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   120篇
  免费   13篇
  国内免费   1篇
儿科学   8篇
妇产科学   6篇
基础医学   16篇
临床医学   23篇
内科学   24篇
皮肤病学   1篇
神经病学   24篇
外科学   8篇
预防医学   8篇
药学   8篇
肿瘤学   8篇
  2021年   1篇
  2019年   1篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   2篇
  2012年   4篇
  2011年   10篇
  2010年   6篇
  2009年   4篇
  2008年   4篇
  2007年   7篇
  2006年   10篇
  2005年   15篇
  2004年   10篇
  2003年   11篇
  2002年   10篇
  2001年   9篇
  2000年   6篇
  1999年   5篇
  1998年   4篇
  1996年   1篇
  1995年   1篇
  1992年   3篇
  1991年   3篇
  1987年   1篇
排序方式: 共有134条查询结果,搜索用时 531 毫秒
1.
The levels of 2 arachidonic acid metabolites formed either by enzymatic activity of cyclooxygenase, i.e. prostaglandin E2 (PGE2), or by free radical-catalyzed peroxidation, i.e. F2-isoprostane 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha), were measured in the CSF of subjects with sporadic and familial Creutzfeldt-Jakob disease (CJD) and in brain homogenates of scrapie-infected mice. The CSF levels of both metabolites were increased in sporadic CJD (n = 52) and familial CJD (n = 10) patients when compared with a group of patients with noninflammatory disorders. Similarly, PGE2 and 8-epi-PGF2alpha levels were higher in brain homogenates obtained from C57BL/6J mice infected with the ME7 scrapie strain than in brain homogenates from control animals. As PGE2 is 1 of the most abundant prostaglandins released during inflammation and 8-epi-PGF2alpha is a quantitative marker of lipid peroxidation, our results provide in vivo biochemical evidence for the occurrence of inflammation and oxidative stress in human and experimental transmissible spongiform encephalopathies (TSEs), a concept so far based mainly on histopathological and in vitro evidence. Interestingly, in sporadic CJD patients, high CSF levels of PGE2, but not 8-epi-PGF2alpha, correlated with short survival time, suggesting that the inflammatory response correlates with the clinical duration of disease.  相似文献   
2.
Background : During embryonic development cell migration plays a principal role in several processes. In past decades, many studies were performed to investigate migrational events, occurring during embryonic organogenesis, neurogenesis, gliogenesis or myogenesis, just to name a few. Although different common techniques are already used for this purpose, one of their major limitations is the static character. However, cell migration is a sophisticated and highly dynamic process, wherefore new appropriate technologies are required to investigate this event in all its complexity. Results and Conclusions: Here we report a novel approach for dynamic analysis of cell migration within embryonic tissue. We combine the modern transfection method of in ovo electroporation with the use of tissue slice culture and state‐of‐the‐art imaging techniques, such as confocal laser scanning microscopy or spinning disc confocal microscopy, and thus, develop a method to study live the migration of myogenic precursors in chicken embryos. The conditions and parameters used in this study allow long‐term imaging for up to 24 hr. Our protocol can be easily adapted for investigations of a variety of other migrational events and provides a novel conception for dynamic analysis of migration during embryonic development. Developmental Dynamics 243:690–698, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   
3.
The role of age of acquisition (AoA) and other variables classically supposed to influence lexical semantic tasks is explored in Alzheimer's disease (AD) patients. A naming test that included living and nonliving items was given to patients and controls. Measures of AoA of the test items were obtained from normal subjects. Living items were acquired earlier than nonliving items. Semipartial correlation analyses were performed to determine the independent contribution of each variable to naming. The "category" (living vs. nonliving items) was included as an independent factor. It emerged that AoA, name agreement and category (with living category predicting lower scores) were the main predictors of naming in AD patients. Only factor agreement reached significance in control groups. The hypothesis is discussed that the category dissociation may be produced by the different nature of the semantic correlation network that makes the categories differentially demanding of processing resources.  相似文献   
4.
OBJECTIVES: Patients with Alzheimer's disease (AD) showing a selective impairment of episodic and semantic memory have recently been classified as affected by focal temporal lobe dysfunction (FTLD) and considered as a distinct subgroup of patients affected by a particular form of AD. The aim was to compare the cerebral perfusion of patients with AD with FTLD and patients with AD with the more typical profile of diffuse cognitive impairment (dAD). METHODS: Ten patients with AD with FTLD, 14 patients with AD with dAD, and 12 normal controls were studied. All the 24 patients with AD underwent a complete neuropsychological assessment. SPECT examination with [(99m)Tc]-HMPAO, using a four head brain dedicated tomograph, was performed in patients and controls. Tracer uptake was quantified in 27 regions of interest (ROIs), including lateral and mesial temporal areas. Mean counts in the 27 ROIs of controls, patients with FTLD and those with dAD were compared using an ANOVA for repeated measures with Bonferroni's correction. A logistic regression analysis, followed by a receiver operating characteristic (ROC) analysis, was also applied to select SPECT patterns which significantly differentiated patients with FTLD and those with dAD. RESULTS: Two scintigraphic patterns of abnormalities, shaping a double dissociation between the FTLD and dAD groups, emerged: a bilateral mesial temporal hypoperfusion, characteristic of FTLD and a posterior parietal (and temporal parietal) hypoperfusion characteristic of patients with dAD. CONCLUSIONS: These scintigraphic findings provide further support to the hypothesis that FTLD is not a mere stage but a distinct anatomoclinical form of AD. The combination of neuropsychological tests and [(99m)Tc]-HMPAO SPECT may be very useful in identifying patients with FTLD from the wider group of patients with dAD. This issue is particularly worthwhile, as there is increasing evidence that patients with FTLD have a slower rate of cognitive decline.  相似文献   
5.
Creutzfeldt-Jakob Disease (CJD) is a rare pathology (about 1 case per million) but it has a great importance for Public Health; the Italian National CJD register has been established in the Istituto Superiore di Sanita (ISS) since 1993, and epidemiological studies on CJD have been carried out as well. This paper reports a mortality study carried out comparing and integrating data from the two available sources: the National CJD Register and the Italian Data Base on Mortality, processed by the ISS Statistics Unit, on the data collected by the Italian Census Bureau (ISTAT). The study allowed to estimate: the underreporting of CJD mortality to both sources, the misclassification of ISTAT data and the integrated mortality rates from CJD in Italy: 1.58 per million persons aged 25 or more, average rate during the period 1993-1999.  相似文献   
6.
7.
8.
9.
The accuracy of measuring angulation of stable proximal humerus fractures using the axillary lateral projection was investigated. A closing wedge osteotomy with apex anterior angulation was performed on two cadaveric humeri to simulate a stable surgical neck fracture. One specimen was fixed at 30 degrees angulation and the other at 55 degrees. Axillary radiographs were taken with each specimen articulating with the glenoid of a cadaveric scapula. The humerus was held in neutral rotation. Abduction was set at 30 degrees, 60 degrees, and 90 degrees. In each position of abduction, an axillary lateral radiograph was taken in 30 degrees forward flexion, neutral, and 30 degrees extension to simulate various arm positions. A total of nine radiographs were taken for each specimen. The axillary view is not accurate for measurement of proximal humerus angulation at the arm positions commonly encountered in the trauma setting.  相似文献   
10.
Expression and prognostic significance in epithelial ovarian cancer   总被引:4,自引:0,他引:4  
BACKGROUND: Insulin-like growth factor binding protein-3 (IGFBP-3) is a glycoprotein with specific binding affinity to peptide hormones insulin-like growth factors (IGFs) which are potent mitogens for a variety of cells. IGFBP-3 can inhibit the activities of IGFs by interfering with the interaction between IGFs and their receptor IGF-IR. Epithelial ovarian cancer (EOC) tissues express IGFBP-3, IGFs and IGF-IR. Moreover, high levels of IGF-I and IGF-IR have been shown in epithelial ovarian cancer, and IGF-I stimulates the growth of ovarian cancer. METHODS: We measured IGFBP-3 levels in ovarian cancer tissues of 147 consecutive patients and we examined its association with clinical and pathological features of the disease and patient survival. The average age of the patients in the study was 55 years and the median follow-up time was 37 months. IGFBP-3 levels were measured in the tissue extracts by a commercial ELISA kit and non-parametric statistics and the Cox regression survival analysis were used to determine the associations of IGFBP-3 with clinical and pathologic variables as well as with patient survival. RESULTS: High IGFBP-3 levels resulted significantly associated with some of the favorable prognostic features of the disease, including early clinical stage (p=0.048), small size of residual tumor (p=0.007), and optimal debulking result (p=0.007). High IGFBP-3 was also associated with a significantly reduced risk for disease progression (RR=0.52, p=0.034) and we showed an inverse dose-dependent relationship between IGFBP-3 and disease progression-free survival (p=0.033). However, the association with disease progression-free survival was no longer statistically significant in a multivariate analysis. An association between IGFBP-3 and overall survival was not shown. CONCLUSIONS: This study suggest that IGFBP-3 may play a role in the progression of epithelial ovarian cancer.  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