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   636313篇
  免费   41850篇
  国内免费   829篇
耳鼻咽喉   8032篇
儿科学   20251篇
妇产科学   16034篇
基础医学   104106篇
口腔科学   17494篇
临床医学   54789篇
内科学   118244篇
皮肤病学   14174篇
神经病学   47869篇
特种医学   23501篇
外国民族医学   79篇
外科学   92233篇
综合类   8982篇
现状与发展   1篇
一般理论   220篇
预防医学   53042篇
眼科学   14034篇
药学   48006篇
中国医学   1221篇
肿瘤学   36680篇
  2019年   5390篇
  2018年   7396篇
  2017年   5721篇
  2016年   6347篇
  2015年   7058篇
  2014年   9600篇
  2013年   14184篇
  2012年   20046篇
  2011年   21462篇
  2010年   12062篇
  2009年   11742篇
  2008年   20061篇
  2007年   21277篇
  2006年   21319篇
  2005年   20421篇
  2004年   19188篇
  2003年   18268篇
  2002年   17719篇
  2001年   28127篇
  2000年   29219篇
  1999年   24237篇
  1998年   6987篇
  1997年   5969篇
  1996年   6369篇
  1995年   5748篇
  1994年   5337篇
  1992年   18298篇
  1991年   18629篇
  1990年   18673篇
  1989年   17874篇
  1988年   16491篇
  1987年   16122篇
  1986年   15215篇
  1985年   14531篇
  1984年   10740篇
  1983年   9199篇
  1982年   5083篇
  1979年   10273篇
  1978年   7371篇
  1977年   6200篇
  1976年   5932篇
  1975年   6743篇
  1974年   8066篇
  1973年   7556篇
  1972年   7335篇
  1971年   7049篇
  1970年   6468篇
  1969年   6176篇
  1968年   5857篇
  1967年   5225篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
1.
2.
3.
4.
5.
6.
7.
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   
8.
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   
9.
10.
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