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排序方式: 共有810条查询结果,搜索用时 10 毫秒
1.
E. N. Medvedeva N. A. Neverova T. E. Fedorova V. A. Babkin E. S. Meteleva A. V. Dushkin T. G. Tolstikova M. V. Khvostov M. P. Dolgikh 《Russian Journal of Bioorganic Chemistry》2010,36(7):853-859
It has been found by gel-penetrating chromatography and quantitative 13C NMR spectroscopy that mechanochemical processing of arabinogalactan isolated from the wood of the Siberian larch changes
the molecular mass distribution, monosaccharide composition, and the degree of branching of its macromolecules. This is due
to the partial destruction of polysaccharide macromolecules and subsequent recombination of resulting fragments. The intensity
of these processes depends on the conditions of mechanochemical processing. Based on the data of IR and 13C NMR spectra, the conclusion has been drawn that no functionalization of arabinogalactan macromolecules occurs under these
conditions. The toxicopharmacological properties of mechanically processed arabinogalactan have been studied. Its acute toxicity
is >5000 mg/kg. 相似文献
2.
The paper submits the results of studies on the kinetics of spermatogenous epithelium cell number after exposure to fast neutrons (60-300 cGy) and gamma-radiation (200-600 cGy). It was shown that a relative decrease in the quantity of spermatocytes is determined by an exponential dose-response curve with D0 of 35 and 120 cGy for neutrons and gamma-radiation respectively. For spermatides and spermatozoa a single D0 value of 20 and 55 cGy was obtained for neutrons and gamma-radiation respectively. As the radiation dose increases the recovery process in the epithelium is substantially decelerated. The equation T1/2 = T1/2(0)e0.0009D well describes the dependence of the half-recovery period T1/2 upon the equivalent dose. 相似文献
3.
L. A. Piruzyan V. A. Sukhanov E. V. Kalinina T. Yu. Fedorova A. N. Saprin 《Biology Bulletin》2002,29(2):115-119
We studied intraspecific features of the main enzymes of metabolism and detoxication of xenobiotics on mice (eight inbred lines) and rats (five lines) for estimation of possible variants of complete or incomplete metabolic equality. Significant genetically determined intraspecific differences for activities of the enzymes of metabolism and detoxication of xenobiotics were described. Generalized criteria for comparison of the metabolic status were proposed on the basis of activities of the main enzymes: cytochrome P-450 (hydroxylation and epoxidation), epoxyhydrolase, glutathione-S-transferase, UDP-glucuronosyl transferase, and sulfotransferase. The proposed criteria for estimation of the metabolic parameters of an individual can serve as a basis of metabolic portraiting. 相似文献
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The method of repeated irradiation has been used to study excision of 8-MOP monoadducts from plasmid and chromosomal DNA in cells of wild type and rad2 mutant of Saccharomyces cerevisiae. The measurement of kinetics of monoadduct removal from chromosomal DNA in intact and competent yeast cells showed that monoadducts were excised in both types of cells with normal repair, but this process was blocked in intact and competent cells of the rad2 mutant. The survival of pYF91 plasmid treated in vitro with 8-MOP plus near UV-light has been studied in the cells of the wild type and in incision-defective rad2 mutant by the measurement of cell transformation frequency. Episomic pYF91 plasmid used in these experiments contained the yeast nuclear LEU2 gene, a portion of 2 mkm DNA and DNA of bacterial plasmid pBR322 with resistance to ampicillin. The pYF91 plasmid was treated with 8-MOP plus near UV-light in vitro, then unbound 8-MOP was removed by dialysis. This DNA was used for transformation. The transformed yeast cells were irradiated repeatedly. The quantitative alteration of the yield of transformants, depending on the time of keeping these yeast cells in complete liquid medium at 30 degrees C, prior to repeated irradiation, allowed to measure the kinetics of monoadduct excision from plasmid DNA. It was shown that monoadducts were removed equally effectively from plasmid DNA introduced into cells of the wild type and rad2 mutant. Possibly, the repair system of both these strains provides excision of monoadducts from plasmid DNA, but this process is blocked in the rad2 mutant, relatively to monoadduct excision from chromosomal DNA. 相似文献
7.
B V Rozynov G B Fedorova O S Reshetova G S Katrukha V N Borisova 《Antibiotiki i khimioterapii͡a》1988,33(6):420-426
Antibiotic 308-I isolated from Actinomadura recticatena and the products of its degradation were studied with the methods of electron impact mass spectrometry, chemical ionization with ammonia, field desorption and ion extraction from solution under atmospheric pressure. It was shown that by its composition and structure antibiotic 308-I was identical to antibiotic BBM-928 A. 相似文献
8.
A L Ksenofontov N V Fedorova S E Glushakova 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1992,(3-4):3-6
The schemes for preparative electrophoretic isolation and purification of major proteins from influenza virus are described. The viral envelope protein, hemagglutinin, two of its subunits, internal M and NP proteins of influenza viruses A/FPV/Rostock (H7N1), A/PR/8/34 (H1N1) and X-31 (H3N2) were obtained in preparative amounts and characterized by amino acid and N-terminus analyses. 相似文献
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The reaction of males of Aedes diantaeus to different auditory stimuli was studied in natural environment during swarming and under laboratory conditions. The males were attracted by 250-420 Hz that corresponds to the main frequencies of flight tones of sympatric females and the range of sensitivity of male Johnston's organs. Behavioural data show that in natural environment swarming males are attracted by flying conspecific and heterospecific females rather than by dead or immobilized females. Contact with heterospecific females always ended in parting of mosquitoes while contact with cospecific females resulted in pairing. Thus, swarming males of Aedes diantaeus localize females by their flight tones but recognize the females of their own species in contact. 相似文献