Scattering properties of singular and aggregate atmospheric hexagonal ice particles

This paper presents the results of calculating and analyzing the light scattering matrix of aggregates of atmospheric hexagonal ice particles located in cirrus clouds. Two types of basic particle shapes for aggregates are considered: a hexagonal column and a hexagonal plate. For both forms, two types of particle arrangement in aggregates were chosen: compact and non-compact. As a result, 4 sets of aggregates were built: compact hexagonal columns, non-compact hexagonal columns, compact hexagonal plates, and non-compact hexagonal plates. Each set consists of 9 aggregates differing in the number of particles in them, and the particles in each individual aggregate have the same shape and size, but different spatial orientation. The light scattering matrices for all aggregates were calculated for the case of arbitrary orientation in the geometric optics approximation. Dependences of the first element of the matrix on the number of particles in aggregate, with different types of particle arrangement, and for two types of shapes are give

Data bank of light backscattering matrices for atmospheric ice crystals of non-convex shape for wavelengths 0.355, 0.532, 1.064 μm

This paper presents the results of calculation and analyzes the light scattering matrix of random oriented ice particles of non-convex shape (hollow column) with cavity angles from 0 to 50 degrees for lidar wavelengths of 0.355, 0.532, and 1.064 microns and refractive indices of 1.3249, 1.3116, and 1.3004. The calculation was carried out within both physical and geometrical optics approximation methods for particle sizes varied from 10 to 100 microns. As a result, it is shown that differential scattering cross-section for non-convex shape (hollow column) demonstrates a power-law dependence on the particle size. However, the linear depolarization ratio has no simple dependence on particle size and is practically independent of wavelength for small particles (L<50 μm). The linear depolarization ratio increases from 0.2 up to 0.5–0.8 with an increase of the cavity angle of the crystal. The elements of the light scattering matrix depending on scattering and cavity angle are give

Calculation of the lidar signal by the DDA method applied to the data of satellite remote sensing of cirrus clouds for climate change detection

The purpose of this work is to solve an important issue: the light scattering problem for ice crystals of cirrus clouds less than 10 μm and matching the obtained solution with the existing solution obtained within the physical optics approximation. The article presents a solution to the problem of light scattering by hexagonal ice particles of cirrus clouds with sizes from 0.05 to 5.17 μm for a wavelength 0.532 μm, obtained within the discrete dipole approximation. It is found that the obtained solution is in good agreement with the physical optics approximation in the vicinity of scattering angles of 0–10є (the vicinity of forward direction scattering). However, to solve the problem of light scattering in the vicinity of the backward scattering direction, which is important for the interpretation of lidar data, it is necessary to continue the calculations to sizes of the order of 20 μm. The results obtained are necessary for constructing algorithms for the interpretation of lidar data obtained by sounding cirrus clouds

Changes in the respiratory function of the heart and brain mitochondria of animals after chronic alcohol intoxication affected by a new GABA derivative

The compound RSPU-260, and the reference drug Mildronate improve mitochondrial oxidative phosphorylation in heart and brain cells, the functioning of antioxidant enzymes in animals after CAI, and can be used to correct alcoholic damage to these organ

Spectral and depolarization ratios for atmospheric ice particles of hexagonal and arbitrary shape within the framework of the physical optics and discrete dipoles

The optical characteristics of atmospheric ice particles are usually calculated within the framework of the physical optics approximation, since particle sizes generally vary from 10 to 1000 microns. However, the results of experimental measurements show that ice crystals up to 10 microns in size are observed in cirrus clouds of the upper tier. The report presents a solution to the problem of light scattering for particles, obtained in the framework of the methods of the physical optics and discrete dipoles. Based on the solution, such important optical characteristics as depolarization and spectral ratios were calculated. Two limiting cases are considered: ideal hexagonal particles and randomly shaped particles

THE COMPLEXITY OF DIAGNOSING IDIOPATHIC PULMONARY ARTERIAL HYPERTENSION

Idiopathic pulmonary arterial hypertension is a progressive, incurable disease of unclear etiology; it is characterized by intensive remodeling of the pulmonary vascular bed with a predominant lesion of the distal pulmonary arteries and arterioles. A diagnostic criterion of the disease is an increase in the average pressure in the pulmonary artery more than 25 mm Hg. Arterial hypertension is difficult to diagnose, especially at the early stages due to non-specific clinical symptoms. The article describes the clinical case of diagnostics and treatment of a child with primary pulmonary hypertension of high degree

Portopulmonary hypertension in a child

The paper deals with portopulmonary hypertension (pulmonary arterial hypertension associated with portal hypertension). Pulmonary hypertension is a rare, prognostically unfavorable complication of portal hypertension, regardless of the etiological factor of the latter. The diagnostic criteria for portopulmonary hypertension are portal hypertension with or without liver disease; a resting mean pulmonary artery pressure &gt;25 mm Hg; a normal pulmonary artery wedge pressure &lt;15 mm Hg; and a pulmonary vascular resistance of more than 3 Wood units/m2. Objective: to describe of the development of the clinical picture, diagnosis, and treatment of portopulmonary hypertension in a patient during corrected portal hypertension. There are challenges in the diagnosis of portopulmonary hypertension because its symptoms are nonspecific. The most characteristic symptoms of the disease are dyspnea, fatigue, exercise intolerance, and syncope

Neonatal screening for life-threatening conditions persistent – pulmonary hypertension in newborns and critical congenital heart disease – by the method of pulse oximetry

Research objective: to assess the diagnostic significance of the pulse oximetry performed by the newborn for the 3rd hour of life to identify critical conditions and to justify the expediency of further introduction of this technology in the work of obstetric institutions.Results. In 5 maternity hospitals of the Republic of Tatarstan, from April 2016 to February 2017, 8358 88.4% of newborns were pulsometrically screened. Positive results were obtained in 95 (1.14%) patients. Because of screening, 13 newborns were diagnosed with congenital heart defects, not diagnosed in utero, in the first hours of life, five of them were critical. All newborns with critical congenital heart defects were successfully operated. Besides, 20 patients had persistent pulmonary hypertension, 30 had intrauterine pneumonia.Conclusions. The measurement of saturation at the 3rd hour of life of a newborn allows avoiding life-threatening complications in children with critical congenital heart defects and persistent pulmonary hypertension and in a stable state to transfer them to a further treatment stage