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   185770篇
  免费   11326篇
  国内免费   489篇
耳鼻咽喉   2353篇
儿科学   5940篇
妇产科学   3930篇
基础医学   25330篇
口腔科学   8015篇
临床医学   13745篇
内科学   41655篇
皮肤病学   4831篇
神经病学   15792篇
特种医学   5650篇
外国民族医学   26篇
外科学   23147篇
综合类   1492篇
现状与发展   1篇
一般理论   65篇
预防医学   19117篇
眼科学   3485篇
药学   11482篇
中国医学   748篇
肿瘤学   10781篇
  2023年   930篇
  2022年   1812篇
  2021年   4130篇
  2020年   2719篇
  2019年   3910篇
  2018年   5429篇
  2017年   3991篇
  2016年   3768篇
  2015年   4378篇
  2014年   6002篇
  2013年   7514篇
  2012年   11768篇
  2011年   12266篇
  2010年   6257篇
  2009年   5664篇
  2008年   9492篇
  2007年   10105篇
  2006年   9405篇
  2005年   9591篇
  2004年   8961篇
  2003年   8257篇
  2002年   6216篇
  2001年   5288篇
  2000年   5263篇
  1999年   4667篇
  1998年   1650篇
  1997年   1393篇
  1996年   1369篇
  1995年   1170篇
  1994年   1154篇
  1993年   1037篇
  1992年   2854篇
  1991年   2747篇
  1990年   2503篇
  1989年   2505篇
  1988年   2255篇
  1987年   2096篇
  1986年   1948篇
  1985年   1873篇
  1984年   1325篇
  1983年   1094篇
  1982年   608篇
  1981年   542篇
  1980年   519篇
  1979年   971篇
  1978年   655篇
  1977年   511篇
  1975年   571篇
  1974年   587篇
  1973年   600篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
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   
33.
34.
35.
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   
36.
37.
38.
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   
39.
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