252 research outputs found
Hall coefficient of LaYSrCuO () at low temperatures under high magnetic fields
The Hall coefficient in the low-temperature tetragonal phase and the
mid-temperature orthorhombic phase of LaYSrCuO
() single crystals is measured under high magnetic fields up to 9 T
in order to investigate the detailed behavior of the transport properties at
low temperatures in the stripe phase. When the superconductivity is suppressed
by high magnetic fields, the Hall coefficient has negative values in low
temperatures, and the temperature region of the negative values spreads as
increasing magnetic fields. This result indicates that the Hall coefficient in
the stripe phase around is a finite negative value, not zero.Comment: 4 pages, 4 figures. to be published to Physical Review
Nonlinear Photomagnetoelectric (PME) Effect in Bi by Laser Irradiation
The transverse (nonoscillatory) and longitudinal (oscillatory) photomagnetoelectric effects have been measured with single crystals of Bi under pulsed illumination by a Q-switched Nd-laser (wavelenghth : 1.06μ) with its peak intensity range from 10^3 to 10^6 W/cm.^2 The superlinearity in the PME voltage is observed for the Faraday configuration for the beam intensity above 1.4×10^5 W/cm.^
Low Temperature Ground States and Field-Induced Phase Transitions in α-(BEDT-TTF)_2-MHg(XCN)_4 (M=K, Tl, Rb, NH_4; X=S, Se) (Research in High Magnetic Fields)
There have been observed in a series of isostructural α-(BEDT-TTF)_2MHg(XCN)_4\u27s a variety of ground states such as spin-density-wave metallic state (M=K, Tl, Rb; X=S), superconducting one (M=NH_4; X=S), and simple metallic one (M=K, Tl; X=Se). Current status of these researches is outlined, including the magnetic field effects on the first group which appear in high fields more than 20T at low temperatures
NMR Study on La and Tl-based High-T_c Cuprates (High Field Superconductors)
NMR study on three types of high-T_C cuprates TlBa_2CaCu_2O_ (Tl1212), La_Ba_xCuO_4 (LBCO) and (La_Y_y)_Ce_xCuO_4 (LYCCO) is reported. First the Knight shift in the superconducting state was investigated for the Zn-substituted TlBa_2Ca(Cu_Zn_z)_2O_, which belongs to the over-doped region. The temperature dependence of the Knight shift was successfully explained in terms of the partially closed d-wave model proposed by Kitaoka et al. The reduction in T_C by Zn-substitution was also consistent with Miyake\u27s theoretical calculation on the potential scattering of the unitarity limit in the d-wave superconductors. Next, the impurity effect on the anomalous suppression of the superconductivity in La_Ba_xCuO_4 (LBCO) around x≅1/8 was investigated by La-NMR and ultrasonic measurements. The transition temperatures of the magnetic order and of the structural phase transformation in Zn^ and Ce^-doped LBCO have shown that the main and direct force to the suppression in the superconductivity is the magnetic ordering, and that the role of the structural phase transformation is the enhancement of the suppression. Lastly, the new electron doped cuprate free from 4f-spins has been synthesized and studied by NMR. Observed spectra of ^Cu without quadrupolar splitting similar to other conventional electron-doped cuprates indicate that the doped carrier in this system is electron like
Highly Strengthened Superconducting Magnet for a 40 T Compact Hybrid Magnet(Magnet Technology)
A 16 T outer superconducting magnet for a 40 T compact hybrid magnet is investigated. A highly strengthened superconducting magnet with a 360 mm room temperature bore can be made using newly developed (Nb, Ti)_3Sn wires with Cu-Al_2O_3 reinforcing stabilizer. The coil weight is outstandingly reduced by as much as 70 %
Molecular basis for bacterial peptidoglycan recognition by LysM domains.
Carbohydrate recognition is essential for growth, cell adhesion and signalling in all living organisms. A highly conserved carbohydrate binding module, LysM, is found in proteins from viruses, bacteria, fungi, plants and mammals. LysM modules recognize polysaccharides containing N-acetylglucosamine (GlcNAc) residues including peptidoglycan, an essential component of the bacterial cell wall. However, the molecular mechanism underpinning LysM-peptidoglycan interactions remains unclear. Here we describe the molecular basis for peptidoglycan recognition by a multimodular LysM domain from AtlA, an autolysin involved in cell division in the opportunistic bacterial pathogen Enterococcus faecalis. We explore the contribution of individual modules to the binding, identify the peptidoglycan motif recognized, determine the structures of free and bound modules and reveal the residues involved in binding. Our results suggest that peptide stems modulate LysM binding to peptidoglycan. Using these results, we reveal how the LysM module recognizes the GlcNAc-X-GlcNAc motif present in polysaccharides across kingdoms
Superconducting Gap Structure of Spin-Triplet Superconductor Sr_2RuO_4 Studied by Thermal Conductivity
To clarify the superconducting gap structure of the spin-triplet
superconductor Sr_2RuO_4, the in-plane thermal conductivity has been measured
as a function of relative orientations of the thermal flow, the crystal axes,
and a magnetic field rotating within the 2D RuO_2 planes. The in-plane
variation of the thermal conductivity is incompatible with any model with line
nodes vertical to the 2D planes and indicates the existence of horizontal
nodes. These results place strong constraints on models that attempt to explain
the mechanism of the triplet superconductivity.Comment: 5 pages, 4 figures, to be published in Phys. Rev. Let
Direct guanylation of amino groups by cyanamide in water: Catalytic generation and activation of unsubstituted carbodiimide by scandium(iii) triflate
Guanylation proceeded efficiently upon treatment of the various amines with cyanamide in the presence of catalytic amounts of scandium(III) triflate under mild conditions. The method did not require the guanylation reagents to be preactivated, and the reaction proceeded efficiently in water. The method, therefore, has practical utility for substrates that dissolve only in aqueous solutions, for example, peptides or pharmacologically important compounds. © Georg Thieme Verlag Stuttgart New York
Expanding the Applicability of the Metal Labeling of Biomolecules by the RIKEN Click Reaction: A Case Study with Gallium-68 Positron Emission Tomography
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Radiolabeled biomolecules with short half-life times are of increasing importance for positron emission tomography (PET) imaging studies. Herein, we demonstrate an improved and generalized method for synthesizing a [radiometal]-unsaturated aldehyde as a lysine-labeling probe that can be easily conjugated into various biomolecules through the RIKEN click reaction. As a case study, 68Ga-PET imaging of U87MG xenografted mice is demonstrated by using the 68Ga-DOTA-RGDyK peptide, which is selective to αVβ3 integrins
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