Genetically-increased taste cell population with Gα-gustducin-coupled sweet receptors is associated with increase of gurmarin-sensitive taste nerve fibers in mice

Background  

The peptide gurmarin is a selective sweet response inhibitor for rodents. In mice, gurmarin sensitivity differs among strains with gurmarin-sensitive C57BL and gurmarin-poorly-sensitive BALB strains. In C57BL mice, sweet-responsive fibers of the chorda tympani (CT) nerve can be divided into two distinct populations, gurmarin-sensitive (GS) and gurmarin-insensitive (GI) types, suggesting the existence of two distinct reception pathways for sweet taste responses. By using the dpa congenic strain (dpa CG) whose genetic background is identical to BALB except that the gene(s) controlling gurmarin sensitivity are derived from C57BL, we previously found that genetically-elevated gurmarin sensitivity in dpa CG mice, confirmed by using behavioral response and whole CT nerve response analyses, was linked to a greater taste cell population co-expressing sweet taste receptors and a Gα protein, Gα-gustducin. However, the formation of neural pathways from the increased taste cell population to nerve fibers has not yet been examined.     

Synthesis of macrocyclic bis(phenylbenzoxazole) derivatives via tandem claisen rearrangement and their fluorescence behavior

Novel macrocyclic bis(phenylbenzoxazole) derivatives were easily synthesized from macrocyclic isobutenyl bis(amide‐ether)s by tandem Claisen rearrangement and subsequent intramolecular cyclization of the amide‐phenol intermediates. The position of substitution of the oligoethylene glycol moiety on the phenylamido groups of the macrocycles did not have a large effect on the yields of the bis(benzoxazole)s for the meta and para derivatives. The fluorescence quantum yields of most of the macrocyclic bis(benzoxa‐zole)s were lower than those of the corresponding nonmacrocyclic bis(benzoxazole) model compounds. The quantum yields of the para‐substituted macrocyclic bis(benzoxazole)s were clearly lower than those of the model compounds and decreased with increasing length of the oligoethylene chain.     

Relation between the adhesion strength and interfacial width for symmetric polystyrene bilayers

Polystyrene (PS) bilayers were prepared and were adhered at a temperature between the surface and bulk glass-transition temperatures for a given time. Then, the interfacial adhesion strength (G_L) was examined with a conventional lap-shear measurement. G_L first increased with increasing adhesion time and then reached a constant value. This result implied that the segments moved across the interface, to a certain depth, even at a temperature below the bulk glass-transition temperature. To confirm this, the interfacial evolution for the PS/deuterated PS bilayers was examined with dynamic secondary-ion mass spectrometry. The G_L value was linearly proportional to the thickness of the interfacial adhesion layer. Finally, we propose a strategy for regulating the adhesion strength based on the chain-end chemistry. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3598–3604, 2006     

Aluminum thickness dependence of resistance change in spin tunneling junctions Co/Al-oxide/Co

The oxidation states of Al-oxide layer and the leakage current density in coercive differential spin tunneling junctions Co/Al-oxide/Co have been investigated in order to clear the mechanism of the increasing resistance change. X-ray photoelectron spectroscopy analysis shows that the resistance change increases with decreasing unoxidized Al, which can be qualitatively explained by using first-principle band calculation based on linear-muffin-tin-orbital atomic-sphere-approximation method. The resistance change decreases with increasing leakage current density, which originates from Schottky effect. Reduction of unoxidized Al and leakage current density originating from Schottky effect is required to obtain the large resistance change in spin tunneling junctions.     

Adsorption behavior of phospholipid vesicles at oil/water interfaces

By measuring the change in interfacial tension after adding phospholipid vesicles to an aqueous solution of electrolyte, we studied the adsorption behavior of phospholipid vesicles at oil/water interfaces. The effects of concentration of three kinds of electrolyte (NaCl, MgCl₂, LaCl₃) and of the mixing ratio of two kinds of phospholipids (phosphatidylcholine and phosphatidylserine), on the adsorption behavior at an oil/water interface were examined. The results were interpreted using the DLVO theory.     

Note on the Paper “The Norm Convergence¶ of the Trotter–Kato Product Formula with Error Bound” by Ichinose and Tamura

The norm convergence of the Trotter–Kato product formula is established with ultimate optimal error bound for the selfadjoint semigroup generated by the operator sum of two selfadjoint operators. A generalization is also given to the operator sum of several selfadjoint operators. Received: 5 October 2000 / Accepted: 12 March 2001     

Mono- and bimetallic ethylene polymerization catalysts having an azanickellacyclopentene skeleton

A series of azanickellacyclopentene complexes having iodo, bromo, chloro, or triflate ligand on the Ni center were prepared, and are subjected to studies on ethylene polymerization catalysis. Activity of these mononuclear azanickellacyclopentene complexes was increased in the order, Ni–Cl < Ni–I ≈ Ni–Br < Ni–OTf; this is explained by the performance of (pseudo)halogeno ligand as a leaving group from the nickel center. Methylalminoxane (MAO) and inexpensive AlEt₂Cl can be used as the cocatalyst. Mechanistic consideration suggested the involvement of neutral Ni-alkyl intermediates as proposed in the SHOP type catalytic system. Interestingly, the catalytic activity is significantly increased by incorporating the second metals into the diimino moiety of mononuclear complex. Two factors should be considered to explain this activity enhancement. One is the increased rigidity of the azanickellacyclopentene ligand backbone, and the other is the possibility of the presence of the two active centers in one molecule.     

Thermal phase transition behaviour of liquid crystals in submicron pores formed with stretched polymer fibrils

This paper discusses thermal phase transitions in a nematic liquid crystal material, filling a highly strained porous polyolefin film. Ruptured and aligned polymer fibrils, whose minimum diameter reaches several tens of nm, formed polymer networks in the porous film. From observations of temperature-controlled composite films using a polarizing microscope, it was noted that the isotropic-to-nematic phase transition temperatures of submicron liquid crystal domains, located in or near molecularly aligned streak-like polymer areas, were significantly higher than those located at some distance from these areas. It was assumed that the highly aligned polymer chains in the fine fibrils promote the nematic phase of the liquid crystal. The stretched porous polymer, exhibiting spatial ordering on a submicron scale, is thus suitable for the control of thermal phase transitions in a liquid crystal.     

Readout of Images on Spatial Light Modulator Using Reading Light Supplier

A readout function of a reading light supplier (RLS) is demonstrated by reading out images from an optical addressable spatial light modulator (SLM). The RLS supplies reading light to the reading side of the SLM and transmits readout images from the SLM. The RLS consists of a fiber plate and a redirector which has micro conical-hollows. The RLS contrast, which is the intensity ratio of the reading light to the stray light, is 9.2 and the power efficiency of the reading light supply is about 5%. A writing pattern on the SLM is a checkered pattern of 5 mm×5 mm cells, and it is read out successfully using the RLS. The maximum contrast of the readout image is 1.9.