OXIDATIVE STRESS AS A PATHOGENETIC LINK OF ACUTE ETHANOL POISONING AND ITS CORRECTION WITH CHELATE ZINC COMPOUNDS

The data on the expressed toxic effect of ethanol in dose DL50 (12 g/kg) on experimental rats were received. The toxic effect was expressed in significant stimulation of processes of lipid peroxidation against the background of antioxidant system suppression. While evaluating the results of statistic analysis it was proved, that new chelate zinc (2,8,9-trihydrozincatrane) in the protective dose of 4 mg/kg under conditions of the acute ethanol poisoning reduces the severity of oxidative stress and normalizes indicators of antioxidant system

P-selectin mobility undergoes a sol-gel transition as it diffuses from exocytosis sites into the cell membrane

In response to vascular damage, P-selectin molecules are secreted onto the surface of cells that line our blood vessels. They then serve as mechanical anchors to capture leucocytes from the blood stream. Here, we track individual P-selectin molecules released at the surface of live endothelial cells following stimulated secretion. We find P-selectin initially shows fast, unrestricted diffusion but within a few minutes, movement becomes increasingly restricted and ~50% of the molecules become completely immobile; a process similar to a sol-gel transition. We find removal of the extracellular C-type lectin domain (ΔCTLD) and/or intracellular cytoplasmic tail domain (ΔCT) has additive effects on diffusive motion while disruption of the adapter complex, AP2, or removal of cell-surface heparan sulphate restores mobility of full-length P-selectin close to that of ΔCT and ΔCTLD respectively. We have found P-selectin spreads rapidly from sites of exocytosis and evenly decorates the cell surface, but then becomes less mobile and better-suited to its mechanical anchoring function

УПРУГОНАПРЯЖЕННЫЕ СЛОИ И НАНООСТРОВКИ GESISN В МНОГОСЛОЙНЫХ ПЕРИОДИЧЕСКИХ СТРУКТУРАХ

This work deals with elastically strained GeSiSn films and GeSiSn islands. Kinetic diagram of GeSiSn growth at different lattice mismatches between GeSiSn and Si has been established. Multilayer periodic structures with pseudomorphic GeSiSn layers and GeSiSn island array have been obtained. The density of the islands in the GeSiSn layer reaches 1.8 ⋅ 1012 cm−2 at an average island size of 4 nm. Analysis of the rocking curves showed that the structures contain smooth heterointerfaces, and strong changes of composition and thickness from period to period have not been found. Photoluminescence has been demonstrated and calculation of band diagram in the model solid theory approach has been carried out. Luminescence for the sample with pseudomorphic Ge0.315Si0.65Sn0.035 layers in narrow range of 0.71—0.82 eV is observed with the maximum intensity near 0.78 eV corresponding to a 1.59 µm wavelength. Based on a band diagram calculation for Si/ Ge0.315Si0.65Sn0.035/Si heterocomposition, one can conclud that luminescence with a photon energy of 0.78 eV corresponds to interband transitions between the X−valley in the Si and the heavy hole subband in the Ge0.315Si0.65Sn0.035 layer.Установлена кинетическая диаграмма морфологического состояния пленок GeSiSn при несоответствии параметров решетки между GeSiSn и Si от 3 до 5 %. На основе подбора толщины пленки GeSiSn выращены многослойные периодические структуры с псевдоморфными слоями и слоями, содержащими массив островков GeSiSn с плотностью до 1,8 ⋅ 1012 см−2 и средним размером 4 нм. Проведен анализ кривых дифракционного отражения для многослойных периодических структур. Показано наличие гладких гетерограниц, псевдоморфное состояние пленок GeSiSn и отсутствие изменений состава, а также толщины от периода к периоду. Получены спектры фотолюминесценции для структуры с псевдоморфными слоями Ge0,315Si0,65Sn0,035 с максимумом интенсивности фотолюминесценции вблизи 0,78 эВ, что соответствует длине волны 1,59 мкм. Проведен расчет зонной диаграммы с использованием подхода model solid theory. Исходя из результатов расчета зонной диаграммы, установлено, что обнаруженный пик люминесценции соответствует межзонным переходам между X−долиной в Si или между ∆4−долиной в Ge0,315Si0,65Sn0,035 и подзоной тяжелых дырок в слое Ge0,315Si0,65Sn0,035. Результаты исследований демонстрируют бездислокационные структуры с упругонапряженными псевдоморфными слоями и слоями, включающими массив островков высокой плотности. Дальнейшее изучение многослойных периодических структур будет направлено на увеличение содержания Sn и сравнение оптических свойств структур с островками и без островков

Acute toxicity of pyridoxine hydrochloride-containing and noncontaining antituberculosis drugs (an experimental study)

This experimental study established DL50 (mg/kg), the degree of toxicity, and a hazard class for 17 antituberculosis drugs (OAO «Farmasintez», Irkutsk). Experiments were performed on experimental biological models: albino outbred rats (n = 3 400) and mice (n = 3 400). The incorporation of pyridoxine hydrochloride into combined antituberculosis drugs was found to considerably decrease their toxicity

Elastically stressed pseudomorphic SiSn island array formation with a pedestal on the Si(1 0 0) substrate using Sn as a growth catalyst

The Sn-rich islands with a Si pedestal on the Si(1 0 0) substrate were obtained by the molecular-beam epitaxy technique. Initially, Sn films of different thicknesses were formed on the Si surface and then annealed to create the Sn island arrays, which were used as nanoobject growth catalysts. The Sn island density reaches up to 6 × 109 cm−2, whereas the Sn island sizes are changed in the range of 40–180 nm. The Sn-rich islands with the Si pedestal were first appeared after the Si deposition on the surface with the Sn islands in the temperature range of 300–450 °C. The new obtained nanostructures have the island density up to 4 × 108 cm−2 and the island sizes, which varied from 60 to 400 nm. The island growth with the pedestal occurred on the vapor-liquid-solid mechanism. The chemical analysis of the samples carried out using the energy-dispersive X-ray spectroscopy indicated the presence of the Sn-rich region on the top of nanoobjects. The intense photoluminescence from the Sn-rich islands with the Si pedestal was detected. The photoluminescence peak takes place at 1.55 µm

The Temperature Interval of the Liquid–Glass Transition of Amorphous Polymers and Low Molecular Weight Amorphous Substances

We present calculation results of the temperature interval δTg characterizing the liquid–glass transition in amorphous materials obtained on the basis of available data of the empirical parameters C1 and C2 in the Williams–Landel–Ferry (WLF) viscosity equation. We consider the unambiguous dependence of the relative transition temperature interval δTg/Tg on the fraction of the fluctuation volume fg frozen at the glass transition temperature Tg utilizing Sanditov’s model of delocalized atoms. The parameter f = ΔVe/V, which determines the molecular mobility characteristic of delocalized atoms in the liquid–glass transition region, is weakly dependent on the nature of most vitreous substances and can be found as fg = 1/C1. We show that the temperature interval δTg is less than 1% of the Tg for most amorphous substances. This result conforms with Simon’s classical idea of a small temperature range in which the structure freezes. The structural relaxation time τg at Tg of polymers and chalcogenide glasses is also calculated

Synthesis of epitaxial films based on Ge-Si-Sn materials with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions

Results of investigations into the synthesis of heterostructures based on Ge–Si–Sn materials by the method of low-temperature molecular beam epitaxy are presented. The formation of epitaxial films during structure growth has been controlled by the reflection high-energy electron diffraction method. Films with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions are grown with Sn content changing from 2 to 10 % at temperatures in the interval 150–350°С. The stressed state, the composition, and the lattice parameter are studied by the x-ray diffraction method using Omega-scan curves and reciprocal space maps. A tensile strain in the Ge film during Ge/Ge0.9Sn0.1/Si structure growth has reached 0.86%

Formation of SnO and SnO2 phases during the annealing of SnO(x) films obtained by molecular beam epitaxy

SnO and SnO2 films were obtained on the SiO2 surface by the molecular-beam epitaxy method. The initial film

Synthesis of epitaxial films based on Ge-Si-Sn materials with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions

Results of investigations into the synthesis of heterostructures based on Ge–Si–Sn materials by the method of low-temperature molecular beam epitaxy are presented. The formation of epitaxial films during structure growth has been controlled by the reflection high-energy electron diffraction method. Films with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions are grown with Sn content changing from 2 to 10 % at temperatures in the interval 150–350°С. The stressed state, the composition, and the lattice parameter are studied by the x-ray diffraction method using Omega-scan curves and reciprocal space maps. A tensile strain in the Ge film during Ge/Ge0.9Sn0.1/Si structure growth has reached 0.86%

Growth of epitaxial SiSn films with high Sn content for IR converters

Growth of SiSn compounds with a Sn content from 10 to 35% is studied. The morphology and surface structure of the SiSn layers are examined and the kinetic diagram of the morphological state of SiSn films is established in the temperature range of 150–450°C. During the growth of SiSn films from 150 to 300°C, oscillations of specular beam were observed. For the first time, periodic multilayer SiSn/Si structures with pseudomorphic monocrystalline SiSn layers with the Sn content from 10 to 25% are grown. The c(8×4) and (5×1) superstructures are identified during the growth of Si on the SiSn layer and the conditions are determined for the formation of the desired Si surface structure by controlling the growth temperature. From the diffraction reflection curves, the lattice parameter, the SiSn composition, and the period in the multilayer periodic structure are defined, which with high precision correspond to the specified values