Effect of (-)epicatechin in modulating calicum-atpase activity in normal and diabetic human erythrocytes

Aqueous extract of the wood ofPterocarpus marsupium, commonly known as ‘bijasar’, is used in Indian Ayurveda system of medicine for treatment of diabetes. The active anti-diabetic principle in its aqueous extract has been found to be (-)epicatechin, a flavonoid. The present work was undertaken to study the effect of (-)epicatechin on erythrocyte membrane Ca⁺⁺-ATPase from type 2 diabetic patients. The activity of erythrocyte Ca⁺⁺-ATPase was significantly lower in type 2 diabetics.In vitro insulin treatment of erythrocyte ghosts, resulted in the increase of Ca⁺⁺-ATPase activity in diabetic patients. Treatment with (-)epicatechin (1mM) resulted in an increase in the activity of erythrocyte Ca⁺⁺-ATPase in both normal individuals and type 2 diabetic patients. The insulin like effect of (-)epicatechin on erythrocyte membrane Ca⁺⁺-ATPase in type 2 diabetics is an interesting finding. Further work is needed to elucidate the mechanism of action of (-)epicatechin on modulation of erythrocyte membrane bound enzymes.     

Spatial decoupling of light absorption and reaction sites in n-Si photocathodes for solar water splitting

Metal-insulator-semiconductor (MIS) photocathodes offer a simple alternative to p-n junction photocathodes in photoelectrochemical water splitting. However, the parasitic light absorption of catalysts and metal layers in the MIS junction, as well as the lack of low work function metals to form a large band offset with p-Si, severely limit their performance. This paper describes an MIS photocathode fabricated from n-Si, rather than the commonly used p-Si, to spatially decouple light absorption from reaction sites, which enables the majority carriers, instead of the commonly used minority carriers, to drive the surface reaction, making it possible to place the reaction sites far away from the light absorption region. Thus, the catalysts could be moved to the backside of the MIS junction to avoid light shielding. Moreover, the adoption of n-Si unlocks a variety of high work function materials for photovoltage generation. The obtained n-Si MIS photocathode exhibits an applied bias photon-to-current efficiency of 10.26% with a stability up to 300 h.     

Water splitting by carbon under visible light

<正>Hydrogen production and storage remain one of the most challenging technologies for a clean and sustainable future energy scenario.If hydrogen is available in large amount and can be stored and transported safely,a hydrogen-based economy/society will be free of any greenhouse gas and the associated pollutant or wastes.Nowadays,hydrogen is mainly produced from fossil sources that