全文获取类型
收费全文 | 16553篇 |
免费 | 735篇 |
国内免费 | 298篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 606篇 |
妇产科学 | 396篇 |
基础医学 | 1947篇 |
口腔科学 | 482篇 |
临床医学 | 1294篇 |
内科学 | 3273篇 |
皮肤病学 | 235篇 |
神经病学 | 803篇 |
特种医学 | 390篇 |
外科学 | 1935篇 |
综合类 | 1033篇 |
现状与发展 | 1篇 |
预防医学 | 2138篇 |
眼科学 | 313篇 |
药学 | 1312篇 |
2篇 | |
中国医学 | 574篇 |
肿瘤学 | 716篇 |
出版年
2024年 | 43篇 |
2023年 | 444篇 |
2022年 | 706篇 |
2021年 | 818篇 |
2020年 | 791篇 |
2019年 | 1636篇 |
2018年 | 1332篇 |
2017年 | 807篇 |
2016年 | 386篇 |
2015年 | 433篇 |
2014年 | 932篇 |
2013年 | 1139篇 |
2012年 | 608篇 |
2011年 | 693篇 |
2010年 | 541篇 |
2009年 | 570篇 |
2008年 | 571篇 |
2007年 | 452篇 |
2006年 | 347篇 |
2005年 | 274篇 |
2004年 | 221篇 |
2003年 | 184篇 |
2002年 | 142篇 |
2001年 | 150篇 |
2000年 | 117篇 |
1999年 | 99篇 |
1998年 | 69篇 |
1997年 | 105篇 |
1996年 | 108篇 |
1995年 | 109篇 |
1994年 | 110篇 |
1993年 | 65篇 |
1992年 | 38篇 |
1991年 | 53篇 |
1990年 | 43篇 |
1988年 | 31篇 |
1986年 | 28篇 |
1985年 | 194篇 |
1984年 | 286篇 |
1983年 | 238篇 |
1982年 | 267篇 |
1981年 | 268篇 |
1980年 | 207篇 |
1979年 | 197篇 |
1978年 | 148篇 |
1977年 | 113篇 |
1976年 | 126篇 |
1975年 | 131篇 |
1974年 | 80篇 |
1973年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《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
2.
3.
Kevin Kyung Ho Choi Santosh Sanagapalli 《World journal of gastrointestinal oncology》2022,14(3):568-586
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations. 相似文献
4.
《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
5.
6.
7.
【目的】 探索建设世界一流科技期刊的策略,以助力中国科技期刊冲刺世界一流水平。【方法】 通过研读相关政策和研究文献,结合对Nature、Science、The Lancet、Cell等不同类型的世界一流科技期刊的分析,解析世界一流科技期刊的概念及内涵,探讨建设世界一流科技期刊的充分条件和必要条件,提出建设世界一流科技期刊的建议。【结果】 卓越的办刊理念、全方位的国际化水平、世界一流的人才队伍、先进的经营管理水平以及汇聚一流前沿成果、卓著的科学声望是建设世界一流科技期刊的必要条件。“高、精、尖”和“稳、准、狠”的办刊策略,是建设世界一流科技期刊的充分条件。建设世界一流科技期刊要理性且准确地认知其内涵,始终坚持卓越的办刊理念、国际化战略、人才战略、质量战略和集群化战略。【结论】 中国科技期刊既要扎根祖国大地,又要学习世界一流期刊的成功经验,从办刊的硬实力和软实力方面吸收借鉴,才能探索出具有中国特色的世界一流科技期刊建设路径。 相似文献
8.
9.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3