Noninvasive spectral imaging of skin chromophores based on multiple regression analysis aided by Monte Carlo simulation

In order to visualize melanin and blood concentrations and oxygen saturation in human skin tissue, a simple imaging technique based on multispectral diffuse reflectance images acquired at six wavelengths (500, 520, 540, 560, 580 and 600 nm) was developed. The technique utilizes multiple regression analysis aided by Monte Carlo simulation for diffuse reflectance spectra. Using the absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are deduced numerically in advance, while oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments with human skin of the human hand during upper limb occlusion and of the inner forearm exposed to UV irradiation demonstrated the ability of the method to evaluate physiological reactions of human skin tissue.     

Another formulation of Euler's formula and its application

This note gives an alternative formulation of Euler's formula.     

High resolution study of24Mg(p,d)23Mg for the Ne-E problem

Nuclear levels of²³Mg near and above the proton threshold were investigated with high resolution. A new level has been identified at 7.643 MeV (66 keV above the proton threshold) with a possible J=(3/2, 5/2)⁺. Some other spin-parity and excitation-energy assignments are also made. These results enable the reaction rate estimate of²²Na(p,)²³Mg with much smaller uncertainties, which is critical for the Ne-E problem in nuclear astrophysics.     

A different approach to the generalized coherent-potential aproximation; Multiple scattering formalism

The single site coherent-potential approximation (SCPA) is generalized in order to treat effects due to clusterization of scatterers, off-diagonal disorder, crystal field and/or short range order. Present formalism is a straightforward generalization of Soven's original method i.e. the multiple scattering formalism by which he derived the SCPA.     

Electronic structure and metal-nonmetal transition in liquid Cs−Sb and Cs−I systems

The electronic structures of liquid Cs–Sb and liquid Cs–I systems have been calculated using the self-consistent semirelativistic APW method within the superlattive model. We have investigated the nature of chemical bonding in connection with the composition dependent metal-nonmetal transition in these systems. It is found that Cs–Sb system is principally ionic as well as Cs–I system, but appreciable admixture of the metallic bonding is observed; this explains the different behavior between the two systems in their composition-induced metal-nonmetal transitions.     

CPA conductivity of a binary alloy with off-diagonal disorder

D.c.-conductivity of a binary alloy A_xB_y with off-diagonal disorder is calculated, assuming Shiba's condition for the random transfer integrals, by means of a modified CPA, i.e.,the renormalization propagator formalism developed elsewhere by one of the authors (K.N.).     

Visualizing of skin chromophore concentrations by use of RGB images

A method is proposed for visualizing simply the concentrations of melanin, oxygenated blood, and deoxygenated blood in skin tissue using digital RGB images. The total blood concentration and oxygen saturation can also be reconstructed. Monte Carlo simulation of light transport specifies a relation between the chromophore concentrations and Commission Internationale de l'Eclairage XYZ, which are compatible with the common RGB working space. Experiments with a tissuelike agar gel phantom demonstrated the possibility of the method. In vivo imaging of a human hand during forearm occlusion demonstrated the ability of the method to evaluate hemodynamics of skin tissue.