A New Model of Salivary Pacemaker-A Proof of Concept and First Clinical Use.

Background and Objectives: Saliva is of utmost importance for maintaining oral health. Management of saliva flow rate deficiency recently includes salivary neuro-electrostimulation. The aim of this paper is to present a new model of salivary pacemaker-the MICROSAL device (MD), an intelligent, miniaturized, and implant-supported oral device used for salivary stimulation. Materials and Methods: This report presents the development, calibration, and first clinical tests which involved the MD. The novel features of this device are the pH sensor and the fact that it communicates with the patient's smartphone, where oral wetness and pH are graphically exposed. Saliva samples were taken before and after the MD was used on a 68-year-old patient suffering from post-irradiation xerostomia, and albumin and total protein were analyzed. Results: The device uses up to 3 V and time intervals of 2 s seconds for stimulation. The total volume of all saliva samples collected during the clinical trial was almost seven times higher after the device was used. Albumin decreased from a maximum of 0.15 g/dL to 0.04 g/dL, and total proteins from 0.65 g/dL to 0.21 g/dL, after salivary stimulation. Conclusions: The MD increased saliva secretion of the patient, and we are confident it will be a good solution for future management of salivary gland hypofunction.

Paraffin-Multilayer Graphene Composite for Thermal Management in Electronics.

Multilayer graphene-paraffin composites with different contents of graphene (0-10 wt.%) were prepared using an ultra-high shear mixer. The aim is to improve the heat transfer in paraffin wax, which will lead to more-efficient thermal buffering in electronic applications. The multi-layer graphenes obtained by supercritical fluid exfoliation of graphite in alcohol were investigated by Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Interesting morphological features were found to be related to the intercalation of paraffins between the multilayer graphene flakes. Thermal properties were also investigated in terms of phase change transition temperatures, latent heat by differential scanning calorimetry and thermal conductivity. It was found that the addition of graphene resulted in a slight decrease in energy storage capacity but a 150% improvement in thermal conductivity at the highest graphene loading level. This phase-change material is then used as a thermal heat sink for an embedded electronic processor. The temperature of the processor during the execution of a pre-defined programme was used as a performance indicator. The use of materials with multilayer graphene contents of more than 5 wt.% was found to reduce the processor operating temperature by up to 20%. This indicates that the use of such composite materials can significantly improve the performance of processors.