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   650篇
  免费   24篇
  国内免费   16篇
儿科学   45篇
妇产科学   35篇
基础医学   72篇
口腔科学   25篇
临床医学   72篇
内科学   126篇
皮肤病学   3篇
神经病学   13篇
特种医学   106篇
外科学   31篇
综合类   40篇
预防医学   27篇
眼科学   17篇
药学   68篇
中国医学   1篇
肿瘤学   9篇
  2022年   6篇
  2021年   3篇
  2020年   6篇
  2019年   7篇
  2018年   8篇
  2017年   4篇
  2016年   7篇
  2015年   16篇
  2014年   15篇
  2013年   27篇
  2012年   22篇
  2011年   14篇
  2010年   28篇
  2009年   18篇
  2008年   16篇
  2007年   20篇
  2006年   13篇
  2005年   23篇
  2004年   14篇
  2003年   12篇
  2002年   17篇
  2001年   16篇
  2000年   24篇
  1999年   17篇
  1998年   28篇
  1997年   36篇
  1996年   29篇
  1995年   25篇
  1994年   24篇
  1993年   21篇
  1992年   5篇
  1991年   6篇
  1990年   13篇
  1989年   29篇
  1988年   24篇
  1987年   18篇
  1986年   10篇
  1985年   7篇
  1984年   6篇
  1983年   8篇
  1982年   4篇
  1981年   8篇
  1980年   10篇
  1979年   4篇
  1978年   6篇
  1977年   4篇
  1976年   4篇
  1975年   2篇
  1925年   1篇
  1924年   1篇
排序方式: 共有690条查询结果,搜索用时 15 毫秒
1.
Abstract

The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest.  相似文献   
2.
Sonoelasticity imaging of prostate cancer: in vitro results   总被引:2,自引:0,他引:2  
  相似文献   
3.
PURPOSE: To review the incidence, underlying pathophysiology, and clinical features of filamentary keratitis and to identify evidence-based best-practice strategies for managing filamentary keratitis. METHODS: A comprehensive review of published literature was undertaken. Recommendations for best-practice management strategies were based on the available evidence. Three cases are presented to illustrate the clinical findings and management of patients with chronic filamentary keratitis. RESULTS: Although the evidence base is limited by the absence of well-designed studies, current evidence indicates the following: (1) Aqueous-deficient dry eye (keratoconjunctivitis sicca) is the most common ocular condition associated with filamentary keratitis. (2) Current best-practice management of filamentary keratitis involves treating the underlying dry eye and specific treatments for the corneal filaments. Proposed treatments include nonpreserved lubricants, topical steroidal and nonsteroidal anti-inflammatory agents, and punctal plugs for aqueous-deficient dry eye as well as mechanical removal of filaments, hypertonic saline, mucolytic agents, and bandage contact lenses for the filaments. (3) Filamentary keratitis can be induced or exacerbated by contact lens wear and ocular surgical procedures such as cataract surgery and corneal graft surgery. Pre- and postoperative ocular surface management strategies should be considered in the surgical planning of patients with, or who are susceptible to, filamentary keratitis. Filamentary keratitis can also be induced and/or exacerbated by chronic use of ocular and/or systemic medications, and alternate medications or additional measures to manage the tear film and ocular surface may be required in these cases. CONCLUSIONS: Filamentary keratitis can be a chronic, recurrent, and debilitating condition. With a systemic approach to diagnosis and management, the condition can be effectively controlled and the incidence and severity of recurrences minimized.  相似文献   
4.
Screening for early ovarian cancer   总被引:5,自引:0,他引:5  
Taylor  KJ; Schwartz  PE 《Radiology》1994,192(1):1
  相似文献   
5.
6.
This study aimed to quantify the patterns of drug use among a group of participants in the rave scene in Perth, Western Australia. Interviews were conducted with 83 people who had recently been to a 'rave'. The study incorporated a semi-structured qualitative interview and a structured quantitative questionnaire. This paper reports on the quantitative data collected concerning patterns of drug use in association with the last rave attended. Use of 'dance drugs' (ecstasy, amphetamines or LSD) was reported by 86.8% of the 76 respondents who had used at least one drug in association with their last rave. Nearly 80% of these had also used at least one other drug on this occasion (mean number used = 2.4). Cannabis and inhalants were the drugs most commonly combined with the 'dance drugs', several respondents used more than one 'dance drug' concurrently and 16.7% had used alcohol. It seems that a significant proportion of those using 'dance drugs' in association with raves and dance parties are mixing these drugs with other substances despite harm reduction advice to the contrary. The need for more research in this area is discussed.  相似文献   
7.
8.
To answer questions about staff's ability to identify, assess, and support victims of woman abuse, St. Joseph's Hospital, Hamilton, Ontario, Canada, organized a task group that included a cross section of staff and representatives of a local women's shelter. A comprehensive literature review strongly confirmed the need for a program that would provide staff with relevant information about abused women and challenge them to examine their values and beliefs. The task group constructed a questionnaire that included six different scales measuring various aspects of respondents' beliefs and attitudes about woman assault. The educational program for the pilot units included a training video, in-service workshops, a resource training manual, and an assessment tool to assist staff in screening female patients. The survey identified some key areas of concern, including some widely held misconceptions about the causes of abuse. After the educational program, test scores showed significant changes, particularly on scales that measured belief in popular myths and the degree to which respondents held perpetrators responsible for their actions. Overall, the project demonstrated that values and beliefs related to woman assault can be significantly affected by an educational approach that combines information sharing with the opportunity for dialogue and questions.  相似文献   
9.
BACKGROUND: Endogenous reactive oxygen species appear to contribute to aging and cancer and dietary antioxidants, present in fruit and vegetables, counteract these effects. OBJECTIVE: The objective was to examine the association between intracellular glutathione, ascorbate (vitamin C), and alpha-tocopherol (vitamin E) in human lymphocytes. DESIGN: The study group consisted of 240 healthy nonsmoking volunteers with an approximately equal number of male and female subjects subdivided into 3 age groups: 18-39, 40-59, and >/=60 y). Glutathione, glutathione disulfide, ascorbate, and alpha-tocopherol were measured in lymphocytes by HPLC. RESULTS: The average concentration of antioxidants in lymphocytes was 27 +/- 8 nmol/mg protein for glutathione, 21 +/- 8 nmol/mg protein for ascorbate, and 0.4 +/- 0.2 nmol/mg protein for alpha-tocopherol. There was a strong positive correlation between glutathione and ascorbate (r = 0.62, P < 0.001). No correlation was observed for glutathione and ascorbate with alpha-tocopherol. The concentration of glutathione in lymphocytes was inversely correlated with age (r = -0.19, P < 0.01), as was that of ascorbate (r = -0.22, P < 0.01), with 10-20% lower values in elderly than in young and elderly subjects. The concentrations of glutathione in lymphocytes were as much as 25% higher and those of ascorbate were as much as 38% higher during the summer than during the winter. The seasonal variation of ascorbate in lymphocytes was described by a linear function for age and a periodic sine function for season. CONCLUSION: Glutathione and ascorbate are directly correlated in human lymphocytes.  相似文献   
10.
Background : Dry eye is a common complication of LASIK surgery. Our clinical impression was that post‐LASIK dry eye was more problematic for our Asian patients. The aim of this study was to determine if dry eye after LASIK is more prevalent, more sustained and more severe in Asian eyes compared with Caucasian eyes. Methods : This study was based on a retrospective analysis of a clinical database. Data (n = 932 eyes, 932 patients) was collected before and after (week 2 and months 1, 3 and 6) LASIK surgery. Patients were defined as Asian if both parents were of East Asian ethic origin. Assessments included dry eye symptoms, ocular surface staining, tear volume, tear secretion, tear film stability and corneal sensation. Results : Asian eyes had greater ocular surface staining, poorer tear film stability and lower tear volume before LASIK and at all times after LASIK. Dry eye symptoms occurring ‘often or constantly’ were more prevalent at all time points after LASIK in Asian eyes. Chronic dry eye persisting six months or more after LASIK was diagnosed in 28 per cent of Asian eyes and 5 per cent of Caucasian eyes (p < 0.001). Asian patients with chronic dry eye were predominantly female, reported dry eye symptoms, had greater ocular surface staining and lower tear secretion, stability and volume before surgery. After LASIK, Asian eyes had a slower return to pre‐operative values for ocular surface staining, tear volume and corneal sensation. Discussion : The risk of chronic dry eye after LASIK was significantly higher in Asian eyes. Contributing factors could include racial differences in eyelid and orbital anatomy, tear film parameters and blinking dynamics and higher attempted refractive corrections in Asian eyes.  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