299 research outputs found
Spin Injection into a Graphene Thin Film at Room Temperature
We demonstrate spin injection into a graphene thin film with high reliability
by using non-local magnetoresistance (MR) measurements, in which the electric
current path is completely separated from the spin current path. Using these
non-local measurements, an obvious MR effect was observed at room temperature;
and the MR effect was ascribed to magnetization reversal of ferromagnetic
electrodes. This result is a direct demonstration of spin injection into a
graphene thin film. Furthermore, this is the first report of spin injection
into molecules at room temperature.Comment: 12 pages, 3 figure
Molecular characterization and validation of commercially available methods for haptoglobin measurement in bottlenose dolphin
AbstractHaptoglobin (Hp) is a positive acute-phase protein and a valuable marker of inflammation in both human and veterinary medicine. The aim of this study was to validate the molecular characterization of Hp in dolphins and to validate commercially available Hp measurement methods such as Hp-ELISA (originally designed for pigs) and Hp–hemoglobin (Hb) binding assay. The dolphin Hp (dHp) amino acid sequence appeared most similar to pig Hp by sequence homology and phylogenetic clustering. Amino acid sequence analysis revealed that dHp comprises the Hp1 form of α1 and β chains. The anti-pig Hp antibody cross-reacted with both recombinant dHp, expressed by Escherichia coli, and dHp from serum. The intra- and inter-assay levels of imprecision of pig Hp-ELISA and the Hp–Hb binding assay were found to be tolerable for the determination of Hp in dolphin, and there was no significant discrepancy between the two determination methods. The ability of the assay to differentiate between healthy and inflammation groups was investigated, and a significant increase in Hp concentration was detected in inflammatory conditions. Thus, Hp is a useful inflammation marker for dolphin, and the Hp concentration in dolphin serum samples can be reliably measured using commercially available pig Hp-ELISA and Hp–Hb binding assay
Measurement of the Mass and Stellar Population Distribution in M82 with the LBT
We present a K-band spectroscopic study of the stellar and gas kinematics,
mass distribution, and stellar populations of the archetypical starburst galaxy
M82. Our results are based on a single spectrum at a position angle of 67.5
degrees through the K-band nucleus. We used the CO stellar absorption band head
at 2.29 {\mu}m (CO_2.29) to measure the rotation curve out to nearly 4 kpc
radius on both the eastern and western sides of the galaxy. Our data show that
the rotation curve is flat from 1 - 4 kpc. This stands in sharp contrast to
some previous studies, which have interpreted H I and CO emission-line
position-velocity diagrams as evidence for a declining rotation curve. The
kinematics of the Br\gamma, H_2, and He I emission lines are consistent with,
although characterized by slightly higher velocities than, the stellar
kinematics. We derived M82's mass distribution from our stellar kinematic
measurements and estimate its total dynamical mass is ~10^10 Msun. We measured
the equivalent width of CO_2.29 (W_2.29) as a function of distance from the
center of the galaxy to investigate the spatial extent of the red supergiant
(RSG) population. The variation in W_2.29 with radius clearly shows that RSGs
dominate the light inside 500 pc radius. M82's superwind is likely launched
from this region, where we estimate the enclosed mass is <= 2 x 10^9 Msun.Comment: 6 pages, 6 figures. Submitted to ApJ. For a brief video explaining
the key result of this paper, see http://www.youtube.com/user/OSUAstronom
Holographic QCD and Pion Mass
To realize massive pions, we study variations of the holographic model of
massless QCD using the D4/D8/anti-D8 brane configuration proposed by Sakai and
Sugimoto. We propose deformations which break the chiral symmetry explicitly
and compute the mass of the pions and vector mesons. The observed value of the
pion mass can be obtained. We also argue a chiral perturbation corresponding to
our deformation.Comment: 23pages, minor changes, references adde
Long-term treatment with hyperbaric air improves hyperlipidemia of db/db mice
Hyperbaric air (HBA) is used to improve healing of wounds including diabetic
ulcer. The aim of this study was to clarify the effects of HBA exposure on lipid and glucose
metabolism in db/db mice. HBA did not influence the weight of db/db mice. Serum
levels of free fatty acid and triglyceride, but not glucose and insulin, were significantly
decreased after 6 weeks of treatment with HBA. The mRNA expressions of CPT-1, PPARα
and PGC-1α genes, which are related to lipid metabolism, were significantly up-regulated
in the muscle and liver. Increases in TNFα and MCP1 mRNA, which impaired lipid metabolism,
were also attenuated by HBA treatment. These results suggest that exposure
of HBA could have beneficial effects on lipid metabolism in patients with type 2 diabetes
mellitus
Growth of galactic bulges by mergers. II. Low-density satellites
Satellite accretion events have been invoked for mimicking the internal
secular evolutionary processes of bulge growth. However, N-body simulations of
satellite accretions have paid little attention to the evolution of bulge
photometric parameters, to the processes driving this evolution, and to the
consistency of this evolution with observations. We want to investigate whether
satellite accretions indeed drive the growth of bulges, and whether they are
consistent with global scaling relations of bulges and discs. We perform N-body
models of the accretion of satellites onto disc galaxies. A Tully-Fisher (M
\propto V_{rot}^ {alpha_TF}) scaling between primary and satellite ensures that
density ratios, critical to the outcome of the accretion, are realistic. We
carry out a full structural, kinematic and dynamical analysis of the evolution
of the bulge mass, bulge central concentration, and bulge-to-disc scaling
relations. The remnants of the accretion have bulge-disc structure. Both the
bulge-to-disc ratio (B/D) and the Sersic index (n) of the remnant bulge
increase as a result of the accretion, with moderate final bulge Sersic
indices: n = 1.0 to 1.9. Bulge growth occurs no matter the fate of the
secondary, which fully disrupts for alpha_TF=3 and partially survives to the
remnant center for alpha_TF = 3.5 or 4. Global structural parameters evolve
following trends similar to observations. We show that the dominant mechanism
for bulge growth is the inward flow of material from the disc to the bulge
region during the satellite decay. The models confirm that the growth of the
bulge out of disc material, a central ingredient of secular evolution models,
may be triggered externally through satellite accretion.Comment: Accepted for publication in A&A, 20 pages, 11 figures. Figs. 1 and 2
are low resolution ones: high-resolution versions available under request to
the author
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