727 research outputs found

    Traveling waves for nonlinear Schr\"odinger equations with nonzero conditions at infinity, II

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    We prove the existence of nontrivial finite energy traveling waves for a large class of nonlinear Schr\"odinger equations with nonzero conditions at infinity (includindg the Gross-Pitaevskii and the so-called "cubic-quintic" equations) in space dimension N≄2 N \geq 2. We show that minimization of the energy at fixed momentum can be used whenever the associated nonlinear potential is nonnegative and it gives a set of orbitally stable traveling waves, while minimization of the action at constant kinetic energy can be used in all cases. We also explore the relationship between the families of traveling waves obtained by different methods and we prove a sharp nonexistence result for traveling waves with small energy.Comment: Final version, accepted for publication in the {\it Archive for Rational Mechanics and Analysis.} The final publication is available at Springer via http://dx.doi.org/10.1007/s00205-017-1131-

    Glucose enhancement of memory is modulated by trait anxiety in healthy adolescent males

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    Glucose administration is associated with memory enhancement in healthy young individuals under conditions of divided attention at encoding. While the specific neurocognitive mechanisms underlying this ‘glucose memory facilitation effect’ are currently uncertain, it is thought that individual differences in glucoregulatory efficiency may alter an individual’s sensitivity to the glucose memory facilitation effect. In the present study, we sought to investigate whether basal hypothalamic–pituitary–adrenal axis function (itself a modulator of glucoregulatory efficiency), baseline self-reported stress and trait anxiety influence the glucose memory facilitation effect. Adolescent males (age range = 14–17 years) were administered glucose and placebo prior to completing a verbal episodic memory task on two separate testing days in a counter-balanced, within-subjects design. Glucose ingestion improved verbal episodic memory performance when memory recall was tested (i) within an hour of glucose ingestion and encoding, and (ii) one week subsequent to glucose ingestion and encoding. Basal hypothalamic–pituitary–adrenal axis function did not appear to influence the glucose memory facilitation effect; however, glucose ingestion only improved memory in participants reporting relatively higher trait anxiety. These findings suggest that the glucose memory facilitation effect may be mediated by biological mechanisms associated with trait anxiety

    Drug Development for Rare Paediatric Epilepsies: Current State and Future Directions

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    Rare diseases provide a challenge in the evaluation of new therapies. However, orphan drug development is of increasing interest because of the legislation enabling facilitated support by regulatory agencies through scientific advice, and the protection of the molecules with orphan designation. In the landscape of the rare epilepsies, very few syndromes, namely Dravet syndrome, Lennox-Gastaut syndrome and West syndrome, have been subject to orphan drug development. Despite orphan designations for rare epilepsies having dramatically increased in the past 10 years, the number of approved drugs remains limited and restricted to a handful of epilepsy syndromes. In this paper, we describe the current state of orphan drug development for rare epilepsies. We identified a large number of compounds currently under investigation, but mostly in the same rare epilepsy syndromes as in the past. A rationale for further development in rare epilepsies could be based on the match between the drug mechanisms of action and the knowledge of the causative gene mutation or by evidence from animal models. In case of the absence of strong pathophysiological hypotheses, exploratory/basket clinical studies could be helpful to identify a subpopulation that may benefit from the new drug. We provide some suggestions for future improvements in orphan drug development such as promoting paediatric drug investigations, better evaluation of the incidence and the prevalence, together with the natural history data, and the development of new primary outcomes

    Relevance of a photo-Fenton like technology based on peroxymonosulphate for 17b-estradiol removal from wastewater

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    The objective of this work was to evaluate the effectiveness of sulphate radical based homogeneous advanced oxidation technologies (SR-AOTs) involving peroxymonosulphate (PMS) as an oxidant and ferrous iron (Fe(II)) as a catalyst, for the removal of 17b-estradiol (E2) from wastewater effluents collected downstream of a biological WWTP in Perpignan (France). This molecule is used as a surrogate for endocrine disrupting compounds (EDCs) due to its high biological activity at very low concentration levels (ng/ L). For this purpose, two different laboratory-scale devices have been employed, one for indoor experiments working with controlled and artificial UV light centered on k = 365 nm emission, and the other at a larger scale for outdoor experiments using direct solar irradiation. Comparison of kinetic studies with those obtained with commonly used hydroxyl radical based advanced oxidation technologies (HR-AOTs), i.e., UV–Vis/H2O2/Fe(II) and UV/TiO2 revealed the higher efficiency of the former over the latter ones. Estrogenicity measurement through bioassays confirmed the complete removal of 17b-estradiol after only a few minutes treatment. Determination of E2 transformation pathways upon sulphate radical reactivity through intermediates identification by mass spectrometry revealed that the oxidation of phenol moiety into quinone might be the main step responsible for the decrease in estrogenicity. UV–Vis/PMS/Fe(II) system appears to be the most suitable method for the treatment of aqueous solutions containing E2

    Convergence of Ginzburg-Landau functionals in 3-d superconductivity

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    In this paper we consider the asymptotic behavior of the Ginzburg- Landau model for superconductivity in 3-d, in various energy regimes. We rigorously derive, through an analysis via {\Gamma}-convergence, a reduced model for the vortex density, and we deduce a curvature equation for the vortex lines. In a companion paper, we describe further applications to superconductivity and superfluidity, such as general expressions for the first critical magnetic field H_{c1}, and the critical angular velocity of rotating Bose-Einstein condensates.Comment: 45 page

    Travelling waves for the Gross-Pitaevskii equation II

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    The purpose of this paper is to provide a rigorous mathematical proof of the existence of travelling wave solutions to the Gross-Pitaevskii equation in dimensions two and three. Our arguments, based on minimization under constraints, yield a full branch of solutions, and extend earlier results, where only a part of the branch was built. In dimension three, we also show that there are no travelling wave solutions of small energy.Comment: Final version accepted for publication in Communications in Mathematical Physics with a few minor corrections and added remark

    Fenfluramine for Treatment-Resistant Seizures in Patients With Dravet Syndrome Receiving Stiripentol-Inclusive Regimens A Randomized Clinical Trial

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    IMPORTANCE Fenfluramine treatment may reduce monthly convulsive seizure frequency in patients with Dravet syndrome who have poor seizure control with their current stiripentol-containing antiepileptic drug regimens. OBJECTIVE To determine whether fenfluramine reduced monthly convulsive seizure frequency relative to placebo in patients with Dravet syndrome who were taking stiripentol-inclusive regimens. DESIGN, SETTING, AND PARTICIPANTS This double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted in multiple centers. Eligible patients were children aged 2 to 18 years with a confirmed clinical diagnosis of Dravet syndrome who were receiving stable, stiripentol-inclusive antiepileptic drug regimens. INTERVENTIONS Patients with 6 or more convulsive seizures during the 6-week baseline period were randomly assigned to receive fenfluramine, 0.4 mg/kg/d (maximum, 17 mg/d), or a placebo. After titration (3 weeks), patients’ assigned dosages were maintained for 12 additional weeks. Caregivers recorded seizures via a daily electronic diary. MAIN OUTCOMES AND MEASURES The primary efficacy end point was the change in mean monthly convulsive seizure frequency between fenfluramine and placebo during the combined titration and maintenance periods relative to baseline. RESULTS A total of 115 eligible patients were identified; of these, 87 patients (mean [SD], age 9.1 [4.8] years; 50 male patients [57%]; mean baseline frequency of seizures, approximately 25 convulsive seizures per month) were enrolled and randomized to fenfluramine, 0.4 mg/kg/d (n = 43) or placebo (n = 44). Patients treated with fenfluramine achieved a 54.0% (95% CI, 35.6%-67.2%; P < .001) greater reduction in mean monthly convulsive seizure frequency than those receiving the placebo. With fenfluramine, 54% of patients demonstrated a clinically meaningful (50%) reduction in monthly convulsive seizure frequency vs 5% with placebo (P < .001). The median (range) longest seizure-free interval was 22 (3.0-105.0) days with fenfluramine and 13 (1.0-40.0) days with placebo (P = .004). The most common adverse events were decreased appetite (19 patients taking fenfluramine [44%] vs 5 taking placebo [11%]), fatigue (11 [26%] vs 2 [5%]), diarrhea (10 [23%] vs 3 [7%]), and pyrexia (11 [26%] vs 4 [9%]). Cardiac monitoring demonstrated no clinical or echocardiographic evidence of valvular heart disease or pulmonary arterial hypertension. CONCLUSIONS AND RELEVANCE Fenfluramine demonstrated significant improvements in monthly convulsive seizure frequency in patients with Dravet syndrome whose conditions were insufficiently controlled with stiripentol-inclusive antiepileptic drug regimens. Fenfluramine was generally well tolerated. Fenfluramine may represent a new treatment option for Dravet syndrome. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT0292689

    Which DSM validated tools for diagnosing depression are usable in primary care research? A systematic literature review

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    IntroductionDepression occurs frequently in primary care. Its broad clinical variability makes it difficult to diagnose. This makes it essential that family practitioner (FP) researchers have validated tools to minimize bias in studies of everyday practice. Which tools validated against psychiatric examination, according to the major depression criteria of DSM-IV or 5, can be used for research purposes
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