Cutaneous streptococcal abscess treated by photodynamic therapy

Background: Photodynamic therapy has been investigated in different areas of health through experimental conditions. Its action can alter fundamental structures for the survival of microorganisms without any development of microbial resistance.Materials and Methods: Young sheep presenting with abscess in the left forelimb caused by Streptococcus spp. was previously treated with antibiotics. There was no clinical improvement with the treatments, and the bacteria presented sensitivity in vitro. Therefore, Photodynamic therapy associating methylene blue and red laser (660 nm) was used to treat the abscess.Results: After a day of treatment, complete healing was witnessed with no recurrence was observed during the 3-month follow-up period.Conclusion: The scientific results of the antimicrobial effect of PDT proved to be a therapeutic option with great potential for clinical application.Keywords: Photoinactivation, Laser, Sheep, Streptococcus spp

Fluorescent bicolour sensor for low-background neutrinoless double β decay experiments

Observation of the neutrinoless double β decay is the only practical way to establish that neutrinos are their own antiparticles. Because of the small masses of neutrinos, the lifetime of neutrinoless double β decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double β decay. The most robust identification of neutrinoless double β decay requires the definition of a signature signal—such as the observation of the daughter atom in the decay—that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double β decay of Xe could be established by detecting the daughter atom, Ba, in its doubly ionized state. Here we demonstrate an important step towards a ‘barium-tagging’ experiment, which identifies double β decay through the detection of a single Ba ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba dication would be captured by one of the molecules and generate a Ba-coordinated species with distinct photophysical properties. The presence of such a single Ba-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba ions in high-pressure xenon gas detectors for barium-tagging experiments.We also acknowledge support from the following agencies and institutions: the European Research Council (ERC) under Advanced Grant 339787-NEXT; the Ministry of Science and Innovation of Spain and FEDER under grants FIS2014-53371-C04, FIS2016-76163-R, MAT2016-78293-C6-5-R, MINECO/FEDER CT2016-80955-P, CTQ2016-80375-P and CTQ2014-51912-REDC; Interred PCTEFA V-A Spain/France/Andorra Program (EFA 194/16/TNSI); the Basque Government (GV/EJ) under grants IT-1346-19 and IT-1180-19; andAgencia de Ciencia y Tecnología de la Región de Murcia (19897/GERM/15). The authors also thank the SGI/IZO-SGIker UPV/EHU, Fundación Séneca and DIPC for computational and analytical resources