全文获取类型
| 收费全文 | 1118960篇 |
| 免费 | 74533篇 |
| 国内免费 | 2816篇 |
专业分类
| 耳鼻咽喉 | 15329篇 |
| 儿科学 | 35262篇 |
| 妇产科学 | 30779篇 |
| 基础医学 | 158044篇 |
| 口腔科学 | 30224篇 |
| 临床医学 | 92663篇 |
| 内科学 | 231223篇 |
| 皮肤病学 | 24824篇 |
| 神经病学 | 90995篇 |
| 特种医学 | 42763篇 |
| 外国民族医学 | 432篇 |
| 外科学 | 170130篇 |
| 综合类 | 19998篇 |
| 一般理论 | 309篇 |
| 预防医学 | 84978篇 |
| 眼科学 | 24371篇 |
| 药学 | 79335篇 |
| 中国医学 | 2496篇 |
| 肿瘤学 | 62154篇 |
出版年
| 2021年 | 9674篇 |
| 2019年 | 10514篇 |
| 2018年 | 16325篇 |
| 2017年 | 11913篇 |
| 2016年 | 12441篇 |
| 2015年 | 14131篇 |
| 2014年 | 18315篇 |
| 2013年 | 28387篇 |
| 2012年 | 41487篇 |
| 2011年 | 43171篇 |
| 2010年 | 24565篇 |
| 2009年 | 21908篇 |
| 2008年 | 39681篇 |
| 2007年 | 42218篇 |
| 2006年 | 41166篇 |
| 2005年 | 40403篇 |
| 2004年 | 38433篇 |
| 2003年 | 36492篇 |
| 2002年 | 35495篇 |
| 2001年 | 45861篇 |
| 2000年 | 47086篇 |
| 1999年 | 40334篇 |
| 1998年 | 10847篇 |
| 1997年 | 9862篇 |
| 1996年 | 9755篇 |
| 1995年 | 9068篇 |
| 1994年 | 8630篇 |
| 1992年 | 30697篇 |
| 1991年 | 29221篇 |
| 1990年 | 28531篇 |
| 1989年 | 27325篇 |
| 1988年 | 25442篇 |
| 1987年 | 24884篇 |
| 1986年 | 23910篇 |
| 1985年 | 22703篇 |
| 1984年 | 16970篇 |
| 1983年 | 14455篇 |
| 1982年 | 8679篇 |
| 1979年 | 15622篇 |
| 1978年 | 10960篇 |
| 1977年 | 9333篇 |
| 1976年 | 8694篇 |
| 1975年 | 9647篇 |
| 1974年 | 11560篇 |
| 1973年 | 11055篇 |
| 1972年 | 10462篇 |
| 1971年 | 9713篇 |
| 1970年 | 9320篇 |
| 1969年 | 8771篇 |
| 1968年 | 8357篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
101.
102.
103.
104.
R. Foley P. Kelly S. Gatault F. Powell 《Journal of the European Academy of Dermatology and Venereology》2021,35(1):62-72
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis. 相似文献
105.
106.
107.
108.
Khaled Adil Marija Popovic Fabio L. Cury Sergio L. Faria Marie Duclos Luis Souhami 《Practical radiation oncology》2019,9(1):24-28
Purpose
This study aimed to investigate 3 planning target volume (PTV) margin expansions and determine the most appropriate volume to be used in bladder preservation therapy when using daily cone beam computed tomography (CBCT). We aimed to establish whether a smaller PTV expansion is feasible without risking geographical miss.Methods and materials
The study included patients with bladder cancer who were treated with a hypofractionated course of radiation therapy delivered with intensity modulated radiation therapy. The clinical target volume (CTV) was the whole empty bladder, and the PTV consisted of a 1.5-cm margin around the bladder (PTV1.5 cm). Patients underwent daily CBCT imaging before treatment to assess the bladder volume and ensure accurate positioning. We investigated 2 additional smaller PTV margin expansions to determine the most appropriate volume to be used with CBCT as a daily image guided radiation therapy modality. These margins were created retrospectively on every CBCT. The first additional volume was a uniform PTV margin of the surrounding 1 cm (PTV1 cm). When considering that the majority of the internal bladder movement was due to the variation in filling that occurs in the superior and anterior directions, a second volume of an anisotropic PTV margin with a 1.5-cm superior/anterior and 1 cm in other directions (PTV1/1.5 cm) was created. We recorded the frequency and measured the volume of bladder falling out of each PTV based on the daily CBCT.Results
For the purpose of this study, we considered an arbitrary 5 cm3 of CTV falling out of the designated PTV as a clinically significant volumetric miss. The frequency of such a miss when applying the uniform PTV1 cm was 1%. However, when applying the uniform PTV1.5 cm and anisotropic PTV1/1.5 cm margins, the frequency was 0.5% and 0.5%, respectively.Conclusions
The anisotropic PTV expansion of 1.5 cm superiorly and anteriorly and 1 cm in all other directions around the bladder (CTV) provides a safe PTV approach when daily CBCT imaging is used to localize an empty bladder. 相似文献109.
110.