Revestimiento de mortero termocrómico en fachada: impacto en la eficiencia energética del edificio

Thermochromic materials, with optical properties changing with temperature, optimize the use of solar energy by the building envelope for the improvement of energy efficiency. The purpose of this research is to determine the impact of a thermochromic mortar (TM) façade coating on the building energy performance in a Mediterranean climate. A new calculation methodology is proposed to implement the dynamical optical properties of the mortar in conventional energetic simulation tools. This study considers a coating with variable optical properties that move from 0,65 to 0,60 solar absorptance value, and a transition temperature moving from 20ºC to 35ºC. The mortar shows a dark grey colour for low temperatures and a light colour for high temperatures. The building with TM coating shows a 3 % lower yearly energy demand than the building with non-variable optical properties, with a maximum heating demand reduction reaching 8 %.Los materiales termocrómicos, con propiedades ópticas variables con la temperatura, optimizan el aprovechamiento de la energía solar por la envolvente del edificio para mejorar su eficiencia energética. El objeto de este estudio es determinar el impacto de un revestimiento de mortero termocrómico (MT) en fachada sobre la eficiencia energética del edificio en un clima mediterráneo. Se propone una metodología de cálculo para implementar las propiedades ópticas variables del mortero en la simulación energética. Se estudia un revestimiento de MT con absortancia solar entre 0,65 y 0,60, y una temperatura de transición entre 20ºC y 35ºC. El mortero muestra color gris oscuro para temperaturas bajas y color claro para temperaturas altas. El edificio presenta una demanda energética anual un 3 % inferior que con revestimiento de propiedades ópticas no variables. La reducción de demanda de calefacción puede llegar a un 8%

Magnetite mineralization inside cross-linked protein crystals

Crystallization in confined spaces is a widespread process in nature that also has important implications for the stability and durability of many man-made materials. It has been reported that confinement can alter essential crystallization events, such as nucleation and growth and, thus, have an impact on crystal size, polymorphism, morphology, and stability. Therefore, the study of nucleation in confined spaces can help us understand similar events that occur in nature, such as biomineralization, design new methods to control crystallization, and expand our knowledge in the field of crystallography. Although the fundamental interest is clear, basic models at the laboratory scale are scarce mainly due to the difficulty in obtaining well-defined confined spaces allowing a simultaneous study of the mineralization process outside and inside the cavities. Herein, we have studied magnetite precipitation in the channels of cross-linked protein crystals (CLPCs) with different channel pore sizes, as a model of crystallization in confined spaces. Our results show that nucleation of an Fe-rich phase occurs inside the protein channels in all cases, but, by a combination of chemical and physical effects, the channel diameter of CLPCs exerted a precise control on the size and stability of those Fe-rich nanoparticles. The small diameters of protein channels restrain the growth of metastable intermediates to around 2 nm and stabilize them over time. At larger pore diameters, recrystallization of the Fe-rich precursors into more stable phases was observed. This study highlights the impact that crystallization in confined spaces can have on the physicochemical properties of the resulting crystals and shows that CLPCs can be interesting substrates to study this process

Enhancing a de novo enzyme activity by computationally-focused ultra-low-throughput screening

Directed evolution has revolutionized protein engineering. Still, enzyme optimization by random library screening remains sluggish, in large part due to futile probing of mutations that are catalytically neutral and/or impair stability and folding. FuncLib is a novel approach which uses phylogenetic analysis and Rosetta design to rank enzyme variants with multiple mutations, on the basis of predicted stability. Here, we use it to target the active site region of a minimalist-designed, de novo Kemp eliminase. The similarity between the Michaelis complex and transition state for the enzymatic reaction makes this system particularly challenging to optimize. Yet, experimental screening of a small number of active-site variants at the top of the predicted stability ranking leads to catalytic efficiencies and turnover numbers ( 2 104 M 1 s 1 and 102 s 1) for this anthropogenic reaction that compare favorably to those of modern natural enzymes. This result illustrates the promise of FuncLib as a powerful tool with which to speed up directed evolution, even on scaffolds that were not originally evolved for those functions, by guiding screening to regions of the sequence space that encode stable and catalytically diverse enzymes. Empirical valence bond calculations reproduce the experimental activation energies for the optimized eliminases to within 2 kcal mol 1 and indicate that the enhanced activity is linked to better geometric preorganization of the active site. This raises the possibility of further enhancing the stabilityguidance of FuncLib by computational predictions of catalytic activity, as a generalized approach for computational enzyme designKnut and Alice Wallenberg Foundation (Wallenberg Academy Fellowship) 2018.0140Human Frontier Science Program RGP0041/2017FEDER Funds/Spanish Ministry of Science, Innovation and Universities BIO2015-66426-R RTI2018-097142-B-100FEDER/Junta de Andalucia - Consejeria de Economia y Conocimiento E.FQM.113.UGR18Swedish National Infrastructure for computing (SNAC) 2018/2-3 2019/2-

Plasticity and cardiovascular applications of multipotent adult progenitor cells

Cardiovascular disease is the leading cause of death worldwide, which has encouraged the search for new therapies that enable the treatment of patients in palliative and curative ways. In the past decade, the potential benefit of transplantation of cells that are able to substitute for the injured tissue has been studied with several cell populations, such as stem cells. Some of these cell populations, such as myoblasts and bone marrow cells, are already being used in clinical trials. The laboratory of CM Verfaillie has studied primitive progenitors, termed multipotent adult progenitor cells, which can be isolated from adult bone marrow. These cells can differentiate in vitro at the single-cell level into functional cells that belong to the three germ layers and contribute to most, if not all, somatic cell types after blastocyst injection. This remarkably broad differentiation potential makes this particular cell population a candidate for transplantation in tissues in need of regeneration. Here, we focus on the regenerative capacity of multipotent adult progenitor cells in several ischemic mouse models, such as acute and chronic myocardial infarction and limb ischemia

Severe cardiac and abdominal manifestations without lung involvement in a child With COVID-19

Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic, affecting humans of all ages. Clinical features of the pediatric population have been published, but there is not yet enough information to make a definitive description. Fever is typical, as it is respiratory symptom. Rarely are the infection and complications severe, and, when they are, it is almost always in a patient with another underlying disease. However, some otherwise healthy children with COVID-19 do suffer critical organ injury, such as acute myocarditis, heart failure and gastrointestinal inflammation. The mechanism of these organ damages remains unclear. An otherwise normally healthy 13-year-old male was admitted to the pediatric intensive care unit with acute abdomen pain, possible myocarditis and a suspected diagnosis of COVID-19. Noteworthy basal findings were ventricular extrasystoles in the electrocardiogram (EKG) and moderate left ventricular systolic dysfunction. Chest X-ray was normal. Blood tests revealed altered levels of inflammation factors (C-reactive protein (CRP), D-dimer, fibrinogen, interleukin 6 (IL-6)), lymphopenia and elevated cardiac enzymes. The first test for polymerase chain reaction (PCR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was negative. The patient’s condition worsened, and he entered cardiogenic shock (hypotension, tachycardia and oliguria). He was vomiting continuously, which made pain control difficult; imaging of his abdomen was undertaken. There was no response to fluid resuscitation, and so milrinone and epinephrine were administered. Empiric treatment began with azithromycin, foscarnet, carnitine and immunoglobulins. Hydroxychloroquine was given before the results of repeated SARSCoV-2 and serology tests were available. Tocilizumab was administered once COVID-19 had been confirmed and massive inflammation had been observed. Progressively the clinical situation and the levels of the parameters studied improved. The patient was discharged 8 days after admission. Most children with SARS-CoV-2 infection are asymptomatic or present only mild symptoms. However, physicians should be aware of atypical and severe manifestations that may occur in the hyperinflammatory phase of the illness

Sustained release of VEGF through PLGA microparticles improves vasculogenesis and tissue remodeling in an acute myocardial ischemia–reperfusion model

The use of pro-angiogenic growth factors in ischemia models has been associated with limited success in the clinical setting, in part owing to the short lived effect of the injected cytokine. The use of a microparticle system could allow localized and sustained cytokine release and consequently a prolonged biological effect with induction of tissue revascularization. To assess the potential of VEGF165 administered as continuous release in ischemic disease, we compared the effect of delivery of poly(lactic–co-glycolic acid) (PLGA) microparticles (MP) loaded with VEGF165 with free-VEGF or control empty microparticles in a rat model of ischemia–reperfusion. VEGF165 loaded microparticles could be detected in the myocardium of the infarcted animals for more than a month after transplant and provided sustained delivery of active protein in vitro and in vivo. One month after treatment, an increase in angiogenesis (small caliber caveolin-1 positive vessels) and arteriogenesis (α-SMA-positive vessels) was observed in animals treated with VEGF microparticles (pb0.05), but not in the empty microparticles or free-VEGF groups. Correlating with this data, a positive remodeling of the heart was also detected in the VEGF-microparticle group with a significantly greater LV wall thickness (pb0.01). In conclusion, PLGA microparticle is a feasible and promising cytokine delivery system for treatment of myocardial ischemia. This strategy could be scaled up and explored in pre-clinical and clinical studies

Autologous intramyocardial injection of cultured skeletal muscle-derived stem cells in patients with non-acute myocardial infarction

AIM: Experimental animal studies suggest that the use of skeletal myoblast in patients with myocardial infarction may result in improved cardiac function. The aim of the study was to assess the feasibility and safety of this therapy in patients with myocardial infarction. METHODS AND RESULTS: Twelve patients with old myocardial infarction and ischaemic coronary artery disease underwent treatment with coronary artery bypass surgery and intramyocardial injection of autologous skeletal myoblasts obtained from a muscle biopsy of vastus lateralis and cultured with autologous serum for 3 weeks. Global and regional cardiac function was assessed by 2D and ABD echocardiogram. 18F-FDG and 13N-ammonia PET studies were used to determine perfusion and viability. Left ventricular ejection fraction (LVEF) improved from 35.5+/-2.3% before surgery to 53.5+/-4.98% at 3 months (P=0.002). Echocardiography revealed a marked improvement in regional contractility in those cardiac segments treated with skeletal myoblast (wall motion score index 2.64+/-0.13 at baseline vs 1.64+/-0.16 at 3 months P=0.0001). Quantitative 18F-FDG PET studies showed a significant (P=0.012) increased in cardiac viability in the infarct zone 3 months after surgery. No statistically significant differences were found in 13N-ammonia PET studies. Skeletal myoblast implant was not associated with an increase in adverse events. No cardiac arrhythmias were detected during early follow-up. CONCLUSIONS: In patients with old myocardial infarction, treatment with skeletal myoblast in conjunction with coronary artery bypass is safe and feasible and is associated with an increased global and regional left ventricular function,improvement in the viability of cardiac tissue in the infarct area and no induction of arrhythmias

Transplantation of mesenchymal stem cells exerts a greater long-term effect than bone marrow mononuclear cells in a chronic myocardial infarction model in rat

The aim of this study is to assess the long-term effect of mesenchymal stem cells (MSC) transplantation in a rat model of chronic myocardial infarction (MI) in comparison with the effect of bone marrow mononuclear cells (BM-MNC) transplant. Five weeks after induction of MI, rats were allocated to receive intramyocardial injection of 106 GFP-expressing cells (BM-MNC or MSC) or medium as control. Heart function (echocardiography and 18F-FDG-microPET) and histological studies were performed 3 months after transplantation and cell fate was analyzed along the experiment (1 and 2 weeks and 1 and 3 months). The main findings of this study were that both BM-derived populations, BM-MNC and MSC, induced a long-lasting (3 months) improvement in LVEF (BM-MNC: 26.61 ± 2.01% to 46.61 ± 3.7%, p < 0.05; MSC: 27.5 ± 1.28% to 38.8 ± 3.2%, p < 0.05) but remarkably, only MSC improved tissue metabolism quantified by 18FFDG uptake (71.15 ± 1.27 to 76.31 ± 1.11, p < 0.01), which was thereby associated with a smaller infarct size and scar collagen content and also with a higher revascularization degree. Altogether, results show that MSC provides a long-term superior benefit than whole BM-MNC transplantation in a rat model of chronic MI