Optical Clearing of the Gastric Mucosa Using 40%-glucose Solution

Abstract

The kinetics of collimated transmittance of the gastric mucosa under the action of an aqueous 40%-glucose solution was experimentally investigated. Based on the analysis of the transmittance kinetics, the value of the effective diffusion coefficient of glucose in the gastric mucosa was estimated and amounted to (1.59±0.96)×10-6 cm 2 /s. The permeability coefficient of the mucosa for glucose, calculated using the first Fick diffusion law, was estimated as (2.81±0.90)×10-5 cm/s. It was shown that the introduction of the glucose solution into the mucosa reduced the light scattering coefficient by approximately 5-10%. The increase in the depth of light penetration was from 5% to 15%, depending on the selected spectral range. The results can be used to develop new methods of diagnosis and treatment of stomach diseases.

In vivo detection of human cutaneous beta‐carotene using computational optical clearing

“…[ 2, 19 ] Tuchin and his colleagues have presented several OC methods to control the absorption and reduced scattering of biological tissues and enhance optical depth in spectroscopic and imaging methods. [ 2, 19–21, 27, 33, 43, 44 ] In 2012, Ermakov and Gellerman applied compression OC to extract the absorbance spectroscopy of beta‐carotene. [ 19 ] The mechanical pressure causes a decrease in the value of blood content at the location of compression reducing the value of the absorption coefficient of skin.…”

“…The water transport (dehydration) and displacing blood help us to see the spectra of beta‐carotene. [ 34 ] Moreover, applying OC agent like glycerol causes an intrinsic refractive index matching may also enhance the efficacy of OC (to decrease absorbance spectra via reduction of light scattering inclusion) [ 2, 33, 34 ] and consequently reduces the parameter Δ. We obtain the relation between parameter Δ and the concentration of beta‐carotene (see Figure 3B): …”

“…that result in diffusion of water from interstitial space and partially replace the interstitial fluid (immersion OC). [ 2, 20–22, 27–29, 33, 34 ] During immersion OC, the light scattering significantly reduces and the penetration depth of light increases. Recently, we simultaneously applied compression and immersion OC using dimethyl sulfoxide (DMSO) to detect the beta‐carotene inside a two‐layer phantom containing mouse ear (top layer) and agarose‐Intralipid® (bottom layer).…”

“…[23,24] Controlling the scattering properties of skin allows us to detect the chromophore hidden by absorption spectrum of blood, melanin and water. They include compression, [2,25] stretching, [26] dehydration, [27] coagulation, [28] immersion with biocompatible chemical agents, [2,6,29] photochemical [30] and photothermal [31][32][33] OC. The scattering properties of skin can be effectively changed by action of hyperosmotic immersion optical clearing agents (OCAs) (polyatomic alcohols, dimethyl sulfoxide, benzyl alcohol, saturated solutions of saccharides [carbohydrates], etc.)…”