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   4150篇
  免费   513篇
  国内免费   2篇
  2021年   38篇
  2020年   40篇
  2019年   76篇
  2018年   61篇
  2017年   37篇
  2016年   68篇
  2015年   92篇
  2014年   108篇
  2013年   178篇
  2012年   193篇
  2011年   181篇
  2010年   110篇
  2009年   100篇
  2008年   186篇
  2007年   166篇
  2006年   158篇
  2005年   153篇
  2004年   147篇
  2003年   110篇
  2002年   139篇
  2001年   124篇
  2000年   124篇
  1999年   99篇
  1998年   58篇
  1997年   49篇
  1996年   63篇
  1995年   61篇
  1994年   49篇
  1993年   48篇
  1992年   100篇
  1991年   80篇
  1990年   64篇
  1989年   85篇
  1988年   99篇
  1987年   83篇
  1986年   66篇
  1985年   106篇
  1984年   84篇
  1983年   73篇
  1982年   46篇
  1981年   42篇
  1980年   37篇
  1979年   55篇
  1978年   64篇
  1976年   40篇
  1975年   43篇
  1974年   43篇
  1973年   51篇
  1971年   44篇
  1969年   39篇
排序方式: 共有4665条查询结果,搜索用时 93 毫秒
91.
A high resolution, two-dimensional (2-D) electrophoretic map of the plasma membrane (PM) polypeptides from the ejaculated boar spermatozoon is described. 2-D silver-stained polyacrylamide gel electrophoresis (PAGE) gels revealed over 250 polypeptides; Coomassie blue staining revealed more than 100. Fifty Coomassie-staining polypeptides were catalogued and biochemically characterized, with twenty of these designated major sperm PM polypeptides. Cavitation pressures ranging from 50 PSI to 1000 PSI were used to enrich 2-D maps either in head PM (50 PSI) or in flagellar PM (1000 PSI) and provided tentative localization of certain PM polypeptides. Immunoabsorption chromatography showed that most major polypeptides seen in the 2-D map were antigenic. Major polypeptide bands from single dimensional (1-D) gels were excised, antibodies against them were produced in rabbits, and the polypeptides were localized via indirect fluorescein isothiocyanate (FITC) technique. Cross-reacting antigenic determinants in the PAGE PM polypeptides were determined by transblotting and staining the transblots by an indirect peroxidase technique. Cross-reactivity was extensive with several polypeptide groups, but specific enough with others to allow tentative localization. Lectin affinity chromatography using Con A, WGA, RCA-1, PNA, and DBA indicated the lectin specificity of PM polypeptides. These data together with periodic acid-Schiff (PAS) and carbohydrate-specific silver staining permitted identification of glycoproteins in the 2-D maps. FITC coupled to specific lectins showed the regional distribution of these lectins on the sperm surface. The 2-D polypeptide map and the catalogue of properties of major Coomassie-stained PM polypeptides provides a reference for future studies in the boar and other species.  相似文献   
92.
93.
We have isolated and sequenced the complete murine I-E alpha immune response gene of the H-2db haplotype. The I-E alpha d gene consists of 5300 basepairs and is organized into five or possibly six exons that correspond to different domains of the alpha chain. The amino acid sequence deduced from the I-E alpha gene shows 75% homology to its human counterpart, the HLA-DR alpha chain. The absence of I-E antigen in H-2 mice is due to lack of E alpha chain synthesis. We show here that this defect is caused by a deletion in the 5' end of the I-E alpha b gene.  相似文献   
94.
A technique is described for determination of rubella hemagglutination-inhibiting antibody in only 50 to 100 muliters of whole blood.  相似文献   
95.
The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES (N-2-hydroxyethylpiperazine N'-2'-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test.  相似文献   
96.
97.
Ribonucleic Acid Synthesis in Bacteria Treated with Toluene   总被引:10,自引:6,他引:4       下载免费PDF全文
Escherichia coli and Bacillus megaterium rendered permeable to ribonucleoside triphosphates by toluene treatment retain the capacity to synthesize discrete ribonucleic acid species.  相似文献   
98.
99.
100.
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