Abstract The vinyl ester resins and natural composites have emerged as a suitable alternative in tribological application due to mechanical behavior, which relates to the conversion of the double bonds. During tribological test the permanent contact between polymeric sample and counterpart can increase the temperature affecting the crosslinking of the samples. These variations have direct implications in the curing rate and the global conversion. In this work, the FTIR evaluation is used to evaluate possible changes on the global conversion of vinyl ester and their composites reinforced with Musaceae fiber bundles and cured using two hardeners, after a specific tribological test. Increments around 15% on global conversion of styrene double bonds were observed for neat matrix and composites using both hardeners, suggesting that during tribology test some alterations on resin structure takes place. These results open alternatives to manipulate the curing conditions in order to control the tribological behavior.

Las lesiones en la cavidad oral son un motivo de consulta frecuente en la edad pediátrica y un amplio número de enfermedades pueden manifestarse de esta manera. El enfoque adecuado del paciente permite establecer el diagnóstico y orientar el tratamiento. Entre las condiciones asociadas a úlceras únicas de la mucosa oral, el trauma, las infecciones y los medicamentos son consideraciones que deben tenerse presentes. La leishmaniasis es una enfermedad parasitaria, endémica en algunas regiones del país, con transmisión principalmente en áreas rurales. La leishmaniasis mucosa es una forma clínica que se caracteriza por el compromiso de la mucosa de cualquier tejido, especialmente del tracto respiratorio superior y la cavidad oral. Es más común en adultos y, aunque poco frecuente, puede comprometer solamente este tipo de tejido del labio. Se presenta el caso de un lactante de 6 meses de edad, indígena de la etnia emberá, residente en zona rural, quien presenta lesión papular en labio inferior, de crecimiento progresivo, que al examen microscópico muestra la presencia de amastigotes de Leishmania spp. y responde en forma favorable al tratamiento instaurado con miltefosina.

Oral cavity lesions are a common complaint among children that have significant number of etiologies. The proper approach helps to establish the diagnosis and to guide the treatment. Several conditions associated with single oral mucosal ulcers, such as trauma, infections and medications, are considerations to keep in mind. Leishmaniasis is a parasitic disease that is endemic in some regions of the country and it is transmitted primarily in rural areas. Mucosal leishmaniasis is characterised by mucosal involvement of any tissue, especially of the upper respiratory tract and oral cavity. It is more common in adults and although rare, may involve only the lip mucosa. We present a case report of a native Embera patient. He was 6 months old and had a papular lesion on his lower lip with progressive enlargement.The microscopic exam revealed amastigotes of Leishmania spp. and he had a good response to treatment.