113 research outputs found

    Effect of Stress on Irradiation-induced Creep and Swelling of Fe-18Cr-10Ni-Ti Steel Pressurized Specimens Irradiated in the BOR-60 Reactor

    Get PDF
    The paper presents the data on the effect of stress of various signs on the irradiationinduced creep strain and swelling of austenitic Fe-18Cr-10Ni-Ti steel pressurized specimens. The pressurized specimens of standard and contoured geometry were irradiated in the BOR-60 reactor up to the damage dose of 90 and 36 dpa, accordingly,under various stress levels applied. Presented are the data resulted from TEM investigations of pressurized specimens performed with the use of the transmission electron microscope

    Decomposition process in a FeAuPd alloy nanostructured by severe plastic deformation

    Full text link
    The decomposition process mechanisms have been investigated in a Fe50Au25Pd25 (at.%) alloy processed by severe plastic deformation. Phases were characterized by X-ray diffraction and microstructures were observed using transmission electron microscopy. In the coarse grain alloy homogenized and aged at 450circC450 ^{circ}\mathrm{C}, the bcc \alpha-Fe and fcc AuPd phases nucleate in the fcc supersaturated solid solution and grow by a discontinuous precipitation process resulting in a typical lamellar structure. The grain size of the homogenized FeAuPd alloy was reduced in a range of 50 to 100nm by high pressure torsion. Aging at 450circC450 ^{circ}\mathrm{C} this nanostructure leads to the decomposition of the solid solution into an equi-axed microstructure. The grain growth is very limited during aging and the grain size remains under 100nm. The combination of two phases with different crystallographic structures (bcc \alpha-Fe and fcc AuPd) and of the nanoscaled grain size gives rise to a significant hardening of the allo

    Identification of electrofacies on the basis of well logging to determine sedimentation environment of horizon JK[2] in Em-Egovskoe field (Western Siberia)

    Get PDF
    Well logging results are one of the ways to study the buried terrigenous rocks genesis. To ensure the most objective characterization of the rock and identification of electrofacies it is necessary to use a complex geological and geophysical survey. The comprehensive investigations of environmental conditions based on well logging have been performed for the horizon JK[2] of Tumenskoe formation in Em-Egovskoe area, Krasnoleninskoe field (Western Siberia). The defined electrofacies were compared with the results of earlier conducted granulometric and mineralogical analyses. The totality of research provided for a conclusion that the investigated sediments of horizon JK2 had been formed within the destructive tidal delta. Thus, objective facies prediction can only be ensured by analyzing core and well logging data comprehensively

    Diverse transcription influences can be insulated by the Drosophila SF1 chromatin boundary

    Get PDF
    Chromatin boundaries regulate gene expression by modulating enhancer–promoter interactions and insulating transcriptional influences from organized chromatin. However, mechanistic distinctions between these two aspects of boundary function are not well understood. Here we show that SF1, a chromatin boundary located in the Drosophila Antennapedia complex (ANT-C), can insulate the transgenic miniwhite reporter from both enhancing and silencing effects of surrounding genome, a phenomenon known as chromosomal position effect or CPE. We found that the CPE-blocking activity associates with different SF1 sub-regions from a previously characterized insulator that blocks enhancers in transgenic embryos, and is independent of GAF-binding sites essential for the embryonic insulator activity. We further provide evidence that the CPE-blocking activity cannot be attributed to an enhancer-blocking activity in the developing eye. Our results suggest that SF1 contains multiple non-overlapping activities that block diverse transcriptional influences from embryonic or adult enhancers, and from positive and negative chromatin structure. Such diverse insulating capabilities are consistent with the proposed roles of SF1 to functionally separate fushi tarazu (ftz), a non-Hox gene, from the enhancers and the organized chromatin of the neighboring Hox genes

    Computational prediction of new magnetic materials

    Get PDF
    The discovery of new magnetic materials is a big challenge in the field of modern materials science. We report the development of a new extension of the evolutionary algorithm USPEX, enabling the search for half-metals (materials that are metallic only in one spin channel) and hard magnetic materials. First, we enabled the simultaneous optimization of stoichiometries, crystal structures, and magnetic structures of stable phases. Second, we developed a new fitness function for half-metallic materials that can be used for predicting half-metals through an evolutionary algorithm. We used this extended technique to predict new, potentially hard magnets and rediscover known half-metals. In total, we report five promising hard magnets with high energy product (|BH|MAX), anisotropy field (Ha), and magnetic hardness (κ) and a few half-metal phases in the Cr-O system. A comparison of our predictions with experimental results, including the synthesis of a newly predicted antiferromagnetic material (WMnB2), shows the robustness of our technique. © 2022 Author(s).Russian Science Foundation, RSF, (19-72-30043)The theoretical study of ferromagnets and DFT + DMFT calculations were supported by the Russian Science Foundation (Grant No. 19-72-30043). We thank Dr. V. A. Mukhanov for assistance in high-pressure experiments and I. V. Blinov, P. Y. Plechov, and A. N. Vasilyev for their help in the initial stages of this project

    Синдромы гематофагоцитоза у пациентов педиатрических отделений реанимации и интенсивной терапии (обзор литературы)

    Get PDF
    Hemophagocytic lymphohistiocytosis (hemophagocytic syndrome, HLH, HPS) is the group of severe life-threatening and hardly diagnosing conditions caused by the immune dysregulation because of systemic inflammatory response with non-controlled proliferation and activation of T-cells, monocytes and macrophages with accumulation in target organs and the development of multiple organ failure. HLH are includes primary (monogenic) and secondary forms associated with various conditions, such as infections, immunopathological, oncohematological diseases. The severity of the condition, association with infections makes these diseases potentially lethal and requiring intensive care. In many critically ill patients in the intensive care unit, the presence of hemophagocytic syndrome remains unrecognized and is often interpreted as generalized infection, sepsis, systemic inflammatory response syndrome, multiple organ failure. Such patients require special attention, timely diagnosis and treatment. Nowadays, we have got a big group of drugs, which can pointwise block one or another pathogenesis pathway, but for a quick and correct choice, we need clear algorithms for deciding on the use of this group of targeted therapy. The article presents the history of the study of the issue and modern approaches to the diagnosis and treatment of these conditions in critically ill patients.Гемофагоцитарный лимфогистиоцитоз (гемофагоцитарный синдром, ГЛГ, ГФС) – группа тяжелых жизнеугрожающих и труднодиагностируемых состояний, вызванных нарушением регуляции иммунной системы вследствие системного воспалительного ответа с неконтролируемой пролиферацией и активацией Т-лимфоцитов, моноцитов и макрофагов с аккумуляцией в органах-мишенях и развитием полиорганной недостаточности. Выделяют первичные (моногенные) и вторичные формы, ассоциированные с различными состояниями, такими как инфекции, иммунопатологические, онкогематологические заболевания. Тяжесть состояния, ассоциация с инфекциями делают данные заболевания потенциально летальными и требующими интенсивной терапии. У многих критически больных пациентов, находящихся в отделении реанимации и интенсивной терапии, наличие гемофагоцитарного синдрома остается нераспознанным и зачастую трактуется как генерализованная инфекция, сепсис, синдром системного воспалительного ответа, полиорганная недостаточность. Такие пациенты требуют особо пристального внимания, своевременной диагностики и лечения. В настоящее время существует большой пласт препаратов, способных точечно блокировать тот или иной путь патогенеза, но для быстрого и правильного выбора необходимы четкие алгоритмы решения об использовании данной группы таргетной терапии. В статье приводится история изучения вопроса и современные подходы к диагностике и лечению данных состояний у критически больных пациентов

    DNA fragments binding CTCF in vitro and in vivo are capable of blocking enhancer activity

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Earlier we identified ten 100-300-bp long CTCF-binding DNA fragments selected earlier from a 1-Mb human chromosome 19 region. Here the positive-negative selection technique was used to check the ability of CTCF-binding human genomic fragments to block enhancer-promoter interaction when inserted into the genome.</p> <p>Results</p> <p>Ten CTCF-binding DNA fragments were inserted between the CMV enhancer and CMV minimal promoter driving the herpes simplex virus thymidine kinase (HSV<it>-tk</it>) gene in a vector expressing also the <it>neo</it><sup>R </sup>gene under a separate promoter. The constructs were then integrated into the genome of CHO cells, and the cells resistant to neomycin and ganciclovir (positive-negative selection) were picked up, and their DNAs were PCR analyzed to confirm the presence of the fragments between the enhancer and promoter in both orientations.</p> <p>Conclusions</p> <p>We demonstrated that all sequences identified by their CTCF binding both <it>in vitro </it>and <it>in vivo </it>had enhancer-blocking activity when inserted between the CMV minimal promoter and enhancer in stably transfected CHO cells.</p

    Real-Time Imaging of HIF-1α Stabilization and Degradation

    Get PDF
    HIF-1α is overexpressed in many human cancers compared to normal tissues due to the interaction of a multiplicity of factors and pathways that reflect specific genetic alterations and extracellular stimuli. We developed two HIF-1α chimeric reporter systems, HIF-1α/FLuc and HIF-1α(ΔODDD)/FLuc, to investigate the tightly controlled level of HIF-1α protein in normal (NIH3T3 and HEK293) and glioma (U87) cells. These reporter systems provided an opportunity to investigate the degradation of HIF-1α in different cell lines, both in culture and in xenografts. Using immunofluorescence microscopy, we observed different patterns of subcellular localization of HIF-1α/FLuc fusion protein between normal cells and cancer cells; similar differences were observed for HIF-1α in non-transduced, wild-type cells. A dynamic cytoplasmic-nuclear exchange of the fusion protein and HIF-1α was observed in NIH3T3 and HEK293 cells under different conditions (normoxia, CoCl2 treatment and hypoxia). In contrast, U87 cells showed a more persistent nuclear localization pattern that was less affected by different growing conditions. Employing a kinetic model for protein degradation, we were able to distinguish two components of HIF-1α/FLuc protein degradation and quantify the half-life of HIF-1α fusion proteins. The rapid clearance component (t1/2 ∼4–6 min) was abolished by the hypoxia-mimetic CoCl2, MG132 treatment and deletion of ODD domain, and reflects the oxygen/VHL-dependent degradation pathway. The slow clearance component (t1/2 ∼200 min) is consistent with other unidentified non-oxygen/VHL-dependent degradation pathways. Overall, the continuous bioluminescence readout of HIF-1α/FLuc stabilization in vitro and in vivo will facilitate the development and validation of therapeutics that affect the stability and accumulation of HIF-1α

    Dermacentor reticulatus: a vector on the rise

    Get PDF
    Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1599-x) contains supplementary material, which is available to authorized users

    For some types of 3-D systems of quadratic differential equations the new types of chaotic attractors are founded. Examples are given

    No full text
    Для некоторых типов 3-D систем квадратичных дифференциальных урав­нений найдены новые типы хаотических аттракторов. Приводятся примеры.Для деяких типів 3-D систем квадратичних дифференціальних рівнянь знайдено нові типи хаотичних атракторів. Наводяться приклади.For some types of 3-D systems of quadratic differential equations the new types of chaotic attractors are founded. Examples are given
    corecore