High Average Gradient in a Laser-Gated Multistage Plasma Wakefield Accelerator.

Plasma wakefield accelerators driven by particle beams are capable of providing accelerating gradient several orders of magnitude higher than currently used radio-frequency technology, which could reduce the length of particle accelerators, with drastic influence on the development of future colliders at TeV energies and the minimization of x-ray free-electron lasers. Since interplasma components and distances are among the biggest contributors to the total accelerator length, the design of staged plasma accelerators is one of the most important outstanding questions in order to render this technology instrumental. Here, we present a novel concept to optimize interplasma distances in a staged beam-driven plasma accelerator by drive-beam coupling in the temporal domain and gating the accelerator via a femtosecond ionization laser.

Effect of positive pressure ventilation and bariatric surgery on extracellular vesicle microRNAs in patients with severe obesity and obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea (OSA) and severe obesity share a common pathophysiological phenomenon, systemic and tissue hypoxia. Hypoxaemia modifies microRNA expression, particularly, extracellular vesicles microRNAs which are involved in the progression of cardiovascular diseases, metabolic syndrome and cancer. We aim to evaluate extracellular vesicle miRNAs among patients with severe obesity with and without OSA and the effect of OSA and severe obesity treatment: continuous positive airway pressure (CPAP) and bariatric surgery. METHODS: Patients were selected from the Epigenetics Modification in Morbid Obesity and Obstructive Sleep Apnea (EPIMOOSA) study (NCT03995836), a prospective observational study of patients undergoing bariatric surgery. Patients were divided into OSA (Apnea-hyponea index (AHI) > 10) and non-OSA (AHI < 10). Patients with OSA were treated with CPAP for 6 months. Then, all patients had bariatric surgery and re-evaluated 12 months later. At each visit, blood samples were obtained for biobanking. Subsequently, extracellular vesicles were extracted, and then, miRNA expression was analysed. RESULTS: 15 patients with OSA and 9 without OSA completed the protocol. At baseline, patients with OSA showed higher miR16, miR126 and miR320 (p < 0.05) and lower miR223 expression (p < 0.05) than those without OSA. In patients with severe obesity and OSA, after 6 months with CPAP, we observed a significant decrease in miR21 (p < 0.01), miR126 (p < 0.001) and miR320 (p < 0.001), with no changes in any miRNA in patients without OSA. No changes were detected in any miRNA after 6 months of bariatric surgery in patients with or without OSA. CONCLUSION: Co-existance of OSA and severe obesity alters the profile of extracellular vesicle miRNAs. Bariatric surgery and weight loss did not reverse this effect meanwhile the treatment with CPAP in patients with severe obesity and OSA showed a recovery outcome in those extracellular vesicle miRNAs. Those facts remark the need for OSA screening in patients with severe obesity. CLINICAL TRIAL REGISTRATION: The study has also been registered at ClinicalTrials.gov identifier: NCT03995836.

Producing multi-coloured bunches through beam-induced ionization injection in plasma wakefield accelerator.

This paper discusses the properties of electron beams formed in plasma wakefield accelerators through ionization injection. In particular, the potential for generating a beam composed of co-located multi-colour beamlets is demonstrated in the case where the ionization is initiated by the evolving charge field of the drive beam itself. The physics of the processes of ionization and injection are explored through OSIRIS simulations. Experimental evidence showing similar features are presented from the data obtained in the E217 experiment at the FACET facility of the SLAC National Laboratory. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.

Betatron radiation and emittance growth in plasma wakefield accelerators.

Beam-driven plasma wakefield acceleration (PWFA) has demonstrated significant progress during the past two decades of research. The new Facility for Advanced Accelerator Experimental Tests (FACET) II, currently under construction, will provide 10 GeV electron beams with unprecedented parameters for the next generation of PWFA experiments. In the context of the FACET II facility, we present simulation results on expected betatron radiation and its potential application to diagnose emittance preservation and hosing instability in the upcoming PWFA experiments. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.

La radiación UVA-1: un nuevo aporte en la fototerapia dermatológica / Ultraviolet radiation A1 (UVA-1): therapeutic use in dermatology

La radiación ultravioleta ha sido usada durante décadas para el tratamiento de diversas enfermedades cutáneas. La radiación ultravioleta A1 (UVA-1) que tiene una longitud de onda entre los 340nm y 400 nm está disponible desde el año 1981, pero recién en las últimas dos décadas se ha estudiado, publicado y reportado su potencial uso terapéutico en la dermatología. Los primeros beneficios de su uso se reportaron en la dermatitis atópica donde se utilizaron dosis altas de UVA-1 para tratar las exacerbaciones severas de esta condición. Luego, nuevas indicaciones terapéuticas de su uso se fueron expandiendo a otras enfermedades cutáneas tales como: morfea, liquen escleroso, queratosis liquenoide, linfomacutáneo de células T y otras dermatopatías. La radiación UVA-1 al tener una longitud de onda más larga penetra a las capas más profundas de la dermis, lo que le permite una acción en la modificación de la respuesta inflamatoria, la respuesta inmunológica y los mecanismos de reparación cutánea.

Ultraviolet light radiation has been used for decades for the treatment of several cutaneous diseases. The ultraviolet radiation A1 (UVA-1) with a wave length between 340 nm-400 nm has been available since 1981, but only in the last two decades it has been studied and published for therapeutic use in dermatology. The first reported benefits of its use were reported in atopic dermatitis in which high doses of UVA-1were used to treat severe exacerbations of this condition. Thereafter, new therapeutic indications expanded its use for other cutaneous diseases like: morphea, lichen sclerosus, lichenoid keratosis, cutaneous T cell lymphoma and other skin conditions. The UVA-1 radiation has a long wavelength that make possible to reach the deep dermis and to modify the inflammatory response, immunological response and the cutaneous repair mechanisms.