Publications by authors named "Kenta Hagiwara"

Bismuth produces different types of ordered superstructures on the InAs(100) surface, depending on the growth procedure and coverage. The (2 × 1) phase forms at completion of one Bi monolayer and consists of a uniformly oriented array of parallel lines of Bi dimers. Scanning tunneling and core level spectroscopies demonstrate its metallic character, in contrast with the semiconducting properties expected on the basis of the electron counting principle.

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18-β-Glycyrrhetinic acid, a major component of licorice, stimulated the proliferation of both dermal papilla cells and outer root sheath cells isolated from human hair follicles. Thus, suggesting that this compound promotes hair growth. Furthermore, this compound inhibited the activity of testosterone 5α-reductase, an enzyme responsible for converting androgen to dihydroandrogen, with an IC of 137.

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Chiral crystals and molecules were recently predicted to form an intriguing platform for unconventional orbital physics. Here, we report the observation of chirality-driven orbital textures in the bulk electronic structure of CoSi, a prototype member of the cubic B20 family of chiral crystals. Using circular dichroism in soft x-ray angle-resolved photoemission, we demonstrate the formation of a bulk orbital-angular-momentum texture and monopolelike orbital-momentum locking that depends on crystal handedness.

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The soft X-ray photoelectron momentum microscopy (PMM) experimental station at the UVSOR Synchrotron Facility has been recently upgraded by additionally guiding vacuum ultraviolet (VUV) light in a normal-incidence configuration. PMM offers a very powerful tool for comprehensive electronic structure analyses in real and momentum spaces. In this work, a VUV beam with variable polarization in the normal-incidence geometry was obtained at the same sample position as the soft X-ray beam from BL6U by branching the VUV beamline BL7U.

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Studies showing that Panax ginseng promotes hair growth have largely been conducted using mice; there are few reports on how P. ginseng affects human hair growth. In particular, little is known about its effect on the telogen to anagen transition.

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Article Synopsis
  • The photoelectron momentum microscope (PMM) at BL6U creates a new method for μm-scale momentum-resolved photoelectron spectroscopy, significantly reducing radiation damage by projecting photoelectron data onto a 2D detector.
  • This technique enables detailed 3D measurements of valence band structures and can analyze variations based on factors like photon energy, polarization, detection position, and temperature.
  • The study showcases examples, including band structure visualization of Ir thin films, detailed measurements of Au(111) surface states, and the effects of temperature on valence band dispersion in 1T-TaS2, while comparing the benefits of different PMMs for these applications.
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Fermi surfaces of transition metals, which describe all thermodynamical and transport quantities of solids, often fail to be modeled by one-electron mean-field theory due to strong correlations among the valence electrons. In addition, relativistic spin-orbit coupling pronounced in heavier elements lifts the degeneracy of the energy bands and further modifies the Fermi surface. Palladium and rhodium, two 4d metals attributed to show significant spin-orbit coupling and electron correlations, are ideal for a systematic and fundamental study of the two fundamental physical phenomena and their interplay in the electronic structure.

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The Achlioptas process, a percolation algorithm on random network, shows a rapid second-order phase transition referred to as explosive percolation. To obtain the transition point and critical exponent β for percolations on a random network, especially for bond percolations, we propose a new scaling analysis that is independent of the system size. The transition point and critical exponent β are estimated for the product-rule (PR) and da Costa-Dorogovtsev-Goltsev-Mendes (dCDGM) (m=2) models of the Achlioptas process, as well as for the Erdős-Rényi (ER) model, which is a classical model in which the analytic values are known.

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A number of synthetic methodologies and applications of carbon quantum dots (CQDs) have been reported since they were first discovered nearly two decades ago. Unlike metal-based or semiconductor-based (e. g.

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Suppression of heavy metal elution from municipal solid waste incineration (MSWI) fly ash by cement or geopolymer solidification was studied. When these approaches are implemented, however, the volume of the solidified body increases as a consequence of the solidifying agent addition. Considering that residual landfill disposal capacity is decreasing in the long term, a novel method to suppress the elution of heavy metals from MSWI fly ash without decreasing the disposal capacity is needed.

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Carbon quantum dots (CQDs; luminescent carbon nanoparticles, size < 10 nm) have attracted much attention with respect to their eco-friendliness and multi-functionality. The solvent-dependent photoluminescence of CQDs has been well investigated to optimize the synthesis process and homogeneous dispersion. Although some alkan-1-ol solvents, such as ethanol, have been well utilized empirically as good solvents when synthesizing highly photoluminescent CQDs, the role of alkan-1-ol solvents, particularly long-chain alkan-1-ols (, 1-nonanol, 1-decanol), has not yet been clarified.

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The peculiar metallic electronic states observed in the Kondo insulator, samarium hexaboride (SmB), has stimulated considerable attention among those studying non-trivial electronic phenomena. However, experimental studies of these states have led to controversial conclusions mainly due to the difficulty and inhomogeneity of the SmB crystal surface. Here, we show the detailed electronic structure of SmB with angle-resolved photoelectron spectroscopy measurements of the three-fold (111) surface where only two inequivalent time-reversal-invariant momenta (TRIM) exist.

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Constraints on light sources that use mercury (arc lamps) are evolving with the establishment of the Minamata Convention, which has led to the proliferation of LEDs. However, no LED light source emits intense ultraviolet radiation at wavelengths below 300 nm for photolytic applications. Thus, it is necessary to develop suitable UV light sources for the decontamination of wastewater and water sterilization processing.

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A rapid, simple technique combining disk solid-phase extraction and handheld X-ray fluorescence (XRF) spectrometry was developed for the on-site determination of As, Se, and Cr(VI) in drinking water. For the preconcentration of As, Se, and Cr(VI), a 50-mL aqueous sample was adjusted to pH 4, followed by passage through a Ti-loaded anion-exchange disk (Ti-AED). Both sides of the Ti-AED were coated with an adhesive cellophane tape prior to drying using a cordless hair iron, followed by a handheld XRF measurement.

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A synergistic effect between strong electron correlation and spin-orbit interaction has been theoretically predicted to realize new topological states of quantum matter on Kondo insulators (KIs), so-called topological Kondo insulators (TKIs). One TKI candidate has been experimentally observed on the KI SmB6(001), and the origin of the surface states (SS) and the topological order of SmB6 has been actively discussed. Here, we show a metallic SS on the clean surface of another TKI candidate YbB12(001) using angle-resolved photoelectron spectroscopy.

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The LitR/CarH protein family transcriptional regulator is a new type of photoreceptor based on the function of adenosyl B12 (AdoB12) as a light-sensitive ligand. Here, we studied a semi-conserved histidine residue (His132) in the light-sensing (AdoB12-binding) domain at the C-terminus of LitR from a thermophilic Gram-negative bacterium, Thermus thermophilus HB27. The in vivo mutation of His132 within LitR caused a reduction in the rate of carotenoid production in response to illumination.

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A 1D metallic surface state was created on an anisotropic InSb(001) surface covered with Bi. Angle-resolved photoelectron spectroscopy (ARPES) showed a 1D Fermi contour with almost no 2D distortion. Close to the Fermi level (E_{F}), the angle-integrated photoelectron spectra showed power-law scaling with the binding energy and temperature.

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A rapid and simple method was developed for As determination in drinking water by solid-phase extraction (SPE)/mobile X-ray fluorescence (XRF) spectrometry. A 50 mL aqueous sample was adjusted to pH 3 with dilute hydrochloric acid, and then passed through a Ti and Zr-loaded carbon disk (TiZr-CD) to pre-concentrate the As. The SPE disk was adhered to an acrylic plate with cellophane tape, and then examined by mobile XRF spectrometry.

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Unlabelled: The LitR/CarH family of proteins is a light-sensitive MerR family of transcriptional regulators that contain an adenosyl B12 (coenzyme B12 or AdoB12)-binding domain at the C terminus. The genes encoding these proteins are found in phylogenetically diverse bacterial genera; however, the biochemical properties of these proteins from Gram-positive bacteria remain poorly understood. We performed genetic and biochemical analyses of a homolog of the LitR protein from Bacillus megaterium QM B1551, a Gram-positive endospore-forming soil bacterium.

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A rapid and simple method using wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry after in situ solid-phase extraction (SPE) was developed for the speciation and evaluation of the concentration of inorganic arsenic (As) in drinking water. The method involves the simultaneous collection of As(III) and As(V) using 13 mm ϕ SPE miniature disks. The removal of Pb(2+) from the sample water was first conducted to avoid the overlapping PbLα and AsKα spectra on the XRF spectrum.

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Cobalamin (Cbl) (synonym, vitamin B12) is the cobalt-containing cofactor produced only by some prokaryotes. Streptomyces is an effective Cbl producer. To study the role of Cbl production in Streptomyces, a knockout mutant for Cbl biosynthesis (cob) was generated in Streptomyces coelicolor A3 (2).

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We successfully generated chimeric DNA aptamers that contained six nucleoside analogs of 2'-O,4'-C-methylene bridged/locked nucleic acid (2',4'-BNA/LNA) in the primer region and multiple guanosine analogs of 2'-deoxy-2'-fluoro-ribonucleic acid (FNA) in the non-primer region using capillary electrophoresis-systematic evolution of ligands by exponential enrichment (CE-SELEX). Active species enrichment became saturated only after five selection rounds, and we obtained DNA-based xeno-nucleic acid (XNA) aptamers that had high binding affinities for the target human thrombin, with dissociation constant (Kd) values of ≥10 nanomolar. Based on sequence and circular dichroism (CD) analyses, these XNA aptamers exhibited RNA-like conformations, which could cause DNA-based strands to adopt structurally diverse conformations.

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LdrP (TT_P0055) (LitR-dependent regulatory protein) is one of the four cAMP receptor protein (CRP)/FNR family transcriptional regulators retained by the extremely thermophilic bacterium Thermus thermophilus. Previously, we reported that LdrP served as a positive regulator for the light-induced transcription of crtB, a carotenoid biosynthesis gene encoded on the megaplasmid of this organism. Here, we showed that LdrP also functions as an activator of the expression of genes clustered around the crtB gene under the control of LitR, an adenosyl B12-bound light-sensitive regulator.

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A simple method of graphite-furnace atomic-absorption spectrometry (GFAAS) after solid-phase extraction (SPE) was developed for the determination of diphenylarsinic acid (DPAA), phenylarsonic acid (PAA), and inorganic arsenic (iAs) in drinking water. This method involves the simultaneous collection of DPAA, PAA, and iAs using three stacked SPE disks, i.e.

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