41 research outputs found
Antikoagulation bei Vorhofflimmern
Zusammenfassung: Vorhofflimmern bewirkt eine Blutstase in den Vorhöfen, was die Thrombusbildung und in der Folge systemische Embolien begünstigt. Bei Patienten mit Vorhofflimmern stellen die Herzinsuffizienz, der Hypertonus, Diabetes mellitus, ein Alter > 75 Jahre sowie ein vorangegangener Schlaganfall die wichtigsten Risikofaktoren für ein zerebrovaskuläres Ereignis dar. Diese Risikofaktoren wurden im CHADS2-Risikoscore (Cardiac failure, Hypertension, Age, Diabetes, Stroke, 2 Punkte) zusammengefasst. Das thromboembolische Risiko variiert bei Patienten mit Vorhofflimmern beträchtlich. Die Behandlungsstrategie muss sich entsprechend am absoluten Risiko für ein thromboembolisches Ereignis und am zu erwartenden Blutungsrisiko orientieren. Patienten mit mittlerem und hohem Risiko profitieren eindeutig von einer Antikoagulation mit einem Vitamin-K-Antagonisten, wohingegen Patienten ohne Risikofaktoren mehrheitlich von einer Therapie mit Thrombozytenaggregationshemmern zu profitieren scheine
Rapid progression of atherosclerotic coronary artery disease in patients with human immunodeficiency virus infection
We describe the case of a 39-year-old human immunodeficiency virus (HIV)-infected man with angiographically documented rapid progression of coronary artery disease. Over a time course of only 2 months, he developed high-grade stenosis of the left anterior descending coronary artery. The risk of myocardial infarction is increased in patients with HIV infection receiving antiretroviral therapy. However, the absolute risk is small and the marked overall benefits of antiretroviral therapy are evident. Patients receiving HIV protease inhibitors should be screened for hyperlipidemia, hyperglycemia, and hypertension. They may be candidates for lipid-lowering therapies depending on their long-term prognosis and individual risk of cardiovascular disease. Care is need because of possible drug interactions between lipid-lowering drugs and antiretroviral therapy. Invasive treatment of acute myocardial infarction does not differ from that in patients not infected with HIV. The rate of progression of coronary artery disease and the restenosis rate, however, are often unexpectedly high in these patient
Big Three Dragons: A [N II] 122 m Constraint and New Dust-continuum Detection of A Bright Lyman Break Galaxy with ALMA
We present new Atacama Large Millimeter/submillimeter Array Band 7
observational results of a Lyman break galaxy at , B14-65666 ("Big
Three Dragons"), which is an object detected in [OIII] 88 , [CII]
158 , and dust-continuum emission during the epoch of reionization.
Our targets are the [NII] 122 fine-structure emission line and
underlying 120 dust continuum. The dust continuum is detected with
a 19 significance. From far-infrared spectral energy
distribution sampled at 90, 120, and 160 , we obtaine a best-fit
dust temperature of K ( K) and an infrared luminosity of () at the emissivity index (1.0). The [NII] 122 line is not detected. The 3 upper limit of the [NII] luminosity is . From the [NII], [OIII], and [CII] line luminosities, we use the
Cloudy photoionization code to estimate nebular parameters as functions of
metallicity. If the metallicity of the galaxy is high (), the ionization parameter and hydrogen density are and -,
respectively, which are comparable to those measured in low-redshift galaxies.
The nitrogen-to-oxygen abundance ratio, , is constrained to be
sub-solar. At , the allowed drastically
increases as the assumed metallicity decreases. For high ionization parameters,
the constraint becomes weak. Finally, our Cloudy models predict the
location of B14-65666 on the BPT diagram, thereby allowing a comparison with
low-redshift galaxies.Comment: 17 pages, 13 figures, 2 tables. accepted for publication in Ap
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection
of the [O III] 88 m line and rest-frame 90 m dust continuum emission
in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier
Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a
spectroscopic redshift of , making this object one of
the furthest galaxies ever identified spectroscopically. The observed 850
m flux density of Jy corresponds to a de-lensed total
infrared (IR) luminosity of if assuming a dust temperature of K and an
emissivity index of , yielding a large dust mass of . The ultraviolet-to-far IR spectral energy distribution modeling
where the [O III] emissivity model is incorporated suggests the presence of a
young ( Myr), star-forming (SFR yr), moderately metal-polluted ()
stellar component with a mass of . An
analytic dust mass evolution model with a single episode of star-formation does
not reproduce the metallicity and dust mass in Myr,
suggesting a pre-existing evolved stellar component with and Gyr as the origin of the
dust mass.Comment: Accepted by ApJ. 18 pages, 10 figures, 5 table
Nearby Optical Galaxies: Selection of the Sample and Identification of Groups
In this paper we describe the Nearby Optical Galaxy (NOG) sample, which is a
complete, distance-limited (6000 km/s) and magnitude-limited
(B14) sample of 7000 optical galaxies. The sample covers 2/3 (8.27
sr) of the sky () and appears to have a good completeness in
redshift (98%). We select the sample on the basis of homogenized corrected
total blue magnitudes in order to minimize systematic effects in galaxy
sampling.
We identify the groups in this sample by means of both the hierarchical and
the percolation {\it friends of friends} methods. The resulting catalogs of
loose groups appear to be similar and are among the largest catalogs of groups
presently available. Most of the NOG galaxies (60%) are found to be
members of galaxy pairs (580 pairs for a total of 15% of objects)
or groups with at least three members (500 groups for a total of
45% of objects). About 40% of galaxies are left ungrouped (field
galaxies). We illustrate the main features of the NOG galaxy distribution.
Compared to previous optical and IRAS galaxy samples, the NOG provides a denser
sampling of the galaxy distribution in the nearby universe. Given its large sky
coverage, the identification of groups, and its high-density sampling, the NOG
is suited for the analysis of the galaxy density field of the nearby universe,
especially on small scales.Comment: 47 pages including 6 figures. Accepted for publication in Ap
Satellite decay in flattened dark matter haloes
We carry out a set of self-consistent N-body calculations to compare the
decay rates of satellite dwarf galaxies orbiting a disc galaxy embedded in a
dark matter halo (DMH). We consider both spherical and oblate axisymmetric DMHs
of aspect ratio q_h=0.6. The satellites are given different initial orbital
inclinations, orbital periods and mass. The live flattened DMHs with embedded
discs and bulges are set-up using a new fast algorithm, MaGalie (Boily, Kroupa
and Pe\~{n}arrubia 2001).
We find that the range of survival times of satellites within a flattened DMH
becomes of the order of 100% larger than the same satellites within a spherical
DMH. In the oblate DMH, satellites on polar orbits have the longest survival
time, whereas satellites on coplanar prograde orbits are destroyed most
rapidly. The orbital plane of a satellite tilts as a result of anisotropic
dynamical friction, causing the satellite's orbit to align with the plane of
symmetry of the DMH. Polar orbits are not subjected to alignment. Therefore the
decay of a satellites in an axisymmetric DMH may provide a natural explanation
for the observed lack of satellites within (0-30) degrees of their host
galaxy's disc (Holmberg 1969; Zaritsky and Gonz\'alez 1999).
The computations furthermore indicate that the evolution of the orbital
eccentricity is highly dependent of its initial value e(t=0) and the DMH's
shape. We also discuss some implications of flattened DMHs for satellite debris
streams.Comment: 13 pages, 9 figures. Accepted by MNRA
Photometric study of the IC 65 group of galaxies
We carry out a photometric study of a poor group of late-type galaxies around
IC 65, with the aim: (a) to search for new dwarf members and to measure their
photometric characteristics; (b) to search for possible effects of mutual
interactions on the morphology and star-formation characteristics of luminous
and faint group members; (c) to evaluate the evolutionary status of this
particular group. We make use of our BRI CCD observations, DPOSS blue and red
frames, and the 2MASS JHK frames. In addition, we use the HI imaging data, the
far-infrared and radio data from the literature. Search for dwarf galaxies is
made using the SExtractor software. Detailed surface photometry is performed
with the MIDAS package. Four LSB galaxies were classified as probable dwarf
members of the group and the BRI physical and model parameters were derived for
the first time for all true and probable group members. Newly found dIrr
galaxies around the IC 65 contain a number of H II regions, which show a range
of ages and propagating star-formation. Mildly disturbed gaseous and/or stellar
morphology is found in several group members. Various structural, dynamical,
and star-forming characteristics let us conclude that the IC 65 group is a
typical poor assembly of late-type galaxies at an early stage of its dynamical
evolution with some evidence of intragroup (tidal) interactions.Comment: 21 pages, 16 figures, submitted to A&
Color, Structure, and Star Formation History of Dwarf Galaxies over the last ~3 Gyr with GEMS and SDSS
We present a study of the colors, structural properties, and star formation
histories for a sample of ~1600 dwarfs over look-back times of ~3 Gyr
(z=0.002-0.25). The sample consists of 401 distant dwarfs drawn from the Galaxy
Evolution from Morphologies and SEDs (GEMS) survey, which provides high
resolution Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS)
images and accurate redshifts, and of 1291 dwarfs at 10-90 Mpc compiled from
the Sloan Digitized Sky Survey (SDSS). The sample is complete down to an
effective surface brightness of 22 mag arcsec^-2 in z and includes dwarfs with
M_g=-18.5 to -14 mag. Rest-frame luminosities in Johnson UBV and SDSS ugr
filters are provided by the COMBO-17 survey and structural parameters have been
determined by S\'ersic fits. We find that the GEMS dwarfs are bluer than the
SDSS dwarfs by ~0.13 mag in g-r, which is consistent with the color evolution
over ~2 Gyr of star formation histories involving moderate starbursts and long
periods of continuous star formation. The full color range of the samples
cannot be reproduced by single starbursts of different masses or long periods
of continuous star formation alone. Furthermore, an estimate of the mechanical
luminosities needed for the gas in the GEMS dwarfs to be completely removed
from the galaxies shows that a significant number of low luminosity dwarfs are
susceptible to such a complete gas loss, if they would experience a starburst.
On the other hand, a large fraction of more luminous dwarfs is likely to retain
their gas. We also estimate the star formation rates per unit area for the GEMS
dwarfs and find good agreement with the values for local dwarfs.Comment: 31 pages, 13 figures, accepted for publication in the Ap