Interference of biodegradable plastics in the polypropylene recycling process

[EN] Recycling polymers is common due to the need to reduce the environmental impact of these materials. Polypropylene (PP) is one of the polymers called commodities polymers' and it is commonly used in a wide variety of short-term applications such as food packaging and agricultural products. That is why a large amount of PP residues that can be recycled are generated every year. However, the current increasing introduction of biodegradable polymers in the food packaging industry can negatively affect the properties of recycled PP if those kinds of plastics are disposed with traditional plastics. For this reason, the influence that generates small amounts of biodegradable polymers such as polylactic acid (PLA), polyhydroxybutyrate (PHB) and thermoplastic starch (TPS) in the recycled PP were analyzed in this work. Thus, recycled PP was blended with biodegradables polymers by melt extrusion followed by injection moulding process to simulate the industrial conditions. Then, the obtained materials were evaluated by studding the changes on the thermal and mechanical performance. The results revealed that the vicat softening temperature is negatively affected by the presence of biodegradable polymers in recycled PP. Meanwhile, the melt flow index was negatively affected for PLA and PHB added blends. The mechanical properties were affected when more than 5 wt.% of biodegradable polymers were present. Moreover, structural changes were detected when biodegradable polymers were added to the recycled PP by means of FTIR, because of the characteristic bands of the carbonyl group (between the band 1700-1800 cm(-1)) appeared due to the presence of PLA, PHB or TPS. 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Effectiveness of acute geriatric units on functional decline, living at home, and case fatality among older patients admitted to hospital for acute medical disorders: meta-analysis

Objective To assess the effectiveness of acute geriatric units compared with conventional care units in adults aged 65 or more admitted to hospital for acute medical disorders

Effect of pine resin derivatives on the structural, thermal, and mechanical properties of Mater-Bi type bioplastic

"This is the peer reviewed version of the following article: Aldas, M., J. M. Ferri, J. Lopez-Martinez, M. D. Samper, and M. P. Arrieta. 2019. Effect of Pine Resin Derivatives on the Structural, Thermal, and Mechanical Properties of Mater-Bi Type Bioplastic. Journal of Applied Polymer Science 137 (4). Wiley: 48236. doi:10.1002/app.48236, which has been published in final form at https://doi.org/10.1002/app.48236. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The effect of three additives derived from pine resin, namely, gum rosin (GR) and two pentaerythritol ester of GR, Lurefor (LF) and Unik Tack (UT), in 5, 10, and 15 wt %, on the properties of Mater-Bi, based on plasticized starch, poly(butylene adipate-co-terephthalate), and poly(epsilon-caprolactone) (PCL), obtained by injection molding processes, was studied. The mechanical, microstructural, and thermal properties were evaluated. LF had a cohesive behavior with the components of Mater-Bi, increasing the toughness of the material up to 250% accompanied by an increase of tensile modulus and tensile strength. UT had an intermediate behavior, conferring cohesive and plasticizing effects, allowing an increase of 105% in impact resistance. GR had a more marked plasticizing effect. This allows processing temperatures of about 50 degrees C lower than those used for neat Mater-Bi. In addition, an increase of the elongation at break, toughness, and impact resistance in 370, 480, and 250%, respectively, was achieved.This work was supported by the Spanish Ministry of Economy and Competitiveness, PROMADEPCOL (MAT2017-84909-C2-2-R). M. P. Arrieta thanks Complutense University of Madrid for "Ayudas para la contratacion de personal postdoctoral en formacion en docencia e investigacion en departamentos de la UCM."Aldas-Carrasco, MF.; Ferri, JM.; López-Martínez, J.; Samper, M.; Arrieta, MP. (2020). 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Optimización de un secadero solar de tipo gabinete: evaluación y modelización del proceso de secado y tipificación del producto seco

Se exponen resultados de actividades emprendidas tendientes a la optimización de un secadero solar de tipo gabinete. El mismo es operado por un establecimiento local de productos frutihortícolas orgánicos (Granja Che Rovia) a la cual el grupo se encuentra prestando asesoramiento en el marco de un convenio firmado entre la Facultad y la Asociación de Productores Orgánicos de Corrientes. Se analizaron diferentes productos realizándose ensayos de secado en laboratorio y campo. El estudio comprende el proceso de secado, propiedades organolépticas y determinación del peso seco de los productos secos. A las curvas de secado, para productos de hoja, obtenidas en laboratorio se aplicó un modelo exponencial de pérdida de peso determinándose los parámetros característicos mediante ajuste de datos a la ecuación teórica del modelo. El modelo ajustado se comparó con resultados de campo. La correlación obtenida indica que su uso permitiría establecer estrategias de operación y producción para productos de hoja. Se determinó en 18% la eficiencia del secadero para el caso de secado de ortiga.Results of activities aimed at the optimisation of a cabinet type solar dryer are presented. The dryer is operated by a local organic farm (Granja Che Rovia) to which this group is lending advice within the frame of an agreement signed between the Association of Organic Producers of Corrientes and the Physics Dpnt of FaCENA - UNNE. Several products were analysed. In all cases drying curves were obtained in the laboratory and with the solar dryer as well as. The study comprises the drying process, physical properties and determination of the dry weight of the dried products. To the drying curves obtained in laboratory for leaf products an exponential model of loss of weight was applied. The characteristic parameters were determined by three-variable parameters curve fitting of experimental data using the theoretical equation as fitting function. The adjusted solution was compared with field results. The correlation obtained indicates, in principle, that it could be used to establish operation and production strategies for leaf products. It was also determined a total thermal efficiency for the dryer in the order of 18%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Optimización de un secadero solar de tipo gabinete: evaluación y modelización del proceso de secado y tipificación del producto seco

Se exponen resultados de actividades emprendidas tendientes a la optimización de un secadero solar de tipo gabinete. El mismo es operado por un establecimiento local de productos frutihortícolas orgánicos (Granja Che Rovia) a la cual el grupo se encuentra prestando asesoramiento en el marco de un convenio firmado entre la Facultad y la Asociación de Productores Orgánicos de Corrientes. Se analizaron diferentes productos realizándose ensayos de secado en laboratorio y campo. El estudio comprende el proceso de secado, propiedades organolépticas y determinación del peso seco de los productos secos. A las curvas de secado, para productos de hoja, obtenidas en laboratorio se aplicó un modelo exponencial de pérdida de peso determinándose los parámetros característicos mediante ajuste de datos a la ecuación teórica del modelo. El modelo ajustado se comparó con resultados de campo. La correlación obtenida indica que su uso permitiría establecer estrategias de operación y producción para productos de hoja. Se determinó en 18% la eficiencia del secadero para el caso de secado de ortiga.Results of activities aimed at the optimisation of a cabinet type solar dryer are presented. The dryer is operated by a local organic farm (Granja Che Rovia) to which this group is lending advice within the frame of an agreement signed between the Association of Organic Producers of Corrientes and the Physics Dpnt of FaCENA - UNNE. Several products were analysed. In all cases drying curves were obtained in the laboratory and with the solar dryer as well as. The study comprises the drying process, physical properties and determination of the dry weight of the dried products. To the drying curves obtained in laboratory for leaf products an exponential model of loss of weight was applied. The characteristic parameters were determined by three-variable parameters curve fitting of experimental data using the theoretical equation as fitting function. The adjusted solution was compared with field results. The correlation obtained indicates, in principle, that it could be used to establish operation and production strategies for leaf products. It was also determined a total thermal efficiency for the dryer in the order of 18%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Optimización de un secadero solar de tipo gabinete: evaluación y modelización del proceso de secado y tipificación del producto seco

Se exponen resultados de actividades emprendidas tendientes a la optimización de un secadero solar de tipo gabinete. El mismo es operado por un establecimiento local de productos frutihortícolas orgánicos (Granja Che Rovia) a la cual el grupo se encuentra prestando asesoramiento en el marco de un convenio firmado entre la Facultad y la Asociación de Productores Orgánicos de Corrientes. Se analizaron diferentes productos realizándose ensayos de secado en laboratorio y campo. El estudio comprende el proceso de secado, propiedades organolépticas y determinación del peso seco de los productos secos. A las curvas de secado, para productos de hoja, obtenidas en laboratorio se aplicó un modelo exponencial de pérdida de peso determinándose los parámetros característicos mediante ajuste de datos a la ecuación teórica del modelo. El modelo ajustado se comparó con resultados de campo. La correlación obtenida indica que su uso permitiría establecer estrategias de operación y producción para productos de hoja. Se determinó en 18% la eficiencia del secadero para el caso de secado de ortiga.Results of activities aimed at the optimisation of a cabinet type solar dryer are presented. The dryer is operated by a local organic farm (Granja Che Rovia) to which this group is lending advice within the frame of an agreement signed between the Association of Organic Producers of Corrientes and the Physics Dpnt of FaCENA - UNNE. Several products were analysed. In all cases drying curves were obtained in the laboratory and with the solar dryer as well as. The study comprises the drying process, physical properties and determination of the dry weight of the dried products. To the drying curves obtained in laboratory for leaf products an exponential model of loss of weight was applied. The characteristic parameters were determined by three-variable parameters curve fitting of experimental data using the theoretical equation as fitting function. The adjusted solution was compared with field results. The correlation obtained indicates, in principle, that it could be used to establish operation and production strategies for leaf products. It was also determined a total thermal efficiency for the dryer in the order of 18%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Fast and reliable calibration of solid substrate fermentation kinetic models using advanced non-linear programming techniques

Calibration of mechanistic kinetic models describing microorganism growth and secondary metabolite production on solid substrates is difficult due to model complexity given the sheer number of parameters needing to be estimated and violation of standard conditions of numerical regularity. We show how advanced non-linear programming techniques can be applied to achieve fast and reliable calibration of a complex kinetic model describing growth of Gibberella fujikuroi and production of gibberellic acid on an inert solid support in glass columns. Experimental culture data was obtained under different temperature and water activity conditions. Model differential equations were discretized using orthogonal collocations on finite elements while model calibration was formulated as a simultaneous solution/optimization problem. A special purpose optimization code (IPOPT) was used to solve the resulting large-scale non-linear program. Convergence proved much faster and a better fitting model was achieved in comparison with the standard sequential solution/optimization approach. Furthermore, statistical analysis showed that most parameter estimates were reliable and accurate

Genetic study of neurexin and neuroligin genes in Alzheimer's disease

The interaction between neurexins and neuroligins promotes the formation of functional synaptic structures. Recently, it has been reported that neurexins and neuroligins are proteolytically processed by presenilins at synapses. Based on this interaction and the role of presenilins in familial Alzheimer's disease (AD), we hypothesized that dysfunction of the neuroligin-neurexin pathway might be associated with AD. To explore this hypothesis, we carried out a meta-analysis of five genome-wide association studies (GWAS) comprising 1, 256 SNPs in the NRXN1, NRXN2, NRXN3, and NLGN1 genes (3,009 cases and 3,006 control individuals). We identified a marker in the NRXN3 gene (rs17757879) that showed a consistent protective effect in all GWAS, however, the statistical significance obtained did not resist multiple testing corrections (OR = 0.851, p = 0.002). Nonetheless, gender analysis revealed that this effect was restricted to males. A combined meta-analysis of the former five GWAS together with a replication Spanish sample consisting of 1,785 cases and 1,634 controls confirmed this observation (rs17757879, OR = 0.742, 95% CI = 0.632-0.872, p = 0.00028, final meta-analysis). We conclude that NRXN3 might have a role in susceptibility to AD in males.Peer Reviewe

Neurexin and neuroligin genes in Alzheimer's disease

Póster presentado en la 11th International Conference on Alzheimer's & Parkinson's Diseases, celebrada en Florencia del 6 al 10 de marzo de 2013.-- Alzheimers Disease Neuroimaging Inititive[Objectives] The interaction between neurexins and neuroligins promotes the formation of functional synaptic structures. Recently, it has been reported that neurexins and neuroligins are proteolytically processed by presenilins at synapses. Based on this interaction and the role of presenilins in familial Alzheimer's disease (AD), we hypothesized that dysfunction of the neuroligin-neurexin pathway might be associated with AD.[Methods] To explore this hypothesis we carried out a meta-analysis of five genome-wide association studies (GWAS) comprising 1256 SNPs in the NRXN1, NRXN2, NRXN3 and NLGN1 genes (3009 cases and 3006 control individuals) using PLINK software.[Results] We identified a marker in the NRXN3 gene (rs17757879) that showed a consistent protective effect in all GWAS, however the statistical significance obtained did not resist multiple testing corrections (OR=0.851, p=0.002). Nonetheless, gender analysis revealed that this effect was restricted to males. A replication study with SNP rs17757879 in a Spanish population (1785 cases and 1634 controls) confirmed this observation (OR=0.752, C.I.=0.570-0.991, p=0.042).[Conclusions] We conclude that NRXN3 might have a role in susceptibility to AD in males (rs17757879, OR=0.742, 95% C.I.=0.632-0.872, p=0.00028, final meta-analysis).Peer Reviewe

Genetic diversity of HLA system in four populations from Baja California, Mexico: Mexicali, La Paz, Tijuana and rural Baja California

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 250 Mexicans from the states of Baja California Norte and Baja California Sur living in Mexicali (N = 100), La Paz (N = 75), Tijuana (N = 25) and rural communities (N = 50) to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes for the Baja California region include nine Native American and five European haplotypes. Admixture estimates revealed that the main genetic components are European (50.45 ± 1.84% by ML; 42.03% of European haplotypes) and Native American (43.72 ± 2.36% by ML; 40.24% of Native American haplotypes), while the African genetic component was less apparent (5.83 ± 0.98% by ML; 9.36% of African haplotypes)