526 research outputs found
Flynn et al. Respond
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Work as an Inclusive Part of Population Health Inequities Research and Prevention. [Am J Public Health. 2018]
New Horizons for Occupational Health Surveillance. [Am J Public Health. 2018
Management of esophageal stricture after complete circular endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Endoscopic submucosal dissection (ESD) permits removal of esophageal epithelial neoplasms <it>en bloc</it>, but is associated with esophageal stenosis, particularly when ESD involves the entire circumference of the esophageal lumen. We examined the effectiveness of systemic steroid administration for control of postprocedural esophageal stricture after complete circular ESD.</p> <p>Methods</p> <p>Seven patients who underwent wholly circumferential ESD for superficially extended esophageal squamous cell carcinoma were enrolled in this study. In 3 patients, prophylactic endoscopic balloon dilatation (EBD) was started on the third post-ESD day and was performed twice a week for 8 weeks. In 4 patients, oral prednisolone was started with 30 mg daily on the third post-ESD day, tapered gradually (daily 30, 30, 25, 25, 20, 15, 10, 5 mg for 7 days each), and then discontinued at 8 weeks. EBD was used as needed whenever patients complained of dysphagia.</p> <p>Results</p> <p><it>En bloc </it>ESD with tumor-free margins was safely achieved in all cases. Patients in the prophylactic EBD group required a mean of 32.7 EBD sessions; the postprocedural stricture was dilated up to 18 mm in diameter in these patients. On the other hand, systemic steroid administration substantially reduced or eliminated the need for EBD. Corticosteroid therapy was not associated with any adverse events. Post-ESD esophageal stricture after complete circular ESD was persistent, requiring multiple EBD sessions.</p> <p>Conclusions</p> <p>Use of oral prednisolone administration may be an effective treatment strategy for reducing post-ESD esophageal stricture after complete circular ESD.</p
Multi-wavelength analysis of 18um-selected galaxies in the AKARI/IRC monitor field towards the North Ecliptic Pole
We present an initial analysis of AKARI 18um-selected galaxies using all 9
photometric bands at 2-24um available in the InfraRed Camera (IRC), in order to
demonstrate new capabilities of AKARI cosmological surveys. We detected 72
sources at 18um in an area of 50.2 arcmin^2 in the AKARI/IRC monitor field
towards the North Ecliptic Pole (NEP). From this sample, 25 galaxies with
probable redshifts z>~ 0.5 are selected with a single colour cut (N2-N3>0.1)
for a detailed SED analysis with ground-based BVRi'z'JK data. Using an SED
radiative transfer model of starbursts covering the wavelength range UV --
submm, we derive photometric redshifts from the optical-MIR SEDs of
18um-selected galaxies. From the best-fit SED models, we show that the IRC
all-band photometry is capable of tracing the steep rise in flux at the blue
side of the PAH 6.2um emission feature. This indicates that the IRC all-band
photometry is useful to constrain the redshift of infrared galaxies,
specifically for dusty galaxies with a less prominent 4000A break. Also, we
find that the flux dip between the PAH 7.7 and 11.2um emission feature is
recognizable in the observed SEDs of galaxies at z~1. By using such a colour
anomaly due to the PAH and silicate absorption features, unique samples of
ULIRGs at z~1, `silicate-break' galaxies, can be constructed from large
cosmological surveys of AKARI towards the NEP, i.e. the NEP-Deep and NEP-Wide
survey. This pilot study suggests the possibility of detecting many interesting
galaxy properties in the NEP-Deep and Wide surveys, such as a systematic
difference in SEDs between high- and low-z ULIRGs, and a large variation of the
PAH inter-band strength ratio in galaxies at high redshifts. [abridged]Comment: Accepted for publication in PASJ, AKARI special issu
Polarization rotation via a monoclinic phase in the piezoelectric 92%PbZn1/3Nb2/3O3-8%PbTiO3
The origin of ultrahigh piezoelectricity in the relaxor ferroelectric
PbZn1/3Nb2/3O3-PbTiO3 was studied with an electric field applied along the
[001] direction. The zero-field rhombohedral R phase starts to follow the
direct polarization path to tetragonal symmetry via an intermediate monoclinic
M phase, but then jumps irreversibly to an alternate path involving a different
type of monoclinic distortion. Details of the structure and domain
configuration of this novel phase are described. This result suggests that
there is a nearby R-M phase boundary as found in the Pb(Ti,Zr)O3 system.Comment: REVTeX file. 4 pages. New version after referees' comment
Theory of Thermal Conductivity in High-Tc Superconductors below Tc: Comparison between Hole-Doped and Electron-Doped Systems
In hole-doped high-Tc superconductors, thermal conductivity increases
drastically just below Tc, which has been considered as a hallmark of a nodal
gap. In contrast, such a coherence peak in thermal conductivity is not visible
in electron-doped compounds, which may indicate a full-gap state such as a
(d+is)-wave state. To settle this problem, we study the thermal conductivity in
the Hubbard model using the fluctuation-exchange (FLEX) approximation, which
predicts that the nodal d-wave state is realized in both hole-doped and
electron-doped compounds. The contrasting behavior of thermal conductivity in
both compounds originates from the differences in the hot/cold spot structure.
In general, a prominent coherence peak in thermal conductivity appears in
line-node superconductors only when the cold spot exists on the nodal line.Comment: 5 pages, to be published in J. Phys. Soc. Jpn. Vol.76 No.
Second harmonic generation and X-ray diffraction studies of pretransitional region in relaxor K(1-x) LixTaO3
Optical second-harmonic-generation(SHG) observations and precise X-ray
diffraction experiments have been performed on quantum paraelectrics KTaO3
(KTO) and relaxor K(1-x)LixTaO3 with x=3% (KLT-3) and 7% (KLT-7). It is found
in KLT-3 and KLT-7 that a pretransitional region exists between two
characteristic temperatures Td and Tp (<Td). The average symmetry of the region
is tetragonal with a weak lattice-deformation but non-polar in average. The
temperature interval between Td and Tp is consistent with the interval on which
neutron diffuse scatterings have been previously reported. These facts strongly
suggest that polar micro-regions (PMRs) nucleate around Td and grow toward Tp.
Below Tp, a larger deformation and a field-induced SH intensity start to
develop, while no significant SHG appear in zero-field cooling process. The
temperature dependence of the SH intensity below Tp coincides well with that of
the tetragonality determined from the lattice deformation. The
Landau-Devonshire phenomenological approach suggests that the ferroelectric
phase transition at Tp is of first order and that it approaches the second
order transition with the decrease of Li concentration. A marked increase of
neutron diffraction intensities below Tp indicates that PMRs are transformed to
ferroelectric micro-domains at Tp, and the micro-domains change to macroscopic
ones under the electric field below Tp.Comment: 31 pages, 10 figure
Direct Comparison of Manganese Detoxification/Efflux Proteins and Molecular Characterization of ZnT10 as a Manganese Transporter
Manganese (Mn) homeostasis involves coordinated regulation of specific proteins involved in Mn influx and efflux. However, the proteins that are involved in detoxification/efflux have not been completely resolved, nor has the basis by which they select their metal substrate. Here, we compared six proteins, which were reported to be involved in Mn detoxification/efflux, by evaluating their ability to reduce Mn toxicity in chicken DT40 cells, finding that human ZnT10 (hZnT10) was the most significant contributor. A domain swapping and substitution analysis between hZnT10 and a zinc-specific transporter hZnT1 showed that residue N43, which corresponds to the His residue constituting the potential intramembranous zinc coordination site in other ZnT transporters, is necessary to impart hZnT10's unique Mn mobilization activity; residues C52 and L242 in transmembrane domains II and V play a subtler role in controlling the metal specificity of hZnT10. Interestingly, the H->N reversion mutant in hZnT1 conferred Mn transport activity and loss of zinc transport activity. These results provide important information about Mn detoxification/efflux mechanisms in vertebrate cells as well as the molecular characterization of hZnT10 as a Mn transporter
Universal Static and Dynamic Properties of the Structural Transition in Pb(Zn1/3Nb2/3)O3
The relaxors Pb(ZnNb)O (PZN) and
Pb(MgNb)O (PMN) have very similar properties based on the
dielectric response around the critical temperature (defined by the
structural transition under the application of an electric field). It has been
widely believed that these materials are quite different below with the
unit cell of PMN remaining cubic while in PZN the low temperature unit cell is
rhombohedral in shape. However, this has been clarified by recent high-energy
x-ray studies which have shown that PZN is rhombohedral only in the skin while
the shape of the unit cell in the bulk is nearly cubic. In this study we have
performed both neutron elastic and inelastic scattering to show that the
temperature dependence of both the diffuse and phonon scattering in PZN and PMN
is very similar. Both compounds show a nearly identical recovery of the soft
optic mode and a broadening of the acoustic mode below . The diffuse
scattering in PZN is suggestive of an onset at the high temperature Burns
temperature similar to that in PMN. In contrast to PMN, we observe a broadening
of the Bragg peaks in both the longitudinal and transverse directions below
. We reconcile this additional broadening, not observed in PMN, in terms
of structural inhomogeneity in PZN. Based on the strong similarities between
PMN and PZN, we suggest that both materials belong to the same universality
class and discuss the relaxor transition in terms of the three-dimensional
Heisenberg model with cubic anisotropy in a random field.Comment: 11 pages, 10 figures. Updated version after helpful referee comment
Structural, magnetic and electrical properties of single crystalline La_(1-x)Sr_xMnO_3 for 0.4 < x < 0.85
We report on structural, magnetic and electrical properties of Sr-doped
LaMnO_3 single crystals for doping levels 0.4 < x < 0.85. The complex
structural and magnetic phase diagram can only be explained assuming
significant contributions from the orbital degrees of freedom. Close to x = 0.6
a ferromagnetic metal is followed by an antiferromagnetic metallic phase below
200 K. This antiferromagnetic metallic phase exists in a monoclinic
crystallographic structure. Following theoretical predictions this metallic
antiferromagnet is expected to reveal an (x^2-y^2)-type orbital order. For
higher Sr concentrations an antiferromagnetic insulator is established below
room temperature.Comment: 8 pages, 7 figure
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