The Experts below are selected from a list of 162489 Experts worldwide ranked by ideXlab platform
Weiguo Song - One of the best experts on this subject based on the ideXlab platform.
-
in situ loading of cu2o nanoparticles on a Hydroxyl Group rich tio2 precursor as an excellent catalyst for the ullmann reaction
Nano Research, 2010Co-Authors: Yan Jiang, Weiguo SongAbstract:An in situ method has been used to load Cu2O nanoparticles on the surface of a Hydroxyl Group rich TiO2 precursor. Cu2O nanoparticles are formed by in situ reduction of Cu(OH)2 with Sn2+ ions linked to the surface of the TiO2 precursor. The initial Cu2O nanoparticles serve as seeds for subsequent particle growth. The resulting Cu2O nanoparticles are evenly dispersed on the surface of the TiO2 precursor, and are heat and air stable. The as-prepared composite is an excellent catalyst for Ullmann type cross coupling reactions of aryl halides with phenol. The composite catalyst also showed good stability, remaining highly active after five consecutive runs.
-
promotion of organic reactions by interfacial hydrogen bonds on Hydroxyl Group rich nano solids
Chemical Communications, 2008Co-Authors: Fang Niu, Changchang Liu, Zhimin Cui, Jin Zhai, Lei Jiang, Weiguo SongAbstract:Surface Hydroxyl Group rich nano-structured solids dramatically increase the rate of several organic reactions; such effect is attributed to the formation of interfacial hydrogen bonds between the surface Hydroxyl Groups and the reactants; this catalytic effect is versatile and applicable for a broad range of reaction conditions.
-
in situ loading of noble metal nanoparticles on Hydroxyl Group rich titania precursor and their catalytic applications
Chemistry of Materials, 2007Co-Authors: Liangshu Zhong, Zhimin Cui, Lijun Wan, Weiguo SongAbstract:A novel in-situ route was developed to load well-dispersed palladium (Pd) nanoparticles on the surface of Hydroxyl-Group-rich titania precursor. Pd nanoparticles are formed by in-situ reduction of Pd(II) by Sn(II); the latter is linked to the surface of TiO2 precursors through inorganic grafting. The initial Pd nanoparticles then serve as seed for subsequent particle growth and allow us to systematically control the amount and size of the Pd nanoparticles by varying the amount of added PdCl2. The Pd nanoparticles, with no protection from ligands, are well-dispersed on the TiO2 precursor surface without aggregation even at a high Pd loading of 22.5 wt %. The method is also extended to introduce other noble metal nanoparticles including Au, Ag, Pt, and their bimetallic nanoparticles onto the TiO2 precursor surface. The as-obtained TiO2 precursor−Pd composite is a promising catalyst in nanocatalysis. As an example, the TiO2 precursor−Pd shows high catalytic activity for Suzuki cross-coupling reaction and can...
Edward A Bayer - One of the best experts on this subject based on the ideXlab platform.
-
cohesin dockerin interaction in cellulosome assembly a single Hydroxyl Group of a dockerin domain distinguishes between nonrecognition and high affinity recognition
Journal of Biological Chemistry, 2001Co-Authors: Adva Mechaly, Henripierre Fierobe, Anne Belaich, Jeanpierre Belaich, Raphael Lamed, Yuval Shoham, Edward A BayerAbstract:Abstract The assembly of enzyme components into the cellulosome complex is dictated by the cohesin-dockerin interaction. In a recent article (Mechaly, A., Yaron, S., Lamed, R., Fierobe, H.-P., Belaich, A., Belaich, J.-P., Shoham, Y., and Bayer, E. A. (2000)Proteins 39, 170–177), we provided experimental evidence that four previously predicted dockerin residues play a decisive role in the specificity of this high affinity interaction, although additional residues were also implicated. In the present communication, we examine further the contributing factors for the recognition of a dockerin by a cohesin domain between the respective cellulosomal systems of Clostridium thermocellum and Clostridium cellulolyticum. In this context, the four confirmed residues were analyzed for their individual effect on selectivity. In addition, other dockerin residues were discerned that could conceivably contribute to the interaction, and the suspected residues were similarly modified by site-directed mutagenesis. The results indicate that mutation of a single residue from threonine to leucine at a given position of theC. thermocellum dockerin differentiates between its nonrecognition and high affinity recognition (K a∼ 109 m −1) by a cohesin fromC. cellulolyticum. This suggests that the presence or absence of a single decisive Hydroxyl Group is critical to the observed biorecognition. This study further implicates additional residues as secondary determinants in the specificity of interaction, because interconversion of selected residues reduced intraspecies self-recognition by at least three orders of magnitude. Nevertheless, as the latter mutageneses served to reduce but not annul the cohesin-dockerin interaction within this species, it follows that other subtle alterations play a comparatively minor role in the recognition between these two modules.
-
cohesin dockerin interaction in cellulosome assembly a single Hydroxyl Group of a dockerin domain distinguishes between nonrecognition and high affinity recognition
Journal of Biological Chemistry, 2001Co-Authors: Adva Mechaly, Henripierre Fierobe, Anne Belaich, Jeanpierre Belaich, Raphael Lamed, Yuval Shoham, Edward A BayerAbstract:The assembly of enzyme components into the cellulosome complex is dictated by the cohesin-dockerin interaction. In a recent article (Mechaly, A., Yaron, S., Lamed, R., Fierobe, H.-P., Belaich, A., Belaich, J.-P., Shoham, Y., and Bayer, E. A. (2000) Proteins 39, 170-177), we provided experimental evidence that four previously predicted dockerin residues play a decisive role in the specificity of this high affinity interaction, although additional residues were also implicated. In the present communication, we examine further the contributing factors for the recognition of a dockerin by a cohesin domain between the respective cellulosomal systems of Clostridium thermocellum and Clostridium cellulolyticum. In this context, the four confirmed residues were analyzed for their individual effect on selectivity. In addition, other dockerin residues were discerned that could conceivably contribute to the interaction, and the suspected residues were similarly modified by site-directed mutagenesis. The results indicate that mutation of a single residue from threonine to leucine at a given position of the C. thermocellum dockerin differentiates between its nonrecognition and high affinity recognition (K(a) approximately 10(9) m(-1)) by a cohesin from C. cellulolyticum. This suggests that the presence or absence of a single decisive Hydroxyl Group is critical to the observed biorecognition. This study further implicates additional residues as secondary determinants in the specificity of interaction, because interconversion of selected residues reduced intraspecies self-recognition by at least three orders of magnitude. Nevertheless, as the latter mutageneses served to reduce but not annul the cohesin-dockerin interaction within this species, it follows that other subtle alterations play a comparatively minor role in the recognition between these two modules.
Rajesh J Tayade - One of the best experts on this subject based on the ideXlab platform.
-
preferential adsorption behavior of methylene blue dye onto surface Hydroxyl Group enriched tio2 nanotube and its photocatalytic regeneration
Journal of Colloid and Interface Science, 2014Co-Authors: Thillai Sivakumar Natarajan, Hari C Bajaj, Rajesh J TayadeAbstract:The present manuscript focus on the synthesis of surface Hydroxyl Group enriched titanium dioxide nanotube (TNT) by hydrothermal method for preferential adsorption of methylene blue (MB) dye. The mixture of methylene blue (MB) and rhodamine B (RhB) dye was used to study the preferential adsorption nature of TNT. The synthesized TNT were characterized by various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, and ammonia-temperature programmed desorption (NH3-TPD) analysis. Result demonstrated that enhancement in the surface area of TNT and higher number of Hydroxyl Group on the surface of TNT. In the binary mixture, the adsorption of MB dye was 12.9 times higher as compared to RhB dye, which clearly indicated the preferential adsorption of MB dye on TNT surface. The preferential interaction of MB on TNT is due to the electrostatic interaction between the cationic MB and negatively charged TNT surface. The preferential adsorption of MB dye was studied by applying Langmuir, Freundlich and Sips isotherm; pseudo-first and second-order kinetic model. Furthermore, the regeneration of dye adsorbed TNT was carried out by eco-friendly photocatalytic process under the irradiation of ultraviolet light.
Adva Mechaly - One of the best experts on this subject based on the ideXlab platform.
-
cohesin dockerin interaction in cellulosome assembly a single Hydroxyl Group of a dockerin domain distinguishes between nonrecognition and high affinity recognition
Journal of Biological Chemistry, 2001Co-Authors: Adva Mechaly, Henripierre Fierobe, Anne Belaich, Jeanpierre Belaich, Raphael Lamed, Yuval Shoham, Edward A BayerAbstract:Abstract The assembly of enzyme components into the cellulosome complex is dictated by the cohesin-dockerin interaction. In a recent article (Mechaly, A., Yaron, S., Lamed, R., Fierobe, H.-P., Belaich, A., Belaich, J.-P., Shoham, Y., and Bayer, E. A. (2000)Proteins 39, 170–177), we provided experimental evidence that four previously predicted dockerin residues play a decisive role in the specificity of this high affinity interaction, although additional residues were also implicated. In the present communication, we examine further the contributing factors for the recognition of a dockerin by a cohesin domain between the respective cellulosomal systems of Clostridium thermocellum and Clostridium cellulolyticum. In this context, the four confirmed residues were analyzed for their individual effect on selectivity. In addition, other dockerin residues were discerned that could conceivably contribute to the interaction, and the suspected residues were similarly modified by site-directed mutagenesis. The results indicate that mutation of a single residue from threonine to leucine at a given position of theC. thermocellum dockerin differentiates between its nonrecognition and high affinity recognition (K a∼ 109 m −1) by a cohesin fromC. cellulolyticum. This suggests that the presence or absence of a single decisive Hydroxyl Group is critical to the observed biorecognition. This study further implicates additional residues as secondary determinants in the specificity of interaction, because interconversion of selected residues reduced intraspecies self-recognition by at least three orders of magnitude. Nevertheless, as the latter mutageneses served to reduce but not annul the cohesin-dockerin interaction within this species, it follows that other subtle alterations play a comparatively minor role in the recognition between these two modules.
-
cohesin dockerin interaction in cellulosome assembly a single Hydroxyl Group of a dockerin domain distinguishes between nonrecognition and high affinity recognition
Journal of Biological Chemistry, 2001Co-Authors: Adva Mechaly, Henripierre Fierobe, Anne Belaich, Jeanpierre Belaich, Raphael Lamed, Yuval Shoham, Edward A BayerAbstract:The assembly of enzyme components into the cellulosome complex is dictated by the cohesin-dockerin interaction. In a recent article (Mechaly, A., Yaron, S., Lamed, R., Fierobe, H.-P., Belaich, A., Belaich, J.-P., Shoham, Y., and Bayer, E. A. (2000) Proteins 39, 170-177), we provided experimental evidence that four previously predicted dockerin residues play a decisive role in the specificity of this high affinity interaction, although additional residues were also implicated. In the present communication, we examine further the contributing factors for the recognition of a dockerin by a cohesin domain between the respective cellulosomal systems of Clostridium thermocellum and Clostridium cellulolyticum. In this context, the four confirmed residues were analyzed for their individual effect on selectivity. In addition, other dockerin residues were discerned that could conceivably contribute to the interaction, and the suspected residues were similarly modified by site-directed mutagenesis. The results indicate that mutation of a single residue from threonine to leucine at a given position of the C. thermocellum dockerin differentiates between its nonrecognition and high affinity recognition (K(a) approximately 10(9) m(-1)) by a cohesin from C. cellulolyticum. This suggests that the presence or absence of a single decisive Hydroxyl Group is critical to the observed biorecognition. This study further implicates additional residues as secondary determinants in the specificity of interaction, because interconversion of selected residues reduced intraspecies self-recognition by at least three orders of magnitude. Nevertheless, as the latter mutageneses served to reduce but not annul the cohesin-dockerin interaction within this species, it follows that other subtle alterations play a comparatively minor role in the recognition between these two modules.
Zhimin Cui - One of the best experts on this subject based on the ideXlab platform.
-
promotion of organic reactions by interfacial hydrogen bonds on Hydroxyl Group rich nano solids
Chemical Communications, 2008Co-Authors: Fang Niu, Changchang Liu, Zhimin Cui, Jin Zhai, Lei Jiang, Weiguo SongAbstract:Surface Hydroxyl Group rich nano-structured solids dramatically increase the rate of several organic reactions; such effect is attributed to the formation of interfacial hydrogen bonds between the surface Hydroxyl Groups and the reactants; this catalytic effect is versatile and applicable for a broad range of reaction conditions.
-
in situ loading of noble metal nanoparticles on Hydroxyl Group rich titania precursor and their catalytic applications
Chemistry of Materials, 2007Co-Authors: Liangshu Zhong, Zhimin Cui, Lijun Wan, Weiguo SongAbstract:A novel in-situ route was developed to load well-dispersed palladium (Pd) nanoparticles on the surface of Hydroxyl-Group-rich titania precursor. Pd nanoparticles are formed by in-situ reduction of Pd(II) by Sn(II); the latter is linked to the surface of TiO2 precursors through inorganic grafting. The initial Pd nanoparticles then serve as seed for subsequent particle growth and allow us to systematically control the amount and size of the Pd nanoparticles by varying the amount of added PdCl2. The Pd nanoparticles, with no protection from ligands, are well-dispersed on the TiO2 precursor surface without aggregation even at a high Pd loading of 22.5 wt %. The method is also extended to introduce other noble metal nanoparticles including Au, Ag, Pt, and their bimetallic nanoparticles onto the TiO2 precursor surface. The as-obtained TiO2 precursor−Pd composite is a promising catalyst in nanocatalysis. As an example, the TiO2 precursor−Pd shows high catalytic activity for Suzuki cross-coupling reaction and can...
