Displaying publications 261 - 280 of 318 in total

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  1. Encapsulation of Ethylene Gas into Granular Cold-Water-Soluble Starch: Structure and Release Kinetics
    Shi L, Fu X, Tan CP, Huang Q, Zhang B
    J Agric Food Chem, 2017 Mar 15;65(10):2189-2197.
    PMID: 28215072 DOI: 10.1021/acs.jafc.6b05749
    Ethylene gas was introduced into granular cold-water-soluble (GCWS) starches using a solid encapsulation method. The morphological and structural properties of the novel inclusion complexes (ICs) were characterized using scanning electron microscopy, X-ray diffractometry, and Raman spectroscopy. The V-type single helix of GCWS starches was formed through controlled gelatinization and ethanol precipitation and was approved to host ethylene gas. The controlled release characteristics of ICs were also investigated at various temperature and relative humidity conditions. Avrami's equation was fitted to understand the release kinetics and showed that the release of ethylene from the ICs was accelerated by increasing temperature or RH and was decelerated by increased degree of amylose polymerization. The IC of Hylon-7 had the highest ethylene concentration (31.8%, w/w) among the five starches, and the IC of normal potato starch showed the best controlled release characteristics. As a renewable and inexpensive material, GCWS starch is a desirable solid encapsulation matrix with potential in agricultural and food applications.
    Matched MeSH terms: Spectrum Analysis, Raman
  2. Enzyme-Mimic Peptide Assembly To Achieve Amidolytic Activity
    Wong YM, Masunaga H, Chuah JA, Sudesh K, Numata K
    Biomacromolecules, 2016 Oct 10;17(10):3375-3385.
    PMID: 27642764
    Amyloid fibers are classified as a new generation of tunable bionanomaterials that exhibit new functions related to their distinctive characteristics, such as their universality, tunability, and stiffness. Here, we introduce the catalytic residues of serine protease into a peptide catalyst (PC) via an enzyme-mimic approach. The rational design of a repeating pattern of polar and nonpolar amino acids favors the conversion of the peptides into amyloid-like fibrils via self-assembly. Distinct fibrous morphologies have been observed at different pH values and temperatures, which indicates that different fibril packing schemes can be designed; hence, fibrillar peptides can be used to generate efficient artificial catalysts for amidolytic activities at mild pH values. The results of atomic force microscopy, Raman spectroscopy, and wide-angle X-ray scattering analyses are used to discuss and compare the fibril structure of a fibrillar PC with its amidolytic activity. The pH of the fibrillation reaction crucially affects the pKa of the side chains of the catalytic triads and is important for stable fibril formation. Temperature is another important parameter that controls the self-assembly of peptides into highly stacked and laminated morphologies. The morphology and stability of fibrils are crucial and represent important factors for demonstrating the capability of the peptides to exert amidolytic activity. The observed amidolytic activity of PC4, one of the PCs, was validated using an inhibition assay, which revealed that PC4 can perform enzyme-like amidolytic catalysis. These results provide insights into the potential use of designed peptides in the generation of efficient artificial enzymes.
    Matched MeSH terms: Spectrum Analysis, Raman
  3. Fulltext A rapid inhibitive enzyme assay for monitoring heavy metals pollution in the Juru Industrial Estate
    Halmi, M.I.E., Baskaran Gunasekaran, Othman, A.R., Shukor, M.Y., Kamaruddin, K., Dahalan, F.A., et al.
    Bioremediation Science and Technology Research, 2015;3(2):7-12.
    MyJurnal
    The volume of contaminated rivers in Malaysia continues to keep rising through the years. The
    cost of instrumental monitoring is uneconomical and prohibits schedule monitoring of
    contaminants particularly heavy metals. In this work, a rapid enzyme assay utilizing the
    molybdenum-reducing enzyme as an inhibitive assay, prepared in crude form from the
    molybdenum-reducing bacterium Serratia sp. strain DRY5 has been developed for monitoring
    the heavy metals mercury, silver, copper and chromium in contaminated waters in the Juru
    Industrial Estate. The crude enzyme extract transformed soluble molybdenum
    (phosphomolybdate) into a deep blue solution, which is inhibited by heavy metals such as
    mercury, silver, copper and chromium. The IC50 and Limits of Detection (LOD) values for
    mercury, copper, silver and cadmium were 0.245, 0.298, 0.367, 0.326, and 0.124, 0.086, 0.088
    and 0.094 mg L-1, respectively. The assay is rapid, and can be carried out in less than 10 minutes.
    In addition, the assay can be carried out at ambient temperature. The IC50 values for these heavy
    metals are more sensitive than several established assays. Water samples from various locations
    in the month of November from the Juru Industrial Estate (Penang) were tested for the presence
    of heavy metals using the developed assay. Enzyme activity was nearly inhibited for water
    samples from several locations. The presence of heavy metals was confirmed instrumentally
    using Atomic Emission Spectrometry and a Flow Injection Mercury System. The assay is rapid
    and simple and can be used as a first screening method for large scale monitoring of heavy
    metals.
    Matched MeSH terms: Spectrum Analysis
  4. Electrochemical exfoliation of graphite in nanofibrillated kenaf cellulose (NFC)/surfactant mixture for the development of conductive paper
    Ardyani T, Mohamed A, Abu Bakar S, Sagisaka M, Umetsu Y, Hafiz Mamat M, et al.
    Carbohydr Polym, 2020 Jan 15;228:115376.
    PMID: 31635739 DOI: 10.1016/j.carbpol.2019.115376
    The effect of incorporating common dodecyl anionic and cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), dodecylethyldimethylammonium bromide (DDAB), and sodium dodecylsulfate (SDS) in nanocomposites of reduced graphene oxide and nanocellulose are described. The stabilization and electrical properties of the nanocomoposites of reduced graphene oxide (RGO) and nanofibrillated kenaf cellulose (NFC) were characterized using four-point probe electrical conductivity measurements. Raman spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy were used to investigate dispersion morphology and the quality of RGO inside the NFC matrices. Small-angle neutron scattering (SANS) was used to study the aggregation behavior of the aqueous surfactant systems and RGO dispersions. The cationic surfactant DTAB proved to be the best choice for stabilization of RGO in NFC, giving enhanced electrical conductivity five orders of magnitude higher than the neat NFC. The results highlight the effects of hydrophilic surfactant moieties on the structure, stability and properties of RGO/NFC composites.
    Matched MeSH terms: Spectrum Analysis, Raman
  5. Ultrasound-assisted weak-acid hydrolysis of crystalline starch nanoparticles for chemical enhanced oil recovery
    Agi A, Junin R, Arsad A, Abbas A, Gbadamosi A, Azli NB, et al.
    Int J Biol Macromol, 2020 Apr 01;148:1251-1271.
    PMID: 31760018 DOI: 10.1016/j.ijbiomac.2019.10.099
    Ascorbic acid was used for the first time to synthesize crystalline starch nanoparticles (CSNP). The physical properties of the CSNP were investigated. Rheological properties of the crystalline starch nanofluid (CSNF) were compared with native cassava starch (CS) and commercial polymer xanthan. Interfacial properties of the CSNF at the interface of oil and water (O/W) were investigated at different concentrations and temperatures. Wettability alteration efficiency of CSNF on oil-wet sandstone surface was investigated using the sessile drop method. Core flooding experiment was conducted at reservoir conditions. The methods were effective in producing spherical and polygonal nanoparticles with a mean diameter of 100 nm and increased in crystallinity of 7%. Viscosity increased with increase in surface area and temperature of the CSNF compared to a decrease in viscosity as the temperature increases for xanthan. Interfacial tension (IFT) decreased with increase in concentration of CSNF, electrolyte and temperature. The results show that CSNF can change the wettability of sandstone at low concentration, high salinity and elevated temperature. Pressure drops data shows stability of CSNF at 120 °C. The formation of oil bank was enough to increase oil recovery by 23%.
    Matched MeSH terms: Spectrum Analysis
  6. Fulltext UV-visible chemometrics approach for the determination of selected adulterants in claimed premixed coffee
    Muhammad Zul Fayyadh Azizo Rahman, Chong, Hui Wen, Lim, Vuanghao
    Malaysian Journal of Medicine and Health Sciences, 2018;14(102):1-6.
    MyJurnal
    Adulterated premixed coffees have turned into an issue in Malaysia lately and have caught the eye of the authorities due to death reports linked to these products. The major cause of this issue is reported that these premixed coffees have passed food inspection test and eventually released to the market for public consumption. These coffees were claimed to be spiked with several sexual enhancers like sildenafil, tadalafil, and vardenafill, which are common drugs used to treat erectile dysfunction. Methods: Chemometrics approach using UV-Vis spectroscopy was developed to detect the selected sexual enhancer drugs found in commercial coffees by employing SIMCA-P software for the multivariate statistical analysis. Seven brands of coffee samples were purchased from local stores, and 30 sachets each were tested, hence totalling to 210 samples. Each sample was named H, J, G, W, N, T, and K, respectively. Results: Three multivariate models were generated, namely principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and partial least squares discriminant analysis (PLS-DA). OPLS-DA was selected as the best model for the overall results as it displayed minimal discriminate. Sildenafil, tadalafil, and vardenafil were detected in sample H, while vardenafil in brand J, and none in samples G, W, N, T, and K. Conclusion: OPLS-DA analysis showed discrimination for the sexual enhancer drugs in two brands of premixed coffee. The UV-Vis spectroscopy-based chemometrics method proved to be reliable and efficient in determining the selected drugs, as well as in saving time and cost.
    Matched MeSH terms: Spectrum Analysis
  7. Characterization of natural fiber obtained from different parts of date palm tree (Phoenix dactylifera L.)
    Alotaibi MD, Alshammari BA, Saba N, Alothman OY, Sanjay MR, Almutairi Z, et al.
    Int J Biol Macromol, 2019 Aug 15;135:69-76.
    PMID: 31116962 DOI: 10.1016/j.ijbiomac.2019.05.102
    The current study is motivated by the strict environmental regulations regarding the utilization and consumption of ecofriendly materials. In this context, the aim of this study has been to prepare and characterize different date palm tree (Phoenix dactylifera L.) fibers processed through the conventional water retting method. The chemical, elemental, crystallinity, thermal and morphological characterization of trunk (DPTRF), leaf stalk (DPLST), sheath or leaf sheath (DPLSH) and fruit bunch stalk (DPFBS) fibers was carried out. Chemical analysis revealed that the four types of date palm fibers display noteworthy differences in the content of cellulose, hemicellulose and lignin. Also, the amount of calcium is relatively high in all the date palm fibers; besides this, DPTRF exhibited 69.2% crystallinity, which is lower than that of DPLSH with 72.4% crystallinity. Moreover, DPLST and DPFBS fibers are more thermally stable (higher thermal degradation temperature) than DPTRF and DPLSH samples. Morphological analysis revealed that the fracture surface of DPFBS was relatively rougher, which would probably lead to increased bonding strength with polymers in composites. Overall, we conclude that DPFBS would be promising alternative sustainable and biomass material for the isolation of respective cellulose nanofibers and cellulose nanocrystals as potential reinforcement in polymer composites.
    Matched MeSH terms: Spectrum Analysis
  8. Silylation of TEMPO oxidized nanocellulose from oil palm empty fruit bunch by 3-aminopropyltriethoxysilane
    Indarti E, Marwan, Rohaizu R, Wanrosli WD
    Int J Biol Macromol, 2019 Aug 15;135:106-112.
    PMID: 31128174 DOI: 10.1016/j.ijbiomac.2019.05.161
    Silylated cellulose has been successfully synthesized using TEMPO-oxidized nanocellulose (TEMPO-NC) from oil palm empty fruit bunch and 3-aminopropyltriethoxysilane (APS) in an ethanol/water medium at a low curing temperature of 40 °C as compared to those reported in the literature of above 100 °C. Confirmation of the grafting process can be seen from the new FTIR peaks at 810 cm-1 and 749 cm-1 which are attributed to the SiC stretching and SiC, and new 13C NMR signals at 10.3, 21.7 and 42.7 ppm which are assigned to C7, C8, and C9 of the silylated TEMPO-NC. The decrease in the intensities of the cellulose peaks of C2, C3, C6 and C6' in the 13C NMR indicates that silylation not only occurs on the hydroxyls, but more importantly on the TEMPO-NC carboxylic moiety of C6', which is postulated as being the primary factor for this successful modification. This is further corroborated by the emergence of three signals at 43, 61, and 69 ppm in the 29Si NMR spectrum which corresponds to Si(OSi)(OR)2R', Si(OSi)2(OR)R', and Si(OSi)3R' units respectively. Additional evidence is provided by the EDX which shows an increase in Si weight percent of 1.94 after reaction. This silylated cellulose from OPEFB has the potentials to be used as bionanocomposite reinforcing elements.
    Matched MeSH terms: Spectrum Analysis
  9. Fulltext Doxorubicin Loading on Functional Graphene as a Promising Nanocarrier Using Ternary Deep Eutectic Solvent Systems
    Zainal-Abidin MH, Hayyan M, Ngoh GC, Wong WF
    ACS Omega, 2020 Jan 28;5(3):1656-1668.
    PMID: 32010840 DOI: 10.1021/acsomega.9b03709
    The application of graphene in the field of drug delivery has attracted massive interest among researchers. However, the high toxicity of graphene has been a drawback for its use in drug delivery. Therefore, to enhance the biocompatibility of graphene, a new route was developed using ternary natural deep eutectic solvents (DESs) as functionalizing agents, which have the capability to incorporate various functional groups and surface modifications. Physicochemical characterization analyses, including field emission scanning electron microscope, fourier-transform infrared spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller, X-ray diffraction, and energy dispersive X-ray, were used to verify the surface modifications introduced by the functionalization process. Doxorubicin was loaded onto the DES-functionalized graphene. The results exhibited significantly improved drug entrapment efficiency (EE) and drug loading capacity (DLC) compared with pristine graphene and oxidized graphene. Compared with unfunctionalized graphene, functionalization with DES choline chloride (ChCl):sucrose:water (4:1:4) resulted in the highest drug loading capacity (EE of 51.84% and DLC of 25.92%) followed by DES ChCl:glycerol:water (1:2:1) (EE of 51.04% and DLC of 25.52%). Following doxorubicin loading, graphene damaged human breast cancer cell line (MCF-7) through the generation of intracellular reactive oxygen species (>95%) and cell cycle disruption by increase in the cell population at S phase and G2/M phase. Thus, DESs represent promising green functionalizing agents for nanodrug carriers. To the best of our knowledge, this is the first time that DES-functionalized graphene has been used as a nanocarrier for doxorubicin, illustrating the potential application of DESs as functionalizing agents in drug delivery systems.
    Matched MeSH terms: Spectrum Analysis, Raman
  10. Degradation of methyl orange and congo red by using chitosan/polyvinyl alcohol/TiO2 electrospun nanofibrous membrane
    Habiba U, Lee JJL, Joo TC, Ang BC, Afifi AM
    Int J Biol Macromol, 2019 Jun 15;131:821-827.
    PMID: 30904531 DOI: 10.1016/j.ijbiomac.2019.03.132
    In this study, chitosan/polyvinyl alcohol/TiO2 nanofiber was fabricated via electrospinning at a pump rate of 1.5 mL/h and voltage 6 kV. Field-emission scanning electron microscopic images showed bead free finer nanofiber. Fourier transform infrared spectra proved the formation of strong bond among chitosan, polyvinyl alcohol and TiO2. X-ray powder diffraction showed that TiO2 became amorphous in the composite nanofiber. Toughness and thermal stability of the chitosan/PVA nanofibrous membrane was increased with addition TiO2. The chitosan/PVA/TiO2 nanofibrous membrane was stable at basic medium. But degraded in acidic and water medium after 93 and 162 h, respectively. The adsorption mechanism of congo red obeyed the Langmuir isotherm model. On the other hand, adsorption characteristic of methyl orange fitted well with both Langmuir and Freundlich isotherm models. The maximum adsorption capacity of the resulting membrane for congo red and methyl orange is 131 and 314 mg/g, respectively. However, a high dose of adsorbent was required for congo red.
    Matched MeSH terms: Spectrum Analysis
  11. Environmental evaluation and nano-mineralogical study of fresh and unsaturated weathered coal fly ashes
    Akinyemi SA, Gitari WM, Petrik LF, Nyakuma BB, Hower JC, Ward CR, et al.
    Sci Total Environ, 2019 May 01;663:177-188.
    PMID: 30711584 DOI: 10.1016/j.scitotenv.2019.01.308
    Coal combustion and the disposal of combustion wastes emit enormous quantities of nano-sized particles that pose significant health concerns on exposure, particularly in unindustrialized countries. Samples of fresh and weathered class F fly ash were analysed through various techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), field-emission gun scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM) coupled with energy dispersive x-ray spectroscopy (EDS), and Raman Spectroscopy. The imaging techniques showed that the fresh and weathered coal fly ash nanoparticles (CFA-NPs) are mostly spherical shaped. The crystalline phases detected were quartz, mullite, ettringite, calcite, maghemite, hematite, gypsum, magnetite, clay residues, and sulphides. The most abundant crystalline phases were quartz mixed with Al-Fe-Si-K-Ti-O-amorphous phases whereas mullite was detected in several amorphous phases of Al, Fe, Ca, Si, O, K, Mg, Mn, and P. The analyses revealed that CFA-NPs are 5-500 nm in diameter and encapsulate several potentially hazardous elements (PHEs). The carbon species were detected as 5-50 nm carbon nanoballs of graphitic layers and massive fullerenes. Lastly, the aspects of health risks related to exposure to some detected ambient nanoparticles are also discussed.
    Matched MeSH terms: Spectrum Analysis, Raman
  12. Synthesis and characterization of interpenetrating polymeric networks based bio-composite alginate film: A well-designed drug delivery platform
    Ghosal K, Das A, Das SK, Mahmood S, Ramadan MAM, Thomas S
    Int J Biol Macromol, 2019 Jun 01;130:645-654.
    PMID: 30797807 DOI: 10.1016/j.ijbiomac.2019.02.117
    This study aimed to develop and characterize the calcium alginate films loaded with diclofenac sodium and other hydrophilic polymers with different degrees of cross-linking obtained by external gelation process. To the formed films different physicochemical evaluation were performed which showed an initial character of the films. The films produced by this external gelation process were found thicker (0.031-0.038 mm) and stronger (51.9-52.9 MPa) but less elastic (2.3%) than those non-cross-linked films (0.029 mm; 39.7 MPa; 4.4%). The lower water vapor permeability (WVP) values of the films were obtained where maximum level of crosslinking occurs. Composite films can be cross-linked in presence of external crosslinking agent to improve the quality of the produced matrices for various uses. The characterization of the film was performed using Differential Scanning Calorimetry (DSC) and Fourier-Transform Infrared Spectroscopy (FT-IR) analysis. The Scanning Electron Microscopy (SEM) study showed the morphology of treated composite films. The kinetic release studies showed a sustained release of the drug from the formulated films as it can be prolonged in composite film. The prepared biodegradable Ca-Alginate bio-composite film may be of clinical importance for its therapeutic benefit.
    Matched MeSH terms: Spectrum Analysis
  13. Superabsorbent hydrogel from oil palm empty fruit bunch cellulose and sodium carboxymethylcellulose
    Salleh KM, Zakaria S, Sajab MS, Gan S, Kaco H
    Int J Biol Macromol, 2019 Jun 15;131:50-59.
    PMID: 30844455 DOI: 10.1016/j.ijbiomac.2019.03.028
    A green regenerated superabsorbent hydrogel was fabricated with mixtures of dissolved oil palm empty fruit bunch (EFB) cellulose and sodium carboxymethylcellulose (NaCMC) in NaOH/urea system. The formation of hydrogel was aided with epichlorohydrin (ECH) as a crosslinker. The resultant regenerated hydrogel was able to swell >80,000% depending on the NaCMC concentrations. The hydrogel absorbed water rapidly upon exposure to water up to 48 h and gradually declined after 72 h. The crosslinked of covalent bond of COC between dissolved EFB cellulose (EFBC) with NaCMC was confirmed with Attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. Crystallinity and thermal stability of the hydrogel samples were depended on the concentrations of NaCMC, crosslinking, and swelling process. The strength and stability of crosslinked network was studied by examining the gel fraction of hydrogel. This study explored the swelling ability and probable influenced factors towards physical and chemical properties of hydrogel.
    Matched MeSH terms: Spectrum Analysis
  14. Graphene oxide and gold nanoparticle based dual platform with short DNA probe for the PCR free DNA biosensing using surface-enhanced Raman scattering
    Khalil I, Yehye WA, Julkapli NM, Rahmati S, Sina AA, Basirun WJ, et al.
    Biosens Bioelectron, 2019 Apr 15;131:214-223.
    PMID: 30844598 DOI: 10.1016/j.bios.2019.02.028
    Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field 'hot spot', formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer.
    Matched MeSH terms: Spectrum Analysis, Raman
  15. Surfactants with aromatic headgroups for optimizing properties of graphene/natural rubber latex composites (NRL): Surfactants with aromatic amine polar heads
    Ardyani T, Mohamed A, Bakar SA, Sagisaka M, Umetsu Y, Mamat MH, et al.
    J Colloid Interface Sci, 2019 Jun 01;545:184-194.
    PMID: 30878784 DOI: 10.1016/j.jcis.2019.03.012
    HYPOTHESIS: The compatibility of surfactants and graphene surfaces can be improved by increasing the number of aromatic groups in the surfactants. Including aniline in the structure may improve the compatibility between surfactant and graphene further still. Surfactants can be modified by incorporating aromatic groups in the hydrophobic chains or hydrophilic headgroups. Therefore, it is of interest to investigate the effects of employing anilinium based surfactants to disperse graphene nanoplatelets (GNPs) in natural rubber latex (NRL) for the fabrication of electrically conductive nanocomposites.

    EXPERIMENTS: New graphene-philic surfactants carrying aromatic moieties in the hydrophilic headgroups and hydrophobic tails were synthesized by swapping the traditional sodium counterion with anilinium. 1H NMR spectroscopy was used to characterize the surfactants. These custom-made surfactants were used to assist the dispersion of GNPs in natural rubber latex matrices for the preparation of conductive nanocomposites. The properties of nanocomposites with the new anilinium surfactants were compared with commercial sodium surfactant sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and the previously synthesized aromatic tri-chain sodium surfactant TC3Ph3 (sodium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate). Structural properties of the nanocomposites were studied using Raman spectroscopy, field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). Electrical conductivity measurements and Zeta potential measurements were used to assess the relationships between total number of aromatic groups in the surfactant molecular structure and nanocomposite properties. The self-assembly structure of surfactants in aqueous systems and GNP dispersions was assessed using small-angle neutron scattering (SANS).

    FINDINGS: Among these different surfactants, the anilinium version of TC3Ph3 namely TC3Ph3-AN (anilinium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate) was shown to be highly efficient for dispersing GNPs in the NRL matrices, increasing electrical conductivity eleven orders of magnitude higher than the neat rubber latex. Comparisons between the sodium and anilinium surfactants show significant differences in the final properties of the nanocomposites. In general, the strategy of increasing the number of surfactant-borne aromatic groups by incorporating anilinium ions in surfactant headgroups appears to be effective.

    Matched MeSH terms: Spectrum Analysis, Raman
  16. Fulltext Fabrication of Si Micropore and Graphene Nanohole Structures by Focused Ion Beam
    Md Ibrahim NNN, Hashim AM
    Sensors (Basel), 2020 Mar 12;20(6).
    PMID: 32178225 DOI: 10.3390/s20061572
    A biosensor formed by a combination of silicon (Si) micropore and graphene nanohole technology is expected to act as a promising device structure to interrogate single molecule biopolymers, such as deoxyribonucleic acid (DNA). This paper reports a novel technique of using a focused ion beam (FIB) as a tool for direct fabrication of both conical-shaped micropore in Si3N4/Si and a nanohole in graphene to act as a fluidic channel and sensing membrane, respectively. The thinning of thick Si substrate down to 50 µm has been performed prior to a multi-step milling of the conical-shaped micropore with final pore size of 3 µm. A transfer of graphene onto the fabricated conical-shaped micropore with little or no defect was successfully achieved using a newly developed all-dry transfer method. A circular shape graphene nanohole with diameter of about 30 nm was successfully obtained at beam exposure time of 0.1 s. This study opens a breakthrough in fabricating an integrated graphene nanohole and conical-shaped Si micropore structure for biosensor applications.
    Matched MeSH terms: Spectrum Analysis, Raman
  17. Thermoluminescence response of X-ray irradiated commercial chalk
    Almugren KS, Sani SFA, Wandira R, Wahib N, Rozaila ZS, Khandaker MU, et al.
    Appl Radiat Isot, 2019 Sep;151:102-110.
    PMID: 31163392 DOI: 10.1016/j.apradiso.2019.04.027
    Present research concerns the TL signal stored in chalk of the variety commercially available for writing on blackboards. Samples of this have been subjected to x-ray irradiation, the key dosimetric parameters investigated including dose and energy response, sensitivity, fading and glow curve analysis. Three types of chalk have been investigated, each in five different colours. The samples were annealed at 323 K prior to irradiation. For all three chalk types and all five colours, the dose response has been found linear over the investigated dose range, 0-9 Gy. Regardless of type or colour, photoelectric energy dependency is apparent at the low energy end down to the lowest investigated accelerating potential of 30 kV. Crayola (Yellow) has shown the greatest TL sensitivity, thus selection has been made to limit further analysis to this medium alone, specifically in respect of glow curve and fading study. In addition, elemental compositional and structural change characterizations were made for the same medium, utilizing Energy Dispersive X-Ray (EDX) and Raman spectroscopy, respectively.
    Matched MeSH terms: Spectrum Analysis, Raman
  18. Poly(lactic acid)/poly(butylene succinate) dual-layer membranes with cellulose nanowhisker for heavy metal ion separation
    Kian LK, Jawaid M, Nasef MM, Fouad H, Karim Z
    Int J Biol Macromol, 2021 Dec 01;192:654-664.
    PMID: 34655581 DOI: 10.1016/j.ijbiomac.2021.10.042
    In this study, poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) dual-layer membranes filled with 0-3 wt% cellulose nanowhisker (CNWs) were fabricated with aim to remove metal ions from wastewater. An integrated method was employed in the membrane fabrication process by combining water vapor-induced and crystallization-induced phase inversions. The membrane thickness was measured in between 11 and 13 μm, which did not pose significant flux deviation during filtration process. The 3% CNW filled membrane showed prominent and well-laminated two layers structure. Meanwhile, the increase in CNWs from 0 to 3% loadings could improve the membrane porosity (43-74%) but reducing pore size (2.45-0.54 μm). The heat resistance of neat membrane enhanced by 1% CNW but decreased with loadings of 2-3% CNWs due to flaming behavior of sulphated nanocellulose. Membrane with 3% CNW displayed the tensile strength (23.5 MPa), elongation at break (7.1%), and Young's modulus (0.75 GPa) as compared to other samples. For wastewater filtration performance, the continuous operation test showed that 3% CNW filled membrane exhibited the highest removal efficiency for both cobalt and nickel metal ions reaching to 83% and 84%, respectively. We concluded that CNWs filled dual-layer membranes have potential for future development in the removal of heavy metal ions from wastewater streams.
    Matched MeSH terms: Spectrum Analysis
  19. Alkaloids from leaves and stem bark of Ervatamia corymbosa
    Zèches M, Mesbah K, Loukaci A, Richard B, Schaller H, Sévenet T, et al.
    Planta Med, 1995 Feb;61(1):97.
    PMID: 7701009
    Matched MeSH terms: Spectrum Analysis
  20. Fulltext Utilization of Carica papaya latex on coating of SPIONs for dye removal and drug delivery
    Samrot AV, Saigeetha S, Mun CY, Abirami S, Purohit K, Cypriyana PJJ, et al.
    Sci Rep, 2021 12 31;11(1):24511.
    PMID: 34972829 DOI: 10.1038/s41598-021-03328-2
    Latex, a milky substance found in a variety of plants which is a natural source of biologically active compounds. In this study, Latex was collected from raw Carica papaya and was characterized using UV-Vis, FTIR and GC-MS analyses. Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) were synthesized, coated with C. papaya latex (PL-Sp) and characterized using UV-Vis, FT-IR, SEM-EDX, XRD, VSM and Zeta potential analyses. SPIONs and latex coated SPIONs (PL-Sp) were used in batch adsorption study for effective removal of Methylene blue (MB) dye, where (PL-Sp) removed MB dye effectively. Further the PL-Sp was used to produce a nanoconjugate loaded with curcumin and it was characterized using UV-Vis spectrophotometer, FT-IR, SEM-EDX, XRD, VSM and Zeta potential. It showed a sustained drug release pattern and also found to have good antibacterial and anticancer activity.
    Matched MeSH terms: Spectrum Analysis
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