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   680篇
  免费   56篇
  国内免费   36篇
耳鼻咽喉   3篇
儿科学   51篇
妇产科学   8篇
基础医学   55篇
口腔科学   16篇
临床医学   107篇
内科学   193篇
皮肤病学   5篇
神经病学   16篇
特种医学   162篇
外科学   35篇
综合类   12篇
预防医学   21篇
眼科学   8篇
药学   46篇
肿瘤学   34篇
  2024年   2篇
  2021年   5篇
  2020年   3篇
  2019年   6篇
  2018年   11篇
  2017年   7篇
  2016年   3篇
  2015年   7篇
  2014年   12篇
  2013年   18篇
  2012年   10篇
  2011年   12篇
  2010年   37篇
  2009年   38篇
  2008年   15篇
  2007年   30篇
  2006年   10篇
  2005年   17篇
  2004年   5篇
  2003年   6篇
  2002年   10篇
  2001年   12篇
  2000年   6篇
  1999年   9篇
  1998年   50篇
  1997年   47篇
  1996年   46篇
  1995年   42篇
  1994年   42篇
  1993年   28篇
  1992年   5篇
  1991年   16篇
  1990年   13篇
  1989年   28篇
  1988年   29篇
  1987年   12篇
  1986年   20篇
  1985年   15篇
  1984年   9篇
  1983年   7篇
  1982年   13篇
  1981年   9篇
  1980年   13篇
  1979年   6篇
  1978年   7篇
  1977年   10篇
  1976年   6篇
  1975年   4篇
  1974年   1篇
  1969年   1篇
排序方式: 共有772条查询结果,搜索用时 0 毫秒
1.
2.
Needle core biopsy guided with mammography: a study of cost- effectiveness   总被引:2,自引:0,他引:2  
Lindfors  KK; Rosenquist  CJ 《Radiology》1994,190(1):217
  相似文献   
3.
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.  相似文献   
4.
We have shown that the heart expresses two distinct forms of adenylylcyclase mRNA, types V and VI. In this study we have characterized the expression of these two mRNA species in heart failure generated by overdrive pacing at a rate of 240 beats/min. After 4 wk, left ventricular end-diastolic pressure and heart rate increased significantly with the appearance of signs of heart failure, i.e., edema, ascites, and exercise intolerance. Basal as well as forskolin-stimulated adenylylcyclase activities decreased significantly, which was accompanied by a reduction in the steady state mRNA levels of adenylylcyclase types V and VI. These data suggest that in this model of cardiomyopathy, the downregulation of adenylylcyclase catalytic activity results, at least in part, from a reduction in the steady state levels of types V and VI adenylylcyclase mRNA levels.  相似文献   
5.
Background: Spherophakia is an uncommon diagnosis. This is the first case report of spherophakia evaluated by ultrasound biomicroscopy.
Methods: Ultrasound biomicroscopy is a new diagnostic technique developed by one of the authors and provides images with microscopic resolution of the anterior segment. A patient with spherophakia was evaluated by ultrasound biomicroscopy (Zeiss-Humphrey, 50MHz) before and after YAG laser iridotomy.
Results: Ultrasound biomicroscopic assessment revealed a shallow anterior chamber, a very steep anterior lens curvature, iridolenticular contact, elongated zonules, and an increased distance between the lens equator and the ciliary processes. Angle closure glaucoma was due to a pupil block mechanism. The pupil block was relieved by YAG laser iridotomy.
Conclusions: Ultrasound biomicroscopy is a useful technique to confirm the diagnosis of spherophakia. The pupil block in spherophakia is relieved by YAG laser iridotomy.  相似文献   
6.
7.
8.
9.
The development of both adenocarcinoma of the jejunum and in situ squamous carcinoma of the oesophagus in an adult coeliac patient is described. Good evidence that adenocarcinoma of jejunum occurs more frequently in patients with coeliac disease has recently become available though this association has been suggested for some time. While oesophageal carcinoma has long been associated with coeliac disease, in situ carcinoma of oesophagus has not been previously described in these circumstances. We feel that the risk of this complication, as calculated from published series, warrants a screening programme for oesophageal malignancy in adult coeliacs.  相似文献   
10.
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