A neutron source on a basis of a subcritical assembly driven by a deuteron linac

The main characteristics of a conceptual thermal neutron source based on a subcritical uranium assembly are presented. A driver for the subcritical assembly is a deuteron linac with output energy of 23 MeV and an average beam current of 1 mA. The initial neutron generation is produced in nuclear reactions as accelerated deuterons bombard a beryllium target.Приведены результаты исследований основных характеристик концептуальной схемы источника тепло- вых нейтронов на основе подкритической урановой сборки, управляемой линейным ускорителем дейтронов с энергией 23 МэВ и средним током 1 мА. Генерация первичных нейтронов обусловлена ядерными реакция- ми при бомбардировке бериллиевой мишени ускоренными дейтронами.Наведені результати досліджень основних характеристик концептуальної схеми джерела теплових нейтронів на базі підкритичної уранової збірки, що керується лінійним прискорювачем дейтронів з енергією 23 МеВ та середнім струмом 1 мА. Генерація первинних нейтронів зумовлена ядерними реакціями внаслідок бомбардування берилієвої мішені прискореними дейтронами

ЭКСПЕРИМЕНТАЛЬНАЯ МОДЕЛЬ АУТОИММУННОГО ПРОЦЕССА: РОЛЬ ЭПИГЕНЕТИЧЕСКОЙ ИЗМЕНЧИВОСТИ В ПОПУЛЯЦИИ МЫШЕЙ-ГИБРИДОВ

Background: At the development of graft versus host disease in genetically homogeneous population of (C57Bl/6 x DBA/2) F1 mice two clinical phenotypes of SLE-like disease were revealed: lupus+ (immune complex glomerulonephritis and hemolytic anemia) and lupus – (hemolytic anemia). The GvHD phenotypic heterogeneity is determined by the Th1 /Th2-polarization: Th2 lymphocyte predominant activity, leads to the lupus+ development, or prevalence activity of Th1 cells, leads to the lupus– development. Objective: Our aim was to evaluate the possibility of using an experimental model of autoimmune disease for studying and testing of epigenetic modifications, shifting Th1 /Th2-balance in vivo. Methods: Сhronic GVHD was induced in B6D2F1 mice by the transplantation of 130×10 6 parental DBA/2 splenocytes. Аnti-ds-DNA, total IgG and IgG1, IgG2а Abs were measured by ELISA. Results: Six- to 8-week-old female DBA/2 and B6D2F1 mice were obtained from Biological Research Laboratory (Novosibirsk). It was established that regular moderate physical activity (unladed swimming) shifted Th1 /Th2 balance towards Th1. This leads to a decrease in a population of recipients the lupus+ mice from 57 to 26% (p 0,001) with significantly reduced hypergammaglobulinemia (IgG from 2,8 to 2,0 mg/ml; p 0,047) and DNA antibodies titer from 0,18 to 0,12 OD (p =0,05). Administration of epigenetic modificator bisphenol A at low doses, which mimicking estrogen effects, enhances the proportion of lupus+ mice in experimental groups from 33 to 64% (p 0,001) and impairs their clinical status by the increasing the urine protein level from 2.8 to 4,2 mg/ml (p 0,001) in animals. Conclusion: Th1 /Th2 – balance presumably is determined by the immune system epigenetic modification in experimental mice, formed on the previous stages of ontogeny and defines the direction of immune processes development in individual animal.В генетически однородной популяции мышей (гибриды F1) при индукции СКВ-подобного заболевания на основе реакции трансплантат против хозяина (РТПХ) выявляются клинические фенотипы lupus+ (гемолитическая анемия + иммунокомплексный гломерулонефрит) и lupus- (гемолитическая анемия). Механизм развития фенотипической гетерогенности обусловлен поляризацией Т-хелперного (Tх1 /Tх2) иммунного ответа: преимущественной активацией Tх1 (lupus-) или Tх2 популяции лимфоцитов (lupus+). Цель исследования: оценить возможность использования экспериментальной модели аутоиммунного заболевания для изучения и тестирования эпигенетических модификаций, сдвигающих Tх1 /Tх2 баланс in vivo. Методы: хроническую РТПХ индуцировали введением B6D2F1 мышам-гибридам 130×10 6 клеток селезенки от родителя DBA/2. Антитела к ДНК, IgG1, IgG2а-подклассам IgG и общий IgG оценивали с помощью иммуноферментного анализа. Результаты: 6–8-недельные самки мышей DBA/2 и B6D2F1 получены из экспериментально-биологической клиники лабораторных животных (Новосибирск). Установлено, что продолжительные регулярные физические нагрузки умеренной интенсивности (плавание без груза) сдвигают баланс Tх1 /Tх2 у реципиентов в сторону Tх1, т.е. в популяции достоверно уменьшается доля мышей lupus+ (с 57 до 26%; p 0,001), у которых достоверно снижается степень выраженности гипергаммаглобулинемии (с 2,8 до 2,0 мг/мл; p 0,047) и титр антител к ДНК (от 0,18 до 0,12 OD; p =0,05). Введение в низких дозах эпигенетического модификатора бисфенола А, имитирующего действие эстрогенов, не только увеличивает долю мышей lupus+ (c 33 до 64%; p 0,001), но и утяжеляет их состояние: концентрация белка у них достоверно повысилась (с 2,8 до 4,2 мг/мл; p 0,001). Заключение: эпигенетические изменения в иммунной системе, сформировавшиеся на предыдущих этапах онтогенеза у мышей-гибридов и связанные с условиями лабораторного содержания животных (двигательная активность, эндокринный статус), по-видимому, определяют соотношение активностей Tх1 и Tх2 субпопуляций, контролирующее выбор варианта, по которому пойдет развитие иммунного процесса в каждом конкретном случае.

The role of thyroid hormones in regulating of fatty acid spectrum of brain lipids: ontogenetic aspect

In experiments on rats of three age groups the role of thyroid hormones in the regulation of fatty acid spectrum of cortical and hippocampus lipids was studied. It was found that on the background of decreased thyroid status content of polyunsaturated fractions of free fatty acids, significantly changed depending on the age of the animals. In particular, in juvenile rats hypothyroidism was accompanied by a decrease almost twice the number of pentacodan acid decreased lipids viscosity in neurocortex. In old rats reduce of pentacodan acid in the cortex (38%) was supplemented by significant (77%) decrease in linoleic and linolenic acids. Unlike the two age groups deficiency of thyroid hormones in young animals caused accumulation of free polyunsatarated fatty acids (C18: 2.3) in the cerebral cortex by 74%, which may be associated with a decrease of this fraction in fatty acid spectrum of lipids and increase of viscosity properties of the membranes. These restruc­turing may be associated with modulation of synaptic transmission of specific neurotransmitter systems in the brain

Dynamics of immunohistochemical changes in the lumbar spinal cord under the conditions of impactwave influence

In connection with the current realities in Ukraine, combat surgical trauma became one of the most urgent problems of 2014 and increased many times. Injuries of the spine and spinal cord in the general structure of combat surgical trauma do not exceed 2%, but are accompanied by high mortality (from 19.1 to 52.9%) and permanent loss of working capacity in most cases of injuries. The purpose of our scientific work was to investigate the dynamics of microscopic changes that occur in the lumbar spinal cord during shock wave exposure using immunohistological research methods. Results. At the microscopic level, after exposure to a shock wave for 7 days, an increase in the size of neurons and interstitial space was found, which indicated the effects of the shock wave, which were more clearly accompanied by patency, hyperemia of vessels and swelling of their endothelium, which immunohistochemically confirmed more accumulation of the marker of endothelial NO-synthase in the first experimental group and a decrease in the accumulation of HIF-1ɑ, a hypoxia marker, in this experimental group, but an increase in the eNos marker in this group compared to the second and third groups, due to the activation of adaptive processes of the microcirculatory bed and the cell energy supply apparatus that occur in neurocytes after the action of the shock wave after 14 days. Conclusion. Thus, the impact of the shock wave has more morphological vascular ulcerative consequences in the acute and early periods, which have a slow but reversible nature of manifestations on the structural elements of the nervous tissue of the spinal cord, but in the late period, as a result of clearly hypoxic processes, these consequences have a more destructively progressive nature , which confirmed at the microscopic level the expression of HIF-1ɑ - a marker of hypoxia in the third experimental group

Дослідження структури та властивостей високоентропійних сплавів системи AlCrFeCoNiCu[x]

The peculiarities of the structure formation of alloys of the system AlCrFeCoNiCuх (where x = 0, 0.5, 1, 2, and 3 moles) were studied. Durometric studies of alloys of this system were carried out. Established that an alloy AlCrFeCoNiCu0.5 has the highest microhardness (6.1 GPa). Heat resistance tests showed that AlCrFeCoNi and AlCrFeCoNiCu have the highest heat resistance. The connection between the scale composition after the test and the mechanism of oxidation of this alloys revealed.Досліджені особливості структуроутворення сплавів системи AlCrFeCoNiCuх (де x = 0, 0,5, 1, 2, 3 моль). Як і фазовий склад, мікроструктури сплавів по мірі збільшення кількості міді зазнають істотних змін. В усьому досліджуваному концентраційному інтервалі зміни вмісту міді спостерігається різна морфологія фаз. Підтверджено, що при збільшенні концентрації міді змінюється характер кристалізації сплавів даної системи. Проведені дюрометричні дослідження сплавів даної системи. Встановлено, що найвищу мікротвердість 6.1 ГПа має сплав AlCrFeCoNiCu0.5. Випробування на жаростійкість показали, що найвищу жаростійкість мають сплави AlCrFeCoNi та AlCrFeCoNiCu. Результати рентгенофлуорисцентного аналізу свідчить про високий вміст алюмінію в окалині. Отже, високу жаростійкість сплавів можна пояснити утворенням на поверхні захисної плівки Al2O3

The role of beneficial bacteria wall elasticity in regulating innate immune response

Background: Probiotics have great potential to contribute to development of healthy dietary regimes, preventive care, and an integrated approach to immunity-related disease management. The bacterial wall is a dynamic entity, depending on many components and playing an essential role in modulating immune response. The impact of cell wall elasticity on the beneficial effects of probiotic strains has not been sufficiently studied. The aim was to investigate the effect of lactic acid bacteria (LAB) and bifidobacteria strains on phagocytic system cells (macrophages) as related to bacterial wall elasticity, estimated using atomic force microscopy (AFM). Methods: We conducted studies on Balb/c line mice 18\u201320 g in weight using lyophilized strains of LAB\u2014Lactobacillus acidophilus IMV B-7279, Lactobacillus casei IMV B-7280, Lactobacillus delbrueckii subsp. bulgaricus IMV B-7281, and bifidobacteria\u2014Bifidobacterium animalis VKL and Bifidobacterium animalis VKB. We cultivated the macrophages obtained from the peritoneal cavity of mice individually with the strains of LAB and bifidobacteria and evaluated their effect on macrophages, oxygen-dependent bactericidal activity, nitric oxide production, and immunoregulatory cytokines. We used AFM scanning to estimate bacterial cell wall elasticity. Results: All strains had a stimulating effect on the functional activity of macrophages and ability to produce NO/NO2 in vitro. Lactobacilli strains increased the production of IL-12 and IFN-\u3b3 in vitro. The AFM demonstrated different cell wall elasticity levels in various strains of LAB and bifidobacteria. The rigidity of the cell walls among lactobacilli was distributed as follows: Lactobacillus acidophilus IMV B-7279 > Lactobacillus casei IMV B-7280 > Lactobacillus delbrueckii subsp. bulgaricus IMV B-7281; among the strains of bifidobacteria: B. animalis VKB > B. animalis VKL. Probiotic strain survival in the macrophages depended on the bacterial cell wall elasticity and on the time of their joint cultivation. Conclusion: LAB and bifidobacteria strains stimulate immune-modulatory cytokines and active oxygen and nitrogen oxide compound production in macrophages. Strains with a more elastic cell wall according to AFM data demonstrated higher resistance to intracellular digestion in macrophages and higher level of their activation. AFM might be considered as a fast and accurate method to assess parameters of probiotic strain cell wall to predict their immune-modulatory properties