Mathematical modeling of high-frequency magamp switch B-H characteristic

The current paper features a problem of high-frequency MagAmp switch modeling for computer aided design programmes to enable MagAmp power converters design automation. A new mathematical model of MagAmp switch B-H characteristic is presented. An algorithm of its computer integration is described. Dependence of B-H characteristic on switching frequency is investigated for two configurations of MagAmp switches with cores of amorphous Co-based alloy with rectangular hysteresis loop. The simulation results are obtained, and maximum modeling error is calculated

Brain vitamin D3-auto/paracrine system in relation to structural, neurophysiological, and behavioral disturbances associated with glucocorticoid-induced neurotoxicity

IntroductionVitamin D3 (VD3) is a potent para/autocrine regulator and neurosteroid that can strongly influence nerve cell function and counteract the negative effects of glucocorticoid (GC) therapy. The aim of the study was to reveal the relationship between VD3 status and behavioral, structural-functional and molecular changes associated with GC-induced neurotoxicity.MethodsFemale Wistar rats received synthetic GC prednisolone (5 mg/kg b.w.) with or without VD3 (1000 IU/kg b.w.) for 30 days. Behavioral, histological, physiological, biochemical, molecular biological (RT-PCR, Western blotting) methods, and ELISA were used.Results and discussionThere was no difference in open field test (OFT), while forced swim test (FST) showed an increase in immobility time and a decrease in active behavior in prednisolone-treated rats, indicative of depressive changes. GC increased the perikaryon area, enlarged the size of the nuclei, and caused a slight reduction of cell density in CA1-CA3 hippocampal sections. We established a GC-induced decrease in the long-term potentiation (LTP) in CA1-CA3 hippocampal synapses, the amplitude of high K+-stimulated exocytosis, and the rate of Ca2+-dependent fusion of synaptic vesicles with synaptic plasma membranes. These changes were accompanied by an increase in nitration and poly(ADP)-ribosylation of cerebral proteins, suggesting the development of oxidative-nitrosative stress. Prednisolone upregulated the expression and phosphorylation of NF-κB p65 subunit at Ser311, whereas downregulating IκB. GC loading depleted the circulating pool of 25OHD3 in serum and CSF, elevated VDR mRNA and protein levels but had an inhibitory effect on CYP24A1 and VDBP expression. Vitamin D3 supplementation had an antidepressant-like effect, decreasing the immobility time and stimulating active behavior. VD3 caused a decrease in the size of the perikaryon and nucleus in CA1 hippocampal area. We found a recovery in depolarization-induced fusion of synaptic vesicles and long-term synaptic plasticity after VD3 treatment. VD3 diminished the intensity of oxidative-nitrosative stress, and suppressed the NF-κB activation. Its ameliorative effect on GC-induced neuroanatomical and behavioral abnormalities was accompanied by the 25OHD3 repletion and partial restoration of the VD3-auto/paracrine system.ConclusionGC-induced neurotoxicity and behavioral disturbances are associated with increased oxidative-nitrosative stress and impairments of VD3 metabolism. Thus, VD3 can be effective in preventing structural and functional abnormalities in the brain and behavior changes caused by long-term GC administration

Преодоление антипрививочного скепсиса: поиски решения выхода из сложившейся ситуации

Background. The problem of distrust of immunization is widespread not only in Russia but also all over the world. Many parents refuse to vaccinate their child reasoning that the vaccines can harm their health, the immune system may not cope with the body burden; and some doctors themselves discourage parents from vaccination. Our aim was to assess the attitude of doctors and parents towards vaccination whose children are vaccinated completely or partially; to study the most frequent reasons for refusals of vaccination by parents. Methods. We used the questionnaires for parents (n = 114) who brought their children for vaccination for the first time or repeatedly; and the questionnaires for students of 4–6 courses and interns of medical universities (n = 336) who expressed their sentiments towards vaccination and demonstrated the knowledge of the national and regional immunization schedules. AstonGroup also conducted studies among physicians of different specialties (n = 307) on the most frequent reasons for refusals of vaccination. Results. In most cases, the parents’ attitude towards vaccination was positive. One in three patient representatives considered that he was fully acquainted with immunization issues, and more than half wanted to be vaccinated only within the national immunization schedule. In almost 100% of cases, parents had trust in information about vaccination received from a doctor. The results of the AstonGroup survey showed that the most frequent medical exemptions were given by neurologists, immunologists, and surgeons. And the parents themselves, who brought their children to see doctors, reasoned their refusals of vaccination with fear of complications and also considered vaccination to be harmful and useless. The doctors participating in the survey offered methods for influencing the parents, namely: providing them with accessible information about vaccinations included in the national immunization schedule as well as about the experience of using vaccines, including other countries. Discussion. The survey revealed insufficient knowledge of the national immunization schedule among students as well as cautious attitude towards vaccination issues and the trust in vaccination myths among legally authorized representatives of patients. Conclusion. The effective measures to combat ‘anti-vaccination scepticism’ are lectures for parents; personal, social and health education at pediatric sites as well as continuing medical education.Обоснование. Проблема недоверия к иммунизации широко распространена не только в России, но и во всем мире. Многие родители отказываются прививать своего ребенка, аргументируя это тем, что вакцины могут нанести вред здоровью, иммунная система может не справиться с нагрузкой на организм, к тому же некоторые врачи сами отговаривают родителей от вакцинации.Цель исследования — оценить отношение к вакцинации врачей и родителей, дети которых привиты полностью либо частично; изучить наиболее частые причины отказов от прививок со стороны родителей.Методы. Использованы вопросники для родителей (n=114), приведших на вакцинацию своих детей впервые или повторно; анкеты для студентов 4–6-х курсов и интернов медицинских вузов (n=336), которые выражали свое отношение к вакцинации и демонстрировали знания национального и регионального календарей профилактических прививок. Компания Aston Group также проводила исследования среди врачей разных специальностей (n=307) о наиболее частых причинах отказов от вакцинации.Результаты. В большинстве случаев отношение родителей к вакцинации было позитивным, каждый третий представитель пациента считал, что полностью информирован в вопросах иммунизации и больше половины хотели прививаться только в рамках национального календаря профилактических прививок. Практически в 100% случаев родители доверяли информации о прививках, полученной от врача. Результаты опроса компании Aston Group показали, что самые частые медотводы давали неврологи, иммунологи и хирурги. А сами родители, приходящие с детьми на прием к врачам, мотивировали свои отказы от прививок боязнью осложнений, а также считали вакцинацию вредной и бесполезной. Врачами, участвующими в опросе, были предложены методы по воздействию на родителей пациентов, а именно: обеспечение их доступной информацией о прививках, входящих в национальный календарь профилактических прививок, а также об опыте применения вакцин, в том числе в других странах.Обсуждение. Проведенный опрос выявил недостаточное знание Национального календаря профилактических прививок среди студентов, а также многочисленные заблуждения в отношении профилактических прививок со стороны других педиатрических специалистов (особенно детских неврологов и детских аллергологов-иммунологов), осторожное отношение в вопросах вакцинации и доверие к «мифам» о прививках среди законных представителей пациентов. Заключение. Эффективными мероприятиями на пути борьбы с антипрививочным скепсисом являются лекции для родителей, санитарно-просветительская работа на педиатрических участках, а также повышение квалификации врачей.КОНФЛИКТ ИНТЕРЕСОВ Л.С. Намазова-Баранова — получение исследовательских грантов от фармацевтических компаний Пьер Фабр, Genzyme Europe B. V., ООО «Астра зенека Фармасьютикалз», Gilead/PRA «Фармасьютикал Рисерч Ассошиэйтс СиАйЭс», «Bionorica», Teva Branded Pharmaceutical products R&D, Inc/ООО «ППД Девелопмент (Смоленск)», «Сталлержен С. А.»/«Квинтайлс ГезмбХ» (Австрия). Остальные авторы данной статьи подтверждают отсутствие конфликта интересов, о котором необходимо сообщит

Restoration of damaged geofoundations in transport using highly-effective repair mortar

The area of the research is geoconstruction and geostructures in transport. The present study provides modified repair mortars characterized by high penetrating performance, which is important in geoconstruction and transport. Penetrating repair mortars increase compression strength by 1-3 classes, water-resistance by 4-10 atm of the operated concrete geofoundation. Modified repair mortars are of increased crack resistance, they are carbon dioxide and magnesia corrosion resistant material and also they are characterized by high adhesion strength to a concrete geofoundation, which creates a monolithic character of both a restored foundation and a repair geocomposition

Restoration of damaged geofoundations in transport using highly-effective repair mortar

The area of the research is geoconstruction and geostructures in transport. The present study provides modified repair mortars characterized by high penetrating performance, which is important in geoconstruction and transport. Penetrating repair mortars increase compression strength by 1-3 classes, water-resistance by 4-10 atm of the operated concrete geofoundation. Modified repair mortars are of increased crack resistance, they are carbon dioxide and magnesia corrosion resistant material and also they are characterized by high adhesion strength to a concrete geofoundation, which creates a monolithic character of both a restored foundation and a repair geocomposition

Overcoming ‘Anti-Vaccination Scepticism’: Seeking a Solution to the Situation

Background. The problem of distrust of immunization is widespread not only in Russia but also all over the world. Many parents refuse to vaccinate their child reasoning that the vaccines can harm their health, the immune system may not cope with the body burden; and some doctors themselves discourage parents from vaccination. Our aim was to assess the attitude of doctors and parents towards vaccination whose children are vaccinated completely or partially; to study the most frequent reasons for refusals of vaccination by parents. Methods. We used the questionnaires for parents (n = 114) who brought their children for vaccination for the first time or repeatedly; and the questionnaires for students of 4–6 courses and interns of medical universities (n = 336) who expressed their sentiments towards vaccination and demonstrated the knowledge of the national and regional immunization schedules. AstonGroup also conducted studies among physicians of different specialties (n = 307) on the most frequent reasons for refusals of vaccination. Results. In most cases, the parents’ attitude towards vaccination was positive. One in three patient representatives considered that he was fully acquainted with immunization issues, and more than half wanted to be vaccinated only within the national immunization schedule. In almost 100% of cases, parents had trust in information about vaccination received from a doctor. The results of the AstonGroup survey showed that the most frequent medical exemptions were given by neurologists, immunologists, and surgeons. And the parents themselves, who brought their children to see doctors, reasoned their refusals of vaccination with fear of complications and also considered vaccination to be harmful and useless. The doctors participating in the survey offered methods for influencing the parents, namely: providing them with accessible information about vaccinations included in the national immunization schedule as well as about the experience of using vaccines, including other countries. Discussion. The survey revealed insufficient knowledge of the national immunization schedule among students as well as cautious attitude towards vaccination issues and the trust in vaccination myths among legally authorized representatives of patients. Conclusion. The effective measures to combat ‘anti-vaccination scepticism’ are lectures for parents; personal, social and health education at pediatric sites as well as continuing medical education

Lietuva stojant į Europos Sąjunga : ekonominė, sociologinė ir demografinė padėties analizė

Socialinių tyrimų institutasVilniaus universiteta