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131.
V. V. Aleksandrov A. V. Branitskii G. S. Volkov E. V. Grabovskii M. V. Zurin S. L. Nedoseev G. M. Oleinik A. A. Samokhin P. V. Sasorov V. P. Smirnov M. V. Fedulov I. N. Frolov 《Plasma Physics Reports》2001,27(2):89-109
Prolonged plasma creation in heterogeneous liners, in which the liner substance is separated into two phase states (a hot plasma and a cold skeleton), is investigated both experimentally and theoretically. This situation is typical of multiwire, foam, and even gas liners in high-current high-voltage facilities. The main mechanisms governing the rate at which the plasma is created are investigated, and the simplest estimates of the creation rate are presented. It is found that, during prolonged plasma creation, the electric current flows through the entire cross section of the produced plasma shell, whose thickness is comparable with the liner radius; in other words, a current skin layer does not form. During compression, such a shell is fairly stable because of its relatively high resilience. It is shown that, under certain conditions, even a thick plasma shell can be highly compressed toward the discharge axis. A simplified numerical simulation of the compression of a plasma shell in a liner with prolonged plasma creation is employed in order to determine the conditions for achieving regimes of fairly compact and relatively stable radial compression of the shell. 相似文献
132.
I/D polymorphism in the angiotensin-converting enzyme gene in men with myocardial infarction at young age] 总被引:1,自引:0,他引:1
O A Berkovich E A Bazhenova E A Volkova M Z Alugishvili I O Kiselev B I Smirnov E I Shvarts E V Shliakhto 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2001,87(5):642-648
The rate of D allele did not differ between patients with ischemic heart disease (IHD) who had myocardial infarction before the age 45, and healthy males. The DD genotype of the ACE gene was much more frequently encountered in the patients than in healthy males. The findings suggest that the DD genotype is an independent risk factor of the IHD and myocardial infarction in young patients. 相似文献
133.
The mitotic indices, villus heights, and crypt depths were determined in each of three jejunal regions (proximal, middle, and distal) for five animals each in the flight, vivarium, and synchronous groups. Because of the rapid turnover of intestinal mucosal cells and the delay in recovering the flight animals, it is not known whether the proliferation of jejunal mucosal cells is affected by microgravity conditions associated with spaceflight. However, since there were no consistent differences between animals in the flight group and those in the synchronous and vivarium control groups, it appears that any effects of microgravity on the turnover of jejunal mucosal cells are short-lived. Thus, this study represents an initial step in determining the effects of microgravity on the proliferation and turnover of intestinal mucosal cells. 相似文献
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136.
Four mutations were studied which lead to increasing the frequency of transposon Tn1 translocation into different replicons. These mutations (het1, het2, het3 and het4) increase the frequency of Tn1 translocation 10-20-fold. The het1 mutation is recessive and has been localized in the 90-94.5 min region of the bacterial chromosome. The mutation effects Tn1 transposition in the presence of F plasmid only. As we have demonstrated recently, F-plasmid inhibits Tn1 transposition in Escherichia coli cells. The het1 mutation eliminates this inhibition. Unlike het2, het3 and het4 mutations, het1 is responsible for resistance to male phages f1, f2, MS2 and inhibition of conjugative transfer in F+ bacteria. 相似文献
137.
138.
G A Kochetkov S G Smirnov S Ia Savranskaia I M Gruber 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1977,(9):123-127
The content of trace elements in the cells served as one of the characteristics of physiological condition of the population. The character of the changes in the trace elements content depending on the rate of the microbial multiplication pointed to the importance of the mineral sources of nutrition for the development of the cells analyzed. 相似文献
139.
Estrophilic forms of rabbit liver cytosolic hydroxysteroid-dehydrogenase (HSD) were obtained as a highly purified preparations by means of fractionation with ammonium sulfate, gel-filtration, ion-exchange chromatography on DEAE-Sephadex A-50, affinity chromatography on estradiol-Sepharose and ion-exchange chromatography on DEAE-Toyopearl 650M. The protein express 4 different kinds of NADP-dependent activities: 3 alpha, 3 beta- and 17 beta-HSD activities with androgens and 20 alpha-HSD with progesterone as substrates. Revealed multiplicity of HSD enzymatic activity is demonstrated here for the first time. 17 beta-HSD activity of the protein preparations with estradiol is extremely low. Absence of a real metabolic activity of the protein with a ligand interacting with it rather intensively suggests that the isolated HSD forms can act not only as an enzyme, but also as a buffer-reserving mechanism for some steroids. 相似文献
140.
Horst Will Tatyana S. Levchenko Dmitri O. Levitsky Vladimir N. Smirnov Albert Wollenberger 《Biochimica et Biophysica Acta (BBA)/General Subjects》1978,543(2):175-193
Pigeon heart microsomes contain three minor size protein kinase substrates of minimal molecular weights of 22 000, 15 000, and 11 500, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. When the microsomes were partially loaded with calcium oxalate and subjected to rate zonal and isopynic centrifugations in sucrose density gradient columns, the 22 000 and the 15 000 dalton proteins settled in the heaviest fraction, which was composed mainly of vesicles of sarcoplasmic reticular membranes; the 11 500 dalton protein was concentrated in the lightest fractions, which consisted chiefly of vesicles of sarcolemmal origin. During incubation of the membrane fractions with Mg[γ-32P]ATP significant amounts of 32P were incorporated into all these proteins. Incorporation of 32P into the 15 000 dalton protein was moderately and 32P incorporation into the 22 000 dalton protein was markedly enhanced in the presence of exogenous soluble cyclic AMP-dependent protein kinase and cyclic AMP. The phosphorylation of the three proteins was virtually unaffected by CA2+ concentrations up to 0.1 mM and by ethyleneglycol-bis(β-aminoethylether)-N,N′-tetraacetic acid in the absence of added Ca2+.Phosphorylation of the 22 000 and the 11 500 dalton proteins occurred mainly at serine residues. In the 15 000 dalton protein threonine residues were the main site of endogenous phosphorylation. Nearly equal amounts of [32P]-phosphate were incorporated into threonine and serine residues of this protein when phosphorylation was supported by exogenous cyclic AMP-dependent protein kinase and cyclic AMP.The 15 000 dalton protein could be removed from its membrane attachment by extraction with an acidic chloroform/methanol mixture. This step opens the way for the purification of this membrane-bound protein kinase substrate. 相似文献