首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   71篇
  免费   1篇
  2020年   1篇
  2019年   3篇
  2018年   3篇
  2016年   5篇
  2015年   2篇
  2014年   4篇
  2012年   3篇
  2011年   2篇
  2009年   3篇
  2008年   5篇
  2007年   3篇
  2006年   2篇
  2004年   4篇
  2003年   4篇
  2002年   8篇
  2001年   10篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1993年   1篇
  1992年   1篇
  1986年   1篇
  1970年   1篇
  1966年   1篇
  1965年   1篇
  1950年   1篇
排序方式: 共有72条查询结果,搜索用时 46 毫秒
51.
52.
Nei's coefficient of genetic differentiation (Gst) was used to estimate the intergroup differentiation of four ethnic geographic groups of Bashkirs and the interethnic differentiation of seven ethnoses (Bashkirs, Tatars, Chuvashes, Udmurts, Maris, Komis, and Mordovians) from the Volga-Ural region. The coefficient of genetic differentiation calculated from data on four polymorphic loci (MET, D7S23, PKU, and apoB) and classical biochemical markers (AB0, MN, Rh, Hp, and AcP) of the nuclear genome was similar in all tested populations. The genetic difference between the ethnoses from the Volga-Ural region (Gst = 1.91%) was intermediate between that in European (Gst = 1.18%) and Siberian (Gst = 5.84%) ethnoses.  相似文献   
53.
In cell suspension of Desulfovibrio desulfuricans B-1388, oxidation of CO as the only energy source is associated with reduction of SO42-. After a 2-h incubation of cells in 8% CO, 81% of the gas is converted. Oxidation of 1 mole CO results in formation of 0.23 mole H2S. Intracellular ATP content increases from 2.5 (control) to 8.3 nmoles/mg (during CO conversion). Dinitrophenol inhibits sulfate reduction and CO oxidation. CO dehydrogenase was detected in cytoplasmic and membrane cell fractions (59 and 34%, respectively).  相似文献   
54.
Multiple sclerosis (MS) is a multifactorial disease of the central nervous system. The apolipoprotein E (APOE) and interleukin 1 β (IL1B) genes are considered to be candidate genes of MS. The aim of the study was to examine the hypothesis of the importance of APOE and IL1B gene polymorphisms in MS development in ethnic Tatars. DNA samples isolated by phenol-chloroform extraction from peripheral blood of 383 ethnic Tatars (120 MS patients and 263 healthy donors) were studied. 112C/R and 158R/C APOE gene polymorphisms as well as ?511T/C IL1B gene polymorphism were analyzed by polymerase chain reaction (PCR) followed by PCR product digestion by endonuclease. Odds ratio (OR) values were used for evaluation of the relative risk of alleles and(or) genotype combinations. It has been shown that APOE*2/*3 genotype is associated with low risk of the disease development (OR = 0.20) in women. A combined effect of APOE and IL1B allelic variants has been discovered indicating the increased risk of the disease development in the carriers of APOE*4 and IL1B*T/*T alleles (OR = 4.76).  相似文献   
55.
Polymorphism at the apolipoprotein E gene (apoE) in populations of the Volga–Ural region was studied by means of polymerase chain reaction. In the region examined the population-specific patterns of the apoE alleles and genotypes frequency distribution were established. The results obtained were compared with the literature data on the apoE polymorphism in other world populations. Substantial heterogeneity of different ethnic populations in respect to the apoE genotypes distribution and frequency was revealed.  相似文献   
56.
The apolipoprotein E (ApoE) gene polymorphism resulting from nucleotide substitutions in exon 4 was analyzed in Russian and Tatar patients with myocardial infarction (MI) from Bashkortostan. Alleles 2, 3, and 4 were identified by PCR. The genotype frequency distribution proved to be age-dependent in healthy Russians, genotype 2/3 increasing in frequency in subjects over 45. Russians who suffered MI under 45 had lower frequencies of genotype E3/3 (50.00% vs. 75.47% in controls of the same age, = 0.013, OR = 0.33) and allele 3 (72.12% vs. 85.85%, = 0.020, OR = 0.43) and a higher frequency of allele 4 (22.12% vs. 10.38%, = 0.030, OR = 2.45). Russians who suffered MI complicated by cardiogenic shock (CS) had a significantly higher frequency of genotype 3/4 and lower frequencies of genotype 3/3 and allele 3 as compared with MI patients without CS. In Tatars, genotype 4/4 occurred at a frequency of 14.29% in patients who suffered MI under 45, and was not detected in healthy subjects of the same age ( = 0.024, OR = 17.85). Thus, the ApoE polymorphism was associated with higher risk of MI in Russians and Tatars under 45.  相似文献   
57.
58.
Triterpene saponins, glycoside analogues of glycyrrhizic acid with a modified carbohydrate chain containing monosaccharide residues attached through ester bonds, were synthesized. To this end, peracetylated glycyrrhizic acid or its 30-methyl ester were glycosylated by 2,3,4,6-tetra-O-acetyl-alpha-D-gluco-or-alpha-D-galactopyranosyl bromide in dichloroethane in the presence of Ag2CO3. Glycerrhetinic acid saponin with D-Galp residues exhibited a higher antiulcer activity than glycyrrhizic acid in rats at a dose of 25 mg/kg. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol. 29, no. 6; see also http://www.maik.ru.  相似文献   
59.
The effects of insufficient and excessive mineral nutrition on the relative growth rate (RGR); the rate of total dark respiration (R); gross photosynthesis (Pg); and the contents of endogenous IAA, ABA, and cytokinins (CK) were studied in 20–60-day-old seedlings of plant species that differed in their responses to these factors: beet root (Amaranthus retroflexusL.), orchard-grass (Dactylis glomerataL.), and common wheat (Triticum aestivumL.). The changes in the level of mineral nutrition lowered the RGR and Pgvalues and the IAA/ABA and CK/ABA ratios and increased the Rand R/Pgvalues and ABA content, especially in A. retroflexusand T. aestivum. The authors propose a new way to assess the respiratory cost of adaptation to stress based on the relation between the RGR and the R/Pgvalues. The adaptation component of Ris shown to relate to the ABA content.  相似文献   
60.
A mutation of wing fragility that was not yet been revealed in adult housefly is described. Criss-cross inheritance of the character of fragility of the wing blade, which indicates localization of gene (fw) for this character in the X chromosome. Phenotypic expression of the mutant allele depends on sex. In male flies, the mutant allele in hemizygous state is expressed at the age of 2-3 weeks and older with penetrance close to 100%. In females, the mutant allele in homozygous state is lethal and in heterozygous state, totally recessive.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号