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   3710053篇
  免费   309798篇
  国内免费   13761篇
耳鼻咽喉   50896篇
儿科学   118363篇
妇产科学   97238篇
基础医学   580798篇
口腔科学   102754篇
临床医学   331345篇
内科学   661376篇
皮肤病学   95201篇
神经病学   316995篇
特种医学   148571篇
外国民族医学   497篇
外科学   572290篇
综合类   113732篇
现状与发展   23篇
一般理论   2375篇
预防医学   309442篇
眼科学   85784篇
药学   259721篇
  22篇
中国医学   10133篇
肿瘤学   176056篇
  2021年   55093篇
  2020年   35087篇
  2019年   58006篇
  2018年   71438篇
  2017年   54470篇
  2016年   60259篇
  2015年   74246篇
  2014年   108526篇
  2013年   173604篇
  2012年   97219篇
  2011年   97646篇
  2010年   117751篇
  2009年   122077篇
  2008年   85385篇
  2007年   88680篇
  2006年   99651篇
  2005年   94755篇
  2004年   97350篇
  2003年   87816篇
  2002年   77680篇
  2001年   120856篇
  2000年   115175篇
  1999年   111716篇
  1998年   67013篇
  1997年   64578篇
  1996年   62575篇
  1995年   58192篇
  1994年   52345篇
  1993年   48883篇
  1992年   82951篇
  1991年   79412篇
  1990年   75954篇
  1989年   74618篇
  1988年   69450篇
  1987年   68138篇
  1986年   64934篇
  1985年   64808篇
  1984年   56582篇
  1983年   51285篇
  1982年   44753篇
  1981年   41911篇
  1980年   39511篇
  1979年   48961篇
  1978年   40956篇
  1977年   36776篇
  1976年   34082篇
  1975年   32839篇
  1974年   35536篇
  1973年   34195篇
  1972年   31693篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
71.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  相似文献   
72.
73.
74.
Pharmaceutical Chemistry Journal - Three extracts were produced from the above-ground part of the meadowsweet Filipendula ulmaria (L.) Maxim. using water, 40% ethanol, and 70% ethanol. Comparative...  相似文献   
75.
76.
77.
78.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  相似文献   
79.
AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXsmiR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXsmiR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.  相似文献   
80.
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