RESUMEN
Manipulating the surface reconstruction of Ni-based catalysts to form NiOOH intermediates is crucial for electrooxidation. Herein, we report a phytate coordination-induced enrichment of NiOOH on phytate-coordinated Ni foam, which exhibited high catalytic performance for 5-hydroxymethylfurfural electro-oxidation. The HMF oxidation rate of 0.76 mmol h-1 outperformed the majority of Ni-based catalysts.
RESUMEN
Coupling acid-electrolyte proton exchange membrane fuel cells for electricity generation and cathodic hydrogenation for valuable chemical production shows great potential in energy and chemical industry. The key for this promising approach is the identification of cathode electrocatalysts with acid resistance, high activity, and low fabrication cost for practical applications. Among various promising cathodic candidates for this integrative approach, the easily available and cheap Cu suffers from low acidic hydrogenation activity due to kinetically arduous proton adsorption/activation. Inspired by the kinetic advantages of the concerted proton-coupled electron transfer (CPET) over the sequential proton-electron transfer process, herein, we use phytate coordination on Cu surface to overcome the kinetic bottleneck for proton adsorption/activation through the CPET pathway in an acidic half-cell setup; this leads to 1 order of magnitude activity enhancement (36.94-fold) for nitrobenzene hydrogenation. Mechanistic analysis confirms that phytate, as proton acceptor, induces the CPET process and overcomes the above kinetic limitations by tuning the d-band center and concentrating protons on the Cu surface. Consequently, the CPET process facilitates the formation of active hydrogen intermediates for efficient cathodic hydrogenation. This work provides a promising approach to integrate electricity generation and chemical production.
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Despite the known efficacy of CeO2 as a promoter in alkaline hydrogen evolution reaction (HER), the underlying mechanism of this effect remains unclear. CoS2 , a pyrite-type alkaline HER electrocatalyst, suffers from sluggish HER kinetics and severe catalyst leaching due to its weak water dissociation kinetics and oxygen-related corrosion. Herein, it is demonstrated that the interfacial Lewis acid-base CeâââS pairs in CeO2 -loaded CoS2 effectively improve the catalytic activity and durability. In CeO2 -loaded CoS2 nanowire array electrodes, these interfacial Lewis acid-base CeâââS pairs with unique electronic and structural configurations efficiently activate water adsorptive dissociation and kinetically accelerate hydrogen evolution, delivering a low overpotential of 36 mV at 10 mA cm-2 in alkaline media. Such CeâââS pairs also weaken O2 adsorption on CoS2 , leading to undecayed activity over 1000 h. These findings are expected to provide guidance for the design of CeO2 -based electrocatalysts as well as other hybrid electrocatalysts for water splitting.
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The dynamic simulation of cucumber growth and development in sunlight greenhouse can provide technical support for the intelligent management of cucumber production. According to the cucumber response characteristics to light and temperature, the cucumber development module based on the algorithm of clock model was established by using data from four-stage experiment with 'Jinyou 35' as experiment variety in two years. Based on the relationship between the leaf growth and key meteorological factors (temperature and radiation), leaf area index (LAI) module was established with the accumulated product of thermal effectiveness and photosynthetically active radiation (TEP) as independent variables. The simulation module of cucumber dry matter production was established by taking into consideration the double integral of LAI and daily length in photosynthesis per unit leaf area as well as the respiratory expenditure of different organs. Combined with water content of organs, fresh weight simulation module of cucumber organs was constructed. The whole cucumber development and growth simulation model in greenhouse was built based on each sub-module. The model parameters were calibrated and determined. The results showed that root mean square error (RMSE) of simulated values and observed values of four deve-lopment stages (from transplanting date to stretch tendril, to initial flowering, to early harvested and to uprooting), was 3.9-10.5 d. The normalized root mean square error (nRMSE) was 6.5%-28.6%. The coincidence index (D) was 0.79-0.97. The relationship between LAI and TEP was the regression of 'S' type curve. The RMSE of simulated and observed LAI values was 0.19. The nRMSE was 17.2%. The D value was 0.90. The RMSE of dry weight of root, stem, leaf, flower and fruit of the simulated values and observed values were 0.39-8.94 g·m-2. The nRMSE were 10.9%-17.7%. The D values were all above 0.98. The growth and development model of cucumber could accurately simulate the key development period of cucumber, leaf area and the dry and fresh weight of various organs and quantify the growth and development of cucumber in sunlight greenhouse.
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Cucumis sativus , Crecimiento y Desarrollo , Fotosíntesis , Hojas de la Planta , Luz SolarRESUMEN
Human monopolar spindle-one-binder 2 (hMOB2) is a member of the hMOB family of proteins, and it has been reported to regulate the nuclear-Dbf2-related kinase (NDR) activation. However, the function of hMOB2 expression in tumor cell adhesion and motility has not been addressed. Herein, the lentiviral-mediated overexpression and the knockdown of hMOB2 in HepG2 and SMMC-7721 cells was established. It was demonstrated that overexpression of hMOB2 significantly reduced the cell motility and enhanced the cell-matrix adhesion, while the hMOB2 knockdown decreased not only the cell motility, but also the cell-matrix adhesion. Immunofluorescence results showed that both hMOB2 overexpression and knockdown altered assembly of the focal adhesions and the actin cytoskeleton rearrangement. Furthermore, the focal adhesion kinase (FAK)-Src-paxillin signal pathway activated by hMOB2 was confirmed to be involved in controlling the cell motility and the cell-matrix adhesion. These results demonstrated that the altered cell-matrix adhesion and cell motility induced by hMOB2 expression was caused by the assembly of focal adhesions as well as the actin cytoskeleton rearrangement through the activation of the FAK-Src-paxillin signal pathway, unveiling a novel mechanism of cell motility and cell-matrix adhesion regulation induced by hMOB2 expression.
Asunto(s)
Adhesión Celular/genética , Movimiento Celular/genética , Adhesiones Focales/genética , Invasividad Neoplásica/genética , Proteínas del Tejido Nervioso/genética , Citoesqueleto de Actina/genética , Adhesión Celular/fisiología , Línea Celular , Línea Celular Tumoral , Movimiento Celular/fisiología , Activación Enzimática/genética , Matriz Extracelular/genética , Matriz Extracelular/patología , Quinasa 1 de Adhesión Focal/genética , Adhesiones Focales/patología , Genes src/genética , Células HEK293 , Células Hep G2 , Humanos , Invasividad Neoplásica/patología , Paxillin/genética , Transducción de Señal/genéticaRESUMEN
We constructed a recombinant adenoviral vector expressing human tissue inhibitors of metalloproteinase-1(TIMP-1), and evaluated the inhibition of TIMP-1 secreted by primary fibroblasts after infection with adenovirus-mediated TIMP-1 gene (Ad-TIMP-1) on tumor cell invasion and metastasis in mouse melanoma. It was found that TIMP-1 was detected in the supernatants of cultured mouse primary fibroblasts after infection with Ad-TIMP-1 by indirect enzyme-linked immunosorbent assay (ELISA). The TIMP-1 secreted by Ad-TIMP-1 infected primary fibroblast significantly inhibited B16BL6 cell invasion and metastasis both in vitro and in vivo. We also demonstrated that the primary fibroblasts transfected by Ad-TIMP-1, after being subcutaneously injected into mouse, can secreted TIMP-1 into the blood of mouse and maintained at the therapeutic in vivo levels of TIMP-1. These results suggest that the preparation of Ad-TIMP-1 infected primary fibroblast be an effective method to deliver TIMP-1 gene in vivo, which provides a new strategy of gene therapy and has the potential for clinical applications in the treatment of tumor cell metastasis.
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Fibroblastos/metabolismo , Melanoma Experimental/patología , Inhibidor Tisular de Metaloproteinasa-1/biosíntesis , Inhibidor Tisular de Metaloproteinasa-1/farmacología , Adenoviridae/genética , Adenoviridae/metabolismo , Animales , Femenino , Terapia Genética , Humanos , Melanoma Experimental/terapia , Ratones , Ratones Endogámicos C57BL , Invasividad Neoplásica , Metástasis de la Neoplasia , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Inhibidor Tisular de Metaloproteinasa-1/genéticaRESUMEN
Melanoma-associated antigen family protein-D1 (MAGE-D1) is a recently identified p75 neurotrophin receptor intracellular binding protein and functions as an adaptor that mediates multiple signaling pathways, including Dlx/Msx-mediated transcription. Here, a new regulatory function for MAGE-D1 in tumor cell motility and adhesion to endothelium is described. MAGE-D1 over-expression suppressed HeLa cell and BEL7402 cell migration, invasion, and adhesion to the monolayer of ECV304 cells. We also report that MAGE-D1 over-expression disrupted actin cytoskeleton rearrangement induced by hypoxia and down-regulated hypoxia inducible factor 1-dependent luciferase gene expression. These findings provide new insight into the ability of MAGE-D1 to suppress the motility and adhesion response of tumor cells by interfering with actin cytoskeleton reorganization and hypoxia inducible factor 1-dependent gene expression.
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Actinas/metabolismo , Antígenos de Neoplasias/metabolismo , Movimiento Celular , Endotelio/patología , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Actinas/química , Adenoviridae/genética , Western Blotting , Adhesión Celular , Hipoxia de la Célula , Línea Celular Tumoral , Proliferación Celular , Citoesqueleto/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes Reporteros , Células HeLa , Humanos , Factor 1 Inducible por Hipoxia/genética , Invasividad Neoplásica , Seudópodos/metabolismo , Cicatrización de HeridasRESUMEN
MAGE-D1 is a member of the MAGE family of proteins, and functions as an adaptor that mediates multiple signaling pathways. The current study for the first time provides evidence for a role of MAGE-D1 in the negative regulation of angiogenic activity in vitro and in vivo models. Our findings showed that MAGE-D1 over-expression significantly suppressed the angiogenic key events such as endothelial cell migration and invasion, adhesion on collagen I substrate, and in vitro differentiation into tube-like structures under both normoxic and hypoxic conditions. MAGE-D1 over-expression also inhibited in vivo angiogenesis in Matrigel plugs that were implanted subcutaneously in mice. With further experiments, we revealed that MAGE-D1 over-expression disrupted actin cytoskeleton organization and lamellipodia formation, and down-regulated HIF-1-dependent gene expression in endothelial cells under hypoxic conditions. These findings demonstrate a new function of MAGE-D1 in the regulation of angiogenesis and provide new insight into the ability of MAGE-D1 to suppress the growth and angiogenic response of endothelial cells by interfering with HIF-1-dependent gene expression, and actin cytoskeleton reorganization, suggesting that MAGE-D1 might be a novel inhibitor of angiogenesis in vitro and in vivo.