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   1618210篇
  免费   135694篇
  国内免费   4092篇
耳鼻咽喉   21736篇
儿科学   53158篇
妇产科学   46366篇
基础医学   229571篇
口腔科学   47547篇
临床医学   143292篇
内科学   317229篇
皮肤病学   34306篇
神经病学   131096篇
特种医学   65636篇
外国民族医学   480篇
外科学   246003篇
综合类   43410篇
现状与发展   5篇
一般理论   545篇
预防医学   124270篇
眼科学   36946篇
药学   123317篇
  14篇
中国医学   4396篇
肿瘤学   88673篇
  2018年   15394篇
  2016年   13531篇
  2015年   15919篇
  2014年   21723篇
  2013年   32431篇
  2012年   43977篇
  2011年   46348篇
  2010年   27487篇
  2009年   26298篇
  2008年   44110篇
  2007年   46368篇
  2006年   46982篇
  2005年   45492篇
  2004年   44849篇
  2003年   43032篇
  2002年   42098篇
  2001年   76268篇
  2000年   78771篇
  1999年   66707篇
  1998年   17942篇
  1997年   16512篇
  1996年   16463篇
  1995年   16131篇
  1994年   15164篇
  1993年   14287篇
  1992年   55499篇
  1991年   53839篇
  1990年   52621篇
  1989年   50878篇
  1988年   47263篇
  1987年   46592篇
  1986年   44307篇
  1985年   42860篇
  1984年   32047篇
  1983年   27571篇
  1982年   16149篇
  1981年   14437篇
  1980年   13565篇
  1979年   30465篇
  1978年   21064篇
  1977年   17764篇
  1976年   16694篇
  1975年   17574篇
  1974年   21486篇
  1973年   20672篇
  1972年   18854篇
  1971年   17772篇
  1970年   16289篇
  1969年   15268篇
  1968年   13949篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
56.
57.
58.
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   
59.
60.
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