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   1270255篇
  免费   95134篇
  国内免费   1587篇
耳鼻咽喉   16396篇
儿科学   41187篇
妇产科学   35117篇
基础医学   190150篇
口腔科学   34846篇
临床医学   118476篇
内科学   249054篇
皮肤病学   27326篇
神经病学   102536篇
特种医学   46916篇
外国民族医学   265篇
外科学   179290篇
综合类   25873篇
现状与发展   3篇
一般理论   579篇
预防医学   105490篇
眼科学   28170篇
药学   93023篇
  6篇
中国医学   2025篇
肿瘤学   70248篇
  2018年   13734篇
  2017年   10560篇
  2016年   11495篇
  2015年   13237篇
  2014年   18257篇
  2013年   27845篇
  2012年   38031篇
  2011年   40448篇
  2010年   23289篇
  2009年   22452篇
  2008年   38087篇
  2007年   40686篇
  2006年   40273篇
  2005年   39409篇
  2004年   37769篇
  2003年   36191篇
  2002年   35072篇
  2001年   56113篇
  2000年   57111篇
  1999年   48196篇
  1998年   13459篇
  1997年   12261篇
  1996年   12693篇
  1995年   11970篇
  1994年   11158篇
  1993年   10435篇
  1992年   38252篇
  1991年   37729篇
  1990年   36490篇
  1989年   35305篇
  1988年   32737篇
  1987年   32069篇
  1986年   30568篇
  1985年   28820篇
  1984年   21976篇
  1983年   19220篇
  1982年   11395篇
  1981年   10347篇
  1979年   20977篇
  1978年   15421篇
  1977年   12812篇
  1976年   11870篇
  1975年   12833篇
  1974年   15614篇
  1973年   15383篇
  1972年   14542篇
  1971年   13576篇
  1970年   12811篇
  1969年   12084篇
  1968年   11242篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
Patients have become increasingly well informed with higher expectations to be involved in decision-making processes regarding their care and treatment. However, few studies have examined the impact of patient involvement on health care providers’ partnership-building communication. The aim of this study was to measure and explore the self-reported effects of patient involvement on the work of physicians and nurses. A questionnaire survey was distributed among cardiology staff in 12 Swedish hospitals (N = 488, response rate 67%). The sample was comprised of registered nurses (RNs, n = 303), licensed practical nurses (LPNs, n = 132), and physicians (MDs, n = 53). Confirmatory factor analysis was used to examine seven questionnaire statements concerning implications of patient involvement for one’s clinical work. Regression analyses were used to examine factors associated with staff’s partnership-building communication. Analysis confirmed two distinct factors accounting for 57% of the total variance, representing both negative—“Hassles”and positive—“Uplifts”aspects of patient involvement. Regression analyses revealed that only positive aspects (i.e., uplifts) of patient involvement predicted staff behavior aimed at involving patients. Working with actively involved patients may be a source of stress, both negative and positive, for health care professionals. By developing work routines for involving patients in their care, health care workplaces may help health care professionals to buffer the negative effects, and enhance the positive effects, of that stress.  相似文献   
43.
We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa’s environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly.  相似文献   
44.
45.
46.
47.
48.
49.
50.
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