RESUMO
Ceramic membranes for MFCs offer a low cost alternative to the expensive ion exchange membranes, whilst promoting catholyte accumulation. However, their physicochemical properties need to be optimised, in order to increase the power output and the catholyte quality from MFCs. Two compositions of fine fire clay (FFC) cured under three firing cycles were manufactured, analysed and tested as ion-exchange and structural material for MFCs. The samples were characterised by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The power and catholyte generated from the ceramic MFCs with different FFC types was also evaluated. The results show a direct correlation between the ohmic resistance, the MFC power generation and the water absorption of the ceramics, giving a maximum power of 1â¯mW from the MFC with the most absorptive FFC (16.37% water absorbance). A slightly more alkaline catholyte was synthesised from the MFCs with higher water absorption FFC.
RESUMO
BACKGROUND: The sphenopalatine foramen is located on the lateral nasal wall and has multiple variants and anatomic landmarks that are important to know to optimize RESULTS in the surgical management of posterior epistaxis. OBJECTIVE: This study describes the endoscopic anatomy of the sphenopalatine foramen, related structures and anatomic variations in a Mexican population. METHODS: We performed a prospective, observational, and experimental study. Five cadaveric specimens were included. Dissections were performed to identify the anatomy of the sphenopalatine foramen and anatomic variants. Measurements were obtained from different anatomic references to the columella. RESULTS: Of a total of ten dissections, in 100% of cases ethmoid crests were identified anterior to the sphenopalatine foramen. Localization of the sphenopalatine foramen in the lateral nasal wall in 60% cases was in the transition from middle meatus with superior meatus. The vidian nerve in 90% of cases was located superior and posterior to the sphenopalatine foramen. For the measurements, no significant differences between the two sides of each specimen were noticed. CONCLUSIONS: The sphenopalatine foramen presents multiple anatomic variants and numerous landmarks, which are important to comprehend in order to perform a successful and safe endoscopic sinus surgery.
ANTECEDENTES: el foramen esfenopalatino se localiza en la pared nasal, con múltiples variantes y referencias anatómicas que es importante conocer para optimizar los RESULTADOS del tratamiento quirúrgico y la epistaxis posterior. OBJETIVO: describir la anatomía endoscópica del foramen esfenopalatino, las estructuras relacionadas, y las variantes anatómicas en población mexicana. MATERIAL Y MÉTODOS: estudio prospectivo, observacional y experimental. Se incluyeron 5 especímenes cadavéricos, se realizaron las disecciones para identificar la anatomía del foramen esfenopalatino y sus variantes anatómicas, se midieron diferentes referencias anatómicas a la columela. RESULTADOS: de 10 disecciones realizadas, en 100% de los casos se identificó la cresta etmoidal anterior al foramen esfenopalatino, la localización en la pared nasal en 60% de los casos fue en la transición del meato medio con el meato superior, el nervio Vidiano en 90% de los casos se localizó posterosuperior al foramen esfenopalatino. En relación con las mediciones no se encontraron diferencias significativas entre ambos lados de cada fosa nasal. CONCLUSIONES: las variantes anatómicas del foramen esfenopalatino son múltiples, por lo que contar con referencias anatómicas es de suma importancia para poder localizarlo durante la cirugía endoscópica nasal. Palabras clave: foramen esfenopalatino, arteria esfenopalatina, nervio vidiano, epistaxis posterior, cresta etmoidal, pared nasal.