Agradecimientos. Expresamos nuestro agradecimiento a las instituciones participantes y a SERONO de Colombia por su colaboración. © 2000, REVISTA DE NEUROLOGÍA INTRODUCCIÓNLa esclerosis múltiple (EM) se caracteriza clínicamente por remisiones y recaídas de curso fluctuante con tendencia a la cronicidad, así como por las lesiones neuropatológicas, sin causa definida; dichas lesiones consisten en numerosas áreas desmielinizantes o placas de desmielinización que se encuentran dispersas en el sistema nervioso, con predilección por los nervios ópticos, el tallo cerebral, la médula espinal y la sustancia blanca periventricular [1].La EM es la enfermedad desmielinizante humana más común y alcanza una prevalencia de hasta un 0,2%, en áreas de frecuente aparición como los países del norte de Europa, Canadá y Estados Unidos [2].Se han postulado muchas hipótesis sobre la etiología de la EM. La más cimentada es la existencia de un proceso autoinmune en el que interactúa una predisposición genética conferida, entre otros, por algunos alelos del sistema mayor de histocompatibilidad (HLA-DR2 o DQα) y vinculada al contexto genético individual, con la presencia de componentes medio ambientales todavía en estudio [2,3].Se ha demostrado que la EM es menos frecuente en las regiones tropicales que en las zonas localizadas en el subtrópico. En Latinoamérica, particularmente, existen algunos estudios que Prevalencia de la esclerosis múltiple en Colombia ORIGINAL PREVALENCE OF MULTIPLE SCLEROSIS IN COLOMBIA Summary. Introduction. Multiple sclerosis (MS) is the commonest demyelinating condition of the nervous system. It is characterized by numerous demyelinating areas or plaques of demyelination which are found dispersed throughout the nervous system. It has been shown that MS is less frequent in tropical regions than in subtropical regions. In Latin America particularly, there are some studies which show this phenomenon. However, in Colombia no studies of prevalence of MS have been done. Objective. To determine the prevalence of multiple sclerosis in five provinces of Colombia (Antioquia, Caldas, Santander, Risaralda and Bolivar). Patients and methods. The capture-recapture method was used for two sources to determine the number of cases defined on the criteria of Poser et al seen between July 1995 and June 2000. Results. The prevalence (cases of MS per 100,000 inhabitants) varied between 1.48 in Antioquia (95% CI 1.12; 1.78) and 4.98 in Risaralda (95% CI 3.52; 6.43). Seventy two percent were women. The regions included in this study represented 25% of the population of Colombia. Conclusions. There is a low prevalence of MS which is as expected in tropical areas. Persons with MS in these regions may be very useful in the study of other factors involved in the aetiology of MS (genetic). The capture-recapture method is an excellent tool for carrying out prevalence studies since it is cheap and requires little time. [REV NEUROL 2000; 31: 1101-3] [http: //www.revneurol.com/3112/j121101.pdf]
Previously, Polyvinyl Alcohol (PVA) and phenolic resin were used for resin impregnated bamboo fiber reinforced PP composites which was manufactures for resin impregnated bamboo fiber with polypropylene (PP). Resin impregnation method can show improvement on tensile strength of fiber. However, to reduce the contact surface area and low inter-facial shear strength (IFSS) between impregnated resin and matrix, using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated composites were produced butphenolic resin impregnated fiber reinforced composition's mechanical properties were decreased. In this study maleic anhydride grafted polypropylene (MAPP) was used to increase interfacial shear strength between resin impregnated fiber and PP. With 10% MAPP, IFSS between resin impregnated fiber and PP increased more than 100% and reinforced composites. MAPP with untreated, phenolic resin and PVA impregnated cases showed similar mechanical properties. Yet in water absorption test, the PVA treatment with bamboo/PP composites increased water absorption ratio. But with 10% MAPP, matrix PP water absorption ratio decreased like phenolic resin impregnated fiber reinforced composites. 10% MAPP with resin impregnated bamboo fiber reinforced PP composites can improve IFSS, mechanical properties of composite and can decrease water absorption PVA resin impregnated bamboo fiber reinforced composites.
Previously bamboo fiber reinforced PP composites was manufactures using Polyvinyl Alcohol (PVA) and Phenolic resin for Resin impregnated bamboo fiber with polypropylene (PP). Using 40% weight fraction of bamboo fiber in PP matrix, PVA impregnated composites with mean flexural and tensile strength 10% higher than untreated were produced. The PVA treatment improved the tensile and flexural strength of bamboo/PP composites and increased water absorption ratio. Next, matrix modified with Maleic Anhydride grafted Polypropylene (MAPP). For matrix PP mixed with 10% of MAPP. In this study, resin impregnation method dose not make different for mechanical properties of composites. Untreated and PVA, Phnolic resin impregnated mechanical properties was almost same. However; it can decreased water absorption PVA resin absorption bamboo fiber composites.
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