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   141294篇
  免费   9954篇
  国内免费   245篇
耳鼻咽喉   1343篇
儿科学   3990篇
妇产科学   2966篇
基础医学   21938篇
口腔科学   3839篇
临床医学   11853篇
内科学   28160篇
皮肤病学   2431篇
神经病学   13935篇
特种医学   5782篇
外国民族医学   20篇
外科学   18182篇
综合类   626篇
现状与发展   1篇
一般理论   145篇
预防医学   15541篇
眼科学   2300篇
药学   8495篇
中国医学   278篇
肿瘤学   9668篇
  2023年   589篇
  2022年   1000篇
  2021年   2118篇
  2020年   1543篇
  2019年   2246篇
  2018年   2808篇
  2017年   2383篇
  2016年   2633篇
  2015年   2920篇
  2014年   3985篇
  2013年   5239篇
  2012年   8018篇
  2011年   8093篇
  2010年   4237篇
  2009年   4413篇
  2008年   7222篇
  2007年   7479篇
  2006年   7185篇
  2005年   6826篇
  2004年   5885篇
  2003年   5616篇
  2002年   5052篇
  2001年   4962篇
  2000年   4928篇
  1999年   4439篇
  1998年   1798篇
  1997年   1497篇
  1996年   1563篇
  1995年   1273篇
  1994年   1195篇
  1993年   1104篇
  1992年   3073篇
  1991年   2809篇
  1990年   2676篇
  1989年   2498篇
  1988年   2311篇
  1987年   2028篇
  1986年   1947篇
  1985年   1854篇
  1984年   1298篇
  1983年   1129篇
  1982年   610篇
  1981年   544篇
  1980年   471篇
  1979年   984篇
  1978年   599篇
  1977年   519篇
  1974年   511篇
  1973年   505篇
  1972年   505篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A review of the literature shows a growing interest in non-auditory effects of noise at work. Somatic, vestibular and psychological effects and different kinds of activity interferences are described. Suggestive evidence of an elevation of the blood pressure by noise exists, although the quality of the studies is limited. Many non-auditory effects can be described in a stress model. Annoyance and stress, however, were seldom the subject of field studies.  相似文献   
82.
83.
84.
85.
86.
This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disease staging), psychology (stages of cognitive development), human development (pubertal stages) and chronic diseases (stages of dementia). Transition probabilities between successive stages are modeled as smoothly varying functions of age. Age‐conditional references are calculated from the modeled probabilities by the mid‐P value. It is possible to eliminate the influence of age by calculating standard deviation scores (SDS). The method is applied to the empirical data to produce reference charts on secondary sexual maturation. The mean of the empirical SDS in the reference population is close to zero, whereas the variance depends on age. The stage line diagram provides quick insight into both status (in SDS) and tempo (in SDS/year) of development of an individual child. Other measures (e.g. height SDS, body mass index SDS) from the same child can be added to the chart. Diagrams for sexual maturation are available as a web application at http://vps.stefvanbuuren.nl/puberty . The stage line diagram expresses status and tempo of discrete changes on a continuous scale. Wider application of these measures scores opens up new analytic possibilities. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
87.
Introduction Choroid plexus cysts can lead to isolation of the lateral ventricles and distension of the third ventricle. We present an ultrasonographic video documentation of an infant with variably shaped and localized choroid plexus cyst of the third ventricle. Case report An infant had periods of increased intracranial pressure with changing dilatation of the first to third ventricle. Cerebral ultrasonography of the not crying boy demonstrated a choroid plexus cyst limply hanging down from the roof of the third ventricle to the beginning of the aqueduct of Sylvius. During crying, the cyst prolapsed from the third into left lateral ventricle and was strangled by the foramen of Monro. Endoscopic cyst fenestration and third ventriculostomy continuously solved the problem of intermittent hydrocephalus occlusus. Conclusion Depending not only on localization and size but also on cyst form and cerebrospinal fluid pressure, a single choroid plexus cyst can cause various obstructions of cerebrospinal fluid pathways.  相似文献   
88.
89.
90.
OBJECTIVE: The purpose of this study was to evaluate the potential benefit of an ultrasonic device in apical surgery on the outcome of treatment. STUDY DESIGN: A randomized prospective design was used in a standardized treatment protocol. Patients were allocated to treatment with an ultrasonic device (P-Max Newtron) or treatment with a bur in an otherwise similar protocol. One year after treatment the results were evaluated by 2 oral and maxillofacial surgeons who were blinded for the therapy. RESULTS: Out of a total group of 399 patients who were included in the study, adequate follow-up could be obtained in 290 patients. The overall success rate in the ultrasonic group was 80.5% and in the group treated with a bur 70.9% (P = .056). In molars, the difference in success rate was significant (P = .02). CONCLUSION: The use of an ultrasonic device in apical surgery improved the outcome of treatment. In molars this effect was significant.  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