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1.
ACS Appl Mater Interfaces ; 16(7): 8717-8732, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38326933

RESUMO

Urea electrolysis is a promising energy-efficient hydrogen production process with environmental benefits, but the lack of efficient and sustainable ampere-level current density electrocatalysts fabricated through simple methods is a major challenge for commercialization. Herein, we present an efficient and stable heterostructure electrocatalyst for full urea and water electrolysis in a convenient and time-efficient preparation manner. Overall, superhydrophilic/superaerophobic CoMn/CuNiP/NF exhibits exceptional performance for the hydrogen evolution reaction (HER) (-33.8, -184.4, and -234.8 mV at -10, -500, and -1000 mA cm-2, respectively), urea electro-oxidation reaction (UOR) [1.28, 1.43, and 1.51 V (vs RHE) at 10, 500, and 1000 mA cm-2, respectively], and oxygen evolution reaction (OER) [1.45, 1.67, and 1.74 V (vs RHE) at 10, 500, and 1000 mA cm-2, respectively]. Moreover, the superaerophobic CoMn/CuNiP/NF demonstrates promising potential in full urea (1.33, 1.57, and 1.60 V at 10, 500, and 1000 mA cm-2, respectively) and water (1.46 V, 1.78, and 1.86 at 10, 500, and 1000 mA cm-2, respectively) electrolysis. Based on X-ray photoelectron spectroscopy results, it was determined that the surface of the CoMn/CuNiP electrode was rich in redox pairs such as Ni2+/Ni3+, Cu+/Cu2+, Co2+/Co3+, and Mn2+/Mn3+, which are crucial for the formation of active sites for the OER and UOR, such as NiOOH, MnOOH, and CoOOH, thereby enhancing the catalytic activity. Besides, the in situ assembled CoMn/CuNiP/NF displayed highly stable performance for HER, OER, and UOR with high Faradaic efficiency for over 500 h. This research offers a simple and efficient method for manufacturing a high-efficiency and stable trifunctional electrocatalyst capable of delivering ampere-level current density in urea-assisted hydrogen production. Our density functional theory calculations reveal the potential of CoMn/CuNiP as an effective catalyst, enhancing the electronic properties and catalytic performance. The near-zero Gibbs free-energy change for HER underscores its promise, while reduced CO2 desorption energies and charge redistribution support efficient UOR. These findings signify CoMn/CuNiP's potential for electrochemical applications.

2.
RSC Adv ; 11(36): 22250-22263, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35480801

RESUMO

We report a facile solvothermal synthesis of novel octahedral CoFe2O4-reduced graphene oxide (RGO) hybrid and pure CoFe2O4 that were used as heterogeneous photo-Fenton catalysts for the degradation of organic dyes in water. We investigated the structures, morphologies and catalytic activity of both the CoFe2O4 nanoparticles and CoFe2O4-RGO hybrids. The morphology of CoFe2O4 nanoparticles displays size-dependent shapes changing from granular (or sheet) to octahedral shapes with the introduction of RGO. Compared with bare CoFe2O4, the octahedral CoFe2O4-RGO hybrids serve as novel bifunctional materials displaying higher saturation magnetization values and excellent heterogeneous activation of H2O2 at nearly neutral pH. The high saturation magnetization (41.98 emu g-1) of CoFe2O4-RGO hybrids aids their separation from the reaction mixture. In addition, the remarkable enhancement in the photo-Fenton activity of the CoFe2O4-RGO hybrids under visible light irradiation was attributed to the graphene/CoFe2O4 heterojunction, which aided the separation of excited electrons and holes. Furthermore, the CoFe2O4-RGO hybrids exhibited better removal efficiency for cationic methylene blue (MB) dye than for anionic methyl orange (MO) dye. Meanwhile, the CoFe2O4-RGO hybrids displayed acceptable photocatalytic stability, and we proposed an activation mechanism of H2O2 by the octahedral CoFe2O4-RGO hybrids.

3.
J Plant Res ; 130(3): 587-598, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28342111

RESUMO

Casein kinase II (CK2), an evolutionarily well-conserved Ser/Thr kinase, plays critical roles in all higher organisms including plants. CKB1 is a regulatory subunit beta of CK2. In this study, homozygous T-DNA mutants (ckb1-1 and ckb1-2) and over-expression plants (35S:CKB1-1, 35S:CKB1-2) of Arabidopsis thaliana were studied to understand the role of CKB1 in abiotic stress and gibberellic acid (GA) signaling. Histochemical staining showed that although CKB1 was expressed in all organs, it had a relatively higher expression in conducting tissues. The ckb1 mutants showed reduced sensitivity to abscisic acid (ABA) during seed germination and seedling growth. The increased stomatal aperture, leaf water loss and proline accumulation were observed in ckb1 mutants. In contrast, the ckb1 mutant had increased sensitivity to polyaluminum chloride during seed germination and hypocotyl elongation. We obtained opposite results in over-expression plants. The expression levels of a number of genes in the ABA and GA regulatory network had changed. This study demonstrates that CKB1 is an ABA signaling-related gene, which subsequently influences GA metabolism, and may play a positive role in ABA signaling.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Giberelinas/metabolismo , Transdução de Sinais , Estresse Fisiológico/genética , Ácido Abscísico/fisiologia , Arabidopsis/enzimologia , Arabidopsis/crescimento & desenvolvimento , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , DNA Bacteriano , DNA de Plantas , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Germinação , Hipocótilo/crescimento & desenvolvimento , Mutação , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Estômatos de Plantas/fisiologia , Prolina/metabolismo , Plântula/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Água/fisiologia
4.
Mol Biol Rep ; 35(2): 179-87, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17390236

RESUMO

It has been reported that mouse Lbh (limb-bud and heart) can regulate cardiac gene expression by modulating the combinatorial activities of key cardiac transcription factors, as well as their individual functions in cardiogenesis. Here we report the cloning and characterization of the human homolog of mouse Lbh gene, hLBH, from a human embryonic heart cDNA library. The cDNA of hLBH is 2927 bp long, encoding a protein product of 105 amino acids. The protein is highly conserved in evolution across different species from zebra fish, to mouse, to human. Northern blot analysis indicates that a 2.9 kb transcript specific for hLBH is most abundantly expressed in both embryonic and adult heart tissue. In COS-7 cells, hLBH proteins are localized to both the nucleus and the cytoplasm. hLBH is a transcription activator when fused to Gal-4 DNA-binding domain. Deletion analysis indicates that both the N-terminal containing proline-dependent serine/threonine kinase group and the C-terminal containing ERK D-domain motif are required for transcriptional activation. Overexpression of hLBH in COS-7 cells activates the transcriptional activities of activator protein-1 (AP-1) and serum response element (SRE). These results suggest that hLBH proteins may act as a transcriptional activator in mitogen-activated protein kinase signaling pathway to mediate cellular functions.


Assuntos
Sistema de Sinalização das MAP Quinases , Miocárdio/metabolismo , Proteínas Nucleares/genética , Homologia de Sequência de Aminoácidos , Elemento de Resposta Sérica/genética , Transativadores/metabolismo , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Proteínas de Ciclo Celular , Chlorocebus aethiops , Sequência Conservada , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Genoma Humano/genética , Humanos , Camundongos , Dados de Sequência Molecular , Filogenia , Transporte Proteico , Frações Subcelulares/metabolismo , Transativadores/genética , Fatores de Transcrição/genética , Ativação Transcricional/genética
5.
Biochem Biophys Res Commun ; 323(1): 9-16, 2004 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-15351693

RESUMO

The tripartite motif (TRIM) proteins play important roles in a variety of cellular functions including cell proliferation, differentiation, development, oncogenesis, and apoptosis. In this study, we report the identification and characterization of the human tripartite motif-containing protein 45 (TRIM45), a novel member of the TRIM family, from a human embryonic heart cDNA library. TRIM45 has a predicted 580 amino acid open reading frame, encoding a putative 64-kDa protein. The N-terminal region harbors a RING finger, two B-boxes, and a predicted alpha-helical coiled-coil domain, which together form the RBCC/TRIM motif found in a large family of proteins, whereas the C-terminal region contains a filamin-type immunoglobulin (IG-FLMN) domain. Northern blot analysis indicates that TRIM45 is expressed in a variety of human adult and embryonic tissues. In the cell, TRIM45 protein is expressed both in cytoplasm and in cell nucleus. Overexpression of TRIM45 in COS-7 cells inhibits the transcriptional activities of ElK-1 and AP-1. These results suggest that TRIM45 may act as a new transcriptional repressor in mitogen-activated protein kinase signaling pathway.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/fisiologia , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Apoptose , Sequência de Bases , Northern Blotting , Células COS , Diferenciação Celular , Divisão Celular , Núcleo Celular/metabolismo , Clonagem Molecular , Biologia Computacional , Citoplasma/metabolismo , DNA Complementar/metabolismo , Éxons , Biblioteca Gênica , Genes Reporter , Humanos , Sistema de Sinalização das MAP Quinases , Dados de Sequência Molecular , Miocárdio/metabolismo , Fases de Leitura Aberta , Filogenia , Estrutura Terciária de Proteína , RNA/química , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Distribuição Tecidual , Ativação Transcricional , Transfecção , Proteínas Elk-1 do Domínio ets
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