Amplificador de potencia doble-banda (1.8 GHz y 2.6 GHz) con alta eficiencia

This work presents a methodology to design highefficient dual-band RF power amplifiers. Using the non-linear model of the selected GaN HEMT device, an analysis of the performance of the transistor to changes in the phases of both the second and the third harmonic has been carried out for both frequencies. Based on this analysis, drain terminating and biasing networks are designed to provide near optima impedance values at the fundamental and higher order harmonics to the selected frequency bands. The experimental characterization of the implemented prototype, which operates at 1.8 GHz and 2.6 GHz, can achieve drain efficiencies around 70 % with output power levels greater than 42 dBm in both frequency bands. Furthermore, PAEs obtained are very close to drain efficiencies after dual-band input matching.Este trabajo ha sido financiado por el Gobierno de Espana bajo los proyectos TEC2014-58341-C4-1-R y TEC2014-58341-C4-2-R del MINECO, por el FEDER, por el FSE, a través de la beca FPI del MINECO del primer autor (BES-2012-061813). Además, el primer autor agradece la beca de movilidad predoctoral del MINECO (EEBB-I-15-10447

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

La escuela intercultural

Artículo (Maestría en Educación y Desarrollo Humano). Universidad de Manizales. Facultad de Ciencias Sociales y Humanas. CINDE, 2011Este texto apunta a una reflexión sobre las dinámicas interculturales que se configuran en la escuela a partir de las interacciones comunicativas de las y los jóvenes, buscando resignificar la idea de la interculturalidad como principio pedagógico, que potencie el reconomiento, el respeto por la diferencia y el valor que el otro y la otra se merecen en los espacios vitales de la escuela, esto genera nuevas expectativas en el trabajo de los educadores, porque ayuda a comprender e interpretar actitudes y comportamientos de los y de las jóvenes que constantemente construyen y reconstruyen su identidad reconociendo su mundo y el de los demás

Los gestos y las palabras de la interculturalidad en la escuela, un estudio con jóvenes del grado noveno de la Institución Educativa República de Uruguay y del Municipio de Medellín

Maestría en Educación y Desarrollo Humano, Facultad de Ciencias Sociales y Humanas.Para la escuela no ha sido fácil reflexionar sobre la interculturalidad como fenómeno social y como experiencia educativa. Los enfoques predominantes sobre el tema han sido eminentemente étnicos y migratorios, y no se ha hecho una mención explícita a la interculturalidad como una experiencia permanente en la escuela que demanda atención desde la inclusión, el respeto, el reconocimiento y la acogida de la diferencia como posibilidad para la construcción de ambientes educativos democráticos, solidarios y dignificantes. Lo anterior cobra especial relevancia cuando se trata de pensar en las relaciones que los/as jóvenes establecen con los otros/as en estos escenarios de encuentros y desencuentros; es allí donde son interpelados desde la presencia, del cuerpo y del gesto de los otros/as. El encuentro/desencuentro con el otro, suele estar marcado por el rechazo, el estigma o el menosprecio frente a esa evidente diferencia de lo que el otro/otra es. Todo aquello que es diferente al yo, se convierte en una presencia intolerable y abominable con la que cuesta cohabitar el espacio escolar. No queda duda de que las diferencias ya no son sólo culturales en términos étnicos o lingüisticos, lo son con respecto a las formas de vestir, de hablar, de relacionarse y de hacer presencia en la escuela. Esas presencias diversas y plurales en la escuela muestran que no hay una única y veradera forma de ser, estar y habitar. Los/as jóvenes encarnan esa posibilidad, que se teje en permanente conflicto, de hacerse sujeto con otros y de hacerse sujeto rechazando a o en tensión con otros

Ghrelin regulates glucose and glutamate transporters in hypothalamic astrocytes

Hypothalamic astrocytes can respond to metabolic signals, such as leptin and insulin, to modulate adjacent neuronal circuits and systemic metabolism. Ghrelin regulates appetite, adiposity and glucose metabolism, but little is known regarding the response of astrocytes to this orexigenic hormone. We have used both in vivo and in vitro approaches to demonstrate that acylated ghrelin (acyl-ghrelin) rapidly stimulates glutamate transporter expression and glutamate uptake by astrocytes. Moreover, acyl-ghrelin rapidly reduces glucose transporter (GLUT) 2 levels and glucose uptake by these glial cells. Glutamine synthetase and lactate dehydrogenase decrease, while glycogen phosphorylase and lactate transporters increase in response to acyl-ghrelin, suggesting a change in glutamate and glucose metabolism, as well as glycogen storage by astrocytes. These effects are partially mediated through ghrelin receptor 1A (GHSR-1A) as astrocytes do not respond equally to desacyl-ghrelin, an isoform that does not activate GHSR-1A. Moreover, primary astrocyte cultures from GHSR-1A knock-out mice do not change glutamate transporter or GLUT2 levels in response to acyl-ghrelin. Our results indicate that acyl-ghrelin may mediate part of its metabolic actions through modulation of hypothalamic astrocytes and that this effect could involve astrocyte mediated changes in local glucose and glutamate metabolism that alter the signals/nutrients reaching neighboring neurons.This work was funded by grants from Fondo de Investigación Sanitaria (PI100747; PI1302195), Ministerio de Ciencia e Innovación (BFU2011–27492; BFU2014-51836-C2-2-R) and Fondos FEDER, Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, and Fundación de Endocrinología y Nutrición. SD was funded by the Swedish Research Council (Vetenskapsrådet grant 2012–1758), Läkarutbildningsavtalet Göteborg grant at Sahlgrenska Hospital (ALFGBG-138741, The European Union Seventh Framework Programme under Grant Agreement 607310, Nudge-it).Peer Reviewe