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   1975206篇
  免费   149339篇
  国内免费   4297篇
耳鼻咽喉   26066篇
儿科学   64987篇
妇产科学   54676篇
基础医学   289873篇
口腔科学   54255篇
临床医学   178245篇
内科学   387403篇
皮肤病学   45903篇
神经病学   154892篇
特种医学   74272篇
外国民族医学   531篇
外科学   294157篇
综合类   44732篇
现状与发展   5篇
一般理论   618篇
预防医学   151930篇
眼科学   45181篇
药学   142875篇
  3篇
中国医学   5270篇
肿瘤学   112968篇
  2019年   15719篇
  2018年   22407篇
  2017年   17094篇
  2016年   19369篇
  2015年   21566篇
  2014年   30253篇
  2013年   45042篇
  2012年   60723篇
  2011年   64387篇
  2010年   37967篇
  2009年   36144篇
  2008年   59572篇
  2007年   63341篇
  2006年   64320篇
  2005年   61667篇
  2004年   59431篇
  2003年   56476篇
  2002年   54670篇
  2001年   99834篇
  2000年   101950篇
  1999年   84377篇
  1998年   23175篇
  1997年   20585篇
  1996年   20826篇
  1995年   19795篇
  1994年   18014篇
  1993年   16853篇
  1992年   63963篇
  1991年   61771篇
  1990年   59638篇
  1989年   57502篇
  1988年   52530篇
  1987年   51245篇
  1986年   48182篇
  1985年   45692篇
  1984年   34366篇
  1983年   28963篇
  1982年   17130篇
  1981年   15171篇
  1979年   30516篇
  1978年   21468篇
  1977年   17965篇
  1976年   17098篇
  1975年   18069篇
  1974年   21453篇
  1973年   20670篇
  1972年   19384篇
  1971年   17745篇
  1970年   16947篇
  1969年   15602篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
42.
43.
OBJECTIVE: Antidepressants are commonly used drugs with potential for numerous drug interactions. This study aims to systematically review the literature on drug interactions with antidepressants. METHODS: We searched MEDLINE (1966 to November 2003) and EMBASE (1980 to 2003), using the heading drug interactions combined with individual antidepressant names. We restricted searches to English-language articles and human studies. We screened drug interaction texts and review articles for relevant studies. We included articles reporting original human data on drug interactions with antidepressants commonly used in North America. Articles were independently evaluated by 2 reviewers on clinical effect, clinical significance, and quality of evidence. Discrepancies were resolved by consensus. RESULTS: There were 904 eligible interactions, involving 9509 patients, for a total of 598 summary interactions. Of these, 439 (73%) demonstrated an interaction, 148 (25%) had no effect, and 11 (2%) had conflicting evidence. For 510 interactions (85%), the quality of evidence was poor. It was fair for 67 (11%) interactions and good for 10 (2%) interactions. There were no interactions with excellent quality of evidence. There were 145 (24%) interactions of major clinical significance. These were predominantly hypertensive emergencies and serotonin syndrome. Most interacting drugs had central nervous system (CNS) activity. As expected, monoamine oxidase inhibitors (MAOIs) appear to be the most problematic family in terms of potential for serious drug interactions. CONCLUSIONS: Drug interactions with antidepressants are an important cause for concern, but this concern is based primarily on poor evidence. We recommend caution when combining antidepressants with other CNS drugs, particularly when coadministering MAOIs with other substances.  相似文献   
44.
45.
46.
47.
48.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
49.
50.
Continual loading and articulation cycles undergone by metallic (e.g., titanium) alloy arthroplasty prostheses lead to liberation of a large number of metallic debris particulates, which have long been implicated as a primary cause of periprosthetic osteolysis and postarthroplasty aseptic implant loosening. Long-term stability of total joint replacement prostheses relies on proper integration between implant biomaterial and osseous tissue, and factors that interfere with this integration are likely to cause osteolysis. Because multipotent mesenchymal stem cells (MSCs) located adjacent to the implant have an osteoprogenitor function and are critical contributors to osseous tissue integrity, when their functions or activities are compromised, osteolysis will most likely occur. To date, it is not certain or sufficiently confirmed whether MSCs endocytose titanium particles, and if so, whether particulate endocytosis has any effect on cellular responses to wear debris. This study seeks to clarify the phenomenon of titanium endocytosis by human MSCs (hMSCs), and investigates the influence of endocytosis on their activities. hMSCs incubated with commercially pure titanium particles exhibited internalized particles, as observed by scanning electron microscopy and confocal laser scanning microscopy, with time-dependent reduction in the number of extracellular particles. Particulate endocytosis was associated with reduced rates of cellular proliferation and cell-substrate adhesion, suppressed osteogenic differentiation, and increased rate of apoptosis. These cellular effects of exposure to titanium particles were reduced when endocytosis was inhibited by treatment with cytochalasin D, and no significant effect was seen when hMSCs were treated only with conditioned medium obtained from particulate-treated cells. These findings strongly suggest that the biological responses of hMSCs to wear debris are triggered primarily by the direct endocytosis of titanium particulates, and not mediated by secreted soluble factors. In this manner, therapeutical approaches that suppress particle endocytosis could reduce the bioreactivity of hMSCs to particulates, and enhance long-term orthopedic implant prognosis by minimizing wear-debris periprosthethic osteolysis.  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