全文获取类型
收费全文 | 3407篇 |
免费 | 678篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 124篇 |
妇产科学 | 62篇 |
基础医学 | 456篇 |
口腔科学 | 94篇 |
临床医学 | 422篇 |
内科学 | 877篇 |
皮肤病学 | 53篇 |
神经病学 | 221篇 |
特种医学 | 76篇 |
外科学 | 511篇 |
综合类 | 88篇 |
一般理论 | 1篇 |
预防医学 | 234篇 |
眼科学 | 106篇 |
药学 | 270篇 |
中国医学 | 33篇 |
肿瘤学 | 404篇 |
出版年
2023年 | 27篇 |
2022年 | 47篇 |
2021年 | 102篇 |
2020年 | 111篇 |
2019年 | 240篇 |
2018年 | 195篇 |
2017年 | 178篇 |
2016年 | 188篇 |
2015年 | 226篇 |
2014年 | 255篇 |
2013年 | 276篇 |
2012年 | 224篇 |
2011年 | 219篇 |
2010年 | 232篇 |
2009年 | 157篇 |
2008年 | 173篇 |
2007年 | 147篇 |
2006年 | 128篇 |
2005年 | 127篇 |
2004年 | 114篇 |
2003年 | 114篇 |
2002年 | 110篇 |
2001年 | 47篇 |
2000年 | 44篇 |
1999年 | 33篇 |
1998年 | 26篇 |
1997年 | 20篇 |
1996年 | 20篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 31篇 |
1991年 | 32篇 |
1990年 | 23篇 |
1989年 | 22篇 |
1988年 | 23篇 |
1987年 | 21篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1972年 | 9篇 |
1971年 | 7篇 |
1970年 | 6篇 |
排序方式: 共有4112条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
66.
Hessam Nowzari DDS PhD Shervin Molayem DDS Ching Hsiu Ketty Chiu DDS Sandra K. Rich RDH PhD 《Clinical implant dentistry and related research》2012,14(4):595-602
Background: The initial thickness of maxillary bone has significant impact on the responding level of facial bone and soft tissue after extraction and immediate implant placement. A prevailing notion is that following implant placement in fresh extraction sites, at least 2 mm of facial bone is needed to prevent soft tissue recession, fenestration, and dehiscence. Purpose: The purpose of this study was to use cone beam computed tomography (CBCT) to measure horizontal width of facial alveolar bone overlying healthy maxillary central incisors and to determine prevalence of bone thickness ≥2 mm. Materials and Methods: Tomographic data from 101 randomly selected patients were evaluated by two independent observers. Assessments were made of facial bone width at levels 1.0 to 10.0 mm apical to the bone crest. Results: Healthy maxillary central incisors (n = 202) were measured from 101 patient scans. The percent of teeth with facial bone ≥2 mm at levels 1, 2, 3, 4, and 5 mm from the bone crest was 0, 1.5, 2.0, 3.0, and 2.5%, respectively. Overall mean thickness of the bone was 1.05 mm for right and left central incisors combined. The range of individual measurements for all levels was 0 to 5.1 mm. The occurrence of ≥2 mm thickness bone measurements increased with increasing depth. However, mean widths observed at levels 6 to 10 mm from the crest ranged only 1.0 to 1.3 mm because of apparent fenestration occurrence (0 mm bone) in approximately 12% of teeth. Overall, no significant differences in bone thickness were found between ethnic, gender, age, or scan groups. Conclusions: Using CBCT, occurrences of ≥2 mm maxillary facial alveolar bone were found on no more than 3% of root surfaces 1.0 to 5.0 mm apical to the bone crest in this sample of maxillary central incisors. The study evidenced prevalence of a thin facial alveolar bone (<2 mm) that may contribute to risk of facial bone fenestration, dehiscence, and soft tissue recession after immediate implant therapy. 相似文献
67.
Youth violence has long been regarded as a major social issue. The past decade has, however, seen the scrutiny which encompasses this violence intensify, largely due to a recent media focus on an apparently increasing tendency amongst some young people to engage in acts of ‘appetitive’ or ‘thrill-seeking’ violence. This is reported to be a new form of violence, in which young people act in an excitable state, rather than the more common form of anger-mediated violence. Whilst incidents of appetitive violence are overly represented in the news media and are presented as a major public concern, there is presently no empirical research exploring the validity of this phenomenon and no systematic analysis of the frequency and severity of this form of violent behaviour. Furthermore, the underlying causes of this type of violence are not understood. As such, preventative practices, risk assessment, treatment requirements and targeted management strategies are lacking. The purpose of this review is to examine the current literature on youth violence, particularly youth involvement in ‘thrill-seeking’ acts of violence, as well as describing a range of contemporary factors highlighted as integral to youth violence; specifically, gang involvement, alcohol use and the possession of weapons. This review will also examine an array of international strategies implemented in response to this form of youth violence. Finally, the General Aggression Model (GAM) will be considered to determine whether its framework can assist in advancing our understanding of appetitive violence, by elucidating those characteristics of the individual and their environment that contribute to its expression. 相似文献
68.
69.
70.
Hao Lun Luo MD Chih Hsiung Kang MD Yen Ta Chen MD Yao Chi Chuang MD Wei Ching Lee MD Yuan Tso Cheng MD Po Hui Chiang PhD MD 《Annals of surgical oncology》2013,20(9):3121-3126