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   1612081篇
  免费   132379篇
  国内免费   2613篇
耳鼻咽喉   21713篇
儿科学   53273篇
妇产科学   46547篇
基础医学   229083篇
口腔科学   47435篇
临床医学   142040篇
内科学   316864篇
皮肤病学   34179篇
神经病学   131211篇
特种医学   65086篇
外国民族医学   474篇
外科学   245261篇
综合类   39961篇
现状与发展   3篇
一般理论   566篇
预防医学   124010篇
眼科学   36695篇
药学   121885篇
  3篇
中国医学   2979篇
肿瘤学   87805篇
  2018年   14890篇
  2016年   13011篇
  2015年   15176篇
  2014年   20832篇
  2013年   31700篇
  2012年   43003篇
  2011年   45294篇
  2010年   26634篇
  2009年   25595篇
  2008年   43509篇
  2007年   45802篇
  2006年   46626篇
  2005年   45212篇
  2004年   44659篇
  2003年   42753篇
  2002年   41850篇
  2001年   75823篇
  2000年   78486篇
  1999年   66596篇
  1998年   17902篇
  1997年   16480篇
  1996年   16447篇
  1995年   16140篇
  1994年   15174篇
  1993年   14340篇
  1992年   55614篇
  1991年   53910篇
  1990年   52662篇
  1989年   50959篇
  1988年   47371篇
  1987年   46689篇
  1986年   44396篇
  1985年   42973篇
  1984年   32174篇
  1983年   27662篇
  1982年   16286篇
  1981年   14561篇
  1980年   13675篇
  1979年   30561篇
  1978年   21179篇
  1977年   17856篇
  1976年   16763篇
  1975年   17651篇
  1974年   21565篇
  1973年   20752篇
  1972年   18911篇
  1971年   17825篇
  1970年   16344篇
  1969年   15310篇
  1968年   13993篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
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   
10.
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