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   2981904篇
  免费   232309篇
  国内免费   6266篇
耳鼻咽喉   43290篇
儿科学   92005篇
妇产科学   81367篇
基础医学   420080篇
口腔科学   84551篇
临床医学   267614篇
内科学   584645篇
皮肤病学   61892篇
神经病学   248521篇
特种医学   120092篇
外国民族医学   1129篇
外科学   453402篇
综合类   68832篇
现状与发展   2篇
一般理论   1181篇
预防医学   235864篇
眼科学   70405篇
药学   221919篇
  4篇
中国医学   5960篇
肿瘤学   157724篇
  2018年   31049篇
  2017年   24102篇
  2016年   26812篇
  2015年   30542篇
  2014年   43567篇
  2013年   65814篇
  2012年   88757篇
  2011年   93501篇
  2010年   55543篇
  2009年   53026篇
  2008年   88207篇
  2007年   93523篇
  2006年   94071篇
  2005年   91799篇
  2004年   88016篇
  2003年   84975篇
  2002年   83676篇
  2001年   135634篇
  2000年   139959篇
  1999年   118611篇
  1998年   34320篇
  1997年   31245篇
  1996年   30992篇
  1995年   29762篇
  1994年   27946篇
  1993年   26176篇
  1992年   95087篇
  1991年   91788篇
  1990年   88768篇
  1989年   85599篇
  1988年   79594篇
  1987年   78374篇
  1986年   74568篇
  1985年   71077篇
  1984年   53786篇
  1983年   45880篇
  1982年   28067篇
  1981年   24861篇
  1979年   50415篇
  1978年   35380篇
  1977年   29965篇
  1976年   28112篇
  1975年   29853篇
  1974年   36582篇
  1973年   34807篇
  1972年   32705篇
  1971年   30179篇
  1970年   28584篇
  1969年   26678篇
  1968年   24592篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The tongue: structure and function relevant to disease and oral health.   总被引:3,自引:0,他引:3  
D F du Toit 《SADJ》2003,58(9):375-6, 380-3
The tongue (L. lingua; G. glossa) functions as a digestive organ by facilitating the movement of food during mastication and assisting swallowing. Other important functions include speech and taste. The tongue consists of striated muscle and occupies the floor of the mouth. The dorsal mucosal surface consists of stratified squamous epithelium, with numerous papillae and taste buds. The tongue, a voluntary muscular structure, is attached by a fold, called the frenulum, to the floor of the mouth. Typically, between 8 and 12 circumvallate papillae are arranged in an inverted V-shape towards the base of the tongue. This anatomical review focuses on structure, function relationships and diseases affecting the tongue. From a primary oral health care perspective, this overview will facilitate the process of differential diagnosis in persons presenting with vesiculo-bullous, ulcerative, atrophic and cystic disorders of the tongue. Suspicious lesions should be biopsied to rule out carcinoma.  相似文献   
82.
Bifid mandibular canal.   总被引:1,自引:0,他引:1  
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women.  相似文献   
83.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed.  相似文献   
84.
85.
86.
87.
88.
89.
We evaluated the acquisition and performance of a high-precision locomotor task in patients with Parkinson's disease (PD) and healthy subjects. All subjects walked on a treadmill and had to step repetitively as low as possible over an obstacle without touching it. During blocks 1 and 2, the subjects had full vision and received additional acoustic warning and feedback signals. During block 3, vision became restricted. Changes in foot clearance and the number of obstacle hits were evaluated. Initially, PD patients performed poorer and improved foot clearance slower. After task repetition, the groups performed similarly. Restricting vision deteriorated performance in both groups. The similar performance of PD patients after task repetition might indicate that adequate training could improve adaptive locomotor behavior in PD patients.  相似文献   
90.
Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use.  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