286 research outputs found

    Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

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    Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron momenta sampled during these simulations were analyzed and justified using theoretically determined boundaries. We present a complete set of tables suited for mean free path calculations of Monte Carlo simulations of the cyclotron scattering process for conditions expected in typical X-ray pulsar accretion columns (0.01<B/B_{crit}<=0.12, where B_{crit}=4.413x10^{13} G and 3keV<=kT<15keV). The sampling of the tables is chosen such that the results have an estimated relative error of at most 1/15 for all points in the grid. The tables are available online at http://www.sternwarte.uni-erlangen.de/research/cyclo.Comment: A&A, in pres

    ΠžΡΠΎΠ±Π΅Π½Π½ΠΎΡΡ‚ΠΈ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€Π½ΠΎΠΉ ПЦР для выявлСния Π²ΠΎΠ·Π±ΡƒΠ΄ΠΈΡ‚Π΅Π»Π΅ΠΉ ΠΈΠ½Ρ„Π΅ΠΊΡ†ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΠ½Π΅Π²ΠΌΠΎΠ½ΠΈΠΈ Ρ‡Π΅Π»ΠΎΠ²Π΅ΠΊΠ°

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    Objectives. The objectives of this work are the development of a multi-primer system based on the polymerase chain reaction (PCR) aimed at the simultaneous detection of six bacterial pathogens that cause human pneumonia and the determination of the parameters important for the optimization of this multi-primer system, including solid-phase PCR systems (biological microarrays).Methods. To determine the optimal parameters of the system, PCR methods were used in monoplex and multiplex formats.Results. Primers for Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenza, Legionella pneumophila, Klebsiella pneumoniae, and Streptococcus pneumoniae detection were designed, and the PCR cycling conditions were optimized. The patterns of primer design for solidphase PCR were revealed.Conclusions. The developed prototype of a system specifically identifies six clinically significant bacterial pathogens. It could be expanded for the analysis of viral and fungal pathogens and used in clinical diagnostics. A prototype of a system for pathogenic agent detection in the immobilized phase (biological microarray) was created.Π¦Π΅Π»ΠΈ. Π Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠ° ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€Π½ΠΎΠΉ систСмы Π½Π° основС ΠΏΠΎΠ»ΠΈΠΌΠ΅Ρ€Π°Π·Π½ΠΎΠΉ Ρ†Π΅ΠΏΠ½ΠΎΠΉ Ρ€Π΅Π°ΠΊΡ†ΠΈΠΈ (ПЦР), Π½Π°ΠΏΡ€Π°Π²Π»Π΅Π½Π½ΠΎΠΉ Π½Π° ΠΎΠ΄Π½ΠΎΠ²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠ΅ выявлСниС ΡˆΠ΅ΡΡ‚ΠΈ основных Π±Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ°Π»ΡŒΠ½Ρ‹Ρ… Π²ΠΎΠ·Π±ΡƒΠ΄ΠΈΡ‚Π΅Π»Π΅ΠΉ ΠΏΠ½Π΅Π²ΠΌΠΎΠ½ΠΈΠΈ Ρ‡Π΅Π»ΠΎΠ²Π΅ΠΊΠ°; выявлСниС ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΎΠ² ΠΈ закономСрностСй, ΠΈΠΌΠ΅ΡŽΡ‰ΠΈΡ… Π²Π°ΠΆΠ½ΠΎΠ΅ Π·Π½Π°Ρ‡Π΅Π½ΠΈΠ΅ для ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€Π½ΠΎΠΉ систСмы, Π² Ρ‚ΠΎΠΌ числС для Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ систСм ПЦР Π² ΠΈΠΌΠΌΠΎΠ±ΠΈΠ»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠΉ Ρ„Π°Π·Π΅ (Π½Π° биологичСском ΠΌΠΈΠΊΡ€ΠΎΡ‡ΠΈΠΏΠ΅).ΠœΠ΅Ρ‚ΠΎΠ΄Ρ‹. Для опрСдСлСния ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»ΡŒΠ½Ρ‹Ρ… ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΎΠ² систСмы использовали ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ ПЦР Π² Ρ‚.Π½. «моноплСксном» ΠΈ ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠΌ Ρ„ΠΎΡ€ΠΌΠ°Ρ‚Π°Ρ….Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹. Бконструированы ΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€Ρ‹, ΠΈ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π½ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΎ-Π²Ρ€Π΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΠΏΡ€ΠΎΡ„ΠΈΠ»ΡŒ провСдСния ПЦР Π² объСмС для выявлСния Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenza, Legionella pneumophila, Klebsiella pneumoniae ΠΈ Streptococcus pneumoniae. ВыявлСны закономСрности конструирования ΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€ΠΎΠ² для ПЦР Π² ΠΈΠΌΠΌΠΎΠ±ΠΈΠ»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠΉ Ρ„Π°Π·Π΅.Π’Ρ‹Π²ΠΎΠ΄Ρ‹. Π˜Π·ΡƒΡ‡Π΅Π½Π½Ρ‹Π΅ закономСрности особСнностСй ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΡ€Π°ΠΉΠΌΠ΅Ρ€Π½Ρ‹Ρ… систСм ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΠ»ΠΈ Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚Π°Ρ‚ΡŒ ΠΏΡ€ΠΎΡ‚ΠΎΡ‚ΠΈΠΏ систСмы, способной спСцифично Π²Ρ‹ΡΠ²Π»ΡΡ‚ΡŒ ΡˆΠ΅ΡΡ‚ΡŒ клиничСски Π·Π½Π°Ρ‡ΠΈΠΌΡ‹Ρ… Π²ΠΎΠ·Π±ΡƒΠ΄ΠΈΡ‚Π΅Π»Π΅ΠΉ ΠΏΠ½Π΅Π²ΠΌΠΎΠ½ΠΈΠΈ Ρ‡Π΅Π»ΠΎΠ²Π΅ΠΊΠ°. ΠŸΡ€ΠΎΡ‚ΠΎΡ‚ΠΈΠΏ систСмы ΠΌΠΎΠΆΠ΅Ρ‚ Π±Ρ‹Ρ‚ΡŒ Ρ€Π°ΡΡˆΠΈΡ€Π΅Π½ для Π°Π½Π°Π»ΠΈΠ·Π° вирусных ΠΈ Π³Ρ€ΠΈΠ±ΠΊΠΎΠ²Ρ‹Ρ… ΠΏΠ°Ρ‚ΠΎΠ³Π΅Π½ΠΎΠ² ΠΈ ΠΏΡ€ΠΈΠΌΠ΅Π½ΡΡ‚ΡŒΡΡ Π² клиничСской диагностикС. Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ изучСния особСнностСй ΠΌΡƒΠ»ΡŒΡ‚ΠΈΠΏΠ»Π΅ΠΊΡΠ½ΠΎΠΉ ПЦР Π² ΠΈΠΌΠΌΠΎΠ±ΠΈΠ»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠΉ Ρ„Π°Π·Π΅ ΠΏΡ€ΠΈΠ²Π΅Π»ΠΈ ΠΊ созданию ΠΏΡ€ΠΎΡ‚ΠΎΡ‚ΠΈΠΏΠ° систСмы для выявлСния ΠΏΠ°Ρ‚ΠΎΠ³Π΅Π½Π½Ρ‹Ρ… Π°Π³Π΅Π½Ρ‚ΠΎΠ² Π½Π° биологичСском ΠΌΠΈΠΊΡ€ΠΎΡ‡ΠΈΠΏΠ΅

    ABOUT DIAGNOSTICS OF THE PATIENT WITH SUSPICION TO SEVERE ACUTE RESPIRATORY SYNDROME (SARS) IN CHITA CITY

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    A complex of diagnostic measures for detection of a suspected SARS patient is analyzed. Clinical course ofΒ the disease in dynamics especially at the early stages allowed to suspect SARS in a worker arrived from China. The diagnosis was cancelled on the basis of the clinical data and laboratory negative results. However,Β this case allowed to practically perfect tactics of interactions between different services during realization ofΒ anti-epidemic measures in a case of SARS suspicion including notification, hospital basis development andΒ PCR-diagnostics adoption

    Emulation of a Target Trial From Observational Data to Compare Effectiveness of Casirivimab/Imdevimab and Bamlanivimab/Etesevimab for Early Treatment of Non-Hospitalized Patients With COVID-19

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    OBJECTIVES: Comparative analysis between different monoclonal antibodies (mAbs) against SARS-CoV-2 are lacking. We present an emulation trial from observational data to compare effectiveness of Bamlanivimab/Etesevimab (BAM/ETE) and Casirivimab/Imdevimab (CAS/IMD) in outpatients with early mild-to-moderate COVID-19 in a real-world scenario of variants of concern (VoCs) from Alpha to Delta. METHODS: Allocation to treatment was subject to mAbs availability, and the measured factors were not used to determine which combination to use. Patients were followed through day 30. Viral load was measured by cycle threshold (CT) on D1 (baseline) and D7. Primary outcome was time to COVID-19-related hospitalization or death from any cause over days 0-30. Weighted pooled logistic regression and marginal structural Cox model by inverse probability weights were used to compare BAM/ETE vs. CAS/IMD. ANCOVA was used to compare mean D7 CT values by intervention. Models were adjusted for calendar month, MASS score and VoCs. We evaluated effect measure modification by VoCs, vaccination, D1 CT levels and enrolment period. RESULTS: COVID19-related hospitalization or death from any cause occurred in 15 of 237 patients in the BAM/ETE group (6.3%) and in 4 of 196 patients in the CAS/IMD group (2.0%) (relative risk reduction [1 minus the relative risk] 72%; p=0.024). Subset analysis carried no evidence that the effect of the intervention was different across stratification factors. There was no evidence in viral load reduction from baseline through day 7 across the two groups (+0.17, 95% -1.41;+1.74, p=0.83). Among patients who experienced primary outcome, none showed a negative RT-PCR test in nasopharyngeal swab (p=0.009) and 82.4% showed still high viral load (p<0.001) on D7. CONCLUSIONS: In a pre-Omicron epidemiologic scenario, CAS/IMD reduced risk of clinical progression of COVID-19 compared to BAM/ETE. This effect was not associated with a concomitant difference in virological response

    Sanitary protection of the territory of Russian Federation. Report 2. The differentiation of the territory of a region of Russian Federation for risk of diseases dangerous for people

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    The risk of emergency situations in the sphere of sanitary-epidemiological welfare associated with diseases dangerous for population varies for different municipalities of a region of Russian Federation. Therefore a differentiation of a region for three types of territories (A, B, C) is necessary. Adequate number of sanitary protection measures is determined for each type of territories. The purpose of this study was the development of methodical reception for differentiation of a region of Russian Federation. Point scoping of criteria of external and. internal epidemiological risks for each of municipality is proposed as this method. Criteria of external epidemiological risk allow to take into account the probability of the importation of infectious diseases, requiring measures for sanitary protection of the territory. Criteria of internal epidemiological risk reflect both actual and. potential dangers: morbidity, the registration of particular nosologic forms of diseases in animals and. detection of pathogens in the living and. non-living environment objects. Assessment of internal risk is carried out in the analysis of information about epizootic and. epidemiological situation of infectious diseases, the list of which is proposed, with, consideration of their epidemiological significance and. can be used for any Russian Federation region. According to the results of total assessment of risks for each of municipalities the complex index of epidemiological risk (CIER) is determined. On the basis of CIER the territory type (A, B, C) is determined. Type A, B or C defines for the municipality the volume of measures for sanitary protection of the territory on the basis of a sufficient level for preparedness of forces and means of public health institutions. The method, based, on the assessment of external and. internal epidemiological risks, that allows to differentiate the region of Russian Federation, at municipal level for risk of diseases dangerous for people, is proposed, as the result of this work. A new methodical approach, will contribute to the increase of the preparedness of public health, institutions to emergency situations in the sphere of sanitary-epidemiological welfare associated, with, diseases dangerous for people

    In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma

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    CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination and poor prognosis. We evaluated the novel CXCR4 probe [(68)Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [(68)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [(68)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [(18)F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34(+) flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [(68)Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases

    Topological spin memory of antiferromagnetically coupled skyrmion pairs in Co/Gd/Pt multilayers

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    Antiferromagnetically (AFM) coupled skyrmions offer potential advantages for spintronic devices, including reduced dipolar fields that may enable smaller skyrmion sizes and a reduction of the skyrmion Hall effect. However, the topological stability of AFM-coupled skyrmions subjected to dramatic spin deformation through low-temperature cycling has not been investigated. Here we report the discovery of a topological spin memory effect for AFM-coupled skyrmion pairs in [Co/Gd/Pt]10 multilayered films. Photoemission electron microscopy imaging shows that bubble skyrmions in the multilayer that are stable at room temperature evolve into complex in-plane spin textures as the temperature is lowered and reform completely when the sample is warmed back up. Simulations demonstrate that Dzyaloshinskii-Moriya interactions play a key role in this spin memory effect, and furthermore reveal that the topological charge is preserved throughout the dramatic spin texture rearrangement and recovery. These results highlight a key aspect of topological protectionβ€”the preservation of the topological properties under continuous deformationβ€”and also provide a promising avenue for information encryption and recovery

    X-ray emission from magnetized neutron star atmospheres at low mass accretion rates. I. Phase-averaged spectrum

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    Recent observations of X-ray pulsars at low luminosities allow, for the first time, to compare theoretical models for the emission from highly magnetized neutron star atmospheres at low mass accretion rates (M˙≲1015\dot{M} \lesssim 10^{15} g sβˆ’1^{-1}) with the broadband X-ray data. The purpose of this paper is to investigate the spectral formation in the neutron star atmosphere at low MΛ™\dot{M} and to conduct a parameter study of physical properties of the emitting region. We obtain the structure of the static atmosphere, assuming that Coulomb collisions are the dominant deceleration process. The upper part of the atmosphere is strongly heated by the braking plasma, reaching temperatures of 30-40 keV, while its denser isothermal interior is much cooler (~2 keV). We numerically solve the polarized radiative transfer in the atmosphere with magnetic Compton scattering, free-free processes, and non-thermal cyclotron emission due to possible collisional excitations of electrons. The strongly polarized emitted spectrum has a double-hump shape that is observed in low-luminosity X-ray pulsars. A low-energy "thermal" component is dominated by extraordinary photons that can leave the atmosphere from deeper layers due to their long mean free path at soft energies. We find that a high-energy component is formed due to resonant Comptonization in the heated non-isothermal part of the atmosphere even in the absence of collisional excitations. The latter, however, affect the ratio of the two components. A strong cyclotron line originates from the optically thin, uppermost zone. A fit of the model to NuSTAR and Swift/XRT observations of GX 304-1 provides an accurate description of the data with reasonable parameters. The model can thus reproduce the characteristic double-hump spectrum observed in low-luminosity X-ray pulsars and provides insights into spectral formation.Comment: 18 pages, 10 figures, A&A accepte
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