A novel differentiation factor for PC12 cells from culture supernatant of mouse hepatocyte cell line MLE-15A2

We have found a factor that induces neurite outgrowth of rat PC12 cells in the culture supernatant of the cell line MLE-15A2. This factor was designated as MDDF. The factor was sensitive to protease, dithiothreitol, and high-temperature treatments. The apparent molecular mass was 80 kDa on Superdex 200 gel filtration. No significant tyrosine phosphorylation was detected after MDDF stimulation in Western blotting analysis with anti-phosphotyrosine antibody, suggesting that the signal transduction may not be mediated by a tyrosine kinase cascade that is involved in signaling of most of the known factors. Activation of MAP kinase was very weak and was seen only 5 min after stimulation, suggesting that prolonged activation of MAP kinase was not required for neurite outgrowth induced by MDDF. Because the biochemical characteristics of MDDF are different from those of any known peptide factors that induce neurite outgrowth of PC12 cells, MDDF may be a novel differentiation factor for PC12 cells.     

Indene Compounds Synthetically Derived from Vitamin D Have Selective Antibacterial Action on Helicobacter pylori

Helicobacter pylori infects the human stomach and is closely linked with the development of gastric cancer. When detected, this pathogen can be eradicated from the human stomach using wide‐spectrum antibiotics. However, year by year, H. pylori strains resistant to the antibacterial action of antibiotics have been increasing. The development of new antibacterial substances effective against drug‐resistant H. pylori is urgently required. Our group has recently identified extremely selective bactericidal effects against H. pylori in (1R,3aR,7aR)‐1‐[(1R)‐1,5‐dimethylhexyl]octahydro‐7a‐methyl‐4H‐inden‐4‐one (VDP1) (otherwise known as Grundmann's ketone), an indene compound derived from the decomposition of vitamin D₃ and proposed the antibacterial mechanism whereby VDP1 induces the bacteriolysis by interacting at least with PtdEtn (dimyristoyl‐phosphatidylethanolamine [di‐14:0 PtdEtn]) retaining two 14:0 fatty acids of the membrane lipid constituents. In this study, we synthesized new indene compounds ((1R,3aR,7aR)‐1‐((2R,E)‐5,6‐dimethylhept‐3‐en‐2‐yl)‐7a‐methyloctahydro‐4H‐inden‐4‐one [VD2‐1], (1R,3aR,7aR)‐1‐((S)‐1‐hydroxypropan‐2‐yl)‐7a‐methyloctahydro‐1H‐inden‐4‐ol [VD2‐2], and (1R,3aR,7aR)‐7a‐methyl‐1‐((R)‐6‐methylheptan‐2‐yl)octahydro‐1H‐inden‐4‐ol [VD3‐1]) using either vitamin D₂ or vitamin D₃ as materials. VD2‐1 and VD3‐1 selectively disrupted the di‐14:0 PtdEtn vesicles without destructing the vesicles of PtdEtn (dipalmitoyl‐phosphatidylethanolamine) retaining two 16:0 fatty acids. In contrast, VD2‐2, an indene compound lacking an alkyl group, had no influence on the structural stability of both PtdEtn vesicles. In addition, VD2‐1 and VD3‐1 exerted extremely selective bactericidal action against H. pylori without affecting the viability of commonplace bacteria. Meanwhile, VD2‐2 almost forfeited the bactericidal effects on H. pylori. These results suggest that the alkyl group of the indene compounds has a crucial conformation to interact with di‐14:0 PtdEtn of H. pylori membrane lipid constituents whereby the bacteriolysis is ultimately induced.     

Calculations of positron states in BEDT-TTF based organic superconductors

We have calculated positron distributions on a series of BEDT-TTF based organic conductors, whose anion species are I₃, Cu(NCS)₂, Cu(CN)[N(CN)₂], Cu[N(CN)₂]Br and KHg(SCN)₄. The results are discussed in connection with Fermiological studies by the positron annihilation method. Lifetimes and band masses of positrons have been calculated also.     

Effect of surface structure on cell growth prepared by the terminal immobilization method

Substrate effects of surface morphology and chemical structure for cell cultures prepared by molecular terminal immobilization method were studied. When we focused attention on a phenyl group as a functional moiety, the cell growth on the surface prepared by the immobilization method showed a better proliferation rate than that of a substrate prepared by the casting method. Further, from the results of mouse fibroblast L929 cell (L‐cell) growth on poly(amino acid)‐immobilized surfaces in Dulbecco's minimal essential medium containing 10% FBS, it was indicated that the amino group was more effective than the phenyl group, and that a slight difference of chemical structure had a substantial influence on cell growth. In addition, mouse bone marrow–derived Sp2/0‐Ag14 cell (Sp2/0 cell) culture in ASF‐104 serum‐free medium, poly(amino acid)‐immobilized substrates showed an almost equal proliferation rate to that in a serum‐containing medium. These results showed that effective cell growth can occur on immobilized surfaces, and that detection of a weak interaction depends on the functional groups. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3001–3008, 2004     

Production of clean fuels by solvent skimming of coal at around 350 °C

The authors have recently presented a new coal extraction method by which various kinds of coals ranging from brown coals to bituminous coals could be extracted up to 80% of the parent coals in a flowing stream of tetralin or a coal derived oil, carbol oil, under 10 MPa at 350 °C. The extract obtained by this method was almost free from inorganic materials. In this study the effect of solvent recycling on the extraction behavior was examined to make the method practically applicable. The solvent recycling was found to be effective in enhancing the extraction yield and in decreasing further the inorganic fraction in the extract. The extract and residue obtained were characterized through various analyses. To examine how inorganic materials are removed by the extraction, the contents of inorganic elements, including harmful trace elements, in the extract were investigated. It was clarified that the presented method was effective in the removal of most of the inorganic elements including even harmful trace elements from coals, although the degree of removal was dependent on the kind of element.     

Modification of transport properties of ion exchange membranes,XIII. Surface-modified cation exchange membranes prepared from polyamines and a copolymer membrane containing p-stryenesulfonyl chloride

A membrane precursor was prepared by the copolymerization of p-styrenesulfonyl chloride and divinylbenzene in the presence of a poly(vinyl chloride) supported cloth. The surface of the membrane was treated with various amines, and then the sulfonyl chloride groups in the internal part of the membrane were hydrolyzed with an aqueous sodium hydroxide solution in organic methanol or acetone solvent. Hydrolysis conditions were examined for the introduction of the sulfonic acid groups. The membrane modified by ethylenediamine exhibited slightly bipolar properties during the electrodialysis of seawater. Surface-modified membranes using tetraethylenepentamine exhibited excellent monovalent cation permselectivity, low membrane electric resistance, and long performance durability during the electrodialysis of seawater.     

Interfacial energy gradient at a front of an electrochemical wave appearing in CuSn-alloy oscillatory electrodeposition

In the present work, we show that a large interfacial energy gradient is produced at a front of an electrochemical wave appearing in CuSn-alloy oscillatory electrodeposition from an aqueous solution by observing the directional lateral motion of an oil droplet put on an electrode surface. During the oscillation, the surface composition of the electrodeposit changed periodically between Cu-rich and Sn-rich alloys. The transition from the Cu-rich phase to the Sn-rich phase, or vice versa, initiated at a region of the electrode and propagated to the entire surface as an electrochemical wave. Contact angle measurements of the droplet revealed that the electrochemical interfacial energy varies largely between during Cu-rich and Sn-rich alloy electrodeposition. Repetitive approaches of the electrochemical wave front to the droplet drives the directional movement of the droplet, indicating the lateral imbalance of the interfacial energy (i.e., the interfacial tension) at the front is so large that the force produced by the imbalance can transport macroscopic objects such as an oil droplet.     

Preparation of a visible-light-active TiO2 photocatalyst by RF plasma treatment

In order to realize a visible (vis)-light-active TiO₂ photocatalyst, reduction treatment using low-temperature hydrogen plasma with elevated temperatures was applied on anatase TiO₂ powder of ST-01 without causing a phase transition to rutile. According to plasma-heat treatment, oxygen was evacuated from ST-01 particles and the colored ST-01, ivory to beige, was obtained. XPS results showed non-stoichiometric, expressed as TiO_2–x } and x was increased with the increase of treating time. Plasma-heat treated ST-01 showed new ESR signal at g = 2.003 assigned to electrons trapped at the oxygen-defect site. This signal was strengthened when vis-light illumination was applied. Results of vis-light activity tests, evaluated by photocatalytic oxidation of benzoic acid in liquid phase and 2-propanol in gas phase using vis-light illumination (>406 nm), showed excellent activity while low ST-01 showed almost no activity on both tests.     

Changes in year-round air temperature and annual energy consumption in office building areas by urban heat-island countermeasures and energy-saving measures

This paper describes the effects of the installation of various countermeasures against urban heat-island (UHI) and energy-saving measures on UHI and global warming. A UHI and energy-consumption simulation model was developed by combining the one-dimensional meteorological canopy and building energy use models; further, the proposed model was expanded to evaluate the year-round air temperature and annual energy consumption. The simulation results showed that the humidification and albedo increase at building-wall surfaces reduced the total number of hours for which the air temperature was more than 30 °C during the daytime by more than 60 (h) per year. The UHI countermeasures reduced the annual energy-consumption despite causing a small increase during the winter period. However, they may result in certain unfavorable conditions for pedestrians. Energy-saving measures, on the other hand, reduce the total number of hours for which the air temperature is more than 30 °C by only a few hours per year. Thus, we demonstrate the effectiveness of the UHI countermeasures and measures against global warming by extending the calculation period from summer to an entire year.     

Mode I fatigue crack-propagation mechanism based on the renewal stochastic damage-accumulation model

A mechanism of mode I fatigue-crack propagation, which involves the initiation and opening of the cleavage-mode crack, is proposed. This approach uses a renewal stochastic damage-accumulation model for crack propagation, in which the parameters are defined based on the dislocation density and the elastic energy of dislocation. The calculated results of ΔK_eff for da/dn agree with the experimental data. ΔK_eff th is calculated under the condition that the energy of cleavage-crack initiation is equal to that given from the outside of material. The plastic-zone size is calculated based on the number of dislocations on each slip line contained within it.