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991.
Yuichiro Shoji Akira Yagi Masahiro Horiuchi Masakazu Morimoto Masahiro Irie 《Israel journal of chemistry》2013,53(5):303-311
Photochromic diarylethene derivatives bearing hydrophilic N,N-bis(2-(2-(2-methoxyethoxy)ethoxy)ethyl)sulfonamide (SO2NTEG2) ( 1 – 3 ) or myo-inositol ( 4 – 6 ) substituents were synthesized. Although the solubility in aqueous solution of the derivatives containing the four tri(ethylene glycol) chains was relatively poor, the solubility was improved by introducing two myo-inositol residues. The derivatives could be dissolved even in pure water and underwent photochromism upon alternate irradiation with ultraviolet (UV) and visible light, in both organic and aqueous solutions. The absorption maxima of the open- and closed-ring isomers of these derivatives and the photostationary conversion ratios from the open- to the closed-ring isomers upon UV irradiation did not change much, even when the solvent polarity was changed. These results indicate that the diarylethene derivatives are mono-molecularly dissolved in aqueous solution and that intermolecular interactions between the derivatives are negligible when the concentration is less than 1×10−4 mol⋅L−1. 相似文献
992.
Makoto Kondo Yoshiaki Hirano Masahiro Nishio Yutaka Furuya Hiromichi Nakamura Tsuyoshi Watanabe 《Journal of food science》2013,78(12):H1935-H1939
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. 相似文献
993.
Stability tests of two quadrupole mass spectrometers (QMSs) were performed using a two-stage flow-dividing system from the following viewpoints: (1) fluctuation and drift of ion current, (2) repeatability of ion current, (3) change in ion current owing to prior conditions of use, (4) long-term stability of sensitivity, and (5) interference effect. These tests were performed at the pressure from 8 × 10−6 Pa to 8 × 10−4 Pa using N2, Ar, He, and H2.The fluctuation and drift of two QMSs over 1 h were within 2%. The repeatabilities at pressures of 8 × 10−6 Pa and 8 × 10−5 Pa were within 2% during eight cycles with an interval of 1 h between each cycle. However, the repeatability at 8 × 10−4 Pa increased to be within 4%. The changes in sensitivities of QMS-1 and QMS-2 for 757 days were less than ±15% and less than ±25%, respectively. The change owing to the interference effect was less than 2% while the partial pressure of the interference gas was under 2 × 10−4 Pa. However, both positive and negative changes were observed less than 60% with increasing the partial pressure of the interference gas until 8 × 10−3 Pa. 相似文献
994.
Amorn Chaiyasat Masahiro Yamada Hiroshi Kobayashi Toyoko Suzuki Masayoshi Okubo 《Polymer》2008,49(13-14):3042-3047
Emulsion copolymerizations of styrene and methacrylic acid with polyoxyethylene nonylphenyl ether nonionic emulsifiers having various hydrophilic–lipophilic balance (HLB) values (13.7, Emulgen 911; 15.5, Emulgen 920; 17.2, Emulgen 931) were performed. The incorporation behavior of the nonionic emulsifiers, comprising polydisperse poly(ethylene oxide) (PEO) chain lengths, inside the particles was investigated. At the completion of the polymerization, the incorporated percentage of the lowest HLB emulsifier was 61%, much higher than that of the highest HLB one (10%). In both polymerizations, the amounts of the incorporated emulsifiers increased with conversion, and shorter PEO chain (i.e., lower molecular weight) components were predominantly incorporated over longer PEO chain components. 相似文献
995.
Masahiro Maeda Kotaro Kushiyama 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2005,20(2):1
In Tokyo Metropolis, the rehabilitation and renewal of sewer systems is an urgent issue due to the aged sewers and increases in wastewater and stormwater runoff. In such urban area, shield tunneling confronts various problems, such as high construction costs, adverse effects on living environments, and densely used surface and underground spaces. To solve these problems, the authors developed a new shield tunneling method, which is called the “compact shield” method. This paper describes the concepts used for the construction of shield sewer tunnels without inner linings and an overview of the segments and a shield machine that were newly developed. 相似文献
996.
Polybenzoxazine-polydimethylsiloxane (PBa-PDMS) hybrids were successfully prepared in situ by the ring-opening polymerization of benzoxazine (Ba) and the sol-gel process of diethoxydimethylsilane (DEDMS). The reaction conditions were optimized, and homogeneous opaque hybrid films were obtained up to 13 wt% of PDMS content by using p-toluenesulfonic acid as the catalyst for sol-gel process. The domain size of PDMS in the PBa matrix was examined by SEM. The tensile strength and elongation at break of the PBa-PDMS hybrid films were higher than those of pristine PBa, because of the toughening effect of PDMS. Dynamic viscoelastic analysis showed that the glass transition temperature of the hybrid was also higher than that of pristine PBa. Moreover, the decomposition temperatures and weight residue at 850 °C increased with the increase of PDMS content as evidenced by thermogravimetric analysis. 相似文献
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1000.
Naoki Takada Norio Mamba Takuya Eriguchi Yasuyuki Kudo Yoshihiro Kotani Masahiro Maki Hideo Satou Shouji Nagao Shinichi Iwasaki Shinya Hashimoto Kenichi Akiyama Tsutomu Furuhashi 《Journal of the Society for Information Display》2010,18(5):351-356
Abstract— High‐resolution displays are now needed for mobile equipment, not only for cell phones but for other devices such as ultra‐mobile PCs (UMPCs) and mobile Internet protocol televisions (IPTVs). A new low‐cost and low‐power driving method for high‐resolution in‐plane‐switching (IPS) liquid‐crystal displays (LCDs) on a low‐temperature polycrystalline‐silicon (LTPS) thin‐film‐transistor (TFT) platform has been developed. Because this method drives common electrodes separated by each line, it can reduce inversion frequency, unlike “dot‐inversion” or “column‐inversion” methods. On the other hand, it was found that horizontal smear is an obstacle to achieve this method. To solve this problem, techniques to optimize the timing of RGB time‐sharing are proposed. A 5‐in. WXGA (1366 × 768) prototype using the new driving method was fabricated, and it was found that the horizontal smear is less than ±1% of the luminance and that the power consumption of the display discharge and charge is 0.245 W. 相似文献