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41.
Enhanced Light Storage of SrAl2O4 Glass‐Ceramics Controlled by Selective Europium Reduction 下载免费PDF全文
Takayuki Nakanishi Kazune Watanabe Jumpei Ueda Koji Fushimi Setsuhisa Tanabe Yasuchika Hasegawa 《Journal of the American Ceramic Society》2015,98(2):423-429
A luminescent Eu, Dy: SrAl2O4 glass‐ceramics with high transparency in the visible region was successfully synthesized using the frozen sorbet technique with the control of O2 partial pressure () for the oxidation of Eu2+ ions. The glass‐ceramics include Eu2+, Eu3+, and Dy3+ ions, and thus exhibits three characteristic types of emission bands, 4f–5d at around 520 nm (Eu2+ ions), 4f–4f at 610 nm (Eu3+ ions), and 480 nm (Dy3+ ions). The Eu, Dy: SrAl2O4 glass‐ceramics provide remarkable long‐persistent luminescence under dark condition. The glass‐ceramics also exhibits color‐changing luminescence in the visible region based on their remarkable light storage properties. The luminescent Eu, Dy: SrAl2O4 glass‐ceramics using the frozen sorbet technique with control of are promising materials for application in novel photonic and light storage materials. 相似文献
42.
Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate
Norishi Ueda 《International journal of molecular sciences》2015,16(3):5076-5124
Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. 相似文献
43.
Tohru Sekino Toshio Nakajima Satoru Ueda Koichi Niihara 《Journal of the American Ceramic Society》1997,80(5):1139-1148
High-density nickel–dispersed-alumina (Al2 O3 /nickel) composites with superior mechanical properties were obtained by the hydrogen reduction and the hot pressing of alumina–nickel oxide (Al2 O3 /NiO) mixed powders. The mixtures were prepared by using NiO or nickel nitrate (Ni(NO3 )2 · n H2 O) as a dispersion source of nickel metal. Microstructural investigations of the composite fabricated using nitrate powder revealed that fine nickel particles, } 100 nm in diameter, dispersed homogeneously at the matrix grain boundaries, forming the intergranular nanocomposite. High strength (.1 GPa) and high-temperature hardness were registered for the composite that contained a small amount of nickel dispersion. The ferromagnetic properties of nickel, such as high coercive force, were observed, because of the fine magnetic dispersions, which indicates a functional value of structural composites. 相似文献
44.
In Part 1 of this paper, different fastness formulae for change in colour were compared. In the present report, the same methodology was used to compare different staining formulae. A set of experimental results was used to test the performance of various staining formulae. The constant grade contours for each formula were also calculated. Their patterns were compared and their differences were identified. 相似文献
45.
Tomoya Higashihara Cenyao Zhang Akimitsu Tsukuda Takashi Ochi Mitsuru Ueda 《应用聚合物科学杂志》2012,124(5):4398-4402
The direct polycondensation of isophthalic acid with a mixture of 1,3‐phenylenediamine (m‐PDA) and 3,4′‐diaminodiphenyl ether (3,4′‐ODA) could be successfully performed in the bulk to afford the expected co‐aramids for the first time. The co‐aramids with low molecular weights and 3,4′‐ODA contents higher than 50 mol% display excellent thermoplasticity and melt‐drawing property. Indeed, several meters long filaments with 12 μm diameter could be produced. In addition, the environmentally friendly method for the preparation of aramid materials as well as the demonstration of their filament formation will open up the new possibility to prepare aramid fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
46.
The development of natural adhesives derived from nonfossil resources is very important for the future. Besides, it is desirable to be safe adhesives without using harmful chemical substances. In this study, application of citric acid as a natural adhesive was investigated. Citric acid powder and bark powder obtained from Acacia mangium were used as raw materials. Citric acid powder was mixed with the bark powder, and the resulting powder mixture was poured into a metal mold. The mold was hot‐pressed at 180°C and 4 MPa for 10 min, and a bark molding was then obtained. The specific modulus of rupture and modulus of elasticity values of the molding containing 20 wt % citric acid were 18.1 MPa and 4.9 GPa, respectively. The molding did not decompose during a repeated boiling treatment. To clarify the effect of tannin on the adhesiveness of molding, bark was separated into tannin and residue. The molding was not obtained while using the tannin due to the marked fluidity, whereas it was obtained while using the residue, the same as while using the bark. It was considered that components other than tannin contributed to the adhesiveness. Based on the results of Fourier transform infrared spectra, the formation of ester linkages between carboxyl groups derived from citric acid and hydroxyl groups in the bark was confirmed. Accordingly, citric acid brought an adhesion by chemical bonding, and it could be used as a safe natural adhesive. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
47.
Keisuke Yoshida Kenji Mishiro Yoshihiro Ueda Takashi Shigeta Takumi Furuta Takeo Kawabata 《Advanced Synthesis \u0026amp; Catalysis》2012,354(17):3291-3298
A highly geometry‐selective organocatalytic acylation of tri‐ and tetra‐substituted 2‐alkylidene‐1,3‐propanediols has been developed. The highly E‐selective acylation of various tetrasubstituted 2‐alkylidene‐1,3‐propanediols was achieved in 96 to >99% selectivity for the first time by a non‐enzymatic protocol. 相似文献
48.
Soares Carlos R.J.; Gomide Fernanda I.C.; Ueda Eric K.M.; Bartolini Paolo 《Protein engineering, design & selection : PEDS》2003,16(12):1131-1138
The influence of different factors acting on Escherichia coliperiplasmic expression of recombinant human growth hormone (hGH)in shake flask cultures has been investigated. Bacterial vectorscontaining the phage 相似文献
49.
Yusuke Yamada Atsushi Ueda Zhen Zhao Toru Maekawa Kengo Suzuki Tadashi Takada Tetsuhiko Kobayashi 《Catalysis Today》2001,67(4):325-387
The rapid evaluation of catalysis is an indispensable technology for the success of combinatorial chemistry. A small-sized, less expensive, easily operating screening is desirable for parallel settings which dramatically shortens the evaluation time. Recent advances in gas sensors have enabled us to use them for the rapid evaluation of oxidation catalysis. Three typical catalytic oxidations over metal oxide catalysts were evaluated by gas sensor systems optimized for each catalytic system. The first one is the total oxidation of carbon monoxide in air. Five catalytic combustion-type gas sensors were used in a parallel reactor system to shorten the evaluation time. The second one is the oxidative dehydrogenation (ODH) of ethane over the mixed oxide of nickel and iron. The evaluation of the ODH catalysis was performed by a selective olefin sensor which determines the concentration of C2H4 in C2H6. The third one is the selective oxidation catalysis of propane over alkali modified Fe/SiO2. The effluents including CO, CO2, aldehydes and ketones in propane were analyzed by the CO, CO2 and semiconductor-type gas sensors selective toward aldehydes and ketones. These evaluation results indicated that gas sensors have a good potential for the rapid evaluation of oxidation catalysts. 相似文献
50.
In order to clarify whether MgMoxOy catalysts with slight excess of molybdenum relative to the stoichiometric MgMoO4 compound showed increased activities for propene formation in the propane oxidative dehydrogenation, we investigated the
catalytic properties of MoO3 supported on MgMoO4 and of MgMoxOy catalysts treated with acid or base. Supporting MoO3 on magnesium-rich MgMo0.99Oy catalysts which are poorly active, or treating them with acetic acid to remove excess magnesium, resulted in drastic activity
increases. On the other hand, the ammonia treatment of molybdenum-rich MgMo1.05Oy catalysts which are highly active turned out to give a remarkable decrease in activity, because surface MoOx dissolved in ammonia water. A clear correlation was observed between the catalytic activities for propane oxidation and the
dehydration of 2-propanol to propene over the supported catalyst and the treated catalysts. Since the bulk structures were
unchanged by supporting or by the treatments, the existence of MoOx clusters formed on the surface of MgMoO4 are responsible for the activities in the oxidative dehydrogenation of propane.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献