Influence of Synthesis Conditions on the Structure and the Surface State of Zirconia Nanoparticles

The paper studies the influence the nature of the salt anion and the base of precipitant, used in the synthesis of zirconia nanoparticles by chemical coprecipitation, on process parameters of the hydrogel drying, xerogel dehydration and crystallization, and the occurrence of polymorphic transitions in crystalline oxide systems are considered in this paper. The features of the structure, surface condition and properties of zirconia nanoparticles, which were obtained by using different precursors, are examined by FTIR and EPR spectroscopy, DSC and XRD methods. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516

Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry

In this paper we examine the role of crystal chemistry factors in creating conditions for formation of magnetoelectric ordering in BiFeO3. It is generally accepted that the main reason of the ferroelectric distortion in BiFeO3 is concerned with a stereochemical activity of the Bi lone pair. However, the lone pair is stereochemically active in the paraelectric orthorhombic beta-phase as well. We demonstrate that a crucial role in emerging of phase transitions of the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order types belongs to the change of the degree of the lone pair stereochemical activity - its consecutive increase with the temperature decrease. Using the structural data, we calculated the sign and strength of magnetic couplings in BiFeO3 in the range from 945 C down to 25 C and found the couplings, which undergo the antiferromagnetic-ferromagnetic transition with the temperature decrease and give rise to the antiferromagnetic ordering and its delay in regard to temperature, as compared to the ferroelectric ordering. We discuss the reasons of emerging of the spatially modulated spin structure and its suppression by doping with La3+.Comment: 18 pages, 5 figures, 3 table

Registration of atmospheric neutrinos with the Baikal neutrino telescope

We present first neutrino induced events observed with a deep underwater neutrino telescope. Data from 70 days effective life time of the BAIKAL prototype telescope NT-96 have been analyzed with two different methods. With the standard track reconstruction method, 9 clear upward muon candidates have been identified, in good agreement with 8.7 events expected from Monte Carlo calculations for atmospheric neutrinos. The second analysis is tailored to muons coming from close to the opposite zenith. It yields 4 events, compared to 3.5 from Monte Carlo expectations. From this we derive a 90 % upper flux limit of 1.1 * 10^-13 cm^-2 sec^-1 for muons in excess of those expected from atmospheric neutrinos with zenith angle > 150 degrees and energy > 10GeV.Comment: 20 pages, 11 figure

КОРРЕКЦИЯ ХРОНИЧЕСКОЙ ПЕЧЕНОЧНОЙ НЕДОСТАТОЧНОСТИ ПРИ ТРАНСПЛАНТАЦИИ КЛЕТОК ПЕЧЕНИ В ВИДЕ СУСПЕНЗИИ И КЛЕТОЧНО-ИНЖЕНЕРНЫХ КОНСТРУКЦИЙ (ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ)

On an experimental model of chronic fibrotic liver damage (male rats Wistar (n=60), damage of CCl4, the duration of the experiment 90 days) it was studied the effectiveness of cell therapy for the correction of chronic liver failure. These rats were divided into 3 experimental groups: in the Ist group (control, n=10) isotonic saline (650 mkl.) was injected; in the IInd group (n=20) suspension of liver cells was applicated in a dose 8-10×106 cells; in the IIIrd group (n=30) suspension of liver cells and bone marrow cells (mesenchymal stromal cells) in ratio 5:1 were used as cell associates on microparticles injectable heterogeneous biopolymer hydrogel «SpheroGEL» (cell-engineering design) in common dose 8-10×106 cells . It was ascertained that in the 2nd and in the 3rd groups the accelerated normalization of disturbed liver functional indices (ALT, AST, ALP) took place – to 30 days, but in the control group only to 90 days. The reliable differences in rats of normalization of functional indices were absent between the IInd and the IIIrd groups. But in 90 days by using special histological dyeing it was found out that defibrotic processes in liver tissue were more expressed in the IIIrd group in comparison with the IIInd group. Received results were consequence of prolonged vital activity of cells (liver cells and mesenchymal stromal bone marrow cells) into cell-engineering designs, which were transplanted in the IIIrd group. The obtained effect can be explained by that the developed cell-engineering designs provide adequate conditions for prolonged vital activity of the transplanted cells. (Авторы: С.В. Готье,М.Ю. Шагидулин, Н.А. Онищенко, М.Е. Крашенинников, И.М. Ильинский, Н.П. Можейко, А.В. Люндуп, Е.А. Волкова, К.И. Петраков, П.В.  Аврамов, Н.В. Перова, В.И. Севастьянов) На экспериментальной модели хронического фиброзирующего повреждения печени (крысы-самцы породы Вистар (n=60), затравка CCl4, длительность эксперимента 90 суток) изучена эффективность клеточной терапии при коррекции хронической печеночной недостаточности. Выполнено 3 группы опытов: I группа (n=10) – контрольная (введение физиологического раствора); II группа (n=20) – введение в печень суспензии клеток донорской печени в дозе 8-10×106 клеток; III группа (n=30) – введение в печень ассоциатов клеток донорской печени и донорских мультипотентных мезенхимальных стромальных клеток костного мозга в соотношении 5:1 и в суммарной дозе 8-10×106 клеток на микрочастицах инъекционного гетерогенного биополимерного гидрогеля СфероГЕЛЬ (клеточно-инженерные конструкции). Установлено, что клеточная терапия во II и III группах опытов способствовала достоверно ускоренной нормализации нарушенных функций печени: к 30 суткам вместо 90 суток в контроле (I группа). При этом достоверные различия в темпе нормализации функциональных показателей печени во II и III группах отсутствовали. Однако гистологический анализ показал, что через 90 суток темп дефиброзирования ткани печени в III группе был существенно более выражен, чем во II группе. Полученный эффект можно объяснить тем, что разработанные клеточно-инженерные конструкции обеспечивают адекватные условия для пролонгированной жизнедеятельности трансплантированных клеток. 

Роль цифровой диаспоры в преодолении уязвимости мигрантов в контексте пандемии covid-19 (кейс молдавских мигрантов)

Contemporary information-communication technologies contribute to the development of the quasi-institution ‘transnational migrant community’ in the form of digital diaspora. It has several functions: maintaining ties with the country of origin, ensuring transnational interaction, constructing the identity of migrants, consolidating their ethnic community and social adaptation, expressing the subjectivity of the diaspora in the public sphere, psycho-emotional support. The relevance of the study of the digital diaspora’s role in overcoming vulnerabilities of migrants under the pandemic is determined by the need to consider the adaptation of migrants in the context of the transformation of migrations and the use of contemporary information-communication technologies by migrants. The object of the study is the online groups of Moldovan migrants, which are characterized by the rapid institutionalization of diaspora organizations. The authors focus on the mechanisms of social adaptation of Moldovan migrants, which serve to overcome their vulnerabilities and risks under the pandemic with information-communication technologies. The study is based on the concept “digital diaspora” and the secondary analysis of the data from the Representative Office of the International Organization for Migration in Moldova on the Internet practices of Moldovan migrants (2017) and on the situation of migrants under the pandemic (2020). The main research method is the analysis of the content of the largest Internet groups of Moldovan migrants in the social network with the techniques “problem tree” and “decision tree”. The study showed that during the pandemic, the Internet groups of Moldovan migrants became a platform for their self-organization and overcoming vulnerabilities, and also performed informational, organizational, representative, mobilization and recreational functions. The authors believe that the experience of the Internet groups of Moldovan migrants can be extrapolated to other migrant communities and other contexts supporting the political, economic and social-cultural subjectivity of migrants.Современные информационно-коммуникативные технологии способствуют становлению квазиинститута транснационального сообщества мигрантов в качестве цифровой диаспоры. Ей свойственны несколько функций: поддержание связей со страной происхождения, обеспечение транснационального взаимодействия, конструирование идентичности мигрантов, консолидация их этнической общности и социальная адаптация, выражение субъектности диаспоры в публичной сфере, психоэмоциональная поддержка. Актуальность исследования роли цифровой диаспоры в преодолении уязвимости мигрантов в контексте пандемии обусловлена необходимостью осмысления адаптации мигрантов в условиях трансформации миграционных процессов и использования мигрантами современных информационно-коммуникативных технологий. Объект исследования - онлайн-группы молдавских мигрантов, которые характеризуются стремительной институционализацией диаспорных организаций. Предмет - механизмы социальной адаптации молдавских мигрантов, призванные преодолеть их уязвимости и риски в условиях пандемии посредством современных информационно-коммуникативных технологий. Исследование основано на концепте «цифровая диаспора» и вторичном анализе данных Представительства Международной организации по миграции в Молдове об интернет-практиках молдавских мигрантов (2017) и положении мигрантов в условиях пандемии (2020). Основной метод исследования - анализ содержания крупнейших интернет-групп молдавских мигрантов в социальной сети. Инструмент анализа - метод построения «дерева проблем» и «дерева решений». Исследование показало, что в период пандемии интернет-группы молдавских мигрантов стали площадкой их самоорганизации и преодоления ряда уязвимостей, а также выполнили информационную, организационную, представительскую, мобилизационную и рекреационную функции. Сделан вывод, что опыт интернет-групп молдавских мигрантов может быть экстраполирован на другие мигрантские сообщества и иные контексты, где целесообразна политическая, экономическая и социокультурная субъектность мигрантов

World Health Organization: story of creation and development

Over its 70-year history, the World Health Organization (WHO) has become the leading global organization in the medical field. The publication analyses the history of the creation of the WHO. The authors also consider international health organizations, that have become the basis for the further creation of a global health organization

A case-based approach to nutritional correction in overweight and obese children and adolescents in outpatient practice

Childhood obesity is one of the major public health problems in the twenty-first century. Up to 90% of all obesity cases in children and adolescents occur in a constitutional exogenous (simple) form. Treatment of obesity in its simple form in children is most appropriate to carry out on an outpatient basis. The main principle of prevention and treatment of overweight and obesity in children is the correction of nutrition and the development of healthy eating behavior. In order to improve the availability and quality of primary health care in the field of “dietetics”, a case-based approach to nutritional correction in overweight and obese children and adolescents has been developed. The proposed case-based approach has a modern scientific and methodological rationale, takes into account time norms for consulting patients during an outpatient appointment, is a plan of thematic consultations for the healthy diet development, ensures a gradual change in patient’s eating habits and individualization of the eating behavior correction, is aimed at the possibility of regular patient monitoring in the treatment process on an outpatient basis and promotes adherence to treatment. The development of the case-based approach is due to the high social significance of obesity, the tendency towards an increase in the number of overweight and obese children and adolescents in the Russian Federation and is aimed at implementing the main directions of the National Projects “Health” and “Demography”. © 2021, Dynasty Publishing House. All rights reserved