The heat, ultraviolet and rihoflavin-sensitized visible inactivations of taka-amylase A are strongly inhibited by the presence of its substrate. The stabilization of the secondary structure of enzyme protein by the conformation change due to the formation of enzyme-substrate and -product complexes is responsible for the protection of enzyme from the heat inactivation. The photoinactivations are...

Phytochromes are multi-domain red light photosensor proteins, which convert red light photons to biological activity utilizing the multitude of structural and chemical reactions. The steady increase in structural information obtained from various bacteriophytochromes has increased understanding about the functional mechanism of the photochemical processes of the phytochromes. Furthermore, a num...

introduction blue light is a part of the spectrum with the highest energy content, which can reach the retina. the damage that it can cause to the retina is called photochemical or blue-light retinal injury. for the retinal injury assessment of the photochemical and aphakic retinal hazards in the wavelength range of 300-700 nm, use of effective spectral radiance limits (w.m-2.sr-1) seems to be ...

New and simple protocols are described for the conversion of the enzymatically-derived and enantiomerically pure cis-1,2-dihydrocatechol (X = I) and its 6-methylated derivative into either antipodal form of compounds embodying the tricyclic frameworks of terpenoids . Key steps include intramolecular Diels-Alder (IMDA) and (in some cases) singlet or triplet-based photochemical processes.

Bathorhodopsin-rhodopsin difference spectra of native 11-cis-rhodopsin and regenerated 9-cis-rhodopsin were measured at room temperature with a double-beam laser spectrophotometer after excitation at 532 nm. A detailed analysis of data obtained at 85 psec after excitation suggests that the bathorhodopsins generated from 11-cis- and 9-cis-rhodopsin differ in their extinction coefficients and tha...

mesoporous tio2 has been prepared using a nonionic block copolymer (pluronic p-123) as structure-directing agent with sol-gel method. characterization of the product was carried out by means of x-ray diffraction (xrd), scanning electron microscopy (sem), thermogravimetry-differential scanning calorimetry (tg-dsc), nitrogen sorption isotherms, and uv-vis absorption spectroscopy. these analyses s...

In this paper, the photochemical degradation of azure-b by Cu2+/S2O82− process has beenpresented. Cu2+ as photocatalyst and S2O82− ion as photooxidant used in this process. Atextremely low concentrations, cupric ion showed true catalytic activity in the overall process.The influence of various parameters on the performance of the treatment process has beenconsidered, such as pH, concentration o...

the resource intensive human activities (such as mining and extraction of mineral oils for betterment of life and modernization of society) have increased environmental pollution several folds. products of mining and petrochemical industries are advantageous for the modern society. but waste generated such as btex from such industries are carcinogenic, toxic and causes adverse effects on enviro...

When a nematic liquid crystal is doped with a large amount of a liquid crystalline azobenzene compound (15 wt %), the photoisomerization of azobenzene under UV and visible light irradiation can give rise to reversible and interconvertible photochemical phase transition and photochemical phase separation. Both normal and reverse modes of photocontrolled switching of transmittance through crossed...