收费全文 | 23223篇 |
免费 | 2022篇 |
国内免费 | 642篇 |
耳鼻咽喉 | 420篇 |
儿科学 | 456篇 |
妇产科学 | 83篇 |
基础医学 | 3455篇 |
口腔科学 | 128篇 |
临床医学 | 1743篇 |
内科学 | 2342篇 |
皮肤病学 | 67篇 |
神经病学 | 8799篇 |
特种医学 | 304篇 |
外国民族医学 | 1篇 |
外科学 | 767篇 |
综合类 | 2254篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 1355篇 |
眼科学 | 574篇 |
药学 | 2021篇 |
6篇 | |
中国医学 | 855篇 |
肿瘤学 | 254篇 |
2024年 | 96篇 |
2023年 | 435篇 |
2022年 | 721篇 |
2021年 | 1064篇 |
2020年 | 933篇 |
2019年 | 988篇 |
2018年 | 928篇 |
2017年 | 954篇 |
2016年 | 932篇 |
2015年 | 823篇 |
2014年 | 1532篇 |
2013年 | 2162篇 |
2012年 | 1295篇 |
2011年 | 1454篇 |
2010年 | 1176篇 |
2009年 | 1180篇 |
2008年 | 1227篇 |
2007年 | 1146篇 |
2006年 | 1035篇 |
2005年 | 809篇 |
2004年 | 750篇 |
2003年 | 605篇 |
2002年 | 512篇 |
2001年 | 417篇 |
2000年 | 314篇 |
1999年 | 268篇 |
1998年 | 247篇 |
1997年 | 232篇 |
1996年 | 212篇 |
1995年 | 201篇 |
1994年 | 131篇 |
1993年 | 129篇 |
1992年 | 126篇 |
1991年 | 97篇 |
1990年 | 81篇 |
1989年 | 68篇 |
1988年 | 59篇 |
1987年 | 41篇 |
1986年 | 42篇 |
1985年 | 97篇 |
1984年 | 72篇 |
1983年 | 57篇 |
1982年 | 58篇 |
1981年 | 41篇 |
1980年 | 26篇 |
1979年 | 25篇 |
1978年 | 17篇 |
1977年 | 20篇 |
1976年 | 19篇 |
1973年 | 14篇 |
Background
Visual and hearing impairments are known to be related to functional disability, cognitive impairment, and depression in community-dwelling older people. The aim of this study was to examine the prevalence of sensory impairment in nursing home residents, and whether sensory impairment is related to other common clinical problems in nursing homes, mediated by functional disability, cognitive impairment, and depressive symptoms.Methods
Cross-sectional data of 4007 nursing home residents in 59 facilities in 8 countries from the SHELTER study were analyzed. Visual and hearing impairments were assessed by trained staff using the interRAI instrument for Long-Term Care Facilities. Generalized linear mixed models adjusted for functional disability, cognitive impairment, and depressive symptoms were used to analyze associations of sensory impairments with prevalence of clinical problems, including behavioral symptoms, incontinence, fatigue, falls, problems with balance, sleep, nutrition, and communication.Results
Of the participants, 32% had vision or hearing impairment (single impairment) and another 32% had both vision and hearing impairments (dual impairment). Residents with single impairment had significantly higher rates of communication problems, fatigue, balance problems, and sleep problems, as compared with residents without any sensory impairment. Those with dual impairment had significantly higher rates of all clinical problems assessed in this study as compared with those without sensory impairment. For each clinical problem, the magnitude of the odds ratio for specific clinical problems was higher for dual impairment than for single impairment.Conclusion
Visual and hearing impairments are associated with higher rates of common clinical problems among nursing home residents, independent of functional disability, cognitive impairment, and depressive symptoms. 相似文献PURPOSE
The concept of mild cognitive impairment (MCI) has recently been introduced into the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) as mild neurocognitive disorder, making it a formal diagnosis. We investigated the prognostic value of such a diagnosis and analyzed the determinants of the future course of MCI in the AgeCoDe study (German Study on Ageing, Cognition, and Dementia in Primary Care Patients).METHODS
We recruited 357 patients with MCI aged 75 years or older from primary care practices and conducted follow-up with interviews for 3 years. Depending on the course of impairment over time, the patients were retrospectively split into 4 groups representing remittent, fluctuating, stable, and progressive courses of MCI. We performed ordinal logistic regression analysis and classification and regression tree (CART) analysis.RESULTS
Overall, 41.5% of the patients had remission of symptoms with normal cognitive function 1.5 and 3 years later, 21.3% showed a fluctuating course, 14.8% had stable symptoms, and 22.4% had progression to dementia. Patients were at higher risk for advancing from one course to the next along this spectrum if they had symptoms of depression, impairment in more than 1 cognitive domain, or more severe cognitive impairment, or were older. The result on a test of the ability to learn and reproduce new material 10 minutes later was the best indicator at baseline for differentiating between remittent and progressive MCI. Symptoms of depression modified the prognosis.CONCLUSIONS
In primary care, about one-quarter of patients with MCI have progression to dementia within the next 3 years. Assessments of memory function and depressive symptoms are helpful in predicting a progressive vs a remittent course. When transferring the concept of MCI into clinical diagnostic algorithms (eg, DSM-5), however, we should not forget that three-quarters of patients with MCI stayed cognitively stable or even improved within 3 years. They should not be alarmed unnecessarily by receiving such a diagnosis. 相似文献Methods: A systematic search and retrieval of the literature was conducted using advanced search techniques. The retrieval identified 589 papers, seven of which were relevant. Review/outcomes criteria were developed and study quality was determined.
Results: There is paucity of high-quality evidence to support use of melatonin for sleep impairment post paediatric ABI. Variation in dosage, screening and outcome measures, data reporting and a lack of impairment delineation and treatment stratification were recurrent themes.
Conclusion: Retrieved evidence for the effectiveness of melatonin for post paediatric ABI sleep impairment appears promising. There is a clear need for further study in this area to inform clinical and research practices. Recommendations are given. 相似文献