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   15195篇
  免费   1263篇
  国内免费   49篇
耳鼻咽喉   149篇
儿科学   514篇
妇产科学   333篇
基础医学   2078篇
口腔科学   425篇
临床医学   1609篇
内科学   3368篇
皮肤病学   248篇
神经病学   1431篇
特种医学   346篇
外国民族医学   2篇
外科学   1881篇
综合类   196篇
一般理论   7篇
预防医学   1576篇
眼科学   285篇
药学   958篇
  2篇
中国医学   50篇
肿瘤学   1049篇
  2023年   145篇
  2022年   228篇
  2021年   535篇
  2020年   298篇
  2019年   507篇
  2018年   557篇
  2017年   409篇
  2016年   357篇
  2015年   413篇
  2014年   528篇
  2013年   753篇
  2012年   986篇
  2011年   945篇
  2010年   573篇
  2009年   494篇
  2008年   762篇
  2007年   839篇
  2006年   727篇
  2005年   677篇
  2004年   623篇
  2003年   585篇
  2002年   557篇
  2001年   269篇
  2000年   279篇
  1999年   261篇
  1998年   124篇
  1997年   128篇
  1996年   100篇
  1995年   86篇
  1994年   92篇
  1993年   79篇
  1992年   209篇
  1991年   224篇
  1990年   190篇
  1989年   185篇
  1988年   176篇
  1987年   162篇
  1986年   159篇
  1985年   120篇
  1984年   104篇
  1983年   106篇
  1982年   50篇
  1981年   49篇
  1980年   50篇
  1979年   77篇
  1976年   55篇
  1974年   51篇
  1973年   56篇
  1970年   53篇
  1969年   52篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
11.
12.
13.
14.
15.
16.
During the first 24 months of the Oregon Liver Transplantation Program, which began in October 1988, 94 patients were formally evaluated and 47 adults underwent 54 liver transplantations. Thirty-four percent of patients were veterans. The recipient operation lasted a mean of 7.4 hours (range: 4 to 16 hours). Veno-venous bypass was used routinely at first but selectively later (7 of the last 26 cases), resulting in reduced operating time. Hepatic artery reconstruction was end-to-end anastomosis in 52 cases and iliac conduit in 2. No arterial thrombosis occurred. Biliary reconstruction was choledochocholedochostomy in 83% and choledochojejunostomy in 17%. Biliary complications occurred in 28%. Operative mortality was 2%, and 1-year actual survival was 80%. Patients with hepatitis B fared worse, with four of six dying at a mean of 7.6 months. Overall, the median hospital stay was 30 days. Patients surviving more than 3 months had a mean Karnofsky score of 82%. No significant difference in outcome was noted in patients receiving prophylactic OKT3 monoclonal antibody (used in 45%) versus conventional immunosuppressive therapy. Overall, allograft rejection occurred in 55% of patients. Retransplantation was required in seven patients, three for primary graft nonfunction, two for uncontrolled rejection during induction therapy with OKT3, and two for graft failure secondary to recurrent hepatitis B.  相似文献   
17.
Forty depressed patients and 36 age- and sex-matched controls were given 250 μg ACTH1–24 by bolus. Plasma steroid hormone levels were measured prior to and 60 min after ACTH administration. The depressed patients had significantly greater cortisol (F), 11-deoxycortisol (S), androstenedione (AD), and 17-hydroxyprogesterone (17-OHP) responses (delta; p<0.05) and a marginally greater 11β-hydroxyandrostenedione (11β-OHAD) response (delta; p=0.091) than the controls. There was no significant difference in the corticosterone (B) response between the two groups.

With the exception of 11β-OHAD, all the steroid hormones were significantly negatively correlated with age in the controls, but only S and AD marginally demonstrated this relationship in the depressed patients. F, S, AD, 17-OHP, and B, but not 11β-OHAD, were significantly positively correlated with each other in the controls, but only F was significantly correlated with AD in the depressed patients. These data suggest that the hypercortisolemia found in some depressed patients involves increased precursor and metabolite levels both at baseline and in response to exogenous ACTH, compared to controls. Furthermore, variability in these precursors is greater in depressed patients, and their relationship to age is lost. These findings are consistent with the hypothesis that adrenal products other than cortisol also could be related to affective symptoms.  相似文献   

18.
Twenty patients with advanced malignant disease submitted to autologous bone marrow transplantation with marrow either unpurged (10 patients) or purged in vitro with mafosfamide (10 patients) after ablative chemotherapy, received simultaneously autologous peripheral blood stem cells (PBSC) collected during one to three 3 h cytapheresis procedures. The kinetics of the hematological recovery of these patients were compared to those of a group of patients suffering from similar diseases and grafted in the same institution with either unpurged marrow only (14 patients) or purged in vitro with mafosfamide (six patients). The median times to reach 10(9)/l leukocytes, 0.5 x 10(9)/l polymorphs, and 50 x 10(9)/l platelets were reduced by 10, 10, and 13 days, respectively, in patients transfused with both autologous bone marrow and peripheral blood stem cells as compared to those receiving bone marrow only. A reduction in the numbers of days spent in hospital post-transplantation (p less than 0.01), of days of fever greater than 38 degrees C (p = NS), and of platelet (p = 0.07) and of red blood cell transfusions (p less than 0.01) were also observed in the group of patients grafted with bone marrow and PBSC.  相似文献   
19.
20.
Actinobacillus actinomycetemcomitans prosthetic valve endocarditis   总被引:4,自引:0,他引:4  
Actinobacillus actinomycetemcomitans, a fastidious gram-negative bacillus, has been reported as the cause of prosthetic valve endocarditis in 11 patients. Two additional patients are reported and the literature is reviewed. All cases occurred greater than 1 year after implantation of the prosthesis. Six of the 13 patients had had recent dental work or had poor dentition. Three patients had received endocarditis prophylaxis. Ten of 13 were cured with antibiotics alone. Only one patient suffered from congestive heart failure, and only one had documented evidence of major systemic emboli during antimicrobial therapy. Valve replacement was necessary in only two during antimicrobial therapy. A actinomycetemcomitans should be considered as a possible etiologic agent in late prosthetic valve endocarditis, particularly when blood cultures are initially negative. A regimen of a beta-lactam antibiotic in combination with an aminoglycoside is recommended for 4-6 weeks. The excellent in vitro activity of the third-generation cephalosporins and rifampin promise new therapeutic options.  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