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   2278168篇
  免费   170473篇
  国内免费   4362篇
耳鼻咽喉   31190篇
儿科学   74588篇
妇产科学   64236篇
基础医学   323377篇
口腔科学   62948篇
临床医学   203851篇
内科学   444994篇
皮肤病学   52876篇
神经病学   182128篇
特种医学   88400篇
外国民族医学   665篇
外科学   342716篇
综合类   49770篇
现状与发展   3篇
一般理论   714篇
预防医学   171541篇
眼科学   51917篇
药学   169731篇
  8篇
中国医学   5473篇
肿瘤学   131877篇
  2019年   17594篇
  2018年   25095篇
  2017年   19393篇
  2016年   21960篇
  2015年   24507篇
  2014年   34293篇
  2013年   50839篇
  2012年   69022篇
  2011年   73137篇
  2010年   43139篇
  2009年   40940篇
  2008年   67762篇
  2007年   71966篇
  2006年   73036篇
  2005年   70214篇
  2004年   67083篇
  2003年   64378篇
  2002年   62159篇
  2001年   117987篇
  2000年   121123篇
  1999年   100878篇
  1998年   26927篇
  1997年   24093篇
  1996年   24190篇
  1995年   22817篇
  1994年   20810篇
  1993年   19581篇
  1992年   76024篇
  1991年   72848篇
  1990年   70695篇
  1989年   67655篇
  1988年   61791篇
  1987年   60131篇
  1986年   56512篇
  1985年   53474篇
  1984年   39880篇
  1983年   33627篇
  1982年   19588篇
  1981年   17157篇
  1979年   35282篇
  1978年   24374篇
  1977年   20979篇
  1976年   19037篇
  1975年   20474篇
  1974年   24284篇
  1973年   23415篇
  1972年   22202篇
  1971年   20454篇
  1970年   19176篇
  1969年   18128篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
73.
74.
75.
76.
77.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
78.
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