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   887篇
  免费   160篇
  国内免费   18篇
耳鼻咽喉   12篇
儿科学   46篇
妇产科学   12篇
基础医学   44篇
口腔科学   11篇
临床医学   152篇
内科学   228篇
皮肤病学   32篇
神经病学   46篇
特种医学   88篇
外科学   176篇
综合类   48篇
现状与发展   20篇
预防医学   57篇
眼科学   25篇
药学   18篇
中国医学   2篇
肿瘤学   48篇
  2024年   7篇
  2023年   42篇
  2021年   17篇
  2020年   22篇
  2019年   9篇
  2018年   50篇
  2017年   45篇
  2016年   31篇
  2015年   40篇
  2014年   40篇
  2013年   55篇
  2012年   21篇
  2011年   29篇
  2010年   47篇
  2009年   64篇
  2008年   35篇
  2007年   24篇
  2006年   31篇
  2005年   17篇
  2004年   13篇
  2003年   16篇
  2002年   13篇
  2001年   17篇
  2000年   12篇
  1999年   18篇
  1998年   29篇
  1997年   32篇
  1996年   44篇
  1995年   29篇
  1994年   17篇
  1993年   21篇
  1992年   7篇
  1991年   8篇
  1990年   10篇
  1989年   12篇
  1988年   15篇
  1987年   14篇
  1986年   11篇
  1985年   12篇
  1984年   4篇
  1983年   6篇
  1982年   8篇
  1981年   4篇
  1980年   5篇
  1978年   12篇
  1977年   8篇
  1976年   7篇
  1975年   5篇
  1964年   5篇
  1963年   4篇
排序方式: 共有1065条查询结果,搜索用时 15 毫秒
991.
Traditional state Medicaid programs that adopt an open managed care model must adapt their oversight from a single drug formulary to multiple formularies. Following the workshop, participants should be able to identify and describe successful strategies for obtaining and analyzing data needed to evaluate appropriateness of multiple drug formularies. Practical experience with obtaining information and creating a database containing multiple formularies, procedures to incorporate analysis of drug therapy by disease sate, and different methods used to categorize drugs for evaluation will be presented. These will be demonstrated by comparing medications used for the treatment of peptic ulcer disease by Medicaid managed care formularies in the state of Tennessee. This workshop is intended for government and healthcare industry decision makers and others involved in quality control and improvement.  相似文献   
992.
993.
994.
995.
996.
997.
This paper describes what the Wellcome Trust has done and aims to do through its population initiative. The Trust is required to spend its funds to improve the physical welfare of mankind, and in this context there can be no more important issue than the rapid changes that are occurring in the human population. The Trust's first involvement was to help fund the New Delhi population summit covered by the world's scientific academics in 1993 and, following discussions with authorities in the field, initiated its funding programme in 1995. Through this programme, the Trust hopes to bring about improved understanding of the relationship between reproductive health, population growth, and sustainable development and create cadres of high quality research scientists in relevant disciplines. Uniquely, funding is available under this programme to suitably qualified applicants from any country other than the USA.   相似文献   
998.
999.
Abstract
Eccentric photorefraction (EPR) is a simple photographic technique for detecting amblyopiogenic conditions. Previous EPR studies to detect refractive errors (RE) have demonstrated high sensitivity but poor predictive value. We have established new criteria for detecting RE involving quantifying retinoscopic reflex crescent widths, thereby achieving 67% predictive value with 100% sensitivity for detecting RE ≥+ 3.5 D in a clinical study of 69 children.
Optical analysis of EPR shows that anticrescent width (light crescent-free portion of the pupil) is independent of pupil diameter. Quantifying anti-crescent widths in the above clinical trial increased the predictive value to 85%.
Schematic eye and human eye EPR studies verify the theoretical prediction that similar ability to detect refractive errors is maintained when the working distance and eccentricity (distance of light source from lens edge) are reduced.
These improvements in EPR reduce its cost and improve its yield; both are essential for its introduction as an acceptable community screening tool.  相似文献   
1000.
In view of reported attempts at marrow grafting after nuclear accidents with a broad range of radiation exposures, the present study explored the total-body irradiation (TBI) conditions needed for engraftment in a canine model by using marrow from DLA-identical littermates. Previous studies have shown that such grafts are consistently successful when recipients are exposed to 920 cGy of TBI delivered at a rate of 7 cGy/min from opposing dual cobalt sources. The present TBI doses were all in the lethal range. Five dogs were administered 450 cGy; seven dogs, 600 cGy; five dogs, 700 cGy; and five dogs, 800 cGy of TBI administered at 7 cGy/min. They received a median of 3.3 x 10(8) marrow cells/kg intravenously after completion of radiation. Results showed transient allogeneic marrow engraftment in all dogs administered the lowest dose of TBI studied (450 cGy). Importantly, transient grafts permitted four of five dogs to live long enough for autologous marrow recovery to occur. At increasing radiation doses, 600, 700, and 800 cGy, the risk of graft failure lessened, with 3 of 7, 2 of 5, and 1 of 5 dogs, respectively, showing graft rejection. Fewer dogs survived with autologous marrow recovery, and more showed sustained allogeneic engraftment (4 of 7, 3 of 5, and 4 of 5 dogs, respectively). We conclude that DLA-identical littermate marrow grafts are beneficial in the setting of otherwise lethal radiation exposures, with most dogs either experiencing sustained allogeneic engraftment or surviving with autologous marrow recovery due to the extended support provided by a transient allogeneic graft.  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