20 research outputs found

    Disentangling Highly Asymmetric Magnetoelectric Effects in Engineered Multiferroic Heterostructures

    Get PDF
    One of the main strategies to control magnetism by voltage is the use of magnetostrictive-piezoelectric hybrid materials, such as ferromagnetic-ferroelectric heterostructures. When such heterostructures are subjected to an electric field, piezostrain-mediated effects, electronic charging, and voltage-driven oxygen migration (magnetoionics) may simultaneously occur, making the interpretation of the magnetoelectric effects not straightforward and often leading to misconceptions. Typically, the strain-mediated magnetoelectric response is symmetric with respect to the sign of the applied voltage because the induced strain (and variations in the magnetization) depends on the square of the ferroelectric polarization. Conversely, asymmetric responses can be obtained from electronic charging and voltage-driven oxygen migration. By engineering a ferromagnetic-ferroelectric hybrid consisting of a magnetically soft 50-nm thick Fe75Al25 (at. %) thin film on top of a (110)-oriented Pb(Mg1/3Nb2/3)O3-32PbTiO3 ferroelectric crystal, a highly asymmetric magnetoelectric response is obtained and the aforementioned magnetoelectric effects can be disentangled. Specifically, the large thickness of the Fe75Al25 layer allows dismissing any possible charge accumulation effect, whereas no evidence of magnetoionics is observed experimentally, as expected from the high resistance to oxidation of Fe75Al25, leaving strain as the only mechanism to modulate the asymmetric magnetoelectric response. The origin of this asymmetric strain-induced magnetoelectric effect arises from the asymmetry of the polarization reversal in the particular crystallographic orientation of the ferroelectric substrate. These results are important to optimize the performance of artificial multiferroic heterostructures

    Current trends in access to treatment for hepatitis B in immigrants vs non-immigrants

    Get PDF
    Universal vaccination for hepatitis B virus (HBV) and migratory movements have changed the demographic characteristics of this disease in Spain and in Europe. Therefore, we evaluated the characteristics of the disease and the possible differences according to origin (immigrants vs non-immigrants) and access to treatment. This is a multicenter cross-sectional study (June 2014 to May 2015) in which outpatients with a positive HBsAg were seen and followed in four Hepatology units. Demographic and clinical data and indication and access to treatment were collected in two different regions of Catalonia (Spain) where there are no barriers to treatment due to a comprehensive coverage under the National Health System. A total of 951 patients were evaluated (48.1% men). Of these, 46.6% were immigrants (58.7% of them were born in Africa) and were significantly younger compared to non-immigrants. The proportions of patients with alcohol consumption, being overweight, and other indicators of metabolic co-morbidities were significantly higher in non-immigrants. Among the 937 patients receiving HBeAg examination, 91.7% were HBeAg-negative. Chronic HBeAg-positive infection was significantly higher in immigrants (3.9% vs 0.6%, P = 0.001) and chronic HBeAg-negative hepatitis was higher non-immigrants (31.7% vs 21.4%, P < 0.001). Not only was the proportion of patients who met treatment criteria significantly higher among non-immigrants (38.4% vs 29.2%, P = 0.003), but also the proportion of those with indication of effectively receiving therapy at the time of data collection (83.2% vs 57.8 %, P < 0.001). The immigrant population with HBV is younger and has a lower prevalence of metabolic co-morbidities and a higher frequency of chronic HBeAg infection. Despite having access to care and an indication for treatment, some do not get adequately treated due to several factors including local adaptation that precludes access to treatment

    Factors related to survival in hepatocellular carcinoma in the geographic area of Sabadell (Catalonia, Spain) Factores relacionados con la supervivencia en el carcinoma hepatocelular en el área geográfica de Sabadell

    No full text
    Background: hepatocellular carcinoma (HCC) is a very frequent tumor. Screening for the disease is effective, but the prognostic factors are difficult to evaluate. Objectives: 1. To determine epidemiological data and the clinical course of HCC in our setting. 2. To compare patient survival according to whether screening is performed or not. 3. To evaluate survival prognostic factors. Patients and methods: data on the epidemiology and clinical course of patients diagnosed with HCC were collected on a prospective basis (January 2004-December 2006). Two groups were considered according to whether screening had been performed (group A) or not (group B). Results: a total of 110 patients were diagnosed with HCC (70% males). The most common etiology of cirrhosis was hepatitis C (56.1%), and 69% presented mild liver failure (Child-Pugh grade A). The median follow-up was 1.8 years. Fifty-one percent had been subjected to screening. The diagnosis of HCC was established by imaging techniques in 48.2% of the cases, and by histological criteria in 51.8%. The median tumor size was 23 mm in group A and 28 mm in group B (p = 0.005). Treatment with curative intent was provided in 72% of the cases in group A and in 48% in group B (p = 0.011). The median overall survival was 1.99 years-2.67 years in group A and 1.75 years in group B (p = 0.05). The multivariate analysis of overall survival showed the type of treatment (OR = 2.82 95%CI: 1.3-6.12, p = 0.009) and liver function (OR = 1.71 95%CI: 1.1-2.68, p = 0.020) to be independent predictors of survival. Conclusions: screening allows the diagnosis of smaller lesions and a higher percentage of curative treatments. The degree of liver function and the provision of curative treatment are independent predictors of survival.Introducción: el carcinoma hepatocelular (CHC) es un tumor muy prevalente. Su cribado es eficaz, pero los factores pronósticos son difíciles de evaluar. Objetivos: 1. Conocer datos epidemiológicos y evolución clínica en nuestra área. 2. Comparar la supervivencia de los pacientes según si seguían cribado o no. 3. Evaluar los factores pronósticos de supervivencia. Pacientes y métodos: se recogieron prospectivamente (enero 2004-diciembre 2006) datos epidemiológicos y evolución clínica de pacientes diagnosticados de CHC. Se estudiaron dos grupos en función del cribado (grupo A = cribado, grupo B = sin cribado). Resultados: 110 pacientes fueron diagnosticados de CHC (70% hombres). La etiología más frecuente de la cirrosis fue por virus C en 56,1%, eran Child A el 69%. El seguimiento mediano fue de 1,8 años. El 51% estaban en programa de cribado. El diagnóstico de CHC fue mediante pruebas de imagen en el 48,2% y 51,8% por criterios histológicos. El tamaño tumoral mediano fue 23 mm en el grupo A y de 28 mm en el B (p = 0,005). El tratamiento con intención curativa fue del 72% en el A y del 48% en el B (p = 0,011). La supervivencia global mediana fue de 1,99 años: grupo A. 2,67 años y grupo B 1,75 años (p = 0,05). El análisis multivariado de la supervivencia global evidenció que el tipo de tratamiento -OR = 2,82 (IC 95%: 1,3-6,12) (p = 0,009)- y la funcionalidad hepática -OR = 1,71 (IC 95%: 1,1-2,68) (p= 0,020)- predicen independientemente la supervivencia. Conclusiones: el cribado permite el diagnóstico de lesiones de menor tamaño y mayor porcentaje de tratamientos curativos. De forma independiente el grado de función hepática y la realización de un tratamiento curativo predicen la supervivencia

    Concordancia inter e intraobservador en el diagnóstico de la gastropatía por hipertensión portal

    No full text
    RESUMEN Introducción: en la actualidad no existe una clasificación endoscópica totalmente aceptada para evaluar el grado de gastropatía de la hipertensión portal (GHP). Hay pocos estudios que evalúen la concordancia inter e intraobservador o el grado de concordancia entre las distintas clasificaciones endoscópicas. Objetivos: evaluar la concordancia inter e intraobservador respecto a la presencia de gastro y enteropatía portal utilizando distintas clasificaciones endoscópicas. Métodos: fueron incluidos pacientes con cirrosis hepática a los que se realizó una enteroscopia bajo sedación. Se describió la localización de las lesiones y el grado de las mismas. Las imágenes se registraron mediante grabación en vídeo que posteriormente fue valorada por tres endoscopistas diferentes de manera independiente, uno de ellos el endoscopista inicial. La concordancia entre observaciones se evaluó utilizando el índice kappa. Resultados: se incluyeron un total de 74 pacientes (edad media de 63,2 años, con una proporción de 53/21 hombre/mujer). La concordancia entre los tres endoscopistas, para la presencia o ausencia de GHP según las clasificaciones de Tanoue y McCormack, fue muy baja: kappa = 0,16 y 0,27 respectivamente. Conclusiones: las actuales clasificaciones de la gastropatía portal presentan un grado de acuerdo intra e interobservador muy bajo tanto para el diagnóstico como para la evaluación de la gravedad de la gastropatía

    Disentangling Highly Asymmetric Magnetoelectric Effects in Engineered Multiferroic Heterostructures

    No full text
    One of the main strategies to control magnetism by voltage is the use of magnetostrictive-piezoelectric hybrid materials, such as ferromagnetic-ferroelectric heterostructures. When such heterostructures are subjected to an electric field, piezostrain-mediated effects, electronic charging, and voltage-driven oxygen migration (magnetoionics) may simultaneously occur, making the interpretation of the magnetoelectric effects not straightforward and often leading to misconceptions. Typically, the strain-mediated magnetoelectric response is symmetric with respect to the sign of the applied voltage because the induced strain (and variations in the magnetization) depends on the square of the ferroelectric polarization. Conversely, asymmetric responses can be obtained from electronic charging and voltage-driven oxygen migration. By engineering a ferromagnetic-ferroelectric hybrid consisting of a magnetically soft 50-nm thick Fe75Al25 (at. %) thin film on top of a (110)-oriented Pb(Mg1/3Nb2/3)O3-32PbTiO3 ferroelectric crystal, a highly asymmetric magnetoelectric response is obtained and the aforementioned magnetoelectric effects can be disentangled. Specifically, the large thickness of the Fe75Al25 layer allows dismissing any possible charge accumulation effect, whereas no evidence of magnetoionics is observed experimentally, as expected from the high resistance to oxidation of Fe75Al25, leaving strain as the only mechanism to modulate the asymmetric magnetoelectric response. The origin of this asymmetric strain-induced magnetoelectric effect arises from the asymmetry of the polarization reversal in the particular crystallographic orientation of the ferroelectric substrate. These results are important to optimize the performance of artificial multiferroic heterostructures

    Impact of treatment with direct-acting antivirals on anxiety and depression in chronic hepatitis C.

    Get PDF
    BACKGROUND AND AIM:Treatment of hepatitis C with direct-acting antiviral agents (DAA) has few side effects. Although pivotal studies suggested that DAA were safe in patients with psychiatric diseases who could not be treated with previous antiviral therapies, their effects on anxiety and depression have not yet been analysed in clinical practice. The aim of our study was to analyse anxiety and depression in the setting of DAA treatment in a clinical practice series. METHODS:All patients starting DAA treatment between November 1, 2014 and October 31, 2015 were eligible. Patients completed the Hospital Anxiety and Depression scale at different times during treatment. The results were plotted on line graphs and evaluated using a linear regression model with repeated measures. RESULTS:One hundred and forty-five patients were included (11% with major psychiatric disorders; 32% on psychiatric treatment). Sustained virologic response (SVR) was achieved in 97.3% of cases. Anxiety and depression measures did not differ between time points. No differences between patients on psychiatric treatment or with advanced fibrosis or cirrhosis were found at any time point analysed. CONCLUSION:DAA treatment had no impact on anxiety or depression during or after chronic hepatitis C infection treatment, even in high-risk patients with major psychiatric disorders

    Factores pronósticos de mortalidad en la cirrosis hepática tras un primer episodio de peritonitis bacteriana espontánea. Estudio multicéntrico

    No full text
    RESUMEN Introducción: la peritonitis bacteriana espontánea es una complicación infecciosa con impacto negativo sobre la supervivencia de los pacientes con cirrosis. Objetivo: analizar la supervivencia a corto y largo plazo después de un primer episodio de peritonitis bacteriana espontánea y los factores pronósticos asociados. Material y métodos: estudio multicéntrico retrospectivo que incluyó a los pacientes ingresados por peritonitis bacteriana espontánea entre 2008 y 2013. Las variables independientes relacionadas con la mortalidad se analizaron mediante regresión logística. Se analizó el poder pronóstico de los índices Child Pugh, MELD y Charlson mediante curva de ROC. Resultados: fueron incluidos 159 pacientes. El 72% fueron hombres con una edad media de 63,5 años y con una puntuación MELD de 19 (DE ± 9,5). La mortalidad a los 30 días, 90 días, al año y a los dos años fue del 21%, 31%, 55% y 69%, respectivamente. La encefalopatía hepática (p = 0,008; OR 3,5; IC 95% 1,4-8,8) y la función renal (p = 0,026; OR 2,7; IC 95% 1,13-16,7) fueron factores independientes de mortalidad a corto y largo plazo. El MELD fue un buen indicador de supervivencia a corto y largo plazo (área bajo la curva [AUC] 0,7: IC 95% 1,02-1,4). El índice de Charlson se relacionó con la mortalidad a largo plazo (AUC 0,68: IC 95% 0,6-0,77). Conclusiones: en la peritonitis bacteriana espontánea la mortalidad a corto y largo plazo sigue siendo elevada. Los principales factores pronósticos de mortalidad son el deterioro de la función hepática y renal. El MELD y el índice de Charlson son unos buenos indicadores de supervivencia
    corecore