71 research outputs found
Microstructure Evolution in a Fast and Ultrafast Sintered Non-Equiatomic Al/Cu HEA
One of the attractive characteristics of high entropy alloys (HEAs) is the ability to tailor their composition to obtain specific microstructures and properties by adjusting the stoichiometry to obtain a body-centered cubic (BCC) or face-centered cubic (FCC) structure. Thus, in this work, the target composition of an alloy of the FeCrCoNi family has been modified by adjusting the Al/Cu ratio in order to obtain a BCC crystalline structure. However, processing conditions always play a key role in the final microstructure and, therefore, in this work, the microstructure evolution of FeCrCoNiAl1.8Cu0.5 HEA sintered by different powder metallurgy (PM) techniques has been investigated. The techniques used range from the conventional PM sintering route, that uses high heating rates and sintering times, going through a fast sintering technique such as spark plasma sintering (SPS) to the novel and promising ultrafast sintering technique electrical resistance sintering (ERS). Results show that the increase in the processing time favours the separation of phases and the segregation of elements, which is reflected in a substantial change in the hardness of the alloy. In conclusion, the ERS technique is presented as a very promising consolidation technique for HEA.The authors gratefully acknowledge the financial support of MAT4.0-CM project funded by Madrid region under programme S2018/NMT-4381. J. Cornide also acknowledges funding from the Spanish Ministry of Science and Innovation (IJCI-2017-31348)
Elevated temperature tensile and bending strength of ultra-high temperature ceramic matrix composites obtained by different processes
Innovative Three-Step Microwave-Promoted Synthesis of N-Propargyltetrahydroquinoline and 1,2,3-Triazole Derivatives as a Potential Factor Xa (FXa) Inhibitors: Drug Design, Synthesis, and Biological Evaluation
The coagulation cascade is the process of the conversion of soluble fibrinogen to insoluble fibrin that terminates in production of a clot. Factor Xa (FXa) is a serine protease involved in the blood coagulation cascade. Moreover, FXa plays a vital role in the enzymatic sequence which ends with the thrombus production. Thrombosis is a common causal pathology for three widespread cardiovascular syndromes: acute coronary syndrome (ACS), venous thromboembolism (VTE), and strokes. In this research a series of N-propargyltetrahydroquinoline and 1,2,3-triazole derivatives as a potential factor Xa (FXa) inhibitor were designed, synthesized, and evaluated for their FXa inhibitor activity, cytotoxicity activity and coagulation parameters. Rational design for the desired novel molecules was performed through protein-ligand complexes selection and ligand clustering. The microwave-assisted synthetic strategy of selected compounds was carried out by using Ullmann-Goldberg, N-propargylation, Mannich addition, Friedel-Crafts, and 1,3-dipolar cycloaddition type reactions under microwave irradiation. The microwave methodology proved to be an efficient way to obtain all novel compounds in high yields (73–93%). Furthermore, a thermochemical analysis, optimization and reactivity indexes such as electronic chemical potential (μ), chemical hardness (η), and electrophilicity (ω) were performed to understand the relationship between the structure and the energetic behavior of all the series. Then, in vitro analysis showed that compounds 27, 29–31, and 34 exhibited inhibitory activity against FXa and the corresponding half maximal inhibitory concentration (IC50) values were calculated. Next, a cell viability assay in HEK293 and HepG2 cell lines, and coagulation parameters (anti FXa, Prothrombin time (PT), activated Partial Thromboplastin Time (aPTT)) of the most active novel molecules were performed to determine the corresponding cytotoxicity and possible action on clotting pathways. The obtained results suggest that compounds 27 and 29 inhibited FXa targeting through coagulation factors in the intrinsic and extrinsic pathways. However, compound 34 may target coagulation FXa mainly by the extrinsic and common pathway. Interestingly, the most active compounds in relation to the inhibition activity against FXa and coagulation parameters did not show toxicity at the performed coagulation assay concentrations. Finally, docking studies confirmed the preferential binding mode of N-propargyltetrahydroquinoline and 1,2,3-triazole derivatives inside the active site of FXa.Fil: Santana Romo, Fabián. Pontificia Universidad Católica de Chile; ChileFil: Lagos, Carlos F.. Universidad San Sebastián; ChileFil: Duarte, Yorley. Universidad Andrés Bello; ChileFil: Castillo, Francisco. Pontificia Universidad Católica de Chile; ChileFil: Moglie, Yanina Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Maestro, Miguel A.. University of A Coruña; EspañaFil: Charbe, Nitin. Pontificia Universidad Católica de Chile; ChileFil: Zacconi, Flavia Cristina Milagro. Pontificia Universidad Católica de Chile; Chil
Medical geography in the study of hepatitis A, in the Coffee-triangle region, Colombia, 2007-2011
Objectives: There are few studies of geographical characterization of viral hepatitis. For this reason, we after estimating the incidence rates for Hepatitis A (HAV), we developed epidemiological GIS-based maps for this viral disease, within a well-defined geographic region (the coffee triangle) in Colombia.
Study design: A retrospective cross-sectional analysis of surveillance data and GIS-based developing of epidemiological maps.
Methods: Surveillance cases data (2007-2011) were used to estimate annual incidence rates using reference population data, on hepatitis, to develop the first maps of HAV in the 53 municipalities of the coffee-triangle region of Colombia (departments Caldas, Quindio, Risaralda). GIS used was Kosmo® 3.1. To summarize and compare the data among municipalities and departments (as units of analysis) we generate indicators such as accumulated incidence rates (AIR) and incidence rates ratios.
Results: 1518 HAV cases were reported, 47% from Quindío, 30% Caldas and 22% Risaralda. Quindio presented with the highest AIR (131.54) among all the administrative units under study (Caldas, AIR: 46.39; Risaralda, AIR: 37.62). Interestingly, the highest rates in Quindio, during the period, could be related to the increased number of cases reported in two municipalities from 2008 (Quimbaya, AIR ratio: 4.0 and Montenegro: 3.61). The causes that underlie this augmentation will be subject to further research.
Conclusions: Incidence rates for HAV is still high in the region. Showing epidemiological data, particularly in maps would allow planning actions oriented to interventions at the different forms of transmission that this disease has, which is highly important for decisions in public health policies
Effect of temperature and nucleotide on the binding of BiP chaperone to a protein substrate
BiP (immunoglobulin heavy-chain Binding Protein) is a Hsp70 monomeric ATPase motor that plays broad and crucial roles maintaining proteostasis inside the cell. Structurally, BiP is formed by two domains, a nucleotide-binding domain (NBD) with ATPase activity connected by a flexible hydrophobic linker to the substrate-binding domain (SBD). While the ATPase and substrate binding activities of BiP are allosterically coupled, the latter is also dependent on nucleotide binding. Recent structural studies have provided new insights into BiP's allostery; however, the influence of temperature on the coupling between substrate and nucleotide binding to BiP remains unexplored. Here we study BiP's binding to its substrate at the single molecule level using thermo-regulated optical tweezers which allows us to mechanically unfold the client protein and explore the effect of temperature and different nucleotides on BiP binding. Our results confirm that the affinity of BiP for its protein substrate relies on nucleotide binding, by mainly regulating the binding kinetics between BiP and its substrate. Interestingly, our findings also showed that the apparent affinity of BiP for its protein substrate in the presence of nucleotides remains invariable over a wide range of temperatures, suggesting that BiP may interact with its client proteins with similar affinities even when the temperature is not optimal. Thus, BiP could play a role as a "thermal buffer" in proteostasis. This article is protected by copyright. All rights reserved
El índice de calidad de la nutrición en las residencias de ancianos (QUINN). Una nueva herramienta para evaluar la calidad de la dieta en las residencias de ancianos
Acknowledgements: the authors would like to thank the cooperation of the personnel of this institution —
Yolanda Velasco, Alfredo Zapatero-Llanos, Carolina Calderon-Niño, and Lidia Peña-Rampérez, and all the
residents of the center who participated in the study. The authors would like to thank Verónica Casanova-
Muñoz for her constructive comments on some aspects of this manuscript.Background: the assessment of diet quality (DQ) is fundamental to the study of disease-diet associations, and it is necesary to implement an easy to-apply tool in nursing homes (NHs). Our objective was to propose and apply a novel diet quality indicator (DQIn) using an a priori approach for NHs. Methods: the QUality Index for Nutrition in Nursing homes (QUINN) was implemented in a public NH located in Valladolid, Spain, during a 5-week period (n = 137 subjects). The choice of the QUINN components was based on a rapid review. The QUINN was based on 15 dietary components — 12 were basic (vegetables, fruits, legumes, olive oil, cereals, dairy, white fish and seafood, white-meat, eggs/positive; other fats, red and processed meat, and sweets/negative), and 3 were supplementary (fruits and vegetables variety, oily-fish, and whole-grains/positive). Each component was classified into 4-categories (0, 1, 2 o 3 points; range: 0-45 points). Results: the QUINN was tested on a menu offered by a NH giving a result of 34 points (good diet). The components with the highest scores were related to the Mediterranean diet (high consumption of legumes, olive oil, white fish and shellfish; low intake of other fats; and a wide variety of fruits and vegetables), together with cereals, white meat, dairy, and eggs. The components that required a major change were red- and processed-meats, sweets, and whole grains. Conclusion: the menu of this Spanish NH showed a good DQ according to the QUINN. The assessment of the DQ in NHs using QUINN will allow the proposal of interventions aimed at improving their diet.Antecedentes: la valoración de la calidad de la dieta es fundamental para el estudio de las asociaciones enfermedad-dieta, y es necesario
implantar una herramienta de fácil aplicación en las residencias de ancianos. Nuestro objetivo fue proponer y aplicar un nuevo indicador de
calidad de la dieta (diet quality indicator, DQIn) utilizando un enfoque a priori para su utilización en residencias de ancianos.
Métodos: el Índice de Calidad Nutricional en Residencias de Ancianos (QUality Index for Nutrition in Nursing homes, QUINN) se aplicó en una
residencia pública de Valladolid durante un periodo de 5 semanas (n = 137 sujetos). La elección de los componentes del QUINN se basó en
una revisión rápida. En el QUINN se consideraron 15 componentes dietéticos, 12 básicos (verduras, frutas, legumbres, aceite de oliva, cereales,
lácteos, pescado blanco y marisco, carnes blancas, huevos/positivos; otras grasas, carnes rojas y procesadas, y dulces/negativos) y 3 adicionales
(variedad de frutas y verduras, pescado azul, y cereales integrales/positivos). Cada componente se clasificó en 4 categorías (0, 1, 2 o 3 puntos;
rango: 0-45 puntos).
Resultados: el QUINN se aplicó en el menú ofertado por una residencia de ancianos dando un resultado de 34 puntos (dieta de buena calidad).
Los componentes con mayor puntuación estaban relacionados con la dieta mediterránea (alto consumo de legumbres, aceite de oliva, pescado
blanco y marisco, bajo consumo de otras grasas y variedad de frutas y verduras), junto con los cereales, las carnes blancas, los lácteos y los
huevos. Los componentes que requerían un cambio importante fueron las carnes rojas y procesadas, los dulces y los cereales integrales.
Conclusión: el menú de esta residencia de ancianos situada en España mostró una calidad de la dieta buena según el QUINN. La evaluación de
la calidad de la dieta en las residencias de ancianos mediante el QUINN permitirá proponer intervenciones para mejorar la dieta
A HIF-LIMD1 negative feedback mechanism mitigates the pro-tumorigenic effects of hypoxia
The adaptive cellular response to low oxygen tensions is mediated by the hypoxia inducible factors (HIFs), a family of heterodimeric transcription factors composed of HIF-α and β subunits. Prolonged HIF expression is a key contributor to cellular transformation, tumourigenesis and metastasis. As such, HIF degradation under hypoxic conditions is an essential homeostatic and tumour suppressive mechanism. LIMD1 complexes with PHD2 and VHL in physiological oxygen levels (normoxia) to facilitate proteasomal degradation of the HIF-α subunit. Here, we identify LIMD1 as a HIF-1 target gene, which mediates a previously uncharacterised, negative regulatory feedback mechanism for hypoxic HIF-α degradation by modulating PHD2-LIMD1- VHL complex formation. Hypoxic induction of LIMD1 expression results in increased HIF-α protein degradation, inhibiting HIF-1 target-gene expression, tumour growth and vascularisation. Furthermore, we report that copy number variation at the LIMD1 locus occurs in 47.1% of lung adenocarcinoma patients, correlates with enhanced expression of a HIF target gene signature and is a negative prognostic indicator. Taken together, our data open a new field of research into the aetiology, diagnosis and prognosis of LIMD1-negative lung cancers
Diet quality index as a predictor of treatment efficacy in overweight and obese adolescents: The EVASYON study
Background & aim: A diet quality index (DQI) is a tool that provides an overall score of an individual''s dietary intake when assessing compliance with food-based dietary guidelines. A number of DQIs have emerged, albeit their associations with health-related outcomes are debated. The aim of the present study was to assess whether adherence to dietary intervention, and the overall quality of the diet, can predict body composition changes. Methods: To this purpose, overweight/obese adolescents (n = 117, aged: 13–16 years; 51 males, 66 females) were recruited into a multi-component (diet, physical activity and psychological support) family-based group treatment programme. We measured the adolescents’ compliance and body composition at baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up. Also, at baseline, after 6 months, and at the end of follow-up we calculated the DQI. Results: Global compliance with the dietary intervention was 37.4% during the intensive phase, and 14.3% during the extensive phase. Physical activity compliance was 94.1% at 2-months and 34.7% at 13months and psychological support compliance were growing over the intervention period (10.3% intensive phase and 45.3% during extensive phase). Adolescents complying with the meal frequency criteria at the end of the extensive phase had greater reductions in FMI z-scores than those did not complying (Cohen''s d = 0.53). A statistically significant association was observed with the diet quality index. DQI-A variation explained 98.1% of BMI z-score changes and 95.1% of FMI changes. Conclusions: We conclude that assessment of changes in diet quality could be a useful tool in predicting body composition changes in obese adolescents involved in a diet and physical activity intervention programme backed-up by psychological and family support
Concursos de Anteproyectos Edificios Consistoriales de nuevas Municipalidades de la Región Metropolitana
Megalin/LRP2 Expression Is Induced by Peroxisome Proliferator-Activated Receptor -Alpha and -Gamma: Implications for PPARs' Roles in Renal Function
BACKGROUND: Megalin is a large endocytic receptor with relevant functions during development and adult life. It is expressed at the apical surface of several epithelial cell types, including proximal tubule cells (PTCs) in the kidney, where it internalizes apolipoproteins, vitamins and hormones with their corresponding carrier proteins and signaling molecules. Despite the important physiological roles of megalin little is known about the regulation of its expression. By analyzing the human megalin promoter, we found three response elements for the peroxisomal proliferator-activated receptor (PPAR). The objective of this study was to test whether megalin expression is regulated by the PPARs. METHODOLOGY/PRINCIPAL FINDINGS: Treatment of epithelial cell lines with PPARα or PPARγ ligands increased megalin mRNA and protein expression. The stimulation of megalin mRNA expression was blocked by the addition of specific PPARα or PPARγ antagonists. Furthermore, PPAR bound to three PPAR response elements located in the megalin promoter, as shown by EMSA, and PPARα and its agonist activated a luciferase construct containing a portion of the megalin promoter and the first response element. Accordingly, the activation of PPARα and PPARγ enhanced megalin expression in mouse kidney. As previously observed, high concentrations of bovine serum albumin (BSA) decreased megalin in PTCs in vitro; however, PTCs pretreated with PPARα and PPARγ agonists avoided this BSA-mediated reduction of megalin expression. Finally, we found that megalin expression was significantly inhibited in the PTCs of rats that were injected with BSA to induce tubulointerstitial damage and proteinuria. Treatment of these rats with PPARγ agonists counteracted the reduction in megalin expression and the proteinuria induced by BSA. CONCLUSIONS: PPARα/γ and their agonists positively control megalin expression. This regulation could have an important impact on several megalin-mediated physiological processes and on pathophysiologies such as chronic kidney disease associated with diabetes and hypertension, in which megalin expression is impaired
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