No abstract

Activated hepatic stellate cell (HSC) is the central link to the occurrence and development of liver fibrosis, which can be reversed by promoting the apoptosis of HSC. The activation of HSC leads to an increase in proliferation, collagen synthesis and the contraction of HSCs. The studies in vitro and in vivo have shown that intracellular Ca2+ plays an important role in the mediating apoptosis and contraction of HSC. The phosphatidyl inositol 3-kinase (PI3K)/Akt signalling pathway is closely related to the occurrence and development of liver fibrosis. In this study, we investigated the effect of PI3K inhibitor PI103 on HSC stimulated by transforming growth factor-β1(TGF-β1) and explored its relevant mechanisms. The results showed PI3K inhibitor PI103 could inhibit the proliferation of activated HSC, increase its apoptosis, decrease intracellular Ca2+ concentration and reduce the expression of signal molecules PI3K and Akt and type I, III collagen as well. Our study demonstrates that Ca2+ and PI3K/Akt-dependent HSC apoptosis may serve as a potential novel target for anti-fibrosis therapy.

In this communication, Ag0.9Na0.1(Nb0.7Ta0.3)O3（ANNT） mixed oxide powder was synthesized by citrate wet chemical method. TG-DTA, XRD and TEM analyses showed that the reaction temperature was 800°C, the calcining time was three hours, and the product was pure ANNT in well-dispersed grain structure (35nm in average).

Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. Biodiesel was synthesized by palm oil using ultrasonication and alkali-acid catalysis method. Its structure was characterized by gas chromatograph, and the effects of various factors on transesterification rate were studied. The results show that biodiesel yield in excess of 95% can be achieved in 30 min, at the 40Hz amplitude level, methanol/oil weight ratio of 1.3, 0.5% of alkaline, reaction temperature of 50-60 °C.

Cellulose treated with fire retardant was studied by thermogravimetry (TG), differential thermal analysis (DTA) and limiting oxygen index (LOI). The kinetic parameters for the thermal degradation are obtained following the method of Broido. For the fire retardant cellulose, the activation energy and decomposition temperature were much decreased while char yield and LOI were increased. The main thermal decomposition of the samples with higher LOI occurs at lower temperatures, while that with lower LOI occurs at higher temperatures.