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   9137篇
  免费   813篇
  国内免费   3篇
  2022年   46篇
  2021年   260篇
  2020年   112篇
  2019年   145篇
  2018年   169篇
  2017年   125篇
  2016年   267篇
  2015年   454篇
  2014年   411篇
  2013年   525篇
  2012年   717篇
  2011年   620篇
  2010年   417篇
  2009年   327篇
  2008年   456篇
  2007年   474篇
  2006年   420篇
  2005年   377篇
  2004年   367篇
  2003年   320篇
  2002年   297篇
  2001年   166篇
  2000年   120篇
  1999年   119篇
  1998年   86篇
  1997年   60篇
  1996年   58篇
  1995年   55篇
  1994年   52篇
  1993年   49篇
  1992年   81篇
  1991年   71篇
  1990年   66篇
  1989年   75篇
  1988年   59篇
  1987年   69篇
  1986年   66篇
  1985年   75篇
  1984年   80篇
  1983年   47篇
  1982年   62篇
  1980年   48篇
  1979年   64篇
  1976年   49篇
  1975年   45篇
  1974年   53篇
  1972年   59篇
  1971年   46篇
  1970年   46篇
  1969年   45篇
排序方式: 共有9953条查询结果,搜索用时 395 毫秒
101.
102.
Sudden oxygenation of a thin film of rat brain homogenate, suspended between the surface of a glass pH-sensitive electrode and a gas-permeable membrane, is accompanied by a fall in pH, which is greater when carbonic anhydrase is inhibited. The result suggests that oxidative decarboxylation yields carbonic acid (HCO(3)- and H(+)), which dissociates to form molecular carbon dioxide. Brain carbonic anhydrase facilitates the formation of carbon dioxide from the decarboxylation products.  相似文献   
103.
Aflatoxicosis and Salmonella gallinarum exert their effects on the body weight and mortality of chickens without any interaction.  相似文献   
104.
105.
Cytosine arabinoside and daunorubicin used in an intensive intermittent regimen have been shown to be an effective combination for the induction of complete remissions in 14 out of 23 adult patients with acute myelogenous leukaemia. This gives an overall complete remission rate of 60%. A further patient had a good partial remission. The addition of L-asparaginase to the regimen has not increased the incidence of remission and there were more side effects in the L-asparaginasetreated group. Of the 10 patients treated with L-asparaginase in addition to cytosine arabinoside and daunorubicin, five achieved a complete remission. Of the 13 patients treated with cytosine arabinoside and daunorubicin without L-asparaginase, nine achieved a complete remission and one a good partial remission.  相似文献   
106.
Summary The literature on the vacuolar structure of the human syncytiotrophoblast is briefly reviewed. Personal observations based on light and electron microscopic investigations are described and illustrated. The nature of the different kinds of syncytial vacuolation is discussed. In particular dilated vacuoles, which may be very large indeed, receive special attention; situated adjacent to the syncytial nuclei they have been called juxtanuclear vacuoles. They are directly continuous with the perinuclear spaces, and often receive tubular communications from the endoplasmic reticular system. The possible functional role of the syncytial vacuolar system is discussed in the light of the authors' findings and the related literature.Dedicated to Professor Dr. Kurt Goerttler on the occasion of his seventieth birthday.  相似文献   
107.
Eleven strains of the crown gall organism, Agrobacterium tumefaciens, tested by intraperitoneal injection into mice, were lethal within 48 hr. Five other species had some lethal strains. The lethal effect of A. tumefaciens appeared to be the result of a toxic rather than an infectious process, since histopathological anomalies were not found in mice injected with live cultures and since heat-killed cultures were lethal. The murine toxin disappeared when A. tumefaciens was grown at 36 C and reappeared when the organism was subsequently incubated below 30 C. The murine toxin itself was not inactivated by exposure to 100 C for 30 min. The toxin was associated with the cells and was not excreted into the medium. Centrifugal fractionation revealed that the toxin was associated with the smaller cells in 3-day stationary-phase cultures. These data suggested a possible relationship between toxin production and the production of the agents responsible for the initiation of plant tumors.  相似文献   
108.
109.
110.
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