Asymptotic expansions of Eisenstein integrals and Fourier transform on symmetric spaces

This paper studies the asymptotic expansions of spherical functions on symmetric spaces and Fourier transform of rapidly decreasing functions of L^p type (0 < p ? 2) on these spaces.     

Efficient preparation of glycoclusters from silsesquioxanes

[structure: see text] A new type of glycocluster based on polyhedral oligosilsesquioxanes (POSS) has been efficiently prepared from unprotected mannoside and lactoside employing a convergent approach of thiol-radical addition reaction. The versatility of this approach was demonstrated by functionalization of mannosides and lactosides of different-length spacers.     

Stereostructure of a novel cytotoxic 18-membered macrolactone antibiotic FD-891

The absolute stereochemistry of FD-891, a novel cytotoxic 18-membered macrolactone antibiotic, was determined by a synthetic approach as well as X-ray diffraction of degradative derivatives. The absolute configuration of FD-891 turned out to be as shown above. The stable conformer of FD-891 was also discussed with respect to biological activity by comparison with the structurally related concanamycin A on the bases of molecular mechanics calculations. [structure: see text]     

Charge microheterogeneity of the beta-trace proteins (lipocalin-type prostaglandin D synthase) in the cerebrospinal fluid of patients with neurological disorders analyzed by capillary isoelectrofocusing.

Charge microheterogeneity of the beta-trace protein (beta-TP = lipocalin-type prostaglandin D synthase) in the cerebrospinal fluid (CSF) of patients with various neurological disorders was analyzed by capillary isoelectric focusing (CIEF). Under the conditions employed, beta-TP in the low-molecular-weight protein fraction of CSF was separated into at least four isoforms with different p/ values. An isoform with the pl value of 4.6-4.8 was usually the most abundant. The total beta-TP level in the CSF was determined by enzyme-linked immunosorbent assay (ELISA) to be elevated in patients recovering from organic damage to the CNS and those with pathological brain atrophy. Changes in the total beta-TP level in the CSF were occasionally accompanied by those in its charge microheterogeneity, as revealed by CIEF. Such quantitative and qualitative changes in beta-TP in human CSF indicated changes in its pathophysiological roles in association with various neurological disorders.     

Switching of energy transfer reaction by the control of orientation factor between porphyrin derivatives on the clay surface

Photochemical energy transfer was examined on the flat clay surface. By the change of surrounding atmosphere, the molecular adsorption orientation angle of dyes can be modulated. It is turned out that the energy transfer efficiency between dyes can be controlled by the relative orientation change between dyes. The change of orientation factor and spectral overlap factor was the main factor to affect the energy transfer efficiency. This technique would be useful to construct the photo-functional materials such as chromic and light harvesting system.     

Anharmonicity and quantum effects in thermal expansion of an Invar alloy

We have investigated the anharmonicity and quantum effects in the Invar alloy Fe(64.6)Ni(35.4) that shows anomalously small thermal expansion. We have performed Fe and Ni K-edge extended x-ray-absorption fine-structure spectroscopic measurements and the computational simulations based on the path-integral effective-classical-potential theory. The first nearest-neighbor (NN) shells around Fe show almost no thermal expansion, while those around Ni exhibit meaningful but smaller expansion than that of fcc Ni. At low temperature, the quantum effect is found to play an essentially important role, which is confirmed by comparing the quantum-mechanical simulations to the classical ones. The anharmonicity (asymmetric distribution) clearly exists for all the first NN shells as in normal thermal expansion systems, implying the breakdown of the direct correspondence between thermal expansion and anharmonicity.     

[NiFe]Hydrogenase from Citrobacter sp. S‐77 Surpasses Platinum as an Electrode for H2 Oxidation Reaction

Reported herein is an electrode for dihydrogen (H₂) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S‐77 ([NiFe]_S77). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe]_S77 or Pt) at 50 mV in a hydrogen half‐cell. The [NiFe]_S77 electrode is also stable in air and, unlike Pt, can be recovered 100 % after poisoning by carbon monoxide. Following characterization of the [NiFe]_S77 electrode, a fuel cell comprising a [NiFe]_S77 anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt.