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   1289123篇
  免费   95395篇
  国内免费   2013篇
耳鼻咽喉   18405篇
儿科学   42639篇
妇产科学   38025篇
基础医学   188900篇
口腔科学   35693篇
临床医学   109411篇
内科学   254268篇
皮肤病学   26761篇
神经病学   100500篇
特种医学   50525篇
外国民族医学   366篇
外科学   199979篇
综合类   26732篇
现状与发展   1篇
一般理论   312篇
预防医学   93632篇
眼科学   29401篇
药学   98592篇
  1篇
中国医学   2503篇
肿瘤学   69885篇
  2018年   12095篇
  2015年   11937篇
  2014年   16401篇
  2013年   25045篇
  2012年   34431篇
  2011年   36938篇
  2010年   21727篇
  2009年   20469篇
  2008年   35898篇
  2007年   38902篇
  2006年   39390篇
  2005年   38787篇
  2004年   37251篇
  2003年   36238篇
  2002年   35751篇
  2001年   58249篇
  2000年   59724篇
  1999年   50844篇
  1998年   14420篇
  1997年   12954篇
  1996年   13213篇
  1995年   12474篇
  1994年   11864篇
  1993年   10973篇
  1992年   41078篇
  1991年   40468篇
  1990年   39969篇
  1989年   38791篇
  1988年   36215篇
  1987年   35425篇
  1986年   33807篇
  1985年   32218篇
  1984年   24019篇
  1983年   20927篇
  1982年   12503篇
  1981年   11040篇
  1980年   10321篇
  1979年   22706篇
  1978年   15966篇
  1977年   13809篇
  1976年   13048篇
  1975年   14264篇
  1974年   16747篇
  1973年   16141篇
  1972年   15359篇
  1971年   14266篇
  1970年   13255篇
  1969年   12749篇
  1968年   11994篇
  1967年   10499篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
171.
172.
Respiratory failure is defined by the inability of the respiratory system to adequately deliver oxygen or remove carbon dioxide from the pulmonary circulation resulting in hypoxemia, hypercapnia or both. A wide variety of disease processes can lead to respiratory failure in children. Multiple interventions can support the paediatric patient with respiratory failure, from simple oxygen delivery devices to high frequency oscillatory ventilation and extracorporeal membrane oxygenation. This article will review available devices to improve oxygenation and ventilation, their advantages and disadvantages, and help guide physicians in the management of children with respiratory failure.  相似文献   
173.
174.
175.
To improve the diagnostic accuracy of electroencephalography (EEG) criteria for nonconvulsive status epilepticus (NCSE), external validation of the recently proposed Salzburg criteria is paramount. We performed an external, retrospective, diagnostic accuracy study of the Salzburg criteria, using EEG recordings from patients with and without a clinical suspicion of having NCSE. Of the 191 EEG recordings, 12 (12%) was classified as an NCSE according to the reference standard. In the validation cohort, sensitivity was 67% and specificity was 89%. The positive predictive value was 47% and the negative predictive value was 95%. Ten patients in the control group (n = 93) were false positive, resulting in a specificity of 89.2%. The interrater agreement between the reference standards and between the scorers of the Salzburg criteria was moderate; disagreement occurred mainly in patients with an epileptic encephalopathy. The Salzburg criteria showed a lower diagnostic accuracy in our external validation study than in the original design, suggesting that they cannot replace the current practice of careful weighing of both clinical and EEG information on an individual basis.  相似文献   
176.
ABSTRACT

Introduction

Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy.  相似文献   
177.
Neurological Sciences - Chronic subdural haematoma (CSDH) is one of the most common neurosurgical pathologies. The recurrence of chronic subdural haematomas is an important concern, considering...  相似文献   
178.
Abstract

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos.  相似文献   
179.
180.
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