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   3239106篇
  免费   269347篇
  国内免费   13740篇
耳鼻咽喉   44259篇
儿科学   103828篇
妇产科学   82895篇
基础医学   521712篇
口腔科学   86990篇
临床医学   291490篇
内科学   564333篇
皮肤病学   88327篇
神经病学   278978篇
特种医学   127348篇
外国民族医学   329篇
外科学   501177篇
综合类   100648篇
现状与发展   23篇
一般理论   2263篇
预防医学   274343篇
眼科学   73849篇
药学   220338篇
  23篇
中国医学   9314篇
肿瘤学   149726篇
  2021年   54831篇
  2020年   35000篇
  2019年   57927篇
  2018年   70741篇
  2017年   53985篇
  2016年   59561篇
  2015年   73703篇
  2014年   107868篇
  2013年   173109篇
  2012年   86651篇
  2011年   86171篇
  2010年   115266篇
  2009年   119984篇
  2008年   73252篇
  2007年   75402篇
  2006年   86562篇
  2005年   81851篇
  2004年   84183篇
  2003年   75205篇
  2002年   64966篇
  2001年   94401篇
  2000年   86935篇
  1999年   88639篇
  1998年   64297篇
  1997年   62351篇
  1996年   60116篇
  1995年   55663篇
  1994年   49934篇
  1993年   46502篇
  1992年   62337篇
  1991年   59450篇
  1990年   56554篇
  1989年   55930篇
  1988年   51592篇
  1987年   51006篇
  1986年   48115篇
  1985年   48633篇
  1984年   45265篇
  1983年   41545篇
  1982年   40681篇
  1981年   38490篇
  1980年   36195篇
  1979年   37047篇
  1978年   33745篇
  1977年   30953篇
  1976年   28454篇
  1975年   26798篇
  1974年   27568篇
  1973年   26525篇
  1972年   24637篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
103.
104.
105.
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   
106.
107.
108.
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   
109.
110.
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