Influencia de la incorporación de nanopartículas de talco sobre las propiedades finales de almidón termoplástico

Las propiedades mecánicas y de barrera son aspectos críticos para desarrollar películas para envasado de alimentos. Así, se propone mejorar ambos aspectos en películas de almidón termoplástico (TPS) incorporando nanopartículas de talco. Se obtuvieron películas por termocompresión con 0, 1, 3 y 5 % p/p de partículas minerales. La incorporación de talco aumentó la estabilidad térmica del TPS y modificó la opacidad y el color, sin alterar la absorción UV. Las permeabilidades al vapor de agua y al oxígeno disminuyeron significativamente. Los bionanocompuestos presentaron mayor resiliencia, tenacidad y módulo elástico que las películas de TPS, sin afectar la elongación a la ruptura.Talc nanoparticles were incorporated to enhance mechanical performance and barrier properties of thermoplastic starch (TPS) based materials in order to obtain adequate films for food packaging. TPS films with talc (0, 1, 3 and 5 % w/w) were obtained by thermocompression. Talc incorporation increased TPS thermal stability as well as modified films opacity and color, without affecting their UV absorption capacity. Water vapor and oxygen permeability were reduced due to particles disposition within the matrix. Bionanocomposites presented higher resilience, toughness and elastic modulus than TPS films, although elongation at break was not affected. Keywords: Thermoplastic starch, talc nanoparticles, thermocompression, oxygen and water vapor permeability, mechanical properties.Fil: Castillo, Luciana Andrea. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Lopez, Olivia Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Garcia, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones En Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Universidad Nacional del Sur; Argentin

Crystalline morphology of thermoplastic starch/talc nanocomposites induced by thermal processing

A structural study about the changes induced by plasticization of native corn starch was carried out in this work. The influence of talc nanoparticles presence during starch thermal processing was also evaluated. Macroscopic observation of the granules appearance evolution during melt-mixing and thermo-compression was supported by a theoretical description related to these processing methods. Melt-mixing induced a polymorphic transformation from A- to Vh-type and a reduction in the degree of crystallinity. Homogenous appearance of the plasticized starch was in accordance to the disruption of granules integrity, evidenced by SEM. This observation agreed to the distinctive XRD pattern of plasticized starch from unprocessed granules. Talc incorporation did not require the adjustment of processing parameters in order to obtain a homogenous thermoplastic material, with an adequate particles distribution within the matrix. Regardless talc presence, plasticized starch presented a Vh-type crystalline structure. Thermo-compression led to particles alignment promoted by talc laminar morphology.Fil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería; ArgentinaFil: Lopez, Olivia Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: García, María Alejandra. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería; ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería; Argentin

Talc nanoparticles influence on thermoplastic corn starch film properties

Nanocomposite films of TPS with talc particles were obtained by thermo-compression in order to study the effect of this filler on structure, optical, and thermal properties. TPS-talc films showed good appearance and homogeneous thickness. Talc addition increased the amount of rigid phase of nanocomposite films, thus their cross-sections resulted more irregular than those of TPS ones. Talc preferential orientation within matrix and good compatibility between particles and TPS were evidenced. TEM observation showed scattered randomly dispersed individual talc platelets. Matrix crystallinity degree was not significantly affected by particles presence. Nanocomposite films were optically transparent due to the laminar morphology and nanosized particles. Materials microstructure presented glycerol- and starch-rich domains. Talc incorporation higher than 3 % w/w increased softening resistance of nanocomposites as stated by DMA assays. TPS relaxation temperature of glycerol-rich phase was shifted to higher values since talc nanoparticles reduce starch chains mobility.Fil: Lopez, Olivia Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Zaritzky, Noemi Elisabet. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Garcia, Maria Alejandra. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Perhalophenyl Three-Coordinate Gold(I) Complexes as TADF Emitters : A Photophysical Study from Experimental and Computational Viewpoints

We report the synthesis of novel perhalophenyl three- coordinated gold( I) complexes using 1,2- bis-(diphenylphosphino)benzene (dppBz) as the chelating ligand and [AuR(tht)] (R = C6F5, C6Cl2F3, C6Cl5) as the perhalophenyl-gold(I) source, leading to [AuR(dppBz)] (R = C6F5 (1), C6Cl2F3 (2), C6Cl5 (3)) complexes. The solid-state structures of compounds 2 and 3 consist of discrete three-coordinated Au(I) complexes, which show a distorted trigonal planar geometry for the gold center with dissimilar Au-P distances. The distorted structural arrangement is closely related to its photophysical properties. The studied complexes display very intense emissions at room temperature (RT) and at 77 K in the solid state. Studies of the emissive properties of the complexes at different temperatures suggest that the emissions are phosphorescent at 77 K and exhibit thermally activated delayed fluorescence (TADF) at RT. First-principle calculations of the photophysical processes yielded rate constants for intersystem crossing and reverse intersystem crossing that are in excellent agreement with experimental data.Peer reviewe

Mini AuAg Wavy Nanorods Displaying Plasmon-Induced Photothermal and Photocatalytic Properties

Alloyed AuAg wavy nanorods (wNRs) of approximate to 24.0 nm length and 3.5 nm width are formed by the mild decomposition of the organometallic complex [Au2Ag2(C6F5)(4)(OEt2)(2)](n) in tetrahydrofuran (THF) in the presence of oleic acid. Ligand exchange with l-glutathione (GSH) or poly(ethylene glycol) methyl ether thiol (PEG-SH) leads to water-soluble nanostructures. These AuAg wNRs display tunable size-dependent longitudinal localized surface plasmon resonance (l-LSPR) broad absorptions beyond 750 nm in the near-infrared (NIR) I and II regions. These intense plasmonic absorptions lead to interesting photothermal, catalytic, and photocatalytic properties, including the catalytic reduction of 4-nitrophenol, the photocatalytic reduction of 4-nitrostyrene, or the photocatalytic dehydrogenation of ammonia borane for H-2 release

Influence of perhalophenyl groups in the TADF mechanism of diphosphino gold(I) complexes

New perhalophenyl three-coordinated gold(i) complexes using the chelate ligand 1,2-bis(diphenyl-phosphino)benzene (dppBz) and [AuR(tht)] (R = C6F5 (1), o-C6BrF4 (2), p-C6BrF4 (3), o-C6F4I (4), p-C6F4I (5); tht = tetrahydrothiophene) have been prepared. The crystal structures of compounds 1 and 2 consist of distorted three-coordinated Au(i) complexes displaying different Au-P distances at the same gold atom. The complexes show intense photoluminescent emission in the solid state at room temperature (RT) and at 77 K. The study of the dependence of the emission lifetime with temperature suggests the existence of thermally activated delayed fluorescence (TADF) processes at RT. We have computed the rate constants for intersystem crossing and reverse intersystem crossing of the photophysical processes through first-principle calculations, supporting the experimental observations with very good agreement.Peer reviewe

Analizar cómo afecta el clima organizacional en la eficiencia de los empleados de la empresa Cerro matoso

La empresa Cerro Matoso es una empresa minera-industrial colombiana ubicada en el municipio de Montelíbano, Córdoba, dedicada a explotar níquel contenido en ferroníquel, necesario en diferentes industrias para dar al acero la propiedad anticorrosiva que lo hace inoxidable y tiene cerca de 2000 trabajadores. El clima organizacional que tiene la empresa es muy bueno, donde no solo se involucra a los trabajadores, clientes, sino a la comunidad en general, se valora las diferencias, se fortalece un estilo de vida saludable, promoviendo el bienestar integral de los empleados y familias. También el respeto y la equidad. Sin duda hay cosas por mejorar dentro de la empresa, pero se están adoptando cambios encaminados en mejorar las condiciones laborales y sociales de cada uno de los empleados.The Cerro Matoso company is a Colombian mining-industrial company located in the municipality of Montelíbano, Córdoba, dedicated to exploiting nickel contained in ferronickel, necessary in different industries to give steel the anticorrosive property that makes it stainless, and has about 2,000 workers. The organizational climate that the company has is very good, where not only workers, clients, but also the community in general are involved, differences are valued, a healthy lifestyle is strengthened, promoting the integral well-being of employees and families. Also respect and fairness. Undoubtedly there are things to improve within the company, but changes are being adopted aimed at improving the working and social conditions of each of the employees

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia.

La actividad realizada da cuenta del fenómeno del conflicto armado, expresado mediante relatos que muestran como este ha traído graves repercusiones en la salud física, pero también afectaciones en el ámbito psicológico, social, político, cultural y económico. En virtud de ello, es importante decir que las personas víctimas del conflicto armado, han tenido la mayoría de ellos que huir en condición de desplazados, en búsqueda de refugio, para satisfacer sus necesidades, dejando como consecuencia rupturas en la estructura familiar. A su vez, es importante decir que como consecuencia de esto, al llegar en condiciones de desplazados, muchas veces le son vulnerados sus derechos, pues ha ocurrido que carecen de empleo, vivienda, alimentación, entre otras cosas que son básicas para la supervivencia humana. Pero también, es fundamental reconocer que los daños psicológicos que resultan como consecuencia del conflicto armado son bastante dañinos, ya que generan diversos tipos de trastornos, como es el caso de depresiones, estrés postraumático, trastorno bipolar afectivo, ansiedades, entre otros. Los cuales afectan no solo la salud física sino la salud mental, donde muchas de las victimas pierden sus deseos de seguir viviendo, en ocasiones tienen ideación suicida, lo cual se constituye un riesgo y a su vez un hecho que enciende las alarmas en entidades de salud, precisamente por sus múltiples repercusiones. Por otra parte, la ley 1448 llamada Ley de víctimas y restitución de tierras, establecida en el año 2011 por el gobierno nacional, ha venido estableciendo intervención a las víctimas mediante el programa PAPSIVI, la cual busaca de una u otra forma mitigar aquellos impactos generados por el conflicto armado, orientado a través de un enfoque Psicosocial. En consecuencia, en el relato seleccionado de Carlos Arturo se pueden observar varias situaciones desencadenantes y que por ende generan procesos de reflexión y análisis, donde se puede ver una familia constituida, con una capacidad de resiliencias, que, aunque los hechos hayan sido demasiados fuertes, logran mantener el equilibro, por eso Carlos Arturo continuo con su vida a pesar de lo vivido y las secuelas físicas a temprana edad, que después del hecho victimizante permanecen como red de apoyo. Esto es significativo para él, ya que Carlos Arturo encuentra la necesidad de seguir adelante y ayudar a las demás personas víctimas del conflicto armado. Sin embargo, se puede resaltar también que como víctima se le vulneran varios derechos, ya que le han tardado en reconocer como víctima, donde carece de un empleo que le permita satisfacer sus necesidades y por ende mejorar la calidad de vida. Esto indica que no se ha dado total reparación de aquellos daños generados por causa del hecho victimizante.The activity carried out accounts for the phenomenon of armed conflict, expressed through stories that show how this has had serious repercussions on physical health, but also effects on the psychological, social, political, cultural and economic spheres. By virtue of this, it is important to say that the victims of the armed conflict have had the majority of them to flee in the condition of displaced persons, in search of refuge, to meet their needs, leaving as a consequence ruptures in the family structure. In turn, it is important to say that as a result of this, when arriving in conditions of displaced people, their rights are often violated, since it has happened that they lack employment, housing, food, among other things that are basic for human survival. But also, it is essential to recognize that the psychological damages that result from the armed conflict are quite harmful, since they generate various types of disorders, such as depressions, post-traumatic stress, bipolar affective disorder, anxieties, among others. Which affect not only physical health but mental health, where many of the victims lose their desire to continue living, sometimes they have suicidal ideation, which constitutes a risk and in turn a fact that ignites alarms in health entities , precisely because of its multiple repercussions. On the other hand, Law 1448 called Victims and Land Restitution Law, established in 2011 by the national government, has been establishing intervention for victims through the PAPSIVI program, which seeks in one way or another to mitigate those impacts generated for the armed conflict, oriented through a psychosocial approach. Consequently, in the selected story of Carlos Arturo, several triggering situations can be observed and that therefore generate reflection and analysis processes, where you can see a constituted family, with a capacity for resilience, which, although the facts have been too strong , manage to maintain the balance, that's why Carlos Arturo continued with his life in spite of his experience and physical consequences at an early age, which after the victimizing event remain as a support network. This is significant for him, as Carlos Arturo finds the need to move on and help other people victims of the armed conflict. However, it can also be noted that as a victim several rights are violated, since it has taken him to recognize as a victim, where he lacks a job that allows him to meet his needs and therefore improve the quality of life. This indicates that there has been no total reparation for those damages caused by the victimizing event

Influence of Neospora caninum intra-specific variability in the outcome of infection in a pregnant BALB/c mouse model

Previous assays in pregnant animals have demonstrated the effect of different host factors and timing of infection on the outcome of neosporosis during pregnancy. However, the influence of Neospora caninum isolate itself has been poorly investigated. Here, we compared the effects on clinical outcome and vertical transmission observed in a pregnant mouse model following infection with 10 different N. caninum isolates. The isolates in our study included the Nc-Liv isolate and nine N. caninum isolates obtained from calves. Female BALB/c mice were inoculated with 2 × 106 tachyzoites at day 7 of pregnancy. Morbidity and mortality, in both dams and offspring during the course of infection, and transmission to progeny at day 30 postpartum were evaluated. The serum IgG1 and IgG2a production in dams were also examined. All dams showed elevated IgG1 and IgG2a responses, confirming N. caninum infection, although signs of disease were only exhibited in dams infected with 4 of the 10 isolates (Nc-Spain 4H, Nc-Spain 5H, Nc-Spain 7 and Nc-Liv). In neonates, clinical signs were observed in all N. caninum-infected groups, and neonatal mortality rates varied from greater than 95% with the isolates mentioned above to less than 32.5% with the other isolates. Vertical transmission rates, as assessed by parasite PCR-detection in neonate brains, also varied from 50% to 100% according to the isolate implicated. These results confirm the wide pathogenic and transmission variability of N. caninum. The intra-specific variability observed herein could help us explain the differences in the outcome of the infection in the natural host

Impaired Antibody-Dependent Cellular Cytotoxicity in a Spanish Cohort of Patients With COVID-19 Admitted to the ICU

SARS-CoV-2 infection causes COVID-19, ranging from mild to critical disease in symptomatic subjects. It is essential to better understand the immunologic responses occurring in patients with the most severe outcomes. In this study, parameters related to the humoral immune response elicited against SARS-CoV-2 were analysed in 61 patients with different presentations of COVID-19 who were recruited in Hospitals and Primary Healthcare Centres in Madrid, Spain, during the first pandemic peak between April and June 2020. Subjects were allocated as mild patients without hospitalization, severe patients hospitalized or critical patients requiring ICU assistance. Critical patients showed significantly enhanced levels of B cells with memory and plasmablast phenotypes, as well as higher levels of antibodies against SARS-CoV-2 with neutralization ability, which were particularly increased in male gender. Despite all this, antibody-dependent cell-mediated cytotoxicity was defective in these individuals. Besides, patients with critical COVID-19 also showed increased IgG levels against herpesvirus such as CMV, EBV, HSV-1 and VZV, as well as detectable CMV and EBV viremia in plasma. Altogether, these results suggest an enhanced but ineffectual immune response in patients with critical COVID-19 that allowed latent herpesvirus reactivation. These findings should be considered during the clinical management of these patients due to the potential contribution to the most severe disease during SARS-CoV-2 infection.This work was supported by the Coordinated Research Activities at the Centro Nacional de Microbiología (CNM, Instituto de Salud Carlos III) (COV20_00679) to promote an integrated response against SARS-CoV-2 in Spain (Spanish Ministry of Science and Innovation) that is coordinated by Dr Inmaculada Casas (WHO National Influenza Center of the CNM) and a generous donation provided by Chiesi España, S.A.U. (Barcelona, Spain). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. This work was also supported by the Spanish Ministry of Economy and Competitiveness (PID2019 110275RB-I00); the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016-2020, Instituto de Salud Carlos III, European Region Development Fund (ERDF); Miguel Servet - AESI, MPY 341/21. The work of ML-H and SR is financed by NIH grant R01AI143567. The work of MT is supported by Instituto de Salud Carlos III (COV20_00679). The work of LV is supported by a predoctoral grant from Instituto de Salud Carlos III (FIS PI16CIII/00034-ISCIII-FEDER).S