全文获取类型
收费全文 | 27358篇 |
免费 | 8589篇 |
国内免费 | 177篇 |
专业分类
耳鼻咽喉 | 282篇 |
儿科学 | 615篇 |
妇产科学 | 506篇 |
基础医学 | 5326篇 |
口腔科学 | 1436篇 |
临床医学 | 3926篇 |
内科学 | 6747篇 |
皮肤病学 | 595篇 |
神经病学 | 2161篇 |
特种医学 | 1768篇 |
外科学 | 6265篇 |
综合类 | 281篇 |
一般理论 | 14篇 |
预防医学 | 3024篇 |
眼科学 | 462篇 |
药学 | 1439篇 |
1篇 | |
中国医学 | 36篇 |
肿瘤学 | 1240篇 |
出版年
2021年 | 441篇 |
2020年 | 388篇 |
2018年 | 499篇 |
2017年 | 459篇 |
2016年 | 636篇 |
2015年 | 1009篇 |
2014年 | 1654篇 |
2013年 | 2320篇 |
2012年 | 963篇 |
2011年 | 851篇 |
2010年 | 1326篇 |
2009年 | 1351篇 |
2008年 | 715篇 |
2007年 | 501篇 |
2006年 | 589篇 |
2005年 | 507篇 |
2004年 | 418篇 |
2003年 | 348篇 |
2002年 | 378篇 |
2001年 | 441篇 |
2000年 | 350篇 |
1999年 | 565篇 |
1998年 | 798篇 |
1997年 | 759篇 |
1996年 | 803篇 |
1995年 | 773篇 |
1994年 | 657篇 |
1993年 | 607篇 |
1992年 | 597篇 |
1991年 | 568篇 |
1990年 | 505篇 |
1989年 | 597篇 |
1988年 | 620篇 |
1987年 | 606篇 |
1986年 | 564篇 |
1985年 | 598篇 |
1984年 | 538篇 |
1983年 | 524篇 |
1982年 | 586篇 |
1981年 | 550篇 |
1980年 | 530篇 |
1979年 | 507篇 |
1978年 | 500篇 |
1977年 | 502篇 |
1976年 | 437篇 |
1975年 | 391篇 |
1974年 | 353篇 |
1973年 | 333篇 |
1972年 | 333篇 |
1971年 | 305篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
1.
2.
3.
Chalub Lucas Orbolato Nunes Gabriel Pereira Ferrisse Túlio Morandin Strazzi-Sahyon Henrico Badaoui Dos Santos Paulo Henrique Gomes-Filho João Eduardo Cintra Luciano Tavares Angelo Sivieri-Araujo Gustavo 《Clinical oral investigations》2022,26(4):3343-3356
Clinical Oral Investigations - The objective of this systematic review and meta-analysis (SRM) was to answer the question whether the use of ultrasonic irrigation (UI) results in less postoperative... 相似文献
4.
5.
6.
7.
8.
Del Lama Rafael Silva Candido Raquel Mariana Chiari-Correia Natália Santana Nogueira-Barbosa Marcello Henrique de Azevedo-Marques Paulo Mazzoncini Tinós Renato 《Journal of digital imaging》2022,35(3):446-458
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to... 相似文献
9.
Louis Anthony Cox Jr. 《Critical reviews in toxicology》2019,49(7):614-635
AbstractCan a single fiber of amphibole asbestos increase the risk of lung cancer or malignant mesothelioma (MM)? Traditional linear no-threshold (LNT) risk assessment assumptions imply that the answer is yes: there is no safe exposure level. This paper draws on recent scientific progress in inflammation biology, especially elucidation of the activation thresholds for NLRP3 inflammasomes and resulting chronic inflammation, to model dose-response relationships for malignant mesothelioma and lung cancer risks caused by asbestos exposures. The modeling integrates a physiologically based pharmacokinetics (PBPK) front end with inflammation-driven two-stage clonal expansion (I-TSCE) models of carcinogenesis to describe how exposure leads to chronic inflammation, which in turn promotes carcinogenesis. Together, the combined PBPK and I-TSCE modeling predict that there are practical thresholds for exposure concentration below which asbestos exposure does not cause chronic inflammation in less than a lifetime, and therefore does not increase chronic inflammation-dependent cancer risks. Quantitative examples using model parameter estimates drawn from the literature suggest that practical thresholds may be within about a factor of 2 of some past exposure levels for some workers. The I-TSCE modeling framework explains previous puzzling aspects of asbestos epidemiology, such as why age at first exposure is a better predictor of lifetime MM risk than exposure duration. It may be a valuable tool for risk analysts when LNT assumptions are not justified due to inflammation response thresholds mediating dose-response relationships. 相似文献
10.
Caio Henrique de Carvalho Assuno Júlio Csar Trabanco Raquel Fornaziero Gomes Renata Rodrigues Moreira Alessandra Giannella Samelli 《La Medicina del lavoro》2019,110(4):304
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices 相似文献