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   1799篇
  免费   107篇
  国内免费   7篇
耳鼻咽喉   10篇
儿科学   127篇
妇产科学   35篇
基础医学   178篇
口腔科学   32篇
临床医学   122篇
内科学   279篇
皮肤病学   15篇
神经病学   220篇
特种医学   265篇
外科学   198篇
综合类   30篇
一般理论   15篇
预防医学   106篇
眼科学   23篇
药学   175篇
中国医学   2篇
肿瘤学   81篇
  2021年   17篇
  2018年   20篇
  2017年   24篇
  2015年   18篇
  2014年   29篇
  2013年   48篇
  2012年   38篇
  2011年   39篇
  2010年   42篇
  2009年   41篇
  2008年   41篇
  2007年   42篇
  2006年   47篇
  2005年   49篇
  2004年   46篇
  2003年   49篇
  2002年   47篇
  2001年   44篇
  2000年   45篇
  1999年   48篇
  1998年   45篇
  1997年   51篇
  1996年   46篇
  1995年   39篇
  1994年   28篇
  1993年   29篇
  1992年   43篇
  1991年   34篇
  1990年   36篇
  1989年   40篇
  1988年   41篇
  1987年   48篇
  1986年   50篇
  1985年   62篇
  1984年   44篇
  1983年   34篇
  1982年   40篇
  1981年   27篇
  1980年   31篇
  1979年   18篇
  1978年   29篇
  1977年   34篇
  1976年   31篇
  1975年   35篇
  1974年   31篇
  1973年   31篇
  1971年   13篇
  1970年   15篇
  1967年   22篇
  1966年   13篇
排序方式: 共有1913条查询结果,搜索用时 15 毫秒
1.
OBJECTIVE: Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for excision of selected benign and malignant rectal neoplasms. It is considered a safe and effective treatment but recurrence rates of 1-13% are reported for benign lesions. The aim of this study was to assess risk factors for local recurrence of benign rectal lesions and to evaluate mortality and morbidity following TEM. METHOD: Data were prospectively collected from all patients undergoing TEM for benign adenomas from January 1998 to March 2005. The procedure was performed by a single surgeon and patients were regularly followed up. RESULTS: One hundred and forty-six procedures were included, with a median patient age of 74 years (range 22-92 years). The mean lesion area was 16 cm(2) (range 0.3-150 cm(2)) and the median distance from the dentate line was 9 cm (range 0-17 cm). Immediate complications included bleeding (six) and acute urinary retention (six). There has been one (0.68%) procedure-related death. After a median follow up of 39 months (range 4-89 months) there have been seven recurrences (4.8%), recurring at a mean time of 23.3 months (range 5-48 months). Only microscopic involvement of the circumferential resection margin was found to be significantly associated with recurrence (P = 0.0059). Recurrence was not associated with age, size of lesion, previous treatment, severity of dysplasia or use of the harmonic scalpel. CONCLUSION: TEM is a safe and effective treatment for benign rectal adenomas. Circumferential resection margin involvement is associated with recurrence, which tends to occur late. Therefore extended follow up is recommended.  相似文献   
2.
3.
BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe and potentially fatal drug reaction characterized by an extensive skin rash with blisters and exfoliation, frequently accompanied by mucositis. The wounds caused by TEN are similar to second-degree burns and severe cases may involve large areas of skin loss. OBJECTIVES: Analysis of our results in patients with TEN and evaluation of the variety of therapeutic interventions that has been studied and suggested in TEN. PATIENTS/METHODS: Retrospective analysis of 19 consecutive patients with TEN treated in our burns centre between 1989 and 2004. RESULTS: Immediate withdrawal of any potentially fatal drug, maximum supportive care, and a restricted and tailored antibiotic, medical and surgical treatment regimen confined mortality to 21%, whereas prognosis scores like APACHE II and SCORTEN predicted mortality of 22 and 30%, respectively. A positive contribution of selective digestive decontamination is suggested but has yet to be established. CONCLUSIONS: Because of a potentially fatal outcome, fast referral of a patient suspected of TEN to a specialized centre (mostly a burns unit or specialized dermatology centre) for expert wound management and tailored comprehensive care is strongly advised and contributes to survival.  相似文献   
4.
1背景 育龄妇女常见慢性下腹痛,可造成身体损害、情绪忧伤及导致巨大的健康服务费用。美国在这方面的花费超过8亿8千万美元(Mathias 1996)。英国全国数据库的一般性诊治资料显示,慢性下腹痛发病率及流行率与偏头痛、背部痛、哮喘发病率相似(Zondervan 1999)。  相似文献   
5.
6.
PURPOSE: Epilepsies in children are complex diseases. Guidelines are needed on the appropriate use of newer versus older anti-epileptic drugs (AEDs). This paper presents an individual patient-sampling model to assess the cost-effectiveness of using newer AEDs as add-on therapy in line with UK prescribing guidance. METHODS: Identification of the relevant parameters and treatment pathways for the model were achieved by a systematic review of the literature and discussions with clinical experts. Data were obtained from the literature and supplemented with data elicited from paediatric neurologists. The model considered paediatric patients over the period of childhood from the age of diagnosis to 18 years. RESULTS: The results suggest that the older and newer AEDs are similar in terms of drug retention rates and the average time in 'good' treatment outcomes. In terms of cost, the results indicate a consistent increase in cost (compared to older AEDs) when all of the newer AEDs are considered. The decision analysis results indicate that there are no important health benefits from the use of newer AEDs when used as add-on therapy. However, the analysis also reveals that the uncertainties in the model are greater than the differences between the drug strategies. CONCLUSIONS: To develop guidelines on the appropriate use of newer AEDs, better information is required from randomised controlled trials as there is insufficient data available in the public domain to accurately estimate the nature of the trade off between older versus newer AEDs.  相似文献   
7.
Orbital volume measured by a low-dose CT scanning technique.   总被引:6,自引:0,他引:6  
A method for measuring orbital volume using low-dose CT with contiguous 3 mm transaxial sections is described. The accuracy of the method is 1.6%, as demonstrated by comparing CT volume measurements with those derived directly from alginate impressions and on repeat scanning the precision of the measurement was judged as 1.3%. Within the same individual, the right and left orbital volumes were observed to be within 0.6 cm3 (s.d. +/- 0.33 cm3) of each other. This study demonstrates that low-dose CT scanning is a practical method of determining orbital volume and could be used to advantage in the management of traumatic enophthalmos and blow-out fractures of the orbit.  相似文献   
8.
9.
The metabolism of the urinary tract analgesic phenazopyridine [2,6-diamino-3-(phenylazo)pyridine; PAP] was studied in the urine of humans, rats, mice, and guinea pigs. Urinary excretion was rapid in human and guinea pig, but in the rat and mouse it was slower and there was significant fecal excretion. Metabolism of PAP was extensive in all four species, and there were marked quantitative differences in the routes of metabolism. The extent of azo bond cleavage was high in the mouse and guinea pig, moderate in the rat, and low in humans. Hydroxylation of both the phenyl and pyridyl rings of PAP was observed in all species. In the human, 5-hydroxyl PAP was the major metabolite (48.3% of the dose). It was concluded that there are marked species differences in the metabolism of PAP, and that none of the species studied resembles the human; the rat comes closest, but cannot be considered a particularly good model.  相似文献   
10.
Assessment of activities of daily living (ADL) in Alzheimer disease (AD) is critical in establishing the diagnosis, monitoring disease progression, evaluating the efficacy of treatment interventions, and determining the need for health and social services. The proper method to measure ADL depends on the purposes to which the scale is to be put. Existing ADL scales differ as to the type of behaviors assessed, the nature of the observations made, and the manner in which the observations are quantified. These scales were not specifically designed to evaluate changes in the nature and extent of the broad spectrum of functional difficulties seen in individuals with AD. We describe the Cleveland Scale for Activities of Daily Living (CSADL), an informant-based instrument designed to expand upon the capacity of existing physical and instrumental ADL scales by assessing both premorbid and current component acts (e.g., initiation versus implementation) of daily living functions.  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