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   393087篇
  免费   33195篇
  国内免费   11955篇
耳鼻咽喉   2666篇
儿科学   7357篇
妇产科学   5899篇
基础医学   60513篇
口腔科学   7831篇
临床医学   28549篇
内科学   56683篇
皮肤病学   5998篇
神经病学   28056篇
特种医学   10865篇
外国民族医学   63篇
外科学   31230篇
综合类   53130篇
现状与发展   51篇
一般理论   8篇
预防医学   25774篇
眼科学   4712篇
药学   53563篇
  78篇
中国医学   20971篇
肿瘤学   34240篇
  2024年   352篇
  2023年   5192篇
  2022年   7079篇
  2021年   15743篇
  2020年   13032篇
  2019年   15274篇
  2018年   14695篇
  2017年   14480篇
  2016年   14179篇
  2015年   15458篇
  2014年   20688篇
  2013年   25634篇
  2012年   21945篇
  2011年   25826篇
  2010年   20061篇
  2009年   20224篇
  2008年   20346篇
  2007年   20962篇
  2006年   19369篇
  2005年   16832篇
  2004年   13948篇
  2003年   12321篇
  2002年   9803篇
  2001年   8639篇
  2000年   7251篇
  1999年   6300篇
  1998年   5255篇
  1997年   5032篇
  1996年   4047篇
  1995年   3873篇
  1994年   3591篇
  1993年   2960篇
  1992年   2625篇
  1991年   2437篇
  1990年   2102篇
  1989年   1729篇
  1988年   1584篇
  1987年   1427篇
  1986年   1386篇
  1985年   2325篇
  1984年   2141篇
  1983年   1502篇
  1982年   1660篇
  1981年   1311篇
  1980年   1225篇
  1979年   990篇
  1978年   679篇
  1977年   592篇
  1976年   552篇
  1975年   406篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
71.
Context: Treatment of primary spinal syringomyelia is still controversial. Among others, shunting syrinx fluid to the subarachnoid, peritoneal or pleural space has been utilized with varying success. Shunt obstruction, migration, and infection represent the most common complications of these procedures.

Findings: The authors present the case of an 81-year-old woman who developed an unusual neurological deterioration resembling a subacute posttraumatic ascending myelopathy (SPAM) after the insertion of a syringosubarachnoid shunt for the treatment of slow-growing D10 syringomyelia.

Conclusion/Clinical Relevance: To date, no cases of SPAM secondary to the insertion of a syringosubarachnoid shunt for the treatment of syringomyelia have been reported. The potential pathogenesis related to this phenomenon is discussed.  相似文献   
72.
《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   
73.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
74.
Background: Extracellular matrix molecular components, previously linked to multisystem syndromes include collagens, fibrillins and laminins. Recently, we described a novel multisystem syndrome caused by the c.9418G>A p.(V3140M) mutation in the laminin alpha-5 (LAMA5) gene, which affects connective tissues of all organs and apparatus in a three generation family. In the same family, we have also reported a myopic trait, which, however, was linked to the Prolyl 4-hydroxylase subunit alpha-2 (P4HA2) gene. Results of investigation on vitreous changes and their pathogenesis are reported in the present study.Materials and Methods: Nineteen family individuals underwent complete ophthalmic examination including best-corrected visual acuity (BCVA), fundus examination, fundus photography, intraocular pressure measurement, axial length measurement using ocular biometry, Goldmann visual field examination, standard electroretinogram, SD-OCT. Segregation analysis of LAMA5 and P4HA2 mutations was performed in enrolled members.Results: The vitreous alterations fully segregated with LAMA5 mutation in both young and adult family members. Slight reduction of retinal thickness and peripheral retinal degeneration in only two patients were reported.Conclusions: In this work we showed that PVD is a common trait of LAMA5 multisystem syndrome, therefore occurring as an age-unrelated trait. We hypothesize that the p.(V3140M) mutation results in a reduction of retinal inner limiting membrane (ILM) stability, leading to a derangement in the macromolecular structure of the vitreous gel, and PVD. Further investigations will be necessary to elucidate the role of wild type and mutated LAMA5 in the pathogenesis of PVD.  相似文献   
75.
76.
李志道教授经过50余年临床实践研究,结合解剖学相关知识,发现委中、承山二穴在针刺深度与传统认识有所不同。其中,委中穴在刺入0. 5~0. 8寸,承山穴在刺入2. 0~3. 0寸时最易达到循经得气的效果,通过调整针尖方向还可较准确达到气至病所的效果,且针感与相应神经分布区域相吻合。该针感在某些疾病,尤其神经压迫相关症状的治疗中疗效明显,且优于传统教材所述针刺深度。  相似文献   
77.
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   
78.
79.
80.
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