https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:22047 Wed 11 Apr 2018 15:53:58 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:13838 Wed 11 Apr 2018 10:06:11 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52445 4+/Ce³⁺ compositions. Using DFT calculations combined with Bader charge analysis, it is demonstrated that stoichiometric ceria registers a higher oxidase mimetic activity than oxygen-deficient ceria with a low Ce⁴⁺/Ce³⁺ ratio due to a higher charge transfer from a substrate, 3,3',5,5' tetramethylbenzidine (TMB), to the ceria surface. We also show that the fluoride ions can significantly increase the charge transfer from the TMB surface to ceria irrespective of the surface Ce⁴⁺/Ce³⁺ ratio. Using this knowledge, we first compare the fluoride sensing properties of nanoceria with high Ce⁴⁺ and mixed Ce⁴⁺/Ce³⁺ oxidation states and further demonstrate that the linear detection range of fluoride ions can be extended to 1-10 ppm for nanoceria with mixed oxidation states. Then, we also demonstrate an assay for fluoride assisted detection of glutathione, an antioxidant with elevated levels during cancer, using nanoceria with a high surface Ce⁴⁺/Ce³⁺ ratio. The addition of fluoride ions in this assay allows the detection of glutathione in the linear range of 2.5-50 ppm with a limit of detection (LOD) of 3.8 ppm. These studies not only underpin the role of the surface Ce⁴⁺/Ce³⁺ ratio in tuning the fluoride assisted boost in the oxidase mimetic activity of nanoceria but also its strategic application in designing better colourimetric assays.]]> Thu 12 Oct 2023 15:28:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:2865 Sat 24 Mar 2018 08:28:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1683 7.5) are not equipped to describe this complex system, largely because the PHREEQ model includes only precipitation reactions, whereas a combination of adsorption and precipitation parameters are required.]]> Sat 24 Mar 2018 08:27:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:12271 Sat 24 Mar 2018 08:10:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:10731 Sat 24 Mar 2018 08:09:48 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30613 −, toxic contaminants CN⁻ and AsO₃³⁻/AsO₄³⁻, and anionic fluorosurfactants. The anionic fluorosurfactants mainly include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), both of which have recently been listed as emerging contaminants and categorised as persistent organic pollutants. This review addresses recent advancements in the development of gold nanoparticle-based nano-sensors for such anions and outlines their performance limitations towards on-site applications.]]> Sat 24 Mar 2018 07:28:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25705 sulfate > nitrate with no difference between sodium, potassium and calcium ions. The effectiveness of sodium halides on browning was fluoride > chloride = bromide > iodide = control. Polyphenol oxidase (PPO) activity of tissue extracted from chloride- and fluoride-treated slices was not different to control but when added into the assay solution, NaF > NaCl both showed lower PPO activity at pH 3-5 compared to control buffer. The level of polyphenols in treated slices was NaF > NaCl > control. Addition of chlorogenic acid to slices enhanced browning but NaCl and NaF counteracted this effect. There was no effect of either halide salt on respiration, ethylene production, ion leakage, and antioxidant activity. Conclusion: Dipping apple slices in NaCl is a low cost treatment with few impediments to commercial use and could be a replacement for other anti-browning additives.]]> Sat 24 Mar 2018 07:28:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:22725 Hill 4 > PSO due to the ability of the Hill models to accommodate sigmoidal kinetics. Removal of fluoride from SPLL under atmospheric CO2 conditions was found to be inhibited with no removal occurring for the first 3000 min with the inhibition times, based on the reaction half-life, reducing with increased CO₂ partial pressure and stirring rate. X-ray diffraction (XRD) analysis revealed that the residual solid filtrate consisted of trona (Na₃(CO₃)(HCO₃)·2H₂O) a potentially valuable mineral kogarkoite (Na₃SO₄F) and fluorite (CaF₂) accounting for fluoride removal, and unreacted calcite (CaCO₃).]]> Sat 24 Mar 2018 07:15:27 AEDT ]]>