全文获取类型
收费全文 | 52764篇 |
免费 | 3642篇 |
国内免费 | 149篇 |
专业分类
耳鼻咽喉 | 595篇 |
儿科学 | 1757篇 |
妇产科学 | 1231篇 |
基础医学 | 6901篇 |
口腔科学 | 816篇 |
临床医学 | 6972篇 |
内科学 | 10609篇 |
皮肤病学 | 1259篇 |
神经病学 | 5133篇 |
特种医学 | 1262篇 |
外科学 | 5557篇 |
综合类 | 475篇 |
一般理论 | 57篇 |
预防医学 | 5974篇 |
眼科学 | 853篇 |
药学 | 3165篇 |
中国医学 | 89篇 |
肿瘤学 | 3850篇 |
出版年
2023年 | 433篇 |
2022年 | 710篇 |
2021年 | 1399篇 |
2020年 | 962篇 |
2019年 | 1337篇 |
2018年 | 1628篇 |
2017年 | 1142篇 |
2016年 | 1251篇 |
2015年 | 1356篇 |
2014年 | 1926篇 |
2013年 | 2678篇 |
2012年 | 4038篇 |
2011年 | 4165篇 |
2010年 | 2205篇 |
2009年 | 2001篇 |
2008年 | 3330篇 |
2007年 | 3470篇 |
2006年 | 3261篇 |
2005年 | 3138篇 |
2004年 | 2779篇 |
2003年 | 2602篇 |
2002年 | 2470篇 |
2001年 | 474篇 |
2000年 | 475篇 |
1999年 | 520篇 |
1998年 | 449篇 |
1997年 | 392篇 |
1996年 | 353篇 |
1995年 | 297篇 |
1994年 | 257篇 |
1993年 | 263篇 |
1992年 | 345篇 |
1991年 | 317篇 |
1990年 | 293篇 |
1989年 | 316篇 |
1988年 | 239篇 |
1987年 | 251篇 |
1986年 | 262篇 |
1985年 | 249篇 |
1984年 | 232篇 |
1983年 | 161篇 |
1982年 | 144篇 |
1981年 | 130篇 |
1980年 | 117篇 |
1979年 | 172篇 |
1978年 | 129篇 |
1976年 | 108篇 |
1974年 | 115篇 |
1973年 | 168篇 |
1970年 | 112篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Martin F. Shapiro 《Journal of general internal medicine》2015,30(10):1392-1393
2.
3.
4.
5.
6.
Children with autism spectrum disorder (ASD) demonstrate limited playfulness. Their difficulty engaging in meaningful interaction with others renders playful engagement in social interactions a challenge. Although little direct evidence exists regarding the promotion of these children’s playful engagement, links can be established with many traits cited in play and social interaction studies. This paper presents the results of a conceptual clarification exercise regarding the key behaviours associated with the construct of playful engagement in preschool-aged children with ASD. Behaviours were identified based on hallmark deficits in early social interactions and play of children with ASD. The analysis revealed the following behaviours: positive affect, engagement, imitation, joint attention, initiation of social interaction, social responsiveness, flexibility, child’s laughter in funny situations and giving and reading non-verbal cues. In conclusion, a conceptually coherent stage has been set for exploring the literature regarding interventions to promote the playful engagement of preschool-aged children with ASD. 相似文献
7.
8.
Julie A. Schmidt Georgina K. Fensom Sabina Rinaldi Augustin Scalbert Paul N. Appleby David Achaintre Audrey Gicquiau Marc J. Gunter Pietro Ferrari Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Anna Karakatsani Eleni Peppa Domenico Palli Sabina Sieri Rosario Tumino Bas Bueno-de-Mesquita Antonio Agudo Maria-Jose Sánchez María-Dolores Chirlaque Eva Ardanaz Nerea Larrañaga Aurora Perez-Cornago Nada Assi Elio Riboli Konstantinos K. Tsilidis Timothy J. Key Ruth C. Travis 《International journal of cancer. Journal international du cancer》2020,146(3):720-730
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer. 相似文献
9.
10.
Flavia M. N. P. Aslanian Maria Teresa Q. Marques Haroldo J. Matos Luciane F. S. Pontes Luis Cristvo S. Porto Lucia M. S. Azevedo Absalom L. Filgueira 《Journal der Deutschen Dermatologischen Gesellschaft》2006,4(10):842-847
Background: Lichen sclerosus (LS) has been identified with increased frequency in families,often associated with HLA markers, mainly DQ7. A genetic co‐etiology seems likely in this setting. Moreover, there is an association of LS with autoimmune disorders, such as the presence of anti‐thyroid peroxidase autoantibodies (anti‐TPO), a hallmark of autoimmune thyroid diseases. Patients and Methods: In 3 families affected by LS, we verified their HLA markers, and identified previously undiagnosed cases of LS and autoimmune disorders. 30 individuals were examined with history, skin biopsy, HLA class I and II typing by PCR‐SSP, and measurement of anti‐TPO, free thyroxine and thyroidstimulating hormones (TSH) levels. Results: There were 8 cases of LS, 50 % of them anti‐TPO+. Autoimmune disorders were found in 40 % (total) and in 87.5 % of those affected. Most common HLA markers were B*15, B*57, CW*03, CW*07, CW*18, DRB1*04, DRB1*07, DRB4*. The three latter have been previously associated with LS. Conclusion: New cases of LS and autoimmune disorders can be detected in first degree relatives of patients with LS. The presence of anti‐TPO antibodies strongly suggests autoimmune thyroiditis. There is intra‐familial association between the haplotype HLA‐B*15 ‐DRB1*04 ‐DRB4* and anti‐TPO,emphasizing their link with thyroiditis. New familial approaches might help to make clear the pathogenesis of LS and its association with autoimmune diseases. 相似文献