Displaying publications 101 - 120 of 640 in total

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  1. Amirul Alam M, Juraimi AS, Rafii MY, Hamid AA, Aslani F, Alam MZ
    Food Chem, 2015 Feb 15;169:439-47.
    PMID: 25236249 DOI: 10.1016/j.foodchem.2014.08.019
    Dry matter (DM), total phenolics, flavonoids, carotenoid contents, and antioxidant activity of 12 purslane accessions were investigated against five levels of salinity (0, 8, 16, 24 and 32dSm(-1)). In untreated plants, the DM contents ranged between 8.0-23.4g/pot; total phenolics contents (TPC) between 0.96-9.12mgGAEg(-1)DW; total flavonoid contents (TFC) between 0.15-1.44mgREg(-1)DW; and total carotenoid contents (TCC) between 0.52BCEg(-1)DW. While FRAP activity ranged from 8.64-104.21mgTEg(-1)DW (about 12-fold) and DPPH activity between 2.50-3.30mgmL(-1) IC50 value. Different levels of salinity treatment resulted in 8-35% increases in TPC; about 35% increase in TFC; and 18-35% increases in FRAP activity. Purslane accessions Ac4, Ac5, Ac6 and Ac8 possessed potentials for salinity-induced augmented production of bioactive compounds which in turn can be harnessed for possible human health benefits.
    Matched MeSH terms: Phenols/analysis
  2. Ghasemzadeh A, Jaafar HZ
    ScientificWorldJournal, 2014;2014:523120.
    PMID: 25147852 DOI: 10.1155/2014/523120
    Response surface methodology was applied to optimization of the conditions for reflux extraction of Pandan (Pandanus amaryllifolius Roxb.) in order to achieve a high content of total flavonoids (TF), total phenolics (TP), and high antioxidant capacity (AC) in the extracts. Central composite experimental design with three factors and three levels was employed to consider the effects of the operation parameters, including the methanol concentration (MC, 40%-80%), extraction temperature (ET, 40-70°C), and liquid-to-solid ratio (LS ratio, 20-40 mL/g) on the properties of the extracts. Response surface plots showed that increasing these operation parameters induced the responses significantly. The TF content and AC could be maximized when the extraction conditions (MC, ET, and LS ratio) were 78.8%, 69.5°C, and 32.4 mL/g, respectively, whereas the TP content was optimal when these variables were 75.1%, 70°C, and 31.8 mL/g, respectively. Under these optimum conditions, the experimental TF and TP content and AC were 1.78, 6.601 mg/g DW, and 87.38%, respectively. The optimized model was validated by a comparison of the predicted and experimental values. The experimental values were found to be in agreement with the predicted values, indicating the suitability of the model for optimizing the conditions for the reflux extraction of Pandan.
    Matched MeSH terms: Phenols/chemistry*
  3. Goh TB, Koh RY, Yam MF, Azhar ME, Mordi MN, Mansor SM
    Food Chem, 2015 Sep 15;183:208-16.
    PMID: 25863630 DOI: 10.1016/j.foodchem.2015.03.044
    Various 6-methoxytetrahydro-β-carboline derivatives, namely BEN (6-methoxy-1-phenyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole), ANI (6-methoxy-1-(4-methoxyphenyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole), ACE (6-methoxy-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole) and VAN (2-methoxy-4-(6-methoxy-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-l)phenol), were prepared via the Maillard reaction using food flavours and 5-methoxytryptamine in aqueous medium and were investigated for their in vitro antioxidant and cytotoxicity properties. These derivatives were found to exhibit moderate antioxidant properties, based on a combination of DPPH, ABTS and FRAP assays. The results suggested that the Maillard reaction could be used to generate β-carboline antioxidants. It was beneficial that VAN showed the highest antioxidant activity but the least cytotoxic activities on non-tumourous cell lines of NIH/3T3, CCD18-Co and B98-5 using MTT assay. ACE, ANI and BEN showed mild toxicity at effective antioxidative concentrations derived from DPPH and ABTS assays. Furthermore, they are safer compared to 5-fluorouracil, cisplatin and betulinic acid on NIH/3T3, CCD18-Co and B98-5 cells. In conclusion, the antioxidant and cytotoxicity properties of 6-methoxytetrahydro-β-carbolines were demonstrated for the first time.
    Matched MeSH terms: Phenols/chemistry*
  4. Tsuji Y, Vanholme R, Tobimatsu Y, Ishikawa Y, Foster CE, Kamimura N, et al.
    Plant Biotechnol J, 2015 Aug;13(6):821-32.
    PMID: 25580543 DOI: 10.1111/pbi.12316
    Bacteria-derived enzymes that can modify specific lignin substructures are potential targets to engineer plants for better biomass processability. The Gram-negative bacterium Sphingobium sp. SYK-6 possesses a Cα-dehydrogenase (LigD) enzyme that has been shown to oxidize the α-hydroxy functionalities in β-O-4-linked dimers into α-keto analogues that are more chemically labile. Here, we show that recombinant LigD can oxidize an even wider range of β-O-4-linked dimers and oligomers, including the genuine dilignols, guaiacylglycerol-β-coniferyl alcohol ether and syringylglycerol-β-sinapyl alcohol ether. We explored the possibility of using LigD for biosynthetically engineering lignin by expressing the codon-optimized ligD gene in Arabidopsis thaliana. The ligD cDNA, with or without a signal peptide for apoplast targeting, has been successfully expressed, and LigD activity could be detected in the extracts of the transgenic plants. UPLC-MS/MS-based metabolite profiling indicated that levels of oxidized guaiacyl (G) β-O-4-coupled dilignols and analogues were significantly elevated in the LigD transgenic plants regardless of the signal peptide attachment to LigD. In parallel, 2D NMR analysis revealed a 2.1- to 2.8-fold increased level of G-type α-keto-β-O-4 linkages in cellulolytic enzyme lignins isolated from the stem cell walls of the LigD transgenic plants, indicating that the transformation was capable of altering lignin structure in the desired manner.
    Matched MeSH terms: Phenols/metabolism
  5. Jamal HAA, Husaini A, Sing NN, Roslan HA, Zulkharnain A, Akinkunmi WA
    Braz J Microbiol, 2022 Dec;53(4):1857-1870.
    PMID: 36109458 DOI: 10.1007/s42770-022-00827-w
    This research evaluates the bioactivity of twelve endophytic fungi successfully isolated and characterised from Gynura procumbens. The fungal extracts displayed inhibitory activity against Staphylococcus aureus, Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Salmonella typhi with the MIC and MBC of 5000 µg/mL. High antioxidant activity using DPPH free radical scavenging assay with inhibition of 86.6% and IC50 value of 104.25 ± 18.51 µg/mL were exhibited by ethyl acetate extract of Macrophomina phaseolina SN6. In contrast, the highest scavenging activity percentage of methanolic extract was exhibited by Mycoleptodiscus indicus SN4 (50.0%). Besides that, the highest ferric reducing antioxidant power (FRAP) value of ethyl acetate and methanolic extract was recorded from M. phaseolina SN6 (239.9 mg Fe (II)/g) and M. indicus SN4 (44.7 mg Fe (II)/g), respectively. Total phenolic content (TPC) and total flavonoid content (TFC) of ethyl acetate and methanolic fungal extracts were determined using Folin-Ciocalteu and aluminium chloride, respectively. The highest TPC for ethyl acetate and methanolic extracts were exhibited by Colletotrichum gloeosporioides SN11 (87.0 mg GAE/g) and M. indicus SN4 (35.0 mg GAE/g), whereas the highest TFC of ethyl acetate and methanolic extracts were showed by M. phaseolina SN6 (122.8 mg QCE/g) and M. indicus SN4 (60.4 mg QCE/g), respectively. Bioactive metabolites of isoelemicin (50.8%), terpinen-4-ol (21.5%), eucalyptol (24.3%), oleic acid (19.8%) and β-pinene (10.9%) were detected. Owing to the higher content of phytochemicals represented in the ethyl acetate extract of M. phaseolina, SN6 is therefore identified to be a superior candidate in exhibiting strong antioxidant and antimicrobial properties be fit for further pharmaceutical studies.
    Matched MeSH terms: Phenols/pharmacology
  6. Ahmad NA, Goh PS, Zakaria NAS, Naim R, Abdullah MS, Ismail AF, et al.
    Chemosphere, 2024 Apr;353:141108.
    PMID: 38423147 DOI: 10.1016/j.chemosphere.2024.141108
    Thin film composite (TFC) reverse osmosis (RO) membrane shows good promise for treating wastewater containing endocrine disrupting chemical (EDC) pollutants. The incorporation of functional materials with exceptional structural and physico-chemical properties offers opportunities for the membranes preparation with enhanced permselectivity and better antifouling properties. The present study aims to improve the EDC removal efficiency of TFC RO membrane using two-dimensional titania nanosheets (TNS). RO membrane was prepared by incorporating TNS in the dense layer of polyamide (PA) layer to form thin film nanocomposite (TFN) membrane. The TNS loading was varied and the influences on membrane morphology, surface hydrophilicity, surface charge, as well as water permeability and rejection of EDC were investigated. The results revealed that the inclusion of TNS in the membrane resulted in the increase of water permeability and EDC rejection. When treating the mixture of bisphenol A (BPA) and caffeine at 100 ppm feed concentration, the TFN membrane incorporated with 0.05% TNS achieved water permeability of 1.45 L/m2·h·bar, which was 38.6% higher than that of unmodified TFC membrane, while maintaining satisfactory rejection of >97%. The enhancement of water permeability for TFN membrane can be attributed to their hydrophilic surface and unique nanochannel structure created by the nanoscale interlayer spacing via staking of TiO2 nanosheets. Furthermore, the 0.05TFN membrane exhibited excellent fouling resistance towards BPA and caffeine pollutants with almost 100% flux recovery for three cycles of operations.
    Matched MeSH terms: Phenols*
  7. Ng MY, Song ZJ, Venkatesan G, Rodriguez-Cuenca S, West JA, Yang S, et al.
    Sci Rep, 2024 Feb 28;14(1):4932.
    PMID: 38418847 DOI: 10.1038/s41598-024-54466-2
    One potential approach for treating obesity is to increase energy expenditure in brown and white adipose tissue. Here we aimed to achieve this outcome by targeting mitochondrial uncoupler compounds selectively to adipose tissue, thus avoiding side effects from uncoupling in other tissues. Selective drug accumulation in adipose tissue has been observed with many lipophilic compounds and dyes. Hence, we explored the feasibility of conjugating uncoupler compounds with a lipophilic C8-hydrocarbon chain via an ether bond. We found that substituting the trifluoromethoxy group in the uncoupler FCCP with a C8-hydrocarbon chain resulted in potent uncoupling activity. Nonetheless, the compound did not elicit therapeutic effects in mice, likely as a consequence of metabolic instability resulting from rapid ether bond cleavage. A lipophilic analog of the uncoupler compound 2,6-dinitrophenol, in which a C8-hydrocarbon chain was conjugated via an ether bond in the para-position (2,6-dinitro-4-(octyloxy)phenol), exhibited increased uncoupling activity compared to the parent compound. However, in vivo pharmacokinetics studies suggested that 2,6-dinitro-4-(octyloxy)phenol was also metabolically unstable. In conclusion, conjugation of a hydrophobic hydrocarbon chain to uncoupler compounds resulted in sustained or improved uncoupling activity. However, an ether bond linkage led to metabolic instability, indicating the need to conjugate lipophilic groups via other chemical bonds.
    Matched MeSH terms: Phenols/pharmacology
  8. You W, Wang C, Zhang J, Ru X, Xu F, Wu Z, et al.
    Food Chem, 2024 Jul 15;446:138866.
    PMID: 38430769 DOI: 10.1016/j.foodchem.2024.138866
    Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.
    Matched MeSH terms: Phenols/metabolism
  9. Tengku-Mazuki TA, Darham S, Convey P, Shaharuddin NA, Zulkharnain A, Khalil KA, et al.
    Braz J Microbiol, 2024 Mar;55(1):629-637.
    PMID: 38110706 DOI: 10.1007/s42770-023-01215-8
    Antarctica has often been perceived as a pristine continent until the recent few decades as pollutants have been observed accruing in the Antarctic environment. Irresponsible human activities such as accidental oil spills, waste incineration and sewage disposal are among the primary anthropogenic sources of heavy metal contaminants in Antarctica. Natural sources including animal excrement, volcanism and geological weathering also contribute to the increase of heavy metals in the ecosystem. A microbial growth model is presented for the growth of a bacterial cell consortium used in the biodegradation of phenol in media containing different metal ions, namely arsenic (As), cadmium (Cd), aluminium (Al), nickel (Ni), silver (Ag), lead (Pb) and cobalt (Co). Bacterial growth was inhibited by these ions in the rank order of Al 
    Matched MeSH terms: Phenols/pharmacology
  10. Tan, C.X., Azrina, A.
    MyJurnal
    Beans are distinctive among a diverse and broad class of legumes. Certain health products claimed their products are high in dietary fibers and total phenolic content (TPC) because they applied bean combinations. This study aimed to determine the dietary fibers and TPC of raw and cooked beans and its combinations. Individual beans studied were kidney bean, mung bean and chickpea. Bean combinations were done by mixing each of the homogenized beans flour in the ratio of 1:1 (w/w) and 1:1:1 (w/w/w). Dietary fibers were determined using enzymaticgravimetrical method whereas TPC was determined spectrophotometrically. Results showed the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), total dietary fiber (TDF) and TPC for individual raw beans varied from 20.52 to 26.61 g/100 g, 1.20 to 2.45 g/100 g, 22.08 to 27.81 g/100 g and 0.48 to 1.04 mg GAE/g, respectively. For raw bean combinations, the IDF, SDF, TDF and TPC varied from 20.74 to 23.96 g/100 g, 2.3 to 2.50 g/100 g, 23.05 to 26.46 g/100 g and 0.80 to 0.85 mg GAE/g, respectively. No significant different (p > 0.05) in IDF and SDF for raw bean combinations and individual raw beans. Meanwhile, certain raw bean combinations contained significant higher (p < 0.05) TDF and TPC than individual raw beans. The IDF, SDF, TDF and TPC for individual cooked beans varied from 14.49 to 26.30 g/100 g, 1.40 to 2.02 g/100 g, 15.88 to 28.31 g/100 g and 0.57 to 1.20 mg GAE/g, respectively. For cooked bean combinations, the IDF, SDF, TDF and TPC varied from 15.73 to 23.03 g/100 g, 1.73 to 2.36 g/100 g, 17.46 to 24.95 g/100 g and 0.61 to 1.08 mg GAE/g, respectively. After cooking, the IDF, SDF, TDF and TPC of certain beans combinations were significantly higher (p < 0.05) than individual beans. This study supports the proposal that bean combinations can possibly be used as a method to increase the amount of dietary fibers and TPC.
    Matched MeSH terms: Phenols
  11. Aziz A, Agamuthu P, Fauziah SH
    Waste Manag Res, 2018 Dec;36(12):1146-1156.
    PMID: 30067147 DOI: 10.1177/0734242X18789062
    The widespread distribution of persistent organic pollutants (POPs) in landfill leachate is problematic due to their acute toxicity, carcinogenicity and genotoxicity effects, which could be detrimental to public health and ecological systems. The objective of this study was to evaluate the effective removal of POPs - namely, p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)- - from landfill leachate using locust bean gum (LBG), and in comparison with commonly used alum. The response surface methodology coupled with a Box-Behnken design was employed to optimize the operating factors for optimal POPs removal. A quadratic polynomial model was fitted into the data with the R2 values of 0.97 and 0.96 for the removal of p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl), (S)-, respectively. The physicochemical characteristics of the flocs produced by LBG and alum were evaluated with Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). The infrared spectra of LBG-treated floc were identical with LBG powder, but there was some variation in the peaks of the functional groups, signifying the chemical interactions between flocculants and pollutant particles resulting from POPs removal. The results showed that p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)- obtained 96% and 100% removal using 500 mg/L of LBG at pH 4. pH have a significant effect on POPs removal in leachate. It is estimated that treating one million gallons of leachate using alum (at 1 g/L dosage) would cost US$39, and using LBG (at 500 mg/L dosage) would cost US$2. LBG is eco-friendly, biodegradable and non-toxic and, hence, strongly recommended as an alternative to inorganic coagulants for the treatment of POPs in landfill leachate.
    Matched MeSH terms: Phenols
  12. Konsue, N., Amron, N.A.
    MyJurnal
    Cruciferous vegetables belong to the mustard family of plants such as Brussels sprouts, kale, broccoli, cabbage and cauliflower. They are well known for their cancer prevention properties which are due to high content of bioactive compounds, isothiocyanates (ITCs). This study was aimed to investigate nitrosation inhibition ability of the cruciferous vegetables commonly consumed with meat products namely, broccoli, cauliflower and cabbage. Aqueous extracts of fresh and steamed (2 and 4 min) vegetables were subjected to determination of antioxidant capacity (DPPH and FRAP assay) and chemical composition i.e. total phenolic and isothiocyanate (ITC) content. It was found that TPC, DPPH and FRAP values of raw vegetables were different in each vegetable and ranged from 17.12-38.91 mg GAE/100 ml, 44.09-63.31% and 1.36-6.81 mg TE/100 ml, respectively. Among three types of cruciferous vegetable, broccoli had the highest PEITC content being 0.21 mmol/100 g compared to cauliflower (0.15 mmol/100 g) and cabbage (0.06 mmol/100 g). Moreover, it was found that steaming process significantly enhanced antioxidant activity, TPC as well as PEITC content in a timedependent manner up to 4 min (p
    Matched MeSH terms: Phenols
  13. Abidin, N.S.A., Rukunudin, I.H., Zaaba, S.K., Wan Omar, W.A.
    MyJurnal
    This work aimed to evaluate the effect of Atmospheric Cold Plasma (ACP) on the quality of mango flour noodles (NMF). ACP treatment of 5 minutes duration on the surface of the noodles strands were performed and evaluated during three days of storage by monitoring parameters related to colour, water activity, antioxidant activity and total phenolic content. The lightness value (L*) was higher for untreated samples (NMF (U)) than for treated samples (NMF (T)), while a greater increased in the redness (a*) and yellowness (b*) values were observed for the NMF (T). The changes in aw, antioxidant activity and total phenolic content (TPC) were negligible. However the NMF (T) showed significant different (p
    Matched MeSH terms: Phenols
  14. Ahmed Asrity, S.M., Tsan, F.Y., Ding, P., Syed Aris, S.R.
    MyJurnal
    Functional property changes in Phaleria macrocarpa fruit during ripening on tree were studied. Results showed that juice extracted from fruit flesh had low acidity and soluble solid content. Fruit acidity decreased but soluble solids increased as the fruit ripened. In terms of antioxidant content, ascorbic acid, DPPH free radical scavenging activities and total phenolic content were, however, the lowest in fully ripe fruit flesh while the unripe fruit flesh had the highest. High percentage of these antioxidants was water soluble. This study suggests that the unripe fruits should be harvested for valuable medicinal product development instead of the fully ripe fruits.
    Matched MeSH terms: Phenols
  15. Dzuhri S, Yuhana N, Khairulazfar M
    Sains Malaysiana, 2015;44:441-448.
    This study utilized the incorporation of nanoparticle filler into an epoxy system to study the effect of different nanosized
    montmorillonite (MMT) fillers on the thermal stability and mechanical properties of epoxy. The sample was prepared
    using diglycidyl ether of bisphenol A (DGEBA) with different surface treatments of montmorillonite filler by mechanical
    stirring. The results of thermal stability and mechanical properties of epoxy/clay system obtained from thermal gravimetric
    analyzer (TGA), universal testing machine (UTM) and scanning electron microscopy (SEM) were discussed. With the same
    amount of filler introduced into the system, different thermal stability of epoxy composite can be observed. Bentonite,
    which contained other contaminant components, can downgrade the enhanced properties of the filler.
    Matched MeSH terms: Phenols
  16. Noor Afiqah Md Noor, Maizura Murad, Effarizah Mohd Esah
    Sains Malaysiana, 2018;47:2047-2054.
    This study was designed to determine the physicochemical, antioxidant and microbial properties of fresh sugarcane juice
    with calamansi juice addition. The sugarcane that was used in the experiments was the black cane variety (Saccharum
    officinarum). Sugarcane pressed with and without their peel was juiced and added with calamansi juice before analysis
    was carried out. Standard method was used to analyse physicochemical properties such as pH, total soluble solids,
    acidity and colour of sugarcane juice. Total phenolic content (TPC), DPPH and FRAP assay were conducted for antioxidant
    properties. Total plate count and yeast and mould count were carried out for the microbiological analyses. Two way
    analysis of variance (ANOVA) shows significant (p<0.05) difference on colour of sugarcane juiced after extraction with and
    without peel. There were no significant (p>0.05) difference shown for pH, acidity and total soluble solids of sugarcane
    juice pressed with and without peel. Sugarcane juice pressed with peel produced higher antioxidant value compared
    to sugarcane pressed without peel. However, sugarcane juice pressed without peeled showed a lower microbial count
    compared to sugarcane juice pressed with peel. The addition of calamansi juice proved to have significant (p<0.05)
    effect on colour, antioxidant and microbial count of the sugarcane juices.
    Matched MeSH terms: Phenols
  17. Chuah TS, Norhafizah MZ, Naimah AH, Ismail BS
    Sains Malaysiana, 2016;45:963-967.
    The allelochemical 2,4-di-tert-butylphenol (2,4-DTBP) is one of the natural compounds present in medicinal plants.
    This compound has been reported to possess herbicidal properties. However, its effect on weed growth parameters is
    unknown for it to be utilized in weed management. Hence, the herbicidal potential of the allelochemical 2,4-DTBP on the
    root and leaf tissues of the grassy weed, Leptochloa chinensis (L.) Nees and the broadleaf weed, Hedyotis verticillata
    (L.) Lam was investigated. After 2,4-DTBP treatment, both bioassay species had abnormal and much shorter root hairs
    compared to those of untreated plants. The roots of H. verticillata were severely damaged with the root nodes turned
    brown. The phytotoxic effect of 2,4-DTBP on L. chinensis and H. verticillata became apparent at seven days and 14 days
    after treatment with symptoms of lamina wilting and necrosis, respectively. These results demonstrated that 2,4-DTBP
    could be used as a natural herbicide for the control of L. chinensis and H. verticillata.
    Matched MeSH terms: Phenols
  18. Kamarudin N, Awang Biak DR, Zainal Abidin Z, Cardona F, Sapuan SM
    Materials (Basel), 2020 Jun 05;13(11).
    PMID: 32516968 DOI: 10.3390/ma13112578
    Heat explosions are sometimes observed during the synthesis of phenol formaldehyde (PF) resin. This scenario can be attributed to the high latent heat that was released and not dissipated leading to the occurrence of a runaway reaction. The synthesis temperature and time played important roles in controlling the heat release, hence preventing the resin from hardening during the synthesis process. This study aims to assess the rheological and viscoelasticity behaviors of the PF resin prepared using paraformaldehyde. The prepared PF resin was designed for laminate applications. The rheological behavior of the PF resin was assessed based on the different molar ratios of phenol to paraformaldehyde (P:F) mixed in the formulation. The molar ratios were set at 1.00:1.25, 1.00:1.50 and 1.00:1.75 of P to F, respectively. The rheological study was focused at specific synthesis temperatures, namely 40, 60, 80 and 100 °C. The synthesis time was observed for 240 min; changes in physical structure and viscosity of the PF resins were noted. It was observed that the viscosity values of the PF resins prepared were directly proportional to the synthesis temperature and the formaldehyde content. The PF resin also exhibited shear thickening behavior for all samples synthesized at 60 °C and above. For all PF resin samples synthesized at 60 °C and above, their viscoelasticity results indicated that the storage modulus (G'), loss modulus(G″) and tan δ are proportionally dependent on both the synthesis temperature and the formaldehyde content. Heat explosions were observed during the synthesis of PF resin at the synthesis temperature of 100 °C. This scenario can lead to possible runaway reaction which can also compromise the safety of the operators.
    Matched MeSH terms: Phenols
  19. Abdul Aziz FA, Suzuki K, Amano K, Moriuchi R, Dohra H, Tashiro Y, et al.
    Microbiol Resour Announc, 2020 Sep 10;9(37).
    PMID: 32912906 DOI: 10.1128/MRA.00597-20
    We report the draft genome sequence of Variovorax boronicumulans strain c24, which was isolated from a soil-inoculated chemostat culture amended with phenol as a sole carbon and energy source. The genome data will provide insights into phenol and other xenobiotic compound degradation mechanisms for bioremediation applications.
    Matched MeSH terms: Phenols
  20. Shehab ZN, Jamil NR, Aris AZ
    J Environ Manage, 2020 Nov 15;274:111141.
    PMID: 32818827 DOI: 10.1016/j.jenvman.2020.111141
    A simplified modelling approach for illustrating the fate of emerging pollutants can improve risk assessment of these chemicals. Once released into aquatic environments, these pollutants will interact with various substances including suspended particles, colloidal or nano particles, which will greatly influence their distribution and ultimate fate. Understanding these interactions in aquatic environments continues to be an important issue because of their possible risk. In this study, bisphenol A (BPA) in the water column of Bentong River, Malaysia, was investigated in both its soluble and colloidal phase. A spatially explicit hydrological model was established to illustrate the associated dispersion processes of colloidal-bound BPA. Modelling results demonstrated the significance of spatial detail in predicting hot spots or peak concentrations of colloidal-bound BPA in the sediment and water columns as well. The magnitude and setting of such spots were system based and depended mainly on flow conditions. The results highlighted the effects of colloidal particles' concentration and density on BPA's removal from the water column. It also demonstrated the tendency of colloidal particles to aggregate and the impact all these processes had on BPA's transport potential and fate in a river water. All scenarios showed that after 7.5-10 km mark BPA's concentration started to reach a steady state with very low concentrations which indicated that a downstream transport of colloidal-bound BPA was less likely due to minute BPA levels.
    Matched MeSH terms: Phenols
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