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   324239篇
  免费   60028篇
  国内免费   15230篇
耳鼻咽喉   3654篇
儿科学   7159篇
妇产科学   5486篇
基础医学   43882篇
口腔科学   9178篇
临床医学   43754篇
内科学   62416篇
皮肤病学   10055篇
神经病学   26303篇
特种医学   10917篇
外国民族医学   101篇
外科学   40189篇
综合类   36957篇
现状与发展   48篇
一般理论   66篇
预防医学   20070篇
眼科学   8127篇
药学   30353篇
  174篇
中国医学   12688篇
肿瘤学   27920篇
  2024年   732篇
  2023年   3649篇
  2022年   9051篇
  2021年   13018篇
  2020年   13373篇
  2019年   17824篇
  2018年   17679篇
  2017年   17930篇
  2016年   18302篇
  2015年   21603篇
  2014年   24263篇
  2013年   23805篇
  2012年   21907篇
  2011年   23612篇
  2010年   20430篇
  2009年   14563篇
  2008年   15117篇
  2007年   14162篇
  2006年   13731篇
  2005年   13596篇
  2004年   9868篇
  2003年   9232篇
  2002年   8159篇
  2001年   7583篇
  2000年   7217篇
  1999年   6946篇
  1998年   3853篇
  1997年   3828篇
  1996年   2946篇
  1995年   2724篇
  1994年   2345篇
  1993年   1559篇
  1992年   2375篇
  1991年   2086篇
  1990年   1741篇
  1989年   1517篇
  1988年   1323篇
  1987年   1236篇
  1986年   983篇
  1985年   786篇
  1984年   504篇
  1983年   388篇
  1982年   234篇
  1981年   204篇
  1980年   192篇
  1979年   247篇
  1978年   143篇
  1977年   112篇
  1976年   97篇
  1974年   117篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
FDA’S Perspectives on Cardiovascular Devices   总被引:1,自引:0,他引:1  
The Food and Drug Administration (FDA) decision process for approving or clearing medical devices is often determined by a review of robust clinical data and extensive preclinical testing of the device. The mission statement for the Center for Devices and Radiological Health (CDRH) is to review the information provided by manufacturers so that it can promote and protect the health of the public by ensuring the safety and effectiveness of medical devices deemed appropriate for human use (Food, Drug & Cosmetic Act, §903(b)(1, 2(C)), December 31, 2004; accessed December 17, 2008 ). For high-risk devices, such as ventricular assist devices (VADs), mechanical heart valves, stents, cardiac resynchronization therapy (CRT) devices, pacemakers, and defibrillators, the determination is based on FDA’s review of extensive preclinical bench and animal testing followed by use of the device in a clinical trial in humans. These clinical trials allow the manufacturer to evaluate a device in the intended use population. FDA reviews the data from the clinical trial to determine if the device performed as predicted and the clinical benefits outweigh the risks. This article reviews the regulatory framework for different marketing applications related to cardiovascular devices and describes the process of obtaining approval to study a cardiovascular device in a U.S. clinical trial.  相似文献   
72.
100例性病患者心理健康状况调查分析   总被引:3,自引:1,他引:2  
目的:探讨性病患者的心理健康状况,为临床治疗和护理提供依据。方法:采用症状自评量表(SCL-90)对100例性病患者的心理健康状况进行测验。结果:100例性病患者SCL-90检测的阳性率为51%,阳性样本因子分居前的是敌对、强迫症状、抑郁、人际敏感。结论:性病患者广泛存在的心理问题,在药用治疗的同时应注意心理方面的治疗和疏导。  相似文献   
73.
74.
75.
A case of untreated fusarial onychomycosis leading to serious consequences is reported. Fusarium solani is a widespread fungus and an occasional human pathogen. It usually invades rapidly in immunocompromised hosts, and often results in a poor outcome despite treatment. We report a woman with diabetes mellitus who had untreated fusarial infection of the nails, which developed into subcutaneous fusariosis, superinfected by bacteria, and then evolved into osteomyelitis that subsequently resulted in septic shock. Early management of mycotic nails in immunocompromised hosts is crucial to prevent life‐threatening disease.  相似文献   
76.
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
77.
78.
79.
经腹及经阴道B超监测卵泡发育的评估   总被引:3,自引:0,他引:3  
应用经腹及经阴道B超对68名不孕症妇女,139个月经周期进行卵泡发育及排卵监测。卵泡检出率TAUS为90.6%,TVUS为98.0%,显著高于前者,P<0.05。成熟卵泡特征影象(卵丘等)在TVUS显象率较高。TVUS监测卵泡发育更实用可靠。  相似文献   
80.
The first‐order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103‐scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first‐order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low‐contrast stimulation condition in mERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma.  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