Structural features of humic acid of the coastal sediment in Ariake Sea tidelands: use of humic acid as an environmental indicator for river basins and coastal regions.

The structural features of humic acid (HA) at the sediment surface of the tideland at the Hayatsuegawa-river mouth at the Ariake Sea were investigated for the utilization of HA toward an environmental indicator of the features of the river basin and coastal region. 1H NMR analysis revealed a high-content hydrocarbon residue with a similar type of terrigenous HA. Direct and methylation-pyrolysis-GC analysis suggested the incorporation of long-chain carboxylate in HA in the tidelands. The incorporation of branched-chain carboxylate residues in HA is the result of the microbial decomposition of detritus; these residues could be one of the characteristic structural features of HA in this area, which is rich in biodiversity and microbial activity. Because the structural features of coastal zone HA appear to reveal the characteristics and activities of the biological environment, these findings suggest the possibility of becoming an indicator of the detailed analysis of the structural features of coastal zone HA.     

Transport properties of Andreev polarons in a superconductor-semiconductor-superconductor junction with superlattice structure

Transport properties of a superconductor-semiconductor-superconductor (Su-Sm-Su) junction with superlattice structure are investigated. Differential resistance as a function of voltage shows oscillatory behavior under the irradiation of radio-frequency (rf) waves with the specific frequency of 1.77 GHz regardless of the superconducting materials and the junction geometries. Experimental data are quantitatively explained in terms of the coupling of superconducting quasiparticles with long-wavelength acoustic phonons indirectly excited by the rf waves. We propose that the strong coupling causes the formation of novel composite particles, Andreev polarons.     

Parabolic Littlewood–Paley operators

In this paper, weak (1,1) and L^p estimates for the parabolic Littlewood–Paley operators on some homogeneous spaces are established, which are extensions of known results. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Hybridization of surface-modified metal nanoparticles and a resin

Mercapto-terminated linear polymers, which were prepared by a reversible addition-fragmentation chain transfer (RAFT) technique, were used to modify metal nanoparticle surfaces. Au and Ag nanoparticles which are approximately 3–6 nm were used. This modification resulted in easy dispersion of the nanoparticles in polymer resins by simple mixing. The quality of the dispersion was confirmed by UV–Vis spectroscopy and transmission electron microscopy.     

A new strategy for deprotonative functionalization of aromatics: transformations with excellent chemoselectivity and unique regioselectivities using t-Bu-P4 base

A new strategy for deprotonative functionalization of aromatics using t-Bu-P4 base has been developed, and highly chemoselective transformations have been achieved with unique regioselectivities.     

Design and synthesis of biologically active carbaglycosylamines: From glycosidase inhibitors to pharmacological chaperones

For over 50 years, our group has been involved in synthetic studies on biologically active cyclitols including carbasugars. Among a variety of compounds synthesized, this review focuses on carbaglycosylamine glycosidase inhibitors, highlighting the following: (1) the naturally occurring N-linked carbaoligosaccharide α-amylase inhibitor acarbose and related compounds; (2) the novel synthetic β-glycosidase inhibitors, 1′-epi-acarviosin and its 6-hydroxy analogue as well as β-valienaminylceramide and its 4′-epimer; (3) the discovery of the β-glycosidase inhibitors with chaperone activity, N-octyl-β-valienamine (NOV) and its 4-epimer (NOEV); and (4) the recent development of the potential pharmacological chaperone N-alkyl-conduramine F-4 derivatives.     

Maximal operator for multilinear Calderón-Zygmund singular integral operators on weighted Hardy spaces

In this paper, the maximal operator associated with multilinear Calderón-Zygmund singular integral operators will be studied by using an improved Coltlar's inequality. Moreover, weighted norm inequalities and some estimates on weighted Hardy spaces are obtained for this maximal operator.     

Sequential perfluoroalkylation and asymmetric reduction of nitriles triggered with perfluoroalkyl titanates: catalytic asymmetric synthesis of perfluoroalkyl amines

Highly enantio-enriched perfluoroalkyl amines are shown to be synthesized by perfluoroalkylation and asymmetric reduction of nitriles. Perfluoroalkylation of nitriles can be attained by the Lewis acidic perfluoroalkyl titanate reagents to give acyclic ketimines. Catalytic asymmetric hydrogenation of the acyclic ketimines affords the perfluoroalkyl amine products in up to 93% ee.     

Triebel-Lizorkin space boundedness of Marcinkiewicz integrals associated to surfaces

In the present paper, we consider the boundedness of Marcinkiewicz integral operator μΩ,h,φalong a surface Γ = {x = φ(|y|)y/|y|)} on the Triebel-Lizorkin space Fαp,q(Rn) for Ωbelonging to H1(Sn-1) and some class W Fα(Sn-1), which relates to Grafakos-Stefanov class.Some previous results are extended and improved.