[en] For the prevention of leukocytopenia after radiotherapy a double blind test of Hypoxanthine riboside was performed on 120 cases, and the results were examined statistically. This drug exerts an inhibitory effect on leukocytopenia in radiotherapy. It causes no change in the red blood cell count. It has a slightly inhibitory effect on thrombocytopenia. It provokes no changes in GPT, GOT, Al-phosphatase, TTT, urine protein, urine sugar, or urobilinogen. It causes a slight rise of the blood level of urine acid, but otherwise, there is no side effect. (Chiba, N.)

[en] The aim of this study was to elucidate whether intrasynovial corticosteroid injections for trigger digit reduced the volume of the tendon and pulley on high-resolution ultrasonography. Twenty-three digits of 20 patients with trigger digit were included. Each affected finger was graded clinically according to the following classification: grade I for pre-triggering, grade II for active triggering, grade III for passive triggering, and grade IV for presence of contracture. Axial ultrasound examinations were performed before an intrasynovial corticosteroid injection and at an average of 31 days after the injection. The transverse diameter, thickness, and cross-sectional area of the tendon and the thickness of the pulley were measured by two independent, blinded researchers. At least 1 grade of improvement was achieved in this study group by the time of the second examination. The transverse diameter and cross-sectional area of the tendon and the thickness of the pulley significantly decreased (P<0.05). The injection of a single dose of betamethasone improved clinical symptoms by reducing the volume of both the tendon and pulley, which may be related to the fact that tendon and pulley ruptures are delayed by corticosteroid injections

[en] We have achieved more than 1000 hours-operation in 266 nm-continuous wave (CW), 100 mW-generation of all-solid-state-UV laser system using Czochralski (Cz)-grown β-BaB₂O₄(BBO) crystal devices. Absorption of the Cz-grown crystal for e-ray at 266 nm was improved to 1%/cm, which is one-third lower than that of the crystal grown by top seeded solution growth (TSSG) method. Degradation rate of 266 nm generation, using 7 kHz repetition rate laser diode pumped Q switched Nd:YAG laser as a fundamental light source, was one order of magnitude lower than that of TSSG-crystal. Surface roughness of the crystal was better than 0.3 rms.-nm. HfO₂ film with extremely high adhesion was deposited on the surfaces using reactive low voltage ion plating method. Our devices can be put to practical use in areas of photolithography, micro fabrication, material processing and ultra high density optical disk mastering. (author)

[en] We report the ⁷⁵As nuclear quadrupole resonance (NQR) and specific heat measurements of the heavily hole-doped superconductor KFe₂As₂ (superconducting transition temperature T_c ≅ 3.5 K). The spin-lattice relaxation rate 1/T₁ in the superconducting state exhibits a gradual temperature dependence with no coherence peak below T_c. The quasiparticle specific heat C_QP/T shows a small jump, which is about 30% of the electronic specific heat coefficient just below T_c. The C_QP/T suggests the existence of low-energy quasiparticle excitation at the lowest measurement temperature T=0.4 K ≅ T_c/10. The T dependences of 1/T₁ and C_QP/T can be explained by a multiple nodal superconducting gap scenario rather than by a multiple fully gapped s_±-wave scenario determined using simple gap analysis. (author)

[en] Many researchers have reported on spin filters using linear Rashba spin–orbit interactions (SOI). However, spin filters using square and cubic Rashba SOIs have not yet been reported. We consider that this is because the Aharonov–Casher (AC) phases acquired under square and cubic Rashba SOIs are ambiguous. In this study, we try to derive the AC phases acquired under square and cubic Rashba SOIs from the viewpoint of non-Abelian SU(2) gauge theory. These AC phases can be derived successfully from the non-Abelian SU(2) gauge theory without the completing square methods. Using the results, we investigate the spin filtering in a double quantum dot (QD) Aharonov–Bohm (AB) ring under linear, square, and cubic Rashba SOIs. This AB ring consists of elongated QDs and quasi-one-dimensional quantum nanowires under an external magnetic field. The spin transport is investigated from the left nanowire to the right nanowire in the above structure within the tight-binding approximation. In particular, we focus on the difference of spin filtering among linear, square, and cubic Rashba SOIs. The calculation is performed for the spin polarization by changing the penetrating magnetic flux for the AB ring subject to linear, square, and cubic Rashba SOIs. It is found that perfect spin filtering is achieved for all of the Rashba SOIs. This result indicates that this AB ring under general Rashba SOIs can be a promising device for spin current generation. Moreover, the AB rings under general Rashba SOIs behave in totally different ways in response to penetrating magnetic flux, which is attributed to linear, square, and cubic behaviors in the in-plane momentum. This result enables us to make a clear distinction between linear, square, and cubic Rashba SOIs according to the peak position of the perfect spin filtering. (paper)

[en] We report the ⁷⁵As nuclear magnetic resonance (NMR) measurement of the hole-doped super-conductor Ba_1-xK_xFe₂As₂ with different lattice parameters and different superconducting volume fractions (T_c≅38 K). ⁷⁵As-NMR spectra revealed that the magnetically ordered and superconducting phases are microscopically separated. The spin-lattice relaxation rate 1/T₁ in the normal state reflects the existence of a large two-dimensional antiferromagnetic spin fluctuation. The 1/T₁ in the superconducting state down to the lowest measurement temperature T varies close to T³. In addition, it exhibits no coherence peak just below T_c. This shows a T dependence similar to those of other iron pnictides. (author)

[en] In this study, we investigate the spin transport in normal metal (NM)/insulator (I)/topological insulator (TI) coupled to ferromagnetic insulator (FI) structures. In particular, we focus on the barrier thickness dependence of the spin transport inside the bulk gap of the TI with FI. The TI with FI is described by two-dimensional (2D) Dirac Hamiltonian. The energy profile of the insulator is assumed to be a square with barrier height V and thickness d along the transport-direction. This structure behaves as a tunnel device for 2D Dirac electrons. The calculation is performed for the spin conductance with changing the barrier thickness and the components of magnetization of FI layer. It is found that the spin conductance decreases with increasing the barrier thickness. Also, the spin conductance is strongly dependent on the polar angle θ, which is defined as the angle between the axis normal to the FI and the magnetization of FI layer. These results indicate that the structures are promising candidates for novel tunneling magnetoresistance devices

No abstract available

[en] Recently, it has been discovered theoretically that there exist novel types of 3-dimensional topological insulators (TIs) whose gapless states manifest themselves at 1-dimensional hinges. They are called second-order topological insulators (SOTIs). Most mathematical models of SOTIs compose of conventional strong topological insulators (STIs) and additional mass terms In this paper, we investigate whether the models made based on weak topological insulators (WTIs) can have hinge states as the same as those made based on the STIs. We found that the models based on WTIs have only trivial ${\mathbb{Z}}_2$ index determined by the Wilson loop formalism unlike the models based on STIs. However, they can be regarded as stacking of 2-dimensional SOTIs along the z direction. Thus, we propose that there are topologically three different phases in our considering system: ordinary insulator, strong SOTI, and weak SOTI phases. This classification suggests the existence of other topological invariants besides the ${\mathbb{Z}}_2$ index. Finally, we propose new indices which can distinguish weak SOTIs from ordinary insulators. (paper)

[en] In this study, we consider a quantum spin Hall (QSH) phase in both the zigzag and the armchair type of honeycomb nanoribbons with two different atoms from the viewpoint of bulk-edge correspondence. Generally, the QSH phase in honeycomb nanoribbons is determined by the topology of the bulk Hamiltonian. However, the armchair type of nanoribbons seems to become the QSH phase in a very different region compared with bulk materials. On the other hand, the zigzag type of nanoribbons seems to become the QSH phase in almost the same region as bulk materials. We study the reason why the QSH phase in nanoribbons seems to be different from that of bulk materials using the extended Kane-Mele Hamiltonian. As a result, there is a clear difference in the edge states in the QSH phase between the zigzag and the armchair type of nanoribbons. We find that the QSH phase region in nanoribbons is actually different from that of bulk materials. This is because the coherence lengths of edge wave functions of nanoribbons are extremely influenced by their edge-shapes. We can conclude that the bulk-edge correspondence does not hold for relatively narrow nanoribbons compared with their coherence lengths and that the edge shapes of nanoribbons make their coherence lengths of edge wavefunctions different, which largely influences the QSH phase. (paper)