186 research outputs found

    A parametric model for analysing atherosclerotic arteries: On the FSI coupling

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    There are many evidences that coronary plaque is not only dependent on the formation and progression of atherosclerosis, but also on the vascular remodelling response. If the local wall shear stress is low, a proliferative plaque may develop. Local inflammatory response will stimulate the formation of a plaque prone to rupture with superimposed thrombus formation (vulnerable plaque). Furthermore, the role of the wall shear stress in the genesis and the development of atherosclerotic diseases has been recently intensively investigated, examining its relationship with the presence of lesions and the intima media thickness. Due to the important role of pulsating blood flow, pressure and hemodynamics factors in atheroma growth, a Fluid Structure Interaction (FSI) parametric study of a 3D atherosclerotic artery has been carried out, with aim of studying the main geometrical risk factors in terms of plaque vulnerability

    Methodology to calibrate the dissection properties of aorta layers from two sets of experimental measurements

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    Aortic dissection is a prevalent cardiovascular pathology that can have a fatal outcome. However, the mechanisms that trigger this disease and the mechanics of its progression are not fully understood. Computational models can help understand these issues, but they need a proper characterisation of the tissues. Therefore, we propose a methodology to obtain the dissection parameters of all layers in aortic tissue via the computational modelling of two different delamination tests: the peel and mixed tests. Both experimental tests have been performed in specimens of porcine aorta, where the intima-media and media-adventitia interfaces, as well as the medial layer, were dissected. These two tests have been modelled using a cohesive zone formulation for the separating interface and a hyperelastic anisotropic material model via an implicit static analysis. The dissection properties of each interface have been calibrated by reproducing the force-displacement curves obtained in the experimental tests. The values of peak and mean force of the experiments were fitted with an error below 10%. With this methodology, we intend to contribute to the development of reliable numerical tools for simulating aortic dissection and aortic aneurysm rupture. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Indicaxanthin prevents eryptosis induced by cigarette smoke extract by interfering with active Fas-mediated signaling

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    A physiological mechanism of programmed cell death called eryptosis occurs in aged or damaged red blood cells (RBCs). Dysregulated eryptosis contributes to abnormal microcirculation and prothrombotic risk. Cigarette smoke extract (CSE) induces a p38 MAPK-initiated, Fas-mediated eryptosis, activating the death-inducing signaling complex (DISC). Indicaxanthin (Ind) from cactus pear fruits, is a bioavailable dietary phytochemical in humans and it is able to incorporate into RBCs enhancing their defense against numerous stimuli. This in vitro work shows that Ind, at concentrations that mimic plasma concentrations after a fruit meal, protects erythrocytes from CSE-induced eryptosis. CSE from commercial cigarettes was prepared in aqueous solution using an impinger air sampler and nicotine content was determined. RBCs were treated with CSE for 3 h in the absence or presence of increasing concentrations of Ind (from 1 to 5 mu M). Cytofluorimetric measurements indicated that Ind reduced CSE-induced phosphatidylserine externalization and ceramide formation in a concentration-dependent manner. Confocal microscopy visualization and coimmunoprecipitation experiments revealed that Ind prevented both CSE-triggered Fas aggregation and FasL/FADD/caspase 8 recruitment in the membrane, indicating inhibition of DISC assembly. Ind inhibited the phosphorylation of p38 MAPK, caspase-8/caspase-3 cleavage, and caspase-3 activity induced by CSE. Finally, Ind reduced CSE-induced ATP depletion and restored aminophospholipid translocase activity impaired by CSE treatment. In conclusion, Ind concentrations comparable to nutritionally relevant plasma concentrations, can prevent Fas-mediated RBC death signaling induced by CSE, which suggests that dietary intake of cactus pear fruits may limit the deleterious effects of cigarette smoking.Indicaxanthin inhibits cigarette smoke-induced eryptosis. Indicaxanthin is able to interfere with the CSE-induced extrinsic pathway of eryptosis. imag

    Anti-Eryptotic Activity of Food-Derived Phytochemicals and Natural Compounds

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    Human red blood cells (RBCs), senescent or damaged due to particular stress, can be removed by programmed suicidal death, a process called eryptosis. There are various molecular mechanisms underlying eryptosis. The most frequent is the increase in the cytoplasmic concentration of Ca2+ ions, later exposure of erythrocytes to oxidative stress, hyperosmotic shock, ceramide formation, stimulation of caspases, and energy depletion. Phosphatidylserine (PS) exposed by eryptotic RBCs due to interaction with endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor, causes the RBCs to adhere to vascular wall with consequent damage to the microcirculation. Eryptosis can be triggered by various xenobiotics and endogenous molecules, such as high cholesterol levels. The possible diseases associated with eryptosis are various, including anemia, chronic kidney disease, liver failure, diabetes, hypertension, heart failure, thrombosis, obesity, metabolic syndrome, arthritis, and lupus. This review addresses and collates the existing ex vivo and animal studies on the inhibition of eryptosis by food-derived phytochemicals and natural compounds including phenolic compounds (PC), alkaloids, and other substances that could be a therapeutic and/or co-adjuvant option in eryptotic-driven disorders, especially if they are introduced through the diet

    A multidisciplinary modeling approach to assess facies-dolomitization-porosity interdependence in a lower cretaceous platform (Northern spain)

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    An innovative methodology for diagenesis characterization and quantification is presented. It includes different geostatistical modeling workflows applied to a partially dolomitized carbonate platform. The case study consists of a Lower Cretaceous (upper Aptian) shallow-water carbonate platform from the Basque\u2013Cantabrian basin (northern Spain), in which a widespread burial dolomitization occurs. Previous studies at basin scale suggested that the flow of dolomitizing fluids through the carbonate succession was channeled by regional faults and that subsequently the dolomite distribution was partially controlled by depositional facies and their modifications after early meteoric diagenesis. Here, at reservoir scale, several carbonate facies were differentiated and grouped in five depositional environments. Two depositional sequences corresponding to transgressive\u2013regressive cycles and three stages of the platform evolution were distinguished. The statistical data treatment indicated that the dolomitization is mainly concentrated in the regressive part of the first sequence, corresponding to the second stage of the platform evolution. The most dolomitized environments are the inner platforms and the shoal. Facies from these shallower/proximal depositional environments were more exposed to early meteoric diagenesis, possibly controlling later dolomitization. The total macroscopic porosity is directly proportional to the degree of dolomitization: pores are most abundant in fully dolomitized portions of the succession, particularly in the rudist-bearing and grain-dominated facies. Abundant aragonitic shells (rudists, corals), easily leached or recrystallized during early meteoric diagenesis, could justify the higher moldic porosity in these facies. For geostatistical modeling purposes, several statistical rules were elaborated in order to associate to each depositional environment, in each of the three platform stages, different proportions of dolomitization and related pore abundance. A direct simulation of the distribution of depositional environments, degree of dolomitization, and pore abundance was achieved using a bi-plurigaussian simulation (PGS) algorithm. A nested-PGS algorithm was used to simulate the same parameters independently: dolomite and pore abundance were distributed within each depositional environment, based on the statistical rules previously defined. These simulations allowed three-dimensional (3D) visualization of the original depositional facies and textures affecting the distribution of dolomitization and pore abundance. Modeling using both bi-PGS and nested simulations accounted for the 3D dolomite body extension: the dolomitized succession is thicker in the north and thins toward the south, in agreement with evidence from mapping of the dolomite geobodies

    Human metapneumovirus as cause of severe community-acquired pneumonia in adults: insights from a ten-year molecular and epidemiological analysis

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    Human metapneumovirus; Severe community-acquired pneumonia; BiomarkersMetapneumovirus humano; Neumonía severa adquirida en la comunidad; BiomarcadoresMetapneumovirus humà; Pneumònia greu adquirida a la comunitat; BiomarcadorsBackground Information on the clinical, epidemiological and molecular characterization of human metapneumovirus in critically ill adult patients with severe community-acquired pneumonia (CAP) and the role of biomarkers identifying bacterial coinfection is scarce. Methods This is a retrospective epidemiological study of adult patients with hMPV severe CAP admitted to ICU during a ten-year period with admission PSI score ≥ 3. Results The 92.8% of the 28 patients with severe CAP due to human metapneumovirus were detected during the first half of the year. Median age was 62 years and 60.7% were male. The genotyping of isolated human metapneumovirus showed group B predominance (60.7%). All patients had acute respiratory failure. Median APACHE II and SOFA score were 13 and 6.55, respectively. The 25% were coinfected with Streptococcus pneumoniae. 60.7% of the patients had shock at admission and 50% underwent mechanical ventilation. Seven patients developed ARDS, three of them younger than 60 years and without comorbidities. Mortality in ICU was 14.3%. Among survivors, ICU and hospital stay were 6.5 and 14 days, respectively. Plasma levels of procalcitonin were higher in patients with bacterial coinfection (18.2 vs 0.54; p < 0.05). The levels of C-reactive protein, however, were similar. Conclusion Human metapneumovirus was associated with severe CAP requiring ICU admission among elderly patients or patients with comorbidities, but also in healthy young subjects. These patients often underwent mechanical ventilation with elevated health resource consumption. While one out of four patients showed pneumococcal coinfection, plasma procalcitonin helped to implement antimicrobial stewardship

    Percepciones del consumidor sobre la carne de caprino en España

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    Se ha realizado una encuesta a consumidores (n=119) con el fin de conocer la percepción que tenían de la carne de caprino frente a la carne de ovino en función de diversos aspectos relacionados con la intención de compra y la percepción de su calidad. El cuestionario constó de 11 enunciados afirmativos, respondidos hedónicamente mediante una escala categórica de 7 puntos (1: “totalmente en desacuerdo”, 7: “totalmente de acuerdo”). El análisis de las respuestas se realizó mediante frecuencias. Los resultados obtenidos han demostrado, globalmente, una sensibilidad positiva hacia la carne de caprino tanto en parámetros decisivos a la hora de la intención de compra como en parámetros de calidad sensorial de la carne. Esto ha sucedido en contra de lo que podría pensarse dado, en nuestro país, el alto consumo y consideración de calidad que tiene la especie ovina.Comisión Interministerial de Ciencia y Tecnología AGL2005-05777- C02-01/GA

    High-frequency subtital-peritidal carbonate cycles of the Lower Aptian (San Esteban Fm., Basque-Cantabrian basin): a record of climatic change

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    El análisis detallado de facies de las calizas de la Formación San Esteban del Aptiense inferior de Cantabria ha permitido caracterizar 15 tipos de litofacies depositadas en ambientes submareales a supramareales. Las facies se organizan en ciclos somerizantes que culminan con superficies de exposición subaérea, evidenciado variaciones relativas del nivel del mar de alta frecuencia/baja amplitud. Se distinguen dos tipos de ciclos en función de las facies y naturaleza de las superficies que los culminan. Los ciclos Tipo-1 están dominados por facies submareales. La secuencia ideal comienza con rudstone bioclástico-intraclástico, seguido de wackestone de Chondrodonta, floatstone de rudistas, boundstone de rudistas y mudstone de milólidos. El techo es una superficie neta con bioturbación y marcas de raíces estilo pseudomicrokarst. Los ciclos Tipo-2 comienzan con floatstone oncolítico-litoclástico, seguido de floatstone de rudistas, packstone-grainstone de foraminíferos, boundstone de rudistas y finalmente rudstone oncolítico, mudstone fenestral y/o estromatolitos laminares a hemiesféricos. Culmina con rasgos subaéreos de desecación y conglomerados calcáreos de cantos negros con microestructura alveolar y rizolitos calcificados. Los ciclos Tipo-1 caracterizaron condiciones ambientales húmedas, mientras que los de Tipo-2 caracterizaron condiciones semi-áridas. La evolución vertical de los ciclos refleja una transición climática de tipo greenhouse a otra coolhouse tras el OAE-1a.High-resolution facies analysis of Lower Aptian platform carbonates from Cantabria has allowed to characterize 15 lithofacies types, which reflect environmental conditions ranging from subtidal to supratidal. The facies are organized in shallowing-upward cycles capped by subaerial exposures, attesting for high-frequency and lowamplitude relative sea-level fluctuations. According to the facies types and nature of the subaerial capping surfaces, two types of cycles have been differentiated, characterizing respectively the lower and upper part of the succession. Type-1 cycles are dominated by subtidal facies. They ideally start with transgressive bioclastic-intraclastic rudstone, followed by Chondrodonta wackestone, rudist floatstone, rudist boundstone and finally miliolid mudstone. They culminate with burrowed and rooted surfaces that resembles to pseudomicrokarst. Type-2 cycles start with transgressive oncoidal-pebbly floatstone, followed by rudist floatstone, foraminiferal packstone-grainstone, rudist boundstone and ending eventually with either oncoidal rudstone, fenestral mudstone and/or laminoid to hemispherical stromatolites. These cycles are capped by subaerial desiccation and limestone conglomerates rich in black-pebbles with alveolar septal microstructure and calcified rhizoliths. Type-1 cycles developed under humid environmental conditions, whereas Type-2 cycles could have formed under semiarid conditions. The cycle stacking pattern may reflect the sedimentary evolution of the platform during the transition from greenhouse to coolhouse conditions after the OAE-1a.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)pu
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