Effect of SMP-500, a novel ACAT inhibitor,on hepatic cholesterol disposition in rats

The effects of SMP-500, a novel ACAT inhibitor, on serum lipid levels, hepatic lipid secretion rate, and hepatic lipid disposition in rats were studied to clarify its lipid-lowering action. SMP-500 reduced the serum cholesterol level in a dose-dependent manner in rats fed a hypercholesterolemic diet. SMP-500 also reduced hepatic free cholesterol content in addition to hepatic total and esterified cholesterol contents. Biliary concentrations of cholesterol and bile acid were increased by SMP-500; however, the bile flow and lithogenic index were not affected. SMP-500 increased cholesterol 7α-hydroxylase mRNA level. Therefore, it is suggested that the increase in concentrations of cholesterol and bile acid in bile is due to both the increase of bile acid production through the increase of cholesterol 7α-hydroxylase and the decrease of hepatic free cholesterol content. An inhibitory effect of SMP-500 both on the cholesterol secretion and on the TG secretion from liver was observed. SMP-500 reduced the serum TG level in sucrose-fed rats. From these results, one may hypothesize that the suppression of hepatic VLDL secretion probably plays an important role on both cholesterol- and TG-lowering effects of SMP-500.     

Structural investigation of microbial poly(ε-L-lysine) derivatives with azo dyes by solid-state 13C and 15 N NMR

Summary Solid-state high-resolution ¹³C and ¹⁵N NMR spectra of microbial poly(-lysine) (-PL) derivatives with azo dyes have been measured. Chemically modified derivatives of -PL, -PL/MO and -PL/DC were prepared through reactions with methyl orange (MO) and dabsyl chloride (DC), respectively. Side chain -amino groups of -PL in -PL/MO are involved in ionic bonds with methyl orange to form poly-ion complexes, (-PL)-NH₃⁺SO₃^--(MO). On the other hand, -PL is allowed to react with dabsyl chloride in -PL/DC to form covalent sulfonamide bonds, (-PL)-NH-SO₂-(DC). These chemically modified -PLs exhibit ¹⁵N NMR signals characteristic of the binding mode at the -amino groups. The spectral analysis reveals that the -PL/DC sample contains a small amount of ion complexes with MO. It has been shown that ¹⁵N solid-state NMR is a useful tool for structural determination of -PL and its derivatives.     

Solid Solubility of Aluminum in O'-SiAlON

Energy -dispersive X-ray spectroscopy(EDXS) analysis was used to investigate the solid solubility of aluminum ( X value) in O -SiAlONs (Si_2-xAl_xO_1+xN_2-x)using transmission electron microscopy in the scanning transmission electron microscopy mode. Lattice parameter a of the O -SiAlONs increased with increased X value =0.16. The X value of 0.16 was the maximum of the X value in SiAlONs precipitated from a Si-Al O-N melt which was sasturated with aluminum and nitrogen at 1700^oC.The X value of O -SiAlONs measured by EDXS were smaller than those calculated on the assumption that the Si₂N₂O structure accommodated the total amount of the doped Al₂O₃ . This result suggested that a considerable amount of Al₂O₃ remained in grain boundaries as secondary phases.     

Design of polymer membrane with permselectivity for water–ethanol mixture. II. Preparation of crosslinked poly(methyl acrylate) membrane with diethylene triamine and its permselectivity

In order to permeate water from a water–ethanol mixture by pervaporation on the basis of the difference in solubility between two components toward a polymer membrane, polymer membrane having polar group, poly(methyl acrylate) (PMA) membrane crosslinked with diethylene triamine (DETA) was prepared. The permselectivity of the membrane was investigated with attention to the feed composition of water–ethanol mixture and the effect of introduction of DETA into the membrane. It is found that water was permeated through PMA–DETA crosslinked membrane preferentially in all ranges of feed composition, the highest permselectivity being observed at 25% ethanol aqueous solution. Moreover, the pervaporation rate of water was found to depend on the ratio of DETA introduction into the membrane. When the ratio of introduction into the membrane was 0.144, water was permeated through the membrane from 25% ethanol aqueous solution at a rate of 1.26 × 10^?1 g m/m² h. These results can be explained by high diffusivity of the membrane due to the low glass transition temperature of PMA and permeation of water through polar DETA moiety in the membrane.     

Synthesis and properties of novel fluoroalkyl end‐capped oligomers containing silsesquioxane segments

Fluoroalkyl end‐capped homo‐ and co‐ oligomers containing silsesquioxane segments were prepared by the reactions of fluoroalkanoyl peroxides with the corresponding methacrylate monomer‐bearing silsesquioxane unit (Si‐MMA) and comonomers such as N,N‐dimethylacrylamide (DMAA) and acrylic acid (ACA). These new fluorinated Si‐MMA oligomers were easily soluble in various organic solvents and were able to reduce the surface tension of m‐xylene effectively. The modified poly(methyl methacrylate) [PMMA] and glass surface treated with fluorinated Si‐MMA homo‐oligomers exhibited a strong oleophobicity, although these fluorinated oligomers possess high oleophilic silsesquioxane segments. In contrast, the modified PMMA surface treated with fluorinated Si‐MMA–DMAA cooligomers exhibited a good hydrophilicity with a strong oleophobicity. In a series of fluorinated Si‐MMA oligomers, fluorinated Si‐MMA homo‐oligomers had a relatively high thermal stability. Therefore, these fluoroalkyl end‐capped Si‐MMA oligomers are suggested to have high potential for new functional materials through their unique properties such as a high solubility and surface active properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3486–3493, 2002     

Electrical breakdown and nanogap formation of indium oxide core/shell heterostructure nanowires

We report the electrical breakdown behavior and subsequent nanogap formation of In(2)O(3)/InO(x) core/shell heterostructure nanowires with substrate-supported and suspended structures. The radial heterostructure nanowires, composed of crystalline In(2)O(3) cores and amorphous In-rich shells, are grown by chemical vapor deposition. As the nanowires broke down, they exhibited two distinct current drops in the current-voltage characteristics. The tips of the broken nanowires were found to have a cone or a volcano shape depending on the width of the nanowire. The shape, the size, and the position of the nanogap depend strongly on the device structure and the nanowire dimensions. The substrate-supported and the suspended devices exhibit distinct breakdown behavior which can be explained by the diffusive thermal transport model. The breakdown temperature of the nanowire is estimated to be about 450?K, close to the melting temperature of indium. We demonstrated the usefulness of this technique by successful fabrication of working pentacene field-effect transistors.     

Evaluation of molecular orientation and alignment of poly(3-hexylthiophene) on Au (111) and on poly(4-vinylphenol) surfaces

The orientation and alignment of regioregular poly(3-hexylthiophene) (P3HT) molecules on Au (111) surface and on poly(4-vinylphenol) (PVP) thin film were investigated. The P3HT molecules on the smooth Au (111) are oriented with both the backbones and the side chains parallel to the substrate (plane-on orientation) as revealed by the scanning tunneling microscope (STM) images. However, the P3HT molecules on the PVP thin films are preferably oriented with side chains perpendicular to the surface (edge-on orientation). Surface modification of the PVP by hexamethyldisilazane (HMDS) can increase the crystalline size in the P3HT semicrystalline films. The performance of an all-polymer organic field-effect transistor (OFET) with the drop-cast P3HT semiconductor layer and the crosslinked PVP gate insulator on poly(ethylene naphthalate) (PEN) substrate was evaluated.     

Double Elimination Protocol for Convenient Synthesis of Dihalodiphenylacetylenes: Versatile Building Blocks for Tailor‐Made Phenylene‐Ethynylenes

Dihalodiphenylacetylenes are conveniently synthesized by a double elimination reaction of β‐substituted sulfones which are readily obtained from halogen‐substituted benzyl sulfone and benzaldehyde derivatives. Halogens can be incorporated at any desired positions in the diphenylacetylene skeleton simply by choosing the substitution position of the halogen on the aromatic rings of the starting compounds. The diphenylacetylenes with different halogen substituents thus obtained undergo sequential carbon‐carbon bond formations due to the different reactivities of the halogens. Thus, various moieties can be incorporated on the diphenylacetylene skeleton at whichever positions so that a variety of tailor‐made phenylene‐ethynylenes with regulated structure and composition could be designed.     

Cathode contact optimization and performance evaluation of intermediate temperature-operating solid oxide fuel cell stacks based on anode-supported planar cells with LaNi0.6Fe0.4O3 cathode

This paper reports the development of intermediate temperature-operating solid oxide fuel cell stacks using anode-supported planar cells with LaNi_0.6Fe_0.4O₃ (LNF)cathode. We developed metallic separators with radial gas flow channels and an anode seal structure. To achieve good power-generating characteristics, we propose two cathode contact methods. According to a performance evaluation at 800 °C, power density of 0.5 W cm⁻² is obtained at the current density of 1.0 A cm⁻² when operating with a sufficient fuel amount, and power conversion efficiency of over 50% LHV is obtained at the current density of more than 0.2 A cm⁻² when operating at a high fuel utilization rate.