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The antioxidant ability of capsanthin and the fatty acid esters was examined by measuring the free radical-oxidation of methyl linoleate. To assess radical scavenging effect, the production of methyl linoleate hydroperoxides and the decomposition of capsanthins in reaction solution were measured by HPLC. Capsanthin suppressed hydroperoxide formation as well as β-carotene, lutein, and zeaxanthin. Interestingly, capsanthin decomposed more slowly than the other carotenoids, and the radical scavenging effect of capsanthin was found to last longer. Also, the capsanthin esterified partially and/or totally with fatty acids (mono- and/or diesterified capsanthin), isolated from paprika color, suppressed oxidation of methyl linoleate in a similar manner as nonesterified capsanthin. This finding suggests that the radical scavenging ability of capsanthin was not influenced by esterification, that is, the ability would contribute to the polyene chain, especially conjugated keto group. It was first found that esterified (monoesterified and diesterified) capsanthins also were good radical scavengers. Keywords: Capsanthin; esterified capsanthin; esterification; antioxidant activity; radical scavenging ability

Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut (11¯02) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazing-incidence X-ray diffraction uncovered an in-plane texture in which WSe2 [101¯0] preferentially aligned with Al2O3 [112¯0]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy.

Rooibos is rich in flavonoids such as aspalathin, which is a unique C-glycosyl dihydrochalcone, that is used as a traditional herbal tea. This study was designed to evaluate the in vitro xanthine oxidase (XOD) inhibitory activity of the aspalathin-rich fraction (ARF) and purified aspalathin from rooibos. The hypouricemic effects of the ARF and aspalathin on hyperuricemic mice were also assessed. The ARF was prepared from aqueous extract of unfermented rooibos leaves and stems, and it was collected by column chromatography; the aspalathin content in this fraction was 21.4%. The ARF and aspalathin inhibited XOD in a dose-dependent manner. The concentrations of the ARF and aspalathin required to inhibit XOD at 50% (IC50 ) were 20.4 μg/mL (4.4 μg/mL aspalathin equivalents) and 4.5 μg/mL, respectively. Lineweaver-Burk plot analysis indicated that aspalathin was a competitive inhibitor of XOD, and the inhibition constant (Ki) was 3.1 μM. In hyperuricemic mice induced by inosine-5'-monophosphate, treatment with the ARF and aspalathin significantly suppressed the increased plasma uric acid level in a dose-dependent manner. The suppressed plasma uric acid level in mice could be attributed to the XOD inhibitory activity of the ARF and aspalathin. Further study is required to determine the effect of aspalathin or its metabolites on XOD activity in vivo.

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When a momentary pressure pulsation takes place in a turbine, and its frequency coincides with the natural frequency of a steel penstock, resonance occurs resulting in noticeable vibration. While the current tendency is to increase the rotation frequency of turbines, penstock plates are gradually becoming thinner. As a result of these trends, the occurrence of oval vibration has been reported at some hydraulic power stations. Since rules on vibration prevention do not always include oval vibration, we sought out detailed information on existing penstocks constructed within the last 30 years. Based on this information and a numerical study, formulae to calculate the natural frequencies of steel penstocks including those with circumferential stiffeners were proposed.

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We have successfully developed (00·1) AlN film with atomically flat surface on (00·1) sapphire substrate using metalorganic chemical vapor deposition (MO-CVD) method. The atomically flat surface of less than Ra=2Å, Ra means mean roughness measured by atomic force microscope(AF M), within the thickness of 1.7µm has been achieved, whose conditions are high substrate temperature of 1200 o C, low pressure of 30Torr, low V-III ratio of 500 and the numerous flow rate of trimethylaluminum (TMA)-back-up H 2 gas of 5.0slm. The temperature-coefficient-of-delay (TCD) of the fabricated surface-acoustic-wave (SAW) device on (00·1)AlN/ (00·1)Al 2 O 3 combination with atomically flat surface are found to be 44.5ppm/ o C at kH=2.25 and 28.5ppm/ o C at kH=3.32, where kH is the normalized thickness by wave number, k is wave number and H is AlN film thickness . These measured TCD are agreed with simulated curve.AlN/Al 2 O 3 combination with atomically flat surface has a potential for zero-TCD at kH=4.5. 0-7803-7582-3/02/$17.00 (c) 2002 IEEE 2002 IEEE ULTRASONICS SYMPOSIUM-135