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   3580024篇
  免费   301672篇
  国内免费   16581篇
耳鼻咽喉   49111篇
儿科学   113884篇
妇产科学   92450篇
基础医学   561510篇
口腔科学   95212篇
临床医学   336198篇
内科学   634611篇
皮肤病学   95156篇
神经病学   309486篇
特种医学   138099篇
外国民族医学   396篇
外科学   549006篇
综合类   106894篇
现状与发展   91篇
一般理论   2334篇
预防医学   307772篇
眼科学   81674篇
药学   242313篇
  27篇
中国医学   10509篇
肿瘤学   171544篇
  2021年   56652篇
  2020年   37741篇
  2019年   59188篇
  2018年   75395篇
  2017年   58217篇
  2016年   64087篇
  2015年   77988篇
  2014年   115024篇
  2013年   180649篇
  2012年   103469篇
  2011年   105025篇
  2010年   123983篇
  2009年   128547篇
  2008年   90558篇
  2007年   93421篇
  2006年   104457篇
  2005年   98752篇
  2004年   99604篇
  2003年   89456篇
  2002年   79019篇
  2001年   108781篇
  2000年   101724篇
  1999年   100574篇
  1998年   67244篇
  1997年   64759篇
  1996年   62143篇
  1995年   57666篇
  1994年   51540篇
  1993年   47970篇
  1992年   71147篇
  1991年   68355篇
  1990年   64776篇
  1989年   63189篇
  1988年   58709篇
  1987年   57293篇
  1986年   54688篇
  1985年   54497篇
  1984年   49420篇
  1983年   44993篇
  1982年   42131篇
  1981年   39673篇
  1980年   37301篇
  1979年   40832篇
  1978年   35979篇
  1977年   32529篇
  1976年   30364篇
  1975年   28604篇
  1974年   30092篇
  1973年   28968篇
  1972年   27122篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
213.
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   
214.
215.
216.
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   
217.
218.
219.
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   
220.
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