The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Kiyotaka Shigehara - One of the best experts on this subject based on the ideXlab platform.
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Preferential cesium ion trapping by 2-pyrone-4,6-dicarboxylic acid (PDC) obtained from a Metabolic Intermediate of lignin, a woody biomass resource
Journal of Nuclear Science and Technology, 2016Co-Authors: Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Yuri Iguchi, Yuko Itoh, Kiyotaka ShigeharaAbstract:ABSTRACT2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable Metabolic Intermediate of lignin, showed preferential Cs+ sedimentation even from the aqueous solutions containing other alkali metal ions, such as Na+. From the crystal structure of the Cs+/PDC complex, Cs+ was revealed to be coordinated by 10 oxygen atoms of PDC and such multiple coordination was the reason of the preferential complex formation of Cs+ with PDC.
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click synthesis and adhesive properties of novel biomass based polymers from lignin derived stable Metabolic Intermediate
Polymer Journal, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:Novel biomass-based polymers composed of 2-pyrone-4,6-dicarboxylic acid (PDC), which was isolated from lignin as a chemically stable Metabolic Intermediate, were synthesized by the copper (Cu) (I)-catalyzed, but ligand-free azide-alkyne cycloaddition reaction. The polymerization progress was monitored by the gel permeation chromatography profiles and IR spectroscopies. Very high-molecular-weight polymers with sufficient solubilities in organic solvents were obtained after the polymerization for 70 h, and their chemical structures were fully characterized. The in-situ prepared PDC polymers displayed adhesive properties to various metal surfaces. Among the investigated metals, the tensile strength with Cu, prepared at 70 °C for 4 h, was the highest (3.70 MPa). This specific adhesion to Cu is probably due to the promoted polymerization using the leached CuI as a catalyst and the crosslinking ability through the interactions with the formed triazole rings. Lignin-derived biomass-based polymers were synthesized by click polymerization using the copper (Cu)I-catalyzed azide-alkyne cycloaddition. The in-situ prepared polymers displayed strong adhesion properties to metal surfaces. In particular, the specific adhesion to Cu with the maximum tensile strength of 3.7 MPa was achieved.
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Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
Bulletin of the Chemical Society of Japan, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:Two cholesterol groups were for the first time attached to a lignin-derived Metabolic Intermediate, 2-pyrone-4,6-dicarboxylic acid (PDC). This PDC molecule showed a liquid crystalline mesophase and...
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Organogels of Lignin-derived Stable Metabolic Intermediate, 2-Pyrone-4,6-dicarboxylic Acid (PDC), Bearing Cholesteryl Groups
Chemistry Letters, 2010Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:The organogelation behavior of a lignin-derived stable Metabolic Intermediate bearing two cholesteryl groups was examined for the first time, and it was found that the carbamate spacers possessing ...
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tenacious epoxy adhesives prepared from lignin derived stable Metabolic Intermediate
Sen-i Gakkaishi, 2009Co-Authors: Yuki Hasegawa, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Shinya Kajita, Kiyotaka ShigeharaAbstract:In this study, the tenacious epoxy adhesive originated from Lignin-derived Intermediate, 2-pyrone-4,6- dicarboxylic acid (PDC), was obtained which is expected for not only a biomass material as alternative to petroleum one but also the usage as an adhesive with higher quality than existing one.
Renaud Brouquisse - One of the best experts on this subject based on the ideXlab platform.
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Multifaceted roles of nitric oxide in plants
Journal of Experimental Botany, 2019Co-Authors: Renaud BrouquisseAbstract:Nitric oxide (NO) is a reactive free radical gaseous molecule with a broad spectrum of regulatory functions in plant growth and development, and in response to abiotic and biotic (pathogenic and symbiotic interactions) factors. It is known to act either as a signaling molecule (mainly via redox-dependent post-translational modifications), a Metabolic Intermediate, or a toxic oxidative by-product. The reviews and research papers in this special issue summarize recent advances in our knowledge of plant NO production and degradation pathways, examine NO signaling mechanisms, and highlight its crosstalk with reactive oxygen species, hydrogen sulfide, and hormone-signaling processes for regulation of plant growth and responses to external stimuli.
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which role for nitric oxide in symbiotic n2 fixing nodules toxic by product or useful signaling Metabolic Intermediate
Frontiers in Plant Science, 2013Co-Authors: Alexandre Boscari, Eliane Meilhoc, Claude Castella, Claude Bruand, Alain Puppo, Renaud BrouquisseAbstract:The interaction between legumes and rhizobia leads to the establishment of a symbiotic relationship characterized by the formation of new organs called nodules, in which bacteria have the ability to fix atmospheric nitrogen (N2) via the nitrogenase activity. Significant nitric oxide (NO) production was evidenced in the N2-fixing nodules suggesting that it may impact the symbiotic process. Indeed, NO was shown to be a potent inhibitor of nitrogenase activity and symbiotic N2 fixation. It has also been shown that NO production is increased in hypoxic nodules and this production was supposed to be linked –via a nitrate/NO respiration process- with improved capacity of the nodules to maintain their energy status under hypoxic conditions. Other data suggest that NO might be a developmental signal involved in the induction of nodule senescence. Hence, the questions were raised of the toxic effects versus signalling/Metabolic functions of NO, and of the regulation of NO levels compatible with nitrogenase activity. The present review analyzes the different roles of NO in functioning nodules, and discusses the role of plant and bacterial (flavo)hemoglobins in the control of NO level in nodules.
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Which role for nitric oxide in symbiotic N2-fixing nodules: toxic by-product or useful signaling/Metabolic Intermediate?
Frontiers in Plant Science, 2013Co-Authors: Alexandre Boscari, Eliane Meilhoc, Claude Castella, Claude Bruand, Alain Puppo, Renaud BrouquisseAbstract:The interaction between legumes and rhizobia leads to the establishment of a symbiotic relationship characterized by the formation of new organs called nodules, in which bacteria have the ability to fix atmospheric nitrogen (N2) via the nitrogenase activity. Significant nitric oxide (NO) production was evidenced in the N2-fixing nodules suggesting that it may impact the symbiotic process. Indeed, NO was shown to be a potent inhibitor of nitrogenase activity and symbiotic N2 fixation. It has also been shown that NO production is increased in hypoxic nodules and this production was supposed to be linked - via a nitrate/NO respiration process - with improved capacity of the nodules to maintain their energy status under hypoxic conditions. Other data suggest that NO might be a developmental signal involved in the induction of nodule senescence. Hence, the questions were raised of the toxic effects versus signaling/Metabolic functions of NO, and of the regulation of NO levels compatible with nitrogenase activity. The present review analyses the different roles of NO in functioning nodules, and discusses the role of plant and bacterial (flavo)hemoglobins in the control of NO level in nodules.
Tsuyoshi Michinobu - One of the best experts on this subject based on the ideXlab platform.
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click synthesis and adhesive properties of novel biomass based polymers from lignin derived stable Metabolic Intermediate
Polymer Journal, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:Novel biomass-based polymers composed of 2-pyrone-4,6-dicarboxylic acid (PDC), which was isolated from lignin as a chemically stable Metabolic Intermediate, were synthesized by the copper (Cu) (I)-catalyzed, but ligand-free azide-alkyne cycloaddition reaction. The polymerization progress was monitored by the gel permeation chromatography profiles and IR spectroscopies. Very high-molecular-weight polymers with sufficient solubilities in organic solvents were obtained after the polymerization for 70 h, and their chemical structures were fully characterized. The in-situ prepared PDC polymers displayed adhesive properties to various metal surfaces. Among the investigated metals, the tensile strength with Cu, prepared at 70 °C for 4 h, was the highest (3.70 MPa). This specific adhesion to Cu is probably due to the promoted polymerization using the leached CuI as a catalyst and the crosslinking ability through the interactions with the formed triazole rings. Lignin-derived biomass-based polymers were synthesized by click polymerization using the copper (Cu)I-catalyzed azide-alkyne cycloaddition. The in-situ prepared polymers displayed strong adhesion properties to metal surfaces. In particular, the specific adhesion to Cu with the maximum tensile strength of 3.7 MPa was achieved.
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Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
Bulletin of the Chemical Society of Japan, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:Two cholesterol groups were for the first time attached to a lignin-derived Metabolic Intermediate, 2-pyrone-4,6-dicarboxylic acid (PDC). This PDC molecule showed a liquid crystalline mesophase and...
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Organogels of Lignin-derived Stable Metabolic Intermediate, 2-Pyrone-4,6-dicarboxylic Acid (PDC), Bearing Cholesteryl Groups
Chemistry Letters, 2010Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:The organogelation behavior of a lignin-derived stable Metabolic Intermediate bearing two cholesteryl groups was examined for the first time, and it was found that the carbamate spacers possessing ...
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a novel biomass based polymer prepared from lignin derived stable Metabolic Intermediate by copper i catalyzed azide alkyne click reaction
Chemistry Letters, 2008Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:The Cu I -catalyzed, but ligand-free azide-alkyne cycloaddition reaction was applied to the polymerization of the newly synthesized diethynyl-functionalized 2-pyrone monomer originally isolated from lignin via Metabolic pathway. The polymerization was monitored by GPC and IR spectra and the resulting high molecular weight polymer was unambiguously characterized by 1 H NMR, thermal analysis, and optical absorption and emission spectra.
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a novel biomass based polymer prepared from lignin derived stable Metabolic Intermediate by copper i catalyzed azide alkyne click reaction
Chemistry Letters, 2008Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:The CuI-catalyzed, but ligand-free azide–alkyne cycloaddition reaction was applied to the polymerization of the newly synthesized diethynyl-functionalized 2-pyrone monomer originally isolated from ...
Yoshihiro Katayama - One of the best experts on this subject based on the ideXlab platform.
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Preferential cesium ion trapping by 2-pyrone-4,6-dicarboxylic acid (PDC) obtained from a Metabolic Intermediate of lignin, a woody biomass resource
Journal of Nuclear Science and Technology, 2016Co-Authors: Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Yuri Iguchi, Yuko Itoh, Kiyotaka ShigeharaAbstract:ABSTRACT2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable Metabolic Intermediate of lignin, showed preferential Cs+ sedimentation even from the aqueous solutions containing other alkali metal ions, such as Na+. From the crystal structure of the Cs+/PDC complex, Cs+ was revealed to be coordinated by 10 oxygen atoms of PDC and such multiple coordination was the reason of the preferential complex formation of Cs+ with PDC.
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click synthesis and adhesive properties of novel biomass based polymers from lignin derived stable Metabolic Intermediate
Polymer Journal, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:Novel biomass-based polymers composed of 2-pyrone-4,6-dicarboxylic acid (PDC), which was isolated from lignin as a chemically stable Metabolic Intermediate, were synthesized by the copper (Cu) (I)-catalyzed, but ligand-free azide-alkyne cycloaddition reaction. The polymerization progress was monitored by the gel permeation chromatography profiles and IR spectroscopies. Very high-molecular-weight polymers with sufficient solubilities in organic solvents were obtained after the polymerization for 70 h, and their chemical structures were fully characterized. The in-situ prepared PDC polymers displayed adhesive properties to various metal surfaces. Among the investigated metals, the tensile strength with Cu, prepared at 70 °C for 4 h, was the highest (3.70 MPa). This specific adhesion to Cu is probably due to the promoted polymerization using the leached CuI as a catalyst and the crosslinking ability through the interactions with the formed triazole rings. Lignin-derived biomass-based polymers were synthesized by click polymerization using the copper (Cu)I-catalyzed azide-alkyne cycloaddition. The in-situ prepared polymers displayed strong adhesion properties to metal surfaces. In particular, the specific adhesion to Cu with the maximum tensile strength of 3.7 MPa was achieved.
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Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
Bulletin of the Chemical Society of Japan, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:Two cholesterol groups were for the first time attached to a lignin-derived Metabolic Intermediate, 2-pyrone-4,6-dicarboxylic acid (PDC). This PDC molecule showed a liquid crystalline mesophase and...
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Organogels of Lignin-derived Stable Metabolic Intermediate, 2-Pyrone-4,6-dicarboxylic Acid (PDC), Bearing Cholesteryl Groups
Chemistry Letters, 2010Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:The organogelation behavior of a lignin-derived stable Metabolic Intermediate bearing two cholesteryl groups was examined for the first time, and it was found that the carbamate spacers possessing ...
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tenacious epoxy adhesives prepared from lignin derived stable Metabolic Intermediate
Sen-i Gakkaishi, 2009Co-Authors: Yuki Hasegawa, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Shinya Kajita, Kiyotaka ShigeharaAbstract:In this study, the tenacious epoxy adhesive originated from Lignin-derived Intermediate, 2-pyrone-4,6- dicarboxylic acid (PDC), was obtained which is expected for not only a biomass material as alternative to petroleum one but also the usage as an adhesive with higher quality than existing one.
Eiji Masai - One of the best experts on this subject based on the ideXlab platform.
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Preferential cesium ion trapping by 2-pyrone-4,6-dicarboxylic acid (PDC) obtained from a Metabolic Intermediate of lignin, a woody biomass resource
Journal of Nuclear Science and Technology, 2016Co-Authors: Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Yuri Iguchi, Yuko Itoh, Kiyotaka ShigeharaAbstract:ABSTRACT2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable Metabolic Intermediate of lignin, showed preferential Cs+ sedimentation even from the aqueous solutions containing other alkali metal ions, such as Na+. From the crystal structure of the Cs+/PDC complex, Cs+ was revealed to be coordinated by 10 oxygen atoms of PDC and such multiple coordination was the reason of the preferential complex formation of Cs+ with PDC.
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click synthesis and adhesive properties of novel biomass based polymers from lignin derived stable Metabolic Intermediate
Polymer Journal, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Seiji Ohara, Yasunori Inazawa, Kiyotaka ShigeharaAbstract:Novel biomass-based polymers composed of 2-pyrone-4,6-dicarboxylic acid (PDC), which was isolated from lignin as a chemically stable Metabolic Intermediate, were synthesized by the copper (Cu) (I)-catalyzed, but ligand-free azide-alkyne cycloaddition reaction. The polymerization progress was monitored by the gel permeation chromatography profiles and IR spectroscopies. Very high-molecular-weight polymers with sufficient solubilities in organic solvents were obtained after the polymerization for 70 h, and their chemical structures were fully characterized. The in-situ prepared PDC polymers displayed adhesive properties to various metal surfaces. Among the investigated metals, the tensile strength with Cu, prepared at 70 °C for 4 h, was the highest (3.70 MPa). This specific adhesion to Cu is probably due to the promoted polymerization using the leached CuI as a catalyst and the crosslinking ability through the interactions with the formed triazole rings. Lignin-derived biomass-based polymers were synthesized by click polymerization using the copper (Cu)I-catalyzed azide-alkyne cycloaddition. The in-situ prepared polymers displayed strong adhesion properties to metal surfaces. In particular, the specific adhesion to Cu with the maximum tensile strength of 3.7 MPa was achieved.
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Liquid Crystallinity and Organogelation Behavior of Lignin-Derived Metabolic Intermediate Bearing Cholesterol Groups
Bulletin of the Chemical Society of Japan, 2011Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:Two cholesterol groups were for the first time attached to a lignin-derived Metabolic Intermediate, 2-pyrone-4,6-dicarboxylic acid (PDC). This PDC molecule showed a liquid crystalline mesophase and...
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Organogels of Lignin-derived Stable Metabolic Intermediate, 2-Pyrone-4,6-dicarboxylic Acid (PDC), Bearing Cholesteryl Groups
Chemistry Letters, 2010Co-Authors: Tsuyoshi Michinobu, Kenta Hiraki, Nozomu Fujii, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Kiyotaka ShigeharaAbstract:The organogelation behavior of a lignin-derived stable Metabolic Intermediate bearing two cholesteryl groups was examined for the first time, and it was found that the carbamate spacers possessing ...
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tenacious epoxy adhesives prepared from lignin derived stable Metabolic Intermediate
Sen-i Gakkaishi, 2009Co-Authors: Yuki Hasegawa, Kazuhiro Shikinaka, Yoshihiro Katayama, Eiji Masai, Masaya Nakamura, Yuichiro Otsuka, Seiji Ohara, Shinya Kajita, Kiyotaka ShigeharaAbstract:In this study, the tenacious epoxy adhesive originated from Lignin-derived Intermediate, 2-pyrone-4,6- dicarboxylic acid (PDC), was obtained which is expected for not only a biomass material as alternative to petroleum one but also the usage as an adhesive with higher quality than existing one.