全文获取类型
收费全文 | 32919篇 |
免费 | 2135篇 |
国内免费 | 1058篇 |
专业分类
耳鼻咽喉 | 312篇 |
儿科学 | 64篇 |
妇产科学 | 53篇 |
基础医学 | 2095篇 |
口腔科学 | 20195篇 |
临床医学 | 1692篇 |
内科学 | 490篇 |
皮肤病学 | 118篇 |
神经病学 | 422篇 |
特种医学 | 665篇 |
外国民族医学 | 2篇 |
外科学 | 2084篇 |
综合类 | 5079篇 |
现状与发展 | 6篇 |
预防医学 | 492篇 |
眼科学 | 59篇 |
药学 | 1253篇 |
60篇 | |
中国医学 | 147篇 |
肿瘤学 | 824篇 |
出版年
2024年 | 134篇 |
2023年 | 961篇 |
2022年 | 1551篇 |
2021年 | 1644篇 |
2020年 | 1839篇 |
2019年 | 1048篇 |
2018年 | 991篇 |
2017年 | 886篇 |
2016年 | 1029篇 |
2015年 | 1430篇 |
2014年 | 2664篇 |
2013年 | 2465篇 |
2012年 | 3093篇 |
2011年 | 3226篇 |
2010年 | 2420篇 |
2009年 | 1979篇 |
2008年 | 1160篇 |
2007年 | 1379篇 |
2006年 | 1147篇 |
2005年 | 768篇 |
2004年 | 689篇 |
2003年 | 639篇 |
2002年 | 499篇 |
2001年 | 491篇 |
2000年 | 395篇 |
1999年 | 291篇 |
1998年 | 219篇 |
1997年 | 218篇 |
1996年 | 136篇 |
1995年 | 95篇 |
1994年 | 72篇 |
1993年 | 82篇 |
1992年 | 94篇 |
1991年 | 80篇 |
1990年 | 53篇 |
1989年 | 55篇 |
1988年 | 51篇 |
1987年 | 55篇 |
1986年 | 32篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 4篇 |
1967年 | 2篇 |
1961年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《International journal of oral and maxillofacial surgery》2022,51(3):332-337
The purpose of this study was to investigate the association between habitual snoring (HS), middle ear disease (MED), and speech problems in children with cleft palate. This cross-sectional study included children aged 2.0–7.9 years with non-syndromic cleft palate anomalies. Parents completed the Pediatric Sleep Questionnaire and a questionnaire about MED. Audiograms and speech assessment were also conducted. Ninety-five children were enrolled; 15.2% of families reported HS, 97.6% MED, and 17.1% speech problems. HS (37.5% vs 10.3%, P = 0.007) and early episodes of MED (92.3% vs 58.2%, P = 0.021) were more likely to be reported for children with isolated cleft palate when compared to those with cleft lip and palate. Children with cleft lip and palate had a higher frequency of MED with effusion compared to those with Robin sequence (86.4% vs 57.1%, P = 0.049). The odds ratio for HS in children with ≥1 episode of MED in the last year was 7.37 (95% confidence interval 1.55–35.15, P = 0.012). There was a trend for children with speech problems reported by parents to have HS (30.8% vs 11.5%, P= 0.076). Anatomical factors play a role in the frequency of upper airway symptoms in children with cleft palate. A recent history of at least one episode of MED was associated with an increased frequency of HS. 相似文献
2.
A 25-year-old, emaciated man without medical treatment was found to have died suddenly at home by his mother. At autopsy, there were no injuries to his body, but significant circulatory insufficiency was observed. Electron microscopy revealed abnormal mitochondria in cells of the cardiac conduction system. The conduction system was filled with mitochondrial size abnormalities and mitochondrial cristae abnormalities. No notable abnormal findings were observed in other organs. Genetic examination of the blood revealed the mitochondrial pathogenetic variant m.3243A>G. Epileptic seizures, diabetic ketoacidosis, and hyperosmolar hyperglycemic state were unlikely to be the cause of sudden death. The cause of death was diagnosed as arrhythmia possibly induced by the failure of the cardiac conduction system due to mitochondrial disease. This is a rare case of sudden death caused by an accumulation of abnormal mitochondria in the cardiac conduction system. 相似文献
3.
4.
5.
6.
7.
8.
9.
10.
《Dental materials》2020,36(1):119-134
ObjectiveThe aim of this systematic review and meta-analysis was to evaluate the effect of surface conditioning methods on the bond strength of industrial indirect composite blocks (ICs).MethodsBased on the PICOS strategy, the Medline via PubMed, Embase and Web of Science (ISI – Web of Knowledge) electronic databases were searched for peer-reviewed articles in both English and Chinese, with no publication year limit. In vitro studies evaluating the effects of surface conditioning on the bond strength of ICs were selected. The meta-analysis was conducted to calculate the mean difference between surface-conditioned ICs and unconditioned controls. Subgroup analysis was performed to evaluate the different surface conditioning methods, separately for polymer-infiltrated ceramic network (PICN) material and the ICs with dispersed fillers (ICDFs). Meta-analyses were performed with a random-effects model at a significance level of 0.05.Results and SignificanceFrom 802 relevant studies, 25 were selected for full-text analysis. Nineteen studies were eligible for inclusion in this systematic review, whereas 9 studies were included in the meta-analysis. A manual search of the principal periodicals specific to the area resulted in no additional articles. The meta-analysis indicated a significant difference in bond strength between the surface-conditioned ICs and controls under both non-aged and aged conditions. The combination of mechanical and chemical conditioning yielded the highest bond strength of ICs. This meta-analysis suggests that chemical etching followed by a universal primer and alumina air abrasion followed by a silane coupling agent could be considered the best strategy for optimizing the bond strength of PICN materials and ICDFs under aged conditions, respectively. 相似文献