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21.
Alzheimer’s disease (AD) is a neurodegenerative disease, characterized histopathologically by intra-neuronal tau-related lesions and by the accumulation of amyloid β-peptide (Aβ) in the brain parenchyma and around cerebral blood vessels. According to the vascular hypothesis of AD, an alteration in the neurovascular unit (NVU) could lead to Aβ vascular accumulation and promote neuronal dysfunction, accelerating neurodegeneration and dementia. To date, the effects of insoluble vascular Aβ deposits on the NVU and the blood–brain barrier (BBB) are unknown. In this study, we analyze different Aβ species and their association with the cells that make up the NVU. We evaluated post-mortem AD brain tissue. Multiple immunofluorescence assays were performed against different species of Aβ and the main elements that constitute the NVU. Our results showed that there are insoluble vascular deposits of both full-length and truncated Aβ species. Besides, insoluble aggregates are associated with a decrease in the phenotype of the cellular components that constitute the NVU and with BBB disruption. This approach could help identify new therapeutic targets against key molecules and receptors in the NVU that can prevent the accumulation of vascular fibrillar Aβ in AD.  相似文献   
22.
The effect of bottom clearance on power draw for anchors is investigated. The results suggest that power input decreases as the bottom clearance ratio b/D increases. A new correlation is proposed in which both bottom and wall clearance effects on power input are considered. The dependence of power input on these effects is additive rather than multiplicative. Thus, the total power consumption is the sum of the power inputs generated by the wall and bottom clearance. Power results from 3D-CFD numerical simulations are also presented. These results confirm fairly well the experimental points.  相似文献   
23.
主要对工业化连续生产对烷的影响因素进行了研究,探讨了原料中重组分含量、反应温度、反应压力等不同条件对对烷的生成所产生的影响。通过试验确定了主要生产工艺参数为:原料中重组分含量不超过1.2%,反应温度185-200℃,反应压力9-11 MPa。  相似文献   
24.
Polycrystalline (pCVD) and single crystal (scCVD) diamond films grown from Chemical Vapour Deposition (CVD), if sufficiently pure at Raman analysis, are very good materials for beam or flux monitors inside accelerators or nuclear reactors. This is because they are very hard to damage in high radiation fields and very resistant to high temperatures. Films of pCVD diamond are, however, not so good as spectroscopy detectors due to inhomogeneities induced by their growth in grains with the consequent presence of grain boundaries which worsen their energy resolution. The latter can be significantly improved by growing scCVD diamond films onto HPHT synthetic diamond substrates. We have shown that it is possible to measure the density of defects inside diamond specimens using as probes suitable penetrating nuclear radiations. With the preliminary results reported here we'll show that, bombarding CVD diamond films grown at Roma “Tor Vergata” with energetic protons and 4He, 6Li and 12C ions produced in the accelerators of Catania laboratories, the pulse height defects are higher than those in silicon detectors and likewise well described by a power law in the deposited energy. Furthermore, we'll show that pulse heights for the same particles seem to depend on the duration of the measurement, thus exhibiting a sort of depolarization of the insulator when exposed to the electric voltage which makes it a particle detector.  相似文献   
25.
The use of natural organic fillers in addition to postconsumer recycled polymers is getting a growing interest during the last years; this is due to many advantages they can provide in terms of cost, aesthetic properties, environmental impact. In this work, several types of wood flour (differing each other with regard to production source and particle size) were added to a recycled polyethylene coming from films for greenhouses and the effects of filler type, content, and size were investigated. Investigation was then focused on the improvement of mechanical properties, through the addition of polar copolymers (ethylene‐co‐acrylic acid, ethylene‐vinyl acetate) and a maleic anhydride‐grafted‐grafted polyethylene (Licocene® PE MA 4351 TP), in order to try to overcome the poor adhesion between polar filler particles and nonpolar polymer chains. Investigation was also based on SEM micrographs. An overall positive influence of these additives was observed. Polym. Eng. Sci. 46:1131–1139, 2006. © 2006 Society of Plastics Engineers.  相似文献   
26.
党的十六大报告中明确了教育在现代化建设中的作用和地位 :“教育是发展科学技术和培养人才的基础 ,在现代化建设中具有先导性全局性作用 ,必须摆在优先发展的战略地位”。同时指出教育的功能是 :“全面贯彻党的教育方针 ,坚持教育为社会主义现代化建设服务 ,为人民服务 ,与生产劳动和社会实践相结合 ,培养德、智、体、美、劳全面发展的社会主义建设者和接班人”。十六大提出了一个新的教育理念 ,这就是教育为人民服务。1 “教育为人民服务”是“三个代表”重要思想在教育观念上的具体体现“为人民服务”是毛泽东同志在 1 944年为纪念一个…  相似文献   
27.
师范生的培养效果如何关乎到未来教师的教学能力,本文通过对当前我国师范生培养现状的分析,探讨如何应用数字化微格教学系统培养师范生的教学能力。  相似文献   
28.
Biclustering numerical data became a popular data-mining task at the beginning of 2000’s, especially for gene expression data analysis and recommender systems. A bicluster reflects a strong association between a subset of objects and a subset of attributes in a numerical object/attribute data-table. So-called biclusters of similar values can be thought as maximal sub-tables with close values. Only few methods address a complete, correct and non-redundant enumeration of such patterns, a well-known intractable problem, while no formal framework exists. We introduce important links between biclustering and Formal Concept Analysis (FCA). Indeed, FCA is known to be, among others, a methodology for biclustering binary data. Handling numerical data is not direct, and we argue that Triadic Concept Analysis (TCA), the extension of FCA to ternary relations, provides a powerful mathematical and algorithmic framework for biclustering numerical data. We discuss hence both theoretical and computational aspects on biclustering numerical data with triadic concept analysis. These results also scale to n-dimensional numerical datasets.  相似文献   
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30.
ABSTRACT

Polyelectrolyte complex (PEC) of chitosan (Chi) and poly (acrylic acid) (PAA)-modified iron sand leachate were prepared and considered for applicability as a proton exchange membrane in fuel cells. Chi-PAA-hematite blended in different weight ratios and the resulting membranes were treated to enable the formation of the polyelectrolyte. The membranes of Chi-PAA polyblend were treated using iron sand leachate and reveal high ion exchange capacity (IEC), proton conductivity, water uptake, and good mechanical stability. The result of research indicated that the membrane with 40 wt% of Chi and 60 wt% of PAA blend which its conductivity of 6.10 × 10?2 S cm?1 was potentially for a proton exchange membrane in fuel cell applications.  相似文献   
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