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%

Elucidating the mechanisms of senescent sweetening in stored potato tubers

Senescent sweetening is a storage disorder that typically occurs following medium to long-term storage of potato tubers in the presence of sprout suppressors at moderate storage temperatures. It represents a significant issue for the processing industry where reducing sugar accumulation results in problems of dark fry colour. Furthermore, the Maillard reaction between reducing sugars and asparagine results in the accumulation of the potential neurotoxin and carcinogen acrylamide in processed products. At present almost nothing is known regarding the mechanisms promoting senescent sweetening which differs from cold-induced sweetening in that it is not reversible by transfer of tubers to higher temperatures. In the present work we set out to test the hypothesis that oxidative damage caused during long term storage is linked to senescent sweetening. A marked difference in storage induced reducing sugar accumulation was observed between a sweetening resistant and a sweetening sensitive cultivar. However, markers of oxidative damage and activities of antioxidant enzymes did not exhibit any specific correlation with reducing sugar accumulation indicating that oxidative damage and senescent sweetening may not be linked. To identify the underlying biochemical causes of sugar accumulation GC/MS was used to quantify a range of primary metabolites in sweetened and unsweetened tubers. Few differences were observed in metabolite profiles however, labelling with [ 13C] glucose indicated a greater capacity for sucrose synthesis in the sweetening resistant compared with the sweetening sensitive cultivar. In addition, differences in specific activity of carbohydrate metabolism enzymes as well as microarray data suggest starch re-synthesis and alternative metabolic sinks for carbon as potential traits linked to sweetening resistance. Moreover, we identified GPT2 as a potential candidate gene associated with the accumulation of sugars during long-term storage. These findings will lead to a better understanding of the mechanisms, processes and genes involved in senescent sweetening and will provide insights into improved storage management in the short-term and the development of senescent sweetening resistant cultivars in the longer term

Una revisión sobre la consolidación empresarial en España

La continua y veloz evolución que están experimentando los mercados actuales de todo el mundo, han propiciado la concentración de numerosas empresas con la finalidad de dar respuesta a las estrategias de crecimiento y la mejora de desarrollo que esta nueva situación conlleva. La importancia del fenómeno de concentración empresarial en España en los últimos años, justifica la necesidad de realizar un nuevo estudio sobre la situación actual española. El presente trabajo toma como unidad de análisis el total de grupos que cotizan en la actualidad en la Bolsa española, tratando de mostrar su realidad. De este modo, permite conocer la estabilidad que tienen dentro del mercado español y, al mismo tiempo, aproximamos al método de consolidación empleado, las características de las sociedades dependientes y otros rasgos claves que faciliten un mayor conocimiento de tales entidades

Educación y Exclusión Social en el mundo actual: Introducción al monográfico núm. 7

Gabriel Robles Gavira y María Revelles Carrasco presentan el número Educación y Exclusión Socia

Presencia de la familia Helicopsychidae (Trichoptera) en la mitad meridional de España peninsular

La familia Helicopsychidae Ulmer, 1906, cuesta con unas 250 especies distribuidas por todo el mundo y pertenecientes en casi su totalidad al género Helicopsyche von Siebold, 1856, salvo una especie endémica de Nueva Zelanda: Rakiura vernale McFarlane, 1973

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

Safety, feasibility, and hemodynamic response of regadenoson for stress perfusion CMR

Owing to its pharmacodynamics and posology, the use of regadenoson for stress cardiac magnetic resonance (CMR) has potential advantages over other vasodilators. We sought to evaluate the safety, hemodynamic response and diagnostic performance of regadenoson stress-CMR in routine clinical practice. All regadenoson stress-CMR examinations performed between May 2017 and July 2020 at our institution were retrospectively reviewed. A total of 698 studies were included for the final analysis. A conventional stress/rest protocol was performed using a 1.5T MRI scanner (Magnetom Aera, Siemens Healthineers, Erlangen, Germany). Adverse events, clinical symptoms, and hemodynamic response were assessed. Diagnostic accuracy of the test was evaluated in patients who underwent invasive coronary angiography. Nearly half of patients (48.5%) remained asymptomatic. Most common clinical symptoms included dyspnea (137, 19.6%), chest pain (116, 16.6%) and flushing (44, 6.3%). Two patients (0.28%) could not complete the examination due to severe hypotension or unbearable chest pain. Overall, an increase in heart rate (HR) response (36.2% [IQR: 22.5–50.9]) and a decrease in systolic and diastolic blood pressure (BP) (median systolic BP response of -5% [IQR: -11.5-0.6]; median diastolic BP response of -6.3 mmHg [IQR: -13.4-0]) was observed. Patients with symptoms induced by regadenoson showed higher HR response (40.3%, IQR: 26.4–56.1 vs. 32.4%, IQR: 19-45.6, p<0.001), whereas a blunted HR response was observed in diabetic (29.6%, IQR: 18.4–42 p<0.001), obese (31.7%, IQR: 20.7–46.2 p=0.005) and patients aged 70 years or older (32.9%, IQR: 22.6–43.1 p<0.001). Overall, regadenoson stress-CMR showed 95.65% (IQ 91.49–99.81) sensitivity, 54.84% (IQ 35.71–73.97) specificity, 86.99% (IQ 82.74–94.68) positive predictive value, and 77.27% (IQ 57.49–97.06) negative predictive value for detecting significant coronary stenosis as compared with invasive coronary angiography. Regadenoson is a well-tolerated vasodilator that can be safely employed for stress perfusion CMR, with high diagnostic performanc

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

Trasplante cardíaco

A heart transplant is at present considered the treatment of choice in cases of terminal cardiac insufficiency refractory to medical or surgical treatment. Due to factors such as the greater life expectancy of the population and the more efficient management of acute coronary syndromes, there is an increasing number of people who suffer from heart failure. It is estimated that the prevalence of the disease in developed countries is around 1%; of this figure, some 10% are in an advanced stage and are thus potential receptors of a heart transplant. The problem is that it is still not possible to offer this therapeutic form to all of the patients that require it. Consequently, it is necessary to optimise the results of the heart transplant through the selection of patients, selection and management of donors, perioperative management and control of the disease due to graft rejection. Since the first transplant carried out in 1967, numerous advances and changes have taken place, which has made it possible to increase survival and quality of life of those who have received a new heart. In this article we review the most relevant aspects of the heart transplant and the challenges that are currently faced