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   4364494篇
  免费   354217篇
  国内免费   15636篇
耳鼻咽喉   61678篇
儿科学   135111篇
妇产科学   113550篇
基础医学   665649篇
口腔科学   120869篇
临床医学   396562篇
内科学   791993篇
皮肤病学   104880篇
神经病学   374691篇
特种医学   173615篇
外国民族医学   913篇
外科学   663549篇
综合类   127245篇
现状与发展   24篇
一般理论   2687篇
预防医学   369182篇
眼科学   102325篇
药学   308061篇
  24篇
中国医学   11511篇
肿瘤学   210228篇
  2021年   56548篇
  2020年   36147篇
  2019年   59450篇
  2018年   74411篇
  2017年   56885篇
  2016年   63415篇
  2015年   76619篇
  2014年   111765篇
  2013年   177724篇
  2012年   123967篇
  2011年   127802篇
  2010年   125507篇
  2009年   128401篇
  2008年   114578篇
  2007年   121813篇
  2006年   130751篇
  2005年   126102篇
  2004年   126581篇
  2003年   117126篇
  2002年   107299篇
  2001年   155050篇
  2000年   151109篇
  1999年   140173篇
  1998年   71962篇
  1997年   68314篇
  1996年   66086篇
  1995年   61922篇
  1994年   55930篇
  1993年   51955篇
  1992年   103965篇
  1991年   99359篇
  1990年   94358篇
  1989年   92013篇
  1988年   85605篇
  1987年   84072篇
  1986年   79736篇
  1985年   78165篇
  1984年   66174篇
  1983年   59068篇
  1982年   48342篇
  1981年   45095篇
  1980年   42333篇
  1979年   58016篇
  1978年   47194篇
  1977年   41742篇
  1976年   38814篇
  1975年   37994篇
  1974年   42581篇
  1973年   40680篇
  1972年   38133篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
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   
162.
163.
164.
165.
166.
167.
168.
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   
169.
170.
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