Detection of cotinine in neonate meconium as a marker for nicotine exposure in utero

Neonate meconium cotinine level was evaluated as a marker of prenatal exposure to nicotine from tobacco smoking by mothers. Mothers admitted to a maternity hospital in Alexandria, Egypt, were divided into 3 groups: 10 active smokers, 10 passive smokers and 10 with no tobacco exposure during pregnancy. Urine and saliva samples were collected from mothers and first-day meconium samples from their neonates. Mean maternal urinary cotinine levels, measured using radioimmunoassay, differed significantly between the 3 groups, as did mean salivary cotinine and mean cotinine levels in meconium.There was a significant positive correlation between cotinine levels in meconium and both maternal urinary and salivary cotinine levels. Meconium is an ideal biological marker for testing direct fetal exposure to tobacco smoke in the neonatal period

Effect of gamma irradiation on stabilized PVC insulators

This study concentrates on following up the deterioration of the properties of PVC insulators as a result of exposure to high-energy ionizing radiation. The effect of gamma-rays in the range of doses up to 600 kGy on mechanical and electrical properties, swelling behavior and solubility of PVC insulator have been studied. As the PVC insulator may come in contact with water during practical conditions of application, its swelling behavior after irradiation different atmospheres is thoroughly investigated. The measurements given in this study were of practical importance and can be used as a guide to predict the deterioration in performance of PVC insulators in radiation environments

Kinetic study on radiation-induced graft polymerization of acrylic acid onto poly [tetrafluoroethylene perfluorovinyl ether [copolymer]

Direct radiation-induced grafting of aqueous acrylic acid [AAG] onto poly [tetrafluoroethylene perfluorovinyl ether] [PFA] film has been studied. The effect of grafting conditions such monomer concentration, exposure dose, dose rate, and film thickness on the grafting yield was investigated. The dependence of the grafting rate on monomer concentration was found to be 1.1 order. The dependence of the grafting rate on dose rate was found to be 0.6 order regardless of the film thickness. The relationship between the grafting rate and film thickness gave a negative first order dependence. The results suggest that the grafting process is mainly controlled by monomer diffusion, and it was concluded that this grafting system proceeded by the front mechanism. The swelling behavior increases linearly with degree of grafting. The swelling behavior, electrical conductivity and mechanical properties for the trunk polymer and grafted films were investigated