The Core Fucose on an IgG Antibody is an Endogenous Ligand of Dectin‐1

The core fucose, a major modification of N‐glycans, is implicated in immune regulation, such as the attenuation of the antibody‐dependent cell‐mediated cytotoxicity of antibody drugs and the inhibition of anti‐tumor responses via the promotion of PD‐1 expression on T cells. Although the core fucose regulates many biological processes, no core fucose recognition molecule has been identified in mammals. Herein, we report that Dectin‐1, a known anti‐β‐glucan lectin, recognizes the core fucose on IgG antibodies. A combination of biophysical experiments further suggested that Dectin‐1 recognizes aromatic amino acids adjacent to the N‐terminal asparagine at the glycosylation site as well as the core fucose. Thus, Dectin‐1 appears to be the first lectin‐like molecule involved in the heterovalent and specific recognition of characteristic N‐glycans on antibodies.     

Reduced stress‐optical coefficient of polycarbonate by antiplasticization

We have investigated the effect of antiplasticization on the stress‐optical behavior of polycarbonate (PC) containing terphenyls (tPh) and di(2‐ethylhexyl)adipate (DEHA). Addition of the three tPhs (p‐, o‐, and m‐tPh) and DEHA at contents of 5–10 wt % increases the tensile storage modulus (E' ) of PC owing to the antiplasticization effect. In particular, p‐tPh increases E' more than the other additives, suggesting that the rod‐like shape matches the free volume of PC in the glassy state. The three tPh isomers improve the glassy birefringence of PC while DEHA does not change the glassy birefringence, which corresponds to the polarizability anisotropy. The stress‐optical coefficient, a ratio of stress and birefringence, of PC decreases with increasing additive content in order of p‐tPh ? o‐tPh > m‐tPh = DEHA. This result is agreement with a restricted rotational motion of additive molecule in PC, which is observed in dynamic mechanical and birefringence data. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1837–1842     

TE-TM Mode Converter Using Optically Active Polymer

A novel TE-TM mode converter using optically active polymer: poly-1-menthylmethacrylate (PMtMA) was studied theoretically and experimentally. In a three-layered slab waveguide consisting of the PMtMA core layer on a fused quartz substrate, a low-loss TE₀-TM₀ mode conversion with an efficiency of 60 to 70% was easily obtained for the first time at a wavelength of 441.6 nm. The method to achieve a phase-matched operation of this polymer TE-TM mode converter was also discussed.     

Application of atomic stereomicroscope to surface science

A stereograph of atomic arrangement was displayed directly on the screen of display-type spherical-mirror analyzer without any computer-aided conversion process for the first time. This stereoscopic photograph enables viewing three-dimensional atomic arrangement. This technique was realized taking advantage of the phenomenon of circular dichroism in photoelectron angular distribution. The azimuthal shifts of forward focusing peaks in a photoelectron angular distribution taken with left and right helicity light in a special arrangement are the same as the parallaxes in a stereo view of atoms. Hence a stereoscopic recognition of three-dimensional atomic arrangement is possible, when the left eye and the right eye respectively view the two images obtained by left and right helicity light simultaneously.     

Photophysical and Photochemical Properties of Ru(bpy)3 2+ in Si-Ti Mixed Oxides Xerogels Prepared by the Sol-Gel Process

The luminescence spectra and lifetime of tris(2,2-bipyridine)ruthenium(II), Ru(bpy)₃ ²⁺, were studied in sol-gel reaction systems of tetramethoxysilane (TMOS) and titanium(IV) isopropoxide (TTIP) with HCl. Luminescence lifetime in the TMOS system increased as the sol-gel reaction proceeded, because diffusion-controlled luminescence quenching such as oxygen and collisional quenching with solvent molecules were suppressed in the rigid matrices. On the other hand, luminescence lifetime in the TTIP system decreased during the sol-gel reaction. The decrease in lifetime was ascribed to electron transfer from photoexcited Ru(bpy)₃ ²⁺ to the conduction band of the TiO₂ xerogels. Extended X-ray absorption fine structure (EXAFS) measurements were done to associate lifetime in the Si-Ti xerogels with the structures of Ti⁴⁺ sites in the xerogels.     

Large-domain colloidal crystal films fabricated using a fluidic cell

The growth of colloidal crystal films from a dispersion of monodispersed silica spheres using a simple cell with one opening was investigated. Colloidal crystal films with large domain sizes were successfully fabricated almost over the cell (approximately 10 cm2) without applying any external force at room temperature. During the drying process, three distinct conditions were observed, in each of which the films exhibited different optical properties. Films with high transmittance were formed in the first stage. Upon further solvent evaporation, the films entered a medium transmittance state via an extremely low transmittance state. Angle-resolved reflection spectroscopy, which was used to analyze the three conditions, revealed that close-packed arrays with water-filled spaces between were formed in the first stage. One-directional flow was generated in the cell because water evaporation occurred only at the opening. The flow caused the spheres to be arranged epitaxially, resulting in a large domain size.     

Indium as a radical initiator in aqueous media: intermolecular alkyl radical addition to CN and CC bond

The carbon-carbon bond-forming method in aqueous media was investigated by using indium as a single-electron transfer radical initiator. The indium-mediated intermolecular alkyl radical addition to imine derivatives and electron-deficient CC bond proceeded effectively.     

Structures of [(CO2)n(H2O)m]- (n=1-4, m=1,2) cluster anions. I. Infrared photodissociation spectroscopy

The infrared photodissociation spectra of [(CO(2))(n)(H(2)O)(m)](-) (n=1-4, m=1, 2) are measured in the 3000-3800 cm(-1) range. The [(CO(2))(n)(H(2)O)(1)](-) spectra are characterized by a sharp band around 3570 cm(-1) except for n=1; [(CO(2))(1)(H(2)O)(1)](-) does not photodissociate in the spectral range studied. The [(CO(2))(n)(H(2)O)(2)](-) (n=1, 2) species have similar spectral features with a broadband at approximately 3340 cm(-1). A drastic change in the spectral features is observed for [(CO(2))(3)(H(2)O)(2)](-), where sharp bands appear at 3224, 3321, 3364, 3438, and 3572 cm(-1). Ab initio calculations are performed at the MP2/6-311++G(**) level to provide structural information such as optimized structures, stabilization energies, and vibrational frequencies of the [(CO(2))(n)(H(2)O)(m)](-) species. Comparison between the experimental and theoretical results reveals rather size- and composition-specific hydration manner in [(CO(2))(n)(H(2)O)(m)](-): (1) the incorporated H(2)O is bonded to either CO(2) (-) or C(2)O(4) (-) through two equivalent OH...O hydrogen bonds to form a ring structure in [(CO(2))(n)(H(2)O)(1)](-); (2) two H(2)O molecules are independently bound to the O atoms of CO(2) (-) in [(CO(2))(n)(H(2)O)(2)](-) (n=1, 2); (3) a cyclic structure composed of CO(2) (-) and two H(2)O molecules is formed in [(CO(2))(3)(H(2)O)(2)](-).     

Fiber-like Gold Particles Prepared in Cationic Micelles by UV Irradiation: Effect of Alkyl Chain Length of Cationic Surfactant on Particle Size

Fiber-like gold particles were prepared by irradiation of HAuCl(4) solutions at 253.7 nm in the presence of alkyltrimethylammonium chlorides (C(n)TAC: n=10, 12, 14, and 16). Fiber-like gold particles were obtained above a threshold concentration of C(n)TAC. The length of fiber-like gold particles increases with increasing alkyl chain length of C(n)TAC. Copyright 2001 Academic Press.     

Tandem carbon-carbon bond-forming radical addition-cyclization reaction of oxime ether and hydrazone

The novel tandem radical addition-cyclization of oxime ethers and hydrazones intramolecularly connected with the alpha,beta-unsaturated carbonyl group is described. The radical reaction of oxime ethers 1, 2, and 4 connected with acryloyl and methacryloyl moieties proceeded smoothly to give the heterocycles via a tandem C-C bond-forming process. The tandem reaction of hydrazone 5 took place in the presence of Zn(OTf)(2) as a Lewis acid to give the trans-cyclic product 17 without the formation of the cis-isomer. The diastereoselective radical addition-cyclization reaction of chiral oxime ether 19 was also studied. The tandem reaction of 19 proceeded smoothly even in aqueous media, providing the novel method for asymmetric synthesis of gamma-butyrolactones and beta-amino acid derivatives.