ABSTRACT
Noncovalent interactions between the polyoxometalate [PMo12O40](3-) and acryloyloxyundecyltrimethyl ammonium bromide surfactant, used during membrane preparation, were evaluated in the frame of density functional theory. The electronic solvation energy of [PMo12O40](3) and bromide anions was also evaluated, at the same level of theory, in order to predict a probable exchange on the polymeric surface between these anions at the water/polymer interface. Energy balances were theoretically assessed, showing that the bromide cannot be exchanged with this nanosized polyanion in large extent. In order to validate this theoretical conclusion, ad hoc and accurate measurements were carried out by using homemade polymeric membranes and by dipping them in an ca. 0.4 mM solution of Na3[PMo12O40] for 4 days. The Br(-) concentration, released in a polyoxometalate solution, was followed at different times during the test period by gravimetrical analysis. The agreement between the theoretical prediction and experimental data was remarkable, as the quantum calculations correctly accounted for the short-range intermolecular interactions involved in this phenomenon. Bearing in mind that the achieved conclusion is based on an ab initio quantum approach, the findings of this study can be considered rather general and then exploitable for other similar systems.
ABSTRACT
Introducción: La consulta pediátrica pretrasplante es fundamental en un programa de trasplante hepático, allí se evalúan diferentes aspectos como, la indicación del trasplante, el estadio de la enfermedad, comorbilidades asociadas y nos permite corregir las mismas ya que estas influirán en la sobrevida postrasplante. El objetivo fue conocer las características de la población pediátrica evaluada como posibles candidatos a trasplante. Pacientes y Métodos: Se realizó estudio retrospectivo. Se incluyeron todos los pacientes pediátricos que fueron referidos para valoración como posibles candidatos a trasplante hepático desde 2005 al 2010. Resultados: Se estudiaron 152 pacientes, 65 (43%) del sexo masculino y 87 (57%) del sexo femenino, con edad promedio de 6,16 + 5,24 años. Al momento del estudio 61 pacientes no tenían indicación de trasplante, 35 se encontraban en evaluación, 28 se trasplantaron, 21 fallecieron y 7 fueron referidos. Las indicaciones de trasplante fueron: disminución de la síntesis hepática 20, síndrome hepatopulmonar 2, hemorragia digestiva 3, síndrome hepatorrenal 2 y un fallo hepático subagudo. De los pacientes trasplantados 16 presentaban algún grado de desnutrición previa, 3 presentaban ascitis, 7 habían presentado hemorragias digestivas, 6 presentaban infecciones (urinarias, respiratorias y absceso dentarios), 24 tenían patologías odontológicas. Los 28 pacientes tenían esquema de inmunización incompleto durante la evaluación. Todos estos problemas fueron tratados previo al trasplante. Conclusión: La consulta pediátrica de hígado pretrasplante es de suma importancia ya que en ella se identifican los pacientes con indicación de trasplante además de valorar de forma integral al paciente, lo que nos permite conocer aquellas morbilidades asociadas a la enfermedad hepática terminal y resolverlas previo al trasplante, mejorando su posterior sobrevida.
Introduction: Pediatric liver pre-transplantation consultation is very important in a liver transplant program, there different aspects are assessed, such as the indication the transplant, disease stage, associated comorbidities and it allows us to correct them as they will affect the survival after transplantation. The objective was to determine the characteristics of the pediatric population evaluated as potential transplant candidates. Patients And Methods: A retrospective study was performed. All pediatric patients who were referred for evaluation as potential candidates for liver transplantation from 2005 to 2010 were included. RESULTS: 152 patients were studied, 65 (43%) were males and 87 (57%) females, mean age 6.16 ± 5.24 years. At the time of the study 61 patients had no indication for transplant, 35 were been evaluated, 28 were transplanted, 21 died and 7 were referred. The indications for transplantation were: decreased hepatic synthesis 20, hepatopulmonary syndrome 2, gastrointestinal bleeding 3, hepatorenal syndrome 2 and one subacute liver failure. Of the transplanted patients 16 had some degree of previous malnutrition, 3 had ascites, 7 had presented gastrointestinal bleeding, 6 had infections (urinary, respiratory and dental abscess), and 24 had dental pathologies. The 28 patients had an incomplete immunization schedule during the evaluation. All these problems were treated prior to transplantation. Conclusion: the pediatric liver pretransplantation consultation is of most importance since in it we identify patients with indication for transplantation; in addition, we can completely asses the patient allowing us to recognize morbidities associated with the end stage liver disease and resolve them before transplantation, improving subsequent survival.
