Displaying publications 741 - 760 of 10538 in total

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  1. Tjong DH, Roesma DI, Aadrean, Agustina NT, Maharani S, Azzahra I
    Pak J Biol Sci, 2024 Jun;27(7):373-379.
    PMID: 39206471 DOI: 10.3923/pjbs.2024.373.379
    <b>Background and Objective:</b> The presence of Asian small-clawed otters (<i>Aonyx cinereus</i>) in West Sumatra has been reported from ecological data in the form of footprints and feces, while its genetic information has not been reported yet. This genetic information needs to be reported along with the determination of <i>A. cinereus</i> as a vulnerable species and is experiencing population decline by the International Union for Conservation of Nature (IUCN). This study aimed to determine the phylogenetic relationship of <i>A. cinereus</i> found in West Sumatra with other regions. <b>Materials and Methods:</b> The samples used were <i>A. cinereus</i> stool collected from several wetland locations in West Sumatra. <i>Aonyx cinereus</i> DNA was extracted from stool samples following the QIAamp Fast DNA Stool Mini Kit protocol (Qiagen). Amplification was performed using the CO1 gene. The IQTree was used to provide phylogenetic information on <i>A. cinereus</i> and MEGA 7 was used to determine the uncorrected genetic distance of <i>A. cinereus</i>. <b>Results:</b> <i>Aonyx cinereus</i> clustered to form three sub-clusters namely <i>A. cinereus</i> Sundaland, Laos lineage and unknown lineage. <i>Aonyx cinereus</i> Sundaland consists of <i>A. cinereus</i> West Sumatra and <i>A. cinereus</i> Sarawak, Malaysia which are closely related with a genetic distance of 0.68%. Moreover, compared to <i>A. cinereus</i> from unknown lineage (including Captive Copenhagen Zoo) and Laos lineage, <i>A. cinereus</i> of West Sumatra had a genetic distance of 0.68-1.20 and 4.18%, respectively. <b>Conclusion:</b> Wetland conversion and the role of humans have influenced the obstacle to connectivity among populations that cause genetic variation.
    Matched MeSH terms: Feces/chemistry
  2. Ye DN, Wang LY, Fei WT, Lin Q, Yan LY, Yang BR, et al.
    Zhongguo Zhong Yao Za Zhi, 2024 Sep;49(18):5095-5101.
    PMID: 39701690 DOI: 10.19540/j.cnki.cjcmm.20240611.401
    Tongkat Ali(Eurycoma longifolia Jack.) is a medicinal plant of Simaroubaceae in Southeast Asia, with centuries of medicinal history. Rich clinical and pharmacological research results have been attained for this plant, which demonstrates diverse and definite effects and high safety, showcasing advantages and broad market prospects to be introduced as a new medicinal plant. Currently, E. longifolia is cultivated in Hainan and Guangdong in China. However, it has not been utilized for the medicinal purpose in China, and the systematic study on its traditional Chinese medicine(TCM) properties remains to be carried out. This paper comprehensively reviews and analyzes the application history, clinical trials, biological activities, chemical composition, and safety of Tongkat Ali and probes into its TCM properties. The results suggest that Tongkat Ali is sweet, bitter, pungent, and plain, with tropism to the kidney, spleen, and liver meridians. Tongkat Ali has the main functions of tonifying kidney and replenishing essence, invigorating spleen and replenishing Qi, and soothing liver and relieving depression. The clinical applications of Tongkat Ali encompass kidney essence deficiency, sex apathy, spleen Qi deficiency, fatigue, liver depression and Qi stagnation. The recommended dosage and usage of this medicine are 2-10 g daily and decoction with water, respectively. This study aims to facilitate the compatible use and product development of Tongkat Ali while providing reference for introducing it as a new TCM resource and studying the TCM properties of ginseng plants abroad.
    Matched MeSH terms: Panax/chemistry
  3. Usman A, Khoo KS, Ariffin MM, Loh SH, Wan Mohd Khalik WMA, Yusoff HM, et al.
    Environ Res, 2024 Oct 01;258:119413.
    PMID: 38876422 DOI: 10.1016/j.envres.2024.119413
    Frequent detection of terbutaline in wastewater highlights its potential risks to human health associated in the environment. Exposure to terbutaline through contaminated water sources or food chain have adverse effects to human health. This work emphasized on the removal of terbutaline from wastewater using adsorption technology. Mechanochemically synthesized [Cu(INA)2] metal-organic frameworks (MOFs) and its magnetic composite ([Cu(INA)2]-MOF@Fe3O4) are designed with higher specific surface areas and tailored features to accommodate the molecular size and structure of terbutaline. Thus, batch experiment has been conducted using the [Cu(INA)2]-MOF and [Cu(INA)2]-MOF@Fe3O4 for the terbutaline adsorption. The adsorption efficiency achieved by the MOFs was 91.8% and 99.3% for the Cu(INA)2]-MOF and [Cu(INA)2]-MOF@Fe3O4 respectively. The optimum for the adsorption study included terbutaline concentration of 40 mg/L, adsorbent dose of 5 mg/L, pH of 11, temperature of 25 °C and equilibrium time of 40 min. The kinetics and isotherms have been described by pseudo-second order and Langmuir models, while the thermodynamics revealed the exothermic and spontaneous nature of the process. The promising performance of the MOFs is manifested on the ease of regeneration and reusability, achieving adsorption efficiency of 85.0% and 94.7% by the Cu(INA)2]-MOF and [Cu(INA)2]-MOF@Fe3O4, respectively at five consecutive cycles. The higher performance of the MOFs demonstrates their excellent potentialities for the terbutaline adsorption from the aqueous solution.
    Matched MeSH terms: Ferric Compounds/chemistry
  4. Qaiser Z, Khalid N, Mahmood A, Rizvi ZF, Lee SY, Aqeel M
    J Hazard Mater, 2024 Dec 05;480:136262.
    PMID: 39471612 DOI: 10.1016/j.jhazmat.2024.136262
    Microplastic (MP) pollution is a growing concern, yet its impacts on agroecosystems remain poorly understood. This study investigates MP contamination in the agroecosystems of Sialkot, Pakistan, and its potential effects on the growth, physio-biochemical attributes, and yield of potato (Solanum tuberosum L.). Plant and soil samples from 10 diverse agricultural fields were collected and analyzed for MP contamination. FTIR analysis revealed widespread MP presence in the soil across all sites. Fragment, film, and fiber types dominated, with low-density polyethylene (22.42 %), high-density polyethylene (18.05 %), and polystyrene (12.3 %) being the most prevalent polymers. A significant variation in plant growth parameters was observed. The number of tubers per plant also exhibited a significant difference, as evidenced by the decline in potato yield with increasing levels of MP contamination. Potato yield showed a negative correlation with MP contamination levels. The nutrients (Zn, Cu, Ni, and Na) uptake in plant shoots was also observed to be decreased except for Mg and Mn at all sites. This study showed that MPs are contaminating our agricultural lands and they may affect growth and yield of potato. Additional research is needed to understand the underlying mechanisms and develop mitigation strategies to improve agricultural productivity and food security.
    Matched MeSH terms: Soil/chemistry
  5. Go ES, Ling JLJ, Solanki BS, Ahn H, Show PL, Lee SH
    Environ Res, 2024 Dec 15;263(Pt 1):119982.
    PMID: 39270960 DOI: 10.1016/j.envres.2024.119982
    Oxy-fuel circulating fluidized bed combustion is known as one of the most potent fuel combustion technologies that capture ultra-low greenhouse gases and pollutant emissions. While many investigations have been conducted for carbon capturing, the associated in-situ desulfurization process using calcium-based sorbents should also be underlined. This paper critically reviews the effects of changes in the operating environment on in-situ desulfurization processes compared to conventional air combustion. A comprehensive understanding of the process, encompassing hydrodynamic, physical and chemical aspects can be a guideline for designing the oxy-fuel combustion process with effective sulfur removal, potentially eliminating the need of a flue gas desulfurization unit. Results from thermogravimetric analyzers and morphological changes of calcium-based materials were presented to offer an insight into the sulfation mechanisms involved in the oxy-fuel circulating fluidized beds. Recently findings suggested that in-situ direct desulfurization is influenced not only by the desulfurization kinetics but also by the fluidization characteristics of calcium-based materials. Therefore, a complex reaction analysis that incorporated oxy-combustion reactions, computational fluid dynamics modeling, in-situ desulfurization reaction models and particle behavior can provide a thorough understanding of desulfurization processes across the reactor. Meanwhile, machine learning as a robust tool to predict desulfurization efficiency and improve operational flexibility should be applied with consideration of environmental improvement and economic feasibility.
    Matched MeSH terms: Sulfur/chemistry
  6. Chellathurai MS, Chung LY, Hilles AR, Sofian ZM, Singha S, Ghosal K, et al.
    Int J Biol Macromol, 2024 Nov;280(Pt 2):135775.
    PMID: 39307491 DOI: 10.1016/j.ijbiomac.2024.135775
    Chitosan (CS) has become a focal point of extensive research in the pharmaceutical industry due to its remarkable biodegradability, biocompatibility and sustainability. Chitosan hydrogels (CS HGs) are characterized by their viscoelasticity, flexibility and softness. The polar surfaces exhibit properties that mitigate interfacial tension between the hydrogel and body fluids. The inherent compatibility of CS HGs with body tissues and fluids positions them as outstanding polymers for delivering therapeutic proteins, peptides, DNA, siRNA, and vaccines. Designed to release drugs through mechanisms such as swelling-based diffusion, bioerosion, and responsiveness to stimuli, CS HGs offer a versatile platform for drug delivery. CS HGs play pivotal roles in serving purposes such as prolonging the duration of preprogrammed drug delivery, enabling stimuli-responsive smart delivery to target sites, protecting encapsulated drugs within the mesh network from adverse environments, and facilitating mucoadhesion and penetration through cell membranes. This review comprehensively outlines various novel preparation methods of CS HGs, delving into the parameters influencing drug delivery system design, providing a rationale for CS HG utilization in drug delivery, and presenting diverse applications across the pharmaceutical landscape. In synthesizing these facets, the review seeks to contribute to a nuanced understanding of the multifaceted role that CS HGs play in advancing drug delivery methodologies.
    Matched MeSH terms: Biocompatible Materials/chemistry
  7. Zhen Y, Peng C, Gao H, Bai L, Song Y, Gao P, et al.
    Biomacromolecules, 2024 Dec 09;25(12):7767-7776.
    PMID: 39526987 DOI: 10.1021/acs.biomac.4c01082
    This study found that the sources of cellulose have a significant effect on the parameters related to the kinks present in nanocellulose. During nanocellulose preparation, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation induced partial depolymerization on whole cellulose and made the amorphous regions more susceptible to consequent mechanical treatment irrespective of cellulose sources. However, plant cellulose microfibrils were prone to break into shorter nanocellulose with fewer kinks, while bacterial and tunicate cellulose were more likely to bend rather than break, thus leading to the generation of more kinks. The kinks did not show significant effects on the size, crystallinity index, and thermal properties of nanocellulose for each cellulose source, though the kink numbers were positively related to the mechanical performance of nanocellulose. Collectively, this study elucidated the kink formation mechanisms and clarified the effects of kinks on nanocellulose performance, thus providing new insights into understanding the source and behaviors of microdefects present in nanocellulose.
    Matched MeSH terms: Nanostructures/chemistry
  8. Omoregie AI, Alhassan M, Ouahbi T
    Int J Biol Macromol, 2024 Dec;283(Pt 2):137770.
    PMID: 39557263 DOI: 10.1016/j.ijbiomac.2024.137770
    Lilium spp. polysaccharides (LSPs) are gaining significant attention for their diverse health benefits, including antioxidant, antitumor, and antibacterial properties. This paper critically analyzes a recent comprehensive review by Li et al., published in International Journal of Biological Macromolecules, focusing on LSP extraction, purification, and health benefits. While the original review offers valuable insights, this critique identifies opportunities to strengthen the bibliometric analysis section. This study employs a comprehensive search strategy in Scopus using specific keywords and covering a broader time frame (1975-2023), revealing 94 research articles on LSPs. The critique proposes improvements to enhance transparency and impact, such as specifying search queries and Boolean operators used across databases, detailing selection criteria, and incorporating advanced analyses. This article discusses author keyword analysis, co-citation analysis of cited authors, and bibliographic coupling analysis of documents using VOSviewer software. The global landscape mapping of LSP relationships involving authors, countries, and keywords was determined using RStudio software. These refinements will provide a more robust foundation for understanding the LSP research landscape and future research directions while also addressing common pitfalls and suggesting improvements in bibliometric analysis for future studies.
    Matched MeSH terms: Antioxidants/chemistry
  9. Yang G, Zhang J, Abdullah R, Cheah WY, Zhao D, Ling TC
    J Microbiol Biotechnol, 2024 Oct 31;35:e2407038.
    PMID: 39639489 DOI: 10.4014/jmb.2407.07038
    Microalgae are recognized as a sustainable resource to produce biofertilizers, biofuels, and pigments, with the added benefits of environmental sustainability, such as carbon sequestration and pollutant removal. However, traditional cultivation methods face challenges like low biomass productivity and high operational costs. This review focuses on the innovative use of hydrogels as a medium for microalgae cultivation, which addresses these challenges by enhancing nutrient permeability, light distribution, and overall growth efficiency. Hydrogels provide a three-dimensional matrix that not only supports higher biomass yields but also facilitates the removal of pollutants from wastewater, contributing to circular economy goals. The review also explores the environmental benefits, challenges, and prospects of integrating hydrogel technology into microalgae cultivation systems. By highlighting influencing factors through which hydrogels improve microalgal productivity and environmental outcomes, this work aims to provide insights into the potential of hydrogel-based systems for sustainable development.
    Matched MeSH terms: Culture Media/chemistry
  10. Eng CC, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM
    ScientificWorldJournal, 2014;2014:213180.
    PMID: 25254230 DOI: 10.1155/2014/213180
    Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.
    Matched MeSH terms: Aluminum Silicates/chemistry; Fruit/chemistry; Methacrylates/chemistry*; Polyesters/chemistry; Polymers/chemistry*; Silanes/chemistry*; Water/chemistry; Lactic Acid/chemistry; Arecaceae/chemistry*; Plant Preparations/chemistry; Nanoparticles/chemistry; Green Chemistry Technology/methods
  11. Bimakr M, Rahman RA, Taip FS, Adzahan NM, Sarker MZ, Ganjloo A
    Molecules, 2013 Jan 15;18(1):997-1014.
    PMID: 23322066 DOI: 10.3390/molecules18010997
    In the present study, supercritical carbon dioxide (SC-CO(2)) extraction of seed oil from winter melon (Benincasa hispida) was investigated. The effects of process variables namely pressure (150-300 bar), temperature (40-50 °C) and dynamic extraction time (60-120 min) on crude extraction yield (CEY) were studied through response surface methodology (RSM). The SC-CO(2) extraction process was modified using ethanol (99.9%) as co-solvent. Perturbation plot revealed the significant effect of all process variables on the CEY. A central composite design (CCD) was used to optimize the process conditions to achieve maximum CEY. The optimum conditions were 244 bar pressure, 46 °C temperature and 97 min dynamic extraction time. Under these optimal conditions, the CEY was predicted to be 176.30 mg-extract/g-dried sample. The validation experiment results agreed with the predicted value. The antioxidant activity and fatty acid composition of crude oil obtained under optimized conditions were determined and compared with published results using Soxhlet extraction (SE) and ultrasound assisted extraction (UAE). It was found that the antioxidant activity of the extract obtained by SC-CO(2) extraction was strongly higher than those obtained by SE and UAE. Identification of fatty acid composition using gas chromatography (GC) showed that all the extracts were rich in unsaturated fatty acids with the most being linoleic acid. In contrast, the amount of saturated fatty acids extracted by SE was higher than that extracted under optimized SC-CO(2) extraction conditions.
    Matched MeSH terms: Ethanol/chemistry; Biphenyl Compounds/chemistry; Carbon Dioxide/chemistry; Fatty Acids/chemistry; Free Radicals/chemistry; Picrates/chemistry; Plant Oils/chemistry; Seeds/chemistry*; Solvents/chemistry; Sulfonic Acids/chemistry; Free Radical Scavengers/chemistry; Cucurbitaceae/chemistry*; Benzothiazoles/chemistry
  12. Ho CL, Tan YC
    Phytochemistry, 2015 Jun;114:168-77.
    PMID: 25457484 DOI: 10.1016/j.phytochem.2014.10.016
    Basal stem rot (BSR) of oil palm roots is due to the invasion of fungal mycelia of Ganoderma species which spreads to the bole of the stem. In addition to root contact, BSR can also spread by airborne basidiospores. These fungi are able to break down cell wall components including lignin. BSR not only decreases oil yield, it also causes the stands to collapse thus causing severe economic loss to the oil palm industry. The transmission and mode of action of Ganoderma, its interactions with oil palm as a hemibiotroph, and the molecular defence responses of oil palm to the infection of Ganoderma boninense in BSR are reviewed, based on the transcript profiles of infected oil palms. The knowledge gaps that need to be filled in oil palm-Ganoderma molecular interactions i.e. the associations of hypersensitive reaction (HR)-induced cell death and reactive oxygen species (ROS) kinetics to the susceptibility of oil palm to Ganoderma spp., the interactions of phytohormones (salicylate, jasmonate and ethylene) at early and late stages of BSR, and cell wall strengthening through increased production of guaiacyl (G)-type lignin, are also discussed.
    Matched MeSH terms: Plant Oils/chemistry*; Spores, Fungal/chemistry; Plant Roots/chemistry; Ganoderma/chemistry
  13. Abou-Zied OK, Zahid NI, Khyasudeen MF, Giera DS, Thimm JC, Hashim R
    Sci Rep, 2015;5:8699.
    PMID: 25731606 DOI: 10.1038/srep08699
    Local heterogeneity in lipid self-assembly is important for executing the cellular membrane functions. In this work, we chemically modified 2-(2'-hydroxyphenyl)benzoxazole (HBO) and attached a C8 alkyl chain in two different locations to probe the microscopic environment of four lipidic phases of dodecyl β-maltoside. The fluorescence change in HBO and the new probes (HBO-1 and HBO-2) shows that in all phases (micellar, hexagonal, cubic and lamellar) three HBO tautomeric species (solvated syn-enol, anionic, and closed syn-keto) are stable. The formation of multi tautomers reflects the heterogeneity of the lipidic phases. The results indicate that HBO and HBO-1 reside in a similar location within the head group region, whereas HBO-2 is slightly pushed away from the sugar-dominated area. The stability of the solvated syn-enol tautomer is due to the formation of a hydrogen bond between the OH group of the HBO moiety and an adjacent oxygen atom of a sugar unit. The detected HBO anions was proposed to be a consequence of this solvation effect where a hydrogen ion abstraction by the sugar units is enhanced. Our results point to a degree of local heterogeneity and ionization ability in the head group region as a consequence of the sugar amphoterism.
    Matched MeSH terms: Anions/chemistry; Benzoxazoles/chemistry; Fluorescent Dyes/chemistry*; Lipids/chemistry*
  14. Jamil W, Perveen S, Shah SA, Taha M, Ismail NH, Perveen S, et al.
    Molecules, 2014 Jun 25;19(7):8788-802.
    PMID: 24968334 DOI: 10.3390/molecules19078788
    Phenoxyacetohydrazide Schiff base analogs 1-28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50=9.20±0.32 µM), 5 (IC50=9.47±0.16 µM), 7 (IC50=14.7±0.19 µM), 8 (IC50=15.4±1.56 µM), 11 (IC50=19.6±0.62 µM), 12 (IC50=30.7±1.49 µM), 15 (IC50=12.0±0.16 µM), 21 (IC50=13.7±0.40 µM) and 22 (IC50=22.0±0.14 µM) showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50=48.4±1.25 µM).
    Matched MeSH terms: Enzyme Inhibitors/chemistry*; Glucuronidase/chemistry; Hydrazines/chemistry*; Phenoxyacetates/chemistry*
  15. Mohd Sultan N, Johan MR
    ScientificWorldJournal, 2014;2014:184604.
    PMID: 25215315 DOI: 10.1155/2014/184604
    Gold nanoparticles (AuNPs) had been synthesized with various molarities and weights of reducing agent, monosodium glutamate (MSG), and stabilizer chitosan, respectively. The significance of chitosan as stabilizer was distinguished through transmission electron microscopy (TEM) images and UV-Vis absorption spectra in which the interparticles distance increases whilst retaining the surface plasmon resonance (SPR) characteristics peak. The most stable AuNPs occurred for composition with the lowest (1 g) weight of chitosan. AuNPs capped with chitosan size stayed small after 1 month aging compared to bare AuNPs. The ability of chitosan capped AuNPs to uptake analyte was studied by employing amorphous carbon nanotubes (α-CNT), copper oxide (Cu2O), and zinc sulphate (ZnSO4) as the target material. The absorption spectra showed dramatic intensity increased and red shifted once the analyte was added to the chitosan capped AuNPs.
    Matched MeSH terms: Gold/chemistry*; Nanotubes, Carbon/chemistry; Chitosan/chemistry*; Nanoparticles/chemistry*
  16. Rabbani G, Khan MJ, Ahmad A, Maskat MY, Khan RH
    Colloids Surf B Biointerfaces, 2014 Nov 1;123:96-105.
    PMID: 25260221 DOI: 10.1016/j.colsurfb.2014.08.035
    The primary objective of this study is to explore the interaction of β-galactosidase with copper oxide nanoparticles (CuO NPs). Steady-state absorption, fluorescence and circular dichroism (CD) spectroscopic techniques have been employed to unveil the conformational changes of β-galactosidase induced by the binding of CuO NPs. Temperature dependent fluorescence quenching results indicates a static quenching mechanism in the present case. The binding thermodynamic parameters delineate the predominant role of H-bonding and van der Waals forces between β-galactosidase and CuO NPs binding process. The binding was studied by isothermal titration calorimetry (ITC) and the result revealed that the complexation is enthalpy driven, the ΔH°<0, ΔS°<0 indicates the formation of hydrogen bonds between β-galactosidase and CuO NPs occurs. Disruption of the native conformation of the protein upon binding with CuO NPs is reflected through a reduced functionality (in terms of hydrolase activity) of the protein CuO NPs conjugate system in comparison to the native protein and CuO NPs exhibited a competitive mode of inhibition. This also supports the general belief that H-bond formation occurs with NPs is associated with a lesser extent of modification in the native structure. Morphological features and size distributions were investigated using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Additionally the considerable increase in the Rh following the addition of CuO NPs accounts for the unfolding of β-galactosidase. Chemical and thermal unfolding of β-galactosidase, when carried out in the presence of CuO NPs, also indicated a small perturbation in the protein structure. These alterations in functional activity of nanoparticle bound β-galactosidase which will have important consequences should be taken into consideration while using nanoparticles for diagnostic and therapeutic purposes.
    Matched MeSH terms: beta-Galactosidase/chemistry*; Copper/chemistry*; Guanidine/chemistry*; Metal Nanoparticles/chemistry*
  17. Peik-See T, Pandikumar A, Nay-Ming H, Hong-Ngee L, Sulaiman Y
    Sensors (Basel), 2014;14(8):15227-43.
    PMID: 25195850 DOI: 10.3390/s140815227
    The fabrication of an electrochemical sensor based on an iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE) and its simultaneous detection of dopamine (DA) and ascorbic acid (AA) is described here. The Fe3O4/rGO nanocomposite was synthesized via a simple, one step in-situ wet chemical method and characterized by different techniques. The presence of Fe3O4 nanoparticles on the surface of rGO sheets was confirmed by FESEM and TEM images. The electrochemical behavior of Fe3O4/rGO/GCE towards electrocatalytic oxidation of DA was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analysis. The electrochemical studies revealed that the Fe3O4/rGO/GCE dramatically increased the current response against the DA, due to the synergistic effect emerged between Fe3O4 and rGO. This implies that Fe3O4/rGO/GCE could exhibit excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA. Moreover, the modified sensor electrode portrayed sensitivity and selectivity for simultaneous determination of AA and DA. The observed DPVs response linearly depends on AA and DA concentration in the range of 1-9 mM and 0.5-100 µM, with correlation coefficients of 0.995 and 0.996, respectively. The detection limit of (S/N = 3) was found to be 0.42 and 0.12 µM for AA and DA, respectively.
    Matched MeSH terms: Carbon/chemistry; Ferric Compounds/chemistry; Graphite/chemistry*; Metal Nanoparticles/chemistry
  18. Riaz N, Bustam MA, Chong FK, Man ZB, Khan MS, Shariff AM
    ScientificWorldJournal, 2014;2014:342020.
    PMID: 25105158 DOI: 10.1155/2014/342020
    Bimetallic Cu-Ni/TiO2 photocatalysts were synthesized using wet impregnation (WI) method with TiO2 (Degussa-P25) as support and calcined at different temperatures (180, 200, and 300°C) for the photodegradation of DIPA under visible light. The photocatalysts were characterized using TGA, FESEM, UV-Vis diffuse reflectance spectroscopy, fourier transform infrared spectroscopy (FTIR) and temperature programmed reduction (TPR). The results from the photodegradation experiments revealed that the Cu-Ni/TiO2 photocatalysts exhibited much higher photocatalytic activities compared to bare TiO2. It was found that photocatalyst calcined at 200°C had the highest photocatalyst activities with highest chemical oxygen demand (COD) removal (86.82%). According to the structural and surface analysis, the enhanced photocatalytic activity could be attributed to its strong absorption into the visible region and high metal dispersion.
    Matched MeSH terms: Quaternary Ammonium Compounds/chemistry*; Copper/chemistry*; Nickel/chemistry*; Photochemistry/methods*; Titanium/chemistry*
  19. Chieng BW, Ibrahim NA, Then YY, Loo YY
    Molecules, 2014;19(10):16024-38.
    PMID: 25299820 DOI: 10.3390/molecules191016024
    Plasticized poly(lactic acid) PLA with epoxidized vegetable oils (EVO) were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO) and mixture of epoxidized palm oil and soybean oil (EPSO), respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.
    Matched MeSH terms: Plant Oils/chemistry*; Plasticizers/chemistry*; Polymers/chemistry*; Lactic Acid/chemistry*
  20. Yap HY, Aziz AA, Fung SY, Ng ST, Tan CS, Tan NH
    Int J Med Sci, 2014;11(6):602-7.
    PMID: 24782649 DOI: 10.7150/ijms.8341
    The Lignosus is a genus of fungi that have useful medicinal properties. In Southeast Asia, three species of Lignosus (locally known collectively as Tiger milk mushrooms) have been reported including L. tigris, L. rhinocerotis, and L. cameronensis. All three have been used as important medicinal mushrooms by the natives of Peninsular Malaysia. In this work, the nutritional composition and antioxidant activities of the wild type and a cultivated strain of L. tigris sclerotial extracts were investigated. The sclerotia are rich in carbohydrates with moderate amount of protein and low fat content. Free radical scavenging activities of L. tigris sclerotial extracts correlate with their phenolic content, which ranges from 6.25 to 45.42 mg GAE/g extract. The FRAP values ranged from 0.002 to 0.041 mmol/min/g extract, while the DPPH(•), ABTS(•+), and superoxide anion (SOA) scavenging activities ranged from 0.18 to 2.53, 0.01 to 0.36, and -4.53 to 10.05 mmol Trolox equivalents/g extract, respectively. L. tigris cultivar shows good prospect to be developed into functional food due to its good nutritional value and potent SOA scavenging activity.
    Matched MeSH terms: Agaricales/chemistry; Antioxidants/chemistry; Phenols/chemistry; Polyporaceae/chemistry*
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