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   17296篇
  免费   3篇
  17299篇
  2012年   198篇
  2011年   378篇
  2010年   130篇
  2008年   367篇
  2007年   434篇
  2006年   423篇
  2005年   467篇
  2004年   466篇
  2003年   495篇
  2002年   455篇
  2001年   447篇
  2000年   480篇
  1999年   473篇
  1998年   42篇
  1992年   590篇
  1991年   749篇
  1990年   752篇
  1989年   743篇
  1988年   747篇
  1987年   669篇
  1986年   611篇
  1985年   574篇
  1984年   424篇
  1983年   396篇
  1982年   129篇
  1981年   110篇
  1980年   121篇
  1979年   360篇
  1978年   318篇
  1977年   254篇
  1976年   281篇
  1975年   371篇
  1974年   384篇
  1973年   411篇
  1972年   377篇
  1971年   336篇
  1970年   325篇
  1969年   295篇
  1968年   296篇
  1967年   288篇
  1966年   256篇
  1965年   207篇
  1959年   69篇
  1958年   147篇
  1957年   115篇
  1956年   96篇
  1955年   96篇
  1954年   58篇
  1953年   22篇
  1952年   16篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
71.
72.
73.
Dependence of hypoxic changes of macro- and microcirculation on the activity of adrenergic receptors in the cooled organism was studied on decentralized shank of cat under perfusion with constant blood flow. After cooling of cat (to 30 degrees C) and blockade of alpha-adrenoreceptors hypoxic hypoxia (10% O2 in N2) caused (a) much greater reduction of precapillary resistance of shank, (b) more striking (by 3 times) increase of capillary filtration coefficient and (c) the increase of capillary pressure and postcapillary resistance in contrast to their decrease to hypoxia under hypothermia before alpha-blockade. Beta-adrenoreceptor blockade had no influence on the changes of the resistance and exchange function of skeletal muscle blood vessels evoked by hypoxia under cooling.  相似文献   
74.
The action of T-activin on peritoneal macrophages of CBA mice after its introduction into the animals has been studied. In intact mice the phagocytic activity of macrophages and their resistance to the cytopathogenic action of Salmonella typhimurium live cells remains unchanged. The injection of corpuscular pertussis vaccine into mice leads to a decrease in the resistance of macrophages to the action of salmonellae. The simultaneous injection of T-activin into mice in doses of 0.1 and 1.0 microgram per animal abolishes the damaging action of the vaccine. The analysis of the in vitro action of T-activin on macrophages of intact mice revealed that the preliminary incubation of cells with the preparation sharply increases their resistance to the action of salmonellae, while its introduction simultaneously with bacteria or after them rapidly leads to the death of macrophages. The action of T-activin is supposed to be linked with triggering the biosynthetic processes mediating the resistance of macrophages to the cytopathogenic action of salmonellae.  相似文献   
75.
Histological and electron microscopy findings suggesting the effect of monochromatic coherent polarized red light on zymosan arthritis in rats are presented. The data obtained have confirmed that treatment of inflamed joints with laser rays exerts an evident therapeutic effect which is determined by activated function of macrophages and fibroblasts of the synovial membrane, resulting in a more rapid change of inflammation phases. Analysis of the cases where the rats were treated with ordinary red light has revealed no essential differences in the joints of the control and irradiated groups.  相似文献   
76.
Activity of phosphodiesterases disintegrating cAMP and cGMP in the cornea, sclera and ciliary body was investigated in health and in different stages of experimental herpetic keratitis. The problems concerning the role of the cyclase system in the pathogenesis of herpetic keratitis and the possibility of applying some of the drugs to the disease treatment are discussed.  相似文献   
77.
A total of 218 batches of blood preparations produced from different raw materials have been studied by means of enzyme immunoassay kits (Abbott Laboratories, USA). The assays have revealed that the preparations under study are nonstandard with respect to the content and isolation rate of HBsAg, the marker of hepatitis B virus. These data necessitate search for the ways of improving the quality of blood preparations.  相似文献   
78.
Lymphocyte proliferation in blood cultures from 23 normal individuals was studied. A simple method of evaluation of cell proliferative kinetics with sister chromatid differential staining using two different points of cell harvesting was suggested. It was shown that different composition of tissue culture medium plays a significant role during the cell exit from G0 stage, the mean doubling generation time of cellular population remaining constant.  相似文献   
79.
The authors describe human cancer strains established from 6 cell lines transplanted to nude mice and rats: cancer of the liver, colon, lung, bladder and Burkitt's lymphoma. In spite of a long history (for several years) of cell line transfers in vitro, on transplantation of tumor cells, nude animals established tumors histologically identical to the primary cancer.  相似文献   
80.
Direct electric current of 3 microA applied through platinum electrode during 10 s to a fine strand teased mechanically from saphenous nerve, inhibits selectively C-fibre spikes in the strand and does not inhibit A-fiber spikes. The selective inhibition of C-fibers spikes in a fine strand is proposed as a method to identify a type of a single nerve fiber.  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