitability as fluorescent indicators of membrane potential inSaccharomyces cerevisiœ in studies performed by flow cytometry. For all these dyes the intensity of fluorescence of stained cells increased with
probe concentration in the range of 60–3000 nmol/L. The optimum staining period was 15–20 min for diS-C3(3). Depolarization of cells by increased extracellular potassium level and by valinomycin elicited with all probes a drop
in fluorescence intensity. In some yeast batches this depolarization was accompanied by a separation of subpopulations with
different fluorescence properties. 相似文献
28.
Nikola Stojšin 《Dialectical Anthropology》1996,21(3-4):363-377
Conclusion This outline of the instrumentality of the technology/technique of representation in postcommunist Serbia is but a brief attempt to address the modes of production of identity in postmodernism, its legitimation in/of dominant discourse, and their embedding in common sense language and practice. Postcommunist Serbia is obviously a special situation:23 a particular case of the social appropriation and construction of enjoyment and desire, intimately related to the desires and various enjoyments of the members of the community, precarious in its collective affirmation. Based on the idea of contingent collectivity, faction-fiction, in its meta-critique seems to signal the emergence of a new régime in the relation between historical reality and its representation in historical narratives.This new régime, obviously, cannot be exhaustively (or even extensively) discussed in a brief paper like this one. Nevertheless, some (three) points of departure for the general discussion of postmodern modes of representation are still possible. One such point of departure is the contingence of representation, another the apparent paradigmatic similarity between trash talk-shows and Echoes and Reactions. And finally, much of iek's discussion does not seem to be restricted to the totalitarian metanarrative, and can be a significant contribution to the debate on power relations.Nikola Stojin is a Serbian Writer and Graduate Student in Comparative Literature at Rutgers University, New Brunswick, New Jersey. 相似文献
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Exploratory data analysis based on multivariate statistical analysis techniques was introduced as a new approach to expressing
the toxicity of chemical substances at the simultaneous acceptance of various cell models. Using principal component analysis
and cluster analysis methods the toxicity of chlorinated phenol derivatives on employing some of the cell models (chlorococcal
algae, cyanobacteria, bacteria, micromycetes, plant and animal cells) was characterized. The previous empirical experience
that the toxicity of chlorinated phenol derivatives will increase with a growing degree of chlorination and that the presence
of the methoxy group will cause a lowering of the toxic effect was demonstrated. The relationship between groups of tests
used was presented. 相似文献