Journal articles: 'Oxidisation'

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Krupińska, Izabela. "The Impact of Potassium Manganate (VII) on the Effectiveness of Coagulation in the Removal of Iron and Manganese from Groundwater with an Increased Content of Organic Substances." Civil and Environmental Engineering Reports 27, no. 4 (December 20, 2017): 29–41. http://dx.doi.org/10.1515/ceer-2017-0048.

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Abstract The article presents the results of studies concerning the impact of the method of Fe(II) ion oxidisation (dissolved oxygen and potassium manganate (VII)) on the effectiveness of coagulation in the removal of iron and manganese from groundwater with an increased content of organic substances. The efficiencies of two coagulants were compared: aluminium sulphate (VI) and polyaluminium chloride (Flokor 1.2A). Among the used methods of iron (II) oxidisation, the best effects have been achieved by potassium manganate (VII) because one of the oxidation products was manganese oxide (IV) precipitating from water. Better results in purifying the water were obtained with the use of a prehydrolysed coagulant Flokor 1.2 A than aluminium sulphate (VI).

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KRUPIŃSKA, Izabela. "THE IMPACT OF THE OXIDISING AGENT TYPE AND COAGULANT TYPE ON THE EFFECTIVENESS OF COAGULATION IN THE REMOVAL OF POLLUTANTS FROM UNDERGROUND WATER WITH AN INCREASED CONTENT OF ORGANIC SUBSTANCES." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 24, no. 1 (March 24, 2016): 70–78. http://dx.doi.org/10.3846/16486897.2015.1113179.

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The article presents the results of studies concerning the impact of the method of Fe(II) ion oxidisation on the effectiveness of coagulation in the removal of pollutants from underground water with an increased content of organic substances (TOC up to 5.338mgC/dm3). In order to oxidise the Fe (II) ions before the coagulation process, the underground water was subjected to aeration, or either potassium manganate (VII) or hydrogen peroxide were dosed in the stoichiometric amount in view of the concentration of Fe (II). The efficiencies of three coagulants were compared: that of aluminium sulphate (VI), polyaluminium chloride (PAX XL-60) and iron (III) sulphate (VI) – PIX-112. Coagulant doses expressed in mgal/dm3 or mgfe/dm3 and changed within the range of 1 to 6 mgal(Fe)/dm3. Volume coagulation was performed in 1-dm3 groundwater samples using 1-minute rapid mix (250 rpm) and 25-minute slow mix (30 rpm) followed by 2-hour sedimentation. It has been proven that the type of oxidising agent and coagulant, as well as their dose, co-determines the effectiveness of the removal of the pollutants. Among the used methods of iron (II) oxidisation, the best effects have been achieved by potassium manganate (VII) with regards to the effects of the reduction of colour, turbidity, concentration of manganese and organic substances, and with regards to the extent of total iron removal, oxidisation with dissolved oxygen was the most effective solution. Hydrogen peroxide was the least useful oxidising agent. Regardless of the oxidising agent the best results in the removal of pollutants in the coagulation process were produced by the coagulant: pre-hydrolysed polyaluminium chloride PAX XL-60, and the worst by the iron coagulant: iron (III) sulphate (VI). Analysis of the results of the studies also showed that the effectiveness of pollutant removal from the underground water in the coagulation process was decreased together with an increase in the value of the TOC/Fetot only in the case of water samples which, after aeration, differed in terms of the coefficient of organic substances and total iron (D). Such a relationship was not found when potassium manganate (VII) and hydrogen peroxide were used for oxidisation before the coagulation process.

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Fabijanić, Ivana, Vesna Janicki, Josep Ferré-Borrull, Matej Bubaš, Vesna Blažek Bregović, Lluis F. Marsal, and Jordi Sancho-Parramon. "Plasmonic Nanoparticles and Island Films for Solar Energy Harvesting: A Comparative Study of Cu, Al, Ag and Au Performance." Coatings 9, no. 6 (June 13, 2019): 382. http://dx.doi.org/10.3390/coatings9060382.

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Alternative materials that can potentially replace Au and Ag in plasmonics and broaden its application potential have been actively investigated over the last decade. Cu and Al have been usually overlooked as plasmonic material candidates because they are prone to oxidisation. In this work the plasmonic performance of Cu and Al is investigated using numerical simulations of different nanostructures (spheres, cubes, rods and particle dimers) and taking into account the presence of oxidisation. It is shown that geometry can play a dominant role over material properties and the performance of Cu and Al becomes comparable to that of Ag and Au for systems of non-spherical particles and strong electromagnetic coupling among particles. This observation is experimentally confirmed by the fabrication and characterisation of Cu and Al metal island films. Optical characterisation of the samples reveals a comparable performance of these metals to that obtained for Ag and Au and suggests that Cu and Al metal island films can offer an efficient low-cost platform for solar energy harvesting, as shown in water vapour generation proof of concept experiments.

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Feng, L., S. Li, H. Luo, and X. Zhao. "Study on the oxidisation behaviour of particles during thermal spray process." Materials Research Innovations 19, sup8 (November 2015): S8–808—S8–812. http://dx.doi.org/10.1179/1432891715z.0000000001807.

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Ohshima, K., T. Yoshiyama, and J. Harada. "The effect of oxidisation on the surface characteristic temperature of copper particles." Journal of Physics C: Solid State Physics 18, no. 15 (May 30, 1985): 3073–82. http://dx.doi.org/10.1088/0022-3719/18/15/016.

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Wang, Haipeng, Fei Wu, Yung Ngothai, and Brian O’Neill. "A kinetic model of the ‘Fe2+ oxidisation’ process for colour enhancement in natural marble." Materials Chemistry and Physics 86, no. 1 (July 2004): 51–58. http://dx.doi.org/10.1016/j.matchemphys.2004.02.019.

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Borangazieva, Akbope K., Yerzhan A. Boleubayev, Zhuldyz U. Ibraimova, Sholpan S. Itkulova, and Gulshara S. Polimbetova. "Catalytic Oxidation of Phosphine by Aqueous Copper–Ammonia Complexes." Catalysts 13, no. 2 (January 25, 2023): 271. http://dx.doi.org/10.3390/catal13020271.

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The furnace gas resulting from the electrothermal production of yellow phosphorus contains up to 95% CO, 2% O2, 2% H2, and 0.3–4.0% impurities, including phosphine (PH3), yellow phosphorus (P4), and hydrogen sulphide (H2S), which are characterized by flammability, explosion hazardousness, corrosiveness, and high toxicity. The presence of toxic impurities does not allow the use of waste gases from phosphorus production, which are mainly composed of valuable carbon monoxide, as chemical raw materials and/or process fuel. The authors propose a method for the purification of furnace gas from the main toxic component, phosphine, by its oxidisation using aqueous copper–ammonia complexes as a catalyst. This approach allows the cleaning process to be conducted under mild conditions. The degree of purification of the model furnace gas from P components is 90–99%, depending on the process conditions.

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Lin, Bing Jing, Hong Tao Zhu, A. Kiet Tieu, and Gerry Triani. "AFM and Ellipsometry Studies of Ultra Thin Ti Film Deposited on a Silicon Wafer." Materials Science Forum 773-774 (November 2013): 616–25. http://dx.doi.org/10.4028/www.scientific.net/msf.773-774.616.

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An ultra- thin Ti film with a thickness of less than 30 nm was deposited on the surface of a silicon wafer by the filtered arc deposition system. A novel technique was adopted to create a height step between the coated area and non-coated area (silicon wafer) during deposition. The surface morphology and thickness of the film was detected by atomic force microscopy (AFM). The AFM results showed that the deposited film formed a smooth structure on the silicon wafer and the height step between the coating and silicon wafer was clear enough to give the thickness of the deposited film. The composition of the deposited film was detected by a combined use of Ellipsometry and AFM. Natural oxidisation of Ti (TiO2) was found on the top of the Ti film after deposition, and the thickness of TiO2 was determined by ellipsometry to be about 0.6 nm.

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Hu, Jingping, James Hodge, Arthur J. Boff, and John S. Foord. "Fabrication of Hybrid Diamond and Transparent Conducting Metal Oxide Electrode for Spectroelectrochemistry." International Journal of Electrochemistry 2011 (2011): 1–7. http://dx.doi.org/10.4061/2011/286458.

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A novel diamond transparent electrode is constructed by integrating conductive diamond film and transparent conducting metal oxide to combine the superior electrochemical properties of diamond and the electrical conductivity of transparent metal oxide (TCO). Direct growth of diamond on indium tin oxide (ITO) and aluminium doped zinc oxide (AZO) was explored, but X-ray photoelectron spectroscopy measurement reveals that both substrates cannot survive from the aggressive environment of diamond growth even if the latter is regarded as one of the most stable TCO. As a second route, a diamond membrane in silicon frame was prepared by selective chemical etching, and a diamond optically transparent electrode (OTE) was constructed by assembling the diamond membrane on the top of an ITO-coated substrate. The resulting device exhibits a high optical transparency and quasireversible electrochemical kinetics, which are competitive to other diamond OTEs reported previously. Its application in UV-Vis spectroelectrochemical studies on the oxidisation of 4-aminophenol was demonstrated.

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Meszaros, Martina, and Andras Bikov. "Obstructive Sleep Apnoea and Lipid Metabolism: The Summary of Evidence and Future Perspectives in the Pathophysiology of OSA-Associated Dyslipidaemia." Biomedicines 10, no. 11 (October 29, 2022): 2754. http://dx.doi.org/10.3390/biomedicines10112754.

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Obstructive sleep apnoea (OSA) is associated with cardiovascular and metabolic comorbidities, including hypertension, dyslipidaemia, insulin resistance and atherosclerosis. Strong evidence suggests that OSA is associated with an altered lipid profile including elevated levels of triglyceride-rich lipoproteins and decreased levels of high-density lipoprotein (HDL). Intermittent hypoxia; sleep fragmentation; and consequential surges in the sympathetic activity, enhanced oxidative stress and systemic inflammation are the postulated mechanisms leading to metabolic alterations in OSA. Although the exact mechanisms of OSA-associated dyslipidaemia have not been fully elucidated, three main points have been found to be impaired: activated lipolysis in the adipose tissue, decreased lipid clearance from the circulation and accelerated de novo lipid synthesis. This is further complicated by the oxidisation of atherogenic lipoproteins, adipose tissue dysfunction, hormonal changes, and the reduced function of HDL particles in OSA. In this comprehensive review, we summarise and critically evaluate the current evidence about the possible mechanisms involved in OSA-associated dyslipidaemia.

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Onyianta, Amaka J., Mark Dorris, and Rhodri L. Williams. "Aqueous morpholine pre-treatment in cellulose nanofibril (CNF) production: comparison with carboxymethylation and TEMPO oxidisation pre-treatment methods." Cellulose 25, no. 2 (December 21, 2017): 1047–64. http://dx.doi.org/10.1007/s10570-017-1631-0.

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12

He, Han Bing. "Behaviour and Material Properties of the Grain Boundary on the Surface of an Anode during the Formation of a Dense Layer." Applied Mechanics and Materials 508 (January 2014): 61–65. http://dx.doi.org/10.4028/www.scientific.net/amm.508.61.

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EPMA was used to investigate the corrosion-evolution mechanism of a dense ceramic spinel layer on the surface of NiFe2O4-10NiO-based cermet inert anodes during electrolysis in a high-temperature molten salt electrolyte. The evolution behaviour of the grain boundary on the surface of a 22(20Ni-Cu)(NiFe2O4-10NiO) anode during the formation of a dense layer was also examined. The experimental results showed that the content of the Al element on the grain boundary at the bottom of both the NiFe2O4,NiAl2O4 and FeAl2O4 was higher than that in the core of the 22(20Ni-Cu)(NiFe2O4-10NiO) anode, and the content of the Al element between the Ni-Cu and the dense layer of NiFe2O4-NiAl2O4-FeAl2O4 was higher than that in both the NiFe2O4,NiAl2O4 and FeAl2O4. It was concluded that the production of the NiAl2O4 was due not only to the reaction of the NiO with the Al2O2F42-, but also to the oxidisation of the Ni, which then reacted with the Al2O2F42-.

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Wang, Wenfang, Yun Yang, Nini Fan, Xinliang Li, and Shaoming Huang. "CuO-nanoparticle-induced controlled synthesis of various Pt nanostructures and their shape-dependent catalytic properties in oxidisation of methanol." Micro & Nano Letters 7, no. 10 (October 1, 2012): 1015–18. http://dx.doi.org/10.1049/mnl.2012.0596.

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Hiraide, Hideto, Masato Yoshida, Saori Sato, and Hiroyuki Yamamoto. "In situ detection of laccase activity and immunolocalisation of a compression-wood-specific laccase (CoLac1) in differentiating xylem of Chamaecyparis obtusa." Functional Plant Biology 43, no. 6 (2016): 542. http://dx.doi.org/10.1071/fp16044.

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The secondary cell wall of compression wood tracheids has a highly lignified region (S2 L) in its outermost portion. To better understand the mechanism of S2 L formation, we focussed on the activity of laccase (a monolignol oxidase) and performed in situ studies of this enzyme in differentiating compression wood. Staining of differentiating compression wood demonstrated that laccase activity began in all cell wall layers before the onset of lignification. We detected no activity of peroxidase (another monolignol oxidase) in any cell wall layer. Thus, laccase likely plays the major role in monolignol oxidisation during compression wood differentiation. Laccase activity was higher in the S2 L region than in other secondary wall regions, suggesting that this enzyme was responsible for the high lignin concentration in this region of the cell wall. Immunolabelling demonstrated the expression of a compression-wood-specific laccase (CoLac1) immediately following the onset of secondary wall thickening, this enzyme was localised to the S2 L region, whereas much less abundant in the S1 layer or inner S2 layer. Thus, the CoLac1 protein is most likely localised to the outer part of S2 and responsible for the high lignin concentration in the S2 L region.

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Lim, Yan Yik, Azizi Miskon, and Ahmad Mujahid Ahmad Zaidi. "CuZn Complex Used in Electrical Biosensors for Drug Delivery Systems." Materials 15, no. 21 (November 1, 2022): 7672. http://dx.doi.org/10.3390/ma15217672.

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This paper is to discuss the potential of using CuZn in an electrical biosensor drug carrier for drug delivery systems. CuZn is the main semiconductor ingredient that has great promise as an electrochemical detector to trigger releases of active pharmaceutical ingredients (API). This CuZn biosensor is produced with a green metal of frameworks, which is an anion node in conductive polymers linked by bioactive ligands using metal–polymerisation technology. The studies of Cu, Zn, and their oxides are highlighted by their electrochemical performance as electrical biosensors to electrically trigger API. The three main problems, which are glucose oxidisation, binding affinity, and toxicity, are highlighted, and their solutions are given. Moreover, their biocompatibilities, therapeutic efficacies, and drug delivery efficiencies are discussed with details given. Our three previous investigations of CuZn found results similar to those of other authors’ in terms of multiphases, polymerisation, and structure. This affirms that our research is on the right track, especially that related to green synthesis using plant extract, CuZn as a nanochip electric biosensor, and bioactive ligands to bind API, which are limited to the innermost circle of the non-enzymatic glucose sensor category.

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Suehiro, J., N. Ikeda, A. Ohtsubo, and K. Imasaka. "Bacterial detection using a carbon nanotube gas sensor coupled with a microheater for ammonia synthesis by aerobic oxidisation of organic components." IET Nanobiotechnology 3, no. 2 (2009): 15. http://dx.doi.org/10.1049/iet-nbt.2008.0011.

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Papanicolaou, Michael, Patrick He, Sandra Rutting, Alaina Ammit, Dikaia Xenaki, David van Reyk, and Brian G. Oliver. "Extracellular Matrix Oxidised by the Granulocyte Oxidants Hypochlorous and Hypobromous Acid Reduces Lung Fibroblast Adhesion and Proliferation In Vitro." Cells 10, no. 12 (November 29, 2021): 3351. http://dx.doi.org/10.3390/cells10123351.

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Chronic airway inflammation and oxidative stress play crucial roles in the pathogenesis of chronic inflammatory lung diseases, with airway inflammation being a key driving mechanism of oxidative stress in the lungs. Inflammatory responses in the lungs activate neutrophils and/or eosinophils, leading to the generation of hypohalous acids (HOX). These HOX oxidants can damage the extracellular matrix (ECM) structure and may influence cell–ECM interactions. The ECM of the lung provides structural, mechanical, and biochemical support for cells and determines the airway structure. One of the critical cells in chronic respiratory disease is the fibroblast. Thus, we hypothesised that primary human lung fibroblasts (PHLF) exposed to an oxidised cell-derived ECM will result in functional changes to the PHLF. Here, we show that PHLF adhesion, proliferation, and inflammatory cytokine secretion is affected by exposure to HOX-induced oxidisation of the cell-derived ECM. Furthermore, we investigated the impact on fibroblast function from the presence of haloamines in the ECM. Haloamines are chemical by-products of HOX and, like the HOX, haloamines can also modify the ECM. In conclusion, this study revealed that oxidising the cell-derived ECM might contribute to functional changes in PHLF, a key mechanism behind the pathogenesis of inflammatory lung diseases.

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Mikkelstrup, Anders F., Anders N. Thomsen, and Morten Kristiansen. "A novel method for approximating local changes in the surface absorption for laser marking using 3D laser scanning." IOP Conference Series: Materials Science and Engineering 1135, no. 1 (November 1, 2021): 012002. http://dx.doi.org/10.1088/1757-899x/1135/1/012002.

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Abstract Laser marking is a non-contact technique, which achieves colouring by using a laser beam to increase surface oxidation. Controlling the amount of heat induced into the part is essential in ensuring the desired degree of oxidisation. However, the induced heat is not only dependent on the process parameters, but also on the surface absorption, which in turn is dependent on the material, laser wavelength, and surface quality, i.e., current degree of oxidation and contaminants as well as surface roughness. This paper proposes a method for correlating backscatter from a 3D laser scanner with the surface absorption of sheet metal parts. The purpose is to determine local changes in the surface absorption caused by surface oxidation and contamination. The method utilises a 3D laser scanner, which projects a laser line at the surface and measures the resulting backscatter at an angle. The proposed solution applies a bi-directional reflectance model to reduce the influence of varying scanning angles. The method’s sensitivity to variations in surface treatments is investigated and validated against backscatter spectroscopy measurements. The results show that the proposed method can identify changes in the absorption. However, these were, in some cases, more than 70% higher compared to spectroscopy measurements.

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Zhang, Hongjie, R. Paul Voroney, G. W. Price, and Andrew J. White. "Sulfur-enriched biochar as a potential soil amendment and fertiliser." Soil Research 55, no. 1 (2017): 93. http://dx.doi.org/10.1071/sr15256.

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Hydrogen sulfide (H2S) is a highly toxic and corrosive contaminant gas co-generated during anaerobic digestion. Studies have shown that biochars have the potential to adsorb H2S and to promote its oxidisation. To date, no studies have investigated the bioavailabilty to plants of the sulfur (S) contained in biochar when used as an S fertiliser. Biochar was packed into the biogas emissions stream to adsorb the H2S being generated. The resulting sulfur-enriched biochar (SulfaChar) and synthetic S fertiliser (control treatment) were amended to potting soils and the growth response of corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] and nutrient uptake were measured after a 90-day greenhouse study. SulfaChar contained 36.5% S (S element and SO42–), confirming it adsorbed significant amounts of H2S. Compared with the control treatment, SulfaChar amendment significantly increased corn plant biomass, ranging from 31% to 49% but only a slight increase in soybean biomass (4 to 14%). SulfaChar also increased corn plant uptake of S and other macro- (N, P, K, Ca, and Mg) and micro-nutrients (Zn, Mn and B). Our results show that SulfaChar was a source of plant available S, suggesting that SulfaChar is either a supplier of these nutrients or that it promoted their uptake.

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Crolet, J. L. "Detailed mechanisms of hydrogen charging and hydrogen stress cracking of steel in liquid ammonia storage." Matériaux & Techniques 107, no. 4 (2019): 401. http://dx.doi.org/10.1051/mattech/2019022.

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When the unprecedented environmental cracking of steel in liquid ammonia was collectively studied, its undisputable “anodic character” was taken as the signature of a stress corrosion cracking mechanism, which is effectively the case in aqueous corrosion. Conversely, when the metallurgical precautions proved to be the same as in sour service, this strongly suggested a hydrogen stress cracking mechanism. In aqueous corrosion, however, this can only occur by cathodic hydrogen charging at low potential, and for 50 years, this basic contradiction could never be overcome. Actually, it occurs that the liquid ammonia solvent (NH3) is 50% richer in hydrogen than the water solvent (OH2), so that hydrogen gas can also be produced by a partial oxidisation into ½ N2 + H2. This therefore induces a theoretical possibility of an “anodic” hydrogen charging, or more exactly a protonic cathodic reaction only running at high potential on passive iron in oxygen contaminated ammonia. And once the detrimental potential is achieved through appropriate combinations of oxygen and water traces, the charging process becomes an autonomous oxidation-reduction at the steel surface NH3 → ½ N2 + H2 + (H+ + e−)steel. In Part II (Jean-Louis Crolet, Matériaux & Techniques 107, 402, 2019), this new assumption will be successfully confronted to all the factual data from both field and laboratory experience.

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Colasante, Claudia, Jiangping Chen, Barbara Ahlemeyer, and Eveline Baumgart-Vogt. "Peroxisomes in cardiomyocytes and the peroxisome / peroxisome proliferator-activated receptor-loop." Thrombosis and Haemostasis 113, no. 03 (May 2015): 452–63. http://dx.doi.org/10.1160/th14-06-0497.

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SummaryIt is well established that the heart is strongly dependent on fatty acid metabolism. In cardiomyocytes there are two distinct sites for the β-oxidisation of fatty acids: the mitochondrion and the peroxisome. Although the metabolism of these two organelles is believed to be tightly coupled, the nature of this relationship has not been fully investigated. Recent research has established the significant contribution of mitochondrial function to cardiac ATP production under normal and pathological conditions. In contrast, limited information is available on peroxisomal function in the heart. This is despite these organelles harbouring metabolic pathways that are potentially cardioprotective, and findings that patients with peroxisomal diseases, such as adult Refsum’s disease, can develop heart failure. In this article, we provide a comprehensive overview on the current knowledge of peroxisomes and the regulation of lipid metabolism by PPARs in cardiomyocytes. We also present new experimental evidence on the differential expression of peroxisome-related genes in the heart chambers and demonstrate that even a mild peroxisomal biogenesis defect (Pex11α-/- ) can induce profound alterations in the cardiomyocyte’s peroxisomal compartment and related gene expression, including the concomitant deregulation of specific PPARs. The possible impact of peroxisomal dysfunction in the heart is discussed and a model for the modulation of myocardial metabolism via a peroxisome/PPAR-loop is proposed.

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Keller, J., H. Haase, and M. Koch. "Hydroxylation and dimerization of zearalenone: comparison of chemical, enzymatic and electrochemical oxidation methods." World Mycotoxin Journal 10, no. 4 (November 30, 2017): 297–307. http://dx.doi.org/10.3920/wmj2017.2213.

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Investigations of the metabolic pathway of mycotoxins by microsomal techniques are often laborious, causing an increasing demand for easy and rapid simulation methods. Thus, the non-microsomal oxidation technique of electrochemistry coupled online to mass spectrometry (EC/MS) was applied to simulate phase I biotransformation of the Fusarium mycotoxin zearalenone (ZEA). The obtained transformation products were identified by high resolution mass spectrometry (FT-ICR) and HPLC-MS/MS. Transformation products (TPs) from EC/MS were compared to those of other oxidative methods, such as Fenton-like and Ce(IV) reactions and metabolites derived from in vitro assays (human and rat liver microsomes). Electrochemical oxidisation of ZEA was achieved by applying a potential between 0 and 2,500 mV vs Pd/H2 using a flow-through cell with a boron-doped diamond working electrode. Several mono-hydroxylated TPs were generated by EC/MS and Fenton-like reaction, which could also be found in microsomal in vitro assays. EC and Ce(IV) led to the formation of structurally different ZEA dimers and dimeric quinones probably connected over covalent biaryl C-C and C-O-C bonds. Although the dimerization of phenolic compounds is often observed in natural processes, ZEA dimers have not yet been reported. This is the first report on the formation of stable ZEA dimers and their related quinones. The tested non-microsomal methods, in particular EC/MS, could be useful in order to predict the biotransformation products of mycotoxins, even in cases where one to one simulation is not always feasible.

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Hung, Chih-Hsien, Cheng-Han Lee, Ming-Hsien Tsai, Chu-Huang Chen, Hsiu-Fen Lin, Chung-Yao Hsu, Chiou-Lian Lai, and Chih-Cheng Chen. "Activation of acid-sensing ion channel 3 by lysophosphatidylcholine 16:0 mediates psychological stress-induced fibromyalgia-like pain." Annals of the Rheumatic Diseases 79, no. 12 (September 9, 2020): 1644–56. http://dx.doi.org/10.1136/annrheumdis-2020-218329.

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ObjectivesFibromyalgia is commonly considered a stress-related chronic pain disorder, and daily stressors are known triggers. However, the relation between stress and pain development remains poorly defined by clinical approaches. Also, the aetiology remains largely unknown.MethodsWe used a newly developed mouse model and lipidomic approaches to probe the causation and explore the biological plausibility for how perceived stress translates into chronic non-inflammatory pain. Clinical and lipidomic investigations of fibromyalgia were conducted for human validation.ResultsUsing non-painful sound stimuli as psychological stressors, we demonstrated that mice developed long-lasting non-inflammatory hyperalgesia after repeated and intermittent sound stress exposure. Elevated serum malondialdehyde level in stressed mice indicated excessive oxidative stress and lipid oxidative damage. Lipidomics revealed upregulation of lysophosphatidylcholine 16:0 (LPC16:0), a product of lipid oxidisation, in stressed mice. Intramuscular LPC16:0 injection triggered nociceptive responses and a hyperalgesic priming-like effect that caused long-lasting hypersensitivity. Pharmacological or genetic inhibition of acid-sensing ion channel 3 impeded the development of LPC16:0-induced chronic hyperalgesia. Darapladib and antioxidants could effectively alleviate the stress-induced hyperalgesia by inhibiting LPC16:0 synthesis. Clinical investigations showed that excessive oxidative stress and LPC16:0 expression also exist in patients with fibromyalgia. Moreover, LPC16:0 expression was correlated with pain symptoms in patients with high oxidative stress and disease severity.ConclusionsOur study provides experimental evidence for the causal effect of psychological stressors on chronic pain development. The findings identify a possible pathophysiological mechanism of stress-induced chronic non-inflammatory pain at molecular, behavioural and clinical levels that might indicate a new therapeutic approach for fibromyalgia.

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Fenlon, Anna, and Lucia Petrera. "Pyrite oxidation: a history of treatments at the Natural History Museum, London." Geological Curator 11, no. 1 (June 2019): 9–18. http://dx.doi.org/10.55468/gc403.

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Whilst surveying the palaeontology collections at the Natural History Museum London (NHM), a team of Conservation Technicians working on 'Project Airless' (a re-storage project for actively deteriorating pyritic specimens) kept a record of specimen labels describing past methods for treating pyrite oxidation, ranging from 'boiling in common soda' to treating with 'Savlon'. This prompted further research into the thinking behind these approaches, and resulted in a historical review of treatments used at the NHM and how they compare to current methods. The oxidisation of unstable pyritic material became a prominent issue during the development of geological collections in the 19th Century, when early collectors provided most insight into best practice storage of affected specimens, although it was not until the 20th century when more intensive research was conducted and recommended treatments for deteriorating pyritic material began to circulate. Regardless of the treatment, however, once specimens were returned to storage conditions of high relative humidity (RH) the reaction would often recur; this instigated the need for a more preventative approach focussing on reducing, if not eliminating, the key agents involved in the oxidation process: oxygen and high RH. Project Airless is the latest attempt at the NHM to combat pyrite oxidation on a large scale by storing affected specimens in anoxic microenvironments to prevent further deterioration. Severely affected specimens are also exposed to ammonia vapour in a method which has evolved from earlier treatments. Although commonly referred to as The Natural History Museum London, the museum was officially known as The British Museum (Natural History) until 1992, so for the purposes of this article the 'BM(NH)' will be referred to until this date, and the 'NHM' thereafter.

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Yang, X. M., J. Y. Li, M. Zhang, G. M. Chai, D. P. Duan, and J. Zhang. "Coupling relationship between dephosphorisation and desulphurisation abilities or potentials for CaO–FeO–Fe2O3–Al2O3–P2O5 slags over a large variation range of slag oxidisation ability during secondary refining process of molten steel." Ironmaking & Steelmaking 45, no. 1 (October 5, 2016): 25–43. http://dx.doi.org/10.1080/03019233.2016.1235674.

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Kän-man, Erik, and Håkan Jönsson. "Including oxidisation of ammonia in the eutrophication impact category." International Journal of Life Cycle Assessment 6, no. 1 (January 2001). http://dx.doi.org/10.1007/bf02977592.

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Sun, Liyun, Huoli Shang, Yuzhen Wu, and Xiujuan Xin. "Hypericin-mediated photodynamic therapy enhances gemcitabine induced Capan-2 cell apoptosis via inhibiting NADPH level." Journal of Pharmacy and Pharmacology, June 5, 2021. http://dx.doi.org/10.1093/jpp/rgab073.

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Abstract Objectives The combination of gemcitabine (Gem) and hypericin (HY) enhances the apoptosis of Capan-2 cells, providing a promising option for the treatment of pancreatic cancer. Our study further explored the cytotoxic mechanism of HY combined with chemotherapy drugs on pancreatic cancer. Methods The proliferation rate of the cells assayed with the MTT method. The ROS (reactive oxygen species) levels of each treatment were evaluated by DCFH-DA oxidisation methods. The activity of glutathione reductase and the levels of reduced glutathione (GSH) and oxidised glutathione (GSSG) were assessed using assay kits. The expression levels of apoptosis-related proteins were analysed by western blotting. Key findings The activity of glucose-6-phosphate dehydrogenase (G6PDH), a key enzyme of the pentose phosphate pathway, significantly decreased in Gem + HY groups, however, the ROS level enhanced accompanying with GSH depleting, mitochondrial membrane depolarisation and cytochrome C release. Gem + HY inhibits the expression of Bcl-2 but stimulates Bax level, triggering caspase activation and PARP cleavage and thus promoted apoptosis of Capan-2 cells. Conclusions We demonstrated that Gem combined HY-PDT could inhibit the proliferation of Capan-2 cells and induce cell apoptosis. HY-PDT combined with Gem had a great potential on pancreatic cancer treatment clinically.

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Miller, W. M., L. Pérez Villar, P. Gómez, M. Ivanovich, B. de la Cruz, P. Rivas, P. Hernán, et al. "The EL Berrocal Project: Geological Characterisation and Radionuclide Migration Studies in a Fractured Granitic Environment." MRS Proceedings 353 (1994). http://dx.doi.org/10.1557/proc-353-1243.

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AbstractEl Berrocal is an abandoned uranium mine in a mineralised quartz vein hosted by a Hercynian granite in central Spain. This mine is the focus of an international project to characterise and model natural elemental migration in a fractured-rock environment as an aid to understanding and predicting processes that may occur in a geological repository for radioactive wastes.Uranium in the mineralised quartz vein has been shown to have originated from the orthomagmatic uraninite in the granite with the elemental removal and migration occurring predominately by hydrothermal fluids. Mobilisation of uranium from the mineralised quartz vein and from granite adjacent to hydraulically-active fractures away from the vein occurred over the geologically-recent past and in the present-day. The most recent mobilisation is evidenced by dissolution features seen in SEM photomicrographs; mineral growth and sorption signatures identified by enhanced uranium concentrations on the surfaces of preexisting minerals; and measured disequilibrium in the uranium series for whole rock close to fracture walls.Present-day groundwaters in the studied area are young meteoric waters. They are generally calcium-sulphate enriched, oxidising and mildly acidic near the surface, becoming more bicarbonate-rich with near neutral pH in the deeper zones, except around the mineralised vein where the waters are acid (pH around 3) due to oxidisation of the sulphide minerals. No deep, chemically-reducing groundwaters have yet been identified in the El Berrocal boreholes.

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Brander, Søren, Stine Lausten, Johan Ø. Ipsen, Kristoffer B. Falkenberg, Andreas B. Bertelsen, Morten H. H. Nørholm, Lars H. Østergaard, and Katja S. Johansen. "Colorimetric LPMO assay with direct implication for cellulolytic activity." Biotechnology for Biofuels 14, no. 1 (February 27, 2021). http://dx.doi.org/10.1186/s13068-021-01902-4.

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Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are important industrial enzymes known for their catalytic degradation of recalcitrant polymers such as cellulose or chitin. Their activity can be measured by lengthy HPLC methods, while high-throughput methods are less specific. A fast and specific LPMO assay would simplify screening for new or engineered LPMOs and accelerate biochemical characterization. Results A novel LPMO activity assay was developed based on the production of the dye phenolphthalein (PHP) from its reduced counterpart (rPHP). The colour response of rPHP oxidisation catalysed by the cellulose-specific LPMO from Thermoascus aurantiacus (TaAA9A), was found to increase tenfold by adding dehydroascorbate (DHA) as a co-substrate. The assay using a combination of rPHP and DHA was tested on 12 different metallo-enzymes, but only the LPMOs catalysed this reaction. The assay was optimized for characterization of TaAA9A and showed a sensitivity of 15 nM after 30 min incubation. It followed apparent Michaelis–Menten kinetics with kcat = 0.09 s−1 and KM = 244 µM, and the assay was used to confirm stoichiometric copper–enzyme binding and enzyme unfolding at a temperature of approximately 60 °C. DHA, glutathione and fructose were found to enhance LPMO oxidation of rPHP and in the optimized assay conditions these co-substrates also enabled cellulose degradation. Conclusions This novel and specific LPMO assay can be carried out in a convenient microtiter plate format ready for high-throughput screening and enzyme characterization. DHA was the best co-substrate tested for oxidation of rPHP and this preference appears to be LPMO-specific. The identified co-substrates DHA and fructose are not normally considered as LPMO co-substrates but here they are shown to facilitate both oxidation of rPHP and degradation of cellulose. This is a rare example of a finding from a high-throughput assay that directly translate into enzyme activity on an insoluble substrate. The rPHP-based assay thus expands our understanding of LPMO catalysed reactions and has the potential to characterize LPMO activity in industrial settings, where usual co-substrates such as ascorbate and oxygen are depleted.

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Janke, Chelsea, Phil Moody, Ryosuke Fujinuma, and Michael Bell. "The Impact of Banding Polymer-Coated Urea on Nitrogen Availability and Distribution in Contrasting Soils." Journal of Soil Science and Plant Nutrition, May 12, 2022. http://dx.doi.org/10.1007/s42729-022-00869-x.

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AbstractPolymer-coated urea (PCU) has been traditionally used for broadcast and/or incorporated application of nitrogen (N) fertilizers. To improve N use efficiency (NUE), there has been an increase in sub-surface banded application of this fertilizer technology. However, there is little information on the release and supply of N from PCU granules when applied in a band. This research aimed to investigate the spatial distribution of key N transformations around PCU bands in soils of contrasting physico-chemical properties, and the implications for NUE. Two experiments, consisting of a 60-day diffusion study and a 91-day incubation, were conducted in a Vertosol and Dermosol, with PCU granules banded at a rate equivalent to 150 kg N ha−1 and band spacing of 1.8 m. Compared to standard urea, PCU provided a sustained release of urea-N to soil solution and the lower urea-N concentrations minimized the toxic conditions associated with rapid hydrolysis of urea-N. Nitrogen release from banded PCU was quicker in the Vertosol (cf. Dermosol), possibly due to a higher volumetric water content and/or greater soil particle surface contact, facilitating rapid water imbibition into granules. However, the proximity of PCU granules to each other in a band restricted the diffusive release of urea-N from PCU granules cf. dispersed application in both soils. Furthermore, the relatively mild chemical conditions in the PCU band (cf. standard urea) resulted in oxidisation of larger proportions of PCU-derived mineral N. Banded application may extend the duration of N release from PCU granules, confounding efforts to predict N availability. Soil characteristics influenced N release and dynamics from banded PCU, although further investigation is required. Higher rates of nitrification of N derived from PCU bands suggest there could be increased risk of N-loss via denitrification or leaching pathways (cf. standard urea bands) if release dynamics are not optimally synchronised with crop demand. This study provides the first mechanistic insights into the impact of application method and soil physico-chemical properties on the efficacy of PCU.

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Journal articles on the topic 'Oxidisation'

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