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   2347571篇
  免费   168633篇
  国内免费   4715篇
耳鼻咽喉   31667篇
儿科学   73162篇
妇产科学   63048篇
基础医学   333868篇
口腔科学   69962篇
临床医学   209972篇
内科学   456554篇
皮肤病学   52084篇
神经病学   182455篇
特种医学   89223篇
外国民族医学   319篇
外科学   361264篇
综合类   52515篇
现状与发展   4篇
一般理论   734篇
预防医学   170424篇
眼科学   56032篇
药学   174965篇
  10篇
中国医学   5883篇
肿瘤学   136774篇
  2019年   17666篇
  2018年   25863篇
  2017年   19833篇
  2016年   21893篇
  2015年   24970篇
  2014年   34371篇
  2013年   50234篇
  2012年   69371篇
  2011年   73012篇
  2010年   43267篇
  2009年   40703篇
  2008年   68765篇
  2007年   72854篇
  2006年   73770篇
  2005年   70447篇
  2004年   68171篇
  2003年   64899篇
  2002年   62826篇
  2001年   125355篇
  2000年   128484篇
  1999年   106485篇
  1998年   27232篇
  1997年   23817篇
  1996年   23925篇
  1995年   22875篇
  1994年   20965篇
  1993年   19410篇
  1992年   80825篇
  1991年   77837篇
  1990年   74994篇
  1989年   72398篇
  1988年   65888篇
  1987年   64263篇
  1986年   60503篇
  1985年   57523篇
  1984年   41976篇
  1983年   35746篇
  1982年   19673篇
  1979年   37265篇
  1978年   25575篇
  1977年   21787篇
  1976年   19952篇
  1975年   21293篇
  1974年   25809篇
  1973年   24726篇
  1972年   23102篇
  1971年   21548篇
  1970年   20223篇
  1969年   18913篇
  1968年   17517篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
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   
33.
34.
35.
36.
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   
37.
38.
Annals of Nuclear Medicine - The Response Evaluation Criteria In Solid Tumors (RECIST) is the most used radiological method for evaluating response after peptide receptor radionuclide therapy...  相似文献   
39.
40.
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