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   1699393篇
  免费   123676篇
  国内免费   3782篇
耳鼻咽喉   21750篇
儿科学   55707篇
妇产科学   46206篇
基础医学   241696篇
口腔科学   48817篇
临床医学   151661篇
内科学   334130篇
皮肤病学   38687篇
神经病学   131495篇
特种医学   63994篇
外国民族医学   242篇
外科学   257692篇
综合类   39015篇
现状与发展   4篇
一般理论   534篇
预防医学   124780篇
眼科学   40353篇
药学   123914篇
  7篇
中国医学   4478篇
肿瘤学   101689篇
  2021年   12837篇
  2019年   13564篇
  2018年   20012篇
  2017年   15251篇
  2016年   16657篇
  2015年   19005篇
  2014年   26282篇
  2013年   38060篇
  2012年   52889篇
  2011年   55602篇
  2010年   32863篇
  2009年   30777篇
  2008年   51668篇
  2007年   54947篇
  2006年   55421篇
  2005年   52714篇
  2004年   50920篇
  2003年   48292篇
  2002年   46508篇
  2001年   91896篇
  2000年   93698篇
  1999年   77074篇
  1998年   19753篇
  1997年   17325篇
  1996年   17421篇
  1995年   16773篇
  1994年   15328篇
  1993年   14114篇
  1992年   57490篇
  1991年   55360篇
  1990年   53046篇
  1989年   50830篇
  1988年   46203篇
  1987年   45003篇
  1986年   42290篇
  1985年   40066篇
  1984年   29407篇
  1983年   24967篇
  1982年   13942篇
  1979年   25584篇
  1978年   17621篇
  1977年   14939篇
  1976年   13901篇
  1975年   14595篇
  1974年   17663篇
  1973年   16986篇
  1972年   15711篇
  1971年   14480篇
  1970年   13451篇
  1969年   12552篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
35.
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   
36.
37.
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   
38.
39.
40.
European Journal of Orthopaedic Surgery & Traumatology - The goals of this study were to compare patient satisfaction and wound-related complications in patients receiving 2-octyl cyanoacrylate...  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