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   932996篇
  免费   66290篇
  国内免费   1342篇
耳鼻咽喉   12968篇
儿科学   24395篇
妇产科学   23262篇
基础医学   132999篇
口腔科学   28259篇
临床医学   80738篇
内科学   183386篇
皮肤病学   19265篇
神经病学   72297篇
特种医学   36812篇
外国民族医学   79篇
外科学   152164篇
综合类   18089篇
现状与发展   1篇
一般理论   235篇
预防医学   61880篇
眼科学   21344篇
药学   72582篇
  3篇
中国医学   2166篇
肿瘤学   57704篇
  2018年   8976篇
  2017年   7049篇
  2016年   7783篇
  2015年   8891篇
  2014年   12031篇
  2013年   17548篇
  2012年   24142篇
  2011年   25103篇
  2010年   14855篇
  2009年   14295篇
  2008年   24666篇
  2007年   25753篇
  2006年   26547篇
  2005年   25500篇
  2004年   24623篇
  2003年   23665篇
  2002年   23193篇
  2001年   54747篇
  2000年   56558篇
  1999年   46969篇
  1998年   10748篇
  1997年   9472篇
  1996年   9595篇
  1995年   8932篇
  1994年   8283篇
  1993年   7594篇
  1992年   35497篇
  1991年   33916篇
  1990年   32745篇
  1989年   31878篇
  1988年   28995篇
  1987年   28252篇
  1986年   26295篇
  1985年   25150篇
  1984年   17834篇
  1983年   15141篇
  1982年   7797篇
  1981年   6773篇
  1979年   15782篇
  1978年   10602篇
  1977年   9054篇
  1976年   7872篇
  1975年   8629篇
  1974年   10467篇
  1973年   9862篇
  1972年   9360篇
  1971年   8854篇
  1970年   8428篇
  1969年   7926篇
  1968年   7205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.
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   
9.
10.
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.  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