Effects of Music Intervention on Stress in Concussed and Non-Concussed Athletes.

Sport-related concussion is a serious public health issue affecting millions of individuals each year. Among the many negative side effects, emotional symptoms, such as stress, are some of the most common. Stress management is repeatedly cited by expert groups as an important intervention for this population. It was shown that music has relaxing effects, reducing stress through the activation of brain areas involved in emotions and pleasure. The objective of this study was to explore the effects of a music-listening intervention compared with silence on experimentally induced stress in concussed and non-concussed athletes. To this aim, four groups of athletes (non-concussed music, non-concussed silence, concussed music, and concussed silence) performed the Trier Social Stress Test, for which both physiological (skin conductance level) and self-reported stress measurements were taken. No significant difference was found in the pattern of stress recovery for self-reported measurements. However, the skin conductance results showed greater and faster post-stress recovery after listening to music compared with silence for concussed athletes only. Taken together, these results suggest that music could be an efficient stress management tool to implement in the everyday life of concussed athletes to help them prevent stress accumulation.

Size Control of Porous Silicon-Based Nanoparticles via Pore-Wall Thinning.

Photoluminescent silicon nanocrystals are very attractive for biomedical and electronic applications. Here a new process is presented to synthesize photoluminescent silicon nanocrystals with diameters smaller than 6 nm from a porous silicon template. These nanoparticles are formed using a pore-wall thinning approach, where the as-etched porous silicon layer is partially oxidized to silica, which is dissolved by a hydrofluoric acid solution, decreasing the pore-wall thickness. This decrease in pore-wall thickness leads to a corresponding decrease in the size of the nanocrystals that make up the pore walls, resulting in the formation of smaller nanoparticles during sonication of the porous silicon. Particle diameters were measured using dynamic light scattering, and these values were compared with the nanocrystallite size within the pore wall as determined from X-ray diffraction. Additionally, an increase in the quantum confinement effect is observed for these particles through an increase in the photoluminescence intensity of the nanoparticles compared with the as-etched nanoparticles, without the need for a further activation step by oxidation after synthesis.