Pyrolysis-gas chromatography-isotope ratio mass spectrometry for monitoring natural additives in polylactic acid active food packages.

Compound-specific isotope analysis (CSIA) usually requires preparative steps (pretreatments, extraction, derivatization) to get amenable chromatographic analytes from bulk geological, biological or synthetic materials. Analytical pyrolysis (Py-GC/MS) can help to overcome such sample manipulation. This communication describe the results obtained by hyphenating analytical pyrolysis (Py-GC) with carbon isotope-ratio mass spectrometry (IRMS) for the analysis of a polylactic acid (PLA) a based bio-plastic extruded with variable quantities of a natural plant extract or oregano essential oil. The chemical structural information of pyrolysates was first determined by conventional analytical pyrolysis and the measure of δ13C in specific compounds was done by coupling a pyrolysis unit to a gas chromatograph connected to a continuous flow IRMS unit (Py-GC-C-IRMS). Using this Py-CSIA device it was possible to trace natural additives with depleted δ13C values produced by C3 photosystem vegetation (cymene: -26.7‰±2.52; terpinene: -27.1‰±0.13 and carvacrol: -27.5‰±1.80 from oregano and two unknown structures: -23.3‰±3.32 and -24.4‰±1.70 and butyl valerate: -24.1‰±3.55 from Allium spp.), within the naturally isotopically enriched bio-plastic backbone derived from corn (C4 vegetation) starch (cyclopentanones: -14.2‰±2.11; lactide enantiomers: -9.2‰±1.56 and larger polymeric units: -17.2‰±1.71). This is the first application of Py-CSIA to characterize a bio-plastic and is shown as a promising tool to study such materials, providing not only a fingerprinting, but also valuable information about the origin of the materials, allowing the traceability of additives and minimizing sample preparation.

Simulador de bajo costo para el entrenamiento en la colocación de accesos vasculares periféricos (AVP) en pediatría / Low-cost simulator for the training of peripheral venous access (PVA) placement in pediatrics

Introducción: El entrenamiento en simuladores permite aprender procedimientos en un marco controlado que protege la seguridad de los pacientes pediátricos y que se integra como una instancia de aprendizaje previa a la realidad con el paciente. En el Centro de Simulación del Hospital de Pediatría Juan P. Garrahan se diseñan y validan simuladores de bajo costo artesanales que permiten contar con recursos propios y de reposición inmediata. Objetivo: Describir el diseño de un simulador de bajo costo para la colocación de accesos vasculares periféricos y reportar la experiencia inicial de validación. Métodos: Se diseñó un simulador artesanal inanimado de punción venosa periférica (parte de miembro superior de un niño de edad aproximada de 8 años) con materiales de bajo costo. En una segunda fase y con el propósito de validarlo, se solicitó la colocación del acceso vascular -en el modelo simulado- a enfermeros del hospital que trabajan en el área de internación (usuarios expertos). Al final de cada experiencia, cada operador reportó su opinión sobre el realismo del modelo y utilidad de la experiencia en forma anónima. Resultados Participaron 43 enfermeros; entre el 75 a 90% de las veces, las repuestas fueron "se parece mucho" o "es igual" a la experiencia real de colocación de un acceso venoso a un niño. El 85% expresó que esta práctica permitía mejorar la destreza, y el 100% que el modelo puede ayudar a enseñarla en forma efectiva. Conclusiones El desarrollo de modelos de simuladores de bajo costo para usos específicos, de baja tecnología, resulta importante para el entrenamiento de habilidades. La aceptación por parte de los usuarios calificados y expertos fue muy buena, encontrando en un alto porcentaje similitud con la realidad (AU)

Introduction: Training on simulators allows for the learning of procedures within a controlled framework that protects the safety of pediatric patients and provides a learning moment previous to working with a real patient. In the Simulation Center at Hospital de Pediatría Juan P. Garrahan low-cost simulators are designed and validated that allow for proper resources and immediate replacement. Aim: To describe the design of a low-cost simulator for the placement of peripheral vascular Access and to report the initial experience with the validation of the device. Methods: An inanimate simulator for peripheral puncture (the upper limb of a child of approximately 8 years of age) was designed using lowcost materials. In a second phase with the purpose of validating the device, nurses of the hospital working in the inpatient area (expert users) were asked to insert a venous catheter in the simulation model. At the end of each procedure, each operator was asked to anonymously give their opinion. Results: 43 nurses participated; between 75 and 90% of times, the answers were "it is very similar "or "it is the same as the experience of placing a real venous catheter in a child. Overall, 85% felt that the training improved their skills and 100% considered that the model may be effective in the teaching process. Conclusions: The development of low-cost, low-technology simulation models is important in the training of skills. Acceptance by qualified users and experts was very good. A high degree of similarity with reality was reported (AU)

Pyrolysis-gas chromatography-isotope ratio mass spectrometry of polyethylene.

Polyethylene is probably the most used plastic material in daily life and its accurate analysis is of importance. In this communication the chemical structure of polyethylenes is studied in detail using conventional analytical pyrolysis (Py-GC/MS), bulk stable isotopic analysis (IRMS) and pyrolysis compound specific stable isotopic analysis (Py-CSIA) to measure stable isotope proportions (δ(13)C, δ(15)N and δD) of polyethylene pyrolysis compounds. Polyethylene pyrolysis yields triplet peaks of n-alkanes, α-alkenes and α,ω-alkanedienes. No differences were found for bulk δ(13)C among different polyethylene types. However, conspicuous differences in δD were evident. It was possible to assign structure δ(13)C and δD values to specific polyethylene pyrolysis products in the range 12-18 carbon chain length. Conspicuous differences were found for the pyrolysis products with unsaturated moieties showing significant higher δD values than saturated chains (alkanes) that were deuterium depleted. In addition, a full isotopic fingerprinting (δ(13)C, δ(15)N and δD) for a dye (o-chloroaniline) contained in a polyethylene is reported. To the best of our knowledge this is the first application Py-CSIA to the study of a synthetic polymer. This hyphenated analytical technique is a promising tool to study synthetic materials, providing not only a fingerprinting, but also allowing the traceability of the polymerization process and the origin of the materials.

Primer hallazgo de toxoplasma Gondii en un bovino del estado Yaracuy, Venezuela / First finding of toxoplasma Gondii from a bovine of the Yaracuy State, Venezuela

Se logro el aislamiento de Toxoplasma gondii en una muestra de diafragma de un bovino clínicamente sano, sacrificado para ser destinado al consumo de la población en el Matadero Industrial Centro Occidental de Barquisimeto, estado Lara. La muestra fue inoculada en ratones blancos los cuales se dejaron en observación durante 30 días, al final de este período se inoculó otro lote de ratones, lográndose el aislamiento 7 días después del pasaje. con esto se confirma la infección inaparente por T.gondii en la especie bivina en Venezuela

[Colonization by Streptococcus group B in full term pregnancy and newborns in a community in Venezuela]. / Colonización por Streptococcus grupo B en embarazadas a término y recién nacidos en una comunidad de Venezuela.

BACKGROUND: The aim of this study was to define the incidence of cervico-vaginal colonization by group B Streptococcus (SGB) in full term pregnancy as well as vertical and horizontal transmission in newborns attended in two public hospitals in Valencia, Venezuela. METHODS: An study cervico-vaginal exudates from 171 full term pregnant women was performed together with general obstetric survey. Oropharyngeal and nasal exudate studies in 118 newborns of the mothers studied were carried out during the first 12 hours after birth as was a neonatologic survey. RESULTS: The global percentage of maternal colonization by SGB were 32.7% while in the NB it was 45.8%. Among the NB colonized by SGB 73.2% were considered to have acquired the bacteria from the mother (vertical) with no significant differences in the data found in the two hospitals. The rate of horizontal colonization of the newborns was 42.3% in one hospital and only 8% in the second. CONCLUSIONS: There were no significant statistical differences between the rate of cervico-vaginal colonization in women attended in two public hospitals in Venezuela. No differences were observed in the rate of vertical colonization of newborns but to the contrary, that of the horizontal (nosocomial) colonization was of 42.3% and 8% in the Charity and University Hospitals, respectively.

Leishmaniasis cutanea canina en Venezuela. / Canine cutaneous leishmaniasis in Venezuela

Con el proposito de detectar la presencia de leishmaniasis natural en perros de zonas endemicas, se emprendio una investigacion que comenzo por el valle de Guamacire, donde en fecha reciente se habia registrado un brote de la enfermedad

Phlebotomiane en una zona de leishmaniasis tegumentaria difusa en Venezuela. / Phlebotominae in a area with diffuse cutaneous leishmaniasis in Venezuela

A raiz de un caso de leishmaniasis tegumentaria difusa hallado en el bosque de Macuto, en Barquisimeto, Venezuela, se decidio investigar las especies de flebotomos del lugar, pues habia indicios de que los vectores del parasito residian alli