285 research outputs found

    Engineered microenvironments for synergistic VEGF - integrin signalling during vascularization

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    We have engineered polymer-based microenvironments that promote vasculogenesis both in vitro and in vivo through synergistic integrin-growth factor receptor signalling. Poly(ethyl acrylate) (PEA) triggers spontaneous organization of fibronectin (FN) into nanonetworks which provide availability of critical binding domains. Importantly, the growth factor binding (FNIII12-14) and integrin binding (FNIII9-10) regions are simultaneously available on FN fibrils assembled on PEA. This material platform promotes synergistic integrin/VEGF signalling which is highly effective for vascularization events in vitro with low concentrations of VEGF. VEGF specifically binds to FN fibrils on PEA compared to control polymers (poly(methyl acrylate), PMA) where FN remains in a globular conformation and integrin/GF binding domains are not simultaneously available. The vasculogenic response of human endothelial cells seeded on these synergistic interfaces (VEGF bound to FN assembled on PEA) was significantly improved compared to soluble administration of VEGF at higher doses. Early onset of VEGF signalling (PLCγ1 phosphorylation) and both integrin and VEGF signalling (ERK1/2 phosphorylation) were increased only when VEGF was bound to FN nanonetworks on PEA, while soluble VEGF did not influence early signalling. Experiments with mutant FN molecules with impaired integrin binding site (FN-RGE) confirmed the role of the integrin binding site of FN on the vasculogenic response via combined integrin/VEGF signalling. In vivo experiments using 3D scaffolds coated with FN and VEGF implanted in the murine fat pad demonstrated pro-vascularization signalling by enhanced formation of new tissue inside scaffold pores. PEA-driven organization of FN promotes efficient presentation of VEGF to promote vascularization in regenerative medicine applications

    El campo laboral de la antropología en México

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    Anthropology in Mexico has a longstanding trajectory of professional involvement, both in academia and public settings. In this essay we stress the work of those professionals of the discipline who work outside academic settings. We undertake the discussion starting from different perspectives expressed by Mexican anthropologists who have advanced contrasting views of anthropological work. We present information about current professional settings where anthropologists are employed in Mexico, stressing the growing diversity of these niches and the challenges that young anthropologists faceEn México, la antropología tiene una larga trayectoria de desempeño profesional tanto en el ámbito académico como fuera de él. En este artículo ponemos el acento en el trabajo de aquellos profesionales de la disciplina que se dedican a actividades diferentes a la investigación académica. Abordamos el tema a partir de aseveraciones de antropólogos mexicanos que han definido la actividad profesional de diversa manera, tanto desde el ámbito académico como del aplicado. Presentamos información sobre la distribución de los antropólogos entre los dos ámbitos y mencionamos diversos terrenos del trabajo antropológico en México en la actualidad, subrayando la creciente diversidad de nuevos nichos y los retos que esto representa p ara los jóvenes antropólogos

    Optimization of electrocatalytic H2O2 production at pilot plant scale for solar-assisted water treatment

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    This manuscript summarizes the successful start-up and operation of a hybrid eco-engineered water treatmentsystem, at pilot scale. The pilot unit, with 100L capacity, has been devised for the efficient electrocatalyticproduction of H2O2at an air-diffusion cathode, triggering the formation of%OH from Fenton's reaction withadded Fe2+catalyst. These radicals, in combination with those formed at a powerful boron-doped diamond(BDD) anode in an undivided cell, are used to degrade a mixture of model pesticides. The capability of the plantto produce H2O2on site was initially optimized using an experimental design based on central composite design(CCD) coupled with response surface methodology (RSM). This aimed to evaluate the effect of key processparameters like current density (j) and solution pH. The influence of electrolyte concentration as well as liquidand air flow rates on H2O2electrogeneration and current efficiency at optimizedjand pH was also assessed. Thebest operation conditions resulted in H2O2mass production rate of 64.9mgmin−1, 89.3% of current efficiencyand 0.4kWh m-3of energy consumption at short electrolysis time. Performance tests at optimum conditions werecarried out with 75L of a mixture of pesticides (pyrimethanil and methomyl) as a first step towards the elim-ination of organic contaminants by solar photoelectro-Fenton (SPEF) process. The combined action of homo-geneous (%OH) and heterogeneous (BDD(%OH)) catalysis along with photocatalysis (UV photons collected at asolar CPC photoreactor) allowed the removal of more than 50% of both pesticides in 5min, confirming the fastregeneration of Fe2+catalyst through cathodic reduction and photo-Fenton reaction

    Spatial behavior of acid mine drainage in a peculiar stream : physical-chemical evolution from the source until the temporarlly receptor in the Iberian Pyrite Belt

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    Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014 (E2KW2014), ISBN 978-84-697-1162-0"The Iberian Pyrite Belt is a vast concentration of massive sulphide, located in the SW of the Iberian Peninsula. Historically, this area has undergone an intense mining activity, which has left a huge amount of mining facilities and unrestored waste dumps. Mineral-water interaction in the waste dumps is responsible for the generation of acid mine drainage (AMD), causing a strong impact in the water systems. The AMD occurs when the sulfide minerals are in the presence of atmospheric oxygen and humidity, suffering oxidation reactions. As a consequence, metals and acidity are mobilized into the receiving watercourses. Such conditions have created a unique scenario in the world by the extreme degradation that characterizes the network of channels and streams in the IPB. In this context, widely described in the scientific literature, the present study aims to monitoring a singular channel affected by AMD (Campanario stream), from its origin (in the waste dump) to its confluence with an unpolluted stream. Such monitoring procedure will allow characterizing the physicochemical evolution and the mineral-water processes that regulate it

    Four abandoned mines, one acid mine drainage affected river and an unsolved issue for a water supply reservoir

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    Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014(E2KW2014)". ISBN 978-84-697-1162-

    Multi-Objective optimisation of oil demisters geometry for Ultra-Low charge ammonia chillers

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    Driven by global climate objectives, the pursuit for eco-friendly refrigeration solutions has catalysed impressive advancements in the sector. Ammonia, a historically utilized refrigerant, is now widely adopted in light industrial applications, largely due to the growth of Ultra-Low Charge package chillers. Opportunities, however, persist for refining system components to further diminish refrigerant charge, fostering safer and more efficient solutions. This paper focuses on optimizing the oil separator geometry of an experimentally tested Ultra-Low Charge ammonia chiller. The principal aim and novelty is to lower the specific refrigerant charge while enhancing the separation efficiency and the pressure drop performance. Assessing the separation efficiency involves an analytical model grounded in the “orbit-equilibrium” concept, while the pressure drop is evaluated with consideration of liquid particles presence. Utilizing the validated model, a Multi-Objective Optimization process driven by the eaMuPlusLambda algorithm produces geometries able to reduce the cut-size diameter by 1.4 % up to 15.4 %, pressure drop by 66.7 % up to 89.1 %, and internal volume by 51.3 % up to 68.9 %, compared to the baseline setup. This accomplishment stems from meaningful parameter adjustments, encompassing a 12.1 – 30.0 % decrease in the main diameter, 35.8 % reduction in the main height, 25.4 – 41.2 % contraction in the outlet diameter, 10.9 – 47.1 % augmentation in the inlet diameter, and the vortex finder elimination. Consequently, this translates to a 5% to 14% decrease in the chiller’s specific charge. This study intends an initial step in optimizing oil separators for Ultra-Low Charge ammonia chillers, presenting prospects for specific charge reduction and inciting further exploration through experimental testing or Computational Fluid Dynamics.Ministerio de Ciencia e Innovación (España) Centro para el Desarrollo Tecnológico Industrial (España) Centro para el Desarrollo Tecnológico Industrial (España)14 página

    Disentangling the main causes and potential origin of an unusual razorbill (Alca torda) die-off in the Mediterranean Sea: an interdisciplinary approach

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    An unprecedented wreck of razorbills (Alca torda) occurred along the Mediterranean Sea during winter 2022-2023. To determine the potential causes of death and origin of these birds, 46 dead razorbills collected on the coast of Malaga (Spain) were analysed. Necropsies revealed poor body 0condition and starvation signs in most birds. Influenza virus was excluded through PCR testing. However, a high prevalence (58%) of gastrointestinal nematodes was found, primarily Contracaecum variegatum, associated with oesophageal and proventricular ulcers in 60% of razorbills. Stable isotope analysis of feathers showed that most of the birds likely were from North Sea colonies, although 33% of the individuals presumably were from other breeding locations. Persistent Atlantic storms likely triggered this wreck by impeding foraging and forcing migration of weakened razorbills. Although starvation induced by harsh weather seemed to be the primary cause of mortality, the high parasite loads and associated digestive ulcers found in most razorbills may have acted synergistically to further weaken these already emaciated birds. The interplay of these factors offers a better understanding of the multifaceted drivers of mass seabird wreck events

    Insights of Active Extension Within a Collisional Orogen From GNSS (Central Betic Cordillera, S Spain)

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    The coexistence of shortening and extensional tectonic regimes is a common feature in orogenic belts. The westernmost end of the Western Mediterranean is an area undergoing shortening related to the 5 mm/ yr NNW‒SSE convergence of the Nubia and Eurasia Plates. In this region, the Central Betic Cordillera shows a regional ENE‒WSW extension. Here, we present GNSS-derived geodetic data along a 170 km-long transect orthogonal to the main active normal faults of the Central Betic Cordillera. Our data indicate that the total extension rate along the Central Betic Cordillera is 2.0 ± 0.3 mm/yr. Extension is accommodated in the eastern (0.8 ± 0.3 mm/yr in the Guadix-Baza Basin) and western (1.3 ± 0.3 mm/yr in the Granada Basin) parts of the Central Betic Cordillera, while no extension is recorded in the central part of the study area. Moreover, our data permit us to quantify, for the first time, short-term fault slip rates of the Granada Fault System, which is one of the main seismogenic sources of the Iberian Peninsula. We deduce a fault slip rate of ∼1.3 ± 0.3 mm/ yr for the whole Granada Basin, with 0.9 ± 0.3 mm/yr being accommodated in the Granada Fault System and 0.4 ± 0.3 mm/yr being accommodated in the southwestern sector of the Granada Basin, where no active faults have been previously described at the surface. The heterogeneous extension in the Central Betic Cordillera could be accommodated by shallow high-angle normal faults that merge with a detachment at depth. Part of the active extension could be derived from gravitational instability because of underlying over-thickened crustThe Generalitat Valenciana (Valencian Regional GovernmentResearch project AICO/2021/196), Spanish Ministry of ScienceInnovation and University (Research Projects RTI2018-100737- B-I00 and PID2021-127967NB-I00),The University of Alicante (Research Project VIGROB053)The University of Jaén (POAIUJA 2021–2022, CEACTEMA and Programa Operativo FEDER Andalucía, 2014–2020—call made by UJA, 2018, Ref. 1263446), P18-RT- 3275 (Junta de Andalucía/FEDER),Junta de Andalucía regional government (RNM282 and RNM 148 research groups)The Institut Cartogràfic Valencià, Agencia Valenciana de Seguridad y Respuesta a las Emergencias (Generalitat Valenciana)Consorcio Provincial para el Servicio de Prevención y Extinción de Incendios y Salvamento de AlicanteDiputaciones Provinciales de Alicante y CastellónAyuntamiento de Almorad

    Daily rhythms of acute stress responses and antioxidant systems in the European sea bass (Dicentrarchus labrax): Effects of the time of the year

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    Fish reared in aquaculture face various acute stressors, including air exposure during handling. Research on the stress response in fish can provide essential insights into their physiology and help define better aquaculture practices. In this study, we investigated the daily rhythms in the stress-axis response of the European sea bass (Dicentrarchus labrax) subjected to an acute stressor consisting of air exposure (1 min), and how this response is influenced by the time of the day and the season of the year. In addition, rhythms in antioxidant systems were also assessed. The experiments were performed in late Autumn (December) and late Spring (June), with natural photoperiod (10 L:14D and 15 L:9D, respectively) and water temperature (ranging from 19.47 ± 0.17 December to 22.13 ± 0.13 ◦ ◦ C in C in June). Samples were collected throughout a 24-h cycle at Zeitgeber time (ZT) 0.5, 4, 7.5, 12, 16, 20, and 24.5 h at both seasons. At each sampling point, an untreated control (CTRL) group was sampled, while a STRESS group was exposed to air for one minute, returned to the tank, and sampled one hour later. Fish were sacrificed to collect plasma samples, hypothalamus and liver. Plasma samples were analyzed for cortisol, glucose, and lactate. In the hypothalamus, the mRNA expression levels of corticotropin-releasing hormone (crh) and crh-binding protein (crh-bp) were quantified using quantitative RT-PCR (qPCR). In the liver, genes related to antioxidant systems (catalase, superoxide dismutase 1, glutathione peroxidase,and glutathione reductase) and mitochondrial markers of stress (uncoupling protein 1, cytochrome c oxidase IV and peroxiredoxin3) were also analyzed by qPCR. The results revealed that most stress indicators (cortisol, cat, sod1, gsh-px, gsr, ucp1, coxIV) displayed daily rhythms. Furthermore, the stress response was significantly influenced by the time of day and the season in which the stressor was applied. In June, cortisol and glucose responses to stress were higher during the day than at night. The increase observed after stress in genes related to the antioxidant system was more significant in June than in December. Conversely, the response of mitochondrial markers was greater in December. Taken together, these findings highlight that the stress response of the European sea bass is time- dependent, both on a daily and a seasonal basis. This emphasizes the importance of considering cyclic environmental factors and circadian rhythms in aquaculture procedures to enhance fish welfare
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