RESUMO
Copolymerization of xylitol usually yields cross-linked materials. In this work, microwave-assisted polyesterification of xylitol and succinic acid produced materials with diverse molecular weights and different branching degrees, and more importantly, no cross-linking was observed, as supported by the solubility behavior and spectroscopic data. Reactions were carried out for short times, less than 20 min, which is not common for production of industrial polyesters. Control over the branching degree was achieved by tuning the reaction conditions, such as temperature, time of exposure, and monomer ratio, during microwave irradiation. No solvent or catalyst was employed during the step-growth polymerization.
RESUMO
En un trabajo retrospectivo se revisa la utilidad de la terapeutica homeopatica en 120 pacientes con diagnostico de asma bronquial provenientes de la poblacion infantil, destacando el uso del medicamento unico, el aumento de la tolerancia a las diferentes noxas y el bajo numero de hospitalizaciones posteriores al inicio del tratamiento. Se presenta la experiencia de un homeopata y se ponen a consideracion sus observaciones