141 research outputs found
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
Surveys of postpartum depression in Miyagi, Japan, after the Great East Japan Earthquake
This study explores the correlation between the impact of the Great East Japan Earthquake and the incidence of postpartum depression in Miyagi prefecture, Japan. The design used was a cross-sectional study with self-administered questionnaires, 6–9 months after the disaster. The results showed the prevalence of postnatal women with Edinburgh Postnatal Depression Scale (EPDS) score of ≥9 to be 21.3 %. Multivariate analysis showed that exposure to tsunami (odds ratio, 1.80; 95 % confidence interval, 1.16–2.78) was significantly and independently associated with an EPDS score of ≥9. Postnatal women and their children should be treated as a vulnerable population, and a protective framework must be established to prepare for future devastating disasters
Living donor liver transplantation using sensitized lymphocytotoxic crossmatch positive graft
We describe a successful living donor liver transplantation (LDLT) using a lymphocytotoxic crossmatch highly positive graft. A 41-year-old woman with alcoholic liver cirrhosis was referred as a potential candidate for LDLT, and her husband was willing to donate his partial liver. As the T-lymphocytotoxic crossmatch titer was over 10,000×, the patient was first infused with rituximab for preoperative desensitization, and then five rounds of plasmapheresis were performed. After the third plasmapheresis, the lymphocytotoxic crossmatch test was negative. A left liver graft including the caudate lobe was implanted, and anti-CD25 antibody (basiliximab) was administered on postoperative days 1 and 4. The postoperative course was uneventful except for an episode of mild acute cellular rejection on postoperative day 27. Although the impact of a lymphocytotoxic crossmatch-positive liver graft on acute cellular rejection and graft survival in LDLT remains controversial, perioperative desensitization may provide benefits when using a highly sensitized liver graft
Annual report of Perinatology Committee, Japan Society of Obstetrics and Gynecology, 2013: Development of Perinatal Emergency Care Systems and Suggestions
Placetal abruption is a disease occurring irrespective of the time and location and requiring maternal-fetal emergency care, so early delivery is indispensable, and the time from the occurrence of placental abruption to delivery should be shortened as much as possible
First-order phase transition to a nonmagnetic ground state in nonsymmorphic NbCrP
We report the discovery of a first-order phase transition at around 125 K in NbCrP, which is a nonsymmorphic crystal with the Pnma space group. From the resistivity, magnetic susceptibility, and nuclear magnetic resonance measurements using crystals made by the Sn-flux method, the high-temperature (HT) phase is characterized to be metallic with a non-negligible magnetic anisotropy. The low-temperature (LT) phase is also found to be a nonmagnetic metallic state with a crystal of lower symmetry. In the LT phase, the spin susceptibility is reduced by ∼30% from that in the HT phase, suggesting that the phase transition is triggered by the electronic instability. The possible origin of the phase transition in NbCrP is discussed based on the electronic structure by comparing it with those in other nonsymmorphic compounds, RuP and RuAs
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