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 ...

Formaldehyde (HCHO) indicates and supports photochemical activity in the atmosphere. Large amounts are expected to found in industrial areas and during biomass burning. HCHO is a major intermediate in the degradation of methane (and many other hydrocarbons). In the absence of heterogenous losses, essentially every methane molecule is converted to HCHO. Therefore it is found throughout the tropo...

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.

In advanced oxidation processes (AOPs) operating in continuous mode, the flow rate and concentration of oxidants such as H2O2 at mixing point influent must be controlled so that oxidant residuals effluent are minimized while organic degradation is maximized. Designing a controller to regulate therefore, its photoreactor influent, needs determination reliable process dynamic model. this study, s...

It has been shown that the photocatalytic activity of doped semiconductor with some nonmetals is higher than a pure semiconductor. Hence, with an attempt to achieve higher photocatalytic activity, doped ZnO with C, N, and S was prepared by a sedimentary process and used for the photocatalytic degradation of Fluocinolone Acetonidin as a drug in aqueous solutions.  ...