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   571篇
  免费   39篇
  国内免费   105篇
儿科学   28篇
妇产科学   4篇
基础医学   77篇
口腔科学   32篇
临床医学   105篇
内科学   157篇
皮肤病学   6篇
神经病学   31篇
特种医学   69篇
外科学   23篇
综合类   38篇
预防医学   32篇
眼科学   5篇
药学   73篇
中国医学   1篇
肿瘤学   34篇
  2021年   6篇
  2020年   5篇
  2019年   6篇
  2018年   11篇
  2017年   11篇
  2016年   11篇
  2015年   14篇
  2014年   13篇
  2013年   24篇
  2012年   26篇
  2011年   23篇
  2010年   29篇
  2009年   25篇
  2008年   21篇
  2007年   72篇
  2006年   25篇
  2005年   27篇
  2004年   17篇
  2003年   9篇
  2002年   16篇
  2001年   9篇
  2000年   16篇
  1999年   11篇
  1998年   46篇
  1997年   37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
  1979年   1篇
  1978年   1篇
  1977年   4篇
  1976年   6篇
  1975年   3篇
  1974年   1篇
  1971年   1篇
  1965年   1篇
  1960年   1篇
排序方式: 共有715条查询结果,搜索用时 15 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 Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy.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.
5.
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   
6.
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   
7.
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   
8.
李峰生  杨曌  江其生 《免疫学杂志》2005,21(Z1):103-105
机体受到一定剂量核辐射后会出现多个器官结构和功能的改变.本文综述了机体受到低剂量核辐射后出现的免疫细胞数量和功能变化,包括淋巴细胞总数和部分亚群数量、淋巴细胞转化率、血清免疫球蛋白含量以及单核细胞功能等变化.同时还综述了核辐射对内分泌及遗传的影响.  相似文献   
9.
Analyses of a replication sample of families collected as part of the National Institute of Mental Health (NIMH) Genetics Initiative for bipolar disorder provide further evidence for linkage to a region of chromosome 16. Families who had a bipolar I (BPI) proband and at least one BPI or schizoaffective, bipolar type (SABP) first-degree relative were ascertained for the purpose of identifying genes involved in bipolar affective disorder. A series of hierarchical models of affected status was used in linkage analyses. Initial genetic analyses of chromosomes 3, 5, 15, 16, 17, and 22, completed at Indiana University in 540 subjects from 97 families, suggested evidence of linkage to chromosomes 5, 16, and 22 [Edenberg et al., 1997: Am J Med Genet 74:238-246]. Genotyping was subsequently performed on these chromosomes in a replication sample of 353 individuals from 56 families. Nonparametric linkage analyses were performed using both affected relative and sibling pair methods. Analyses in the new sample on chromosome 16, using the broadest model of affected status, corroborate previously reported suggestive linkage to the marker D16S2619. Combining the initial and replication samples further increased the evidence of linkage to this region, with a peak lod score of 2.8.  相似文献   
10.
Hypospadias trends in two US surveillance systems   总被引:6,自引:0,他引:6  
OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted.  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