首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5390篇
  免费   829篇
  国内免费   70篇
耳鼻咽喉   51篇
儿科学   48篇
妇产科学   33篇
基础医学   307篇
口腔科学   243篇
临床医学   659篇
内科学   415篇
皮肤病学   19篇
神经病学   191篇
特种医学   356篇
外科学   997篇
综合类   879篇
一般理论   8篇
预防医学   1143篇
眼科学   22篇
药学   482篇
  7篇
中国医学   348篇
肿瘤学   81篇
  2024年   20篇
  2023年   183篇
  2022年   275篇
  2021年   463篇
  2020年   362篇
  2019年   404篇
  2018年   279篇
  2017年   343篇
  2016年   316篇
  2015年   308篇
  2014年   339篇
  2013年   403篇
  2012年   295篇
  2011年   326篇
  2010年   250篇
  2009年   215篇
  2008年   257篇
  2007年   206篇
  2006年   185篇
  2005年   138篇
  2004年   139篇
  2003年   123篇
  2002年   77篇
  2001年   50篇
  2000年   57篇
  1999年   35篇
  1998年   39篇
  1997年   25篇
  1996年   21篇
  1995年   15篇
  1994年   10篇
  1993年   11篇
  1992年   9篇
  1991年   9篇
  1990年   6篇
  1989年   9篇
  1988年   16篇
  1987年   14篇
  1986年   5篇
  1985年   14篇
  1984年   9篇
  1983年   4篇
  1982年   5篇
  1981年   5篇
  1980年   6篇
  1979年   5篇
  1978年   2篇
  1977年   2篇
排序方式: 共有6289条查询结果,搜索用时 0 毫秒
31.
【目的】 研究以开放透明为导向的新一代期刊评价体系TOP Factor的来源及应用,为我国科技期刊界参与并推动开放科学运动提供参考。【方法】 利用网络调研法、文献调研法及数据分析法,探究TOP Factor的产生背景及340余种期刊的得分情况。【结果】 TOP Factor的产生主要归因于学术界已认识到影响因子评价体系存在漏洞,需要建立一套可以客观反映期刊发表内容质量,提高研究透明度和再现性的严谨、透明的期刊评价体系。TOP Factor共有10项指标,每项指标分为0~3分4个等级,目前已进行评估的期刊中心理学领域的期刊得分较高。【结论】 开放透明已成为今后学术出版的大趋势,TOP Factor是从出版源头推进开放科学,随着其在促进数据开放共享、提高学术成果可重复性方面的优势逐渐突显,使用TOP Factor的期刊和出版商将会越来越多。我国科技期刊应重视这一趋势并积极制定与开放科学相关的期刊政策,努力打造开放透明的学术生态。  相似文献   
32.
嘎木朱尔涂膜剂的毒性试验研究   总被引:4,自引:0,他引:4  
目的:为使嘎木朱尔涂膜剂的临床用药安全、合理,而对其毒性作用进行了考察。方法:将嘎木朱尔涂膜剂分为高、中、低三个剂量组(按其浓度为0.172g/ml,0.086g/ml,0.043g/ml)给药,用于家兔皮肤,同时做空白基质对照,测定其涂膜剂对家兔皮肤的急性毒性、长期毒性试验。结果:各给药剂量组和空白基质对照组对家兔的体重增长,脏器系数(g/ml)、血液常规,生物化学等项指标的测定均无显著性差异(P<0.05)。结论:嘎木朱尔涂膜剂用于家兔皮肤无毒并能加快受损皮肤的愈合。  相似文献   
33.
医学是什么?—对现代医学归属的思考   总被引:1,自引:1,他引:0  
什么是医学,从人的属性的多元化,医学的整体化、综合化发展趋势,以及现代医学与人文社会医学和艺术的密切关系,认为现代医学不应该属于自然科学;从医学的本质和人文社会医学的局限性来看,现代医学也不可能属于人文社会科学。提出:为了使生物医学和人文社会医学更好地交叉、融合,协调发展,从而达到医学的目的,完成医学所面临的任务,现代医学应该属于与自然科学和人文社会科学平行的,能独立发展又能相互渗透的科学领域。  相似文献   
34.
Background: Hand and distal forearm allotransplantation has advanced over the last 20 years from experimental to a viable treatment option for bilateral upper extremity amputation. Despite widespread growth of this field, there are few technical reports that elaborate the details of donor arm procurement. This article details a technique for rapid donor procurement through the elbow for mid to distal forearm-level hand allograft procurement. Methods: Nine arm procurements were performed on deceased tissue-only donors provided by the local organ procurement organization, including two bilateral and five unilateral cases. Technique highlights include using a fishmouth incision through the lateral and medical epicondyles, identification of the neurovascular structures, and disarticulating the elbow joint. Results: Procuring through the elbow provides straightforward anatomy, bypasses the need to cut through bone, and allows tissue allotransplantation teams to achieve procurement, flushing, and packaging within 20 minutes. Conclusions: Procurement through the elbow is a simple procedure that streamlines the process for multi-organ donors by minimizing the time needed for hand allograft procurement. Team coordination and surgical rehearsals are essential for successful hand and upper extremity procurement and allotransplantation.  相似文献   
35.
36.
37.
In several murine models of transplantation, the “cross-dressing” of recipient antigen presenting cells (APCs) with intact donor major histocompatibility complex (MHC) derived from allograft-released small extracellular vesicles (sEVs) has been recently described as a key mechanism in eliciting and sustaining alloimmune responses. Investigation of these processes in clinical organ transplantation has, however, been hampered by the lack of sensitivity of conventional instruments and assays. We have employed advanced imaging flow cytometry (iFCM) to explore the kinetics of allograft sEV release and the extent to which donor sEVs might induce cross-dressing following liver and kidney transplantation. We report for the first time that recipient APC cross-dressing can be transiently detected in the circulation shortly after liver, but not kidney, transplantation in association with the release of HLA-bearing allograft-derived sEVs. In liver transplant recipients the majority of circulating cells exhibiting donor HLA are indeed cross-dressed cells and not passenger leukocytes. In keeping with experimental animal data, the downstream functional consequences of the transfer of circulating sEVs harvested from human transplant recipients varies depending on the type of transplant and time posttransplant. sEVs released shortly after liver, but not kidney, transplantation exhibit immunoinhibitory effects that could influence liver allograft immunogenicity.  相似文献   
38.
Ischemia-reperfusion injury (IRI) results in increased rates of delayed graft function and early graft loss. It has recently been reported that hydrogen sulfide (H2S) protects organ grafts against prolonged IRI. Here, we investigated whether the preservation of pancreas in University of Wisconsin (UW) solution supplemented with AP39, which is a mitochondrial-targeted H2S donor, protected pancreatic islets against IRI and improved islet function. Porcine pancreata were preserved in the UW solution with AP39 (UW + AP39) or the vehicle (UW) for 18 h, followed by islet isolation. The islet yields before and after purification were significantly higher in the UW + AP39 group than in the UW group. The islets isolated from the pancreas preserved in UW + AP39 exhibited significantly decreased levels of reactive oxygen species (ROS) production and a significantly increased mitochondrial membrane potential as compared to the islets isolated from the pancreas preserved in the vehicle. We found that the pancreas preserved in UW + AP39 improved the outcome of islet transplantation in streptozotocin-induced diabetic mice. These results suggest that the preservation of pancreas in UW + AP39 protects the islet grafts against IRI and could thus serve as a novel clinical strategy for improving islet transplantation outcomes.  相似文献   
39.
Platelet activation and thrombus formation have been implicated to be detrimental for intraportal pancreatic islet transplants. The platelet-specific collagen receptor glycoprotein VI (GPVI) plays a key role in thrombosis through cellular activation and the subsequent release of secondary mediators. In aggregometry and in a microfluidic dynamic assay system modeling flow in the portal vein, pancreatic islets promoted platelet aggregation and triggered thrombus formation, respectively. While platelet GPVI deficiency did not affect the initiation of these events, it was found to destabilize platelet aggregates and thrombi in this process. Interestingly, while no major difference was detected in early thrombus formation after intraportal islet transplantation, genetic GPVI deficiency or acute anti-GPVI treatment led to an inferior graft survival and function in both syngeneic mouse islet transplantation and xenogeneic human islet transplantation models. These results demonstrate that platelet GPVI signaling is indispensable in stable thrombus formation induced by pancreatic islets. GPVI deficiency resulted in thrombus destabilization and inferior islet engraftment indicating that thrombus formation is necessary for a successful intraportal islet transplantation in which platelets are active modulators.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号