Iron oxide nanomaterial is a typical example of a magnetic resonance imaging probe for negative contrast. It has also been shown how this nanomaterial can be synthesized for positive contrast by ...modification of the composition and size of the core. However, the role of the organic coating in the relaxometric properties is largely unexplored. Here, maghemite nanoparticles with either excellent positive or very good negative contrast performance are obtained by modifying coating thickness while the core is kept unchanged. Different nanoparticles with tailored features as contrast agent according to the coating layer thickness have been obtained in a single-step microwave-driven synthesis by heating at different temperatures. A comprehensive analysis is conducted of how the composition and structure of the coating affects the final magnetic, relaxometric, and imaging performance. These results show how the organic coating plays a fundamental role in the intrinsic relaxometric parameters of iron oxide-based contrast media.
Endothelial cells in the vascular system are constantly subjected to the frictional force of shear stress due to the pulsatile nature of blood flow. Although several proteins form part of the shear ...stress mechano-sensing pathway, the identification of mechano-transducing pathways is largely unknown. Given the increasing evidence for a signaling function of mitochondria in endothelial cells, the aim of this study was to investigate their role as mechano-sensor organelles during laminar shear stress (LSS). We demonstrated that LSS activates intracellular signaling pathways that modulate not only mitochondrial dynamics but also mitochondrial function. At early time points of LSS, the fission-related protein Drp1 was recruited from the cytosol to mitochondria and activated mitochondrial fission. LSS-dependent increase in intracellular Ca2+ concentration was indispensable for mitochondrial fission. As alterations in mitochondrial dynamics have been related to changes in bioenergetics profiles, we studied mitochondrial function after LSS. We found that LSS decreased respiration rate, increased mitochondrial membrane potential and promoted the mitochondrial generation of ROS with the subsequent oxidation and activation of the antioxidant enzyme PRX3. Our data support a novel and active role for mitochondria in endothelial cells as active players, able to transduce the mechanical force of shear stress in the vascular endothelium into a biological response.
•LSS causes a profound disruption of the mitochondrial tubular network.•Drp1 and extracellular calcium are essential for LSS-induced mitochondrial fission.•LSS modifies the mitochondrial profile in bioenergetics.•PRX3 is a mitochondrial redox sensor of LSS.
The use of fallacies in public debates in political, health, economic and social contexts is detrimental in that it hinders understanding between the parties and facilitates the manipulation of ...public opinion and the propagation of misinformation. Recently, datasets containing various types of fallacies have become available, allowing experimentation in tasks such as automatic fallacy classification. In this paper, we present the first corpus of fallacies in Spanish, with two distinct sections: one formed by prototypical examples extracted from educational materials, and the other by spontaneous examples extracted from on-line comments to news items. Both sections include examples of non-fallacious texts of similar subject matter. Preliminary results on the detection and classification tasks using the corpus we have created show that it is a challenging task (especially when focused on spontaneous fallacies) that could be a good candidate to be part of the tasks with which the latest advances in language models are evaluated.
Betalains are bioactive compounds with attractive antioxidant properties for the food industry, endowing them with potential application in food coatings to maintain quality and extend shelf life. ...However, they have low stability to factors such as light, temperature, and humidity. An alternative to protect bioactive compounds is nanoencapsulation; one of the most used techniques to produce an encapsulation is coaxial electrospraying. In this research, the preparation and characterization of gelatin–betalain nanoparticles were carried out using the coaxial electrospray technique. Betalains were extracted from pitaya (Stenocereus thurberi) and encapsulated in gelatin. The obtained material was evaluated by SEM, FTIR, TGA, and DSC techniques and for its antioxidant capacity. By SEM, nanoparticles with spherical and monodisperse morphologies were observed, with betalain concentrations of 1 and 3% w/v and average diameters of 864 and 832 μm, respectively. By FTIR, the interaction between betalain and gelatin was observed through amino groups and hydrogen bonds. Likewise, the antioxidant activity of the betalains was maintained at the time of encapsulation, increasing the antioxidant activity as the concentration increased. The results of the DPPH, ABTS, and total phenols methods were 645.4592 μM T/g, 832.8863 ± 0.0110 μM T/g, and 59.8642 ± 0.0279 mg GAE/g for coaxial nanoparticles with 3% betalains, respectively. Therefore, the coaxial electrospray technique was useful for obtaining nanoparticles with good antioxidant properties, and due to the origin of its components and since the use of toxic solvents is not necessary in the technique, the material obtained can be considered food grade with potential application as a coating on functional foods.
•Business Process Management systems can improve educational environments.•RubricaSoft is a new BPM implementation aimed at managing university courses.•BPM enables optimization of digital ...interactive versions of learning processes.•Implemented BPM models include peer evaluation and gamification features.•Rubrics clarify evaluation methods reducing user resistance to change.
Enterprise Information Systems are enjoying an extensive trajectory in the optimization of organizations worldwide, of which predominantly the Business Process Management (BPM) systems stand out for their great flexibility. BPM models describe business workflows and are highly useful in detecting errors and bottlenecks and in identifying possible improvements. On the other hand, educational management software tools offer a large number of functionalities, but have yet to take advantage of these techniques. Our main objective is to perform an empirical analysis in this unexplored area to evaluate the advantages of applying BPM in the implementation of innovative and dynamic teaching activities.
Using this methodology, we have designed RubricaSoft, a BPM system focused on providing dynamic educational processes. It automates multiple tasks, including peer evaluation, information integration and the management of deadlines. The results have been very promising from the point of view of the three axes upon which the evaluation has been carried out: satisfaction of students, improvement in academic results and increase in the productivity of teachers. In one of the processes, the time spent by the teacher has been reduced by 80% and student participation increased by 41%.
Cell-cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier strength. We ...identify the Ig superfamily member EMMPRIN (also known as basigin) as a coordinator of forces at endothelial junctions. EMMPRIN localization at junctions correlates with endothelial junction strength in different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased junction permeability. Lack of EMMPRIN alters the localization and function of VE-cadherin (also known as cadherin-5) by decreasing both actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin (also known as junction plakoglobin) and Nm23 (also known as NME1), a nucleoside diphosphate kinase, thereby locally providing ATP to fuel the actomyosin machinery. These results provide a novel mechanism for the regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly.
Mitochondria are important organelles not only as efficient ATP generators but also in controlling and regulating many cellular processes. Mitochondria are dynamic compartments that rearrange under ...stress response and changes in food availability or oxygen concentrations. The mitochondrial electron transport chain parallels these rearrangements to achieve an optimum performance and therefore requires a plastic organization within the inner mitochondrial membrane. This consists in a balanced distribution between free respiratory complexes and supercomplexes. The mechanisms by which the distribution and organization of supercomplexes can be adjusted to the needs of the cells are still poorly understood. The aim of this review is to focus on the functional role of the respiratory supercomplexes and its relevance in physiology. This article is part of a Special Issue entitled: Dynamic and ultrastructure of bioenergetic membranes and their components.
•The plasticity model explains the organization of respiratory complexes (RCs).•It proposes that RCs can be free or super-assembled with other complexes.•The dynamic supra-organization of the RCs is a short-term regulation of metabolism.•Fuel utilization is optimized by mitochondrial supercomplex dynamics.
Trust and Reputation Systems constitute an essential part of many social networks due to the great expansion of these on-line communities in the past few years. As a consequence of this growth, some ...users try to disturb the normal atmosphere of these communities, or even to take advantage of them in order to obtain some kind of benefits. Therefore, the concept of trust is a key point in the performance of on-line systems such as on-line marketplaces, review aggregators, social news sites, and forums. In this work we propose a method to compute a ranking of the users in a social network, regarding their trustworthiness. The aim of our method is to prevent malicious users from illicitly gaining high reputation in the network by demoting them in the ranking of users. We propose a novel system intended to propagate both positive and negative opinions of the users through a network, in such way that the opinions from each user about others influence their global trust score. Our proposal has been evaluated in different challenging situations. The experiments include the generation of random graphs, the use of a real-world dataset extracted from a social news site, and a combination of both a real dataset and generation techniques, in order to test our proposals in different environments. The results show that our method performs well in every situations, showing the propagation of trust and distrust to be a reliable mechanism in a Trust and Reputation System.
Excess of visceral adipose tissue (VAT) characteristic of obesity leads to a proinflammatory state disrupting the insulin signaling pathway, triggering insulin resistance (IR) and inflammation, the ...main processes contributing to obesity comorbidities. Ursolic acid (UA), a pentacyclic triterpenoid occurring in a variety of plant foods, exhibits anti-inflammatory properties. The aim of this study was to evaluate UA effects on IR, hyperinsulinemia, and inflammation in experimental diet-induced obesity. Forty male Wistar rats were randomly assigned to eight groups (
= 5). One group was used for time 0. Three groups were labeled as OBE (control): receiving high-fat diet (HFD; fat content 45.24% of energy) during 3, 6, or 9 weeks; three groups UA-PREV: exposed to simultaneous HFD and UA during 3, 6, or 9 weeks to evaluate UA preventive effects; one group UA-REV: receiving HFD for 6 weeks, followed by simultaneous HFD and UA for three additional weeks to analyze UA reversal effects. Measurements were performed after 3, 6, or 9 weeks of treatment. Adiposity was calculated by weighing VAT after sacrifice. Serum markers were quantified through colorimetric and enzyme-linked immunosorbent assay methods. VAT adipokines RNAm expression was evaluated by quantitative reverse transcriptase-polymerase chain reaction. Data were analyzed by Kruskal-Wallis and Mann-Whitney
tests. UA significantly decreased adiposity, IR, hyperinsulinemia, triacylglycerides, and cholesterol levels, and also VAT mRNA expression of MCP-1 (monocyte chemoattractant protein-1), IL (interleukin)-1
and IL-6, concomitantly increasing adiponectin levels. UA metabolic effects demonstrated in this study support its potential therapeutic utility to improve IR, hyperinsulinemia, and inflammation observed in obesity and diabetes.
The samples used were metallic surfaces and solid samples containing HEMs. Keywords: Highly energetic materials detection, infrared spectroscopy, Raman spectroscopy, HQI, PLS-DA discriminant ...analysis. 1. Los resultados muestran que podemos determinar si una muestra tiene material altamente energético utilizando los algoritmos HQI (Hit Quality Index) y Análisis discriminante por mínimos cuadrados parciales (PLS-DA). A continuación, la luz se devuelve por reflexión a la superficie de la muestra, produciendo un punto ligeramente mayor en la misma posición.
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