Displaying publications 1 - 20 of 349 in total

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  1. Ahmed Hamdi OA, Syed Abdul Rahman SN, Awang K, Abdul Wahab N, Looi CY, Thomas NF, et al.
    ScientificWorldJournal, 2014;2014:321943.
    PMID: 25126594 DOI: 10.1155/2014/321943
    Curcuma zedoaria also known as Temu putih is traditionally used in food preparations and treatment of various ailments including cancer. The cytotoxic activity of hexane, dichloromethane, ethyl acetate, methanol, and the methanol-soxhlet extracts of Curcuma zedoaria rhizomes was tested on two human cancer cell lines (Ca Ski and MCF-7) and a noncancer cell line (HUVEC) using MTT assay. Investigation on the chemical components in the hexane and dichloromethane fractions gave 19 compounds, namely, labda-8(17),12 diene-15,16 dial (1), dehydrocurdione (2), curcumenone (3), comosone II (4), curcumenol (5), procurcumenol (6), germacrone (7), zerumbone epoxide (8), zederone (9), 9-isopropylidene-2,6-dimethyl-11-oxatricyclo[6.2.1.0(1,5)]undec-6-en-8-ol (10), furanodiene (11), germacrone-4,5-epoxide (12), calcaratarin A (13), isoprocurcumenol (14), germacrone-1,10-epoxide (15), zerumin A (16), curcumanolide A (17), curcuzedoalide (18), and gweicurculactone (19). Compounds (1-19) were evaluated for their antiproliferative effect using MTT assay against four cancer cell lines (Ca Ski, MCF-7, PC-3, and HT-29). Curcumenone (3) and curcumenol (5) displayed strong antiproliferative activity (IC50 = 8.3 ± 1.0 and 9.3 ± 0.3 μg/mL, resp.) and were found to induce apoptotic cell death on MCF-7 cells using phase contrast and Hoechst 33342/PI double-staining assay. Thus, the present study provides basis for the ethnomedical application of Curcuma zedoaria in the treatment of breast cancer.
    Matched MeSH terms: Microscopy, Fluorescence
  2. Zaini Hamzah, Wan Noorhayani Wan Rosdi, Abdul Khalik Wood
    MyJurnal
    Well water is a renewable natural resources and one of the drinking water sources. The well water may constituted of dissolved essential chemicals such as K+, Ca''+ and Na+ ; and natural radionuclides such as radioisotopes from uranium-thorium decay series. The geology and mineral composition of the soil will determined the kinds and levels of chemical contents in the groundwater resources. The water flows through the geological formation and dissolved the chemicals before reaching the aquifers. To evaluate how much chemicals and natural radioactive in the water resources, a study has been carried out. Well water samples in this study were taken from 3 districts in Kelantan, which is Bachok, Machang and Kuala Krai. Similarly, in situ water quality parameters were measured using YSI portable water quality parameter include pH, salinity, dissolve oxygen(DO), conductivity, turbidity and total dissolved solids(TDS). The concentrations of K', Ca" and Na' were determined using Energy Dispersive X-ray Fluorescence (EDXRF). Five ml of filtered sample was pipette into the sample cup and, irradiated and measured for 100 seconds counting times. The type of filter used for measuring If+ and Cat{ was Al-thin and default for Nat The ranged of concentration of Kt Ce and Na+ is 23.04-251.89, 3.12-.45.41, and 3.71-125.75 ppm, respectively.
    Matched MeSH terms: Fluorescence
  3. Shuib S, Saaid NN, Zakaria Z, Ismail J, Abdul Latiff Z
    Malays J Pathol, 2017 Apr;39(1):77-81.
    PMID: 28413209 MyJurnal
    Potocki-Lupski syndrome (PTLS), also known as duplication 17p11.2 syndrome, trisomy 17p11.2 or dup(17)(p11.2p11.2) syndrome, is a developmental disorder and a rare contiguous gene syndrome affecting 1 in 20,000 live births. Among the key features of such patients are autism spectrum disorder, learning disabilities, developmental delay, attention-deficit disorder, infantile hypotonia and cardiovascular abnormalities. Previous studies using microarray identified variations in the size and extent of the duplicated region of chromosome 17p11.2. However, there are a few genes which are considered as candidates for PTLS which include RAI1, SREBF1, DRG2, LLGL1, SHMT1 and ZFP179. In this report, we investigated a case of a 3-year-old girl who has developmental delay. Her chromosome analysis showed a normal karyotype (46,XX). Analysis using array CGH (4X44 K, Agilent USA) identified an ~4.2 Mb de novo duplication in chromosome 17p11.2. The result was confirmed by fluorescence in situ hybridization (FISH) using probes in the critical PTLS region. This report demonstrates the importance of microarray and FISH in the diagnosis of PTLS.
    Matched MeSH terms: In Situ Hybridization, Fluorescence*
  4. Ali AQ, Teoh SG, Salhin A, Eltayeb NE, Khadeer Ahamed MB, Abdul Majid AM
    PMID: 24607427 DOI: 10.1016/j.saa.2014.01.086
    New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency.
    Matched MeSH terms: Spectrometry, Fluorescence
  5. Mohamad Ashari ZS, Sulong S, Hassan R, Husin A, Sim GA, Abdul Wahid SF
    Asian Pac J Cancer Prev, 2014;15(4):1863-9.
    PMID: 24641422
    The amplification of telomerase component (TERC) gene could play an important role in generation and treatment of haematological malignancies. This present study was aimed to investigate copy number amplification status of TERC gene in chronic myeloid leukaemia (CML) patients who were being treated with imatinib mesylate (IM). Genomic DNA was extracted from peripheral blood of CML-IM Resistant (n=63), CML-IM Respond (n=63) and healthy individuals (n=30). TERC gene copy number predicted (CNP) and copy number calculated (CNC) were determined based on Taqman® Copy Number Assay. Fluorescence in situ hybridization (FISH) analysis was performed to confirm the normal signal pattern in C4 (calibrator) for TERC gene. Nine of CML patients showed TERC gene amplification (CNP=3), others had 2 CNP. A total of 17 CML patients expressed CNC>2.31 and the rest had 2.31>CNC>1.5. TERC gene CNP value in healthy individuals was 2 and their CNC value showed in range 1.59-2.31. The average CNC TERC gene copy number was 2.07, 1.99 and 1.94 in CML- IM Resistant patients, CML-IM Respond and healthy groups, respectively. No significant difference of TERC gene amplification observed between CML-IM Resistant and CML-IM Respond patients. Low levels of TERC gene amplification might not have a huge impact in haematological disorders especially in terms of resistance towards IM treatment.
    Matched MeSH terms: In Situ Hybridization, Fluorescence
  6. Dahalan FA, Sidek HM, Murtey MD, Embi MN, Ibrahim J, Fei Tieng L, et al.
    Biomed Res Int, 2016;2016:1645097.
    PMID: 27525262 DOI: 10.1155/2016/1645097
    Plasmodium falciparum mitogen-activated protein (MAP) kinases, a family of enzymes central to signal transduction processes including inflammatory responses, are a promising target for antimalarial drug development. Our study shows for the first time that the P. falciparum specific MAP kinase 2 (PfMAP2) is colocalized in the nucleus of all of the asexual erythrocytic stages of P. falciparum and is particularly elevated in its phosphorylated form. It was also discovered that PfMAP2 is expressed in its highest quantity during the early trophozoite (ring form) stage and significantly reduced in the mature trophozoite and schizont stages. Although the phosphorylated form of the kinase is always more prevalent, its ratio relative to the nonphosphorylated form remained constant irrespective of the parasites' developmental stage. We have also shown that the TSH motif specifically renders PfMAP2 genetically divergent from the other plasmodial MAP kinase activation sites using Neighbour Joining analysis. Furthermore, TSH motif-specific designed antibody is crucial in determining the location of the expression of the PfMAP2 protein. However, by using immunoelectron microscopy, PPfMAP2 were detected ubiquitously in the parasitized erythrocytes. In summary, PfMAP2 may play a far more important role than previously thought and is a worthy candidate for research as an antimalarial.
    Matched MeSH terms: Microscopy, Fluorescence
  7. Faraj FL, Zahedifard M, Paydar M, Looi CY, Abdul Majid N, Ali HM, et al.
    ScientificWorldJournal, 2014;2014:212096.
    PMID: 25548779 DOI: 10.1155/2014/212096
    Two new synthesized and characterized quinazoline Schiff bases 1 and 2 were investigated for anticancer activity against MCF-7 human breast cancer cell line. Compounds 1 and 2 demonstrated a remarkable antiproliferative effect, with an IC50 value of 6.246×10(-6) mol/L and 5.910×10(-6) mol/L, respectively, after 72 hours of treatment. Most apoptosis morphological features in treated MCF-7 cells were observed by AO/PI staining. The results of cell cycle analysis indicate that compounds did not induce S and M phase arrest in cell after 24 hours of treatment. Furthermore, MCF-7 cells treated with 1 and 2 subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS formation. We also found activation of caspases-3/7, -8, and -9 in compounds 1 and 2. Moreover, inhibition of NF-κB translocation in MCF-7 cells treated by compound 1 significantly exhibited the association of extrinsic apoptosis pathway. Acute toxicity results demonstrated the nontoxic nature of the compounds in mice. Our results showed significant activity towards MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway and are potential candidate for further in vivo and clinical breast cancer studies.
    Matched MeSH terms: Microscopy, Fluorescence
  8. Lee WC, Khoo BE, Abdullah AFL
    Forensic Sci Int, 2016 06;263:1-9.
    PMID: 27061146 DOI: 10.1016/j.forsciint.2016.03.046
    Evidence in crime scenes available in the form of biological stains which cannot be visualized during naked eye examination can be detected by imaging their fluorescence using a combination of excitation lights and suitable filters. These combinations selectively allow the passage of fluorescence light emitted from the targeted stains. However, interference from the fluorescence generated by many of the surface materials bearing the stains often renders it difficult to visualize the stains during forensic photography. This report describes the use of background correction algorithm (BCA) to enhance the visibility of seminal stain, a biological evidence that fluoresces. While earlier reports described the use of narrow band-pass filters for other fluorescing evidences, here, we utilize BCA to enhance images captured using commonly available colour filters, yellow, orange and red. Mean-based contrast adjustment was incorporated into BCA to adjust the background brightness for achieving similarity of images' background appearance, a crucial step for ensuring success while implementing BCA. Experiment results demonstrated the effectiveness of our proposed colour filters' approach using the improved BCA in enhancing the visibility of seminal stains in varying dilutions on selected surfaces.
    Matched MeSH terms: Fluorescence*
  9. Yiau SK, Lee C, Mohd Tohit ER, Chang KM, Abdullah M
    J Recept Signal Transduct Res, 2019 Jun;39(3):276-282.
    PMID: 31509041 DOI: 10.1080/10799893.2019.1660899
    Acute myeloid leukemia (AML) constitutively express growth factors and cytokines for survival. Chemotherapy alters these signals to induce cell death. However, drug resistance in AML remains a major hindrance to successful treatment and early warning is unavailable. Modulation of signaling pathways during chemotherapy may provide a window to detect response and predict treatment outcome. Blood samples collected from AML patients before and at day-3 of induction therapy were compared for changes in expression of CD117, CD34, pro-inflammatory cytokines and mediators of Akt and MAPK pathways, using multi-color flow cytometry. Nine patients were diagnosed as drug-resistant and seven sensitive to chemotherapy. Twelve were paired. Average percentages of CD34 (66.8 ± 11.7% vs. 26.2 ± 5.8%, p = 0.033) and pBAD (66.9 ± 8.2% vs. 28.9 ± 8.2%, p = 0.016) were significantly increased in chemo-resistant (N = 9) compared to chemo-sensitive (N = 5) samples. Percentages of CD34 were strongly correlated with pBAD (R = 0.785; p = 0.001; N = 14) and pFKHR (R = 0.755; p = 0.002; N = 14) at day-3 induction. Chemo-sensitive cases expressed significantly higher percentages of IL-18Rα (71.9 ± 9.6% vs. 29.8 ± 5.8%, p = 0.016). Though not significantly different in the outcome, IL-1β was strongly associated with activated Akt-S473, IL-6 with phosphorylated JNK and FKHR while TNF-α appeared to trigger Bim, in treated samples. These preliminary results suggested AML cells resistant to chemotherapy increased expression of CD34 and may signal through pBAD while cells sensitive to chemotherapy-induced IL18Rα expression. These were observed early during induction therapy. Identifying CD34 is interesting as it is a convenient marker to monitor drug-resistance in AML patients. Inhibition of CD34 and pBAD signaling may be important in treating drug-resistant AML.
    Matched MeSH terms: Fluorescence
  10. Siti Aishah Md Ali, Ilina Isahak, Dahlan Sabil, Fatimah Sahlan, Lokman Saim, Abdullah Sani Mohamed
    Medicine & Health, 2006;1(1):5-13.
    MyJurnal
     
    The reciprocal translocation t(9;22)(q34;q11) which gives rise to the Philadelphia (Ph1) chromosome and BCR/ABL fusion gene, plays a pivotal role in the diagnosis and pathogenesis of chronic myeloid leukemia (CML). In this study, we evaluated the role of fluorescence in situ hybridisation (FISH) in detecting the BCR/ABL rearrangement in CML patients. The sensitivity, specificity and detection rate of BCR/ABL gene using FISH, PCR and conventional cytogenetics (karyotyping) methods were also compared. 18 bone marrow samples of patients with clinically diagnosed CML and suspected of CML were collected. The sensitivity, specificity and positive predictive values of FISH were altogether 100% while the sensitivity, specificity and positive predictive values for conventional cytogenetics (karyotyping) were 85%, 100% and 100% respectively. Convetional cytogenetics (karyotyping) detected an additional chromosomal aberration in addition to the Ph1 chromosome. In conclusion, FISH is a highly sensitive method in detecting the BCR/ABL gene. Conventional cytogenetics (karyotyping) remains an important investigation in the work up of suspected CML patients since there is a possibility of detecting chromosomal aberrations in addition to the Ph1 translocation. Therefore, conventional cytogenetics (karyotyping) and FISH are complementary techniques and their results should be interpreted together with clinical information.
    Matched MeSH terms: Fluorescence
  11. Ling I, Taha M, Al-Sharji NA, Abou-Zied OK
    PMID: 29316482 DOI: 10.1016/j.saa.2018.01.005
    The ability of human serum albumin (HSA) to bind medium-sized hydrophobic molecules is important for the distribution, metabolism, and efficacy of many drugs. Herein, the interaction between pyrene, a hydrophobic fluorescent probe, and HSA was thoroughly investigated using steady-state and time-resolved fluorescence techniques, ligand docking, and molecular dynamics (MD) simulations. A slight quenching of the fluorescence signal from Trp214 (the sole tryptophan residue in the protein) in the presence of pyrene was used to determine the ligand binding site in the protein, using Förster's resonance energy transfer (FRET) theory. The estimated FRET apparent distance between pyrene and Trp214 was 27Å, which was closely reproduced by the docking analysis (29Å) and MD simulation (32Å). The highest affinity site for pyrene was found to be in subdomain IB from the docking results. The calculated equilibrium structure of the complex using MD simulation shows that the ligand is largely stabilized by hydrophobic interaction with Phe165, Phe127, and the nonpolar moieties of Tyr138 and Tyr161. The fluorescence vibronic peak ratio I1/I3 of bound pyrene inside HSA indicates the presence of polar effect in the local environment of pyrene which is less than that of free pyrene in buffer. This was clarified by the MD simulation results in which an average of 5.7 water molecules were found within 0.5nm of pyrene in the binding site. Comparing the fluorescence signals and lifetimes of pyrene inside HSA to that free in buffer, the high tendency of pyrene to form dimer was almost completely suppressed inside HSA, indicating a high selectivity of the binding pocket toward pyrene monomer. The current results emphasize the ability of HSA, as a major carrier of several drugs and ligands in blood, to bind hydrophobic molecules in cavities other than subdomain IIA which is known to bind most hydrophobic drugs. This ability stems from the nature of the amino acids forming the binding sites of the protein that can easily adapt their shape to accommodate a variety of molecular structures.
    Matched MeSH terms: Fluorescence Resonance Energy Transfer/methods*
  12. Bwatanglang IB, Mohammad F, Yusof NA, Abdullah J, Hussein MZ, Alitheen NB, et al.
    Int J Nanomedicine, 2016;11:413-28.
    PMID: 26858524 DOI: 10.2147/IJN.S90198
    In this study, we synthesized a multifunctional nanoparticulate system with specific targeting, imaging, and drug delivering functionalities by following a three-step protocol that operates at room temperature and solely in aqueous media. The synthesis involves the encapsulation of luminescent Mn:ZnS quantum dots (QDs) with chitosan not only as a stabilizer in biological environment, but also to further provide active binding sites for the conjugation of other biomolecules. Folic acid was incorporated as targeting agent for the specific targeting of the nanocarrier toward the cells overexpressing folate receptors. Thus, the formed composite emits orange-red fluorescence around 600 nm and investigated to the highest intensity at Mn(2+) doping concentration of 15 at.% and relatively more stable at low acidic and low alkaline pH levels. The structural characteristics and optical properties were thoroughly analyzed by using Fourier transform infrared, X-ray diffraction, dynamic light scattering, ultraviolet-visible, and fluorescence spectroscopy. Further characterization was conducted using thermogravimetric analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray fluorescence, and X-ray photoelectron spectroscopy. The cell viability and proliferation studies by means of MTT assay have demonstrated that the as-synthesized composites do not exhibit any toxicity toward the human breast cell line MCF-10 (noncancer) and the breast cancer cell lines (MCF-7 and MDA-MB-231) up to a 500 µg/mL concentration. The cellular uptake of the nanocomposites was assayed by confocal laser scanning microscope by taking advantage of the conjugated Mn:ZnS QDs as fluorescence makers. The result showed that the functionalization of the chitosan-encapsulated QDs with folic acid enhanced the internalization and binding affinity of the nanocarrier toward folate receptor-overexpressed cells. Therefore, we hypothesized that due to the nontoxic nature of the composite, the as-synthesized nanoparticulate system can be used as a promising candidate for theranostic applications, especially for a simultaneous targeted drug delivery and cellular imaging.
    Matched MeSH terms: Spectrometry, Fluorescence
  13. Norazizah S, AbuBakar S
    JUMMEC, 1999;4:41-46.
    Dengue 2 New Guinea C (NGC) virus NS3 protein, a potentially important virulence factor was cloned to the N-terminus of the Aeqirorea victoria enhanced green fluorescent protein (EGFP) using the pEGFP-N1 mammalian expression vector. During amplification of the recombinant plasmid in E. coli, transformants expressing the EGFP were detected in vivo when viewed using fluorescence microscopy. This inadvertent expression of the recombinant fusion protein was confirmed further by detection of the T7.Tag peptide cloned to the aluino terminal of the fusion protein using T 7.Tag specific monoclonal antibody. These findings represent perhaps the first reported expression of the T7.Tag-NS3-EGFP fusion protein using the pEGFP-N1 mammalian expression vector in E. coli. KEYWORDS: Dengue, NS3, pEGFP-N1, fusion protein.
    Matched MeSH terms: Fluorescence
  14. Kunasegaran T, Mustafa MR, Murugan DD, Achike FI
    Biochimie, 2016 Jun;125:131-9.
    PMID: 27012965 DOI: 10.1016/j.biochi.2016.03.008
    This study investigated the effects of combined minimal concentrations of quercetin and pioglitazone on angiotensin II-induced contraction of the aorta from fructose-streptozotocin (F-STZ)-induced type 2 diabetic rats and the possible role of superoxide anions (O2(-)) and nitric oxide (NO) in their potential therapeutic interaction. Contractile responses to Ang II of aortic rings from Sprague-Dawley (SD) and F-STZ rats were tested following pre-incubation of the tissues in the vehicle (DMSO; 0.05%), quercetin (Q, 0.1 μM), pioglitazone (P, 0.1 μM) or their combination (P + Q; 0.1 μM each). The amount of superoxide anion was evaluated by lucigenin-enhanced chemiluminescence and dihydroethidium fluorescence, and NO by assay of total nitrate/nitrite, and 4-Amino-5-Methylamino-2',7'-Difluorofluorescein (DAF-FM) diacetate. The synergistic reduction of Ang II-induced contraction of diabetic but not normal aorta with minimally effective concentrations of P + Q occurs through inhibiting O2(-) and increasing NO bioavailability. This finding opens the possibility of maximal vascular protective/antidiabetic effects with low dose pioglitazone combined with quercetin, thus minimizing the risk of adverse effects.
    Matched MeSH terms: Fluorescence
  15. Lim KT, Zahari Z, Amanah A, Zainuddin Z, Adenan MI
    Exp Parasitol, 2016 Mar;162:49-56.
    PMID: 26772786 DOI: 10.1016/j.exppara.2016.01.002
    To accelerate the discovery of novel leads for the treatment of Human African Trypanosomiasis (HAT), it is necessary to have a simple, robust and cost-effective assay to identify positive hits by high throughput whole cell screening. Most of the fluorescence assay was made in black plate however in this study the HTS assay developed in 384-well format using clear plate and black plate, for comparison. The HTS assay developed is simple, sensitive, reliable and reproducible in both types of plates. Assay robustness and reproducibility were determined under the optimized conditions in 384-well plate was well tolerated in the HTS assay, including percentage of coefficient of variation (% CV) of 4.68% and 4.74% in clear and black 384-well plate, signal-to-background ratio (S/B) of 12.75 in clear 384-well plate and 12.07 in black 384-well plate, Z' factor of 0.79 and 0.82 in clear 384-well plate and black 384-well plate, respectively and final concentration of 0.30% dimethylsulfoxide (DMSO) in both types of plate. Drug sensitivity was found to be comparable to the reported anti-trypanosomal assay in 96-well format. The reproducibility and sensitivity of this assay make it compliant to automated liquid handler use in HTS applications.
    Matched MeSH terms: Fluorescence
  16. Ahmad Saat, Nurulhuda Kassim, Zaini Hamzah, Ahmad Farisz
    MyJurnal
    Taman Negara is a famous tourism destination for nature lover in Malaysia. The area is well kept from human activities and disturbances. Since there is no data for human exposure to natural radiation, there is a need to do this study. It will give a baseline data for surface dose and radionuclide concentrations and one can estimate the external hazards index for the visitor to this unexplored area, i.e. UiTM-Perhilitan research station, Kuala Keniam, Taman Negara, Malaysia. The surface dose rate measurements were done in-situ using portable radiation survey meter at the surface and 1 m above the surface. The top soil samples were taken using hand auger up to 15 cm depth at nine locations around research station. Samples were brought back to the UiTM laboratory in Shah Alam, dried, ground to powder form, and sieved using 250 μm sieve. Then the uranium and thorium concentrations were analyzed using Energy Dispersive X-Ray Fluorescence (EDXRF).The mean value for surface dose rates on surface were 0.164 μSv/hr while the mean value for surface dose rates on 1m above the surface were 0.161 μSv/hr. The mean concentration of thorium was 2.62μg/g while the mean concentration of uranium was 0.61μg/g.
    Matched MeSH terms: Fluorescence
  17. Ting T, Crouse K, Ahmad H
    Sains Malaysiana, 2015;44:619-628.
    Three novel ruthenium(II) complexes of the general formula [Ru(II)(bpy)2
    L]2+ were synthesized, where L =
    1,10-phenanthroline derivatives of position 2 imidazole having 3,4-didecyloxy-phenyl (ddip), 3,4-ditetradecyloxy-phenyl
    (dtip) and 3,4-dihexadecyloxy-phenyl (dhip). All complexes were characterized by elemental analysis, 1
    H-NMR and ESI-MS.
    Their photophysical properties have also been studied by UV-visible spectroscopy and fluorescence spectroscopy. The
    complexes exhibit Ru(II) metal centered emission at approximately 610 nm in acetonitrile solution at room temperature. DNA
    binding studies were carried out by UV-visible titration, luminescence titration and viscosity studies. The results indicated
    that [Ru(bpy)2
    (ddip)]2+ binds to CT-DNA by partial intercalation mode, while [Ru(bpy)2
    (dtip)]2+ and [Ru(bpy)2
    (dhip)]2+
    bind intercalatively via extended ligands.
    Matched MeSH terms: Spectrometry, Fluorescence
  18. Manan FAA, Hong WW, Abdullah J, Yusof NA, Ahmad I
    PMID: 30889711 DOI: 10.1016/j.msec.2019.01.082
    Novel biosensor architecture based on nanocrystalline cellulose (NCC)/CdS quantum dots (QDs) nanocomposite was developed for phenol determination. This nanocomposite was prepared with slight modification of nanocrystalline cellulose (NCC) with cationic surfactant of cetyltriammonium bromide (CTAB) and further decorated with 3-mercaptopropionic acid (3-MPA) capped CdS QDs. The nanocomposite material was then employed as scaffold for immobilization of tyrosinase enzyme (Tyr). The electrocatalytic response of Tyr/CTAB-NCC/QDs nanocomposite towards phenol was evaluated using differential pulse voltammetry (DPV). The current response obtained is proportional to the concentration of phenol which attributed to the reduction of o-quinone produced at the surface of the modified electrode. Under the optimal conditions, the biosensor exhibits good linearity towards phenol in the concentration range of 5-40 μM (R2 = 0.9904) with sensitivity and limit of detection (LOD) of 0.078 μA/μM and 0.082 μM, respectively.
    Matched MeSH terms: Spectrometry, Fluorescence
  19. Zaini Hamzah, Marlinda Musa, Ahmad Saat
    MyJurnal
    There are many essential and non-essential elements including metals and radionuclides present in vegetables. Howeve r, the accumulation of the several metals and radionuclides might cause the contamination to vegetables itself. Green m ustard (Brasissca rapa var. Parachinesis L.) was selected to represent the vegetable in this study. Objectives of this stud y are to determine the concentration of metals and radionuclides in the samples and to calculate the enrichment factor ( EF) and also to estimate the uptake, base on biological accumulation coefficient (BAC), for the various parts of selecte d vegetables. Three farmlands in the Cameron Highlands were studied namely Bharat, Kg Raja and Bertam area. The g reen mustard and soil samples were collected during the harvest season. Samples were dried, ground and sieved prior t o analysis. Analyses for both samples were done by using X-rays Fluorescence Spectroscopy (XRF) to measure the conc entration of Fe, Zn, Hg, U and Th. The concentration of all elements in the soils is lower than their concentration in the control soil, except for Zn, U and Th. The concentration of all elements in Green Mustard is lower than their concentrat ion in the soil where it was grown. The EF values in the Brasissca rapa var. Parachinesis L are lower than 2 except for U and Th, indicating some degree of contamination due to anthropogenic activities or naturally origin. The BAC values show that Zn and Hg were accumulated in the green mustard, depending on where the plant grows.
    Matched MeSH terms: Spectrometry, Fluorescence
  20. Zaini Hamzah, Mohd Najif Ab Rahman, Siti Mariam Sumari, Yamin Yasin, Ahmad Saat
    MyJurnal
    Layered double hydroxide (LDH) with Mg/Al molar ratio of 4/1 (MAN-4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was allowed to undergo ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP-4). The solid produced was characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of copper solution by MAHP-4 was carried out using batch experiment by mixing the copper solution and the sorbent MAHP-4. The effects of
    various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for copper removal was found to be 4 and the optimum time of copper removal was found at 4 hours. The isotherm data was analysed using model isotherm Langmuir with the correlation coefficient of 0.999 was recorded. The maximum adsorption capacity, Qo (mg/g) of 142.8 mg/g was also recorded from the Langmuir isotherm. The remaining copper solution was determined by using EDXRF (Energy Dispersive XRay Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP-4 has potential as an effective adsorbent for removing copper from aqueous solution.
    Matched MeSH terms: Spectrometry, Fluorescence
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