全文获取类型
收费全文 | 81327篇 |
免费 | 6296篇 |
国内免费 | 1666篇 |
专业分类
耳鼻咽喉 | 1065篇 |
儿科学 | 2918篇 |
妇产科学 | 1623篇 |
基础医学 | 8728篇 |
口腔科学 | 1178篇 |
临床医学 | 6919篇 |
内科学 | 14672篇 |
皮肤病学 | 1206篇 |
神经病学 | 16380篇 |
特种医学 | 2113篇 |
外国民族医学 | 11篇 |
外科学 | 7511篇 |
综合类 | 5661篇 |
现状与发展 | 4篇 |
一般理论 | 13篇 |
预防医学 | 5570篇 |
眼科学 | 1476篇 |
药学 | 5964篇 |
31篇 | |
中国医学 | 2817篇 |
肿瘤学 | 3429篇 |
出版年
2023年 | 1662篇 |
2022年 | 2231篇 |
2021年 | 4216篇 |
2020年 | 4103篇 |
2019年 | 4840篇 |
2018年 | 4586篇 |
2017年 | 3771篇 |
2016年 | 2924篇 |
2015年 | 2891篇 |
2014年 | 5998篇 |
2013年 | 7505篇 |
2012年 | 4886篇 |
2011年 | 4778篇 |
2010年 | 3719篇 |
2009年 | 3461篇 |
2008年 | 3322篇 |
2007年 | 2703篇 |
2006年 | 2305篇 |
2005年 | 1912篇 |
2004年 | 1884篇 |
2003年 | 1669篇 |
2002年 | 1290篇 |
2001年 | 1091篇 |
2000年 | 1034篇 |
1999年 | 837篇 |
1998年 | 588篇 |
1997年 | 584篇 |
1996年 | 414篇 |
1995年 | 513篇 |
1994年 | 467篇 |
1993年 | 408篇 |
1992年 | 354篇 |
1991年 | 312篇 |
1990年 | 270篇 |
1989年 | 236篇 |
1988年 | 210篇 |
1987年 | 164篇 |
1985年 | 693篇 |
1984年 | 714篇 |
1983年 | 463篇 |
1982年 | 536篇 |
1981年 | 454篇 |
1980年 | 361篇 |
1979年 | 349篇 |
1978年 | 296篇 |
1977年 | 233篇 |
1976年 | 223篇 |
1975年 | 244篇 |
1974年 | 174篇 |
1973年 | 183篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Hyun Cheol Chung MD PhD Yoon-Koo Kang MD PhD Zhendong Chen MD Yuxian Bai MD Wan Zamaniah Wan Ishak MD Byoung Yong Shim MD Young Lee Park MD Dong-Hoe Koo MD PhD Jianwei Lu MD Jianming Xu MD Hong Jae Chon MD Li-Yuan Bai MD Shan Zeng MD Ying Yuan MD Yen-Yang Chen MD Kangsheng Gu MD Wen Yan Zhong PhD Shu Kuang MD Chie-Schin Shih MD Shu-Kui Qin MD PhD 《Cancer》2022,128(5):995-1003
22.
23.
25.
Giuseppe Brisinda Maria Michela Chiarello Anna Crocco Neill James Adams Pietro Fransvea Serafino Vanella 《World journal of gastroenterology : WJG》2022,28(3):381-398
BACKGROUND Surgery for gastric cancer is a complex procedure and lymphadenectomy is often mandatory.Postoperative mortality and morbidity after curative gastric cancer surgery is not insignificant.AIM To evaluate the factors determining mortality and morbidity in a population of patients undergoing R0 resection and D2 lymphadenectomy for gastric cancer.METHODS A retrospective analysis of clinical data and pathological characteristics(age,sex,primary site of the tumor,Lauren histotype,number of positive lymph nodes resected,number of negative lymph nodes resected,and depth of invasion as defined by the standard nomenclature)was conducted in patients with gastric cancer.For each patient we calculated the Kattan’s score.We arbitrarily divided the study population of patients into two groups based on the nomogram score(<100 points or≥100 points).Prespecified subgroups in these analyses were defined according to age(≤65 years or>65 years),and number of lymph nodes retrieved(≤35 lymph nodes or>35 lymph nodes).Uni-and multivariate analysis of clinical and pathological findings were performed to identify the factors affecting postoperative mortality and morbidity.RESULTS One-hundred and eighty-six patients underwent a curative R0 resection with D2 lymphadenectomy.Perioperative mortality rate was 3.8%(7 patients);a higher mortality rate was observed in patients aged>65 years(P=0.002)and in N+patients(P=0.04).Following univariate analysis,mortality was related to a Kattan’s score≥100 points(P=0.04)and the presence of advanced gastric cancer(P=0.03).Morbidity rate was 21.0%(40 patients).Surgical complications were observed in 17 patients(9.1%).A higher incidence of morbidity was observed in patients where more than 35 lymph nodes were harvested(P=0.0005).CONCLUSION Mortality and morbidity rate are higher in N+and advanced gastric cancer patients.The removal of more than 35 lymph nodes does not lead to an increase in mortality. 相似文献
26.
《Saudi Dental Journal》2022,34(7):596-603
ObjectiveStudies have shown that gingival crevices may be a significant route for SARS-CoV-2 entry. However, the role of oral health in the acquisition and severity of COVID-19 is not known.DesignA retrospective analysis was performed using electronic health record data from a large urban academic medical center between 12/1/2019 and 8/24/2020. A total of 387 COVID-19 positive cases were identified and matched 1:1 by age, sex, and race to 387 controls without COVID-19 diagnoses. Demographics, number of missing teeth and alveolar crestal height were determined from radiographs and medical/dental charts. In a subgroup of 107 cases and controls, we also examined the rate of change in alveolar crestal height. A conditional logistic regression model was utilized to assess association between alveolar crestal height and missing teeth with COVID-19 status and with hospitalization status among COVID-19 cases.ResultsIncreased alveolar bone loss, OR = 4.302 (2.510 – 7.376), fewer missing teeth, OR = 0.897 (0.835–0.965) and lack of smoking history distinguished COVID-19 cases from controls. After adjusting for time between examinations, cases with COVID-19 had greater alveolar bone loss compared to controls (0.641 ± 0.613 mm vs 0.260 ± 0.631 mm, p < 0.01.) Among cases with COVID-19, increased number of missing teeth OR = 2.1871 (1.146– 4.174) was significantly associated with hospitalization.ConclusionsAlveolar bone loss and missing teeth are positively associated with the acquisition and severity of COVID-19 disease, respectively. 相似文献
27.
28.
【目的】 在“中国科技期刊卓越行动计划”实施三周年之际,有必要对我国科技期刊2035年迈入“世界第一方阵”目标的具体任务进行重新审视和预判,以进一步明确发展方向,动态调整推进思路。【方法】 采用国内外科技期刊、科技论文、科技期刊评价成果的系统性发展数据对科技期刊“世界第一方阵” 国家(或地区)在高水平科技期刊数量与质量层面的入围标准进行界定,在深入总结现有基础和优势的同时,对我国科技期刊综合实力与“世界第一方阵”国家(或地区)的现实差距进行逐一梳理和剖析,并对实现目标的可行性和推进思路进行研判和设计。【结果】 必须继续加强高水平英文科技期刊创办和培育力度、持续加大优秀中文科技期刊的建设强度、快速推进国内外科技期刊论文等质同效评价制度的建设与引导,并积极探索建立科学家和科研机构办好一流科技期刊的责任制度和贡献激励机制、创新发展编辑人才队伍培养与激励管理思路、深入实践灵活多样的期刊出版市场资本运作模式、稳步推进期刊出版市场机制和管理制度改革,为我国科技期刊事业的高质量发展提速增效。【结论】 虽然当前阶段目标任务艰巨,但迈入“世界第一方阵”未来可期。 相似文献
29.
30.