Evidence for spin-triplet superconducting correlations in metal-oxide heterostructures with non-collinear magnetization

Heterostructures composed of ferromagnetic La0.7Sr0.3MnO3, ferromagnetic SrRuO3, and superconducting YBa2Cu3Ox were studied experimentally. Structures of composition Au/La0.7Sr0.3MnO3/SrRuO3/YBa2Cu3Ox were prepared by pulsed laser deposition, and their high quality was confirmed by X-ray diffraction and reflectometry. A non-collinear magnetic state of the heterostructures was revealed by means of SQUID magnetometry and polarized neutron reflectometry. We have further observed superconducting currents in mesa-structures fabricated by deposition of a second superconducting Nb layer on top of the heterostructure, followed by patterning with photolithography and ion-beam etching. Josephson effects observed in these mesa-structures can be explained by the penetration of a triplet component of the superconducting order parameter into the magnetic layers.Comment: 10 pages, 6 figure

PENSAMIENTO COMPUTACIONAL Y EDUCACIÓN STEM: REFLEXIONES PARA UNA EDUCACIÓN INCLUSIVA DESDE LAS PRÁCTICAS PEDAGÓGICAS

This pedagogical reflection, which arises from a significant experience in an official institution in the city of Manizales (Colombia) on the use and appropriation of computational thinking in regular classrooms characterized by having a high percentage of students with disabilities, has the purpose of demonstrating how inclusive education is not a limitation to develop this thinking. To this end, a dialogue was held between the teachers about their classroom practices, disconnected activities were carried out and technological tools were used. The above made them aware of the importance of its use and allowed them to include in the curriculum some strategies of education in Science, Technology, Engineering and Mathematics (STEM) and computational thinking to be part of the institutional culture, taking into account the diversity present in the classroom. The results of the reflection show that: a. in addition to computational thinking, STEM strategies allow the development of 21st century skills, b. students with disabilities respond in an assertive and motivated way, c. Peer work enriches own and collective learning, d. the greater the number of teachers linked, the more coverage the project reaches. This article contributes to the field of knowledge as a motivating and guiding reference for those who wish to incorporate new practices and use of technologies in educational contexts with a diverse population, also contributing to the reduction of imaginary established by fear or misinformation about working with a population that has a disability.Esta reflexión pedagógica, que nace de una experiencia significativa en una institución oficial de la ciudad de Manizales (Colombia) sobre el uso y apropiación del pensamiento computacional en aulas regulares caracterizadas por tener un porcentaje alto de estudiantes con discapacidad, tiene el propósito de demostrar cómo la educación inclusiva no es una limitante para desarrollar este pensamiento. Para tal fin se sostuvo un diálogo entre los docentes acerca de sus prácticas de aula, se realizaron actividades desconectadas y se usaron herramientas tecnológicas. Lo anterior los concientizó acerca de la importancia de su utilización y les permitió incluir en el currículo algunas estrategias de la educación en Ciencia, Tecnología, Ingeniería y Matemáticas (STEM) y del pensamiento computacional para ser parte de la cultura institucional, teniendo en cuenta la diversidad presente en el aula. Los resultados de la reflexión demuestran que: a. además del pensamiento computacional, las estrategias STEM permiten desarrollar competencias propias del siglo XXI, b. los estudiantes con discapacidad responden de forma asertiva y motivada, c. el trabajo entre pares enriquece los aprendizajes propios y colectivos, d. a mayor número de docentes vinculados, más cobertura alcanza el proyecto. Este artículo contribuye al campo de conocimiento como referente motivador y orientador para quienes deseen efectuar incorporación de nuevas prácticas y empleo de tecnologías en contextos educativos con población diversa, aportando también a la disminución de imaginarios instaurados por el miedo o la desinformación sobre el trabajo con población que presenta discapacidad

Treatment of combined atlantoaxial fractures in the elderly with C1-C2 posterior screw-rod instrumentation

Introducción: Dado que la instrumentación posterior tornillo-barra C1-C2 ha demostrado tener buenos resultados postoperatorios en diferentes tipos de patologías con inestabilidad atlantoaxial independiente de la edad, es razonable pensar en su potencial aplicabilidad en el escenario de las fracturas atlantoaxiales combinadas en pacientes adultos mayores, para quienes el manejo quirúrgico ha demostrado ser beneficioso. Objetivo: Realizar una descripción retrospectiva de los resultados postoperatorios obtenidos en pacientes adultos mayores con fracturas atlantoaxiales combinadas llevados a manejo quirúrgico con instrumentación posterior tornillo-barra C1-C2. Materiales y Métodos: Se realizó revisión de las historias clínicas de pacientes mayores de 65 años admitidos a dos hospitales de la ciudad de Bogotá DC entre enero de 2016 hasta enero de 2017, diagnosticados con fracturas traumáticas agudas combinadas del atlas y del axis y llevados a instrumentación posterior C1-C2 con constructos tornillo-barra. De la historia clínica se tomaron datos demográficos, clínicos, tipos de fractura, estado neurológico, estado de dolor, estado de fusión ósea, entre otros. Resultados: Se obtuvieron siete pacientes masculinos, con edad promedio 72,3 años. Ninguno presentó complicaciones perioperatorias o deterioro neurológico postoperatorio. Se evidenció fusión ósea y estabilidad del constructo en el 100% de los pacientes al año postoperatorio, con resolución completa del dolor cervical en 5 individuos, y parcial en los dos restantes. Conclusiones: La instrumentación posterior con constructos tornillo-barra C1-C2 es una excelente opción para el manejo quirúrgico de pacientes adultos mayores con fracturas atlantoaxiales combinadas dada su baja tasa de complicaciones y alta tasa de fusión ósea.Introduction: Since C1-C2 posterior screw-rod instrumentation has shown good postoperative results in different types of pathologies with atlantoaxial instability independent of age, it is reasonable to think about its potential applicability in the scenario of combined atlantoaxial fractures in elderly patients, for whom surgical management has proven beneficial. Objective: To perform a retrospective description of the postoperative results obtained in elderly patients with combined atlantoaxial fractures brought to surgical management with C1-C2 posterior screw-rod instrumentation. Materials and Methods: Medical records of patients older than 65 years admitted to two hospitals in the city of Bogotá DC from January 2016 to January 2017, diagnosed with combined acute traumatic fractures of the atlas and the axis, taken to later C1-C2 posterior screw-rod instrumentation were reviewed. Demographic and clinical data, type of fractures, neurological status, pain status, bone fusion status, among others, were collected. Results: Seven male patients were obtained, with an average age of 72.3 years. None presented perioperative complications or postoperative neurological deterioration. Bone fusion and stability of the construct were evidenced in 100% of the patients a year after surgery, with complete resolution of cervical pain in 5 individuals, and partial resolution in the remaining two. Conclusions: C1-C2 posterior screw-rod instrumentation is an excellent option for the surgical management of elderly patients with combined atlantoaxial fractures given its low rate of complications and high rate of bone fusion

Element-specific magnetization redistribution at YBa2Cu3O7/La2/3Ca1/3MnO3{\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}/{\mathrm{La}}_{2/3}{\mathrm{Ca}}_{1/3}{\mathrm{MnO}}_{3} interfaces

We study the element-specific magnetic depth profiles of a YBa2Cu3O7/La2/3Ca1/3MnO3 (YBCO/LCMO) superlattice using soft x-ray resonant magnetic reflectometry (XRMR). This allows us to study the magnetic proximity effect (MPE) that is observed at the YBCO/LCMO interface, characterized by the occurrence of a depleted layer on the manganite side and an induced magnetization in the YBCO. Using the element-specific depth profiling capability of XRMR, we show that the Cu moments (0.28μB per interfacial Cu ion) reside on the YBCO side of the interface and originate from the CuO2 plane that is located at the interface. We also rule out the possibility that the Cu moments originate from the migration of Cu atoms into the LCMO layer (interdiffusion). Finally, we show that the suppression of the Mn moment on the LCMO side is only partial for the interface of LCMO deposited on YBCO (0.62μB per Mn ion), compared to the complete suppression for the interface of YBCO deposited on LCMO. These differences in the LCMO depleted layers indicate the strong variations in the MPE between the case of YBCO on LCMO and the case of LCMO on YBCO

Importance of long-chain polyunsaturated fatty acids in infant feeding: quantification of these acids in some of the milk formulas for babies aged 0 to 6 months marketed in the city of Medellin, 2012

ABSTRACT: To compare the content of polyunsaturated fatty acids (pufas) appearing in the nutrition facts labels of infant milk formulas sold in supermarkets of Medellin city against an experimentally determined quantity. Methodology: the researchers studied a total of 13 infant initiation formulas collected from the stands where they were displayed at the supermarkets. The procedure for extracting and quantifying the fatty acids in the samples was performed in compliance with the methods developed in the laboratory. Results: upon comparing the content of the pufas displayed in the label of each milk formula with the data obtained experimentally, the researchers found that the products contain less than 30% of the reported values. This variation was not attributable to the expiration date, but to the storage temperature. Discussion: the study's findings are worrisome given the fact that health professionals recommend such products because of the similarity of their nutritional composition with that of breast milk. Moreover, these professionals expect the pufas content to be at least equal to or equivalent to that of breast milk so in order to provide the baby with the necessary nutrients for an appropriate development. For this reason, it is necessary that infant feeding experts strictly regulate the addition of these fatty acids to infant foodRESUMEN: Comparar el contenido de ácidos grasos poliinsaturados (lcpufa) reportados en las etiquetas nutricionales de las fórmulas lácteas infantiles, comercializadas en supermercados de la ciudad de Medellín frente a la cantidad determinada experimentalmente. Metodología: se estudiaron trece fórmulas infantiles de iniciación, recolectadas del stand donde se encontraban exhibidas. El procedimiento para la extracción, cuantificación y análisis de los ácidos grasos de las muestras se realizaron según métodos desarrollados por el laboratorio. Resultados: al comparar el contenido de los lcpufa de la etiqueta de cada fórmula láctea con los datos obtenidos experimentalmente, se encontró que los productos contenían menos del 30% de lo reportado, aspecto que no fue atribuible a la fecha de vencimiento pero sí posiblemente a la temperatura de almacenamiento. Discusión: los hallazgos del estudio son preocupantes, porque los profesionales de la salud, recomiendan dichos productos, por su similitud en la composición nutricional con la leche materna esperando que su contenido en lcpufa sea como mínimo, igual o equivalente al de ésta, proporcionando al bebé su adecuado desarrollo. Por lo anterior, es necesario que los expertos en alimentación infantil reglamenten de manera estricta la adición de estos ácidos grasos en alimentos para lactantes

Reporting Recommended Patch Density from Vehicle Panel Vibration Convergence Studies using both DAF and TBL Fits of the Spatial Correlation Function

Using the patch method to represent the continuous spatial correlation function of a phased pressure field over a structural surface is an approximation. The approximation approaches the continuous function as patches become smaller. Plotting comparisons of the approximation vs the continuous function may provide insight revealing: (1) For what patch size/density should the approximation be very good? (2) What the approximation looks like when it begins to break down? (3) What the approximation looks like when the patch size is grossly too large. Following these observations with a convergence study using one FEM may allow us to see the importance of patch density. We may develop insights that help us to predict sufficient patch density to provide adequate convergence for the intended purpose frequency range of interes

ESTUDIO ELECTROQUÍMICO DE LA ADSORCIÓN SUPERFICIAL DE FOSFATOS SOBRE MEZCLAS DE ÁCIDO POLILÁCTICO CON VIDRIO BIOACTIVO Y ÁCIDO POLILÁCTICO CON HIDROXIAPATITA

RESUMEN Se evaluó la interacción entre hidroxiapatita, vidrio bioactivo y ácido poliláctico, los cuales fueron sintetizados por métodos de precipitación acuosa, sol – gel y policondensación, respectivamente; y caracterizados mediante FTIR, DRX, DSC. Se obtuvieron probetas con diferentes porcentajes de polímero - cerámico para estudiar su capacidad de adsorber fosfatos, y de esta manera reconocer cuál de estas mezclas presenta una mejor respuesta a la oseointegración en presencia de fluido corporal simulado. Las probetas fueron sumergidas en el medio con diferentes relaciones de Ca/P y su capacidad de adsorción fue evaluada mediante EIS. Los parámetros electroquímicos obtenidos permitieron estimar los elementos resistivos y capacitivos de un circuito equivalente que relacionan los parámetros termodinámicos asociados al fenómeno de adsorción experimentado. Finalmente se determinó la cantidad de iones adsorbidos mediante AAS.  Palabras clave: Biomateriales, recubrimientos, oseointegración   ABSTRACT The interaction between hydroxyapatite, bioactive glass and polylactic acid was evaluated, which were synthesized by aqueous precipitation methods, sol - gel and polycondensation respectively, and they were characterized by FTIR, XRD, DSC. Samples with different percentages of polymer and ceramic were obtained to study their ability to absorb phosphate, and later to identify which of these samples of materials present a better response to osseointegration in the presence of simulated body fluid. Samples were immersed in that fluid with different relations of Ca/P and their adsorption capacity was evaluated by EIS. The electrochemical parameters obtained allowed to estimate the resistive and capacitive elements of an equivalent circuit linking the thermodynamic parameters associated with adsorption phenomena experienced. Finally, the amount of adsorbed ions was determined by AAS. Keywords: Biomaterials, coatings, osseointegration

Excess degassing drives long-term volcanic unrest at Nevado del Ruiz

This study combines volcanic gas compositions, SO2 flux and satellite thermal data collected at Nevado del Ruiz between 2018 and 2021. We find the Nevado del Ruiz plume to have exhibited relatively steady, high CO2 compositions (avg. CO2/ST ratios of 5.4 ± 1.9) throughout. Our degassing models support that the CO2/ST ratio variability derives from volatile exsolution from andesitic magma stored in the 1–4 km depth range. Separate ascent of CO2-rich gas bubbles through shallow (< 1 km depth), viscous, conduit resident magma causes the observed excess degassing. We infer that degassing of ~ 974 mm3 of shallow (1–4 km) stored magma has sourced the elevated SO2 degassing recorded during 2018–2021 (average flux ~ 1548 t/d). Of this, only < 1 mm3 of magma have been erupted through dome extrusion, highlighting a large imbalance between erupted and degassed magma. Escalating deep CO2 gas flushing, combined with the disruption of passive degassing, through sudden accumulation and pressurization of bubbles due to lithostatic pressure, may accelerate volcanic unrest and eventually lead to a major eruption

Surfactant lung delivery with LISA and InSurE in adult rabbits with respiratory distress

Background In preterm infants, InSurE (Intubation–Surfactant–Extubation) and LISA (less invasive surfactant administration) techniques allow for exogenous surfactant administration while reducing lung injury associated with mechanical ventilation. We compared the acute pulmonary response and lung deposition of surfactant by LISA and InSurE in surfactant-depleted adult rabbits. Methods Twenty-six spontaneously breathing surfactant-depleted adult rabbits (6–7 weeks old) with moderate RDS and managed with nasal continuous positive airway pressure were randomized to 3 groups: (1) 200 mg/kg of surfactant by InSurE; (2) 200 mg/kg of surfactant by LISA; (3) no surfactant treatment (Control). Gas exchange and lung mechanics were monitored for 180 min. After that, surfactant lung deposition and distribution were evaluated monitoring disaturated-phosphatidylcholine (DSPC) and surfactant protein C (SP-C), respectively. Results No signs of recovery were found in the untreated animals. After InSurE, oxygenation improved more rapidly compared to LISA. However, at 180’ LISA and InSurE showed comparable outcomes in terms of gas exchange, ventilation parameters, and lung mechanics. Neither DSPC in the alveolar pool nor SP-C signal distributions in a frontal lung section were significantly different between InSurE and LISA groups. Conclusions In an acute setting, LISA demonstrated efficacy and surfactant lung delivery similar to that of InSurE in surfactant-depleted adult rabbits. Impact Although LISA technique is gaining popularity, there are still several questions to address. This is the first study comparing LISA and InSurE in terms of gas exchange, ventilation parameters, and lung mechanics as well as surfactant deposition and distribution. In our animal study, three hours post-treatment, LISA method seems to be as effective as InSurE and showed similar surfactant lung delivery. Our findings provide some clarifications on a fair comparison between LISA and InSurE techniques, particularly in terms of surfactant delivery. They should reassure some of the concerns raised by the clinical community on LISA adoption in neonatal units