全文获取类型
收费全文 | 877791篇 |
免费 | 72636篇 |
国内免费 | 1933篇 |
专业分类
耳鼻咽喉 | 12981篇 |
儿科学 | 24868篇 |
妇产科学 | 25324篇 |
基础医学 | 126573篇 |
口腔科学 | 25894篇 |
临床医学 | 76869篇 |
内科学 | 167873篇 |
皮肤病学 | 17464篇 |
神经病学 | 72017篇 |
特种医学 | 36298篇 |
外国民族医学 | 171篇 |
外科学 | 139120篇 |
综合类 | 24698篇 |
现状与发展 | 2篇 |
一般理论 | 268篇 |
预防医学 | 67447篇 |
眼科学 | 20709篇 |
药学 | 65778篇 |
中国医学 | 1605篇 |
肿瘤学 | 46401篇 |
出版年
2018年 | 7800篇 |
2015年 | 8308篇 |
2014年 | 11812篇 |
2013年 | 17575篇 |
2012年 | 24031篇 |
2011年 | 25243篇 |
2010年 | 14733篇 |
2009年 | 13869篇 |
2008年 | 23739篇 |
2007年 | 25803篇 |
2006年 | 25601篇 |
2005年 | 25201篇 |
2004年 | 24646篇 |
2003年 | 23707篇 |
2002年 | 22725篇 |
2001年 | 35987篇 |
2000年 | 36578篇 |
1999年 | 31048篇 |
1998年 | 9352篇 |
1997年 | 8692篇 |
1996年 | 8551篇 |
1995年 | 8078篇 |
1994年 | 7789篇 |
1992年 | 26707篇 |
1991年 | 26137篇 |
1990年 | 25653篇 |
1989年 | 24712篇 |
1988年 | 23246篇 |
1987年 | 22901篇 |
1986年 | 21767篇 |
1985年 | 21111篇 |
1984年 | 16400篇 |
1983年 | 14006篇 |
1982年 | 8864篇 |
1981年 | 8206篇 |
1980年 | 7680篇 |
1979年 | 16742篇 |
1978年 | 12122篇 |
1977年 | 10184篇 |
1976年 | 9330篇 |
1975年 | 10153篇 |
1974年 | 12646篇 |
1973年 | 12141篇 |
1972年 | 11542篇 |
1971年 | 10688篇 |
1970年 | 10221篇 |
1969年 | 9912篇 |
1968年 | 8903篇 |
1967年 | 8232篇 |
1966年 | 7654篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
L.‐Q. Zheng X.‐C. Han Y. Huang H.‐W. Li X.‐D. Niu J. Li 《Clinical and experimental dermatology》2015,40(3):293-297
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis. 相似文献
43.
Benyam Kinde Harrison W. Gabel Caitlin S. Gilbert Eric C. Griffith Michael E. Greenberg 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(22):6800-6806
DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system. 相似文献
44.
Dynamic LVOT Obstruction and Aortic Stenosis in the Same Patient: A Case of Challenging Doppler Hemodynamics
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Matthew W. Parker M.D. Francis J. Kiernan M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1030-1032
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction. 相似文献
45.
46.
47.
48.
49.
Paul J. Devlin Brian W. McCrindle James K. Kirklin Eugene H. Blackstone William M. DeCampli Christopher A. Caldarone Ali Dodge-Khatami Pirooz Eghtesady James M. Meza Peter J. Gruber Kristine J. Guleserian Bahaaladin Alsoufi Linda M. Lambert James E. OBrien Erle H. Austin Jeffrey P. Jacobs Tara Karamlou 《The Journal of thoracic and cardiovascular surgery》2019,157(2):684-695.e8