Displaying publications 81 - 100 of 10152 in total

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  1. Jamion NA, Lee KE, Mokhtar M, Goh TL
    Environ Sci Pollut Res Int, 2024 Mar;31(11):16291-16308.
    PMID: 38315340 DOI: 10.1007/s11356-024-32140-4
    Ex-mining lake-converted constructed wetlands play a significant role in the carbon cycle, offering a great potential to sequester carbon and mitigate climate change and global warming. Investigating the quantity of carbon storage capacity of ex-mining lake-converted constructed wetlands provides information and justification for restoration and conservation efforts. The present study aims to quantify the carbon pool of the ex-mining lake-converted constructed wetlands and characterise the physicochemical properties of the soil and sediment. Pearson's correlation and a one-way ANOVA were performed to compare the different sampling stations at Paya Indah Wetland, Selangor, Malaysia. An analysis of 23 years of ex-mining lake-converted constructed wetlands of Paya Indah Wetlands, Selangor, Malaysia, revealed that the estimated total carbon pool in soil and sediment accumulated to 1553.11 Mg C ha-1 (equivalent to 5700 Mg CO2 ha-1), which translates to an annual carbon sink capacity of around 67.5 Mg C ha-1 year-1. The characterisation showed that the texture of all soil samples was dominated by silt, whereas sediments exhibited texture heterogeneity. Although the pH of the soil and sediment was both acidic, the bulk density was still optimal for plant growth and did not affect root growth. FT-IR and WDXRF results supported that besides the accumulation and degradation of organic substances, which increase the soil and sediment carbon content, mineral carbonation is a mechanism by which soil and sediment can store carbon. Therefore, this study indicates that the ex-mining lake-converted constructed wetlands of Paya Indah Wetlands, Selangor, Malaysia have a significant carbon storage potential.
    Matched MeSH terms: Soil/chemistry
  2. Hamidon TS, Idris NN, Adnan R, Haafiz MKM, Zahari A, Hussin MH
    Int J Biol Macromol, 2024 Mar;262(Pt 2):130239.
    PMID: 38367788 DOI: 10.1016/j.ijbiomac.2024.130239
    Herein, cellulose nanocrystals were synthesized from oil palm fronds (CNC-OPF) involving two pretreatment approaches, viz. autohydrolysis and soda pulping. The pretreatments were applied individually to OPF fibers to assess their influence on CNCs' physicochemical and thermal properties. CNC-OPF samples were assessed using complementary characterization techniques, which confirmed their purity and characteristics. CP/MAS 13C NMR and TEM studies revealed that autohydrolysis pretreatment yielded CNCs with effective hemicellulose and extractives removal compared to that of soda pulping. XRD analysis demonstrated that autohydrolysis-treated CNC-OPF contained a much higher crystallinity index compared to soda pulping treatment. BET measurement disclosed a relatively higher surface area and wider pore diameter of autohydrolysis-treated CNC-OPF. Autohydrolysis-treated CNCs were applied as a reinforcement filler in alginate-based hydrogel beads for the removal of 4-chlorophenol from water, which attained a qmax of 19.168 mg g-1. BET analysis revealed the less porous nature of CNC-ALG hydrogel beads which could have contributed to hydrogel beads' relatively lower adsorption capacity. The point of zero charge of CNC-ALG hydrogel beads was 4.82, suggesting their applicability only within a short solution pH range. This study directs future studies to unveil the possibilities of functionalizing CNCs in order to enhance the adsorption performance of CNC-immobilized hydrogel beads towards 4-chlorophenol and other organic contaminants.
    Matched MeSH terms: Cellulose/chemistry; Hydrogels/chemistry
  3. Cheong NDH, Mohamed E, Haron N, Camalxaman SN, Abdullah A, Mohamad Yusof MI, et al.
    Med J Malaysia, 2024 Mar;79(Suppl 1):34-39.
    PMID: 38555883
    INTRODUCTION: Parkia speciosa Hassk., commonly known as bitter bean or twisted cluster bean, is a tropical leguminous plant species native to Southeast Asia. The plant's edible pods have been traditionally used in various cuisines, particularly in Malaysian, Thai, and Indonesian cooking. Apart from being used as a food ingredient, the pods of P. speciosa also have a range of potential applications in other fields, including medicine, agriculture, and industry. The pods are said to have several phytochemicals that hold great therapeutic values such as reducing inflammation, improving digestion, and lowering blood sugar levels. However, there is limited information on the specific phytochemical contents of the pods in the literature. Thus, the aim of this study is to quantify the total phenolic and flavonoid compounds and to determine the concentrations of four selected phytochemical compounds in the P. speciosa pod extract (PSPE).

    MATERIALS AND METHODS: Quantification of the total phenolic (TPC) and flavonoid contents (TFC) in PSPE were done via colourimetric methods; and the determination of the concentrations of four specific phytochemicals (gallic acid, caffeic acid, rutin, and quercetin) were done via High- Performance Liquid Chromatography (HPLC).

    RESULTS: Colourimetric determination of PSPE showed TPC and TFC values of 84.53±9.40 mg GAE/g and 11.96±4.51 mg QE/g, respectively. Additional analysis of the phytochemicals using HPLC revealed that there were 6.45±3.36 g/kg, 5.91±1.07 g/kg, 0.39±0.84 g/kg, and 0.19±0.47 g/kg of caffeic acid, gallic acid, rutin, and quercetin, respectively.

    CONCLUSION: The findings show that PSPE contains substantial amounts of caffeic acid, gallic acid, rutin, and quercetin, which may indicate its potential as antibacterial, anti-inflammatory, anti-lipid, and antiviral medicines.

    Matched MeSH terms: Phenols/chemistry
  4. Yan Sim X, He N, Mohamed Abdul P, Keong Yeap S, Woh Hui Y, Foong Tiang M, et al.
    Ultrason Sonochem, 2024 Mar;104:106811.
    PMID: 38394823 DOI: 10.1016/j.ultsonch.2024.106811
    Durian peel, an abundant waste in Malaysia could be a potential substrate for fermentable sugar recovery for value-added biochemical production. Common pretreatment such as acid or alkaline pretreatment resulted in the need for extensive solid washing which generated wastewater. Herein, this study aims to introduce sonication on top of chemical pretreatment to destruct lignin and reduce the chemical usage during the durian peel pretreatment process. In this study, the morphology and the chemical composition of the pretreated durian peels were studied. The sugar yield produced from the chemical pretreatment and the combined ultrasound and chemical pretreatment were compared. The morphology and chemical structure of durian peels were investigated by Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) analysis and X-ray diffraction (XRD). The SEM images showed that the structural change became more significant when sonication was introduced. Second, XRD profile indicated a relatively higher crystallinity index and FTIR spectra displayed a lower intensity of lignin and hemicellulose for ultrasound plus alkaline (UB) pretreatment as compared to acid, alkaline and ultrasound plus acid (UA) pretreatment. UB and UA pretreatment portrayed higher yield (376.60 ± 12.14 and 237.38 ± 3.96 mg reducing sugar/g dry biomass, respectively) than their controls without the application of ultrasound. Therefore, it could be concluded that ultrasound was able to intensify the fermentable sugar recovery from durian peel by inducing physical and chemical effect of cavitation to alter the morphology of durian peel. Fermentation of UB treated durian peel resulted in 2.68 mol hydrogen/mol consumed sugar and 131.56 mL/Lmedium/h of hydrogen productivity. This study is important because it will shed light on a way to handle durian waste disposal problems and generate fermentable sugars for the production of high value-added products.
    Matched MeSH terms: Lignin/chemistry
  5. Zailan AAD, Karunakaran T, Santhanam R, Suriaty Yaakop A, Mohan S, Abu Bakar MH, et al.
    Chem Biodivers, 2024 Mar;21(3):e202301936.
    PMID: 38268343 DOI: 10.1002/cbdv.202301936
    The genus Calophyllum from the family Calophyllaceae has been extensively investigated in the past due to its rich source of bioactive phenolics such as coumarins, chromanones, and xanthones. In this study, phytochemical investigation on the stem bark of Calophyllum havilandii has afforded a new 4-propyldihydrocoumarin derivative, havilarin (1) together with calolongic acid (2), caloteysmannic acid (3), isocalolongic acid (4), euxanthone (5), and β-sitosterol (6). The chemical structure of compound 1 was elucidated and established based on detailed spectroscopic techniques, including MS, IR, UV, 1D and 2D NMR. The results of anti-bacillus study indicated that the chloroform extract showed promising activities with MIC value ranging between 0.5 to 1 μg/mL on selected bacillus strains. Besides, the plant extracts and compounds 1-4 were assessed for their cytotoxicity potential on HL-7702 cell line. All the tested plant extracts and respective chemical constituents displayed non-cytotoxic activity on HL-7702 cell line.
    Matched MeSH terms: Plant Extracts/chemistry; Plant Bark/chemistry
  6. Chong WH, Chan DJC, Liu CZ, Lim J
    Electrophoresis, 2024 Mar;45(5-6):357-368.
    PMID: 38044267 DOI: 10.1002/elps.202300042
    The spatiotemporal accuracy of microscale magnetophoresis has improved significantly over the course of several decades of development. However, most of the studies so far were using magnetic microbead composed of nanosphere particle for magnetophoretic actuation purpose. Here, we developed an in-house method for magnetic sample analysis called quadrupole magnetic steering control (QMSC). QMSC was used to study the magnetophoretic behavior of polystyrene microbeads decorated with iron oxide nanospheres-coated polystyrene microbeads (IONSs-PS) and iron oxide nanorods-coated polystyrene microbeads (IONRs-PS) under the influence of a quadrupole low field gradient. During a 4-s QMSC experiment, the IONSs-PS and IONRs-PS were navigated to perform 180° flip and 90° turn formations, and their kinematic results (2 s before and 2 s after the flip/turn) were measured and compared. The results showed that the IONRs-PS suffered from significant kinematic disproportion, translating a highly uneven amount of kinetic energy from the same magnitude of magnetic control. Combining the kinematic analysis, transmission electron microscopy micrographs, and vibrating sample magnetometry measurements, it was found that the IONRs-PS experienced higher fluid drag force and had lower consistency than the IONSs-PS due to its extensive open fractal nanorod structure on the bead surface and uneven magnetization, which was attributed to its ferrimagnetic nature.
    Matched MeSH terms: Polystyrenes/chemistry
  7. Md Yusop AH, Wan Ali WFF, Jamaludin FH, Szali Januddi F, Sarian MN, Saad N, et al.
    Biotechnol J, 2024 Mar;19(3):e2300464.
    PMID: 38509814 DOI: 10.1002/biot.202300464
    The present study evaluates the corrosion behavior of poly[xylitol-(1,12-dodecanedioate)](PXDD)-HA coated porous iron (PXDD140/HA-Fe) and its cell-material interaction aimed for temporary bone scaffold applications. The physicochemical analyses show that the addition of 20 wt.% HA into the PXDD polymers leads to a higher crystallinity and lower surface roughness. The corrosion assessments of the PXDD140/HA-Fe evaluated by electrochemical methods and surface chemistry analysis indicate that HA decelerates Fe corrosion due to a lower hydrolysis rate following lower PXDD content and being more crystalline. The cell viability and cell death mode evaluations of the PXDD140/HA-Fe exhibit favorable biocompatibility as compared to bare Fe and PXDD-Fe scaffolds owing to HA's bioactive properties. Thus, the PXDD140/HA-Fe scaffolds possess the potential to be used as a biodegradable bone implant.
    Matched MeSH terms: Durapatite/chemistry
  8. Abdul Rahman SNS, Chai YH, Lam MK
    J Environ Manage, 2024 Mar;355:120447.
    PMID: 38460326 DOI: 10.1016/j.jenvman.2024.120447
    This research explicitly investigates the utilization of Chlorella Vulgaris sp. microalgae as a renewable source for lipid production, focusing on its application in bioplastic manufacturing. This study employed the supercritical fluid extraction technique employing supercritical CO2 (sCO2) as a green technology to selectively extract and produce PHA's precursor utilizing CO2 solvent as a cleaner solvent compared to conventional extraction method. The study assessed the effects of three extraction parameters, namely temperature (40-60 °C), pressure (15-35 MPa), and solvent flow rate (4-8 ml/min). The pressure, flowrate, and temperature were found to be the most significant parameters affecting the sCO2 extraction. Through Taguchi optimization, the optimal parameters were determined as 60 °C, 35 MPa, and 4 ml/min with the highest lipid yield of 46.74 wt%; above-average findings were reported. Furthermore, the pretreatment process involved significant effects such as crumpled and exhaustive structure, facilitating the efficient extraction of total lipids from the microalgae matrix. This study investigated the microstructure of microalgae biomatrix before and after extraction using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fourier-transform infrared spectroscopy (FTIR) was utilized to assess the potential of the extracted material as a precursor for biodegradable plastic production, with a focus on reduced heavy metal content through inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis. The lipid extracted from Chlorella Vulgaris sp. microalgae was analysed using gas chromatography-mass spectrometry (GC-MS), identifying key constituents, including oleic acid (C18H34O2), n-Hexadecanoic acid (C16H32O2), and octadecanoic acid (C18H36O2), essential for polyhydroxyalkanoate (PHA) formation.
    Matched MeSH terms: Carbon Dioxide/chemistry; Solvents/chemistry
  9. Chang CH, See Too WC, Lim BH, Few LL
    Acta Parasitol, 2024 Mar;69(1):426-438.
    PMID: 38172465 DOI: 10.1007/s11686-023-00763-1
    PURPOSE: Entamoeba histolytica is one of the death-causing parasites in the world. Study on its lipid composition revealed that it is predominated by phosphatidylcholine and phosphatidylethanolamine. Further study revealed that its phosphorylated metabolites might be produced by the Kennedy pathway. Here, we would like to report on the characterizations of enzymes from this pathway that would provide information for the design of novel inhibitors against these enzymes in future.

    METHODOLOGY: E. histolytica HM-1:IMSS genomic DNA was isolated and two putative choline/ethanolamine kinase genes (EhCK1 and EhCK2) were cloned and expressed from Escherichia coli BL21 strain. Enzymatic characterizations were further carried out on the purified enzymes.

    RESULTS: EhCK1 and EhCK2 were identified from E. histolytica genome. The deduced amino acid sequences were more identical to its homologues in human (35-48%) than other organisms. The proteins were clustered as ethanolamine kinase in the constructed phylogeny tree. Sequence analysis showed that they possessed all the conserved motifs in choline kinase family: ATP-binding loop, Brenner's phosphotransferase motif, and choline kinase motif. Here, the open reading frames were cloned, expressed, and purified to apparent homogeneity. EhCK1 showed activity with choline but not ethanolamine. The biochemical characterization showed that it had a Vmax of 1.9 ± 0.1 µmol/min/mg. Its Km for choline and ATP was 203 ± 26 µM and 3.1 ± 0.4 mM, respectively. In contrast, EhCK2 enzymatic activity was only detected when Mn2+ was used as the co-factor instead of Mg2+ like other choline/ethanolamine kinases. Highly sensitive and specific antibody against EhCK1 was developed and used to confirm the endogenous EhCK1 expression using immunoblotting.

    CONCLUSIONS: With the understanding of EhC/EK importance in phospholipid metabolism and their unique characteristic, EhC/EK could be a potential target for future anti-amoebiasis study.

    Matched MeSH terms: Protozoan Proteins/chemistry
  10. Amjad M, Mohyuddin A, Ulfat W, Goh HH, Dzarfan Othman MH, Kurniawan TA
    J Environ Manage, 2024 Feb 27;353:120287.
    PMID: 38335595 DOI: 10.1016/j.jenvman.2024.120287
    Textile wastewater laden with dyes has emerged as a source of water pollution. This possesses a challenge in its effective treatment using a single functional material. In respond to this technological constraint, this work presents multifunctional cotton fabrics (CFs) within a single, streamlined preparation process. This approach utilizes the adherence of Ag NPs (nanoparticles) using Si binder on the surface of CFs, resulting in Ag-coated CFs through a pad dry method. The prepared samples were characterized using scanning electron microscope-energy dispersive X-ray electroscopy (SEM-EDS), thermal gravimetric analysis (TGA), Fourier transformation infrared (FT-IR). It was found that the FT-IR spectra of Ag NPs-coated CFs had peaks appear at 3400, 2900, and 1200 cm-1, implying the stretching vibrations of O-H, C-H, and C-O, respectively. Based on the EDX analysis, the presence of C, O, and Ag related to the coated CFs were detected. After coating the CFs with varying concentrations of Ag NPs (1%, 2% and 3% (w/w)), they were used to remove dyes. Under the same concentration of 10 mg/L and optimized pH 7.5 and 2 h of reaction time, 3% (w/w) Ag-coated CFs exhibited a substantial MB degradation of 98 %, while removing 95% of methyl orange, 85% of rhodamine B, and 96% of Congo red, respectively, following 2 h of Vis exposure. Ag NPs had a strong absorption at 420 nm with 2.51 eV of energy band gap. Under UV irradiation, electrons excited and produced free radicals that promoted dyes photodegradation. The oxidation by-products included p-dihydroxybenzene and succinic acid. Spent Ag-coated CFs attained 98% of regeneration efficiency. The utilization of Ag-coated CFs as a photocatalyst facilitated treated effluents to meet the required discharge standard of lower than 1 mg/L mandated by national legislation. The integration of multifunctional CFs in the treatment system presents a new option for tackling water pollution due to dyes.
    Matched MeSH terms: Water/chemistry
  11. Qutob M, Rafatullah M, Muhammad SA, Alamry KA, Hussein MA
    J Environ Manage, 2024 Feb 27;353:120179.
    PMID: 38295641 DOI: 10.1016/j.jenvman.2024.120179
    Natural soil minerals often contain numerous impurities, resulting in comparatively lower catalytic activity. Tropical soils are viewed as poor from soil organic matter, cations, and anions, which are considered the main impurities in the soil that are restricted to utilizing natural minerals as a catalyst. In this regard, the dissolved iron and hematite crystals that presented naturally in tropical soil were evaluated to activate oxidants and degrade pyrene. The optimum results obtained in this study were 73 %, and the rate constant was 0.0553 h-1 under experimental conditions [pyrene] = 300 mg/50 g, pH = 7, T = 55 °C, airflow = 260 mL/min, [Persulfate (PS)] = 1.0 g/L, and humic acid (HA) ( % w/w) = 0.5 %. The soil characterization analysis after the remediation process showed an increase in moieties and cracks of the soil aggregate, and a decline in the iron and aluminium contents. The scavengers test revealed that both SO4•- and O2•- were responsible for the pyrene degradation, while HO• had a minor role in the degradation process. In addition, the monitoring of by-products, degradation pathways, and toxicity assessment were also investigated. This system is considered an efficient, green method, and could provide a step forward to develop low-cost soil remediation for full-scale implementation.
    Matched MeSH terms: Minerals/chemistry; Soil/chemistry
  12. Ravikumar OV, Marunganathan V, Kumar MSK, Mohan M, Shaik MR, Shaik B, et al.
    Mol Biol Rep, 2024 Feb 24;51(1):352.
    PMID: 38400866 DOI: 10.1007/s11033-024-09289-9
    BACKGROUND: Oral diseases are often attributed to dental pathogens such as S. aureus, S. mutans, E. faecalis, and C. albicans. In this research work, a novel approach was employed to combat these pathogens by preparing zinc oxide nanoparticles (ZnO NPs) capped with cinnamic acid (CA) plant compounds.

    METHODS: The synthesized ZnO-CA NPs were characterized using SEM, FTIR, and XRD to validate their composition and structural features. The antioxidant activity of ZnO-CA NPs was confirmed using DPPH and ABTS free radical scavenging assays. The antimicrobial effects of ZnO-CA NPs were validated using a zone of inhibition assay against dental pathogens. Autodock tool was used to identify the interaction of cinnamic acid with dental pathogen receptors.

    RESULTS: ZnO-CA NPs exhibited potent antioxidant activity in both DPPH and ABTS assays, suggesting their potential as powerful antioxidants. The minimal inhibitory concentration of ZnO-CA NPs against dental pathogens was found 25 µg/mL, indicating their effective antimicrobial properties. Further, ZnO-CA NPs showed better binding affinity and amino acid interaction with dental pathogen receptors. Also, the ZnO-CA NPs exhibited dose-dependent (5 µg/mL, 15 µg/mL, 25 µg/mL, and 50 µg/mL) anticancer activity against Human Oral Epidermal Carcinoma KB cells. The mechanism of action of apoptotic activity of ZnO-CA NPs on the KB cells was identified through the upregulation of BCL-2, BAX, and P53 genes.

    CONCLUSIONS: This research establishes the potential utility of ZnO-CA NPs as a promising candidate for dental applications. The potent antioxidant, anticancer, and effective antimicrobial properties of ZnO-CA NPs make them a valuable option for combating dental pathogens.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  13. Tan YS, Ng MP, Tan CH, Tang WK, Sim KS, Yong KT, et al.
    J Nat Prod, 2024 Feb 23;87(2):286-296.
    PMID: 38284153 DOI: 10.1021/acs.jnatprod.3c00960
    Nine new alkaloids, eugeniinalines A-H (1-8) and (+)-eburnamenine N-oxide (9), comprising one quinoline, six indole, and two isogranatanine alkaloids, were isolated from the stem-bark extract of the Malayan Leuconotis eugeniifolia. The structures and absolute configurations of these alkaloids were established based on the analysis of the spectroscopic data, GIAO NMR calculations, DP4+ probability analysis, TDDFT-ECD method, and X-ray diffraction analysis. Eugeniinaline A (1) represents a new pentacyclic quinoline alkaloid with a 6/6/5/6/7 ring system. Eugeniinaline G (7) and its seco-derivative, eugeniinaline H (8), were the first isogranatanine alkaloids isolated as natural products. The known alkaloids leucolusine (10) and melokhanine A (11) were found to be the same compound, based on comparison of the spectroscopic data of both compounds, with the absolute configuration of (7R, 20R, 21S). Eugeniinalines A and G (1 and 7) showed cytotoxic activity against the HT-29 cancer cell line with IC50 values of 7.1 and 7.2 μM, respectively.
    Matched MeSH terms: Indole Alkaloids/chemistry; Secologanin Tryptamine Alkaloids/chemistry
  14. Navaneethan RD, N C J PL, Ramaiah M, Ravindran R, T AK, Chinnathambi A, et al.
    Nanotechnology, 2024 Feb 21;35(19).
    PMID: 38320329 DOI: 10.1088/1361-6528/ad26d9
    The phytochemicals found inCaralluma pauciflorawere studied for their ability to reduce silver nitrate in order to synthesise silver nanoparticles (AgNPs) and characterise their size and crystal structure. Thunbergol, 1,1,6-trimethyl-3-methylene-2-(3,6,9,13-tetram, Methyl nonadecanoate, Methyl cis-13,16-Docosadienate, and (1R,4aR,5S)-5-[(E)-5-Hydroxy-3-methylpent were the major compounds identified in the methanol extract by gas chromatography-mass spectrum analysis. UV/Vis spectra, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscope with Energy Dispersive Xâray Analysis (EDAX), Dynamic Light Scattering (DLS) particle size analyser and atomic force microscope (AfM) were used to characterise theCaralluma paucifloraplant extract-based AgNPs. The crystal structure and estimated size of the AgNPs ranged from 20.2 to 43 nm, according to the characterization data. The anti-cancer activity of silver nanoparticles (AgNPs) synthesised fromCaralluma paucifloraextract. The AgNPs inhibited more than 60% of the AGS cell lines and had an IC50 value of 10.9640.318 g, according to the findings. The cells were further examined using fluorescence microscopy, which revealed that the AgNPs triggered apoptosis in the cells. Furthermore, the researchers looked at the levels of reactive oxygen species (ROS) in cells treated with AgNPs and discovered that the existence of ROS was indicated by green fluorescence. Finally, apoptotic gene mRNA expression analysis revealed that three target proteins (AKT, mTOR, and pI3K) were downregulated following AgNP therapy. Overall, the findings imply that AgNPs synthesised from Caralluma pauciflora extract could be used to treat human gastric cancer.
    Matched MeSH terms: Plant Extracts/chemistry
  15. Shanmugam P, Parasuraman B, Boonyuen S, Thangavelu P, AlSalhi MS, Zheng ALT, et al.
    Environ Geochem Health, 2024 Feb 17;46(3):92.
    PMID: 38367085 DOI: 10.1007/s10653-024-01871-1
    A facile and cost-effective hydrothermal followed by precipitation method is employed to synthesize visible light-driven ZnS-Ag ternary composites supported on carbon aerogel (CA). Extensive studies were conducted on the structural, morphological, and optical properties, confirming the successful formation of ternary nanocomposites. The obtained results evidently demonstrate the successful loading of ZnS and Ag onto the surface of the CA. High-resolution transmission electron microscopy analysis revealed that ZnS and Ag nanoparticles (AgNPs) were uniformly distributed on the surface of the CA with an average diameter of 18 nm. The biomass-derived CA, containing a hierarchical porous nano-architecture and an abundant number of -NH2 functional groups on the surface, can greatly prevent the agglomeration, stability and reduce particle size. Brunauer-Emmett-Teller analysis results indicated specific surface areas of 4.62 m2 g-1 for the CA, 48.50 m2 g-1 for the CA/ZnS composite, and 62.62 m2 g-1 for the CA/ZnS-Ag composite. These values demonstrate an increase in surface area upon the incorporation of ZnS and Ag into the CA matrix. Under visible light irradiation, the synthesized CA/ZnS-Ag composites displayed remarkably improved photodegradation efficiency of methylene blue (MB). Among the tested samples, the CA/ZnS-Ag composites exhibited the highest percentage of photodegradation efficiency, surpassing ZnS, CA, and CA/ZnS. The obtained percentages of degradation efficiency for CA, ZnS, CA/ZnS, and CA/ZnS-Ag composites were determined as 26.60%, 52.12%, 68.39%, and 98.64%, respectively. These results highlight the superior photocatalytic performance of the CA/ZnS-Ag composites in the degradation of MB under visible light conditions. The superior efficiency of the CA/ZnS-Ag composite can be attributed to multiple factors, including its elevated specific surface area, inhibition of electron-hole pair recombination, and enhanced photon absorption within the visible light spectrum. The CA/ZnS-Ag composites displayed consistent efficiency over multiple cycles, confirming their stable performance, reusability, and enduring durability, thereby showcasing the robust nature of this composite material.
    Matched MeSH terms: Methylene Blue/chemistry; Silver/chemistry
  16. Low JY, Khe CS, Usman F, Hassan YM, Lai CW, You KY, et al.
    Environ Res, 2024 Feb 15;243:117840.
    PMID: 38081342 DOI: 10.1016/j.envres.2023.117840
    Since the establishment of the first global refinery in 1856, crude oil has remained one of the most lucrative natural resources worldwide. However, during the extraction process from reservoirs, crude oil gets contaminated with sediments, water, and other impurities. The presence of pressure, shear forces, and surface-active compounds in crude oil leads to the formation of unwanted oil/water emulsions. These emulsions can take the form of water-in-oil (W/O) emulsions, where water droplets disperse continuously in crude oil, or oil-in-water (O/W) emulsions, where crude oil droplets are suspended in water. To prevent the spread of water and inorganic salts, these emulsions need to be treated and eliminated. In existing literature, different demulsification procedures have shown varying outcomes in effectively treating oil/water emulsions. The observed discrepancies have been attributed to various factors such as temperature, salinity, pH, droplet size, and emulsifier concentrations. It is crucial to identify the most effective demulsification approach for oil/water separation while adhering to environmental regulations and minimizing costs for the petroleum sector. Therefore, this study aims to explore and review recent advancements in two popular demulsification techniques: chemical demulsification and magnetic nanoparticles-based (MNP) demulsification. The advantages and disadvantages of each technique are assessed, with the magnetic approach emerging as the most promising due to its desirable efficiency and compliance with environmental and economic concerns. The findings of this report are expected to have a significant impact on the overall process of separating oil and water, benefiting the oil and gas industry, as well as other relevant sectors in achieving the circular economy.
    Matched MeSH terms: Emulsions/chemistry
  17. Agatonovic-Kustrin S, Wong S, Dolzhenko AV, Gegechkori V, Morton DW
    J Pharm Biomed Anal, 2024 Feb 15;239:115912.
    PMID: 38128161 DOI: 10.1016/j.jpba.2023.115912
    Olive trees are one of the most widely cultivated fruit trees in the world. The chemical compositions and biological activities of olive tree fruit and leaves have been extensively researched for their nutritional and health-promoting properties. In contrast, limited data have been reported on olive flowers. The present study aimed to analyse bioactive compounds in olive flower extracts and the effect of fermentation-assisted extraction on phenolic content and antioxidant activity. High-performance thin-layer chromatography (HPTLC) hyphenated with the bioassay-guided detection and spectroscopic identification of bioactive compounds was used for the analysis. Enzymatic and bacterial in situ bioassays were used to detect COX-1 enzyme inhibition and antibacterial activity. Multiple zones of antibacterial activity and one zone of COX-1 inhibition were detected in both, non-fermented and fermented, extracts. A newly developed HPTLC-based experimental protocol was used to measure the high-maximal inhibitory concentrations (IC50) for the assessment of the relative potency of the extracts in inhibiting COX-1 enzyme and antibacterial activity. Strong antibacterial activities detected in zones 4 and 7 were significantly higher in comparison to ampicillin, as confirmed by low IC50 values (IC50 = 57-58 µg in zone 4 and IC50 = 157-167 µg in zone 7) compared to the ampicillin IC50 value (IC50 = 495 µg). The COX-1 inhibition by the extract (IC50 = 76-98 µg) was also strong compared to that of salicylic acid (IC50 = 557 µg). By comparing the locations of the bands to coeluted standards, compounds from detected bioactive bands were tentatively identified. The eluates from bioactive HPTLC zones were further analysed by FTIR NMR, and LC-MS spectroscopy. Multiple zones of antibacterial activity were associated with the presence of triterpenoid acids, while COX-1 inhibition was related to the presence of long-chain fatty acids.
    Matched MeSH terms: Plant Extracts/chemistry; Flowers/chemistry
  18. Dong CD, Huang CP, Chen CW, Lam SS, Sonne C, Kang CK, et al.
    Environ Pollut, 2024 Feb 15;343:123173.
    PMID: 38110049 DOI: 10.1016/j.envpol.2023.123173
    Polycyclic aromatic hydrocarbons (PAHs) are critical environmental concerns due to their intrinsic toxic aromatic nature and concomitant circumstances that potentially harm the ecological and human health. In this study, converting mahogany (Swietenia macrophylla King) pericarps to value-added biochar by pyrolysis for evaluating the potential formation/destruction of biochar-bound PAHs was studied for the first time. This study designed and optimized the thermal processing conditions at 300-900 °C in the CO2 or N2 atmosphere, and heteroatoms (N, O, B, NB, and NS) were modified for mahogany pericarps biochar (MPBC) production. The MPBC500 exhibited significantly higher pyrolysis products of PAHs (2780 ± 38 ng g-1) than that of MPBC900 (78 ± 6 ng g-1) under N2 without introducing modified elements. Specifically, the inhibition capacity of MPBC500 for PAHs under CO2 was improved most efficiently by the active nitrogen species of the pyridinic N and pyrrolic N groups. The pyrolysis conditions and heteroatom modification of MPBC altered its physicochemical properties, that is, aromaticity and hydrophobicity, affecting the PAH concentration and composition in the pyrolysis products. This study reveals sustainable approaches to reduce the environmental footprint of biochar by focusing on increases in PAHs pollution in sustainable biochar produced from a low-carbon bioeconomy perspective.
    Matched MeSH terms: Charcoal/chemistry
  19. Taheri A, Khandaker MU, Moradi F, Bradley DA
    Phys Med Biol, 2024 Feb 15;69(4).
    PMID: 38286017 DOI: 10.1088/1361-6560/ad2380
    Objective. Gold nanorods (GNRs) have emerged as versatile nanoparticles with unique properties, holding promise in various modalities of cancer treatment through drug delivery and photothermal therapy. In the rapidly evolving field of nanoparticle radiosensitization (NPRS) for cancer therapy, this study assessed the potential of gold nanorods as radiosensitizing agents by quantifying the key features of NPRS, such as secondary electron emission and dose enhancement, using Monte Carlo simulations.Approach. Employing the TOPAS track structure code, we conducted a comprehensive evaluation of the radiosensitization behavior of spherical gold nanoparticles and gold nanorods. We systematically explored the impact of nanorod geometry (in particular size and aspect ratio) and orientation on secondary electron emission and deposited energy ratio, providing validated results against previously published simulations.Main results. Our findings demonstrate that gold nanorods exhibit comparable secondary electron emission to their spherical counterparts. Notably, nanorods with smaller surface-area-to-volume ratios (SA:V) and alignment with the incident photon beam proved to be more efficient radiosensitizing agents, showing superiority in emitted electron fluence. However, in the microscale, the deposited energy ratio (DER) was not markedly influenced by the SA:V of the nanorod. Additionally, our findings revealed that the geometry of gold nanoparticles has a more significant impact on the emission of M-shell Auger electrons (with energies below 3.5 keV) than on higher-energy electrons.Significance. This research investigated the radiosensitization properties of gold nanorods, positioning them as promising alternatives to the more conventionally studied spherical gold nanoparticles in the context of cancer research. With increasing interest in multimodal cancer therapy, our findings have the potential to contribute valuable insights into the perspective of gold nanorods as effective multipurpose agents for synergistic photothermal therapy and radiotherapy. Future directions may involve exploring alternative metallic nanorods as well as further optimizing the geometry and coating materials, opening new possibilities for more effective cancer treatments.
    Matched MeSH terms: Gold/chemistry
  20. Yu H, Zheng Y, Zhou C, Liu L, Wang L, Cao J, et al.
    Carbohydr Polym, 2024 Feb 01;325:121583.
    PMID: 38008470 DOI: 10.1016/j.carbpol.2023.121583
    The potential of ultrasonication-driven molecular self-assembly of whey protein isolate (WPI) with chitosan (CS)/chitooligosaccharide (COS) to stabilize Pickering emulsions was examined, based on CS/COS ligands-induced partial unfolding in remodeling the Pickering particles features. Multi-spectral analysis suggested obvious changes in conformational structures of WPI due to interaction with CS/COS, with significantly higher unfolding degrees of WPI induced by COS. Non-covalent interactions were identified as the major forces for WPI-CS/COS conjugates. Ultrasonication enhanced electrostatic interaction between CS's -NH3 groups and WPI's -COO- groups which improved emulsification activity and storability of WPI-COS stabilized Pickering emulsion. This was attributed to increased surface hydrophobicity and decreased particle size compared to WPI-CS associated with differential unfolding degrees induced by different saccharide ligands. CLSM and SEM consistently observed smaller emulsion droplets in WPI-COS complexes than WPI-CS/COS particles tightly adsorbed at the oil-water interface. The electrostatic self-assembly of WPI with CS/COS greatly enhanced the encapsulation efficiency of quercetin than those stabilized by WPI alone and ultrasound further improved encapsulation efficiency. This corresponded well with the quantitative affinity parameters between quercetin and WPI-CS/COS complexes. This investigation revealed the great potential of glycan ligands-induced conformational transitions of extrinsic physical disruption in tuning Pickering particle features.
    Matched MeSH terms: Whey Proteins/chemistry; Emulsions/chemistry
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