1,007 research outputs found
Spin Currents Induced by Nonuniform Rashba-Type Spin-Orbit Field
We study the spin relaxation torque in nonmagnetic or ferromagnetic metals
with nonuniform spin-orbit coupling within the Keldysh Green's function
formalism. In non-magnet, the relaxation torque is shown to arise when the
spin-orbit coupling is not uniform. In the absence of an external field, the
spin current induced by the relaxation torque is proportional to the vector
chirality of Rashba-type spin-orbit field (RSOF). In the presence of an
external field, on the other hand, spin relaxation torque arises from the
coupling of the external field and vector chirality of RSOF. Our result
indicates that spin-sink or source effects are controlled by designing RSOF in
junctions.Comment: 3 figure
Mass Spectra-Based Framework for Automated Structural Elucidation of Metabolome Data to Explore Phytochemical Diversity
A novel framework for automated elucidation of metabolite structures in liquid chromatography–mass spectrometer metabolome data was constructed by integrating databases. High-resolution tandem mass spectra data automatically acquired from each metabolite signal were used for database searches. Three distinct databases, KNApSAcK, ReSpect, and the PRIMe standard compound database, were employed for the structural elucidation. The outputs were retrieved using the CAS metabolite identifier for identification and putative annotation. A simple metabolite ontology system was also introduced to attain putative characterization of the metabolite signals. The automated method was applied for the metabolome data sets obtained from the rosette leaves of 20 Arabidopsis accessions. Phenotypic variations in novel Arabidopsis metabolites among these accessions could be investigated using this method
One-neutron knockout reaction of 17C on a hydrogen target at 70 MeV/nucleon
First experimental evidence of the population of the first 2- state in 16C
above the neutron threshold is obtained by neutron knockout from 17C on a
hydrogen target. The invariant mass method combined with in-beam gamma-ray
detection is used to locate the state at 5.45(1) MeV. Comparison of its
populating cross section and parallel momentum distribution with a Glauber
model calculation utilizing the shell-model spectroscopic factor confirms the
core-neutron removal nature of this state. Additionally, a previously known
unbound state at 6.11 MeV and a new state at 6.28(2) MeV are observed. The
position of the first 2- state, which belongs to a member of the lowest-lying
p-sd cross shell transition, is reasonably well described by the shell-model
calculation using the WBT interaction.Comment: 15 pages, 3 figure
Successful Late Management of Esophageal Perforation with T-Tube Drainage
The late management of spontaneous esophageal perforation is the most challenging problem for the surgeon. In this paper, we present a case in whom a spontaneous esophageal perforation was successfully treated by T-tube drainage after unsuccessful conservative treatment. The patient, a 68-year-old male, was admitted to the hospital with sudden upper abdominal pain. After 2 days, esophageal perforation was diagnosed, and conservative management was begun. Thereafter, the subcutaneous emphysema disappeared, and the patient's temperature decreased. However, on day 13, the patient's temperature spiked above 38°C, and computed tomography showed a mediastinal abscess. An emergency left thoracotomy with laparotomy was performed. Since a 2-cm longitudinal perforation with severe inflammatory reactions was observed, the T-tube drainage method was performed. The patient was discharged without postoperative complications and has not experienced any gastrointestinal symptoms, such as gastroesophageal reflux or dysphagia. In conclusion, the T-tube drainage method appears to be a simple and effective method for the late management of esophageal perforation with severe inflammatory reaction
Ferroelectric Nanotubes
We report the independent invention of ferroelectric nanotubes from groups in
several countries. Devices have been made with three different materials: lead
zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium
bismuth tantalate SrBi2Ta2O9 (SBT). Several different deposition techniques
have been used successfully, including misted CSD (chemical solution
deposition) and pore wetting. Ferroelectric hysteresis and high optical
nonlinearity have been demonstrated. The structures are analyzed via SEM, TEM,
XRD, AFM (piezo-mode), and SHG. Applications to trenching in Si dynamic random
access memories, ink-jet printers, and photonic devices are discussed.
Ferroelectric filled pores as small as 20 nm in diameter have been studied
Identification of distinct loci for de novo DNA methylation by DNMT3A and DNMT3B during mammalian development
De novo establishment of DNA methylation is accomplished by DNMT3A and DNMT3B. Here, we analyze de novo DNA methylation in mouse embryonic fibroblasts (2i-MEFs) derived from DNA-hypomethylated 2i/L ES cells with genetic ablation of Dnmt3a or Dnmt3b. We identify 355 and 333 uniquely unmethylated genes in Dnmt3a and Dnmt3b knockout (KO) 2i-MEFs, respectively. We find that Dnmt3a is exclusively required for de novo methylation at both TSS regions and gene bodies of Polycomb group (PcG) target developmental genes, while Dnmt3b has a dominant role on the X chromosome. Consistent with this, tissue-specific DNA methylation at PcG target genes is substantially reduced in Dnmt3a KO embryos. Finally, we find that human patients with DNMT3 mutations exhibit reduced DNA methylation at regions that are hypomethylated in Dnmt3 KO 2i-MEFs. In conclusion, here we report a set of unique de novo DNA methylation target sites for both DNMT3 enzymes during mammalian development that overlap with hypomethylated sites in human patients
14Be(p,n)14B reaction at 69 MeV in inverse kinematics
A Gamow-Teller (GT) transition from the drip-line nucleus 14Be to 14B was
studied via the (p,n) reaction in inverse kinematics using a secondary 14Be
beam at 69 MeV/nucleon. The invariant mass method is employed to reconstruct
the energy spectrum. A peak is observed at an excitation energy of 1.27(2) MeV
in 14B, together with bumps at 2.08 and 4.06(5) MeV. The observed forward
peaking of the state at 1.27 MeV and a good description for the differential
cross section, obtained with a DWBA calculation provide support for the 1+
assignment to this state. By extrapolating the cross section to zero momentum
transfer the GT-transition strength is deduced. The value is found to compare
well with that reported in a beta-delayed neutron emission study.Comment: 5 pages, 2 figure
Measurement of the cross-section and forward-backward charge asymmetry for the b and c-quark in e+e- annihilation with inclusive muons at sqrt(s) = 58 GeV
We have studied inclusive muon events using all the data collected by the
TOPAZ detector at sqrt(s)=58 GeV with an integrated luminosity of 273pb-1. From
1328 inclusive muon events, we measured the ratio R_qq of the cross section for
qq-bar production to the total hadronic cross section and forward-backward
asymmetry A^q_FB for b and c quarks. The obtained results are R_bb =
0.13+-0.02(stat)+-0.01(syst), R_cc = 0.36+-0.05(stat)+-0.05(syst), A^b_FB =
-0.20+-0.16(stat)+-0.01(syst) and A^c_FB = -0.17+-0.14(stat)+-0.02(syst), in
fair agreement with a prediction of the standard model.Comment: To be published in EPJ C. 24 pages, 12 figure
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