1,641 research outputs found

    The stabilization of unstable detonation waves for the mixture of nitromethane/methanol

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    Mass velocity profiles of detonation waves in mixtures of nitromethane with acetone and methanol with added diethylenetriamine sensitizer were measured using a VISAR laser interferometer. It was found that even small, about 1%, concentrations of acetone and methanol, inert diluents, led to instability of the one-dimensional detonation front in nitromethane. The results of the experiment show that the use of the sensitizer is an effective method of flow stabilization and if the concentration of the inert diluent does not exceed 10%, the detonation front becomes stable with the addition of 1% diethylenetriamine. At a higher diluent concentration, the sensitizer does not suppress the instability but decreases the oscillation amplitude by several times. The addition of diethylenetriamine to the mixture has been found to increase the detonation velocity

    Development of an automated prototype of THz filter based on magnetic fluids

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    Many new investigation approaches or techniques that rely on THz radiation are emerging today. It requires the development of devices for controlling THz radiation characteristics intensity, polarization, spectral properties, etc. One of the promising approaches to the implementation of such devices is the use of ferromagnetic fluids. Earlier, the efficient operation of polarizers and non selective THz attenuators based on ferromagnetic liquids was demonstrated. The liquids used consisted of 5BDSR alloy particles obtained by the mechanical synthesis in a planetary mill or Fe particles obtained by the electric explosion, dispersed in synthetic engine oil. Magnetic fluids were controlled using an external magnetic field generated by Helmholtz coils. In this study, we propose a prototype of a THz filter based on previously developed ferromagnetic fluids. Filter consists of a quartz or polymer cuvette with a magnetic fluid, several Helmholtz coils and a control circuit. This device allows one to orient the magnetic particles and to create ordered structures in the form of extended clusters. As a result, physical properties of electromagnets were optimized for effective controlling of particle clusters; the control process itself was automated. Spectral properties in the THz range are studied for various filter states. For reliable continuous operations, the device was supplemented with a homogenization system, based on mechanical mixing or sonication. The developed device can be used as a polarizer or an attenuator for polarized radiation in the range of 0.3-3 THz

    Discovery of an unrecognized nidovirus associated with granulomatous hepatitis in rainbow trout

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    Rainbow trout (Oncorhynchus mykiss) is the principal species of inland-farmed fish in the Western hemisphere. Recently, we diagnosed in farmed rainbow trout a disease in which the hallmark is granulomatous-like hepatitis. No biotic agents could be isolated from lesions. Still, unbiased high-throughput sequencing and bioinformatics analyses revealed the presence of a novel piscine nidovirus that we named “Trout Granulomatous Virus” (TGV). TGV genome (28,767 nucleotides long) is predicted to encode non-structural (1a and 1 ab) and structural (S, M, and N) proteins that resemble proteins of other known piscine nidoviruses. High loads of TGV transcripts were detected by quantitative RT-PCR in diseased fish and visualized in hepatic granulomatous sites by fluorescence in situ hybridization. Transmission electron microscopy (TEM) revealed coronavirus-like particles in these lesions. Together, these analyses corroborated the association of TGV with the lesions. The identification and detection of TGV provide means to control TGV spread in trout populations

    Security methods for a group of mobile robots according to the requirements of Russian and foreign legislation

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    This paper is devoted to the problem of creating security methods for mobile robotic systems. The urgency of the problem of ensuring the security of mobile robotic systems is associated with the presence of a contradiction between the growing popularity of the mobile robotic systems and the presence of many vulnerabilitie

    Developing models of IoT infrastructures to identify vulnerabilities and analyse threats

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    This article describes the developing stands of typical IoT infrastructure Technologies, which are designed to identify vulnerabilities and analyse potential threats. Scenarios of attacks typical for such systems have been developed, and the consequences of implementing attacks have been determined. Attacker can use the developed scenarios, been motivated by different goal

    Comparative analysis of the concentrations of proinflammatory cytokines and glycosylated ferritin in patients with idiopathic recurrent pericarditis and adult-onset Still's disease

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    Idiopathic recurrent pericarditis (IRP) and adult-onset Still's disease (AOSD) are polygenic autoinflammatory diseases, in the pathogenesis of which pro-inflammatory cytokines from the interleukin-1 superfamily play a central role.Aim. To compare serum concentrations of proinflammatory cytokines and glycosylated ferritin (GF) in patients with IRP and AOSD during an exacerbation.Material and methods. The study included 15 patients with AOSD, 15 — IRP. The diagnosis of AOSD was established using the Yamaguchi criteria (1992). IRP was diagnosed in accordance with the 2015 European Society of Cardiology on the diagnosis and management of pericardial diseases. Blood sampling from all patients was carried out during the recurrence period prior to the anti-inflammatory therapy initiation. The serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-18 (IL-18), procalcitonin, total ferritin and GF was assessed. The results obtained were compared with levels of biochemical parameters, high-sensitivity C-reactive protein (CRP), as well as with white blood cell (WBC) and neutrophil counts.Results. The median age in the AOSD group was 28 years, and the IRP — 55 years. An increase WBC count >10*109/L was detected in 10 and 9 patients in the AOSD and IRP groups, respectively. The concentration of CRP was increased in all patients and did not differ in the study groups (p=0,836).The highest values of ferritin and GF levels were found in the AOSD group (1416 ng/ml vs 408 ng/ml, p=0,008) and (12% vs 33,9%, p=0,067), respectively. In both groups, increased concentrations of IL-6 and IL-18 were determined. In the AOSD group, the concentration of IL-18 was higher than in the IRP group (2114 pg/ml vs 161,5 pg/ml, p<0,001). IL-6 concentrations in the study groups did not differ (33,9 pg/ml vs 24,9 pg/ml, p=0,4). IL-1β serum concentration in all subjects corresponded to normal values.Correlation analysis in the AOSD group revealed a direct relationship between the IL-18 and ferritin concentrations (rs=0,73, p=0,03).Conclusion. The study established a similar pattern of changes in inflammatory biomarkers in patients with AOSD and IRI. The most informative marker of inflammation was IL-18

    Fast flowing populations are not well mixed

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    In evolutionary dynamics, well-mixed populations are almost always associated with all-to-all interactions; mathematical models are based on complete graphs. In most cases, these models do not predict fixation probabilities in groups of individuals mixed by flows. We propose an analytical description in the fast-flow limit. This approach is valid for processes with global and local selection, and accurately predicts the suppression of selection as competition becomes more local. It provides a modelling tool for biological or social systems with individuals in motion.Comment: 19 pages, 8 figure

    Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method

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    This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/he/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within ±1\pm 1% of the true values and the fractional energy resolution is [(58±3)/E+(2.5±0.3)[(58\pm3)% /\sqrt{E}+(2.5\pm0.3)%]\oplus (1.7\pm0.2)/E. The value of the e/he/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74±0.041.74\pm0.04 and agrees with the prediction that e/h>1.7e/h > 1.7 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM

    Molecular genetic characteristics of colorectal cancer depending on the status of microsatellite instability

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    Introduction. The emergence of new markers that determine the choice of therapy for metastatic colorectal cancer (CRC) has led to an increase in overall survival. The optimal treatment tactics now take into account both clinical and molecular-genetic characteristics of the tumor.Aim. Investigation of the features of the KRAS, NRAS and BRAF mutations and amplification of the HER2 gene depending on microsatellite instability (MSI) in CRC.Materials and methods. The study included 400 patients with CRC. MSI, BRAF V600E mutation, mutations in the KRAS and NRAS genes was identified to them. MSI was determined by fragment analysis, and mutations in the KRAS, NRAS, BRAF genes by realtime PCR. HER2 amplification was determined in 100 patients with a negative RAS/BRAF. NTRK translocations were determined in all patients with MSI. Data on preoperative levels of CEA and CA19-9 were obtained from 185 patients.Results and discussion. The prevalence of MSI was 6.8%. The prevalence of KRAS, NRAS, BRAF mutations in CRC with MSI was 66.7%, and in CRC with MSS - 52.3%. In patients with MSI, the level of CEA was lower than in MSS (p = 0.0061). The overall prevalence of KRAS and NRAS mutations was 45% and 2.5%. The overall prevalence of the BRAF V600E mutation was 5.8% and was more common in MSI-positive tumors (p < 0.0001). Regardless of MSI, BRAF-positive tumors were characterized by right-sided localization (p < 0.0001), category T3-4 (p = 0.013), lymph node involvement (p = 0.004), carcinomatosis (p = 0.046), high levels of CA19-9 (p = 0.014). HER2 amplification was found in 7% of wild-type RAS/BRAF cases and was associated with rectal cancer (p = 0.044), category T3-4 (p = 0.041), and distant metastases (p = 0.038). HER2 amplifications and NTRK translocations were not detected in cases with MSI.Conclusion. MSI-positive CRC had a higher prevalence of mutations in major genes. CRC with the BRAF V600E mutation and HER2 amplification had aggressive clinical and morphological parameters
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