40 research outputs found

    Thermal behaviour of zircon/zirconia-added chemically durable borosilicate porous glass

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    Macroporous alkali resistant glass has been developed by making additions of zirconia (ZrO2) and zircon (ZrSiO4) to the sodium borosilicate glass system SiO2–B2O3 Na2O. The glass was made using a traditional high temperature fusion process. Differential thermal analysis (DTA) was carried out to identify the glass transition temperature (Tg) and crystallisation temperature (Tx). Based on these findings, controlled heat-treatments were implemented to separate the glass into two-phases; a silica-rich phase, and an alkali-rich borate phase. X-ray diffraction (XRD) was used to identify any crystal phases present in the asquenched and heat-treated glasses. Fourier transform infrared (FTIR) spectroscopy also proved effective in investigating phase separation and crystallisation behaviour. After leaching, a silica-rich skeleton with an interconnected pore structure and a uniform pore distribution was observed. Pore characterisation was carried out using mercury porosimetry. The size and shape of the pores largely depended on the heattreatment temperature and time. ZrO2/ZrSiO4 additions increased the alkali resistance of the porous glass 3–4 times

    Western diet‐induced increase in colonic bile acids compromises epithelial barrier in nonalcoholic steatohepatitis

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    There is compelling evidence implicating intestinal permeability in the pathogenesis of nonalcoholic steatohepatitis (NASH), but the underlying mechanisms remain poorly understood. Here we examined the role of bile acids (BA) in western diet (WD)‐induced loss of colonic epithelial barrier (CEB) function in mice with a genetic impairment in intestinal epithelial barrier function, junctional adhesion molecule A knockout mice, F11r−/−. WD‐fed knockout mice developed severe NASH, which was associated with increased BA concentration in the cecum and loss of CEB function. Analysis of cecal BA composition revealed selective increases in primary unconjugated BAs in the WD‐fed mice, which correlated with increased abundance of microbial taxa linked to BA metabolism. In vitro permeability assays revealed that chenodeoxycholic acid (CDCA), which was elevated in the cecum of WD‐fed mice, increased paracellular permeability, while the BA‐binding resin sevelamer hydrochloride protected against CDCA‐induced loss of barrier function. Sequestration of intestinal BAs by in vivo delivery of sevelamer to WD‐fed knockout mice attenuated colonic mucosal inflammation and improved CEB. Sevelamer also reduced hepatic inflammation and fibrosis, and improved metabolic derangements associated with NASH. Collectively, these findings highlight a hitherto unappreciated role for BAs in WD‐induced impairment of the intestinal epithelial barrier in NASH.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155502/1/fsb220488.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155502/2/fsb220488_am.pd

    Influence of active admixtures onto tellurite glass refractive index

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    The goal of this work was to investigate the influence of rare earth ions such as Tm3+, Yb3+ on physico-chemical properies of tellurite glass from the TeO2-WO3-PbO-PbF2-Na2O system. The thermal characteristic of tellurite glass Tm3+, Yb3+ doped have been presented. The effect of the glass crystallization on thermal stability of the glass and crystallizing phases formed upon heat treatment were investigated by DTA/DSC/, XRD methods. The spectral dependence of ellipsometric angles of the tellurite glass samples, have been studied. The influence of ions of rare earth elements, i.e. Tm 3+ and Yb3+, onto changes of refractive index of glass P1 (without RE admixture) were examined. The optical measurements were conducted on Woollam M2000 spectroscopic ellipsometer, in spectral range of 190–1700 nm

    Waste immobilization and environmental sustainability in glass-ceramics glazes development

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    The current work investigated the formulation of glazes using recycled CRT (Cathode Ray Tube) waste glass powder mixed with basalt, kaolin and other additives. New glaze compositions can be crystallized in order to improve the mechanical and chemical properties of fast-fired glazed tiles. These glazes are characterized by high resistance to abrasion

    DTA/DSC study of nanocrystallization in oxyfluoride glasses

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    Waste immobilization and environmental sustainability in glass-ceramics glazes development

    No full text
    The current work investigated the formulation of glazes using recycled CRT (Cathode Ray Tube) waste glass powder mixed with basalt, kaolin and other additives. New glaze compositions can be crystallized in order to improve the mechanical and chemical properties of fast-fired glazed tiles. These glazes are characterized by high resistance to abrasion
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