[Subthreshold micropulse laser treatment of the foveal region in chronic central serous chorioretinopathy (case study)]. / Subporogovoe mikroimpul'snoe vozdeistvie v foveal'noi oblasti pri khronicheskoi tsentral'noi seroznoi khorioretinopatii (klinicheskoe nablyudenie).

The article presents a clinical case of subthreshold micropulse laser (SML) treatment of chronic central serous chorioretinopathy (CSC) in the left eye of a 44-year-old female patient K. with dye allergy. The patient first noticed a gray spot, distortion of objects in February, 2018. During 2018-2020 she suffered 5 relapses, repeated unsuccessful conservative treatment, and completed a course of antiangiogenic therapy in the form of three monthly intravitreal injections of ranibizumab. After experiencing stress on 11.08.20 she noted acute deterioration. Laser treatment was carried out on 20.09.20 with the Navilas 577s navigation system (wavelength 577 nm). After the power titration and calculation, the contact-free subthreshold micropulse laser treatment was carried out without anesthesia in three zones: 200 mW for fovea, 240 mW for parafovea and 340 mW for periphovea. Other settings: pulse duration - 200 ms, spot diameter - 100 µm, duty cycle - 5%. Total number of laser pulses - 1000. The retina reattached completely despite the patient having previously recovered from the coronavirus infection and the use of corticosteroids.

Effect of the Peptide Calcium Channel Blocker ω-hexatoxin-Hv1a on Cell Death during Ischemia/Reperfusion in vitro.

Apoptosis and necrosis during reperfusion after ischemia are key mechanisms at the cellular level leading to damage. The development of pathological conditions is preceded by intracellular calcium ion overload both at the stage of ischemia and at the stage of reperfusion. In this regard, one of the strategies aimed at reducing damage during ischemia/reperfusion is associated with the use of calcium channel blockers. The aim of the study was to study the effect of a peptide toxin, a calcium channel blocker ω-hexatoxin-Hv1a, on different types of epithelial cell death during in vitro reconstruction of ischemia/reperfusion conditions characteristic of organ transplantation. Materials and Methods: In this study, we used CHO-K1 epithelial cell culture. Changes in apoptosis, necrosis, cell index, and calcium ion concentration were assessed when modeling ischemia/reperfusion processes in vitro with the addition of a calcium channel blocker toxin. Ischemic and reperfusion injury was achieved by oxygen and nutrient deprivation followed by reperfusion in a complete nutrient medium. The measurements were performed using a multimodal plate reader-fluorimeter. Results: An increase in apoptosis, necrosis, and the concentration of calcium ions was recorded when modeling ischemia/reperfusion processes. A decrease in the level of apoptosis and necrosis, as well as the concentration of calcium ions to a physiological level or a level close to physiological, was noted when the toxin was added at a concentration of 50 nM at the reperfusion stage. The cell index showed a faster restoration in the presence of the toxin. Conclusion: The experimental data confirm the hypothesis of a beneficial effect of peptide calcium channel blockers on the state of epithelial cells during reperfusion after ischemia and can be considered for further study as a strategy for organ adaptation before reperfusion.

Optically stimulated electron paramagnetic resonance: Simplicity, versatility, information content.

A simple technique for observing optically stimulated electron paramagnetic resonance (OSEPR) is proposed and investigated. The versatility and information content of the described technique is demonstrated by the example of the OSEPR spectra of systems that are unpopular for this type of spectroscopy: a crystal with rare-earth ions Nd3+ and a doped semiconductor GaAs. In addition, the OSEPR spectrum of atomic cesium is presented, in which an optical nonlinearity is observed that makes it possible to estimate the Rabi frequency for the relevant optical transition. The effects observed in the described experiments (switching of peaks to dips, light-induced splitting of the OSEPR lines, and the appearance of a spectral feature at the double-Larmor frequency) are interpreted using the model proposed in the theoretical part of the work. The suggested interpretation shows the possibility of using the described OSEPR technique to estimate not only 'magnetic' parameters of the model Hamiltonian (g-factors, spin relaxation times), but also the Rabi frequencies characterizing optical transitions.

[Widefield optical coherence tomography as an effective method for detecting imperceptible flap retinal tears (clinical observation)]. / Shirokopol'naya opticheskaya kogerentnaya tomografiya ­ effektivnyi metod vyyavleniya klapannogo razryva setchatki (klinicheskoe nablyudenie).

Certain late peripheral ruptures after acute posterior vitreous detachment (PVD) may remain undetected during the initial examination of the fundus due to the presence of vitreous hemorrhages and other factors, but they can lead to rhegmatogenic retinal detachment in the future. Hence, it is necessary to conduct an additional thorough examination using optical coherence tomography (OCT) of the vitreoretinal interface periphery in the presence of tear predictors: retinal and vitreal hemorrhages, vitreous pigment cells ("tobacco dust") in the anterior segment of the vitreous body, as well as hyper-reflective dots ("starry sky") in the vitreous body according to OCT scans of patients with acute symptomatic detachment of the hyaloid membrane. The article presents the case of a patient with a clinically imperceptible flap tear detected during acute posterior vitreous detachment. Widefield OCT of the vitreoretinal interface was performed by "sliding" from the center to the periphery of the retina, and revealed a flap tear located next to a dot retinal hemorrhage. OCT scanning of the retinal periphery is an effective modern diagnostic method in the ophthalmological clinical practice.

Photoplethysmographic Imaging of Hemodynamics and Two-Dimensional Oximetry.

The review of recent papers devoted to actively developing methods of photoplethysmographic imaging (the PPGI) of blood volume pulsations in vessels and non-contact two-dimensional oximetry on the surface of a human body has been carried out. The physical fundamentals and technical aspects of the PPGI and oximetry have been considered. The manifold of the physiological parameters available for the analysis by the PPGI method has been shown. The prospects of the PPGI technology have been discussed. The possibilities of non-contact determination of blood oxygen saturation SpO2 (pulse saturation O2) have been described. The relevance of remote determination of the level of oxygenation in connection with the spread of a new coronavirus infection SARS-CoV-2 (COVID-19) has been emphasized. Most of the works under consideration cover the period 2010-2021.

[The research activity of students in "The public health and health care, health care economics" discipline].

The article considers research work of students in "The Public health and health care, health economics" discipline in 2001-2020, organized in course of public health and health care of the Medical Institute of Petrozavodsk State University. The article reveals such concepts as student scientific activity, knowledge requirements for discipline to prepare student research work, classification of student research works by degree of collection and analysis of material, levels of student work performance, stages and classes of social hygienic research, requirements for content of presentation, criteria of evaluating report and presentation. During 2001-2021, 250 students of medical institute in the section "Public health and health care" made more than 200 reports, published more than 20 thesis and articles. The annual plan of 30 topics for student research works was developed, including requirements for content of presentation, 3 indices to evaluate quality of work. The text of presentation-report in 90% included information on one discipline "Public health and health care, health economics". At that, topic was disclosed in format of describing research objectives with construction of diagrams and graphs, comparison of indices and only 10% of reports contained statistical analysis of the results.

Federal medical biological agency of Russia's efforts to support Russian athletes during COVID-19 outbreak.

This paper dwells upon COVID-19-related efforts of the Center for Sports Medicine, Federal Medical and Biological Agency of Russia. The Agency has the following precautions in place: regular polymerase chain reaction (PCR) testing of athletes and staff; double PCR testing before going to training camps or medical examinations; isolating athletes and their traceable contacts when COVID is suspected; observation and isolation wards set up at training camp venues. Athlete vaccination has begun. Athletes are provided online advice on health, diet, and exercising plus special care for chronically ill athletes and remote psychological counseling. Athletes recovering from COVID-19 are offered rehabilitation programs and doctor-supervised return to training. Specialists of the Research Department at FMBA's Center for Sports Medicine carried out a research dedicated to the prevalence of COVID-19 and different variants of its course in Russian athletes. The study period lasted from March to December 2020. A total of 27,438 records were analyzed. In May, June, July and August 2020, the percentage of positive PCR tests for athletes was significantly lower than the nationwide percentage at p < 0.05, Pearson's chi-squared test. However, the differences were nullified by September-October. The disease was mild or asymptomatic in most patients. Athletes of summer sports were found to be most likely to contract COVID-19.

[OCT visualization of hyporeflective lacuna in the retrolental space]. / OKT-assotsiirovannaya vizualizatsiya giporeflektivnoi lakuny v retrolental'nom prostranstve.

PURPOSE: To investigate the vitreo-lenticular interface and anterior vitreous using high-resolution optical coherence tomography (OCT). MATERIAL AND METHODS: This prospective single-center pilot study included 34 patients (68 eyes) - 6 males and 28 females with a mean age of 58.4±12.0 years (age range 24-81 years). OCT scanning was performed on the spectral domain optical coherence tomography (SD-OCT) device SOLIX (OPTOVUE, USA) in the Full Range AC mode with the following scan parameters: from 14 to 18 mm in horizontal length and 6.25 mm in the axial dimension. To improve the signal-to-noise ratio and increase image clarity of the final scan, averaging of eight simultaneous scans was performed. RESULTS: In all healthy volunteers, hyporeflective retrolental cavities-lacunae were observed in both eyes during visualization of the retrolental space in the horizontal and vertical planes. The median distance from the posterior pole of the lens to the lacuna was 697 µm. The median width of the lacuna was 157 µm. CONCLUSION: To the best of our knowledge, we consider this to be one of the first in vivo visualizations of a previously undescribed structure - hyporeflective retrolental lacuna - using SOLIX high-resolution OCT device. The retrolental lacuna may play the role of a buffer system, or belong to the lymphatic system of the vitreous body and the eye.

[Evaluation of choriocapillaris with high-speed spectral-domain optical coherence tomography angiography and image averaging]. / Otsenka statusa khoriokapillyarisa s pomoshch'yu vysokoskorostnoi spektral'noi opticheskoi kogerentnoi tomografii s funktsiei angiografii i tekhnologii usredneniya izobrazhenii.

PURPOSE: To study the capabilities of high-speed spectral-domain optical coherence tomography angiography (SD-OCTA) with image averaging in the evaluation of choriocapillaries in healthy individuals and patients with central serous chorioretinopathy (CSC). MATERIAL AND METHODS: All participants underwent OCTA examination on the SOLIX tomograph (Optovue, USA) using quadruplicate 3×3 mm scan with image averaging. Image analysis was performed in 9-µm custom slab with Phansalkar auto local threshold algorithm and calculation of flow voids larger than 5000 µm2 and 10 000 µm2. The optimal slab depth was determined in healthy eyes by consecutive analysis of the slabs with a 3-µm shift from zero position to 33 µm below Bruch's membrane. RESULTS: The study included 18 eyes of 18 healthy volunteers (40.4±6.0 years old) and 18 fellow eyes of 18 unilateral CSC patients (37.4±10.7 years old). The slab 12 µm below the Bruch's membrane showed the minimal number of flow voids (23.1±7.0 of >5000 µm2 voids per scan) and was chosen for further analysis. The number of flow voids of >5000 µm2 in healthy paired eyes of CSC patients was statistically significantly higher than in the eyes of healthy individuals (32.7±10.7 and 25.3±8.1 voids/scan, respectively; p=0.022). The number of flow voids of >10000 µm2 was also statistically significantly higher in CSC eyes compared to healthy eyes (5.6±3.3 and 3.5±1.9 voids/scan, respectively; p=0.045). There was no statistically significant difference in total area of the voids between the eyes of healthy individuals and CSC patients (96406.1±3924.5 µm2 and 95395.7 ± 3615.1 µm2, respectively; p=0.42). CONCLUSION: The optimal settings for choriocapillaris imaging on the SOLIX tomograph include 9-µm slab 9 to 18 µm below the Bruch's membrane. Using a 9-µm slab 12 µm below the Bruch's membrane, a substantial difference was found in choriocapillaris perfusion between eyes of healthy individuals and CSC patients.

Raman scattering model of the spin noise.

The mechanism of formation of the polarimetric signal observed in the spin noise spectroscopy (SNS) is analyzed from the viewpoint of the light scattering theory. A rigorous calculation of the polarimetric signal (Faraday rotation or ellipticity) recorded in the SNS is presented in the approximation of single scattering. We show that it is most correctly to consider this noise as a result of scattering of the probe light beam by fluctuating susceptibility of the medium. Fluctuations of the gyrotropic (antisymmetric) part of the susceptibility tensor lead to appearance of the typical for the SNS Faraday rotation noise at the Larmor frequency. At the same time, fluctuations of linear anisotropy of the medium (symmetric part of the susceptibility tensor) give rise to the ellipticity noise of the probe beam spectrally localized at the double Larmor frequency. The results of the theoretical analysis well agree with the experimental data on the ellipticity noise in cesium vapor.

Immune Response of Mice Against Babesia canis Antigens is Enhanced When Antigen is Coupled to Gold Nanoparticles.

PURPOSE: The aim of this study was to isolate Babesia canis soluble antigens and to investigate the effect of their conjugates with gold nanoparticles on the immunogenicity in laboratory animals. METHODS: A procedure was developed for isolating and purifying B. canis antigens. The isolated culture antigen of B. canis 495 was coupled to gold nanoparticles, and the conjugate was used to immunize laboratory mice. RESULTS: Western blotting showed that the resultant antiserum specifically recognized the proteins of the B. canis strains isolated from naturally infected dogs. The antibody titer, the respiratory activity of peritoneal macrophages, the proliferative activity of splenocytes, and the production of cytokines were maximal when the animals were immunized with the antigen-nanoparticle conjugate emulsified in complete Freund's adjuvant. Without adjuvant, the babesial antigen was weakly immunogenic. CONCLUSION: Therefore, the use of gold nanoparticles as an antigen carrier induced a broad immune response involving both cellular and humoral responses. The antibodies raised by the proposed procedure are potentially effective at immunodetection of Babesia canis infections in dogs.

[Characteristics of changes in retinal and optic nerve microvascularisature in Leber hereditary optic neuropathy patients seen with optical coherence tomography angiography]. / Osobennosti mikrososudistykh izmenenii setchatki i zritel'nogo nerva u patsientov s nasledstvennoi opticheskoi neiropatiei po dannym opticheskoi kogerentnoi tomografii-angiografii.

PURPOSE: To investigate the features of various parameters of the density of retinal blood vessels, optic nerve head (ONH) and peripapillary region in hereditary optic neuropathy (HON) patients revealed with optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: The study included 29 HON patients divided into three groups based on symptoms duration (less than 1 year; 1-5 years, more than 5 years) and visual acuity (0.5-1.0; 0.04-0.4; 0.03 and lower). Relative macular, optic disc and peripapillary vessel density (VD, %) was assessed by OCTA (xR Avanti, Optovue Inc., USA). RESULTS: Significant progressive VD reduction in superficial capillary plexus (SCP) was detected in all parafovea sectors and in the temporal sector of perifovea over the course of disease progression. No significant differences of these parameters were found in correlation with visual acuity. Patients with VA of 0.5-1.0 turned out to have greater VD in deep capillary plexus (DCP), whereas no differences were found in relation to the duration of HON. A strong significant correlation between the SCP and DCP VD only in central foveal area was revealed in all groups depending on the VA and symptoms duration. Over the course of HON progression, VD in the temporal sector and in temporal segments of superior and inferior sectors has gradually reduced. In patients with VA of 0.5-1.0, the retinal nerve fibers layer (RNFL) thickness in the temporal sector and optic nerve VD was notably greater compared to patients with lower VA. The most significant correlation was established between VA and structural changes (K=0.75, p<0.001) and VD in the temporal sector (K=0.57-0.61, p<0.001). CONCLUSION: The obtained data suggest that derivative microvascular changes play an active role in the clinical progression of the disease.

[Structural and functional changes in the retina and optic nerve in patients with toxic optic neuropathy caused by acute methanol poisoning]. / Osobennosti strukturnykh i funktsional'nykh izmenenii setchatki i zritel'nogo nerva u patsientov s toksicheskoi opticheskoi neiropatiei na fone otravleniya metanolom.

PURPOSE: To identify the specifics of structural and functional changes in patients with toxic optical neuropathy caused by acute methanol poisoning. MATERIAL AND METHODS: One female patient with toxic optic neuropathy (TON), 2 male patients with partial optic atrophy caused by methanol poisoning, and 1 male patient with methanol intoxication after ethanol containing alcohol use were examined with kinetic perimetry and optical coherence tomography. RESULTS: Patients with TON caused by acute methanol poisoning were observed to have decreasing visual acuity to the extent of complete blindness. OCT follow-up studies revealed thinning of the retinal nerve fiber layer (RNFL) as well as formation of microcysts in the inner retinal layers, destruction of ellipsoid zone and outer segments of photoreceptors. The patient with methanol intoxication after use of ethanol containing alcohol had retained his visual functions; he was found to have microcysts and RNFL thinning during the first few months after the intoxication, but they were within normal range of OCT parameters. CONCLUSION: Patients with TON caused by acute methanol poisoning are common to have optic atrophy with either residual visual functions or complete blindness as well as microcysts formation, structural changes and destruction of the ellipsoid zone and outer segments of photoreceptors. In patient with methanol intoxication after use of ethanol, which is known to be an antidote, complete visual recovery was observed, although some microcystic changes and ganglion cells layer thinning were noted.

[Preventive laser treatment of tractional symptomatic retinal flap tears: long-term outcomes]. / Otdalennye rezul'taty profilakticheskogo lazernogo lecheniya traktsionnykh simptomaticheskikh klapannykh razryvov setchatki.

Tractional flap tears are the main cause of the development of regmatogenic retinal detachment (RRD). The main immediate treatment method for it is laser retinal coagulation. PURPOSE: Case monitoring of tractional symptomatic flap tears after laser treatment. MATERIAL AND METHODS: From 2014 to 2019 we observed 119 patients (130 eyes) with peripheral flap (horseshoe) retinal tears in acute posterior vitreous detachment. Laser coagulation of the retina was performed using Navilas 577s (577 nm), OcuLight GL (532 nm). Laser retinotomy of horseshoe tear flap and dissection of overhanging vessels were performed using Nd:YAG-ultra Q Reflex laser (1064 nm) and controlled with RTVue XR Avanti. RESULTS: At the initial examination before the preventive laser coagulation, the following conditions were found: regmatogenous retinal detachment (RRD) - 8 eyes (6.2%), partial hemophthalmus - 29 (22.3%), preretinal hemorrhage - 15 (11.5%), epiretinal membrane - 9 (6.9%), non-full-thickness macular retinal breaks - 6 (4.6%), peripheral changes: retinal holes - 16 (12.3%), tears with operculum - 5 (3.8%), retinal degenerations - 40 eyes (30.8%). Observation for 5 years after laser retinopexy revealed new pathological changes: flap tears - 13 (10.6%); holes - 9 (7.4%); tears with operculum - 5 (4.1%); vitreoretinal tuft - 6 (4.9%); RRD - 3 cases (2.5%). In 16 patients (16 eyes) with horseshoe tear and pronounced vitreoretinal traction, the flap retinotomy was performed, which eliminated the traction component and prevented the development of RRD. CONCLUSION: Follow-up of tractional symptomatic flap tears for 5 years after preventive laser retinopexy revealed the appearance of retinal detachment in 2.5% of cases. Laser retinotomy of horseshoe tear after barrier retinopexy eliminated the traction component and helped prevent the development of RRD.

Insitu magnesium calcium phosphate cements formation: From one pot powders precursors synthesis to in vitro investigations.

Calcium phosphate cements are of great interest for researchers and their applications in medical practice expanded. Nevertheless, they have a number of drawbacks including the insufficient level of mechanical properties and low degradation rate. Struvite (MgNH4PO4) -based cements, which grew in popularity in recent years, despite their neutral pH and acceptable mechanical performance, release undesirable NH4 + ions during their resorption. This issue could be avoided by replacement of ammonia ions in the cement liquid with sodium, however, such cements have a pH values of 9-10, leading to cytotoxicity. Thus, the main goal of this investigation is to optimize the composition of cements to achieve the combination of desirable properties: neutral pH, sufficient mechanical properties, and the absence of cytotoxicity, applying Na2HPO4-based cement liquid. For this purpose, cement powders precursors in the CaO-MgO-P2O5 system were synthesized by one-pot process in a wide composition range, and their properties were investigated. The optimal performance was observed for the cements with (Ca + Mg)/P ratio of 1.67, which are characterized by newberyite phase formation during setting reaction, pH values close to 7, sufficient compressive strength up to 22 ± 3 MPa (for 20 mol.% of Mg), dense microstructure and adequate matrix properties of the surface. This set of features make those materials promising candidates for medical applications.

Detuning effects in Brillouin ring microresonator laser.

Brillouin lasers, with their unique properties, offer an intriguing solution for many applications, yet bringing their performance to integrated platforms has remained questionable. We present a theoretical framework to describe Brillouin lasing in integrated ring microcavities. Specifically, a general case of a mismatch between the Brillouin shift and the microresonator inter-mode spacing is considered. We show that although the lasing threshold is increased with the frequency detuning, a significant enhancement of the laser power in comparison with the pure resonant interaction could be achieved. Moreover, there is an optimal pump frequency detuning from the resonant mode frequency, when the effect is most pronounced. An increase of the Brillouin threshold with the pump frequency detuning is accompanied by narrowing the pump frequency range available for lasing. Importantly, at the optimal value of the pump frequency detuning when the Brillouin signal is maximal, Brillouin signal noise level is minimal. Analytical results obtained in the steady-state approach are in quantitative agreement with the results of numerical simulations.

[Pattern electroretinogram and macular perfusion in glaucoma]. / Pattern-élektroretinogramma i makuliarnaia gemoperfuziia pri glaukome.

PURPOSE: To study microcirculatory and functional changes in macula in patients with Primary Open-Angle Glaucoma (POAG). MATERIAL AND METHODS: The study included 95 POAG patients and 42 healthy control subjects. Whole en face image vessel density (wiVDRetina) was measured both in fovea and in parafovea using OCT-angiography (OCT-A) by means of SD-OCT AngioVue on Avanti RtVue xR (Optovue Inc., U.S.A.). Macular thickness and parameters of macular ganglion cell complex (GCC) were measured on the same day. Blood flow in the retrobulbar vessels was evaluated by means of Color Doppler Imaging (CDI). Pattern electroretinogram (PERG) was also taken from the study eyes. Correlations between PERG, SD-OCT GCC, macular thickness, and the parameters of OCT-A and CDI were studied. RESULTS: The amplitude of t-PERG P50 decreased from 6.1±1.3 µV in normal eyes to 2.8±1.6 µV (p<0.0001) in early glaucoma and to 2.3±1.5 µV (p=0.93) in advanced stages. Relative vessel density of the capillary bed decreased from 51.3±3.0% in normal eyes to 45.9±5.0% (p<0.001) and to 41.8±5.0% (p=0.023) in early and advanced glaucoma respectively. The parameters of OCT-A and CDI correlated with morphological and functional parameters in normal and early glaucomatous eyes. CONCLUSION: The study revealed reduction of macular microcirculation and decrease of PERG in early glaucoma. Correlations between the circulatory parameters and functional changes were found in early stages of the disease.

[Pattern visual evoked potentials and their relation to the peripapillary and retrobulbar blood flow in glaucoma]. / Patternzritel'nye vyzvannye potentsialy i ikh sviaz' s peripapilliarnym i retrobul'barnym krovotokom pri glaukome.

PURPOSE: To examine the relationship between the development of bioelectric response of retinal cell elements to pattern stimulus and the ocular blood flow. MATERIAL AND METHODS: Electrophysiological studies, including pattern-reversal visual evoked potentials (VEP) with large 1 degree (1°) and small 0.25° checks, Color Doppler imaging (CDI) of the retrobulbar vessels, and OCT Angiography in the area of the optic disc and peripapillary retina were performed in 48 patients with initial primary open-angle glaucoma (POAG), 47 patients with advanced POAG, and 42 control subjects. Authors also studied the correlations between VEP values and the parameters used in CDI and OCT-A examination. RESULTS: The most noticeable differences between the study groups were the amplitudes of P100 pattern VEP values for small and large patterns and the OCT-A parameters: Whole-image Disc Vessel Density (widVD), Peripapillary Vessel Density (pVD), Peripapillary Vessel Density Inferior Temporalis (pVD IT). In initial glaucoma, a strong correlation was observed between the amplitude of P100 pattern VEP 1° and pVD IT (r=0.75; p<0.0001); the blood flow rates in ophthalmic artery, central retinal artery, central retinal vein and short posterior ciliary arteries were below normal, while the blood flow in these vessels had statistically reliable correlation with the amplitude of P100 pattern VEP (p<0.05). No correlation was found in patients with advanced stages of glaucoma. CONCLUSION: Pattern VEP is an informative method of glaucoma diagnostics which accuracy can be enhanced by combining it with OCT-A blood flow examination.

[Evaluation of YAG-laser vitreolysis effectiveness based on quantitative characterization of vitreous floaters]. / Otsenka éffektivnosti YAG-lazernogo vitreolizisa na osnove ob''ektivnoi kolichestvennoi otsenki plavaiushchikh pomutnenii v steklovidnom tele.

PURPOSE: To develop methods for evaluating effectiveness of YAG-laser vitreolysis of vitreous floaters. MATERIAL AND METHODS: The study included 144 patients (173 eyes) who had underwent YAG-laser vitreolysis and were under observation from 01.09.16 to 31.01.18. The patients were 34 to 86 years old (mean age 62.7±10.2 years), 28 (19.4%) patients were male, 116 (80.6%) - female. All patients underwent standard and additional examination: ultrasonography (Accutome B-scan plus, U.S.A.), optic biometry (Lenstar 900, Haag-Streit, Switzerland), spectral optical coherence tomography using RTVue XR Avanti scanner (Optovue, U.S.A.) in modes Enhanced HD Line, 3D Retina, 3D Widefield MCT, Cross Line, Angio Retina, and scanning laser ophthalmoscopy (SLO) using Navilas 577s system. Laser vitreolysis was performed using the Ultra Q Reflex laser (Ellex, Australia). RESULTS: This paper presents methods of objective quantitative and qualitative assessment of artifactual shadows of vitreous floaters with spectral optical coherence tomographic scanner RTVue xR Avanti employing an algorithm of automatic detection of non-perfusion zones in modes Angio Retina, HD Angio Retina, as well as foveal avascular zone (FAZ) measurement with Angio Analytics® software. SLO performed with Navilas 577s was used as method of visualizing floaters and artifactual shadows in retinal surface layers prior to surgical treatment and after YAG-laser vitreolysis. CONCLUSION: Suggested methods of quantitative and qualitative assessment of artifactual shadows of the floaters in retinal layers are promising and may prove to be highly relevant for clinical monitoring of patients, optimization of treatment indications and evaluating effectiveness of YAG-laser vitreolysis. Further research of laser vitreolysis effectiveness in patients with vitreous floaters is necessary.

The biological acoustic sensor to record the interactions of the microbial cells with the phage antibodies in conducting suspensions.

The acoustic biological sensor for the analysis of the bacterial cells in conducting suspension was developed. The sensor represented the two channel delay line based on the piezoelectric plate of Y-X lithium niobate thick of 0.2mm. Two pairs of the interdigital transducers (IDT) for the excitation and reception of shear horizontal acoustic wave of zero order (SH0) in each channel were deposited by the method of photolithography. One channel of the delay line was electrically shorted by the deposition of thin aluminum film between IDTs. The second channel remained as electrically open. The liquid container with the volume of 5ml was fixed on the plate surface between IDTs by the glue, which did not cause the additional insertion loss. For the first time the influence of the conductivity of the cell suspension on the registration of the specific and nonspecific interactions of the bacterial cells with phage-antibodies (phage-Abs) was studied by means of the developed sensor. The dependencies of the change in insertion loss and phase of the output signal on the conductivity of the buffer solution at specific/nonspecific interactions for the electrically open and shorted channels of the delay line were obtained. It was shown that the sensor successfully registered the interactions of microbial cells with phage-Abs in the range of the conductivity of 2-20 µS/cm on the model samples A. brasilense Sp245 - specific phage-Abs. The sensor in the time regime of the operation fast reacted on the specific/nonspecific interaction and the time of the stabilization of the output parameters did not exceed 10min.