Effect of the Mechanism Transfer Function on the Positioning Law

Parametric synthesis of mechanical system consisting of actuator, transfer mechanism and control device is considered. Planar and spatial mechanisms with one degree of freedom can be included in the system. Mechanism structure and the type of the actuator are considered to be given preliminary.     Keywords: synthesis, mechanism, drive, contro

Using a microheterogeneous model to assess the applicability of ion-exchange membranes in the process of reverse electrodialysis

Received: 30.03.2021. Revised: 28.04.2021. Accepted: 30.04.2021. Available online: 30.04.2021.This paper shows the possibility of using a microheterogeneous model to describe the properties of ion-exchange membranes and calculate the characteristics of a reverse electrodialyzer from the data obtained. We studied the properties of eight samples of heterogeneous cation exchange membranes (two samples of each type of membrane). The samples differed in the year of issue and storage conditions. It is shown that for heterogeneous ion-exchange membranes MK-40 and MA-41, the samples' properties can differ significantly. The counterions transport numbers calculated within the framework of the microheterogeneous model for Ralex membranes differ insignificantly. The counterion transport number in 1 mol/L sodium chloride solution is 0.96 for Ralex CM and 0.98 ± 0.01 for Ralex AMH. For the MK-40 membrane, the transport number in the same solution is 0.94 ± 0.04, and for the MA-41 membrane, it is 0.85 ± 0.1. The possibility of calculating the transport numbers and predicting the open-circuit voltage based on simple physicochemical measurements allows selecting the best membrane pairs for the reverse electrodialysis process. Comparison of the open-circuit potential value calculated using the obtained transfer numbers with experimental data showed that in the case of using Ralex membranes, the difference between the experimental and calculated values is 2%. The calculated value of the open circuit potential was 0.19 V/membrane pair or 1.69 V for the investigated reverse electrodialyzer with nine pair chambers.The research was carried out with the financial support of the Kuban science Foundation in the framework of the scientific project № IFR-20.1/110

MELT INCLUSIONS IN OLIVINE AS A SOURCE OF INFORMATION ON THE COMPOSITION AND EVOLUTION OF DEEP MELTS OF AILLIKITES (ULTRAMAFIC LAMPROPHYRES) OF THE ILBOKICHI UPLIFT, THE SW SIBERIAN PLATFORM

Aillikites are kimberlite-like rocks, important for understanding the composition and processes occurring in the mantle. Melt inclusions represent a reliable source of information. The paper provides the first results of studies (Raman, EDS) on primary and secondary melt inclusions in olivine from the Ilbokich uplift aillikites. The composition of primary inclusions is close to that of parent melt of aillikites. It was significantly enriched in CO2, H2O, phosphorus and titanium. Phlogopite, diopside, dolomite, calcite, apatite, Ti-containing phases (brookite, perovskite, Ti-magnetite) and lizardite were identified in these inclusions. The similarity of the composition and ratios of the daughter phases with the aillikite matrix indicates a slight change in the parent melt when it is rising to the surface. As to the secondary inclusions, there are wide variations in compositions and a smaller amount of silicates, as compared to the primary ones. The main daughter phases are carbonates, e.g. dolomite, calcite, magnesite and alkaline carbonates. In addition, phlogopite, clinopyroxene, apatite, halite, pyrrhotite and magnetite, graphite and CO2 were discovered. The variability of the compositions of the secondary inclusions might be due to the silicate-carbonate immiscibility that appeared during the rising of the aillikite melt at pressures <4 GPa

Composition of oils of carbonate reservoirs in current and ancient water-oil contact zones

© 2015 Springer Science+Business Media New York. Differences in the composition of heavy oils from ancient and current water-oil contact (WOC) zones of productive strata of carbonate reservoirs of deposits of Bashkir and Turnei (Tatarstan) stages are discerned by applying a host of physicochemical methods, namely, elemental analysis, liquid-adsorption chromatography, gas chromatography, IR spectroscopy, and EPR spectroscopy. There is no direct connection of the composition of the hydrocarbons with the secondary changes of the reservoirs and their filtration-capacity parameters. Signs of seepage of light hydrocarbons are detected in the ancient WOC zones characterized by the presence of products of biochemical degradation of high-molecular-weight components of residual oil. This provides a basis for suggesting that these zones are not only fluid-supports but also migration channels for interstratal seepages of hydrocarbons during formation and development of oil reservoirs

Distress symptoms development after a single episode of ultrasound exposure

Aim. To study the influence of a single 24-hour episode of exposure to ultrasound waves propagating in air on microcirculation and parameters of hemostasis in rats. Methods. The study was performed on 28 Wistar male rats. The experimental group was exposed to ultrasound for 24 hours. Geometric mean frequency was 25 kHz, acoustic pressure was 84.3 dB. Parameters of microcirculation of experimental rats received by laser Doppler flowmetry were compared with those of intact animals. Also comparative analysis of platelet and coagulation hemostasis, anticoagulant and fibrinolytic plasma activity was performed in rats from both groups. Results. In experimental rats in response to 24-hour exposure to ultrasound, significant decrease of the studied active and passive factors of blood flow modulation occurred compared to those of intact animals: parameters of microcirculation, flax, endothelial and vasomotor wave amplitude, respiratory and pulse wave amplitude. When studying the parameters of hemostasis, significant hypercoagulation of extrinsic pathway and at the latest stages of coagulation which worsened with anticoagulant plasma activity inhibition along with decrease of fibrinolytic activity. The character of changes of hemostatic parameters confirmed the development of stress-reaction in rats registered during the study of microcirculation. Conclusion. 24-hour ultrasound exposure causes significant disorders of microcirculation and unfavorable shifts in hemostasis - the signs of distress

Структурные особенности синтетических гликоконъюгатов и эффективность их взаимодействия с гликопротеиновыми рецепторами на поверхности гепатоцитов

Objectives. Over the last few years, medicinal chemistry research has been focusing on the creation of molecules that can target particular body systems, organs and tissues, thus abating systemic toxicity and side effects, and, most of all, boosting therapeutic potential. This goal can be achieved through the specific interaction of such drugs with active sites of cellular receptors. For example, glycoprotein receptors that can be found on cellular surfaces in neural tissues and liver parenchyma, selectively bind various glycoproteins and glycosides, facilitating their penetration into cells. This review describes how certain parameters of ligand structure (the nature and length of the spacer between carbohydrate and non-carbohydrate fragments of the molecule, number of carbohydrate residues per molecule, etc.) influence the penetration efficiency of synthetic glycoconjugates into liver cells.Methods. This review article summarizes 75 research papers and discusses data from in vitro and in vivo experiments showing which structures of synthetic carbohydrate derivatives are optimal for targeted drug delivery into liver cells.Results. The surface of liver cells (hepatocytes) contains a significant number of asialoglycoprotein receptors (ASGP-R) that are almost never found elsewhere. This makes ASGP-R an ideal target for the directed treatment of liver diseases, including such difficult, socially important conditions as hepatocellular carcinoma and Hepatitis C. A number of various ligands and targeted (to ASGP-R) delivery systems have been designed. Such molecules always contain derivatives of mono- and disaccharides, most commonly D-glucose, D-galactose, D-lactose and N-acetylglucosamines. This review contains the chemical structures of carbohydrate-based ligands.Conclusions. Glycolipids based on D-carbohydrates, when in liposomes, facilitate penetration into liver cells by a receptor-mediated, clathrin-dependent endocytosis mechanism that is activated upon contact of the carbohydrate-containing ligand fragment with the active site of ASGP-R. It can be addressed by the use of monovalent derivatives of carbohydrates as well as polyvalent glycoconjugates. Alterations in the ligand structure and the number of liposomal modifications can boost the therapeutic effect. The distance between the liposomal surface and the carbohydrate residue (spacer length), as well as the hydrophilic-lipophilic balance of the ligand molecule, have a great effect on the affinity and cellular response.Цели. Последние несколько лет исследования в области медицинской химии уделяют большое внимание созданию молекул, направленно воздействующих на конкретные системы организма человека, органы и ткани, что помогает снизить общее токсическое воздействие препаратов на их основе, уменьшить степень проявления побочных эффектов, а самое главное – многократно усилить их терапевтический эффект. Это может быть достигнуто при помощи специфического взаимодействия подобных веществ с активными центрами клеточных рецепторов. Например, класс гликопротеиновых рецепторов, располагающихся на поверхности клеток нервной ткани и паренхимы печени, селективно связывает различные гликопротеины и гликозиды, способствуя их проникновению внутрь клеток. В обзоре рассмотрено влияние таких особенностей структуры лигандов, как природа и длина связующего звена (спейсера) между углеводной и неуглеводной частями молекулы, количество углеводных остатков в составе одной молекулы, а также ряда других, на эффективность проникновения синтетических гликоконъюгатов в клетки печени.Методы. В обзоре проанализировано 75 публикаций и обобщены результаты исследований, в которых с помощью in vitro и in vivo экспериментов устанавливается, какая структура искусственно синтезированных производных углеводов окажется наиболее оптимальной для направленной доставки лекарственных средств в клетки печени.Результаты. На поверхности гепатоцитов (клеток печени) в большом количестве представлен асиалогликопротеиновый рецептор (ASGP-R), который почти не встречается на других типах клеток, что делает его идеальным рецептором-мишенью для направленного лечения заболеваний печени, в том числе таких трудно излечимых социально значимых заболеваний, как гепатоцеллюлярная карцинома и гепатит С. Разработан ряд разнообразных лигандов и систем направленной доставки к ASGP-R. Такие молекулы обязательно имеют в составе производные монои дисахаридов, чаще всего применяются D-глюкоза, D-галактоза, D-лактоза и N-ацетилглюкозамины. В обзоре приводятся примеры химических структур углеводсодержащих лигандов.Заключение. Гликолипиды на основе D-углеводов в составе липосом обеспечивают их проникновение в клетки печени по механизму рецептор-опосредованного клатрин-зависимого эндоцитоза, который активируется при контакте углеводсодержащей части лиганда с активным центром ASGP-R. Показано, что для этого можно использовать как моновалентные производные углеводов, так и поливалентные гликоконъюгаты. Варьируя структуру лиганда и количество добавляемых к липосоме модификаций, можно достичь наибольшего терапевтического эффекта. Большое влияние на аффинность и клеточный ответ оказывают расстояние от поверхности липосомы до углеводного остатка (длина спейсера) и гидрофильно-липофильный баланс молекулы лиганда

2-AZINYL QUINAZOLINES: SYNTHESIS AND PHOTOPHYSICAL PROPERTIES

This work was supported by the Russian Scientific Foundation (project 22-23-00006)

THE SPECTRAL ANALYSIS OF HEART RATE VARIABILITY - A NEW VIEW ON THE PROBLEM OF AUTONOMIC DYSFUNCTION IN CHILDREN WITH ASTHMA

Purpose: To investigate the state of autonomic nervous system in patients with asthma during the period of both aggravation and remission of the disease.Materials and Methods: 121 patients are examined in the study (81 during the period of an exacerbation of a disease and 40 during the remission). The study of autonomic nervous system state was performed by using cardioanalizator «ANKAR-131».Results: According to the spectral analysis of heart rate variability in children of both groups the predominance of slow waves II order were noted in spectrogram, it testifying to increase of humoral-metabolic effects. The VLF waves made 2700,275±248,35мс2 values spectral power averaged in children during the period of remission of the disease. The vagosympathetic balance factor (LF/ HF) in 33,3% of patients experiencing an attack of asthma and in 42,5% of patients during the remission of the disease is greater than 2,0, it indicating activation of sympathetic nervous system.Summary: Analyzing the data one can say that the findings of the spectral analysis of heart rate variability in children with asthma are early markers of abnormal autonomic regulation

Patterns in recent and Holocene pollen accumulation rates across Europe - the Pollen Monitoring Programme Database as a tool for vegetation reconstruction

The collection of modern, spatially extensive pollen data is important for the interpretation of fossil pollen assemblages and the reconstruction of past vegetation communities in space and time. Modern datasets are readily available for percentage data but lacking for pollen accumulation rates (PARs). Filling this gap has been the motivation of the pollen monitoring network, whose contributors monitored pollen deposition in modified Tauber traps for several years or decades across Europe. Here we present this monitoring dataset consisting of 351 trap locations with a total of 2742 annual samples covering the period from 1981 to 2017. This dataset shows that total PAR is influenced by forest cover and climate parameters, which determine pollen productivity and correlate with latitude. Treeless vegetation produced PAR values of at least 140 grains cm(-2) yr(-1). Tree PAR increased by at least 400 grains cm(-2) yr(-1) with each 10% increase in forest cover. Pollen traps situated beyond 200 km of the distribution of a given tree species still collect occasional pollen grains of that species. The threshold of this long-distance transport differs for individual species and is generally below 60 grains cm(-2) yr(-1). Comparisons between modern and fossil PAR from the same regions show similar values. For temperate taxa, modern analogues for fossil PARs are generally found downslope or southward of the fossil sites. While we do not find modern situations comparable to fossil PAR values of some taxa (e.g. Corylus), CO2 fertilization and land use may cause high modern PARs that are not documented in the fossil record. The modern data are now publicly available in the Neotoma Paleoecology Database and aid interpretations of fossil PAR data.Peer reviewe

Genome-Wide Mycobacterium tuberculosis Variation (GMTV) Database: A New Tool for Integrating Sequence Variations and Epidemiology

Background Tuberculosis (TB) poses a worldwide threat due to advancing multidrug-resistant strains and deadly co-infections with Human immunodeficiency virus. Today large amounts of Mycobacterium tuberculosis whole genome sequencing data are being assessed broadly and yet there exists no comprehensive online resource that connects M. tuberculosis genome variants with geographic origin, with drug resistance or with clinical outcome. Description Here we describe a broadly inclusive unifying Genome-wide Mycobacterium tuberculosis Variation (GMTV) database, (http://mtb.dobzhanskycenter.org) that catalogues genome variations of M. tuberculosis strains collected across Russia. GMTV contains a broad spectrum of data derived from different sources and related to M. tuberculosis molecular biology, epidemiology, TB clinical outcome, year and place of isolation, drug resistance profiles and displays the variants across the genome using a dedicated genome browser. GMTV database, which includes 1084 genomes and over 69,000 SNP or Indel variants, can be queried about M. tuberculosis genome variation and putative associations with drug resistance, geographical origin, and clinical stages and outcomes. Conclusions Implementation of GMTV tracks the pattern of changes of M. tuberculosis strains in different geographical areas, facilitates disease gene discoveries associated with drug resistance or different clinical sequelae, and automates comparative genomic analyses among M. tuberculosis strains