311 research outputs found

    Application of Airborne Sound Waves to Mass Transfer Enhancement

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    Intermetallic coatings produced by mechanical alloying method

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    The technique of mechanical alloying (MA) was used to coat the metal substrate with other metals. The Al-Ti and Al-Ni binary systems were investigated, at that, all the elements were used both as substrates and as coating powders. Thickness and quality of coating depending on the MA treatment parameters, such as intensity and duration of milling, amount of loaded powder, were investigated. As-synthesized coatings showed structures with high apparent density and free of porosity. However, the surface morphology of the MA-coatings was very rough. Annealing treatment led to the leveling of surface microstructure and formation of different aluminide phases in the coatings. MA allows to produce thick coatings for a relatively short time with good adherence

    Thermal conduction in hot gas of galaxy clusters

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    Study of Highly Pixelated CdZnTe Detector for PET Applications

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    AbstractWe are investigating the feasibility of a high-resolution PET insert device based on a Cadmium Zinc Telluride (CdZnTe) detector with 350μm anode pixel pitch to be integrated into a conventional animal PET scanner to improve its image resolution to sub-500 micrometer range. In this work, we have used a simplified version of the future 2048-pixel CdZnTe planar detector with 250μm anode pixel size and 100μm gap. This simplified 9 anode pixel structure makes it possible to conduct experiments without a complete ASIC readout system (with 2048 channels) that is still under development. We characterized this CdZnTe detector by investigating it charge sharing, spatial resolution, and energy resolution. We imaged a Na-22 point source using the coincidence events between this 350μm pixelated CdZnTe detector and a lutetium oxyorthosilicate (LSO) based Siemens Inveon PET detector. The reconstructed PET image shows a resolution of 590μm full width at half maximum (FWHM) by using single-pixel events. When we included double-pixel charge sharing events in the image reconstruction, the image resolution was degraded to 655μm, but the sensitivity of the coincidence system increased 2.5 to 3 times

    Seasonal nitrogen remobilization and the role of auxin transport in poplar trees

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    Seasonal nitrogen (N) cycling in Populus, involves bark storage proteins (BSPs) that accumulate in bark phloem parenchyma in the autumn and decline when shoot growth resumes in the spring. Little is known about the contribution of BSPs to growth or the signals regulating N remobilization from BSPs. Knockdown of BSP accumulation via RNAi and N sink manipulations were used to understand how BSP storage influences shoot growth. Reduced accumulation of BSPs delayed bud break and reduced shoot growth following dormancy. Further, 13N tracer studies also showed that BSP accumulation is an important factor in N partitioning from senescing leaves to bark. Thus, BSP accumulation has a role in N remobilization during N partitioning both from senescing leaves to bark and from bark to expanding shoots once growth commences following dormancy. The bark transcriptome during BSP catabolism and N remobilization was enriched in genes associated with auxin transport and signaling, and manipulation of the source of auxin or auxin transport revealed a role for auxin in regulating BSP catabolism and N remobilization. Therefore, N remobilization appears to be regulated by auxin produced in expanding buds and shoots that is transported to bark where it regulates protease gene expression and BSP catabolism

    HIV-1 Reverse Transcriptase Promotes Tumor Growth and Metastasis Formation via ROS-Dependent Upregulation of Twist

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    Funding Information: https://orcid.org/0000-0002-6160-2203 Bayurova Ekaterina [email protected] 1 2 Jansons Juris [email protected] 3 4 Skrastina Dace [email protected] 3 4 https://orcid.org/0000-0002-4980-9754 Smirnova Olga [email protected] 5 Mezale Dzeina [email protected] 3 Kostyusheva Anastasia [email protected] 6 Kostyushev Dmitry [email protected] 6 Petkov Stefan [email protected] 7 Podschwadt Philip [email protected] 7 https://orcid.org/0000-0003-0365-570X Valuev-Elliston Vladimir [email protected] 5 Sasinovich Sviataslau [email protected] 7 https://orcid.org/0000-0003-2278-4451 Korolev Sergey [email protected] 8 Warholm Per [email protected] 9 https://orcid.org/0000-0002-2260-6551 Latanova Anastasia [email protected] 1 5 https://orcid.org/0000-0003-2183-0858 Starodubova Elizaveta [email protected] 1 5 https://orcid.org/0000-0001-8506-2339 Tukhvatulin Amir [email protected] 1 Latyshev Oleg [email protected] 1 Selimov Renat [email protected] 10 Metalnikov Pavel [email protected] 10 Komarov Alexander [email protected] 10 https://orcid.org/0000-0002-3673-4714 Ivanova Olga [email protected] 5 Gorodnicheva Tatiana [email protected] 11 https://orcid.org/0000-0002-7443-6961 Kochetkov Sergey [email protected] 5 Gottikh Marina [email protected] 8 Strumfa Ilze [email protected] 3 https://orcid.org/0000-0002-5659-9679 Ivanov Alexander [email protected] 5 Gordeychuk Ilya [email protected] 1 2 12 https://orcid.org/0000-0001-9382-2254 Isaguliants Maria [email protected] 1 2 3 7 García-Rivas Gerardo 1 NF Gamaleya Research Center of Epidemiology and Microbiology Moscow Russia 2 Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences Moscow Russia chumakovs.ru 3 Department of Pathology Riga Stradins University Riga Latvia rsu.lv 4 Latvian Biomedical Research and Study Centre Riga Latvia lu.lv 5 Engelhardt Institute of Molecular Biology Russian Academy of Sciences Moscow Russia ras.ru 6 National Medical Research Center for Tuberculosis and Infectious Diseases Moscow Russia 7 Department of Microbiology Tumor and Cell Biology Karolinska Institutet Stockholm Sweden ki.se 8 Chemistry Department and Belozersky Institute of Physico-Chemical Biology Lomonosov Moscow State University Moscow Russia msu.ru 9 Science for Life Laboratory Stockholm University Stockholm Sweden su.se 10 Russian State Center for Quality and Standardization of Veterinary Drugs and Feed (VGNKI) Moscow Russia 11 Evrogen Moscow Russia 12 Sechenov First Moscow State Medical University Moscow Russia mma.ru 2019 2 12 2019 2019 08 05 2019 01 11 2019 05 11 2019 2 12 2019 2019 Copyright © 2019 Ekaterina Bayurova et al. This is an open access article distributed under the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. HIV-induced immune suppression results in the high prevalence of HIV/AIDS-associated malignancies including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. HIV-infected people are also at an increased risk of “non-AIDS-defining” malignancies not directly linked to immune suppression but associated with viral infections. Their incidence is increasing despite successful antiretroviral therapy. The mechanism behind this phenomenon remains unclear. Here, we obtained daughter clones of murine mammary gland adenocarcinoma 4T1luc2 cells expressing consensus reverse transcriptase of HIV-1 subtype A FSU_A strain (RT_A) with and without primary mutations of drug resistance. In in vitro tests, mutations of resistance to nucleoside inhibitors K65R/M184V reduced the polymerase, and to nonnucleoside inhibitors K103N/G190S, the RNase H activities of RT_A. Expression of these RT_A variants in 4T1luc2 cells led to increased production of the reactive oxygen species (ROS), lipid peroxidation, enhanced cell motility in the wound healing assay, and upregulation of expression of Vimentin and Twist . These properties, particularly, the expression of Twist , correlated with the levels of expression RT_A and/or the production of ROS. When implanted into syngeneic BALB/C mice, 4T1luc2 cells expressing nonmutated RT_A demonstrated enhanced rate of tumor growth and increased metastatic activity, dependent on the level of expression of RT_A and Twist . No enhancement was observed for the clones expressing mutated RT_A variants. Plausible mechanisms are discussed involving differential interactions of mutated and nonmutated RTs with its cellular partners involved in the regulation of ROS. This study establishes links between the expression of HIV-1 RT, production of ROS, induction of EMT, and enhanced propagation of RT-expressing tumor cells. Such scenario can be proposed as one of the mechanisms of HIV-induced/enhanced carcinogenesis not associated with immune suppression. Ministry of Science and Higher Education of the Russian Federation 075-15-2019-1660 Latvian Science Council LZP-2018/2-0308 EU VACTRAIN Russian Foundation for Basic Research 17-00-00085 17_04_00583 17_54_30002 Publisher Copyright: © 2019 Ekaterina Bayurova et al.HIV-induced immune suppression results in the high prevalence of HIV/AIDS-associated malignancies including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. HIV-infected people are also at an increased risk of "non-AIDS-defining" malignancies not directly linked to immune suppression but associated with viral infections. Their incidence is increasing despite successful antiretroviral therapy. The mechanism behind this phenomenon remains unclear. Here, we obtained daughter clones of murine mammary gland adenocarcinoma 4T1luc2 cells expressing consensus reverse transcriptase of HIV-1 subtype A FSU_A strain (RT_A) with and without primary mutations of drug resistance. In in vitro tests, mutations of resistance to nucleoside inhibitors K65R/M184V reduced the polymerase, and to nonnucleoside inhibitors K103N/G190S, the RNase H activities of RT_A. Expression of these RT_A variants in 4T1luc2 cells led to increased production of the reactive oxygen species (ROS), lipid peroxidation, enhanced cell motility in the wound healing assay, and upregulation of expression of Vimentin and Twist. These properties, particularly, the expression of Twist, correlated with the levels of expression RT_A and/or the production of ROS. When implanted into syngeneic BALB/C mice, 4T1luc2 cells expressing nonmutated RT_A demonstrated enhanced rate of tumor growth and increased metastatic activity, dependent on the level of expression of RT_A and Twist. No enhancement was observed for the clones expressing mutated RT_A variants. Plausible mechanisms are discussed involving differential interactions of mutated and nonmutated RTs with its cellular partners involved in the regulation of ROS. This study establishes links between the expression of HIV-1 RT, production of ROS, induction of EMT, and enhanced propagation of RT-expressing tumor cells. Such scenario can be proposed as one of the mechanisms of HIV-induced/enhanced carcinogenesis not associated with immune suppression.publishersversionPeer reviewe
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