Kinetics and mechanisms of electrochemical reactions on platinum with solutions of iodine-sodium iodide in acetonitrile

The kinetics of the iodine-tri-iodide-iodide electrode in acetonitrile has been investigated in the temperature range from 0 to 30°C. Current/voltage curves were determined using a platinum rotating disk electrode working at 200 to 3000 rpm. The anodic and cathodic current/voltage curves are characterized by two well defined waves. The total reactions related to the first and second anodic waves are respectively 3I− = I3− + 2 e and 2I3− = 3I2 + 2 e, while the reverse reactions represent the second and first cathodic waves respectively. The diffusion coefficients of the diffusing species have been evaluated. Current/voltage curves in the region preceding the limiting cd exhibit a measurable irreversibility. The kinetic parameters related to the activated process were determined, and the kinetics of the reactions interpreted in terms of reaction mechanisms that involve an ion plus atom reaction as rate determining step for the anodic process and the reverse reaction for the cathodic process.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Kinetics and mechanisms of electrochemical reactions on platinum with solutions of iodine-sodium iodide in acetonitrile

The kinetics of the iodine-tri-iodide-iodide electrode in acetonitrile has been investigated in the temperature range from 0 to 30°C. Current/voltage curves were determined using a platinum rotating disk electrode working at 200 to 3000 rpm. The anodic and cathodic current/voltage curves are characterized by two well defined waves. The total reactions related to the first and second anodic waves are respectively 3I− = I3− + 2 e and 2I3− = 3I2 + 2 e, while the reverse reactions represent the second and first cathodic waves respectively. The diffusion coefficients of the diffusing species have been evaluated. Current/voltage curves in the region preceding the limiting cd exhibit a measurable irreversibility. The kinetic parameters related to the activated process were determined, and the kinetics of the reactions interpreted in terms of reaction mechanisms that involve an ion plus atom reaction as rate determining step for the anodic process and the reverse reaction for the cathodic process.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Kinetics and mechanisms of electrochemical reactions on platinum with solutions of iodine-sodium iodide in acetonitrile

The kinetics of the iodine-tri-iodide-iodide electrode in acetonitrile has been investigated in the temperature range from 0 to 30°C. Current/voltage curves were determined using a platinum rotating disk electrode working at 200 to 3000 rpm. The anodic and cathodic current/voltage curves are characterized by two well defined waves. The total reactions related to the first and second anodic waves are respectively 3I− = I3− + 2 e and 2I3− = 3I2 + 2 e, while the reverse reactions represent the second and first cathodic waves respectively. The diffusion coefficients of the diffusing species have been evaluated. Current/voltage curves in the region preceding the limiting cd exhibit a measurable irreversibility. The kinetic parameters related to the activated process were determined, and the kinetics of the reactions interpreted in terms of reaction mechanisms that involve an ion plus atom reaction as rate determining step for the anodic process and the reverse reaction for the cathodic process.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Correlation between SERS of Pyridine and Electrochemical Response of Silver Electrodes in Halide-Free Alkaline Solutions

Surface-enhanced Raman scattering (SERS) of pyridine (Py) on Ag electrodes in alkaline solutions free of halide ions was obtained at 25°C as a function of the applied potential. The Ag surface was activated for SERS through repetitive oxidation-reduction cycles (ORC), the effect being dependent on the electrochemical electrode history. The SERS effect was correlated to the activation for the hydrogen evolution reaction (HER), which can be obtained by means of potentiodynamic as well as potentiostatic procedures. The maximum SERS activity was achieved at potentials near the potential of zero charge (pzc) of polycrystalline Ag and appeared to be related to the maximum observed in the roughness factor vs potential curve. These results can be interpreted through the formation of a new uniform globular overlayer structure on the electroreduced Ag surface, which apparently exhibits a certain degree of preferred crystallographic orientation. Three well-defined potential regions can be distinguished for the complex competitive interactions between H2O, OH- ion, and Py with the new Ag electrode surface.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Risk factors for bronchiolitis hospitalization during the first year of life in a multicenter Italian birth cohort

BACKGROUND: Respiratory Syncytial Virus (RSV) is one of the main causes of respiratory infections during the first year of life. Very premature infants may contract more severe diseases and 'late preterm infants' may also be more susceptible to the infection. The aim of this study is to evaluate the risk factors for hospitalization during the first year of life in children born at different gestational ages in Italy. METHODS: A cohort of 33-34 weeks gestational age (wGA) newborns matched by sex and age with two cohort of newborns born at 35-37 wGA and > 37 wGA were enrolled in this study for a three-year period (2009-2012). Hospitalization for bronchiolitis (ICD-9 code 466.1) during the first year of life was assessed through phone interview at the end of the RSV season (November-March) and at the completion of the first year of life. RESULTS: The study enrolled 2314 newborns, of which 2210 (95.5 %) had a one year follow-up and were included in the analysis; 120 (5.4 %) were hospitalized during the first year of life for bronchiolitis. Children born at 33-34 wGA had a higher hospitalization rate compared to the two other groups. The multivariate analysis carried out on the entire population associated the following factors with higher rates for bronchiolitis hospitalization: male gender; prenatal treatment with corticosteroids; prenatal exposure to maternal smoking; singleton delivery; respiratory diseases in neonatal period; surfactant therapy; lack of breastfeeding; siblings <10 years old; living in crowded conditions and/or in unhealthy households and early exposure to the epidemic RSV season. When analysis was restricted to preterms born at 33-34 wGA the following variables were associated to higher rates of bronchiolitis hospitalization: male gender, prenatal exposure to maternal smoking, neonatal surfactant therapy, having siblings <10 years old, living in crowded conditions and being exposed to epidemic season during the first three months of life. CONCLUSION: Our study identified some prenatal, perinatal and postnatal conditions proving to be relevant and independent risk factors for hospitalization for bronchiolitis during the first year of life. The combination of these factors may lead to consider palivizumab prophylaxis in Italy

Prenatal tobacco smoke exposure increases hospitalizations for bronchiolitis in infants

BACKGROUND: Tobacco smoke exposure (TSE) is a worldwide health problem and it is considered a risk factor for pregnant women's and children's health, particularly for respiratory morbidity during the first year of life. Few significant birth cohort studies on the effect of prenatal TSE via passive and active maternal smoking on the development of severe bronchiolitis in early childhood have been carried out worldwide. METHODS: From November 2009 to December 2012, newborns born at ≥ 33 weeks of gestational age (wGA) were recruited in a longitudinal multi-center cohort study in Italy to investigate the effects of prenatal and postnatal TSE, among other risk factors, on bronchiolitis hospitalization and/or death during the first year of life. RESULTS: Two thousand two hundred ten newborns enrolled at birth were followed-up during their first year of life. Of these, 120 (5.4%) were hospitalized for bronchiolitis. No enrolled infants died during the study period. Prenatal passive TSE and maternal active smoking of more than 15 cigarettes/daily are associated to a significant increase of the risk of offspring children hospitalization for bronchiolitis, with an adjHR of 3.5 (CI 1.5-8.1) and of 1.7 (CI 1.1-2.6) respectively. CONCLUSIONS: These results confirm the detrimental effects of passive TSE and active heavy smoke during pregnancy for infants' respiratory health, since the exposure significantly increases the risk of hospitalization for bronchiolitis in the first year of lif

A classification system for argumentation schemes

This paper explains the importance of classifying argumentation schemes, and outlines how schemes are being used in current research in artificial intelligence and computational linguistics on argument mining. It provides a survey of the literature on scheme classification. What are so far generally taken to represent a set of the most widely useful defeasible argumentation schemes are surveyed and explained systematically, including some that are difficult to classify. A new classification system covering these centrally important schemes is built

Toll-like receptor 4 and high-mobility group box-1 are involved in ictogenesis and can be targeted to reduce seizures

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Similarity, precedent and argument from analogy

In this paper, it is shown (1) that there are two schemes for argument from analogy that seem to be competitors but are not, (2) how one of them is based on a distinctive type of similarity premise, (3) how to analyze the notion of similarity using story schemes illustrated by some cases, (4) how arguments from precedent are based on arguments from analogy, and in many instances arguments from classification, and (5) that when similarity is defined by means of episode schemes, we can get a clearer idea of how it integrates with the use of argument from classification and argument from precedent in case-based reasoning by using a dialogue structure