Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling.

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

Ferroelectric Control of Interface Spin Filtering in Multiferroic Tunnel Junctions.

The electronic reconstruction occurring at oxide interfaces may be the source of interesting device concepts for future oxide electronics. Among oxide devices, multiferroic tunnel junctions are being actively investigated as they offer the possibility to modulate the junction current by independently controlling the switching of the magnetization of the electrodes and of the ferroelectric polarization of the barrier. In this Letter, we show that the spin reconstruction at the interfaces of a La_{0.7}Sr_{0.3}MnO_{3}/BaTiO_{3}/La_{0.7}Sr_{0.3}MnO_{3} multiferroic tunnel junction is the origin of a spin filtering functionality that can be turned on and off by reversing the ferroelectric polarization. The ferroelectrically controlled interface spin filter enables a giant electrical modulation of the tunneling magnetoresistance between values of 10% and 1000%, which could inspire device concepts in oxides-based low dissipation spintronics.

Miocardiopatía no compactada asociada a síndrome 1P36 / Non-compaction cardiomyopathy associated to 1P36 syndrome

La miocardiopatía no compa da (MNC) es una enf medad congénita caracterizada por la ausencia de compaqctación del miocardio ventricular. Tiene una gran variabilidad genética, clinica, evolutiva y pronóstica. Presentamos a una recién nacida pretérmino (34 semanas) con restrición del crecimiento intrauterino, fenotipo peculiar, hipotonia generalizada y distrés respiratono. La ecocardiografía objetiva ausencia de compactación del ventrículo izquierdo y disfunción sistólica leve, que se trata con captopril y ácido acetilsalicílico. Desarrolla crisis convulsivas parciales resistentes al tratamiento y se evidencia ausencia de respuesta en potenciales auditivo-visuales del tronco del encéfalo. El cariotipo convencional es normal pero el estudio de microarrays revela deleción 1p36.33-p36.23. El estudio carddiológico y genético de los progenitores es normal. El conocimiento de esta cardiopatía permite un diagnóstico precoz. Debe realizarse despistaje a familiares de primer grado. Dada la frecuente asociación entre MNC y síndrome 1p36 recomendamos incluir estudio genético mediante microarrays en pacientes con sospecha de asociación sindrómica y normalidad en el cariotipo convencional, como en el caso que presentamos (AU)

The non-compaction cardiomypathy (MNC) is a congenital disorder characterized by the absence of the compaction ventricular myocardium. It presents a high variability, genetic, clinical, evolutionary and prognostic. We report a preterm newborn (34 weeks) with intrauterine growth restriction particular phenotype, generalized hypotonia and respiratory distress. Echocardiography objective absence of compaction left ventricular myocardium and mild sistolic dysfunction, treated with captopril and acetylsalicylic acid. Develops resistant treatment partial seizurcs and lack response evident in visual-auditory evoked potentials brainstem. The conventional kariotype is normal but the microarray study revealed 1p.36-p36.23 deletion. Cardiological and genetic study of the parents are normal. Thebest knowledge of the MNC allows earlier diagnosis. Have to perform screening for first-degree relatives. Given the frequent association between MNC and lp36 syndrome, we recommend using microarray genetic study in patients with suspected syndromic association and normality in the conventional as in the case presented (AU)

Hiperfrecuentadores en Urgencias Pediátricas: ¿es toda la culpa de los padres? / Frequent users in Pediatric Emergency Departments, it is all the parents' fault?

Introducción: existe poca información sobre el abuso de las Urgencias Pediátricas. El objetivo principal es determinar el perfil de los padres hiperfrecuentadores en un hospital de media complejidad y estimar el grado de preocupación de los padres según respuestas a una encuesta telefónica. Pacientes y métodos: estudio descriptivo, transversal y unicéntrico. Se realiza un análisis retrospectivo de los informes de alta en niños ≤ 14 años con ≥ 10 consultas en Urgencias Pediátricas en el periodo desde el 1 de enero al 31 de diciembre de 2015. A través de entrevista telefónica, se preguntó a los padres si acudirían o no a Urgencias ante 25 supuestos clínicos. Análisis de datos mediante SPSS(R) v22.0. Resultados: 21 niños realizaron ≥ 10 consultas, que suponen 246 episodios (1,17% del total de Urgencias). Edad mediana de 1,5 años; 52,2% varones. La relación entre el número de consultas en el centro de salud frente a Urgencias Pediátricas fue < 1 en el 38%. Solo nueve de 246 (3,65%) precisaron ingreso. Solo en 74 (30,1%) fue necesaria una atención que no hubiera podido ser solucionada en Atención Primaria. Se observa una relación entre los motivos de consulta y los antecedentes personales. Conclusiones: determinar qué pacientes son hiperfrecuentadores es una tarea fácil. Contactar con los padres de estos niños y ofrecer consultas de educación sanitaria constituye una opción plausible y eficiente, que contaría con aceptación por parte de la población, mejoraría la calidad percibida y podría ahorrar costes al Sistema Nacional de Salud. Este tipo de consultas informativas constituyen parte de un proyecto que se implementará en nuestro hospital en 2017 (AU)

Introduction: there is little information regarding the abuse of consultations in the Pediatric Emergency Departments (PED). The aims of the study are to determine the characteristics of frequent users in a public general hospital, and to estimate the concerns of parents guided by responses to a telephone survey. Patients and methods: a descriptive, cross-sectional, unicentric and local study was conducted from January to December 2015. All children ≤ 14 years visiting Pediatric Emergency Departments ≥ 10 times were included. Through a telephone interview, parents were asked whether or not they would go to the Emergency Room for 25 supposed clinical cases. SPSS v22.0(R) was used for statistical analysis. Results: 21 children (52.2% males) visited PED ≥ 10 times, involving 246 clinical cases (1.17% of total emergencies). Median age was 1.5 years. The ratio of the number of visits at Primary Care vs. PED' was < 1 in 38%. Admission was required only in 9 of 246 (3.65%) children. Visits that could not be solved at Primary Care were observed only in 74 cases (30.1%). Reasons for a pediatric visit and personal history were related. Conclusions: to determine which patients are frequent users is an easy task. To contact the parents of these children and to provide health education could be a feasible and efficient chance, which would be accepted by the population, it also would improve the perceived quality and could save costs to the National Health System. This kind of visits promoting health education are part of a project which will be implemented in our hospital in 2017 (AU)

Adecuación del diagnóstico y tratamiento de la faringoamigdalitis aguda a las guías actuales / Appropriateness of diagnosis and treatment of acute pharyngotonsillitis to current guidelines

Introducción: la faringoamigdalitis aguda (FAA) es una de las enfermedades más comunes en la infancia. El manejo diagnóstico y terapéutico es sencillo y, desde 2011, está consensuado. El objetivo principal es analizar la adecuación al consenso en un hospital de media complejidad, donde trabaja uno de los autores de dicho documento de consenso. Pacientes y métodos: estudio descriptivo, transversal, unicéntrico y de ámbito local. Se realiza un análisis retrospectivo de los informes de alta y pruebas complementarias en todos los niños ≤ 14 años diagnosticados de FAA en Urgencias Pediátricas. Periodo: del 1 de enero al 31 de diciembre de 2015. Resultados: se analizan 176 FAA (el 52,3%, niñas). La valoración clínica se realiza siempre mediante la escala de McIsaac. El 46,5% recibieron antibióticos antes de la realización de una técnica de detección rápida de antígeno estreptocócico o cultivo, en todos ellos. El 100% de los antibióticos y dosis prescritas se ajustaron al consenso. Los intervalos de dosis y la duración del tratamiento fueron adecuados en > 85% de los casos. Las prescripciones inadecuadas fueron pautadas por solo dos de los 17 pediatras del hospital. Conclusiones: la adecuación es superior a lo descrito en otras series. El uso apropiado de antibióticos puede mejorar mediante la formación continuada y regular por parte de pediatras especializados en enfermedades infecciosas. Además, se sugiere que los tratamientos inadecuados se analicen según prescriptor, para seleccionar qué facultativos deben recibir una formación específica. Es prioritario adecuar la prescripción de antimicrobianos en la FAA a la evidencia científica en nuestro país (AU)

Introduction: acute tonsillopharyngitis (ATP) is one of the most common childhood diseases. The diagnosis and therapeutic management is simple. Further, a consensus document exists in Spain since 2011. The aim of this study is to analyze the appropriateness to consensus in a general hospital, where an author of the consensus document is working. Patients and methods: a descriptive, cross-sectional, single-center and local study was conducted from January to December 2015. All children ≤ 14 years diagnosed as ATP in the Pediatric Emergency room were included. Clinical records and complementary tools were retrospectively studied. Results: a total of 176 ATP were analyzed (52.3% girls). Clinical assessment was always performed by McIsaac score. After conducting culture or a rapid antigen-detection test, 46.5% of children received antibiotics. Selection of antimicrobials and prescribed doses were 100% adjusted to consensus. Dose ranges and duration of treatment were >85% appropriated. Only two of 17 pediatricians working on the hospital were responsible of inappropriate prescriptions. Conclusions: appropriateness is higher than reported in other studies. Rational use of antibiotics could be improved through continuous and regular training by experts in pediatric infectious diseases. In addition, it is suggested to analyze inappropriate prescribers to select pediatricians that should receive specific training. In Spain, it is of primordial importance to adapt the prescribing of antibiotics to the scientific evidence (AU)

¿Por qué no utilizamos amoxicilina-clavulánico por vía intravenosa en neonatos? / What about the use of intravenous amoxicillin-clavulanate in neonates?

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Cesárea electiva en una paciente con síndrome de sensibilidad química múltiple / Elective cesarean section in a patient with multiple chemical sensitivity syndrome

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Síndrome hereditario de hiperferritinemia y cataratas: mutación de novo / Hereditary hyperferritinemia and cataract syndrome: a de novo mutation

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