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   791篇
  免费   34篇
  国内免费   18篇
耳鼻咽喉   1篇
儿科学   11篇
基础医学   44篇
口腔科学   16篇
临床医学   79篇
内科学   316篇
皮肤病学   3篇
神经病学   100篇
特种医学   20篇
外科学   130篇
综合类   11篇
预防医学   13篇
眼科学   3篇
药学   43篇
肿瘤学   53篇
  2023年   5篇
  2022年   7篇
  2021年   24篇
  2020年   18篇
  2019年   23篇
  2018年   28篇
  2017年   24篇
  2016年   16篇
  2015年   26篇
  2014年   41篇
  2013年   29篇
  2012年   67篇
  2011年   78篇
  2010年   58篇
  2009年   33篇
  2008年   43篇
  2007年   44篇
  2006年   49篇
  2005年   44篇
  2004年   44篇
  2003年   36篇
  2002年   42篇
  2001年   5篇
  2000年   4篇
  1999年   5篇
  1998年   6篇
  1997年   6篇
  1996年   5篇
  1995年   5篇
  1994年   4篇
  1993年   8篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1964年   1篇
  1929年   2篇
排序方式: 共有843条查询结果,搜索用时 109 毫秒
1.
There are no reports on detailed endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADET) except for relatively small case series. Herein, we conducted a prospective observational study to investigate the relationship between endoscopic findings and histopathological diagnosis of SNADET. A total of 163 SNADET diagnosed using magnified endoscopic examination with image-enhanced endoscopy (IEE-ME) were prospectively registered in this study. We investigated location, size, macroscopic type, color, and IEE-ME findings including surface structure (closed- or open-loop) and presence of white opaque substance (WOS) in SNADET. We analyzed association between these findings and histopathological diagnosis of SNADET based on the Vienna classification (VCL) using logistic regression analysis. In univariate analysis, lesion size, superficial structure, and WOS deposition showed statistical significance, and the oral side of the lesion location showed statistical tendency for association with VCL C4/5. In multivariate analysis, lesion size (odds ratio [OR], 2.92; 95% CI, 1.94–4.39; P < 0.05) and negative WOS (OR, 5.59; 95% CI, 1.72–18.1; P < 0.05) were significantly associated with VCL C4/5 lesions. Superficial structures with a closed-loop pattern on the surface showed statistical tendency for predicting VCL C4/5 lesions (OR, 2.15; 95% CI, 0.86–5.37; P = 0.10). Based on these findings, we concluded that negative WOS by IEE-ME and lesion size were independent predictors of VCL C4/5 SNADET. These factors may help us to understand of pathophysiology of SNADET and to select appropriate therapeutic strategies.  相似文献   
2.
3.
4.
5.
6.
BackgroundAlthough lung transplantation from donation after cardiac death (DCD), especially uncontrolled DCD, is limited by warm ischemic periods, the molecular mechanism of warm ischemia–reperfusion-injury (IRI) has not been well elucidated. The purpose of this study was to clarify the particular longitudinal mechanisms of molecular factors involved in warm IRI.MethodsCold ischemic-time (CIT)-group lungs were retrieved and subjected to 3-h of cold preservation, whereas warm ischemic-time (WIT)-group lungs were retrieved after 3-h of warm ischemia. Orthotopic rat lung transplantation was performed and the grafts were reperfused for 1 or 4-h. The graft functions, gene expression, and activation of inflammatory molecules in the grafts were analyzed. Exhaled-carbon-monoxide-concentration (ExCO-C) was measured during reperfusion.ResultsOnly the WIT-group showed obvious primary graft dysfunction at 1-h reperfusion, but the graft function was recovered during 4-h reperfusion. Most of pro-inflammatory cytokines and stress-induced molecules showed different expression and activation patterns between CIT and WIT groups. In the WIT-group, the expressions of anti-inflammatory molecules, IL-10 and HO-1, were significantly increased at 1-h reperfusion compared to the CIT-group, and these high levels were maintained through 4-h reperfusion. Furthermore, ExCO-C levels in the WIT-group increased immediately after reperfusion compared to the CIT-group.ConclusionsThis study indicates that warm IRI may involve a different mechanism than cold IRI and anti-inflammatory pathways may play important roles in the graft recovery after lung transplantation from uncontrolled DCD.  相似文献   
7.
8.
Osteoclasts are bone-resorbing, multinucleated giant cells that are essential for bone remodeling and are formed through cell fusion of mononuclear precursor cells. Although receptor activator of nuclear factor-kappaB ligand (RANKL) has been demonstrated to be an important osteoclastogenic cytokine, the cell surface molecules involved in osteoclastogenesis are mostly unknown. Here, we report that the seven-transmembrane receptor-like molecule, dendritic cell-specific transmembrane protein (DC-STAMP) is involved in osteoclastogenesis. Expression of DC-STAMP is rapidly induced in osteoclast precursor cells by RANKL and other osteoclastogenic stimulations. Targeted inhibition of DC-STAMP by small interfering RNAs and specific antibody markedly suppressed the formation of multinucleated osteoclast-like cells. Overexpression of DC-STAMP enhanced osteoclastogenesis in the presence of RANKL. Furthermore, DC-STAMP directly induced the expression of the osteoclast marker tartrate-resistant acid phosphatase. These data demonstrate for the first time that DC-STAMP has an essential role in osteoclastogenesis.  相似文献   
9.
10.
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