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   26690篇
  免费   1344篇
  国内免费   152篇
耳鼻咽喉   277篇
儿科学   554篇
妇产科学   623篇
基础医学   3414篇
口腔科学   1046篇
临床医学   1932篇
内科学   7167篇
皮肤病学   697篇
神经病学   2014篇
特种医学   496篇
外科学   4335篇
综合类   174篇
一般理论   3篇
预防医学   1936篇
眼科学   441篇
药学   1468篇
中国医学   123篇
肿瘤学   1486篇
  2023年   208篇
  2022年   436篇
  2021年   955篇
  2020年   438篇
  2019年   893篇
  2018年   1027篇
  2017年   575篇
  2016年   589篇
  2015年   756篇
  2014年   1101篇
  2013年   1381篇
  2012年   2192篇
  2011年   2238篇
  2010年   1318篇
  2009年   1143篇
  2008年   1807篇
  2007年   1864篇
  2006年   1707篇
  2005年   1523篇
  2004年   1412篇
  2003年   1341篇
  2002年   1234篇
  2001年   157篇
  2000年   126篇
  1999年   168篇
  1998年   191篇
  1997年   146篇
  1996年   144篇
  1995年   123篇
  1994年   99篇
  1993年   84篇
  1992年   71篇
  1991年   50篇
  1990年   51篇
  1989年   36篇
  1988年   42篇
  1987年   32篇
  1986年   20篇
  1985年   38篇
  1984年   36篇
  1983年   40篇
  1982年   46篇
  1981年   45篇
  1980年   44篇
  1979年   18篇
  1978年   24篇
  1977年   26篇
  1975年   22篇
  1974年   21篇
  1973年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Prior meta‐analyses have shown a higher gastrointestinal risk of nonselective NSAIDs versus placebo and a lower gastrointestinal risk of coxibs versus nonselective NSAIDs. However, the available data about gastrointestinal risk for coxibs versus placebo are scarce. The aim of this study was to review the current evidence on the use of coxibs and to evaluate the risk of gastrointestinal adverse outcomes (GAO) associated with coxibs versus nonexposed. Search was conducted on PubMed and Embase databases. We selected cohort observational, case‐control, nested case‐control and case‐crossover studies that reported the risk of GAO associated with coxibs versus nonexposed as relative risk (RR), odds ratio (OR), hazard ratio (HR) or incidence rate ratio (IRR). It was estimated the pooled RR and the 95% confidence interval (CI) for coxibs both individually and as a whole by the DerSimonian and Laird method. Twenty‐eight studies met inclusion criteria. Overall, coxibs were associated with a significant increment in the risk of GAO [RR 1.64 (95% CI 1.44–1.86)]. The analysis by individual drugs showed that etoricoxib [RR 4.85 (95% CI 2.64–8.93)] presented the highest gastrointestinal risk, followed by rofecoxib [RR 2.02 (95% CI 1.56–2.61)] and celecoxib [RR 1.53 (95% CI 1.19–1.97)]. Gastrointestinal risk was also high for the subgroups aged <65 years and low‐dose coxibs. The use of coxibs is associated with a statistically significant increased risk of GAO, which would be high even for low‐dose coxibs and <65‐year‐old subgroups. The risk would be higher for etoricoxib than for celecoxib and rofecoxib.  相似文献   
993.
994.
995.
996.
The epidemiological cycle of zoonotic phlebotomine‐borne Leishmania infantum is a complex system in which domestic animals and wildlife interact and participate in its maintenance and transmission. In this study, we combined entomological surveillance, xenomonitoring of L. infantum and identification of host feeding sources of engorged females to investigate the potential contribution of a periurban wildlife park to leishmaniosis in neighbouring residential areas. Overall, 7,309 sand flies were collected in 111 trap‐days during the summers of 2016–2018 in an endemic area in south‐east Spain. Five different sand fly species were captured, with Phlebotomus perniciosus, the main L. infantum vector in this region, representing the most common species. Sand fly distribution was spatially heterogeneous in terms of species, sexes and female physiological stage (unfed, gravid and engorged females) and related to host distribution and management, and environmental features. None of the 602 sand flies analysed for L. infantum infection by kinetoplast real‐time PCR were positive. We used molecular tools to identify the vertebrate hosts of sand flies and identified 17 host species, mainly mammals. Human DNA was not identified in engorged sand flies. This study provides evidence that wildlife parks in south‐east Spain are ideal grounds for sand fly vectors but do not necessarily increase L. infantum infection risk to humans and dogs living in surrounding residential areas. This is probably because vectors feed mostly on non‐L. infantum competent hosts and this should be investigated for a better understanding of the contribution of wildlife parks to the local epidemiology of L. infantum.  相似文献   
997.
998.
999.
1000.
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