691 research outputs found

    A clinical trial of antazoline in the treatment of arrhythmias

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    Antazoline is a comparatively safe and effective antiarrhythmic drug in many situations, for both the conversion and prevention of arrhythmias. It appeared to be most effective in the abolition of ventricular tachycardia, possibly helpful in 2 cases of cardiac arrest due to ventricular fibrillation and beneficial in the prevention of atrial and ventricular premature beats. It was useful and deserves further trial in the prevention of paroxysmal ventricular tachycardia. It was almost ineffective in the conversion and prophylaxis of atrial flutter and atrial fibrillation but appeared to be of value in the prevention of paroxysmal atrial tachycardia.There was a high incidence of mild side effects, mostly of the gastrointestinal type, some of which were prevented by taking the drug with meals or with an antacid preparation. No irreversible or serious side actions were encountered, but diarrhea, central nervous system symptoms and chills and fever necessitated stopping the drug in a small percentage of patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32096/1/0000146.pd

    Intrinsic Absorption in the Spectrum of NGC 7469: Simultaneous Chandra, FUSE, and STIS Observations

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    We present simultaneous X-ray, far-ultraviolet, and near-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 obtained with the Chandra X-Ray Observatory, the Far Ultraviolet Spectroscopic Explorer, and the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. Previous non-simultaneous observations of this galaxy found two distinct UV absorption components, at -560 and -1900 km/s, with the former as the likely counterpart of the X-ray absorber. We confirm these two absorption components in our new UV observations, in which we detect prominent O VI, Ly alpha, N V, and C IV absorption. In our Chandra spectrum we detect O VIII emission, but no significant O VIII or O VII absorption. We also detect a prominent Fe K alpha emission line in the Chandra spectrum, as well as absorption due to hydrogen-like and helium-like neon, magnesium, and silicon at velocities consistent with the -560 km/s UV absorber. The FUSE and STIS data reveal that the H I and C IV column densities in this UV- and X-ray- absorbing component have increased over time, as the UV continuum flux decreased. We use measured H I, N V, C IV, and O VI column densities to model the photoionization state of both absorbers self-consistently. We confirm the general physical picture of the outflow in which the low velocity component is a highly ionized, high density absorber with a total column density of 10^20 cm^-2, located near the broad emission line region, although due to measurable columns of N V and C IV, we assign it a somewhat smaller ionization parameter than found previously, U~1. The high velocity UV component is of lower density, log N=18.6, and likely resides farther from the central engine as we find its ionization parameter to be U=0.08.Comment: Minor correction to abstract; STScI eprint #1683; 50 pages, incl. 19 figures, 4 tables; Accepted to Ap

    National surveillance for human and pet contact with oral rabies vaccine baits, 2001–2009

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    Objective—To determine the rate and absolute number of human and pet exposures to oral rabies vaccine (ORV) bait containing liquid vaccinia rabies glycoprotein recombinant vaccine and to evaluate factors that might affect human contact with bait to modify the program and reduce human exposure to the vaccine. Design—Retrospective analysis of surveillance data (2001 to 2009). Sample—Reports on human and pet contact with ORV baits in states with ORV surveillance programs. Procedures—Data were collected from passive, multistate ORV surveillance systems in Alabama, Arizona, Florida, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, Vermont, Virginia, and West Virginia. Data collected included the nature of human or pet contact with bait and vaccine, the caller’s knowledge of the ORV bait program, local human population density, and other relevant demographic data. Results—All 18 states participated in the surveillance program for at least 1 year, for a combined 68 years of observation. One thousand four hundred thirty-six calls were reported, representing 3,076 found baits (6.89/100,000 baits dropped); 296 (20%) calls were related to human contact with ruptured bait, and 550 (38%) involved pet contact with the bait. Six adverse events in humans were reported, one of which required hospitalization. Fifty-nine adverse events in pets were noted, all of which were nonserious. Conclusions and Clinical Relevance—Findings from surveillance activities have been used to improve baiting strategies and minimize human and pet contact with ORV baits. Overall, human and pet contact with ORV baits was infrequent. Surveillance has led to early identification of persons exposed to ORV and rapid intervention

    The Ionized Gas and Nuclear Environment in NGC 3783 V. Variability and Modeling of the Intrinsic Ultraviolet Absorption

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    We present results on the location, physical conditions, and geometry of the outflow in the Seyfert 1 galaxy NGC 3783 from a study of the variable intrinsic UV absorption. Based on 18 observations with HST/STIS and 6 observations with FUSE, we find: 1) The absorption from the lowest-ionization species in each of the three strong kinematic components varied inversely with the continuum flux, indicating the ionization structure responded to changes in the photoionizing flux over the weekly timescales sampled by our observations. 2) A multi- component model with an unocculted NLR and separate BLR and continuum line-of-sight covering factors predicts saturation in several lines, consistent with the lack of observed variability. 3) Column densities for the individual metastable levels are measured from the resolved C III *1175 absorption complex observed in one component. Based on our computed metastable level populations, the electron density of this absorber is ~3x10^4 cm^-3. Photoionization modeling results place it at ~25 pc from the central source. 4) Using time-dependent calculations, we are able to reproduce the detailed variability observed in this absorber, and derive upper limits on the distances for the other components of 25-50 pc. 5) The ionization parameters derived for the higher ionization UV absorbers are consistent with the modeling results for the lowest-ionization X-ray component, but with smaller total column density. They have similar pressures as the three X-ray ionization components. These results are consistent with an inhomogeneous wind model for the outflow in NGC 3783. 6) Based on the predicted emission-line luminosities, global covering factor constraints, and distances derived for the UV absorbers, they may be identified with emission- line gas observed in the inner NLR of AGNs. (abridged)Comment: 30 pages, 18 figures (7 color), emulateapj, accepted for publication in The Astrophysical Journa

    Intrinsic Absorption in the Spectrum of Mrk 279: Simultaneous Chandra, FUSE, and STIS Observations

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    We present a study of the intrinsic X-ray and far-ultraviolet absorption in the Seyfert 1.5 galaxy Markarian 279 using simultaneous observations from the Chandra X-ray Observatory, the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope, and the Far Ultraviolet Spectroscopic Explorer (FUSE). We also present FUSE observations made at three additional epochs. We detect the Fe K-alpha emission line in the Chandra spectrum, and its flux is consistent with the low X-ray continuum flux level of Mrk 279 at the time of the observation. Due to low signal-to-noise ratios in the Chandra spectrum, no O VII or O VIII absorption features are observable in the Chandra data, but the UV spectra reveal strong and complex absorption from HI and high-ionization species such as O VI, N V, and C IV, as well as from low-ionization species such as C III, N III, C II, and N II in some velocity components. The far-UV spectral coverage of the FUSE data provides information on high-order Lyman series absorption, which we use to calculate the optical depths and line and continuum covering fractions in the intrinsic HI absorbing gas in a self-consistent fashion. The UV continuum flux of Mrk 279 decreases by a factor of ~7.5 over the time spanning these observations and we discuss the implications of the response of the absorption features to this change. From arguments based on the velocities, profile shapes, covering fractions and variability of the UV absorption, we conclude that some of the absorption components, particularly those showing prominent low-ionization lines, are likely associated with the host galaxy of Mrk 279, and possibly with its interaction with a close companion galaxy, while the remainder arises in a nuclear outflow.Comment: To appear in 2004 May ApJS; double-column format; 58 pages, incl. 29 figures, 9 tables; minor changes to tex

    The Fate of High-Velocity Clouds: Warm or Cold Cosmic Rain?

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    We present two sets of grid-based hydrodynamical simulations of high-velocity clouds (HVCs) traveling through the diffuse, hot Galactic halo. These HI clouds have been suggested to provide fuel for ongoing star formation in the Galactic disk. The first set of models is best described as a wind-tunnel experiment in which the HVC is exposed to a wind of constant density and velocity. In the second set of models we follow the trajectory of the HVC on its way through an isothermal hydrostatic halo towards the disk. Thus, we cover the two extremes of possible HVC trajectories. The resulting cloud morphologies exhibit a pronounced head-tail structure, with a leading dense cold core and a warm diffuse tail. Morphologies and velocity differences between head and tail are consistent with observations. For typical cloud velocities and halo densities, clouds with H{\small{I}} masses <104.5< 10^{4.5} M⊙_\odot will lose their H{\small{I}} content within 10 kpc or less. Their remnants may contribute to a population of warm ionized gas clouds in the hot coronal gas, and they may eventually be integrated in the warm ionized Galactic disk. Some of the (still over-dense, but now slow) material might recool, forming intermediate or low velocity clouds close to the Galactic disk. Given our simulation parameters and the limitation set by numerical resolution, we argue that the derived disruption distances are strong upper limits.Comment: 12 pages, 8 figures, accepted by Ap
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