Determination of synephrine in Oriental pharmaceutical decoctions containing aurantii nobilis pericarpium by ion-pair high-performance liquid chromatography. II

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of synephrine in thirty three species of oriental pharmaceutical decoctions containing Aurantii Nobilis Pericarpium. An ODS column and a mixed solvent system of water, acetonitrile, sodium dodecyl sulfate and phosphoric acid as a mobile phase were used for the separation. Synephrine was eluted without interference of other coexisting components within 15 min.     

Hepatic veno-occlusive disease in a case of polymyositis associated with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome

A 50-year-old woman was treated with prednisolone for polymyositis. During the therapy, thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) occurred. Neither plasma infusion nor plasma exchange could relieve the clinical manifestations of TTP/HUS. Moreover, massive ascites appeared and worsened her condition. She died approximately one year after the diagnosis of polymyositis. The autopsy revealed centri-lobular hepatic necrosis and nonthrombotic obliteration of hepatic small veins. The diagnosis of hepatic veno-occlusive disease (VOD) was made. It was suspected that common factors other than cytoreductive therapy had damaged the endothelium and caused TTP/HUS and VOD in a case of polymyositis.     

Synthesis of a photoimmobilizable histidine polymer for surface modification

A novel photoreactive polymer with histidine polar groups was synthesized through the copolymerization of two types of methacrylic acid, one carrying histidine groups and the other carrying azidoaniline groups. The polymer was photoimmobilized on polyester disks for surface modification. The effect of the surface modification on the hydrophilic and biofouling properties was investigated. Static contact angle measurements showed that the polymeric surface was modified to be comparatively hydrophilic in the polymer‐immobilized region. Micropattern immobilization was carried out with a photolithographic method. Atomic force microscopy measurements showed that the polymer was formed on the disks in response to ultraviolet irradiation. Protein adsorption was reduced on the polymer‐immobilized regions, and in those regions, spreading and adhesion of mammalian cells were reduced in comparison with that in nonimmobilized regions. In conclusion, a novel histidine‐containing polymer was photoreactively immobilized on a conventional polymer surface, and it had reduced interaction with proteins and cells. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Transient phenomena of current and field distortion due to dynamics of packet‐like charges in LDPE films

Simultaneous measurements of space charge and external current were carried out using a PEA measurement system with an electrometer on the back of a grounding electrode in order to clarify the physical situation of a huge packet of positive space charges in LDPE films. A large number of positive charges from a semiconducting anode were accumulated at the interface between LDPE and an Al‐cathode at a mean applied field of 1.5 MV/cm and then finally disappeared. The results of simultaneous measurements showed that the external current kept a relatively high value during charge accumulation and further increased when the charges disappeared. Both the charge dynamics and the external current were restricted by addition of a low‐molecular‐weight paraffin wax, indicating that carrier transport was influenced by the microstructure of the polymer. The dynamics of the residual charges after short‐circuiting is also discussed. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(4): 10–17, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21256     

Effect of re-oxidation on dielectric properties in Ni-MLCC

The effect of re-oxidation treatment on the solubility of dopants and the dielectric properties of rare-earths (La, Ho) and V-substituted BaTiO₃ solid solutions, assuming the shell phase of X7R dielectrics, was investigated. Ho-V-substituted samples showed larger increase of the lattice parameter and T _c by re-oxidation treatment compared with La-V-substituted samples. Electron spin resonance measurements revealed that the oxidation of V³⁺ to V⁴⁺ or V⁵⁺ appeared in the range in which the increase of lattice parameter by re-oxidation treatment was observed. This suggests that the increase of T _c is due to the change of preferential occupational site of Ho ion from A-site to B-site, being accompanied with the oxidation of V³⁺. We also investigated the effect of re-oxidation treatment on the electrical properties and microstructure in Ni-MLCC samples, using rare-earths (La, Ho, Yb) and acceptors (Mn, V) doped BaTiO₃ based X7R dielectrics. The change in temperature characteristic of the dielectric constant by re-oxidation treatment was observed for the MLCC samples containing V with smaller content. In the case of Ho-V- and Yb-V-doped samples showed larger increase of the dielectric constant at around 120 °C compared with La-V-doped samples. The relationship between the microstructure and electrical properties of the MLCC sample was investigated by impedance measurement at elevated temperature.     

Surface passivation of the thin‐film LAPS with perhydropolysilazane‐derived silica treated by O2 plasma

Here, we describe a novel method for surface passivation of the thin‐film light addressable potentiometric sensor (LAPS). To form a uniform passivation layer, perhydropolysilazane (PHPS) was utilized as a spin‐coatable precursor of silica. After transformation of PHPS into silica by baking, we introduced an O₂ plasma treatment aiming for enhancement of the water resistance of the PHPS‐derived silica (PDS) film by completing the PHPS‐to‐silica conversion. To confirm the effect of the O₂ plasma treatment, the PDS film was deposited on a thin‐film LAPS electrode and tested by immersion in a cell culturing medium. The immersion test demonstrated that the plasma‐treated PDS film could keep the electrode stable longer than the untreated could. With the treated PSD film of 600 nm in thickness, a lifetime of the thin‐film LAPS was estimated at over 2 weeks, which is sufficient for cell culturing experiments. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Rapid discharge performance of composite electrode of hydrated sodium manganese oxide and acetylene black

Hydrated sodium manganese oxide was synthesized by reducing permanganate ion using ethanol by a sol–gel method. By including acetylene black in the synthetic reaction, we obtained composite materials in which sodium manganese oxide hydrate particles were small and mixed well with the acetylene black. We evaluated those composites as a lithium battery cathode and found that they showed 170 mA h g⁻¹ under 5 mA g⁻¹ and 117 mA h g⁻¹ under 5 A g⁻¹ on the basis of composite weight. This rapid discharge performance was probably caused by the favorable contact condition of the composite constituents.     

Synthesis of Sintered Diamond with High Electrical Resistivity and Hardness

Diamond and diamond-ultrafine Co powder mixtures were sintered at 7.7 GPa and 1800° to 2000°C. A well-sintered body with a fine-grained homogeneous microstructure, high hardness, and high electrical resistivity was produced when a diamond-5 vol% Co powder mixture was used as the starting material.