Heterogeneous photocatalysis has emerged as a promising alternative for both micropollutant removal and bacterial inactivation under solar irradiation. Among variety of photocatalysts explored in the literature, graphite carbon nitride (g-C3N4) is metal-free semiconductor with acceptable chemical stability, low toxicity, excellent cost-effectiveness. To minimize its high charge recombination ra...

The adsorption of cationic organic dyes (methylene blue, thionine, and thiopyronine) on Qbeta bacteriophage was studied by UV-visible and fluorescence spectroscopy. The dyes have shown a strong affinity to the virus and some have been used as sensitizers for photo-induced inactivation of virus. In the methylene blue concentration range of 0.1-5 microM and at high ratios of dye to virus (greater...

In order to assess the roles of specific amino acid residues in the delta 5-3-ketosteroid isomerase from Pseudomonas putida biotype B during catalysis, we replaced aspartic acid 40 with asparagine (D40N) and tyrosine 16 with phenylalanine (Y16F) in the enzyme by site-directed mutagenesis. Both purified mutant enzymes resulted in profound decreases in catalytic activities, 10(3.3)-fold in the Y1...

The indexes for agonistic activity (pD2 values) and for antagonistic activity (pA2 values) of some beta-adrenergic partial agonists were estimated in the isolated taenia caecum and tracheal preparation of guinea pig. The pK1 values, negative log of dissociation constants, were also estimated by photoinactivation of the beta-adreneoceptor in the taenia caecum. The pD2 values of the partial agoni...

The bioluminescence of the ctenophore Mnemiopsis takes place when the photoprotein mnemiopsin in the photocytes reacts with Ca2+. The luminescence is inhibited in sunlight and this photoinhibition is reversible by keeping the live specimens in the dark. The extracts of mnemiopsin are similarly photoinhibited, but the photoinhibition cannot be reversed in the dark. We have found that photo-inhib...

A number of Zn(II)- phthalocyanines bearing peripheral substituents of cationic nature due to the presence of quaternarized anilinium or ammonium groups were shown to be efficient photoantimicrobial agents: a 4-5 log decrease in the survival of both wild-type or methicillin-resistant Staphylococcus aureus was obtained upon short irradiation times in the presence of phthalocyanine concentrations...

Visible blue light emitting diodes (LED) have been studied to inactivate Escherichia coli (E. coli) O157:H7 in agar gels. The LED array was optimized attain uniform illumination, and the intensity distribution visualized through optical simulation. uniformity of assessed, evenly spaced showed best with a Petri factor 0.99. Microbial populations gels prepared without dye were analyzed after irra...

One possibility of treatment in Aesthetics for folliculitis is a blue LED, as it acts on microbial control. Studies describe that the with 405-470nm wavelength, has bactericidal effect when irradiated certain bacteria such Staphylococcus aureus. This study aimed to evaluate 450 nm LED's efficacy modality aesthetic treatments photoinactivation planktonic strains S. aureus and epidermidis power d...