Films bicapa de almidón-policaprolactona con potencial efecto bioactivo obtenidos mediante moldeo por compresión

[ES] El objetivo de este trabajo fue estudiar la influencia del ácido ascórbico (AA) y el sorbato de potasio (SP) sobre las propiedades estructurales, térmicas, fisicoquímicas y estabilidad con el tiempo, de films bicapa a base de almidón de maíz y policaprolactona, obtenidos mediante moldeo por compresión. Se elaboraron un total 6 films bicapa. En todos los casos, una capa estaba formada por PCL puro, mientras que la otra estuvo constituida por almidón (S), o por una matriz a base de almidón con 5% de PCL (S95), sin adición o con adición de AA o SP. Se encontraron cambios entre las formulaciones S y S95 debidas a la mayor heterogeneidad de la matriz S95 y al establecimiento de interacciones más intensas en la interfase S95-PCL, que provocaron una mayor permeabilidad al agua (WVP) y al oxígeno (OP) de dichos films, además de una mayor elasticidad y menor rigidez, brillo, contenido de humedad y solubilidad en agua. Por otra parte, se vio como la formación de los films bicapa supone una serie de ventajas frente a los films monocapa: WVP y OP muy bajas, reducción del fenómeno de retrogradación y una mayor conservación de las propiedades mecánicas con el tiempo. En general, AA no consiguió cambios relevantes en ninguna propiedad, pero SP provocó un importante descenso en el inicio de degradación térmica del almidón y de PCL, una reducción de la WVP y de la OP y un aumento del brillo. Además, las condiciones de trabajo del segundo prensado del moldeo por compresión parecen no afectar a la estabilidad térmica de ninguno de los dos bioactivos.[EN] The aim of this work was to study the effect of ascorbic acid (AA) and potassium sorbate (SP) on structural, thermal, physicochemical properties, and stability during time, of bilayer corn starch and polycaprolactone based films, obtained by a compression-molding process. For this purpose, 6 bilayer films were prepared. In all cases, one layer was formed by pure PCL, while the other one was formed either by starch (S) or a starch-based matrix with a 5% PCL (S95), with or without AA or SP. Some changes were found between S and S95 formulations due to the higher heterogeneity of S95 matrix and stronger interactions in S95-PCL interphase, which caused higher WVP and OP in these films, higher elongation and less: rigidity, gloss, humidity content and water solubility. On the other hand, it was observed that bilayer films formation led to some advantages in comparison to monolayer films: very low WVP and OP, reduction of the retrogradation phenomenon and higher conservation of mechanical properties during time. In general, AA did not show relevant changes on any property, but SP caused a significant drop of starch thermal degradation, a decrease of WVP and OP and a gloss increase. Furthermore, work conditions of the second stage in compression-molding process seem not to affect the bioactives thermal stability.[CA] L’objectiu d’aquest treball va ser estudiar la influència de l’àcid ascòrbic (AA) i el sorbat de potassi (SP) sobre les propietats estructurals, tèrmiques, fisicoquímiques, i estabilitat amb el temps de films bicapa constituïts per midó de dacsa i policaprolactona obtinguts mitjançant un procés de moldeig per compressió. Per tal d’aconseguir-ho, es varen preparar un total de 6 films bicapa. En tots els casos, una de les capes estava formada per PCL pur, mentre que l’altra capa estava constituïda per midó (S), o per una matriu a base de midó amb un 5% de PCL (S95). Es detectaren canvis entre les formulacions del grup S i del S95 deguts a la major heterogeneïtat de la matriu S95 i a l’establiment d’interaccions més intenses en la interfase S95-PCL, que van resultar en una major permeabilitat a l’aigua (WVP) i a l’oxigen (OP) d’aquests films, a més d’una major elasticitat i menor: rigidesa, brillantor, contingut d’humitat i solubilitat en aigua. Per altra banda, es va vore com la formació dels films bicapa suposa una sèrie d’avantatges front als films monocapa: WVP i OP molt baixes, reducció del fenomen de retrogradació i una major conservació de les propietats mecàniques amb el temps. En general, AA no va aconseguir canvis rellevants sobre cap propietat, però SP va provocar una important disminució de l’inici de la degradació tèrmica del midó i de PCL, una reducció de la WVP i de la OP i un augment de la brillantor. A més, les condicions de treball del segon prensat del moldeig per compressió semblen no afectar la estabilitat tèrmica de cap dels dos bioactius.Morey Serra, I. (2014). Films bicapa de almidón-policaprolactona con potencial efecto bioactivo obtenidos mediante moldeo por compresión. http://hdl.handle.net/10251/57313.Archivo delegad

Active bilayer films of thermoplastic starch and polycaprolactone obtained by compression molding

Chapter 7 of the DOCTORAL THESIS "Development and characterization of corn starch films by blending with more hydrophobic compounds" by Rodrigo Ortega Toro https://riunet.upv.es/handle/10251/52521[EN] Bilayer films consisting of one layer of PCL with either one of thermoplastic starch (S) or one of thermo-plastic starch with 5% PCL (S95) were obtained by compression molding. Before compression, aqueoussolutions of ascorbic acid or potassium sorbate were sprayed onto the S or S95 layers in order to plas-ticize them and favor layer adhesion. S95 films formed bilayers with PCL with very good adhesion andgood mechanical performance, especially when potassium sorbate was added at the interface. All bilayersenhanced their barrier properties to water vapour (up to 96% compared to net starch films) and oxygen(up to 99% compared to PCL pure). Bilayers consisting of PCL and starch containing 5% PCL, with potas-sium sorbate at the interface, showed the best mechanical and barrier properties and interfacial adhesionwhile having active properties, associated with the antimicrobial action of potassium sorbate.The authors acknowledge the financial support from the Spanish Ministerio de Educacion y Ciencia throughout the project AGL2013-42989-R. Rodrigo Ortega-Toro thanks the Conselleria de Educacio de la Comunitat Valenciana for the Santiago Grisolia grant (GROSO-LIA 2012/001). Authors also thank to Electron Microscopy Service of the UPV for their technical assistance.Ortega-Toro, R.; Morey, I.; Talens Oliag, P.; Chiralt, A. (2015). Active bilayer films of thermoplastic starch and polycaprolactone obtained by compression molding. Carbohydrate Polymers. 127:282-290. https://doi.org/10.1016/j.carbpol.2015.03.080S28229012

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

The histone variant macroH2A is an epigenetic regulator of key developmental genes

The histone variants macroH2A1 1 and macroH2A2 are associated with X chromosome inactivation in female mammals. However, the physiological function of macroH2A proteins on autosomes is poorly understood. Microarray-based analysis in human male pluripotent cells uncovered occupancy of both macroH2A variants at many genes encoding key regulators of development and cell fate decisions. On these genes, the presence of macroH2A1+2 is a repressive mark that overlaps locally and functionally with Polycomb repressive complex 2. We demonstrate that macroH2A1+2 contribute to the fine-tuning of temporal activation of HOXA cluster genes during neuronal differentiation. Furthermore, elimination of macroH2A2 function in zebrafish embryos produced severe but specific phenotypes. Taken together, our data demonstrate that macroH2A variants constitute an important epigenetic mark involved in the concerted regulation of gene expression programs during cellular differentiation and vertebrate development.Peer Reviewe

Active bilayer films of thermoplastic starch and polycaprolactone obtained by compression molding

Chapter 7 of the DOCTORAL THESIS "Development and characterization of corn starch films by blending with more hydrophobic compounds" by Rodrigo Ortega Toro https://riunet.upv.es/handle/10251/52521[EN] Bilayer films consisting of one layer of PCL with either one of thermoplastic starch (S) or one of thermo-plastic starch with 5% PCL (S95) were obtained by compression molding. Before compression, aqueoussolutions of ascorbic acid or potassium sorbate were sprayed onto the S or S95 layers in order to plas-ticize them and favor layer adhesion. S95 films formed bilayers with PCL with very good adhesion andgood mechanical performance, especially when potassium sorbate was added at the interface. All bilayersenhanced their barrier properties to water vapour (up to 96% compared to net starch films) and oxygen(up to 99% compared to PCL pure). Bilayers consisting of PCL and starch containing 5% PCL, with potas-sium sorbate at the interface, showed the best mechanical and barrier properties and interfacial adhesionwhile having active properties, associated with the antimicrobial action of potassium sorbate.The authors acknowledge the financial support from the Spanish Ministerio de Educacion y Ciencia throughout the project AGL2013-42989-R. Rodrigo Ortega-Toro thanks the Conselleria de Educacio de la Comunitat Valenciana for the Santiago Grisolia grant (GROSO-LIA 2012/001). Authors also thank to Electron Microscopy Service of the UPV for their technical assistance.Ortega-Toro, R.; Morey, I.; Talens Oliag, P.; Chiralt, A. (2015). Active bilayer films of thermoplastic starch and polycaprolactone obtained by compression molding. Carbohydrate Polymers. 127:282-290. https://doi.org/10.1016/j.carbpol.2015.03.08028229012

Interaction of #alpha# titanium with high parameter water in the thermonuclear reactor and the effect of reactor radiation

Translated from Russian (Fiz. Khim. Obrab. Mater. 1988 v. 22(1) p. 5-8)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4024)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo