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   183467篇
  免费   11065篇
  国内免费   475篇
耳鼻咽喉   2366篇
儿科学   5969篇
妇产科学   3886篇
基础医学   25115篇
口腔科学   7989篇
临床医学   14136篇
内科学   40790篇
皮肤病学   4615篇
神经病学   15484篇
特种医学   5547篇
外国民族医学   26篇
外科学   22048篇
综合类   1517篇
现状与发展   1篇
一般理论   70篇
预防医学   19507篇
眼科学   3394篇
药学   11138篇
中国医学   732篇
肿瘤学   10677篇
  2023年   1012篇
  2022年   2173篇
  2021年   4109篇
  2020年   2713篇
  2019年   3883篇
  2018年   5301篇
  2017年   3974篇
  2016年   3695篇
  2015年   4347篇
  2014年   5913篇
  2013年   7524篇
  2012年   11732篇
  2011年   12306篇
  2010年   6221篇
  2009年   5590篇
  2008年   9536篇
  2007年   10106篇
  2006年   9391篇
  2005年   9609篇
  2004年   8997篇
  2003年   8250篇
  2002年   6277篇
  2001年   5028篇
  2000年   4999篇
  1999年   4406篇
  1998年   1680篇
  1997年   1366篇
  1996年   1350篇
  1995年   1141篇
  1994年   1136篇
  1993年   1032篇
  1992年   2684篇
  1991年   2596篇
  1990年   2367篇
  1989年   2347篇
  1988年   2119篇
  1987年   1975篇
  1986年   1852篇
  1985年   1771篇
  1984年   1281篇
  1983年   1035篇
  1982年   595篇
  1981年   537篇
  1980年   521篇
  1979年   935篇
  1978年   612篇
  1977年   482篇
  1975年   552篇
  1974年   544篇
  1973年   544篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
32.
33.
34.
35.
36.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
37.
38.
39.
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices  相似文献   
40.
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