FEATURES OF OUTFLOW OF INTRAOCULAR LIQUID AFTER AN EKSIMERLAZER SKLEREKTOMY (PILOT STUDY)

Modern approaches to surgical glaucoma treatment is based on the safe and effective methods. In recent years, great attention is paid to the techniques of stimulating uveoscleral path outtake aqueous humor from the eye. Uveoscleral space in the extended outflow pathways is dominant and constitutes about 72%. Sclera is a field of the greatest interest, as the end stages of the outflow of aqueous humor via the uveoscleral path. The aim of the study was to investigate the influence of excimer laser sclerectomy on the drainage function of the eye and development of a mathematical model based on the permeability of the sclera of the amount of laser ablation at a defined area of laser exposure and the level of IOP. Studies were conducted on 12 human cadaver eyes isolated person. The domestic excimer laser “MicroScan Vizum” with a wavelength of 193нм (0,193 µm) was used for the thinning of sclera. In the experiment used a special computer program provided ablation of scleral tissue, the scleral bed forming a rectangular shape with a size 7,0x5,0 mm. the Depth of influence started from 100 microns to 600 microns in increments of 50 µn. The exposure was carried out at a constant perfusion pressure of 25 mm Hg After each impact was measured of the coefficient ease the outflow. A correlation was established between the factor and effective features, i.e., between the excimer laser deep sclerectomy (µm) and ratio of lightness outflow (mm3/min/mm Hg.St). Thinning of the sclera leads to an improvement of its permeability and increasing the coefficient ease the outflow. A mathematical model, allowing to achieve the desired ratio of lightness outflow experiment by excimer laser sclerectomy was developed. The mathematical model has the form of the regression equation.The sclera is a promising object for further developments in the surgical treatment of glaucoma. Laser ablation of the sclera leads to an improvement of outflow via the uveoscleral path and reduce intraocular pressure

НЕОДНОРОДНОСТЬ РАСПРЕДЕЛЕНИЯ ЭЛЕКТРИЧЕСКИХ ТРАНСМЕМБРАННЫХ ПОТЕНЦИАЛОВ ПРИ ДЕФИБРИЛЛЯЦИИ СЕРДЦА

The need for emergency cessation of ventricular fibrillation is one of the problems of modern reanimatology. In spite of searches for novel methods, there is the only effective method — electrical cardiac defibrillation.Objective: to investigate the effect of different forms of pulses on cell membranes in a model experiment and to assess their use for effective cardiac defibrillation.Materials and methods. The Maxwell model was used for theoretical analysis of the spatial distribution of an electric field in the red blood cell membrane. The electric effect on a single cell was calculated using the experimental findings and the equivalent electrical circuit of the myocardial structure during a defibrillation procedure. The cardiomyocyte membrane potential upon exposure to defibrillator discharge was estimated. Exposure of the red blood cell membrane to single, two unipolar and two heteropolar pulses was examined.Results. There is non-additivity of speeds upon double exposure as compared to single one. Single pulse causes a lower effect of electroporation than two double pulses. Hyperpolarization and depolarization processes in the cardiomyocyte membranes occur successively during electrical cardiac defibrillation.Conclusion. Two heteropolar pulses cause an effect of biological membrane electroporation with a greater probability than two unipolar ones.Одной из проблем современной реаниматологии является необходимость экстренного прекращения фибрилляции желудочков сердца. Несмотря на поиски новых методов, существует лишь единственный эффективный метод – электрическая дефибрилляция сердца.Цель работы — исследование действия импульсов различных форм на мембраны клеток в модельном эксперименте и оценка их использования для проведения эффективной дефибрилляции сердца.Материалы и методы. Для теоретического анализа пространственного распределения электрического поля в мембране эритроцитов использовалась модель Максвелла. Расчет электрического воздействия на отдельную клетку проведен по полученным экспериментальным данным и исходя из эквивалетной электрической схемы структуры миокарда при проведении процедуры дефибрилляции. Рассчитывали потенциал, наводимый на мембране кардиомиоцита при воздействии разряда дефибриллятора. Изучали воздействие монополярного, двух однополярных и двух разнополярных импульсов на мембраны эритроцитов.Результаты. Наблюдается неаддитивность скоростей при двухкратном действии по сравнению с однократным. Одиночный импульс вызывает меньший эффект электропорации, чем два двойных. При электрической дефибрилляции сердца последовательно реализуются процессы гиперполяризации и деполяризации мембран кардиомиоцитов.Заключение. Два разнополярных импульса с большей вероятностью вызывают эффект электропорации биологических мембран по сравнению с двумя однополярными

Planet Consumption and Stellar Metallicity Enhancements

The evolution of a giant planet within the stellar envelope of a main-sequence star is investigated as a possible mechanism for enhancing the stellar metallicities of the parent stars of extrasolar planetary systems. Three-dimensional hydrodynamical simulations of a planet subject to impacting stellar matter indicate that the envelope of a Jupiter-like giant planet can be completely stripped in the outer stellar convection zone of a solar-mass star. In contrast, Jupiter-like and less massive Saturn-like giant planets are able to survive through the base of the convection zone of a 1.22 solar-mass star. Although strongly dependent on details of planetary interior models, partial or total dissolution of giant planets can result in significant enhancements in the metallicity of host stars with masses between about 1.0 and 1.3 solar masses. The implications of these results with regard to planetary orbital migration are briefly discussed.Comment: 11 pages, 2 figures, accepted for ApJ Letter

An algebraic method of classification of S-integrable discrete models

A method of classification of integrable equations on quad-graphs is discussed based on algebraic ideas. We assign a Lie ring to the equation and study the function describing the dimensions of linear spaces spanned by multiple commutators of the ring generators. For the generic case this function grows exponentially. Examples show that for integrable equations it grows slower. We propose a classification scheme based on this observation.Comment: 11 pages, workshop "Nonlinear Physics. Theory and Experiment VI", submitted to TM

Classification of integrable discrete Klein-Gordon models

The Lie algebraic integrability test is applied to the problem of classification of integrable Klein-Gordon type equations on quad-graphs. The list of equations passing the test is presented containing several well-known integrable models. A new integrable example is found, its higher symmetry is presented.Comment: 12 pages, submitted to Physica Script

Extremely polysubstituted magnetic material based on magnetoplumbite with a hexagonal structure: Synthesis, structure, properties, prospects

Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the µm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure barium hexaferrite BaFe 12 O 19 matrix. The polysubstituted high-entropy single-phase product contains five doping elements at a high concentration level. According to the EDX data, the new compound has a formula of Ba(Fe6Ga1.25In1.17Ti1.21Cr1.22Co1.15)O19. The calculated cell parameter values were a = 5.9253(5) Å, c = 23.5257(22) Å, and V = 715.32(9) Å3. The increase in the unit cell for the substituted sample was expected due to the different ionic radius of Ti/In/Ga/Cr/Co compared with Fe3+. The electrodynamicmeasurements were performed. The dielectric and magnetic permeabilities were stable in the frequency range from 2 to 12 GHz. In this frequency range, the dielectric and magnetic losses were??0.2/0.2. Due to these electrodynamic parameters, this material can be used in the design of microwave strip devices. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The work was supported by the Russian Science Foundation, project No. 18-73-10049