431 research outputs found

    Highly selective hydrogenation of furfural over supported Pt nanoparticles under mild conditions

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    The selective liquid phase hydrogenation of furfural to furfuryl alcohol over Pt nanoparticles supported on SiO₂, ZnO, γ-Al2O₃, CeO₂ is reported under extremely mild conditions. Ambient hydrogen pressure, and temperatures as low as 50 °C are shown sufficient to drive furfural hydrogenation with high conversion and >99% selectivity to furfuryl alcohol. Strong support and solvent dependencies are observed, with methanol and n-butanol proving excellent solvents for promoting high furfuryl alcohol yields over uniformly dispersed 4 nm Pt nanoparticles over MgO, CeO₂ and γ-Al₂O₃. In contrast, non-polar solvents conferred poor furfural conversion, while ethanol favored acetal by-product formation. Furfural selective hydrogenation can be tuned through controlling the oxide support, reaction solvent and temperature

    Enhanced Thermoelectric Properties of a Semiconducting Two-Dimensional Metal–Organic Framework via Iodine Loading

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    We report the first result of a study in which molecular iodine has been incorporated via incipient wetness impregnation into the two-dimensional semiconducting metal–organic framework (MOF) Cu3(2,3,6,7,10,11-hexahydroxytriphenylene)2 Cu3(HHTP)2 to enhance its thermoelectric properties. A power factor of 0.757 μW m–1 K–2 for this MOF was obtained which demonstrates that this provides an effective route for the preparation of moderate-performance thermoelectric MOFs

    Paternal low protein diet programs preimplantation embryo gene expression, fetal growth and skeletal development in mice

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    Defining the mechanisms underlying the programming of early life growth is fundamental for improving adult health and wellbeing. While the association between maternal diet, offspring growth and adult disease risk is well-established, the effect of father's diet on offspring development are largely unknown. Therefore, we fed male mice an imbalanced low protein diet (LPD) to determine the impact on post-fertilisation development and fetal growth. We observed that in preimplantation embryos derived from LPD fed males, expression of multiple genes within the central metabolic AMPK pathway was reduced. In late gestation, paternal LPD programmed increased fetal weight, however, placental weight was reduced, resulting in an elevated fetal:placental weight ratio. Analysis of gene expression patterns revealed increased levels of transporters for calcium, amino acids and glucose within LPD placentas. Furthermore, placental expression of the epigenetic regulators Dnmt1 and Dnmt3L were increased also, coinciding with altered patterns of maternal and paternal imprinted genes. More strikingly, we observed fetal skeletal development was perturbed in response to paternal LPD. Here, while offspring of LPD fed males possessed larger skeletons, their bones comprised lower volumes of high mineral density in combination with reduced maturity of bone apatite. These data offer new insight in the underlying programming mechanisms linking poor paternal diet at the time of conception with the development and growth of his offspring

    Isolated PdO sites on SiO2-supported NiO nanoparticles as active sites for allylic alcohol selective oxidation

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    Silica-supported NiO nanoparticles as hosts for isolated PdO catalytic sites. Isolate PdO is confirmed as the species responsible for the chemoselective oxidation of cinnamyl alcohol to cinnamaldehyde by operando X-ray absorption spectroscop

    The antimicrobial efficacy of hypoxia mimicking cobalt oxide doped phosphate-based glasses against clinically relevant Gram positive, Gram negative bacteria and a fungal strain

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    Bioactive phosphate glasses are of considerable interest for a range of soft and hard tissue engineering applications. The glasses are degradable and can release biologically important ions in a controlled manner. The glasses can also potentially be used as an antimicrobial delivery system. In the given study, novel cobalt-doped phosphate-based glasses, (P 2O 5) 50(Na 2O) 20(CaO) 30-x(CoO) x where 0 ≤ x (mol %) ≤ 10, were manufactured and characterized. As the cobalt oxide concentration increased, the rate of dissolution was observed to decrease. The antimicrobial potential of the glasses was studied using direct and indirect contact methods against both Escherichia coli (NCTC 10538) Staphylococcus aureus (ATCC 6538) and Candida albicans (ATCC 76615). The results showed strong, time dependent, and strain specific antimicrobial activity of the glasses against microorganisms when in direct contact. Antimicrobial activity (R) ≥ 2 was observed within 2 h against Escherichia coli, whereas a similar effect was achieved in 6 h against Staphylococcus aureus and Candida albicans. However, when in indirect contact, the dissolution products from the bioactive glasses failed to show an antimicrobial effect. Following direct exposure to the glasses for 7 days, osteoblast-like SAOS-2 cells showed a 5-fold increase in VEGF mRNA while THP-1 monocytic cells showed a 4-fold increase in VEGF mRNA expression when exposed to 10% CoO-doped glass compared with the cobalt free control glass. Endothelial cells stimulated with conditioned medium taken from cell cultures of THP-1 monocytes exposed to 10% CoO doped glass showed clear tubelike structure (blood vessel) formation after 4 h

    Development and Characterization of Gallium-Doped Bioactive Glasses for Potential Bone Cancer Applications

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    In this study, we have developed a series of novel gallium oxide doped bioactive glasses to specifically target osteosarcoma cells while aiding new bone formation. The results show that osteosarcoma (Saos-2) cell death is induced through the addition of gallium oxide. Relative to the gallium-free control glass (0% Ga) glasses containing 1, 2, and 3% Ga decreased Saos-2 cell viability in a dose dependent manner. After 72 h in media preconditioned with 3% Ga Saos-2 cell viability was reduced by over 50%. Corresponding studies undertaken on primary normal human osteoblast cells (NHOst) demonstrated no adverse effects to the gallium containing glasses. Hydroxyapatite formation was observed for all glasses when exposed to simulated body fluid

    Follistatin protein enhances satellite cell counts in reinnervated muscle

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    Background Muscle recovery following peripheral nerve repair is sup-optimal. Follistatin (FST), a potent muscle stimulant, enhances muscle size and satellite cell counts following reinnervation when administered as recombinant FST DNA via viral vectors. Local administration of recombinant FST protein, if effective, would be more clinically translatable but has yet to be investigated following muscle reinnervation. Objective  The aim of this study is to assess the effect of direct delivery of recombinant FST protein on muscle recovery following muscle reinnervation. Materials and Methods  In total, 72 Sprague-Dawley rats underwent temporary (3 or 6 months) denervation or sham denervation. After reinnervation, rats received FST protein (isoform FS-288) or sham treatment via a subcutaneous osmotic pump delivery system. Outcome measures included muscle force, muscle histomorphology, and FST protein quantification. Results  Follistatin treatment resulted in smaller muscles after 3 months denervation ( p  = 0.019) and reduced force after 3 months sham denervation ( p  < 0.001). Conversely, after 6 months of denervation, FST treatment trended toward increased force output ( p  = 0.066). Follistatin increased satellite cell counts after denervation ( p  < 0.001) but reduced satellite cell counts after sham denervation ( p  = 0.037). Conclusion  Follistatin had mixed effects on muscle weight and force. Direct FST protein delivery enhanced satellite cell counts following reinnervation. The positive effect on the satellite cell population is intriguing and warrants further investigation

    Tunable Silver-Functionalized Porous Frameworks for Antibacterial Applications

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    Healthcare-associated infections and the rise of drug-resistant bacteria pose significant challenges to existing antibiotic therapies. Silver nanocomposites are a promising solution to the current crisis, however their therapeutic application requires improved understanding of underpinning structure-function relationships. A family of chemically and structurally modified mesoporous SBA-15 silicas were synthesized as porous host matrices to tune the physicochemical properties of silver nanoparticles. Physicochemical characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES) and porosimetry demonstrate that functionalization by a titania monolayer and the incorporation of macroporosity both increase silver nanoparticle dispersion throughout the silica matrix, thereby promoting Ag₂CO₃ formation and the release of ionic silver in simulated tissue fluid. The Ag₂CO₃ concentration within functionalized porous architectures is a strong predictor for antibacterial efficacy against a broad spectrum of pathogens, including C. difficile and methicillin-resistant Staphylococcus aureus (MRSA)

    Development of Ca/KIT-6 adsorbents for high temperature CO2 capture

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    The incorporation of CaO into an inert porous solid support has been identified as an effective approach to improve the stability of adsorbents for CO2 capture. In this work, we focus on enhancing the capacity of carbon capture and cyclic stability of CaO by impregnating CaO particles into a three-dimensional mesoporous silica (KIT-6) support. At a low CaO loading, the three-dimensional mesoporous support was filled with CaO nano-particles. The further increase of CaO loading resulted in the aggregation of CaO particles on the external surface of the support material, as identified by electron microscopy analysis. These CaO/KIT-6 adsorbents show excellent high-temperature CO2 carbonation/calcination stability over multiple cycles of CaO carbonation and calcination. The enhancement of the performance of carbon capture is attributed to the interaction between CaO and the silica skeleton of KIT-6 through the formation of interfacial CaSiO3 and Ca2SiO4 which enhanced the resistance of CaO sintering

    Facile synthesis of hierarchical Cu2O nanocubes as visible light photocatalysts

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    Hierarchically structured Cu2O nanocubes have been synthesized by a facile and cost-effective one-pot, solution phase process. Self-assembly of 5 nm Cu2O nanocrystallites induced through reduction by glucose affords a mesoporous 375 nm cubic architecture with superior visible light photocatalytic performance in both methylene blue dye degradation and hydrogen production from water than conventional non-porous analogues. Hierarchical nanocubes offer improved accessible surface active sites and optical/electronic properties, which act in concert to confer 200–300% rate-enhancements for the photocatalytic decomposition of organic pollutants and solar fuels
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