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   1846篇
  免费   113篇
  国内免费   22篇
耳鼻咽喉   11篇
儿科学   126篇
妇产科学   31篇
基础医学   204篇
口腔科学   37篇
临床医学   177篇
内科学   289篇
皮肤病学   23篇
神经病学   209篇
特种医学   219篇
外科学   204篇
综合类   31篇
一般理论   15篇
预防医学   117篇
眼科学   20篇
药学   186篇
中国医学   2篇
肿瘤学   80篇
  2021年   14篇
  2019年   16篇
  2018年   19篇
  2017年   26篇
  2016年   17篇
  2015年   17篇
  2014年   36篇
  2013年   59篇
  2012年   41篇
  2011年   49篇
  2010年   51篇
  2009年   48篇
  2008年   42篇
  2007年   55篇
  2006年   45篇
  2005年   54篇
  2004年   42篇
  2003年   48篇
  2002年   46篇
  2001年   44篇
  2000年   48篇
  1999年   54篇
  1998年   55篇
  1997年   69篇
  1996年   54篇
  1995年   30篇
  1994年   37篇
  1993年   26篇
  1992年   54篇
  1991年   38篇
  1990年   37篇
  1989年   36篇
  1988年   51篇
  1987年   46篇
  1986年   46篇
  1985年   49篇
  1984年   43篇
  1983年   29篇
  1982年   32篇
  1981年   27篇
  1980年   23篇
  1979年   18篇
  1978年   27篇
  1977年   27篇
  1976年   23篇
  1975年   32篇
  1974年   30篇
  1973年   31篇
  1970年   14篇
  1967年   22篇
排序方式: 共有1981条查询结果,搜索用时 187 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.
4.
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   
5.
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   
6.
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   
7.
Factors influencing women to undergo screening mammography   总被引:2,自引:0,他引:2  
  相似文献   
8.
9.
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   
10.
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