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   16128篇
  免费   792篇
  国内免费   126篇
耳鼻咽喉   151篇
儿科学   319篇
妇产科学   351篇
基础医学   1862篇
口腔科学   393篇
临床医学   1215篇
内科学   5034篇
皮肤病学   412篇
神经病学   1282篇
特种医学   290篇
外科学   2233篇
综合类   96篇
一般理论   8篇
预防医学   1047篇
眼科学   302篇
药学   889篇
中国医学   37篇
肿瘤学   1125篇
  2024年   13篇
  2023年   138篇
  2022年   306篇
  2021年   696篇
  2020年   310篇
  2019年   622篇
  2018年   683篇
  2017年   404篇
  2016年   417篇
  2015年   449篇
  2014年   734篇
  2013年   803篇
  2012年   1468篇
  2011年   1475篇
  2010年   766篇
  2009年   687篇
  2008年   1097篇
  2007年   1101篇
  2006年   950篇
  2005年   908篇
  2004年   833篇
  2003年   671篇
  2002年   681篇
  2001年   69篇
  2000年   56篇
  1999年   81篇
  1998年   101篇
  1997年   96篇
  1996年   66篇
  1995年   44篇
  1994年   46篇
  1993年   38篇
  1992年   24篇
  1991年   19篇
  1990年   17篇
  1989年   14篇
  1988年   13篇
  1987年   10篇
  1986年   9篇
  1985年   6篇
  1984年   14篇
  1983年   9篇
  1982年   11篇
  1981年   12篇
  1980年   11篇
  1979年   8篇
  1975年   11篇
  1971年   9篇
  1970年   5篇
  1967年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Intraperitoneal chemotherapy was administered to 13 patients with peritoneal carcinomatosis, using acute peritoneal dialysis catheters immediately before the administration of the chemotherapy. A total of 59 cycles were administered, with insertion of the corresponding catheter. There were no inflow or outflow problems and no insertion-related complications. With the removal of the catheter after its use, there is no risk of abdominal infections.  相似文献   
22.
23.
OBJECTIVE: The present study was designed to determine the influence of a 12-week exercise program on the activity of erythrocyte glutathione peroxidase (GPX) in adolescents with Down syndrome. DESIGN: An interventional study with before-after comparison. SETTING: Sport Medicine School, University of Cadiz (Andalusia, Spain). PATIENTS: Thirty-one male adolescents (16.3+/-1.1) with Down syndrome. None of them suffered acute medical problems at that moment and had not taken part in any physical activity program in the last 6 months. INTERVENTION: A 12-week training program with 3 days per week, consisting of warm up (15 min) followed by a main part (20 to 35 min) at a work intensity of 60% to 75% of peak heart rate (HRmax=194.5-[0.56xage]) and by a cool-down period (10 min). MAIN OUTCOME MEASUREMENT: Erythrocyte activity of GPX. RESULTS: Preexercise and postexercise GPX activity in adolescents with Down syndrome were 24.8+/-3.1 [23.1 to 26.5] U/g hemoglobin and 29.3+/-2.9 [28.1 to 30.5] U/g hemoglobin, respectively. When compared with baseline values it was increased significantly (24.8+/-3.1 vs. 29.3+/-2.9; P=0.011). CONCLUSION: Regular exercise increased significantly GPX activity. Further studies are required to assess the behavior of other antioxidant enzymes to highlight potential benefits of regular exercise in redox metabolism.  相似文献   
24.
Stress is known to be one of the risk factors of stroke. Most of the knowledge on the effects of stress on cerebrovascular disease in humans is restricted to catecholamines and glucocorticoids effects on blood pressure and/or development of atherosclerosis. However, few experimental studies have examined the possible mechanisms by which stress may affect stroke outcome. We have used an acute stress protocol consisting of the exposure of male Fischer rats to an acute, single exposure immobilisation protocol (6 h) prior to permanent middle cerebral artery occlusion (MCAO), and we have found that stress worsens behavioural and neurological outcomes and increased infarct size after MCAO. The possible regulatory role of the TNFalpha and IL-1beta was studied by looking at the release of these cytokines in brain. The results of the present study showed an increase in IL-1beta release in cerebral cortex after exposure to acute stress. Brain levels of IL-1beta are also higher in previously stressed MCAO rats than in MCAO animals without stress. Pharmacological blockade of IL-1beta with an antibody anti-IL-1beta led to a decrease in the infarct size as well as in neurological and behavioural deficits after MCAO. In summary, our results indicate that IL-1beta, but not TNFalpha, accounts at least partly for the worsening of MCAO consequences in brain of rats exposed to acute stress.  相似文献   
25.
26.
27.
28.
29.
30.
Older age is not considered a contraindication for liver transplantation, but age-related morbidity may be a cause of mortality. Survival and the incidence of the main post-transplant complications were assessed in 111 adult liver transplant recipients. They were divided in two groups according to their age (patients younger than 60 years, n=54; patients older than 60 years, n=57) and both groups were compared. Older patients were more frequently transplanted for hepatitis C (p= 0.03) and hepatocellular carcinoma (p= 0.05) and their liver disease was less advanced (Child-Pugh and MELD scores were significantly lower; p=0.004 and p=0.05, respectively). After transplantation, older patients had a significantly lower survival (p=0.02). Higher age was independently associated with mortality (hazard ratio for each 10-year increase: 2.1; 95% confidence interval: 1.1- 4.0; p=0.02). The incidence of de novo neoplasia and nonskin neoplasia were higher in older patients (p=0.02 and p =0.007, respectively). Malignancy was the cause of death in one patient younger than 60 years and in 12 patients older than 60 years (p =0.002). In multivariate analysis, a higher age and smoking were independently associated with a higher risk of dying of de novo neoplasia. In conclusion, older liver transplant recipients have a significantly lower survival than younger patients. Malignancy is responsible for this decreased survival.  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