Hoffmann, J. (Jan)

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    ODS ferritic steels obtained from gas atomized powders through the STARS processing route: Reactive synthesis as an alternative to mechanical alloying
    (Elsevier BV, 2018) Kuzmin, A. (Alexei); Ordas-Mur, N. (Nerea); Iturriza-Zubillaga, I. (Iñigo); Purans, J. (Juri); Hoffmann, J. (Jan); Pazos, D. (David); Leguey, T. (Teresa); Fernández, P. (Pilar); Anspoks, A. (Andris); García-Vargas, W. (Wilfredo); Castro, V. (Vanessa) de; Cintins, A. (Arturs)
    Oxide Dispersion Strengthened Ferritic Stainless Steels (ODS FS) are candidate materials for structural components in fusion reactors. Their ultrafine microstructure and the presence of a very stable dispersion of Y-Ti-O nanoclusters provide reasonable fracture toughness, high mechanical and creep strength, and resistance to radiation damage at the operation temperature, up to about 750 °C. An innovative route to produce ODS FS with composition Fe-14Cr-2W-0.3Ti-0.3Y2O3 (wt.%), named STARS (Surface Treatment of gas Atomized powder followed by Reactive Synthesis), is presented. This route avoids the mechanical alloying (MA) of the elemental or prealloyed powders with yttria to dissolve the yttrium in the ferritic matrix. In this study, starting powders containing Ti and Y are obtained by gas atomization at laboratory and industrial scale. Then, a metastable Cr- and Fe- rich oxide layer is formed on the surface of the powder particles. During consolidation by HIP the metastable oxide layer at Prior Particle Boundaries (PPBs) dissociates, the oxygen diffuses towards saturated solutions or metallic Ti- and Y-rich particles, and Y-Ti-O nano-oxides (mainly Y2TiO5) precipitate in the ferritic matrix. Detailed Microstructural characterization by X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of powders and consolidated materials is presented and correlated with mechanical behaviour.
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    Non-invasive vagus nerve stimulation (nVNS) for the preventive treatment of episodic migraine: The multicentre, double-blind, randomised, sham-controlled PREMIUM trial
    (SAGE Publications, 2019) Silver, N. (Nicholas); Goadsby, P.J. (Peter J.); Ashina, M. (Messoud); Pozo-Rosich, P. (Patricia); Irimia, P. (Pablo); Diener, H.C. (Hans Christoph); Mitsikostas, D. (Dimos); Marin, J. (Juana); Hoffmann, J. (Jan); Liebler, E. (Eric); Ferrari, M.D. (Michel D.); Al-Mahdi-Al-Karagholi, M. (Mohammad); Sinclair, A. (Alexandra); Láinez, J.M. (J.M); Gaul, C. (Charly); Magis, D. (Delphine)
    Introduction: Non-invasive vagus nerve stimulation (nVNS; gammaCore) has the potential to prevent migraine days in patients with migraine on the basis of mechanistic rationale and pilot clinical data. Methods: This multicentre study included a 4-week run-in period, a 12-week double-blind period of randomised treatment with nVNS or sham, and a 24-week open-label period of nVNS. Patients were to administer two 120-second stimulations bilaterally to the neck three times daily (6–8 hours apart). Results: Of 477 enrolled patients, 332 comprised the intent-to-treat (ITT) population. Mean reductions in migraine days per month (primary outcome) were 2.26 for nVNS (n ¼ 165; baseline, 7.9 days) and 1.80 for sham (n ¼ 167; baseline, 8.1 days) (p ¼ 0.15). Results were similar across other outcomes. Upon observation of suboptimal adherence rates, post hoc analysis of patients with 67% adherence per month demonstrated significant differences between nVNS (n ¼ 138) and sham (n ¼ 140) for outcomes including reduction in migraine days (2.27 vs. 1.53; p ¼ 0.043); therapeutic gains were greater in patients with aura than in those without aura. Most nVNS device-related adverse events were mild and transient, with application site discomfort being the most common. Conclusions: Preventive nVNS treatment in episodic migraine was not superior to sham stimulation in the ITT population. The ‘‘sham’’ device inadvertently provided a level of active vagus nerve stimulation. Post hoc analysis showed significant effects of nVNS in treatment-adherent patients.