Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements

[EN] In this work, green composites from renewable resources were manufactured and characterized. A fibrous material derived from Posidonia oceanica wastes with high cellulose content (close to 90 wt% of the total organic component) was used as reinforcing material. The polymeric matrix to bind the fibers was a protein (wheat gluten) type material. Composites were made by hot-press molding by varying the gluten content on composites in the 10¿40 wt% range. Mechanical properties were evaluated by standardized flexural tests. Thermo-mechanical behavior of composites was evaluated with dynamic mechanical analysis (torsion DMA) and determination of heat deflection temperature. Morphology of samples was studied by scanning electronic microscopy and the water uptake in terms of the water submerged time was evaluated to determine the maximum water uptake of the fibers in the composites. Composites with 10¿40 wt% gluten show interesting mechanical performance, similar or even higher to many commodity and technical plastics, such as polypropylene. Water resistance of these composites increases with the amount of gluten. Therefore, the sensitiveness to the water of the composites can be tailored with the amount of gluten in their formulation.The authors would like to acknowledge the Wallenberg and Lars-Erik Thunholms Foundation for the economical support through the concession of a Postdoctoral Fellowship in Forest related. Authors would also like to thank Marcos and Elena for helping in collecting P. oceanica balls.Ferrero Penadés, B.; Boronat Vitoria, T.; Moriana Torró, R.; Fenollar Gimeno, OÁ.; Balart Gimeno, RA. (2013). Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements. Polymer Composites. 34(10):1663-1669. doi:10.1002/pc.22567S16631669341

Poly(3-hydroxybutyrate-co-hydroxyvalerate) and wheat straw fibers biocomposites produced by co-grinding: Processing and mechanical behavior

International audienceThe main objective of this work was to explore for the first time the potential of the co-grinding process using a high-energy vibrated ball mill to prepare poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/wheat straw fibers biocomposites. Grinding conditions of virgin PHBV pellets were examined by focusing on the evolution of particle size, morphology, crystallinity, and molecular weight. Temperature and grinding duration were demonstrated to be the key parameters affecting PHBV milling. In a second step, mechanical properties of biocomposites prepared by cryo-co-grinding were discussed in relation to the processing conditions and the resulting structure of materials. Comparing to virgin PHBV, the reinforcing effect of wheat straw fibers was very poor, regardless of the good dispersion of fibers within the polymer matrix induced by co-grinding. The increased brittleness and decreased toughness of biocomposites were attributed to (a) a poor interfacial compatibility between wheat straw fibers and PHBV and (b) the degradation of PHBV during processing, as revealed by the decrease in molecular weight

Biocomposites from wheat proteins and fibers: Structure/mechanical properties relationships

For the first time, biocomposites from wheat by-products, i.e. wheat gluten and wheat straw fibers, were prepared using a thermomechanical process. Three types of wheat straw fibers displaying contrasted sizes (median diameter d(50) = 1.1 mm, 62 mu m and 8 mu m), morphologies and surface reactivities were prepared by successive grinding processes (cut milling (CM), impact milling (IM) and ball milling (BM), respectively). The main objectives of the present study were (i) to gain further scientific knowledge about the impact of fibers characteristics on the mechanical properties of these composite materials, and (ii) to evaluate in which extent the addition of wheat straw fibers could decrease the final cost of materials without altering their mechanical properties. Mechanical properties were assessed through tensile tests and discussed in relation to the structure of materials, especially to the interfacial adhesion between the fiber and the matrix. Globally, an increasing fiber content up to 11.1 vol% led to an increase in both the Young's modulus and the stress at break, and to a reduction in the strain at break. Experimental Young's moduli were well predicted by the Tsai-Pagano model for the three types of fibers. Data of specific mechanical energy consumed upon processing, contact angle measurements and observations of cryo-fractured surfaces allowed to demonstrate that the adhesion at the interface wheat straw fiber/wheat gluten was improved by (i) an increased hydrophobicity of wheat straw fibers, which was induced by successive grinding, and (ii) a higher specific surface of fibers which was favoured in the case of small fibers. The interfacial adhesion was improved in the order BM > IM > CM whereas the fiber aspect ratio decreased in the order CM > IM > BM. Thus, a competition between these parameters could occur, explaining why no significant difference in reinforcing effect was achieved between the three types of fibers. Finally, the reinforcing effect of wheat straw fibers was also ascribed to a deplasticizing effect, which was particularly pronounced for BM wheat straw fibers. (C) 2012 Elsevier B.V. All rights reserved

Intervención educativa sobre cáncer bucal en pacientes de alto riesgo entre 35-59 años

Introduction: mortality from oropharyngeal cancer ranked tenth among cancer types in Cuba in 2020 and 2021. Objective: to implement an educational intervention on oral cancer in high-risk patients between 35-59 years old. Method: an educational intervention with a quasi-experimental design, before-after type, was carried out in consulting room 19, La Demajagua, Isla de la Juventud between April-September 2023. The population was 126 patients, the sample being made up of 80 at high risk of oral cancer. Theoretical, empirical and mathematical-statistical methods were used and the variables were used: risk to predict oral cancer, risk factors, oral hygiene, teaching aids and level of knowledge about oral cancer, oral hygiene, risk factors and oral self-examination. Results: the risk of suffering from oral cancer was high in 63 % of the patients between 35-59 years old in the study office. Before the intervention, bad knowledge predominated, representing 48,7 % of the sample, managing to raise it to good after the intervention by 96,3 % . The Wilcoxon test demonstrated highly significant differences. Conclusions: the main risk factors were: poor oral hygiene, smoking, consumption of hot or spicy foods and stress. The use of the website contributed to raising knowledge about oral cancer, the main risk factors associated with its appearance and oral self-examination, allowing the transformation of modes of action and the evaluation of the educational intervention implemented in high-risk patients between 35 and 35 years old as satisfactory.Introducción: la mortalidad por cáncer orofaríngeo ocupó el décimo lugar entre los tipos de cáncer en Cuba en 2020 y 2021. Objetivo: implementar una intervención educativa sobre cáncer bucal en pacientes de alto riesgo entre 35-59 años. Método: se realizó una intervención educativa con diseño cuasi-experimental, tipo antes-después, en el consultorio 19, La Demajagua, Isla de la Juventud entre abril-septiembre de 2023. La población fue de 126 pacientes, quedando conformada la muestra por 80 con alto riesgo a padecer cáncer bucal. Se utilizaron métodos teóricos, empíricos y matemáticos-estadísticos y las variables: riesgo para predecir cáncer bucal, factores de riesgo, higiene bucal, medios de enseñanza y nivel de conocimiento sobre cáncer bucal, higiene bucal, factores de riesgo y autoexamen bucal. Resultados: el riesgo a padecer cáncer bucal fue alto en el 63 % de los pacientes entre 35-59 años del consultorio en estudio. Antes de la intervención predominó un conocimiento malo representando el 48,7 % de la muestra, logrando elevarlo a bueno después de la misma en un 96,3 % . La prueba de Wilcoxon demostró diferencias altamente significativas. Conclusiones: los principales factores de riesgo fueron: mala higiene bucal, tabaquismo, consumo de alimentos calientes o picantes y el estrés. El uso de la página web contribuyó a elevar el conocimiento sobre cáncer bucal, los principales factores de riesgo asociados a su aparición y el autoexamen bucal, permitiendo transformar los modos de actuación y evaluar como satisfactoria la intervención educativa implementada en pacientes de alto riesgo entre 35-59 años

La calidad de la vida del paciente diabético

Se investigó la totalidad de los diabéticos pertenecientes al Policlínico Docente "Cerro" que cuenta con una población de 35 157 habitantes, encontrándose una tasa de 39,5 x 1,000 habitantes para esta enfermedad. Se analizaron las características, complicaciones, mortalidad y estilo de vida de estos enfermos. Proponemos el programa "Mejorar la Calidad de la Vida del Diabético" y se expone su estructura y su dinámica. La primera está basada en la interrelación entre el nivel primario de salud y el secundario constituido por los hospitales clínico-quirúrgicos, pediátricos y ginecoobstétricos; la dinámica del programa se basa en la aplicación de lo que hemos llamado "Las 7 Leyes del Éxito del Paciente Diabético", aspirando a disminuir la mortalidad, las complicaciones y los costos de la diabetes mellitus a razón de un 10 % anua