activeoxygen aminoacids analysis biochemistry cellcommunication cellinteraction cells cellularsignaltransduction chemistry chromium chromiumions clinicalmedicine diseases environmentalpollutants environmentaltoxicology evidence-basedmedicine fitness general health internalmedicine medical metabolism methodology organic oxidants oxidation oxidation-reductionreaction oxidativestress pathophysiology peptides physiological physiologicaleffect physiologicaloxidation physiology pollutants proteins qu125 qu125r31852008 qu375h234r2008 research signaltransduction stress(physiology)