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   1864149篇
  免费   124808篇
  国内免费   2748篇
耳鼻咽喉   25925篇
儿科学   61278篇
妇产科学   51440篇
基础医学   282364篇
口腔科学   49947篇
临床医学   160628篇
内科学   362882篇
皮肤病学   40881篇
神经病学   142589篇
特种医学   70847篇
外国民族医学   499篇
外科学   279888篇
综合类   33637篇
现状与发展   2篇
一般理论   456篇
预防医学   140389篇
眼科学   42595篇
药学   141463篇
  2篇
中国医学   3883篇
肿瘤学   100110篇
  2018年   22314篇
  2017年   16127篇
  2016年   17841篇
  2015年   20207篇
  2014年   26195篇
  2013年   40041篇
  2012年   58895篇
  2011年   62616篇
  2010年   35512篇
  2009年   31747篇
  2008年   58361篇
  2007年   63322篇
  2006年   62600篇
  2005年   61154篇
  2004年   58673篇
  2003年   56435篇
  2002年   54885篇
  2001年   78394篇
  2000年   80336篇
  1999年   68066篇
  1998年   18867篇
  1997年   16610篇
  1996年   16839篇
  1995年   15871篇
  1994年   14904篇
  1992年   53685篇
  1991年   53897篇
  1990年   53397篇
  1989年   51903篇
  1988年   48299篇
  1987年   47370篇
  1986年   44932篇
  1985年   42908篇
  1984年   31966篇
  1983年   27677篇
  1982年   16040篇
  1981年   14257篇
  1979年   30410篇
  1978年   21396篇
  1977年   18281篇
  1976年   17686篇
  1975年   19908篇
  1974年   23265篇
  1973年   22468篇
  1972年   21175篇
  1971年   19931篇
  1970年   18603篇
  1969年   17779篇
  1968年   16721篇
  1967年   14810篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
84.
85.
86.
87.
88.
Delayed contrast enhancement after injection of a gadolinium-chelate (Gd-chelate) is a reference imaging method to detect myocardial tissue changes. Its localization within the thickness of the myocardial wall allows differentiating various pathological processes such as myocardial infarction (MI), inflammatory myocarditis, and cardiomyopathies. The aim of the study was first to characterize benign myocarditis using quantitative delayed-enhancement imaging and then to investigate whether the measure of the extracellular volume fraction (ECV) can be used to discriminate between MI and myocarditis.In 6 patients with acute benign myocarditis (32.2 ± 13.8 year-old, subepicardial late gadolinium enhancement [LGE]) and 18 patients with MI (52.3 ± 10.9 year-old, subendocardial/transmural LGE), myocardial T1 was determined using the Modified Look-Locker Imaging (MOLLI) sequence at 3 Tesla before and after Gd-chelate injection. T1 values were compared in LGE and normal regions of the myocardium. The myocardial T1 values were normalized to the T1 of blood, and the ECV was calculated from T1 values of myocardium and blood pre- and post-Gd injection.In both myocarditis and MI, the T1 was lower in LGE regions than in normal regions of the left ventricle. T1 of LGE areas was significantly higher in myocarditis than in MI (446.8 ± 45.8 vs 360.5 ± 66.9 ms, P = 0.003) and ECV was lower in myocarditis than in MI (34.5 ± 3.3 vs 53.8 ± 13.0 %, P = 0.004).Both inflammatory process and chronic fibrosis induce LGE (subepicardial in myocarditis and subendocardial in MI). The present study demonstrates that the determination of T1 and ECV is able to differentiate the 2 histological patterns.Further investigation will indicate whether the severity of ECV changes might help refine the predictive risk of LGE in myocarditis.  相似文献   
89.
90.
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