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.     

Microstructure and Faraday effect of Tb2O3-Al2O3-SiO2-B2O3 glasses for fiber-based magneto-optical applications

For the fiber-based magneto-optical (MO) devices, like Faraday optical isolator, the target MO glasses are supposed to strike a balance among the following properties: high Verdet constant, chemical and physical stabilities, compatibility with the fiber drawing process, and the connectivity to the silica glass fiber networks. In this work, we report on the MO application of Tb₂O₃-Al₂O₃-SiO₂-B₂O₃ (TASB) glasses as a derivative of the yttrium aluminum silicate (YAS) glass fiber systems which have been intensively studied for their huge potential in the context of all-fiber lasers. We found that MO properties of the obtained TASB glasses vary systematically with the B₂O₃ contents. The effects of B₂O₃ on the local glass structures and the valence state of Tb ions were clarified via nuclear magnetic resonance, electron spin resonance, X-ray photoemission spectroscopy, and Raman spectroscopy. B₂O₃ content in TASB glasses leads to a certain degree of depolymerization in glass network and most of Tb⁴⁺ ions from the raw material of Tb₄O₇ are reduced to Tb³⁺ ions even in air, resulting in an improved MO properties. Due to the relatively high Verdet constant (∼70 rad/T/m) and suitable rheology of the glass melt speculated from the thermal analysis, TASB glass system in this work is adaptable to stable fiber-based Faraday effect devices.     

ON OPTIMAL LOCAL BUFFER ALLOCATION IN FLEXIBLE MANUFACTURING SYSTEMS

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Ferroelectric Sr3Zr2O7: Competition between Hybrid Improper Ferroelectric and Antiferroelectric Mechanisms

In contrast to polar cation displacements driving oxides into noncentrosymmetric and ferroelectric states, inversion‐preserving anion displacements, such as rotations or tilts of oxygen octahedra about cation coordination centers, are exceedingly common. More than one nonpolar rotational mode in layered perovskites can lift inversion symmetry and combine to induce an electric polarization through a hybrid improper ferroelectric (HIF) mechanism. This form of ferroelectricity expands the compositional palette to new ferroelectric oxides because its activity derives from geometric rather than electronic origins. Here, the new Ruddlesden–Popper HIF Sr₃Zr₂O₇, which is the first ternary lead‐free zirconate ferroelectric, is reported and room‐temperature polarization switching is demonstrated. This compound undergoes a first‐order ferroelectric‐to‐paraelectric transition, involving an unusual change in the “sense” of octahedral rotation while the octahedral tilt remains unchanged. Our experimental and first‐principles study shows that the paraelectric polymorph competes with the polar phase and emerges from a trilinear coupling of rotation and tilt modes interacting with an antipolar mode. This form of hybrid improper “antiferroelectricity” is recently predicted theoretically but has remained undetected. This work establishes the importance of understanding anharmonic interactions among lattice degrees of freedom, which is important for the discovery of new ferroelectrics and likely to influence the design of next‐generation thermoelectrics.     

Preparation of Novel Fluoroalkyl End‐Capped Oligomer/Hydroxyapatite Nanocomposites

Novel fluoroalkyl end‐capped oligomer/hydroxyapatite nanocomposites have been easily prepared by the reaction of disodium hydrogenphosphate and calcium chloride in the presence of self‐assembled molecular aggregates formed by fluoroalkyl end‐capped oligomers in aqueous media. The fluorinated hydroxyapatite nanocomposites thus obtained were found to exhibit a good dispersibility in a variety of media, and were applied to the surface modification of glass.

     

Coal liquefaction using iron complexes as catalysts

Hydroliquefaction of Japanese Miike and Taiheiyo coals was carried out using various iron complexes as catalysts in tetralin at 375–445 °C. Iron pentacarbonyl (Fe(CO)₅) showed the highest catalytic activity, increasing coal conversion by about 10% at 425 °C under an initial hydrogen pressure of 5 MPa. Amounts of hydrogen transferred to coal increased from 1.4–2.3 wt% of daf coal in the absence of the catalyst to 2.5–4.2 wt% of daf coal in the presence of Fe(CO)₅ at 425 °C.     

Strong Spin‐Lattice Coupling Through Oxygen Octahedral Rotation in Divalent Europium Perovskites

First‐principles calculations reveal that in divalent europium perovskites EuMO₃ (M = Ti, Zr, and Hf), antiferromagnetic superexchange interactions via nd states of the B‐site M cations (n = 3, 4, and 5, respectively) are enhanced by rotations of the MO₆ octahedra. The octahedral rotations involved in a structural change from cubic $ Pm{\bar 3}m $ to orthorhombic Pbnm structures not only reduce energy gaps between the Eu 4f and M nd bands but also point the M nd orbitals at the Eu sites, leading to a significant overlap between the M nd and Eu 4f orbitals. These results reveal that the octahedral rotations are indispensable for antiferromagnetic ordering observed for EuZrO₃ and EuHfO₃, and put these perovskites into a class of materials exhibiting a novel type of strong coupling between their magnetism and octahedral rotations.     

Site Investigations for Involvement of Water Films in Lateral Flow in Liquefied Ground

Previous research indicates that if layered sand deposits are liquefied during earthquakes, water films are likely to develop beneath less permeable sublayers and lead to the destabilization of sloping ground. In Niigata City, large lateral flow displacements were reported in almost flat areas during the 1964 Niigata earthquake. The involvement of water films in lateral flow failure during the earthquake is examined in this research based on site investigation data. Soil profiles in the investigated areas estimated from many borehole logs indicate that continuous or partially continuous sublayers of fine soil that cap liquefiable loose sand exist. Elevation contours of 0.1 m increments are drawn based on an in situ leveling survey and local maps. The ground slopes obtained are found to be closely related to flow displacements evaluated in previous research, indicating that a gentle slope of less than 1% results in displacement of several meters. This strongly suggests that water films with literally no shear resistance formed beneath fine soil sublayers were highly responsible for the large lateral flow displacements in these areas during the Niigata earthquake.     

Carrier-state infection of feline T-lymphoblastoid cells with feline calicivirus

The susceptibility of feline T lymphocytes to feline calicivirus (FCV) in vitro was investigated using feline T-lymphoblastoid cell lines, namely MYA-1 and FL74 cells. The virus titers of supernatants in FCV-infected MYA-1 and FL74 cell cultures increased rapidly, and FCV antigens were also detected in the FCV-infected cells. There were slight differences in the molecular weights of capsid proteins expressed in FCV-infected MYA-1, FL74 and Crandell feline kidney cells. MYA-1 and FL74 cells were productively and persistently infected with FCV, and FCV antigens were observed in the FCV-infected cells for more than one month. At 3 months post infection, FCV-infected FL74 cells that stopped producing infectious FCV could be reinfected with FCV. However, no cytopathic effects were observed.     

Synthesis and properties of novel perfluorocyclohexylated compounds with bis(perfluorocyclohexane carbonyl) peroxide

Bis(perfluorocyclohexane carbonyl) peroxide was prepared by the reaction of the corresponding acyl fluoride and hydrogen peroxide. This peroxide was applied to the preparation of perfluorocyclohexylated end‐capped oligomers via a radical process under very mild conditions. In cyclic perfluorocyclohexylated end‐capped oligomers containing hydroxy segments, these oligomers could cause a gelation in water and in polar organic solvents such as MeOH, EtOH, dimethylformamide (DMF), and dimethylsulfoxide (DMSO), and the gelling ability of these oligomers was superior to that of the corresponding linear perfluorooxaalkylated oligomers. Furthermore, perfluroocyclohexylation of polystyrene or benzene was proceeded via a single electron transfer reaction by using this peroxide. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1101–1108, 1999