Displaying publications 201 - 220 of 403 in total

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  1. Pressure sensitive organic sensor based on CNT-V02 (3fl) composite
    Khan A, Karimov KS, Zubair Armad, Khaulah Sulaiman, Shah M, Moiz S
    Sains Malaysiana, 2014;43:903-908.
    In this paper, fabrication and investigation of organic pressure sensor based on AlICIVT-VO 2(3j7)ICu composite is reported. The active layer of the composite was deposited by drop-casting of the blend CN'T-VO 2 (3fl) on a glass substrate (with prefabricated copper (Cu) electrode). The thin film of the blend consists of carbon nanotube CNT, (2.55 wt. %) and vanadium oxide (VO 2 (3fl)) micropowder, (3 wt. %) in benzol (1 mL). The thickness of the composite was in the range of 20-40 ,um. It was found that the fabricated sensor was sensitive to pressure and showed good repeatability. The decrease in resistance of the sensor was observed by increasing the external uniaxial pressure up to 50 kNm-2 . The experimentally obtained results were compared with the simulated results and showed reasonable agreement with each other.
    Matched MeSH terms: Oxides
  2. Synthesis of zinc selenide/graphene oxide composite via direct and indirect hydrothermal method
    Kee LH, Ying Chyi JL, Zainal Abidin Talib, Mohammad Shuhazlly Mamat, Hong Ngee JL, Fakhrurrazi Ashari, et al.
    Sains Malaysiana, 2016;45:1201-1206.
    Zinc selenide/graphene oxide (ZnSe/GO) composite is synthesized using hydrothermal method. Two different methods
    such as direct and indirect route have been investigated to form the ZnSe/GO composite. In this research, the graphene
    oxide used was in sheet and liquid form. The synthesized composite was then characterized using X-ray diffraction (XRD)
    for phase identification, field emission scanning electron microscopy (FESEM) for morphology analysis and ultravioletvisible
    spectroscopy (UV-Vis) for optical properties. ZnSe/GO composite showed absorption peak ranging from 460 to
    480 nm with the optical band gap obtained through Tauc equation. The optical band gap of the ZnSe/GO composite has
    been tuned down to a smaller value as compared to the bulk ZnSe compound. The optical band gap has been reduced
    to around 2.53 eV when liquid graphene oxide was used while around 2.23 to 2.32 eV when graphene oxide sheet was
    used. The purity of ZnSe/GO composite synthesis via indirect hydrothermal method is higher than those synthesized via
    direct hydrothermal method. The type of graphene oxide will affect the morphology of the composite where the ZnSe
    compound was either wrapped by tiny thorn-like substance or graphene oxide layer.
    Matched MeSH terms: Oxides
  3. Coordination polymer-derived cobalt-embedded and N/S-doped carbon nanosheet with a hexagonal core-shell nanostructure as an efficient catalyst for activation of oxone in water
    Tuan DD, Oh WD, Ghanbari F, Lisak G, Tong S, Andrew Lin KY
    J Colloid Interface Sci, 2020 Nov 01;579:109-118.
    PMID: 32574728 DOI: 10.1016/j.jcis.2020.05.033
    As sulfate-radical (SR)-based advanced oxidation processes are increasingly implemented, Oxone has been frequently-used for generation of SR. While Co3O4 nanoparticle (NP) has been widely-accepted as a promising catalyst for activating Oxone, Co3O4 NPs tend to aggregate in water, losing their reactivity. Thus, many attempts have immobilized Co3O4 NPs on supports, especially carbonaceous substrates, because combination of Co NPs with carbon substrates offers synergistic effects for boosting catalytic activities. Moreover, carbon substrates doped with hetero-atoms (N and S) further increase electron transfer and reactivity. Therefore, it is even promising to immobilize Co NPs onto N/S-doped carbon (NSC) to form Co-embedded NSC (denoted as CoNSC) for enhancing Oxone activation. In this study, a convenient and facile technique is proposed to prepare such a CoNSC via a simple carbonization treatment of a coordination polymer of Co and trithiocyanuric acid (TTCA). The resulting CoNSC exhibits the sheet-like hexagonal morphology with the core-shell configuration, and Co NPs are well-embedded into the N/S-doped carbonaceous matrix, making it an advantageous heterogeneous catalyst for Oxone activation. As Azorubine S (ARS) decolorization is employed as a model reaction of Oxone activation, CoNSC exhibits a higher catalytic activity than pristine Co3O4 and NSC for Oxone activation to decolorize ARS. In comparison to the other reported catalysts, CoNSC also possesses a much lower Ea for ARS decolorization. CoNSC can be also reusable and stable for Oxone activation over multiple cycles without loss of catalytic activity. These features validate that CoNSC is a promising and useful Co-based catalyst for Oxone activation.
    Matched MeSH terms: Oxides
  4. Cytotoxicity evaluation of poly(ethylene) oxide nanofibre in MCF-7 breast cancer cell line
    Jamil M, Mustafa IS, Ahmed NM, Sahul Hamid SB
    Biomater Adv, 2022 Dec;143:213178.
    PMID: 36368056 DOI: 10.1016/j.bioadv.2022.213178
    Biocompatible polymers have received significant interest from researchers for their potential in diagnostic applications. This type of polymer can perform with an appropriate host response or carrier for a specific purpose. The current study aims to fabricate and characterise poly(ethylene) oxide (PEO) nanofibres with different concentrations for cytotoxicity evaluation in human breast cancer cell lines (MCF-7) and to get an optimal PEO nanofibre concentration (permissible limit) as a suitable polymer matrix or carrier with potential use in diagnostic applications. The fabrication of PEO nanofibres was done using electrospinning and was characterised by structure and morphology, surface roughness, chemical bonding and release profiles. The functional effects of PEO nanofibres were evaluated with MTS assay and colony formation assay in MCF-7 cells. The results showed that viscosity plays a vital role in synthesising a polymer solution in electrospinning for producing beadless nanofibrous mats ranging from 4.7 Pa·s to 77.7 Pa·s. As the PEO concentration increases, the nanofibre diameter and thickness will increase, but the surface roughness will be decreased. The average fibre diameter for 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 129 ± 70 nm, 185 ± 55 nm and 192 ± 53 nm, respectively. In addition, the fibre thickness for 4 wt% PEO, 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 269 ± 3 μm, 664 ± 4 μm, 758 ± 7 μm and 1329 ± 44 μm, respectively. Contrarily, the surface roughness for 4 wt% PEO, 5 wt% PEO, 6 wt% PEO and 7 wt% PEO nanofibres were 55.6 ± 9 nm, 42.8 ± 6 nm, 42.7 ± 7 nm and 36.6 ± 1 nm, respectively. PEO nanofibres showed the same burst release pattern and rate due to the same molecular weight of PEO with a stable release rate profile after 15 min. It also demonstrates that the percentage of PEO nanofibre release increased with the increasing PEO concentration due to the fibre diameter and thickness. The findings showed that all PEO nanofibres formulations were non-toxic to MCF-7 cells. It is suggested that 5 wt% PEO nanofibre exhibited non-cytotoxic characteristics by maintaining the cell viability from dose 0-1000 μg/ml and did not induce the number of colonies. Therefore, 5 wt% PEO nanofibre is the optimal nanofibre concentration and was suggested as a suitable base polymer matrix or carrier with potential use for diagnostic purposes. The findings in this study have demonstrated the influence of cell growth and viability, including the effects of PEO nanofibre formulations on cancer progress characteristics to achieve a permissible PEO nanofibre concentration limit that can be a benchmark in medical applications, particularly diagnostic applications.
    Matched MeSH terms: Oxides
  5. Removal of free fatty acid (FFA) in crude palm oil (CPO) using potassium oxide/dolomite as an adsorbent: Optimization by Taguchi method
    Nor Shafizah I, Irmawati R, Omar H, Yahaya M, Alia Aina A
    Food Chem, 2022 Mar 30;373(Pt B):131668.
    PMID: 34848088 DOI: 10.1016/j.foodchem.2021.131668
    In this study, potassium oxide supported on dolomite adsorbent was used as an adsorbent for free fatty acids (FFAs) treatment in crude palm oil (CPO). The characteristics of the adsorbent were determined by TGA, XRD, SEM, BET and TPD-CO2. Taguchi method was utilized for experimental design and optimum condition determination. There were four parameters and three levels involved in this study: time (30, 60, 90 min), stirring rate (300, 500, 700 rpm), adsorbent dosage (1, 3, 5 wt%) and K2O concentration (5, 10, 15 wt%). The adsorbent had a larger pore size, higher basic strength, and more basic sites in greater efficiency (63%) in FFAs removal from CPO. The optimum conditions were at 30 min time, 700 rpm stirring rate, 5 wt% adsorbent dosage and 15 wt% K2O concentration. Taguchi method simplified determination of experimental parameters and minimized the operating costs.
    Matched MeSH terms: Oxides
  6. Fulltext Chitosan-Coated-PLGA Nanoparticles Enhance the Antitumor and Antimigration Activity of Stattic - A STAT3 Dimerization Blocker
    Fong SS, Foo YY, Saw WS, Leo BF, Teo YY, Chung I, et al.
    Int J Nanomedicine, 2022;17:137-150.
    PMID: 35046650 DOI: 10.2147/IJN.S337093
    Purpose: The use of nanocarriers to improve the delivery and efficacy of antimetastatic agents is less explored when compared to cytotoxic agents. This study reports the entrapment of an antimetastatic Signal Transducer and Activator of Transcription 3 (STAT3) dimerization blocker, Stattic (S) into a chitosan-coated-poly(lactic-co-glycolic acid) (C-PLGA) nanocarrier and the improvement on the drug's physicochemical, in vitro and in vivo antimetastatic properties post entrapment.

    Methods: In vitro, physicochemical properties of the Stattic-entrapped C-PLGA nanoparticles (S@C-PLGA) and Stattic-entrapped PLGA nanoparticles (S@PLGA, control) in terms of size, zeta potential, polydispersity index, drug loading, entrapment efficiency, Stattic release in different medium and cytotoxicity were firstly evaluated. The in vitro antimigration properties of the nanoparticles on breast cancer cell lines were then studied by Scratch assay and Transwell assay. Study on the in vivo antitumor efficacy and antimetastatic properties of S@C-PLGA compared to Stattic were then performed on 4T1 tumor bearing mice.

    Results: The S@C-PLGA nanoparticles (141.8 ± 2.3 nm) was hemocompatible and exhibited low Stattic release (12%) in plasma. S@C-PLGA also exhibited enhanced in vitro anti-cell migration potency (by >10-fold in MDA-MB-231 and 5-fold in 4T1 cells) and in vivo tumor growth suppression (by 33.6%) in 4T1 murine metastatic mammary tumor bearing mice when compared to that of the Stattic-treated group. Interestingly, the number of lung and liver metastatic foci was found to reduce by 50% and 56.6%, respectively, and the average size of the lung metastatic foci was reduced by 75.4% in 4T1 tumor-bearing mice treated with S@C-PLGA compared to Stattic-treated group (p < 0.001).

    Conclusion: These findings suggest the usage of C-PLGA nanocarrier to improve the delivery and efficacy of antimetastatic agents, such as Stattic, in cancer therapy.

    Matched MeSH terms: Cyclic S-Oxides
  7. Incorporation of surface plasmon resonance with novel valinomycin doped chitosan-graphene oxide thin film for sensing potassium ion
    Zainudin AA, Fen YW, Yusof NA, Al-Rekabi SH, Mahdi MA, Omar NAS
    Spectrochim Acta A Mol Biomol Spectrosc, 2018 Feb 15;191:111-115.
    PMID: 29024848 DOI: 10.1016/j.saa.2017.10.013
    In this study, the combination of novel valinomycin doped chitosan-graphene oxide (C-GO-V) thin film and surface plasmon resonance (SPR) system for potassium ion (K+) detection has been developed. The novel C-GO-V thin film was deposited on the gold surface using spin coating technique. The system was used to monitor SPR signal for K+ in solution with and without C-GO-V thin film. The K+ can be detected by measuring the SPR signal when C-GO-V thin film is exposed to K+ in solution. The sensor produces a linear response for K+ ion up to 100ppm with sensitivity and detection limit of 0.00948°ppm-1 and 0.001ppm, respectively. These results indicate that the C-GO-V film is high potential as a sensor element for K+ that has been proved by the SPR measurement.
    Matched MeSH terms: Oxides
  8. Advances in Photocatalytic CO₂ Reduction with Water: A Review
    Nahar S, Zain MFM, Kadhum AAH, Hasan HA, Hasan MR
    Materials (Basel), 2017 Jun 08;10(6).
    PMID: 28772988 DOI: 10.3390/ma10060629
    In recent years, the increasing level of CO₂ in the atmosphere has not only contributed to global warming but has also triggered considerable interest in photocatalytic reduction of CO₂. The reduction of CO₂ with H₂O using sunlight is an innovative way to solve the current growing environmental challenges. This paper reviews the basic principles of photocatalysis and photocatalytic CO₂ reduction, discusses the measures of the photocatalytic efficiency and summarizes current advances in the exploration of this technology using different types of semiconductor photocatalysts, such as TiO₂ and modified TiO₂, layered-perovskite Ag/ALa₄Ti₄O15 (A = Ca, Ba, Sr), ferroelectric LiNbO₃, and plasmonic photocatalysts. Visible light harvesting, novel plasmonic photocatalysts offer potential solutions for some of the main drawbacks in this reduction process. Effective plasmonic photocatalysts that have shown reduction activities towards CO₂ with H₂O are highlighted here. Although this technology is still at an embryonic stage, further studies with standard theoretical and comprehensive format are suggested to develop photocatalysts with high production rates and selectivity. Based on the collected results, the immense prospects and opportunities that exist in this technique are also reviewed here.
    Matched MeSH terms: Oxides
  9. Fulltext A review study on Diesel and Natural Gas and its impact on CI Engine Emissions
    Hayder A. Alrazen, Ahmad, K.A.
    Pertanika Journal of Science & Technology, 2017;25(3):983-994.
    MyJurnal
    Diesel engines produce high emissions of nitrogen oxide, smoke and particulate matter. The challenge is to reduce exhaust emissions but without making changing their mechanical configuration. This paper is an overview of the effect of natural gas on the diesel engine emissions. Literature review suggests that engine load, air-fuel ratio, and engine speed play a key role in reducing the pollutants in the diesel engine emissions with natural gas enrichment. It is found that increasing the percentage of natural gas (CNG) will affect emissions. Nitrogen oxide (NOx) is decreased and increased at part loads and high loads respectively when adding CNG. The reduction in carbon dioxide (CO2), particulate matter (PM) and smoke are observed when adding CNG. However, carbon monoxide (CO) and unburned hydrocarbon (HC) are increased when CNG is added.
    Matched MeSH terms: Nitrogen Oxides
  10. Experimental and theoretical approach on the optical properties of zinc borotellurite glass doped with dysprosium oxide
    Halimah MK, Ami Hazlin MN, Muhammad FD
    Spectrochim Acta A Mol Biomol Spectrosc, 2018 Apr 15;195:128-135.
    PMID: 29414569 DOI: 10.1016/j.saa.2017.12.054
    A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Dy2O3)xwhere x=0.01, 0.02, 0.03, 0.04 and 0.05M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3,TeO4and TeO3vibrational groups. The density of the glass systems is increased with the addition of Dy2O3while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the4F9/2→6H15/2and4F9/2→6H13/2transitions of Dy3+ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region.
    Matched MeSH terms: Oxides
  11. Nanostructured Co-Mn containing perovskites for degradation of pollutants: Insight into the activity and stability
    Miao J, Sunarso J, Duan X, Zhou W, Wang S, Shao Z
    J Hazard Mater, 2018 May 05;349:177-185.
    PMID: 29425884 DOI: 10.1016/j.jhazmat.2018.01.054
    The efficient oxidative removal of persistent organic components in wastewater relies on low-cost heterogeneous catalysts that offer high catalytic activity, stability, and recyclability. Here, we designed a series of nanostructured Co-Mn containing perovskite catalysts, LaCo1-xMnxO3+δ (LCM, x = 0, 0.3, 0.5, 0.7, and 1.0), with over-stoichiometric oxygen (δ > 0) to show superior catalytic activity for the degradation of a variety of persistent aqueous organic pollutants by activating peroxymonosulfate (PMS). The nature of LCM for catalysis was comprehensively investigated. A "volcano-shaped" correlation was observed between the catalytic activity and electron filling (eg) of Co in LCM. Among these compounds, LaCo0.5Mn0.5O3+δ (LCM55) exhibited an excellent activity with eg = 1.27. The high interstitial oxygen ion diffusion rate (DO2- = 1.58 ± 0.01 × 10-13 cm2 s-1) of LCM55 also contributes to its catalytic activity. The enhanced stability of LCM55 can be ascribed to its stronger relative acidity (3.22). Moreover, an increased solution pH (pH ≥ 7) generated a faster organic degradation rate and a decrease in metal leaching (0.004 mM) for LCM55 perovskite, justifying it as a potential material for environmental remediation.
    Matched MeSH terms: Oxides; Peroxides
  12. Synthesis and characterization of magnetic graphene oxide for arsenic removal from aqueous solution
    Sherlala AIA, Raman AAA, Bello MM
    Environ Technol, 2019 May;40(12):1508-1516.
    PMID: 29300679 DOI: 10.1080/09593330.2018.1424259
    A magnetic graphene oxide (MGO) was developed for the adsorption of As(III) from aqueous solution. The characteristics of MGO were investigated using Fourier-transform infrared (FTIR), X-ray diffraction and field emission scanning electron microscope-E/energy-dispersive X-ray analyses. Batch adsorption experiments were designed using central composite design, and the effects of adsorbent dosage, pH, contact time and concentration of As(III) were investigated. The MGO showed an excellent performance, removing up to 99.95% of As(III) under the following condition: initial As(III) concentration = 100 mg/L, pH = 7, adsorbent dosage = 0.3 g/L and contact time = 77 min. MGO dosage and initial pH were the most significant parameters influencing the process performance. FTIR analysis of the used adsorbent confirms the adsorption of As(III) through complexation between surface functional groups of the MGO and the oxyanions of As(III). The adsorbent maintained a significant level of performance even after four cycles of adsorption. Thus, the developed MGO has the potential to be used for the abatement of arsenic pollution.
    Matched MeSH terms: Oxides
  13. Fulltext SrCo1-xTixO3-δ perovskites as excellent catalysts for fast degradation of water contaminants in neutral and alkaline solutions
    Miao J, Sunarso J, Su C, Zhou W, Wang S, Shao Z
    Sci Rep, 2017 03 10;7:44215.
    PMID: 28281656 DOI: 10.1038/srep44215
    Perovskite-like oxides SrCo1-xTixO3-δ (SCTx, x = 0.1, 0.2, 0.4, 0.6) were used as heterogeneous catalysts to activate peroxymonosulfate (PMS) for phenol degradation under a wide pH range, exhibiting more rapid phenol oxidation than Co3O4 and TiO2. The SCT0.4/PMS system produced a high activity at increased initial pH, achieving optimized performance at pH ≥ 7 in terms of total organic carbon removal, the minimum Co leaching and good catalytic stability. Kinetic studies showed that the phenol oxidation kinetics on SCT0.4/PMS system followed the pseudo-zero order kinetics and the rate on SCT0.4/PMS system decreased with increasing initial phenol concentration, decreased PMS amount, catalyst loading and solution temperature. Quenching tests using ethanol and tert-butyl alcohol demonstrated sulfate and hydroxyl radicals for phenol oxidation. This investigation suggested promising heterogeneous catalysts for organic oxidation with PMS, showing a breakthrough in the barriers of metal leaching, acidic pH, and low efficiency of heterogeneous catalysis.
    Matched MeSH terms: Oxides; Peroxides
  14. Efficiencies and mechanisms of steel slag with ferric oxides for removing phosphate from wastewater using a column filter system
    Ahmad SZN, Al-Gheethi A, Hamdan R, Othman N
    Environ Sci Pollut Res Int, 2020 Oct;27(28):35184-35194.
    PMID: 32583114 DOI: 10.1007/s11356-020-09582-7
    The current study aimed to investigate the efficiencies and mechanisms of slag filter media for removing phosphorus from synthetic wastewater. The steel slag with high ferric oxides (Fe2O3) was subjected for the electric arc furnace (EAF) and selected as the filter media (HFe). The chemical characteristics of HFe were determined using pH, point of zero charge (PZC) and XRF. The phosphorus removal efficiency was studied in a designed vertical steel slag column rock filters in unaerated HFe (UEF) and aerated HFe (AEF) system. The microstructure of HFe was analyzed by FTIR, XRD and SEM-EDX analysis. The results of XRF revealed that ferric oxide (Fe2O3) ranged from 26.1 to 38.2%. PZC for Filter HFe was recorded at pH 10.55 ± 0.27. The highest efficiencies were recorded by UEF and AEF systems at pH 3 and pH 5 (89.97 ± 4.02% and 79.95 ± 6.25% at pH 3 and 72.97 ± 8.38% and 66.00 ± 12.85% at pH 5 for UEF and AEF, respectively). These findings indicated that AEF exhibiting higher removal than UEF systems might be due to presence high Fe concentration in AEF which play important role in the phosphorus removal. The main elements available on the surface of HFe included carbon, oxygen, iron, calcium, magnesium, silicon, platinum, sulphur, manganese, titanium and aluminium. The XRD analysis indicated that the precipitation of orthophosphate as calcium and iron-phosphates was the removal mechanism as confirmed using FT-IR analysis. These findings demonstrated the efficiency of HFe in removing of phosphorus from wastewater.
    Matched MeSH terms: Oxides
  15. Fulltext Cellulosic fiber nanocomposite application review with zinc oxide antimicrobial agent nanoparticle: an opt for COVID-19 purpose
    Azizan A, Samsudin AA, Shamshul Baharin MB, Dzulkiflee MH, Rosli NR, Abu Bakar NF, et al.
    Environ Sci Pollut Res Int, 2023 Feb;30(7):16779-16796.
    PMID: 35084685 DOI: 10.1007/s11356-022-18515-5
    Cellulosic fiber (CF) in nanoform is emergingly finding its way for COVID-19 solution for instance via nanocomposite/nanoparticle from various abundant biopolymeric waste materials, which may not be widely commercialized when the pandemic strikes recently. The possibility is wide open but needs proper collection of knowledge and research data. Thus, this article firstly reviews CF produced from various lignocellulosic or biomass feedstocks' pretreatment methods in various nanoforms or nanocomposites, also serving together with metal oxide (MeO) antimicrobial agents having certain analytical reporting. CF-MeO hybrid product can be a great option for COVID-19 antimicrobial resistant environment to be proposed considering the long-established CF and MeO laboratory investigations. Secondly, a preliminary pH investigation of 7 to 12 on zinc oxide synthesis discussing on Fouriertransform infrared spectroscopy (FTIR) functional groups and scanning electron microscope (SEM) images are also presented, justifying the knowledge requirement for future stable nanocomposite formulation. In addition to that, recent precursors suitable for zinc oxide nanoparticle synthesis with emergingly prediction to serve as COVID-19 purposes via different products, aligning with CFs or nanocellulose for industrial applications are also reviewed.
    Matched MeSH terms: Oxides
  16. Carbide lime as substrates to boost energy recuperation and dyestuff removal in constructed wetland-microbial fuel cell integrated with copper oxide/carbon cloth cathode
    Leow GY, Lam SM, Sin JC, Zeng H, Li H, Huang L, et al.
    Environ Sci Pollut Res Int, 2024 Apr;31(16):23647-23663.
    PMID: 38427169 DOI: 10.1007/s11356-024-32637-y
    Methylene blue (MB) was regarded as a highly toxic and hazardous substance owing to its irreparable hazard and deplorable damage on the ecosystem and the human body. The treatment of this colorant wastewater appeared to be one of the towering challenges in wastewater treatment. In this study, a microbial fuel cell coupled with constructed wetland (CW-MFC) with effective MB elimination and its energy recuperation concurrently based on the incorporation of carbide lime as a substrate in a new copper oxide-loaded on carbon cloth (CuO/CC) cathode system was studied. The crucial influencing parameters were also delved, and the MB degradation and chemical oxygen demand (COD) removal efficiencies were correspondingly incremented by 97.3% and 89.1% with maximum power output up to 74.1 mW m-2 at optimal conditions (0.2 g L-1 carbide lime loading and 500 Ω external resistance). The carbide lime with high calcium ion content was greatly conducive for the enrichment of critical microorganism and metabolic activities. The relative abundances of functional bacteria including Proteobacteria and Actinobacteriota were vividly increased. Moreover, the impressive results obtained in printed ink wastewater treatment with a COD removal efficiency of 81.3% and a maximum power density of 58.2 mW m-2, which showcased the potential application of CW-MFC.
    Matched MeSH terms: Oxides
  17. The induction of nitrate reductase and the preferential assimilation of ammonium in germinating rice seedlings
    Shen TC
    Plant Physiol, 1969 Nov;44(11):1650-5.
    PMID: 16657253
    Nitrate reduotase is induced by nitrate in excised embryos and germinating intact seedlings of rice (Oryza sativa L.). The enzyme is induced 24 hr after imbibition. The rate of enzyme formation increases with the age of seedlings. There is a lag period of 30 to 40 min between the addition of substrate and the formation of nitrate reductase. Formation of the enzyme is promoted by the presence of ammonium. Chloramphenicol, actinomycin D and cycloheximide effectively inhibit the formation of nitrate reductase.Rice seedlings can assimilate nitrate from the beginning of germination. However, the utilization of nitrate is completely suppressed by the presence of ammonium. As soon as ammonium is depleted from the medium, nitrate utilization is resumed. Ammonium inhibits the first step of nitrate reduction, i.e., NO(-) (3) --> NO(-) (2), but does not inhibit the assimilation of nitrite. This provides an example of feedback inhibition in higher plants.
    Matched MeSH terms: Nitrogen Oxides
  18. Dual Functions of a Hybrid Magnetic Magnesium Oxide Nanocomposite as a Fungicide and Plant Growth Promoter in Agriculture Applications
    Wee JL, Chan YS, Law MC
    ACS Appl Bio Mater, 2023 Nov 20;6(11):4972-4987.
    PMID: 37910790 DOI: 10.1021/acsabm.3c00515
    The use of nanometal oxides in nanoagronomy has garnered considerable attention due to their excellent antifungal and plant growth promotion properties. Hybrid nanometal oxides, which combine the strengths of individual nanomaterials, have emerged as a promising class of materials. In this study, nanomagnesium oxide (n-MgO) and hybrid magnetic nanomagnesium oxide (m/n-MgO) were successfully synthesized via the ultrasound-mediated sol-gel method. Characterization results, including TGA, XRD, VSM, and FTIR, confirmed the successful synthesis of m/n-MgO. Both n-MgO and m/n-MgO underwent antifungal assays and plant growth promotion ability studies, benchmarked against the conventional fungicide-copper oxychloride. This study bridges a significant gap by simultaneously reporting the antifungal properties of both n-MgO and m/n-MgO and their impact on plant growth. The disc diffusion assay suggested that the antifungal activity of n-MgO and m/n-MgO against F. oxysporum was inversely related to the particle size. Notably, n-MgO exhibited superior antifungal performance (lower minimum inhibitory concentration (MIC)) and sustained efficacy compared with m/n-MgO, owing to distinct antifungal mechanisms. Nanorod-shaped MgO, with a smaller size (8.24 ± 5.61 nm) and higher aspect ratio, allowed them to penetrate the fungal cell wall and cause intercellular damage. In contrast, cubical m/n-MgO, with a larger size (20.95 ± 9.99 nm) and lower aspect ratio, accumulate on the fungal cell wall surface, disrupting the wall integrity, albeit less effectively against F. oxysporum. Moreover, in plant growth promotion studies, m/n-MgO-treated samples exhibited a 15.7% stronger promotion effect compared to n-MgO at their respective MICs. In addition, both n-MgO and m/n-MgO outperformed copper oxychloride in terms of antifungal and plant growth promoting activities. Thus, m/n-MgO presents a promising alternative to conventional copper-based fungicides, offering dual functionality as a fungicide and plant growth promoter, while the study also delves into the antifungal mechanisms at the intracellular level, enhancing its novelty.
    Matched MeSH terms: Oxides
  19. Long-term evaluation of palm oil mill effluent (POME) steam reforming over lanthanum-based perovskite oxides
    Cheng YW, Chong CC, Cheng CK, Wang CH, Ng KH, Witoon T, et al.
    J Environ Manage, 2024 Feb;351:119919.
    PMID: 38157572 DOI: 10.1016/j.jenvman.2023.119919
    To replace the obsolete ponding system, palm oil mill effluent (POME) steam reforming (SR) over net-acidic LaNiO3 and net-basic LaCoO3 were proposed as the POME primary treatments, with promising H2-rich syngas production. Herein, the long-term evaluation of POME SR was scrutinized with both catalysts under the optimal conditions (600 °C, 0.09 mL POME/min, 0.3 g catalyst, & 74-105 μm catalyst particle size) to examine the catalyst microstructure changes, transient process stability, and final effluent evaluation. Extensive characterization proved the (i) adsorption of POME vapour on catalysts before SR, (ii) deposition of carbon and minerals on spent SR catalysts, and (iii) dominance of coking deactivation over sintering deactivation at 600 °C. Despite its longer run, spent LaCoO3 (50.54 wt%) had similar carbon deposition with spent LaNiO3 (50.44 wt%), concurring with its excellent coke resistance. Spent LaCoO3 (6.12 wt%; large protruding crystals) suffered a harsher mineral deposition than spent LaNiO3 (3.71 wt%; thin film coating), confirming that lower reactivity increased residence time of reactants. Transient syngas evolution of both SR catalysts was relatively steady up to 4 h but perturbed by coking deactivation thereafter. La2O2CO3 acted as an intermediate species that hastened the coke removal via reverse Boudouard reaction upon its decarbonation. La2O2CO3 decarbonation occurred continuously in LaCoO3 system but intermittently in LaNiO3 system. LaNiO3 system only lasted for 13 h as its compact ash blocked the gas flow. LaCoO3 system lasted longer (17 h) with its porous ash, but it eventually failed because KCl crystallites blocked its active sites. Relatively, LaCoO3 system offered greater net H2 production (72.78%) and POME treatment volume (30.77%) than LaNiO3 system. SR could attain appreciable POME degradation (>97% COD, BOD5, TSS, & colour intensity). Withal, SR-treated POME should be polished to further reduce its incompliant COD and BOD5.
    Matched MeSH terms: Oxides
  20. Synthesis of geranyl propionate in a solvent-free medium using Rhizomucor miehei lipase covalently immobilized on chitosan-graphene oxide beads
    Isah AA, Mahat NA, Jamalis J, Attan N, Zakaria II, Huyop F, et al.
    Prep Biochem Biotechnol, 2017 Feb 07;47(2):199-210.
    PMID: 27341522 DOI: 10.1080/10826068.2016.1201681
    The chemical route of producing geranyl propionate involves the use of toxic chemicals, liberation of unwanted by-products as well as problematic separation process. In view of such problems, the use of Rhizomucor miehei lipase (RML) covalently bound onto activated chitosan-graphene oxide (RML-CS/GO) support is suggested. Following analyses using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetry, properties of the RML-CS/GO were characterized. A response surface methodological approach using a 3-level-four-factor (incubation time, temperature, substrate molar ratio, and stirring rate) Box-Behnken design was used to optimize the experimental conditions to maximize the yield of geranyl propionate. Results revealed that 76 ± 0.02% of recovered protein had yielded 7.2 ± 0.04 mg g(-1) and 211 ± 0.3% U g(-1) of the maximum protein loading and esterification activity, respectively. The actual yield of geranyl propionate (49.46%) closely agreed with the predicted value (49.97%) under optimum reaction conditions (temperature: 37.67°C, incubation time: 10.20 hr, molar ratio (propionic acid:geraniol): 1:3.28, and stirring rate: 100.70 rpm) and hence, verifying the suitability of this approach. Since the method is performed under mild conditions, the RML-CS/GO biocatalyst may prove to be an environmentally benign alternative for producing satisfactory yield of geranyl propionate.
    Matched MeSH terms: Oxides/chemistry
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