Thermal and vibrational characterization of human skin

Abstract

OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible.

Radial variation in biochemical composition of the bovine caudal intervertebral disc

“…Thus, the majority of water molecules are mobile and free to diffuse out of the disc during loading or dehydration. The relative bound water content in the NP agreed well with reported values for cartilage (~4%), but the concentration of bound water in the NP and AF was lower than the concentration measured for bovine pericardium, skin, and muscle (25%‐40%) …”

“…The second endothermic peak, observed to start at temperatures as low as 65°C, is associated with collagen denaturation, where interchain hydrogen bonds rupture, causing irreversible damage to the collagen structure . Denaturation temperatures for the NP and AF were similar to each other and to other biological tissues, such as bovine pericardium, rat‐tail tendon, and human skin . The small kink observed between 65°C and 70°C (Figure —“*”) has been associated with cleavage of weak bonds between water and matrix macromolecules or conformational changes within fibrils (eg, partial fibril shrinkage), rather than breaking of stronger bonds, which occurs at a slightly higher temperature (~80°C) …”

“…In contrast, differences in the high‐frequency region (ie, >2800 cm −1 ) were easily identifiable and used to determine radial distributions of bound and free water (sometimes referred to as “mobile” or “freezable” water) . While freeze‐ or air‐drying tissue specimens is frequently used to remove free water molecules, removal of bound water is more difficult, requiring drying under very low pressures and high temperatures or chemical treatments (eg, acetone or ethanol) .…”

“…or "freezable" water). 27,[61][62][63] While freeze-or air-drying tissue specimens is frequently used to remove free water molecules, removal of bound water is more difficult, requiring drying under very low pressures and high temperatures or chemical treatments (eg, acetone or ethanol). 27,64 Hence, water content values commonly reported only refer to the amount of free water in the tissue.…”

The Skin Tissue of the Human Head Subjected to Thermal Diffusion

“…Morimoto et al [21] studied the time constants of the temperature elevations in human head and body models exposed to simulated radiation from dipole antennas, electromagnetic beams, and plane waves within frequency range considered to be from 1 to 30 GHz. Tang et al discussed the thermal and vibrational characterization of human skin to find suitable and reproducible biomarkers for further clinical studies on intrinsic and extrinsic aging of dermis [22].…”