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   4510篇
  免费   473篇
  国内免费   1篇
  2021年   51篇
  2020年   47篇
  2019年   43篇
  2018年   43篇
  2017年   58篇
  2016年   89篇
  2015年   133篇
  2014年   183篇
  2013年   192篇
  2012年   280篇
  2011年   246篇
  2010年   156篇
  2009年   138篇
  2008年   197篇
  2007年   244篇
  2006年   215篇
  2005年   179篇
  2004年   156篇
  2003年   174篇
  2002年   144篇
  2001年   92篇
  2000年   89篇
  1999年   70篇
  1998年   66篇
  1997年   55篇
  1996年   55篇
  1995年   48篇
  1994年   51篇
  1993年   46篇
  1992年   78篇
  1991年   48篇
  1990年   72篇
  1989年   70篇
  1988年   81篇
  1987年   51篇
  1986年   60篇
  1985年   56篇
  1984年   60篇
  1983年   39篇
  1982年   31篇
  1981年   51篇
  1980年   36篇
  1979年   51篇
  1978年   46篇
  1977年   40篇
  1976年   42篇
  1975年   28篇
  1974年   50篇
  1973年   31篇
  1972年   27篇
排序方式: 共有4984条查询结果,搜索用时 15 毫秒
81.
82.
Calcium-induced cleavage and breakdown of spectrin in the rat lens   总被引:3,自引:0,他引:3  
Incubation of intact rat lenses under conditions that stimulated a net influx of calcium resulted in a pronounced loss of transparency and a major decrease in the levels of spectrin. The progressive loss of this cytoskeletal component coincided with the appearance of polypeptides of approximately 150 kDa which showed immunoreactivity with an antibody raised to spectrin. These bands disappeared on further incubation. It is, therefore, suggested that a calcium-activated protease is present in the lens which is capable of degrading spectrin by the initial removal of approximately 90 kDa fragments. This process calcium-induced proteolysis may be the basis for the cytoskeletal reorganisation observed during the differentiation of lens fibre cells and may be involved in cataract development.  相似文献   
83.
There was a strong correlation between measurements of red core disease of strawberry, assessed as percentage lengths of the adventitious roots with red steles, and ELISA values obtained from the same root systems using a polyclonal antiserum raised to Phytophthora fragariae. ELISA grouped twelve host cultivar/pathogen isolate combinations into three categories, highly resistant, partially resistant and susceptible, which agreed with disease incidence after inoculation.  相似文献   
84.
85.
86.
Duncan A. Gordon 《CMAJ》1963,88(2):61-67
The extrarenal manifestations of hypernephroma in 34 medical patients are described, and the literature on this subject is reviewed. One case presented with hematuria and 11 other cases with metastases. Presentation was not obviously related to metastases in 22 patients. Eight were first seen because of fever or general weakness. Vascular disturbances in six included hypertension, thrombophlebitis, inferior vena caval obstruction and varicocele. Four patients had gastrointestinal complaints; one had hypercalcemia and another musculoskeletal symptoms. Two cases had neurological syndromes, one of which proved to be due to metastases. The overall incidence of systemic features was greater and included anemia, eosinophilia, a leukemoid reaction and thrombocytosis. Polycythemia, amyloidosis and hyponatremia were not encountered. Urographic procedures were performed in half of the patients, most of whom had an abdominal mass. Calcium was visible radiologically in the tumour in five cases. The diagnosis was not made in 19 and was an unexpected finding at autopsy in 10. Appreciation of the extrarenal manifestations of hypernephroma might lead to earlier diagnosis.  相似文献   
87.
88.
89.
90.
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