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   1710198篇
  免费   113290篇
  国内免费   3722篇
耳鼻咽喉   21897篇
儿科学   55723篇
妇产科学   46169篇
基础医学   241716篇
口腔科学   48834篇
临床医学   151736篇
内科学   334523篇
皮肤病学   38693篇
神经病学   131598篇
特种医学   63994篇
外国民族医学   246篇
外科学   257722篇
综合类   38966篇
现状与发展   4篇
一般理论   532篇
预防医学   124418篇
眼科学   40291篇
药学   123950篇
  47篇
中国医学   4478篇
肿瘤学   101673篇
  2021年   13117篇
  2019年   14003篇
  2018年   20047篇
  2017年   15314篇
  2016年   16709篇
  2015年   18990篇
  2014年   26266篇
  2013年   37988篇
  2012年   52796篇
  2011年   55504篇
  2010年   32818篇
  2009年   30746篇
  2008年   51579篇
  2007年   54861篇
  2006年   55329篇
  2005年   52596篇
  2004年   50787篇
  2003年   48220篇
  2002年   46422篇
  2001年   91838篇
  2000年   93656篇
  1999年   77015篇
  1998年   19740篇
  1997年   17284篇
  1996年   17409篇
  1995年   16753篇
  1994年   15301篇
  1993年   14085篇
  1992年   57416篇
  1991年   55289篇
  1990年   52998篇
  1989年   50772篇
  1988年   46151篇
  1987年   44960篇
  1986年   42253篇
  1985年   40007篇
  1984年   29367篇
  1983年   24927篇
  1982年   13912篇
  1979年   25541篇
  1978年   17586篇
  1977年   14910篇
  1976年   13881篇
  1975年   14566篇
  1974年   17635篇
  1973年   16951篇
  1972年   15683篇
  1971年   14458篇
  1970年   13438篇
  1969年   12522篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
S L Lee 《JAMA》1991,266(2):217-218
  相似文献   
942.
A tax reform strategy to deal with the uninsured   总被引:1,自引:0,他引:1  
S M Butler 《JAMA》1991,265(19):2541-2544
The high level of ininsurance in the United States is due in large measure to the tax treatment of health care, which is based on the tax exclusion for company-provided plans. Correcting the perverse incentives for providers and patients resulting from this tax treatment is the crucial step to creating a national health care system that is affordable and efficient. The Heritage Foundation proposal calls for the elimination of the current tax exclusion and its replacement with a system of refundable tax credits for the purchase of health insurance and medical services.  相似文献   
943.
An empirical investigation of the perceived role of robotics and artificial computer intelligence in the future of health care reveals factors favoring a positive attitude by health administrators. The study employed a two-part survey administered in late 1989 and early 1990 to health care managers in hospitals and nursing homes. Part One of the survey asked about the participant, his or her work habits and work environment. Part Two obtained a psychological profile of rationality vs. intuition in problem solving. Through bivariate and multivariate post hoc statistical tests, we discovered the following variables which significantly determined attitudes toward robotics and artificial computer intelligence: sex, number of employees supervised; perceptions of waste and inefficiency in the workplace; perceptions of time-consuming personnel problem; perceived need to make more efficient use of time, money, and facilities; and perceived favorable climate for innovation. Among the factors which did not have an effect on attitudes toward advanced technology were three measures of rationality vs. intuition in problem solving.  相似文献   
944.
Several studies have reported that the heart is severely affected by chronic malnutrition. However, the influence of these alterations on cardiac function remains unclear. The aim of this study was to evaluate the effects of subacute starvation on the heart chronotropic response to a beta-adrenergic agonist (isoproterenol). Twelve rats were fed rat chow ad libitum or a 50%-restricted diet for 17 days. The rats were killed, the right atrium was isolated and incubated, and in vitro spontaneous cardiac contractions and frequency were registered. Cumulative doses of isoproterenol were added to the solution until maximal cardiac frequency was achieved. A deficit of 25% in the weight gain was observed in study rats compared with controls (92.6 +/- 10.2 vs. 113.8 +/- 19.2 g, p less than 0.05). Mean daily food intake was 4.8 +/- 0.1 and 9.8 +/- 0.5 g/day for semistarved and control rats, respectively. The in vitro cardiac frequency of the semistarved rats was similar to that of controls (290 +/- 15 and 305 +/- 23 beats/min, respectively, NS). However, when isoproterenol was added to the solution, maximal cardiac frequency of the semistarved rats (435 +/- 51 beats/min) was lower than that of control rats (508 +/- 34 beats/min, p less than 0.005). These findings suggest that subacute starvation may alter the cardiac response to beta-adrenergic agonists.  相似文献   
945.
946.
Growth plate: roentgenologic findings in a case of tyrosinosis   总被引:1,自引:0,他引:1  
S Morrison  D Kerr 《Pediatrics》1989,83(4):599-600
  相似文献   
947.
948.
949.
950.
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