全文获取类型
收费全文 | 2901篇 |
免费 | 436篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 61篇 |
妇产科学 | 7篇 |
基础医学 | 54篇 |
口腔科学 | 138篇 |
临床医学 | 415篇 |
内科学 | 1238篇 |
皮肤病学 | 14篇 |
神经病学 | 343篇 |
特种医学 | 46篇 |
外科学 | 344篇 |
综合类 | 130篇 |
一般理论 | 1篇 |
预防医学 | 248篇 |
眼科学 | 12篇 |
药学 | 108篇 |
9篇 | |
中国医学 | 20篇 |
肿瘤学 | 144篇 |
出版年
2024年 | 6篇 |
2023年 | 110篇 |
2022年 | 128篇 |
2021年 | 218篇 |
2020年 | 208篇 |
2019年 | 204篇 |
2018年 | 208篇 |
2017年 | 151篇 |
2016年 | 143篇 |
2015年 | 146篇 |
2014年 | 194篇 |
2013年 | 244篇 |
2012年 | 123篇 |
2011年 | 130篇 |
2010年 | 70篇 |
2009年 | 106篇 |
2008年 | 81篇 |
2007年 | 102篇 |
2006年 | 79篇 |
2005年 | 89篇 |
2004年 | 68篇 |
2003年 | 68篇 |
2002年 | 48篇 |
2001年 | 64篇 |
2000年 | 33篇 |
1999年 | 21篇 |
1998年 | 31篇 |
1997年 | 31篇 |
1996年 | 18篇 |
1995年 | 20篇 |
1994年 | 20篇 |
1993年 | 34篇 |
1992年 | 20篇 |
1991年 | 22篇 |
1990年 | 15篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有3346条查询结果,搜索用时 15 毫秒
81.
82.
《JACC: Cardiovascular Imaging》2021,14(9):1819-1828
ObjectivesThis study sought to describe worldwide variations in the use of myocardial perfusion imaging hardware, software, and imaging protocols and their impact on radiation effective dose (ED).BackgroundConcerns about long-term effects of ionizing radiation have prompted efforts to identify strategies for dose optimization in myocardial perfusion scintigraphy. Studies have increasingly shown opportunities for dose reduction using newer technologies and optimized protocols.MethodsData were submitted voluntarily to the INCAPS (International Atomic Energy Agency Nuclear Cardiology Protocols Study) registry, a multinational, cross-sectional study comprising 7,911 imaging studies from 308 labs in 65 countries. The study compared regional use of camera technologies, advanced post-processing software, and protocol characteristics and analyzed the influence of each factor on ED.ResultsCadmium-zinc-telluride and positron emission tomography (PET) cameras were used in 10% (regional range 0% to 26%) and 6% (regional range 0% to 17%) of studies worldwide. Attenuation correction was used in 26% of cases (range 10% to 57%), and advanced post-processing software was used in 38% of cases (range 26% to 64%). Stress-first single-photon emission computed tomography (SPECT) imaging comprised nearly 20% of cases from all world regions, except North America, where it was used in just 7% of cases. Factors associated with lower ED and odds ratio for achieving radiation dose ≤9 mSv included use of cadmium-zinc-telluride, PET, advanced post-processing software, and stress- or rest-only imaging. Overall, 39% of all studies (97% PET and 35% SPECT) were ≤9 mSv, while just 6% of all studies (32% PET and 4% SPECT) achieved a dose ≤3 mSv.ConclusionsNewer-technology cameras, advanced software, and stress-only protocols were associated with reduced ED, but worldwide adoption of these practices was generally low and varied significantly between regions. The implementation of dose-optimizing technologies and protocols offers an opportunity to reduce patient radiation exposure across all world regions. 相似文献
83.
Bouman A van Rossum E Ambergen T Kempen G Knipschild P 《Journal of the American Geriatrics Society》2008,56(3):397-404
OBJECTIVES: To evaluate the effectiveness of a home visiting program on health-related measures in a population of older people with poor health status.
DESIGN: Randomized, clinical trial.
SETTING: Community-dwelling citizens in the Netherlands.
PARTICIPANTS: Three hundred thirty people aged 70 to 84 randomly assigned to an intervention group (n=160) or a control group (n=170).
INTERVENTION: Eight home visits, lasting 1 hour or more, with telephone follow-up, over an 18-month period, conducted by experienced home nurses under supervision of a public health nurse; key elements of the (systematic) visits were assessment of health problems and risks, advice, and referral to professional and community services.
MEASUREMENTS: Self-rated health, functional status, quality of life, and changes in self-reported problems.
RESULTS: No differences were found between the intervention and control group in these and other outcome measures at the end of the intervention period (18 months).
CONCLUSION: The home visiting program did not appear to have any effect on the health status of older people with poor health and are probably not beneficial for such persons. 相似文献
DESIGN: Randomized, clinical trial.
SETTING: Community-dwelling citizens in the Netherlands.
PARTICIPANTS: Three hundred thirty people aged 70 to 84 randomly assigned to an intervention group (n=160) or a control group (n=170).
INTERVENTION: Eight home visits, lasting 1 hour or more, with telephone follow-up, over an 18-month period, conducted by experienced home nurses under supervision of a public health nurse; key elements of the (systematic) visits were assessment of health problems and risks, advice, and referral to professional and community services.
MEASUREMENTS: Self-rated health, functional status, quality of life, and changes in self-reported problems.
RESULTS: No differences were found between the intervention and control group in these and other outcome measures at the end of the intervention period (18 months).
CONCLUSION: The home visiting program did not appear to have any effect on the health status of older people with poor health and are probably not beneficial for such persons. 相似文献
84.
Reliable atrial septostomy by stenting of the atrial septum. 总被引:1,自引:0,他引:1
Saar Danon Daniel S Levi Juan C Alejos John W Moore 《Catheterization and cardiovascular interventions》2005,66(3):408-413
The aim of this report was to describe our experience with creating an interatrial communication by stenting the interatrial septum. In many forms of congenital heart disease, the presence of an appropriate interatrial shunt is critical. After the first several weeks of life, balloon atrial septostomy is not effective, and success with other methods is limited. Clinical records, echocardiograms, and catheterization data in patients who had an atrial septal stent placed between 2001 and 2004 at UCLA were reviewed. Changes in atrial pressures and systemic saturations were analyzed. Follow-up data and explant pathology were reviewed as available. Thirteen patients had stenting of the atrial septum (four restrictive, nine nonrestrictive). In patients with elevated right and left atrial pressures, there was a mean reduction of 2.4 and 7.4 mm Hg in right atrial and left atrial pressures, respectively. In patients with transposition physiology, there was a mean increase in oxygen saturation of 11.3%. Follow-up echocardiograms revealed patent stents with excellent position relative to the atrial septum. In six cases, the stents were removed during subsequent surgery and appeared endothelialized and patent. Stenting of the atrial septum is safe and effective in selected cases, allowing for a reliable, long-lasting, restrictive or nonrestrictive interatrial communication. 相似文献
85.
Andreas W. Schoenenberger André Moser Dominic Bertschi Peter Wenaweser Stephan Windecker Thierry Carrel Andreas E. Stuck Stefan Stortecky 《JACC: Cardiovascular Interventions》2018,11(4):395-403
Objectives
This study sought to evaluate whether frailty improves mortality prediction in combination with the conventional scores.Background
European System for Cardiac Operative Risk Evaluation (EuroSCORE) or Society of Thoracic Surgeons (STS) score have not been evaluated in combined models with frailty for mortality prediction after transcatheter aortic valve replacement (TAVR).Methods
This prospective cohort comprised 330 consecutive TAVR patients ≥70 years of age. Conventional scores and a frailty index (based on assessment of cognition, mobility, nutrition, and activities of daily living) were evaluated to predict 1-year all-cause mortality using Cox proportional hazards regression (providing hazard ratios [HRs] with confidence intervals [CIs]) and measures of test performance (providing likelihood ratio [LR] chi-square test statistic and C-statistic [CS]).Results
All risk scores were predictive of the outcome (EuroSCORE, HR: 1.90 [95% CI: 1.45 to 2.48], LR chi-square test statistic 19.29, C-statistic 0.67; STS score, HR: 1.51 [95% CI: 1.21 to 1.88], LR chi-square test statistic 11.05, C-statistic 0.64; frailty index, HR: 3.29 [95% CI: 1.98 to 5.47], LR chi-square test statistic 22.28, C-statistic 0.66). A combination of the frailty index with either EuroSCORE (LR chi-square test statistic 38.27, C-statistic 0.72) or STS score (LR chi-square test statistic 28.71, C-statistic 0.68) improved mortality prediction. The frailty index accounted for 58.2% and 77.6% of the predictive information in the combined model with EuroSCORE and STS score, respectively. Net reclassification improvement and integrated discrimination improvement confirmed that the added frailty index improved risk prediction.Conclusions
This is the first study showing that the assessment of frailty significantly enhances prediction of 1-year mortality after TAVR in combined risk models with conventional risk scores and relevantly contributes to this improvement. 相似文献86.
Fenestrated Amplatzer device for percutaneous creation of interatrial communication in patients after Fontan operation. 总被引:1,自引:0,他引:1
Ritu Chatrath Allison K Cabalka David J Driscoll Donald J Hagler 《Catheterization and cardiovascular interventions》2003,60(1):88-93
A customized Amplatzer septal device with a 5 mm fenestration was used to create an interatrial communication in two patients with previous Fontan operation and clinical indication for fenestration. At follow-up, device fenestration was occluded in both patients. In both patients, the device fenestration was reopened and patency maintained by placement of two stents within the communicating channel. 相似文献
87.
88.
89.
Matteo Brucoli Paolo Boffano Irene Romeo Chiara Corio Arnaldo Benech Muhammad Ruslin Tymour Forouzanfar Thomas Starch‐Jensen Tanía Rodríguez‐Santamarta Juan Carlos de Vicente Johanna Snll Hanna Thorn Marko Tarle Emil Dediol Petia Pechalova Nikolai Pavlov Hristo Daskalov Iva Doykova Kadri Kelemith Tiia Tamme Andrey Kopchak Ievgen Shumynskyi Pierre Corre Helios Bertin Quentin Goguet Marine Anquetil Aurlien Louvrier Christophe Meyer Tadej Dovak David Vozli
Ane Birk Boban Ani
i Vitomir S. Konstantinovic 《Dental traumatology》2020,36(3):241-246
90.
Factors influencing decision‐making processes for unwell residents in residential aged care: Hospital transfer or Residential InReach referral? 下载免费PDF全文
Sanka Amadoru Jo‐Anne Rayner Rajni Joseph Paul Yates 《Australasian journal on ageing》2018,37(2):E61-E67