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   15600篇
  免费   2269篇
  国内免费   639篇
耳鼻咽喉   45篇
儿科学   200篇
妇产科学   100篇
基础医学   3364篇
口腔科学   202篇
临床医学   1195篇
内科学   2122篇
皮肤病学   297篇
神经病学   1798篇
特种医学   360篇
外国民族医学   1篇
外科学   866篇
综合类   2298篇
现状与发展   5篇
预防医学   1709篇
眼科学   183篇
药学   1618篇
  16篇
中国医学   1475篇
肿瘤学   654篇
  2024年   128篇
  2023年   649篇
  2022年   882篇
  2021年   1531篇
  2020年   1212篇
  2019年   918篇
  2018年   733篇
  2017年   649篇
  2016年   662篇
  2015年   771篇
  2014年   1113篇
  2013年   1230篇
  2012年   961篇
  2011年   1091篇
  2010年   867篇
  2009年   739篇
  2008年   862篇
  2007年   681篇
  2006年   564篇
  2005年   393篇
  2004年   320篇
  2003年   285篇
  2002年   191篇
  2001年   137篇
  2000年   120篇
  1999年   119篇
  1998年   119篇
  1997年   113篇
  1996年   73篇
  1995年   75篇
  1994年   71篇
  1993年   41篇
  1992年   32篇
  1991年   31篇
  1990年   22篇
  1989年   24篇
  1988年   17篇
  1987年   6篇
  1986年   16篇
  1985年   13篇
  1984年   6篇
  1983年   6篇
  1982年   10篇
  1981年   5篇
  1980年   5篇
  1979年   2篇
  1978年   5篇
  1977年   5篇
  1975年   1篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
61.
论网络化时代电视教材的重要性   总被引:7,自引:3,他引:4  
针对教学实践中重视计算机辅助教学忽视电视教材的倾向,本文通过对网络时代中电视教材的作用和地位的分析,阐述了加强计算机辅助教学的必要性和加强电视教材制作及应用的重要性以及二者间的关系。  相似文献   
62.
本文介绍了教学设备网络管理系统模型及其技术指标、软硬件环境、功能、程序设计和主要特点。  相似文献   
63.
多媒体网络教学的构成及其解决方案   总被引:6,自引:4,他引:2  
作为一所教学医院,如何更好的提供教学服务,培养出高质量的军事医疗人员,在未来的战争中做好医疗保障是我们教学的目标。利用计算机多媒体网络技术将临床、科研和教学有效的组织起来,为优化教学内容、提高教学质量奠定了基础。  相似文献   
64.
BACKGROUND: Microbial intestinal colonization in early in life is regarded to play a major role for the maturation of the immune system. Application of non-pathogenic probiotic bacteria during early infancy might protect from allergic disorders but underlying mechanisms have not been analysed so far. OBJECTIVE: The aim of the current study was to investigate the immune effects of oral application of probiotic bacteria on allergen-induced sensitization and development of airway inflammation and airway hyper-reactivity, cardinal features of bronchial asthma. METHODS: Newborn Balb/c mice received orally 10(9) CFU every second day either Lactobacillus rhamnosus GG or Bifidobacterium lactis (Bb-12) starting from birth for consecutive 8 weeks, during systemic sensitization (six intraperitoneal injections, days 29-40) and airway challenge (days 54-56) with ovalbumin. RESULTS: The administration of either Bb-12 or LGG suppressed all aspects of the asthmatic phenotype: airway reactivity, antigen-specific immunoglobulin E production and pulmonary eosinophilia (mean: 137 vs. 17 and 13 cellsx10(3)/mL, respectively). Antigen-specific recall proliferation by spleen cells and T-helper type 2 cytokine production (IL-4, IL-5 and IL-10) by mesenteric lymph node cells also showed significant reduction, while TGF production remained unchanged. Oral LGG administration particularly suppressed allergen-induced proliferative responses and was associated with an increase in numbers of TGF-beta-secreting CD4+/CD3+ T cells in mesenteric lymph nodes (6.5, 16.7%) as well as nearly 2-fold up-regulation of Foxp3-expressing cells in peribronchial lymph nodes. CONCLUSIONS: Neonatal application of probiotic bacteria inhibits subsequent allergic sensitization and airway disease in a murine model of asthma by induction of T regulatory cells associated with increased TGF-beta production.  相似文献   
65.
基于无线网络及条形码技术的图书排架、定位系统   总被引:3,自引:2,他引:1  
利用无线网络与条形码技术,建立起图书排架、定位系统,可实现图书排架和图书的准确定位.该系统可有效地解决传统管理方法易产生的乱架和死书问题,提高图书借阅效率并降低管理人员的工作强度.  相似文献   
66.
Summary A comprehensive review of the literature on the anatomy, electrophysiology and pharmacology of thesubstantia nigra is presented. A diagram is developed taking into account the interneuronal interactions of neurotransmitters and receptors that control firing rates and neurotransmitter releases. The central features of the diagram are a positive dopaminergic feedforward process and a positive feedback mechanism mediated by extrasynaptic substance P diffusing from striatal terminals to dopaminergic dendrites of thezona compacta neurons. This loop can enhance the transmission of information from thestriatum through thepars reticulata output neurons. The loop is controlled at the level of zona compacta neurons by a negative feedback supported by the dendritic release of dopamine and boosted by pedunculopontine activation mediated by muscarinic receptors. The output of the loop is controlled by two negative feedforward processes, both involving GABAergic striatonigral afferents. Application of the model to pharmacological studies of diverse behaviors including seizures, turning, and conditioned behaviors reveals unforseen relationships and may offer insights into, and directions for, further analysis of the mechanisms and functions involved.  相似文献   
67.
诱发电位的提取是脑电信号处理领域的前沿课题近年来 ,通过少次甚至单次试验提取诱发电位已经成为研究的主流。本文对近年来提取诱发电位的信号处理方法进行了简要的回顾 ,并分别从小波变换、神经网络、高阶累积量、独立分量分析等四个方面对算法进行了介绍  相似文献   
68.
69.
Objective To evaluate the association of 2616c/T polymorphism in iron regulatory protein 2(IRP2)gene with Alzheimer disease(AD)and Vascular dementia(VD).Methods In this study,281 patients with AD,60 with VD,and 285 normal aged were recruited.The 2616C/T polymorphism in IRP2 gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism.And the cognitive function was assessed with the Mini-Mental State Examination(MMSE).Results (1)No significant difieFences were demonstrated in IRP2 genotype or allele frequencies between AD patients and controls(χ2=2.46,P=0.292;χ2=2.17,P=0.141 respectively).However,when AD patients were stratified by disease severity.the frequency of T allele carriers in the moderate to severe AD patients was 78.0%,significantly higher than that in controls(69.8%;χ2=4.106,P<0.05).Logistic regression analysis demonstrated that the age-,sex-and ApoE-adiusted OR of modcrate to severe AD patient with T allele was 1.62(95% CI=1.03-2.54).The frequency of T allele carriers or T allele in VD patients was higher than that of controls,but the difference was not statistically significant(P>0.05).(2)The frequency of tit genotype or T allele in the moderate to severe AD patients was significantly higher than that in mild AD patients(25.8%vs.12.5%,χ2=5.477,P<0.05;51.9%vs.40.3%,χ2=5.803,P<0.05 respectively).(3)MMSE scores of the AD patients with TT genotype was significantly lower than ones with CC or CT genotype(P=0.028;P=0.014 respectively).Conclusion The 2616C/T polymorphism in the IRP2 gene is possibly associated with moderate to severe AD.but not associated with VD.And the TT genotype may be a risk factor for cognitive impairment of patients with AD in Chinese Han.  相似文献   
70.
The Van der Woude syndrome: a case report and review of the literature   总被引:1,自引:0,他引:1  
The Van der Woude syndrome is a rare autosomal dominant developmental malformation usually associated with bilateral lower lip pits. These congenital lip pits appear clinically as a malformation in the vermilion border of the lip, with or without excretion. As a genetic defect has been identified as a microdeletion of chromosome bands 1q32-q41, genetic counselling of patients may be considered. A nonsense mutation in the interferon regulatory factor-6 (IRF-6) is discussed as a pathogenic relevant factor. Therapeutic intervention is generally not necessary, although surgical excision is especially indicated in patients with recurrent inflammation. Physicians should be aware of the Van der Woude syndrome because it has been reported to be associated with a variety of malformations or other congenital disorders.  相似文献   
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