Stimulative effect of high-level hypergravity on differentiated functions of osteoblast-like cells

The exposure of freshly isolated osteoblasts and osteoblast-like cells to high-level hypergravity caused the inhibition of cell growth, elevation of cAMP content, and the stimulation of differentiated functions such as alkaline phosphatase activity, collagen synthesis, and osteocalcin synthesis. Blockage of elevation of cAMP by SQ22536, an inhibitor of adenylate cyclase, resulted in the inhibition of the hypergravity-stimulated alkaline phosphatase activity, indicating that cAMP is the intracellular mediator of this action of hypergravity. H89, an inhibitor of cAMP-dependent protein kinase (PKA), further inhibited the cell growth that was already inhibited by the hypergravity, and further stimulated the alkaline phosphatase activity that was already stimulated by hypergravity. If cAMP acts through the PKA system, H89 should have blocked the changes in cell function effected by the exposure to hypergravity. Therefore the elevated intracellular cAMP by the exposure of hypergravity caused the changes in cell function by a PKA-independent pathway.     

Palladium on Carbon‐Catalyzed Aqueous Transformation of Primary Alcohols to Carboxylic Acids Based on Dehydrogenation under Mildly Reduced Pressure

The catalytic dehydrogenation of alcohols to carbonyl products is a green sustainable oxidation with no production of waste except for hydrogen, which can be an energy source. Additionally, a reusable heterogeneous catalyst is valuable from the viewpoint of process chemistry and water is a green solvent. We have accomplished the palladium on carbon (Pd/C)‐catalyzed dehydrogenation of primary alcohols to carboxylic acids in water under a mildly reduced pressure (800 hPa). The reduced pressure can be easily controlled by the vacuum controller of the rotary evaporator to remove the excess of generated hydrogen, which causes the reduction (reverse reaction) of aldehydes to alcohols (starting materials) and other undesirable side reactions. The present method is applicable to the reaction of various aliphatic and benzylic alcohols to the corresponding carboxylic acids, and the Pd/C could be reused at least 5 times.

     

PID controller optimization for H∞ control by linear programming

The constraints on the PID gains, which are derived from the H_∞ norm performance index by discretization of the frequency, are convex or concave depending on frequencies. This problem is a non‐convex problem, and a new method of approximating these constraints as adequate linear inequalities is proposed. Then, the optimal solution can be efficiently and successfully searched for by applying linear programming iteratively. This method is compared with methods based on barrier function and linear matrix inequality. Copyright © 2000 John Wiley & Sons, Ltd.     

HAM1, the gene controlling 6-N-hydroxylaminopurine sensitivity and mutagenesis in the yeast Saccharomyces cerevisiae

The ham1 mutant of yeast Saccharomyces cerevisiae is sensitive to the mutagenic and lethal effects of the base analog, 6-N-hydroxylaminopurine (HAP). We have isolated a clone from a centromere-plasmid-based genomic library complementing HAP sensitivity of the ham1 strain. After subcloning, a 3·4 kb functional fragment was sequenced. It contained three open reading frames (ORFs) corresponding to proteins 353, 197 and 184 amino acids long. LEU2⁺ disruptions of the promoter and N-terminal part of the gene coding 197 amino acids long protein led to moderate and strong sensitivity to HAP, respectively, and were allelic to the original ham1-1 mutation. Thus this ORF represents the HAM1 gene. The deduced amino acid sequence of HAM1 protein was not similar to any protein sequence of the SwissProt database. The HAM1 gene was localized on the right arm of chromosome X between cdc8 and cdc11. Spontaneous mutagenesis was not affected by the ham1::LEU2 disruption mutation.     

Intercalation of Diphenyl Sulfide into Nanogalleries and Preparation of Poly(p‐phenylenesulfide)‐Based Nanocomposites

Summary: For the reference system of PPS‐based nanocomposites, we investigated the intercalation behavior of DFS molecules into nano galleries based on OMLFs consisting of different types of intercalants and nanofillers with different surface charge densities. The smaller initial interlayer opening led to the larger interlayer expansion, regardless of the miscibility between the intercalant and DFS. We examined the preparation of PPS‐based nanocomposites with and/or without shear processing at 300 °C. The finer dispersion of OMLFs in the nanocomposite was observed when using OMLF having small initial interlayer opening. The delamination of the stacked nanofillers was governed by the initial interlayer opening, whereas the uniform dispersion of the nanofillers was affected by the shear.

Plot of initial interlayer opening versus Δ opening for various OMLFs intercalated with DFS.     

Influence of the pre-reformer in steam reforming of dodecane using a Pd alloy membrane reactor

Dodecane, one of the main components in kerosene, was used as a model material to investigate reactions in a palladium membrane reactor for steam reforming of kerosene. The influence of pre-reforming on the performance of the membrane reactor was investigated. A decrease in hydrogen yield caused by coke formation was suppressed through pre-reforming by lowering the concentration of olefins, aromatics and unreacted dodecane in the feed to the membrane reactor. In addition, the proportion of total hydrogen production that permeated the membrane was clearly higher with pre-reforming compared with that without pre-reforming. Pre-reforming prevented deactivation of both the catalyst and the membrane, resulting in efficient separation of hydrogen from the reaction field and therefore achieving a higher hydrogen yield.     

Studies on the radical polymerization of vinyl acetate in benzene,chlorobenzene and ethyl acetate by 1H NMR spectroscopy

Summary Polymerizations of vinyl acetate were carried out with AIBN in benzene, chlorobenzene and ethyl acetate, and the resultant polymers were analyzed for terminal group by using ¹H NMR technique. The results revealed that a part of the polymer molecules prepared in aromatic solvent contained one solvent fragment at the chain end, indicating the incorporation of aromatic molecule through the chain transfer reaction and not by the copolymerization. It was found that there existed at least 0.7 branching per a molecule in the polymer prepared in ethyl acetate, whereas almost no branching in the polymer prepared in aromatic solvents.     

EXAFS and XANES studies of americium dioxide with fluorite structure

EXAFS and XANES analyses were applied in a study of americium dioxide (AmO₂) with fluorite structure. EXAFS result for Am-L_III absorption edge of AmO₂ was in good agreement with the long-ranged structural data from X-ray diffraction analysis. In order to characterize XANES in aspect of the electronic structure, the theoretical assignment for the AmO₂ was performed with the relativistic DV-Xα molecular orbital method. The calculated XANES spectrum well reproduced the experimental spectrum. From this theoretical assignment, it was found that the peaks of the XANES spectrum were created due to the specific hybridization of orbital components.