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   415篇
  免费   31篇
  国内免费   105篇
儿科学   27篇
妇产科学   5篇
基础医学   43篇
口腔科学   34篇
临床医学   102篇
内科学   99篇
皮肤病学   6篇
神经病学   8篇
特种医学   69篇
外科学   23篇
综合类   37篇
预防医学   10篇
眼科学   5篇
药学   51篇
中国医学   1篇
肿瘤学   31篇
  2021年   4篇
  2020年   2篇
  2019年   3篇
  2018年   5篇
  2017年   6篇
  2016年   7篇
  2015年   11篇
  2014年   6篇
  2013年   16篇
  2012年   6篇
  2011年   12篇
  2010年   17篇
  2009年   17篇
  2008年   4篇
  2007年   58篇
  2006年   11篇
  2005年   24篇
  2004年   12篇
  2003年   9篇
  2002年   13篇
  2001年   5篇
  2000年   11篇
  1999年   6篇
  1998年   45篇
  1997年   35篇
  1996年   38篇
  1995年   17篇
  1994年   22篇
  1993年   14篇
  1992年   10篇
  1991年   3篇
  1990年   11篇
  1989年   13篇
  1988年   14篇
  1987年   12篇
  1986年   12篇
  1985年   5篇
  1984年   3篇
  1982年   3篇
  1981年   4篇
  1980年   3篇
  1977年   4篇
  1976年   6篇
  1975年   3篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1965年   1篇
  1960年   1篇
排序方式: 共有551条查询结果,搜索用时 406 毫秒
1.
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.  相似文献   
2.
3.
4.
Urea rebound and delivered Kt/V determination with a continuous urea sensor   总被引:3,自引:1,他引:2  
BACKGROUND: The recent introduction of urea sensors for dialysis monitoring has made possible new approaches to urea kinetic modelling. In this study we show how the equilibrated postdialysis urea concentration (Ceq) and Kt/V corrected for double-pool urea kinetics (Kt/Vdp) can be accurately determined using an on-line sensor providing a continuous measure of blood water urea. A modification of the Smye constant volume double-pool theory led to the following equations for Ceq and Kt/Vdp [formula: see text] where Cpre is the blood concentration measured at the start of dialysis, t is the length of the dialysis session (in min) and S(ex) is the constant slope of the blood urea logarithm concentration decline following development of the intercompartmental urea concentration gradient in the first 30-60 min of dialysis. METHODS: These equations were tested in 11 patients undergoing 165-240 min of paired filtration dialysis with continuous monitoring of blood urea concentration. Cpre was determined as the plateau concentration during a preliminary period of 15-20 min of slow isolated ultrafiltration. S(ex) was accurately determined from linear regression applied to the urea sensor data from the 80-min point to the end of dialysis. RESULTS: Ceq and Kt/Vdp determined from the above equations compared closely to values determined from 25-40 min of urea rebound monitoring with the urea sensor: 10.6 +/- 3.0 versus 10.8 +/- 2.7 mmol/l (mean +/- SD) for Ceq and 1.21 +/- 0.24 versus 1.18 +/- 0.20 for Kt/Vdp, compared to single-pool values of Kt/V = 1.34 +/- 0.23. CONCLUSION: This technique may be readily programmed into on-line urea monitors to provide current and extrapolated values of Ceq and Kt/Vdp from about the first hour of dialysis.   相似文献   
5.
6.
7.
SARS-CoV isa newly identified coronavirus that causes severe acute respiratory syndrome (SARS). Currently, there is no effective method available for prophylaxis and treatment of SARS-CoVinfections. In the present study, the influence of small interfering RNA (siRNA) on SARS-CoV nucleocapsid (N) protein expression was detected in cultured cells and mouse muscles. Four siRNA expression cassettes driven by mouse U6 promoter targeting SARS-CoV N gene were prepared, and their inhibitory effects on expression of N and enhanced green fluorescence protein (EGFP) fusion protein were observed.  相似文献   
8.
溴莫尼定对视网膜缺血性损伤神经保护作用的实验研究   总被引:1,自引:1,他引:0  
徐力  陆蓓 《眼视光学杂志》2003,5(3):156-159
目的:探讨溴莫尼定(brimonidine)对视网膜缺血性损伤神经的保护作用。方法:新西兰大耳白兔32只,随机分为正常对照组、生理盐水治疗组、噻吗心安(timolol)治疗组、brimonidine治疗组,每组8只。后3组为损伤治疗组,通过生理盐水前房高压灌注的方法,制成视网膜缺血动物模型,在视网膜缺血前lh其结膜囊内分剐给予生理盐水、0.5%timolol眼液或0.2%brimonidine眼液局部治疗。在灌注后7d,观察图形视网膜电图(P-ERG)b波振幅变化,并进行组织形态学观察和视网膜神经节细胞(RGC)计数分析。结果:灌注后7d,3个损伤治疗组相对b波振幅恢复率为:7%、11%和64%,RGC标准丢失率为:43%、38%和12%,brimori-die治疗组视网膜组织形态结构接近正常对照组,而生理盐水治疗组和timolol治疗组视网膜内层组织结构损伤明显。结论:Brimonidine局部治疗对缺血诱导的视网膜结构和功能的损害有明显的神经保护作用。  相似文献   
9.
Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup.  相似文献   
10.
The ramification of the portal vein at the porta hepatis was studied by anatomic dissection performed in 32 formalin fixed human livers. In all the specimens there were branches which ran towards the caudate lobe, arising from the portal vein and either from the left or the right portal branches. Tri-and quadrifurcation of the portal vein was observed. In 5 cases (16%) there were branches arising from left portal branch or portal vein and directed anteriorly to the quadrate lobe or to the region of the gall-bladder sulcus. These branches ranged from 1.0 to 6.0 mm in diameter. The portal caudate branches were divided into 3 groups.Group 1: Branches to the papillary process; 1 or 2 branches in 26 cases (82%), 3 or 5 branches in 3 cases (9%) and no branches in 3 cases (9%);  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