Displaying publications 41 - 60 of 518 in total

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  1. TEMPO-oxidized nanocellulose films derived from coconut residues: Physicochemical, mechanical and electrical properties
    Hassan SH, Velayutham TS, Chen YW, Lee HV
    Int J Biol Macromol, 2021 Jun 01;180:392-402.
    PMID: 33737185 DOI: 10.1016/j.ijbiomac.2021.03.066
    The present work focuses on the development of cellulose nanofibrils (CNF) film that derived from sustainable biomass resources, which potentially to work as bio-based conductive membranes that assembled into supercapacitors. The chemically purified cellulose was isolated from different parts of coconut (coconut shell and its husk) and further subjected to 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation for CNF preparation. Physicochemical properties of prepared CNFs were studied in terms of chemical characteristics & crystallinity, surface functionalities, surface morphology, and thermal properties. Both coconut shell-derived CNF and coconut husk-derived CNF fulfilled with nanocellulose's characteristics with fibres width ranged of 70-120 nm and 150-330 nm, respectively. CNF films were further prepared by solvent casting method to measure the modulus elasticity, piezoelectric and dielectric properties of the films. Mechanical study indicated that coconut shell-derived CNF film showed a higher value of elastic modulus than the coconut husk-derived CNF film, which was 8.39 GPa and 5.36 GPa, respectively. The effectiveness of electrical aspects for CNF films are well correlated with the crystallinity and thermal properties, associated with it's composition of different coconut's part.
    Matched MeSH terms: Oxidation-Reduction
  2. Fulltext Unexpected acceleration of Ultrasonic-Assisted iodide dosimetry in the catalytic presence of ionic liquids
    Krishnan S, Abd Ghani N, Aminuddin NF, Quraishi KS, Razafindramangarafara BL, Baup S, et al.
    Ultrason Sonochem, 2021 Jun;74:105576.
    PMID: 33975186 DOI: 10.1016/j.ultsonch.2021.105576
    This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs' anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.
    Matched MeSH terms: Oxidation-Reduction
  3. Fulltext Coenzyme Q10, oxidative stress, and male infertility: A review
    Alahmar AT, Calogero AE, Singh R, Cannarella R, Sengupta P, Dutta S
    Clin Exp Reprod Med, 2021 Jun;48(2):97-104.
    PMID: 34078005 DOI: 10.5653/cerm.2020.04175
    Male infertility has a complex etiopathology, which mostly remains elusive. Although research has claimed that oxidative stress (OS) is the most likely underlying mechanism of idiopathic male infertility, the specific treatment of OS-mediated male infertility requires further investigation. Coenzyme Q10 (CoQ10), a vitamin-like substance, has been found in measurable levels in human semen. It exhibits essential metabolic and antioxidant functions, as well as playing a vital role in mitochondrial bioenergetics. Thus, CoQ10 may be a key player in the maintenance of biological redox balance. CoQ10 concentrations in seminal plasma directly correlate with semen parameters, especially sperm count and sperm motility. Seminal CoQ10 concentrations have been shown to be altered in various male infertility states, such as varicocele, asthenozoospermia, and medical or surgical regimens used to treat male infertility. These observations imply that CoQ10 plays an important physiological role in the maintenance and amelioration of semen quality. The present article thereby aimed to review the possible mechanisms through which CoQ10 plays a role in the regulation of male reproductive function, and to concisely discuss its efficacy as an ameliorative agent in restoring semen parameters in male infertility, as well as its impact on OS markers, sperm DNA fragmentation, pregnancy, and assisted reproductive technology outcomes.
    Matched MeSH terms: Oxidation-Reduction
  4. Triphenyl methyl phosphonium tosylate as an efficient phase transfer catalyst for ultrasound-assisted oxidative desulfurization of liquid fuel
    Desai K, Dharaskar S, Khalid M, Gupta TCSM
    Environ Sci Pollut Res Int, 2021 Jun;28(21):26747-26761.
    PMID: 33491146 DOI: 10.1007/s11356-021-12391-1
    The novel phosphonium-based ionic liquid (IL), triphenyl methyl phosphonium tosylate ([TPMP][Tos]), has been synthesized and applied as a phase transfer catalyst (PTC) in the ultrasound-assisted oxidative desulfurization (UAODS). Oxidation of model fuel (MF) containing dibenzothiophene (DBT) was carried out using an equimolar mixture of H2O2-CH3COOH as an oxidant at 40-70 °C in the presence of IL. The sulfur compound is converted into polar sulfone, and the maximum desulfurization efficiency was examined. The effect of process parameters such as reaction temperature, reaction time, molar ratio of oxidant to sulfur (n(O/S)), and the mass ratio of ionic liquid to model fuel (m(IL/MF)) was studied, and the conditions for maximizing the DBT conversion rate were found. Maximum conversion (> 99%) was obtained at a temperature of 70 °C with m(IL/MF) of 0.8. The oxidation reactivity of various sulfur compounds was studied at different time intervals. To verify the effect of ionic liquid and ultrasound irradiation, extractive desulfurization (EDS), oxidative desulfurization (ODS), and UAODS in the presence of IL were carried out. The experimental results show that the UAODS process gives the highest desulfurization efficiency. A kinetic study was performed to estimate the rate constant and the order of oxidation reaction.
    Matched MeSH terms: Oxidation-Reduction
  5. Fulltext Microbiological Reduction of Molybdenum to Molybdenum Blue as a Sustainable Remediation Tool for Molybdenum: A Comprehensive Review
    Yakasai HM, Rahman MF, Manogaran M, Yasid NA, Syed MA, Shamaan NA, et al.
    Int J Environ Res Public Health, 2021 May 27;18(11).
    PMID: 34071757 DOI: 10.3390/ijerph18115731
    Molybdenum (Mo) microbial bioreduction is a phenomenon that is beginning to be recognized globally as a tool for the remediation of molybdenum toxicity. Molybdenum toxicity continues to be demonstrated in many animal models of spermatogenesis and oogenesis, particularly those of ruminants. The phenomenon has been reported for more than 100 years without a clear understanding of the reduction mechanism, indicating a clear gap in the scientific knowledge. This knowledge is not just fundamentally important-it is specifically important in applications for bioremediation measures and the sustainable recovery of metal from industrial or mine effluent. To date, about 52 molybdenum-reducing bacteria have been isolated globally. An increasing number of reports have also been published regarding the assimilation of other xenobiotics. This phenomenon is likely to be observed in current and future events in which the remediation of xenobiotics requires microorganisms capable of degrading or transforming multi-xenobiotics. This review aimed to comprehensively catalogue all of the characterizations of molybdenum-reducing microorganisms to date and identify future opportunities and improvements.
    Matched MeSH terms: Oxidation-Reduction
  6. Fulltext Elucidation of Gram-Positive Bacterial Iron(III) Reduction for Kaolinite Clay Refinement
    Jing H, Liu Z, Kuan SH, Chieng S, Ho CL
    Molecules, 2021 May 21;26(11).
    PMID: 34064160 DOI: 10.3390/molecules26113084
    Recently, microbial-based iron reduction has been considered as a viable alternative to typical chemical-based treatments. The iron reduction is an important process in kaolin refining, where iron-bearing impurities in kaolin clay affects the whiteness, refractory properties, and its commercial value. In recent years, Gram-negative bacteria has been in the center stage of iron reduction research, whereas little is known about the potential use of Gram-positive bacteria to refine kaolin clay. In this study, we investigated the ferric reducing capabilities of five microbes by manipulating the microbial growth conditions. Out of the five, we discovered that Bacillus cereus and Staphylococcus aureus outperformed the other microbes under nitrogen-rich media. Through the biochemical changes and the microbial behavior, we mapped the hypothetical pathway leading to the iron reduction cellular properties, and found that the iron reduction properties of these Gram-positive bacteria rely heavily on the media composition. The media composition results in increased basification of the media that is a prerequisite for the cellular reduction of ferric ions. Further, these changes impact the formation of biofilm, suggesting that the cellular interaction for the iron(III)oxide reduction is not solely reliant on the formation of biofilms. This article reveals the potential development of Gram-positive microbes in facilitating the microbial-based removal of metal contaminants from clays or ores. Further studies to elucidate the corresponding pathways would be crucial for the further development of the field.
    Matched MeSH terms: Oxidation-Reduction
  7. Arsenic removal in aqueous solutions using FeS2
    Fu D, Kurniawan TA, Lin L, Li Y, Avtar R, Dzarfan Othman MH, et al.
    J Environ Manage, 2021 May 15;286:112246.
    PMID: 33667817 DOI: 10.1016/j.jenvman.2021.112246
    This study tested the technical feasibility of pyrite and/or persulfate oxidation system for arsenic (As) removal from aqueous solutions. The effects of persulfate on As removal by the pyrite in the integrated treatment were also investigated. Prior to the persulfate addition into the reaction system, the physico-chemical interactions between As and the pyrite alone in aqueous solutions were explored in batch studies. The adsorption mechanisms of As by the adsorbent were also presented. At the same As concentration of 5 mg/L, it was found that As(III) attained a longer equilibrium time (8 h) than As(V) (2 h), while the pyrite worked effectively at pH ranging from 6 to 11. At optimum conditions (0.25 g/L of pyrite, pH 8.0 and 5 mg/L of As(III) concentration), the addition of persulfate (0.5 mM) into the reaction promoted a complete removal of arsenic from the solutions. Consequently, this enabled the treated effluents to meet the arsenic maximum contaminant limit (MCL) of <10 μg/L according to the World Health Organization (WHO)'s requirements. The redox mechanisms, which involved electron transfer from the S22- of the pyrite to Fe3+, supply Fe2+ for persulfate decomposition, oxidizing As(III) to As(V). The sulfur species played roles in the redox cycle of the Fe3+/Fe2+ of the pyrite by giving its electrons, while the As(III) oxidation to As(V) was attributed to the pyrite. Overall, this work reveals the applicability of the pyrite as an adsorbent for water treatment and the importance of persulfate addition to promote a complete As removal from aqueous solutions.
    Matched MeSH terms: Oxidation-Reduction
  8. Melatonin improves cognitive behavior, oxidative stress, and metabolism in tumor-prone lethal giant larvae mutant of Drosophila melanogaster
    Wong KC, Sankaran S, Jayapalan JJ, Subramanian P, Abdul-Rahman PS
    Arch Insect Biochem Physiol, 2021 May;107(1):e21785.
    PMID: 33818826 DOI: 10.1002/arch.21785
    Mutant lethal giant larvae (lgl) flies (Drosophila melanogaster) are known to develop epithelial tumors with invasive characteristics. The present study has been conducted to investigate the influence of melatonin (0.025 mM) on behavioral responses of lgl mutant flies as well as on biochemical indices (redox homeostasis, carbohydrate and lipid metabolism, transaminases, and minerals) in hemolymph, and head and intestinal tissues. Behavioral abnormalities were quantitatively observed in lgl flies but were found normalized among melatonin-treated lgl flies. Significantly decreased levels of lipid peroxidation products and antioxidants involved in redox homeostasis were observed in hemolymph and tissues of lgl flies, but had restored close to normalcy in melatonin-treated flies. Carbohydrates including glucose, trehalose, and glycogen were decreased and increased in the hemolymph and tissues of lgl and melatonin-treated lgl flies, respectively. Key enzymes of carbohydrate metabolism showed a significant increment in their levels in lgl mutants but had restored close to wild-type baseline levels in melatonin-treated flies. Variables of lipid metabolism showed significantly inverse levels in hemolymph and tissues of lgl flies, while normalization of most of these variables was observed in melatonin-treated mutants. Lipase, chitinase, transaminases, and alkaline phosphatase showed an increment in their activities and minerals exhibited decrement in lgl flies; reversal of changes was observed under melatonin treatment. The impairment of cognition, disturbance of redox homeostasis and metabolic reprogramming in lgl flies, and restoration of normalcy in all these cellular and behavioral processes indicate that melatonin could act as oncostatic and cytoprotective agents in Drosophila.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  9. Performance of platinum doping on spent alkaline battery-based catalyst for complete oxidation of o-xylene
    Park YK, Jung SC, Jung HY, Foong SY, Lam SS, Kim SC
    Environ Sci Pollut Res Int, 2021 May;28(19):24552-24557.
    PMID: 32533488 DOI: 10.1007/s11356-020-09575-6
    Oxidation of o-xylene was performed using alkaline battery-based catalyst doped with platinum to investigate the properties and activities. O-xylene was selected as the model of volatile organic compound (VOC) in this work. Physicochemical properties of the selected catalysts were characterized by FE/TEM (field emission transmission electron microscopy), BET (Brunauer-Emmett-Teller) analysis, XRD (X-ray powder diffraction), SEM/EDX (scanning electron microscopy/energy dispersive X-ray spectroscopy), and H2-TPR (hydrogen temperature programmed reduction). Major elements of the spent alkaline battery-based catalyst treated with sulfuric acid solution [SAB (400) catalyst] were manganese, zinc, iron, oxygen, carbon, chlorine, aluminum, sodium, silicon, and potassium. Increasing the doping amount of platinum on SAB (400) catalyst from 0.1 to 1 wt% increased particle size of platinum and lowered the temperature of TPR (TTP) for SAB (400) catalyst. Better redox properties were achieved with an increase in the o-xylene conversion according to the doping amount of platinum. When GHSV (gas hourly space velocity) was 40,000 h-1, o-xylene was oxidized completely over SAB (400) catalyst and 1.0 wt% Pt/SAB(400) catalyst at temperatures of 400 °C and 280 °C, respectively.
    Matched MeSH terms: Oxidation-Reduction
  10. Effective toluene oxidation under ozone over mesoporous MnOx/γ-Al2O3 catalyst prepared by solvent deficient method: Effect of Mn precursors on catalytic activity
    Reddy KHP, Kim BS, Lam SS, Jung SC, Song J, Park YK
    Environ Res, 2021 04;195:110876.
    PMID: 33592225 DOI: 10.1016/j.envres.2021.110876
    In this study, the role of manganese precursors in mesoporous (meso) MnOx/γ-Al2O3 catalysts was examined systematically for toluene oxidation under ozone at ambient temperature (20 °C). The meso MnOx/γ-Al2O3 catalysts developed with Mn(CH3COO)2, MnCl2, Mn(NO3)2.4H2O and MnSO4 were prepared by an innovative single step solvent-deficient method (SDM); the catalysts were labeled as MnOx/Al2O3(A), MnOx/Al2O3(C), MnOx/Al2O3(N), and MnOx/Al2O3(S), respectively. Among all, MnOx/Al2O3(C) showed superior performance both in toluene removal (95%) as well as ozone decomposition (88%) followed by acetate, nitrate and sulphated precursor MnOx/Al2O3. The superior performance of MnOx/Al2O3(C) in the oxidation of toluene to COx is associated with the ozone decomposition over highly dispersed MnOx in which extremely active oxygen radicals (O2-, O22- and O-) are generated to enhance the oxidation ability of the catalysts greatly. In addition, toluene adsorption over acid support played a vital role in this reaction. Hence, the properties such as optimum Mn3+/Mn4+ ratio, acidic sites, and smaller particle size (≤2 nm) examined by XPS, TPD of NH3, and TEM results are playing vital role in the present study. In summary, the MnOx/Al2O3 (C) catalyst has great potential in environmental applications particularly for the elimination of volatile organic compounds with low loading of manganese developed by SDM.
    Matched MeSH terms: Oxidation-Reduction
  11. Fulltext Beneficial Role of Carica papaya Extracts and Phytochemicals on Oxidative Stress and Related Diseases: A Mini Review
    Kong YR, Jong YX, Balakrishnan M, Bok ZK, Weng JKK, Tay KC, et al.
    Biology (Basel), 2021 Apr 01;10(4).
    PMID: 33916114 DOI: 10.3390/biology10040287
    Oxidative stress is a result of disruption in the balance between antioxidants and pro-oxidants in which subsequently impacting on redox signaling, causing cell and tissue damages. It leads to a range of medical conditions including inflammation, skin aging, impaired wound healing, chronic diseases and cancers but these conditions can be managed properly with the aid of antioxidants. This review features various studies to provide an overview on how Carica papaya help counteract oxidative stress via various mechanisms of action closely related to its antioxidant properties and eventually improving the management of various oxidative stress-related health conditions. Carica papaya is a topical plant species discovered to contain high amounts of natural antioxidants that can usually be found in their leaves, fruits and seeds. It contains various chemical compounds demonstrate significant antioxidant properties including caffeic acid, myricetin, rutin, quercetin, α-tocopherol, papain, benzyl isothiocyanate (BiTC), and kaempferol. Therefore, it can counteract pro-oxidants via a number of signaling pathways that either promote the expression of antioxidant enzymes or reduce ROS production. These signaling pathways activate the antioxidant defense mechanisms that protect the body against both intrinsic and extrinsic oxidative stress. To conclude, Carica papaya can be incorporated into medications or supplements to help manage the health conditions driven by oxidative stress and further studies are needed to investigate the potential of its chemical components to manage various chronic diseases.
    Matched MeSH terms: Oxidation-Reduction
  12. Fulltext Counteracting the Ramifications of UVB Irradiation and Photoaging with Swietenia macrophylla King Seed
    Mahendra CK, Abidin SAZ, Htar TT, Chuah LH, Khan SU, Ming LC, et al.
    Molecules, 2021 Apr 01;26(7).
    PMID: 33916053 DOI: 10.3390/molecules26072000
    In this day and age, the expectation of cosmetic products to effectively slow down skin photoaging is constantly increasing. However, the detrimental effects of UVB on the skin are not easy to tackle as UVB dysregulates a wide range of molecular changes on the cellular level. In our research, irradiated keratinocyte cells not only experienced a compromise in their redox system, but processes from RNA translation to protein synthesis and folding were also affected. Aside from this, proteins involved in various other processes like DNA repair and maintenance, glycolysis, cell growth, proliferation, and migration were affected while the cells approached imminent cell death. Additionally, the collagen degradation pathway was also activated by UVB irradiation through the upregulation of inflammatory and collagen degrading markers. Nevertheless, with the treatment of Swietenia macrophylla (S. macrophylla) seed extract and fractions, the dysregulation of many genes and proteins by UVB was reversed. The reversal effects were particularly promising with the S. macrophylla hexane fraction (SMHF) and S. macrophylla ethyl acetate fraction (SMEAF). SMHF was able to oppose the detrimental effects of UVB in several different processes such as the redox system, DNA repair and maintenance, RNA transcription to translation, protein maintenance and synthesis, cell growth, migration and proliferation, and cell glycolysis, while SMEAF successfully suppressed markers related to skin inflammation, collagen degradation, and cell apoptosis. Thus, in summary, our research not only provided a deeper insight into the molecular changes within irradiated keratinocytes, but also serves as a model platform for future cosmetic research to build upon. Subsequently, both SMHF and SMEAF also displayed potential photoprotective properties that warrant further fractionation and in vivo clinical trials to investigate and obtain potential novel bioactive compounds against photoaging.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  13. Is the Mitochondrial Function of Keloid Fibroblasts Affected by Cytoglobin?
    Jusman SWA, Azzizah IN, Sadikin M, Hardiany NS
    Malays J Med Sci, 2021 Apr;28(2):39-47.
    PMID: 33958959 DOI: 10.21315/mjms2021.28.2.4
    Background: A keloid is a benign skin tumour characterised by excessive proliferation of fibroblasts, a process that requires a sufficient amount of energy. The energy needs are associated with adequate oxygen (O2) flow and well-functioning mitochondria. It is known that cytoglobin (CYGB) has a function in O2 distribution. The aim of the present study was to explore whether the inhibition of CYGB expression caused impaired mitochondrial function of keloid fibroblasts.

    Methods: An in vitro study was conducted on a keloid fibroblast derived from our previous study. The study was carried out in the laboratory of the Biochemistry & Molecular Biology Department, Faculty of Medicine, Universitas Indonesia (FMUI), from July to December 2018. CYGB expression was inhibited by small interfering ribonucleic acid (siRNA) and CYGB. Analysis of mitochondrial function was observed through peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), a mitochondrial biogenesis marker and the activity of the succinate dehydrogenase (SDH) enzyme in mitochondria.

    Results: The CYGB gene and protein were downregulated after treatment with CYGB siRNA. Inhibition of CYGB expression with siRNA also tended to decrease the levels of PGC-1α messenger ribonucleic acid (mRNA) and protein, as well as SDH enzyme activity.

    Conclusion: Inhibition of CYGB expression with siRNA tended to decrease mitochondrial biogenesis and function. This may be useful for understanding the excessive proliferation of fibroblasts in keloids and for development of treatment for keloids.

    Matched MeSH terms: Oxidation-Reduction
  14. Fulltext A Short Review on the Phase Structures, Oxidation Kinetics, and Mechanical Properties of Complex Ti-Al Alloys
    Lim HP, Liew WYH, Melvin GJH, Jiang ZT
    Materials (Basel), 2021 Mar 29;14(7).
    PMID: 33805462 DOI: 10.3390/ma14071677
    This paper reviews the phase structures and oxidation kinetics of complex Ti-Al alloys at oxidation temperatures in the range of 600-1000 °C. The mass gain and parabolic rate constants of the alloys under isothermal exposure at 100 h (or equivalent to cyclic exposure for 300 cycles) is compared. Of the alloying elements investigated, Si appeared to be the most effective in improving the oxidation resistance of Ti-Al alloys at high temperatures. The effect of alloying elements on the mechanical properties of Ti-Al alloys is also discussed. Significant improvement of the mechanical properties of Ti-Al alloys by element additions has been observed through the formation of new phases, grain refinement, and solid solution strengthening.
    Matched MeSH terms: Oxidation-Reduction
  15. Fulltext Electrodeposited Hybrid Biocathode-Based CO2 Reduction via Microbial Electro-Catalysis to Biofuels
    Anwer AH, Khan N, Umar MF, Rafatullah M, Khan MZ
    Membranes (Basel), 2021 Mar 22;11(3).
    PMID: 33810075 DOI: 10.3390/membranes11030223
    Microbial electrosynthesis is a new approach to converting C1 carbon (CO2) to more complex carbon-based products. In the present study, CO2, a potential greenhouse gas, was used as a sole carbon source and reduced to value-added chemicals (acetate, ethanol) with the help of bioelectrochemical reduction in microbial electrosynthesis systems (MES). The performance of MES was studied with varying electrode materials (carbon felt, stainless steel, and cobalt electrodeposited carbon felt). The MES performance was assessed in terms of acetic acid and ethanol production with the help of gas chromatography (GC). The electrochemical characterization of the system was analyzed with chronoamperometry and cyclic voltammetry. The study revealed that the MES operated with hybrid cobalt electrodeposited carbon felt electrode yielded the highest acetic acid (4.4 g/L) concentration followed by carbon felt/stainless steel (3.7 g/L), plain carbon felt (2.2 g/L), and stainless steel (1.87 g/L). The alcohol concentration was also observed to be highest for the hybrid electrode (carbon felt/stainless steel/cobalt oxide is 0.352 g/L) as compared to the bare electrodes (carbon felt is 0.22 g/L) tested, which was found to be in correspondence with the pH changes in the system. Electrochemical analysis revealed improved electrotrophy in the hybrid electrode, as confirmed by the increased redox current for the hybrid electrode as compared to plain electrodes. Cyclic voltammetry analysis also confirmed the role of the biocatalyst developed on the electrode in CO2 sequestration.
    Matched MeSH terms: Oxidation-Reduction
  16. Quality assessment of refined red palm-pressed mesocarp olein
    Teh SS, Lau HLN
    Food Chem, 2021 Mar 15;340:127912.
    PMID: 32916404 DOI: 10.1016/j.foodchem.2020.127912
    Palm-pressed mesocarp oil has been found to contain plenty of naturally occurring valuable phytonutrients. The application and study of the oil are limited, therefore, quality assessment of refined red palm-pressed mesocarp olein (PPMO) is deemed necessary to provide data in widening the applications as a niche products or raw material for the nutraceutical industry. Results showed that refined PPMO has comparable physicochemical properties and oxidative stability with commercial cooking oil, palm olein (PO). The food safety parameters and contaminants (PAH, 3-MCPD ester, 2-MCPD ester, glycidyl ester and trace metals) analyses proven that refined PPMO is safe to be consumed. Besides, refined PPMO contains remarkably greater concentrations of phytonutrients including carotenoids, phytosterols, squalene and vitamin E than PO, postulating its protective health benefits. The overall quality assessment of refined PPMO showed that it is suitable for human consumption and it is a good source for food applications and dietary nutritional supplements.
    Matched MeSH terms: Oxidation-Reduction
  17. Mitigation of indoor air pollution: A review of recent advances in adsorption materials and catalytic oxidation
    Yue X, Ma NL, Sonne C, Guan R, Lam SS, Van Le Q, et al.
    J Hazard Mater, 2021 03 05;405:124138.
    PMID: 33092884 DOI: 10.1016/j.jhazmat.2020.124138
    Indoor air pollution with toxic volatile organic compounds (VOCs) and fine particulate matter (PM2.5) is a threat to human health, causing cancer, leukemia, fetal malformation, and abortion. Therefore, the development of technologies to mitigate indoor air pollution is important to avoid adverse effects. Adsorption and photocatalytic oxidation are the current approaches for the removal of VOCs and PM2.5 with high efficiency. In this review we focus on the recent development of indoor air pollution mitigation materials based on adsorption and photocatalytic decomposition. First, we review on the primary indoor air pollutants including formaldehyde, benzene compounds, PM2.5, flame retardants, and plasticizer: Next, the recent advances in the use of adsorption materials including traditional biochar and MOF (metal-organic frameworks) as the new emerging porous materials for VOCs absorption is reviewed. We review the mechanism for mitigation of VOCs using biochar (noncarbonized organic matter partition and adsorption) and MOF together with parameters that affect indoor air pollution removal efficiency based on current mitigation approaches including the mitigation of VOCs using photocatalytic oxidation. Finally, we bring forward perspectives and directions for the development of indoor air mitigation technologies.
    Matched MeSH terms: Oxidation-Reduction
  18. Effects of drying methods on oxidative stability of roselle seed oil (Hibiscus Sabdariffa): an optimization approach
    Jahurul MHA, Shian OK, Sharifudin MS, Hasmadi M, Lee JS, Mansoor AH, et al.
    J Food Sci Technol, 2021 Mar;58(3):902-910.
    PMID: 33678873 DOI: 10.1007/s13197-020-04604-1
    The objective of this study was to optimize the extraction of oil from pre-dried roselle seeds using response surface methodology (RSM). We also determined the oxidative stability of oil extracted from oven and freeze-dried roselle seed in terms of iodine value (IV), free fatty acid (FFA) value, peroxide value (PV), P-anisidine and total oxidation values (TOTOX value). The RSM was designated based on the central composite design with the usage of three optimum parameters ranged from 8 to 16 g of sample weight, 250-350 mL of solvent volume, and 6-8 h of extraction time. The highest oil yielded from roselle seed using the optimization process was 22.11% with the parameters at sample weight of 14.4 g, solvent volume of 329.70 mL, and extraction time of 7.6 h. Besides, the oil extracted from the oven dried roselle seed had the values of 89.04, 2.11, 4.13, 3.76 and 12.03 for IV, FFA, PV, P-anisidine, and TOTOX values, respectively. While for the oil extracted from freeze-dried roselle seed showed IV of 90.31, FFA of 1.64, PV of 2.47, P-anisidine value of 3.48, and TOTOX value of 8.42. PV and TOTOX values showed significant differences whereas; IV, FFA, and P-anisidine values showed no significant differences between the oven and freeze-dried roselle seed oils.
    Matched MeSH terms: Oxidation-Reduction
  19. A portable electrochemical sensor for detection of the veterinary drug xylazine in beverage samples
    Saisahas K, Soleh A, Promsuwan K, Phonchai A, Mohamed Sadiq NS, Teoh WK, et al.
    J Pharm Biomed Anal, 2021 Feb 08;198:113958.
    PMID: 33662759 DOI: 10.1016/j.jpba.2021.113958
    A portable electrochemical sensor was developed to determine xylazine in spiked beverages by adsorptive stripping voltammetry (AdSV). The sensor was based on a graphene nanoplatelets-modified screen-printed carbon electrode (GNPs/SPCE). The electrochemical behavior of xylazine at the GNPs/SPCE was an adsorption-controlled irreversible oxidation reaction. The loading of graphene nanoplatelets (GNPs) on the modified SPCE, electrolyte pH, and AdSV accumulation potential and time were optimized. Under optimal conditions, the GNPs/SPCE provided high sensitivity, linear ranges of 0.4-6.0 mg L-1 (r = 0.997) and 6.0-80.0 mg L-1 (r = 0.998) with a detection limit of 0.1 mg L-1 and a quantitation limit of 0.4 mg L-1. Repeatability was good. The accuracy of the proposed sensor was investigated by spiking six beverage samples at 1.0, 5.0, and 10.0 mg L-1. The recoveries from this method ranged from 80.8 ± 0.2-108.1 ± 0.3 %, indicating the good accuracy of the developed sensor. This portable electrochemical sensor can be used to screen for xylazine in beverage samples as evidence in cases of sexual assault or robbery.
    Matched MeSH terms: Oxidation-Reduction
  20. Oxidative hydrothermal surface modification of activated carbon for sevoflurane removal
    Ang TN, Young BR, Burrell R, Taylor M, Aroua MK, Baroutian S
    Chemosphere, 2021 Feb;264(Pt 2):128535.
    PMID: 33045509 DOI: 10.1016/j.chemosphere.2020.128535
    The emission of waste anaesthetic gas is a growing contributor to global warming and remains a factor in atmospheric ozone depletion. Volatile anaesthetics in medical waste gases could be removed via adsorption using suitable activated carbon materials possessing an enhanced affinity to anaesthetic molecules. In this work, the effects of surface physical and chemical properties on sevoflurane adsorption were investigated by oxidative hydrothermal surface modification of a commercial activated carbon using only distilled water. The hydrothermal surface modification was carried out at different treatment temperatures (150-300 °C) for varying durations (10-30 min), and adsorption was conducted under fixed conditions (bed depth = 10 cm, inlet concentration = 528 mg/L, and flow rate = 3 L/min). The hydrothermal treatment generally increased the BET surface area of the activated carbons. At oxidation temperatures above 200 °C, the micropore volume of the samples diminished. The relative amount of surface oxygen was enriched as the treatment temperature increased. Treatment duration did not significantly affect the introduction of relative amount of surface oxygen, except at higher temperatures. There were no new types of functional groups introduced. However, disappearance and re-formation of oxygen functional groups containing C-O structures (as in hydroxyl and ether groups) occurred when treatment temperature was increased from 150 to 200 °C, and when treatments were conducted above 200 °C, respectively. The ester/acetal groups were enriched under the temperature range studied. The findings suggested that the re-formation of surface oxygen functionalities might lead to the development of functional groups that improve sevoflurane adsorption.
    Matched MeSH terms: Oxidation-Reduction
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