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   563篇
  免费   27篇
  国内免费   7篇
儿科学   10篇
妇产科学   5篇
基础医学   108篇
口腔科学   8篇
临床医学   63篇
内科学   115篇
皮肤病学   10篇
神经病学   22篇
特种医学   157篇
外科学   28篇
综合类   4篇
预防医学   25篇
眼科学   2篇
药学   19篇
中国医学   1篇
肿瘤学   20篇
  2023年   3篇
  2022年   8篇
  2021年   8篇
  2020年   8篇
  2019年   6篇
  2018年   10篇
  2017年   7篇
  2016年   7篇
  2015年   5篇
  2014年   6篇
  2013年   16篇
  2012年   11篇
  2011年   19篇
  2010年   15篇
  2009年   14篇
  2008年   12篇
  2007年   17篇
  2006年   21篇
  2005年   19篇
  2004年   11篇
  2003年   12篇
  2002年   9篇
  2001年   11篇
  2000年   7篇
  1999年   12篇
  1998年   16篇
  1997年   23篇
  1996年   23篇
  1995年   16篇
  1994年   23篇
  1993年   14篇
  1992年   6篇
  1991年   15篇
  1990年   6篇
  1989年   27篇
  1988年   22篇
  1987年   14篇
  1986年   24篇
  1985年   16篇
  1984年   15篇
  1983年   5篇
  1982年   13篇
  1981年   6篇
  1980年   6篇
  1979年   2篇
  1978年   5篇
  1977年   10篇
  1976年   6篇
  1975年   6篇
  1935年   1篇
排序方式: 共有597条查询结果,搜索用时 15 毫秒
1.
Proximal femoral focal deficiency, an uncommon congenital anomaly, necessitates early radiologic classification for surgical planning and treatment. Objective radiographic criteria, including femoral length index, acetabular depth index, acetabular angle index, and shape of the proximal femur were determined in 49 patients before cartilaginous ossification of the femoral capital epiphysis; final classification was based on follow-up radiographs or findings at arthrography or surgery. These parameters were analyzed to determine the accuracy and contributions of each in classification. Correct classification into one of three groups was possible in 86% of cases with use of three of the parameters: femoral length index, acetabular depth index, and shape of the proximal femur. The acetabular angle was found to contribute insignificantly to classification. Magnetic resonance imaging, used in only one case, depicted the nonossified cartilaginous femoral capital epiphysis, thus obviating the need for invasive diagnostic procedures and facilitating early classification.  相似文献   
2.
3.
4.
5.
The role of the complement system in innate immunity   总被引:4,自引:0,他引:4  
Complement is a major component of innate immune system involved in defending against all the foreign pathogens through complement fragments that participate in opsonization, chemotaxis, and activation of leukocytes and through cytolysis by C5b-9 membrane attack complex. Bacterias and viruses have adapted in various ways to escape the complement activation, and they take advantage of the complement system by using the host complement receptors to infect various cells. Complement activation also participates in clearance of apoptotic cells and immune, complexes. Moreover at sublytic dose, C5b-9 was shown to promote cell survival. Recently it was also recognized that complement plays a key role in adaptive immunity by modulating and modifying the T cell responses. All these data suggest that complement activation constitutes a critical link between the innate and acquired immune responses.  相似文献   
6.
The role of complement activation in atherosclerosis   总被引:6,自引:0,他引:6  
Atherosclerosis is a chronic inflammatory disease in which dyslipidemia, inflammation, and the immune system play an important pathogenetic role. A role in atherogenesis was demonstrated for monocyte/macrophages, complement system, and T-lymphocytes. Complement activation and C5b-9 deposition occurs both in human and experimental atherosclerosis. Complement C6 deficiency has a protective effect on diet-induced atherosclerosis, indicating that C5b-9 assembly is required for the progression of atherosclerotic lesions. The maturation of atherosclerotic lesions beyond the foam cell stage was shown to be strongly dependent on an intact complement system. C5b-9 may be responsible for cell lysis, and sublytic assembly of C5b-9 induces smooth muscle cell (SMC) and endothelial cell (EC) activation and proliferation. All these data suggest that activation of the complement system plays an important role in atherogenesis.  相似文献   
7.
8.
Life expectancy in British Marfan syndrome populations   总被引:2,自引:0,他引:2  
A total of 206 patients with Marfan syndrome were ascertained throughout genetic clinics in Wales and Scotland during the period 1970–1990. There were 45 deaths representing 22% of the cohort. Mean age at death was 45.3 ± 16.5 years. 50% median cumulative survival in the total cohort (n = 206) was 53 years for males and 72 years for females. Multivariate analysis confirmed severity as the best independent indicator of survival. These findings and survival curves will assist in the counselling of British families and individuals with Marfan syndrome.  相似文献   
9.
ABSTRACT

Early detection of apoptotic cells on histological slides is of major importance for both diagnostic and research areas. In the current study, the aim was to propose a convenient method to stain the mitochondria and establish whether hepatocytes undergoing apoptosis can be identified in tissue sections using the proposed method. Liver tissue from five adult chinchillas was fixed with 10% neutral buffered formalin for Goldner’s trichrome (GT) and Groat’s iron hematoxylin and eosin (HE) stains and with Kolster’s fixative for the Heidenhain’s iron hematoxylin procedure. The HE and GT-stained sections showed the morphological features consistent with apoptosis i.e., homogenous intensely acidophilic cytoplasm, cell shrinkage with an irregular outline, nuclear shrinkage with cloudy karyoplasm, and karyopyknosis in the late stage. Sections stained with Heidenhain’s iron hematoxylin method was used to pinpoint mitochondria and revealed cells which were undergoing the first stages of the apoptosis process i.e., disappearance of mitochondria from the cell, chromatin condensation and margination, paracentral localization of nucleoli, and vacuolated nuclei. In more advanced stages of apoptosis, cells presented significant nuclear and cytoplasmic changes. It was concluded that this is the first report targeting the mitochondria, by performing inexpensive histological staining techniques, in order to assess dead cells in situ.  相似文献   
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