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   1977377篇
  免费   144917篇
  国内免费   3780篇
耳鼻咽喉   28706篇
儿科学   66561篇
妇产科学   55585篇
基础医学   280839篇
口腔科学   53931篇
临床医学   170878篇
内科学   394448篇
皮肤病学   42487篇
神经病学   156119篇
特种医学   78725篇
外国民族医学   939篇
外科学   305483篇
综合类   43008篇
现状与发展   1篇
一般理论   594篇
预防医学   148006篇
眼科学   44587篇
药学   145178篇
  2篇
中国医学   3872篇
肿瘤学   106125篇
  2018年   20013篇
  2017年   15414篇
  2016年   16785篇
  2015年   19053篇
  2014年   26791篇
  2013年   41223篇
  2012年   56146篇
  2011年   59543篇
  2010年   35838篇
  2009年   34107篇
  2008年   56985篇
  2007年   60937篇
  2006年   61225篇
  2005年   59901篇
  2004年   58037篇
  2003年   56264篇
  2002年   55215篇
  2001年   93325篇
  2000年   96554篇
  1999年   82145篇
  1998年   22664篇
  1997年   20635篇
  1996年   20886篇
  1995年   19658篇
  1994年   18663篇
  1993年   17421篇
  1992年   64802篇
  1991年   63208篇
  1990年   61643篇
  1989年   58835篇
  1988年   54357篇
  1987年   53550篇
  1986年   50371篇
  1985年   48336篇
  1984年   36203篇
  1983年   30654篇
  1982年   18151篇
  1981年   16247篇
  1979年   32933篇
  1978年   22951篇
  1977年   19414篇
  1976年   18298篇
  1975年   19902篇
  1974年   23569篇
  1973年   22651篇
  1972年   21101篇
  1971年   19243篇
  1970年   18394篇
  1969年   16851篇
  1968年   15769篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
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   
43.
44.
45.
46.
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   
47.
48.
AimsThe aims were to 1) develop the pharmacokinetics model to describe and predict observed tanezumab concentrations over time, 2) test possible covariate parameter relationships that could influence clearance and distribution and 3) assess the impact of fixed dosing vs. a dosing regimen adjusted by body weight.MethodsIndividual concentration–time data were determined from 1608 patients in four phase 3 studies conducted to assess efficacy and safety of intravenous tanezumab. Patients received two or three intravenous doses (2.5, 5 or 10 mg) every 8 weeks. Blood samples for assessment of tanezumab PK were collected at baseline, 1 h post‐dose and at weeks 4, 8, 16 and 24 (or early termination) in all studies. Blood samples were collected at week 32 in two studies. Plasma samples were analyzed using a sensitive, specific, validated enzyme‐linked immunosorbent assay.ResultsA two compartment model with parallel linear and non‐linear elimination processes adequately described the data. Population estimates for clearance (CL), central volume (V 1), peripheral volume (V 2), inter‐compartmental clearance, maximum elimination capacity (VM) and concentration at half‐maximum elimination capacity were 0.135 l day–1, 2.71 l, 1.98 l, 0.371 l day–1, 8.03 μg day–1 and 27.7 ng ml–1, respectively. Inter‐individual variability (IIV) was included on CL, V 1, V 2 and VM. A mixture model accounted for the distribution of residual error. While gender, dose and creatinine clearance were significant covariates, only body weight as a covariate of CL, V 1 and V 2 significantly reduced IIV.ConclusionsThe small increase in variability associated with fixed dosing is consistent with other monoclonal antibodies and does not change risk : benefit.  相似文献   
49.
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