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   1283760篇
  免费   93381篇
  国内免费   2002篇
耳鼻咽喉   18399篇
儿科学   42497篇
妇产科学   38016篇
基础医学   187843篇
口腔科学   35556篇
临床医学   108932篇
内科学   252877篇
皮肤病学   26723篇
神经病学   99742篇
特种医学   50333篇
外国民族医学   366篇
外科学   198899篇
综合类   26656篇
现状与发展   1篇
一般理论   308篇
预防医学   93146篇
眼科学   29171篇
药学   98019篇
  1篇
中国医学   2496篇
肿瘤学   69162篇
  2018年   11896篇
  2015年   11704篇
  2014年   16118篇
  2013年   24551篇
  2012年   33789篇
  2011年   36204篇
  2010年   21364篇
  2009年   20155篇
  2008年   35211篇
  2007年   38228篇
  2006年   38791篇
  2005年   38093篇
  2004年   36621篇
  2003年   35665篇
  2002年   35198篇
  2001年   58296篇
  2000年   59820篇
  1999年   50889篇
  1998年   14297篇
  1997年   12874篇
  1996年   13145篇
  1995年   12416篇
  1994年   11815篇
  1993年   10931篇
  1992年   41180篇
  1991年   40558篇
  1990年   40070篇
  1989年   38914篇
  1988年   36263篇
  1987年   35519篇
  1986年   33894篇
  1985年   32306篇
  1984年   24058篇
  1983年   20915篇
  1982年   12452篇
  1981年   10996篇
  1980年   10270篇
  1979年   22753篇
  1978年   15964篇
  1977年   13792篇
  1976年   13039篇
  1975年   14264篇
  1974年   16762篇
  1973年   16202篇
  1972年   15393篇
  1971年   14311篇
  1970年   13310篇
  1969年   12815篇
  1968年   12047篇
  1967年   10551篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
BACKGROUND CONTEXT: Substantial variation exists regarding the use of sedation before interventional spine techniques. Patient preference should play an important role in decision making regarding the need for sedation. However, little is known about patients' anxiety levels before spinal injections and their perceptions about the necessity of sedation. PURPOSE: To determine patient perception for need for sedation before epidural steroid injections and zygapophyseal joint injections. STUDY DESIGN/SETTING: Survey of consecutive spinal injection patients in an outpatient spine center. PATIENT SAMPLE: 500 consecutive lumbar, thoracic, and cervical patients receiving spinal injections. OUTCOME MEASURES: A 12-item questionnaire assessing patients' perceived anxiety before to a spinal injection. METHODS: Subjects were given the questionnaire after their spinal injection. Percentages requesting sedation for a first and potential second procedure were assessed. Additionally, anxiety level and pain rating, location of injection, age, sex, and other medication use were analyzed to determine the effect on the request for sedation. RESULTS: 17% of patients questioned requested sedation before an injection, and 28% would request sedation if they were to have a second injection. CONCLUSIONS: Routine sedation before diagnostic and therapeutic injections is not necessary as the majority of patients would not request sedation before the procedure when given the option. However, in some patients sedation is indicated, and all patients would benefit from educational material on sedation before the injection.  相似文献   
52.
AIMS: To report clinical outcomes of a large series of cases with advanced thyroid cancer. STUDY DESIGN: Three hundred and eighty-five patients at the UICC stages III and IV were selected for the study with thyroid cancer. RESULTS: Papillary carcinoma and sclerosing carcinoma have better survival than the Hürthle cell and insular types. Lymphatic metastasis does not appear to worsen the prognosis. All the tumour forms offer the chance of long survival. CONCLUSIONS: Surgical treatment is the primary treatment of thyroid carcinoma. The combined treatments of surgery, metabolic beam therapy, suppressive hormone therapy, radiotherapy and chemotherapy cure a high percentage of patients with the tumour at an advanced stage.  相似文献   
53.
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   
54.
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   
55.
56.
57.
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   
58.
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   
59.
60.
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