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   3714篇
  免费   176篇
  国内免费   7篇
耳鼻咽喉   46篇
儿科学   220篇
妇产科学   26篇
基础医学   447篇
口腔科学   140篇
临床医学   390篇
内科学   808篇
皮肤病学   67篇
神经病学   221篇
特种医学   195篇
外科学   500篇
综合类   25篇
一般理论   1篇
预防医学   201篇
眼科学   96篇
药学   297篇
中国医学   5篇
肿瘤学   212篇
  2021年   48篇
  2020年   36篇
  2019年   58篇
  2018年   60篇
  2017年   41篇
  2016年   50篇
  2015年   58篇
  2014年   87篇
  2013年   122篇
  2012年   196篇
  2011年   183篇
  2010年   112篇
  2009年   93篇
  2008年   156篇
  2007年   180篇
  2006年   180篇
  2005年   179篇
  2004年   148篇
  2003年   167篇
  2002年   151篇
  2001年   118篇
  2000年   111篇
  1999年   118篇
  1998年   48篇
  1997年   39篇
  1996年   27篇
  1995年   28篇
  1994年   22篇
  1993年   19篇
  1992年   66篇
  1991年   70篇
  1990年   57篇
  1989年   46篇
  1988年   52篇
  1987年   50篇
  1986年   69篇
  1985年   49篇
  1984年   45篇
  1983年   30篇
  1982年   26篇
  1981年   28篇
  1980年   21篇
  1979年   40篇
  1978年   24篇
  1975年   22篇
  1974年   28篇
  1973年   26篇
  1972年   27篇
  1971年   30篇
  1969年   18篇
排序方式: 共有3897条查询结果,搜索用时 15 毫秒
61.
Tetraspanins are integral transmembrane proteins organized in microdomains displaying specific and direct interactions with other tetraspanins and molecular partners. Among them, CD81 has been implicated in a variety of physiological and pathological processes. CD81 also plays a crucial role in pathogen entry into host cells, including hepatitis C virus (HCV) entry into hepatocytes. HCV is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV entry into hepatocytes is a complex process that requires the coordinated interaction of viral and host factors for the initiation of infection, including CD81, scavenger receptor BI, claudin-1, occludin, membrane-bound host cell kinases, Niemann-Pick C1 Like 1, Harvey rat sarcoma viral oncogene homolog (HRas), CD63 and transferrin receptor 1. Furthermore, recent data in HCV model systems have demonstrated that targeting critical components of tetraspanins and associated cell membrane proteins open new avenues to prevent and treat viral infection.  相似文献   
62.
63.
64.
65.
66.

Background

Mild traumatic brain injury (TBI) is a serious public health concern affecting more than 1.7 million people in the United States annually. Mild TBI is difficult to diagnose and is clinically associated with impaired motor coordination and cognition.

Methods

We subjected mice to a mild TBI (mTBI-1 or mTBI-2) induced by a weight drop model. We assessed brain injury histologically and biochemically, the latter by serum neuron-specific enolase and glial fibrillary acidic protein. Systemic and brain inflammation were measured by cytokine array. We determined blood–brain barrier integrity by cerebral vascular leakage of micromolecular and macromolecular fluorescent molecules. We evaluated mice using a rotarod device and novel object recognition to measure motor coordination and cognition, respectively.

Results

Mice undergoing mTBI-1 or mTBI-2 had significant deficits in motor coordination and cognition for several days after injury compared with controls. Furthermore, both mTBI-1 and mTBI-2 caused micromolecular leakage in the blood–brain barrier, whereas only mTBI-2 caused macromolecular leakage. Serum neuron-specific enolase and glial fibrillary acidic protein were elevated acutely and corresponded to the degree of injury, but returned to baseline within 24 h. Serum cytokines interleukin-6 and keratinocyte-derived chemokine were significantly increased within 90 min of TBI. Interleukin-6 levels correlated with the degree of injury.

Conclusions

The current study provides a reproducible model of mild TBI in mice that exhibits pathologic features of mild TBI in humans. Furthermore, our data suggest that serum cytokines, such as IL-6, may be effective biomarkers for severity of head injury.  相似文献   
67.
68.
Midregional proadrenomedullin (MR-proADM) is elevated in patients with heart failure and myocardial infarction. The aim of this study was to evaluate the association of MR-proADM with the grade of coronary artery stenosis, presence of coronary artery soft plaques and coronary artery calcification score (CACS), determined by 64-multislice computed tomography (MSCT) in patients without known prior cardiovascular disease. This retrospective study included 107 patients undergoing MSCT for confirmation (or exclusion) of coronary artery disease. MR-proADM levels were measured in all patients. The assessment of coronary artery stenoses, CACS and soft coronary plaques was made by MSCT using known criteria. The MR-proADM [median (25th–75th percentiles)] level was 0.33 (0.21–0.43)?nmol/l. The MR-proADM level was 0.28 (0.22–0.40)?nmol/l in patients with coronary stenoses ≥50% (n?=?23) versus 0.33 (0.27–0.40)?nmol/l in patients with coronary stenoses <50% (n?=?83, P?=?0.59), 0.33 (0.26–0.40)?nmol/l in patients with soft plaques (n?=?56) versus 0.33 (0.25–0.41)?nmol/l in patients without soft plaques (n?=?50, P?=?0.73) and 0.33 (0.25–0.39)?nmol/l in patients with CACS?<200 (n?=?81) versus 0.32 (0.26–0.44)?nmol/l in patients with CACS?≥200 (n?=?26, P?=?0.77). In multivariate analysis, the MR-proADM level was a significant correlate of coronary artery stenoses [odds ratio (OR)?=?0.93; 95% confidence interval (CI) 0.86–0.99; P?=?0.026] and soft plaques (OR?=?0.94; 95% CI 0.90–0.99; P?=?0.015) but not of CACS (OR?=?0.98; 95% CI 0.93–1.03; P?=?0.36). A decreased MR-proADM level is an independent correlate of the presence of coronary artery disease and of soft atherosclerotic plaques. Patients with decreased MR-proADM levels may need invasive examinations to diagnose more severe forms of coronary artery disease.  相似文献   
69.
Graefe's Archive for Clinical and Experimental Ophthalmology - This study assesses short-term intraocular pressure (IOP) change in the fellow eye of glaucoma patients after mitomycin...  相似文献   
70.
Abstract

Extracranial to intracranial bypass surgery was used in 27 cases of intracranial giant aneurysm to prevent ischemic complications. In 19 of 21 patients the aneurysm was considered unfit for a direct clipping or ligation, and an EC-IC bypass was done in conjunction with staged clipping of the internal carotid artery or occlusion of the middle cerebral artery. All bypass grafts have remained patent postoperatively. None of the patients have developed ischemic complications in the 6-41 month period of follow-up.  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