Probiotics and their potential applications in active edible films and coatings.

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El uso de las ecuaciones como guía para pensar y resolver problemas: una aproximación a la enseñanza de la Física

Within the proposals for the teaching of science we can differentiate various procedures that are effective if you have the right knowledge, reorienting them towards the understanding of the basic conceptual nuclei of science in particular, which can be considered mainly three types of verbal contents: data, concepts and principles. In the teaching of Physics the monitoring of these conditions is applied to the solution of problems and, using the appropriate formulation of equations, students are facilitated the understanding of this science.Dentro de las propuestas para la enseñanza de las ciencias podemos diferenciar diversos procedimientos que son eficaces si se dispone de los conocimientos adecuados, reorientando estos hacia la comprensión de los núcleos conceptuales básicos de la ciencia en particular, en la que pueden considerarse principalmente tres tipos de contenidos verbales: datos, conceptos y principios. En la enseñanza de la Física el seguimiento de estas condiciones se aplica a la solución de problemas y, utilizando la apropiada formulación de ecuaciones, se facilita a los estudiantes la comprensión de esta ciencia

A review on additive manufacturing and materials for catalytic applications: Milestones, key concepts, advances and perspectives

Catalysis, a driving force of the chemical industry is increasingly being influenced by additive manufacturing. The link between them is based on the need to intensify catalytic processes in order to make them more efficient and sustainable. Additive manufacturing can satisfy such a need, generating devices with an advanced design, easy production, and great adaptation, in addition to their catalytic functionality. The exponential growth of examples reported on the application of 3D-printing in catalysis has led to the need to compile and analyse these cases and thus establish, through this review, the most in-depth analysis done to date. The manuscript includes a brief background of the history of additive manufacturing and the classification of the different printing techniques. Subsequently, it identifies the intensification of processes, among other aspects, as the key for understanding the union of additive manufacturing and catalysis. Then, it explores in detail how such a combination occurs, establishing the most comprehensive classification to date between the two large groups of printable devices with catalytic properties. Finally, a series of perspectives are proposed in which the most probable courses of new advances in this field of research are identified.O.H. Laguna agradece a la Universidad de Jaén por el apoyo el contrato postdoctoral a través de la ‘‘Acción 6 del Plan de Apoyo a la Investigación de la Universidad de Jaén (2017-2019).

Relativistic Static Thin Disks: The Counter-Rotating Model

A detailed study of the Counter-Rotating Model (CRM) for generic finite static axially symmetric thin disks with nonzero radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating perfect fluids. We also found expressions for the energy density and pressure of the counter-rotating fluids. Then we shown that, in general, there is not possible to take the two counter-rotating fluids as circulating along geodesics neither take the two counter-rotating tangential velocities as equal and opposite. An specific example is studied where we obtain some CRM with well defined counter-rotating tangential velocities and stable against radial perturbations. The CRM obtained are in agree with the strong energy condition, but there are regions of the disks with negative energy density, in violation of the weak energy condition.Comment: 19 pages, 6 figures. Submitted to Physical Review

SUSTENTABILIDAD COMO OPCIÓN DE VIDA: AGRICULTURA URBANA.

Como lo propone Rondón & Gil (2015) puesto que una óptima calidad de vida no solo depende de la decodificación del ambiente en la vida cotidiana, sino que, al contrario, la falencia que se presenta en la sociedad actual refiere a la apropiación del territorio debido a la dificultad de una “educación ambiental” en el contexto colombiano.De lo anterior se implementan estrategias de concientización y cambio, desde el espacio del Club de Ciencias Infundiendo Pensamiento Científico de la I.E.D. Liceo Femenino Mercedes Nariño de manera lúdico-recreativa a través de la implementación y desarrollo de agricultura urbana, cuyo impacto a nivel socio-escolar tiene como fin mejorar la calidad ambiental minimizando las afectaciones consecuentes generando un impacto en la comunidad, sobre las dinámicas y los hechos que se vivencian a diario que perjudican a todo el planeta y nuestro entorno de forma directa o indirecta, además el cómo estas acciones perjudican a todo el planeta. A modo de colofón se observa que el taller permitió la reflexión con relación a la agricultura urbana que propende por aprovechar imaginativamente cualquier espacio disponibl

Astrocyte-derived tissue Transglutaminase affects fibronectin deposition, but not aggregation, during cuprizone-induced demyelination

Astrogliosis as seen in Multiple Sclerosis (MS) develops into astroglial scarring, which is beneficial because it seals off the site of central nervous system (CNS) damage. However, astroglial scarring also forms an obstacle that inhibits axon outgrowth and (re) myelination in brain lesions. This is possibly an important cause for incomplete remyelination in the CNS of early stage MS patients and for failure in remyelination when the disease progresses. In this study we address whether under demyelinating conditions in vivo, tissue Transglutaminase (TG2), a Ca2+-dependent enzyme that catalyses posttranslational modification of proteins, contributes to extracellular matrix (ECM) deposition and/or aggregation. We used the cuprizone model for de- and remyelination. TG2 immunoreactivity and enzymatic activity time-dependently appeared in astrocytes and ECM, respectively, in the corpus callosum of cuprizone-treated mice. Enhanced presence of soluble monomeric and multimeric fibronectin was detected during demyelination, and fibronectin immunoreactivity was slightly decreased in cuprizone-treated TG2(-/-) mice. In vitro TG2 overexpression in astrocytes coincided with more, while knock-down of TG2 with less fibronectin production. TG2 contributes, at least partly, to fibronectin production, and may play a role in fibronectin deposition during cuprizone-induced demyelination. Our observations are of interest in understanding the functional implications of TG2 during astrogliosis

SUSTENTABILIDAD COMO OPCIÓN DE VIDA: REFLEXIÓN EN TORNO AL RECURSO HÍDRICO

Se vuelve necesario replantear la formación de los futuros actores políticos en el área de la investigación y en el área de las ciencias, generando espacios que permitan la integración de la formación disciplinar e investigativos, reconociendo la formación investigativa, como una de las posibilidades para el desarrollo de procesos de formación más consecuentes con el contexto social, político, económico y cultural, en el que se desenvuelve la educación en ciencia; por lo cual es de resaltar espacios de formación centrados en actividades de investigación, con el propósito de promover mayor experiencia, desde la articulación del interés mismo de los individuos con el trabajo investigativo partiendo del conocimiento adquirido en los espacios curriculares o extracurriculares, asumiendo la toma de decisiones y el control del propio aprendizaje, empezando a desempeñar el papel protagónico desde la acción investigativa (Dieleman & Juarez, 2008). Con esto se puede redefinir el rol de “estudiantes pasivos” por el de “estudiantes investigadores” propendiendo por la formación de entes transformadores del cambio educativo-social, que estén en la capacidad de reconocer la importancia de la función de investigación.Partiendo de lo anterior se espera un cambio de paradigma de transmisión?recepción, convirtiendo ciudadanos en agentes activos, críticos y creadores del conocimiento, participando activamente en procesos de transformación social a través de la integración del conocimiento científico y la investigación, particularmente para este caso la importancia del recurso hídrico, como estrategia de abordaje y apropiación del conocimiento científico desde el contexto inmediato, reflexionando desde las dinámicas de consumo y hábitos en torno al manejo del agua

Development and evaluation of superabsorbent hydrogels based on natural polymers

Superabsorbent hydrogels (SAHs) are three dimensional networks formed by polymers that can absorb aqueous solution of over 100% of their initial weight. This work aimed to develop and characterize SAHs of Chitosan/Xanthan gum (CG), Chitosan/Alginate (CA) and controlled Chitosan (C), Xanthan gum (G), and Alginate (A) produced using “onion-like” methodology. The swelling performance, the morphological structure, the crystallinity, and the Fourier transformed infrared spectroscopy characteristics of SAH were used for the characterization of polyelectrolytes complex. Swelling analysis showed that chitosan has a strong influence on the maintenance of hydrogels structure after swelling, mainly in the acid environment (pH=2). The chitosan hydrogel presented around 3000% of acidic fluid absorption after 24 h. The chitosan:xanthan gum (1:1 and 2:1 named as C1G1 and C2G1, respectively) hydrogels were the best combination regarding swelling performance in an acid environment, reaching 1665% and 2024%, respectively, as well at pH 7.0, presenting 1005% (C1G1) and 667% (C2G1). Scanning electron microscopy analysis showed samples with pores, and with different shapes. The X-ray diffraction showed the presence of a characteristic peak at 2θ=20° in all developed composition because of the crystalline nature of chitosan. This work shows the possibility of developing eco-friendly biopolymer-based SAHs at a low cost with a good swelling capacity and stability.The research was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES/Brazil), Fundação de Amparo a Pesquisa do Estado de Sergipe (FAPITEC, MS/CNPq/FAPITEC/SE/SESN◦06/2018) e do Conselho Nacional de Pesquisas (CNPq, Apoio a Projetos de Pesquisa/MCTI/CNPQ/Universal 14/2014) for supporting funds. EBS acknowledges the Portuguese Science and Technology Foundation (FCT) for the funded projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund) financed from national funds, and cofinanced education (FCT/MEC) from national funds and FEDER, under the Partnership Agreement PT2020. J.J. acknowledges the Ministry of Science and Technical Development of the Republic of Serbia, through Contract Number 200051 172015 OI.info:eu-repo/semantics/publishedVersio

ATR Mutations Promote the Growth of Melanoma Tumors by Modulating the Immune Microenvironment.

Melanomas accumulate a high burden of mutations that could potentially generate neoantigens, yet somehow suppress the immune response to facilitate continued growth. In this study, we identify a subset of human melanomas that have loss-of-function mutations in ATR, a kinase that recognizes and repairs UV-induced DNA damage and is required for cellular proliferation. ATR mutant tumors exhibit both the accumulation of multiple mutations and the altered expression of inflammatory genes, resulting in decreased T cell recruitment and increased recruitment of macrophages known to spur tumor invasion. Taken together, these studies identify a mechanism by which melanoma cells modulate the immune microenvironment to promote continued growth

Tissue transglutaminase in astrocytes is enhanced by inflammatory mediators and is involved in the formation of fibronectin fibril-like structures

Abstract Background During multiple sclerosis (MS) lesion formation, inflammatory mediators are produced by microglial cells and invading leukocytes. Subsequently, hypertrophic astrocytes fill the lesion and produce extracellular matrix (ECM) proteins that together form the astroglial scar. This is beneficial because it seals off the site of central nervous system (CNS) damage. However, astroglial scarring also forms an obstacle that inhibits remyelination of brain lesions. This is possibly an important cause for incomplete remyelination of the CNS in early stage MS patients and for failure of remyelination when the disease progresses. Tissue transglutaminase (TG2), a Ca2+-dependent enzyme that can cross-link proteins, appears in astrocytes in inflammatory MS lesions and may contribute to the rearrangement of ECM protein deposition and aggregation. Methods The effect of different inflammatory mediators on TG2 and fibronectin, an ECM protein, protein levels was examined in primary rat microglia and astrocytes by western blotting. Also, TG2 activity was analyzed in primary rat astrocytes by a TG activity assay. To determine the role of TG2 in the deposition and cross-linking of fibronectin, a TG2 inhibitor and TG2 knockdown astrocytes were used. Results Our data show that under inflammatory conditions in vitro, TG2 production is enhanced in astrocytes and microglia. We observed that in particular, astrocytes produce fibronectin that can be cross-linked and aggregated by exogenous TG2. Moreover, inflammatory stimulus-induced endogenously produced TG2 is involved in the appearance of morphological fibril-like fibronectin deposits but does not lead to cross-linked fibronectin aggregates. Conclusions Our in vitro observations suggest that during MS lesion formation, when inflammatory mediators are produced, astrocyte-derived TG2 may contribute to ECM rearrangement, and subsequent astroglial scarring