C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm...C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.展开更多
以骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)作为诱导小鼠间充质干细胞C3H10T1/2定向成骨分化的细胞因子,观察过表达S100A6对成骨分化的影响。用重组腺病毒AdBMP9与AdS100A6共感染C3H10T1/2细胞,随后检测成骨分化标志物,包括...以骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)作为诱导小鼠间充质干细胞C3H10T1/2定向成骨分化的细胞因子,观察过表达S100A6对成骨分化的影响。用重组腺病毒AdBMP9与AdS100A6共感染C3H10T1/2细胞,随后检测成骨分化标志物,包括Runx2、碱性磷酸酶(alkaline phosphatase,ALP)、骨桥素(osteopontin,OPN)和钙盐沉积;检测方法包括免疫细胞化学、ALP染色、活性分析以及茜素红S染色;同时,用Western blot检测β-catenin的表达。过表达S100A6对所诱导的间充质干细胞C3H10T1/2成骨分化的早期指标Runx2的蛋白水平无明显影响(P>0.05;ICC法),对第7天的ALP和第18天钙盐的沉积也无明显影响(P>0.05);但是,能够引起第12天的OPN升高(P<0.05);同时,S100A6对BMP9诱导的C3H10T1/2细胞中的β-catenin水平的影响在第3、7天不明显(P>0.05),但在第12天时可致β-catenin水平下调(P<0.05)。过表达S100A6可促进BMP9诱导的C3H10T1/2细胞中OPN的表达,但对最终的成骨分化无明显影响。展开更多
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(No.IRT1146)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.
