78 research outputs found

    Copper-Catalyzed Intermolecular Carboamination of Alkenes Induced by Visible Light

    No full text
    A photoinduced copper-catalyzed three-component reaction involving carbohalide, alkene and amine has been developed, leading to valuable fluoroalkyl-containing amines. A sole inexpensive CuCl is used as the photo- and coupling catalyst. A broad array of substrates are capable coupling partners. The diverse method is compatible with a broad range of functional groups and can be further applied to the late-stage functionalization of bioactive pharmaceuticals

    Presentation_1_Ectopic Expression of PtoMYB74 in Poplar and Arabidopsis Promotes Secondary Cell Wall Formation.PDF

    No full text
    In vascular plants, R2R3-MYB transcription factors are important regulators of secondary cell wall formation. Although 192 annotated R2R3 MYB genes were identified in the poplar genome, only a few members were characterized to participate in the regulation of the secondary cell wall biosynthesis. In this paper, we identify an R2R3-MYB transcription factor, PtoMYB74, which is predicted to be an ortholog of Arabidopsis AtMYB61, a transcription activator that regulates the secondary cell wall formation, lignin biosynthesis, stomatal aperture, and the mucilage of seed coat. PtoMYB74 is mainly expressed in the stems, especially in the xylem tissues and organs. PtoMYB74 as a transcriptional activator is localized to the nucleus. The overexpression of PtoMYB74 increased the secondary cell wall thickness of vessels in transgenic poplar and changed the secondary cell wall compositions. The expression levels of lignin and cellulose biosynthetic genes were elevated in the transgenic poplar overexpressing PtoMYB74 compared to the wild type, while there was no change in the xylan biosynthetic genes. Transcriptional activation assays demonstrated that PtoMYB74 could activate the promoters of structural genes in the lignin and cellulose biosynthetic pathways. Taken together, our data show that PtoMYB74 positively regulates the secondary cell wall biosynthesis in poplar.</p

    Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation

    No full text
    Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly­(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly­(caffeic acid) through a simple dipping–cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly­(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye’s mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification

    Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation

    No full text
    Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly­(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly­(caffeic acid) through a simple dipping–cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly­(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye’s mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification

    Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation

    No full text
    Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly­(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly­(caffeic acid) through a simple dipping–cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly­(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye’s mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification

    Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation

    No full text
    Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly­(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly­(caffeic acid) through a simple dipping–cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly­(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye’s mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification

    Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation

    No full text
    Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly­(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly­(caffeic acid) through a simple dipping–cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly­(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye’s mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification

    Sequence-Regulated Supracolloidal Copolymers via Copolymerization-Like Coassembly of Binary Mixtures of Patchy Nanoparticles

    No full text
    Synthetic copolymers of molecular systems serve as an inspiration for creation of one-dimensional copolymer-like superstructures via coassembly of anisometric nanoparticles. In contrast to the covalent and molecular copolymers, the details of formation mechanisms of copolymer-like superstructures, as well as the factors determining their length and the sequences of arranged nanoparticles, are still poorly understood. Herein, we propose a joint theoretical–computational framework to probe into the coassembly mechanism and kinetics of binary mixtures of patchy nanoparticles. By applying the coarse-grained molecular dynamics simulations, it is demonstrated that the coassembly of patchy nanoparticles markedly resembles many aspects of molecular step-growth copolymerization, and the sequences of nanoparticles inside the copolymer-like superstructures can be finely regulated by the relative activity and the initial ingredient of patchy nanoparticles as well as the coassembly strategy. A quantitatively copolymerization-like model is developed to account for the coassembly kinetics of patchy nanoparticles and the sequence distribution of arranged nanoparticles, all governed by the elaborate design of lower-level building units. The jointly theoretical and simulated studies offer mechanistic insights into the copolymerization-like kinetics and the sequence prediction for the coassembly of binary mixtures of patchy nanoparticles, paving the way toward the rational design of copolymer-like superstructures with various sequences and functionalities
    corecore