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   805549篇
  免费   183739篇
  国内免费   29906篇
  2018年   7929篇
  2016年   10072篇
  2015年   13651篇
  2014年   15897篇
  2013年   21358篇
  2012年   23970篇
  2011年   24392篇
  2010年   18485篇
  2009年   21943篇
  2008年   22782篇
  2007年   23488篇
  2006年   21032篇
  2005年   20752篇
  2004年   20515篇
  2003年   19718篇
  2002年   19691篇
  2001年   33988篇
  2000年   32551篇
  1999年   30293篇
  1998年   16216篇
  1997年   15950篇
  1996年   15131篇
  1995年   15000篇
  1994年   14498篇
  1993年   14056篇
  1992年   27026篇
  1991年   26618篇
  1990年   26660篇
  1989年   25634篇
  1988年   23802篇
  1987年   22735篇
  1986年   21276篇
  1985年   21194篇
  1984年   17665篇
  1983年   15484篇
  1982年   12823篇
  1981年   11971篇
  1980年   11252篇
  1979年   17345篇
  1978年   13887篇
  1977年   13089篇
  1976年   12409篇
  1975年   13154篇
  1974年   14164篇
  1973年   13934篇
  1972年   13246篇
  1971年   11835篇
  1970年   10409篇
  1969年   10142篇
  1968年   9118篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Replication of the flavivirus Kunjin virus is associated with virus-induced membrane structures within the cytoplasm of infected cells; these membranes appear as packets of vesicles associated with the sites of viral RNA synthesis and as convoluted membranes (CM) and paracrystalline arrays (PC) containing the components of the virus-specified protease (E. G. Westaway, J. M. Mackenzie, M. T. Kenney, M. K. Jones, and A. A. Khromykh, J. Virol. 71:6650-6661, 1997). To determine the cellular origins of these membrane structures, we compared the immunolabelling patterns of several cell markers in relation to these sites by immunofluorescence and immunoelectron microscopy. A marker for the trans-Golgi membranes and the trans-Golgi network, 1,4-galactosyltransferase (GalT), was redistributed to large foci in the cytoplasm of Kunjin virus-infected cells, partially coincident with immunofluorescent foci associated with the putative sites of viral RNA synthesis. As determined by immunoelectron microscopy, the induced vesicle packets contained GalT, whereas the CM and PC contained a specific protein marker for the intermediate compartment (ERGIC53). A further indicator of the role of cellular organelles in their biogenesis was the observation that the Golgi apparatus-disrupting agent brefeldin A prevented further development of immunofluorescent foci of induced membranes if added before the end of the latent period but that once formed, these membrane foci were resistant to brefeldin A dispersion. Reticulum membranes emanating from the induced CM and PC were also labelled with the rough endoplasmic reticulum marker anti-protein disulfide isomerase and were obviously redistributed during infection. This is the first report identifying trans-Golgi membranes and the intermediate compartment as the apparent sources of the flavivirus-induced membranes involved in events of replication.  相似文献   
72.
73.
74.
Over the past 10 years the AIDS crisis has produced a large volume of writing. Much of this is documentary. Dozens of studies of AIDS from various clinical and political perspectives have been complemented by just as many published diaries, autobiographies, novels, plays, and poems. A few of these works have risen to the surface not only as extraordinarily valuable testimonies to the changes AIDS has wrought in individual and collective life but also as first-rate literary works, worth reading because beyond their immediate purposes they articulate with extraordinary lucidity and compassion some deep truths about the human--and the modern--condition. Paul Monette's Borrowed Time is among the most distinctive of those. It speaks not only for the community of people with AIDS and those who support them but for a generation.  相似文献   
75.
76.
77.
78.
79.
80.
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