41 research outputs found

    Metabolically protective cytokines adiponectin and fibroblast growth factor-21 are increased by acute overfeeding in healthy humans

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    Context: Circulating levels of metabolically protective and adverse cytokines are altered in obese humans and rodent models. However, it is not clear whether these cytokines are altered rapidly in response to over-nutrition, or as a later consequence of the obese state. Methods: Forty sedentary healthy individuals were examined prior to and at 3 and 28 days of high fat overfeeding (+1250 kCal/day, 45% fat). Insulin sensitivity (hyperinsulinaemic-euglycaemic clamp), adiposity, serum levels of adiponectin and fibroblast growth factor-21 (FGF21), fatty acid binding protein-4 (FABP4), lipocalin-2 and plasminogen activator factor-1 (PAI1) were assessed. Statistics were performed by repeated measures ANOVA. Results: Overfeeding increased weight, body fat and liver fat, fasting glucose, insulin and reduced insulin sensitivity by clamp (all P <0.05). Metabolically protective cytokines, adiponectin and FGF21 were increased at day 3 of overfeeding (P ≤0.001) and adiponectin was also elevated at day 28 (P=0.001). FABP4, lipocalin-2 and PAI-1 were not changed by overfeeding at either time point. Conclusion: Metabolically protective cytokines, adiponectin and FGF-21, were increased by over nutrition and weight gain in healthy humans, despite increases in insulin resistance. We speculate that this was in attempt to maintain glucose homeostasis in a state of nutritional excess. PAI-I, FABP4 and lipocalin 2 were not altered by overfeeding suggesting that changes in these cytokines may be a later consequence of the obese state.Leonie K. Heilbronn, Lesley V. Campbell, Aimin Xu, Dorit Samocha-Bone

    Functionalized zeolite-solvent catalytic systems for microwave-assisted dehydration of fructose to 5-hydroxymethylfurfural

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    This study investigates the structure-performance relationships in different zeolite-solvent systems that are suitable for microwave-assisted dehydration of food waste-derived fructose to 5-hydroxymethylfurfural (HMF). Different types of zeolites (MFI, BEA, and Y) were examined as acid catalysts. Water was first tested as the greenest solvent (baseline), followed by dimethyl sulfoxide (DMSO), acetone, -valerolactone (GVL), and propylene carbonate (PC)/water (1:1 v/v) binary solvent systems. The results showed that the HMF yield was independent of particle size of MFI zeolite in water. The secondary porosities improved the HMF yield, while byproducts formation (via rehydration or polymerization) was also increased due to the enlarged channels in zeolites. All tested zeolites showed higher fructose conversion, HMF yield, and HMF selectivity in organic-water solvent systems than in water. The synergistic effects of the substrates, catalysts, and solvent-product interactions in the hydrophobic Y zeolite/DMSO system yielded the highest fructose conversion (72.4%) and HMF yield (49.2%). This study advances our understanding of green solvents and functionalized zeolites for microwave-assisted biomass conversion in sustainable biorefinery

    Sustainable production of high-value gluconic acid and glucaric acid through oxidation of biomass-derived glucose : a critical review

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    202203 bcfcAccepted ManuscriptRGCOthersHong Kong International Airport Environmental Fund [Phase 2] Publishe

    Revealing OH species in situ generated on low-valence Cu sites for selective carbonyl oxidation

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    202411 bcchVersion of RecordRGCOthersMOE AcRF Tier 1PublishedC

    Life-cycle assessment on food waste valorisation to value-added products

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    202308 bcchAccepted ManuscriptOthersHong Kong International Airport Environmental Fund; Environment and Conservation FundPublishe

    Photo-Fenton abatement of aqueous organics using metal-organic frameworks: an advancement from benchmark zeolite

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    A new and environmentally benign photocatalyst is introduced in this study, which was synthesized via incipient wetness impregnation onto MIL-47(V) using an ethanolic Fe(III) chloride solution. The resultant materials were characterized by XRD, FE-SEM, and HR-TEM analyses. The photocatalytic capability of Fe/MIL-47 towards removal of methylene blue (MB) was evaluated in comparison to MIL-53(Al), Cu/MIL-47, and Fe/zeolite-Y. The unmodified MIL-47 achieved 55% MB removal after 20-min exposure to UV/H2O2, through photodegradation as the dominant mechanism. Incorporation of Fe species into MIL-47 significantly increased the MB removal rate by 2.4-fold and accomplished nearly complete removal (98.2%) in 60 min, outcompeting the performance of Cu/MIL-47 and Fe/zeolite-Y. Based on the results of XRD, the impregnation of Fe retained the crystalline characteristics of MIL-47. The significance of temperature, catalyst dose, pH, and molar ratio of H2O2:MB was also evaluated in governing the photocatalytic activity of Fe/MIL-47. The reusability of Fe/MIL-47 was evidenced through its repetitive uses in MB photodegradation. The current work highlighted the potential of Fe impregnation for modification of MOFs in order to fabricate highly efficient and water-stable heterogeneous photocatalyst for degradation of organic pollutants. With the use of an economical and environmentally safe reagent (i.e., Fe), robust photocatalyst can exhibit high sustainability to warrant clean environmental remediation

    Life-cycle cost-benefit analysis on sustainable food waste management : the case of Hong Kong International Airport

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    202308 bcchAccepted ManuscriptOthersHong Kong International Airport Environmental Fund and Hong Kong Environment and Conservation FundPublishe

    Valorization of humins from food waste biorefinery for synthesis of biochar-supported lewis acid catalysts

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    202303 bcfcAccepted ManuscriptRGCOthersHong Kong International Airport Environmental Fund (Phase 2); PolyU Project of Strategic ImportancePublishe

    A review of biochar-based catalysts for chemical synthesis, biofuel production, and pollution control

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    202308 bcchAccepted ManuscriptOthersHong Kong International Airport Environmental Fund; Environment and Conservation FundPublishe
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