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   6051篇
  免费   514篇
  国内免费   18篇
耳鼻咽喉   55篇
儿科学   237篇
妇产科学   127篇
基础医学   747篇
口腔科学   100篇
临床医学   735篇
内科学   1327篇
皮肤病学   51篇
神经病学   469篇
特种医学   189篇
外科学   1011篇
综合类   114篇
一般理论   2篇
预防医学   611篇
眼科学   120篇
药学   389篇
中国医学   15篇
肿瘤学   284篇
  2023年   31篇
  2022年   45篇
  2021年   87篇
  2020年   73篇
  2019年   98篇
  2018年   118篇
  2017年   90篇
  2016年   100篇
  2015年   119篇
  2014年   147篇
  2013年   234篇
  2012年   417篇
  2011年   390篇
  2010年   199篇
  2009年   173篇
  2008年   306篇
  2007年   367篇
  2006年   361篇
  2005年   378篇
  2004年   388篇
  2003年   332篇
  2002年   269篇
  2001年   125篇
  2000年   114篇
  1999年   124篇
  1998年   78篇
  1997年   72篇
  1996年   53篇
  1995年   51篇
  1994年   52篇
  1993年   54篇
  1992年   62篇
  1991年   86篇
  1990年   73篇
  1989年   66篇
  1988年   64篇
  1987年   60篇
  1986年   48篇
  1985年   54篇
  1984年   42篇
  1983年   46篇
  1982年   28篇
  1981年   40篇
  1980年   37篇
  1979年   35篇
  1978年   29篇
  1976年   40篇
  1975年   35篇
  1973年   32篇
  1972年   26篇
排序方式: 共有6583条查询结果,搜索用时 0 毫秒
21.
Epirubicin (4'-epi-adriamycin) was used in the treatment of widespread superficial carcinoma of the bladder. Thirty-seven patients received 50 mg in 50 ml of saline retained for 60 min. There was an overall response rate of 59% but this was of short duration. Thirty percent of patients progressed despite therapy. Therapy was associated with an incidence of side effects which necessitated therapy withdrawal in 12 (32.4%) patients. It is concluded that epirubicin, in the dose used in this study, cannot be recommended for routine intravesical chemotherapy and that further studies, at a reduced dosage, are necessary to evaluate this agent.  相似文献   
22.
23.
24.
25.
Despite continued improvement in incidence of acute immune injury and short-term graft survival, late allograft dysfunction remains a significant problem in the renal transplant population. Recent reports suggest that rates of renal function decline are quite varied in the overall recipient population, and that individual rates for many recipients may not change substantially over time. Moreover, analyses also reveal distinct predictive factors for both early and late functional decline. Long-term outcome studies for renal transplantation, however, might be significantly limited by incomplete data sets for assessing clinical endpoints. In view of the heterogeneous factors that may cause progressive allograft injury, more routine biopsy sampling would allow a more complete characterization of induced injuries. Elucidating mechanisms of renal fibrosis in response to injury, in experimental systems and humans, is also an important goal in better understanding chronic allograft damage. Regulation of cell senescence genes and epithelial to mesenchymal transition, studied in other models of renal fibrosis, are likely relevant to studies of renal allograft dysfunction. Recent technical advances in analyzing biological samples may play a pivotal role in identifying and validating surrogate markers of allograft function for future interventional trials in transplantation.  相似文献   
26.
27.
BACKGROUND: Hydroxymethylglutaryl CoA reductase inhibitors (statins) have been demonstrated to reduce the risk of developing coronary allograft vasculopathy (CAV) following heart transplantation in adults and are used routinely in many centers. CAV and lipid abnormalities have been reported to be less prevalent in pediatric heart transplant recipients. It is not known whether statins reduce the risk of CAV in this population METHODS: A retrospective review was performed to analyze the risk factors for developing CAV following pediatric heart transplantation with particular attention to the impact of pravastatin therapy. The study population was comprised of 129 pediatric patients who underwent 142 heart transplants at our institution from 1988 to 2003. The outcome variable was freedom from CAV, CAV being determined by coronary angiography or autopsy. RESULTS: CAV was identified in 25 recipients at a median of 3.7 years after transplantation. There were 331 patient-years of pravastatin therapy. Pravastatin therapy resulted in a reduction in total cholesterol levels, 162 +/- 29 to 137 +/- 20 mg/dl, p = 0.01. In multivariate analysis the use of pravastatin was associated with a lower incidence of CAV (p = 0.03), whereas an increased frequency of late rejection (p = 0.003) and earlier year of transplantation (p = 0.04) were associated with increased risk of CAV. CONCLUSIONS: The routine use of pravastatin was associated with a lower risk following pediatric heart transplantation. Further studies into the relationship between lipid abnormalities, inflammation and rejection, and the development of CAV in children are warranted.  相似文献   
28.
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care.  相似文献   
29.
30.
Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.  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