Microwave Heating of Water, Ice and Saline Solution: Molecular Dynamics Study

In order to study the heating process of water by the microwaves of 2.5-20GHz frequencies, we have performed molecular dynamics simulations by adopting a non-polarized water model that have fixed point charges on rigid-body molecules. All runs are started from the equilibrated states derived from the I$_{c}$ ice with given density and temperature. In the presence of microwaves, the molecules of liquid water exhibit rotational motion whose average phase is delayed from the microwave electric field. Microwave energy is transferred to the kinetic and inter-molecular energies of water, where one third of the absorbed microwave energy is stored as the latter energy. The water in ice phase is scarcely heated by microwaves because of the tight hydrogen-bonded network of water molecules. Addition of small amount of salt to pure water substantially increases the heating rate because of the weakening by defects in the water network due to sloshing large-size negative ions.Comment: 21 pages, 13 figure

Molecular Chaperones and Protein Quality Control System in the Canine Model of Brain Aging and Neurodegenerative Diseases

Aged dogs naturally develop cognitive dysfunction and represent a valuable spontaneous animal model for studying normal aging and neurodegeneration. Elderly canines also share neuropathological hallmarks similar to those observed in humans, especially Alzheimer’s disease-like pathology or amyotrophic lateral sclerosis. In addition, pet dogs share similar living conditions and diets to humans. Increasing oxidative damage, as well as alterations of the intracellular protein quality control system, including ubiquitin-proteasome system (UPS) and Heat shock proteins (Hsp), have been observed in the brain of aged dogs. Thus, future researches carried out on the canine spontaneous model may be useful to define the involvement of age-related alterations in Hsp expression and UPS activity in the pathogenesis of neurodegenerative diseases, as well as to perform translational antioxidant treatment/prevention studies. The possibility to design novel therapeutic approaches, including Hspbased therapies, may help to increase chaperone protection against proteotoxic stress occurring in human and canine brain during aging