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   1305822篇
  免费   95055篇
  国内免费   2403篇
耳鼻咽喉   18465篇
儿科学   43112篇
妇产科学   38295篇
基础医学   191195篇
口腔科学   35845篇
临床医学   110890篇
内科学   257543篇
皮肤病学   27142篇
神经病学   101377篇
特种医学   51104篇
外国民族医学   379篇
外科学   201201篇
综合类   27770篇
现状与发展   2篇
一般理论   302篇
预防医学   94971篇
眼科学   29646篇
药学   99951篇
  7篇
中国医学   3103篇
肿瘤学   70980篇
  2018年   12727篇
  2016年   10697篇
  2015年   12437篇
  2014年   17046篇
  2013年   25703篇
  2012年   35464篇
  2011年   37892篇
  2010年   22418篇
  2009年   21029篇
  2008年   36382篇
  2007年   39386篇
  2006年   39897篇
  2005年   39091篇
  2004年   37511篇
  2003年   36473篇
  2002年   35926篇
  2001年   58941篇
  2000年   60409篇
  1999年   51459篇
  1998年   14542篇
  1997年   13066篇
  1996年   13283篇
  1995年   12526篇
  1994年   11933篇
  1993年   11007篇
  1992年   41388篇
  1991年   40745篇
  1990年   40241篇
  1989年   39044篇
  1988年   36459篇
  1987年   35624篇
  1986年   34020篇
  1985年   32410篇
  1984年   24116篇
  1983年   20959篇
  1982年   12464篇
  1981年   11001篇
  1979年   22790篇
  1978年   15971篇
  1977年   13812篇
  1976年   13049篇
  1975年   14278篇
  1974年   16791篇
  1973年   16153篇
  1972年   15416篇
  1971年   14292篇
  1970年   13291篇
  1969年   12803篇
  1968年   12054篇
  1967年   10547篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The new treatment strategy for Peritoneal Surface Malignancy combines a cytoreductive surgery and perioperative intraperitoneal chemotherapy. Cytoreduction removes all macroscopic tumor. Intraperitoneal chemotherapy avoids implantation of microscopic residual tumor cells on intra-abdominal surfaces when it is administered intraoperatively and/or early in the postoperative period. Delivering cytotoxic drugs directly into the peritoneal cavity maximizes dose intensity and minimizes systemic toxicity. Hyperthermia is selectively cytotoxic for malignant cells and potentiates the effect of chemotherapy. Implementation of this procedure makes the perioperative personnel to face a risk of exposure to cytotoxic agents. Furthermore, peritonectomies and electro-evaporation of tumor nodules are performed with high voltage electrocautery, generating a large amount of surgical smoke during several hours. Inhalation of these fumes may be also a risk for healthcare workers. In this article, we analyse in depth these new risks of the operating room personnel, we review the literature, and we give guidelines for secure performance of cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy, as well as for early postoperative intraperitoneal chemotherapy administration. These new procedures are safe techniques for patients and healthcare workers provided adequate policies are adopted to avoid occupational exposure.  相似文献   
82.
灾难的时代错误:灾害医学的过去、现在和将来(一)   总被引:1,自引:0,他引:1  
灾难,特别是地震、火山、洪水以及与战争有关的事件如饥饿和流行性传染病,是人类有记录的经历的一部分。从意大利庞贝的火山爆发,到约翰斯顿的洪水、第二次世界大战和黑色瘟疫,到西班牙流感,都发生了灾难,这不会被传说和历史书籍长期忘却。不过,在20世纪中叶以前,那些灾难的发生相对较少,且相距时间较长。从20世纪中叶以来,灾难的本质发生了变化。从恐怖分子使用“新技术”,到与气候有关的导致亿万美元经济损失的事件,表明这个世界正在发生变化。仅仅在最近的50~60年间,造成多种多样的伤亡事件,其危险性和频率的增加引人注目,并且注定要在接…  相似文献   
83.
84.
The age association and alterations in vascular structure and function at both the cellular and molecular levels are increasingly recognized as major risk factors for CV disease. The arterial remodeling during aging that may be enhanced by the CV risk factors are supersensitive to the age-related risk factors. The aging process may well be influenced by a combination of hereditary and environmental factors. Much can be done to modify environmental risk factors, very little to genetics except for choosing your parents.  相似文献   
85.
86.
Abstract Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region. A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the elderly, as early diagnosis leads to effective treatment and prevention of complications.  相似文献   
87.
OBJECTIVE: This study aimed to describe the use of the P300 event-related potential as a control signal in a brain computer interface (BCI) for healthy and paralysed participants. METHODS: The experimental device used the P300 wave to control the movement of an object on a graphical interface. Visual stimuli, consisting of four arrows (up, right, down, left) were randomly presented in peripheral positions on the screen. Participants were instructed to recognize only the arrow indicating a specific direction for an object to move. P300 epochs, synchronized with the stimulus, were analyzed on-line via Independent Component Analysis (ICA) with subsequent feature extraction and classification by using a neural network. RESULTS: We tested the reliability and the performance of the system in real-time. The system needed a short training period to allow task completion and reached good performance. Nonetheless, severely impaired patients had lower performance than healthy participants. CONCLUSIONS: The proposed system is effective for use with healthy participants, whereas further research is needed before it can be used with locked-in syndrome patients. SIGNIFICANCE: The P300-based BCI described can reliably control, in 'real time', the motion of a cursor on a graphical interface, and no time-consuming training is needed in order to test possible applications for motor-impaired patients.  相似文献   
88.
89.
90.
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