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   25013篇
  免费   1601篇
  国内免费   500篇
耳鼻咽喉   131篇
儿科学   509篇
妇产科学   750篇
基础医学   1593篇
口腔科学   505篇
临床医学   2642篇
内科学   3492篇
皮肤病学   235篇
神经病学   845篇
特种医学   738篇
外科学   2348篇
综合类   3599篇
一般理论   10篇
预防医学   4099篇
眼科学   336篇
药学   2759篇
  61篇
中国医学   1986篇
肿瘤学   476篇
  2024年   129篇
  2023年   456篇
  2022年   882篇
  2021年   1116篇
  2020年   1076篇
  2019年   1295篇
  2018年   1206篇
  2017年   1001篇
  2016年   849篇
  2015年   809篇
  2014年   1592篇
  2013年   1900篇
  2012年   1471篇
  2011年   1480篇
  2010年   1095篇
  2009年   965篇
  2008年   984篇
  2007年   861篇
  2006年   749篇
  2005年   555篇
  2004年   418篇
  2003年   376篇
  2002年   266篇
  2001年   245篇
  2000年   213篇
  1999年   147篇
  1998年   111篇
  1997年   107篇
  1996年   105篇
  1995年   90篇
  1994年   77篇
  1993年   62篇
  1992年   58篇
  1991年   44篇
  1990年   33篇
  1988年   35篇
  1987年   32篇
  1985年   291篇
  1984年   488篇
  1983年   406篇
  1982年   406篇
  1981年   342篇
  1980年   319篇
  1979年   391篇
  1978年   284篇
  1977年   195篇
  1976年   284篇
  1975年   249篇
  1974年   256篇
  1973年   245篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
多媒体技术在护理心理学教学中的作用   总被引:2,自引:1,他引:1  
阐述了在护理心理学教学中应用多媒体技术进行教学的作用。  相似文献   
52.
OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.  相似文献   
53.
54.
55.
刘瑾  杨青  王绵珍  兰亚佳 《现代预防医学》2003,30(5):689-693,696
基质金属蛋白酶(matrix metalloproteinases,MMPs)是一组锌离子依赖的蛋白水解酶,在ECM降解中起着重要作用。目前研究表明,MMPs活性异常不仅能促进肿瘤血管形成,还是人类多种肿瘤侵袭和转移的必要条件。本文就与肺癌侵袭和转移有关的MMPs研究作一综述。  相似文献   
56.
BACKGROUND: The availability of recombinant allergens and recent advances in biochip technology led to the development of a novel test system for the detection of allergen-specific IgE. OBJECTIVE: To test the performance of this allergen microarray in a serological analytical study. METHODS: Standard allergens contained in grass pollen (Phl p 1, Phl p 2, Phl p 5 and Phl p 6) and tree pollen (Bet v 1 and Bet v 2) were used as a model system. The detection of allergen-specific serum IgE using microarrays was compared with standard test systems: CAP/RAST and an in-house ELISA. In order to test the analytical sensitivity of the assays, geometric dilutions of a serum pool containing high levels of pollen-specific IgE from allergic individuals were tested in each system. To assess the analytical specificity, the sera of 51 patients with presumptive allergic symptoms were collected before diagnosis. Thereafter, the results for grass/tree-pollen-specific IgE were compared. RESULTS: The microarray has a good dynamic range similar to the CAP/RAST system. Microarray and ELISA showed comparable analytical sensitivity exceeding the CAP/RAST system. With respect to the analytical specificity, no significant cross-reactivity of the allergens was observed. For two of the allergens tested, weak positive signals were detected in the microarray test system, whereas they were not detectable by CAP/RAST. CONCLUSION: A good correlation of presently used methods to detect serum IgE and the novel microarray test system was observed. As a next step, a careful validation of this method for a multitude of allergens and a thorough clinical evaluation has to be provided. Microarray testing of allergen-specific IgE can be presumed to be the method of choice for a prospective component-resolved diagnosis of Type I allergy, and the basis for the design and monitoring of a patient-tailored specific immunotherapy in the future.  相似文献   
57.
可视化技术及其在抗击SARS中的应用   总被引:1,自引:0,他引:1  
本文主要介绍了可视化技术,其中重点阐述了科学计算可视化、信息可视化和地学可视化,最后总结了可视化技术在这次抗击非典型肺炎中所起到的重要作用.  相似文献   
58.
This paper reports an attempt to develop self-directed learning skills in second-year medical students by introducing case-based projects into the gross anatomy course at a long-established medical school. The programme and students' responses to a questionnaire completed at the end of the year are presented. Information on the various resources used by students to find information is given. The performance of students in the case-based components of the course has been evaluated and also in the more traditional end-of-year written examination. The data confirm that students have recognized that the projects were about obtaining a deeper understanding of the anatomy, and the programme appears to have promoted the use and study of library texts.  相似文献   
59.
Clinical Evaluation of a New Type of Centrifugal Pump   总被引:2,自引:0,他引:2  
Abstract: The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump group, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass.  相似文献   
60.
This article reviews a focused helical appendiceal computed tomographic technique and discusses an approach to appendiceal computed tomographic interpretation.  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