Search results for "Oxide"

Determination of lead on the airborne particulates of urban Valencia city

1991

A method for the determination of lead in airborne particulates by graphite furnace atomic absorption spectrometry after extraction with HCl-HNO3 (120–150°C) is described. Particulate lead levels in the atmosphere have been measured in samples collected throughout a year, sampling has been made at eleven sites within the city of Valencia. The results obtained in this study show that annual means of lead levels are within the range of 0.526 to 7.033 μg/m3 depending upon the sampling site. Lead levels are higher in winter and autumn. Lead and nitrogen oxide levels are well correlated.

Nitric Oxide Reductase (P450nor) from Fusarium oxysporum

2008

An interpretation of EPR spectra of azide ligated superoxide dismutase from Propionibacterium shermanii

1995

A self-consistent description of the EPR spectra of the azide ligated SOD is obtained by taking into account the general configuration of the crystal field splitting in the crystal field Hamiltonian. The spread in the rhombicity parameter due to the presence of different conformational substates is introduced.

Copper(II) Polyamine Complexes withN-Benzothiazole Sulfonamides as Counterions — Synthesis, Crystal Structures, and Properties of [Cu(dien)2](L1)2[HL…

2003

Copper(II) complexes of new N-benzothiazole sulfonamides (HL1= N-2-(benzothiazole)naphtalensulfonamide and HL2 = N-2-(6-chlorobenzothiazole)toluenesulfonamide) with ethylenediamine (en) and diethylenetriamine (dien) have been synthesized and characterised. The crystal structures of [Cu(dien)2](L1)2 (1) and [Cu(en)2(H2O)2](L2)2 (2) compounds have been determined. The metal centre adopts a “4+2” distorted octahedral environment in both complexes. Unusually, the sulfonamidate anions act as counterions. Spectroscopic properties are in good agreement with the crystal structures. The superoxide dismutase (SOD)-like activity of complex 2 has been tested. Kupfer(II)-Polyamin-Komplexe mit N-Benzothi…

2002

Previous observations have suggested a role for nitric oxide in the activity of the globus pallidus, but this functional involvement has not yet been tested in vivo. The extracellular activity of single units of the globus pallidus was recorded, and neuronal nitric oxide synthase was inhibited by systemically administering 7-nitro-indazole to a group of anaesthetised rats. Forty-five per cent of cells responded with a decrease in the firing rate. In another group of rats, the microiontophoretic administration of 3-morpholino-sydnonimin-hydrocloride (a nitric oxide donor) induced an increase in neuronal firing rate (24/28 cells), whereas the administration of Nω-nitro-L-arginine methyl ester…

PIXE ANALYSES OF THE SOLUBLE AND MEMBRANE SE-CONTAINING PROTEINS EXTRACTED FROMCUPRIAVIDUS METALLIDURANSCH34 AFTER SELENIUM OXIDES CHALLENGE

2008

The soil bacterium Cupriavidus metallidurans CH34 resist selenite by reducing it into the insoluble and less toxic elemental selenium. Two mechanisms of reduction of selenium oxides in C. metallidurans CH34 were highlighted: assimilation leading to organic species and detoxification leading to precipitation of selenite in nanoparticules of elemental selenium. The alkyl selenide detected as an intermediate product during assimilation of selenite or as the major accumulated chemical form during assimilation of selenate was identified as selenomethionine.Soluble and membrane proteins were extracted from C. metallidurans CH34 submitted to selenium oxides challenge. After separation by SDS-PAGE,…

Prevention of fungal infestation of rainbow trout (Oncorhynchus mykiss) eggs using UV irradiation of the hatching water

2013

Abstract Fungal infestation by water mold Saprolegnia spp. causes great losses in aquaculture and fish egg hatching. To find a safe and effective alternative for the fungal prevention, we studied continuous disinfection of the inlet water by UV irradiation and ozonation combined with low concentration hydrogen peroxide (H 2 O 2 ) treatments in a rainbow trout ( Oncorhynchus mykiss ) egg hatching system. High dose of UV irradiation (400 mWs/cm 2 ) of the inlet water decreased the mortality of rainbow trout eggs from the 77.3% to 14.3% in a 28 day trial. UV irradiation did not modify water quality parameters, while combination of UV irradiation and H 2 O 2 caused up to fivefold increase in th…

The active center of superoxide dismutase from Propionibacterium shermanii

1996

A self-consistent description of the EPR spectra and of the Mossbauer spectra of the natural superoxide dismutase from Propionibacterium shermanii with ferric iron as an active centre is presented. The spectra were measured at pH 6.5, 7.8 and 9.4. The theoretical approach is based on the use of the complete crystal field Hamiltonian for the high-spin ferric complexes with due regard for the terms of the fourth power of the electronic spin. It is shown that a SOD molecule can exist in two conformations. The low-pH conformation has predominantly trigonal symmetry, while the high-pH conformation has the symmetry close to the «extreme rhombic». This interpretation is in full agreement with EXAF…

2,2′-[2,3,5,6-Tetramethyl-p-phenylenebis(methylenethio)]bis(pyridineN-oxide)

2008

Mol-ecules of the title compound, C(22)H(24)N(2)O(2)S(2), lie across centres of inversion. The two thio-pyridine N-oxide groups adopt a stepped trans configuration with respect to the benzene ring, by virtue of the symmetry. The oxopyridinium ring forms a dihedral angle of 79.9 (2)° with the benzene ring. The crystal structure is stabilized by a strong π-π inter-action between the pyridinium rings of adjacent mol-ecules [ring centroid-centroid distance = 3.464 (3) Å].

Squaraine Dyes for Photodynamic Therapy: Mechanism of Cytotoxicity and DNA Damage Induced by Halogenated Squaraine Dyes Plus Light (>600 nm)¶

2004

Halogenated squaraine dyes 1 and 2 possess favorable photophysical and in vitro photobiological properties that make these new class of molecules interesting for photodynamic therapeutic applications. For a better understanding of the mechanism of their photobiological activity, we have analyzed the DNA damage and the cytotoxicity induced by these photosensitizers in mammalian cells and cell-free systems in the presence and absence of various additives and scavengers. Both photoactivated squaraines were found to be similar efficient in inducing single-strand breaks (SSB) in cell-free DNA when compared with the cellular DNA. Superoxide dismutase and catalase did not show any influence. Howev…