177 research outputs found
A comparative study of hydrophilic phosphine hexanuclear rhenium cluster complexes’ toxicity
Octahedral rhenium cluster compound Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] has recently emerged as a very promising X-ray contrast agent for biomedical applications. However, the synthesis of this compound is rather challenging due to difficulty to control the hydrolysis of initial P(C2H4CN)3 ligand during the reaction process. Therefore, in this report we compare the in vitro and in vivo toxicity of Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] with those of related compounds featuring fully hydrolysed form of the phosphine ligand, namely Na2H14[{Re6Q8}(P(C2H4COO)3)6] (Q = S or Se). Our results demonstrate that cytotoxicity and acute in vivo toxicity of the complex Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] solutions were considerably lower than those of compounds with fully hydrolysed ligand P(C2H4COOH)3. Such behavior can be explained by the higher osmolality of Na2H14[{Re6Q8}(P(C2H4COO)3)6] versus Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6]
COST 296 scientific results designed for operational use
The main objective of the COST 296 Action «Mitigation of Ionospheric Effects on Radio Systems» is the establishment/
improvement of ionospheric services by coordinating the development of specific algorithms, models, and tools capable of operating in a near-real-time mode.
Key elements of these activities are contributions related to monitoring, modelling, and imaging of customer-relevant
ionospheric quantities. COST stimulates, coordinates, and supports Europe’s goals of development and global cooperation by providing high quality information and knowledge of ionospheric and plasmaspheric conditions enabling high quality and reliable operation of radio systems.
It also provides a platform for sharing such tools as algorithms or models, and for the joint development of advanced
technologies. It takes advantage of many national and European service initiatives, for example DIAS
(http://dias.space.noa.gr), SWACI (http://w3swaci.dlr.de), ESWUA (http://www.eswua.ingv.it/ingv), RWC-Warsaw
(http://www.cbk.waw.pl/rwc), the COST Prompt Ionospheric Database http://www.wdc.rl.ac.uk/cgibin/
digisondes/cost_database.pl, http://www.izmiran.ru/services, and others.
Existing national capabilities are taken into account to develop synergies and avoid duplication. The enhancement of environment monitoring networks and associated instrumentation yields mutual advantages for European and regional services specialized for local user needs.
It structurally increases the integration of limited-area services, and generates a platform employing the same approach to each task differing mostly in input and output data. In doing so it also provides a complementary description of the environmental state within issued information, as well as providing a platform for interaction among local end users, who define what kind of information they need, for system providers, who finalize the
tools necessary to obtain required information, and for local service providers, who do the actual processing of
data, tailoring it to specific users’ needs. Such an initiative creates a unique opportunity for small national services
to consolidate their product design so that is no longer limited to their own activity, but can serve the wider European services.
The development and improvement of techniques for mitigating ionospheric effects on radio systems by the
COST 296 Action prepared those services that implemented the new design techniques for the newly announced EU and ESA policy-Space Situation Awareness (SSA). COST 296 developments applied to nowcasting and forecasting services are an essential input to the Operational SSA Ionosphere
Ionospheric Modelling using GPS to Calibrate the MWA. II : Regional ionospheric modelling using GPS and GLONASS to estimate ionospheric gradients
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Publications of the Astronomical Society of Australia (PASA), after peer review and technical editing by the publisher. The version of record is available on line at https://doi.org/10.1017/pasa.2016.22 COPYRIGHT: © Astronomical Society of Australia 2016.We estimate spatial gradients in the ionosphere using the Global Positioning System (GPS) and GLONASS (Russian global navigation system) observations, utilising data from multiple GPS stations in the vicinity of Murchison Radio-astronomy Observatory (MRO). In previous work the ionosphere was characterised using a single-station to model the ionosphere as a single layer of fixed height and this was compared with ionospheric data derived from radio astronomy observations obtained from the Murchison Widefield Array (MWA). Having made improvements to our data quality (via cycle slip detection and repair) and incorporating data from the GLONASS system, we now present a multi-station approach. These two developments significantly improve our modelling of the ionosphere. We also explore the effects of a variable-height model. We conclude that modelling the small-scale features in the ionosphere that have been observed with the MWA will require a much denser network of Global Navigation Satellite System (GNSS) stations than is currently available at the MRO.Peer reviewe
Effects of early neonatal proinflammatory stress on the expression of BDNF transcripts in the brain regions of prepubertal male rats
Early postnatal proinflammatory stress provokes behavioral impairments in adulthood; however, underlying mechanisms are still elusive. Brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroplastic changes in health as well as at pathology. The BDNF gene is transcribed to exon-specific mRNAs and the pattern of their expression depends on stimulus. We suggest that disturbances of exonspecific BDNF mRNA expression in the brain regions after stress induced by proinflammatory stimuli in early postnatal period could be one of the underlying mechanisms of consequent behavioral impairments. Thus, the aim of the study was to investigate the effects of proinflammatory stress in early postnatal ontogeny on the expression of BDNF and the patterns of expression of the BDNF gene in the neocortex and hippocampus of prepubertal male rats. The proinflammatory stress was induced by subcutaneous administration of bacterial lipopolysaccharide (LPS) to rat pups on postnatal days 3 and 5, while BDNF expression was analyzed in 36-day-old rats. BDNF polypeptide concentration was estimated by means of an enzyme-linked immunosorbent assay, while quantitative polymerase chain reaction followed by reverse transcription was used to detect exon-specific BDNF mRNA expression. The levels of BDNF and transcripts, containing common exon IX were similar in the control and LPS-treated rats. In the rats treated with LPS, the level of BDNF mRNA, containing exon IV, was lower in the neocortex, but not in the hippocampus. No changes in the expression of the transcripts containing exons I and VI were observed in any brain structure studied. We suggest that specific alterations in BDNF expression may be involved in the susceptibility to the development of behavioral impairments of animals subjected to early proinflammatory stress
ТЕРМОДИНАМИКА И КИНЕТИКА ПРОЦЕССА ТЕРМИЧЕСКОЙ ДИССОЦИАЦИИ ДОЛОМИТА
Here we present the results of studying thermodynamic principles and kinetics of thermal dissociation of dolomites in the Urals deposits. Dolomite samples vary by fractions and grain size of calcite inclusions that determines the differences in their dissociation kinetics. It was found that dolomite dissociation occurs based on the two-stage model limited at the first stage by the reaction on a three-dimensional surface and at the second stage – by the kinetic equation with a degree close to 0,3 and 0,6. Приведены результаты исследований термодинамических основ и кинетики процессов термической диссоциации доломитов уральских месторождений. Образцы доломита отличаются долей и крупностью включений кальцита, что определяет отличия в кинетике их диссоциации. Установлено, что диссоциация доломитов протекает по двухстадийной модели, лимитируемой на первой стадии реакцией на трехмерной поверхности, а на второй – кинетическим уравнением, имеющим порядок, близкий к 0,3 и 0,6.
Directional Sensitivity of the NEWSdm Experiment to Cosmic Ray Boosted Dark Matter
We present a study of a directional search for Dark Matter boosted forward
when scattered by cosmic-ray nuclei, using a module of the NEWSdm experiment.
The boosted Dark Matter flux at the edge of the Earth's atmosphere is expected
to be pointing to the Galactic Center, with a flux 15 to 20 times larger than
in the transverse direction.
The module of the NEWSdm experiment consists of a 10 kg stack of Nano Imaging
Trackers, i.e.~newly developed nuclear emulsions with AgBr crystal sizes down
to a few tens of nanometers. The module is installed on an equatorial
telescope. The relatively long recoil tracks induced by boosted Dark Matter,
combined with the nanometric granularity of the emulsion, result in an
extremely low background. This makes an installation at the INFN Gran Sasso
laboratory, both on the surface and underground, viable. A comparison between
the two locations is made. The angular distribution of nuclear recoils induced
by boosted Dark Matter in the emulsion films at the surface laboratory is
expected to show an excess with a factor of 3.5 in the direction of the
Galactic Center. This excess allows for a Dark Matter search with directional
sensitivity. The surface laboratory configuration prevents the deterioration of
the signal in the rock overburden and it emerges as the most powerful approach
for a directional observation of boosted Dark Matter with high sensitivity. We
show that, with this approach, a 10 kg module of the NEWSdm experiment exposed
for one year at the Gran Sasso surface laboratory can probe Dark Matter masses
between 1 keV/c and 1 GeV/c and cross-section values down to
~cm with a directional sensitive search.Comment: 15 pages, 14 figures, updated references, clarified discussion in
intro section. Submitted to JCA
Cholinergic Deficit Induced by Central Administration of 192IgG-Saporin Is Associated With Activation of Microglia and Cell Loss in the Dorsal Hippocampus of Rats
Alzheimer’s disease (AD) is associated with degeneration of cholinergic neurons in the basal forebrain. Administration of the immunotoxin 192IgG-saporin to rats, an animal model of AD, leads to degeneration of cholinergic neurons in the medial septal area. In the present study, cholinergic cell death was induced by intracerebroventricular administration of 192IgG-saporin. One and a half months after injection, we studied the histopathology of the hippocampus and the responses of microglia and astrocytes using immunohistochemistry and neuroglial gene expression. We found that treatment with 192IgG-saporin resulted in neuronal loss in the CA3 field of the hippocampus. Microglial proliferation was observed in the dentate gyrus of the dorsal hippocampus and white matter. Massive proliferation and activation of microglia in the white matter was associated with strong activation of astrocytes. However, the expression of microglial marker genes significantly increased only in the dorsal hippocampus, not the ventral hippocampus. These effects were not related to non-specific action of 192IgG-saporin because of the absence of the Nerve growth factor receptor in the hippocampus. Additionally, 192IgG-saporin treatment also induced a decrease in the expression of genes that are associated with transport functions of brain vascular cells (Slc22a8, Ptprb, Sdpr), again in the dorsal hippocampus but not in the ventral hippocampus. Taken together, our data suggest that cholinergic degeneration in the medial septal area induced by intracerebroventricular administration of 192IgG-saporin results in an increase in the number of microglial cells and neuron degeneration in the dorsal hippocampus
ВЛИЯНИЕ НЕРАВНОВЕСНОЙ КРИСТАЛЛИЗАЦИИ НА СОСТАВ ФАЗ СПЛАВА Al–Mo–Ti
Using X-ray phase analysis, X-ray spectral analysis and microscopy, phase composition, micro- and crystalline structure of AMT alloy (TU-48-4-366), which is applied as alloying material in melting of titanium alloys, have been investigated. The lattice parameters of ε, p, δ-phases are calculated and their element compositions are determined. The formation of Mo3Al refractory phase (tm = 2150 °C) is not observed during primary crystallization in non-equilibrium conditions of Al-Mo-Ti alloy. Its presence in the foundry alloy is caused by the secondary recrystallization processes in the course of which ultrafine mixture of Mo3Al + Mo3Al8 + TiMoAl6 phases is formed at temperatures of 1311 °C and 1314 °C. Ultrafine silicon-containing σ-phase of average Mo2,4Ti2,1Si0,8Al4,7 composition produced in the non-equilibrium conditions of crystallization is found. The parameters and interplanar spacing of its lattice are defined. It is found that the greatest inhomogeneity in molybdenum in the peritectic of primary crystals occurs at high speed of crystallization, i.e. in the lower part of Al-Mo-Ti ingot.Методами рентгенофазового, рентгеноспектрального микроанализа и микроскопии исследованы фазовый состав, микро- и кристаллическая структура лигатурного сплава АМТ ТУ-48-4-366, который применяется в качестве легирующего материала при выплавке титановых сплавов. Рассчитаны параметры решеток ε, p, δ-фаз и выявлен их элементный состав. При первичной кристаллизации в неравновесных условиях лигатурного сплава Al–Mo–Ti образование тугоплавкой фазы Mo3Al (tпл = 2150 °С) не наблюдается. Ее присутствие в лигатуре обусловлено протеканием процессов вторичной кристаллизации, в ходе которых образуется ультрадисперсная смесь фаз Mo3Al + Mo3Al8 + TiMoAl6 при температурах 1311 и 1314 °С. Выявлена ультрадисперсная кремнийсодержащая σ-фаза среднего состава Mo2,4Ti2,1Si0,8Al4,7, полученная в неравновесных условиях кристаллизации. Определены параметры и межплоскостные расстояния ее решетки. Установлено, что наибольшая неоднородность по молибдену в перитектике первичных кристаллов имеет место при высокой скорости кристаллизации, т.е. в нижней части слитка Al–Mo–Ti
СИСТЕМНЫЙ ПОДХОД В ОРГАНИЗАЦИИ ДЕЯТЕЛЬНОСТИ ПРЕПОДАВАТЕЛЕЙ ВУЗА
The paper identifies the most important factors, which determine the quality of students training at university; they are professors qualification, quality of teaching and learning materials, quality of educational process, students’ motivation to learning educational programs, social and pedagogical aspects, graduates’ being in demand on the labour market. The author supposes, all the factors should be developed in interaction and influence on each other by means of applying system approach. Education should be built and based on the system approach as well. It is necessary to pay attention not only to official side of educational process (educational programs correspondence to the State Educational Standards), but to the methods the professors apply when lecturing and teaching (organization and technologies of educational process). The research carried out reveals peculiarities in interaction between subjects of educational process in double-degree system and divides the concepts “studying” and “training”. The article analyzes possibilities of applying USSR experience of higher education and enhancing studying by means of applying the modern information technologies. The author concentrates on analyzing interactions in education systems, influence of feed-backs on training results, peculiarities of education alignment and harmonization. The author considers, applying of recommended statements allows strengthening integrity of educational process and developing institution efficiency. Nowadays, development of educational process in higher institutions of Russia is implemented by means of legal regulation. A lot of attention is paid to education system as a whole but not to training which demands attention of all managerial levels in university, including strategic and operating level. It requires attention of scientists and practical specialists to the issues considered.К важнейшим факторам, определяющим качество подготовки студентов в университете, относятся уровень качества образовательных программ, квалификация профессорско-преподавательского состава, информационно-методическое обеспечение учебного процесса, качество процесса обучения, мотивация студентов к освоению образовательных программ, социальная и воспитательная составляющая, востребованность выпускников на рынке труда. Все эти факторы в университете должны развиваться во взаимной связи и взаимовлиянии на основе системного подхода, в соответствии с которым в учебном заведении должна быть создана единая система обучения. При этом необходимо уделять внимание не только формальной стороне образовательного процесса (соответствие учебных программ государственным образовательным стандартам), но и методике работы преподавателей при проведении ими аудиторных занятий (организации и технологии учебного процесса). В результате проведенных исследований выявлены особенности взаимодействия субъектов учебного процесса в рамках двухуровневой системы образования, разграничены понятия «учеба» и «обучение». Проанализированы возможности использования опыта высшего образования в СССР и направления совершенствования учебной работы с использованием современных информационных технологий. Особое внимание уделено анализу видов связей в образовательных системах, влиянию обратных связей на результативность обучения, особенностям процедур унификации и гармонизации учебного процесса. Использование предложенных рекомендаций преподавателями вузов позволит усилить интегративность образовательного процесса и улучшить эффективность деятельности вуза. В настоящее время совершенствование образовательного процесса в российских вузах осуществляется в основном посредством правого регулирования. В России сейчас больше обращают внимание на систему образования в целом, но не на обучение как процесс, требующий постоянного внимания всех уровней управления в вузе, включая стратегический и оперативный уровень, что требует внимания ученых и практиков к рассмотренным вопросам
Влияние интрамиокардиальной инъекции аутологичных клеток костного мозга, обработанных эритропоэтином, на перфузию миокарда по данным ОФЭКТ с 99mТc-МИБИ в отдаленный период наблюдения
Purpose. To evaluate the changes of myocardial perfusion using 99mТс-MIBI single-photon emission computed tomography (SPECT) after the intramyocardial implantation of erythropoietin preconditioned autologous bone marrow cells (ABMC) in laser channels during coronary artery disease (CAD) surgery.Materials and methods. Randomized study of 40 patients (mean age 58.0 ± 6.9, 9 females) with diffuse and (or) distal right coronary artery disease (RCA). Patients of the study group (n = 23) underwent coronary artery bypass grafting (CABG) of the left coronary artery (LCA) system and intramyocardial implantation of erythropoietin preconditioned ABMC in the left ventricular (LV) inferior wall. Patients of the control group (n = 17) underwent CABG of the LCA system only. 99mТс-MIBI SPECT performed 1–2 days before and 12 months after surgery.Results. In study group after 12-month follow-up the summed stress score in a typical RCA supply area (SSSRCA) improved from 7.0 [5.5; 10.5] to 4.0 [1.0; 5.5] (p <0.01), summed rest score (SRSRCA) improved from 3.0 [0.0; 7.0] to 1.0 [0.0; 3.5] (p <0.01), and summed different score (SDSRCA) improved from 3.0 [1.0; 4.0] to 1.0 [0.0; 2.0] (p = 0.03). Control group patients after 12-month follow-up showed significant improvement of SSS RCA only – from 8.0 [6.0; 12.0] to 5.0 [4.0; 7.0] (p <0.01).Conclusion. After 12-month follow-up in patients with diffuse and (or) distal RCA disease, the procedure of intramyocardial implantation of the erythropoietin preconditioned ABMC in laser channels is demonstrated to be safe and induces the improvement of myocardial perfusion. Цель – оценить изменения миокардиальной перфузии по данным однофотонной эмиссионной компьютерной томографии (ОФЭКТ) с 99mТс-МИБИ после применения трансмиокардиальной лазерной реваскуляризации в сочетании с имплантацией прекондиционированных эритропоэтином аутологичных клеток костного мозга (АККМ) в хирургии ишемической болезни сердца (ИБС).Материалы и методы. Больные ИБС (n = 40, средний возраст (58,0 ± 6,9) лет, 9 женщин) с диффузным и (или) дистальным поражением правой коронарной артерии (ПКА) рандомизированы на две группы. Пациентам из группы исследования (n = 23) выполнено аортокоронарное шунтирование (АКШ) системы левой коронарной артерии (ЛКА) c имплантацией прекондиционированных эритропоэтином АККМ в область нижней стенки левого желудочка (ЛЖ), пациентам из группы контроля (n = 17) выполнено АКШ системы ЛКА. Оценка показателей перфузии миокарда (SSS, SRS, SDS) по данным ОФЭКТ с 99mТс-МИБИ проведена за 1–2 сут до и через 12 мес после оперативного лечения.Результаты. При прицельной оценке перфузии миокарда в типичном бассейне кровоснабжения ПКА у пациентов из группы исследования выявили уменьшение SSSRCA с 7,0 [5,5; 10,5] до 4,0 [1,0; 5,5] (p < 0,01), SRSRCA с 3,0 [0,0; 7,0] до 1,0 [0,0; 3,5] (p < 0,01) и SDSRCA с 3,0 [1,0; 4,0] до 1,0 [0,0; 2,0] (p = 0,03). У пациентов из группы контроля в бассейне кровоснабжения ПКА выявили значимое уменьшение только SSSRCA c 8,0 [6,0; 12,0] до 5,0 [4,0; 7,0] (p < 0,01).Заключение. В отдаленные сроки наблюдения процедура трансмиокардиальной лазерной реваскуляризации в сочетании с имплантацией прекондиционированных эритропоэтином АККМ вызывает улучшение перфузии миокарда у пациентов с диффузным и (или) дистальным поражением ПКА
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