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   1234939篇
  免费   78153篇
  国内免费   1799篇
耳鼻咽喉   17510篇
儿科学   39914篇
妇产科学   32031篇
基础医学   176155篇
口腔科学   34188篇
临床医学   107508篇
内科学   233780篇
皮肤病学   28575篇
神经病学   96930篇
特种医学   51169篇
外国民族医学   224篇
外科学   188858篇
综合类   22827篇
现状与发展   1篇
一般理论   307篇
预防医学   82096篇
眼科学   28606篇
药学   97176篇
  7篇
中国医学   3108篇
肿瘤学   73921篇
  2021年   9241篇
  2019年   9398篇
  2018年   14231篇
  2017年   11303篇
  2016年   13433篇
  2015年   15010篇
  2014年   19306篇
  2013年   27817篇
  2012年   39352篇
  2011年   40791篇
  2010年   23975篇
  2009年   21961篇
  2008年   38082篇
  2007年   41034篇
  2006年   41580篇
  2005年   40157篇
  2004年   38320篇
  2003年   36866篇
  2002年   35607篇
  2001年   64654篇
  2000年   65932篇
  1999年   55008篇
  1998年   13877篇
  1997年   12165篇
  1996年   11878篇
  1995年   11050篇
  1994年   10000篇
  1993年   9437篇
  1992年   39545篇
  1991年   37945篇
  1990年   37363篇
  1989年   35836篇
  1988年   32205篇
  1987年   31359篇
  1986年   29454篇
  1985年   27630篇
  1984年   20114篇
  1983年   16884篇
  1982年   9381篇
  1979年   18008篇
  1978年   12153篇
  1977年   10832篇
  1976年   9415篇
  1975年   10834篇
  1974年   12459篇
  1973年   12024篇
  1972年   11519篇
  1971年   10820篇
  1970年   9907篇
  1969年   9552篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
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   
6.
7.
8.
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   
9.
10.
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.  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