Analysis of interaction between liposome membranes induced by stress condition: Utilization of liposomes immobilized on indium tin oxide electrode

NBD-cholesterol (NBD-Ch)-modified liposome was immobilized on indium tin oxide (ITO) electrode via the covalent binding method. The transfer of NBD-Ch between the immobilized liposomes and the target liposomes was observed by using a fluorescent microscope. The addition of liposome suspension co-incubated with α-chymotrypsin or stimuli-responsive polymer to the surface of the above ITO electrode, enhanced the liposome–liposome interaction, resulting in the promotion of NBD-Ch transfer. The apparent transfer rate constant of NBD-Ch was found to be correlated with the index for the liposome–liposome interaction evaluated by an immobilized liposome chromatography. This suggests that the present method using the liposome-immobilized ITO electrode was effective to evaluate the liposome–liposome interaction induced by the protein or the stimuli-responsive polymer under stress conditions.     

Glycothermal synthesis of vanadium(III) phosphate hydrates

Glycothermal reaction of various vanadium compounds with triethyl phosphate yielded two hydrate phases of vanadium(III) phosphate having tetragonal (Phase 1) and monoclinic (Phase 2) crystal systems, depending on the reaction conditions such as phosphorus/vanadium ratio, vanadium starting material, reaction temperature and solvent. Thermal treatment of Phase 2 in an anaerobic condition caused transformation to Phase 1 which finally transformed to VPO₄ through an intermediate phase (Phase M). Heat treatment of both the phases in an aerobic condition caused the formation of β-VOPO₄.     

Two siblings of type 3 GM1 gangliosidosis with different clinical features and different ages of onset

We experienced two siblings of type 3 GM1 gangliosidosis. A 33-year-old woman developed dysarthria, dysbasia and bradykinesia at around the age of 30. Her 28-year-old brother showed locomotor retardation and skeletal deformity in infancy. He lost the ability to stand walk at childhood, and developed progressive dystonia. The major neurologic manifestations were parkinsonian symptoms in the elder sister, and progressive dystonia in her brother. Both had markedly reduced beta-galactosidase activity in peripheral blood lymphocyte and were diagnosed as having type 3 GM1 gangliosidosis. Gene analysis revealed that these patients were homozygotes of the adult type mutant gene. The two siblings are unique in that the clinical manifestations and the age of onset of symptoms differed markedly between them despite the same mutant gene in both cases.     

High concentration of glucose increases mitogenic responsiveness to heparin-binding epidermal growth factor-like growth factor in rat vascular smooth muscle cells

The effect of a high extracellular glucose concentration on the mitogenic response of rat vascular smooth muscle cells (SMCs) to heparin-binding epidermal growth factor-like growth factor (HB-EGF) was investigated. The mitogenic effect of HB-EGF was significantly greater in SMCs cultured in high glucose (25 mmol/L) than in cells cultured in low glucose (5.5 mmol/L) or at high osmolarity (5.5 mmol/L glucose plus 19.5 mmol/L mannitol). The mitogenic effect of epidermal growth factor (EGF), which shares the EGF receptor with HB-EGF, was not affected by glucose concentration. The mitogenic effect of HB-EGF was greater when incubated with heparan sulfate (HS) isolated from SMCs cultured in high glucose than with HS from cells cultured in low glucose. HS synthesized by cells in high glucose was of smaller molecular size and less sulfated than HS synthesized by cells in low glucose. The abundance of mRNA encoding HS-N-deacetylase/N-sulfotransferase (HS-NdAc/NST), a regulatory enzyme in the biosynthesis of HS, was decreased by high glucose in a protein kinase C-independent manner. These observations suggest that the enhanced mitogenic response to HB-EGF in SMCs cultured in high glucose may be attributable to changes in cell-associated HS. Downregulation of HS-NdAc/NST gene expression by high glucose may be related to the altered HS biosynthesis.     

Cloning and nucleotide sequence of the beta-D-glucosidase gene from Bifidobacterium breve clb, and expression of beta-D-glucosidase activity in Escherichia coli

Genomic DNA encoding a beta-D-glucosidase (EC 3.2.1.21), which has beta-D-fucosidase activity, was cloned from Bifidobacterium breve clb. We sequenced a 1.9-kbp cloned DNA fragment that contained a single open reading frame encoding 460 amino acids with a calculated molecular mass of 51,513 Da. A putative ribosome binding site was found 5 bp upstream of the initiation codon. The amino acid sequence of this beta-D-glucosidase from Bifidobacterium breve clb had 46% identity with that of beta-glucosidase from Microbispore bispore. The enzyme of Bifidobacterium breve clb was expressed in Escherichia coli. A cell-free extract prepared from the recombinant strain showed 80 to 90-fold more beta-D-glucosidase activity than that from Bifidobacterium breve clb. The recombinant enzyme was purified to homogeneity from cell-free extracts of the recombinant strain using 4 column chromatographies. The recovery of enzyme from the recombinant strain was about 138-fold-higher than that of Bifidobacterium breve clb. The enzymatic properties were similar to those of Bifidobacterium breve clb. For application of this recombinant enzyme, we attempted to synthesize a disaccharide that seemed to be specifically assimilated by Bifidobacteria using the condensation activity of the enzyme.     

Formation of niobium double oxides by the glycothermal method

Thermal reaction of niobium alkoxide in organic media at 300°C yielded amorphous niobia, which maintained a surface area above 130 m²/g after calcination at 500°C. Niobium double oxides (LiNbO₃, Zr₆Nb₂O₁₇, CaNb₂O₆, CrNbO₄, FeNbO₄, ZnNb₂O₆ and R₃NbO₇ (R; rare earth)) were directly obtained by the reaction of niobium alkoxide with the corresponding metal alkoxide, acetate or acetylacetonate in 1,4-butanediol at 300°C. In some cases, amorphous product was obtained; however, double oxides (SrNb₂O₆, Co₄Nb₂O₉, etc.) crystallized from the products at low temperatures.     

Grain-size effects on microwave ferrite magnetic properties

This paper presents a review of polycrystalline microwave ferrites with specific reference made to the grain size. Fine-grained ferrites and large-grained ferrites as referred to in this article stand for the ferrites with an average grain size of 2 μm or less and those of 100 μm or larger, respectively. Fine-graining of ferrites is one of the state-of-the-arts techniques for obtaining high-power ferrites. Large-graining is a newly developed technique for further improving the family of narrow resonance linewidth garnet materials. Starting with some ceramics-oriented topics including the definition of the average grain-size and so forth, the present review covers the grain-size dependence of initial permeability and the grain-size dependence of microwave properties (ΔH, ΔHeff, and ΔHk) both in the theoretical and in the experimental phases. Successful device applications of newly developed "single-crystal-like" large-grained ferrites are also reviewed.     

New power consolidation-inversion-control system for faraday MHD generator

The authors propose a new power consolidation-inversion-control system for the Faraday MHD generator using the voltage source PWM inverters. The dc output power for each electrodes pair of the MHD generator is at first inverted into three-phase ac power by a voltage source PWM inverter, and then the ac powers are consolidated by transformers. The proposed system does not need such expensive equipment as an ac filter or phase modifier and can independently and simultaneously control the active and reactive powers provided to the electric power system. Numerical simulations of the whole system, including the Faraday MHD generator, the proposed power consolidation-inversion-control system, and the electric power system, show that the proposed system can stably and steadily transmit and control the electric power from the MHD generator to the electric power system. It is also confirmed that the proposed system can independently and simultaneously control the active and reactive powers and can be used as a fast power controller.