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   3381577篇
  免费   268332篇
  国内免费   6069篇
耳鼻咽喉   48583篇
儿科学   107836篇
妇产科学   93273篇
基础医学   476017篇
口腔科学   99642篇
临床医学   307540篇
内科学   654721篇
皮肤病学   70411篇
神经病学   281573篇
特种医学   134564篇
外国民族医学   1247篇
外科学   508004篇
综合类   83119篇
现状与发展   4篇
一般理论   1448篇
预防医学   273065篇
眼科学   79961篇
药学   252778篇
  7篇
中国医学   6252篇
肿瘤学   175933篇
  2018年   33699篇
  2016年   28986篇
  2015年   33138篇
  2014年   47051篇
  2013年   72011篇
  2012年   96781篇
  2011年   102390篇
  2010年   60483篇
  2009年   57738篇
  2008年   97515篇
  2007年   103309篇
  2006年   104446篇
  2005年   101565篇
  2004年   98627篇
  2003年   94956篇
  2002年   93722篇
  2001年   153615篇
  2000年   159095篇
  1999年   135128篇
  1998年   39280篇
  1997年   35599篇
  1996年   35094篇
  1995年   34031篇
  1994年   32004篇
  1993年   29948篇
  1992年   109829篇
  1991年   106160篇
  1990年   103017篇
  1989年   99557篇
  1988年   92552篇
  1987年   91307篇
  1986年   86713篇
  1985年   83149篇
  1984年   63106篇
  1983年   54144篇
  1982年   32763篇
  1981年   29277篇
  1980年   27578篇
  1979年   59910篇
  1978年   42181篇
  1977年   35593篇
  1976年   33370篇
  1975年   35318篇
  1974年   43551篇
  1973年   41592篇
  1972年   38753篇
  1971年   36073篇
  1970年   33682篇
  1969年   31450篇
  1968年   28688篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
42.
43.
44.
45.
46.
47.
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
48.
49.
50.
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   
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