An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin c...An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin content(M),blood content(B),tissue oxygen saturation(S),water content(W),fraction of scattering due to Rayleigh scattering(f)and due to Mie scattering(1−f),and the reduced scattering coefficient at 500-nm wavelength(µs 500 nm).The sensitivity of reflectance spectra to variation in the various parameters is illustrated.展开更多
The mechanism of action of clearing agents to improve optical imaging of mouse skin during reflectance-mode confocal microscopy was tested.The dermal side of excised dorsal mouse skin was exposed for one hour to salin...The mechanism of action of clearing agents to improve optical imaging of mouse skin during reflectance-mode confocal microscopy was tested.The dermal side of excised dorsal mouse skin was exposed for one hour to saline,glycerin,or 80% DMSO,then the clearing agent was removed and the dermis placed against a glass cover slip through which a confocal microscope measured reflectance at 488 nm wavelength.An untreated control was also measured.The axial attenuation of reflectance signal,R(z_(f))versus increasing depth of focus zf behaved as R=ρexp(−μz_(f) 2G),where ρ is tissue reflectivity and μ is attenuation[cm^(−1)].The factor 2G accounts for the in/out path of photons,and the numerical aperture of the lens.The ρ,μ data were mapped to values of scattering coefficient(μ_(s)[cm^(−1)])and anisotropy of scattering(g).Images showed that glycerin significantly increased the g of dermis from about 0.7 to about 0.99,with little change in the μ_(s) of dermis at about 300cm^(−1).DMSO and saline had only slight and inconsistent effects on g and μ_(s).展开更多
The molar entropy(OS)and molar enthalpy(△H)for the denaturation event that triggers cutaneous erythema was determined to be △S=190J/(mole K)and△H=146.9×10^(3) J/mole.The experiment involved placing heated wate...The molar entropy(OS)and molar enthalpy(△H)for the denaturation event that triggers cutaneous erythema was determined to be △S=190J/(mole K)and△H=146.9×10^(3) J/mole.The experiment involved placing heated water against the skin of the forearm,for a range of termperatures and exposure times.Exposing the skin to 45℃ for 22 s was at the threshold for producing erythema,which was similar to the threshold for a slight degree of pain.展开更多
Light scattering by a tissue has a wavelength dependence that depends on the size distribution of scatterers in the tissue.By measuring the wavelength dependence of scattering,one can deduce changes in the nanoscale a...Light scattering by a tissue has a wavelength dependence that depends on the size distribution of scatterers in the tissue.By measuring the wavelength dependence of scattering,one can deduce changes in the nanoscale architecture of cells and tissues.This report discusses the connection between nanoscale architecture and measurable light scattering.The significance of this work is to develop label-free optical imaging that describes tissue structure,to complement the absorption,fluorescence,and Raman scattering spectra that describe the chemical constituents of a tissue.展开更多
基金the National Institutes of Health(RO1-HL084013).
文摘An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin content(M),blood content(B),tissue oxygen saturation(S),water content(W),fraction of scattering due to Rayleigh scattering(f)and due to Mie scattering(1−f),and the reduced scattering coefficient at 500-nm wavelength(µs 500 nm).The sensitivity of reflectance spectra to variation in the various parameters is illustrated.
基金the National Institutes of Health(R01-CA113947,R01-HL084013)in the USAsupported by the National Institutes of Health under the Ruth L.Kirschstein National Research Service Award 5-T32-CA106195-05,“Training in the Molecular Basis of Skin Pathobiology”,from the National Cancer Institute and the OHSU Cancer Institutefunded by the National Cancer Institute,CA-069533.
文摘The mechanism of action of clearing agents to improve optical imaging of mouse skin during reflectance-mode confocal microscopy was tested.The dermal side of excised dorsal mouse skin was exposed for one hour to saline,glycerin,or 80% DMSO,then the clearing agent was removed and the dermis placed against a glass cover slip through which a confocal microscope measured reflectance at 488 nm wavelength.An untreated control was also measured.The axial attenuation of reflectance signal,R(z_(f))versus increasing depth of focus zf behaved as R=ρexp(−μz_(f) 2G),where ρ is tissue reflectivity and μ is attenuation[cm^(−1)].The factor 2G accounts for the in/out path of photons,and the numerical aperture of the lens.The ρ,μ data were mapped to values of scattering coefficient(μ_(s)[cm^(−1)])and anisotropy of scattering(g).Images showed that glycerin significantly increased the g of dermis from about 0.7 to about 0.99,with little change in the μ_(s) of dermis at about 300cm^(−1).DMSO and saline had only slight and inconsistent effects on g and μ_(s).
文摘The molar entropy(OS)and molar enthalpy(△H)for the denaturation event that triggers cutaneous erythema was determined to be △S=190J/(mole K)and△H=146.9×10^(3) J/mole.The experiment involved placing heated water against the skin of the forearm,for a range of termperatures and exposure times.Exposing the skin to 45℃ for 22 s was at the threshold for producing erythema,which was similar to the threshold for a slight degree of pain.
文摘Light scattering by a tissue has a wavelength dependence that depends on the size distribution of scatterers in the tissue.By measuring the wavelength dependence of scattering,one can deduce changes in the nanoscale architecture of cells and tissues.This report discusses the connection between nanoscale architecture and measurable light scattering.The significance of this work is to develop label-free optical imaging that describes tissue structure,to complement the absorption,fluorescence,and Raman scattering spectra that describe the chemical constituents of a tissue.
