This PDF file contains the front matter associated with SPIE Proceedings Volume 11457, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

Macroscopic fluorescence spectroscopy parameters of colon benign and malignant tissues were obtained with spectrofluorimeter FluoroLog 3 (HORIBA Jobin Yvon, France). Investigated biological tissue samples were excised during standard surgical procedure for tumour removal, with cancerous and healthy tissue and the measurements are performed as soon as possible after the excision. The tissue samples were stored in safe-keeping perfusion solution and isothermal conditions and transported from the hospital to the spectroscopy laboratory. The fluorescence spectroscopy measurements were performed for excitation wavelengths in the range of 280-440 nm, with 10 nm increment step, and emission was detected in the range of 300-800 nm for the healthy and cancerous areas of the sample with a step of 1 nm.

Micro-spectroscopy was performed with confocal laser scanning microscopy system using 405 nm excitation for fluorescence images of tissue pathologies. We had used a Leica TCS SP system (Leica Inc.). Images were acquired using a 40x magnification objective with a numerical aperture of 0.75. In Lambda-scan regime the spectral data about the selected areas of normal and abnormal tissue sites were obtained and compared. A spectral and image detection in the range of 420-680 nm had place. Fixed tissue samples are unstained, deparaffinized and rehydrated histology tissue slides. Comparison between the evaluated optical macro and micro spectroscopy parameters and their value for clinical application of autofluorescence spectroscopy in cancer diagnosis are presented and discussed.

The paper is devoted to a new method of time-domain lifetime fluorescence molecular tomography. It is based on the use of early arriving diffuse photons and original measurement data, which are determined for the individual time gates of the diffuse temporal responses for fluorescence and exiting radiation. The paper presents in short the theoretical foundation of the method and describes a numerical experiment on the separate reconstruction of fluorophore absorption coefficient and fluorescence lifetime for 3D reflectance geometry that is suitable for small animal imaging. We show our first reconstruction results for the 3D scattering object region 11×11×8 mm³ in size with two spherical fluorescent inclusions 1 mm in diameter. The ways how to improve these results in the future are discussed.

Determining cutaneous carotenoid plays an important role in the human health and nutrition studies. Recently, compression optical clearing (OC) was applied to detect dermal carotenoid using reflection spectroscopy. This study aims to improve compression OC to detect the absorption spectrum of beta-carotene inside the human dermal skin. We utilize a combination of experimental (including compression-immersion OC) and computational OC to enhance the ability of reflectance spectroscopy to detect the beta-carotene inside palm of hand. The presented OC techniques can be applied for determining chromophores, such as melanin and bilirubin that have good abilities for nutrition and oncology researches.

Light-tissue interactions caused by cardiac pulses in blood vessels and tissue boundaries give rise to several pulse components in the measurement volume of a diffused optical signal. These pulses can be used to reconstruct the optical waveform and to estimate such phenomenon as arterial stiffness. Commonly, this is done by using so called pulse decomposition analysis. In functional near-infrared spectroscopy (fNIRS) based brain studies cardiac pulses are typically low pass filtered as an artefact, because normally of interest are low frequency fluctuations in fNIRS signal that reflect neural activations. Here we focus on analysis on the cardiac pulse that is usually visible in unfiltered fNIRS signals measured from the brain and propose the use of fNIRS and pulse decomposition analysis for in vivo assessment of brain tissue stiffness. We study possibilities to distinguish different wave components from the cardiac pulse in fNIRS signal when measuring the brain cortex using source-detector separation distance of 3 cm. Since cardiac pulses, particularly central artery pulse, and blood pressure changes cause pulsatile motion in the brain tissue we hypothesize that this pulsation can reflect brain tissue stiffness and/or changes in intracranial pressure (ICP), which are important parameters for brain health. Further, this analysis technique could be eventually utilized in diagnostics of brain disorders, for instance, brain edema and neurodegeneration related disorders such as dementia.

Skin Carcinoma is one of the most frequent and spreaded type of skin cancers. Its diagnosis and the resulting surgical treatment are complicated due to the lack of precise surgical margin delineation approaches. Optical methods are very promising and effective tools for bringing a clinically compatible solution to this problem because of their non-invasive principles and high informativity. Spatially Resolved Multi-Modal Spectroscopy (SRMMS) provide in vivo information with depth resolution about cancer specific features with high precision by analyzing skin Diffuse Reflectance and and Autofluorescence spectra at specific locations on tissue. Due to multiple light scattering, absorption and reflectance of the photons in the biological tissue it results in very poor photons penetration into the deeper areas and, consecutively, low depth sensitivity. Potential solution of this problem is optical clearing technology. In this work, we analyzed the time kinetics of DR and multiply excited AF spectra collected on an ex vivo skin strip on top of ex vivo skin/gel hybrid model following topical application of OCA at 4 different acquisition distances and 5 different excitation wavelengths. We then investigated the possible impact of probe pressure as well as drying of the skin sample on the spectroscopic signals, besides the optical clearing effect. The results obtained showed that the studied OCA solutions reduced autofluorescence of the skin and improved the depth sensitivity of the spectroscopy applied to the skin. Another notable effect is the strong increasing of collected exogenous fluorescence of a bottom layer in a “dry” conditions.

As was shown earlier in the animal experiments, compression optical coherence elastography (OCE) is a highly sensitive method for studying the morphological features of biological tissues. An attempt was made to study the possibilities of the OCE method for identifying and differentiating from each other various morphological structures in human tissues. Postoperative samples of human breast cancer and human colon cancer were studied. Histological examination identified areas of morphological structures - (I) adipose tissue, (II) stroma and (III) tumor tissue in breast cancer samples; and areas of (I) mucous membrane and (II) tumor tissue in colon cancer samples. For these areas, an accurate comparison was made with OCE images and stiffness ranges for morphological structures were obtained. This observation allows us to make a conclusion that OСE can be a promising method for studying the structure of human tissue in clinics.

The article describes the development of the optical phantom mimicking flavin adenine dinucleotide (FAD) and skin collagen fluorescence. The results of experimental studies using fluorescence imaging and fluorescence spectroscopy methods are demonstrated. The method of optical phantom production for quick calibration of fluorescence imaging devices for further application in clinical practice is proposed.

This study presents results on application of compressional optical coherence elastography (OCE) for visualization of a transitional zone between peri-tumoral (normal) and tumor region of breast tissue. The assessment of non-tumor/tumor regions is made based on percentage of pixels with different characteristic stiffness (“stiffness spectrum”) in the OCE image, also taking into account spatial localization of different-stiffness regions. The OCE-based stiffness maps and corresponding histograms of normalized stiffness spectrum demonstrate clear the boundary between normal (peritumoral) tissue and an invasive tumor. The normal breast tissue is fairly heterogeneous on the OCE images with increased stiffness in the region of the lobular structures and lower stiffness in the surrounded soft fibrous and especially adipose tissue of the mammary gland. The invasive breast cancer includes mechanically more dense stiffer accumulations of tumor cells, as well as less stiffer hyalinized tumor stroma. The corresponding histograms of stiffness show clearly dominating and ever increasing percentage of stiff regions in the tumor tissue showing gradually diminishing share of the normal stromal component in tissue. Thus, analysis of the so-obtained normalized histograms (“stiffness spectrum”) may be used to assess the negative surgical margin of resection in the future.

Minimal erythema dose (MED) is the amount of ultraviolet (UV) radiation needed to induce a mild skin erythema reaction after 24 hours following exposure. Determination of MED is based on the assessment of UV-erythema and traditionally performed visually by naked eye, which is subjective and connected with errors due to high intrarater and interrater variability. The application of non-invasive and quantitative techniques such as optical methods could improve MED calculation, allowing us to detect and quantify alterations in epidermis and dermis induced by UV irradiation. In the current study the analysis of microcirculation parameters by non-invasive optical methods revealed the relationship between the oxygen consumption and a dose of UV radiation. Results also showed the correlation of oxygen consumption of UV-exposed tissues normalized to intact skin with a dose of UV. Moreover, we described tendencies in dynamics of porphyrin fluorescence intensity at different time points after UV-exposure. Optical methods have some prospects in non-invasive and predictive evaluation of UV erythema and MED and more research should be conducted in this field.

A method, based on optical coherence angiography (OCA), for the intraoperative diagnosis of blood microcirculation in the ischemic intestine has been tested. The pilot clinical study involved 18 patients who had undergone urgent operations for thrombosis of segments II or III of the superior mesenteric artery, as well as for infringement of the bowel and the mesenteric vessels. In the OCA images regions of preserved blood microcirculation in the intestinal wall were characterized by the presence of branched networks of intramural microvessels and a bright background in the OCA images. Regions of the intestine in which the intramural vessels were interrupted or could not be visualized were considered as potentially non-viable. These data were used to determine the boundaries for intestinal resection. In comparison with the traditional method of intraoperative diagnosis of intestinal blood flow, the use of such OCA criteria meant the volume of bowel resection could be decreased by 21.5 [14.1; 36.0]% (p = 0.037). This observation demonstrates the great potential of OСA in the intraoperative detection of the boundaries of damaged and healthy intestinal wall in ischemic bowel disease.

Chronic hyperglycemia in diabetes mellitus (DM) is the pathogenetic basis for the occurrence and development of macro- and microvascular disorders, which provoke the development of retinopathy, nephropathy and cause the accelerated development of atherosclerosis with damage to the coronary, cerebral and peripheral vessels. This determines the relevance of developing new methods for the correction of disorders of carbohydrate metabolism, including nonpharmacological ones. Using the method of laser Doppler flowmetry, microcirculation disorders in rats caused by alloxan insulin deficiency were studied. Disruption of microcirculation was manifested by a decrease in perfusion index on the skin of the dorsum of the foot in combination with a decrease in the normalized amplitudes of endothelial and neurogenic oscillations. An animals that have non-pharmacological correction (autotransplantation of the skin flap) of carbohydrate metabolism disorders, an increase in perfusion index relative to the comparison group was observed on day 42 of the experiment, indicating an improvement in microcirculation. An increase in the normalized amplitudes of endothelial and neurogenic oscillations relative to the comparison group was also noted. The data obtained allow us to conclude that the use of laser Doppler fluometry in the study of the functional state of the microvasculature and the diagnosis of vascular complications of diabetes is very promising.

When administered into the bloodstream, upconversion nanoparticles used in therapeutic / diagnostic purposes can affect red blood cells. In this work, using light optical microscopy, we show that the removal of citrate groups from the surface of NaYF₄: Er³⁺ , Yb³⁺ nanoparticles synthesized by the hydrothermal method prevents the formation of large clod-like aggregates from a suspension of washed rat erythrocytes incubated with the nanoparticles. However, the tendency toward a change in cell shape with an increase in nanoparticles concentration is still manifested.

The present work demonstrates the temperature dependences of the spectral characteristics of the skin measured in vitro. Changes in the spectral characteristics of the rat skin upon skin heat treatment at elevated temperatures have been characterized. The spectra were recorded with a stepwise increase in temperature in the range of 25-70ºC, as well as in the process of keeping the sample at a fixed temperature for 60 min. The dynamics of the changes in collimated transmittance of rat skin is shown to be temperature-dependent. It is assumed that the changes in spectral characteristics of the skin might be caused by changes in the size and refractive index of the scatterers.

The ubiquitin-proteasome system is a major protein degradative pathway involved in the maintenance of cellular structure and function. Actin cytoskeleton plays a critical role in the morphology and structural changes of the nerve cells. Cofilin is a main regulator of actin filament assembly/disassembly. Many diseases of the nerve system are associated with actin-cofilin remodeling. Nevertheless, the role of ubiquitylation in the regulation of cofilin activity and actin cytoskeleton structure in the nerve cells is little investigated. Confocal fluorescence microscopy-based methods are valuable tools for the precise imaging and quantitative evaluation of actin cytoskeleton changes. The aim of this research was to analyze the effect of a proteasome inhibitor MG132 on actin cytoskeleton remodeling in the nerve cells using fluorescence imaging. Cofilin was shown to be colocalized with actin filaments and ubiquitin in hippocampal cells. Analysis of cofilin proteoforms revealed the presence of cofilin modified by K63-linked multiubiquitin chains. The treatment of hippocampal cells with MG132 led to the changes in the structure of actin cytoskeleton, expression of cofilin, and activation of autophagy. Therefore, the results suggest the relationship between cofilin ubiquitylation and actin cytoskeleton remodeling in the nerve cells. It may be important for the development of new methods of diagnosis and treatment of the nerve system disorders.

Leukocytes are the main cells of immune system, but also contribute to other systems and participate in pathogenesis of different diseases. In particular, leukocytes are involved in the progression of diabetic retinopathy due to their hyperactivation in diabetes. However, a connection between diabetes and the dysfunction of leukocytes is poorly understood. For a more complete picture, studies of the leukocytes activation under the influence of various substances are necessary. Arachidonic acid (AA) and its metabolites are the strongest activating factors of leukocytes. However, the studies involving AA are complicated because it is water-insoluble. Here we describe the method to study activation using photolabile analogs of AA.

Dystrophic diseases of the vulva represent a large group of dermatoses. The clinical picture of these lesions is often nonspecific, and non-invasive diagnosis is ineffective. The in vivo diagnosis of dystrophic diseases is difficult due to the lack of informative imaging methods for examining the vulvar mucosa. The new method of multimodal optical coherence tomography (OCT) is a non-invasive approach for biological tissues visualization with high spatial resolution, which does not require contrasting agents. Here we report the application of multimodal OCT to in vivo study the vulvar mucosa structure and its lymphatic and blood microcirculation. Multimodal OCT showed that normally the mucous membrane of the vulva has a good blood supply and a well-developed lymphatic vessels network. The difference in the diameter of the vessels in depth is clearly traced. In the subepithelial zone, only blood capillary loops are visualized. Lymphatic capillaries are visualized starting from submucosa.

In this report, the influence of C. psittaci (CP) antigens on the process of a development of a malignant solid tumor in the inbred Wistar white rats in experimental conditions has been successfully studied. Velocity of growing of a tumor has been estimated by s-LASCA technique. Measurement of statement of a tumor has been performed daily after each of three serial injections of the CP specific ornithosis antigen derived from two different CP strains, the Rostinovo-70 and the АМК. Single injection solutions were administered in a volume of 1 ml. We found, that both antigens could initiate the marked decrease of the growth of malignant tumors in the animal model used.

Two models of diabetes, such as alloxan and streptozotocin, were used in the study to verify the influence of both on the optical properties and molecular permeability of skin ex vivo. Kinetics of collimated transmittance of control and diabetic skin samples immersed in aqueous 70%-glycerol solution was measured and then processed for estimation of diffusion coefficient of glycerol in skin. As a result, the slower glycerol diffusion rate was observed for both models of diabetes.

The study of blood microcirculation is one of the most important problems of the medicine. This is caused by the fact that many diseases, such as cardio-vascular diseases, atherosclerosis, diabetes, chronic venous insufficiency, oncology diseases, cause functional and morphological changes of microcirculation of blood flow. The results of experimental study of changes of blood microcirculation of pancreas in rats with diabetes measured by using Laser Speckle Contrast Imaging (LSCI) at application of optical clearing agents are presented. Laser speckle contrast techniques are based on the spatial and temporal statistics of the speckle pattern, calculating of contrast of time-averaged dynamic speckles in dependence on the exposure time at the registration of the speckle-modulated images. In research, 38 Wistar rats weighing 300-500 g were used. Alloxan induced animal model and streptozotocin model of diabetes was explored. The influence of solution of glycerol, Omnipaque®-300 was investigated. Application of 70%-aqueous glycerol solution demonstrates 50%-decrease of blood flow velocity in the group of aloxan diabetic animals, to 10th min blood flow velocity was completely restored. In a group of animals with streptozotocin diabetes, the blood flow rate decreased by 54%, by 10 minutes the speed did not reach the initial value. Blood flow in the control group almost stopped, to 10 min has not recovered. Application of Omnipaque®-300 demonstrates 65%-increase of blood flow in the group of alloxan diabetic animals and an increase of bloode flow in the first 2 minutes of applying the solution by 45%. In both cases to 10th min, blood flow velocity was completely restored. Blood flow in the control group did not show any noticeable changes.

The reactivity of skin microcirculation was compared in 3 groups of patients. Group 1 included healthy volunteers without cardiovascular diseases (n = 19), Group 2 included patients with diseases that increase the risk of cardiovascular events (arterial hypertension and / or angina pectoris and / or diabetes mellitus) (n = 40), Group 3 included patients with a history of cardiovascular events (myocardial infarction and / or stroke and / or coronary revascularization) (n = 20). Microcirculation measurement was performed by Laser Doppler flowmetry using LAKK 02 device during the heating test. Patients from Group 2 had a decrease in the reactivity of skin microcirculation compared with the control group, while the reactivity of skin microcirculation in these patients was better than in patients from Group 3. The highest difference was observed for the Slope_180 parameter (slope of the regression line of the microcirculation curve for the first 180 seconds of heating). Using the machine learning we developed a method for classifying patients into Group 1, Group 2, Group 3 according to the Slope_180 parameter. The sensitivity and specificity of Slope_180 parameter in identifying patients with cardiovascular diseases, diabetes (groups 2 and 3 together) was 82% and 68%, respectively. Such methods may be a promising for health screening. Thus, the relationship between the severity of skin microcirculation disorders and the “severity” of cardiovascular disease demonstrates the prospect of studying microcirculatory disorders as a cardiovascular risk factor.

This study is devoted to the trials of wearable diagnostic system that implements the laser Doppler flowmetry technique to analyse the blood microcirculation. We do preliminary test with involvement of limited group of healthy volunteers of different age and in patients with type 2 diabetes. During the series of measurements, the microcirculation parameters was measured for 10 minutes in the palmar surfaces of the big toes and in the inner sides of the upper thirds of the shins. A statistically significant differences was found in bypass index, nutritive and shunt blood ow in shins between older group of volunteers and patients' group as well as in shunt blood flow in fingers between younger and older groups of volunteers.

The aim of the study is investigation of morphological features of the testicles of rat newborns with different models of intrauterine hypoxia. Fifteen white outbred female rats aged from 4 to 10 months with a weight of 200 ± 30 g were used. Laboratory animals were divided into 3 experimental groups, 5 rats in each. The first group was subjected to a hypoxic hypoxia during pregnancy (21 days). The hypoxia was simulated in accordance with the method of N.N. Karkishchenko (2010). The second group was subjected to a hemic hypoxia during the second and third weeks of pregnancy, in accordance with the methodology of L.M. Sosedova (2012). The third (control) group was not exposed to any treatment during the pregnancy. After delivery, the newborn rat pups were subjected to the measurements of oxygenation degree using the methods of reflectance spectroscopy, then the animals were withdrawn from the experiment; and a morphological study of the testicle tissues was performed. Histological examination of the tissues of the testicles of newborn rats showed signs of impaired blood circulation, dystrophic and necrobiotic changes in the parenchyma.

Nowadays, imaging and spectroscopy systems operating in the long-wavelength infrared range (LWIR) are rapidly developed and extensively applied in numerous demanding branches of science and technology. This pushes further developments into the realms of improving the sensitivity and performance of the LWIR systems, as well as reducing their dimensions and cost. Among modern LWIR technologies, uncooled shutterless bolometric matrices form a favorable platform for addressing these challenging problems, being technologically reliable, compact, and cost-effective. Nevertheless, such detectors features high noises and require real-time digital signal processing. In this work, we developed a portable LWIR camera, which relies on a commercial uncooled bolometric matrix, and proposed few approaches aimed at the image acquisition improvement. We described algorithms for image calibration, compression of a dynamic range, and suppression of noises. This algorithms were implemented experimentally in a processing module relying on the Field-Programmable Gate Array (FPGA) and the highspeed double data rate Synchronous Dynamic Random Access Memory (SDRAM). The developed LWIR camera holds strong potential in such applications, as non-destructive sensing and medical imaging.

This work consists of two parts and describes an original portable Long-Wavelength Infrared Range (LWIR) camera, which was developed based on a commercial uncooled bolometric matrix and aided by few approaches, aimed at the image acquisition improvement. In the second part of our paper, we focused on numerical methods applied for compression of the dynamic range, enhancement of the image details, and suppression of image noises. These algorithms were implemented in a hardware using the Field-Programmable Gate Array (FPGA) and the high-speed double data rate Synchronous Dynamic Random Access Memory (SDRAM). In our opinion, the described camera is capable of solving numerous demanding problems of IR optics and biophotonics.

The terahertz (THz) attenuated total reflectance (ATR) imaging of normal and pathological skin under the action of various dehydration agents was carried out in vivo. Studies were conducted on animal models (the mouse), patients with diabetes, and healthy volunteers. For measurements, each animal was leaned against the ATR prism of the skin surface, and several locations in the skin of each animal were analyzed. Places on the skin for analysis were chosen so that the intensity spectra of the THz signal were practically the same for selected points. THz spectra measurements were carried out every 10 minutes within 45 minutes interval under the action of a dehydration agent. 40% glucose was shown to provide the most effective improving tissue optical clearing effect in the THz range.

The target-specific drug release which is depending on the pH of the medium appears precious approach for increasing of drug selectivity and further efficacy in photodynamic diagnosis (PDD) and therapy (PDT) of cancer. A strongly hydrophobic Zn (II) phthalocyanine (ZnPc) along with its liposomal formulates belongs to the clinically approved phthalocyanines for cancer photodiagnosis PDD and PDT. Nevertheless closed to the ideal photo-physicochemical properties the planar molecular structure of ZnPc easily forms aggregates which finally limit the phototoxic effect. Different strategies are on hand, all aiming to minimize the formation of photo-inactive associates. At present time, the polymeric carrier systems are still under development as carrier systems for biomedical applications. The present work evaluated the efficiency of two recently proposed graft - copolymers namely polyimide (PI)-graft-polymethacrylic acid (PAT2 and PAT3) as vehicles of hydrophobic ZnPc. The potential of the proposed polymeric brushes with great number of carboxylic groups, for conformational changes in different pH media, can be used for ZnPc release as studied by fluorescence spectroscopy. Complexes developed were investigated in vivo on rat model system of gastric carcinoma lesions for photodiagnosis and photodynamic treatment of neoplasia and compared with the application of ZnPcs solely. The contrast achieved of the fluorescence detection using polymer brushes - phthalocyanine conjugate is about twice higher that standard applied photosensitizer using same protocol and doses of application. The photodynamic treatment efficacy was also significantly improved allowing to receive full response using doses of 0,5-1 mg/kg of the conjugates. |To obtain same efficiency for the ZnPc PDT in the gastric lesions treated drug doses of 1,5-2 mg/kg had to be applied. Initially detected fluorescence signal and photo-bleaching dynamics were used for the monitoring of the processes of accumulation and photodynamic treatment processes.

One of the most significant effects of helium- neon laser radiation is a positive effect on the microcirculatory disturbances. The increase of antithrombin- III activity- the most important primary anticoagulant occurs under the laser radiation. The generation of secondary weak EHF-radiation is one way of effect’s implementation of laser radiation. Studies have been conducted to research the possibility for correction of platelet adhesive and aggregation activity of patients with inflammatory periodontal diseases after a course of complex treatment included combined effect of laser and EHF radiations as a component of the pathogenetic therapy directed toward the correction of microcirculatory disorders.

Laser surgery of the changing cartilage shape is based on photothermal effect on tissue components, which leads to its plasticization and, consequently, reshaping of this tissue. With the rapid laser heating, an optoacoustic wave is generated in the tissue, by the propagation and amplitude of which one can understand the changes in the mechanical properties of the tissue. In this work, data were obtained on the relative time variation of the mechanical stresses of the cartilage tissue upon heating and its temporal characteristics (relaxation time and system response time). A simultaneous recording of the electrical conductivity response of the cartilaginous tissue and mechanical stresses on a pulsed - periodic laser exposure is presented. As a result of this study, it was found that the mechanical stresses in the tissue are in good agreement with the electrical response of the tissue and a drop in resistance. It has been found that the continuation of tissue impedance falling down after the laser exposure switched off causes relaxation of the internal stresses. These studies are the base for the development of a control system for laser operations on cartilage tissue.

To determine optimal lighting conditions for contrast imaging of surgical objects, optical characteristics of biological tissues and spectral characteristics of smart light "LED light" source based on RGBW LED are compared. The spectral characteristics of tissues and organs have been investigated. Optimal lighting conditions for contrast imaging of biological tissues during surgery were studied. The optimal colour of light for working with individual organs against the background of the whole organism is selected. Perspective of light fixture application with the possibility of dynamic colour control is shown.

The aim of the present work was to investigate the ability of inhibiting the growth of various strains of Staphylococcus aureus by low-intensity laser light. As object of research used methicillin-sensitive and methicillinresistant strains of Staphylococcus aureus. For irradiation was used a semiconductor laser, which generates linearly polarized radiation of the red spectral region (λ - 660 nm). Power density was 100 mW/cm², irradiation time – 5, 10, 15 and 30 min, heat density respectively 30, 60, 90, and 180 J/cm². It was established that low-intensity laser radiation has an inhibitory effect on growth of colonies of both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus. But resistant strain is more sensitive to the action of red light, as the bacteriostatic effect is detected at the lower doses.

We propose a new method to strudy photothermal effect in large arrays of coupled plasmonic nanoparticles based on monitoring of surface acoustic waves propagating in LiNbO₃ substrate. A photothermal effect induced by deposited nanosystem/metasurface results in SAW velocity alteration which a phase shift is detected. In proof-of-concept experiment the visible/near IR polarization/wavelength dependent photothermal responses of macroscopic monolayer of Au plasmonic coupled nanoparticles prepared by self-assembling and the one for larger isolated particles produced by heat treatment were characterized.

Considering the considerable use of sedative drugs like methadone as a frequent substitution for additive drugs, we have investigated their effect on the cell activity via highly-resolved optical sensing method. Using plasmonic ellipsometry technique, a conspicuous shift in plasmonic resonance wavelength of the cultured chips was observed due to methadone presence during the cell culture of mesenchymal stem cells. This highly-sensitive platform can open new avenues towards the detection of drug effect on human cells and in large scale, on human organs.

It is now believed that the on-resonance excitation of the plasmonic nanoparticle is necessary to increase the Raman signal intensity of nearby molecules. On this basis, researchers try to fabricate rationally designed nanoparticles for surface-enhanced Raman scattering (SERS) applications with plasmon resonance close to wavelength of excitation. However, existing experiments show inconsistent results of measuring the dependence of the enhancement factor as a function of nanopaticle plasmon resonance. To fill the gap, we use the method of controllable etching to prepare set of Au nanorod colloids with the equal concentration, nanorod width, shape and tunable plasmon resonance that incrementally spanned 650-920 nm. Nanorods were functionalized with 4-nitrobenzenethiol and surface-enhanced Raman spectra were measured in colloid under 785 nm laser excitation. As a result we observe weak correlation between nanorod plasmon peak and SERS response. The ratio of SERS signals for on-resonance and of-resonance excitation was below 2. Nanorods were further overgrowth to have dumbbell morphology. This transformation leads to strong increase in SERS enhancement factor. Thus tuning of nanoparticles shape is more important factor towards highest SERS response compared to nanoparticle plasmonic peak.

Tags based on surface-enhanced Raman scattering spectroscopy (SERS tags) contains a plasmon-resonant core and Raman reporter molecules located in the area of high local electromagnetic field. These tags are widely used in bioimaging and sensing. Gap enhanced Raman tag (GERT) is a novel type of SERS tag which consists of a plasmon core coated by noble metal shell with Raman reporter molecules embedded between metal layers. The optical properties of these particles are determined by the material and size of the core and shell, the thickness of the internal gap containing reporter molecules, and also by the laser wavelength. From the point of view of its optical and chemical properties, gold is one of the most suitable materials for the synthesis of the core and shell. However, it is necessary to select the optimal parameters for the synthesis of GERTs with the maximum enhancement of the SERS signal. In this work we examined the dependence of SERS signal of gold nanorod-based GERTs from the thickness of outer gold shell by using a Raman spectrometer with a wavelength of 785 nm, which is inside the transparency window of biological tissues. It is known that the intensity of SERS signal from the Raman reporter molecules incorporated inside the intermetallic gap is highly dependent from the gold shell thickness. We found that with a decrease in the gold shell thickness from 51 nm a gradual decrease in the intensity of the SERS signal is observed.

Bimetallic Au-Ag SERS tags with aromatic Raman reporters embedded between layers have emerged as new type of nanoparticles with high potential for application in various fields of biochemistry and biomedicine. Particular interest is based on their high SERS enhancement factor under non-resonant laser irradiation. The thickness and shape of the outer silver layer is one of the factors determining the SERS properties of bimetallic nanoprobes. Here we studied eight types of AuNR core@embedded Raman reporter (4-nitrobenzenthiol)@Ag shell nanoparticles with various shell thicknesses from 2 to 40 nm. The SERS enhancement factor for our samples varied in the range of 2.35-6.68×10⁵; the maximum value was observed for particles with an outer shell thickness of 3 nm along the long nanorod axis of the rod and 16 nm along the short one. Simulation of the electromagnetic field by the FDTD method showed the presence of socalled “hot spots” at the boundary of the metal layers in a series of samples with high SERS EF.

The article presents the results of a comparative analysis of the adsorption properties of detonation nanodiamonds (DNDs) with different surface functionalization (carboxyl and hydroxyl groups) with respect to folic acid (FA). A significant dependence of the adsorption activity of nanodiamonds on the type of functional surface groups was found. The amount of adsorbed FA on DNDs with hydroxyl groups is 3.5 times higher than the amount of FA adsorbed on DNDs with carboxyl groups, however, the bond strength of the hydroxyl groups of DND with FA is almost 300 times weaker than the bond strength in the DND-COOH+FA complex. Based on the experimental results and calculations of the charge distribution of the deprotonated FA molecule, a model for the interaction of DND with FA is proposed.

In this paper we report a synthesis of bifunctional material. Dual magnetic and fluorescent inorganic nanoparticles, providing the ability of control by a magnetic field and a high MRI contrast along with strong photoluminescence, are widely used in biology and medicine. The current work is aimed to the combination of magnetic and luminescence properties in one nanocomposite that would be enable the engineering of unique multifunctional nanoscale devices. We studied the methods of synthesis of bifunctional nanoparticles based on luminescent luminescent carbon nanostructures and Fe₃O₄ nanoparticles, stabilized by ethylenediamine and citric acid.

Color is an easily observable parameter of colloidal systems. The direction of the growth process of gold nanorods can be characterized by the color change of the colloid during the synthesis, therefore to determine the color dependences of gold mixtures on size, form-factor, and polydispersity index is the actual task. The results of this theoretical work are the color dependences of gold nanorod mixtures on various geometric sizes and polydispersion indexes.

Alloyed quantum dots (QDs) are the popular material for the fabrication of the light-emitting diodes because of their optical parameters advantages. One of the most interesting features peculiar to this QDs class is the ability to controlled size-independent emission peak tuning via compound amounts changing. The same advantages can be valuable in bioanalytical methods and sensor systems development. Facile one-pot synthesis of the bright quaternary alloyed QDs made by Cd_xZn_1-xSe_yS_1-y/ZnS semiconductor composition with narrow (FWHM < 26 nm) emission peak (548 nm) and photoluminescence quantum yield (PLQY) up to 50% was described. Obtained QDs were stabilized in water by the dihydrolipoic acid (DHLA) ligand exchange approach with insignificant PLQY loss relative initial (16%) and great colloidal stability period (6 months). This article summarizes the easiest ways of the alloyed QDs synthesis and subsequent hydrophilization for the potential simplification of their large-amounts manufacturing procedure.

The use of Dunaliella salina microalgae as bioreactors allows to produce gold nanoparticles with anticancer activity by means of green chemistry. The method has been reported for the synthesis of gold nanoparticles using extract of D. salina. This green synthesis technique involves using bright sunlight that we consider as poorly controlled condition. The mechanism of nanoparticles toxicity is not yet elucidated. The toxic effect might arise either from toxic intermediates production during bioreduction of gold ions or from physical adsorption of bioactive molecules on nanoparticles surfaces. This research aimed to optimize gold nanoparticles biosynthesis using aqueous extract of D. salina (AED) and to clarify cytotoxic properties of synthesized nanoparticles. The synthesis of nanoparticles involved heating the reaction mixture and was carried out without using sunlight exposure. The fluorometric alamar blue-based toxicity tests with mammalian cell cultures HeLa and Vero were conducted. The following pollutants were tested: biogenic nanoparticles (AED-AuNPs), 15 nm citrate-capped gold nanoparticles stabilized by aqueous extract of D. salina (Cit-AuNPs@AED), 15 nm citrate-capped gold nanoparticles stabilized by polyethylene glycol (Cit-AuNPs@PEG). We have shown that heating the reaction mixture during bioreduction of HAuCl4 by AED led to the formation of gold nanoparticles with average diameter 12.1±4.1 nm. It has been shown that AED-AuNPs exerted a selective cytotoxic effect on the cancer cell line HeLa. Kidney epithelial cell line Vero appeared to be much more resistant to AED-AuNP than HeLa cells over testconcentration range 50-400 mg Au/L. Cit-AuNPs@AED were found to be non toxic. This evidence indicate that the toxicity of biogenic nanoparticles is likely to be associated with biotransformation of D. salina metabolites during the bioreduction of chloroaurate ions.

CLE peptides are important signaling molecules that regulate the balance of proliferation and differentiation of plant cells. In this work, we conjugated gold nanospheres (15 nm) with a chemically synthesized peptide (12 amino acid residues) that the amino acid sequence corresponds to the natural peptides CLE41/44. The "golden number" for CLE41/44 was 2 Μg/mL. A stable conjugate was used to produce rabbit polyclonal antibody. By the method of dot analysis, the presence of antibodies to CLE41/44 was detected in antiserum. Using Western blot and ELISA methods, the reaction of the obtained antibody with a conjugate of CLE41/44 with BSA molecules was demonstrated. The obtained antibody is can potentially be used to the quantitative determination and identification of the localization of peptides in plant tissues.

The results of a study of the dependences of the inductor current and heating kinetics on the power consumption value for titanium samples in the course of treatment with high frequency currents in the range from 88 to 120 kHz were presented. The effect of the inductor current in the range from 0.6 to 8.5 kA on the heating kinetics of equimass samples of disk and cylindrical shapes in the temperature range from 800 °C to 1700 °C in air was established. It was shown that the kinetics of a one- and two-cycle induction treatment had differences at the alpha-phase temperature.

In this contribution, we report synthesis of water-soluble Ag−In−S /ZnS quantum dots (QDs) using low toxic precursors as well as investigation of their optical properties. The QDs were successfully obtained directly in an aqueous environment in two ways: traditional one-pot water synthesis and hydrothermal synthesis in the presence of thioglycolic acid as a stabilizing and reactivity controlling agent. The effect of hydrothermal treatment on water-soluble Ag−In−S/ZnS QDs was shown and it was found that they are resistant for 4 hours autoclaving.

The combined structures of a "tool steel – titanium – oxide" system are used in tool industry. For this purpose, the application of resistance welding, which is widely used in the automotive industry, can be considered quite promising. It is possible to improve the quality of a joint of this type due to induction treatment. Thus, in the current study, the results of simulation of the induction heat treatment of bimetallic products, the structure of which contains a bearing base of X91CrMoV18 chromium tool steel, a protective coating of titanium and a thin wear-resistant oxide layer, were shown.

We report on a novel-designed superlattice (SL) InGaAs/InAlAs with artificially introduced epitaxial stresses into functional layers. The optimized and fabricated strained SL demonstrates a sub-picosecond photocarrier lifetime of 1.7 ps nevertheless featuring a rather moderate mobility. By means of numerical simulation we observe a decrease in the energy band gap of strained photoconductive layer InGaAs. In addition, the timedomain spectroscopic measurements reveal an increase in the spectrum amplitude of surface THz emission in the strained SL compared to lattice-matched one. We associate the decrease in photocarrier lifetime as well as the increase in the spectrum amplitude with residual strain in the SL caused by epitaxial stresses. The obtained results are of specific interest to THz science community since they open a way toward fabrication of cost-effective THz photoconductive devices for biomedical applications.

Results of development and experimental verification of a bench-top system for synthesis of highly porous polymer matrices are presented. Synthesis of the matrices is based on the initial plasticization of a raw polymer material provided using a subcritical/supercritical fluidic agent with the follow-up foaming of the plasticized polymer due to gradual depressurization of a working volume of the high-pressure reactor. The design of the reactor makes it possible to provide the quasi-real-time optical control of the polymer foaming using various optical probes (e.g., the small-angle diffuse transmittance measurements at various wavelengths, the multi-speckle diffusing wave spectroscopy, the polarimetric measurements using a transmitted light, the direct imaging of a foamed volume in the trans-illumination mode, etc.). The optical control is carried out through a set of sapphire glass windows symmetrically located around the working volume of the reactor. A precise control of the pressure and temperature in the working volume is synchronized with the optical probing of the foamed volume. Bench-top tests of the developed system were carried out using two extreme foaming modes: the quasi-adiabatic foaming under the condition of fast depressurization of the working volume, and the quasiisothermal foaming provided with the extremely slow depressurization and the constant temperature in the working volume. In the experiments, a granular polylactide from the PURACORB Inc. was used as the raw polymer material and carbon dioxide was applied as the plasticizing/foaming agent. The results of pilot foaming experiments for these extreme modes of polylactide foaming are presented.

On the basis of "green chemistry" a simple, fast and effective synthetic method for producing photoluminescent carbon nanostructures was developed. The use of CaCO₃ microparticles as microreactors makes it possible to use aqueous solutions for synthesis in a microwave oven. Microwave synthesis allows to get СNS quickly and without any complex multi-stage procedures. When comparing two syntheses (microwave and hydrothermal) to obtain photoluminescent carbon nanostructures under conditions of spatial limitation, they showed similar results. This allows the use of microwave synthesis as an alternative to obtain СNS and reduce the synthesis time to 30-60 minutes.

Microstructured waveguides with hollow core (HC-MOW) are of great interest for chemical and biological sensing. Due to the high overlap between a guiding light mode and an optical signal of analyte solution, filling of one or several fiber capillaries, such systems are able to provide strong sensitivity with respect to variations in the refractive index and the thickness of filling materials. Our approach is based on layer-by-layer assembly of oppositely charged polyelectrolytes with different molecular weights on the inner surface of HC-MOW. It was shown, the deposition of polyelectrolyte layers on the inner surface of hollow core causes a redshift in the transmission spectra. In particular, transmission shifts of up to 13 nm were detected for a multilayer polymer coating (5 bilayers).

Structural identification of biogenic hydroxyapatite (bioHA) was carried out by IR-Raman-XRD spectroscopy, electron microscopy. By the method of dissolution / deposition of bioHA powders, isomorphic substitution of Ca by europium and terbium was carried out and its photoluminescent spectra were studied.

Psycho-emotional stress is the cause of many diseases. Cortisol is a marker of psychoemotional stress, an increase in the level of this hormone in human biological fluids may indicate experienced stress. As a physiological indicator of the level of stress experienced, the content of cortisol in human biological fluids is used. The most convenient detection of cortisol in saliva. Immunochromatography allows you to get the result outside the hospital and in a short period of time. However, one of its significant drawbacks is the qualitative rather than quantitative nature of the analysis. In this work, we propose conducting a dot-immunoassay of cortisol in saliva using a thermographic method and comparing it with visual observation.

In this article, we have demonstrated the promising separation methods for hydrothermally obtained fluorescent molecule formed from citric acid and 1,2 – ethylenediamine. This fluorophore is a derivative of citrazinic acid and is known as a 1,2,3,5-tetrahydro-5-oxo-imidazo[1,2-a]pyridine-7-carboxylic acid (IPCA). Gel electrophoresis and dialysis were applied for the extraction the fluorophore from start materials. IPCA molecule has strong absorption at 350 nm and luminescence at 450 nm with a high quantum yield of around 85±5%. The structure of the fluorophore and polymer-like structures was researched by spectrophotometry, spectrofluorimetry, IR and NMR spectroscopy.

The results of investigation of the absorption spectra of ascorbic acid solutions with varying pH value are presented. The acidity of the solutions changed with increasing concentration, with the addition of hydrogen peroxide and sodium hydroxide. It was found that the position of the maximum absorption of ascorbic acid solutions depends on the pH value. The position of the absorption maxima shifts from 243 nm to 268 nm if the pH increases from 2 to 9. The change in the spectra is due to the stronger oxidation of ascorbic acid in alkaline solutions, which is accompanied by the removal of protons.

We demonstrate the synthesis of a luminescent derivative of biotin molecules with preservation its ability to interact with streptavidin. The luminescent biotin derivative was obtained via hydrothermal treatment of biotin water solution at different temperatures 140-240°C for 2 hours. Modified biotin showed a strong blue emission in the area of 390 nm with an optimal excitation wavelength at 320 nm and the relative quantum yield was 15±2 % for the sample obtained at the highest temperature. It was shown that hydrothermal treatment leads to biotin modifying with a saving of its biological activity.

Optical sensing is a powerful tool for recognition interactions in biosystems. Nowadays sensor systems allow to determinate the biomolecules interactions in biological fluids with high sensitivity, reproducibility and minimum standard error. Usually analyses are carried out in a heterogeneous format, which significantly complicates the procedure and increases the single analysis cost. The swap from heterogeneous to homogeneous analysis format is a promising solution. Microstructured optical fibers (MOFs) are a possible platform for creation of such sensors. Manuscript describe the possibility to detect antigen-antibody interactions in the hollow core microstructured optical fibers (HC MOFs). The determination of such interactions was carried out both in heterogeneous and homogeneous formats. Results demonstrate the prospects of HC MOF as a platform for the detection of antigen-antibody interactions.

Digital diaphanoscopy method has potential to separate normal and pathological conditions of the maxillary sinuses. The entirety of all the features of the investigated area (the presence or absence of pathology, its etiology and morphological features) affects the resulting images of the maxillary sinuses by the digital diaphanoscopy. In this work, the MonteCarlo numerical simulation method was used to determine the patterns of propagation of light radiation in biological tissue. A biologically heterogeneous environment, represented by structures of the skull and maxillary sinuses, as well as pathological changes in them was modelled in the TracePro software.

The possibility of endovenous laser coagulation using C-doped and Ti-doped optothermal fiber converters is discussed. Optical and thermal models have been developed to estimate the distribution of light and temperature in the vein at endovenous laser coagulation using a 980 nm diode laser. It is shown that the distribution of light in the vein when using Ti-doped converter is significantly different from the distribution obtained using C-doped converter and clear quartz fiber. As a result of the thermal calculation, for 980 nm laser power equal to 20 W, the dynamic of blood vessel wall temperature was determined. The effect of blood flow speed (1.5 mm/s) on the temperature of the vein wall was taken to account. It is shown that the blood vessel wall can be heated up to a temperature of 80 °C, which is needed for collapse of the vein, after 21 seconds of laser exposure by C-doped converter and after 43 seconds of laser exposure by Ti-doped converter at endovenous 980 nm laser coagulation of vein with a diameter 5 mm.

The interpretation of OCT signals from layered strongly scattering media in the form of the sum of a diffuse and lowstep- scattered components is discussed. It is shown that when the latter component dominates over the diffuse contribution, the depth distribution of the backscattering efficiency can be recovered using the detrending of exponential attenuation of the OCT signal. The feasibility conditions for such detrending are discussed. Examples of experimental verification of this approach are presented.

The paper presents theoretical study of magnetic nanoparticles through blood stream in the presence of magnetic field. This field created from a permanent magnet localized outside the tube and perpendicular to flow direction. The capillary tube has a rectangular cross-section with a length l and a width w. Behavior of such particles in a permanent magnet depends on the intensity of magnetic field. Therefore, under a uniform magnetic field, particles aligned along the lines of magnetic field strength. However, for a non-uniform magnetic field, the particles move towards the area where the magnetic field strength is higher and, thus, concentration of particles in this region becomes bigger. The capture and accumulation of particles depend on many parameters, such as magnetic field strength and distance between the surface of magnet and the capillary wall. The motion equation describing magnetic nanoparticles / blood flow and governed by a combination of the magnetic equation for the permanent magnet and the Navier-Stokes equation for fluid (blood) was solved numerically using the COMSOL Multiphysics® Modeling Software.

Photoacoustic imaging is going to play an important role in clinical imaging methods by recent progress in illumination and detection techniques. Combining good contrast optical imaging with the high spatial resolution of ultrasound imaging converts this imaging to be an indispensable imaging method for skin tissue. Here, we study the abilities of this method for imaging the variation of depth of blood vessel in the skin. In order to do it, we simulate the generation and propagation of photoacoustic signals inside the skin using a hybrid model based on the Monte Carlo method and acoustic wave equation. The effects of depth of vessel on simulated photoacoustic signal are studied. In addition the axial and lateral resolution of this method is assessed. Finally the frequency dependence of spatial resolution in the spectrum of 5- 75 MHz is also estimated. These results show that photoacoustic imaging method can be applied to study the skin diseases such as hemangioma and Port-wine stain.

A method for evaluation of the shear modulus for the large blood vessel walls is described. Structural images of the investigated part of the blood vessel wall with aneurysm are sequentially obtained using intravascular optical coherence tomography (IOCT) system for at least several cardiocycles. B-scans correspondent to diastole and shear deformation stages between systole and diastole are taken for the evaluation from a sequence of structural images. The pulse wave is considered to be the only deforming stimulus. The surface area of the deforming force is considered to be equal to the scanning area of the IOCT system. B-scans’ profiles are processed and plotted according to the average truncated level of the interference signal intensity. These profiles are divided into overlapping blocks. Shear deformation is estimated for overlapping blocks by the abscissa projection of the average displacement vector. The dimensions of the deformed region are to be equal to corresponding coherence probing depth. Shear modulus in the point of interest of the blood vessel wall is calculated using the classical formula and verified using known values of the Young's modulus and Poisson's ratio.

A method for tissue-like phantoms preparation for cerebral arteries with aneurysms is presented. Magnetic resonance angiography (MRA) images are used as a source of structural information about the geometry of the simulated cerebral arteries and surrounding brain tissue. Blood vessels were reconstructed as hollow structures with three-layer walls. The inner layer corresponds to the intima of the real vessel, its middle layer - media, and the outer layer - adventitia. The basis for the reconstruction of the first layer of hollow structures and mold for casting surrounding brain tissue were 3D printed. Hollow structures were reconstructed applying layer-by-layer method with use of two-component transparent silicone gel with a variable mass fraction of two components, A and B. Variation the mass fraction of the components and thickness for each layer allows achieving the necessary stress-related properties. Equivalence to the real structure of the cerebral arteries and optical properties were achieved by variation of mass fraction of the additives for each layer matrix. A powder of titanium dioxide was used as scattering particles and a special gel colourant for silicone was applied as an absorbing agent. Hollow structures were added in the mold for casting surrounding brain tissue simulator, so that their geometrical arrangement corresponds to associated blood vessels. The proximal and distal ends of hollow structures are equipped with forked catheters.

А numerical simulation algorithm of the interference signal acquired from biological fluids’ flow in Doppler optical coherence tomography (OCT) system is described. The suggested numerical approach has four key features: i) hydrodynamic characteristics of the part of the geometric layout in the intravascular space are not static, but dynamically change in numerical simulation of the photon transport; ii) dynamic changes include fluctuations of the optical characteristics and geometry of the parts of the intravascular space and were made for all pixels (B-scan) or voxels (Cscan) of the acquired data; iii) pixels and voxels of the intravascular space are considered to have the optical properties either of blood plasma or of the red blood cells; iv) the flow velocity is different for different types of pixels (voxels) which replace each other in the intravascular space: v) velocity value is chosen to obtain the desired shape of the flow velocity profile. The numerical model of the flow with a complex structure in soft biological tissues was implemented as the dedicated software using the LabVIEW package. The interference signal (A-scan) simulating software was successfully tested using hydrodynamic phantoms and can be used to study flow characteristics and their dynamic changes.

The retina phantom and a method for making pulsating flows of a fluid in human eye retina vessels are described. The retina phantom was made from two-component transparent silicone. A special gel colourant for silicone was used as an absorbing agent and TiO₂ (titanium dioxide) nanoparticles were used as scatterers. The central retinal artery and vein were constructed as a set of related extended cavities in the phantom. The proximal and distal ends of the cavities were connected to standard catheters. First catheter was connected to the fluid supply tank using a flexible transparent tube. The second catheter was connected to a container for the out coming fluid using another tube. Hemodynamic setup for fluid supply contains: i) a tank with sufficient quantity of the fluid; ii) a pump for making a laminar fluid flow; iii) a unit to make laminar to turbulent flow transformation regime; iv) flow meter and control unit. Periodically repeated controlled twisting of a flexible tube with a laminar flow was used to make pulsations. Vibrations were used to simulate flow changes associated with patient movements and tremor. The described system can be used for developing quantification algorithms to study relative changes and absolute values of blood flow velocity using ophthalmic Doppler optical coherence tomography systems.

Nowadays methods of non-invasive analysis are widely used in medicine, biology and other fields of applied science. One of the most accurate and relatively easy-to-use methods is the laser speckle imaging method. Laser speckle imaging is a powerful method for studying blood flow, especially in weakly scattering media. This method can also be used in tissues that have strong scattering properties, such as skin. Speckle imaging provides a full-speed map of a relatively large area of an object without laser beam scanning, with good temporal and spatial resolutions. In this work, the accuracy of the installation and the decorrelation period are determined by using a phase correlation method. Also, a few digital techniques of speckle image processing to characterize flows are presented and discussed.

Chlamydia trachomatis biodiversity has been detected in clinical urogenital samples of Chlamydia patients in the Southeastern European Region of Russia. In this paper three absolutely new nucleotide sequences of “Saratov” strains (Saratov E1/61.8-B1, Saratov E2/61.46-L38, Saratov E6/61.35-B1) have been described and transformed into the form of GB-speckles. It has been demonstrated that identification of single polymorphism in nucleotide sequences can be easily performed on the base of GB-speckles. Procedure of detection of polymorphism can be made essentially faster in the case of using of Matlab Parallel Computing Toolbox.

Gene-based speckles (GB-speckles) have been implied for interpretation of the nucleotide sequences of the seven “housekeeping genes” of Listeria monocytogenes (LM). The 1st order statistics and correlation functions of 2D speckle structures corresponding to the several concatenated nucleotide sequences of two different sequence types (STs) of LM bacteria have been analyzed. Two nucleotide sequences, namely ST7 and ST106 (the clonal complex СС7) have been compared using the related GB-speckles. Differences in the GB-speckle-structures, corresponding to two different LM STs are evidently demonstrated.

Gene-based speckles (GB-speckles) have been implied for interpretation of nucleotide sequences of the target genes of HPAIV. The 1st order statistics and correlation functions of 2D speckle structures corresponding to the several nucleotide sequences of HPAIV have been analyzed. The GB-speckles, generated for highly-pathogenic strains A/Gs/HK/739.2/02 (H5N1) and HPAIV (A/Chicken/Hong Kong/YU562/01 (H5N1)) neuraminidase (NA) have been compared with the speckles, related to three low-pathogenic strains (Influenza A virus (A/chicken/Ganzhou/GZ43/2016(H3N2)) segment 6 neuraminidase (NA) gene, Influenza A virus A/pheasant/Korea/LBM180/2008(H9N2)) segment 6 neuraminidase (NA) gene, and Influenza A virus A/chicken/Alkharj/910/2018(H5N8)) segment 6 neuraminidase (NA) gene). Perspectives of fast and precise discrimination of nucleotide sequences of the different avian influenza strains, including HPAIV variants, based on GBspeckles, are demonstrated.

As it has been demonstrated earlier, different types of re-coding of bacterial nucleotide sequences to gene-based specklepatterns (GB-speckles) can be used. In this paper an advanced study, devoted to optimization of this algorithm, is presented. With this purpose, investigations of statistical properties of the GB-speckles, generated on the nucleotide sequences of the gatA gene of Chlamydia trachomatis has been performed. The first- and second-order statistics of intensity fluctuations in GB-speckles have been analyzed. Perspectives of the gene identification using a statistical analysis of the homologous laser GB-speckles have been demonstrated. The analyzed nucleotide sequences of the gatA gene of C. trachomatis strains isolated in the Republic of Belarus were compared with those recently isolated in Russian Federation.

As it has been demonstrated earlier, different types of re-coding of nucleotide sequences to gene-based speckle-patterns (GB-speckles) can be used. In this paper an advanced study, devoted to optimization of this algorithm, is presented. With this purpose, investigations of statistical properties of the GB-speckles, generated on the nucleotide sequences of the fumC gene of Chlamydia trachomatis, have been performed. The first- and the second-order statistics of intensity fluctuations in GB-speckles have been analyzed. Perspectives of the gene identification using a statistical analysis of laser GB-speckles have been demonstrated. The analyzed nucleotide sequences of the fumC gene of C. trachomatis strains have been isolated in the Republic of Belarus.

We address the problem of differential diagnostics of chronic spontaneous urticaria and urticarial vasculitis. The clinical pictures of these two allergy diagnoses are similar, however a well-trained pathologist can see the differences in skin tissue on the microscopic level, and thus the histological study of skin biopsy is usually performed to prescribe the right treatment. To increase the throughput and quality of the histological study and differential diagnostics of chronic spontaneous urticaria and urticarial vasculitis, we propose an imaging system with neural-network-based classification of skin tissue structures. The capabilities of a hyperspectral microscopic visualization system with acousto-optical module for increasing the efficiency of neural network training are also being considered.

This study presents autonomous system for microorganisms’ growth analysis in laboratory environment. As shown in previous research, laser speckle analysis allows detecting submicron changes of substrate with growing bacteria. By using neural networks for speckle analysis, it is possible to develop autonomous system, that can evaluate microorganisms’ growth by using cheap optics and electronics elements.

System includes embedded processing module, CMOS camera, 670nm laser diode and optionally WiFi module for connecting to external image storage system. Due to small size, system could be fully placed in laboratory incubator with constant humidity and temperature. By using laser diode, Petri dish with microorganisms’ substrate is illuminated with speckle pattern. Embedded camera and processing system obtain images and stores them for processing with neural network.

Neural network utilizes “3D ConvNets” architecture with ability to encode not only spatial speckle variance, but also their changes in time. Convolutive approach allows significantly reduce the number of trained parameters, therefore reducing training and detection time. Neural network training used 200 bacteria colonies and additional 300 areas without bacteria. In the result, trained neural network reaches 0.95 accuracy score, that proves correctness of the approach.