The Second Pluri-Genus of Surface Singularities

This paper studies the second pluri-genus of surface singularities. We give a formula for this invariant of a Gorenstein singularity, and several inequalities relating the invariant with the Milnor number, Tjurina number and the modality of a hypersurface singularity.     

Aqueous self-aggregates of amphiphilic zinc 3-hydroxy- and 3-methoxy-chlorins for supramolecular light-harvesting systems

Aqueous aggregates of zinc 3¹-hydroxy- and 3¹-methoxy-13¹-oxo-chlorins possessing a hydrophilic tetraoxyethylene chain were prepared. Zinc 3¹-methoxy-chlorin formed a well-ordered aggregate without intermolecular hydrogen bonding which has been widely accepted in most structural models for BChl-c, d, e aggregates in a major light-harvesting antenna of green photosynthetic bacteria, chlorosome.     

Several contributions to soil compactibility induced by cyclic loading test

To investigate the soil compactibility during the cyclic loading, three different kinds of paddy field soils were prepared so as to clarify interrelationships among stress amplitude ratio, bulk density, soil water content and pore water pressure. The presetting values of specimen include the soil water content(percent dry basis) and bulk density of 25% d.b. and 1.1 Mg/m³ respectively. The relation between the number of cyclic loading and axial strain exhibited an asymptotically increasing trend, converging toward a specific value for each experimental condition. Possible effect caused by elastic–plastic characteristics could be recognized, when axial strain for 0.5 Hz excitation becomes greater than the one of 1.0 Hz under same stress amplitude ratio. When the stress amplitude ratio took 0.1, the absolute value of axial strain of 0.5 Hz was greater than the one of 1.0 Hz, whereas its decreasing trend was recognized in the sequence of silt, clay and silty sand. The qualitative relations between pore water pressure and number of cyclic loading were also examined to scrutinize the effect of effective water pressure to the soil compactibility.     

The multiplicity of abelian covers of splice quotient singularities

From a resolution graph with certain conditions, Neumann and Wahl constructed an equisingular family of surface singularities called splice quotients. For this class some fundamental analytic invariants have been computed from their resolution graph. In this paper we give a method to compute the multiplicity of an abelian covering of a splice quotient from its resolution graph and the Galois group.     

Evaluation of the abilities of ��-cyclodextrin to form complexes by surface plasmon resonance with a Biacore? system

Although phase-solubility studies have often been used to evaluate the interaction of cyclodextrins (CDs) with various drugs, hundreds of milligrams of both CD and drug are required to prepare a phase diagram. A method that would require considerably less material for evaluating complex formation between a CD and guest compound is therefore needed. We previously reported the detection of the interactions between ??-CD and various drugs using a Biacore^® system. In this study, we succeeded in immobilizing 6-monodeoxy-6-monoamino-??-CD on the gold surface of a sensor chip and in detecting the interactions between the immobilized ??-CD and various drugs. The interaction processes were kinetically analyzed using Biacore^®. The surface plasmon resonance sensorgrams indicated that the association and dissociation rates of the interactions between ??-CD and drugs were faster than those between ??-CD and drugs. Although the association constants calculated from the sensorgrams were smaller than those calculated from phase-solubility studies, good correlation was shown between these data.     

Bioinert surface to protein adsorption with higher generation of dendrimer SAMs

Interactions between proteins and biomaterial surfaces correlate with many important phenomena in biological systems. Such interactions have been used to develop various artificial biomaterials and applications, in which regulation of non-specific protein adsorption has been achieved with bioinert properties. In this research, we investigated the protein adsorption behavior of polymer brushes of dendrimer self-assembled monolayers (SAMs) with other generations. The surface adsorption properties of proteins with different pI values were examined on gold substrates modified with poly(amidoamine) dendrimer SAMs. The amount of fibrinogen adsorption was greater than that of lysozyme, potentially because of the surface electric charge. However, as the generations increased, protein adsorption decreased regardless of the surface charge, suggesting that protein adsorption was also affected by density of terminal group.     

Anti-biofouling properties of an amphoteric polymer brush constructed on a glass substrate

An amphoteric copolymer brush of methacrylic acid (MA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) was prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization using both a free chain transfer agent (n-butylsulfanylthiocarbonylsulfanyl-2-methyl propionic acid) and a radical initiator (4,4'-azobis(4-cyanopentanoic acid)) covalently fixed to a glass substrate. An aqueous solution of the copolymer, Poly(MA-r-DMAEMA), which was simultaneously obtained in liquid phase, had a sufficiently small polydispersity in its molecular weight. The copolymer brush showed effective suppression of non-specific adsorption of bovine serum albumin and egg white lysozyme to the brush. In contrast, both negatively charged PolyMA and positively charged PolyDMAEMA brushes significantly adsorbed the proteins irrespective of their net charges. Upon ion beam irradiation, furthermore, a hollow space with a designed shape could be made on the glass substrate, and both HEK293 and HepG2 cells non-specifically adhered to the space, forming aggregates, while no adhesion to the non-treated area on the brush was observed. These results suggest that the amphoteric polymer brushes will be useful materials for biomedical applications.     

Development of novel synthetic method of carbon nanotubes from electrospun polystyrene fibers by using microwave heating

We have developed a novel synthetic method that enables us to easily synthesize metal‐capsulated carbon nanotubes (CNTs) in a laboratory by using a combined technology of electrospinning‐metallization and microwave heating. These techniques greatly shorten the time for the synthesis of the CNTs in comparison with the conventional methods. TEM analysis confirmed a successful formation of the CNTs, and the resulting CNTs were multi‐walled and found to be about 25–100 nm in diameters. The products prepared by heating at 600 and 900°C exhibited less‐developed and strongly curved CNTs, whereas the products prepared by heating at 700 and 800°C relatively well‐developed long CNTs. Copyright © 2010 John Wiley & Sons, Ltd.