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   2445173篇
  免费   173483篇
  国内免费   4997篇
耳鼻咽喉   32645篇
儿科学   78873篇
妇产科学   64774篇
基础医学   357322篇
口腔科学   64529篇
临床医学   217969篇
内科学   478104篇
皮肤病学   53080篇
神经病学   195448篇
特种医学   92094篇
外国民族医学   489篇
外科学   371896篇
综合类   48399篇
现状与发展   12篇
一般理论   848篇
预防医学   192871篇
眼科学   55227篇
药学   179204篇
  11篇
中国医学   4585篇
肿瘤学   135273篇
  2021年   19009篇
  2019年   19567篇
  2018年   35506篇
  2017年   27316篇
  2016年   31637篇
  2015年   26694篇
  2014年   37249篇
  2013年   55770篇
  2012年   77408篇
  2011年   87357篇
  2010年   53753篇
  2009年   50074篇
  2008年   82624篇
  2007年   89342篇
  2006年   81256篇
  2005年   79944篇
  2004年   76949篇
  2003年   75302篇
  2002年   72006篇
  2001年   109671篇
  2000年   112397篇
  1999年   94245篇
  1998年   27718篇
  1997年   24484篇
  1996年   24880篇
  1995年   23663篇
  1994年   21738篇
  1993年   20445篇
  1992年   72749篇
  1991年   70757篇
  1990年   68988篇
  1989年   66203篇
  1988年   60816篇
  1987年   59700篇
  1986年   55653篇
  1985年   53535篇
  1984年   39743篇
  1983年   33771篇
  1982年   20265篇
  1979年   36257篇
  1978年   25955篇
  1977年   21484篇
  1976年   20601篇
  1975年   22000篇
  1974年   26337篇
  1973年   24937篇
  1972年   23317篇
  1971年   22127篇
  1970年   20363篇
  1969年   19425篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
背景/目的:从1978-2000年,有10对联体双胞胎成功接受了手术分离,结果14人存活。其中6对是因为他们的联体同胞死亡或濒临死亡而接受紧急分离手术。剩余的4对,每对至少一个同胞接受至少一次的急诊手术后,才接受联体分离手术。方法:对这一独特的队列进行包含6个项目的问卷调查。问题的设计是开放式的,为父母/家庭提供有关信息的最大机会。对每个家庭就相同的问题也进行了当面的问卷调查。医师询问了与身体健康和疾病相关的一些问题。而社会工作询问了与发育、教育、社会心理和家庭功能相关的问题。结果:前面提及的14人存活的双胞胎中,4人大学毕业,1人于1981年完成中学学业,剩余9人正在上学。14人在最初的手术后,还需要接受再次手术,尤其是需要矫正泌尿系统、畸形、神经外科和小儿外科的问题。结论:通过超声检查对联体双胎进行宫内诊断,可以使医师和胎儿父母在孕早期决定在终止妊娠时是进行双胎分离还是保全其中一个。这些病例报道通过描述14例手术存活的长期体格检查和心理学检查结果,为医师和父母在关键时刻做出决定提供了另外有助的依据。  相似文献   
73.
74.
目的:探讨福赛类杆菌与人类唾液富脯蛋白相互作用的蛋白分子。方法:Western—blot方法。将人工合成唾液富脯蛋白用生物素标记,福赛类杆菌全菌蛋白凝胶电泳,半干转移至纤维膜上,观察二者的相互作用。结果:富脯蛋白能与分子量为85KD、65KD、60KD、以及49KD的福赛类杆菌蛋白发生结合。结论:福赛类杆菌存在与人类唾液富脯蛋白相互结合的粘附素。  相似文献   
75.
76.
77.
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning.  相似文献   
78.
Neurons and related cell types often contain two major classes of neurosecretory vesicles, synaptic vesicles (SVs) and dense-core granules (DCGs), which store and release distinct cargo. SVs store and release classic neurotransmitters, which facilitate propagation of action potentials across the synaptic cleft, whereas DCGs transport, store, and release hormones, proteins, and neuropeptides, which facilitate neuronal survival, synaptic transmission, and learning. Over the past few years, there has been a major surge in our understanding of many of the key molecular mechanisms underlying cargo release from SVs and DCGs. This surge has been driven largely by the use of fluorescence microscopy (especially total internal reflection fluorescence microscopy) to visualize SVs or DCGs in living cells. This review highlights some of the recent insights into cargo release from neurosecretory vesicles provided by fluorescence microscopy, with emphasis on DCGs.  相似文献   
79.
Abstract Guillain-Barré syndrome (GBS) is a disease of the peripheral nervous system, which is caused by aberrant immune responses directed against some components of peripheral nerves. GBS is rarely accompanied by cardiovascular involvement. We describe a case of acute neuropathy complicated by sudden heart failure and left ventricular dysfunction which had a presumably neurogenic origin. Pathogenesis of acute heart failure is probably due to transitorial stunned myocardium and neurogenic cardiac injury. We show a rare case of transitorial and acute cardiac dysfunction by echocardiography and laboratory markers of heart failure.  相似文献   
80.
A 27-year-old man was admitted with high fever and shivers eleven days after returning from vacation in Indonesia. Physical examination, laboratory values, abdominal ultrasound, and chest x-ray were not conclusive. All blood cultures yielded growth of Salmonella enterica serovar Typhi, and typhoid fever was diagnosed. Subsequently, the patient developed septic shock and pulmonary edema.In this case report epidemiological, clinical, and therapeutic aspects of typhoid fever are discussed with special emphasis on criteria for severe typhoid fever, which is treated with additional glucocorticoids.  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