scholarly journals Оптическое просветление кожи человека in vivo рядом моносахаридов

2019 ◽  
Vol 127 (8) ◽  
pp. 329
Author(s):  
К.В. Березин ◽  
К.Н. Дворецкий ◽  
М.Л. Чернавина ◽  
В.В. Нечаев ◽  
А.М. Лихтер ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Rate Of Change ◽  
Scattering Coefficient ◽  
Optical Clearing ◽  
Collagen Peptide ◽  
Cleaning Agents ◽  
Optical Immersion

AbstractWe present the results of in vivo optical immersion clearing of human skin by aqueous solutions of some immersion agents (ribose, glucose, and fructose monosaccharides and glycerol), obtained using optical coherence tomography (OCT). To assess the efficiency of optical clearing, we determined the values of the rate of change of the light scattering coefficient, obtained using the averaged A-scan of the OCT signal in the derma section at a depth of 350–700 μm. A good correlation was observed between the rate of change of the light scattering coefficient and the potential of the optical clearing. Using complex molecular simulation of the interaction of a number of immersion clearing agents with collagen mimetic peptide (GPH)_3 using classical molecular dynamics and quantum chemistry, we found correlations between the efficiency of optical clearing and the energy of intermolecular interaction of cleaning agents with a fragment of collagen peptide.

scholarly journals Molecular modeling of post-diffusion stage of biotissue optical clearing under effect of iohexol aqueous solution

2021 ◽  
Vol 2103 (1) ◽  
pp. 012048
Author(s):  
I T Shagautdinova ◽  
A M Likhter ◽  
K V Berezin ◽  
K N Dvoretsky ◽  
V V Nechaev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Molecular Modeling ◽  
Biological Tissues ◽  
Optical Clearing ◽  
X Ray ◽  
Diffusion Stage ◽  
Collagen Peptide ◽  
Main Components

Abstract Interaction of iohexol (Omnipaque), an X-Ray contrast agent, with a mimetic peptide of collagen (GPH)3 as one of the main components of biological tissues has been studied with the use of methods of classical molecular dynamics (GROMACS). Complex molecular modeling of the post-diffusion stage of optical clearing allowed to evaluate such parameters as the average number of hydrogen bonds, formed between the clearing agent and collagen per unit time, and the immersion agent’s effect on changes in the collagen peptide volume. The obtained results are compared with similar results for glycerol, a polyatomic alcohol, and with the existing experimental data on the efficiency of optical clearing of these immersion agents.

scholarly journals Imaging depth extension of optical coherence tomography in rabbit eyes using optical clearing agents

2020 ◽  
Vol 245 (18) ◽  
pp. 1629-1636
Author(s):  
Ruiming Kong ◽  
Wenjuan Wu ◽  
Rui Qiu ◽  
Lei Gao ◽  
Fengxian Du ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Ex Vivo ◽  
Light Attenuation ◽  
Anterior Segment ◽  
Posterior Segment ◽  
Glycerol Solution ◽  
Optical Coherence ◽  
Optical Clearing ◽  
Imaging Depth

Optical coherence tomography has become an indispensable diagnostic tool in ophthalmology for imaging the retina and the anterior segment of the eye. However, the imaging depth of optical coherence tomography is limited by light attenuation in tissues due to optical scattering and absorption. In this study of rabbit eye both ex vivo and in vivo, optical coherence tomography imaging depth of the anterior and posterior segments of the eye was extended by using optical clearing agents to reduce multiple scattering. The sclera, the iris, and the ciliary body were clearly visualized by direct application of glycerol at an incision on the conjunctiva, and the posterior boundary of sclera and even the deeper tissues were detected by submerging the posterior segment of eye in glycerol solution ex vivo or by retro-bulbar injection of glycerol in vivo. The ex vivo rabbit eyes recovered to their original state in 60 s after saline-wash treatment, and normal optical coherence tomography images of the posterior segment of the sample eyes proved the self-recovery of in vivo performance. Signal intensities of optical coherence tomography images obtained before and after glycerol treatment were compared to analysis of the effect of optical clearing. To the best of our knowledge, this is the first study for imaging depth extension of optical coherence tomography in both the anterior and posterior segments of eye by using optical clearing agents.

CHARACTERIZATION OF VITILIGO BY IN VIVO SCATTERING COEFFICIENT OF HUMAN SKIN

2011 ◽  
Vol 04 (01) ◽  
pp. 67-72 ◽  
Author(s):  
WANRONG GAO ◽  
PENG LEE ◽  
XIANLING ZHANG
Keyword(s):  
Optical Coherence Tomography ◽  
Human Skin ◽  
Experimental Results ◽  
Scattering Coefficient ◽  
Optical Coherence ◽  
Scattering Coefficients ◽  
Significant Difference

Scattering coefficients of human skin in vivo with and without vitiligo were measured with optical coherence tomography (OCT). The experimental results show that there exist significant difference between the scattering coefficient of the epidermis of in vivo human skin with and without vitiligo disease. The results may be helpful for quantitatively diagnosing or evaluating the treatment of the disease.

scholarly journals Early detection of enamel demineralization by optical coherence tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Meng-Tsan Tsai ◽  
Yen-Li Wang ◽  
Ting-Wei Yeh ◽  
Hsiang-Chieh Lee ◽  
Wen-Ju Chen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Optical Coherence Tomography ◽  
Early Stage ◽  
Scattering Coefficient ◽  
Tooth Surface ◽  
Acidic Environment ◽  
Optical Coherence ◽  
Tooth Demineralization

AbstractEnamel is the outermost layer of the tooth that protects it from invasion. In general, an acidic environment accelerates tooth demineralization, leading to the formation of cavities. Scanning electron microscopy (SEM) is conventionally used as an in vitro tool for the observation of tooth morphology changes with acid attacks. Yet, SEM has intrinsic limitations for the potential application of in vivo detection in the early demineralization process. In this study, a high-resolution optical coherence tomography (OCT) system with the axial and transverse resolutions of 2.0 and 2.7 μm in teeth has been utilized for characterizing the effect of the acidic environment (simulated by phosphoric acid) on the enamel topology. The scattering coefficient and the surface roughness of enamel can be directly derived from the OCT results, enabling a quantitative evaluation of the topology changes with demineralization. The dynamic process induced by the acid application is also recorded and analyzed with OCT, depicting the evolution of the demineralization process on enamel. Notably, the estimated enamel scattering coefficient and surface roughness significantly increase with the application time of acid and the results illustrate that the values of both parameters after demineralization are significantly larger than those obtained before the demineralization, illustrating both parameters could be effective to differentiate the healthy and demineralized teeth and determine the severity. The obtained results unambiguously illustrate that demineralization of the tooth surface can be successfully detected by OCT and further used as an indicator of early-stage cavity formation.

ALTERATIONS IN AUTOFLUORESCENCE SIGNAL FROM RAT SKIN EX VIVO UNDER OPTICAL IMMERSION CLEARING

2010 ◽  
Vol 03 (03) ◽  
pp. 147-152 ◽  
Author(s):  
E. V. MIGACHEVA ◽  
A. B. PRAVDIN ◽  
V. V. TUCHIN
Keyword(s):  
Fluorescence Spectroscopy ◽  
Ex Vivo ◽  
Rat Skin ◽  
Optical Clearing ◽  
Spectral Curves ◽  
The Common ◽  
First Time ◽  
Tissue Optical Clearing ◽  
Optical Immersion

For the first time, the changes in autofluorescence spectra of ex vivo rat skin have been experimentally investigated using the combination of fluorescence spectroscopy and optical immersion clearing. The glucose, glycerol and propylene glycol solutions were used as clearing agents. The optical clearing was performed from the dermal side of skin imitating the in vivo injection of clearing agent under the dermal layers. In this contribution, the common properties of autofluorescence variation during optical immersion clearing were determined. The tendency of autofluorescence signal to decrease with reduction of scattering in tissue was noticed and discussed in detail. However, the differences in the shape of spectral curves under application of different clearing agents showed that optical clearing affects the autofluorescence properties of tissue differently depending on the type of clearing liquid. The results obtained are useful for the understanding of tissue optical clearing mechanisms and for improving techniques such as fluorescence spectroscopy.

scholarly journals Мониторинг процесса иммерсионного оптического просветления коллагеновых волокон с помощью оптической когерентной томографии

2019 ◽  
Vol 127 (8) ◽  
pp. 337
Author(s):  
М.Е. Швачкина ◽  
Д.Д. Яковлев ◽  
Е.Н. Лазарева ◽  
А.Б. Правдин ◽  
Д.A. Яковлев
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Properties ◽  
Biological Tissues ◽  
Dehydration Process ◽  
Immersion Liquid ◽  
Reliable Technique ◽  
Optical Clearing ◽  
Osmotic Effect

AbstractFuture development of the method of immersion optical clearing of biological tissues—this method is widely used in the study of the morphology and pathologies of tissues in vitro and considered promising for in vivo applications in biophysical research and medicine—requires knowledge of the details of interaction of immersion liquids with the tissue, in particular, the characteristics both of the tissue dehydration process, which is caused by the osmotic effect of the immersion liquid, and the process of diffusion of the immersion agent (IA) into the tissue. The optical properties of skin dermis, eye sclera, tendon, and many other tissues are determined by the properties of collagen bundles, abundant in these tissues. In the present work, a convenient and reliable technique for monitoring the optical properties and geometry of collagen bundles in the course of their immersion clearing in vitro, based on optical coherence tomography (OCT), is proposed. The main advantage of this technique is that it allows one to monitor changes in the geometric and optical properties of the tissue simultaneously, without interrupting the natural course of the immersion clearing process, and to obtain reliable estimates of the characteristic times and rates of both the process of tissue dehydration and process of diffusion of the IA into the tissue.

scholarly journals Decorrelation Time Analysis Using Dynamic Light Scattering with Optical Coherence Tomography in an in vivo Mouse Tumour Model

2021 ◽  
Author(s):  
Timothy Wan Hei Luk
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Near Infrared ◽  
Imaging Modality ◽  
Preclinical Study ◽  
Infrared Light ◽  
Target Tissue ◽  
Optical Coherence

Optical coherence tomography (OCT) is an imaging modality that uses near infrared light interferometry for non-invasive, near-histological resolution imaging at the micron level. Concepts from dynamic light scattering (DLS) can be adapted to OCT to detect and measure the motions in the target tissue. Tissue dynamics can be observed by measuring the speckle decorrelation time (DT) of the tissue. DT analysis was performed in a preclinical study to demonstrate the repeatability and feasibility of using DLS-OCT to observe mouse tumours undergoing cisplatin treatment over a 48-hour period. Differences in the average DT data were observed for control and cisplatin-injected mice. Image segmentation based on DT values was also performed to subtract the DT contributions of pixels at blood vessel locations, resulting in the improvement of average DT calculations of the tumour tissue. The results presented are a preliminary step to analyzing and monitoring tumour growth and treatment response in vivo.

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