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   531204篇
  免费   59626篇
  国内免费   336篇
  2018年   5220篇
  2017年   5084篇
  2016年   6944篇
  2015年   8761篇
  2014年   10475篇
  2013年   15247篇
  2012年   16950篇
  2011年   17327篇
  2010年   11691篇
  2009年   10732篇
  2008年   15141篇
  2007年   15696篇
  2006年   14666篇
  2005年   14059篇
  2004年   13923篇
  2003年   13279篇
  2002年   12814篇
  2001年   28365篇
  2000年   28222篇
  1999年   21992篇
  1998年   6727篇
  1997年   7301篇
  1996年   6532篇
  1995年   6207篇
  1994年   5980篇
  1993年   5957篇
  1992年   17034篇
  1991年   16291篇
  1990年   15697篇
  1989年   15207篇
  1988年   13916篇
  1987年   12931篇
  1986年   12033篇
  1985年   11809篇
  1984年   9656篇
  1983年   8082篇
  1982年   5993篇
  1981年   5370篇
  1980年   5094篇
  1979年   8937篇
  1978年   6807篇
  1977年   6269篇
  1976年   5643篇
  1975年   6234篇
  1974年   6757篇
  1973年   6534篇
  1972年   5974篇
  1971年   5427篇
  1970年   4678篇
  1969年   4398篇
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
971.
972.
A study was made of the fatty acid composition and the content of triglycerides, phospholipids and nonesterified fatty acids (NFA) in adipose and muscle tissues of rats with alloxan diabetes. The concentration of NFA in alloxan diabetes was found to be considerably reduced in both adipose and muscle tissues. Meanwhile the content of NFA and phospholipids did not experience any substantial changes. The fatty acid composition of triglycerides of the tissues under study was characterized by considerable alterations under diabetes.  相似文献   
973.
974.
The effect of different chemical anxiolytic agents on ethanol consumption has been studied on the model of experimental alcoholism in rats. The decrease of ethanol consumption was dose-dependent. The existence of non-benzodiazepine anxiolytic systems is suggested.  相似文献   
975.
976.
Actin is a major antigen involved in the reaction of smooth muscle antibody positive sera from patients with chronic active hepatitis. In the present study, actin extracted from rabbit skeletal muscle was denatured by sodium dodecyl sulfate and was immunized into the rabbit, a homologous animal for actin. The rabbits, thus immunized, produced antibodies reactive with actins of homologous and heterologous animals. In addition, the antibodies showed reactivity with autologous actin. It indicates that the denatured homologous actin is capable of terminating immunological tolerance to actin and induces formation of autoantibody to rabbit actin. This phenomenon may be implicated in the occurrence of anti-actin antibody in sera from patients with chronic liver disease and several other diseases.  相似文献   
977.
978.
979.
980.
Mechanism of mda-5 Inhibition by Paramyxovirus V Proteins   总被引:1,自引:0,他引:1       下载免费PDF全文
The RNA helicases encoded by melanoma differentiation-associated gene 5 (mda-5) and retinoic acid-inducible gene I (RIG-I) detect foreign cytoplasmic RNA molecules generated during the course of a virus infection, and their activation leads to induction of type I interferon synthesis. Paramyxoviruses limit the amount of interferon produced by infected cells through the action of their V protein, which binds to and inhibits mda-5. Here we show that activation of both mda-5 and RIG-I by double-stranded RNA (dsRNA) leads to the formation of homo-oligomers through self-association of the helicase domains. We identify a region within the helicase domain of mda-5 that is targeted by all paramyxovirus V proteins and demonstrate that they inhibit activation of mda-5 by blocking dsRNA binding and consequent self-association. In addition to this commonly targeted domain, some paramyxovirus V proteins target additional regions of mda-5. In contrast, V proteins cannot bind to RIG-I and consequently have no effect on the ability of RIG-I to bind dsRNA or to form oligomers.  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