1,987 research outputs found
Checking the dark matter origin of 3.53 keV line with the Milky Way center
We detect a line at 3.539 +/- 0.011 keV in the deep exposure dataset of the
Galactic Center region, observed with the XMM-Newton. The dark matter
interpretation of the signal observed in the Perseus galaxy cluster, the
Andromeda galaxy [1402.4119] and in the stacked spectra of galaxy clusters
[1402.2301], together with non-observation of the line in blank sky data, put
both lower and upper limits on the possible intensity of the line in the
Galactic Center data. Our result is consistent with these constraints for a
class of Milky Way mass models, presented previously by observers, and would
correspond to radiative decay dark matter lifetime tau_dm ~ (6-8) x 10^{27}
sec. Although it is hard to exclude an astrophysical origin of this line based
the Galactic Center data alone, this is an important consistency check of the
hypothesis that encourages to check it with more observational data that are
expected by the end of 2015.Comment: 12 pages, 3 figures. Accepted by Phys. Rev. Let
Severity of cardiovascular disease and health-related quality of life in men with prostate cancer: a longitudinal analysis from CaPSURE.
ObjectiveTo evaluate the influence of comorbid cardiovascular disease severity on health-related quality of life (HRQL) in men treated with radical prostatectomy (RP) or radiotherapy (RT) for early stage prostate cancer.MethodsSubjects (n=830) with non-metastatic disease who had been diagnosed in 2000-2002 were drawn from Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE). We evaluated the influence of cardiovascular disease (CVD) severity on generic and disease-specific HRQL before and 6, 12, 18, and 24 months after treatment with RP or RT. HRQL was measured with the SF-36 and the UCLA Prostate Cancer Index.ResultsMen with moderate (n=193) or severe (n=51) cardiovascular disease had worse pre-treatment HRQL than did men without CVD (n=293) (P<0.01); HRQL scores were worse in men referred for RT. During 24 months of follow-up, men with moderate or severe CVD had worse SF-36 physical and mental component summaries and worse bowel function at all time points (P<0.05). Men with severe CVD also experienced a slower recovery in physical function (P=0.03) and sexual functioning (P=0.02) than did men without CVD.ConclusionsProstate cancer patients with moderate to severe CVD have worse HRQL during follow-up. Those with severe CVD recover their physical and sexual functioning more slowly after treatment
Metal-insulator transition and the Pr/Pr valence shift in (PrY)CaCoO
The magnetic, electric and thermal properties of the
(Y)CaCoO perovskites (~=~Pr, Nd) were
investigated down to very low temperatures. The main attention was given to a
peculiar metal-insulator transition, which is observed in the praseodymium
based samples with and 0.15 at and 132~K, respectively.
The study suggests that the transition, reported originally in
PrCaCoO, is not due to a mere change of cobalt ions from
the intermediate- to the low-spin states, but is associated also with a
significant electron transfer between Pr and Co/Co sites,
so that the praseodymium ions occur below in a mixed
Pr/Pr valence. The presence of Pr ions in the insulating
phase of the yttrium doped samples (PrY)CaCoO
is evidenced by Schottky peak originating in Zeeman splitting of the ground
state Kramers doublet. The peak is absent in pure PrCaCoO
in which metallic phase, based solely on non-Kramers Pr ions, is
retained down to the lowest temperature.Comment: 10 figure
Magnetism in heavy-fermion U(Pt,Pd)3 studied by mSR
We report mSR experiments carried out on a series of heavy-electron
pseudobinary compounds U(Pt1-xPdx)3 (x<=0.05). For x<=0.005 the zero-field muon
depolarisation is described by the Kubo-Toyabe function. However the
temperature variation of the Kubo-Toyabe relaxation rate does not show any sign
of the small-moment antiferromagnetic phase with TN~6 K (signalled by neutron
diffraction), in contrast to previous reports. The failure to detect the small
ordered moment suggests it has a fluctuating (> 10 MHz) nature, which is
consistent with the interpretation of NMR data. For 0.01<=x<=0.05 the muon
depolarisation in the ordered state is described by two terms of equal
amplitude: an exponentially damped spontaneous oscillation and a Lorentzian
Kubo-Toyabe function. These terms are associated with antiferromagnetic order
with substantial moments. The Knight-shift measured in a magnetic field of 0.6
T on single-crystalline U(Pt0.95Pd0.05)3 in the paramagnetic state shows two
signals for B perpendicular to c, while only one signal is observed for B||c.
The observation of two signals for B perpendicular to c, while there is only
one muon localisation site (0,0,0), points to the presence of two spatially
distinct regions of different magnetic response.Comment: 25 pages including 12 figures (PS), J. Phys.: Condens. Matter, in
prin
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