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   1928466篇
  免费   134747篇
  国内免费   3782篇
耳鼻咽喉   26374篇
儿科学   63907篇
妇产科学   53317篇
基础医学   275961篇
口腔科学   54058篇
临床医学   173229篇
内科学   367567篇
皮肤病学   44111篇
神经病学   149205篇
特种医学   75370篇
外国民族医学   497篇
外科学   291177篇
综合类   42450篇
现状与发展   1篇
一般理论   630篇
预防医学   143440篇
眼科学   44588篇
药学   146995篇
  9篇
中国医学   4364篇
肿瘤学   109745篇
  2018年   20137篇
  2017年   15692篇
  2016年   17906篇
  2015年   20053篇
  2014年   27427篇
  2013年   41029篇
  2012年   55178篇
  2011年   58589篇
  2010年   34821篇
  2009年   32676篇
  2008年   54601篇
  2007年   58235篇
  2006年   59185篇
  2005年   56678篇
  2004年   54774篇
  2003年   52607篇
  2002年   50780篇
  2001年   96907篇
  2000年   99486篇
  1999年   83141篇
  1998年   22051篇
  1997年   19558篇
  1996年   19533篇
  1995年   18569篇
  1994年   17050篇
  1993年   16043篇
  1992年   64449篇
  1991年   62404篇
  1990年   61588篇
  1989年   59367篇
  1988年   53723篇
  1987年   53174篇
  1986年   49838篇
  1985年   47533篇
  1984年   35101篇
  1983年   29620篇
  1982年   17004篇
  1981年   15114篇
  1979年   31838篇
  1978年   22149篇
  1977年   19378篇
  1976年   17557篇
  1975年   19115篇
  1974年   22653篇
  1973年   21941篇
  1972年   20550篇
  1971年   19202篇
  1970年   17707篇
  1969年   16866篇
  1968年   15325篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n > 400 total) examining the power of society’s widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which—notably—remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.  相似文献   
12.
13.
Vaskulitiden     
  相似文献   
14.
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   
15.
16.
17.
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   
18.
19.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
20.
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