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   1484篇
  免费   90篇
  国内免费   1篇
  1575篇
  2022年   21篇
  2021年   32篇
  2020年   19篇
  2019年   25篇
  2018年   32篇
  2017年   35篇
  2016年   51篇
  2015年   51篇
  2014年   68篇
  2013年   78篇
  2012年   94篇
  2011年   94篇
  2010年   57篇
  2009年   56篇
  2008年   63篇
  2007年   69篇
  2006年   49篇
  2005年   66篇
  2004年   44篇
  2003年   35篇
  2002年   27篇
  2001年   17篇
  2000年   24篇
  1999年   23篇
  1997年   7篇
  1993年   6篇
  1992年   17篇
  1991年   25篇
  1990年   24篇
  1989年   30篇
  1988年   17篇
  1987年   19篇
  1986年   19篇
  1985年   21篇
  1984年   15篇
  1983年   18篇
  1982年   13篇
  1981年   10篇
  1980年   22篇
  1979年   24篇
  1978年   11篇
  1977年   14篇
  1976年   15篇
  1975年   14篇
  1974年   20篇
  1973年   10篇
  1972年   10篇
  1971年   12篇
  1970年   9篇
  1969年   9篇
排序方式: 共有1575条查询结果,搜索用时 0 毫秒
31.
Recent studies in our laboratory using the Zucker obese (ZO) and Zucker diabetic fatty (ZDF) rat models resulted in unexpectedly high mortality rates in all genotypes including healthy homozygous lean Zucker rats, possibly because of renal dysfunction. Therefore, we evaluated left ventricular (LV) and kidney morphology and function in young ZO, Zucker diabetic fatty obese (ZDFO), homozygous Zucker/ZDF lean (ZL), and Sprague-Dawley (SD) rats. Hydronephrosis was evident in ZL, ZO, and ZDFO but not SD kidneys. ZDFO rats exhibited impaired LV shortening and relaxation with increased arterial stiffness. LV wall thickness was lower and LV end-systolic wall stress was higher in ZDFO compared with SD rats. Plasma ANG II was lower in ZO and ZDFO rats, which may be a result of reduced renal parenchyma with hydronephrosis; norepinephrine was higher in ZDFO rats than SD controls. Covariate analysis indicated that LV end-systolic wall stress was associated with renal dysfunction. The presence of hydronephrosis and its association with LV dysfunction potentially limits the ZDF model for study of the effects of diabetes on renal and cardiovascular function.  相似文献   
32.
Numerous experimental techniques and computational studies, proposed in recent times, have revolutionized the understanding of protein-folding paradigm. The complete understanding of protein folding and intermediates are of medical relevance, as the aggregation of misfolding proteins underlies various diseases, including some neurodegenerative disorders. Here, we describe the unfolding of M-crystallin, a βγ-crystallin homologue protein from archaea, from its native state to its denatured state using multidimensional NMR and other biophysical techniques. The protein, which was earlier characterized to be a predominantly β-sheet protein in its native state, shows different structural propensities (α and β), under different denaturing conditions. In 2 M GdmCl, the protein starts showing two distinct sets of peaks, with one arising from a partially unfolded state and the other from a completely folded state. The native secondary structural elements start disappearing as the denaturant concentration approaches 4 M. Subsequently, the protein is completely unfolded when the denaturant concentration is 6 M. The 15N relaxation data (T1/T2), heteronuclear 1H-15N Overhauser effects (nOes), NOESY data, and other biophysical data taken together indicate that the protein shows a consistent, gradual change in its structural and motional preferences with increasing GdmCl concentration.  相似文献   
33.
Diethylcarbamazine (DEC) reacted with liver cell plasma membrane of rodent hosts-cotton rat, albino rat and Mastomys natalensis exhibiting the presence of both saturable and unsaturable components. The presence of lectins or sugar derivatives did not affect the binding significantly. The drug showed similar binding pattern with serum but the saturation was reached at a much lower concentration of the ligand. Data obtained with a variety of macromolecules, particularly with the homopolymers of amino acids indicate that DEC does not require any specific constituent of the membrane for binding. The nonspecific nature of DEC binding does not provide any convincing clue for the accumulation of microfilariae specifically in the liver following the drug treatment.  相似文献   
34.
Mycopathologia - In experimental models, the expression of glucose-regulated protein 78 (GRP78) in endothelial cells played a role in the pathogenesis of mucormycosis. However, the role of GRP78 in...  相似文献   
35.
Summary Genotyping of mitochondrial aldehyde dehydrogenase (ALDH I) was performed in enzymatically amplified DNA of 20 Chinese, Japanese and South Korean families (85 individuals) and in 113 unrelated persons by employing allele-specific oligonucleotide probes and dot blot hybridization. Genotyping individuals with phenotypic deficiency of ALDH I activity always showed the presence of at least one mutant allele. The data are compatible with a model assuming dominant inheritance of the mutant allele, which we have previously suggested on the basis of a population study.  相似文献   
36.
37.
Summary A total of 168 autopsy liver extracts from Japanese individuals were examined for the glutathione S-transferase (GST) isozymes by means of starch gel electrophoresis. The gene frequencies of GST1*1, GST1*2, and GST1*0 in Japanese were 0.252, 0.057, and 0.691, respectively. GST1*3 was detected as a rare variant allele. The incidence of GST1 0 in 41 liver biopsy samples from patients suffering from various liver diseases was investigated using polyacrylamide gel isoelectric focusing. The GST1 0 phenotype was found more frequently in livers with hepatitis and carcinoma than in control livers. The isozymes coded by different GST loci were partially purified and characterized to study their biochemical properties. The apparent Km values with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate for the isozymes at the GST1, GST2, GST3, and GST4 loci were 604, 1345, 776 and 591 M, respectively.  相似文献   
38.
Short tandem repeats are highly polymorphic sequences of nucleotides, which are abundant in eukaryotic genome. They form approximately 3% of the total human genome and occur on average in every 10, 000 nucleotides. Due to their small dimension, low mutation, and high level of polymorphism, these markers are intensely used as important genetic markers for mapping studies, disease diagnosis, and human identity testing. In the present study allelic distribution of four autosomal short tandem repeat markers (D21S2055, D21S11, D21S1435 and D21S1411) has been analyzed in Indian population. For determination of heterogeneity and their allelic frequency QF-PCR analysis have been done. All the loci were found highly polymorphic. Marker D21S1411 was the most informative (93.6%) and D21S1435 (70.1%) was the least informative marker in Indian population.  相似文献   
39.
40.
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