全文获取类型
收费全文 | 328篇 |
免费 | 28篇 |
国内免费 | 22篇 |
专业分类
儿科学 | 27篇 |
妇产科学 | 5篇 |
基础医学 | 40篇 |
口腔科学 | 7篇 |
临床医学 | 46篇 |
内科学 | 66篇 |
皮肤病学 | 4篇 |
神经病学 | 45篇 |
特种医学 | 72篇 |
外科学 | 7篇 |
综合类 | 13篇 |
预防医学 | 15篇 |
药学 | 12篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 10篇 |
2012年 | 19篇 |
2011年 | 14篇 |
2010年 | 15篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 23篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 16篇 |
1997年 | 21篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 9篇 |
1993年 | 12篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 7篇 |
1986年 | 18篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有378条查询结果,搜索用时 296 毫秒
61.
62.
63.
Ocular complications of orbital venography 总被引:1,自引:0,他引:1
64.
Sachdev PS Lipnicki DM Crawford J Reppermund S Kochan NA Trollor JN Draper B Slavin MJ Kang K Lux O Mather KA Brodaty H;the Sydney Memory Ageing Study Team 《The American journal of geriatric psychiatry》2012,20(10):854-865
OBJECTIVES:: To examine age- and sex-related differences in risk and protective factors for mild cognitive impairment (MCI) in community-based elderly individuals. DESIGN:: Cross-sectional study. SETTING:: The population-based Sydney Memory and Ageing Study. PARTICIPANTS:: A total of 757 nondemented, community-dwelling elderly individuals from an English-speaking background categorized as younger (70-79 years) or older (80-90 years). MEASUREMENTS:: Risk of MCI was determined for sociodemographic, lifestyle, and cardiac, physical, mental, and general health factors using age- (and sex-) adjusted multiple regressions comprising initially significant univariate factors. RESULTS:: The point prevalence of MCI within our sample was 39.1% overall: it was lowest in younger women (32.3%) and similar across men and older women (41.9%-43.6%). The risk of MCI across all participants was increased by the APOE ?4 allele, high homocysteine, and heart disease; and decreased by better odor identification, visual acuity, and mental activity. Risk factors in all younger participants were slow 6-m walk, poor odor identification, and high homocysteine. Risk of MCI was associated in younger women with history of depression, less mental activity, slower 6-m walk, poorer visual acuity, and higher homocysteine; and in younger men with poorer odor identification and higher homocysteine. Older participants showed no significant risk factors for MCI, except for poorer visual acuity in men. Supporting these findings were statistically significant interactions that reflected the differences in risk factor profiles between age and/or sex groups. CONCLUSIONS:: Risk factors for MCI differ in men and women and vary with age. This has implications for preventing MCI and possibly dementia. 相似文献
65.
Brodaty H Heffernan M Draper B Reppermund S Kochan NA Slavin MJ Trollor JN Sachdev PS 《Journal of Alzheimer's disease : JAD》2012,31(2):411-420
Neuropsychiatric symptoms (NPS) are non-cognitive disturbances such as depression. Rates of NPS have been shown to increase as cognitive ability declines and may be useful in predicting transition from mild cognitive impairment (MCI) to dementia. This community-based study reports the association between NPS and cognitive decline over two years. Participants included 873 community dwelling adults aged 70-90 years enrolled in the Sydney Memory and Ageing Study. NPS were assessed by the Neuropsychiatric Inventory (NPI). Cognitive impairment was defined by diagnosis (MCI or incident dementia) or neuropsychological test performance across five cognitive domains. Cognitive decline was defined by progression to dementia or worse neuropsychological performance. Total NPS at baseline did not differ between those without cognitive impairment (26.2%) and those with MCI (28.8%), but agitation and apathy were associated with MCI. Only baseline depression was associated with dementia at follow-up. Total NPS at baseline was cross-sectionally associated with cognitive impairment in executive function, attention, and global cognition, but did not predict cognitive decline. Depression, anxiety, agitation, anxiety, and apathy were all associated with impairment in at least one cognitive domain, but only anxiety and agitation were significantly associated with cognitive decline. Sensitivity analyses applied more stringent criteria for NPS and cognitive impairment in MCI but did not alter interpretation of results from the main analysis. Overall rates of NPS at baseline were not associated with MCI, dementia, or cognitive decline over two years. Additional follow-up is needed to further examine this association over a longer time course. 相似文献
66.
Simone Reppermund Rachael C. Birch John D. Crawford Jacqueline Wesson Brian Draper Nicole A. Kochan Julian N. Trollor Katharina Luttenberger Henry Brodaty Perminder S. Sachdev 《Journal of the American Medical Directors Association》2017,18(2):117-122
Objectives
The distinction between dementia and mild cognitive impairment (MCI) relies upon the evaluation of independence in instrumental activities of daily living (IADL). Self- and informant reports are prone to bias. Clinician-based performance tests are limited by long administration times, restricted access, or inadequate validation. To close this gap, we developed and validated a performance-based measure of IADL, the Sydney Test of Activities of Daily Living in Memory Disorders (STAM).Design
Prospective cohort study (Sydney Memory and Ageing Study).Setting
Eastern Suburbs, Sydney, Australia.Participants
554 community-dwelling individuals (54% female) aged 76 and older with normal cognition, MCI, or dementia.Measurements
Activities of daily living were assessed with the STAM, administered by trained psychologists, and the informant-based Bayer-Activities of Daily Living Scale (B-ADL). Depressive symptoms were measured with the Geriatric Depression Scale (15-item version). Cognitive function was assessed with a comprehensive neuropsychological test battery. Consensus diagnoses of MCI and dementia were made independently of STAM scores.Results
The STAM showed high interrater reliability (r = 0.854) and test-retest reliability (r = 0.832). It discriminated significantly between the diagnostic groups of normal cognition, MCI, and dementia with areas under the curves ranging from 0.723 to 0.948. A score of 26.5 discriminated between dementia and nondementia with a sensitivity of 0.831 and a specificity of 0.864. Correlations were low with education (r = 0.230) and depressive symptoms (r = ?0.179), moderate with the B-ADL (r = ?0.332), and high with cognition (ranging from r = 0.511 to r = 0.594). The mean time to complete the STAM was 16 minutes.Conclusions
The STAM has good psychometric properties. It can be used to differentiate between normal cognition, MCI, and dementia and can be a helpful tool for diagnostic classification both in clinical practice and research. 相似文献67.
Darren M. Lipnicki John Crawford Nicole A. Kochan Julian N. Trollor Brian Draper Simone Reppermund Kate Maston Karen A. Mather Henry Brodaty Perminder S. Sachdev 《Journal of the American Medical Directors Association》2017,18(5):388-395
Background
The nature and commonality of late-life risk factors for mild cognitive impairment (MCI), dementia, and mortality remain unclear. Our aim was to investigate potential risk factors, simultaneously in a single cohort including many individuals initially with normal cognition and followed for 6 years.Methods
We classified 873 community-dwelling individuals (70–90 years old and without dementia at baseline) from the Sydney Memory and Ageing Study as cognitively normal (CN), having MCI or dementia, or deceased 6 years after baseline. Associations with baseline demographic, lifestyle, health, and medical factors were investigated, including apolipoprotein (APOE) genotype, MCI at baseline, and reversion from MCI to CN within 2 years of baseline.Results
Eighty-three (9.5%) participants developed dementia and 114 (13%) died within 6 years; nearly 33% had MCI at baseline, of whom 28% reverted to CN within 2 years. A core set of baseline factors was associated with MCI and dementia at 6 years, including older age (per year: odds ratios and 95% confidence intervals = 1.08, 1.01–1.14 for MCI; 1.19, 1.09–1.31 for dementia), MCI at baseline (5.75, 3.49–9.49; 8.23, 3.93–17.22), poorer smelling ability (per extra test point: 0.89, 0.79–1.02; 0.80, 0.68–0.94), slower walking speed (per second: 1.12, 1.00–1.25; 1.21, 1.05–1.39), and being an APOE ε4 carrier (1.84, 1.07–3.14; 3.63, 1.68–7.82). All except APOE genotype were also associated with mortality (age: 1.11, 1.03–1.20; MCI: 3.87, 1.97–7.59; smelling ability: 0.83, 0.70–0.97; walking speed: 1.18, 1.03–1.34). Compared with stable CN participants, individuals reverting from MCI to CN after 2 years were at greater risk of future MCI (3.06, 1.63–5.72). Those who reverted exhibited some different associations between baseline risk factors and 6-year outcomes than individuals with stable MCI.Conclusion
A core group of late-life risk factors indicative of physical and mental frailty are associated with each of dementia, MCI, and mortality after 6 years. Tests for slower walking speed and poorer smelling ability may help screen for cognitive decline. Individuals with normal cognition are at greater risk of future cognitive impairment if they have a history of MCI. 相似文献68.
69.
p53 and MDM2 expression in odontogenic cysts and tumours 总被引:1,自引:0,他引:1
OBJECTIVE: The aim of this report was to assess p53 and MDM2 expression in odontogenic cysts and tumours, as they are known to play important roles in cell proliferation and tumorigenesis. MATERIALS AND METHODS: The expression of p53 and MDM2 proteins was determined immunohistochemically in 51 formalin-fixed, paraffin embedded specimens of odontogenic cysts and tumours.RESULTS: No positivity to p53 was found in the cases studied. MDM2 expression in ameloblastoma was higher than in radicular cysts, but lower than that observed in odontogenic keratocysts. No difference was observed between MDM2 expression in radicular cyst and adenomatoid odontogenic tumour. The clear-cell odontogenic ameloblastoma presented strong immunoreaction to this antigen.CONCLUSIONS: The results suggest that MDM2 overexpression may be involved in the pathogenesis of some odontogenic lesions. 相似文献
70.
BACKGROUND: Exposure to Aspergillus fumigatus allergens results in enhanced total serum IgE and peripheral blood eosinophils in mice. The associated pulmonary inflammation and immunologic responses are comparable to those detected in human allergic bronchopulmonary aspergillosis. Allergen-induced cytokines are thought to regulate the inflammatory and immune responses in these animals. METHODS: In the present study, we exposed C57BL/6 and BALB/c mice to A. fumigatus antigen. Both wild-type and IL-4 knockout phenotypes of animals of both strains were used. Some animals were also treated with anti-IL-5 or anti-IFN-gamma. Total serum IgE, Aspergillus species IgG subclass, peripheral blood eosinophils, and lung histology were studied. RESULTS: The results demonstrate similar lung inflammation in all wild-type and IL-4-/- animals exposed to A. fumigatus antigen. Similarly, in spite of the diverse immune response produced by the anticytokine treatment, no major differences were detected among any of the animal groups studied. CONCLUSIONS: It can be concluded that A. fumigatus exposure in an immunologically unaltered host is predominantly of a Th2 type, and that depletion of the Th2 cytokine leads to a similar lung inflammation but with a characteristic Th1 response, suggesting that the pathogenesis of allergic aspergillosis is the result of multiple induction pathways. 相似文献