Ammonium Persulphate Initiated Graft Copolymerization of Aniline onto Chitosan-A Comparative Kinetic Study

Ammonium persulphate (APS) has been used as efficient initiator for graft copolymerization of the aniline (ANI) onto chitosan at 25±0.1°C. Graft copolymerization of ANI onto chitosan has taken place through the cation radical initiation process. The grafting parameters have been evaluated by varying concentration of ANI, APS and chitosan. The effects of concentration of APS, ANI, chitosan and reaction time on graft copolymerization were studied by determining the grafting percentage (%G), grafting efficiency (%E) and percentage add-on. It was observed that bout rate of homopolymerization (Rh) and rate of graft coplymerization (Rg) increased with the increase in concentration of each component. On the basis of the experimental observations, initiating steps have been proposed and a suitable rate expression for graft copolymerization has been derived. Electrical conductivity of grafted polyaniline (PANI) onto chitosan (Chit-g-PANI, chitaline) was measured by the four probe method.

Cdc20 protects cells from Ara-c-induced apoptosis in AML via targeting autophagy

ObjectiveThis study aims to explore the role and mechanism of Cdc20 on Ara-c chemosensitivity of AML cells.MethodsEvaluation experiments of effects of Cdc20 on Ara-c chemosensitivity were performed with AML cell transfected with constructs overexpressing Cdc20 or AML cell transfected with Cdc20 shRNA through observing cell viability, apoptosis rate,expression of apoptosis protein.The level of autophagy was assessed by transmission electron microscopy and western blotting.ResultsAfter exposure to Ara-c, Cdc20 expression is down-regulated. Intracellular Cdc20 expression inhibited Ara-c-induced apoptosis as shown by increasing cell viability and decreasing expression of cleaved caspase3.The expression of LC3B was mediated by Cdc20 expression,which further inhibits autophagy. Moreover, Cdc20 mediated LC3B-decreasing promotes the expression of P-Akt and P-ERK and inhibits ROS generation.ConclusionIt was determined that Cdc20 promoted the degradation of LC3B, thereby inhibiting autophagy and decreasing Ara-c-induced apoptosis in AML cells.

Simplified Rate Expression for Palm Kernel Oil (PKO) and Methanol Alkali Catalyzed Transesterification Reaction

The need for the development of simplified kinetics rates expression (-RA) for Vegetable Oils Alkali catalyzed Transesterification processes to enhance biodiesel production motivated this study. The study, therefore aimed at proposing unified simple rate expression that may be a useful prelude to design various reactor types for Alkali Catalyzed Transesterification of palm kernel oil (PKO) and Methanol reactions. The kinetics rate expression is proposed using simple explicit algebraic technique with the consideration that alkali catalyzed transesterification reaction of palm kernel oil and methanol is a reversible bimolecular reaction. The proposed kinetic reaction rate expression is developed as a function of conversion (XA), reactants and products concentration and reaction rate constants (k1 and k2). The kinetics reaction rate expression obtained is further evaluated on the basis of reactants and product molar masses and densities. The developed models were simulated using Matlab codes programming techniques. The results for kinetic reaction rates (-RA & -ReA) decreases with decrease in fractional volume change (e) and increase in fractional conversion at constant reaction time. The results were quite compatible with those of inferential laboratory physicochemical characterization reported.

Kinetics and mechanisms of polycondensation reactions between aryl halides and bisphenol A

Computational and experimental verification of a second-order rate expression for polysulfones synthesized using diphenyldichloro sulfone versus a third-order rate expression for polysulfones synthesized using diphenyldifluoro sulfone.

Kinetics and mechanisms of alcohol dehydration pathways on alumina materials

Ethanol dehydration on α,γ,η-alumina mechanistically and kinetically described by the same rate expression implicating similar active sites on all alumina materials.