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   3525153篇
  免费   266447篇
  国内免费   6880篇
耳鼻咽喉   49775篇
儿科学   112209篇
妇产科学   94713篇
基础医学   496184篇
口腔科学   103305篇
临床医学   321226篇
内科学   681834篇
皮肤病学   74954篇
神经病学   286486篇
特种医学   136648篇
外国民族医学   1084篇
外科学   531575篇
综合类   84128篇
现状与发展   5篇
一般理论   1398篇
预防医学   278891篇
眼科学   84288篇
药学   262709篇
  11篇
中国医学   7484篇
肿瘤学   189573篇
  2018年   37642篇
  2017年   28776篇
  2016年   31835篇
  2015年   36060篇
  2014年   51221篇
  2013年   77065篇
  2012年   104916篇
  2011年   110931篇
  2010年   65703篇
  2009年   62045篇
  2008年   104267篇
  2007年   111106篇
  2006年   112049篇
  2005年   108719篇
  2004年   104694篇
  2003年   100480篇
  2002年   98256篇
  2001年   166847篇
  2000年   172097篇
  1999年   144867篇
  1998年   41168篇
  1997年   36716篇
  1996年   36381篇
  1995年   35192篇
  1994年   32857篇
  1993年   30461篇
  1992年   114881篇
  1991年   111221篇
  1990年   107323篇
  1989年   103677篇
  1988年   95727篇
  1987年   94028篇
  1986年   88894篇
  1985年   84814篇
  1984年   63862篇
  1983年   54425篇
  1982年   32247篇
  1981年   28801篇
  1979年   58823篇
  1978年   41095篇
  1977年   34925篇
  1976年   32679篇
  1975年   34494篇
  1974年   42448篇
  1973年   40524篇
  1972年   37925篇
  1971年   35024篇
  1970年   32897篇
  1969年   30612篇
  1968年   28116篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
41.
42.
43.
44.
45.
46.
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   
47.
48.
49.
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   
50.
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