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91.
Disruption of retinal pigment epithelial (RPE barrier integrity is a hallmark feature of various retinal blinding diseases, including diabetic macular edema and age-related macular degeneration, but the underlying causes and pathophysiology are not completely well-defined. One of the most conserved phenomena in biology is the progressive decline in mitochondrial function with aging leading to cytopathic hypoxia, where cells are unable to use oxygen for energy production. Therefore, this study aimed to thoroughly investigate the role of cytopathic hypoxia in compromising the barrier functionality of RPE cells. We used Electric Cell-Substrate Impedance Sensing (ECIS) system to monitor precisely in real time the barrier integrity of RPE cell line (ARPE-19) after treatment with various concentrations of cytopathic hypoxia-inducing agent, Cobalt(II) chloride (CoCl2). We further investigated how the resistance across ARPE-19 cells changes across three separate parameters: Rb (the electrical resistance between ARPE-19 cells), α (the resistance between the ARPE-19 and its substrate), and Cm (the capacitance of the ARPE-19 cell membrane). The viability of the ARPE-19 cells and mitochondrial bioenergetics were quantified with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and seahorse technology, respectively. ECIS measurement showed that CoCl2 reduced the total impedance of ARPE-19 cells in a dose dependent manner across all tested frequencies. Specifically, the ECIS program’s modelling demonstrated that CoCl2 affected Rb as it begins to drastically decrease earlier than α or Cm, although ARPE-19 cells’ viability was not compromised. Using seahorse technology, all three concentrations of CoCl2 significantly impaired basal, maximal, and ATP-linked respirations of ARPE-19 cells but did not affect proton leak and non-mitochondrial bioenergetic. Concordantly, the expression of a major paracellular tight junction protein (ZO-1) was reduced significantly with CoCl2-treatment in a dose-dependent manner. Our data demonstrate that the ARPE-19 cells have distinct dielectric properties in response to cytopathic hypoxia in which disruption of barrier integrity between ARPE-19 cells precedes any changes in cells’ viability, cell-substrate contacts, and cell membrane permeability. Such differences can be used in screening of selective agents that improve the assembly of RPE tight junction without compromising other RPE barrier parameters.  相似文献   
92.
电池组内单体电池的分散性问题降低了电池组的可用容量和循环寿命.针对电池成组方式对电池组可用容量与循环寿命的影响问题,基于电池的Thevenin等效模型,分析了并联电池间不平衡电流交叉现象产生的原因及作用;研究了不同成组方式对电池组可用容量的影响,提出了表征电池组容量分散性的容量极差和容量分散度指标;通过仿真分析,得到了提升电池组可用容量的组合方式.搭建了电池组性能测试平台,比较了6种拓扑结构锂离子电池模组的寿命衰减特征,遴选出了减缓电池组循环寿命衰减的成组结构.  相似文献   
93.
MGH956合金TLP连接机理及接头组织分析   总被引:2,自引:0,他引:2       下载免费PDF全文
MGH956合金是采用机械合金化方法制造的氧化物弥散强化高温合金,具有高温力学性能好、高温抗氧化和抗腐蚀性能好的综合优势。自行研制了中间层合金KCol进行MGH956合金过渡液相(TLP)扩散连接试验,分析了接头组织、成分和连接工艺的关系,确定了MGH956合金TLP扩散连接机理。同时,对MGH956合金焊接接头中产生的夹渣缺陷进行了深入的分析。结果表明:在连接温度1240℃、保温8h条件下,可以获得焊接缺陷少、完整连续的焊接接头。  相似文献   
94.
Volumetric gas—liquid mass transfer coefficient (kLa) data available in the literature for larger tanks (T = 0.39 m to 2.7 m) have been analyzed on the basis of relative dispersion parameter, N/Ncd. It was observed that at a given superficial gas velocity (VG), kLa values were approximately the same irrespective of geometric configuration (size of the tank, type and size of the impellers, type of the sparger, etc.) at a particular N/Ncd. A single correlation based on N/Ncd is presented which shows satisfactory agreement with the kLa data of different workers.  相似文献   
95.
搅拌槽内的液-液临界分散   总被引:2,自引:0,他引:2  
在φ391mm搅拌槽中,分别采用双层Brumagin桨、双层三叶后掠式桨和双层A310桨与7种内构件相组合,在无乳化剂下对油水比(质量比)分别为1∶1.5,1∶2.0的煤油-水体系的液-液临界分散进行了研究。从工业实用的角度出发,对前两种桨找到了一种可替代“轻液挡板”的小挡板及其安装方法:内冷管上均布4块小挡板,B/D=0.08,插入液面深度为0.2D。在φ188mm搅拌槽中,于全挡板条件下,以歧化松香皂为乳化剂,分别采用3种不同几何参数的双层Brumagin桨对油水质量比为1∶1.5的煤油-水体系的临界分散进行了研究。结果表明,与无乳化剂情况相比,液-液临界分散转速(N_c)下降30%~40%,临界分散功耗(P_(cv))下降53%~66%;桨径减小会使N_c和P_(cv)增加。  相似文献   
96.
A non-intrusive dye tracing technique, laser-induced fluorescence (LIF), has been applied to investigate the co-current flow of two immiscible organic-aqueous liquid flows in a vertical pipe. This technique allowed detailed visualization of the dynamic evolution of the flows. Flow structures in liquid-liquid flows at high dispersed phase fraction were revealed which had not been seen before. In pipe flow, an unstable range was found in the flow pattern map in which oil-in-water (o/w) and water-in-oil (w/o) dispersions could co-exist. Secondary dispersions (o/w/o and w/o/w) were observed for most volume fractions and velocities, especially in the unstable range. It was observed that, when the flow is in the unstable region, both w/o/w and o/w/o secondary dispersions could appear in the same set of experiments. It was found that this unstable range in the pipe flow, in spite of the similar appearance, was different to the ambivalent range seen in agitated systems. The one-dimensional drift flux model of Wallis (1969) for dispersed flow and a laminar model for co-current downward annular flow, were also applied to predict the in situ oil holdup; good agreement was obtained.  相似文献   
97.
叶黄素的提取及制备进展   总被引:7,自引:0,他引:7  
叶黄素是一种新型的食用功能型色素。可以从天然植物中提取含有叶黄素的酯类皂化制得。本文通过参考国外有关文献报道及国内实际情况。分析和阐述了提取及制备叶黄素的发展情况及适宜国内的技术方向。  相似文献   
98.
新型大红陶瓷色料的研制   总被引:1,自引:3,他引:1  
徐研  高雅春  李美霞 《陶瓷》2006,(4):24-27,44
通过在具有晶体结构的三元氧化物(ABO3)中添加少量的Cr^3+(钙钛矿)作为发色剂,可制得一种新型的大红陶瓷色料,在生成一次制品和一次性烧成砖的高温情况下,此色料色彩纯正,热稳定性好。  相似文献   
99.
采用液相反应法研制了釉上金红颜料,给出了颜料和熔剂配方及其制备方法。  相似文献   
100.
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