Monolithic porous magnesium silicide

Macroporous magnesium silicide monoliths were successfully prepared by a two-step synthesis procedure. The reaction of gaseous magnesium vapor with macro-/mesoporous silicon, which was generated from hierarchically organized meso-/macroporous silica by a magnesiothermic reduction reaction, resulted in monolithic magnesium silicide with a cellular, open macroporous structure. By adjusting the reaction conditions, such as experimental set-up, temperature and time, challenges namely loss of porosity or phase purity of Mg2Si were addressed and monolithic magnesium silicide with a cellular network builtup was obtained.(VLID)192544

From solgel prepared porous silica to monolithic porous Mg2Si/MgO composite materials

Mg2Si is apart from its conductivity properties expected to be a promising candidate for thermoelectric applications due to its low toxicity, low costs, and the high abundance of its precursor chemicals. Through the addition of a homogeneous distribution of nanoparticles (e.g. MgO) and by reducing the size of Mg2Si to the nanometer regime, it is possible to decrease the thermal conductivity by increasing phonon-interface scattering and, as a result, improve the thermoelectric properties. However, classical approaches do not allow for the synthesis of nanocomposites from Mg2Si and MgO. In this work, a straightforward route is presented towards homogeneously mixed Mg2Si/MgO via a two-step magnesiothermic reduction process starting from solgel derived hierarchically organized porous silica. Monolithic materials composed of Mg2Si and MgO in variable molar ratios are built up from a macroporous network of Mg2Si with homogeneously distributed MgO particles exhibiting a crystallite size in the range of 2437nm.(VLID)286459

The effect of alpha-tocopherol on the expression of epidermal growth factor receptor and transforming growth factor beta genes in three developmental stages of echinococcus granulosus

Background: In recent decades platyhelminths have been used as model organisms to ad-dress some of the fundamental questions related to the growth and development of animal organisms. Epidermal Growth Factor Receptors (EGFR) and Transforming Growth Factor beta (TGF-beta) have a regulatory role in the growth and development of Echinococcus spe-cies. This study determined the effect of alpha-tocopherol on the expression of EGFR and TGF-beta genes in three in vitro developmental stages of E. granulosus. Methods: E. granulosus protoscoleces were cultured in diphasic medium containing bovine serum and CMRL 1066. Three developmental stages of E. granulosus, i.e. invaginated proto-scoleces, evaginated protoscoleces and three-proglottid worms, were treated by alpha-tocopherol (250 μg/ml for 36 h) and the expression of EGFR and TGF-beta genes were evaluated by using qPCR analysis. Results: Intact protoscoleces were successfully developed to the segmented worms in di-phasic culture media. Higher levels of both EGFR and TGF-beta gene expression were observed in the invaginated protoscoleces as well as the segmented worms in comparison to the non-treated controls. Conclusion: Administration of alpha-tocopherol to different developmental stages of E. granulosus significantly enhanced EGFR and TGF-beta expression in the parasite. Both oxidant and non-oxidant activities of alpha-tocopherol could explain the study findings. Over-expression of the genes could in turn enhance growth factor effects and facilitates the vi ability of the parasite. © 2020, Tehran University of Medical Sciences (TUMS). All rights reserved

In vitro effects of glutathione on Transforming Growth Factor beta and epidermal Growth Factor Receptor genes expression in the protoscoleces and strobilated worms of Echinococcus granulosus

Cystic Echinococcosis (CE) caused by the small taeniid cestode Echinococcus granulosus, is a globally distributed zoonosis. Administration of some chemicals or natural compounds could lead to significant effects on the expression of some developmentally important genes including Transforming Growth Factor beta (TGF-β) and Epidermal Growth Factor Receptor (EGFR) in other parasitic organisms. The main purpose of this study was to describe the effect of glutathione (GSH) on the expression of TGF-β and EGFR genes in different developmental stages of E. granulosus. Protoscoleces of hydatid cysts collected from naturally infected sheep liver were cultured in diphasic CMRL1066 medium. Glutathione Mono-ethyl Ester (GME) at 250 μg/ml concentration was applied on the invaginated protoscoleces (PSCi), evaginated protoscoleces (PSCe) and strobilated worms (SW3) in vitro. TGF-β and EGFR genes expression were evaluated by using Real Time qPCR analysis compared to the controls. In response to GME treatment TGF-β expression was affected, however no significant effect was observed in EGFR expression. The results indicate a significant difference of TGF-β expression in the intact protoscoleces and the strobilated worms comparing to the controls. In intact invaginated protoscoleces TGF-β expression was significantly increased (p < 0.01) while in the strobilated worms a significant decrease was observed comparing to no-treatment controls (p < 0.001). None of the three developmental stages of E. granulosus demonstrated significant changes in EGFR expression. The results indicated that administration of GSH modified TGF-β expression in the protoscoleces and strobilar stages of E. granulosus. To improve our understanding of the physiology and biochemistry of the parasite more in depth in vitro and in vivo studies on the morphological and molecular effects of glutathione on the parasite is recommended. Further investigation on the gene profiles in other stages including microcysts and germinal layer cells is also suggested. This paves the way for the effective treatment and control of cystic echinococcosis. © 2020 Elsevier Inc