Observation of edge states derived from topological helix chains.

Introducing the concept of topology has revolutionized materials classification, leading to the discovery of topological insulators and Dirac-Weyl semimetals1-3. One of the most fundamental theories underpinning topological materials is the Su-Schrieffer-Heeger (SSH) model4,5, which was developed in 1979-decades before the recognition of topological insulators-to describe conducting polymers. Distinct from the vast majority of known topological insulators with two and three dimensions1-3, the SSH model predicts a one-dimensional analogue of topological insulators, which hosts topological bound states at the endpoints of a chain4-8. To establish this unique and pivotal state, it is crucial to identify the low-energy excitations stemming from bound states, but this has remained unknown in solids because of the absence of suitable platforms. Here we report unusual electronic states that support the emergent bound states in elemental tellurium, the single helix of which was recently proposed to realize an extended version of the SSH chain9,10. Using spin- and angle-resolved photoemission spectroscopy with a micro-focused beam, we have shown spin-polarized in-gap states confined to the edges of the (0001) surface. Our density functional theory calculations indicate that these states are attributed to the interacting bound states originating from the one-dimensional array of SSH tellurium chains. Helices in solids offer a promising experimental platform for investigating exotic properties associated with the SSH chain and exploring topological phases through dimensionality control.

Asymmetric Phosphorus Incorporation in Homoepitaxial P-Doped (111) Diamond Revealed by Photoelectron Holography.

Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.

Removal methods of rigid stylets to minimise adverse force and tracheal tube movement: a mathematical and in-vitro analysis in manikins.

This study investigated displacement of the tracheal tube caused by different methods of intubating stylet removal, using in-vitro experiments and mathematical analysis. In the first in-vitro experiment, we measured the distance travelled by the tube tip during stylet extraction. Then, we investigated the ideal technique for stylet extraction using mathematical analysis, which would cause minimal tube displacement. Then, using a training manikin, we measured the force applied to the vocal cords and stylet extraction force during tracheal intubation. When the stylet was extracted along a straight path towards the stylet end, the distance travelled by the tube tip significantly increased as the bending angle increased. Mathematical analysis revealed that the stylet should be diagonally extracted (in the sagittal plane) at an appropriate angle, rather than along a straight path towards the direction of the stylet end. In simulated tracheal intubation, extraction force and force applied to the vocal cords both significantly increased as the bending angle increased. Compared with the 'hockey stick'-shaped stylet, the arcuate-shaped stylet resulted in reduced force. Our results indicate the potential risk for vocal cord injury when using hockey stick-shaped stylets with large bending angles.

Scaphoid nonunion with carpal ligament injury - radiological, arthroscopical assessment and clinical results.

The purpose of this study was to review the clinical results of carpal ligaments injuries with scaphoid nonunion. We hypothesized that scaphoid nonunion with carpal ligament injury is associated with clinical result. We retrospectively reviewed 60 cases of -Herbert screw fixation with bone graft for scaphoid nonunions. Scapholunate (SL) and lunotriquetral (LT) ligaments lesions were confirmed by arthroscopy. Approximately half of the nonunion scaphoid cases had carpal ligaments injuries. At final follow-up evaluation, wrist function as evaluated by the Mayo wrist score was excellent in 34 patients, good in 16 patients, fair in 8 patients, and poor in 2 patients. Cases with both SL/LT ligaments injuries tended to have decreased wrist flexion-extension motion. Our results suggest that there is an indication for arthroscopy in scaphoid nonunion if surgical fixation is offered to avoid detrimental effects of an undiagnosed ligament tear.

One-dimensional edge states with giant spin splitting in a bismuth thin film.

To realize a one-dimensional (1D) system with strong spin-orbit coupling is a big challenge in modern physics, since the electrons in such a system are predicted to exhibit exotic properties unexpected from the 2D or 3D counterparts, while it was difficult to realize genuine physical properties inherent to the 1D system. We demonstrate the first experimental result that directly determines the purely 1D band structure by performing spin-resolved angle-resolved photoemission spectroscopy of Bi islands on a silicon surface that contains a metallic 1D edge structure with unexpectedly large Rashba-type spin-orbit coupling suggestive of the nontopological nature. We have also found a sizable out-of-plane spin polarization of the 1D edge state, consistent with our first-principles band calculations. Our result provides a new platform to realize exotic quantum phenomena at the 1D edge of the strong spin-orbit-coupling systems.

Effect of herpes simplex virus vector-mediated interleukin-4 gene therapy on bladder overactivity and nociception.

We investigated the effects of replication-defective herpes simplex virus (HSV) vector expression of interleukin-4 (IL-4) on bladder overactivity and nociception. HSV vector expressing murine interleukin-4 (S4IL4) or the control vector expressing ß-galactosidase (SHZ) were injected to the rat bladder wall. At 1 week after viral injection, in cystometry performed under urethane anesthesia, the S4IL4-treated group did not show the intercontraction intervals reduction during intravesical administration of 10 nM resiniferatoxin (RTx). At 2 weeks after viral injection, behavioral studies were performed on vector-injected animals in an awakened state. Freezing behavior induced by 3 µM RTx, administered for 1 min into the bladder, was significantly suppressed in the S4IL4 group compared with the SHZ group. Murine IL-4 levels examined by ELISA were significantly increased in bladder and bladder afferent dorsal root ganglia at 2 weeks after viral injection. The expression of IL-1ß and IL-2 and bladder inflammatory responses were significantly suppressed in the RTx-irritated bladder of S4IL4-injected rats. These results indicate that HSV vector-mediated interleukin-4 expression in the bladder and bladder afferent pathways reduces the inflammatory response, bladder overactivity and nociceptive behavior induced by bladder irritation in the rat model. Therefore, IL-4 gene therapy could be a new strategy for treating urinary frequency and/or bladder pain.

Atomic-layer alignment tuning for giant perpendicular magnetocrystalline anisotropy of 3d transition-metal thin films.

The magnetocrystalline anisotropy (MA) of Fe-based transition-metal thin films, consisting of only magnetic 3d elements, was systematically investigated from full-potential linearized augmented plane-wave calculations. The results predict that giant MA with a perpendicular magnetic easy axis (PMA) can be achieved by tuning the atomic-layer alignments in an Fe-Ni thin film. This giant PMA arises from the spin-orbit coupling interaction between occupied and unoccupied Ni dx2-y2,xy bands crossing the Fermi level. A promising 3d transition-metal thin film for the MgO-based magnetic tunnel junctions with the giant PMA was, thus, demonstrated.

Quantum oscillations of the metallic triangular-lattice antiferromagnet PdCrO2.

We report the electronic and transport properties of the triangular antiferromagnet PdCrO(2) at high magnetic fields up to 33 T, using measurements of the de Haas-van Alphen oscillations and the Hall resistivity. The de Haas-van Alphen oscillations below the magnetic ordering temperature T(N) reveal several two-dimensional Fermi surfaces of smaller size than those found in nonmagnetic PdCoO(2), consistent with the band structure calculations. This evidences Fermi surface reconstruction due to the 120° helical ordering of the localized Cr spins, suggesting significant coupling of the itinerant electrons to the underlying spin texture. This induces the nonlinear Hall resistivity at low temperatures via the magnetic breakdown in the reconstructed Fermi surface. Furthermore, such a coupling leads to the unconventional anomalous Hall effects near T(N) due to the field-induced spin chirality at high magnetic fields.

Antiferromagnetic topological insulator with selectively gapped Dirac cones.

Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.

Origin of the metallic properties of heavily boron-doped superconducting diamond.

The physical properties of lightly doped semiconductors are well described by electronic band-structure calculations and impurity energy levels. Such properties form the basis of present-day semiconductor technology. If the doping concentration n exceeds a critical value n(c), the system passes through an insulator-to-metal transition and exhibits metallic behaviour; this is widely accepted to occur as a consequence of the impurity levels merging to form energy bands. However, the electronic structure of semiconductors doped beyond n(c) have not been explored in detail. Therefore, the recent observation of superconductivity emerging near the insulator-to-metal transition in heavily boron-doped diamond has stimulated a discussion on the fundamental origin of the metallic states responsible for the superconductivity. Two approaches have been adopted for describing this metallic state: the introduction of charge carriers into either the impurity bands or the intrinsic diamond bands. Here we show experimentally that the doping-dependent occupied electronic structures are consistent with the diamond bands, indicating that holes in the diamond bands play an essential part in determining the metallic nature of the heavily boron-doped diamond superconductor. This supports the diamond band approach and related predictions, including the possibility of achieving dopant-induced superconductivity in silicon and germanium. It should also provide a foundation for the possible development of diamond-based devices.

Detecting halfmetallic electronic structures of spintronic materials in a magnetic field.

Band-gap engineering is one of the fundamental techniques in semiconductor technology and also applicable in next generation spintronics using the spin degree of freedom. To fully utilize the spintronic materials, it is essential to optimize the spin-dependent electronic structures in the operando conditions by applying magnetic and/or electric fields. Here we present an advanced spectroscopic technique to probe the spin-polarized electronic structures by using magnetic circular dichroism (MCD) in resonant inelastic soft X-ray scattering (RIXS) under an external magnetic field. Thanks to the spin-selective dipole-allowed transitions in RIXS-MCD, we have successfully demonstrated the direct evidence of the perfectly spin-polarized electronic structures for the prototypical halfmetallic Heusller alloy [Formula: see text]. RIXS-MCD is a promising tool to probe the spin-dependent carriers and band-gap induced in the buried magnetic layers in an element specific way under the operando conditions.

Orbital-dependent modifications of electronic structure across the magnetostructural transition in BaFe2As2.

Laser angle-resolved photoemission spectroscopy (ARPES) is employed to investigate the temperature (T) dependence of the electronic structure in BaFe2As2 across the magnetostructural transition at T{N} approximately 140 K. A drastic transformation in Fermi surface (FS) shape across T{N} is observed, as expected by first-principles band calculations. Polarization-dependent ARPES and band calculations consistently indicate that the observed FSs at k{z} approximately pi in the low-T antiferromagnetic state are dominated by the Fe3d{zx} orbital, leading to the twofold electronic structure. These results indicate that magnetostructural transition in BaFe2As2 accompanies orbital-dependent modifications in the electronic structure.

The effect of co-existing solutes on arsenate removal with hydrotalcite compound.

Hydrotalcite (HTAL-Cl), an inorganic anion exchanger, is of use as an adsorbent for the removal of arsenate (As(V)) in water systems. The adsorption properties of HTAL-Cl for As(V) and the effects of co-existing anions on the As(V) removal performance were investigated in this work. Under the conditions of pH>or=4, the adsorption capacity for As(V) gradually decreased with an increase of pH, but As(V) was removed effectively within the range of pH = 5-8. Co-existing anions interfered As(V) removal, and the effect decreased in the order of HPO(4)(2-) > HCO(3)(-) > SO(4)(2-) > Cl(-). In binary solute systems containing phosphate and As(V), the maximum adsorption capacity of HTAL-Cl was 0.95 mmol g(-1) for phosphate and 0.65 mmol g(-1) for As(V): the total of these values corresponded to the maximum adsorption capacity for As(V) in single solute systems. The adsorption isotherms in these binary solute systems were approximated by the following modified Langmuir equations:As(V): q(As) = 18.7 radicalC(As)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)), phosphate : q(P) = 33.1 radicalC(P)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)). The column adsorption experiments showed that the adsorbed As(V) was released by the phosphate adsorption, because phosphate was adsorbed more strongly on HTAL-CL than As(V).

Conversion of a conventional superconductor into a topological superconductor by topological proximity effect.

Realization of topological superconductors (TSCs) hosting Majorana fermions is a central challenge in condensed-matter physics. One approach is to use the superconducting proximity effect (SPE) in heterostructures, where a topological insulator contacted with a superconductor hosts an effective p-wave pairing by the penetration of Cooper pairs across the interface. However, this approach suffers a difficulty in accessing the topological interface buried deep beneath the surface. Here, we propose an alternative approach to realize topological superconductivity without SPE. In a Pb(111) thin film grown on TlBiSe2, we discover that the Dirac-cone state of substrate TlBiSe2 migrates to the top surface of Pb film and obtains an energy gap below the superconducting transition temperature of Pb. This suggests that a Bardeen-Cooper-Schrieffer superconductor is converted into a TSC by the topological proximity effect. Our discovery opens a route to manipulate topological superconducting properties of materials.

Factors that affect hearing level in individuals with the mitochondrial 1555A.G mutation.

The mitochondrial 1555A>G mutation is one of the most common mutations responsible for hearing loss in Asians. Although the association with aminoglycoside exposure is well known, there is great variation in the severity of hearing loss. We analyzed hearing levels in 221 Japanese individuals with this mutation and attempted to identify relevant covariants including (i) age, (ii) aminoglycoside exposure, (iii) heteroplasmy ratio, and (iv) other gene mutations. At every age, average hearing levels were worse than those in normal subjects, suggesting that mitochondrial function itself may affect the severity of hearing loss. Although the hearing loss in individuals with the 1555A>G mutation progressed with age, the rate did not differ from that of the normal subjects. Those who had reported aminoglycoside exposure had moderate-to-severe hearing impairment regardless of age, confirming that such exposure is the most important environmental variable. We also confirmed the presence of heteroplasmy, which is known to modify the expression of other mitochondrial diseases, but found no evidence for a significant correlation with hearing impairment. A high prevalence of GJB2 heterozygous mutations was noted, indicating that these mutations may exhibit epistatic interaction with the 1555A>G mutation.

A first-principles study on the Rashba effect in surface systems.

The Rashba effect in several surface systems, Au(111), Au(110), Ag(111), Sb(111) and Si(111)-Bi, is studied by means of first-principles relativistic density-functional calculations. The importance of the asymmetric behavior around the surface atom is emphasized as a crucial factor to determine the magnitude of Rashba spin splitting in addition to the size of the spin-orbit coupling. The Rashba effect at the Brillouin-zone boundary is generally described with time-reversal symmetry. Distinctive features in the spin splitting and spin direction for a two-dimensional hexagonal system are discussed with the use of symmetry in the double group of k.

The localization of proteins encoded by CRYM, KIAA1199, UBA52, COL9A3, and COL9A1, genes highly expressed in the cochlea.

Genes that are highly expressed in the inner ear, as revealed by cDNA microarray analysis, may have a crucial functional role there. Those that are expressed specifically in auditory tissues are likely to be good candidates to screen for genetic alterations in patients with deafness, and several genes have been successfully identified as responsible for hereditary hearing loss. To understand the detailed mechanisms of the hearing loss caused by the mutations in these genes, the present study examined the immunocytochemical localization of the proteins encoded by Crym, KIAA1199 homolog, Uba52, Col9a3, and Col9a1 in the cochlea of rats and mice. Confocal microscopic immunocytochemistry was performed on cryostat sections. Ultrastructurally, postembedding immunogold cytochemistry was applied using Lowicryl sections. Crym protein was predominantly distributed in the fibrocytes in the spiral ligament, as well as the stria vascularis in rats. KIAA1199 protein homolog was localized in various supporting cells, including inner phalangeal, border, inner and outer pillar, and Deiters' cells. Uba52 protein was restrictedly localized within the surface of the marginal cells of the stria vascularis. Collagen type IX was found within the tectorial membrane as well as fibrocytes in the spiral ligament. The present results showed cell-specific localization of the encoded proteins of these highly expressed genes, indicating that the coordinated actions of various molecules distributed in different parts of the cochlea are essential for maintenance of auditory processing in the cochlea.

Bul1, a new protein that binds to the Rsp5 ubiquitin ligase in Saccharomyces cerevisiae.

We characterized a temperature-sensitive mutant of Saccharomyces cerevisiae in which a mini-chromosome was unstable at a high temperature and cloned a new gene which encodes a basic and hydrophilic protein (110 kDa). The disruption of this gene caused the same temperature-sensitive growth as the original mutation. By using the two-hybrid system, we further isolated RSP5 (reverses Spt- phenotype), which encodes a hect (homologous to E6-AP C terminus) domain, as a gene encoding a ubiquitin ligase. Thus, we named our gene BUL1 (for a protein that binds to the ubiquitin ligase). BUL1 seems to be involved in the ubiquitination pathway, since a high dose of UBI1, encoding a ubiquitin, partially suppressed the temperature sensitivity of the bul1 disruptant as well as that of a rsp5 mutant. Coexpression of RSP5 and BUL1 on a multicopy plasmid was toxic for mitotic growth of the wild-type cells. Pulse-chase experiments revealed that Bul1 in the wild-type cells remained stable, while the bands of Bul1 in the rsp5 cells were hardly detected. Since the steady-state levels of the protein were the same in the two strains as determined by immunoblotting analysis, Bul1 might be easily degraded during immunoprecipitation in the absence of intact Rsp5. Furthermore, both Bul1 and Rsp5 appeared to be associated with large complexes which were separated through a sucrose gradient centrifugation, and Rsp5 was coimmunoprecipitated with Bul1. We discuss the possibility that Bul1 functions together with Rsp5 in protein ubiquitination.

Effects of depression and inflammatory factors on chronic conditions of the wrist.

AIMS: Chronic conditions of the wrist may be difficult to manage because pain and psychiatric conditions are correlated with abnormal function of the hand. Additionally, intra-articular inflammatory cytokines may cause pain. We aimed to validate the measurement of inflammatory cytokines in these conditions and identify features associated with symptoms. PATIENTS AND METHODS: The study included 38 patients (18 men, 20 women, mean age 43 years) with a chronic condition of the wrist who underwent arthroscopy. Before surgery, the Self-Rating Depression Scale (SDS), Hand20 questionnaire and a visual analogue scale (VAS) for pain were used. Cytokine and chemokine levels in the synovial fluid of the wrist were measured using enzyme-linked immunosorbent assays and correlations between the levels with pain were analysed. Gene expression profiles of the synovial membranes were assessed using quantitative polymerase chain reaction. RESULTS: Older patients had high pre-operative Hand20 scores. One-year post-operative Hand20 and VAS scores and pre-operative VAS scores correlated with SDS scores. Post-operative VAS scores negatively correlated with the expression of nerve growth factor and SDS scores positively correlated with the expression of tumour necrosis factor-alpha and negatively correlated with the expression of tumour necrosis factor-converting enzyme. CONCLUSION: There was a positive correlation between depression and chronic conditions of the wrist. Levels of some cytokines correlate with pain and depression. Additionally, cytokines may be important in the assessment and treatment of chronic conditions of the wrist and depression. Cite this article: Bone Joint J 2016;98-B:961-8.

Laceration of gastric mucosa associated with dialysis-related amyloidosis.

We report a 72-year-old female on long-term hemodialysis, who was admitted to the hospital because of hematemesis. On emergency laparotomy, pylorogastrectomy was performed. The resected specimen showed a giant hematoma and traversing fissure along the lesser curvature of the body of the stomach. Histologically, the specimen showed wide hematoma formation and amyloid deposits in the submucosal layer, especially in the wall of blood vessels. These deposits reacted positively to antihuman beta2-microglobulin antibody. The post-operative course was favorable, and the patient was discharged on the 35th hospital day. In this case, the laceration site on the gastric mucosa was almost intact and did not demonstrate ischemic change, suggesting that the giant hematoma was caused by submucosal vessel rupture, which led to the gastric mucosa laceration. To our knowledge, this is the first case of gastric mucosa laceration associated with dialysis-related amyloidosis.