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Masa-aki Kakimoto 《复旦学报(自然科学版)》2005,44(5):736-737
Hyperbranched polymers have been paid attention because of their unique structures. Especially, they have many terminals whose number is the same as that of repeating units as far as they are synthesized from AB2 type monomers. These characteristics of the hyperbranched polymers make them new functionalized polymers. Polysiloxanes have unique properties such as low Tg, high decomposition temperature, water repulsion, and good dielectric property. They are widely fabricated from liquid (oil) to solid (resin) by changing the extent of crosslinking. We have studied dendrimers and hyperbrached polymers possessing polysiloxane structure. These materials have the amphiphilic nature when they have amine functional group at the terminal position. 相似文献
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Identification of CRE1 as a cytokinin receptor from Arabidopsis 总被引:29,自引:0,他引:29
Inoue T Higuchi M Hashimoto Y Seki M Kobayashi M Kato T Tabata S Shinozaki K Kakimoto T 《Nature》2001,409(6823):1060-1063
Cytokinins are a class of plant hormones that are central to the regulation of cell division and differentiation in plants. It has been proposed that they are detected by a two-component system, because overexpression of the histidine kinase gene CKI1 induces typical cytokinin responses and genes for a set of response regulators of two-component systems can be induced by cytokinins. Two-component systems use a histidine kinase as an environmental sensor and rely on a phosphorelay for signal transduction. They are common in microorganisms, and are also emerging as important signal detection routes in plants. Here we report the identification of a cytokinin receptor. We identified Arabidopsis cre1 (cytokinin response 1) mutants, which exhibited reduced responses to cytokinins. The mutated gene CRE1 encodes a histidine kinase. CRE1 expression conferred a cytokinin-dependent growth phenotype on a yeast mutant that lacked the endogenous histidine kinase SLN1 (ref. 10), providing direct evidence that CRE1 is a cytokinin receptor. We also provide evidence that cytokinins can activate CRE1 to initiate phosphorelay signalling. 相似文献
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Negotiation is both an important topic in multi-agent systems research and an important aspect of daily life. Many real-world negotiations are complex and involve multiple interdependent issues, therefore, there has been increasing interest in such negotiations. Existing nonlinear automated negotiation protocols have difficulty in finding solutions when the number of issues and agents is large. In automated negotiations covering multiple independent issues, it is useful to separate out the issues and reach separate agreements on each in turn. In this paper, we propose an effective approach to automated negotiations based on recursive partitioning using an issue dendrogram. A mediator first finds partial agreements in each sub-space based on bids from the agents, then combines them to produce the final agreement. When it cannot find a solution, our proposed method recursively decomposes the negotiation sub-problems using an issue dendrogram. In addition, it can improve the quality of agreements by considering previously-found partial consensuses. We also demonstrate experimentally that our protocol generates higher-optimality outcomes with greater scalability than previous methods. 相似文献
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