Superoxide reductase SOR is an enzyme involved in superoxide detoxification in some microorganisms. Its active site consists of a non-heme ferrous center in an unusual [Fe(NHis)(4) (SCys)(1)] square pyramidal pentacoordination that efficiently reduces superoxide into hydrogen peroxide. In previous works, the reaction mechanism of the SOR from Desulfoarculus baarsii enzyme, studied by pulse radi...

1. The reaction time of the direct growth response of the sporangiophore of Phycomyces to light consists of a series of at least three major identifiable components: (a) an exposure period during which photochemical change occurs; (b) a latent period involving products directly consequent upon the photochemical action; and (c) an action-time occupying a further interval before the growth accele...

We show that the main photochemical processes involved in the phototransformation of anionic ibuprofen (IBP) in surface waters are the reaction with (•)OH, the direct photolysis and possibly the reaction with the triplet states of chromophoric dissolved organic matter ((3)CDOM). These conclusions were derived by use of a model of surface water photochemistry, which adopted measured parameters o...

By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring sys­ tems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenc...

Photoisomerization, that is, a photochemical reaction leading to a change of molecular structure after absorption of a photon, can have detrimental effects such as leading to DNA damage under solar irradiation, or as a limiting factor for the efficiency of solar cells. Here, we show that strong coupling of organic molecules to a confined light mode can be used to strongly suppress photoisomeriz...

The first nucleic acid-directed catalytic photochemical reaction that is induced by nontoxic red light was developed. This reaction is fast, high yielding, sequence specific, and enables one to functionalize an oligonucleotide.

The autocatalytic photochemical reaction, which is potentially controlled by any selected nucleic acid, is highly sequence specific and not inhibited by its products, was developed. This reaction generates colored and fluorescent products, which can be monitored by the naked eye.

The Sydney basin region experiences some high ozone episodes in summer, especially in the north west and south west of Sydney. Observation-based methods can be used to provide a means to access the potential extent of photochemical smog problem at various regions in the Sydney area. In this study, the observation-based Integrated Empirical Rates (IER) model is used to determine and understand t...

The dual nature of ~3-~2-~4-~N,N-diethylamino!phenyl!ethenyl!-5,5-dimethyl-1,2-cyclohexenylidene!propanedinitrile ~Lemke-e! allows us to write both quasipermanent and erasable holographic gratings in the same storage volume. In the presence of a triplet excited sensitizer, Lemke-e undergoes a photochemical reaction allowing the creation of quasipermanent photochemical holographic gratings. In a...

Photochemical reactions of microcystin-LR, a toxic compound produced by some blue green algae, were investigated. Ultraviolet absorption of microcystin-LR was assessed. Time-dependent density functional theory (TDDFT) calculations indicated that absorption peak at 238 nm was mainly due to excitation of electrons from the linear chain structure Adda of microcystin-LR. Irradiation of microcystin-...