396 research outputs found

    Antirheumatische Therapie und Reproduktion: Einfluss auf Fertilität, Schwangerschaft und Stillzeit

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    Zusammenfassung: Antirheumatische Medikamente können bei männlichen und weiblichen Patienten einen negativen Einfluss auf die Fortpflanzung haben. Mögliche negative Effekte sind: Beeinträchtigung der Fertiltät, Fruchtschädigung während der Schwangerschaft und Nebenwirkungen beim gestillten Kind. Bei der Frau können nichtsteroidale Antiphlogistika (NSAR) und Cyclophosphamid die Fertilität beeinträchtigen. Beim Mann kann Infertilität bei der Behandlung mit Salazopyrin und Cyclophosphamid auftreten. Vor dem Start einer Therapie mit Basistherapeutika sollte abgeklärt sein, ob ein Kinderwunsch besteht. Die Behandlung mit NSAR ist in einigen Abschnitten der Schwangerschaft möglich, ebenso können sie während der Stillzeit eingesetzt werden. Eine begrenzte Anzahl von Basistherapeutika sind mit einer Schwangerschaft vereinbar und werden vorgestellt. Medikamente wie Zytostatika und Leflunomid erfordern prophylaktisches Absetzen bereits vor einer geplanten Schwangerschaft. TNFα-Blocker müssen bei Eintritt einer Schwangerschaft abgesetzt werden. Bei Medikamenten, die toxisch für die Gonaden sind oder fruchtschädigend wirken können, muss während der Anwendung sicher verhütet werden. Die Anwendung von immunsuppressiven Medikamenten während der Stillzeit ist wegen unzureichender Datenlage sehr begrenz

    J08069+1527: A newly discovered high amplitude, hybrid subdwarf B pulsator

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    We present our discovery of a new hybrid pulsating subdwarf B star, J08069+1527. The effective temperature and surface gravity of 28,500±\pm400\,K and 5.37±\pm0.04\,dex, respectively, place this object inside the instability strip and also among other pulsating hot subdwarfs of a hybrid nature, right next to another fascinating star: Balloon\,090100001. From this proximity, we anticipated this star could pulsate in both high and low frequency modes. Indeed, our analysis of photometric data confirmed our prediction. We detected two peaks in the high frequency region and two other peaks at low frequencies. In addition, the amplitude of the dominant mode is very high and comparable to the dominant peaks in other hybrid subdwarf B stars. Since this star is bright, we performed time-series low resolution spectroscopy. Despite a low signal-to-noise (S/N) ratio, we were able to detect the main peak from these data. All our results strongly indicate that J08069+1527 is a high amplitude pulsating hot subdwarf B star of hybrid nature. By analogy to the other pulsating sdB star, we judge that the dominant mode we detected here has radial nature. Future stellar modeling should provide us with quite good constrains as p- and g-modes presented in this star are driven in different parts of its interior.Comment: 7 pages, 10 figures, accepted for publication in MNRA

    First Kepler results on compact pulsators VIII: Mode identifications via period spacings in gg-mode pulsating Subdwarf B stars

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    We investigate the possibility of nearly-equally spaced periods in 13 hot subdwarf B (sdB) stars observed with the Kepler spacecraft and one observed with CoRoT. Asymptotic limits for gravity (g-)mode pulsations provide relationships between equal period spacings of modes with differing degrees and relationships between periods of the same radial order but differing degrees. Period transforms, Kolmogorov-Smirnov tests, and linear least-squares fits have been used to detect and determine the significance of equal period spacings. We have also used Monte Carlo simulations to estimate the likelihood that the detected spacings could be produced randomly. Period transforms for nine of the Kepler stars indicate ell=1 period spacings, with five also showing peaks for ell=2 modes. 12 stars indicate ell=1 modes using the Kolmogorov-Smirnov test while another shows solely ell=2 modes. Monte Carlo results indicate that equal period spacings are significant in 10 stars above 99% confidence and 13 of the 14 are above 94% confidence. For 12 stars, the various methods find consistent regular period spacing values to within the errors, two others show some inconsistencies, likely caused by binarity, and the last has significant detections but the mode assignment disagrees between methods. We find a common ell=1 period spacing spanning a range from 231 to 272 s allowing us to correlate pulsation modes with 222 periodicities and that the ell=2 period spacings are related to the ell=1 spacings by the asymptotic relationship 1/31/\sqrt{3}. We briefly discuss the impact of equal period spacings which indicate low-degree modes with a lack of significant mode trappings.Comment: 27 pages, 4 figures, 17 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

    Unravelling the baffling mystery of the ultrahot wind phenomenon in white dwarfs

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    The presence of ultra-high excitation (UHE) absorption lines (e.g., O VIII) in the optical spectra of several of the hottest white dwarfs poses a decades-long mystery and is something that has never been observed in any other astrophysical object. The occurrence of such features requires a dense environment with temperatures near 10610^6K, by far exceeding the stellar effective temperature. Here we report the discovery of a new hot wind white dwarf, GALEXJ014636.8+323615. Astonishingly, we found for the first time rapid changes of the equivalent widths of the UHE features, which are correlated to the rotational period of the star (P=0.242035P=0.242035d). We explain this with the presence of a wind-fed circumstellar magnetosphere in which magnetically confined wind shocks heat up the material to the high temperatures required for the creation of the UHE lines. The photometric and spectroscopic variability of GALEXJ014636.8+323615 can then be understood as consequence of the obliquity of the magnetic axis with respect to the rotation axis of the white dwarf. This is the first time a wind-fed circumstellar magnetosphere around an apparently isolated white dwarf has been discovered and finally offers a plausible explanation of the ultra hot wind phenomenon.Comment: Published in MNRAS Letter

    Seismic evidence for a weak radial differential rotation in intermediate-mass core helium burning stars

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    The detection of mixed modes that are split by rotation in Kepler red giants has made it possible to probe the internal rotation profiles of these stars, which brings new constraints on the transport of angular momentum in stars. Mosser et al. (2012) have measured the rotation rates in the central regions of intermediate-mass core helium burning stars (secondary clump stars). Our aim was to exploit& the rotational splittings of mixed modes to estimate the amount of radial differential rotation in the interior of secondary clump stars using Kepler data, in order to place constraints on angular momentum transport in intermediate-mass stars. We selected a subsample of Kepler secondary clump stars with mixed modes that are clearly rotationally split. By applying a thorough statistical analysis, we showed that the splittings of both gravity-dominated modes (trapped in central regions) and p-dominated modes (trapped in the envelope) can be measured. We then used these splittings to estimate the amount of differential rotation by using inversion techniques and by applying a simplified approach based on asymptotic theory (Goupil et al. 2013). We obtained evidence for a weak radial differential rotation for six of the seven targets that were selected, with the central regions rotating 1.8±0.31.8\pm0.3 to 3.2±1.03.2\pm1.0 times faster than the envelope. The last target was found to be consistent with a solid-body rotation. This demonstrates that an efficient redistribution of angular momentum occurs after the end of the main sequence in the interior of intermediate-mass stars, either during the short-lived subgiant phase, or once He-burning has started in the core. In either case, this should bring constraints on the angular momentum transport mechanisms that are at work.Comment: 16 pages, 8 figures, accepted in A&

    The blue-edge problem of the V1093 Her instability strip revisited using evolutionary models with atomic diffusion

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    We have computed a new grid of evolutionary subdwarf B star (sdB) models from the start of central He burning, taking into account atomic diffusion due to radiative levitation, gravitational settling, concentration diffusion, and thermal diffusion. We have computed the non-adiabatic pulsation properties of the models and present the predicted p-mode and g-mode instability strips. In previous studies of the sdB instability strips, artificial abundance enhancements of Fe and Ni were introduced in the pulsation driving layers. In our models, the abundance enhancements of Fe and Ni occur naturally, eradicating the need to use artificial enhancements. We find that the abundance increases of Fe and Ni were previously underestimated and show that the instability strip predicted by our simulations solves the so-called blue edge problem of the subdwarf B star g-mode instability strip. The hottest known g-mode pulsator, KIC 10139564, now resides well within the instability strip {even when only modes with low spherical degrees (l<=2) are considered.Comment: 7 pages, 7 figures. Accepted for publication in Astronomy & Astrophysic

    A search for new hot subdwarf stars by means of Virtual Observatory tools

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    Hot subdwarf stars are faint, blue objects, and are the main contributors to the far-UV excess observed in elliptical galaxies. They offer an excellent laboratory to study close and wide binary systems, and to scrutinize their interiors through asteroseismology, as some of them undergo stellar oscillations. However, their origins are still uncertain, and increasing the number of detections is crucial to undertake statistical studies. In this work, we aim at defining a strategy to find new, uncatalogued hot subdwarfs. Making use of Virtual Observatory tools we thoroughly search stellar catalogues to retrieve multi-colour photometry and astrometric information of a known sample of blue objects, including hot subdwarfs, white dwarfs, cataclysmic variables and main sequence OB stars. We define a procedure to discriminate among these spectral classes, particularly designed to obtain a hot subdwarf sample with a low contamination factor. In order to check the validity of the method, this procedure is then applied to two test sky regions: the Kepler FoV and to a test region of around (RA:225, DEC:5) deg. As a result, we obtained 38 hot subdwarf candidates, 23 of which had already a spectral classification. We have acquired spectroscopy for three other targets, and four additional ones have an available SDSS spectrum, which we used to determine their spectral type. A temperature estimate is provided for the candidates based on their spectral energy distribution, considering two-atmospheres fit for objects with clear infrared excess. Eventually, out of 30 candidates with spectral classification, 26 objects were confirmed to be hot subdwarfs, yielding a contamination factor of only 13%. The high rate of success demonstrates the validity of the proposed strategy to find new uncatalogued hot subdwarfs. An application of this method to the entire sky will be presented in a forthcoming work.Comment: 13 pages, 7 figure

    Interaction between rheumatoid arthritis and pregnancy: correlation of molecular data with clinical disease activity measures

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    Objective. The factors that induce remission of RA during pregnancy and the relapse occurring after delivery remain an enigma. In a previous study, we investigated gene-expression profiles of peripheral blood mononuclear cells (PBMC) in patients with RA and healthy women in late pregnancy and postpartum. Profiles of samples from both groups were similar in late pregnancy with elevated monocyte and decreased lymphocyte signatures. Postpartum, in RA PBMC the high level of monocyte transcripts persisted. Further increase was observed in adhesion, migration and signalling processes related to monocytes but also in lymphocytes despite similar clinical activity due to intensified drug treatment. This prompted us to investigate correlations between clinical parameters of disease activity and gene profiles. Methods. Transcriptome data were correlated with RADAI, CRP, monocyte and lymphocyte counts. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations, monocytes and lymphocytes signatures were used as reference information. Results. Comparative analysis of PBMC expression profiles from RA patients during and after pregnancy with RADAI and CRP revealed a correlation of these disease activity parameters predominantly with monocyte transcripts. Genes related to cellular programs of adhesion, migration and response to infections were upregulated. Comparing clinically active and not-active RA patients postpartum revealed a cluster of 19 genes that could also identify active disease during pregnancy. Conclusion. The data suggest that an increase of the RADAI and an elevation of CRP is a consequence of molecular activation of monocytes. Furthermore, they indicate that molecular activation of T lymphocytes may remain clinically unrecognized postpartum. It is conceivable that a set of 19 genes may qualify as molecular disease activity marke
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