RESUMO
Water, being the universal solvent, acts as a competing agent in fundamental processes, such as folding, aggregation or biomolecular recognition. A molecular understanding of hydrophobic hydration is of central importance to understanding the subtle free energy differences, which dictate function. Ab initio and classical molecular dynamics simulations yield two distinct hydration water populations in the hydration shell of solvated tert-butanol noted as "HB-wrap" and "HB-hydration2bulk". The experimentally observed hydration water spectrum can be dissected into two modes, centered at 164 and 195 cm-1. By comparison to the simulations, these two bands are attributed to the "HB-wrap" and "HB-hydration2bulk" populations, respectively. We derive a quantitative correlation between the population in each of these two local water coordination motifs and the temperature dependence of the solvation entropy. The crossover from entropy to enthalpy dominated solvation at elevated temperatures, as predicted by theory and observed experimentally, can be rationalized in terms of the distinct temperature stability and thermodynamic signatures of "HB-wrap" and "HB-hydration2bulk".
RESUMO
This study aimed to evaluate the efficacy of low-tech augmentative and alternative communication (AAC) aids in improving quality of life (QoL) and mood disorders, as well as the psychosocial impact of assistive devices, in 10 patients affected by amyotrophic lateral sclerosis (ALS) in the early stage of the disease, when speech difficulties appear. The AACtraining (AAC-T) study lasted around six months and comprised two phases of three months each: AAC-intervention (AAC-I) followed by AAC-familiarization (AAC-F). All the patients were assessed at the beginning (T0) and at the end (T1) of AAC-I, as well as at the end of AAC-F (T2). During the AAC-I phase, we applied a three-phase AAC intervention model to evaluate intelligibility of language, participation patterns, communication needs and adaptation to the AAC tools. All the patients showed a gradual and significant improvement, especially in acceptance of the AAC aids, mood and QoL. Moreover, a reduction of caregiver burden was noted. Our study has demonstrated the utility of the AAC aids also in the early stages of the disease in patients with ALS presenting with dysarthria. In our opinion, AAC-T may act as a bridge between the initial and later phases of the disease, when patients need to use high-tech aids, including an eye-tracking communication device. In conclusion, in this study we highlighted how early AAC-T in patients with ALS may be a valuable tool to demonstrate how specific strategies and low-technology aids can improve QoL of these patients and their caregivers, also decreasing stress and depression.