149 research outputs found

    Physical crosslinking of pea protein-based bioplastics: Effect of heat and UV treatments

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    Climate change and the enhancement of ecology have generated the need to create packaging that is biodegradable and, at the same time, allows food to be preserved efficiently in order to avoid the accumulation of plastic and minimize food waste. In this sense, protein-based bioplastics are a promising alternative, but due to their limited properties they need additional crosslinking in order to compete with conventional plastics. Among them, physical crosslinking is of special interest in the food industry, as it does not generate toxicity problems. In this way, the overall objective of this work was to develop pea protein-based bioplastics by injection moulding, using two different physical crosslinking methods: heat treatment (50ºC-24 h, 120 ºC-4 h and 120 ºC-24 h) and ultraviolet (UV) treatment (50, 120 and 500 mJ/cm2). Thus, different bioplastics were compared based on their mechanical, functional and antimicrobial properties. The relevance of this study is based on the improvement of certain aspects of the mechanical and functional properties of bioplastics by the addition of an extra physical crosslinking stage to the fabrication process. In fact, UV treatment improves the antimicrobial activity of bioplastics, which gives it a significant improvement to compete with conventional plastics in the food sector.This work is part of a research project sponsored by “Ministerio de Ciencia e Innovaci´on-Agencia Estatal de Investigaci´on” (MCI/AEI/ FEDER, EU) from the Spanish Government (Ref. RTI2018–097100-BC21). The authors gratefully acknowledge their financial support. This work is also possible thanks to the postdoctoral contract of Víctor M. P´erez Puyana from the “Contrataci´on de Personal Investigador Doctor” supported by the European Social Fund and Junta de Andalucía (PAIDI DOCTOR – Convocatoria 2019–2020, DOC_00586) and for the predoctoral grant of Mercedes Jim´enez Rosado from "Ministerio de Educaci´on y Formaci´on Profesional" (FPU17/01718)

    Assessment of the structures contribution (crystalline and mesophases) and mechanical properties of polycaprolactone/pluronic blends

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    Films of biodegradable blends of polycaprolactone (PCL) and Pluronics F68 and F127 were manufactured by an industrial thermo-mechanical process to be applied as potential delivery systems. The effects of Pluronics on the structure (mesophase organization), and thermal and mechanical properties of polycaprolactone were investigated using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), polarized optical microscopy (POM) and tensile mechanical tests. The addition of Pluronics affected the crystallization process by changing the relative amounts of crystalline, amorphous, and meso- (condis + plastic) phases. The melting transition and XRD profiles were deconvoluted to assess the individual contribution of the different crystal morphologies. Furthermore, it was found that the mechanical properties of the blends depended on the ratio and type of Pluronic. Thus, Pluronic F127 showed a larger mesophase content than its F68 counterpart with PCL and blends with enhanced ductilityFunding for open access charge was provided by Universidad de Huelva / CBUA. The authors gratefully acknowledge the financial support

    Influence of the Aliphatic Chain Length on the Crosslinking Properties of Aldehydes on Sustainable Bioplastics Obtained from Pea Protein

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    Conventional plastics can be substituted for protein-based bioplastics due to their natural origin and their biodegradability. Nevertheless, their properties are inferior to those obtained for synthetic plastics. The chemical crosslinking of these bioplastics with aldehydes could improve their properties to compete in the actual market. Thus, the main goal of this article was to assess the influence of the incorporation of aldehydes with different aliphatic chain length on the physicochemical (crosslinking degree, colour and transparency), mechanical (flexural and tensile behaviour) and functional (water uptake capacity and biodegradability) properties of protein-based bioplastics. In this sense, pea protein, a by-product of food industry, was used as raw material, processing it by injection moulding to obtain the bioplastics. Formaldehyde, glyoxal and glutaraldehyde were the aldehydes used as crosslinking agents. The results show the rise of the mechanical properties with the incorporation of the aldehydes, depending on the degree of crosslinking they generate. All this also causes a consequent loss of the water uptake capacity and an increase in biodegradability time. In conclusion, this work opens a new alternative to develop sustainable bioplastics that can be used in the market.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Ministerio de Ciencia e Innovación- Agencia Estatal de Investigación (MCI/AEI/FEDER, EU) from the Spanish Government (Ref. PID2021-124294OB-C21). Junta de Andalucía and European Social Fund (Ref. PAIDI DOCTOR – Convocatoria 2019/2020, DOC_00586). Ministerio de Educación y Formación Profesional (Ref. FPU17/01718)

    A comparison of Clinical Risk Index for babies (CRIB-II), Score for Neonatal Acute Physiology (SNAP-II) and SNAPPE-II in predicting parenteral nutrition necessity in low birth weight preterm neonates.

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    Advances in perinatal care have made it possible to improve survival of low birth weight neonates. Clinical risk index for babies (CRIB-II), score for neonatal acute physiology (SNAP-II), and SNAP-perinatal extension-II (SNAPPE-II) have been used as mortality predictors for preterm infants. Feeding intolerance is very frequent in preterm neonates, and the development of an early effective biomarker for its prediction could be useful for carrying out a proper feeding strategy. Our aim was to compare the ability of CRIB-II, SNAP-II and SNAPPE-II in predict the feeding intolerance and parenteral nutrition necessity in preterm neonates. Methods: A retrospective cohort study on preterm neonates’ born at Jaen Hospital Complex with low birth weight and ≤ 36 weeks of gestation was done. Epidemiological, clinical and clinical scores CRIB II, SNAP-II and SNAPPE-II were recorded. Results: 255 low birth weight preterm neonates, 131 males (51.4%), aged ≤32 weeks of gestation (71%), were enrolled at our hospital. Parenteral nutrition needed were significantly higher in preterm neonates weighed 2500-1500 g (73.3%) and ≤ 1000g (87%). CRIB-II, SNAP-II and SNAPPE-II mean values were higher in neonates group subjected to parenteral nutrition compared with oral nutrition (p<0.05). CRIB-II and SNAPPE-II scores significantly correlated with parenteral nutrition days (p<0.05). Overall mortality rate was 11%. The 78.6% of all deceased infants needed parenteral nutrition. Conclusion: Clinical Risk Index for babies (CRIB-II) better than SNAPPE-II correlated with the feeding intolerance and thus the parenteral nutrition days in preterm neonates with low birth weight.Subvencionado: Ayuda del Plan Propio de Investigación de la UMA. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Efecto neuroprotector de IGF-II en situaciones de estrés neuronal inducido por corticosterona

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    Presentado en el 15º Congreso Nacional de la SENC 2013El daño por estrés en tejido neuronal mediado por la presencia de elevados niveles de corticosterona, se relaciona con la producción de alteraciones en funciones cognitivas. Así, el estrés agudo induce un aumento importante en los niveles plasmáticos de corticosterona que se asocia con alteraciones de plasticidad neuronal. Datos previos de nuestro grupo demuestran un efecto neuroprotector a dosis bajas del factor de crecimiento similar a insulina (IGF-II) en ratas de edad avanzada, donde el estrés de tipo oxidativo se encuentra involucrado en el propio proceso senil y en el desarrollo de diferentes enfermedades neurodegenerativas. Objetivos: En el presente trabajo se pretenden estudiar las propiedades antioxidantes de dosis bajas de IGF-II en cultivos primarios de corteza neuronal de ratas adultas, sometidos a elevadas concentraciones transitorias de corticosterona. Métodos: Los parámetros de estrés oxidativo se determinaron mediante citometria de flujo y espectrofotometría. Resultados: Las neuronas corticales incubadas con corticosterona mostraron un aumento de especies reactivas de oxígeno (ROS), del consumo de reserva antioxidante celular (etax), y de la peroxidación lipídica (LOOH) todo ello corno consecuencia de un desequilibrio entre factores pro-oxidantes (ej. daño mitocondrial, NOS) y factores antioxidantes (ej. GSH, SOD). La co-incubación de corticosterona y dosis bajas de IGF-II reequilibra estos factores. Este efecto neuroprotector podría estar mediado al menos en parte por la interacción de IGF-II con sus receptores específicos, ya que su bloqueo origina de nuevo un desequilibro entre los factores antioxidantes/pro-oxidantes. Conclusión: Las dosis bajas de IGF-II ejercen un efecto neuroprotector en situaciones de estrés oxidativo inducido por altos niveles de corticosterona.Laboratorios Lilly (Madrid) por cesion del IGF-II y Ayuda de la Universidad de Malaga. Campus de Excelencia Andalucia Tec

    Graphene derivative scaffolds facilitate in vitro cell survival and maturation of dopaminergic SN4741 cells

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    The emerging carbon nanomaterial Graphene (G), in the form of scaffold structure, has an efficient bioconjugation with common biomolecules and activates cell differentiation of neuronal stem cells, providing a promising approach for neural regeneration. We propose the use of G as a scaffold to re-address the dopaminergic (DA) neurons and the residual axons from dead or apoptotic DA neurons in Parkinson´s disease (PD). G could act as a physical support to promote the axonal sprout as a “deceleration” support for the DA cells derived from neural stem cells or DA direct cell conversion, allowing the propagation of nerve impulses. We cultured a clonal substantia nigra (SN) DA neuronal progenitor cell line (SN4741) in presence of G as scaffold. This cell line derived from mouse embryos was cultured in Dulbecco’s modified Eagle’s medium/10% FCS to about 80% confluence. Cells were incubated in three chemically different G derivatives and two different presentation matrixes as powder and films: 1) G oxide (GO); 2) partially reduced GO (PRGO) which is hydrophobic; and 3) fully reduced GO (FRGO). Cell viability was determined using the MTT assay after adding the following G concentrations: 1mg/ml; 0.1mg/ml; 0.05mg/ml; 0.02mg/ml and 0.01mg/ml, in each type of GO. To study cellular morphology and assessment of cell engraftment into GO films (GO film, PRGO film, FRGO film), we analyzed the immunostaining of the anti-rabbit neuron-specific DNA-binding protein (NeuN) antibody, the anti-rat Beta-3-tubulin antibody in combination with the mitochondrial marker mouse anti-ATP synthase antibody, and the anti-rabbit DCX as immature neuronal marker. Hoechst label was used as nuclei marker. Reactive oxidative species (ROS) were measured by flow cytometry to study the influence of G on the cell redox-state. With this purpose, cells were loaded with dihydroethidium. The mitochondrial membrane potential after JC-1 incubation was studied by flow cytometry. Our results show an increase of survival and metabolism (30-40%) at low concentrations of PRGO and FRGO (0.05-0.01 mg/ml) respect to the higher concentration (1 mg/ml), while no changes were seen in the GO group. LDH concentration was measured in the supernatant using a COBAS analyzer showing a neuroprotective action at low concentrations. Furthermore, either PRGO film or FRGO film show an increase in the effective anchorage capacity to nest into the G matrix and in the maturation of the SN 4741 cells. We conclude that the use of G scaffolds in the research of neurological diseases like PD could offer a powerful platform for neural stem cells, direct cell conversion techniques and neural tissue engineering.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Norwegian Research Council (grant nº 215086

    Light-responsive bent-core liquid crystals as candidates for energy conversion and storage

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    IDC would like to thank the Universitat Politècnica de València (UPV), for the FPI grant (PAID-2019-SP20190013), the Generalitat Valenciana (GVA) and the European Social Fund (ESF), for the FPI grant (ACIF/2020/233) and the mobility grant (CIBEFP/2021/53). NFKA would like to thank Universiti Teknologi MARA (UiTM) for sponsoring her academic sabbatical leave and allowing her to work on this project. AMF would like to thank the Carnegie Trust for the Universities of Scotland, for the Research Incentive Grant RIG008586, the Royal Society and Specac Ltd., for the Research Grant RGS\R1\201397, the Royal Society of Chemistry for the award of a mobility grant (M19- 0000), and the Scottish Government and the Royal Society of Edinburgh for the award of a SAPHIRE project. The authors from INMA greatly appreciate financial support from projects of the Spanish Government PGC2018-093761-B-C31 [MCIU/AEI/FEDER, UE] and the Gobierno de Aragón/FEDER (research group E47_20R). Thanks are given to the nuclear magnetic resonance, mass spectrometry, and thermal analysis services of the INMA (Univ. Zaragoza-CSIC)Peer reviewedPostprin

    New Bitumens Obtained from Physical Distillation of a Conventional Bitumen Mixed with EVA Copolymer

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    Bitumen phases separated from 5% and 12% EVA/bitumen blends are investigated. Basic characterization is carried out using a peculiar thin layer chromatographer, the Iatroscan. The rheological and technical analysis lead us to conclude that these macromolecular materials, obtained from physical distillation of the blends, constitute new bitumens of unique properties

    Clinical response to pandemic H1N1 influenza virus from a fatal and mild case in ferrets

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    Methods: Viral strains isolated from a patient showing mild disease-M (A/CastillaLaMancha/RR5661/2009) or from a fatal case-F (A/CastillaLaMancha/RR5911/2009), both without known comorbid conditions, were inoculated in two groups of ferrets and clinical and pathological conditions were analysed. Results: Mild to severe clinical symptoms were observed in animals from both groups. A clinical score distribution was applied in which ferrets with mild clinical signs were distributed on a non-severe group (NS) and ferrets with severe clinical signs on a severe group (S), regardless of the virus used in the infection. Animals on S showed a significant decrease in body weight compared to animals on NS at 4 to 7 days post-infection (dpi). Clinical progress correlated with histopathological findings. Concentrations of haptoglobin (Hp) and serum amyloid A (SAA) increased on both groups after 2 dpi. Clinically severe infected ferrets showed a stronger antibody response and higher viral titres after infection (p = 0.001). Conclusions: The severity in the progress of infection was independent from the virus used for infection suggesting that the host immune response was determinant in the outcome of the infection. The diversity observed in ferrets mimicked the variability found in the human population.The authors kindly thank Dr. Juan Ortín for his scientific contribution. This work was partially supported by Instituto de Salud Carlos III (Programa especial de investigación sobre la gripe pándemica GR09/0023, GR09/0040, GR09/0039), AGL2013-48923-C2-02 and CIBER de Enfermedades Infecciosa

    Factores Pedagógicos que Favorecen el Éxito Escolar en Estudiantes de Enseñanza Postobligatoria

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    El foco del presente estudio ha sido el éxito escolar: la continuidad, la permanencia en el sistema educativo, lo cual implica transitar de forma adecuada por sus diversas etapas y modalidades formativas. En particular, hemos buscado conocer qué factores pedagógicos -vinculados a los procesos de enseñanza-aprendizaje y a la relación profesor/a-alumno/a- constituyen condiciones favorables para el éxito y la continuidad escolar de chicas y de chicos de enseñanza secundaria postobligatoria (Bachillerato y Ciclos Formativos). Hemos tratado de visibilizar el éxito escolar de chicos y de chicas en la educación secundaria, de analizar las experiencias y las trayectorias de estudiantes que, más allá del periodo obligatorio, dan continuidad a su vida escolar con éxito académico, de prestar atención a las diferencias entre estudiantes de Bachillerato y Ciclos Formativos y, por último, de analizar de forma diferenciada la experiencia de las chicas y de los chicos, indagando en los elementos de la construcción de la subjetividad en ambos sexos. Para ello, hemos trabajado con una muestra intencional de 26 estudiantes (12 chicas y 14 chicos), 16 de Bachillerato y 10 de Ciclos Formativos, seleccionados por sus docentes, en 12 centros urbanos y semiurbanos de Málaga, Sevilla, Granada, Cádiz y Almería. Los datos han sido recogidos a través de entrevistas semiestructuradas, con el apoyo de la técnica de foto-lenguaje y un cuestionario de contexto.Fundación Centro de Estudios Andaluces - [PRY031/11
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