Comparación de una antena dipolo doblada de hilos vs una antena dipolo doblada sobre placa con 2 sustratos diferentes

En la presente investigación se lleva a cabo una comparación entre dos variantes de antenas dipolo: una antena dipolo doblada de hilos y una antena dipolo doblada sobre placa con dos sustratos diferentes. El objetivo de este estudio es analizar y comparar el rendimiento de estas dos configuraciones de antenas en términos de S11, VSWR, y patrón de radiación. Para lograrlo, se utilizarán métodos de simulación en el software ANSYS HFFS, donde analizarán los parámetros de dispersión de estas antenas en la frecuencia de resonancia de 6 GHz, se propone evidenciar la influencia de los sustratos (conductores y dieléctricos), y las consecuencias de sus efectos en las antenas propuestas. Se determinó que la antena dipolo sobre la placa microstrip ofrece mejores prestaciones a nivel de parámetros objetivo, en comparación del dipolo doblado de hilos, ya que sus valores de S (1,1) es de -37.4668 y el VSWR es de 1.0271, estos datos son los más destacables en cada simulación a comparación de la antena dipolo doblado de hilos que tiene como resultado S (1,1) de -34.8782 y VSWR de 1.0367.En la presente investigación se lleva a cabo una comparación entre dos variantes de antenas dipolo: una antena dipolo doblada de hilos y una antena dipolo doblada sobre placa con dos sustratos diferentes. El objetivo de este estudio es analizar y comparar el rendimiento de estas dos configuraciones de antenas en términos de S11, VSWR, y patrón de radiación. Para lograrlo, se utilizarán métodos de simulación en el software ANSYS HFFS, donde analizarán los parámetros de dispersión de estas antenas en la frecuencia de resonancia de 6 GHz, se propone evidenciar la influencia de los sustratos (conductores y dieléctricos), y las consecuencias de sus efectos en las antenas propuestas. Se determinó que la antena dipolo sobre la placa microstrip ofrece mejores prestaciones a nivel de parámetros objetivo, en comparación del dipolo doblado de hilos, ya que sus valores de S (1,1) es de -37.4668 y el VSWR es de 1.0271, estos datos son los más destacables en cada simulación a comparación de la antena dipolo doblado de hilos que tiene como resultado S (1,1) de -34.8782 y VSWR de 1.0367

Multiscale porous high-temperature heat exchanger using ceramic co-extrusion

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ESTIMATIVA DA PRODUÇÃO DE SEDIMENTOS DA PILHA DE DISPOSIÇÃO DE ESTÉRIL (PDE) CONVAP, COMPLEXO MINERADOR DE ITABIRA (MG): Estimate of sediment production from the sterile pile (PDE) Convap, Itabira Mining Complex (MG)

Improper management in the construction and/or operation of a sterile pile (PDE) can result in negative environmental impacts mainly related to the production of sediment. Since these structures are necessary for the mining activity, this article sought to evaluate the sediment production estimate of the PDE Convap, located in the Minerador Complex of Itabira (MG) through the application of the Universal Soil Loss Equation. Considering the data from the Cauê rainfall station obtained between 1987 and 2020, an average annual rainfall of 1,627.98 mm was observed, resulting in an annual erosivity of 12,896.34 MJ.mm.ha-1.h-1. As for the topographic factor, the values obtained ranged between 0 and 26.4, with the smallest being verified in the region of the CEMIG I reservoir. Data from drilling holes in a PDE neighboring Convap indicate an average erodibility of 0.02679 t.MJ-1.h.mm-1. The mainland uses in the analyzed area correspond to degraded pasture (12.2%), water bodies (12.9%), eucalyptus and forests (27.0%) and exposed soil (42.6%). It was noted that the erosion rate of the PDE Convap corresponds to 273,871.5 t.year-1, with an average of 1,267.9 t.ha-1.year-1, being compatible with the Dredging Plan for the CEMIG I Dam, located downstream of this structure.A gestão inadequada na construção e/ou operação de uma pilha de disposição de estéril (PDE) pode resultar em impactos ambientais negativos relacionados, principalmente, à produção de sedimentos. Uma vez que essas estruturas são necessárias à atividade minerária, este artigo buscou avaliar a estimativa de produção de sedimentos da PDE Convap, localizada no Complexo Minerador de Itabira (MG) por meio da aplicação da Equação Universal de Perda de Solos. Considerando os dados da estação pluviométrica Cauê obtidos entre os anos de 1987 e 2020, observou-se uma pluviometria média anual de 1.627,98 mm, resultando em uma erosividade anual de 12.896,34 MJ.mm.ha-1.h-1. Quanto ao fator topográfico, os valores obtidos variaram entre 0 e 26,4, com os menores sendo verificados na região do reservatório de CEMIG I. Dados provenientes de furos de sondagem em uma PDE vizinha à Convap indicam uma erodibilidade média de 0,02679 t.MJ-1.h.mm-1. Os principais usos do solo na área analisada correspondem a pastagem degradada (12,2%), corpos hídricos (12,9%), eucaliptos e matas (27,0%) e solo exposto (42,6%). Notou-se que a taxa de erosão da PDE Convap corresponde a 273.871,5 t.ano-1, com média de 1.267,9 t.ha-1.ano-1, sendo compatível com o Plano de Dragagem da Barragem CEMIG I, localizada a jusante desta estrutura

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

CORRELACIÓN ENTRE NIVELES PLASMÁTICOS DE ADRENOMEDULINA Y MASA DEL VENTRÍCULO EN PACIENTES CON SÍNDROME METABÓLICO

Objetivo: Estudiar la correlación entre masa del ventrículo izquierdo y los niveles plasmáticos de adrenomedulina como predoctores de riesgo cardiovascular.Metodología: Se realizó un estudio observacional, transversal, analítico-correlativo, en el que se seleccionaron 21 sujetos, 12 de sexo femenino y 9 de masculino, entre 22 a 58 años, con diagnóstico de SM según la Federación Internacional de Diabetes (IDF), y se cotejaron con 19 controles, de un grupo etario similar sin fenotipo ni valores bioquímicos para confirmar el diagnóstico de SM. Se determinaron los valores de: glicemia, lípidos sanguíneos y adrenomedulina plasmática. Se cuantificó la masa del ventrículo izquierdo (MVI) a través de ecocardiografía transtorácica bidimensional y unidimensional.Resultados: No se presentaron diferencias estadísticamente significativas en las variables sociodemográficas de los pacientes. Tampoco hubo diferencia significativa en la talla entre ambos grupos. (P > 0,05). Al evaluar los datos antropométricos de los pacientes se pudo constatar, que el peso, el IMC, la circunferencia abdominal (CA) fueron significativamente mayores en los pacientes con SM (p< 0,001). Los pacientes con SM evidenciaron cifras tensiónales significativamente superiores que los controles. El grupo experimental presentó niveles significativamente más altos de glicemia (p=0,001), colesterol total (p=0,01), C-LDL (p=0,03), C-VLDL (p=0,005), triglicéridos (p=0,002), cociente Tg/C-HDL (p=0,0001) y adrenomedulina (3,49 ± 1,21 vs 1,69 ± 0,92 ng/mL; p=0,0001) y más bajos de C-HDL (p=0,02) comparado con el grupo control. Al cuantificar la MVI en los pacientes con SM se pudo constatar que estos presentaron un valor significativamente mas elevado que los controles medido a través de eco cardiografía modo M y modo B. Se estableció una correlación positiva y significativa entre la MVI y la concentración plasmática de Adrenomedulina (r = 0,80 y p < 0,01). En el análisis de regresión lineal múltiple, la adrenomedulina plasmática fue la variable con mayor correlación con la MVI (R2=0,550; p=0,0001).Conclusión: Estos hallazgos nos permiten concluir que existe una correlación positiva entre MVI y niveles plasmáticos de adrenomedulina en pacientes con SM, los cuales pudieran ser empleados a futuro como predictores de riesgo cardiovascular, en razón de su asociación con la actividad elelectromecanica del corazón.&nbsp