Breakage of shunt devices (Sophy programmable pressure valve) following implantation in the hypochondriac region

We report on three cases in which shunt devices (Sophy programmable pressure valve) broke while implanted in the hypochondriac region. None of these patients had an apparent history of trauma related to the shunt valve. The outlet connector was broken at the same site in each case. The dissociation between the movement of the thorax and that of the abdomen may have caused the formation of a crack in the outlet connector.     

Role of neurofibromin in modulation of expression of the tyrosinase-related protein 2 gene

Tyrosinase-related protein 2 (TRP-2)/DOPAchrome tautomerase is an enzyme involved in melanin biosynthesis and plays an important role in cytoprotection by preventing the production of a toxic melanin precursor, 5,6-dihydroxyindole. Neurofibromin is the protein product of a gene linked to neurofibromatosis type 1 (NF1), which is characterized by multiple neurofibromas and abnormalities in skin pigmentation. To explore the pathogenesis of NF1, we studied the role of neurofibromin in the regulation of TRP-2 gene expression. By means of transient cotransfection assays, we show that the expression of a reporter gene under the control of the TRP-2 gene promoter was increased by a neurofibromin-dependent signal through the 71-bp region (positions -415 to -345). A Lys-to-Glu substitution at position 1425 in neurofibromin abrogated this activating function. A dominant negative Ki-ras inhibitor mimics neurofibromin's function, and additively increases TRP-2 promoter activity when coexpressed with neurofibromin. Therefore, we suggest that neurofibromin is involved in the regulation of TRP-2 gene expression. Moreover, we found a single case of a glioblastoma multiforme that expresses TRP-2 mRNA but not tyrosinase mRNA, suggesting that TRP-2 may function in human neural tissues under certain conditions.     

A new family of NAD(P)H-dependent oxidoreductases distinct from conventional Rossmann-fold proteins

A new family of NAD(P)H-dependent oxidoreductases is now recognized as a protein family distinct from conventional Rossmann-fold proteins. Numerous putative proteins belonging to the family have been annotated as malate dehydrogenase (MDH) or lactate dehydrogenase (LDH) according to the previous classification as type-2 malate/L-lactate dehydrogenases. However, recent biochemical and genetic studies have revealed that the protein family consists of a wide variety of enzymes with unique catalytic activities other than MDH or LDH activity. Based on their sequence homologies and plausible functions, the family proteins can be grouped into eight clades. This classification would be useful for reliable functional annotation of the new family of NAD(P)H-dependent oxidoreductases.     

Development of a Method for Preparing a Highly Reactive and Stable,Recyclable and Environmentally Benign Organopalladium Catalyst Supported on Sulfur‐Terminated Gallium Arsenide(001): A Three‐Component Catalyst, {Pd}‐S‐GaAs(001), and its Properties

We have developed a method for preparing a recyclable and environmentally benign organopalladium catalyst for the Heck reaction supported on sulfur‐terminated gallium arsenide(001). This three‐component catalyst, {Pd}‐S‐GaAs(001), exhibited high stability and activity, furthermore, it tolerated reuse in 10 runs of the Heck reaction (average yield, 97 %) under aerobic conditions. The sulfur layer was very important to stabilize this catalyst. Only trace amounts of Pd were leached from this catalyst to the reaction mixture, as measured by ICP‐mass. The valence of immobilized Pd was zero by XPS spectrometry.     

Near-term location planning of hydrogen refueling stations in Yokohama City

Establishing hydrogen refueling stations is key to transition into a hydrogen economy. To achieve this, a near-term, city-level roll-out plan is required, as Japan is shifting from the demonstration to implementation stage of a hydrogen economy. The aim of this study was to devise a plan to identify near-term locations to build hydrogen refueling stations in Yokohama City, Japan. Our plan provides information on the potential location of hydrogen refueling stations for 2020–2030. We considered mobile and parallel-siting type refueling stations; the locations of these stations were determined by matching the supply and demand estimated from hybrid vehicle ownership data and the available space in existing gas stations based on a safety perspective. The results reaffirmed the importance of planning the locations of hydrogen refueling stations and highlighted the suitability of using mobile-type stations. This was based on the uncertainty in fuel demand for fuel cell vehicles during the implementation stage of the hydrogen economy.     

Coagulation and sedimentation of bacteria using a highly biodegradable polymeric coagulant

Copolymer of acrylamide with N‐benzyl‐4‐vinylpyridinium chloride (PAAM‐co‐BVP) produced coagulation and sedimentation of Escherichia coli, Bacillus subtillus, Pseudomonas aeruginosa, and Staphylococcus aureus. Addition of more than 50 mg L^?1 of PAAM‐co‐BVP produced bacterial flocks that precipitated at a rate of around 200 cm h^?1. Supernatant population reduced in the range 1/30,000–1/25,000,000. Reduction of supernatant population was most effective when about 200 mg L^?1 of PAAM‐co‐BVP was added. PAAM‐co‐BVP was highly biodegradable and the half‐life estimated was 2.4 days when treated with activated sludge. The ratio of biochemical oxygen demand for 5 days (BOD₅) to total organic carbon (TOC) was 0.607. Coagulation and sedimentation of bacteria using PAAM‐co‐BVP is expected to improve the water disinfection processes by saving chlorine and other hazardous chemical fungicides and by reducing the formation of trihalomethanes and other toxic chemical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1618–1623, 2006     

Swelling of hydrophilic polymers. IV

The swelling of five types of spherical crosslinked dextrans (Sephadex) that are either nonionic (G) or ionic [carboxymethyl (CM), sulphopropyl (SP), diethylaminoethyl (DEAE), and diethyl-(2-hydroxypropyl)aminoethyl (QAE)] in the same skeleton has been studied in water at different dissolved oxygen concentrations by microscopic observation and by dilatometry. The maximum specific volume, V_max/V₀ obtained by microscopic observation increased with the lowered dissolved oxygen concentration for each Sephadex. The change of the maximum specific volume was closely related to the changes of the dissolved oxygen concentrations. The maximum changes of the total volume took the larger negative values at the lower dissolved oxygen concentration. The effect of the difference in the dissolved oxygen on the change of the total volume with swelling was closely related to the viscosity B coefficient of the Jones-Dole equation. From these results, we conclude that the structure of water on the inside of the gel differs from that on the outside of the gel. © 1995 John Wiley & Sons, Inc.     

Mechanism of Texture Development in Bi0.5(Na,K)0.5TiO3 prepared by the Templated Grain Growth Process

The mechanisms of texture evolution in Bi_0.5(Na,K)_0.5TiO₃ (BNKT) prepared by the templated grain growth method are examined using platelike SrBi₄Ti₄O₁₅ and Al₂O₃ powders and SrTiO₃ and Al₂O₃ single crystals as templates. These templates give rise to a 〈100〉 texture in the BNKT matrix. The mechanism of texture evolution is dependent on the template species. When SrBi₄Ti₄O₁₅ and SrTiO₃ are used, a new grain (terrace) forms between the matrix and the template grains. The terrace has the same crystallographic orientation as the template. The terrace grows at the expense of the matrix grains, resulting in texture evolution. For the Al₂O₃ template, no terrace forms between the matrix and the template grains. Instead, the matrix grains directly attach to the template surface. The formation of a phase boundary with a specific orientation gives rise to texture evolution for this template.