Manufacturing and characterization of poly(lactic acid) composites with hydroxyapatite

This is the peer reviewed version of the following article: Ferri, J.M., Jordà Sempere, José Jorge, Montanes, N. , Fenollar, Octavio, Balart, Rafael. (2017). Manufacturing and characterization of poly(lactic acid) composites with hydroxyapatite.Journal of Applied Polymer Science, 0. DOI: 10.1177/0892705717729014 , which has been published in final form at http://doi.org/10.1177/0892705717729014. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Hydroxyapatite (HA), a naturally occurring calcium orthophosphate, possesses the most similar chemical composition to human bone. In this research work, composite materials were prepared using poly(lactic acid) (PLA) as a polymer matrix and HA as an osteoconductive filler for potential use in medical applications. Composites with varying HA content comprised in the 10¿30 wt% range were obtained by extrusion-compounding followed by injection molding. The effect of the HA loading on overall properties was assessed by mechanical characterization using tensile, flexural, impact, and hardness standard tests. Main thermal transitions of PLA-HA composites were obtained by differential scanning calorimetry (DSC) and degradation/decomposition at high temperatures was followed by thermogravimetric analysis. Dynamical behavior was assessed by dynamic mechanical thermal analysis and the dimensional stability was studied by thermomechanical analysis (TMA). As per the results, PLA-HA composites with 20¿30 wt% HA offer the best-balanced properties with a remarkable increase in the Young¿s modulus. The glass transition temperature remained almost constant with slight changes of less than 1C as measured by both DSC and TMA. TMA also revealed a remarkable decrease in the coefficient of linear thermal expansion. The overall results confirm the usefulness of these materials from a mechanical point of view for biomedical applications as they are characterized by high stiffness, tensile strength, and dimensional stability.The authors want to acknowledge the Ministry of Economy and Competitiveness (MINECO) for their financial support through the grant number MAT2014-59242- C2-1-R.Ferri, J.; Jordà Sempere, JJ.; Montanes, N.; Fenollar, O.; Balart, R. (2017). Manufacturing and characterization of poly(lactic acid) composites with hydroxyapatite. Journal of Applied Polymer Science. https://doi.org/10.1177/0892705717729014

Poly(lactic acid) formulations with improved toughness by physical blending with thermoplastic starch

This is the peer reviewed version of the following article: Ferri, J.M., Garcia-Garcia, D., Carbonell-Verdu, A., Fenollar, Octavio, Balart, Rafael. (2018). Poly(lactic acid) formulations with improved toughness by physical blending with thermoplastic starch.Journal of Applied Polymer Science, 135, 4, 45751-. DOI: 10.1002/app.45751, which has been published in final form at http://doi.org/10.1002/app.45751. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] This work focuses on poly(lactic acid) (PLA) formulations with improved toughness by physical blending with thermoplastic maize starch (TPS) plasticized with aliphatic¿aromatic copolyester up to 30 wt %. A noticeable increase in toughness is observed, due to the finely dispersed spherical TPS domains in the PLA matrix. It is worth to note the remarkable increase in the elongation at break that changes from 7% (neat PLA) up to 21.5% for PLA with 30 wt % TPS. The impact-absorbed energy is markedly improved from the relatively low values of neat PLA (1.6 J/m2) up to more than three times. Although TPS is less thermally stable than PLA due to its plasticizer content, in general, PLA/TPS blends offer good balanced thermal stability. The morphology reveals high immiscibility in PLA/TPS blends, with TPS-rich domains with an average size of 1 micrometre, finely dispersed which, in turn, is responsible for the improved toughness.Authors thank the Ministry of Economy and Competitiveness (MINECO), Ref.: MAT2014–59242-C2-1-R for their support. Authors also thank “Conselleria d’Educacio, Cultura i Esport”- Generalitat Valenciana, Ref.: GV/2014/008 for financial support.Ferri, J.; Garcia-Garcia, D.; Carbonell-Verdu, A.; Fenollar, O.; Balart, R. (2018). Poly(lactic acid) formulations with improved toughness by physical blending with thermoplastic starch. Journal of Applied Polymer Science. 135(4). https://doi.org/10.1002/app.45751S45751135

Manufacturing and compatibilization of PLA/PBAT binary blends by cottonseed oil-based derivatives

[EN] This research work aims at the compatibilization of poly(lactic acid)/poly(butylene adipate-co-terephthalate), PLA/PBAT binary blends by using cottonseed oil derivatives, i.e. epoxidized (ECSO) and maleinized (MCSO) cottonseed oil. The potential of these vegetable oil-based compatibilizers are compared versus the effects of a conventional styrene-acrylic oligomer. The base PLA/PBAT binary blend composition was 80 wt% PLA/20 wt% PBAT and the amount of compatibilizer was set to 1 and 7.5 wt%. The effects of the different compatibilizers were evaluated on PLA/PBAT films in terms of mechanical and thermal properties as well as blend's morphology by field emission scanning electron microscopy (FESEM). Complementary, biodisintegration tests in controlled compost soil and surface properties were evaluated to assess the effects of the compatibilizers. Addition of 1 wt% ECSO and MCSO led to a remarkable increase in the elongation at break up to values over 100% with regard to neat PLA. Despite this, maximum elongation at break was obtained for the compatibilized PLA/PBAT blend with 7.5 wt% MCSO, reaching values of about 321.2% respect neat PLA keeping mechanical resistant properties, such as Young's modulus and tensile strength, at high levels. Therefore, vegetable oil-derived compatibilizers stand out as environmentally friendly additives for PLA/PBAT binary blends with improved properties.This work was supported by the Ministry of Economy and Competitiveness (MINECO) (grant number MAT2017-84909-C2-2-R). A. Carbonell-Verdu wants to thank Universitat Politecnica de Valencia for financial support through an FPI grant.Carbonell-Verdu, A.; Ferri, J.; Dominici, F.; Boronat, T.; Sanchez-Nacher, L.; Balart, R.; Torre, L. (2018). Manufacturing and compatibilization of PLA/PBAT binary blends by cottonseed oil-based derivatives. eXPRESS Polymer Letters. 12(9):808-823. https://doi.org/10.3144/expresspolymlett.2018.69S80882312

Effect of Epoxidized and Maleinized Corn Oil on Properties of Polylactic Acid (PLA) and Polyhydroxybutyrate (PHB) Blend

[EN] The present work analyzes the influence of modified, epoxidized and maleinized corn oil as a plasticizing and/or compatibilizing agent in the PLA¿PHB blend (75% PLA and 25% PHB wt.%). The chemical modification processes of corn oil were successfully carried out and different quantities were used, between 0 and 10% wt.%. The different blends obtained were characterized by thermal, mechanical, morphological, and disintegration tests under composting conditions. It was observed that to achieve the same plasticizing effect, less maleinized corn oil (MCO) is needed than epoxidized corn oil (ECO). Both oils improve the ductile properties of the PLA¿PHB blend, such as elongation at break and impact absorb energy, however, the strength properties decrease. The ones that show the highest ductility values are those that contain 10% ECO and 5% MCO, improving the elongation of the break of the PLA¿PHB blend by more than 400% and by more than 800% for the sample PLA.This work was supported by the Spanish Ministry of Science and Innovation, NANOCIRCOIL (PID2021-123753NA-C33)Sempere-Torregrosa, J.; Ferri, J.; Rosa-Ramírez, HDL.; Pavón-Vargas, CP.; Samper, M. (2022). Effect of Epoxidized and Maleinized Corn Oil on Properties of Polylactic Acid (PLA) and Polyhydroxybutyrate (PHB) Blend. Polymers. 14(19):1-16. https://doi.org/10.3390/polym14194205116141

Modification of poly (lactic acid) through the incorporation of gum rosin and gum rosin derivative: Mechanical performance and hydrophobicity

"This is the peer reviewed version of the following article: De La Rosa-Ramírez, Harrison, Miguel Aldas, José Miguel Ferri, Juan López-Martínez, and María Dolores Samper. 2020. "Modification of Poly (Lactic Acid) through the Incorporation of Gum Rosin and Gum Rosin Derivative: Mechanical Performance and Hydrophobicity." Journal of Applied Polymer Science 137 (44). Wiley: 49346. doi:10.1002/app.49346, which has been published in final form at https://doi.org/10.1002/app.49346. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The modification of PLA by melt compound with gum rosin (GR) and pentaerythritol ester of GR (PEGR) was investigated by studying the mechanical and thermal performance, blends morphology, wettability, and water absorption. Standard testing specimens for characterization were made at a variate resin content of 5, 10, and 15 part per hundred resin (phr) and manufactured by injection molding. It was found that GR and PEGR had a lubricating effect in PLA polymeric chains, resulting in a remarkable increase of 790 and 193% in melt flow index with only 5 phr GR and PEGR contents, respectively. A significant change in more than 10 degrees of increasing water contact angle was observed for PLA with 15 phr PEGR. Thermogravimetric analysis reveals that PEGR led to delayed PLA degradation/decomposition process to higher temperature, increasing the onset temperature (T-5%) in more than 7 degrees C for PLA with 15 phr PEGR.This research was supported by the Ministry of Economy and Competitiveness-PROMADEPCOL Ref: (MAT2017-84909-C2-2-R). Authors also want to acknowledge the postdoc contract offered to José Miguel Ferri by the Generalitat Valenciana, which project title is "BIONANOCOMPOSITES BASADOS EN MEZCLAS DE PLA Y TPS CON MEMORIA" (APOSTD/2019/122) GENERALITAT VALENCIANA (2019-2021).Rosa-Ramírez, HDL.; Aldás-Carrasco, MF.; Ferri, J.; López-Martínez, J.; Samper, M. (2020). 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Análise da influência do nível de actividade física no ciclo menstrual das desportistas

Resumen: Introducción: El ciclo menstrual supone grandes cambios hormonales en el cuerpo de las mujeres que pueden influir en el desempeño de sus hábitos deportivos. Objetivo: conocer si mujeres deportistas con diferente nivel de actividad física, presentan alteraciones en el ciclo menstrual como consecuencia de la práctica físico-deportiva y cómo durante la menstruación se puede ver perjudicada la realización de actividad física. Métodos: La muestra constó de 298 mujeres con un rango de edad media de 23,24 años. Los instrumentos utilizados fueron la “Historia de salud reproductiva” y el “IPAQ”, realizados de forma electrónica. Resultados y discusión: se observó que la mayoría de mujeres realizan una actividad física vigorosa. El tiempo medio entre periodos fue de 25 y 33 días, con una duración del mismo de tres a cinco días. Un alto porcentaje de las mujeres tenía dolor menstrual. Finalmente, el consumo pastillas anticonceptivas no afectó a la realización de actividad física pero sí una disminución de dolor y regulación del ciclo menstrual. Algunos autores defienden el conocimiento por parte del entrenador de las distintas fases menstruales para adaptar el entrenamiento a cada atleta. Conclusiones: Estos resultados pueden ayudar a individualizar el entrenamiento deportivo acorde a sus ciclos hormonales para conseguir un rendimiento óptimo.Abstract: Introduction: Menstrual cycle involves major hormonal changes in women's bodies that can influence the performance of their sports habits. Aim: To know if sportswomen with different levels of physical activity present alterations in the menstrual cycle due to physical-sports practice and how during menstruation physical activity can be impaired. Methods: The sample consisted of 298 women with an average age range of 23.24 years. The instruments used were the "Reproductive Health History" and the "IPAQ", carried out electronically. Results & discussion: It was noted that most women engage in vigorous physical activity. The average time between periods was 25-33 days, with a duration of three to five days. A high percentage of the women had menstrual pain. Finally, the use of contraceptive pills did not affect the performance of physical activity but did affect a decrease in pain and regulation of the menstrual cycle. Some authors defend the coach's knowledge of the different menstrual phases in order to adapt training to each athlete. Conclusions: These results can help individualize sports training according to your hormonal cycles for optimal performance.Resumo: Introdução: O ciclo menstrual envolve grandes alterações hormonais no corpo da mulher que podem influenciar o desempenho dos seus hábitos desportivos. Objectivos: Saber se as atletas com diferentes níveis de actividade física apresentam alterações no ciclo menstrual como consequência da prática físico-desportiva e como durante a menstruação o desempenho da actividade física pode ser prejudicado. Métodos: A amostra consistiu em 298 mulheres com uma média de idades de 23,24 anos. Os instrumentos utilizados foram a "História da Saúde Reprodutiva" e o "IPAQ", realizado por via electrónica. Resultados e discussão: observou-se que a maioria das mulheres praticava uma actividade física vigorosa. O tempo médio entre os períodos foi de 25-33 dias, com uma duração de três a cinco dias. Uma elevada percentagem das mulheres tinha dores menstruais. Finalmente, o uso de pílulas contraceptivas não afectou o desempenho da actividade física, mas afectou uma diminuição da dor e a regulação do ciclo menstrual. Alguns autores defendem o conhecimento do treinador sobre as diferentes fases menstruais, a fim de adaptar o treino a cada atleta. Conclução: Os resultados podem ajudar a individualizar o treino desportivo de acordo com os seus ciclos hormonais para um desempenho óptimo

The Trithorax protein Ash1L promotes myoblast fusion by activating Cdon expression

Myoblast fusion (MF) is required for muscle growth and repair, and its alteration contributes to muscle diseases. The mechanisms governing this process are incompletely understood, and no epigenetic regulator has been previously described. Ash1L is an epigenetic activator belonging to the Trithorax group of proteins and is involved in FSHD muscular dystrophy, autism and cancer. Its physiological role in skeletal muscle is unknown. Here we report that Ash1L expression is positively correlated with MF and reduced in Duchenne muscular dystrophy. In vivo, ex vivo\ua0and in vitro experiments support a selective and evolutionary conserved requirement for Ash1L in MF. RNA- and ChIP-sequencing indicate that Ash1L is required to counteract Polycomb repressive activity to allow activation of selected myogenesis genes, in particular the key MF gene Cdon. Our results promote Ash1L as\ua0an important epigenetic regulator of MF and suggest that its activity could be targeted to improve cell therapy for muscle diseases

Using indigenous knowledge to link land cover mapping with land use in the Venezuelan Amazon.

Remote sensing and traditional ecological knowledge (TEK) can be combined to advance conservation of remote tropical regions, e.g. Amazonia, where intensive in situ surveys are often not possible. Integrating TEK into monitoring and management of these areas allows for community participation, as well as for offering novel insights into sustainable resource use. In this study, we developed a 250-m-resolution land-cover map of the western Guyana Shield (Venezuela) based on remote sensing, and used TEK to validate its relevance for indigenous livelihoods and land uses. We first employed a hyper-temporal remotely sensed vegetation index to derive a land classification system. During a 1,300-km, 8-day fluvial expedition in roadless areas in the Amazonas State (Venezuela), we visited six indigenous communities who provided geo-referenced data on hunting, fishing and farming activities. We overlaid these TEK data onto the land classification map, to link land classes with indigenous use. Several classes were significantly connected with agriculture, fishing, overall hunting, and more specifically the hunting of primates, red brocket deer, black agouti, and white-lipped peccary. We then characterized land classes using greenness and topo-hydrological information, and proposed 12 land-cover types, grouped into five main landscapes: 1) water bodies; 2) open lands/forest edges; 3) evergreen forests; 4) submontane semideciduous forests, and 5) cloud forests. Our results show that TEK-based approaches can serve as a basis for validating the livelihood relevance of landscapes in high-value conservation areas, which can form the basis for furthering the management of natural resources in these regions

The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends

[EN] In this work, poly(lactic acid), PLA and thermoplastic starch, TPS blends (with a fixed content of 30 wt.% TPS) were prepared by melt extrusion process to increase the low ductile properties of PLA. The TPS used contains an aliphatic/aromatic biodegradable polyester (AAPE) that provides good resistance to aging and moisture. This blend provides slightly improved ductile properties with an increase in elongation at break of 21.5% but phase separation is observed due to the lack of strong interactions between the two polymers. Small amounts of maleinized linseed oil (MLO) can positively contribute to improve the ductile properties of these blends by a combined plasticizing-compatibilizing effect. The elongation at break increases over 160% with the only addition of 6 phr MLO. One of the evidence of the plasticizing-compatibilizing effect provided by MLO is the change in the glass transition temperature (Tg) with a decrease of about 10 °C. Field emission scanning electron microscopy (FESEM) of PLA-TPS blends with varying amounts of maleinized linseed oil also suggests an increase in compatibility.This research was supported by the Ministry of Economy and Competitiveness-MINECO, Ref: MAT2014-59242-C2-1-R. Authors also thank to "Conselleria d'Educacio, Cultura i Esport"-Generalitat Valenciana, Ref: GV/2014/008 for financial support.Ferri Azor, JM.; García García, D.; Sánchez Nacher, L.; Fenollar Gimeno, OÁ.; Balart Gimeno, RA. (2016). The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends. Carbohydrate Polymers. 147:60-68. https://doi.org/10.1016/j.carbpol.2016.03.082S606814

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated