RESUMEN
Poly-4-vinylpyridine grafted poly(vinylidene difluoride) (P4VP-g-PVDF) nanoporous polymer electrodes were found to be sensitive for Hg(II) analysis. The fabrication and characterization of functionalized nanoporous membrane-electrodes by FESEM and FTIR are presented. Functionalized nanopore charge state versus a large range of pH (1-10) was investigated by registering the streaming potential. This isoelectric point is achieved at the pKa of P4VP (pH = 5). Mercury adsorption at solid-liquid interface obeys a Langmuir law. A protocol for accurate Hg(II) analysis at ppb level was established. Calibration curves were performed and different real water samples (mineral water, ground water, surface water) were spiked and analyzed. The resulting sensor is intended to be integrated into existing systems or used standalone as portable devices. A first generation prototype exhibiting its own integrated potentiostat, its software and set of membrane-electrode pads is presented.
RESUMEN
Previous research on infant temperament has implicated a variety of prenatal and perinatal conditions, but most studies have investigated a single source of infant variability. This study examined the impact of several prenatal and perinatal factors on infant outcome according to a conceptual system of hypothetical models of influence. Seventy-five couples expecting their first child were recruited and interveiwed in the last trimester of pregnancy, providing demographic data and measures of the pregnancy experience and expectations of parenting. Childbirth information was obtained from hospital records, and infant behaviors were measured at three days of age by the Neonatal Behavioral Assessment Scale. Results indicate that the antecedent variables are themselves intercorrelated in that older, more highly educated, and financially secure couples are more likely to have a satisfying pregnancy and to be confident about childbirth and parenting than their young, more anxious counterparts. Two statistical methods--partial correlation and path analysis--were used to analyze relative relationships with infant behaviors. Results from both methods indicate that most of the antecedent variables (parental characteristics of age and socioeconomics, parental pregnancy orientation, and use of obstetric anesthesia) must be considered sources of infant behaviors. These findings thus demonstrate the imprecision of inferring a single causal pathway of parental or perinatal influence on infant temperament.
Asunto(s)
Conducta Infantil , Desarrollo de la Personalidad , Factores de Edad , Anestesia Obstétrica , Actitud , Peso al Nacer , Parto Obstétrico , Femenino , Humanos , Recién Nacido , Entrevista Psicológica , Masculino , Actividad Motora , Padres , Embarazo , Factores Sexuales , Factores SocioeconómicosRESUMEN
Administration of local-regional anesthesia during norgnal deliveries was correlated significantly with newborn behaviors as evaluated by the Brazelton neonatal assessment scale. Three days after birth, infants whose mothers received local-regional anesthesia were more irritable and motorically less mature than those infants whose mothers were not medicated.
