529 research outputs found

    Spin-Hall nano-oscillator with oblique magnetization and Dzyaloshinskii-Moriya interaction as generator of skyrmions and nonreciprocal spin-waves

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    Spin-Hall oscillators are promising sources of spin-wave signals for magnonics applications, and can serve as building blocks for magnonic logic in ultralow power computation devices. Here, we analytically and micromagnetically study magnetization dynamics excited in a Spin-Hall oscillator with oblique magnetization when the spin-Hall effect and interfacial Dzyaloshinskii-Moriya interaction act simultaneously. Our key results are (i) excitation of nonreciprocal spin-waves propagating perpendicularly to the in-plane projection of the static magnetization, (ii) skyrmions generation by pure spin-current, (iii) excitation of a new spin-wave mode with a spiral spatial profile originating from a gyrotropic rotation of a dynamical skyrmion. These results demonstrate that Spin-Hall oscillators can be used as generators of magnetic skyrmions and different types of propagating spin-waves for magnetic data storage and signal processing applications

    One-year follow-up diagnostic stability of autism spectrum disorder diagnosis in a clinical sample of children and toddlers

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    Some studies show that the diagnosis of Autism Spectrum Disorder could be considered reliable and stable in children aged 18 to 24 months. Nevertheless, the diagnostic stability of early ASD diagnosis has not yet been fully demonstrated. This observational study examines the one-year diagnostic stability of autism spectrum disorder diagnosis in a clinical sample of 147 children diagnosed between 18 and 48 months of age. The ADOS-2 scores were used in order to stratify children in three levels of symptom severity: Autism (AD; comparison score 5–7), Autism Spectrum Disorder (ASD; comparison score 3–4), and Sub-Threshold Symptoms; (STS; comparison score 1–2). Results: Overall, the largest part of children and toddlers diagnosed with autism spectrum disorder between 18 and 48 months continued to show autistic symptoms at one-year follow-up evaluation. Neverthe-less, a significant percentage of children with higher ADOS severity scores exhibited a reduction of symptom severity and, therefore, moved towards a milder severity class one year later. Conversely, the number of subjects of the STS group meaningfully increased. Therefore, at one-year follow-up a statistically significant (χ2 (2) = 181.46, p < 0.0001) percentage of subjects (25.2% of the total) who had received a categorical diagnosis of Autistic Disorder or Autism Spectrum Disorder in baseline no longer met the criteria for a categorical diagnosis. Furthermore, children who no longer met the criteria for autism spectrum disorder continue to show delays in one or more neurodevelopmental areas, possibly related to the emergence of other neurodevelopmental/neuropsychiatric disorders. Overall, the comprehensive results of the study account for a high sensibility but a moderate stability of ASD early diagnosis

    Evaluation of acute cardiovascular effects of immediate-release methylphenidate in children and adolescents with attention-deficit hyperactivity disorder

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    Attention-deficit hyperactivity disorder is a frequent condition in children and often extends into adulthood. Use of immediate-release methylphenidate (MPH) has raised concerns about potential cardiovascular adverse effects within a few hours after administration. This study was carried out to investigate acute effects of MPH on electrocardiogram (ECG) in a pediatric population. A total of 54 consecutive patients with attention-deficit hyperactivity disorder (51 males and 3 females; mean age =12.14±2.6 years, range 6–19 years), receiving a new prescription of MPH, underwent a standard ECG 2 hours before and after the administration of MPH 10 mg per os. Basal and posttreatment ECG parameters, including mean QT (QT interval when corrected for heart rate [QTc]), QTc dispersion (QTd) interval duration, T-peak to T-end (TpTe) intervals, and TpTe/QT ratio were compared. Significant modifications of both QTc and QTd values were not found after drug administration. QTd fluctuated slightly from 25.7±9.3 milliseconds to 25.1±8.4 milliseconds; QTc varied from 407.6±12.4 milliseconds to 409.8±12.7 milliseconds. A significant variation in blood pressure (systolic blood pressure 105.4±10.3 vs 109.6±11.5; P<0.05; diastolic blood pressure 59.2±7.1 vs 63.1±7.9; P<0.05) was observed, but all the data were within normal range. Heart rate moved from 80.5±15.5 bpm to 87.7±18.8 bpm. No change in TpTe values was found, but a statistically significant increase in TpTe/QTc intervals was found with respect to basal values (0.207±0.02 milliseconds vs 0.214±0.02 milliseconds; P<0.01). The findings of this study show no significant changes in ECG parameters. TpTe values can be an additional parameter to evaluate borderline cases

    Hepatopulmonary hydatidosis in a ten-year-old girl: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hydatid disease is a parasitic infection caused by the tapeworm <it>Echinococcus granulosus </it>and is characterised by cystic lesions in the liver and lungs. Concomitant pulmonary and hepatic localization of hydatid cysts in childhood is unusual and represents a distinct clinical entity called hepatopulmonary hydatidosis.</p> <p>Case presentation</p> <p>A ten-year-old Caucasian girl, a permanent resident of rural Greece, was admitted to hospital reporting a nonspecific symptomatology compatible with a diagnosis of viral infection. Chest radiography revealed a large homogenous circular opacity in the right lung field. On the basis of imaging studies, a diagnosis of hydatidosis was made with synchronous hepatic and pulmonary involvement, successfully managed through a single-stage transthoracic surgical approach.</p> <p>Conclusion</p> <p>This case report highlights the necessity of realizing that hydatid disease continues to be a public health problem, which often remains asymptomatic for years. Therefore, the presence of any homogeneous cystic spherical opacity on routine chest radiography should raise the suspicion of hydatid disease, mainly in endemic areas such as Greece. General practitioners and physicians involved in pediatric care need to be familiar with the diagnosis and management of the variable clinical manifestations of hydatid disease. Taking into consideration that hepatopulmonary hydatidosis represents a special entity that requires a different therapeutic approach may positively affect its economic and social-related burden.</p

    Perilipin 2 levels are increased in patients with in-stent neoatherosclerosis: A clue to mechanisms of accelerated plaque formation after drug-eluting stent implantation

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    Background: Perilipin 2 (PLIN2) is a protein that potentially facilitates atherogenesis in native coronary arteries or arteries with an implanted drug-eluting stent (DES). The aim of the study was to determine PLIN2 protein levels in peripheral monocytes of enrolled subjects and compare them between patients with native coronary artery disease (CAD) and those with an in-stent restenosis (ISR) due to neoatherosclerosis occurring >1 year after DES implantation. Methods: Forty-two patients were prospectively enrolled in the study in 3:1 fashion and underwent coronary catheterization. Both groups were angiographically matched for CAD burden with respect to the number of diseased vessels. Neoatherosclerosis was determined by intracoronary optical coherence tomography (OCT) among patients with ISR. Results: Patients with ISR due to neoatherosclerosis had significantly higher PLIN2 protein levels in peripheral blood monocytes compared to patients with native CAD (342.47 ± 75.63[SE] versus 119.51 ± 20.95, p < 0.001). PLIN2 protein levels did not significantly differ between unstable and stable disease phenotype (125.59 ± 131.02 vs. 146.14 ± 111.87, p = 0.109). Conclusions: In this explorative study, PLIN2 protein levels are significantly increased in patients with neoatherosclerosis, irrespective of clinical presentation, implicating that it might play a pathogenetic role in accelerated atherosclerosis after DES implantation. Further larger clinical studies are warranted to confirm these initial findings

    Investigation of a Pt3Sn/C Electro-Catalyst in a Direct Ethanol Fuel Cell Operating at Low Temperatures for Portable Applications

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    A 20% Pt3Sn/C catalyst was prepared by reduction with formic acid and used in a direct ethanol fuel cell at low temperatures. The electro-catalytic activity of this bimetallic catalyst was compared to that of a commercial 20% Pt/C catalyst. The PtSn catalyst showed better results in the investigated temperature range (30 degrees-70 degrees C). Generally, Sn promotes ethanol oxidation by adsorption of OH species at considerably lower potentials compared to Pt, allowing the occurrence of a bifunctional mechanism. The bimetallic catalyst was physico-chemically characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The presence of SnO2 in the bulk and surface of the catalyst was observed. It appears that SnO2 can enhance the ethanol electro-oxidation activity at low potentials due to the supply of oxygen-containing species for the oxidative removal of CO and CH3CO species adsorbed on adjacent Pt active sites.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
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