211 research outputs found
The model of control system of return pendulum
Данная статья рассказывает о комплексе лабораторных работ, который позволяет студентам изучить курс «Микропроцессорные системы управления» не только теоретически, но и получить начальные практические навыки.This article tells about a complex of laboratory works which allows students to study a course «Microprocessor control systems» not only theoretically, but also to receive initial practical skills
Plagiarism and “self-plagiarism” in scientific works in the age of digital technologies
As well as streamlining academic research activities, contemporary technologies provide opportunities to infringe on the intellectual property of others through plagiarism. However, plagiarism has yet to be adequately dealt with in national legislations, which either do not contain any provision in this connection or fail to adequately define the relevant terms. Moreover, there continues to be much discussion as to what plagiarism is, as well as how and in what cases it should be punishable. The situation is further complicated by the various approaches to plagiarism and the lack of consensus on whether so-called “self-plagiarism” should be treated separately from the intentional infringement of other people’s intellectual property or be deemed as a form of plagiarism. With the aim of clarifying these questions, the authors of the present paper compare different approaches taken to the problem of plagiarism and consider some contemporary approaches to plagiarism detection
Relationships between piezoelectric and energy-harvesting characteristics of 1–2–2 composites based on domain-engineered single crystals
The paper reports on the piezoelectric performance, electromechanical coupling and related energy-harvesting figures of merit of three forms of 1–2–2 composites based on domain-engineered single crystals. The effect of the single-crystal piezoelectric properties and elastic properties of the laminar polymer matrix on the appropriate figures of merit of the composite is studied. The main active components of the studied composites are [0 0 1]-poled perovskite-type single crystals with chemical compositions: 0.92Pb(Zn1/3Nb2/3)O3–0.08PbTiO3, 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 and [Li x (K1−y Na y)1−x ](Nb1−z Ta z)O3: Mn, where x = 0.06, y = 0.1–0.3, z = 0.07–0.17, and the level of Mn doping is 0.25 mol. %. Examples of non-monotonic volume-fraction dependences of the piezoelectric properties, figures of merit and anisotropy factors are analysed. New diagrams are first built to demonstrate the volume-fraction regions where a large anisotropy of the piezoelectric coefficients d 3j * and electromechanical coupling factors k 3j * is achieved, and where energy-harvesting figures of merit of the composite are at least five times larger than analogous parameters of single-crystal components. The studied 1–2–2 composites are of interest as anisotropic materials with high piezoelectric sensitivity and large figures of merit which are important for sensor, energy-harvesting and related applications.</p
Hourly average values of solar wing parameters (flow rate and ion temperatures) according to data of measurements of the Venera-9 and Venera-10 automatic interplanetary stations on an Earth-Venus during the period June 1975 - April 1976
Four electrostatic analyzers with channel electron multipliers as detectors were used to measure solar wind ionic flow. The axes of the fields of vision of two of these analyzers were directed along the axis of the automatic interplanetary station, oriented towards the Sun, while the other two were turned in one plane at angles of +15 deg and -15 deg. The full hemisphere of the angular diagram of each analyzer was approximately 5 deg. The energetic resolution was approximately 6%, and the geometric energy was 0.002 sq cm ave. keV. Each analyzer covered an energetic range of approximately 10 in eight energetic intervals. Spectral distributions were processed in order to obtain the velocity and temperature of the protons. Tabular data show the hour interval (universal time) and the average solar wind velocity in kilometers per second
Frequency of Interferon-Resistance Conferring Substitutions in Amino Acid Positions 70 and 91 of Core Protein of the Russian HCV 1b Isolates Analyzed in the T-Cell Epitopic Context
Funding Information: This study was supported by the grant of the Russian Science Foundation (Project ID 15-15-30039). Mobility and training of the researchers was supported by the grants of the Swedish Institute (TP 09272/2013 and PI 19806/2016). Publisher Copyright: © 2018 V. S. Kichatova et al.Amino acid substitutions R70Q/H and L91M in HCV subtype 1b core protein can affect the response to interferon and are associated with the development of hepatocellular carcinoma. We found that the rate of R70Q/H in HCV 1b from Russia was 31.2%, similar to that in HCV strains from Asia (34.0%), higher than that in the European (18.0%, p=0.0010), but lower than that in the US HCV 1b strains (62.8%, p<0.0001). Substitution L91M was found in 80.4% of the Russian HCV 1b isolates, higher than in Asian isolates (43.8%, p<0.0001). Thus, a significant proportion of Russian HCV 1b isolates carry the unfavorable R70Q/H and/or L91M substitution. In silico analysis of the epitopic structure of the regions of substitutions revealed that both harbor clusters of T-cell epitopes. Peptides encompassing these regions were predicted to bind to a panel of HLA class I molecules, with substitutions impairing peptide recognition by HLA I molecules of the alleles prevalent in Russia. This indicates that HCV 1b with R70Q/H and L91M substitutions may have evolved as the immune escape variants. Impairment of T-cell recognition may play a part in the negative effect of these substitutions on the response to IFN treatment.Peer reviewe
Changes of photosynthesis and carbon metabolism in typha angustifolia L grown in conditions of nitrate nitrogen overload
Nitrates may induce alterations in NO-signaling system and change photosynthesis in plants. Significant reduction of 14CO 2 fixation was noted at concentration of 3.96 mM NaNO 3 in an aquatic macrophyte (Typha angustifolia L.). Assimilation of 14CO 2 seven days after the introduction of nitrates did not differ between control and experimental samples. There were changes in distribution of 14C among products of 4CO 2 fixation 4 h after NaNO 3 addition, resulting in increased sugar radioactivity in experimental plants. It was suggested that the observed changes may have regulatory importance. © 2012 by Acta Botanica Croatica, the Faculty of Science, University of Zagreb
Antimicrobial resistance in clinical <I>Escherichia coli</I> isolates obtained from animals
The article presents data on the phenotypic and genotypic characteristics of antimicriobial resistance in Escherichia coli clinical isolates recovered from bovine microbiota (secretions from mammary glands, cervical swabs). 127 Escherichia coli isolates were studied, i.e. 44 from mammary glands secretions and 83 from cervical swabs. Disk diffusion method was used to study antimicrobial resistance of the cultures; minimum inhibitory concentrations of antimicrobials were determined in a serial dilution method; resistance genes were detected by polymerase chain reaction. The carried out research demonstrates a wide distribution of the isolates belonging to the phenotype resistant to ansamycins (rifampicin), semi-synthetic penicillins (ampicillin and amoxicillin), tetracyclines (doxycycline). The isolates showed a lower level of resistance to macrolides (azithromycin), amphenicols (levomycetin) and aminoglycosides (tobramycin). It was found that Escherichia coli clinical isolates are sensitive to third-generation cephalosporins and fluoroquinolone antimicrobials. However, since 28.46% of cultures demonstrate intermediate resistance to third-generation cephalosporins and 49.02% of Escherichia coli DNA samples isolated from mammal gland secretions had blaDHA gene associated with resistance to this group of antimicrobials, these antimicrobials could be hardly recommended as antibiotics of choice. Absence of VIM carbapenemase-encoding gene in the DNA of the recovered isolates and a low level of phenotypic resistance (10.22% of isolates from cervical swabs) can be one of the reasons for recommending first-line carbapenems as antibiotics of choice to treat animal diseases associated with Escherichia coli, along with fluoroquinolones as reserve antimicrobials. It was found that the recovered Escherichia coli isolates are more sensitive to combination antibiotics than to mono-antibiotics
Clinical-Laboratory Effectiveness of Immune-Replacement Therapy of Hemorrhagic Fever with Renal Syndrome
Currently, hemorrhagic fever with renal syndrome (HFRS) remains the most common natural focal disease of viral etiology in the Russian Federation. Effective antiviral drugs have not yet been developed. Pathogenetic and symptomatic drugs are mainly used in the treatment of HFRS.The aim of the study was to evaluate the clinical and laboratory effectiveness of intravenous gabriglobin in the treatment of moderate forms of HFRS.Materials and methods. The study included 22 patients with a diagnosis “HFRS of moderate severity” in the febrile stage of the disease. In the febrile period of HFRS, patients of the main group (n=10) were given gabriglobin via intravenous route at a dose of 0.1 g/kg per day along with pathogenetic therapy. The course of treatment was 2–3 infusions. The control group (n=12) received only pathogenetic therapy.Results and conclusions. As a result of the studies, the clinical and laboratory efficacy of intravenous administration of gabriglobin in the treatment of patients with moderate-grade HFRS was revealed, which was manifested by a decrease in the duration of the febrile period by 2.1 days, the severity of oliguria and a decrease in the duration of thrombocytopenia by 3.5 days compared with the group of patients receiving only pathogenetic therapy
Tuning strategy for Curie-temperature enhancement in the van der Waals magnet Mn<sub>1+x</sub>Sb<sub>2−x</sub>Te<sub>4</sub>
The van-der-Waals antiferromagnetic topological insulator MnBi2Te4 is one of the few materials that realize the sought-after quantum anomalous Hall (QAH) state and quantized surface charge transport. To assess the relevance of its isostructural analog MnSb2Te4 as a potential QAH candidate, the roles of Mn/Sb site mixing and cationic vacancies need to be clarified. Recent findings have shown that non-stoichiometry in Mn1±xSb2∓xTe4 is an efficient tuning knob to achieve a net spin-polarized state and to raise the magnetic ordering temperature well above that of MnBi2Te4. Here, we report the crystal structure, the bulk and the surface magnetism of two new Mn1+xSb2−xTe4 samples: Mn1.08Sb1.92Te4(x ≈ 0.1) with TC = 44 K, and Mn2.01Sb1.19Te4(x ≈ 1.0) with the record TC = 58 K. We quantify the site mixing comprehensively by combining various structural probes on powders and single crystals, and then employ bulk, local (electron spin resonance), and spectroscopic (x-ray magnetic circular dichroism) probes to connect these insights to the magnetism of these materials. We demonstrate that Mn over-stoichiometry up to x = 1.0, in combination with a particular Mn/Sb intermixing pattern and the increasingly three-dimensional character of the magnetic order, push the TC upwards. The tendency towards more robust ferromagnetism mediated by stronger interlayer exchange in Mn1+xSb2−xTe4 upon increasing x is confirmed by bulk magnetometry and by a series of density-functional-theory calculations of model structures with varying intermixing.</p
- …