Valence State Ce(Yb), Electron Structure and Physical Properties of New Ternary Intermetallic Compounds

High-energy spectroscopy (XES, XAS and XPS) has been used to study the electron structure of the investigated new ternary intermetallic compounds. In recent years there has been a continually increasing interest in investigation of ternary compounds with crystallize in the YNi9Si2, CeGa2Al2, Yb2Fe4Si9, ThMn12 and AlB2, which have a large variety of ground state properties. LIII -absorption spectra Ce(Yb) in ternary compounds were obtained at 80K and 300K using a tube spectrometer. The mixed valence state of Ce(Yb) was obtained in the investigation compounds. The measurements were carried out both with classical methods as well with the Mossbauer effect in order to establish parameters of the hyperfine interactions (only for confirm Fe atoms compounds). The calculations of electron energy bands E(k) and partial DOS for compounds new R.E.M2X2 were performed by the semi relativistic linear muffin-tin orbital method without considerations of spin-orbit interactions A satisfactory agreement between theoretical and experimental data is achieved

High-energy spectroscopy of YbM2P2 compounds

We have studied experimentally and theoretically the electronic structure and x-ray absorption spectrum at the Yb L3-edge and x-ray emission spectra of M and P at the K- and L2,3 -edges in the mixed valence compound YbM2P2 (with ThCr2Si2 type crystal structure), where M=Fe, Co, Ni. The theoretical calculations have been carried out by means of the ab initio fully-relativistic spin-polarized Dirac linear muffin-tin orbital method. The calculations show good agreement with the experimental measurements. The LSDA +U with Ueff > 8.8 eV produces two independent self-consistent solutions YbNi2P2 with divalent Yb2+ and trivalent Yb3+ ions. For the divalent Yb ion we found a non-magnetic solution with fourteen 4f electron bands completely occupied and situated far below the Fermi level. For trivalent Yb3+ solution thirteen 4f electron bands are situated well below the Fermi level. The hole 4f level for the Yb3+ solution the completely empty and situated sufficiently far from the Fermi level, therefore YbNi2P2 belong to the in homogeneously mixed-valence compounds. The calculated total magnetic moment for the Yb3+ solution moment is dominated by the 4f compounds, the spin Ms and orbital Ml moments are 0.365 μB, and 1.135 μB, respectively. The spin and orbital moments at the Ni and P sites are very small: Ms Ni= - 0.0028 B, MsP=-0.0017 μB, MlNi =-0.0019 μB and MlP =0.0004 μB. Both the trivalent and the divalent Yb ions in are reflected in the experimentally measured Yb L3 x-ray absorption spectrum simultaneously. We found that the best agreement between the experimental spectrum and sum of the theoretically calculated Yb2+ and Yb3+ spectra is achieved with 73% ytterbium ions 2+ state and 27% ions in 3+ state. We found that the effect of the electronic quadrupole E2 transitions as well as the core-hole effect in the final states has minor influence on the intensity and the shape of the Ni and P K and L2.3 emission spectra as well as on the Yb L3 absorption spectrum. We would like to point out that the LSDA +U method which combines LSDA with a basically static, i.e. Hartree-Fock-like, mean –field approximation for a multi-band Anderson lattice model does not contain true many body physics. However, this method can be considered as the first step towards a better description of strongly correlated electron systems. The LSDA +U method provides the correct energy position of 4f energy bands and gives a reasonable description of the XAS and XES properties in YbNi2P2. However, the energy band structure for finite temperatures and the presumed Kondo lattice and mixed valence behavior in YbNi2P2 clearly requires a treatment that goes beyond a static mean-field approximation and includes dynamical effects, e.g., the frequency dependence of the sell-energy

Effect of Methionine Diet on Metabolic and Histopathological Changes of Rat Hippocampus

Hyperhomocysteinemia (hHcy) is regarded as an independent and strong risk factor for cerebrovascular diseases, stroke, and dementias. The hippocampus has a crucial role in spatial navigation and memory processes and is being constantly studied for neurodegenerative disorders. We used a moderate methionine (Met) diet at a dose of 2 g/kg of animal weight/day in duration of four weeks to induce mild hHcy in adult male Wistar rats. A novel approach has been used to explore the hippocampal metabolic changes using proton magnetic resonance spectroscopy (1H MRS), involving a 7T MR scanner in combination with histochemical and immunofluorescence analysis. We found alterations in the metabolic profile, as well as remarkable histo-morphological changes such as an increase of hippocampal volume, alterations in number and morphology of astrocytes, neurons, and their processes in the selective vulnerable brain area of animals treated with a Met-enriched diet. Results of both methodologies suggest that the mild hHcy induced by Met-enriched diet alters volume, histo-morphological pattern, and metabolic profile of hippocampal brain area, which might eventually endorse the neurodegenerative processes

Alzheimer’s Disease-like Pathological Features in the Dorsal Hippocampus of Wild-Type Rats Subjected to Methionine-Diet-Evoked Mild Hyperhomocysteinaemia

Multifactorial interactions, including nutritional state, likely participate in neurodegeneration’s pathogenesis and evolution. Dysregulation in methionine (Met) metabolism could lead to the development of hyperhomocysteinaemia (hHcy), playing an important role in neuronal dysfunction, which could potentially lead to the development of Alzheimer’s disease (AD)-like pathological features. This study combines proton magnetic resonance spectroscopy (1H MRS) with immunohistochemical analysis to examine changes in the metabolic ratio and histomorphological alterations in the dorsal rat hippocampus (dentate gyrus—DG) subjected to a high Met diet. Male Wistar rats (420–480 g) underwent hHcy evoked by a Met-enriched diet (2 g/kg of weight/day) lasting four weeks. Changes in the metabolic ratio profile and significant histomorphological alterations have been found in the DG of hHcy rats. We have detected increased morphologically changed neurons and glial cells with increased neurogenic markers and apolipoprotein E positivity parallel with a diminished immunosignal for the N-Methyl-D-Aspartate receptor 1 in hHcy animals. A Met diet induced hHcy, likely via direct Hcy neurotoxicity, an interference with one carbon unit metabolism, and/or epigenetic regulation. These conditions lead to the progression of neurodegeneration and the promotion of AD-like pathological features in the less vulnerable hippocampal DG, which presents a plausible therapeutic target

Role of homocysteine in the ischemic stroke nad development of ischemic tolerance

Homocysteine (Hcy) is a toxic, sulfur-containing intermediate of methionine metabolism. Hyperhomocysteinemia (hHcy), as a consequence of impaired Hcy metabolism or defects in crucial co-factors that participate in its recycling, is assumed as an independent human stroke risk factor. Neural cells are sensitive to prolonged hHcy treatment, because Hcy cannot be metabolized either by the transsulfuration pathway or by the folate/vitamin B12 independent remethylation pathway. Its detrimental effect after ischemia-induced damage includes accumulation of reactive oxygen species (ROS) and posttranslational modifications of proteins via homocysteinylation and thiolation. Ischemic preconditioning (IPC) is an adaptive response of the CNS to sub-lethal ischemia, which elevates tissues tolerance to subsequent ischemia. The main focus of this review is on the recent data on homocysteine metabolism and mechanisms of its neurotoxicity. In this context, the review documents an increased oxidative stress and functional modification of enzymes involved in redox balance in experimentally induced hyperhomocysteinemia. It also gives an interpretation whether hyperhomocysteinemia alone or in combination with IPC affects the ischemia-induced neurodegenerative changes as well as intracellular signalling. Studies document that hHcy alone significantly increased Fluoro-Jade C- and TUNEL-positive cell neurodegeneration in the rat hippocampus as well as in the cortex. IPC, even if combined with hHcy, could still preserve the neuronal tissue from the lethal ischemic effects. This review also describes the changes in the mitogen-activated protein kinase (MAPK) protein pathways following ischemic injury and IPC. These studies provide evidence for the interplay and tight integration between ERK and p38 MAPK signalling mechanisms in response to the hHcy and also in association of hHcy with ischemia/IPC challenge in the rat brain. Further investigations of the protective factors leading to ischemic tolerance and recognition of the co-morbid risk factors would result in development of new avenues for exploration of novel therapeutics against ischmia and stroke

Формування технологічних умінь у майбутніх інженерів-педагогів швейного профілю

The results of development of methods of formation of technological abilities at the future engineers-teachers sewing profile аге presents in this article. The concepts of "skill", "professional skills", "technological skills." The model of formation of technological abilities at the future engineers-teachers sewing profile, which contains the following components: motivational, informative, organizational-activity, assessment and performance. The developed model was the basis for the construction of a methods of formation of technological abilities at the future engineers-teachers in the process of sewing profile of the discipline "Technology of garments", the components of which include the goals, objectives, principles (scientific, systematic and consistency, accessibility, communication training with practice activities, clarity, emotional learning, innovation), the content, methods of implementation and evaluation criteria. Content methods presented theoretical and practical parts in a 2 modules: Module 1 "The technology of processing individual parts outerwear", module 2 "Processing Technology clothing costume Coat-range." The basis for implementation of innovative technologies chosen method of learning, such as: "Aquarium" - workshops; "Algorithm-labyrinth" - a method of tasks; Briefing the group - a method of incidents; "A folder with incoming documents" - a method of case studies; group dynamics - brainstorming; Debates - programmed instructions; discussion; Case technology, training, games - a decision highly specialized issues; short rotation - role-playing games. The criteria for evaluation of methods to determine the motivation of educational activity, the level of development of technological skills, the students' ability to self-control and self-esteemВ статье представлены результаты разработки методики формирования технологических умений у будущих инженеров-педагогов швейного профиля. Определены понятия “умение”, “профессиональные умения”, “технологические умения”. Разработана модель формирования технологических умений у будущих инженеров-педагогов швейного профиля, которая содержит следующие компоненты: целемотивационный, содержательный, организационно-деятельностный, оценочно-результативный. Разработанная модель стала основой построения методики формирования технологических умений у будущих инженеров-педагогов швейного профиля в процессе изучения дисциплины “Технология швейных изделий”, к компонентам которой относятся цели, задачи, принципы, содержание, способы реализации и критерии оценки. Основой реализации методики выбраны инновационные технологии обучения: “Аквариум” - мастерские; “Алгоритм-лабиринт” - метод задач; брифинг-группы - метод инцидентов; “Папка с входящими документами” - метод кейсов; групповая динамика - мозговой штурм; дебаты - программируемые инструкции; дискуссия; кейс-технологии, тренинги, игры - решение узкоспециальных вопросов; кратковременные ротации - ролевые игрыУ статті наведено результати розроблення методики формування технологічних умінь у майбутніх інженерів-педагогів швейного профілю. Визначено поняття “уміння”, “професійні уміння”, “технологічні уміння”. Розроблено модель формування технологічних умінь у майбутніх інженерів-педагогів швейного профілю, яка містить такі компоненти: цілемотиваційний, змістовний, організаційно-діяльнісний, оціночно-результативний. Модель стала основою побудови методики формування технологічних умінь у майбутніх інженерів-педагогів швейного профілю в процесі вивчення дисципліни “Технологія швейних виробів”, до компонентів якої належать мета, завдання, принципи, зміст, способи реалізації та критерії оцінювання. Основою реалізації методики обрано інноваційні технології навчання: “Акваріум” ‒ майстерні; “Алгоритм-лабіринт” ‒ метод завдань; брифінг-групи ‒ метод інцидентів; “Папка з вхідними документами” ‒ метод кейсів; групова динаміка ‒ мозковий штурм; дебати ‒ програмовані інструкції; дискусія ‒ розмова; кейс-технології, тренінги, ігри ‒ рішення вузькоспеціальних питань; короткочасні ротації ‒ рольові ігри

Methionine Diet Evoked Hyperhomocysteinemia Causes Hippocampal Alterations, Metabolomics Plasma Changes and Behavioral Pattern in Wild Type Rats

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons’ vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in “methylation index” of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake