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   2239篇
  免费   280篇
  国内免费   5篇
耳鼻咽喉   45篇
儿科学   68篇
妇产科学   21篇
基础医学   235篇
口腔科学   175篇
临床医学   329篇
内科学   489篇
皮肤病学   45篇
神经病学   180篇
特种医学   34篇
外科学   284篇
综合类   25篇
一般理论   1篇
预防医学   278篇
眼科学   22篇
药学   137篇
肿瘤学   156篇
  2024年   3篇
  2023年   49篇
  2022年   22篇
  2021年   43篇
  2020年   44篇
  2019年   45篇
  2018年   77篇
  2017年   70篇
  2016年   64篇
  2015年   74篇
  2014年   115篇
  2013年   131篇
  2012年   152篇
  2011年   164篇
  2010年   109篇
  2009年   107篇
  2008年   116篇
  2007年   171篇
  2006年   121篇
  2005年   130篇
  2004年   148篇
  2003年   137篇
  2002年   123篇
  2001年   17篇
  2000年   15篇
  1999年   24篇
  1998年   35篇
  1997年   34篇
  1996年   24篇
  1995年   23篇
  1994年   16篇
  1993年   16篇
  1992年   12篇
  1991年   6篇
  1990年   7篇
  1989年   6篇
  1988年   5篇
  1987年   8篇
  1985年   6篇
  1984年   7篇
  1983年   4篇
  1982年   8篇
  1981年   3篇
  1980年   7篇
  1979年   3篇
  1977年   2篇
  1976年   6篇
  1966年   3篇
  1960年   2篇
  1936年   2篇
排序方式: 共有2524条查询结果,搜索用时 234 毫秒
141.
142.
p73: Friend or foe in tumorigenesis   总被引:1,自引:0,他引:1  
  相似文献   
143.
144.
Uncertainty exists regarding the necessity of continuing triple therapy consisting of mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisone (Pred) after kidney transplantation (RTx). At 6 mo after RTx, 212 patients were randomized to stop CsA (n = 63), stop Pred (n = 76), or continue triple drug therapy (n = 73). The MMF dose was 1000 mg twice daily, target CsA trough levels were 150 ng/ml, and Pred dose was 0.10 mg/kg per d. Follow-up was until 24 mo after RTx. Biopsy-proven acute rejection occurred in 14 (22%) of 63 patients after CsA withdrawal compared with 3 (4%) of 76 in the Pred withdrawal group (P = 0.001) and 1 (1.4%) of 73 in the control group (P = 0.0001). Biopsy-proven chronic rejection was present in one patient in the control group, in nine patients after CsA withdrawal (P = 0.006 versus control group); and in four patients after discontinuation of Pred (NS). Graft loss occurred in two versus one patient after CsA or Pred withdrawal, respectively, and in two patients in the control group (NS). Patients who successfully withdrew CsA had a significantly lower serum creatinine during follow-up. Pred withdrawal resulted in a reduction in mean arterial pressure, and the total cholesterol/HDL ratio increased. In conclusion, rapid CsA withdrawal at 6 mo after RTx results in a significantly increased incidence of biopsy-proven acute and chronic rejection. Pred withdrawal was safe and resulted in a reduction in mean arterial pressure. However, patient and graft survival and renal function 2 yr after RTx were not different among groups.  相似文献   
145.
BACKGROUND: Oral cancer has been identified as a significant public health threat. Systematic evaluation of the impact of this disease on the US population is of great importance to health care providers and policy makers. METHODS: This study used the National Cancer Data Base (NCDB) to evaluate associations between demographic and disease characteristics, treatment, and survival for patients with oral cavity cancer in the United States. Of patients diagnosed between 1985 and 1996, 58,976 were extracted from the NCDB. ANOVAs were performed on selected cross-tabulations, and relative survival was used to calculate outcome. RESULTS: Median age of patients was 64.0 years. Men made up 60.2% of patients. Pathologic diagnosis was squamous cell carcinoma (SCC) in 86.3% of cases. Younger patients had a much higher frequency of non-SCC, and this was related to survival in these patients. African-Americans (independent of income), lower income patients, and patients with higher grade disease were seen more frequently with advanced-stage SCC. Five-year relative survival for SCC cases was lower for older patients, men, and African-Americans. CONCLUSIONS: This study addressed many issues related to oral cancer that have been previously discussed in the literature. The demographic, site, stage, histologic, and survival data available for this large number of cases in the NCDB allowed an accurate characterization of the contemporary status of oral cancer in the United States.  相似文献   
146.
The objective of this study was to evaluate the duration of oral pleconaril (a picornavirus inhibitor) effect on intestinal and hepatic cytochrome P450 (P450) 3A activity as assessed by oral midazolam. Healthy adults received oral midazolam (0.075 mg/kg) on days 1 (baseline), 7, 9, 13, 20, 27, and 34. Oral pleconaril (400 mg) three times daily for 15 doses was administered on days 2 through 7. Blood samples were collected during each day of midazolam dosing to determine plasma midazolam concentrations. On days 5, 6, and 7, blood samples were collected to determine plasma pleconaril concentrations. Midazolam pharmacokinetics were determined by noncompartmental analyses, with bioequivalence assessed by least-squares geometric mean ratios (LS-GMR) and 90% confidence intervals (90% CI). Eighteen subjects completed the study. Midazolam C(max) (LS-GMR; 90% CI) decreased 24% on day 7 (0.76; 0.66-0.87). Midazolam oral clearance increased 53% on day 7 (1.53; 1.38-1.69). Midazolam oral clearance remained different on days 9 (1.38; 1.25-1.52) and 13 (1.19; 1.07-1.31) versus day 1. Midazolam volume of distribution (1.82; 1.57-2.11) and elimination half-life (1.19; 1.03-1.38) were also different on day 7 in comparison with day 1. Oral pleconaril increased intestinal and hepatic CYP3A activity. The duration of increased CYP3A activity by pleconaril was at least 6 days (but no longer than 13 days) after pleconaril discontinuation.  相似文献   
147.
Although the relationship between socioeconomic status and health has received careful attention from health researchers over the past half-century, the means by which income, education and occupational prestige are accumulated in society have received relatively short shrift in the health literature. This article explores the degree to which neo-Marxist conceptualizations of class position are ‘upstream’ determinants of health and well-being. Utilizing data from a survey sample of randomly selected and full-time employed residents of 25 communities in the Canadian province of British Columbia, it evaluates the usefulness of class position distinctions derived from the work of Erik Olin Wright as predictors of physical and mental health before and after controlling for socioeconomic status.  相似文献   
148.
149.
150.
A workshop was held on October 26-27, 2004, in Bonn, Germany, to discuss the potential use of omic technologies for regulatory non-clinical safety testing of pharmaceuticals. The meeting was hosted by the European Federation of Pharmaceutical Industries and Associations (EFPIA). The workshop was held in conjunction with the 6th European preclinical assessors meeting, which was organized in Bonn by the German Federal Institute for Drugs and Medical Devices (BfArM) and the Safety Working Party (SWP) of the Committee for Medicinal Products for Human Use (CHMP). Approximately 100 scientists, roughly half from the European pharmaceutical industry and half from European regulatory authorities, attended the workshop. The authors of this report constitute the organizing committee members.  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