Pharmacokinetic profile and anticholinesterase properties of phenamiphos in male rats.

The pharmacokinetics and anticholinesterase properties of a single oral dose 6 mg/Kg of technical phenamiphos [ethyl 4-(methylthio)-m-tolyl isopropylphosphoramidate] were investigated in male rats. Animals were killed at each time intervals of 0.5, 1.0, 1.5, 3, 6, 12, 24, 48, and 72 hrs after dosing. The total recovered amount of phenamiphos from brain and plasma tissues reached high level at the first time interval and disappeared biexponentially from both tissues to low level at the end of the experiment. Brain tissue has a greater affinity to phenamiphos than plasma tissue. The half-life of the elimination of phenamiphos from brain and plasma were 100 and 212 hr corresponding to the rate constant values of 0.01 and 0.003 hr-1, respectively. Plasma AUC (area under the curve) value was 1239.81 micrograms hr/L, explaining there was no tendency for the compound to accumulate in the brain tissue (AUC = 774.38 micrograms hr/Kg) compared to the plasma. On the other hand, determination of cholinesterase activity showed that, phenamiphos inhibited the enzymes in both brain and plasma, where the depression of ChE activity was usually more marked in plasma than in brain.     

Photocatalytic degradation of humic acid in saline waters. Part 1. Artificial seawater: influence of TiO2, temperature,pH, and air-flow

We report the first systematic study on the photocatalytic oxidation of humic acid (HA) in artificial seawater (ASW). TiO(2) (Degussa P25) dispersions were used as the catalyst with irradiation from a medium-pressure mercury lamp. The optimum quantity of catalyst was found to be between 2 and 2.5 gl(-1); while the decomposition was fastest at low pH values (pH 4.5 in the range examined), and the optimum air-flow, using an immersion well reactor with a capacity of 400 ml, was 850 ml min(-1). Reactivity increased with air-flow up to this figure, above which foaming prevented operation of the reactor. Using pure oxygen, an optimal flow rate was observed at 300 ml min(-1), above which reactivity remains essentially constant. Following treatment for 1 h, low-salinity water (2700 mg l(-1)) was completely mineralised, whereas ASW (46000 mg l(-1)) had traces of HA remaining. These effects are interpreted and kinetic data presented. To avoid problems of precipitation due to change of ionic strength humic substances were prepared directly in ASW, and the effects of ASW on catalyst suspension and precipitation have been taken into account. The Langmuir-Hinshelwood kinetic model has been shown to be followed only approximately for the catalytic oxidation of HA in ASW. The activation energy for the reaction derived from an Arrhenius treatment was 17 (+/-0.6) kJ mol(-1).     

Sustainable ternary cement blends with high-volume ground granulated blast furnace slag–fly ash

Environment, Development and Sustainability - Coal fly ash and granulated ground blast furnace slag (GGBS) are more widely used as supplementary cementitious materials in cement production. This...