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   901篇
  免费   55篇
  国内免费   6篇
耳鼻咽喉   6篇
儿科学   60篇
妇产科学   25篇
基础医学   118篇
口腔科学   9篇
临床医学   68篇
内科学   184篇
皮肤病学   11篇
神经病学   55篇
特种医学   22篇
外科学   181篇
综合类   19篇
一般理论   2篇
预防医学   67篇
眼科学   3篇
药学   40篇
中国医学   3篇
肿瘤学   89篇
  2023年   3篇
  2022年   26篇
  2021年   43篇
  2020年   19篇
  2019年   43篇
  2018年   38篇
  2017年   20篇
  2016年   20篇
  2015年   22篇
  2014年   36篇
  2013年   43篇
  2012年   46篇
  2011年   68篇
  2010年   40篇
  2009年   31篇
  2008年   55篇
  2007年   48篇
  2006年   59篇
  2005年   64篇
  2004年   42篇
  2003年   25篇
  2002年   29篇
  2001年   20篇
  2000年   22篇
  1999年   12篇
  1998年   5篇
  1997年   8篇
  1996年   5篇
  1995年   4篇
  1993年   4篇
  1992年   10篇
  1991年   4篇
  1990年   7篇
  1989年   3篇
  1988年   2篇
  1986年   2篇
  1985年   3篇
  1984年   5篇
  1983年   2篇
  1981年   3篇
  1979年   2篇
  1978年   3篇
  1975年   2篇
  1974年   2篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有962条查询结果,搜索用时 15 毫秒
1.
Controversy persists regarding whether the efficacy of closed instrumental mitral commissurotomy compares well enough with that of open commissurotomy to warrant its continued use. The purpose of this study was to compare the results of operation as determined by catheterization studies in 63 patients with pure, severe, and noncalcified mitral stenosis. The patients were randomly assigned to one of two groups: thirty-two patients were operated on by the closed technique (group I) and 31 by the open technique (group II). All patients underwent left-sided and right-sided catheterization before and 4 months after operation. Preoperatively the two groups were statistically similar with regard to major clinical data and hemodynamic findings. There were no deaths at operation or systemic embolism in the two groups. The prevalence of surgically induced mitral regurgitation was similar in the two groups (12.4% versus 12.9%). Pulmonary arterial pressure and arteriolar and total pulmonary vascular resistance decreased significantly in the two groups. Pulmonary capillary wedge pressure decreased from 23.3 +/- 8.5 to 15.8 +/- 7 mm Hg in group I (p less than 0.001) and from 23.7 +/- 6 to 14 +/- 5.8 mm Hg in group II (p less than 0.001). Cardiac index increased from 2.86 +/- 0.84 to 3.14 +/- 0.78 L/min/m2 in group I, but this increase did not reach statistical significance. In group II cardiac index increased from 2.89 +/- 0.6 to 3.6 +/- 0.6 L/min/m2 (p less than 0.005). The mean and end-diastolic transmitral pressure gradients decreased significantly in the two groups, but the decrease was statistically greater in the open mitral commissurotomy group (p less than 0.001). Mitral valve area increased from 0.82 +/- 0.18 to 1.4 +/- 0.40 cm2 in group I (p less than 0.01) and from 0.84 +/- 0.15 to 2.14 +/- 0.53 cm2 in group II (p less than 0.001). The mean increase in mitral valve area was 0.61 cm2 in group I and 1.34 cm2 in group II (p less than 0.001). At exercise, in patients with resting pulmonary capillary wedge pressures of 18 mm Hg or less, cardiac index increased by 36% in group I (23 patients) and 48% in group II (24 patients), because of a smaller mitral valve area in group I (1.61 +/- 0.39 cm2) than in group II (2.45 +/- 0.65 cm2). Thus open commissurotomy improved hemodynamic values to a greater extent than closed commissurotomy at both rest and exercise.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
2.
A wide variety of health care options--home-based, indigenous, and cosmopolitan--exists in northern Balochistan, Pakistan. This paper examines health-seeking behavior in the area of mother and child health for villagers in this pluralistic medical setting. The analysis of a specific series of illness episodes shows that the majority of cases obtain treatment from different medical systems for a single episode. Interest in medications takes precedence over practitioners, and the meaning the villagers attach to such substances is explored. Long-established patterns of behavior relating to indigenous medicine continue to occur when cosmopolitan medicine is utilized. Information presented here helps to explain problems in utilization of cosmopolitan pharmaceuticals and delineates areas for future health programme activity.  相似文献   
3.
The immunogenicity of recombinant protein or anti-viral DNA vaccines can be significantly improved by the addition of tandem copies of the complement fragment C3d. We sought to determine if the efficacy of a circumsporozoite protein (CSP)-based DNA vaccine delivered to mouse skin by gene gun was improved by using this strategy. Instead, we found that C3d suppressed the protective immunity against Plasmodium berghei malaria infection and deviated immunity, most notably by suppressing the induction of antibodies specific for the CSP C-terminal flanking sequence and by suppressing the induction of CSP-specific IL-4-producing spleen cells. We further showed that C3d bound to the C-terminal flanking sequence of the CSP, which may explain the immune deviation observed in CS/C3d chimeric antigen. We have thus identified C3d-mediated epitope masking and shifting of both the humoral and cellular immune responses as a potential novel escape mechanism, which plasmodia may use to divert the induction of protective immunity.  相似文献   
4.
The pathogenesis of diffuse connective tissue diseases (DCTD) is still unknown and has been extensively studied regarding its autoimmunity aspects related to extracellular matrix (ECM) remodelling, with an emphasis on the collagens at the inflammatory site. The present paper describes the pulmonary architectural and repair/remodelling responses to injury after immunization of rabbits with human type V collagen. The animal model consisted of rabbits immunized with collagen mixed with Freund's adjuvant and sacrificed 7, 15, 30, 75, and 120 days after the first of four doses of antigen. Pulmonary architecture remodelling response was evaluated by histology, morphometry, and the immunofluorescence method, according to compartments of reference (parenchyma and interstitium) and injury: 1 inflammation (polymorphonuclear and mononuclear cells); 2-repair (fibrosis) and 3-ECM remodelling (collagen system). The results showed an intense inflammatory involvement of the pulmonary vascular and bronchiolar parenchyma, characterized by increased wall thickness in small arteries, infiltrations by pseudoeosinophils, and mononuclear cells. Progressive remodelling of the pulmonary ECM was characterized by collagen deposition in the septal and bronchovascular interstitium, especially in rabbits sacrifices at 75 and 120 days. The ECM remodelling process was not reproduced when rabbits were inoculated with collagen types I and III. We conclude that the model reproduces morphologic changes similar to those observed in many DCTD, encouraging realization of other experiments to gain a better understanding of the pathogenesis of these diseases.  相似文献   
5.
6.
7.
The opening in the intra hepatic bile ducts is the most common complication of hepatic hydatid cyst. The opening in the gallbladder is unusual.We report the case of a 65-year-old woman with complaints of right upper quadrant pain and fever. Various explorations have found a hydatid acute cholecystitis due to an opening of a hydatid cyst of the liver in the gallbladder. Treatment was surgical.  相似文献   
8.
9.
10.
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