全文获取类型
收费全文 | 2511篇 |
免费 | 161篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 78篇 |
妇产科学 | 39篇 |
基础医学 | 285篇 |
口腔科学 | 91篇 |
临床医学 | 236篇 |
内科学 | 572篇 |
皮肤病学 | 78篇 |
神经病学 | 183篇 |
特种医学 | 127篇 |
外科学 | 518篇 |
综合类 | 14篇 |
预防医学 | 80篇 |
眼科学 | 46篇 |
药学 | 133篇 |
中国医学 | 2篇 |
肿瘤学 | 173篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 19篇 |
2021年 | 55篇 |
2020年 | 31篇 |
2019年 | 49篇 |
2018年 | 61篇 |
2017年 | 50篇 |
2016年 | 66篇 |
2015年 | 58篇 |
2014年 | 124篇 |
2013年 | 121篇 |
2012年 | 195篇 |
2011年 | 226篇 |
2010年 | 142篇 |
2009年 | 133篇 |
2008年 | 216篇 |
2007年 | 232篇 |
2006年 | 199篇 |
2005年 | 182篇 |
2004年 | 144篇 |
2003年 | 136篇 |
2002年 | 143篇 |
2001年 | 25篇 |
2000年 | 7篇 |
1999年 | 14篇 |
1998年 | 20篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 2篇 |
1971年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有2690条查询结果,搜索用时 569 毫秒
21.
Sofie Gillis Carlos De Wagter Joerg Bohsung Bruce Perrin Peter Williams Ben J Mijnheer 《Radiotherapy and oncology》2005,76(3):340-353
BACKGROUND AND PURPOSE: IMRT necessitates extension of existing inter-centre quality assurance programs due to its increased complexity. We assessed the feasibility of an inter-centre verification method for different IMRT techniques. MATERIALS AND METHODS: Eight European radiotherapy institutions of the QUASIMODO network, have designed an IMRT plan for a horseshoe-shaped PTV surrounding a cylindrical OAR in a simplified pelvic phantom. All centres applied common plan objectives but used their own equipment for planning and delivery. They verified the delivery of this plan according to a common protocol with radiographic film and ionisation chamber measurements. The irradiated films, the results of the ionisation chamber measurements and the computed dose distributions were sent to one analysis centre that compared the measured and computed dose distributions with the gamma method and composite dose-area histograms. RESULTS: 4% (relative to the prescribed dose) and 3mm (distance-to-agreement) were decided feasible gamma criteria. The composite dose-area histograms showed a maximum local deviation of 3.5% in the mean dose of the PTV and 5% in the OAR. Systematic differences could be identified, and in some cases explained. CONCLUSIONS: This multi-centre dosimetric verification study demonstrated both the feasibility of a multi-centre quality assurance network to evaluate any IMRT planning and delivery system combination, as well as the validity of the methodology involved. 相似文献
22.
Joachim Schuster Hanns-Christian Mahler Susanne Joerg Vinay Kamuju Joerg Huwyler Roman Mathaes 《Journal of pharmaceutical sciences》2021,110(6):2386-2394
Changes in the environment from the drug product to the human physiology might lead to physical and/or chemical modifications of the protein drug, such as in vivo aggregation and fragmentation. Although subcutaneous (SC) injection is a common route of administration for therapeutic proteins, knowledge on in vivo stability in the SC tissue is limited. In this study, we developed a physiologic in vitro model simulating the SC environment in patients. We assessed the stability of two monoclonal antibodies (mAbs) in four different protein-free fluids under physiologic conditions. We monitored protein stability over two weeks using a range of analytical methods, in analogy to testing purposes of a drug product. Both mAbs showed an increase of protein aggregates, fragments, and acidic species. mAb1 was consistently more stable in this in vitro model than mAb2, highlighting the importance of comparing the stability of different mAbs under physiologic conditions. Throughout the study, both mAbs were substantially less stable in bicarbonate buffers as compared to phosphate-buffered saline. In summary, our developed model was able to differentiate stability between molecules. Bicarbonate buffers were more suitable compared to phosphate-buffered saline in regards to simulating the in vivo conditions and evaluating protein liabilities. 相似文献
23.
24.
Joerg Kellermair Gitter Roland Mair Rudolf Sigler Matthias Grund Michael Steinwender Clemens 《The Canadian journal of cardiology》2018,34(12):1688.e13-1688.e15
Transcatheter pulmonary valve (TPV) replacement is an effective therapy of right ventricular outflow tract conduit dysfunction. Acute complications after TPV implantation include infective endocarditis, stent fracture, and device dislocation. We present a novel, life-threatening complication: an acute, noninfectious TPV thrombosis. Within 24 hours after implantation of a Melody system (Medtronic, Inc, Minneapolis, MN), the patient developed an acute TPV thrombosis characterized by severe TPV stenosis on echocardiography and contrast filling defects on computed tomography pulmonary angiography images. Genetic testing revealed heterozygous prothrombin G20210A polymorphism and homozygous 4G/4G polymorphism of the plasminogen-activator-inhibitor. The patient recovered after surgical valve replacement with a pulmonary homograft. 相似文献
25.
26.
27.
Pantelis D Beissel A Kahl P Vilz TO Stoffels B Wehner S Kalff JC 《International journal of colorectal disease》2011,26(6):737-746
Purpose
Prevention of perioperative activation of intestinal muscularis macrophages is a promising intervention to avoid post-traumatic gastrointestinal tract dysfunction. However, impaired macrophage function could have deleterious consequences on anastomotic healing, especially in complications aggravating the healing process itself, such as infectious problems either as preexisting local inflammation or infection (e.g., complicated diverticulitis) or endotoxemia due to early postoperative infections (e.g., pneumonia). Aim of this study was to investigate colonic anastomotic healing in macrophage-depleted mice in the presence of endotoxemia. 相似文献28.
29.
Noemie Luong-Gardiol Imran Siddiqui Irene Pizzitola Beena Jeevan-Raj Mélanie Charmoy Yun Huang Anja Irmisch Sara Curtet Georgi S. Angelov Maxime Danilo Mélanie Juilland Beat Bornhauser Margot Thome Oliver Hantschel Yves Chalandon Gianni Cazzaniga Jean-Pierre Bourquin Joerg Huelsken Werner Held 《Cancer cell》2019,35(4):649-663.e10
30.
The oral epithelial barrier separates the host from the environment and provides the first line of defense against pathogens, exogenous substances and mechanical stress. It consists of underlying connective tissue and a stratified keratinized epithelium with a basement membrane, whose cells undergo terminal differentiation resulting in the formation of a mechanically resistant surface. Gingival keratinocytes are connected by various transmembrane proteins, such as tight junctions, adherens junctions and gap junctions, each of which has a specialized structure and specific functions. Periodontal pathogens are able to induce inflammatory responses that lead to attachment loss and periodontal destruction. A number of studies have demonstrated that the characteristics of pathogenic oral bacteria influence the expression and structural integrity of different cell–cell junctions. Tissue destruction can be mediated by host cells following stimulation with cytokines and bacterial products. Keratinocytes, the main cell type in gingival epithelial tissues, express a variety of proinflammatory cytokines and chemokines, including interleukin‐1alpha, interleukin‐1beta, interleukin‐6, interleukin‐8 and tumor necrosis factor‐alpha. Furthermore, the inflammatory mediators that may be secreted by oral keratinocytes are vascular endothelial growth factor, prostaglandin E2, interleukin‐1 receptor antagonist and chemokine (C‐C motif) ligand 2. The protein family of matrix metalloproteinases is able to degrade all types of extracellular matrix protein, and can process a number of bioactive molecules. Matrix metalloproteinase activities under inflammatory conditions are mostly deregulated and often increased, and those mainly relevant in periodontal disease are matrix metalloproteinases 1, 2, 3, 8, 9, 13 and 24. Viral infection may also influence the epithelial barrier. Studies show that the expression of HIV proteins in the mucosal epithelium is correlated with the disruption of epithelial tight junctions, suggesting a possible enhancement of human papilloma virus infection by HIV‐associated disruption of tight junctions. Altered expression of matrix metalloproteinases was demonstrated in keratinocytes transformed with human papilloma virus‐16 or papilloma virus‐18,. To summarize, the oral epithelium is able to react to a variety of exogenous, possibly noxious influences. 相似文献