2,742 research outputs found
Detection of antiferromagnetic ordering in heavily doped LaFeAsO1-xHx pnictide superconductors using nuclear-magnetic-resonance techniques
We studied double superconducting (SC) domes in LaFeAsO1-xHx by using 75As-
and 1H-nuclear magnetic resonance techniques, and unexpectedly discovered that
a new antiferromagnetic (AF) phase follows the double SC domes on further H
doping, forming a symmetric alignment of AF and SC phases in the electronic
phase diagram. We demonstrated that the new AF ordering originates from the
nesting between electron pockets, unlike the nesting between electron and hole
pockets as seen in the majority of undoped pnictides. The new AF ordering is
derived from the features common to high-Tc pnictides: however, it has not been
reported so far for other high-Tc pnictides because of their poor electron
doping capability.Comment: 5 figures, in press in PR
Dementia-specific risks of scabies: Retrospective epidemiologic analysis of an unveiled nosocomial outbreak in Japan from 1989-90
Background: Although senile dementia patients in long-term care facilities are at leading risk of scabies, the epidemiologic characteristics of this disease have yet to be fully clarified. This study documents the findings of a ward-scale nosocomial outbreak in western Japan from 1989-90, for which permission to publish was only recently obtained. Methods: A retrospective epidemiologic study was performed to identify specific risk factors of scabies among patients with dementia. Analyses were based on a review of medical and nursing records. All inpatients in the affected ward at the time of the outbreak were included in the study. Observational and analytical approaches were employed to assess the findings. Results: Twenty of 65 inpatients in the ward met the case definition of scabies. The outbreak. lasted for almost 10 months and as a result, the spatial distribution of infections showed no localized patterns in the latter phase of the outbreak. The duration of illness significantly decreased after initiation of control measures (P = 0.0067). Movement without assistance (Odds Ratio [OR] = 11.3; 95% Confidence Interval [CI]: 2.9,44.8) and moving beyond the room (but within the ward) (OR=4.1; 95% CI: 1.4, 12.5) were significantly associated with infection, while types of room (Western or Japanese) and sleeping arrangement (on beds or futons laid directly on the floor) appeared not to be risk factors. Conclusion: Univariate analysis demonstrated the importance of patients' behaviours during daily activities in controlling scabies among senile dementia patients. The findings also support previous evidence that catching scabies from fomites is far less common. Moreover, since cognitive disorders make it difficult for individuals to communicate and understand the implications of risky contacts as well as treatment method, and given the non-specific nature of individual contacts that are often unpredictable, real-time observations might help improve control practices. © 2005 Tsutsumi et al., licensee BioMed Central Ltd.published_or_final_versio
The Chaman and Paghman active faults, west of Kabul, Afghanistan: active tectonics, geomorphology, and evidence for rupture in the destructive 1505 earthquake
The city of Kabul, Afghanistan, lies within the Kabul Block, which is bounded by the Sarobi, Gardez and Paghman fault, the northern extension of the Chaman fault, accommodating oblique convergence between the Indian and Eurasian plates. In this paper, we describe the geologic structure and tectonic geomorphology of the northeast-striking Paghman fault and a ∼10-km-long portion of the Chaman fault using a combination of field observations and remote sensing data, and assess evidence for rupturing in the 1505 historical earthquake. The Paghman fault is predominantly a left-lateral strike-slip fault with a minor dip-slip component along the eastern margin of the Paghman Mountains. The Chaman and Paghman faults displaces Paleogene to Quaternary units with clear displacement of recent deposits. Continuous left-lateral movement of the both faults have caused stream deflection, capturing, abandonment, and finally, incision of alluvial deposits inside the Kabul Basin. We identify several stages in the alluvial fan development and displacement that were once a continuous unit displaced left-laterally as a single fan but are now incised by beheaded and offset stream channels. An approximately 30-km-long active fault trace is identified with geomorphic evidence of recent faulting and vertical offset ∼0.5–3 m, which we interpret is related to the historical 1505 earthquake in the area along the Chaman and Paghman faults. Our observations indicate significant along-strike variations in faults trace geometry. The seismic event comprises several fault segments separated by discontinuities such as stepovers. The two faults have accumulated enough elastic strain to cause a larger earthquake since the 1505 quake
Spin density wave and superconductivity in CaFe_{1-x}Co_{x}AsF studied by nuclear magnetic resonance
We performed nuclear magnetic resonance (NMR) measurements to investigate the
evolution of spin-density-wave (SDW) and superconducting (SC) states upon
electron doping in CaFe_{1-x}Co_{x}AsF, which exhibits an intermediate phase
diagram between those of LaFeAsO_{1-x}F_x and Ba(Fe_{1-x}Co_x)_2As_2. We found
that homogeneous coexistence of the incommensurate SDW and SC states occurs
only in a narrow doping region around the crossover regime, which supports
S_{+-}-wave symmetry. However, only the structural phase transition survives
upon further doping, which agrees with predictions from orbital fluctuation
theory. The transitional features upon electron doping imply that both spin and
orbital fluctuations are involved in the superconducting mechanism
Homogeneous coexistence of SDW and SC states in CaFe(1-x)Co(x)AsF studied by nuclear magnetic resonance
We investigated the homogeneous coexistence of spin-density-wave (SDW) and
superconducting (SC) states via 75As-nuclear magnetic resonance (NMR) in
CaFe(1-x)Co(x)AsF and found that the electronic and magnetic properties of this
compound are intermediate between those of LaFeAsO(1-x)F(x) and
Ba(Fe(1-x)Co(x))2As2. For 6% Co-doped samples, the paramagnetic spectral weight
completely disappears in the crossover regime between the SDW and SC phases
followed by the anomalous behavior of relaxation rate (1/T1), implying that the
two phases are not segregated. The 59Co-NMR spectra show that spin moments are
not commensurate but spatially modulated. These experimental results suggest
that incommensurate SDW (IC-SDW) and SC states are compatible in this compound.Comment: 5 pages, 4 figure
Development of a novel DDS for site-specific PEGylated proteins
Because of the shifted focus in life science research from genome analyses to genetic and protein function analyses, we now know functions of numerous proteins. These analyses, including those of newly identified proteins, are expected to contribute to the identification of proteins of therapeutic value in various diseases. Consequently, pharmacoproteomic-based drug discovery and development of protein therapies attracted a great deal of attention in recent years. Clinical applications of most of these proteins are, however, limited because of their unexpectedly low therapeutic effects, resulting from the proteolytic degradation in vivo followed by rapid removal from the circulatory system. Therefore, frequent administration of excessively high dose of a protein is required to observe its therapeutic effect in vivo. This often results in impaired homeostasis in vivo and leads to severe adverse effects. To overcome these problems, we have devised a method for chemical modification of proteins with polyethylene glycol (PEGylation) and other water-soluble polymers. In addition, we have established a method for creating functional mutant proteins (muteins) with desired properties, and developed a site-specific polymer-conjugation method to further improve their therapeutic potency. In this review, we are introducing our original protein-drug innovation system mentioned above
Evidence for time-reversal symmetry breaking of the superconducting state near twin-boundary interfaces in FeSe
Junctions and interfaces consisting of unconventional superconductors provide
an excellent experimental playground to study exotic phenomena related to the
phase of the order parameter. Not only the complex structure of unconventional
order parameters have an impact on the Josephson effects, but also may
profoundly alter the quasi-particle excitation spectrum near a junction. Here,
by using spectroscopic-imaging scanning tunneling microscopy, we visualize the
spatial evolution of the local density of states (LDOS) near twin boundaries
(TBs) of the nodal superconductor FeSe. The rotation of the
crystallographic orientation across the TB twists the structure of the
unconventional order parameter, which may, in principle, bring about a
zero-energy LDOS peak at the TB. The LDOS at the TB observed in our study, in
contrast, does not exhibit any signature of a zero-energy peak and an apparent
gap amplitude remains finite all the way across the TB. The low-energy
quasiparticle excitations associated with the gap nodes are affected by the TB
over a distance more than an order of magnitude larger than the coherence
length . The modification of the low-energy states is even more
prominent in the region between two neighboring TBs separated by a distance
. In this region the spectral weight near the Fermi level
(0.2~meV) due to the nodal quasiparticle spectrum is almost
completely removed. These behaviors suggest that the TB induces a fully-gapped
state, invoking a possible twist of the order parameter structure which breaks
time-reversal symmetry.Comment: 12 pages, 6 figure
Imaging Simulations of the Sunyaev-Zel'dovich Effect for ALMA
We present imaging simulations of the Sunyaev-Zel'dovich effect of galaxy
clusters for the Atacama Large Millimeter/submillimeter Array (ALMA) including
the Atacama Compact Array (ACA). In its most compact configuration at 90GHz,
ALMA will resolve the intracluster medium with an effective angular resolution
of 5 arcsec. It will provide a unique probe of shock fronts and relativistic
electrons produced during cluster mergers at high redshifts, that are hard to
spatially resolve by current and near-future X-ray detectors. Quality of image
reconstruction is poor with the 12m array alone but improved significantly by
adding ACA; expected sensitivity of the 12m array based on the thermal noise is
not valid for the Sunyaev-Zel'dovich effect mapping unless accompanied by an
ACA observation of at least equal duration. The observations above 100 GHz will
become excessively time-consuming owing to the narrower beam size and the
higher system temperature. On the other hand, significant improvement of the
observing efficiency is expected once Band 1 is implemented in the future.Comment: 16 pages, 12 figures. Accepted for publication in PASJ. Note added in
proof is include
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