Glucocorticoids for acute urticaria: study protocol for a double-blind non-inferiority randomised controlled trial

INTRODUCTION: This study protocol describes a trial designed to investigate whether antihistamine alone in patients with acute urticaria does not increase the 7-day Urticaria Activity Score (UAS7) in comparison with an association of antihistamine and glucocorticoids and reduces short-term relapses and chronic-induced urticaria. METHODS AND ANALYSIS: This is a prospective, double-blind, parallel-group, multicentre non-inferiority randomised controlled trial. Two-hundred and forty patients with acute urticaria admitted to emergency department will be randomised in a 1:1 ratio to receive levocetirizine or an association of levocetirizine and prednisone. Randomisation will be stratified by centre. The primary outcome will be the UAS7 at day 7. The secondary outcomes will encompass recurrence of hives and/or itch at day 7; occurrence of spontaneous hives or itch for >6 weeks; patients with angioedema at day 7, and 2, 6, 12 and 24 weeks; new emergency visits for acute urticaria recurrences at days 7 and 14, and 3 months; Dermatology Life Quality Index at days 7 and 14, and 3 and 6 months; and Chronic Urticaria Quality of Life Questionnaire at 6 weeks. ETHICS AND DISSEMINATION: The protocol has been approved by the and will be carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. A steering committee will oversee the progress of the study. Findings will be disseminated through national and international scientific conferences and publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03545464

Proton linear accelerators: A theoretical and historical introduction

From the beginning, the development of linear accelerators has followed a number of different directions. This report surveys the basic ideas and general principles of such machines, pointing out the problems that have led to the various improvements, with the hope that it may also aid further progress. After a brief historical survey, the principal aspects of accelerator theory are covered in some detail: phase stability, focusing, radio-frequency accelerating structures, the detailed calculation of particle dynamics, and space-charge effects at high intensities. These developments apply essentially to proton and ion accelerators, and only the last chapter deals with a few aspects relative to electrons. 134 refs

Direct axisymmetric Vlasov simulations of space charge dominated beams

A numerical method for the direct simulation of the axisymmetricVlasov equation is introduced. It is based on a modified formulationof the Vlasov equation using the invariance of the canonical angularmomentum. This leads in particular to a straightforward and very efficientparallel algorithm. Then it is applied to simulations of a RMS-matched semi-Gaussian beam and a perturbed thermal equilibrium

Nonlinear dynamics of periodically focused intense particle beams

We extend a previous study [R. Pakter and F. B. Rizzato, Phys. Rev. Lett. 87, 044801 (2001)] and investigate the nonlinear dynamics of periodically focused intense particle beams. We show that (i) the scenario as the focusing field increases is not the existence of a single threshold above which stable matched (equilibrium) solutions are absent, as believed so far, but the existence of successive regions of stability interrupted by gaps where periodic solutions are either unstable or simply do not exist; (ii) the beam can be focused to tighter radii using stable matched solutions found for focusing field strengths greater than the previous threshold. A comprehensive analysis is carried out as a function of the relevant parameters of the system. Self-consistent simulations validate the findings. The gaps are of crucial importance because they must be avoided if the goal is beam confinement with matched solutions; we develop an analytical model to determine the gap structure, which agrees well with computer simulations