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   4726篇
  免费   152篇
  国内免费   24篇
耳鼻咽喉   25篇
儿科学   77篇
妇产科学   18篇
基础医学   509篇
口腔科学   6篇
临床医学   556篇
内科学   465篇
皮肤病学   15篇
神经病学   1548篇
特种医学   122篇
外科学   153篇
综合类   396篇
预防医学   485篇
眼科学   11篇
药学   443篇
中国医学   43篇
肿瘤学   30篇
  2024年   3篇
  2023年   44篇
  2022年   104篇
  2021年   186篇
  2020年   192篇
  2019年   122篇
  2018年   145篇
  2017年   184篇
  2016年   190篇
  2015年   175篇
  2014年   378篇
  2013年   450篇
  2012年   342篇
  2011年   413篇
  2010年   281篇
  2009年   288篇
  2008年   294篇
  2007年   220篇
  2006年   215篇
  2005年   118篇
  2004年   112篇
  2003年   63篇
  2002年   71篇
  2001年   39篇
  2000年   38篇
  1999年   26篇
  1998年   28篇
  1997年   16篇
  1996年   23篇
  1995年   21篇
  1994年   18篇
  1993年   6篇
  1992年   11篇
  1991年   5篇
  1990年   10篇
  1989年   6篇
  1988年   10篇
  1987年   6篇
  1986年   7篇
  1985年   8篇
  1984年   4篇
  1983年   3篇
  1982年   9篇
  1979年   4篇
  1976年   5篇
  1975年   2篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有4902条查询结果,搜索用时 15 毫秒
1.
This systematic review aims to summarize cognitive reserve (CR) evaluation approaches and to examine the role of seven selected modifiable lifestyle factors (diet, smoking, alcohol consumption, physical activity, cognitive leisure activity, sleep, and meditation) in mitigating the impacts of age- or disease-related brain changes on cognition. Eighteen population-based English empirical studies were included. We summarize the study designs and identify three CR models that were broadly used in these studies, including a residual model assessing lifestyle factors in relation to unexplained variance in cognition after accounting for brain markers, a moderation model testing whether lifestyle factors moderate the relationship between brain status and cognition, and a controlling model examining the associations between lifestyle factors and cognition when controlling for brain measures. We also present the findings for the impact of each lifestyle factor. No studies examined diet, sleep, or meditation, and only two studies focused on smoking and alcohol consumption each. Overall, the studies suggest lifestyle activity factors (physical and cognitive leisure activities) may contribute to CR and attenuate the damaging impact of brain changes on cognition. Standardized measurements of lifestyle factors and CR are needed, and mechanisms underlying CR need to be further addressed as well.  相似文献   
2.
PurposeTo examine the longitudinal associations of subjectively-measured physical activity (PA) and screen time with multiple domains of cognitive development in a sample of young children.MethodsParticipants were 96 children (baseline age: 3.69 ± 0.78 years) and their parents from Edmonton, Canada in the Physical Activity and Cognition in Early Childhood (PACE) study. Different types of PA (organized, non-organized) and screen time (television viewing, video games) were measured using a parental questionnaire at baseline and at 6- and 12-month follow-ups. Total proxy-reported PA, total screen time, and meeting/not meeting the screen time recommendations (2–4 years: ≤1 h/d; 5 years: ≤2 h/d) of the Canadian 24-Hour Movement Guidelines were also calculated. Working memory (Nebraska Barnyard task) and inhibitory control (Fish-Shark Go/No-Go task) were assessed at the three time points. Intellectual ability, including language development, inductive reasoning, and perceptual speed, were assessed using the Woodcock-Johnson III test battery at 6- and 12-month follow-ups. Multilevel growth modeling was conducted.ResultsOrganized PA (B = 1.26; 95%CI: 0.19,2.33), non-organized PA (B = 0.89, 95%CI: 0.08, 1.71), and total proxy-reported PA (B = 1.03, 95%CI: 0.41,1.66) were positively associated with intellectual ability. In particular, positive associations in regard to language development and inductive reasoning were observed. As for screen time, most associations were not significant, except for positive associations of meeting the screen recommendation with intellectual ability (B = 3.19; 95%CI: 0.002,6.38) and language development (B = 4.32; 95%CI: 0.34,8.30).ConclusionFor young children, promoting PA participation in organized and non-organized activities, as well as meeting the screen time recommendations, appears important for cognitive development.  相似文献   
3.
Background: The practice of Norwegian occupational therapists (OTs) in municipal practice is a little explored area and with the Coordination Reform Act from 2012, Norwegian OTs in municipal practice have received responsibilities concerning clients with cognitive impairments. The aim of this study was to explore municipal OTs experiences with assessment of clients with cognitive impairments.

Method: Fourteen individual interviews with OTs who worked with clients with cognitive impairments, were conducted. An inductive thematic analysis, using text condensation and coding, was performed.

Results: The results revealed three themes; power of occupation, advantages and disadvantages of assessments used and the need for competencies within municipal services. The participants emphasized using observation in the assessment process and reflected on pros and cons of the standardized assessment tools they used. They expressed a need for competence development, although it was difficult to prioritize to do so.

Conclusion: This study illustrated a conflicted practice related to choices OTs make in their practices. They valued the importance of working occupation based, however, they chose to use impairment based standardized assessments. They expressed a need to engage in professional development, but due to heavy workloads, the limited power they experienced and lack of knowledge, this was difficult.  相似文献   

4.
BackgroundImpaired self-awareness (ISA) has frequently been found to be both frequent and deleterious in patients with moderate to severe traumatic brain injury (TBI).ObjectivesThe present paper is the first of a two-part systematic review of ISA after traumatic brain injury (TBI), focusing on assessment methods, clinical aspects and recovery.MethodsFollowing the PRISMA guidelines, 95 articles meeting the inclusion criteria were included.ResultsISA occurs in 30% to 50% of patients with moderate to severe TBI, although it tends to improve with time. There is no one single gold-standard measure of ISA. Self-proxy discrepancy scores, with scales such as the Patient Competency Rating Scale or the Awareness Questionnaire, or a structured interview such as the Self Awareness of Deficits Interview, are the most frequently used assessment methods, with adequate psychometric properties. Scores on these different scales correlate only moderately with each other, which suggests that they may address different aspects of self-awareness. ISA mainly concerns cognitive and behavioral problems rather than physical or sensory impairments and may concern different areas of functioning, such as anticipatory, emergent or meta-cognitive awareness.ConclusionISA is a complex and multifaceted issue that should be systematically assessed in rehabilitation settings using a range of relatively well-validated tools. The consequences and predictors of ISA after TBI will be addressed in a companion paper.  相似文献   
5.
Introduction: It is well established that behavioral variant frontotemporal dementia can impair social and emotional function. However, there is no consensus regarding how Alzheimer’s disease can affect facial expression recognition. We aim to systematically review all the literature addressing this issue over the last 10 years.

Method: We conducted a search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search for literature was undertaken on 19 September 2017, using Pubmed, SciELO, BIREME, and Thomson Reuters Web of Science electronic databases. The key terms for the search were: Alzheimer’s disease, dementia, and facial expression recognition.

Results: We screened 173 articles, and 22 of them were selected. The most common methodology involved showing participants photographs of people expressing the six basic emotions—fear, anger, sadness, disgust, surprise, and happiness. Results were ambiguous. Among people with mild Alzheimer’s disease, happiness was easier to recognize than the other five basic emotions, with sadness and anger the most difficult to recognize. In addition, the intensity level of the emotions presented seems to be important, and facial expression recognition is related to specific cognitive capacities, including executive function and visuoperceptual abilities. Impairment in facial expression recognition does not appear to be a consistent neuropsychological finding in Alzheimer’s disease.

Conclusions: The lack of standardized assessment instruments and the heterogeneity of the methods and samples used across studies hamper comparisons. Future researches should investigate facial expression recognition through more ecological and standardized methods.  相似文献   

6.
Evidence suggests that yoga can improve executive functioning (EF) and psychological well-being, but there is no evidence whether flow-based, moderate-intensity forms of yoga can deliver similar benefits. The purpose of this randomized controlled trial was to test the aforementioned effects of engaging in a 30-min, video-guided sun salutation exercise (n = 25), relative to aerobic exercise (n = 22) and attentional control (n = 24). Low-active participants (Mage = 27.84; 87.3% female), with symptoms of stress, completed psychosocial assessments and tasks assessing EF, before and after the session. Results showed a significant group difference for state anxiety (p = .01, ηp2 = 0.13) and stress (p < .05, ηp2 = 0.09), in favor of the yoga group. No significant between-groups differences in EF were observed. Results suggest that video-guided, flow-based forms of yoga can induce immediate improvements in well-being, yet extended involvement may be required to realize performance improvements in memory and processing speed.  相似文献   
7.
BackgroundDementia is a debilitating syndrome that significantly impacts individuals over the age of 65 years. There are currently no disease-modifying treatments for dementia. Impairment of nutrient sensing pathways has been implicated in the pathogenesis of dementia, and may offer a novel treatment approach for dementia.AimsThis systematic review collates all available evidence for Food and Drug Administration (FDA)-approved therapeutics that modify nutrient sensing in the context of preventing cognitive decline or improving cognition in ageing, mild cognitive impairment (MCI), and dementia populations.MethodsPubMed, Embase and Web of Science databases were searched using key search terms focusing on available therapeutics such as ‘metformin’, ‘GLP1’, ‘insulin’ and the dementias including ‘Alzheimer’s disease’ and ‘Parkinson’s disease’. Articles were screened using Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia). The risk of bias was assessed using the Cochrane Risk of Bias tool v 2.0 for human studies and SYRCLE’s risk of bias tool for animal studies.ResultsOut of 2619 articles, 114 were included describing 31 different ‘modulation of nutrient sensing pathway’ therapeutics, 13 of which specifically were utilized in human interventional trials for normal ageing or dementia. Growth hormone secretagogues improved cognitive outcomes in human mild cognitive impairment, and potentially normal ageing populations. In animals, all investigated therapeutic classes exhibited some cognitive benefits in dementia models. While the risk of bias was relatively low in human studies, this risk in animal studies was largely unclear.ConclusionsModulation of nutrient sensing pathway therapeutics, particularly growth hormone secretagogues, have the potential to improve cognitive outcomes. Overall, there is a clear lack of translation from animal models to human populations.  相似文献   
8.
9.
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