No abstract

In this study, the mass transfer and reaction kinetics of soybean oil epoxidation using concentrated hydrogen peroxide in a formic acidautocatalyzed reaction system were studied in detail. Studying the mass transfer of formic acid showed that the influence of reactant diffusion near the interface is eliminated when the stirring rate is > 120 rpm in a double-stirred cell, and the mass transfer rate decreases greatly with the conversion of double bonds and a decrease of reaction temperature. A temperature increase has little impact on the equilibrium of formic acid in the oil/water system, while an increase of epoxidized soybean oil significantly increases the value of the partition coefficient of formic acid. Another important aspect in the kinetic study is the decomposition of performic acid, which can cause the reduction of H 2 O 2 and formic acid during the reaction. Finally, a biphasic model, which considers all reactions in oil and aqueous phases, the equilibrium and mass transfer of reagents and products between the phases, and the evolution of proton concentrations with time, was developed to describe the epoxidation process.

No abstract

Graft injury after small-for-size liver transplantation impairs graft function and threatens the survival of the recipients. The use of adipose-derived stem cells (ADSCs) for liver injury protection and repair is promising.Our aim was to investigate the role of vascular endothelial growth factor (VEGF) secreted by ADSCs in the treatment of small-for-size liver graft injury. Studies were performed using ADSCs with VEGF secretion blocked by RNA interference. In vitro, ADSCs prevented apoptosis of freshly isolated liver sinusoidal endothelial cells (LSECs) by secretion of VEGF. Syngeneic 35% orthotopic liver transplantation followed by implantation of syngeneic ADSCs through the portal vein system was performed using Wistar rats. We found VEGF secreted by implanted ADSCs improved graft microcirculatory disturbances, serum liver function parameters and survival. The improved microcirculatory status was also reflected by reduced hepatocellular damage, especially LSEC apoptosis and improved liver regeneration. These effects were accompanied by decreased expression of endothelin receptor type A, increased Bcl-2/Bax ratio, decreased expression of Bad and elevated proportion of phosphorylated Bad. In conclusion, implanted syngeneic ADSCs attenuated small-for-size liver graft injuries and subsequently enhanced liver regeneration in a rat 35% liver transplantation model. The VEGF secreted by implanted ADSCs played a crucial role in this process.