Interferon regulatory factor 7- (IRF7-) mediated immune response affects Newcastle disease virus replication in chicken embryo fibroblasts

Interferon regulatory factor 7 (IRF7) is essential for the induction of an antiviral response. Previous studies have shown that virus replication causes the activation or expression of Type I interferon (IFN) in cells, which further activates IFN-stimulated genes (ISGs) to retard virus growth. In this study, after infection of chicken embryo fibroblasts (CEFs) with the lentogenic Newcastle disease virus (NDV) strain LaSota or the velogenic NDV strain GM, the mRNA and protein levels of IRF7 showed a significant increase, and part of the IRF7 protein was translocated from the cytoplasm to the nucleus. In order to further explore the effect of IRF7-mediated innate immune response on the replication of NDV in CEFs, the mRNA levels of IFN-α, IFN-β and STAT1 were measured and the replication kinetics of NDV determined. The results showed that specific siRNA could inhibit the expression of IRF7 and limit the mRNA level of IFN-α, IFN-β and STAT1 and, accordingly, the replication kinetics of both NDVs were enhanced after the inhibition of IRF7. In conclusion, IRF7 is an important nuclear transcription factor for the induction of Type I IFNs during the antiviral response, which can affect the replication of NDV and spread to CEFs in the early phase of viral infection

Effects of Cl − on Cu 2 O nanocubes for direct epoxidation of propylene by molecular oxygen

Abstract(#br)Promoters have been widely used in industrial catalysis but understanding the mechanism behind their function is still a challenging subject. As ideal model catalysts, nanocrystal catalysts with well−defined exposing facets and relatively large specific surface have attracted intense attention. We explored the effect of Cl − loading on Cu 2 O nanocubes enclosed by (100) facets for the direct epoxidation of propylene by molecular oxygen. Interestingly, a volcano−type curve was obtained when the selectivity and conversion are plotted as a function of the loading amount of Cl − , indicating that optimal surface O/Cl − ratio is critical for desirable catalytic performance

Synthesis of size-controlled monodisperse Pd nanoparticles via a non-aqueous seed-mediated growth

We demonstrated that stepwise seed-mediated growth could be extended in non-aqueous solution (solvothermal synthesis) and improved as an effective method for controlling the uniform size of palladium nanoparticles (Pd NPs) in a wide range. The monodisperse Pd NPs with the size of about 5 nm were synthesized by simply reducing Pd(acac)(2) with formaldehyde in different organic amine solvents. By an improved stepwise seed-mediated synthesis, the size of the monodisperse Pd NPs can be precisely controlled from approximately 5 to 10 nm. The as-prepared Pd NPs could self assemble to well-shaped superlattice crystal without size selection process.National Basic Research Program of China [2011CBA00508]; National Natural Science Foundation of China [21171141]; National Fund for Fostering Talents of Basic Science [J1030415

One-step synthesis of thermally stable artificial multienzyme cascade system for efficient enzymatic electrochemical detection

Abstract(#br)Recently, metal-organic framework (MOF)-based multienzyme systems integrating different functional natural enzymes and/or nanomaterial-based artificial enzymes are attracting increasing attention due to their high catalytic efficiency and promising application in sensing. Simple and controllable integration of enzymes or nanozymes within MOFs is crucial for achieving efficient cascade catalysis and high stability. Here, we report a facile electrochemical assisted biomimetic mineralization strategy to prepare an artificial multienzyme system for efficient electrochemical detection of biomolecules. By using the GO x @Cu-MOF/copper foam (GO x @Cu-MOF/CF) architecture as a proof of concept, efficient enzyme immobilization and cascade catalysis were achieved by in situ..

High-efficiently visible light-responsive photocatalysts: Ag3PO4 tetrahedral microcrystals with exposed {111} facets of high surface energy

National Basic Research Program of China [2011CBA00508, 2013CB933901]; National Natural Science Foundation of China [21333008, 21131005, 21021061, 21171141]In this article, single-crystalline tetrahedral Ag3PO4 microcrystals with exposed {111} facets was successfully synthesized via a facile wet chemical method. The tetrahedral Ag3PO4 with exposed {111} facets showed the highest photocatalytic activity in visible light irradiation among the {111}, {110} and {100} facets. By DFT calculations, it is demonstrated that the surface energy of the {111} facets is higher than that of the {110} and {100} facets. It was found that the largest band gap of the Ag3PO4 {111} surface is likely to suppress the recombination of electron-hole pairs by exploring the electronic structures of the different surfaces of Ag3PO4. Meanwhile, the dispersion between the valence bands and conduction bands of the {111} surface is beneficial for the separation of photogenerated electrons and holes on the {111} surface, which further improves the photocatalytic activity of the {111} surface

Intense and wavelength-tunable photoluminescence from surface functionalized MgO nanocrystal clusters

We report fancy brilliant photoluminescence (PL) from surface functionalized MgO nanocrystal clusters (NCs). Single-crystal-like MgO NCs were prepared by a simple one-pot pyrolysis method in the mixed organic solvent of octylamine (OTA) and oleic acid (OA) using magnesium acetate as a precursor. Under the chemical equilibrium of etching and re-growth with the assistance of OA, the MgO products were surface functionalized. It was found that such surface functionalized MgO NCs exhibited intense visible light PL with high PL thermal-stability, and the apparent quantum yield was as high as 19 +/- 1%. In addition, through controlling the synthetic temperature and the reaction time, the functionalized surfaces of MgO NCs were facilely tuned, resulting in the tuneable wavelength of the PL from blue-violet to yellow. Different low-coordinated oxygen sites, capping OA and carbonate species on the surface of the MgO nanocrystals were thought to be the origin of PL at different wavelengths. Considering the intense PL, high PL stability at ambient conditions, low cost and low toxicity, such MgO NCs might have potential applications in medicine and biology as a new kind of fluorescent label.National Natural Science Foundation of China[20725310, 20721001, 21073145, 20801045]; National Basic Research Program of China[2007CB815303, 2011CBA00508

Solid state precursor strategy for synthesizing hollow TiO(2) boxes with a high percentage of reactive {001} facets exposed

Three-dimensional, hollow, anatase TiO(2) boxes, each was enclosed by six single-crystalline TiO(2) plates exposed with highly reactive {001} facets, were facilely obtained by calcining a cubic TiOF(2) solid precursor at 500-600 degrees C. The formation of such particular nanostructures is attributed to the hard self-template restriction and the adsorption of F(-) ions from the TiOF(2).National Natural Science Foundation of China[20725310, 20801045, 21021061, 21073145]; National Basic Research Program of China[2007CB815303, 2011CBA00508

Solvothermal synthesis and Curie temperature of monodispersed barium titanate nanoparticles

Barium titanate (BaTiO3) nanoparticles with various particle sizes were prepared by a solvothermal method X-ray powder diffraction (XRPD) patterns show that the as-prepared powders are of pure perovskite BaTiO3 Scanning electron microscopy (SEM) reveals that all the particles of BaTiO3 with different sizes are dispersed homogenously and have uniform size The room temperature and in situ high temperature XRD analyses indicate that both the proportion of the tetragonal phase and the Curie temperature of BaTiO3 Increase with increasing particles size The effects of the reaction parameters such as the concentration of reactants the polarity of solvent the reaction temperature and the amount of surfactant on the size morphology and uniformity of BaTiO3 nanoparticles are studied in detail (C) 2010 Elsevier B V All rights reservedNatural Science and Engineering Research Council of Canada (NSERC) ; National Natural Science Foundation of China [20725310, 91022020]; National Basic Research Program of China [2007CB815303

Tuning electronic structure of PdZn nanocatalyst via acid-etching strategy for highly selective and stable electrolytic nitrogen fixation under ambient conditions

Abstract(#br)Although ambient nitrogen fixation powered by renewable electricity is emerging as a highly attractive alternative to the classical Haber–Bosch process, it still remains extremely challenging. In this work, a facile acid-etching strategy was employed to synthesize defect-rich PdZn nanoparticles (NPs) supported on N-doped hollow carbon polyhedrons (etched-PdZn/NHCP), which could serve as an attractive and efficient electrocatalyst for the nitrogen reduction reaction (NRR). The synthesized etched-PdZn/NHCP electrocatalyst achieved higher NH 3 yields (5.28 μg mg -1 cat. h -1 ) than pristine PdZn NPs in a phosphate buffer solution. Remarkably, the existence of abundant defects in the etched PdZn NPs favored N 2 adsorption and activation, resulting in significantly high Faradaic efficiency (FE) of 16.9% towards NH 3 and outperforming previously reported Pd-based NRR electrocatalysts. Furthermore, the etched-PdZn/NHCP cathode exhibited good long-term electrochemical durability with both the NH 3 production and the FE remaining practically stable after 50 h of electrolysis