全文获取类型
收费全文 | 6527篇 |
免费 | 94篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 46篇 |
妇产科学 | 53篇 |
基础医学 | 161篇 |
口腔科学 | 34篇 |
临床医学 | 446篇 |
内科学 | 2911篇 |
皮肤病学 | 274篇 |
神经病学 | 285篇 |
特种医学 | 312篇 |
外科学 | 509篇 |
综合类 | 36篇 |
预防医学 | 828篇 |
眼科学 | 419篇 |
药学 | 177篇 |
4篇 | |
中国医学 | 23篇 |
肿瘤学 | 99篇 |
出版年
2023年 | 389篇 |
2022年 | 441篇 |
2021年 | 761篇 |
2020年 | 632篇 |
2019年 | 866篇 |
2018年 | 776篇 |
2017年 | 294篇 |
2016年 | 73篇 |
2015年 | 104篇 |
2014年 | 518篇 |
2013年 | 259篇 |
2012年 | 143篇 |
2011年 | 198篇 |
2010年 | 117篇 |
2009年 | 172篇 |
2008年 | 213篇 |
2007年 | 250篇 |
2006年 | 82篇 |
2005年 | 104篇 |
2004年 | 48篇 |
2003年 | 57篇 |
2002年 | 26篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 17篇 |
1998年 | 16篇 |
1997年 | 13篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有6625条查询结果,搜索用时 389 毫秒
21.
22.
Benjamin R. Griffin J. Pedro Teixeira Sophia Ambruso Michael Bronsert Jay D. Pal Joseph C. Cleveland T. Brett Reece David A. Fullerton Sarah Faubel Muhammad Aftab 《The Journal of thoracic and cardiovascular surgery》2021,161(4):1346-1355.e3
ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity. 相似文献
23.
重视医学信用伦理的研究与开发 总被引:7,自引:3,他引:4
医疗行业市场化是必然趋势。在医疗行业市场化进程中,医学伦理道德除了道德价值之外,还含有积极的经济内涵。医学伦理道德也是重要的医疗资源,通过参与医疗市场资源的配制和运作,也可以产生经济效益,转化为医疗资本。医疗行业要重视医学伦理道德资源的开发。信用伦理是在市场经济条件下形成的,这是医学伦理学所面临的新课题。笔者认为,不说谎、不期诈,兑现承诺,保证医疗质量,发扬医学人道主义,是医学信用伦理的四项基本标准。 相似文献
24.
In medical studies with censored data Kaplan and Meier's product limit estimator has frequent use as the estimate of the survival function. Simultaneous confidence intervals for the survival function at various time points constitute a useful addition to the analysis. This study compares several such methods. We consider in a simulation investigation two whole curve confidence bands and four methods based on the Bonferroni inequality. The results show that three Bonferroni-type methods are essentially equivalent, all being better than the other methods when the number of time points is small (3 or 5). 相似文献
25.
26.
Donald B. White Cynthia A. Walawander Dong Y. Liu Thaddeus H. Grasela 《Journal of pharmacokinetics and pharmacodynamics》1992,20(3):295-313
In a simulation study of inference on population pharmacokinetic parameters, two methods of performing tests of hypotheses comparing two populations using NONMEM were evaluated. These two methods are the test based upon 95% confidence intervals and the likelihood ratio test. Data were simulated according to a monoexponential model and, in that context, power curves for each test were generated for (i)the ratio of mean clearance and (ii)the ratio of the population standard deviations of clearance. To generate the power curves, a range of these parameters was employed; other pharmacokinetic parameters were selected to reflect the variability typically present in a Phase II clinical trial. For tests comparing the means, the confidence interval tests had approximately the same power as the likelihood ratio tests and were consistently more faithful to the nominal level of significance. For comparison of the standard deviations, and when the volume of information available was relatively small, however, the likelihood ratio test was more able to detect differences between the two groups. These results were then compared to results on parameter estimation in order to gain insight into the question of power. As an example, the nonnormality of estimates of the ratio of standard deviations plays an important role in explaining the low power for the confidence interval tests. We conclude that, except for the situation of modeling standard deviations with only sparse information, NONMEM produces tests of significance that are effective at detecting clinically significant differences between two populations.Partial support from the Upjohn Company, NIH-BRSG SO RR 07066, and the Burroughs Wellcome Foundation. 相似文献
27.
Fear of falling and postural control in Parkinson's disease. 总被引:4,自引:0,他引:4
This study investigated the relationship between fear of falling (FOF) and qualitative and quantitative postural control in Parkinson's disease (PD). Fifty-eight nondemented PD patients were studied along with age-matched healthy controls. The degree of FOF was estimated using the Activities-specific Balance Confidence scale. Qualitative postural control was evaluated using a component of the Unified Parkinson Disease Rating Scale. Postural control was quantified, using centre of pressure measures obtained from a force plate, for eight standing balance tests of different challenges. The results showed that FOF was more evident for PD patients when compared with healthy individuals of similar age. Furthermore, FOF was significantly associated with a qualitative estimate of postural control in PD; individuals with PD who had a greater degree of posture impairment reported greater FOF. The results also showed that an estimate of FOF may help to explain quantitative postural instability in PD. FOF, when coupled with a qualitative estimate of postural control, was able to explain a greater amount of variation in quantitative balance performance for five of the eight balance tests. When considered independently, the qualitative measure of postural control, in general, could not well predict quantitative balance performance. The greater degree of FOF and its possible association with altered postural control suggests that FOF should be considered as an important, independent risk factor in the assessment and treatment of postural instability in patients with PD. 相似文献
28.
Gaëlle Dzangué-Tchoupou Kuberaka Mariampillai Loïs Bolko Damien Amelin Wladimir Mauhin Aurélien Corneau Catherine Blanc Yves Allenbach Olivier Benveniste 《Autoimmunity reviews》2019,18(4):325-333
Background
Myositis is a heterogeneous group of muscular auto-immune diseases with clinical and pathological criteria that allow the classification of patients into different sub-groups. Inclusion body myositis is the most frequent myositis above fifty years of age. Diagnosing inclusion body myositis requires expertise and is challenging. Little is known concerning the pathogenic mechanisms of this disease in which conventional suppressive-immune therapies are inefficacious.Objectives
Our aim was to deepen our understanding of the immune mechanisms involved in inclusion body myositis and identify specific biomarkers.Methods
Using a panel of thirty-six markers and mass cytometry, we performed deep immune profiling of peripheral blood cells from inclusion body myositis patients and healthy donors, divided into two cohorts: test and validation cohorts. Potential biomarkers were compared to myositis controls (anti-Jo1-, anti-3-hydroxyl-3-methylglutaryl CoA reductase-, and anti-signal recognition particle-positive patients).Results
Unsupervised analyses revealed substantial changes only within CD8+ cells. We observed an increase in the frequency of CD8+ cells that expressed high levels of T-bet, and containing mainly both effector and terminally differentiated memory cells. The senescent marker CD57 was overexpressed in CD8+T-bet+ cells of inclusion body myositis patients. As expected, senescent CD8+T-bet+ CD57+ cells of both patients and healthy donors were CD28nullCD27nullCD127null. Surprisingly, non-senescent CD8+T-bet+ CD57- cells in inclusion body myositis patients expressed lower levels of CD28, CD27, and CD127, and expressed higher levels of CD38 and HLA-DR compared to healthy donors. Using classification and regression trees alongside receiver operating characteristics curves, we identified and validated a frequency of CD8+T-bet+ cells >51.5% as a diagnostic biomarker specific to inclusion body myositis, compared to myositis control patients, with a sensitivity of 94.4%, a specificity of 88.5%, and an area under the curve of 0.97.Conclusion
Using a panel of thirty-six markers by mass cytometry, we identify an activated cell population (CD8+T-bet+ CD57- CD28lowCD27lowCD127low CD38+ HLA-DR+) which could play a role in the physiopathology of inclusion body myositis, and identify CD8+T-bet+ cells as a predominant biomarker of this disease. 相似文献29.
Eleanor R. Bull BA MSc PgDip CPsychol Hannah Dale BSc MSc PhD CPsychol 《Health & social care in the community》2021,29(1):270-283
Community health and social care practitioners play an increasingly important role in the health promotion agenda, but lack confidence in having effective health behaviour change (HBC) conversations with members of the public. This study reports the development and evaluation of a training intervention based on health psychology to improve health and social care practitioner self-rated confidence, competence and intention to use five behaviour change techniques (BCTs) in their HBC conversations. A 2-day behavioural science interprofessional skills training course plus online learning module was designed for health and social care staff across North East Scotland, teaching five evidence-based BCTs (e.g. Action Planning), plus person-centred communication skills. Participants rated confidence, competence and future intention to use the BCTs on likert scales (1–10) pre-course and post-course, and provided acceptability data. 177 participants aged 20–64 took part, qualitative and quantitative data suggested that the course had high acceptability. Paired samples t tests (n = 120 with complete data) showed significant improvements in confidence, competence and intention following the course, which remained significant with a conservative analysis (n = 174) assuming no change for missing data. Perceived competence in Action Planning increased most during the course (mean change 3.09). In conclusion, health psychology-based skills training can improve practitioner confidence, competence and intention to use evidence-based BCTs; further evaluation is needed to assess practice change. 相似文献
30.
《Vaccine》2022,40(27):3761-3770