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   4219565篇
  免费   361418篇
  国内免费   15063篇
耳鼻咽喉   60890篇
儿科学   132521篇
妇产科学   111869篇
基础医学   645068篇
口腔科学   118634篇
临床医学   383742篇
内科学   760665篇
皮肤病学   103146篇
神经病学   361362篇
特种医学   170449篇
外国民族医学   913篇
外科学   648554篇
综合类   125977篇
现状与发展   23篇
一般理论   2584篇
预防医学   355710篇
眼科学   100413篇
药学   300599篇
  19篇
中国医学   10974篇
肿瘤学   201934篇
  2021年   50063篇
  2020年   35499篇
  2019年   58619篇
  2018年   73225篇
  2017年   55591篇
  2016年   61916篇
  2015年   75179篇
  2014年   109953篇
  2013年   175335篇
  2012年   117817篇
  2011年   120931篇
  2010年   122944篇
  2009年   126108篇
  2008年   108105篇
  2007年   114642篇
  2006年   124158篇
  2005年   119223篇
  2004年   120201篇
  2003年   110743篇
  2002年   100983篇
  2001年   153782篇
  2000年   149541篇
  1999年   137308篇
  1998年   65495篇
  1997年   61950篇
  1996年   59741篇
  1995年   60948篇
  1994年   55134篇
  1993年   51151篇
  1992年   103254篇
  1991年   98987篇
  1990年   94012篇
  1989年   91612篇
  1988年   85156篇
  1987年   83698篇
  1986年   79387篇
  1985年   77843篇
  1984年   65692篇
  1983年   58482篇
  1982年   47725篇
  1981年   44457篇
  1980年   41729篇
  1979年   57541篇
  1978年   46733篇
  1977年   41194篇
  1976年   38326篇
  1975年   37568篇
  1974年   42247篇
  1973年   40405篇
  1972年   37974篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
51.
52.
53.
54.
BackgroundEpstein-Barr virus (EBV) is a member of the herpesvirus family that is known to ubiquitously infect people worldwide. However, the actual prevalence of EBV infection in diseased patients in Nigeria, remains unknown. This study was thus conducted to ascertain the true prevalence.MethodsA systematic review and meta-analysis of published data was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Electronic databases including PubMed, Scopus, ScienceDirect, and Google Scholar were searched for studies reporting the occurrence of EBV infection among patients with established diseases. Studies were included if they assessed EBV infection in diseased patients in Nigeria. Data were extracted and subsequently analysed using R software. Funnel plot and Egger's regression test was used to assess publication bias, while JBI prevalence tool was used to assess study quality.ResultsA total of 13 studies covering 228 cases of EBV infection among 1157 diseased patients were included. Summary estimates were computed using random-effects model. The pooled prevalence of EBV infection was 20.3% (95% CI: 10.8–34.9, I2 ?= ?92.26, p ?< ?0.001). When stratified according to the type of disease, higher estimates were obtained for patients suffering from Kaposi's sarcoma (98.7%, 95% CI: 82.2–99.9) and Nasopharyngeal malignancy (85.7%, 95% CI: 70.0–93.9). A prevalence of 13.4% (95% CI: 6.0–27.4) and 12.2% (95% CI: 4.8–27.8) was derived for the most reported patient populations, lymphoma and HIV, respectively.ConclusionThis first meta-analysis on the prevalence of EBV among Nigerian patients suffering from various diseases reveals a prevalence that emphasises the need to routinely monitor EBV infection in all EBV-associated diseases in Nigeria.  相似文献   
55.
Neuroscience and Behavioral Physiology - Objective. To determine the frequency, structure, and severity of cognitive impairments in patients with bipolar affective disorder (BAD) in remission....  相似文献   
56.
57.
The widely accepted Cytokine Milieu Hypothesis proposes that the cytokine milieu, in which antigen activates CD4 T cells, from a non-T cell source, primarily determines the Th subset to which the ensuing effector Th cells belong. We focus on the generation of Th1 and Th2 cells. We briefly restate the grounds for the Threshold Hypothesis we favour for how the Th1/Th2 phenotype of a response is primarily determined: tentative and robust thresholds of antigen-mediated CD4 T cell interactions lead to the generation of Th1 and Th2 cells. The component antigens of pathogens are present in different amounts. It is expected, within the context of the threshold mechanism that, although there is often an initial predominance of Th1 or Th2 cells, some Th cells of the opposing type are initially generated. An initially somewhat heterogeneous Th response is known to become with time more ‘coherent’ in its Th1/Th2 phenotype. I propose The Cytokine Implementation Hypothesis as a mechanism for how coherence is achieved. Most cytokines made by Th cells of one subset tend to facilitate the further generation of Th cells of this subset and/or inhibit the generation of Th cells of opposing subsets, accounting for how coherence may be achieved. Many observations on which The Cytokine Milieu Hypothesis is based are accounted for by this alternative hypothesis. We outline predictions of the new hypothesis and discuss the importance of coherence of immune responses for their efficacy in protecting against foreign invaders.  相似文献   
58.
59.
Biomedical Engineering - A mathematical model of a thermoelectric device for the treatment of whitlow by local hypothermia is discussed. The model is based on a solution of the heat conduction task...  相似文献   
60.
Journal of Behavioral Medicine - Understanding associations between mothers’ and children’s physical activity and sedentary behavior on more fine-grained timescales can provide insights...  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