3,109 research outputs found
Economic evaluation of ASCOT-BPLA: Antihypertensive treatment with an amlodipine-based regimen is cost-effective compared to an atenolol-based regimen
Copyright © 2010 BMJ Publishing Group Ltd & British Cardiovascular Society. Internal or personal use of this material is permitted. However, permission to reprint/republish this material must be obtained from the Publisher.Objective: To compare the cost effectiveness of an amlodipine-based strategy and an atenolol-based strategy in the treatment of hypertension in the UK and Sweden.
Design: A prospective, randomised trial complemented with a Markov model to assess long-term costs and health effects.
Setting: Primary care.
Patients: Patients with moderate hypertension and three or more additional risk factors.
Interventions: Amlodipine 5â10 mg with perindopril 4â8 mg added as needed or atenolol 50â100 mg with bendroflumethiazide 1.25â2.5 mg and potassium added as needed
Main outcome measures: Cost per cardiovascular event and procedure avoided, and cost per quality-adjusted life-year gained.
Results: In the UK, the cost to avoid one cardiovascular event or procedure would be âŹ18â965, and the cost to gain one quality-adjusted life-year would be âŹ21â875. The corresponding figures for Sweden were âŹ13â210 and âŹ16â856.
Conclusions: Compared with the thresholds applied by NICE and in the Swedish National Board of Health and Welfareâs Guidelines for Cardiac Care, an amlodipine-based regimen is cost effective for the treatment of hypertension compared with an atenolol-based regimen in the population studied.The study was supported by the principal funding source, Pfizer, New York, USA
Discovery of a supernova associated with GRB 031203: SMARTS Optical-Infrared Lightcurves from 0.2 to 92 days
Optical and infrared monitoring of the afterglow site of gamma-ray burst
(GRB) 031203 has revealed a brightening source embedded in the host galaxy,
which we attribute to the presence of a supernova (SN) related to the GRB ("SN
031203"). We present details of the discovery and evolution of SN 031203 from
0.2 to 92 days after the GRB, derived from SMARTS consortium photometry in I
and J bands. A template type Ic lightcurve, constructed from SN 1998bw
photometry, is consistent with the peak brightness of SN 031203 although the
lightcurves are not identical. Differential astrometry reveals that the SN, and
hence the GRB, occurred less than 300 h_71^-1 pc (3-sigma) from the apparent
galaxy center. The peak of the supernova is brighter than the optical afterglow
suggesting that this source is intermediate between a strong GRB and a
supernova.Comment: 11 pages, 3 figures, submitted to ApJ Letter
Imaging X-ray, Optical, and Infrared Observations of the Transient Anomalous X-ray Pulsar XTE J1810-197
We report X-ray imaging, timing, and spectral studies of XTE J1810-197, a
5.54s pulsar discovered by Ibrahim et al. (2003) in recent RXTE observations.
In a set of short exposures with the Chandra HRC camera we detect a strongly
modulated signal (55+/-4% pulsed fraction) with the expected period located at
(J2000) 18:09:51.08, -19:43:51.7, with a uncertainty radius of 0.6 arcsec (90%
C.L.). Spectra obtained with XMM-Newton are well fitted by a two-component
model that typically describes anomalous X-ray pulsars (AXPs), an absorbed
blackbody plus power law with parameters kT = 0.67+/-0.01 keV, Gamma=3.7+/-0.2,
N_H=(1.05+/-0.05)E22 cm^-2, and Fx(0.5-10 keV) = 3.98E-11 ergs/cm2/s.
Alternatively, a 2T blackbody fit is just as acceptable. The location of CXOU
J180951.1-194351 is consistent with a point source seen in archival Einstein,
Rosat, & ASCA images, when its flux was nearly two orders-of-magnitude fainter,
and from which no pulsations are found. The spectrum changed dramatically
between the "quiescent" and "active" states, the former can be modeled as a
softer blackbody. Using XMM timing data, we place an upper limit of 0.03 lt-s
on any orbital motion in the period range 10m-8hr. Optical and infrared images
obtained on the SMARTS 1.3m telescope at CTIO show no object in the Chandra
error circle to limits V=22.5, I=21.3, J=18.9, & K=17.5. Together, these
results argue that CXOU J180951.1-194351 is an isolated neutron star, one most
similar to the transient AXP AX J1844.8-0256. Continuing study of XTE J1810-197
in various states of luminosity is important for understanding and possibly
unifying a growing class of isolated, young neutron stars that are not powered
by rotation.Comment: 12 pages, 7 figures, AAS LaTex, uses emulateapj5.sty. Updated to
include additional archival data and a new HRC observation. To appear in The
Astrophysical Journa
Adequacy of a pre-participation examination form: a study of Hawaii physicians.
Many states currently require a medical screening prior to participation in organized sports. The purpose of this study was to examine the adequacy of the existing pre-participation examination form in Hawaii. One hundred forty-eight physicians who perform school health/pre-participation physical examinations were surveyed. The results indirectly suggest that these physicians agreed that the form should be modified and improved (p, .001)
On the binary nature of 1RXS J162848.1-415241
We present spectroscopy of the optical counterpart to 1RXS J162848.1-41524,
also known as the microquasar candidate MCQC J162847-4152. All the data
indicate that this X-ray source is not a microquasar, and that it is a
single-lined chromospherically active binary system with a likely orbital
period of 4.9 days. Our analysis supports a K3IV spectral classification for
the star, which is dominant at optical wavelengths. The unseen binary component
is most likely a late-type (K7-M) dwarf or a white dwarf. Using the high
resolution spectra we have measured the K3 star's rotational broadening to be
vsini = 43 +/- 3 km/s and determined a lower limit to the binary mass ratio of
q(=M2/M1)>2.0. The high rotational broadening together with the strong CaII H &
K / Halpha emission and high-amplitude photometric variations indicate that the
evolved star is very chromospherically active and responsible for the
X-ray/radio emission.Comment: 15 pages, 5 figures, accepted for publication in Ap
X-Ray Observations of V4641 SGR (= SAX J1819.3-2525) During the Brief and Violent Outburst of 2003
We present the results of detailed analysis of pointed X-ray observations by
RXTE PCA/HEXTE of the black hole X-ray binary (BHXRB) system V4641 Sgr (= SAX
J1819.3-2525) during its outburst of August 2003. Soft X-ray (3-20 keV) flux
variations by factors of 10 or more on timescales of minutes or shorter were
seen. The rapid and strong variability of this source sets it apart from
typical XRBs. In spite of large luminosity fluctuations, the spectral state of
the source did not change significantly during the dwells which suggests that
the physical emission processes did not change much during the observations.
The energy spectra during the dwells were dominated by a hard Comptonized
powerlaw component, indicative of the canonical low/hard state observed in
other BHXRBs. No soft thermal component was found in three out of the four RXTE
pointings. However spectral deconvolution of the observation with largest
average luminosity suggests an obscured, hot accretion disk. During one of the
observations we detected a short term (about 100s) soft X-ray dropout which is
apparently due to variability in the observed column density. Strong Fe
K fluorescent emisssion line near 6.5 keV was detected with large
equivalent widths in the range of 700 - 1000eV. In the temporal domain, the
Fourier power spectra were dominated by red noise below a few Hz. Poisson noise
dominated at higher frequencies and no high frequency features were detected.
The strong Comptonized spectra, broad iron emission line, absence of disk
component in the spectra, absence of any timing variability above few Hz and
occasional large changes in the column density along the line-of-sight, all
support an enshrouded black hole with occasional outflow and a very dynamic
environment.Comment: 27 pages, 10 figures (1 color figure), accepted for publication in
the Astrophysical Journal. It is tentatively scheduled for the ApJ 01
February 2006, v637, 2 issu
Absence of overscreened Kondo effect in ferromagnetic host
We study the low temperature behavior of a boundary magnetic impurity S'=1/2
in an open ferromagnetic Takhatajian-Babujian spin-S chain. For
antiferromagnetic Kondo coupling, it is show via Bethe ansatz solution that the
impurity spin is always locked into the critical behavior the bulk. At low
temperature, a local composite of spin S-1/2 forms near the impurity site and
its contribution to specific heat is of simple power law T^{1/2}. The absence
of overscreened Kondo effect is due to the large correlation length of host
spins which is divergent near the quantum critical point.Comment: 4 pages. to appear in Phys. Rev. B1(R4A)(2000
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