全文获取类型
收费全文 | 2151篇 |
免费 | 101篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 23篇 |
妇产科学 | 19篇 |
基础医学 | 285篇 |
口腔科学 | 74篇 |
临床医学 | 211篇 |
内科学 | 479篇 |
皮肤病学 | 105篇 |
神经病学 | 192篇 |
特种医学 | 64篇 |
外科学 | 255篇 |
综合类 | 3篇 |
一般理论 | 48篇 |
预防医学 | 261篇 |
眼科学 | 9篇 |
药学 | 104篇 |
肿瘤学 | 115篇 |
出版年
2023年 | 10篇 |
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 31篇 |
2018年 | 37篇 |
2017年 | 48篇 |
2016年 | 37篇 |
2015年 | 48篇 |
2014年 | 68篇 |
2013年 | 88篇 |
2012年 | 152篇 |
2011年 | 166篇 |
2010年 | 88篇 |
2009年 | 78篇 |
2008年 | 117篇 |
2007年 | 160篇 |
2006年 | 133篇 |
2005年 | 148篇 |
2004年 | 165篇 |
2003年 | 160篇 |
2002年 | 125篇 |
2001年 | 38篇 |
2000年 | 29篇 |
1999年 | 13篇 |
1998年 | 21篇 |
1997年 | 28篇 |
1996年 | 22篇 |
1995年 | 25篇 |
1994年 | 22篇 |
1993年 | 20篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 5篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1968年 | 1篇 |
排序方式: 共有2257条查询结果,搜索用时 883 毫秒
81.
Mark F J Stolk Marco C J M Becx Karel C Kuypers Cees A Seldenrijk 《Clinical gastroenterology and hepatology》2006,4(7):908-911
BACKGROUND AND AIMS: Ezetimibe was introduced recently as a new class of cholesterol-lowering drugs. Until now only limited increases of transaminase levels were reported. METHODS: We studied 2 patients with severe hepatic side effects of ezetimibe in a general community hospital. RESULTS: Ezetimibe may lead to 2 distinct types of severe hepatic side effects. CONCLUSIONS: Ezetimibe may rarely cause hepatotoxicity, severe cholestatic hepatitis, or acute autoimmune hepatitis. 相似文献
82.
Comijs HC van Tilburg T Geerlings SW Jonker C Deeg DJ van Tilburg W Beekman AT 《Aging clinical and experimental research》2004,16(3):226-232
BACKGROUND AND AIMS: Some prospective studies show that depression is a risk factor for cognitive decline. So far, the explanation for the background of this association has remained unclear. The present study investigated 1) whether depression is etiologically linked to cognitive decline; 2) whether depression and cognitive decline may be the consequence of the same underlying subcortical pathology, or 3) whether depression is a reaction to global cognitive deterioration. METHODS: A cohort of 133 depressed and 144 non-depressed older persons was followed at eight successive observations over 3 years. All subjects were participants in the Longitudinal Aging Study Amsterdam (LASA). Depression symptoms were measured by means of the CES-D at eight successive waves. Cognitive function (memory function, information processing speed, global cognitive functioning) was assessed at baseline and at the last CES-D measurement. RESULTS: The severity and duration of depressive symptoms were not associated with subsequent decline in memory functioning or global cognitive decline. There was an association between both chronic mild depression and chronic depression, and decline in speed of information processing. CONCLUSIONS: These results support the hypothesis that, in older persons, chronic depression as well as cognitive decline may be the consequence of the same underlying subcortical pathology. 相似文献
83.
Ellen G.H.M. van den Heuvel Natasja M. van Schoor Paul Lips Elke J.P. Magdeleyns Dorly J.H. Deeg Cees Vermeer Martin den Heijer 《Maturitas》2014
Objectives
Vitamin K plays a pivotal role in the synthesis of Matrix Gla protein (MGP), a calcification inhibitor in vascular tissue. Vascular calcification has become an important predictor of cardiovascular disease. The aim of the current study was to examine the potential association of circulating desphospho-carboxylated and -uncarboxylated MGP (dp-cMGP and dp-ucMGP), reflecting vitamin K status, with the incidence of cardiovascular events and disease (CVD) in older individuals.Study design
The study was conducted in 577 community-dwelling older men and women of the Longitudinal Aging Study Amsterdam (LASA), aged >55 year, who were free of cardiovascular disease at baseline. Multivariate Cox proportional hazards models were used to analyze the data.Main outcome measures
Incidence of CVD.Results
After a mean follow-up of 5.6 ± 1.2 year, we identified 40 incident cases of CVD. After adjustment for classical confounders and vitamin D status, we observed a more than 2-fold significantly higher risk of CVD for the highest tertile of dp-ucMGP with a HR of 2.69 (95% CI, 1.09–6.62) as compared with the lowest tertile. Plasma dp-cMGP was not associated with the risk of CVD.Conclusions
Vitamin K insufficiency, as assessed by high plasma dp-ucMGP concentrations is associated with an increased risk for cardiovascular disease independent of classical risk factors and vitamin D status. Larger epidemiological studies on dp-ucMGP and CVD incidence are needed followed by clinical trials to test whether vitamin K-rich diets will lead to a decreased risk for cardiovascular events. 相似文献84.
85.
86.
Hoffmann R Lepper W Heussen N Elkelini M Sieswerda GT Kamp O de Cock CC Voci P Visser CA Hanrath P 《The international journal of cardiovascular imaging》2004,20(1):27-35
Analysis of coronary flow velocity pattern has been used to assess microvascular function post acute myocardial infarction (AMI). This study sought to analyze whether the flow level has an impact on parameters of coronary flow velocity pattern. Parameters of coronary flow velocity pattern were determined at baseline and during increased flow due to maximal hyperemia induced by adenosine in 25 patients after PTCA for first AMI using Doppler flow wires. Patients were divided into those with depressed (global wall motion index (GWMI) > or = 1.5; n = 14) and those with preserved (GWMI < 1.5; n = 11) left ventricular (LV) function at 4 weeks. Coronary flow velocity pattern at rest was different between patients with depressed and patients with preserved LV function at follow-up. A difference in flow pattern between the groups remained at increased flow level. However, increase of flow altered parameters of flow pattern. Diastolic deceleration rate (DSR) increased for patients with preserved LV function (53.7+/-25.6 at baseline vs. 67.0+/-29.8 cm/s2 with adenosine) and depressed LV function (95.3+/-58.6 vs. 110.7+/-61.4 cm/s2, respectively, p = 0.0012). Induction of hyperemia resulted also in increased systolic and diastolic peak flow velocity and diastolic deceleration time (DDT). Higher flow had no impact on early systolic retrograde flow, systolic flow duration and diastolic-systolic velocity ratio (DSVR). The coronary flow velocity pattern allows prediction of LV function at 4 weeks after AMI. However, it should be considered that some parameters of the flow velocity pattern are affected by the coronary flow level. 相似文献
87.
Susanne Coleman BSc RGN E. Andrea Nelson PhD RGN Justin Keen MSc PhD Lyn Wilson MA RGN Elizabeth McGinnis MSc PhD RGN Carol Dealey PhD RGN Nikki Stubbs MSc RGN Delia Muir BA Amanda Farrin MSc Dawn Dowding PhD RN Jos M.G.A. Schols MD PhD Janet Cuddigan PhD RN FAAN Dan Berlowitz MD MPH Edward Jude MD MRCP Peter Vowden MD FRCS Dan L. Bader PhD DSc Amit Gefen PhD Cees W.J. Oomens PhD Lisette Schoonhoven PhD RN Jane Nixon PhD RN 《Journal of advanced nursing》2014,70(10):2339-2352
88.
Claar D. van der Maarel-Wierink Judith M.M. Meijers Luc M.J. De Visschere Cees de Baat Ruud J.G. Halfens Jos M.G.A. Schols 《International journal of nursing studies》2014
Background
Dysphagia has been found to be strongly associated with aspiration pneumonia in frail older people. Aspiration pneumonia is causing high hospitalization rates, morbidity, and often death. Better insight in the prevalence of (subjective) dysphagia in frail older people may improve its early recognition and treatment.Objective
First, to assess the prevalence of subjective dysphagia in care home residents in the Netherlands. Second, to assess the associations of subjective dysphagia with potential risk factors of dysphagia.Design
Retrospective data-analysis of a cross-sectional, multi-centre point prevalence measurement.Setting
119 care homes in the Netherlands.Participants
Data of 8119 care home residents aged 65 years or older were included and analyzed.Methods
Subjective dysphagia was assessed by a resident's response to a dichotomous question with regard to experiencing swallowing problems. If a resident was not able to respond (e.g. residents with dementia or aphasia), the question was answered by the ward care provider, or the resident's file was consulted for registered swallowing complaints and/or dysphagia. Several residents’ data were collected: gender, age, (number of) diseases, the presence of malnutrition, the Care Dependency Scale score, and the body mass index.Results
Subjective dysphagia was found in 751 (9%) residents. A final model for subjective dysphagia after multivariate backward stepwise regression analysis revealed eight significant variables: age (B −0.022), Care Dependency Scale score (B −0.985), ‘malnutrition’ (OR 1.58; 95% CI 1.31–1.90), ‘comorbidity’ (OR 1.07; 95% CI 1.01–1.14), and the disease clusters ‘dementia’ (OR 0.55; 95% CI 0.45–0.66), ‘nervous system disorder’ (OR 1.55; 95% CI 1.20–1.99), ‘cardiovascular disease’ (OR 0.81; 95% CI 0.67–0.99) and ‘cerebrovascular disease/hemiparesis’ (OR 1.74; 95% CI 1.45–2.10).Conclusion
It seems justified to conclude that subjective dysphagia is a relevant care problem in older care home residents in the Netherlands. Care Dependency Scale score, ‘malnutrition’, and the disease clusters ‘dementia’, ‘nervous system disorder’, and ‘cerebrovascular disease/hemiparesis’ were associated with the presence of subjective dysphagia in this study. Age, ‘comorbidity’ and ‘cardiovascular disease’ showed very small influence. 相似文献89.
90.