antioxidants are compounds which can prevent biological and chemical substances from oxidative damage by reactive oxygen species. flavonoids are the most important class of polyphenolic compounds that because of their antioxidant characters possess biological activities and pharmacological effects. chrysin-6-c-fucopyranoside and chrysin-3-malonyl-6-c-fucopyranoside are mono c-glycosyl derivativ...

This paper is designed to examine the binding behavior of Coumarin with bovine -casein (βCN) through fluorescence spectroscopy and molecular modeling techniques. The data analysis on fluorescence titration experiments at various temperatures represents the enthalpy driven nature for the formation of Coumarin–βCN complex and the prevailed role of hydrogen bonds and van der Waals interactions in...

Hydrogen detection is essential for its implementation as an energy vector. So far, palladium is considered to be the most effective hydrogen sensing material. Here we show that palladium-capped hafnium thin films show a highly reproducible change in optical transmission in response to a hydrogen exposure ranging over six orders of magnitude in pressure. The optical signal is hysteresis-free wi...

Thermodynamic parameters of the hydriding reaction of a hydride electrode can be obtained by two different methods. The results show that the change of enthalpy AH, change of entropy AS and hydrogen pressure calculated from e-c-T curves of electrochemical reactions have much larger inherent errors compared with those obtained from p-c-T curves of alloys in hydriding reactions with hydrogen gas ...

Dissolution kinetics of the (110) face of salicylic acid in aqueous solution is determined by hopping intermittent contact scanning electrochemical microscopy (HIC-SECM) using a 2.5 μm diameter platinum ultramicroelectrode (UME). The method operates by translating the probe UME towards the surface at a series of positions across the crystal and inducing dissolutio n via the reduction of protons...

a thermodynamic study of copper ions by jack bean urease (jbu) was carried out at two temperatures of 27 and 37?c in tris buffer (30 mm; ph=7.0) using an isothermal titration calorimetry. there is a set of twelve identical and non-interacting binding sites for copper ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 285 µm and ?15.2 kj/mol at 27?c and 3...

Simple energy calculations show that there is a significant interaction between a hydrogen bond donor (like the greater than NH group) and the centre of a benzene ring, which acts as a hydrogen bond acceptor. This interaction, which is about half as strong as a normal hydrogen bond, contributes approximately 3 kcal/mol (1 cal = 4.184 J) of stabilizing enthalpy and is expected to play a signific...

The reversible LiBH(4)/Mg(2)NiH(4) combined hydride system for hydrogen storage displays a concerted dehydrogenation reaction beginning at 250 degrees C with significantly low enthalpy (DeltaH = 15.4 +/- 2 kJ mol(-1) H(2)) and entropy (DeltaS = 62.2 +/- 3 J K(-1) mol(-1) H(2)).