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   12377篇
  免费   1210篇
  国内免费   2篇
  2023年   59篇
  2021年   269篇
  2020年   185篇
  2019年   193篇
  2018年   227篇
  2017年   201篇
  2016年   325篇
  2015年   545篇
  2014年   582篇
  2013年   720篇
  2012年   917篇
  2011年   844篇
  2010年   528篇
  2009年   492篇
  2008年   676篇
  2007年   634篇
  2006年   576篇
  2005年   502篇
  2004年   491篇
  2003年   399篇
  2002年   439篇
  2001年   196篇
  2000年   219篇
  1999年   186篇
  1998年   127篇
  1997年   95篇
  1996年   92篇
  1995年   88篇
  1994年   64篇
  1993年   65篇
  1992年   165篇
  1991年   138篇
  1990年   174篇
  1989年   121篇
  1988年   117篇
  1987年   121篇
  1986年   110篇
  1985年   109篇
  1984年   91篇
  1983年   66篇
  1982年   100篇
  1981年   86篇
  1980年   79篇
  1979年   92篇
  1978年   83篇
  1977年   82篇
  1976年   60篇
  1975年   75篇
  1973年   64篇
  1972年   58篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
The review focuses on the multiple separating regimes that offers the free flow electrophoresis technique: free flow zone electrophoresis, isoelectric focusing, isotachophoresis, free flow step electrophoresis. Also, the feasibility to apply either interval or continuous flow electrophoresis is evaluated. The free flow zone electrophoresis regime is generally selected for the separation of cells, organelles and membranes while the other regimes find their largest fields of applications in the purification of proteins and peptides. The latter regimes present the highest resolution efficiency. Therefore, a large part of this review is devoted to the applicabilities of these different regimes to the purification of organelles and membrane vesicles at the preparative scale. Recent developments, both in instrumentation and procedures, are described. The major achievements in plant membrane fractionation obtained with free flow electrophoresis are outlined. The related procedures are both analytical and preparative: they separate tonoplast and plasma membrane simultaneously from the same homogenate, they discriminate for one type of membrane vesicles of opposite orientation, and process large quantities of membrane material by reason of the continuous flow mode. Recent advances using electromigration techniques that permit confirmation of the dynamic state of membranes, characterisation of complex membrane-dependent functions and discovery of new membrane-localised activities are presented.  相似文献   
3.
J L Weber  E Cutz 《CMAJ》1980,123(2):112-117
  相似文献   
4.
Quantitative histology of the hypertrophied human heart   总被引:1,自引:0,他引:1  
Myocardial hypertrophy accompanies systemic hypertension and aortic stenosis, i.e., pressure overload. In man cardiac failure only appears after years of pressure overload, during which time cardiac function had been maintained. The structural correlates of cardiac failure have been a subject of much interest for many years. Several hypotheses relating alterations in muscle fiber alignment, capillary density, or collagen content have been offered. The application of morphometric techniques has provided essential quantitative information on the structural components of the normal and diseased heart. These data indicate that muscle fiber alignment remains normal in the pressure overloaded heart despite the presence of hypertrophy or the appearance of clinical failure. On the other hand, capillary density is decreased and collagen content is increased in hypertrophied hearts. Chemical studies on collagen concentration however have yielded inconsistent results. The relative contribution of the microcirculation and collagenous structure of the myocardium on its respective O2 availability, mechanical behavior, and deterioration in pump function will require further investigation.  相似文献   
5.
6.
Applications of Genome Polymorphism Scans range from the relatively simple such as gender determination and confirmation of biological relationships, to the relatively complex such as determination of autozygosity and propagation of genetic information throughout pedigrees. Unlike nearly all other clinical DNA tests, the Scan is a universal test – it covers all people and all genes. In balance, I argue that the Genome Polymorphism Scan is the most powerful, affordable clinical DNA test available today.  相似文献   
7.
8.
9.

Introduction  

Sj?gren's syndrome (SS) is a systemic autoimmune disease that mainly targets the exocrine glands. The aim of this study was to investigate the involvement of 87 proteins measured in serum and 75 proteins analyzed in saliva in spontaneous experimental SS. In addition, we intended to compute a model of the immunological situation representing the overt disease stage of SS.  相似文献   
10.
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