Non-Kondo mechanism for resistivity minimum in spin ice conduction systems

We present a mechanism of resistivity minimum in conduction electron systems coupled with localized moments, which is distinguished from the Kondo effect. Instead of the spin-flip process in the Kondo effect, electrons are elastically scattered by local spin correlations which evolve in a particular way under geometrical frustration as decreasing temperature. This is demonstrated by the cellular dynamical mean-field theory for a spin-ice type Kondo lattice model on a pyrochlore lattice. Peculiar temperature dependences of the resistivity, specific heat, and magnetic susceptibility in the non-Kondo mechanism are compared with the experimental data in metallic Ir pyrochlore oxides.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter

Effects of Fermi surface and superconducting gap structure in the field-rotational experiments: A possible explanation of the cusp-like singularity in YNi2_2B2_2C

We have studied the field-orientational dependence of zero-energy density of states (FODOS) for a series of systems with different Fermi surface and superconducting gap structures. Instead of phenomenological Doppler-shift method, we use an approximate analytical solution of Eilenberger equation together with self-consistent determination of order parameter and a variational treatment of vortex lattice. First, we compare zero-energy density of states (ZEDOS) when a magnetic field is applied in the nodal direction ($\nu_{node}(0)$) and in the antinodal direction ($\nu_{anti}(0)$), by taking account of the field-angle dependence of order parameter. As a result, we found that there exists a crossover magnetic field $H^*$ so that $\nu_{anti}(0) > \nu_{node}(0)$ for $H \nu_{anti}(0)$ for $H > H^*$, consistent with our previous analyses. Next, we showed that $H^*$ and the shape of FODOS are determined by contribution from the small part of Fermi surface where Fermi velocity is parallel to field-rotational plane. In particular, we found that $H^*$ is lowered and FODOS has broader minima, when a superconducting gap has point nodes, in contrast to the result of the Doppler-shift method. We also studied the effects of in-plane anisotropy of Fermi surface. We found that in-plane anisotropy of quasi-two dimensional Fermi surface sometimes becomes larger than the effects of Doppler-shift and can destroy the Doppler-shift predominant region. In particular, this tendency is strong in a multi-band system where superconducting coherence lengths are isotropic. Finally, we addressed the problem of cusp-like singularity in YNi$_2$B$_2$C and present a possible explanation of this phenomenon.Comment: 13pages, 23figure

Number of Circulating CD14-Positive Cells and the Serum Levels of TNF-α Are Raised in Acute Charcot Foot

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Simultaneous Optical Model Analyses of Elastic Scattering, Breakup, and Fusion Cross Section Data for the 6^{6}He + 209^{209}Bi System at Near-Coulomb-Barrier Energies

Based on an approach recently proposed by us, simultaneous $\chi^{2}$-analyses are performed for elastic scattering, direct reaction (DR) and fusion cross sections data for the $^{6}$He+$^{209}$Bi system at near-Coulomb-barrier energies to determine the parameters of the polarization potential consisting of DR and fusion parts. We show that the data are well reproduced by the resultant potential, which also satisfies the proper dispersion relation. A discussion is given of the nature of the threshold anomaly seen in the potential

Smoking influences the yield of dendritic cells for cancer immunotherapy

Background: Dendritic cell (DC)-based vaccination is considered to be a potentially effective therapeutic strategy against advanced cancer. The aim of this study was to address the smoking history that might affect the preparation of DC vaccines in validated instructional manufacture. Materials and Methods: Data on mature DCs generated from 102 sessions of leukapheresis performed on 92 patients with advanced cancer or sarcoma were retrospectively evaluated and compared in relation to the data between their smoking history and the generation of DCs from these patients. 61 patients with adenocarcinoma, including 7 with lung, 10 with breast, 8 with stomach, 12 with colorectal, and 23 with pancreatic adenocarcinoma were enrolled. Results: The average yield of autologous DCs (15.5 ± 8.3x107) was thought to be dependent on the number of monocytes (124.2 ± 74.1x107) collected by leukapheresis. The average ratio of DCs/apheresed monocytes (DC/aM ratio) was lower in the smoker group (11.1 ± 7.2%) than that in the non-smoker group (17.2 ± 9.3%, p=0.001). The number of DCs and the DC/aM ratio were lower in the patients with gastric and pancreatic cancer than in those with adenocarcinoma of other sites. Conclusions: As cancer therapy moves forward into the field of personaArticlePharmaceutical Regulatory Affairs. 4(1):133 (2015)journal articl

Optical conductivity of rattling phonons in type-I clathrate Ba8_8Ga16_{16}Ge30_{30}

A series of infrared-active optical phonons have been detected in type-I clathrate Ba$_8$Ga$_{16}$Ge$_{30}$ by terahertz time-domain spectroscopy. The conductivity spectra with the lowest-lying peaks at 1.15 and 1.80 THz are identified with so-called rattling phonons, i.e., optical modes of the guest ion Ba$^{2+}(2)$ with $T_{1u}$ symmetry in the oversized tetrakaidecahedral cage. The temperature dependence of the spectra from these modes are totally consistent with calculations based on a one-dimensional anharmonic potential model that, with decreasing temperature, the shape becomes asymmetrically sharp associated with a softening for the weight to shift to lower frequency. These temperature dependences are determined, without any interaction effects, by the Bose-factor for optical excitations of anharmonic phonons with the nonequally spaced energy levels.Comment: 4 pages, 4 figure

Slow Relaxation of Spin Structure in Exotic Ferromagnetic Phase of Ising-like Heisenberg Kagome Antiferromagnets

In the corner-sharing lattice, magnetic frustration causes macroscopic degeneracy in the ground state, which prevents systems from ordering. However, if the ensemble of the degenerate configuration has some global structure, the system can have a symmetry breaking phenomenon and thus posses a finite temperature phase transition. As a typical example of such cases, the magnetic phase transition of the Ising-like Heisenberg antiferromagnetic model on the kagome lattice has been studied. There, a phase transition of the two-dimensional ferromagnetic Ising universality class occurs accompanying with the uniform spontaneous magnetization. Because of the macroscopic degeneracy in the ordered phase, the system is found to show an entropy-driven ordering process, which is quantitatively characterized by the number of ``weathervane loop''. We investigate this novel type of slow relaxation in regularly frustrated system.Comment: 4 pages, 6 figure