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   3287662篇
  免费   231865篇
  国内免费   5794篇
耳鼻咽喉   47146篇
儿科学   104250篇
妇产科学   90938篇
基础医学   477753篇
口腔科学   93596篇
临床医学   292481篇
内科学   632028篇
皮肤病学   73549篇
神经病学   259696篇
特种医学   125213篇
外国民族医学   894篇
外科学   499325篇
综合类   71142篇
现状与发展   16篇
一般理论   1189篇
预防医学   248297篇
眼科学   78061篇
药学   246126篇
  15篇
中国医学   6805篇
肿瘤学   176801篇
  2018年   34491篇
  2017年   26354篇
  2016年   29480篇
  2015年   33130篇
  2014年   46746篇
  2013年   70809篇
  2012年   96090篇
  2011年   102250篇
  2010年   60922篇
  2009年   57934篇
  2008年   96738篇
  2007年   104018篇
  2006年   104865篇
  2005年   101902篇
  2004年   97902篇
  2003年   94640篇
  2002年   92077篇
  2001年   148902篇
  2000年   152790篇
  1999年   128999篇
  1998年   37133篇
  1997年   32789篇
  1996年   32450篇
  1995年   30775篇
  1994年   28470篇
  1993年   26828篇
  1992年   100507篇
  1991年   98088篇
  1990年   95954篇
  1989年   92904篇
  1988年   85921篇
  1987年   84504篇
  1986年   79858篇
  1985年   76596篇
  1984年   57040篇
  1983年   48635篇
  1982年   29102篇
  1981年   26252篇
  1979年   53442篇
  1978年   38300篇
  1977年   32491篇
  1976年   30466篇
  1975年   33620篇
  1974年   40138篇
  1973年   38531篇
  1972年   36487篇
  1971年   34434篇
  1970年   32152篇
  1969年   30728篇
  1968年   28418篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
The Impella 5.0, a percutaneously inserted left ventricular assist device, has been used to support patients who have severe heart failure or who are undergoing high-risk percutaneous coronary intervention. We report our surgical placement of the Impella 5.0, through a graft sewn to the aorta, to unload the left ventricle of a 59-year-old man who was undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy shock. The patient underwent successful placement of a long-term left ventricular assist device before his discharge from the hospital. The versatility of the Impella 5.0 is exemplified in this patient who was successfully bridged to long-term support.  相似文献   
132.
133.
The jobs of Latino manual laborers place their mental and physical health at risk. This study evaluates the associations among musculoskeletal pain, mental health, and work organization in Latino manual laborers. Farmworkers and nonfarmworkers (n = 189) in North Carolina were interviewed for self-reported musculoskeletal pain, depressive symptoms, stress, work safety climate, and precarious job status. More nonfarmworkers than farmworkers had neck and shoulder pain, but they did not differ in other areas of musculoskeletal pain. Depressive symptoms had a significant association with neck and shoulder pain (p < .05). Precariousness had a significant association with back pain (p < .05). Farmworker participants had H-2A visas and were afforded some protection compared to nonfarmworker manual workers. Research is needed to improve policy that relieves pain and improves mental health for all Latino manual workers.  相似文献   
134.
135.
136.
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.

Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.

Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.

Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality.  相似文献   
137.
138.
139.
140.
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