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   1341篇
  免费   83篇
  国内免费   8篇
耳鼻咽喉   7篇
儿科学   29篇
妇产科学   17篇
基础医学   177篇
口腔科学   6篇
临床医学   186篇
内科学   335篇
皮肤病学   16篇
神经病学   116篇
特种医学   26篇
外科学   205篇
综合类   7篇
预防医学   84篇
眼科学   37篇
药学   73篇
中国医学   5篇
肿瘤学   106篇
  2024年   3篇
  2023年   21篇
  2022年   38篇
  2021年   84篇
  2020年   31篇
  2019年   73篇
  2018年   79篇
  2017年   37篇
  2016年   43篇
  2015年   38篇
  2014年   54篇
  2013年   75篇
  2012年   138篇
  2011年   99篇
  2010年   60篇
  2009年   34篇
  2008年   58篇
  2007年   61篇
  2006年   53篇
  2005年   49篇
  2004年   42篇
  2003年   23篇
  2002年   33篇
  2001年   23篇
  2000年   16篇
  1999年   15篇
  1998年   4篇
  1996年   6篇
  1995年   3篇
  1994年   3篇
  1992年   9篇
  1991年   12篇
  1990年   6篇
  1989年   9篇
  1987年   8篇
  1986年   4篇
  1979年   4篇
  1977年   3篇
  1975年   4篇
  1974年   3篇
  1973年   7篇
  1972年   11篇
  1971年   3篇
  1970年   3篇
  1969年   5篇
  1968年   4篇
  1967年   3篇
  1923年   2篇
  1914年   3篇
  1913年   2篇
排序方式: 共有1432条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
Risk stratification of patients with pulmonary embolism represents an important step and may help to guide initial therapeutic management. Pulmonary embolism can be stratified into several groups, with different risk of early death or complications based on the presence of several risk factors. High-risk pulmonary embolism is defined by shock or peripheral signs of hypoperfusion. It is a life-threatening emergency with high short-term mortality (>25%) requiring specific therapeutic strategy with inotropic agents and fibrinolysis. In normotensive patients with pulmonary embolism, the presence of right ventricular dysfunction assessed by echocardiography or myocardial injury based on elevated levels of biomarkers, is associated with an intermediate risk of early death. These patients require close monitoring, and the role of thrombolytic treatment is currently assessed in a large trial. Lastly, patients with normotensive pulmonary embolism and without right ventricular dysfunction or myocardial injury have a low risk of death and complications. These patients may be candidates for home treatment. Several scores combining these risk factors have been described.  相似文献   
45.
46.
47.
48.
ObjectiveThe thymus plays a crucial role in immune system homeostasis. Thymic abnormalities have been reported in many autoimmune diseases, but data for systemic sclerosis (SSc) and rheumatoid arthritis (RA) are sparse. The aim of this study was to evaluate the prevalence and correlates of radiological incomplete involution of the thymus in SSc and RA patients, and in a non-autoimmune group of controls.MethodsAll patients were at least 40 years old: 96 SSc patients (median age 59 years, 80% women) and 65 RA patients (median age 57 years, 88% women) were compared with 32 control individuals (median age 63 years, 62% women). Pulmonary CT-scans performed for lung assessment were available for all individuals. For the purpose of our study, complete involution of the thymus was defined as the absence of a residual thymus or a gland thickness, corresponding to the short axis on the axial slice, of less than 7 mm. We defined incomplete involution of the thymus as a residual thymic tissue more than 7 mm thick.ResultsThe frequency of incomplete thymus involution was significantly higher in SSc and RA patients (respectively 15 and 14%) than in the control group (0%; P < 0.05). Incomplete thymus involution was associated with pulmonary restrictive syndrome in SSc patients, and with biotherapy and an absence of antinuclear antibodies in RA patients.ConclusionOur findings show that two autoimmune diseases, SSc and RA, are associated with incomplete thymus involution.  相似文献   
49.
Implicit memory is generally supposed to be preserved in Alzheimer’s disease (AD). Yet, some implicit priming effects are impaired and others are not. The preserved/impaired priming effects are often interpreted according to the perceptual/conceptual or identification/production distinctions. Perceptual–identification priming paradigms shall be preserved and conceptual–production priming paradigms impaired. A third interpretation is yet possible based on the disconnection syndrome hypothesis which states that patients with AD should fail tasks requiring relatively complex brain communications. In this case, patients with AD should not demonstrated a significant perceptual priming effect in an identification task if this one involved complex brain communications. The present study tests this latter hypothesis with two cross-modal priming experiments using a categorization task. A visual meaningless mask presented with half of the auditory primes tested the nature of the cross-modal priming effect. The control group exhibited significant priming effects for unmasked primes. The interference effect of the mask demonstrated that the priming effect was perceptually driven. Patients with AD did not present any priming effect nor mask interference. The present findings therefore showed that perceptual priming using an identification task could be impaired in AD supporting the disconnection syndrome hypothesis.  相似文献   
50.
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