the mechanism by which bi-and trivalent cations affect human liver phosphatidatephosphohydrolase (pap) activity was investigated. bivalent cations up to 1 mm increased pap activity whereas at higher concentrations the activity of the enzyme decreased. the stimulatory concentration for trivalent cations such as al3+ and cr3+, however, was much lower being 2 m m and 1 m m, respectively. all catio...

objective: dental caries is a common infectious disease. streptococcus mutans is the prevalent decay microorganism. the anti streptococcus mutans activity of non fermented and semi-fermented tea has been shown. the aim of this study was to determine the anti streptococcus mutans activity of iranian green and black tea (non fermented and fermented type). materials and methods: the study was expe...

abstract kinetic properties of root of peroxidase of gundelia tournefortii investigated at different ph, temperature and different inhibitors. maximum activity of peroxidase achieved at ph 5.5-6 in according to type of substrate. activity of peroxidase increased at constant concentration of h2o2 and different concentration of guaiacol, catechol and pyrogallol. the maximum activity in presence o...