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   1370篇
  免费   69篇
  国内免费   25篇
耳鼻咽喉   19篇
儿科学   56篇
妇产科学   20篇
基础医学   157篇
口腔科学   27篇
临床医学   106篇
内科学   334篇
皮肤病学   18篇
神经病学   122篇
特种医学   120篇
外科学   197篇
综合类   16篇
预防医学   104篇
眼科学   12篇
药学   58篇
  1篇
肿瘤学   97篇
  2023年   9篇
  2022年   25篇
  2021年   32篇
  2020年   15篇
  2019年   27篇
  2018年   38篇
  2017年   23篇
  2016年   28篇
  2015年   31篇
  2014年   45篇
  2013年   48篇
  2012年   70篇
  2011年   68篇
  2010年   52篇
  2009年   43篇
  2008年   76篇
  2007年   89篇
  2006年   52篇
  2005年   70篇
  2004年   51篇
  2003年   60篇
  2002年   50篇
  2001年   49篇
  2000年   50篇
  1999年   27篇
  1998年   26篇
  1997年   18篇
  1996年   11篇
  1995年   9篇
  1994年   12篇
  1993年   8篇
  1992年   17篇
  1991年   14篇
  1990年   16篇
  1989年   12篇
  1988年   12篇
  1987年   16篇
  1986年   19篇
  1985年   14篇
  1984年   15篇
  1983年   7篇
  1981年   9篇
  1980年   8篇
  1979年   10篇
  1975年   11篇
  1973年   7篇
  1971年   6篇
  1969年   5篇
  1968年   8篇
  1967年   6篇
排序方式: 共有1464条查询结果,搜索用时 31 毫秒
71.
在当前医学教育持续变革的背景中,医学教师的专业发展成为广泛关注的焦点.为了解目前美国以提高教师的教学技能为目标的教师专业发展(faculty development,FD)活动的参与率、课程设计、教学方法和评估策略等情况,美国约翰·霍普金斯大学预防、流行病学和临床研究中心采取邮件调查的方式,对美国277家教学医院进行了调查.  相似文献   
72.
73.
ABSTRACT: BACKGROUND: The application of new technologies to the education of health professionals is both a challenge and a necessity. Virtual worlds are increasingly being explored as a support for education. Aim: The aim of this work is to study the suitability of Second Life (SL) as an educational tool for primary healthcare professionals. METHODS: Design: Qualitative study of accredited clinical sessions in SL included in a continuing professional development (CPD) programme for primary healthcare professionals. Location: Zaragoza I Zone Family and Community Medicine Education Unit (EU) and 9 health centres operated by the Aragonese Health Service, Aragon, Spain. METHOD: The EU held two training workshops in SL for 16 healthcare professionals from 9 health centres by means of two workshops, and requested them to facilitate clinical sessions in SL. Attendance was open to all personnel from the EU and the 9 health centres. After a trail period of clinical sessions held at 5 health centres between May and November 2010, the CPD-accredited clinical sessions were held at 9 health centres between February and April 2011. Participants: 76 healthcare professionals attended the CPD-accredited clinical sessions in SL. Main measurements: Questionnaire on completion of the clinical sessions. RESULTS: Response rate: 42-100%. Questionnaire completed by each health centre on completion of the CPD-accredited clinical sessions: Access to SL: 2 centres were unable to gain access. Sound problems: 0% (0/9). Image problems: 0% (0/9). Voice/text chat: used in 100% (10/9); 0 incidents. Questionnaire completed by participants in the CPD-accredited clinical sessions: Preference for SL as a tool: 100% (76/76). Strengths of this method: 74% (56/76) considered it eliminated the need to travel; 68% (52/76) believed it made more effective use of educational resources; and 47% (36/76) considered it improved accessibility. Weaknesses: 91% (69/76) experienced technical problems, while; 9% (7/76) thought it was impersonal and with little interaction. 65.79% (50/76) believed it was better than other distance learning methods and 38.16% (29/76) believed it was better than face-to-face learning. CONCLUSIONS: SL is a tool that allows educational activities to be designed that involve a number of health centres in different geographical locations, consequently eliminating the need to travel and making more effective use of educational resources.  相似文献   
74.
75.
76.
Denervation-activated inward rectifier in frog slow skeletal muscle fibers   总被引:1,自引:0,他引:1  
We tested whether the absence of an inward rectifier channel in slow skeletal muscle fibers of the frog is regulated by innervation. Normal and denervated slow fibers were identified according to their passive electrical properties. In current-clamp experiments, anomalous rectification was quantified as the ratio of effective resistances for hyperpolarizing and depolarizing pulses. In isotonic potassium solution, this ratio was 0.45 +/- 0.1 (n = 14) for twitch fibers, whereas slow fibers displayed linear behavior [ratio = 1.0 +/- 0.05 (n = 15)]. However, denervated slow fibers showed anomalous rectification (ratio, 0.48 +/- 0.07; n = 5). This finding was supported by voltage-clamp experiments in which denervated slow fibers displayed (1) an inward rectifier current during hyperpolarizing pulses, (2) an increase in this current when [K(+)](o) was increased, and (3) a current inhibition after application of Ba(2+). These results suggest that frog slow fibers, which normally do not possess inward rectifier channels, can express them after denervation.  相似文献   
77.
The influence of direct electric stimulation on nerve regeneration was studied in a model of crush injury of the sciatic nerve of rats. Forty-three rats were used and distributed in four groups according to the procedure: (1) intact nerve, inactive circuit; (2) crush injury, inactive circuit; (3) intact nerve, active circuit; (4) crush injury, active circuit. The low intensity continuous current circuit (1 microA) was implanted in the lumbar region, the anode being fixed to the muscles proximally and the cathode below the nerve distally to the lesion site. The Sciatic Functional Index (SFI) was evaluated at weekly intervals for 3 weeks, the sciatic nerve being resected on the 21st day for histologic and morphometric studies. The SFI progressively improved and the average fiber nerve density recovered to a nearly normal value in Group 2 and increased in Group 4 compared with the control groups (1 and 3), but this was accompanied by a decreased average fiber nerve diameter. Both number and diameter of inter and intra-fascicular blood vessels increased in the stimulated nerves. We conclude that low intensity direct electric stimulation enhances nerve regeneration following a controlled nerve crush injury and increases blood supply by increasing number and diameter of vasa nervorum.  相似文献   
78.
This study was designed to evaluate early post partum rapid HIV testing of infants as surrogates for their mothers. In a screening of 971 infants whose mother's HIV-1 status was not known at delivery, 22 (= 2.26%) were found positive for antibodies by ELISA. Five were new cases and two (40%) were from transmitting mothers. This is in contrast with the UPR Women and Infants Transmission Study (UPR WITS) in which of 186 HIV-1 infected mothers none were transmitters. These were selected among thousands screened for anti-HIV-1 antibodies over a period of almost 5 years studied (September, 1996 through August, 2001). These results clearly indicate that all mothers at delivery should have a rapid test to determine their HIV-1 status to allow in the positive cases rapid intervention strategies to prevent perinatal transmission.  相似文献   
79.
We present an usual case of intracranial dural arteriovenous fistula with perimedullary and spinal cord venous plexus drainage and discuss its etiological, physiopathological, diagnostic and therapeutic aspects.  相似文献   
80.
We carried out an ecological study in the most archaic area of Sardinia to obtain a reliable estimate of the prevalence of multiple sclerosis (MS) and to investigate the geographical variation in the prevalence across the 100 administrative communes. To estimate the area-specific prevalence rate, we adopted a Bayesian approach that makes it possible to filter out the random variation from the estimates and to obtain a map that reflects the true geographical variation in MS prevalence. 428 resident cases were identified by the case register, including 69 multiplex families. The overall prevalence was 157 per 100,000 inhabitants. The Bayesian area-specific prevalence ranged from 143 to 262/100,000. The high prevalence and its moderate geographical variation in a genetically homogeneous population, as well as the high number of multiplex families observed in the communes with the highest prevalence, could be interpreted as representing a high susceptibility of the population to MS.  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