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   225744篇
  免费   19195篇
  国内免费   7696篇
耳鼻咽喉   1836篇
儿科学   3689篇
妇产科学   2939篇
基础医学   32738篇
口腔科学   4153篇
临床医学   17883篇
内科学   39421篇
皮肤病学   3067篇
神经病学   16101篇
特种医学   5365篇
外国民族医学   53篇
外科学   17595篇
综合类   30263篇
现状与发展   20篇
一般理论   6篇
预防医学   13374篇
眼科学   2227篇
药学   33843篇
  80篇
中国医学   9285篇
肿瘤学   18697篇
  2024年   430篇
  2023年   4341篇
  2022年   6374篇
  2021年   12190篇
  2020年   9390篇
  2019年   8122篇
  2018年   7849篇
  2017年   7531篇
  2016年   7568篇
  2015年   8555篇
  2014年   13908篇
  2013年   15073篇
  2012年   13277篇
  2011年   15128篇
  2010年   12463篇
  2009年   12656篇
  2008年   12209篇
  2007年   11269篇
  2006年   9856篇
  2005年   8675篇
  2004年   7190篇
  2003年   6395篇
  2002年   5005篇
  2001年   4146篇
  2000年   3447篇
  1999年   3131篇
  1998年   2879篇
  1997年   2684篇
  1996年   2387篇
  1995年   2124篇
  1994年   1927篇
  1993年   1660篇
  1992年   1420篇
  1991年   1331篇
  1990年   1091篇
  1989年   922篇
  1988年   857篇
  1987年   741篇
  1986年   654篇
  1985年   1002篇
  1984年   964篇
  1983年   676篇
  1982年   679篇
  1981年   545篇
  1980年   463篇
  1979年   373篇
  1978年   256篇
  1977年   210篇
  1976年   198篇
  1975年   127篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
目的:构建基于SERVQUAL模型的医养结合型养老机构卫生服务质量评价指标体系。方法:围绕医养结合型养老机构卫生服务的概念、特性、内涵、内容等,采用文献研究法、半结构式访谈法、Delphi—AHP法等定性与定量相结合的研究方法,构建指标体系并确定指标权重。结果:构建了具有7个一级指标,27个二级指标和77个三级指标的养老机构卫生服务质量评价指标体系。指标体系三轮咨询专家权威系数Cr均高于0.84,专家综合权威性系数均高于0.83;总体专家协调系数Kendall W第一、二轮为0.309,第三轮为0.706,且均通过显著性检验;内容效度指数I-CVI介于0.90~1.00之间,S-CVI为0.94,kappa值均高于0.74;信度系数Cronbachα总体为0.972,各维度Cronbachα系数在0.792~0.921之间。评价指标体系具有较好的稳定性、可靠性和一致性。结论:本研究建立的评价指标体系有利于医养结合型养老机构全面建立贴近老年人卫生服务需求的内设医疗机构,改善机构内卫生服务质量。在对指标体系进行应用时,可转化为机构中老年人对各指标项目的感受(P)与期望(E),以两者的差值(P-E)代表机构的卫生服务质量。根据专家赋权结果,应重点加强医养结合养老机构对可靠性、有效性、经济性等指标项目的建设。  相似文献   
63.
《Clinical neurophysiology》2020,131(7):1444-1452
ObjectiveTo investigate cognitive functions in non-demented patients with early-onset Parkinson's disease (PD), and to compare PARK2 gene mutation carriers and non-carriers by means of event-related brain potentials (ERPs).MethodsThe participants comprised patients with early-onset PD (EOPD) and healthy controls (HC). Patients with EOPD were divided into two groups as carriers of known pathogenic variants of PARK2 gene (EOPD-PC) and non-carriers of genes involved in familial PD (EOPD-NC). ERP data were collected during auditory oddball and visual continuous performance test (CPT).ResultsBoth EOPD groups (EOPD-PC and EOPD-NC) displayed reduced and delayed P3 in response to oddball target and CPT NoGo. CPT Go P3 was reduced in EOPD-NC but not in EOPD-PC. Oddball target N1 was reduced and P2 was enhanced in both EOPD-PC and EOPD-NC. In both cognitive tasks, RTs were prolonged and accuracy was lower in EOPD-PC and EOPD-NC.ConclusionsWe found several EOPD-related neurophysiologic changes, implying impairments in cognitive functions. Pairwise comparisons between EOPD-PC and EOPD-NC revealed no significant ERP marker.SignificanceIn this study, the confounding effect of normative aging was somewhat excluded compared with many previous studies. In contrast with the many oddball studies in non-demented PD, we clearly observed reduced and prolonged P3 in early-onset PD. Our NoGo P3 findings also contribute to the limited ERP research concerning response inhibition.  相似文献   
64.
65.
目的:观察电针双侧"足三里"穴对脾气虚模型大鼠小肠黏膜上皮组织内的钠依赖葡萄糖转运体(SGLT1),葡萄糖运载蛋白2(GLUT2)的基因及蛋白表达的影响。方法:将40只SD雄性大鼠随机分为正常组、脾气虚组、足三里组、非经非穴组,每组10只。所有大鼠均在SPF级动物实验中心饲养。除正常组外,其余3组均采用劳倦过度和不规则饮食复合法建立脾气虚证的大鼠模型。造模成功之后,对足三里组、非经非穴组大鼠分别进行电针"足三里"穴、非经非穴点干预处理7天。采用HE染色方法观察各组大鼠小肠黏膜组织形态变化;采用荧光定量PCR法检测大鼠小肠黏膜上皮的SGLT1和GLUT2的mRNA表达水平;采用蛋白质免疫印迹法(WB)检测大鼠小肠黏膜上皮组织内的SGLT1和GLUT2的蛋白含量变化。结果:脾气虚组大鼠小肠黏膜组织部分损伤,足三里组的小肠黏膜组织有一定程度的恢复;脾气虚组和非经非穴组大鼠小肠黏膜组织内的SGLT1和GLUT2蛋白和基因表达水平均明显低于正常组(P 0. 05);足三里组大鼠小肠黏膜组织内的SGLT1和GLUT2蛋白和基因表达水平相比于脾气虚组有所升高(P 0. 05),非经非穴组未见显著性差异(P 0. 05)。结论:电针"足三里"穴可以调节脾气虚大鼠小肠黏膜上皮组织内的SGLT1和GLUT2基因及蛋白的异常表达,参与小肠对葡萄糖的吸收作用进而改善脾气虚证。  相似文献   
66.
67.
ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.  相似文献   
68.
COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19.  相似文献   
69.
Trigeminal neuralgia is a debilitating condition, and the pain easily spreads to other parts of the face. Here, we established a mouse model of partial transection of the infraorbital nerve (pT-ION) and found that the Connexin 36 (Cx36) inhibitor mefloquine caused greater alleviation of pT-ION-induced cold allodynia compared to the reduction of mechanical allodynia. Mefloquine reversed the pT-ION-induced upregulation of Cx36, glutamate receptor ionotropic kainate 2 (GluK2), transient receptor potential ankyrin 1 (TRPA1), and phosphorylated extracellular signal regulated kinase (p-ERK) in the trigeminal ganglion. Cold allodynia but not mechanical allodynia induced by pT-ION or by virus-mediated overexpression of Cx36 in the trigeminal ganglion was reversed by the GluK2 antagonist NS102, and knocking down Cx36 expression in Nav1.8-expressing nociceptors by injecting virus into the orofacial skin area of Nav1.8-Cre mice attenuated cold allodynia but not mechanical allodynia. In conclusion, we show that Cx36 contributes greatly to the development of orofacial pain hypersensitivity through GluK2, TRPA1, and p-ERK signaling.Electronic supplementary materialThe online version of this article (10.1007/s12264-020-00594-4) contains supplementary material, which is available to authorized users.  相似文献   
70.
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