著者

Kawaguchi Takumi Suzuki Tomohiro Kobayashi Yuka Kodani Shinya Hirai Hirofumi Nagai Kaoru Kawagishi Hirokazu

出版者

Elsevier

雑誌

Tetrahedron (ISSN:00404020)

巻号頁・発行日

vol.66, no.2, pp.504-507, 2010-01-09

被引用文献数

26

著者

Song Wenbo Okamura Masayuki Kondo Toshihiro Uosaki Kohei

出版者

Elsevier

雑誌

Journal of Electroanalytical Chemistry (ISSN:00220728)

巻号頁・発行日

vol.612, no.1, pp.105-111, 2008-01-01

被引用文献数

9

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Amounts of gold nanoclusters (GNCs) in multilayer assembly with polymer binding layers has been demonstrated to be controlled by pH and ionic strength of the polymer solution when GNCs covered with mercaptoundecanoic acid (MUA) were assembled on a solid substrate in a layer-by-layer (LBL) fashion utilizing terminal carboxylate groups as charged sites to electrostatically bind to protonated amine groups of poly(allylamine hydrochloride) (PAH), which was used as a binding layer. Formation of these GNC multilayers was followed by monitoring the electrochemical response of the ferrocene moiety attached to the GNC core, which acted as a redox probe. The apparent acid dissociation constant of MUA on the GNC surface estimated from correlation between the amount of adsorbed GNCs and pH of the PAH solutions was in good agreement with those previously reported. Facile charge transport within LBL multilayer assemblies formed under various pH and/or ionic strengths of polymer solution revealed an open porous film microstructure contributing to facile charge transfer by hopping through GNC sites as well as with the aid of electrolyte in pores in such architectures. This study provides significant fundamental basis for construction of highly charged complex structures containing redox groups and useful applications in catalysis and devices fabrication based on charge transfer.

著者

Tsutsumi Shinichi Shimazu Atsushi Miyazaki Kazuko Pan Haiou Koike Chika Yoshida Eri Takagishi Kenji Kato Yukio

出版者

Elsevier

雑誌

Biochemical and Biophysical Research Communications (ISSN:0006291X)

巻号頁・発行日

vol.288, no.2, pp.413-419, 2001-10-26

被引用文献数

11 473

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Mesenchymal stem cells (MSC) that can differentiate to various connective tissue cells may be useful for autologous cell transplantation to defects of bone, cartilage, and tendon, if MSC can be expanded in vitro. However, a short life span of MSC and a reduction in their differentiation potential in culture have limited their clinical application. The purpose of this study is to identify a growth factor(s) involved in self-renewal of MSC and the maintenance of their multilineage differentiation potential. Fibroblast growth factor-2 (FGF-2) markedly increased the growth rate and the life span of rabbit, canine, and human bone marrow MSC in monolayer cultures. This effect of FGF-2 was more prominent in low-density cultures than in high-density cultures. In addition, all MSC expanded in vitro with FGF-2, but not without FGF-2, differentiated to chondrocytes in pellet cultures. The FGF(+) MSC also retained the osteogenic and adipogenic potential throughout many mitotic divisions. These findings suggest that FGFs play a crucial role in self-renewal of MSC.

著者

Ma Tieju Nakamori Yoshiteru

出版者

Elsevier

雑誌

European Journal of Operational Research (ISSN:03772217)

巻号頁・発行日

vol.166, no.3, pp.741-755, 2005-11-01

被引用文献数

60

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This paper describes a multi-agent model built to simulate the process of technological innovation, based on the widely accepted theory that technological innovation can be seen as an evolutionary process. The actors in the simulation include producers and a large number of consumers. Every producer will produce several types of products at each step. Each product is composed of several design parameters and several performance parameters (fitness components). Kauffman’s famous NK model is used to deal with the mapping from design parameter space (DPS) to performance parameter space (PPS). In addition to the constructional selection, which can be illustrated by the NK model, we added environmental selection into the simulation and explored technological innovation as the result of the interaction between these two kinds of selection.