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   1534篇
  免费   190篇
  国内免费   14篇
耳鼻咽喉   13篇
儿科学   68篇
妇产科学   22篇
基础医学   279篇
口腔科学   38篇
临床医学   215篇
内科学   265篇
皮肤病学   12篇
神经病学   83篇
特种医学   219篇
外科学   239篇
综合类   51篇
预防医学   112篇
眼科学   2篇
药学   78篇
肿瘤学   42篇
  2021年   11篇
  2019年   18篇
  2018年   21篇
  2017年   15篇
  2016年   20篇
  2015年   15篇
  2014年   28篇
  2013年   66篇
  2012年   45篇
  2011年   53篇
  2010年   39篇
  2009年   27篇
  2008年   35篇
  2007年   42篇
  2006年   44篇
  2005年   32篇
  2004年   36篇
  2003年   38篇
  2002年   36篇
  2001年   39篇
  2000年   26篇
  1999年   50篇
  1998年   49篇
  1997年   57篇
  1996年   49篇
  1995年   55篇
  1994年   38篇
  1993年   40篇
  1992年   47篇
  1991年   49篇
  1990年   51篇
  1989年   38篇
  1988年   54篇
  1987年   36篇
  1986年   40篇
  1985年   30篇
  1984年   22篇
  1983年   24篇
  1982年   31篇
  1981年   21篇
  1980年   27篇
  1979年   19篇
  1978年   23篇
  1977年   29篇
  1976年   22篇
  1975年   22篇
  1974年   15篇
  1973年   11篇
  1972年   13篇
  1970年   14篇
排序方式: 共有1738条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Bottomley  PA; Lee  Y; Weiss  RG 《Radiology》1997,204(2):403
  相似文献   
6.
Experiments were conducted to investigate the microaerobic culture of Helicobacter pylori in a liquid medium by using gas-permeable Lifecell tissue culture flasks. Growth in Lifecell tissue culture flasks was 1.2 to 1.6 log units greater than that in glass control bottles. These results were comparable to those reported by the use of gyrated media.  相似文献   
7.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
8.
9.
Gastric campylobacter-like organisms (CLO) were isolated from gastric tissues removed at sacrifice from 17 mature ferrets; all animals were colonized, but no macroscopic mucosal lesions or histological features of chronic gastritis were seen. The isolates resembled Campylobacter pylori in many cultural and biochemical characteristics, and produced substantial urease activity, but there were sufficient differences from C. pylori to suggest that ferret gastric CLO represents a separate species. Comparison of human C. pylori and ferret gastric CLO may help to elucidate the pathogenicity of the former in patients with gastritis, and the ferret may serve as a useful animal model for the study of C. pylori infection.  相似文献   
10.
The biliary surgeon in the 1990s must be familiar with all of the available techniques for the treatment of bile duct stones. Experience and judgment are important in the successful management of the individual patient with intrahepatic or extrahepatic stones. Knowledge of the nonsurgical methods of stone removal is important in the decision-making process. However, the biliary surgeon must resist the temptation to do less than a thorough removal of all stones at the operation lest the patient be subjected to additional procedures, which carry their own risks of morbidity and death. The goal should be to clear the stones from the biliary system with the fewest procedures offering the lowest morbidity and mortality risks to the patient.  相似文献   
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