Acceleration of lipid peroxidation in alpha-tocopherol transfer protein-knockout mice following the consumption of drinking water containing a radical initiator

To assess the antioxidative role of vitamin E (VE) in a mouse model of severe VE deficiency by using biomarkers, alpha-tocopherol transfer protein (alpha-TTP(-/-))-knockout mice were maintained on a VE-deficient diet for 28 weeks [KO group, n = 6]. Wild-type C57BL/6 mice were maintained on a diet containing 0.002% alpha-tocopherol [WT group, n = 6]. The animals were housed individually in a metabolic cage from the age of 9 weeks (Week 0) to 27 weeks. Urine was collected every week, and the levels of total hydroxyoctadecadienoic acid (tHODE), 7-hydroxycholesterol (t7-OHCh), and 8-iso-prostaglandin F(2alpha)(t8-isoPGF(2alpha)), which are biomarkers for lipid peroxidation, were measured by gas chromatography (GC)-mass spectrometry. From the age of 21 weeks (Week 12), three mice in each group were provided drinking water containing the water-soluble radical initiator 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH) until the end of the study (Week 19). Blood and tissue samples were collected, and the levels of the abovementioned biomarkers therein were assessed. AIPH consumption clearly elevated the plasma and erythrocyte levels of tHODE and t8-isoPGF(2alpha) in both the WT and KO groups except for the erythrocyte level of tHODE in the WT group. Furthermore, this elevation was more prominent in the KO group than in the WT group. Interestingly, AIPH consumption reduced the stereoisomer ratio of HODE (ZE/EE), which is reflective of the efficacy of a compound as an antioxidant in vivo; this suggests that free radical-mediated oxidation reduces the antioxidant capacity in vivo. The urine levels of tHODE, t7-OHCh, and t8-isoPGF(2alpha) tended to increase with AIPH consumption, but these individual levels fluctuated. It was clearly demonstrated by the proposed biomarkers that maintaining alpha-TTP(-/-) mice on a VE-deficient diet results in a severe VE deficiency and promotes lipid peroxidation.     

Relative susceptibilities of linoleates and cholesterol to oxidation assessed by total hydroxyoctadecadienoic acid and 7-hydroxycholesterol

We have investigated the relative susceptibilities of cholesterol and linoleates to free radical-mediated oxidation in vitro using model compounds to understand the in vivo observation chemically. It was found that linoleates were preferentially oxidized in the plasma, while cholesterol was concomitantly oxidized with linoleates in the erythrocytes. Importantly, the oxidizability depends on the kinds of solvent, implying that the in vivo oxidation may be in part influenced by the milieu where the substrates exist.     

Grain-Size Dependence of Thermal-Shock Resistance of Yttria-Doped Tetragonal Zirconia Polycrystals

Thermal-shock fracture behavior of yttria-doped tetragonal zirconia polycrystals (Y-TZP) of various grain sizes was evaluated by the quenching method using water as the quenching solvent. The tetragonal-to-monoclinic phase transformation behavior of Y-TZP around cracks introduced by thermal stress was investigated by using Raman microprobe spectroscopy. The critical quenching temperature difference (Δ T _c ) of Y-TZP ceramics increased from 250° to 425°C with increasing grain size of zirconia from 0.4 to 3.0 μm, while the fracture strength decreased from 900 to 680 MPa. The improvement of Δ T _c of Y-TZP with increasing grain size of zirconia corresponded with the quantity of tetragonal-to-monoclinic phase transformation around cracks introduced by thermal stress.     

Electrophoretic and viscometric properties of poly (dicarboxylic acids)

The electrochemical and conformational properties of maleic acid—methyl vinyl ether copolymer, maleic acid—styrene copolymer and poly(itaconic acid) were investigated as functions of pH by means of electrophoresis and viscosity. The electrophoretic mobility and viscosity were measured in the pH range 3–10 by using different buffer solutions at 0.1 ionic strength. The curves of limiting mobility (U_c→0) and intrinsic viscosity ([η]) against pH and the relationship between [η] and U_c→0 were obtained and compared with those of poly(monocarboxylic acid). The U_c→0 and [η] curves were also compared with the potentiometric titration curve of each poly(dicarboxylic acid) obtained in 0.1N NaCl solution. These results are discussed in terms of the dissociation property of each poly(dicarboxylic acid).     

Sintering and Mechanical Properties of Yttria-Doped Tetragonal ZrO2 Polycrystal/Mullite Composites

Yttria-doped tetragonal ZrO₂ polycrystal (Y-TZP)lmullite composites were sintered at 1450° to 1500°C in air to disperse rodlike mullite grains at the grain boundary of Y-TZP and the mechanical and thermal properties were investigated. The aspect ratios of mullite grain were >2. High fracture strength of 1000 MPa and fracture toughness of 12 MPa·m^1/2 were obtained by dispersing <20 vol% of mullite into Y-TZP. The thermal expansion coefficient of Y-TZP/mullite composites decreased with increasing mullite content. The thermal shock resistance of Y-TZP was greatly improved by dispersion of rodlike mullite grains.     

Limit measures of inhomogeneous discrete-time quantum walks in one dimension

We treat three types of measures of the quantum walk (QW) with the spatial perturbation at the origin, which was introduced by Konno (Quantum Inf Proc 9:405, 2010): time averaged limit measure, weak limit measure, and stationary measure. From the first two measures, we see a coexistence of the ballistic and localized behaviors in the walk as a sequential result following (Konno in Quantum Inf Proc 9:405, 2010; Quantum Inf Proc 8:387–399, 2009). We propose a universality class of QWs with respect to weak limit measure. It is shown that typical spatial homogeneous QWs with ballistic spreading belong to the universality class. We find that the walk treated here with one defect also belongs to the class. We mainly consider the walk starting from the origin. However when we remove this restriction, we obtain a stationary measure of the walk. As a consequence, by choosing parameters in the stationary measure, we get the uniform measure as a stationary measure of the Hadamard walk and a time averaged limit measure of the walk with one defect respectively.     

Monitoring x-ray beam damage on lipid films by an integrated Brewster angle microscope/x-ray diffractometer

We describe an integrated Brewster angle microscope (BAM), Langmuir trough, and grazing incidence x-ray diffraction assembly. The integration of these three techniques allows for the direct observation of radiative beam damage to a lipid monolayer at the air-water interface. Although beam damage has been seen in x-ray measurements, it has not been directly observed in situ at the micron scale. Using this integrated assembly, we examined the effects of radiative beam damage on Langmuir monolayers of 1,2-dimyristoyl-sn-glycero-3-[phospho-L-serine] (DMPS), 1:1 DMPS:1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1:1 DMPS:1,2-dioleoyl-sn-glycero-3-phosphocholine held at a constant surface pressure. For constant surface pressure experiments, we observed a marked decrease in the surface area of the film upon exposure to the beam due to photodissociation. For a condensed lipid film, a change in refractive index of the film was observed post-beam-exposure, indicating areas of damage. For DMPS in an oxygenated environment, the Bragg peak intensity decreased with beam exposure. In mixed monolayer systems, with saturated and unsaturated lipids, an increase in the number of small saturated lipid domains was seen as the unsaturated lipid was preferentially damaged and lost from the monolayer. We show that BAM is a highly effective technique for in situ observation of the effects of radiative damage at the air/water interface during a synchrotron experiment.     

Ettringite formation and microstructure of rapid hardening cement

This paper reports the formation and microstructure development of ettringite during hydration of two rapid hardening cements under various handling times. The rapid hardening component of one of these cements is crystalline calcium fluoroaluminate while that of the other is an amorphous calcium aluminate. During hydration, the crystalline fluoroaluminate component forms ettringite from the very beginning. The amount of ettringite increases with time producing needle-shaped crystal of various sizes. The amorphous calcium aluminate component, on the other hand, exhibits an initial induction period after which there is a rapid formation of needle-shaped ettringite crystals of nearly uniform size.     

Small-hole drilling in engineering plastics sheet and its accuracy estimation

In recent manufacturing processes, the small diameter hole drilling process is frequently used owing to its good characteristics. The drilling process can easily be adapted to wide variations in lot size, processing accuracy, processing spot patterns where holes are made, and so on. Many machine elements, which have small diameter holes, are manufactured using engineering plastics of superior material and machining properties. However, it is not easy to drill holes with a diameter smaller than 1 mm, in recent machining technology as well. In this report, 1-mm diameter holes are drilled on two engineering plastics sheets and their drilling accuracy is discussed.