24 research outputs found

    Evaluation of Fungi Toxic Activity of Tannins and a Tannin-Copper Complex from the Mesocarp of Cocos Nucifera Linn

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    The fibrous envelope of the coconut tree is an agroindustrial waste product that possesses relevant properties, such as a high resistance to biological degradation, because of its phenolic compound composition. In this study, the fungitoxic activity of tannins and a tannin-copper complex from the mesocarp of Cocos nucifera Linn was conducted. An extract from the coconut mesocarp was obtained in acidic media using a 2.0 wt % solution of NaHSO3. Bioassays were conducted on alder wood (Alnus acuminata ssp. glabrata H.B.K.) using two types of aqueous solutions: 1) crude extract from the coconut mesocarp diluted at several concentrations (0.5, 1.0, 2.0, and 4.0 wt %); and 2) a tannin-copper complex formed in two stages by impregnation of the alder wood samples, first with the coconut mesocarp extract solutions followed by addition of a CuCl2 solution. The fungitoxic capacity of the tannin and tannin-copper complex solutions was evaluated by means of bioassays with Trametes versicolor (L. ex. Fr.) Pilát according to ASTM D 1413-07. The bioassays showed poor fungal inhibition for the wood samples impregnated with the crude extract solutions. However, the tannin-copper complex solutions showed greater fungal inhibition. Retention values of 4.03 and 1.76 kg m-3 were obtained. These values revealed high fungal inhibition for Trametes versicolor

    Fungitoxic Potential of Extracts of Four Pinus spp. Bark to Inhibit Fungus Trametes versicolor (L. ex. Fr.) Pilát

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    Antifungal potential of bark crude extracts of Pinus strobus L., Pinus douglasiana Martinez, Pinus caribaea Morelet [var. Hondurensis (scheclauze) W. H. G. Barrett & Golfari] and Pinus leiophylla Schltdl. & Cham, for inhibiting mycelial growth to fungus Trametes versicolor (L. ex Fr.) Pilát was investigated. Pinus bark was extracted through a mixture of acetone-hexane-water 54:44:2 V. Bioassays were performed according to the agar dilution method (petri dish) using concentrations of 0.1, 0.5, and 1.0 mg mL-1 for each of the obtained extracts. All extracts showed some inhibition degree. Crude extracts of P. strobus bark showed the greatest inhibition degree. Antifungal potential of all tested extracts at a concentration of 1.0 mg mL-1 was classified as toxic. Through simple regression models, concentrations were calculated in order to achieve a 50% inhibition (IC50) and the minimal inhibition concentration (MIC). MIC values were 1.58, 1.72, 1.24, and 1.94 mg mL-1 for bark extracts of P. strobus, P. douglasiana, P. caribaea, and P. leiophylla, respectively

    Utilization of Wood Flour from White Oak Branches as Reinforcement in a Polypropylene Matrix: Physical and Mechanical Characterization

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    Compared to other fibrous materials, plant fibers can act as a reinforcement in plastics due to their relatively high strength and rigidity, low cost, low density, biodegradability, and renewability. In this context, this study examines the effect of the particle size and content of white oak wood flour (Quercus laeta Liemb), obtained from its branches, on the properties of commercial polypropylene. In Mexico, wood from the branches of Quercus laeta Liemb is barely utilized despite its abundance and viability. The main objective of this study is to demonstrate that this waste material can be exploited to prepare useful materials, in this case composites with competitive properties. Tensile and flexural tests, as well as impact strength and melt flow index were evaluated. In addition, density and water absorption capacity were also tested. Results showed that the water absorption increased with the incorporation of wood particles. Mechanical properties were strongly influenced by particle content. A reduction in elongation and strength was observed, while Young’s modulus and flexural modulus increased with the incorporation of wood particles. Impact strength increased with particle size and particle content

    Utilization of Wood Flour from White Oak Branches as Reinforcement in a Polypropylene Matrix: Physical and Mechanical Characterization

    No full text
    Compared to other fibrous materials, plant fibers can act as a reinforcement in plastics due to their relatively high strength and rigidity, low cost, low density, biodegradability, and renewability. In this context, this study examines the effect of the particle size and content of white oak wood flour (Quercus laeta Liemb), obtained from its branches, on the properties of commercial polypropylene. In Mexico, wood from the branches of Quercus laeta Liemb is barely utilized despite its abundance and viability. The main objective of this study is to demonstrate that this waste material can be exploited to prepare useful materials, in this case composites with competitive properties. Tensile and flexural tests, as well as impact strength and melt flow index were evaluated. In addition, density and water absorption capacity were also tested. Results showed that the water absorption increased with the incorporation of wood particles. Mechanical properties were strongly influenced by particle content. A reduction in elongation and strength was observed, while Young’s modulus and flexural modulus increased with the incorporation of wood particles. Impact strength increased with particle size and particle content

    The effects of implementing a smoking cessation intervention in Spain on morbidity, mortality and health care costs.

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    [ES] Objetivo Se valoran los efectos que tendría una intervención destinada a reducir el uso de tabaco en la población española de fumadores sobre la morbilidad, la mortalidad y los costes asociados al consumo de tabaco. Método Se ha adaptado el modelo Health and Economic Consequences of Smoking patrocinado por la OMS y desarrollado por The Lewin Group. La intervención propuesta incluye el acceso a asistencia farmacológica de un 35% de los fumadores que intentan dejar de fumar, y obtienen una tasa global de cesación al año del 7,2%. Las enfermedades estudiadas son: cáncer de pulmón, enfermedad coronaria, enfermedad cerebrovascular, EPOC, asma y bajo peso al nacer. Se estiman los casos de enfermedad y muerte atribuibles al consumo de tabaco evitados y la reducción en el coste sanitario debidos a la intervención, proyectados a 20 años. Resultados Sin intervención, en el año 1 del modelo 2.136.094 fumadores padecen alguna de las condiciones clínicas atribuibles al consumo de tabaco, el coste asistencial es de 4.286 millones de euros y las muertes atribuibles son 26.537. La intervención propuesta evita 2.613, 9.192, 17.415 y 23.837 casos de enfermedad atribuible al consumo de tabaco en los años 2, 5, 10 y 20 del modelo, respectivamente. Los costes asistenciales acumulados evitados son 3,5 millones de euros en el año 2 y 386 millones de euros a los 20 años. Las muertes acumuladas evitadas son 284 en el año 2 y 9.205 a los 20 años de la intervención. La intervención añade un total de 78.173 años de vida al final del período considerado. Conclusiones La disponibilidad de nuevas intervenciones eficaces en el tratamiento del tabaquismo y el incremento de la accesibilidad a las mismas pueden contribuir de forma relevante a la reducción de la morbilidad, la mortalidad y los costes sanitarios asociados al tabaquismo en España. [EN] We estimated the effect that a smoking cessation intervention in the Spanish population of smokers would have on smoking-related morbidity, mortality and health care costs. We adopted the model Health and Economic Consequences of Smoking sponsored by the WHO Health Organization and developed by the The Lewin Group. The smoking cessation intervention proposed includes pharmacological treatment to 35% of smokers who are trying to quit smoking and obtains a quit rate of 7.2%. The diseases studied are: lung cancer, heart disease, stroke, chronic obstructive pulmonary disease, asthma exacerbation, and low birth weight. The smoking-related cases of disease and of averted death and the reduction in health care expenditure due to the intervention were estimated. Without intervention, at year 1 of the model, 2,136,094 smokers would be affected by some smoking-related disease; health care expenditure would be 4,286 million e and deaths attributable to smoking would total 26,537. The proposed intervention would prevent 2,613, 9,192, 17,415 and 23,837 cases of smoking-related disease at years 2, 5, 10 and 20 of the model, respectively. The saving in accumulated health care costs would amount to 3.5 million e at year 2 and 386 million e over 20 years. The accumulated prevented deaths are 284 at year 2 and 9,205 over 20 years. The intervention would save a total of 78,173 life-years by the end of the period considered. The availability of new effective smoking cessation interventions and the increase in accessibility to such interventions may contribute significantly to reducing morbidity, mortality and health care costs associated with smoking in Spain.S

    Evaluation of the Fungitoxic Effect of Extracts from the Bark of <i>Quercus laeta</i> Liebm, the Cob of <i>Zea mays</i> and the Leaves of <i>Agave tequilana</i> Weber Blue Variety against <i>Trametes versicolor</i> L. Ex Fr

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    Wood products used in outdoor applications can be degraded by xylophage organisms. For this reason, such products require treatments based on biocides in order to delay their service life. This brings troubles of its own due to the inherent toxicity of these treatments towards humans and the environment. Therefore, it is imperative to find less-toxic natural preservatives. In this context, this work deals with the evaluation of the fungitoxic effect of raw extracts obtained from three types of agroindustrial waste materials: bark of Quercus laeta spp., the cob of Zea mays, and the leaves of Agave tequilana Weber Blue variety. Extracts were incorporated into the test wood Alnus acuminata (Aile wood) via a full-cell process. Bark extracts provided excellent protection against the attack of Trametes versicolor (L. ex. Fr.) Pilát, improving the decay resistance of Aile wood from being nonresistant to resistant. Also, bark extracts from Q. laeta showed less leaching than the other extracts
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