scholarly journals Spectral Optical Properties of Rabbit Brain Cortex between 200 and 1000 nm

Photochem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 190-208
Author(s):  
Tânia M. Gonçalves ◽  
Inês S. Martins ◽  
Hugo F. Silva ◽  
Valery V. Tuchin ◽  
Luís M. Oliveira
Keyword(s):  
Optical Properties ◽  
Spectral Range ◽  
Brain Cortex ◽  
Near Infrared ◽  
Biological Tissues ◽  
Optical Methods ◽  
Brain Diseases ◽  
Rabbit Brain ◽  
Rabbit Brain Cortex ◽  
The Brain

The knowledge of the optical properties of biological tissues in a wide spectral range is highly important for the development of noninvasive diagnostic or treatment procedures. The absorption coefficient is one of those properties, from which various information about tissue components can be retrieved. Using transmittance and reflectance spectral measurements acquired from ex vivo rabbit brain cortex samples allowed to calculate its optical properties in the ultraviolet to the near infrared spectral range. Melanin and lipofuscin, the two pigments that are related to the aging of tissues and cells were identified in the cortex absorption. By subtracting the absorption of these pigments from the absorption of the brain cortex, it was possible to evaluate the true ratios for the DNA/RNA and hemoglobin bands in the cortex—12.33-fold (at 260 nm), 12.02-fold (at 411 nm) and 4.47-fold (at 555 nm). Since melanin and lipofuscin accumulation increases with the aging of the brain tissues and are related to the degeneration of neurons and their death, further studies should be performed to evaluate the evolution of pigment accumulation in the brain, so that new optical methods can be developed to aid in the diagnosis and monitoring of brain diseases.

scholarly journals Spectral Optical Properties of Rabbit Brain Cortex Between 200 and 1000 nm

2021 ◽  
Author(s):  
Tânia Gonçalves ◽  
Inês Soraia Martins ◽  
Hugo Silva ◽  
Valery Tuchin ◽  
Luís Oliveira
Keyword(s):  
Optical Properties ◽  
Spectral Range ◽  
Brain Cortex ◽  
Near Infrared ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Rabbit Brain ◽  
Rabbit Brain Cortex ◽  
Infrared Spectral ◽  
The Brain

The knowledge of the optical properties of biological tissues in a wide spectral range is highly important for the development of noninvasive diagnostic or treatment procedures. The absorption coefficient is one of those properties, from which various information about tissue components can be retrieved. Using transmittance and reflectance spectral measurements acquired from ex vivo rabbit brain cortex samples, allowed to calculate its optical properties in the ultraviolet to the near infrared spectral range. Melanin and lipofuscin, the two pigments that are related to the ageing of tissues and cells were identified in the cortex absorption. By subtracting the absorption of these pigments from the absorption of the brain cortex, it was possible to evaluate the true ratios for the DNA/RNA and hemoglobin bands in the cortex – 12.33 fold (at 260 nm), 12.02 fold (at 411 nm) and 4.47 fold (at 555 nm). Due to the fact that the accumulation of melanin and lipofuscin increases with the ageing of the brain tissues and are related to the degeneration of neurons and their death, further studies should be performed to evaluate the evolution of pigment accumulation in the brain to prevent the development of Alzheimer, Parkinson and stroke pathologies in the brain.

Optical properties of selected native and coagulated human brain tissues in vitro in the visible and near infrared spectral range

2002 ◽  
Vol 47 (12) ◽  
pp. 2059-2073 ◽  
Author(s):  
A N Yaroslavsky ◽  
P C Schulze ◽  
I V Yaroslavsky ◽  
R Schober ◽  
F Ulrich ◽  
...  
Keyword(s):  
Optical Properties ◽  
Human Brain ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Brain Tissues

scholarly journals Lipofuscin-Type Pigment as a Marker of Colorectal Cancer

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1805
Author(s):  
Sónia Carvalho ◽  
Isa Carneiro ◽  
Rui Henrique ◽  
Valery Tuchin ◽  
Luís Oliveira
Keyword(s):  
Colorectal Cancer ◽  
Optical Properties ◽  
Wavelength Dependence ◽  
Biological Tissues ◽  
Diagnostic Methods ◽  
Optical Methods ◽  
Published Data ◽  
Spectral Measurements ◽  
Absorption Bands ◽  
Colorectal Mucosa

The study of the optical properties of biological tissues for a wide spectral range is necessary for the development and planning of noninvasive optical methods to be used in clinical practice. In this study, we propose a new method to calculate almost all optical properties of tissues as a function of wavelength directly from spectral measurements. Using this method, and with the exception of the reduced scattering coefficient, which was obtained by traditional simulation methods, all the other optical properties were calculated in a simple and fast manner for human and pathological colorectal tissues. The obtained results are in good agreement with previous published data, both in magnitude and in wavelength dependence. Since this method is based on spectral measurements and not on discrete-wavelength experimental data, the calculated optical properties contain spectral signatures that correspond to major tissue chromophores such as DNA and hemoglobin. Analysis of the absorption bands of hemoglobin in the wavelength dependence of the absorption spectra of normal and pathological colorectal mucosa allowed to identify differentiated accumulation of a pigment in these tissues. The increased content of this pigment in the pathological mucosa may be used for the future development of noninvasive diagnostic methods for colorectal cancer detection.

scholarly journals Subclassification of the presynaptic α2-autoreceptors in rabbit brain cortex

1991 ◽  
Vol 103 (1) ◽  
pp. 1251-1255 ◽  
Author(s):  
Norbert Limberger ◽  
Leni Späth ◽  
Klaus Starke
Keyword(s):  
Brain Cortex ◽  
Rabbit Brain ◽  
Rabbit Brain Cortex

Optical properties of normal and cancerous human skin in the visible and near-infrared spectral range

2006 ◽  
Vol 11 (6) ◽  
pp. 064026 ◽  
Author(s):  
Elena Salomatina ◽  
Brian Jiang ◽  
John Novak ◽  
Anna N. Yaroslavsky
Keyword(s):  
Optical Properties ◽  
Human Skin ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral

scholarly journals Optical investigation of bovine grey and white matters in visible and near-infrared ranges

2021 ◽  
Vol 27 (1) ◽  
pp. 99-107
Author(s):  
Ali Shahin ◽  
Wesam Bachir ◽  
Moustafa Sayem El-Daher
Keyword(s):  
Optical Properties ◽  
Absorption Coefficient ◽  
Wavelength Range ◽  
Grey Matter ◽  
Near Infrared ◽  
Biological Tissues ◽  
Integrating Sphere ◽  
Visible Range ◽  
Optical Investigation

Abstract Introduction: Due to enormous interests for laser in medicine and biology, optical properties characterization of different tissue have be affecting in development processes. In addition, the optical properties of biological tissues could be influenced by storage methods. Thus, optical properties of bovine white and grey tissues preserved by formalin have been characterized over a wide wavelength spectrum varied between 440 nm and 1000 nm. Materials and Methods: To that end, a single integrating sphere system was assembled for spectroscopic characterization and an inverse adding-doubling algorithm was used to retrieve optical coefficients, i.e. reduced scattering and absorption coefficients. Results: White matter has shown a strong scattering property in comparison to grey matter. On the other hand, the grey matter has absorbed light extensively. In comparison, the reduced scattering profile for both tissue types turned out to be consistent with prior works that characterized optical coefficients in vivo. On the contrary, absorption coefficient behavior has a different feature. Conclusion: Formalin could change the tissue’s optical properties because of the alteration of tissue’s structure and components. The absence of hemoglobin that seeps out due to the use of a formalin could reduce the absorption coefficient over the visible range. Both the water replacement by formalin could reduce the refractive index of a stored tissue and the absence of hemoglobin that scatters light over the presented wavelength range should diminish the reduced scattering coefficients over that wavelength range.

scholarly journals Измерение оптических свойств десны и дентина человека в спектральном диапазоне 350–800 нм

2020 ◽  
Vol 20 (4) ◽  
pp. 258-267
Author(s):  
Alexey Andreevich Selifonov ◽  
◽  
Olga Anatolyevna Zyuryukina ◽  
Ekaterina Nikolaevna Lazareva ◽  
Julia Sergeevna Skibina ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectral Range ◽  
Photothermal Therapy ◽  
Diffuse Reflection ◽  
Biological Tissues ◽  
Transmission Spectra ◽  
Tissue Samples ◽  
Scattering Coefficients ◽  
Total Transmission

Knowledge of the optical properties of biological tissues is important for the development of optical diagnostics, photodynamic and photothermal therapy of various diseases. However, despite the significant number of works devoted to the determination of the optical properties of tissues, the optical properties of human gums and dentin remain currently poorly understood. In this work, we experimentally studied the optical properties of human gums and dentin in the spectral range from 350 nm to 800 nm. Basing on measured diffuse reflection and total transmission spectra and using the Inverse Adding Doubling (IAD) method, the spectral dependences of absorption and scattering coefficients of the studied tissue samples were calculated.

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