Combinatorial synthesis of phosphors using arc-imaging furnace

We have applied a novel ‘melt synthesis technique’ rather than a conventional solid-state reaction to rapidly synthesize phosphor materials. During a synthesis, the mixture of oxides or their precursors is melted by light pulses (10–60 s) in an arc-imaging furnace on a water-cooled copper hearth to form a globule of 1–5 mm diameter, which is then rapidly cooled by turning off the light. Using this method, we synthesized several phosphor compounds including Y₃Al₅O₁₂:Ce(YAG) and SrAl₂O₄:Eu,Dy. Complex phosphor oxides are difficult to produce by conventional solid-state reaction techniques because of the slow reaction rates among solid oxides; as a result, the oxides form homogeneous compounds or solid solutions. On the other hand, melt reactions are very fast (10–60 s) and result in homogeneous compounds owing to rapid diffusion and mixing in the liquid phase. Therefore, melt synthesis techniques are suitable for preparing multi component homogeneous compounds and solid solutions.     

Estimation of the current peak value distribution of all lightning to the ground by electro‐geometric model

When we examine the lightning frequency and the lightning shielding e?ect of the electro‐geometric model (EGM), we need the current distribution of all lightning to the ground. The distribution of lightning current to structures is di?erent from this distribution, but it has been used in EGM conventionally. We assumed the lightning striking distance coe?cient related to the height of structures in order to obtain a result which corresponds to the observed frequency of lightning to structures, and estimated the current distribution of all lightning to the ground from data listed in the IEC 62305 series of EGM. The estimated distribution adjusted by the LLS detection e?ciency agreed well with the distribution observed by LLS. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 14–26, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22356     

Ultrahigh-resolution immunofluorescence microscopy using ultrathin cryosections: subcellular distribution of caveolin-1alpha and CD31 in human placental endothelial cells

We compared the z-axis resolutions achieved by immunofluorescence (IF) microscopic imaging of tissue sections of different thicknesses (ultrathin cryosections, optical sections of cryostat sections and conventional cryostat sections). We used these images to determine the distribution of caveolin-1alpha (CAV-1alpha) and CD31 in endothelial cells of full-term, human placenta. Anti-CAV-1alpha antibody was used to visualize caveolae, which are among the smallest organelles. By using ultrathin cryosections as substrates for IF microscopy, we were able to resolve discrete caveolae that were primarily present immediately beneath the endothelial cell surface. In contrast, neither conventional nor confocal images from cryostat sections were able to resolve individual caveolae, despite dramatic reductions in the confocal image degradation that arises from out-of-focus fluorescence signals. Anti-CD31 antibody labeled the endothelial cell surface exclusively. Quantitative analysis of ultrathin cryosections showed that about 2.5 times more CD31 was expressed on the luminal surface of cells than on the abluminal surface. Our results demonstrate that ultrathin cryosections can serve as excellent substrates for ultrahigh-resolution IF microscopy.     

Accelerated aromatic compounds degradation in aquatic environment by use of interaction between Spirodela polyrrhiza and bacteria in its rhizosphere

Accelerated degradation of organic chemicals by aquatic plant-bacterial associations was reported for the first time with elucidation of the role and contribution of aquatic plant and bacteria in its rhizosphere using a fast-growing giant duckweed, Spirodela polyrrhiza. The results clearly showed the accelerated degradation of all the three aromatic compounds (phenol, aniline and 2,4-dichlorophenol [2,4-DCP]) tested by aquatic plant-bacterial associations. In phenol degradation system, phenol-degrading bacteria indigenous to the rhizosphere fraction of S. polyrrhiza mainly contributed, while in aniline degradation system S. polyrrhiza mainly contributed by stimulating aniline-degrading bacteria both in the rhizosphere and balk water fraction. On the other hand in 2,4-DCP degradation system, S. polyrrhiza itself mainly contributed to its removal by uptake and degradation. Thus, the mechanisms for accelerated removal of aromatic compounds were quite different depending on the substrates. S. polyrrhiza showed selective accumulation of phenol-degrading bacteria in its rhizosphere fraction, while aniline- and 2,4-DCP-degrading bacteria were not much accumulated. S. polyrrhiza secreted peroxidase and laccase. However, both of the enzymatic activities increased with the addition of aromatic compounds, degrading ability of S. polyrrhiza itself should be owing to the production of peroxidase rather than laccase because the change of peroxidase activity and concentration of each aromatic compound well concurred. From the results obtained in the present study, it can be concluded that the feasibility of the use of aquatic plant-bacterial associations to accelerate the degradation of organic chemicals especially recalcitrant compounds in aquatic environment was shown.     

Cynomolgus monkey embryonic stem cell lines express green fluorescent protein

We successfully established cynomolgus monkey embryonic stem (cES) cell lines expressing enhanced green fluorescent protein (GFP) by introducing a GFP-encoding gene under cytomegalovirus immediate early enhancer (CMVIE) promoter regulation into cES cells. The cells maintained the ability of in vitro differentiation toward ectodermal, mesodermal, and endodermal lineages, and produced teratomas composed of tissues derived from the three embryonic germ layers when transplanted into severe combined immunodeficient disease mice. GFP expression was also observed in the differentiated cells. These GFP-expressing cES cell lines are considered useful for basic research, including cell transplantation.     

Catechol siderophore excretion by magnetotactic bacterium Magnetospirillum magneticum AMB-1

Siderophore activity was detected in the culture supernatant of the magnetotactic bacterium Magnetospirillum magneticum AMB-1. Here we report the first structural elucidation of a siderophore produced by a magnetotactic bacterium. The structure of the purified compound was 3,4-dihydroxybenzoic acid as determined by nuclear magnetic resonance (NMR) and electro-spray ionization mass spectroscopy (ESI-MS).     

Analysis of disulfoton sulfoxide in chingentsuai by pulsed splitless mass spectrometry using programmed temperature vaporization (PTV) inlet

A peak considered to be due to disulfoton sulfoxide as a metabolite of disulfoton was detected in the analysis of the chingentsuai extraction solution of vegetables by GC-FPD. In the analysis by GC/MS for identification, though the retention time and the mass spectrum were the same as those of the standard, the spectrum was different from MS library data. It appeared that decomposition of disulfoton sulfoxide occurred at the inlet. Therefore, we used a programmed temperature vaporization (PTV) inlet in the pulsed splitless mode to achieve a low inlet temperature and high injection pressure. As a result, the expected mass spectrum of disulfoton sulfoxide was obtained. Under this condition, the peak obtained from chingentsuai was identified as disulfoton sulfoxide. Disulfoton sulfoxide was detected from 2 of 25 chingentsuai samples, at concentrations of 0.66 microg/g and 0.14 microg/g.     

Preparation and Characterization of Hybrid Chitosan/Acrylic Resin Emulsions and Their Films

Summary: Solutions containing chitosan of different molecular weights and several acidic monomers were prepared under various aging conditions. Hybrid chitosan/acrylic resin emulsions were prepared from these solutions by emulsion polymerization. The viscosities of the hybrid chitosan/acrylic resin emulsions were influenced significantly by the molecular weight of chitosan, the acidic monomer used, and the aging conditions. DSC and FT‐IR spectroscopy of the hybrid chitosan/acrylic resin films indicated that chitosan was well distributed in the films. The water absorption and formaldehyde adsorption abilities of the acrylic resin films prepared with chitosan were higher than the corresponding films prepared without chitosan, and they increased with increasing molecular weight of the chitosan. The morphology of these films, studied by TEM, revealed that the distribution of chitosan in the hybrid chitosan/acrylic resin emulsion was dependent on the molecular weight of chitosan, the acidic monomer used, and the aging conditions.

Chitosan salts with acrylic acid (R = ? CH?CH₂), methacrylic acid (R = ? C(CH₃)?CH₂) and itaconic acid (R = ? CH₂(COOH)C?CH₂).     

Enzymatic preparation of hollow magnetite microspheres for hyperthermic treatment of cancer

Ferrimagnetic materials can be expected to be useful as thermal seeds for hyperthermic treatment of cancer, especially where the cancer is located in deep parts of body, as they can generate heat by magnetic hysteretic loss when they are placed in an alternating magnetic field. In this study, hollow magnetite (Fe₃O₄) particles were prepared using an enzymatic reaction of urease. A hollow particle was obtained by using a Pasteur pipette. The particle was 500 μm in size and was composed of Fe₃O₄. Its saturation magnetization and coercive force were 57 emu⋅g⁻¹ and 183 Oe, respectively. Its heat generation under an alternating magnetic field of 300 Oe at 100 kHz was estimated to be 45 W⋅g⁻¹. Microspheres 30 μm in diameter were also successfully obtained by using a spray gun.