全文获取类型
收费全文 | 36726篇 |
免费 | 2807篇 |
国内免费 | 542篇 |
专业分类
耳鼻咽喉 | 1122篇 |
儿科学 | 696篇 |
妇产科学 | 578篇 |
基础医学 | 2272篇 |
口腔科学 | 387篇 |
临床医学 | 5674篇 |
内科学 | 3671篇 |
皮肤病学 | 389篇 |
神经病学 | 3693篇 |
特种医学 | 734篇 |
外科学 | 2632篇 |
综合类 | 5133篇 |
预防医学 | 5679篇 |
眼科学 | 180篇 |
药学 | 4121篇 |
20篇 | |
中国医学 | 1535篇 |
肿瘤学 | 1559篇 |
出版年
2024年 | 67篇 |
2023年 | 687篇 |
2022年 | 1509篇 |
2021年 | 2165篇 |
2020年 | 2062篇 |
2019年 | 1588篇 |
2018年 | 1581篇 |
2017年 | 1490篇 |
2016年 | 1394篇 |
2015年 | 1283篇 |
2014年 | 3315篇 |
2013年 | 2724篇 |
2012年 | 2489篇 |
2011年 | 2597篇 |
2010年 | 1923篇 |
2009年 | 1986篇 |
2008年 | 1893篇 |
2007年 | 1789篇 |
2006年 | 1403篇 |
2005年 | 1117篇 |
2004年 | 862篇 |
2003年 | 670篇 |
2002年 | 494篇 |
2001年 | 395篇 |
2000年 | 376篇 |
1999年 | 317篇 |
1998年 | 208篇 |
1997年 | 207篇 |
1996年 | 170篇 |
1995年 | 147篇 |
1994年 | 117篇 |
1993年 | 116篇 |
1992年 | 84篇 |
1991年 | 87篇 |
1990年 | 62篇 |
1989年 | 41篇 |
1988年 | 41篇 |
1987年 | 41篇 |
1986年 | 32篇 |
1985年 | 46篇 |
1984年 | 55篇 |
1983年 | 36篇 |
1982年 | 40篇 |
1981年 | 33篇 |
1978年 | 27篇 |
1977年 | 31篇 |
1976年 | 34篇 |
1975年 | 35篇 |
1974年 | 27篇 |
1973年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Journal of Radiology Nursing》2022,41(4):264-268
Measuring outcomes in health care have become mandatory as regulatory agencies, institutional guidelines, employers, and consumer groups advocate for quality health care focusing on improving patient outcomes. System-level quality departments often provide a framework for performance improvement (PI) that supports the organizational PI plan. However, nurses must learn to lead and be actively involved in projects in the radiology department to ensure key performance indicators are developed with on-the-ground quality management to improve patient outcomes, system performance, and professional development. This article explores such efforts at a large women’s specialty hospital in the Southern United States. 相似文献
2.
《Journal of pediatric surgery》2023,58(9):1613-1617
BackgroundThe goal of this study was to characterize contemporary performance benchmarks and risk factors associated with negative appendectomy (NA) in children with suspected appendicitis.MethodsA multicenter retrospective cohort analysis of children undergoing appendectomy for suspected appendicitis was performed using data from the 2016–2021 NSQIP-Pediatric Appendectomy Targeted Public Use Files. Multivariable regression was used to evaluate the influence of year, age, sex, and WBC count on NA rate, and to generate rate estimates for NA based on different combinations of demographic characteristics and WBC profiles.Results100,322 patients were included from 140 hospitals. The overall NA rate was 2.4%, and rates decreased significantly during the study period (2016: 3.1% vs. 2021: 2.3%, p < 0.001). In adjusted analyses, the highest risk for NA was associated with a normal WBC (<9000/mm3; OR 5.31 [95% CI: 4.87–5.80]), followed by female sex (OR 1.55 [95% CI: 1.42–1.68]) and age <5 years (OR 1.64 [95% CI 1.39, 1.94]). Model-estimated risk for NA varied significantly across demographic and WBC strata, with a 14.4-fold range in rates between subgroups with the lowest and highest predicted risk (males 13–17 years with elevated WBC [1.1%] vs. females 3–4 years with normal WBC [15.8%]).ConclusionsContemporary NA rates have decreased over time, however NA risk remains high in children without a leukocytosis, particularly for girls and children <5 years of age. These data provide contemporary performance benchmarks for NA in children with suspected appendicitis and identify high-risk populations where further efforts to mitigate NA risk should be targeted.Level of EvidenceIII. 相似文献
3.
目的:通过中英文文献了解结直肠癌患者生命质量研究现状及发展趋势。方法:运用CiteSpace对中国知网(CNKI)、万方数据知识服务平台、中国生物医学文献数据库、Web of Science核心数据集、PubMed、Cochrane Library中收录的关于结直肠癌患者生命质量研究的中英文文献进行可视化分析。结果:检索得到中文文献1 285篇,英文文献871篇,中英文文献发文量均呈上升趋势,相关研究关注的重点主要是结直肠癌患者造口、抑郁、免疫、肠道功能、化疗及化疗药物,但机构之间、学者之间合作程度及研究类型等方面存在一定差异。结论:中文文献相关研究起步晚、发展快,但在研究质量与研究深度等方面与英文文献相比还有一定差距;国内学者之间、机构之间应加强合作,关心患者肠道功能、心理状况,提高患者体力活动水平,开展更多高质量研究。 相似文献
4.
目的探讨衰减伪影对冠心病患者门控心肌灌注显像(GMPI)图像质量及灌注结果的影响。资料与方法回顾性分析2020年3月—2021年3月在郑州大学第一附属医院核医学科经冠状动脉造影证实且于造影前后1周行GMPI的99例冠心病患者的图像,定性及半定量分析衰减校正前后GMPI图像结果,比较衰减校正前后左心室各壁段平均放射性计数及灌注结果的差异,进一步分析衰减校正前后灌注结果不一致部分的受检者的节段性室壁运动及增厚情况。结果与衰减校正前比较,衰减校正后左心室间隔、下后壁及侧壁的平均放射性计数较高(Z=-7.302、-8.014、-3.991,P均<0.001),心尖部较低(Z=-8.021,P<0.001)。其中女性衰减校正后前壁平均放射性计数减低(Z=-2.314,P=0.021)。男性衰减校正前后下后壁放射性计数差值明显高于女性(t=-8.408,P<0.05)。衰减校正后44%(44/99)的左前降支及37%(37/99)的右冠状动脉分支供血区域显像结果发生改变,结合超声心动图及GMPI结果显示其中85%(35/41)的左前降支及81%(29/36)的右冠状动脉分支供血区域室壁运动及室壁增厚率均正常。结论衰减伪影对GMPI的图像质量和灌注结果有较大影响,结合室壁运动和增厚情况等有助于鉴别衰减伪影,提高诊断准确度与特异度。 相似文献
5.
IntroductionEvidence for the relationship between movement behaviors and mental health among adolescents is inconclusive. We aimed to identify profiles of digital media use (including related bedtime delay) and leisure-time physical activity (LTPA) in adolescence, and to examine whether preadolescent mental health predicted later behavior profiles.MethodsThis study included 1285 participants assessed at 11 years of age, and followed-up four years later. Participants completed the Self-Perception Profile for Children (SPPC), Center for Epidemiological Studies Depression Scale for Children (CES-DC) and Screen for Child Anxiety-Related Emotional Disorders (SCARED) at baseline, and reported digital media use (active and passive use, gaming, and related bedtime delays) and LTPA at follow-up. A latent class approach was employed to identify behavior profiles, membership of which was then predicted with mental health and covariates, including baseline digital media use and LTPA.ResultsWe identified four behavior profiles: 1) high digital media use/moderate LTPA (20% of adolescents; 78% boys), 2) moderate digital media use/high LTPA (31%; 28%), 3) high digital media use/high LTPA (26%; 15%), 4) high passive digital media use and gaming/low LTPA (23%; 89%). After adjusting for covariates, higher LTPA and better perception of athletic competence at baseline associated with higher odds of belonging to any other profile than to the unhealthiest profile (4) at follow-up. Symptoms of depression or anxiety did not associate with later behavior profiles.ConclusionsLTPA and related self-esteem seem to be stronger predictors of future digital media use and LTPA behavior during adolescence than mental health symptoms alone. 相似文献
6.
《Research in social & administrative pharmacy》2022,18(9):3694-3698
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area. 相似文献
7.
8.
《Sleep medicine》2020
ObjectivesPrior evidence suggests that sleep duration and sleep difficulties may be associated with cognitive function in old age, but little is known about the sleep–cognition association in late mid-life. Our aim was to examine the associations of accelerometer-based sleep duration as well as subjective sleep difficulties with different domains of cognitive function among aging workers.MethodsThe study population consisted of 289 participants (mean age 62.4 years, SD 1.02; 83% women) from the Finnish Retirement and Aging Study (FIREA). Sleep difficulties were measured using Jenkins Sleep Problem Scale (difficulties falling asleep, difficulties maintaining sleep, waking up too early in the morning, and nonrestorative sleep). Sleep duration was measured with wrist-worn accelerometer and self-report, and participants were divided into short (<7 h/night), mid-range (7–9 h/night) and long (≥9 h/night) sleepers. Participants underwent extensive cognitive testing covering three domains: (1) memory, (2) executive function, and (3) attention and information processing.ResultsGreater difficulties in waking up too early in the morning were associated with poorer executive function measured with Spatial Working Memory (SWM) test (p = 0.005). Additionally, nonrestorative sleep was associated with poorer executive function measured with Trail Making Test, B–A, (p = 0.036) and borderline significantly with lower SWM (p = 0.056). Compared to mid-range sleepers, long sleepers tended to have poorer cognitive function (all memory function tests and SWM), but the associations were not statistically significant due to small number of long sleepers.ConclusionsSubjective sleep difficulties may be linked to poorer executive function in a relatively healthy population of older workers in their 60 s. Thus, promoting good sleep quality may translate into better cognitive health in late mid-life. 相似文献
9.
《Disability and health journal》2020,13(3):100885
BackgroundA majority of youth with Autism Spectrum Disorder (ASD) have disrupted sleep patterns, but there has been limited research examining factors associated with sleep in this population. Objective: The objective of this study was to compare demographic and lifestyle behaviors with sleep quality in youth with ASD. Methods: A total of 49 children (12.44 years; 78% male) with ASD wore the Actigraph GT9X accelerometer over seven days and nights to assess moderate to vigorous physical activity (MVPA), sedentary behavior (SB), total sleep duration, and sleep efficiency. Parents reported their child’s weekly amount of screen time and demographic information. Participants were classified according to whether they met sleep criteria for duration and efficiency (8–9 h of sleep duration and ≥85% sleep efficiency). T-tests and ANOVA were used to compare demographic and lifestyle factors between the groups. Results: Participants who meet both sleep duration and efficiency criteria had greater minutes of MVPA per day (113.65 min/day) than participants who only met sleep efficiency criteria (40.27 min/day) and participants who did not meet either sleep criteria (67.5 min/day; p < 0.0001). Additionally, participants who met both sleep criteria had fewer minutes of SB compared to those who only met sleep efficiency criteria (384.79 vs 526.05 min/day; p = 0.02). Conclusions: Youth who had indicators of good sleep quality had greater amounts of MVPA and lower amounts of SB. Studies should further examine the relationship between sleep and health behaviors in youth with ASD to determine causal mechanisms, leading to more effective sleep interventions. 相似文献
10.
《Journal of Evidence》2019,19(2):131-139
ObjectivesThe aims of this article are to identify all the published systematic reviews (SRs) and meta-analyses (MAs) that studied the relationship between periodontal and systemic diseases and to assess their quality using 2 scales (the Overview Quality Assessment Questionnaire [OQAQ] and A Measurement Tool to Assess Systematic Reviews [AMSTAR] checklist).MethodsFor SRs and MAs to be included, they should have investigated one of the following systemic diseases: pulmonary conditions, cardiac conditions, endocrine conditions, cancer, blood disorders, psychological conditions, anxiety, depression, mood disorders, and several other diseases. Two investigators screened MEDLINE via PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systematic Reviews. The tools used to evaluate quality were the AMSTAR scale and OQAQ. The protocol was prospectively registered in PROSPERO (CRD42018102208).ResultsThe search strategy found 691 unique articles, 42 of which met the eligibility criteria and were included in this review. Diabetes mellitus was the most investigated disease (14 out of 42 studies), followed by obesity (11 studies) and cardiovascular diseases (5 studies). A total of 40 reviews reported on the characteristics of included studies, and, as per the AMSTAR scale, 39 reviews had an a priori design. The number of reviews that fulfilled the status of publication criterion was the lowest (7 reviews only), followed by the number used in the assessment of publication bias (11 reviews). The number of high-quality reviews was higher with the OQAQ than with the AMSTAR checklist (33 vs 25 studies), but the AMSTAR showed a higher number of medium-quality reviews than the OQAQ (14 vs 6 studies). Both showed the same number of low-quality reviews.ConclusionsHigh-quality SRs and MAs are crucial to understanding the relationship between systemic and periodontal diseases. Medical practitioners must be able to inform patients about oral health and specific periodontal health concerns. 相似文献