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   181131篇
  免费   10908篇
  国内免费   468篇
耳鼻咽喉   2341篇
儿科学   5786篇
妇产科学   3839篇
基础医学   24690篇
口腔科学   8707篇
临床医学   13235篇
内科学   40595篇
皮肤病学   4595篇
神经病学   15117篇
特种医学   5478篇
外国民族医学   26篇
外科学   22616篇
综合类   1425篇
现状与发展   1篇
一般理论   65篇
预防医学   18541篇
眼科学   3400篇
药学   11030篇
中国医学   756篇
肿瘤学   10264篇
  2023年   904篇
  2022年   1703篇
  2021年   3952篇
  2020年   2640篇
  2019年   3727篇
  2018年   5249篇
  2017年   3900篇
  2016年   3658篇
  2015年   4324篇
  2014年   5879篇
  2013年   7439篇
  2012年   11611篇
  2011年   12270篇
  2010年   6200篇
  2009年   5549篇
  2008年   9408篇
  2007年   9997篇
  2006年   9185篇
  2005年   9444篇
  2004年   8878篇
  2003年   8053篇
  2002年   6107篇
  2001年   5136篇
  2000年   5079篇
  1999年   4487篇
  1998年   1604篇
  1997年   1321篇
  1996年   1312篇
  1995年   1111篇
  1994年   1105篇
  1993年   1005篇
  1992年   2694篇
  1991年   2605篇
  1990年   2385篇
  1989年   2374篇
  1988年   2133篇
  1987年   1977篇
  1986年   1848篇
  1985年   1768篇
  1984年   1274篇
  1983年   1030篇
  1982年   581篇
  1981年   524篇
  1980年   502篇
  1979年   931篇
  1978年   622篇
  1977年   485篇
  1975年   560篇
  1974年   557篇
  1973年   557篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
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   
35.
36.
37.
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   
38.
39.
40.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  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