Displaying publications 1 - 20 of 108 in total

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  1. Salleh A, Zainuddin ZZ, Tarmizi RMM, Yap CK, Jeng CR, Zamri-Saad M
    Animals (Basel), 2021 Apr 20;11(4).
    PMID: 33923894 DOI: 10.3390/ani11041173
    An adult female Sumatran rhinoceros was observed with a swelling in the left infraorbital region in March 2017. The swelling rapidly grew into a mass. A radiograph revealed a cystic radiolucent area in the left maxilla. In June 2017, the rhinoceros was euthanized. At necropsy, the infraorbital mass measured 21 cm × 30 cm. Samples of the infraorbital mass, left parotid gland, and left masseter muscle were collected for histopathology (Hematoxylin & Eosin, Von Kossa, Masson's trichrome, cytokeratin AE1/AE3, EMA, p53, and S-100). Numerous neoplastic epithelial cells showing pleomorphism and infiltration were observed. Islands of dentinoid material containing ghost cells and keratin pearls were observed with the aid of the two special histochemistry stains. Mitotic figures were rarely observed. All the neoplastic odontogenic cells and keratin pearls showed an intense positive stain for cytokeratin AE1/AE3, while some keratin pearls showed mild positive stains for S-100. All samples were negative for p53 and S-100 immunodetection. The mass was diagnosed as a dentinogenic ghost cell tumor.
  2. Aldurrah Z, Mohd Kauli FS, Abdul Rahim N, Zainal Z, Afzan A, Al Zarzour RH, et al.
    PMID: 37301417 DOI: 10.1016/j.cbpc.2023.109678
    Andrographis paniculata (A. paniculata) showed an anti-depressive effect in rodent models. Zebrafish has recently emerged as a worthy complementary translational model for antidepressant drug discovery study. This study investigates the anti-depressive effect of A. paniculata extract and andrographolide in the chronic unpredictable stress (CUS)- zebrafish model. Four groups of zebrafish (n = 10/group), i.e. control, CUS (stressed, untreated), CUS + A. paniculata (100 mg/L) and CUS + fluoxetine (0.01 mg/L) were assessed in open-field and social interaction tests, 24 h after treatment. After extract screening, behavioural and cortisol analysis of andrographolide (5, 25 and 50 mg/kg, i.p.) and fluoxetine (10 mg/kg, i.p.) were evaluated. Before the behavioural study, acute toxicity and characterization of A. paniculata extract using UHPLC-ESI-MS/MS were performed. A significant reduction in freezing duration was found in A. paniculata- (t-test, p = 0.0234) and fluoxetine-treated groups (t-test, p 
  3. Taufiq-Yap, Y. H., Ong, P. S., Zainal, Z.
    MyJurnal
    In this work, 10 mol% yttrium-doped ceria powders, Ce0.9Y0.1O1.95, were synthesised using a new mechanical technique, mechanochemical reaction, in which both impact action and shearing forces were applied for efficient fine grinding, subsequently leading to higher homogeneity of the resultant powders. Ce0.9Y0.1O1.95 prepared using this new technique was systematically compared with a sample of the same prepared using conventional solid-state methodology. X-ray diffraction analysis showed all prepared samples were single phase with a cubic fluorite structure. Generally, Y2O3-doped CeO2 electrolytes prepared by mechanochemical reactions were stable at a lower temperature (1100 °C) compared with a sample of the same synthesised using the conventional solid-state method. Characterisations using differential thermal analysis (DTA) and thermogravimetric analysis (TGA) showed no thermal changes and phase transitions, indicating all materials were thermally stable. The electrical properties of the samples investigated by AC impedance spectroscopy in the temperature range 200–800 ˚C are presented and discussed. Scanning electron microscopy (SEM) was used to study the morphology of the materials. Fine-grained powders with uniform grain-size distribution were obtained from the mechanochemical reaction.
  4. Anis S, Zainal ZA
    Bioresour Technol, 2014 Jan;151:183-90.
    PMID: 24231266 DOI: 10.1016/j.biortech.2013.10.065
    Kinetic model parameters for toluene conversion under microwave thermocatalytic treatment were evaluated. The kinetic rate constants were determined using integral method based on experimental data and coupled with Arrhenius equation for obtaining the activation energies and pre-exponential factors. The model provides a good agreement with the experimental data. The kinetic model was also validated with standard error of 3% on average. The extrapolation of the model showed a reasonable trend to predict toluene conversion and product yield both in thermal and catalytic treatments. Under microwave irradiation, activation energy of toluene conversion was lower in the range of 3-27 kJ mol(-1) compared to those of conventional heating reported in the literatures. The overall reaction rate was six times higher compared to conventional heating. As a whole, the kinetic model works better for tar model removal in the absence of gas reforming within a level of reliability demonstrated in this study.
  5. Anis S, Zainal ZA
    Bioresour Technol, 2013 Dec;150:328-37.
    PMID: 24185417 DOI: 10.1016/j.biortech.2013.10.010
    This study focused on improving the producer gas quality using radio frequency (RF) tar thermocatalytic treatment reactor. The producer gas containing tar, particles and water was directly passed at a particular flow rate into the RF reactor at various temperatures for catalytic and thermal treatments. Thermal treatment generates higher heating value of 5.76 MJ Nm(-3) at 1200°C. Catalytic treatments using both dolomite and Y-zeolite provide high tar and particles conversion efficiencies of about 97% on average. The result also showed that light poly-aromatic hydrocarbons especially naphthalene and aromatic compounds particularly benzene and toluene were still found even at higher reaction temperatures. Low energy intensive RF tar thermocatalytic treatment was found to be effective for upgrading the producer gas quality to meet the end user requirements and increasing its energy content.
  6. Yeoh KH, Shafie SA, Al-Attab KA, Zainal ZA
    Bioresour Technol, 2018 Oct;265:365-371.
    PMID: 29925052 DOI: 10.1016/j.biortech.2018.06.024
    In this study, three different methods for high quality solid fuel production were tested and compared experimentally. Oil palm empty fruit bunches, mesocarp fibers, palm kernel shells and rubber seeds shells were treated using thermal (TC), hydrothermal (HTC) and vapothermal (VTC) carbonization. All thermochemical methods were accomplished by using a custom made batch-type reactor. Utilization of novel single reactor equipped with suspended internal container provided efficient operation since both steam generator and raw materials were placed inside the same reactor. Highest energy densification was achieved by VTC process followed by TC and HTC processes. The heating value enhancement in VTC and TC was achieved by the increase in fixed carbon content and reduction in volatile matter. The formation of the spherical components in HTC hydrochar which gave a sharp peak at 340 °C in the DTG curves was suggested as the reason that led to the increment in energy content.
  7. Hussein MZ, Jaafar AM, Yahaya AH, Masarudin MJ, Zainal Z
    Int J Mol Sci, 2014;15(11):20254-65.
    PMID: 25380526 DOI: 10.3390/ijms151120254
    Multi-walled carbon nanotubes (MWCNTs) were prepared via chemical vapor deposition (CVD) using a series of different catalysts, derived from FeCoNiAl, CoNiAl and FeNiAl layered double hydroxides (LDHs). Catalyst-active particles were obtained by calcination of LDHs at 800 °C for 5 h. Nitrogen and hexane were used as the carrier gas and carbon source respectively, for preparation of MWCNTs using CVD methods at 800 °C. MWCNTs were allowed to grow for 30 min on the catalyst spread on an alumina boat in a quartz tube. The materials were subsequently characterized through X-ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, field emission scanning electron microscopy and transmission electron microscopy. It was determined that size and yield of MWCNTs varied depending on the type of LDH catalyst precursor that is used during synthesis. MWCNTs obtained using CoNiAl-LDH as the catalyst precursor showed smaller diameter and higher yield compared to FeCoNiAl and FeNiAl LDHs.
  8. Ee SF, Mohamed-Hussein ZA, Othman R, Shaharuddin NA, Ismail I, Zainal Z
    ScientificWorldJournal, 2014;2014:840592.
    PMID: 24678279 DOI: 10.1155/2014/840592
    Polygonum minus is an aromatic plant, which contains high abundance of terpenoids, especially the sesquiterpenes C15H24. Sesquiterpenes were believed to contribute to the many useful biological properties in plants. This study aimed to functionally characterize a full length sesquiterpene synthase gene from P. minus. P. minus sesquiterpene synthase (PmSTS) has a complete open reading frame (ORF) of 1689 base pairs encoding a 562 amino acid protein. Similar to other sesquiterpene synthases, PmSTS has two large domains: the N-terminal domain and the C-terminal metal-binding domain. It also consists of three conserved motifs: the DDXXD, NSE/DTE, and RXR. A three-dimensional protein model for PmSTS built clearly distinguished the two main domains, where conserved motifs were highlighted. We also constructed a phylogenetic tree, which showed that PmSTS belongs to the angiosperm sesquiterpene synthase subfamily Tps-a. To examine the function of PmSTS, we expressed this gene in Arabidopsis thaliana. Two transgenic lines, designated as OE3 and OE7, were further characterized, both molecularly and functionally. The transgenic plants demonstrated smaller basal rosette leaves, shorter and fewer flowering stems, and fewer seeds compared to wild type plants. Gas chromatography-mass spectrometry analysis of the transgenic plants showed that PmSTS was responsible for the production of β -sesquiphellandrene.
  9. Barahuie F, Hussein MZ, Fakurazi S, Zainal Z
    Int J Mol Sci, 2014;15(5):7750-86.
    PMID: 24802876 DOI: 10.3390/ijms15057750
    Layered hydroxides (LHs) have recently fascinated researchers due to their wide application in various fields. These inorganic nanoparticles, with excellent features as nanocarriers in drug delivery systems, have the potential to play an important role in healthcare. Owing to their outstanding ion-exchange capacity, many organic pharmaceutical drugs have been intercalated into the interlayer galleries of LHs and, consequently, novel nanodrugs or smart drugs may revolutionize in the treatment of diseases. Layered hydroxides, as green nanoreservoirs with sustained drug release and cell targeting properties hold great promise of improving health and prolonging life.
  10. Barahuie F, Hussein MZ, Hussein-Al-Ali SH, Arulselvan P, Fakurazi S, Zainal Z
    Int J Nanomedicine, 2013;8:1975-87.
    PMID: 23737666 DOI: 10.2147/IJN.S42718
    In the study reported here, magnesium/aluminum (Mg/Al)-layered double hydroxide (LDH) was intercalated with an anticancer drug, protocatechuic acid, using ion-exchange and direct coprecipitation methods, with the resultant products labeled according to the method used to produce them: "PANE" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the ion-exchange method) and "PAND" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the direct method), respectively. Powder X-ray diffraction and Fourier transform infrared spectroscopy confirmed the intercalation of protocatechuic acid into the inter-galleries of Mg/Al-LDH. The protocatechuic acid between the interlayers of PANE and PAND was found to be a monolayer, with an angle from the z-axis of 8° for PANE and 15° for PAND. Thermogravimetric and differential thermogravimetric analysis results revealed that the thermal stability of protocatechuic acid was markedly enhanced upon intercalation. The loading of protocatechuic acid in PANE and PAND was estimated to be about 24.5% and 27.5% (w/w), respectively. The in vitro release study of protocatechuic acid from PANE and PAND in phosphate-buffered saline at pH 7.4, 5.3, and 4.8 revealed that the nanocomposites had a sustained release property. After 72 hours incubation of PANE and PAND with MCF-7 human breast cancer and HeLa human cervical cancer cell lines, it was found that the nanocomposites had suppressed the growth of these cancer cells, with a half maximal inhibitory concentration of 35.6 μg/mL for PANE and 36.0 μg/mL for PAND for MCF-7 cells, and 19.8 μg/mL for PANE and 30.3 μg/mL for PAND for HeLa cells. No half maximal inhibitory concentration for either nanocomposite was found for 3T3 cells.
  11. Daud MN, Zakaria A, Jafari A, Ghazali MS, Abdullah WR, Zainal Z
    Int J Mol Sci, 2012;13(5):5706-14.
    PMID: 22754325 DOI: 10.3390/ijms13055706
    CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111) orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the CdTe film increased with the increase of CdTe concentration. The optical energy band gap of film decreased with the increase of CdTe concentration, and with the increase of isothermal bath temperature. The film thickness increased with respect to the increase of CdTe concentration and bath temperature, and following, the numerical expression for the film thickness with respect to these two variables has been established.
  12. Roslan ND, Yusop JM, Baharum SN, Othman R, Mohamed-Hussein ZA, Ismail I, et al.
    Int J Mol Sci, 2012;13(3):2692-706.
    PMID: 22489118 DOI: 10.3390/ijms13032692
    P. minus is an aromatic plant, the leaf of which is widely used as a food additive and in the perfume industry. The leaf also accumulates secondary metabolites that act as active ingredients such as flavonoid. Due to limited genomic and transcriptomic data, the biosynthetic pathway of flavonoids is currently unclear. Identification of candidate genes involved in the flavonoid biosynthetic pathway will significantly contribute to understanding the biosynthesis of active compounds. We have constructed a standard cDNA library from P. minus leaves, and two normalized full-length enriched cDNA libraries were constructed from stem and root organs in order to create a gene resource for the biosynthesis of secondary metabolites, especially flavonoid biosynthesis. Thus, large-scale sequencing of P. minus cDNA libraries identified 4196 expressed sequences tags (ESTs) which were deposited in dbEST in the National Center of Biotechnology Information (NCBI). From the three constructed cDNA libraries, 11 ESTs encoding seven genes were mapped to the flavonoid biosynthetic pathway. Finally, three flavonoid biosynthetic pathway-related ESTs chalcone synthase, CHS (JG745304), flavonol synthase, FLS (JG705819) and leucoanthocyanidin dioxygenase, LDOX (JG745247) were selected for further examination by quantitative RT-PCR (qRT-PCR) in different P. minus organs. Expression was detected in leaf, stem and root. Gene expression studies have been initiated in order to better understand the underlying physiological processes.
  13. Hussein MZ, Rahman NS, Sarijo SH, Zainal Z
    Int J Mol Sci, 2012;13(6):7328-42.
    PMID: 22837696 DOI: 10.3390/ijms13067328
    Herbicides, namely 4-(2,4-dichlorophenoxy) butyrate (DPBA) and 2-(3-chlorophenoxy) propionate (CPPA), were intercalated simultaneously into the interlayers of zinc layered hydroxide (ZLH) by direct reaction of zinc oxide with both anions under aqueous environment to form a new nanohybrid containing both herbicides labeled as ZCDX. Successful intercalation of both anions simultaneously into the interlayer gallery space of ZLH was studied by PXRD, with basal spacing of 28.7 Å and supported by FTIR, TGA/DTG and UV-visible studies. Simultaneous release of both CPPA and DPBA anions into the release media was found to be governed by a pseudo second-order equation. The loading and percentage release of the DPBA is higher than the CPPA anion, which indicates that the DPBA anion was preferentially intercalated into and released from the ZLH interlayer galleries. This work shows that layered single metal hydroxide, particularly ZLH, is a suitable host for the controlled release formulation of two herbicides simultaneously.
  14. Ebrahimiasl S, Yunus WM, Kassim A, Zainal Z
    Sensors (Basel), 2011;11(10):9207-16.
    PMID: 22163690 DOI: 10.3390/s111009207
    Nanocrystalline SnO(x) (x = 1-2) thin films were prepared on glass substrates by a simple chemical bath deposition method. Triethanolamine was used as complexing agent to decrease time and temperature of deposition and shift the pH of the solution to the noncorrosive region. The films were characterized for composition, surface morphology, structure and optical properties. X-ray diffraction analysis confirms that SnO(x) thin films consist of a polycrystalline structure with an average grain size of 36 nm. Atomic force microscopy studies show a uniform grain distribution without pinholes. The elemental composition was evaluated by energy dispersive X-ray spectroscopy. The average O/Sn atomic percentage ratio is 1.72. Band gap energy and optical transition were determined from optical absorbance data. The film was found to exhibit direct and indirect transitions in the visible spectrum with band gap values of about 3.9 and 3.7 eV, respectively. The optical transmittance in the visible region is 82%. The SnO(x) nanocrystals exhibit an ultraviolet emission band centered at 392 nm in the vicinity of the band edge, which is attributed to the well-known exciton transition in SnO(x). Photosensitivity was detected in the positive region under illumination with white light.
  15. Sarijo SH, Hussein MZ, Yahaya AH, Zainal Z
    J Hazard Mater, 2010 Oct 15;182(1-3):563-9.
    PMID: 20633986 DOI: 10.1016/j.jhazmat.2010.06.070
    The release of chlorophenoxyherbicides agrochemicals, namely 2-chloro- (2CPA), 4-chloro and 2,4,5-trichloro (TCPA) phenoxyacetates from their nanohybrids into various aqueous solutions; carbonate, sulfate and chloride was found to be controlled by pseudo-second order rate expression. The percentage saturated released was found to be anionic-dependent, in the order of carbonate>sulfate>chloride for the release media and 2CPA>4CPA>TCPA for the anionic guests. This study demonstrates that the release of the phenoxyherbicides agrochemicals from the nanohybrid compounds can be tuned by choosing the right combination of exchangeable anions both the incoming and the outgoing anions.
  16. Ong ST, Lee CK, Zainal Z
    Bioresour Technol, 2007 Nov;98(15):2792-9.
    PMID: 17400446
    Wastewaters from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. Rice hull, an agricultural by-product, was modified using ethylenediamine to introduce active sites on its surface to enable it to function as a sorbent for both basic and reactive dyes. The sorption characteristics of Basic Blue 3 (BB3) and Reactive Orange 16 (RO16) by ethylenediamine modified rice hull (MRH) were studied under various experimental conditions. Sorption was pH and concentration dependent. Simultaneous removal of BB3 and RO16 occurred at pH greater than 4. The kinetics of dye sorption fitted a pseudo-second order rate expression. Increase in agitation rate had no effect on the sorption of BB3 but increased uptake of RO16 on MRH. Decreasing particle size increased the uptake of dyes in binary dye solutions. Equilibrium data could be fitted into both the Langmuir and Freundlich isotherms. Maximum sorption capacities calculated from the Langmuir model are 14.68 and 60.24 mg/g for BB3 and RO16, respectively in binary dye solutions. This corresponds to an enhancement of 4.5 and 2.4 fold, respectively, compared to single dye solutions. MRH therefore has the potential of being used as an efficient sorbent for the removal of both dyes in textile wastewaters.
  17. Isha A, Yusof NA, Ahmad M, Suhendra D, Yunus WM, Zainal Z
    Spectrochim Acta A Mol Biomol Spectrosc, 2007 Aug;67(5):1398-402.
    PMID: 17141557
    Fatty hydroxamic acid (FHA) immobilized in polyvinyl chloride (PVC) has been studied as a sensor element of an optical fibre chemical sensor for V(V). By using this instrument, V(V) in solution has been determined in the log concentration range of 0-2.5 (i.e. 1.0-300 mg/L). The detection limit was 1.0 mg/L. The relative standard deviation (R.S.D.) of the method for the reproducibility study at V(V) concentration of 200 mg/L and 300 mg/L were calculated to be 2.9% and 2.0%, respectively. Interference from foreign ions was also studied at 1:1 mole ratio of V(V):foreign ions. It was found that, Fe(III) ion interfered most in the determination of vanadium(V). Excellent agreement with ICP-AES method was achieved when the proposed method was applied towards determination of V(V).
  18. Ee SF, Oh JM, Mohd Noor N, Kwon TR, Mohamed-Hussein ZA, Ismail I, et al.
    Mol Biol Rep, 2013 Mar;40(3):2231-41.
    PMID: 23187733 DOI: 10.1007/s11033-012-2286-4
    The importance of plant secondary metabolites for both mankind and the plant itself has long been established. However, despite extensive research on plant secondary metabolites, plant secondary metabolism and its regulation still remained poorly characterized. In this present study, cDNA-amplified fragment length polymorphism (cDNA-AFLP) transcript profiling was applied to generate the expression profiles of Polygonum minus in response to salicylic acid (SA) and methyl jasmonate (MeJA) elicitations. This study reveals two different sets of genes induced by SA and MeJA, respectively where stress-related genes were proved to lead to the expression of genes involved in plant secondary metabolite biosynthetic pathways. A total of 98 transcript-derived fragments (TDFs) were up-regulated, including 46 from SA-treated and 52 from MeJA-treated samples. The cDNA-AFLP transcripts generated using 64 different Mse1/Taq1 primer combinations showed that treatments with SA and MeJA induced genes mostly involved in scavenging reactive oxygen species, including zeaxanthin epoxidase, cytosolic ascorbate peroxidase 1 and peroxidase. Of these stress-related genes, 15 % of other annotated TDFs are involved mainly in secondary metabolic processes where among these, two genes encoding (+)-delta cadinene synthase and cinnamoyl-CoA reductase were highlighted.
  19. Tang PL, Lee CK, Low KS, Zainal Z
    Environ Technol, 2003 Oct;24(10):1243-51.
    PMID: 14669804
    The sorption characteristics of Cr(VI) and Cu(II) by ethylenediamine modified rice hull from single and binary metal ion solutions were evaluated under various experimental conditions. Optimal Cr(VI) and Cu(II) removal from single metal ion solutions occurred at pH 2.0 and 5.5, respectively. Simultaneous removal of Cr(VI) and Cu(II) occurred at pH greater than 3.0. The sorption kinetics of Cr(VI) and Cu(II) from single and binary metal ion solutions were studied with reference to metal concentration, agitation rate and particle size. Sorption of Cr(VI) was more rapid than Cu(II). The kinetics of metal ion sorption fitted a pseudo-second order expression. The variation in the initial uptake rates was very small at an agitation rate beyond 150 rpm and sorption was generally independent of particle size. Equilibrium sorption data could be fitted into the Langmuir isotherm equation. Maximum sorption capacities of ethylenediamine modified rice hull for Cr(VI) at pH 2 and Cu(II) at pH 4 in single metal solutions were 0.45 and 0.06 mmol g(-1), respectively. This corresponds to an enhancement factor of 2.6 and 3 fold for Cr(VI) and Cu(II), respectively, compared to natural rice hull. A synergistic effect was observed for sorption of these ions in binary metal solutions.
  20. Chiroma AA, Khaza'ai H, Abd Hamid R, Chang SK, Zakaria ZA, Zainal Z
    PLoS One, 2020;15(11):e0241112.
    PMID: 33232330 DOI: 10.1371/journal.pone.0241112
    Natural α-tocopherol (α-TCP), but not tocotrienol, is preferentially retained in the human body. α-Tocopherol transfer protein (α-TTP) is responsible for binding α-TCP for cellular uptake and has high affinity and specificity for α-TCP but not α-tocotrienol. The purpose of this study was to examine the modification of α-TTP together with other related vitamin E-binding genes (i.e., TTPA, SEC14L2, and PI-TPNA) in regulating vitamin E uptake in neuronal cells at rest and under oxidative stress. Oxidative stress was induced with H2O2 for an hour which was followed by supplementation with different ratios of α-TCP and tocotrienol-rich fraction (TRF) for four hours. The cellular levels of vitamin E were quantified to determine bioavailability at cellular levels. The expression levels of TTPA, SEC14L2, and PI-TPNA genes in 0% α-TCP were found to be positively correlated with the levels of vitamin E in resting neuronal cells. In addition, the regulation of all the above-mentioned genes affect the distribution of vitamin E in the neuronal cells. It was observed that, increased levels of α-TCP secretion occur under oxidative stress. Thus, our results showed that in conclusion vitamin E-binding proteins may be modified in the absence of α-TCP to produce tocotrienols (TCT), as a source of vitamin E. The current study suggests that the expression levels of vitamin E transport proteins may influence the cellular concentrations of vitamin E levels in the neuronal cells.
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