495 research outputs found
Quantum repeaters and computation by a single module
We present a protocol of remote nondestructive parity measurement (RNPM) on a
pair of quantum memories. The protocol works as a single module for key
operations such as entanglement generation, Bell measurement, parity check
measurement, and an elementary gate for extending one-dimensional cluster
states. The RNPM protocol is achieved by a simple combination of devices such
as lasers, optical fibers, beam splitters, and photon detectors. Despite its
simplicity, a quantum repeater composed of RNPM protocols is shown to have a
communication time that scales sub-exponentially with the channel length, and
it can be further equipped with entanglement distillation. With a reduction in
the internal losses, the RNPM protocol can also be used for generating cluster
states toward measurement-based quantum communication.Comment: 7 pages, 4 figure
Superlattice formation lifting degeneracy protected by non-symmorphic symmetry through a metal-insulator transition in RuAs
The single crystal of RuAs obtained by Bi-flux method shows obvious
successive metal-insulator transitions at T_MI1~255 K and T_MI2~195$ K. The
X-ray diffraction measurement reveals a formation of superlattice of 3x3x3 of
the original unit cell below T_MI2, accompanied by a change of the crystal
system from the orthorhombic structure to the monoclinic one. Simple
dimerization of the Ru ions is nor seen in the ground state. The multiple As
sites observed in nuclear quadrupole resonance (NQR) spectrum also demonstrate
the formation of the superlattice in the ground state, which is clarified to be
nonmagnetic. The divergence in 1/T_1 at T_MI1 shows that a symmetry lowering by
the metal-insulator transition is accompanied by strong critical fluctuations
of some degrees of freedom. Using the structural parameters in the insulating
state, the first principle calculation reproduces successfully the reasonable
size of nuclear quadrupole frequencies for the multiple As sites, ensuring the
high validity of the structural parameters. The calculation also gives a
remarkable suppression in the density of states (DOS) near the Fermi level,
although the gap opening is insufficient. A coupled modulation of the
calculated Ru d electron numbers and the crystal structure proposes a formation
of charge density wave (CDW) in RuAs. Some lacking factors remain, but it shows
that a lifting of degeneracy protected by the non-symmorphic symmetry through
the superlattice formation is a key ingredient for the metal-insulator
transition in RuAs.Comment: 10 pages, 10 figure
Metastatic carcinoma of the colon similar to Crohn's disease: a case report.
A 68-year-old Japanese man with a history of linitis plastica carcinoma of the stomach and subsequent gastrectomy 8 years previously presented with lower abdominal pain. Radiological and endoscopic examinations showed multiple submucosal nodular lesions similar to Crohn's disease in the ileocecal area. A firm diagnosis could not be made after initial multiple biopsies. Finally, a submucosal biopsy revealed adenocarcinoma. The ileocecal lesion was diagnosed as a recurrence because of the histological findings, which included mucosal preservation, a similarity with the histologic type of stomach carcinoma, and atypical immunoreactivity for primary colon carcinoma; the lesion was negative for both cytokeratin 7 and cytokeratin 20. In cases where metastatic carcinoma of the colon is suspected, we recommend early consideration of a submucosal biopsy.</p
Galactose-ƒ¿-1,3-galactose (ƒ¿-gal)-specific IgE test is highly useful for predicting cetuximab-induced anaphylaxis
Intrinsic anomalous Hall effect arising from antiferromagnetic structure revealed by high-quality NbMnP
The large anomalous Hall effect (AHE) in antiferromagnetic (AF) materials
arises from symmetry breaking equivalent to a ferromagnetic (FM) state.
Consequently, this suggests that the observed AHE is induced by the intrinsic
mechanism of the band structure effect, which in turn induces dissipationless
transverse conductivity. Confirmation of impurity-insensitive anomalous Hall
conductivity (AHC) is crucial to conclude this interpretation; however,
experimental investigations in AF materials are limited by the lack of high
quality systems. In this study, we show that the AF material NbMnP, which
exhibits a large AHE, offers a high quality single crystal. Our findings
clearly revealed that the large AHC and the tiny net magnetization of
/Mn are inherent in this material, irrespective
of disorder. NbMnP is a novel AF material that generates FM responses in the
regime where there is less impurity scattering.Comment: 11 pages, 4 figure
Maternal exposure to nanoparticulate titanium dioxide during the prenatal period alters gene expression related to brain development in the mouse
<p>Abstract</p> <p>Background</p> <p>Nanotechnology is developing rapidly throughout the world and the production of novel man-made nanoparticles is increasing, it is therefore of concern that nanomaterials have the potential to affect human health. The purpose of this study was to investigate the effects of maternal exposure to nano-sized anatase titanium dioxide (TiO<sub>2</sub>) on gene expression in the brain during the developmental period using cDNA microarray analysis combined with Gene Ontology (GO) and Medical Subject Headings (MeSH) terms information.</p> <p>Results</p> <p>Analysis of gene expression using GO terms indicated that expression levels of genes associated with apoptosis were altered in the brain of newborn pups, and those associated with brain development were altered in early age. The genes associated with response to oxidative stress were changed in the brains of 2 and 3 weeks old mice. Changes of the expression of genes associated with neurotransmitters and psychiatric diseases were found using MeSH terms.</p> <p>Conclusion</p> <p>Maternal exposure of mice to TiO<sub>2 </sub>nanoparticles may affect the expression of genes related to the development and function of the central nervous system.</p
Behavioral Cost-Based Recommendation Model for Wanderers in Town
Abstract. This paper proposes a new model for recommendation based on the behavioral cost of recommendees in town. The model is based on cost-benefit analysis of the information provided to the user, referring to the model of temporal discounting and preference reversal. Here we assume that behavioral cost may be regarded as time in temporal discounting. A recommender system based on this model can select information, which is located in the surrounding area (not so far away) and may be preferred by the user, if the system can estimate where the reversal phenomenon may occur. The experiments were made using an experimental social service, called "pin@clip", which is an iPhone-based social bookmarking service in Shibuya, Tokyo, Japan that has been operating since December 2009. The experimental results show that the phenomenon of preference reversals might occur, even though the authors could not obtain statistically significant data
Elastic properties of the Non-Fermi liquid metal and the Dense Kondo semiconductor
We have investigated the elastic properties of the Ce-based filled
skutterudite antimonides CeRuSb and CeOsSb by means
of ultrasonic measurements. CeRuSb shows a slight increase around
130 K in the temperature dependence of the elastic constants ,
(-)/2 and . No apparent softening toward low
temperature due to a quadrupolar response of the 4-electronic ground state
of the Ce ion was observed at low temperatures. In contrast CeOsSb
shows a pronounced elastic softening toward low temperature in the longitudinal
as a function of temperature () below about 15 K, while a slight
elastic softening was observed in the transverse below about 1.5 K.
Furthermore, CeOsSb shows a steep decrease around a phase
transition temperature of 0.9 K in both and. The elastic
softening observed in below about 15 K cannot be explained
reasonably only by the crystalline electric field effect. It is most likely to
be responsible for the coupling between the elastic strain and the
quasiparticle band with a small energy gap in the vicinity of Fermi level. The
elastic properties and the 4 ground state of Ce ions in CeRuSb
and CeOsSb are discussed from the viewpoint of the crystalline
electric field effect and the band structure in the vicinity of Fermi level.Comment: 9 pages, 11 figures, regular pape
Systematic Study of Lattice Specific Heat of Filled Skutterudites
The lattice specific heat C lat of La-based filled skutterudites La T 4 X 12 ( T = Fe, Ru and Os; X = P, As, and Sb) has been systematically studied, and both the Debye temperature Θ D and the Einstein temperature Θ E of La T 4 X 12 were carefully estimated. We confirmed that a correlation exists between Θ D and the reciprocal of the square root of average atomic mass for La T 4 P 12 , La T 4 As 12 , and La T 4 Sb 12 . The Θ D of filled skutterudites was found to depend mainly on the nature of the species X forming the cage. The temperature dependence of C lat / T 3 for La T 4 X 12 exhibited a large broad maximum at low temperatures (10–30 K), which suggests a nearly dispersionless low-energy optical mode characterized by Einstein specific heat. Since no such broad maximum exists for the unfilled skutterudite RhP 3 , the low-energy optical modes are associated with vibration involving La ions in the X 12 cage (the so-called “guest ion modes”). The Θ E of filled skutterudites was found to roughly correspond to the energy of low-energy guest ion optical modes. Furthermore, a good correlation was shown to exist between Θ E and r R–X - r R3+ , where r R–X is the R – X distance and r R3+ is the effective ionic radius of R 3+ . As r R–X - r R3+ increased, Θ E was found to decrease
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