Reduction of atmospheric turbulence using optical duplicate system in free-space optical communications

Optical Review - To reduce the effect of atmospheric turbulence and stabilize the optical link in free-space optical (FSO) communications, we have proposed to use an optical duplicate system (ODS)...     

On neutrino masses via CPT violating Higgs interaction in the Standard Model

The Lorentz invariant CPT   violation by using non-local interactions is naturally incorporated in the Higgs coupling to neutrinos in the Standard Model, without spoiling the basic SU_(2)L×U(1)$\mathit{SU}{(2)}_L\times U(1)$ gauge symmetry. The neutrino–antineutrino mass splitting is thus realized by the mechanism which was proposed recently, assuming the neutrino masses to be predominantly Dirac-type in the Standard Model.     

Theory of recoil effects of elastically scattered electrons and of photoelectrons

Quasi-elastic scatterings of high-energy electrons are studied with quantum scattering theory including recoil effects by use of correlation functions. Two different types of recoil processes are investigated; one is free atom recoil and the other is phonon excited recoil processes within harmonic vibration approximation where Mermin’s theorem works. The recoil effects of photoelectrons excited by high-energy X-rays are also studied, where the atomic displacement after the core-hole production also plays some important roles. For practical calculations the Debye approximation is used for phonon spectra, which gives rise to the simple free atom recoil energy shift. The broadenings of the spectra depend on the temperature in contrast to the energy shift, and is quite different from the free atom approximation in particular at low temperature. Numerical calculations are carried out for Be, C (graphite), Si and Ge powders. The energy shifts for solids composed of light elements are comparable with typical chemical shifts.     

Near–Infrared‐Responsive Peptide that Targets Collagen Fibrils to Induce Cytotoxicity

A novel conjugate, PHG10 dye, was synthesized using a collagen peptide and a near–infrared (NIR)‐responsive dye to achieve targeted cytotoxicity. The collagen peptide motif, ‐(Pro‐Hyp‐Gly)₁₀‐ (PHG10), was incorporated for targeting collagen fibrils that are excessively produced by activated fibroblasts around tumor cells. PHG10 dye was purified by HPLC and identified by MALDI‐MS. The phototoxicity and cytotoxicity of PHG10 dye were examined using human glioma cells (HGCs). Fluorescent images indicated that PHG10 dye preferably assembled to collagen‐coated HGCs compared with noncoated HGCs. Under irradiation with NIR light, effective cytotoxicity was observed on collagen‐coated HGCs within 20 min. Because phototoxicity and cytotoxicity are dependent on the assembled amount of PHG10 dye, the targeting of collagen fibrils by the collagen peptide motif PHG10 is assured.     

Hydrotalcite-bound ruthenium as a multifunctional heterogeneous catalyst for one-pot synthesis of α-alkylated nitriles and quinolines

This article reviews our recent progress in one-pot syntheses of α-alkylated nitriles and quinolines by heterogeneous catalysis with hydrotalcite-bound ruthenium based on cooperative action between cationic Ru species and the base sites of the hydrotalcite surface.     

Single-nucleus polycrystallization in thin film epitaxial growth

We have observed, by use of low-energy electron microscopy, the first direct evidence of self-driven polycrystallization evolved from a single nucleus in the case of epitaxial pentacene growth on the Si(111)-H terminated surface. In this Letter we demonstrate that such polycrystallization can develop in anisotropic systems (in terms of crystal structure and/or the intermolecular interactions) when kinetic growth conditions force the alignment of the intrinsic preferential growth directions along the density gradient of diffusing molecules. This finding gives new insight into the crystallization of complex molecular systems, elucidating the importance of nanoscale control of the growth conditions.     

The alignment of nematic liquid crystals on photolithographic micro-groove patterns

Abstract

The alignment of nematic liquid crystals on micro-groove patterns was studied. It has been found that the order of the alignments is determined by the edge shape, spacing, and line pitch of the micro-groove patterns. On coarse patterns, with pitches greater than 2 μm, striped patterns of the liquid crystal alignment were observed using polarized light which manifested different orientations of the liquid crystals on the top, edge, and bottom of the grooves, respectively. On fine patterns, with pitches less than 2 μm, a uniform device-quality alignment has been realized, with which twisted nematic cells were constructed in combination with the rubbed alignment layer on the opposite substrate. Their viewing angle characteristics and tilt orientations of the director were also investigated.     

Application of band theory to experimental eigen-state energies of In0.53Ga0.47As quantum wells lattice-matched to InP

Nonparabolic band structure of InGaAs/InAlAs multi-quantum wells was studied theoretically and experimentally. The electron effective mass was derived even from eigen-states and this nonparabolicity was explicitly determined as a function of energy. Electron eigen-state energies applying Kane’s bulk band theory fitted very well with our experiments in the multi-quantum wells.     

Determination of glyoxylic acid in urine by liquid chromatography with fluorescence detection, using a novel derivatization procedure based on the Petasis reaction

The Petasis reaction is the multi-component reaction of a carbonyl compound, amine, and arylboronic acid to form an α-amino acid or a β-aminoalcohol. In this work, as the first analytical application of the Petasis reaction, a high-performance liquid chromatographic (HPLC) method with fluorescence detection was developed for determination of glyoxylic acid. The glyoxylic acid was derivatized with 1-pyreneboronic acid, as fluorescent arylboronic acid, in the presence of N-methylbutylamine, as amine, to give a fluorescent α-amino acid. HPLC separation of the fluorescent derivative was performed within 30 min on an octyl column eluted with a gradient prepared from acetonitrile and 50 mmol L(-1) acetate buffer (pH 4.0). The detection limit (S/N=3) for glyoxylic acid was 5.0 nmol L(-1) (20 fmol/injection). The method can be used to determine the concentration of glyoxylic acid in human urine without interference from biological components.