全文获取类型
收费全文 | 3017篇 |
免费 | 226篇 |
国内免费 | 13篇 |
学科分类
医药卫生 | 3256篇 |
出版年
2023年 | 23篇 |
2022年 | 16篇 |
2021年 | 101篇 |
2020年 | 75篇 |
2019年 | 112篇 |
2018年 | 115篇 |
2017年 | 73篇 |
2016年 | 70篇 |
2015年 | 108篇 |
2014年 | 124篇 |
2013年 | 191篇 |
2012年 | 241篇 |
2011年 | 253篇 |
2010年 | 181篇 |
2009年 | 133篇 |
2008年 | 194篇 |
2007年 | 188篇 |
2006年 | 188篇 |
2005年 | 177篇 |
2004年 | 181篇 |
2003年 | 152篇 |
2002年 | 120篇 |
2001年 | 17篇 |
2000年 | 26篇 |
1999年 | 29篇 |
1998年 | 23篇 |
1997年 | 17篇 |
1996年 | 4篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 17篇 |
1992年 | 3篇 |
1991年 | 11篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1964年 | 3篇 |
排序方式: 共有3256条查询结果,搜索用时 31 毫秒
71.
72.
Introduction of subspecialty examinations by the European Board of Ophthalmology (EBO) in close collaboration with European Subspecialty Ophthalmological Societies: FEBO‐SA 下载免费PDF全文
73.
Accounting for Attribute‐Level Non‐Attendance in a Health Choice Experiment: Does it Matter? 下载免费PDF全文
An extensive literature has established that it is common for respondents to ignore attributes of the alternatives within choice experiments. In most of the studies on attribute non‐attendance, it is assumed that respondents consciously (or unconsciously) ignore one or more attributes of the alternatives, regardless of their levels. In this paper, we present a new line of enquiry and approach for modelling non‐attendance in the context of investigating preferences for health service innovations. This approach recognises that non‐attendance may not just be associated with attributes but may also apply to the attribute's levels. Our results show that respondents process each level of an attribute differently: while attending to the attribute, they ignore a subset of the attribute's levels. In such cases, the usual approach of assuming that respondents either attend to the attribute or not, irrespective of its levels, is erroneous and could lead to misguided policy recommendations. Our results indicate that allowing for attribute‐level non‐attendance leads to substantial improvements in the model fit and has an impact on estimated marginal willingness to pay and choice predictions.Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
74.
Mak Lung-Yi Huang Qi Wong Danny Ka-Ho Stamm Luisa Cheung Ka-Shing Ko Kwan-Lung Yan Ran Ouyang Lea Fung James Seto Wai-Kay Yuen Man-Fung 《Journal of gastroenterology》2021,56(5):479-488
Journal of Gastroenterology - We aimed to assess whether residual hepatitis B virus (HBV) viraemia is associated with HCC development. This is a case–control study of 104 patients [52 HCC and... 相似文献
75.
Bazoukis George Tyrovolas Konstantinos Letsas Konstantinos P. Vlachos Konstantinos Radford Danny Chung Cheuk To Liu Tong Efremidis Michael Tse Gary Baranchuk Adrian 《Heart failure reviews》2022,27(6):2067-2076
Heart Failure Reviews - Left ventricular non-compaction cardiomyopathy (LVNC) is a congenital heart disease with autosomal dominant inheritance. This review aims to summarize the existing data... 相似文献
76.
77.
78.
Satoshi Inoue Zhenyue Hao Andrew J. Elia David Cescon Lily Zhou Jennifer Silvester Bryan Snow Isaac S. Harris Masato Sasaki Wanda Y. Li Momoe Itsumi Kazuo Yamamoto Takeshi Ueda Carmen Dominguez-Brauer Chiara Gorrini Iok In Christine Chio Jillian Haight Annick You-Ten Susan McCracken Andrew Wakeham Danny Ghazarian Linda J.Z. Penn Gerry Melino Tak W. Mak 《Genes & development》2013,27(10):1101-1114
79.
Histone modifications and chromatin-associated protein complexes are crucially involved in the control of gene expression, supervising cell fate decisions and differentiation. Many promoters in embryonic stem (ES) cells harbor a distinctive histone modification signature that combines the activating histone H3 Lys 4 trimethylation (H3K4me3) mark and the repressive H3K27me3 mark. These bivalent domains are considered to poise expression of developmental genes, allowing timely activation while maintaining repression in the absence of differentiation signals. Recent advances shed light on the establishment and function of bivalent domains; however, their role in development remains controversial, not least because suitable genetic models to probe their function in developing organisms are missing. Here, we explore avenues to and from bivalency and propose that bivalent domains and associated chromatin-modifying complexes safeguard proper and robust differentiation. 相似文献
80.
José Francisco S.S. da Rocha Erica D. de Avila Maria Sílvia M. Rigolin Paula A. Barbugli Danny O.M. Marin Francisco A. Mollo Junior Janaina H. Jorge 《The Journal of prosthetic dentistry》2021,125(1):165-174
Statement of problemChanges in physicochemical properties because of implant material aging and natural deterioration in the oral environment can facilitate microbial colonization and disturb the soft-tissue seal between the implant surfaces.PurposeThe purpose of this in vitro study was to investigate the effect of aging time on the physicochemical profile of titanium (Ti) and zirconia (ZrO2) implant materials. Further microbiology and cell analyses were used to provide insights into the physicochemical implications of biological behavior.Material and methodsDisk-shaped specimens of Ti and ZrO2 were submitted to roughness, morphology, and surface free energy (SFE) analyses before nonaging (NA) and after the aging process (A). To simulate natural aging, disks were subjected to low-temperature degradation (LTD) by using an autoclave at 134 ºC and 0.2 MPa pressure for 20 hours. The biological activities of the Ti and ZrO2 surfaces were determined by analyzing Candida albicans (C. albicans) biofilms and human gingival fibroblast (HGF) cell proliferation. For the microbiology assays, a variance analysis method (ANOVA) was used with the Tukey post hoc test. For the evaluation of cellular proliferation, the Kruskal-Wallis test followed by Dunn multiple comparisons were used.ResultsTi nonaging (TNA) and ZrO2 nonaging (ZNA) disks displayed hydrophilic and lipophilic properties, and this effect was sustained after the aging process. Low-temperature degradation resulted in a modest change in intermolecular interaction, with 1.06-fold for TA and 1.10-fold for ZA. No difference in biofilm formation was observed between NA and A disks of the same material. After 48 hours, the viability of the attached HGF cells was very similar to that in the NA and A groups, regardless of the tested material.ConclusionThe changes in the physicochemical properties of Ti and ZrO2 induced by the aging process do not interfere with C. albicans biofilm formation and HGF cell attachment, even after long-term exposure. 相似文献