Displaying publications 261 - 280 of 10432 in total

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  1. Fulltext Floating ZnO QDs-Modified TiO2/LLDPE Hybrid Polymer Film for the Effective Photodegradation of Tetracycline under Fluorescent Light Irradiation: Synthesis and Characterisation
    Iqbal A, Saidu U, Adam F, Sreekantan S, Yahaya N, Ahmad MN, et al.
    Molecules, 2021 Apr 25;26(9).
    PMID: 33923041 DOI: 10.3390/molecules26092509
    In this work, mesoporous TiO2-modified ZnO quantum dots (QDs) were immobilised on a linear low-density polyethylene (LLDPE) polymer using a solution casting method for the photodegradation of tetracycline (TC) antibiotics under fluorescent light irradiation. Various spectroscopic and microscopic techniques were used to investigate the physicochemical properties of the floating hybrid polymer film catalyst (8%-ZT@LLDPE). The highest removal (89.5%) of TC (40 mg/L) was achieved within 90 min at pH 9 due to enhanced water uptake by the LDDPE film and the surface roughness of the hybrid film. The formation of heterojunctions increased the separation of photogenerated electron-hole pairs. The QDs size-dependent quantum confinement effect leads to the displacement of the conduction band potential of ZnO QDs to more negative energy values than TiO2. The displacement generates more reactive species with higher oxidation ability. The highly stable film photocatalyst can be separated easily and can be repeatedly used up to 8 cycles without significant loss in the photocatalytic ability. The scavenging test indicates that the main species responsible for the photodegradation was O2●-. The proposed photodegradation mechanism of TC was demonstrated in further detail based on the intermediates detected by LC-time-of-flight/mass spectrometry (LC/TOF-MS).
    Matched MeSH terms: Polymers/chemistry*; Tetracycline/chemistry*; Titanium/chemistry; Zinc Oxide/chemistry; Polyethylene/chemistry
  2. Fulltext Improved Hydrophobicity of Macroalgae Biopolymer Film Incorporated with Kenaf Derived CNF Using Silane Coupling Agent
    Oyekanmi AA, Saharudin NI, Hazwan CM, H P S AK, Olaiya NG, Abdullah CK, et al.
    Molecules, 2021 Apr 13;26(8).
    PMID: 33924692 DOI: 10.3390/molecules26082254
    Hydrophilic behaviour of carrageenan macroalgae biopolymer, due to hydroxyl groups, has limited its applications, especially for packaging. In this study, macroalgae were reinforced with cellulose nanofibrils (CNFs) isolated from kenaf bast fibres. The macroalgae CNF film was after that treated with silane for hydrophobicity enhancement. The wettability and functional properties of unmodified macroalgae CNF films were compared with silane-modified macroalgae CNF films. Characterisation of the unmodified and modified biopolymers films was investigated. The atomic force microscope (AFM), SEM morphology, tensile properties, water contact angle, and thermal behaviour of the biofilms showed that the incorporation of Kenaf bast CNF remarkably increased the strength, moisture resistance, and thermal stability of the macroalgae biopolymer films. Moreover, the films' modification using a silane coupling agent further enhanced the strength and thermal stability of the films apart from improved water-resistance of the biopolymer films compared to unmodified films. The morphology and AFM showed good interfacial interaction of the components of the biopolymer films. The modified biopolymer films exhibited significantly improved hydrophobic properties compared to the unmodified films due to the enhanced dispersion resulting from the silane treatment. The improved biopolymer films can potentially be utilised as packaging materials.
    Matched MeSH terms: Biopolymers/chemistry*; Cellulose/chemistry*; Silanes/chemistry*; Hibiscus/chemistry; Nanocomposites/chemistry
  3. Technical aspects of preparing PEG-PLGA nanoparticles as carrier for chemotherapeutic ‎agents by nanoprecipitation method
    Almoustafa HA, Alshawsh MA, Chik Z
    Int J Pharm, 2017 Nov 25;533(1):275-284.
    PMID: 28943210 DOI: 10.1016/j.ijpharm.2017.09.054
    Nanoprecipitation is a simple and increasingly trending method for nanoparticles preparation. The self-assembly feature of poly (ethylene glycol)-poly (lactide-co-glycolic acid) (PEG-PLGA) amphiphilic copolymer into a nanoparticle and its versatile structure makes nanoprecipitation one of the best methods for its preparation. The aim of this study is to review currently available literature for standard preparation of PEG-PLGA nanoparticles using nanoprecipitation technique in order to draw conclusive evidenceto draw conclusive evidence that can guide researchers during formulation development. To achieve this, three databases (Web of Science, Scopus and PubMed) were searched using relevant keywords and the extracted articles were reviewed based on defined inclusion and exclusion criteria. Data extraction and narrative analysis of the obtained literature was performed when appropriate, along with our laboratory observations to support those claims wherever necessary. As a result of this analysis, reports that matched our criteria conformed to the general facts about nanoprecipitation techniques such as simplicity in procedure, low surfactants requirement, narrow size distribution, and low resulting concentrations. However, these reports showed interesting advantages for using PEG-PLGA as they are frequently reported to be freeze-dried and active pharmaceutical ingredients (APIs) with low hydrophobicity were reported to successfully be encapsulated in the particles.
    Matched MeSH terms: Antineoplastic Agents/chemistry*; Drug Carriers/chemistry*; Polyesters/chemistry*; Polyethylene Glycols/chemistry*; Nanoparticles/chemistry*
  4. Structural and Ionic Transport Properties of Protonic Conducting Solid Biopolymer Electrolytes Based on Carboxymethyl Cellulose Doped with Ammonium Fluoride
    Ramlli MA, Isa MI
    J Phys Chem B, 2016 11 10;120(44):11567-11573.
    PMID: 27723333
    Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transference number measurement (TNM) techniques were applied to investigate the complexation, structural, and ionic transport properties of and the dominant charge-carrier species in a solid biopolymer electrolyte (SBE) system based on carboxymethyl cellulose (CMC) doped with ammonium fluoride (NH4F), which was prepared via a solution casting technique. The SBEs were partially opaque in appearance, with no phase separation. The presence of interactions between the host polymer (CMC) and the ionic dopant (NH4F) was proven by FT-IR analysis at the C-O band. XRD spectra analyzed using Origin 8 software disclose that the degree of crystallinity (χc%) of the SBEs decreased with the addition of NH4F, indicating an increase in the amorphous nature of the SBEs. Analysis of the ionic transport properties reveals that the ionic conductivity of the SBEs is dependent on the ionic mobility (μ) and diffusion of ions (D). TNM analysis confirms that the SBEs are proton conductors.
    Matched MeSH terms: Quaternary Ammonium Compounds/chemistry*; Biopolymers/chemistry*; Carboxymethylcellulose Sodium/chemistry*; Electrolytes/chemistry; Fluorides/chemistry*
  5. Polymeric nanoparticles for topical delivery of alpha and beta arbutin: preparation and characterization
    Ayumi NS, Sahudin S, Hussain Z, Hussain M, Samah NHA
    Drug Deliv Transl Res, 2019 04;9(2):482-496.
    PMID: 29569027 DOI: 10.1007/s13346-018-0508-6
    To investigate the use of chitosan nanoparticles (CS-TPP-NPs) as carriers for α- and β-arbutin. In this study, CS-TPP-NPs containing α- and β-arbutin were prepared via the ionic cross-linking of CS and TPP and characterized for particle size, zeta potential, and dispersity index. The entrapment efficiency and loading capacity of various β-arbutin concentrations (0.1, 0.2, 0.4, 0.5, and 0.6%) were also investigated. SEM, TEM FTIR, DSC and TGA analyses of the nanoparticles were performed to further characterize the nanoparticles. Finally, stability and release studies were undertaken to ascertain further the suitability of the nanoparticles as a carrier system for α- and β-arbutin. Data obtained clearly indicates the potential for use of CS-TPP-NPs as a carrier for the delivery of α- and β-arbutin. The size obtained for the alpha nanoparticles (α-arbutin CSNPs) ranges from 147 to 274 d.nm, with an increase in size with increasing alpha arbutin concentration. β-arbutin nanoparticles (β-arbutin CSNPs) size range was from 211.1 to 284 dn.m. PdI for all nanoparticles remained between 0.2-0.3 while the zeta potential was between 41.6-52.1 mV. The optimum encapsulation efficiency and loading capacity for 0.4% α-arbutin CSNPs were 71 and 77%, respectively. As for β-arbutin, CSNP optimum encapsulation efficiency and loading capacity for 0.4% concentration were 68 and 74%, respectively. Scanning electron microscopy for α-arbutin CSNPs showed a more spherical shape compared to β-arbutin CSNPs where rod-shaped particles were observed. However, under transmission electron microscopy, the shapes of both α- and β-arbutin CSNP nanoparticles were spherical. The crystal phase identification of the studied samples was carried out using X-ray diffraction (XRD), and the XRD of both α and β-arbutin CSNPs showed to be more crystalline in comparison to their free form. FTIR spectra showed intense characteristic peaks of chitosan appearing at 3438.3 cm-1 (-OH stretching), 2912 cm-1 (-CH stretching), represented 1598.01 cm-1 (-NH2) for both nanoparticles. Stability studies conducted for 90 days revealed that both α- and β-arbutin CSNPs were stable in solution. Finally, release studies of both α- and β-arbutin CSNPs showed a significantly higher percentage release in comparison to α- and β-arbutin in their free form. Chitosan nanoparticles demonstrate considerable promise as a carrier system for α- and β-arbutin, the use of which is anticipated to improve delivery of arbutin through the skin, in order to improve its efficacy as a whitening agent.
    Matched MeSH terms: Arbutin/chemistry*; Drug Carriers/chemistry*; Chitosan/chemistry*; Nanoparticles/chemistry*; Skin Lightening Preparations/chemistry*
  6. The formation of hybrid carbon nanomaterial by chemical vapor deposition: an efficient adsorbent for enhanced removal of methylene blue from aqueous solution
    Alayan HM, Alsaadi MA, Das R, Abo-Hamad A, Ibrahim RK, AlOmar MK, et al.
    Water Sci Technol, 2018 Mar;77(5-6):1714-1723.
    PMID: 29595174 DOI: 10.2166/wst.2018.057
    In this study, carbon species were grown on the surface of Ni-impregnated powder activated carbon to form a novel hybrid carbon nanomaterial by chemical vapor deposition. The carbon nanomaterial was obtained by the precipitation of the methane elemental carbon atoms on the surface of the Ni catalyst. The physiochemical properties of the hybrid material were characterized to illustrate the successful growth of carbon species on the carbon substrate. The response surface methodology was used for the evaluation of adsorption parameters effect such as pH, adsorbent dose and contact time on the percentage removal of MB dye from aqueous solution. The optimum conditions were found to be pH = 11, adsorbent dose = 15 mg and contact time of 120 min. The material we prepared showed excellent removal efficiency of 96% for initial MB concentration of 50 mg/L. The adsorption of MB was described accurately by the pseudo-second-order model with R2 of 0.998 and qe of 163.93 (mg/g). The adsorption system showed the best agreement with Langmuir model with R2 of 0.989 and maximum adsorption capacity (Qm) of 250 mg/g.
    Matched MeSH terms: Carbon/chemistry*; Charcoal/chemistry; Methylene Blue/chemistry*; Water Pollutants, Chemical/chemistry*; Nanostructures/chemistry*
  7. Modification of oil palm fronds lignin by incorporation of m-cresol for improving structural and antioxidant properties
    Sa'don NA, Rahim AA, Ibrahim MNM, Brosse N, Hussin MH
    Int J Biol Macromol, 2017 Nov;104(Pt A):251-260.
    PMID: 28602987 DOI: 10.1016/j.ijbiomac.2017.06.038
    Lignin extracted from oil palm fronds (OPF) underwent chemical modification by incorporating m-cresol into the lignin matrix. This study reports on the physicochemical properties and antioxidant activity of unmodified autohydrolyzed ethanol organosolv lignin (AH EOL) and the modified autohydrolyzed ethanol organosolv lignin (AHC EOL). The lignin samples were analyzed by FTIR, 1H and 13C NMR spectroscopy, 2D NMR: HSQC spectroscopy, CHN analysis, molecular weight distribution analysis; GPC and thermal analysis; DSC and TGA. The lignin modification has reduced the hydrophobicity of its complex structure by providing better quality lignin with smaller fragments and higher solubility rate in water (DAHCEOL: 42%>DAHEOL: 25%). It was revealed that the modification of lignin has improved their structural and antioxidant properties, thus venture their possible applications.
    Matched MeSH terms: Antioxidants/chemistry*; Cresols/chemistry*; Lignin/chemistry*; Water/chemistry; Arecaceae/chemistry*
  8. Synthesis of nanostructured titanium dioxide layer onto kaolin hollow fibre membrane via hydrothermal method for decolourisation of reactive black 5
    Mohtor NH, Othman MHD, Bakar SA, Kurniawan TA, Dzinun H, Norddin MNAM, et al.
    Chemosphere, 2018 Oct;208:595-605.
    PMID: 29890498 DOI: 10.1016/j.chemosphere.2018.05.159
    Hydrothermal method has been proven to be an effective method to synthesise the nanostructured titanium dioxide (TiO2) with good morphology and uniform distribution at low temperature. Despite of employing a well-known and commonly used glass substrate as the support to hydrothermally synthesise the nanostructured TiO2, this study emphasised on the application of kaolin hollow fibre membrane as the support for the fabrication of kaolin/TiO2 nanorods (TNR) membrane. By varying the hydrothermal reaction times (2 h, 6 h, and 10 h), the different morphology, distribution, and properties of TiO2 nanorods on kaolin support were observed by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). It was found that the well-dispersed of TiO2 nanorods have improved the surface affinity of kaolin/TNR membrane towards water, allowing kaolin/TNR membrane prepared from 10 h of hydrothermal reaction to exhibit the highest water permeation of 165 L/h.m2.bar. In addition, this prepared membrane also showed the highest photocatalytic activity of 80.3% in the decolourisation of reactive black 5 (RB5) under UV irradiation. On top of that, the kaolin/TNR membrane prepared from 10 h of hydrothermal reaction also exhibited a good resistance towards photocorrosion, enabling the reuse of this membrane for three consecutive cycles of photocatalytic degradation of RB5 without showing significant reduction in photocatalytic efficiency towards the decolourisation of RB5.
    Matched MeSH terms: Chemistry Techniques, Analytical; Kaolin/chemistry*; Naphthalenesulfonates/chemistry*; Titanium/chemistry*; Nanostructures/chemistry
  9. Influence of a nonionic surfactant on curcumin delivery of nanocellulose reinforced chitosan hydrogel
    Sampath Udeni Gunathilake TM, Ching YC, Chuah CH, Illias HA, Ching KY, Singh R, et al.
    Int J Biol Macromol, 2018 Oct 15;118(Pt A):1055-1064.
    PMID: 30001596 DOI: 10.1016/j.ijbiomac.2018.06.147
    Nanocellulose reinforced chitosan hydrogel was synthesized using chemical crosslinking method for the delivery of curcumin which is a poorly water-soluble drug. Curcumin extracted from the dried rhizomes of Curcuma longa was incorporated to the hydrogel via in situ loading method. A nonionic surfactant (Tween 20) was incorporated into the hydrogel to improve the solubility of curcumin. After the gas foaming process, hydrogel showed large interconnected pore structures. The release studies in gastric medium showed that the cumulative release of curcumin increased from 0.21% ± 0.02% to 54.85% ± 0.77% with the increasing of Tween 20 concentration from 0% to 30% (w/v) after 7.5 h. However, the entrapment efficiency percentage decreased with the addition of Tween 20. The gas foamed hydrogel showed higher initial burst release within the first 120 min compared to hydrogel formed at atmospheric condition. The solubility of curcumin would increase to 3.014 ± 0.041 mg/mL when the Tween 20 concentration increased to 3.2% (w/v) in simulated gastric medium. UV-visible spectra revealed that the drug retained its chemical activity after in vitro release. From these findings, it is believed that the nonionic surfactant incorporated chitosan/nanocellulose hydrogel can provide a platform to overcome current problems associated with curcumin delivery.
    Matched MeSH terms: Cellulose/chemistry*; Polysorbates/chemistry*; Surface-Active Agents/chemistry*; Hydrogels/chemistry*; Chitosan/chemistry*
  10. Chemically crosslinked hydrogel and its driving force towards superabsorbent behaviour
    Salleh KM, Zakaria S, Sajab MS, Gan S, Chia CH, Jaafar SNS, et al.
    Int J Biol Macromol, 2018 Oct 15;118(Pt B):1422-1430.
    PMID: 29964115 DOI: 10.1016/j.ijbiomac.2018.06.159
    Dissolved oil palm empty fruit bunch (EFB) cellulose in NaOH/urea solvent was mixed with sodium carboxymethylcellulose (NaCMC) to form a green regenerated superabsorbent hydrogel. The effect of concentration of epichlorohydrin (ECH) as the crosslinker on the formation, physical, and chemical properties of hydrogel was studied. Rapid formation and higher gel content of hydrogel were observed at 10% concentration of ECH. The superabsorbent hydrogel was successfully fabricated in this study with the swelling ability >100,000%. Hydrogel with higher concentration of ECH showed opposite trend by having higher superabsorbent property than that of lower concentration. The covalent bond of COC was observed with Attenuated total reflectance fourier transform infrared (ATR-FT-IR) spectroscopy to confirm the occurrence of crosslinking. The physical and chemical properties of hydrogel were affected by swelling phenomenon. Hydrogel with higher degree of swelling exhibited lower moisture retention and higher transparency. Moreover, the weight of the superabsorbent hydrogel increased with the decrement of pH value of external media (distilled water). This study provided substantial information on the effect of different percentage of ECH as crosslinker on hydrogel basic properties. Furthermore, this study affords correlation of many essential driving forces that affected hydrogel superabsorbent property.
    Matched MeSH terms: Cellulose/chemistry; Sodium Hydroxide/chemistry; Urea/chemistry; Water/chemistry; Hydrogels/chemistry*
  11. Functional properties of dually modified sago starch/κ-carrageenan films: An alternative to gelatin in pharmaceutical capsules
    Oladzadabbasabadi N, Ebadi S, Mohammadi Nafchi A, Karim AA, Kiahosseini SR
    Carbohydr Polym, 2017 Mar 15;160:43-51.
    PMID: 28115099 DOI: 10.1016/j.carbpol.2016.12.042
    The aim of this study was development a composite film based on sago starch and κ-carrageenan to find a gelatin alternative in the pharmaceutical capsules processing. Hydrolyzed-Hydroxypropylated (dually modified) sago starch was mixed with κ-carrageenan (0.25, 0.5, 0.75, and 1%). The drying kinetics, thermomechanical, physicochemical, and barrier properties of composite films were estimated and compared with bovine gelatin. Results show that drying kinetics and mechanical properties of the composite films were comparable to those of gelatin. The water vapor permeability and moisture content of the composite films were lower than those of gelatin. The solubility of the composite films was higher than that of gelatin, and the composite films were more stable at higher relative humidity than were the gelatin films. These results show that dually modified sago starch in combination with κ-carrageenan has properties similar to those of gelatin, thus proposed system can be used in pharmaceutical capsules processes.
    Matched MeSH terms: Carrageenan/chemistry*; Chemistry, Pharmaceutical*; Gelatin/chemistry; Starch/chemistry*
  12. Characterisation of electrospun gelatine nanofibres encapsulated with Moringa oleifera bioactive extract
    Hani NM, Torkamani AE, Azarian MH, Mahmood KW, Ngalim SH
    J Sci Food Agric, 2017 Aug;97(10):3348-3358.
    PMID: 27981649 DOI: 10.1002/jsfa.8185
    BACKGROUND: Drumstick (Moringa oleifera) leaves have been used as a folk herbal medicine across many cultures since ancient times. This is most probably due to presence of phytochemicals possessing antioxidant properties, which could retard oxidative stress, and their degenerative effect. The current study deals with nanoencapsulation of Moringa oleifera (MO) leaf ethanolic extract within fish sourced gelatine matrix using electrospinning technique.

    RESULTS: The total phenolic and flavonoid content, radical scavenging (IC50 ) and metal reducing properties were 67.0 ± 2.5 mg GAE g-1 sample 32.0 ± 0.5 mg QE g-1 extract, 0.08 ± 0.01 mg mL-1 and 510 ± 10 µmol eq Fe(II) g-1 extract, respectively. Morphological and spectroscopic analysis of the fibre mats confirmed successful nanoencapsulation of MO extract within defect free nanofibres via electrospinning process. The percentage encapsulation efficiency (EE) was between 80% and 85%. Furthermore, thermal stability of encapsulated fibres, especially at 3% and 5% of core loading content, was significantly improved. Toxicological analysis revealed that the extract in its original and encapsulated form was safe for oral consumption.

    CONCLUSION: Overall, the present study showed the potential of ambient temperature electrospinning process as a safe nanoencapsulation method, where MO extract retained its antioxidative capacities. © 2016 Society of Chemical Industry.

    Matched MeSH terms: Antioxidants/chemistry; Gelatin/chemistry*; Plant Extracts/chemistry*; Moringa oleifera/chemistry*; Nanofibers/chemistry*
  13. Fulltext Influence of La3+ Substitution on Structure, Morphology and Magnetic Properties of Nanocrystalline Ni-Zn Ferrite
    Dasan YK, Guan BH, Zahari MH, Chuan LK
    PLoS One, 2017;12(1):e0170075.
    PMID: 28081257 DOI: 10.1371/journal.pone.0170075
    Lanthanum substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5LaxFe1-xO4; 0.00 ≤x≤ 1.00) synthesized by sol-gel method were presented. X-ray diffraction patterns reveal the typical single phase spinel cubic ferrite structure, with the traces of secondary phase for lanthanum substituted nanocrystals. In addition, the structural analysis also demonstrates that the average crystallite size varied in the range of 21-25 nm. FTIR spectra present the two prominent absorption bands in the range of 400 to 600 cm-1 which are the fingerprint region of all ferrites. Surface morphology of both substituted and unsubstituted Ni-Zn ferrite nanoparticle samples was studied using FESEM technique and it indicates a significant increase in the size of spherical shaped particles with La3+ substitution. Magnetic properties of all samples were analyzed using vibrating sample magnetometer (VSM). The results revealed that saturation magnetization (Ms) and coercivity (Hc) of La3+ substituted samples has decreased as compared to the Ni-Zn ferrite samples. Hence, the observed results affirm that the lanthanum ion substitution has greatly influenced the structural, morphology and magnetic properties of Ni-Zn ferrite nanoparticles.
    Matched MeSH terms: Ferric Compounds/chemistry*; Lanthanum/chemistry*; Nickel/chemistry; Zinc/chemistry; Nanoparticles/chemistry*
  14. Fulltext Treated Rhizophora mucronata tannin as a corrosion inhibitor in chloride solution
    Agi A, Junin R, Rasol M, Gbadamosi A, Gunaji R
    PLoS One, 2018;13(8):e0200595.
    PMID: 30089104 DOI: 10.1371/journal.pone.0200595
    Treated Rhizopora mucronata tannin (RMT) as a corrosion inhibitor for carbon steel and copper in oil and gas facilities was investigated. Corrosion rate of carbon-steel and copper in 3wt% NaCl solution by RMT was studied using chemical (weight loss method) and spectroscopic (FTIR) techniques at various temperatures in the ranges of 26-90°C. The weight loss data was compared to the electrochemical by the application of Faraday's law for the conversion of corrosion rate data from one system to another. The inhibitive efficiency of RMT was compared with commercial inhibitor sodium benzotriazole (BTA-S). The best concentration of RMT was 20% (w/v), increase in concentration of RMT decreased the corrosion rate and increased the inhibitive efficiency. Increase in temperature increased the corrosion rate and decreased the inhibitive efficiency but, the rate of corrosion was mild with RMT. The FTIR result shows the presence of hydroxyl group, aromatic group, esters and the substituted benzene group indicating the purity of the tannin. The trend of RMT was similar to that of BTA-S, but its inhibitive efficiency for carbon-steel was poor (6%) compared to RMT (59%). BTA-S was efficient for copper (76%) compared to RMT (74%) at 40% (w/v) and 20% (w/v) concentration respectively. RMT was efficient even at low concentration therefore, the use of RMT as a cost effective and environmentally friendly corrosion inhibiting agent for carbon steel and copper is herein proposed.
    Matched MeSH terms: Copper/chemistry; Sodium Chloride/chemistry*; Steel/chemistry; Tannins/chemistry*; Triazoles/chemistry
  15. Immobilized Talaromyces thermophilus lipase as an efficient catalyst for the production of LML-type structured lipids
    Lian W, Wang W, Tan CP, Wang J, Wang Y
    Bioprocess Biosyst Eng, 2019 Feb;42(2):321-329.
    PMID: 30421172 DOI: 10.1007/s00449-018-2036-7
    LML-type structured lipids are one type of medium- and long-chain triacylglycerols. LML was synthesized using immobilized Talaromyces thermophilus lipase (TTL)-catalyzed interesterification of tricaprylin and ethyl linoleate. The resin AB-8 was chosen, and the lipase/support ratio was determined to be 60 mg/g. Subsequently, the immobilized TTL with strict sn-1,3 regiospecificity was applied to synthesize LML. Under the optimized conditions (60 °C, reaction time 6 h, enzyme loading of 6% of the total weight of substrates, substrate of molar ratio of ethyl linoleate to tricaprylin of 6:1), Triacylglycerols with two long- and one medium-chain FAs (DL-TAG) content as high as 52.86 mol% was obtained. Scale-up reaction further verified the industrial potential of the established process. The final product contained 85.24 mol% DL-TAG of which 97 mol% was LML after purification. The final product obtained with the high LML content would have substantial potential to be used as functional oils.
    Matched MeSH terms: Enzymes, Immobilized/chemistry*; Lipase/chemistry*; Lipids/chemistry*; Oils/chemistry; Triglycerides/chemistry
  16. Ice-templated graphene oxide/chitosan aerogel as an effective adsorbent for sequestration of metanil yellow dye
    Lai KC, Hiew BYZ, Lee LY, Gan S, Thangalazhy-Gopakumar S, Chiu WS, et al.
    Bioresour Technol, 2019 Feb;274:134-144.
    PMID: 30502604 DOI: 10.1016/j.biortech.2018.11.048
    Graphene oxide/chitosan aerogel (GOCA) was prepared by a facile ice-templating technique without using any cross-linking reagent for metanil yellow dye sequestration. The adsorption performance of GOCA was investigated by varying the adsorbent mass, shaking speed, initial pH, contact time, concentration and temperature. The combined effects of adsorption parameters and the optimum conditions for dye removal were determined by response surface methodology. GOCA exhibited large removal efficiencies (91.5-96.4%) over a wide pH range (3-8) and a high adsorption capacity of 430.99 mg/g at 8 mg adsorbent mass, 400 mg/L concentration, 35.19 min contact time and 175 rpm shaking speed. The adsorption equilibrium was best represented by the Langmuir model. GOCA could be easily separated after adsorption and regenerated for re-use in 5 adsorption-desorption cycles thereby maintaining 80% of its adsorption capability. The relatively high adsorption and regeneration capabilities of GOCA render it an attractive adsorbent for treatment of azo dye-polluted water.
    Matched MeSH terms: Azo Compounds/chemistry*; Coloring Agents/chemistry; Gels/chemistry; Graphite/chemistry*; Chitosan/chemistry*
  17. Iron nanoflorets on 3D-graphene-nickel: A 'Dandelion' nanostructure for selective deoxynivalenol detection
    Ong CC, Siva Sangu S, Illias NM, Chandra Bose Gopinath S, Saheed MSM
    Biosens Bioelectron, 2020 Apr 15;154:112088.
    PMID: 32056954 DOI: 10.1016/j.bios.2020.112088
    Deoxynivalenol (DON), a cosmopolitan mycotoxin found in agricultural commodities causes serious health maladies to human and animals when accidently consumed even at a low quantity. It necessitates selective and sensitive devices to analyse DON as the conventional methods are complex and time-consuming. This study is focused on developing a selective biosensing system using iron nanoflorets graphene nickel (INFGN) as the transducer and a specific aptamer as the biorecognition element. 3D-graphene is incorporated using a low-pressure chemical vapour deposition followed by the decoration of iron nanoflorets using electrochemical deposition. INFGN enables a feasible bio-capturing due to its large surface area. The X-ray photoelectron spectroscopy analysis confirms the presence of the hydroxyl groups on the INFGN surface, which acts as the linker. Clear Fourier-transform infrared peak shifts affirm the changes with surface chemical modification and biomolecular assembly. The limit of detection attained is 2.11 pg mL-1 and displays high stability whereby it retains 30.65% of activity after 48 h. The designed INFGN demonstrates remarkable discrimination of DON against similar mycotoxins (zearalenone and ochratoxin A). Overall, the high-performance biosensor shown here is an excellent, simple and cost-effective alternative for detecting DON in food and feed samples.
    Matched MeSH terms: Graphite/chemistry*; Iron/chemistry*; Nickel/chemistry; Trichothecenes/chemistry; Nanostructures/chemistry
  18. Fulltext Synthesis, Characterization, and Application of Poly(4,4'-Cyclohexylidene Bisphenol Oxalate) for Solid-Phase Extraction of DNA
    Al Balawi AN, Yusof NA, Kamaruzaman S, Mohammad F, Wasoh H, Al Abbosh KF, et al.
    Biomed Res Int, 2019;2019:7064073.
    PMID: 30868072 DOI: 10.1155/2019/7064073
    The present study has synthesized poly(4,4'-cyclohexylidene bisphenol oxalate) by the condensation of oxalyl chloride with 4,4'-cyclohexylidene bisphenol, where its efficacy was tested for the solid-phase extraction of DNA. The synthesized polymer in the form of a white powder was characterized by FTIR, TGA-DTG, SEM, and BET analysis. The study utilized solid-phase application of the resulting polymer to extract DNA. The analysis of results provided the information that the extraction efficiency is a strong dependent of polymer amount and binding buffer type. Among the three types of buffers tested, the GuHCl buffer produced the most satisfactory results in terms of yield and efficiency of extraction. Moreover, the absorbance ratio of A260/A280 in all of the samples varied from 1.682 to 1.491, thereby confirming the capability of poly(4,4'-cyclohexylidene bisphenol oxalate) to elute pure DNA. The results demonstrated an increased DNA binding capacity with respect to increased percentage of the polymer. The study has concluded that poly(bisphenol Z oxalate) can be applied as one of the potential candidates for the high efficiency extraction of DNA by means of a simple, cost-effective, and environmentally friendly approach compared to the other traditional solid-phase methods.
    Matched MeSH terms: Benzhydryl Compounds/chemistry; DNA/chemistry; Oxalates/chemistry*; Phenols/chemistry; Polymers/chemistry
  19. Characterization and properties of cellulose microfibers from water hyacinth filled sago starch biocomposites
    Syafri E, Jamaluddin, Wahono S, Irwan A, Asrofi M, Sari NH, et al.
    Int J Biol Macromol, 2019 Sep 15;137:119-125.
    PMID: 31252021 DOI: 10.1016/j.ijbiomac.2019.06.174
    The cellulose microfibers (CMF) from water hyacinth (WH) fiber as a filler in sago starch (SS) biocomposites was investigated. The CMF was isolated by pulping, bleaching and acid hydrolysis methods. The addition of CMF in sago matrix was varied i.e. 0, 5, 10, 15 and 20 wt%. Biocomposites were made by using solution casting and glycerol as a plasticizer. The biocomposites were also determined by tensile test, FTIR, X-Ray, thermogravimetric, SEM, and soil burial tests. The results show that the SS15CMF sample has the highest tensile strength of 10.23 MPa than those other samples. Scanning Electron Microscope (SEM) images show that the strong interaction was formed between CMF WH and matrix. Fourier Transform Infra-red (FTIR) indicated that the functional group of biocomposites was a hydrophilic cluster. The addition of CMF WH in sago starch biocomposites lead to the moisture barrier, crystallinity, and thermal stability increased; it is due to the pure sago starch film was more rapidly degraded than its biocomposites.
    Matched MeSH terms: Cellulose/chemistry*; Soil/chemistry; Starch/chemistry*; Arecaceae/chemistry*; Eichhornia/chemistry*
  20. Effect of diacylglycerol interfacial crystallization on the physical stability of water-in-oil emulsions
    Yang J, Qiu C, Li G, Lee WJ, Tan CP, Lai OM, et al.
    Food Chem, 2020 Oct 15;327:127014.
    PMID: 32434126 DOI: 10.1016/j.foodchem.2020.127014
    The influence of diacylglycerol (DAG) combined with polyglycerol polyricinoleate (PGPR) on the stability of water-in-oil (W/O) emulsions containing hydrogenated palm oil (HPO) was studied. Polarized light microscope revealed that DAG promoted HPO to crystallize at the water-oil interface, providing the combination of Pickering and network stabilization effects. It was proposed that the molecular compatibility of fatty acids in DAG with HPO accounted for the promotional effect. The interfacial crystallization of DAG together with the surface activity of PGPR led to the formation of emulsions with uniform small droplets and high freeze-thaw stability. Further exploration of physical properties indicated that the combination of DAG and PGPR dramatically improved the emulsion's viscoelasticity and obtained a larger deformation yield. Water droplets in DAG-based emulsions acted as active fillers to improve the network rigidity. Therefore, DAG is a promising material to be used as emulsifier to enhance the physical stability of W/O emulsions.
    Matched MeSH terms: Diglycerides/chemistry*; Emulsions/chemistry*; Glycerol/chemistry; Ricinoleic Acids/chemistry; Water/chemistry
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