132 research outputs found

    Possibilities to Improve the Therapy of the Patients with Ureteral Concretions

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    The aim of the given study was to improve the results of treatment of patients with concretions of the upper third of the ureter.Materials and methods. The clinical trial was carried out as a non-interventional open, controlled, in two groups of patients with baseline control. The inclusion criteria concerned the patients with concretions of the upper third of the ureter 0.7-0.9 mm in size, which had one session of an extracorporeal shock-wave lithotripsy (ESWL), and after the procedure the size of the concretions fragments was up to3 mm. The study involved 60 patients, all patients in the main group (n = 30) were treated using phytotherapy, within 1 month starting with basic therapy under hospital conditions and continuing with preventative treatment in an outpatient setting. The control group (n = 30) received baseline therapy (up to 10 days) at the stationary stage. Results and discussion. In patients of the main group, fragments of concretions came out significantly faster, namely: in the main group, the fragments came out in 21 patients (70.0 %), while in the control group in 15 patients (50.0 %) (p1- p2, p <0.05) to the 7th day, and in the main group, the fragments came out in one patient more than 14 days, and in the control group – in 5 patients, p <0.05. The "stone path" in the bottom third of the ureter was in 1 patient (3.3 %) of the main group and in 3 patients (10.0 %) in the control group (p1-p2, p <0.05). The "stone path" departure time in patients of the main group was 2 days, and in patients of the control group it was 4.1 days from the time of its formation (p1-p2, p <0.05). Bacteriuria was observed in the main group on the 10th day 6.6 % less relative to the control group.Conclusion. At comparing the obtained results in patients of both groups in 1 month it was noted that high efficacy of the treatment was registered in 6 (20 %) patients of the main group and in 3 patients (10 %) of the control group (p <0.05), moderate efficiency was registered in 23 (76.7 %) patients of the main group and in 22 (73.3 %) patients of the control group respectively, low efficacy was registered in 1 (3.33 %) patient in the main group and 5 (16.7 %) patients of the control group (p <0,05), which points to the effectiveness of Urolesan capsules use in complex therapy of patients with concretions of the one third of ureter

    Orbital parameters, chemical composition, and magnetic field of the Ap binary HD 98088

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    HD 98088 is a synchronised, double-lined spectroscopic binary system with a magnetic Ap primary component and an Am secondary component. We study this rare system using high-resolution MuSiCoS spectropolarimetric data, to gain insight into the effect of binarity on the origin of stellar magnetism and the formation of chemical peculiarities in A-type stars. Using a new collection of 29 high-resolution Stokes VQU spectra we re-derive the orbital and stellar physical parameters and conduct the first disentangling of spectroscopic observations of the system to conduct spectral analysis of the individual stellar components. From this analysis we determine the projected rotational velocities of the stars and conduct a detailed chemical abundance analysis of each component using both the SYNTH3 and ZEEMAN spectrum synthesis codes. The surface abundances of the primary component are typical of a cool Ap star, while those of the secondary component are typical of an Am star. We present the first magnetic analysis of both components using modern data. Using Least-Squares Deconvolution, we extract the longitudinal magnetic field strength of the primary component, which is observed to vary between +1170 and -920 G with a period consistent with the orbital period. There is no field detected in the secondary component. The magnetic field in the primary is predominantly dipolar, with the positive pole oriented approximately towards the secondary.Comment: Accepted for publication by MNRAS, 17 pages, 12 figure

    Abundance and stratification analysis of the CP star HD 103498

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    Slow rotation and absence of strong mixing processes in atmospheres of chemically peculiar stars develop ideal conditions for the appearance of abundance anomalies through the mechanism of microscopic particle diffusion. This makes these objects look spectroscopically and photometrically different from their "normal" analogs. As a result, it is often difficult to accurately determine atmospheric parameters of these stars and special methods are needed for the consistent analysis of their atmospheres. The main aim of the present paper is to analyse atmospheric abundance and stratification of chemical elements in the atmosphere of the chemically peculiar star HD 103498. We find that two model atmospheres computed with individual and stratified abundances provide reasonable fit to observed spectroscopic and photometric indicators: Teff=9300 K, logg=3.5 and Teff=9500K, logg=3.6. It is shown that Mg has a large abundance gradient in the star's atmosphere with accumulation of Mg ions in the uppermost atmospheric layers, whereas Si demonstrates opposite behaviour with accumulation in deep layers. In addition, a detailed non-LTE analysis showed that none of Mg transitions under consideration is a subject of noticeable non-LTE effects. Comparing observed photometry transformed to physical units we estimated the radius of HD 103498 to be between R=(4.56 +/- 0.77)Rsun for Teff=9300K, logg=3.5 and R=(4.39 +/- 0.75)Rsun for Teff=9500K, logg=3.6 models respectively. We note that the lack of suitable observations in absolute units prevents us to uniquely determine the Teff of the star at the current stage of analysis.Comment: 9 pages, 7 figures and 3 tables, accepted for publication in MNRA

    Non-local thermodynamic equilibrium effects determine the upper atmospheric temperature structure of the ultra-hot Jupiter KELT-9b

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    Several results indicate that the atmospheric temperature of the ultra-hot Jupiter KELT-9b in the main line formation region is a few thousand degrees higher than predicted by self-consistent models. We test whether non-local thermodynamic equilibrium (NLTE) effects are responsible for the presumably higher temperature. We employ the Cloudy NLTE radiative transfer code to self-consistently compute the upper atmospheric temperature-pressure (TP) profile of KELT-9b, assuming solar metallicity. The Cloudy NLTE TP profile is \approx2000 K hotter than that obtained with previous models assuming local thermodynamic equilibrium (LTE). In particular, in the 1-107^{-7} bar range the temperature increases from \approx4000 K to \approx8500 K, remaining roughly constant at lower pressures. We find that the high temperature in the upper atmosphere of KELT-9b is driven principally by NLTE effects modifying the Fe and Mg level populations, which strongly influence the atmospheric thermal balance. We employ Cloudy to compute LTE and NLTE synthetic transmission spectra on the basis of the TP profiles computed in LTE and NLTE, respectively, finding that the NLTE model generally produces stronger absorption lines than the LTE model (up to 30%), which is largest in the ultraviolet. We compare the NLTE synthetic transmission spectrum with the observed Hα\alpha and Hβ\beta line profiles obtaining an excellent match, thus supporting our results. The NLTE synthetic transmission spectrum can be used to guide future observations aiming at detecting features in the planet's transmission spectrum. Metals, such as Mg and Fe, and NLTE effects shape the upper atmospheric temperature structure of KELT-9b and thus affect the mass-loss rates derived from it. Finally, our results call for checking whether this is the case also of cooler planets.Comment: Accepted for publication on A&A. The abstract has been shortened to fit the available spac

    Spectral analysis of Kepler SPB and Beta Cep candidate stars

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    We determine the fundamental parameters of SPB and Beta Cep candidate stars observed by the Kepler satellite mission and estimate the expected types of non-radial pulsators by comparing newly obtained high-resolution spectra with synthetic spectra computed on a grid of stellar parameters assuming LTE and check for NLTE effects for the hottest stars. For comparison, we determine Teff independently from fitting the spectral energy distribution of the stars obtained from the available photometry. We determine Teff, log(g), micro-turbulent velocity, vsin(i), metallicity, and elemental abundance for 14 of the 16 candidate stars, two of the stars are spectroscopic binaries. No significant influence of NLTE effects on the results could be found. For hot stars, we find systematic deviations of the determined effective temperatures from those given in the Kepler Input Catalogue. The deviations are confirmed by the results obtained from ground-based photometry. Five stars show reduced metallicity, two stars are He-strong, one is He-weak, and one is Si-strong. Two of the stars could be Beta Cep/SPB hybrid pulsators, four SPB pulsators, and five more stars are located close to the borders of the SPB instability region.Comment: 10 pages, 10 figures, 10 table

    The CARMENES search for exoplanets around M dwarfs: Radial-velocity variations of active stars in visual-channel spectra

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    Previous simulations predicted the activity-induced radial-velocity (RV) variations of M dwarfs to range from 1\sim1 cm/s to 1\sim1 km/s, depending on various stellar and activity parameters. We investigate the observed relations between RVs, stellar activity, and stellar parameters of M dwarfs by analyzing CARMENES high-resolution visual-channel spectra (0.50.5-11μ\mum), which were taken within the CARMENES RV planet survey during its first 2020 months of operation. During this time, 287287 of the CARMENES-sample stars were observed at least five times. From each spectrum we derived a relative RV and a measure of chromospheric Hα\alpha emission. In addition, we estimated the chromatic index (CRX) of each spectrum, which is a measure of the RV wavelength dependence. Despite having a median number of only 1111 measurements per star, we show that the RV variations of the stars with RV scatter of >10>10 m/s and a projected rotation velocity vsini>2v \sin{i}>2 km/s are caused mainly by activity. We name these stars `active RV-loud stars' and find their occurrence to increase with spectral type: from 3%\sim3\% for early-type M dwarfs (M0.00.0-2.52.5V) through 30%\sim30\% for mid-type M dwarfs (M3.03.0-5.55.5V) to >50%>50\% for late-type M dwarfs (M6.06.0-9.09.0V). Their RV-scatter amplitude is found to be correlated mainly with vsiniv \sin{i}. For about half of the stars, we also find a linear RV-CRX anticorrelation, which indicates that their activity-induced RV scatter is lower at longer wavelengths. For most of them we can exclude a linear correlation between RV and Hα\alpha emission. Our results are in agreement with simulated activity-induced RV variations in M dwarfs. The RV variations of most active RV-loud M dwarfs are likely to be caused by dark spots on their surfaces, which move in and out of view as the stars rotate.Comment: A&A accepte

    Magnetic field, chemical composition and line profile variability of the peculiar eclipsing binary star AR Aur

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    AR Aur is the only eclipsing binary known to contain a HgMn star, making it an ideal case for a detailed study of the HgMn phenomenon. HgMn stars are a poorly understood class of chemically peculiar stars, which have traditionally been thought not to possess significant magnetic fields. However, the recent discovery of line profile variability in some HgMn stars, apparently attributable to surface abundance patches, has brought this belief into question. In this paper we investigate the chemical abundances, line profile variability, and magnetic field of the primary and secondary of the AR Aur system, using a series of high resolution spectropolarimetric observations. We find the primary is indeed a HgMn star, and present the most precise abundances yet determined for this star. We find the secondary is a weak Am star, and is possibly still on the pre-main sequence. Line profile variability was observed in a range of lines in the primary, and is attributed to inhomogeneous surface distributions of some elements. No magnetic field was detected in any observation of either stars, with an upper limit on the longitudinal magnetic field in both stars of 100 G. Modeling of the phase-resolve longitudinal field measurements leads to a 3 sigma upper limit on any dipole surface magnetic field of about 400 G.Comment: Accepted for publication in MNRAS, 11 pages, 9 figure

    A detailed analysis of the Gl 486 planetary system

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    Context. The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with a warm transiting rocky planet of about 1.3 R-circle plus and 3.0 M-circle plus. It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets. Aims. To prepare for future studies, we aim to thoroughly characterise the planetary system with new accurate and precise data collected with state-of-the-art photometers from space and spectrometers and interferometers from the ground. Methods. We collected light curves of seven new transits observed with the CHEOPS space mission and new radial velocities obtained with MAROON-X at the 8.1 m Gemini North telescope and CARMENES at the 3.5 m Calar Alto telescope, together with previously published spectroscopic and photometric data from the two spectrographs and TESS. We also performed near-infrared interferometric observations with the CHARA Array and new photometric monitoring with a suite of smaller telescopes (AstroLAB, LCOGT, OSN, TJO). This extraordinary and rich data set was the input for our comprehensive analysis. Results. From interferometry, we measure a limb-darkened disc angular size of the star Gl 486 at theta(LDD) = 0.390 +/- 0.018 mas. Together with a corrected Gaia EDR3 parallax, we obtain a stellar radius R-* = 0.339 +/- 0.015 R-circle plus. We also measure a stellar rotation period at P-rot = 49.9 +/- 5.5 days, an upper limit to its XUV (5-920 A) flux informed by new Hubble/STIS data, and, for the first time, a variety of element abundances (Fe, Mg, Si, V, Sr, Zr, Rb) and C/O ratio. Moreover, we imposed restrictive constraints on the presence of additional components, either stellar or sub-stellar, in the system. With the input stellar parameters and the radial-velocity and transit data, we determine the radius and mass of the planet Gl 486 b at R-p = 1.343(-0.062)(+0.063) R-circle plus and M-p = 3.00(-0.12)(+0.13) M-circle plus, with relative uncertainties of the planet radius and mass of 4.7% and 4.2%, respectively. From the planet parameters and the stellar element abundances, we infer the most probable models of planet internal structure and composition, which are consistent with a relatively small metallic core with respect to the Earth, a deep silicate mantle, and a thin volatile upper layer. With all these ingredients, we outline prospects for Gl 486 b atmospheric studies, especially with forthcoming James Webb Space Telescope (Webb) observations.The David & Lucile Packard FoundationHeising-Simons FoundationGemini ObservatoryUniversity of ChicagoMax Planck SocietyConsejo Superior de Investigaciones Cientificas (CSIC)Spanish GovernmentEuropean Commission FICTS-2011-02 ICTS-2017-07-CAHA-4 CAHA16-CE-3978German Research Foundation (DFG) FOR2544National Science Foundation (NSF) AST-1636624 AST-2034336 2108465 DGE 1746045European Research Council (ERC) 639889National Aeronautics & Space Administration (NASA) XRP NNX16AD43GNational Science Foundation (NSF) AST 1909165Wise Observatory, Tel-Aviv University, Israel TAU2021A-015Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the ERDF PID2019-109522GB-C5[1:4] PID2019-107061GBC64 PID2019-110689RB-100 PGC2018-095317-B-C21 PGC2018-102108-BI00Centre of Excellence "Severo Ochoa" CEX2019-000920-SCentre of Excellence "Maria de Maeztu" CEX2019-000920-SInstituto de Astrofisica de Andalucia SEV-2017-0709Centro de Astrobiologia MDM2017-0737German Research Foundation (DFG)European Commission FOR2544 (KU 3625/2-1)Germany's Excellence Strategy to the Excellence Cluster ORIGINS EXC-2094 -390783311European Research Council (ERC)European Commission 639889Bulgarian National Science Fund through VIHREN-2021 KP-06-DB/5Schweizerischer Nationalfonds zur Forderung der wissenschaftlichen Forschung/Fonds national suisse de la recherche scientifique PZ00P2_174028United Kingdom Science Technology and Facilities Council 630008203Princeton UniversityUniversidad La Laguna through the Margarita Salas Fellowship from the Spanish Ministerio de UniversidadesEU Next Generation funds UNI/551/2021Generalitat de Catalunya (CERCA programme

    A data-driven approach to constraining the atmospheric temperature structure of KELT-9b

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    Context. Observationally constraining the atmospheric temperature-pressure (TP) profile of exoplanets is an important step forward for improving planetary atmosphere models, further enabling one to place the detection of spectral features and the measurement of atomic and molecular abundances through transmission and emission spectroscopy on solid ground. Aims. The aim is to constrain the TP profile of the ultra-hot Jupiter KELT-9b by fitting synthetic spectra to the observed Hα\alpha and Hβ\beta lines and identify why self-consistent planetary TP models are unable to fit the observations. Methods. We construct 126 one-dimensional TP profiles varying the lower and upper atmospheric temperatures, as well as the location and gradient of the temperature rise. For each TP profile, we compute transmission spectra of the Hα\alpha and Hβ\beta lines employing the Cloudy radiative transfer code, which self-consistently accounts for non-local thermodynamic equilibrium (NLTE) effects. Results. The TP profiles leading to best fit the observations are characterised by an upper atmospheric temperature of 10000-11000 K and by an inverted temperature profile at pressures higher than 104^{-4} bar. We find that the assumption of local thermodynamic equilibrium (LTE) leads to overestimate the level population of excited hydrogen by several orders of magnitude, and hence to significantly overestimate the strength of the Balmer lines. The chemical composition of the best fitting models indicate that the high upper atmospheric temperature is most likely driven by metal photoionisation and that FeII and FeIII have comparable abundances at pressures lower than 106^{-6} bar, possibly making the latter detectable. Conclusions. Modelling the atmospheres of ultra-hot Jupiters requires one to account for metal photoionisation. [abridged]Comment: Accepted for publication by A&
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