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   1813496篇
  免费   147660篇
  国内免费   3446篇
耳鼻咽喉   24078篇
儿科学   58470篇
妇产科学   50372篇
基础医学   254323篇
口腔科学   51486篇
临床医学   163151篇
内科学   358085篇
皮肤病学   37065篇
神经病学   151933篇
特种医学   73851篇
外国民族医学   487篇
外科学   277020篇
综合类   42335篇
现状与发展   4篇
一般理论   706篇
预防医学   139320篇
眼科学   41593篇
药学   135394篇
  3篇
中国医学   3259篇
肿瘤学   101667篇
  2019年   14929篇
  2018年   20133篇
  2017年   15571篇
  2016年   17153篇
  2015年   20028篇
  2014年   27902篇
  2013年   41487篇
  2012年   57637篇
  2011年   60528篇
  2010年   35273篇
  2009年   33634篇
  2008年   57100篇
  2007年   60026篇
  2006年   60484篇
  2005年   58913篇
  2004年   57616篇
  2003年   54579篇
  2002年   53020篇
  2001年   77845篇
  2000年   80076篇
  1999年   68507篇
  1998年   20244篇
  1997年   18375篇
  1996年   18126篇
  1995年   17678篇
  1994年   16529篇
  1993年   15686篇
  1992年   56624篇
  1991年   54886篇
  1990年   53545篇
  1989年   51791篇
  1988年   48088篇
  1987年   47419篇
  1986年   45103篇
  1985年   43697篇
  1984年   33010篇
  1983年   28420篇
  1982年   17141篇
  1981年   15384篇
  1979年   31049篇
  1978年   21612篇
  1977年   18266篇
  1976年   17194篇
  1975年   17951篇
  1974年   21902篇
  1973年   21034篇
  1972年   19095篇
  1971年   18004篇
  1970年   16484篇
  1969年   15444篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
66.
67.
68.
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.  相似文献   
69.
70.
There is an increasing number of effective therapies for fracture prevention in adults at risk of osteoporosis. However, shortcomings in the evidence underpinning our management of osteoporosis still exist. Evidence of antifracture efficacy in the groups of patients who most commonly use calcium and vitamin D supplements is lacking, the safety of calcium supplements is in doubt, and the safety and efficacy of high doses of vitamin D give cause for concern. Alendronate, risedronate, zoledronate and denosumab have been shown to prevent spine, nonspine and hip fractures; in addition, teriparatide and strontium ranelate prevent both spine and nonspine fractures, and raloxifene and ibandronate prevent spine fractures. However, most trials provide little information regarding long‐term efficacy or safety. A particular concern at present is the possibility that oral bisphosphonates might cause atypical femoral fractures. Observational data suggest that the incidence of this type of fracture increases steeply with duration of bisphosphonate use, resulting in concern that the benefit–risk balance may become negative in the long term, particularly in patients in whom the osteoporotic fracture risk is not high. Therefore, reappraisal of ongoing use of bisphosphonates after about 5 years is endorsed by expert consensus, and ‘drug holidays’ should be considered at this time. Further studies are needed to guide clinical practice in this area.  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