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   5043941篇
  免费   379111篇
  国内免费   15643篇
耳鼻咽喉   70078篇
儿科学   161281篇
妇产科学   134302篇
基础医学   755125篇
口腔科学   139648篇
临床医学   460803篇
内科学   916687篇
皮肤病学   121844篇
神经病学   412139篇
特种医学   194639篇
外国民族医学   704篇
外科学   764399篇
综合类   142774篇
现状与发展   23篇
一般理论   2821篇
预防医学   417207篇
眼科学   121950篇
药学   356320篇
  28篇
中国医学   13755篇
肿瘤学   252168篇
  2021年   56929篇
  2019年   59316篇
  2018年   76489篇
  2017年   58521篇
  2016年   65031篇
  2015年   77296篇
  2014年   111827篇
  2013年   177488篇
  2012年   145202篇
  2011年   154604篇
  2010年   133017篇
  2009年   131719篇
  2008年   139781篇
  2007年   150458篇
  2006年   157526篇
  2005年   152178篇
  2004年   152127篇
  2003年   141371篇
  2002年   129971篇
  2001年   199035篇
  2000年   195956篇
  1999年   175564篇
  1998年   76087篇
  1997年   70404篇
  1996年   68448篇
  1995年   63725篇
  1994年   57782篇
  1993年   53449篇
  1992年   128122篇
  1991年   123773篇
  1990年   118934篇
  1989年   115878篇
  1988年   106548篇
  1987年   104363篇
  1986年   98597篇
  1985年   96242篇
  1984年   77886篇
  1983年   68840篇
  1982年   51535篇
  1981年   47798篇
  1980年   44785篇
  1979年   68363篇
  1978年   53596篇
  1977年   47004篇
  1976年   43870篇
  1975年   44683篇
  1974年   50344篇
  1973年   48323篇
  1972年   45219篇
  1971年   42123篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
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   
82.
83.
84.
85.
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   
86.
87.
88.
89.
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   
90.
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   
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