全文获取类型
收费全文 | 405篇 |
免费 | 40篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 47篇 |
妇产科学 | 5篇 |
基础医学 | 73篇 |
口腔科学 | 4篇 |
临床医学 | 26篇 |
内科学 | 90篇 |
皮肤病学 | 7篇 |
神经病学 | 31篇 |
特种医学 | 33篇 |
外科学 | 62篇 |
综合类 | 5篇 |
预防医学 | 18篇 |
眼科学 | 3篇 |
药学 | 10篇 |
肿瘤学 | 28篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 2篇 |
2019年 | 10篇 |
2018年 | 21篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 16篇 |
2014年 | 15篇 |
2013年 | 12篇 |
2012年 | 20篇 |
2011年 | 17篇 |
2010年 | 11篇 |
2009年 | 11篇 |
2008年 | 19篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 10篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1947年 | 1篇 |
排序方式: 共有446条查询结果,搜索用时 19 毫秒
11.
Hourvash Haghighinejad Minoo Tarakemehzadeh Peyman Jafari Mahtab Jafari Mani Ramzi Arvin Hedayati 《Psychiatry investigation》2021,18(3):179
ObjectiveThe aims of this study were to evaluate the psychometric properties of Persian translation of the Yale Food Addiction Scale 2.0 (YFAS 2.0) as a widely accepted questionnaire for the first time and to establish a cut off score for Food Craving Questionnaire-Trait-reduced (FCQ-T-r). MethodsIn this cross-sectional study, 330 visitors of family physician clinics in Shiraz, a city located in south of Iran, were selected. The English version of YFAS 2.0 was translated into Persian and used in this study as well as the Persian version of FCQ-T-r. ResultsConfirmatory factor analysis of YFAS-2 confirmed one dimensional structure and factor loading in all eleven symptoms was above 0.4. Internal consistency for eleven symptoms was 0.813. Prevalence of food addiction in participants was 6.7% (22 participants). BMI and FCQ-T-r questionnaire score both were positively correlated with the number of food addiction symptoms but age was negatively correlated with the number of the symptoms. The ROC curve analysis showed the best suggested cut-off point for FCQ-T-r questionnaire to detect food addiction was 32.5. ConclusionThe present study confirmed validity and reliability of Persian version of YFAS-2. It is suggested that food addiction occurs in different level of food craving behavior in different food cultures or genetics. 相似文献
12.
Externally controlled ventricular pacing was employed in a patient with recurrent disabling supraventricular tachycardia and frequent sinus pauses between attacks of tachyarrhythmia. A permanent transthoracic demand pacemaker was inserted after electrophysiologic study demonstrated the effectiveness of ventricular stimulation in terminating induced supraventricular tachycardia. Subsequently, spontaneous recurrences of tachyarrhythmia failed to respond to fixed rate left ventricular stimulation accomplished by placing a magnet externally over the pacemaker pack. During an induced supraventricular tachycardia, repeat electrophysiologic study demonstrated that paced left ventricular beats failed to invade the A-V junctional area before it was depolarized previously by the corresponding tachycardia beat. Right ventricular stimulation from a transvenous pacemaker could depolarize the site of the reentrant circuit and terminate an induced supraventricular tachycardia. The addition of propranolol increased the ease by which spontaneous attacks of tachyarrhythmia could be terminated by right ventricular endocardial pacing. 相似文献
13.
Mohammad Reza Alizadeh John T. Abatzoglou Charles H. Luce Jan F. Adamowski Arvin Farid Mojtaba Sadegh 《Proceedings of the National Academy of Sciences of the United States of America》2021,118(22)
Increases in burned area and large fire occurrence are widely documented over the western United States over the past half century. Here, we focus on the elevational distribution of forest fires in mountainous ecoregions of the western United States and show the largest increase rates in burned area above 2,500 m during 1984 to 2017. Furthermore, we show that high-elevation fires advanced upslope with a median cumulative change of 252 m (−107 to 656 m; 95% CI) in 34 y across studied ecoregions. We also document a strong interannual relationship between high-elevation fires and warm season vapor pressure deficit (VPD). The upslope advance of fires is consistent with observed warming reflected by a median upslope drift of VPD isolines of 295 m (59 to 704 m; 95% CI) during 1984 to 2017. These findings allow us to estimate that recent climate trends reduced the high-elevation flammability barrier and enabled fires in an additional 11% of western forests. Limited influences of fire management practices and longer fire-return intervals in these montane mesic systems suggest these changes are largely a byproduct of climate warming. Further weakening in the high-elevation flammability barrier with continued warming has the potential to transform montane fire regimes with numerous implications for ecosystems and watersheds.Fire is an integral component of most forested lands and provides significant ecological services (1). However, burned area, fire size, the number of large fires, and the length of fire season have increased in the western United States in recent decades (2, 3). Increasing fire activity and the expansion of wildland urban interface (4) collectively amplified direct and indirect fire-related loss of life and property (5, 6) and contributed to escalating fire suppression costs (7). While increased biomass due to a century of fire exclusion efforts is hypothesized to have partially contributed to this trend (8), climate change is also implicated in the rise of fire activity in the western United States (9–11).Although increases in forest fire activity are evident in all major forested lands in the western United States (2, 12, 13), an abundance of moisture—due to snowpack persistence, cooler temperatures, and delayed summer soil and fuel drying—provides a strong buffer of fire activity (13) and longer fire-return intervals (14) at high elevations. Recent studies, however, point to changing fire characteristics across many ecoregions of the western United States (15), including high-elevation areas of the Sierra Nevada (16), Pacific Northwest, and Northern Rockies (12, 17). These studies complement documented changes in montane environments including amplified warming with elevation (18), widespread upward elevational shift in species (19), and increased productivity in energy-limited high-elevation regions that enhance fuel growth and connectivity (20). These changes have been accompanied by longer snow-free periods (21), increased evaporative demand (9), and regional declines in fire season precipitation frequency (11) across the western United States promoting increased fuel ignitability and flammability that have well-founded links to forest burned area. A warmer climate is also conducive to a higher number of convective storms and more frequent lightning strikes (22).In this study, we explore changes in the elevational distribution of burned forest across the western United States and how changes in climate have affected the mesic barrier for high-elevation fire activity. We focus on changes in high-elevation forests that have endured fewer direct anthropogenic modifications compared to drier low-elevation forests that had frequent low-severity fires prior to European colonization and have been more subject to changes in settlement patterns as well as fire suppression and harvest (23, 24); we also pose the following questions: 1) Has the elevational distribution of fire in the western US forests systematically changed? and 2) What changes in biophysical factors have enabled such changes in high-elevation fire activity? We explore these questions across 15 mountainous ecoregions of the western United States using records from large fires (>405 ha) between 1984 and 2017 [Monitoring Trends in Burn Severity (MTBS) (25)], a 10-m–resolution digital elevation model, and daily high-spatial–resolution surface meteorological data [gridMET (26)].We focus on the trends in Z90—defined as the 90th percentile of normalized annual elevational distribution of burned forest in each ecoregion. Here, the term “normalized” essentially refers to the fraction of forest area burned by elevation. We complement this analysis by examining trends in burned area by elevational bands and using quantile regression of normalized annual forest fire elevation. We then assess the interannual relationships between Z90 and vapor pressure deficit (VPD) and compare the upslope advance in montane fire to elevational climate velocity of VPD during 1984 to 2017. Specifically, we use VPD trends and VPD–high-elevation fire regression to estimate VPD-driven changes in Z90 and BA90— defined as annual burned area above the 90th percentile of forest elevational distribution in each ecoregion—during 1984 to 2017. 相似文献
14.
Martin Than Louise Cullen Sally Aldous William A. Parsonage Christopher M. Reid Jaimi Greenslade Dylan Flaws Christopher J. Hammett Daren M. Beam Michael W. Ardagh Richard Troughton Anthony F.T. Brown Peter George Christopher M. Florkowski Jeffrey A. Kline W. Frank Peacock Alan S. Maisel Swee Han Lim Arvin Lamanna A. Mark Richards 《Journal of the American College of Cardiology》2012
15.
Prasad R. Shankar Katherine E. Maturen Arvin K. George Tudor Borza Chandy Ellimoottil Jeffrey S. Montgomery John T. Wei Brian T. Denton Matthew S. Davenport 《Journal of the American College of Radiology》2019,16(10):1385-1392
PurposeTo assess the temporary health impact of prostate multiparametric MRI (mpMRI) and transrectal prostate biopsy in an active surveillance prostate cancer population.MethodsA two-arm institutional review board–approved HIPAA-compliant prospective observational patient-reported outcomes study was performed from November 2017 to July 2018. Inclusion criteria were men with Gleason 6 prostate cancer in active surveillance undergoing either prostate mpMRI or transrectal prostate biopsy. A survey instrument was constructed using validated metrics in consultation with the local patient- and family-centered care organization. Study subjects were recruited at the time of diagnostic testing and completed the instrument by phone 24 to 72 hours after testing. The primary outcome measure was summary testing-related quality of life (summary utility score), derived from the testing morbidities index (TMI) (scale: 0 = death and 1 = perfect health). TMI is stratified into seven domains, with each domain scored from 1 (no health impact) to 5 (extreme health impact). Testing-related quality-of-life measures in the two cohorts were compared with Mann-Whitney U test.ResultsIn all, 122 subjects were recruited, and 90% (110 of 122 [MRI 55 of 60, biopsy 55 of 62]) successfully completed the survey instrument. The temporary quality-of-life impact of transrectal biopsy was significantly greater than that of prostate mpMRI (0.82, 95% confidence interval [CI] 0.79-0.85, versus 0.95, 95% CI 0.94-0.97; P < .001). The largest mean domain-level difference was for intraprocedural pain (transrectal biopsy 2.6, 95% CI 2.4-2.8, versus mpMRI 1.3, 95% CI 1.1-1.5; P < .001).ConclusionTransrectal prostate biopsy has greater temporary health impact (lower testing-related quality-of-life measure) than prostate mpMRI. 相似文献
16.
17.
Gershon AA Arvin AM Shapiro E 《The New England journal of medicine》2007,356(25):2648-9; author reply 2648-9
18.
Amir Arvin Sazgar Azadeh Kheradmand Ali Razfar Shabnam Hajialipour Amir Keyvan Sazgar 《Revista brasileira de otorrinolaringologia (English ed.)》2021,87(2):188-192
IntroductionThe caudal extension graft is usually a cartilage graft that overlaps the caudal margin of the nasal septum. A combination of the caudal extension graft and the tongue-in-groove technique is used to stabilize the nasal base, set tip projection, and refine the alar-columellar relationship.ObjectivesIn this study we present some new modifications to the placement of caudal extension grafts in rhinoplasty.MethodsThis study is a retrospective review of a prospectively collected database of 965 patients who underwent septorhinoplasty from June 2011 to July 2015. Of these, 457 patients required a caudal extension graft and were included in the study. Minimum follow-up was 13.2 months with a mean follow-up time of 17.4 months.ResultsIn most cases, comparison of photographs before and after surgery were satisfactory and showed improved contour. Minor deformity was detected in 41 patients and 11 patients needed revision surgery.ConclusionWith these modifications the surgeon can employ the caudal extension graft even in angulated caudal septal deviations. A variety of methods have been proposed for correction of caudal nasal deviation. 相似文献
19.
Arvin Bhana Claude A. Mellins Inge Petersen Stacey Alicea Nonhlahla Myeza Helga Holst 《AIDS care》2014,26(1):1-11
An increasing number of adolescents born with HIV in South Africa are on antiretroviral treatment and have to confront complex issues related to coping with a chronic, stigmatizing and transmittable illness. Very few evidence-based mental health and health promotion programs for this population exist in South Africa. This study builds on a previous collaboratively designed and developmentally timed family-based intervention for early adolescents (CHAMP). The study uses community-based participatory approach as part of formative research to evaluate a pilot randomized control trial at two hospitals. The paper reports on the development, feasibility, and acceptability of the VUKA family-based program and its short-term impact on a range of psychosocial variables for HIV + preadolescents and their caregivers. A 10-session intervention of approximately 3-month duration was delivered to 65 preadolescents aged 10–13 years and their families. VUKA participants were noted to improve on all dimensions, including mental health, youth behavior, HIV treatment knowledge, stigma, communication, and adherence to medication. VUKA shows promise as a family-based mental and HIV prevention program for HIV + preadolescents and which could be delivered by trained lay staff. 相似文献
20.
Seyed Taghi Norbakhsh Zohreh Zafarani Arvin Najafi Hamidreza Aslani 《Archives of orthopaedic and trauma surgery》2014,134(12):1723-1730