Browse publications by year: 2014

  1. Ang HY, Subramani T, Yeap SK, Omar AR, Ho WY, Abdullah MP, et al.
    Exp Ther Med, 2014 Jun;7(6):1733-1737.
    PMID: 24926376
    Immunomodulators are agents that are able to stimulate or inhibit the immune response. The leaf extracts from Potentilla indica and Dendrophthoe pentandra were analyzed in vitro for immunomodulatory activity and an MTT colorimetric assay was conducted to determine the proliferation of mice splenocytes and thymocytes. A bromodeoxyuridine assay was performed to analyze DNA synthesis and the Trypan blue exclusion method was conducted to evaluate the changes in total cell population. The results indicated that treatment with P. indica and D. pentandra produced a time- and dose-dependent increase in cell viability and proliferation. Following 72 h of treatment with P. indica and D. pentandra, thymocyte proliferation was augmented by 18 and 41%, respectively and splenocyte proliferation increased by 35 and 42%, respectively, when compared with untreated cells. The present study demonstrated that these extracts may act as potential immunostimulants and, thus, represent an alternative source of immunomodulatory compounds for the treatment of human immune-mediated diseases.
    MeSH terms: Adjuvants, Immunologic; Central Nervous System Stimulants; Animals; Bromodeoxyuridine; Cell Survival; Colorimetry; DNA; Humans; Immunologic Factors; Plant Extracts; Spleen; Trypan Blue; Uridine; Potentilla; Cell Proliferation; Mice; Thymocytes
  2. Das NS, Usman J, Choudhury D, Abu Osman NA
    PLoS One, 2014;9(6):e100028.
    PMID: 24927127 DOI: 10.1371/journal.pone.0100028
    Cricket has over the years gained much popularity in Asia, thus the number of cricket players has also grown in tandem. However, cricket players are not as fortunate as other athletes as they do not always have a standard cricket infrastructure to practice; therefore, the injury prevalence is expected to be high. Unfortunately, very few studies have been conducted to investigate the nature and pattern of cricket injuries prevalent to cricketers in this region. Therefore, a prospective cohort injury surveillance study was conducted during the Asian Cricket Council (ACC) Under-19 Elite Cup held in June 2013 in order to gather more data on the type of injuries sustained by cricket players. Overall, 31 injuries occurred to 28 players throughout the tournament, of which 7 injuries happened during practice sessions. The overall injury incidence rate (IIR) was 292.0 per 10,000 player hours (95% CI 176.9-407.1) and 10.4 per 10,000 balls faced and 2.6 per 1000 overs bowled delivered during batting and bowling, respectively. Injuries to the lower limb (IIR: 146; 95% CI 1.8-98.2) were the most frequent, followed by injuries to the upper limb (97.3;95% CI 30.2-164.5) and to the trunk and back (IIR: 36.5;95% CI 0.0-77.7). Sprain/strains (IIR 109.5;95% CI 38.4-180.7) to muscle/tendon and joint/ligament were the most commonly reported nature of injury. This is the first study investigating injury incidence among the players of the ACC. It provides an overview of injuries sustained by elite players' under-19 years of age from 10 Asian countries. The overall IIR is similar to earlier studies conducted in well-established cricket playing nations.
    MeSH terms: Adolescent; Asia; Athletic Injuries/epidemiology*; Child; Child, Preschool; Competitive Behavior; Humans; Male; Sprains and Strains/epidemiology*; Incidence; Young Adult
  3. Uddin MJ, Khan WA, Amin NS
    PLoS One, 2014;9(6):e99384.
    PMID: 24927277 DOI: 10.1371/journal.pone.0099384
    The unsteady two-dimensional laminar g-Jitter mixed convective boundary layer flow of Cu-water and Al2O3-water nanofluids past a permeable stretching sheet in a Darcian porous is studied by using an implicit finite difference numerical method with quasi-linearization technique. It is assumed that the plate is subjected to velocity and thermal slip boundary conditions. We have considered temperature dependent viscosity. The governing boundary layer equations are converted into non-similar equations using suitable transformations, before being solved numerically. The transport equations have been shown to be controlled by a number of parameters including viscosity parameter, Darcy number, nanoparticle volume fraction, Prandtl number, velocity slip, thermal slip, suction/injection and mixed convection parameters. The dimensionless velocity and temperature profiles as well as friction factor and heat transfer rates are presented graphically and discussed. It is found that the velocity reduces with velocity slip parameter for both nanofluids for fluid with both constant and variable properties. It is further found that the skin friction decreases with both Darcy number and momentum slip parameter while it increases with viscosity variation parameter. The surface temperature increases as the dimensionless time increases for both nanofluids. Nusselt numbers increase with mixed convection parameter and Darcy numbers and decreases with the momentum slip. Excellent agreement is found between the numerical results of the present paper with published results.
    MeSH terms: Computer Simulation; Hot Temperature; Models, Chemical*; Permeability; Surface Properties; Viscosity; Porosity; Convection; Nanotechnology/methods*
  4. Yam H, Rahim AA, Mohamad S, Mahadi NM, Manaf UA, Shu-Chien AC, et al.
    PLoS One, 2014;9(6):e99218.
    PMID: 24927285 DOI: 10.1371/journal.pone.0099218
    Burkholderia pseudomallei is an opportunistic pathogen and the causative agent of melioidosis. It is able to adapt to harsh environments and can live intracellularly in its infected hosts. In this study, identification of transcriptional factors that associate with the β' subunit (RpoC) of RNA polymerase was performed. The N-terminal region of this subunit is known to trigger promoter melting when associated with a sigma factor. A pull-down assay using histidine-tagged B. pseudomallei RpoC N-terminal region as bait showed that a hypothetical protein BPSS1356 was one of the proteins bound. This hypothetical protein is conserved in all B. pseudomallei strains and present only in the Burkholderia genus. A BPSS1356 deletion mutant was generated to investigate its biological function. The mutant strain exhibited reduced biofilm formation and a lower cell density during the stationary phase of growth in LB medium. Electron microscopic analysis revealed that the ΔBPSS1356 mutant cells had a shrunken cytoplasm indicative of cell plasmolysis and a rougher surface when compared to the wild type. An RNA microarray result showed that a total of 63 genes were transcriptionally affected by the BPSS1356 deletion with fold change values of higher than 4. The expression of a group of genes encoding membrane located transporters was concurrently down-regulated in ΔBPSS1356 mutant. Amongst the affected genes, the putative ion transportation genes were the most severely suppressed. Deprivation of BPSS1356 also down-regulated the transcriptions of genes for the arginine deiminase system, glycerol metabolism, type III secretion system cluster 2, cytochrome bd oxidase and arsenic resistance. It is therefore obvious that BPSS1356 plays a multiple regulatory roles on many genes.
    MeSH terms: Bacterial Proteins/genetics*; Bacterial Proteins/metabolism*; Genes, Bacterial; Microscopy, Electron; Microscopy, Electron, Scanning; Molecular Sequence Data; Mutation; DNA-Directed RNA Polymerases/metabolism; DNA-Directed RNA Polymerases/chemistry; Transcription Factors/genetics*; Transcription Factors/metabolism*; Gene Expression Regulation, Bacterial; Burkholderia pseudomallei/genetics*; Burkholderia pseudomallei/physiology; Burkholderia pseudomallei/ultrastructure; Biofilms; Gene Expression Profiling
  5. Saminathan M, Tan HY, Sieo CC, Abdullah N, Wong CM, Abdulmalek E, et al.
    Molecules, 2014 Jun 12;19(6):7990-8010.
    PMID: 24927368 DOI: 10.3390/molecules19067990
    Condensed tannins (CTs) form insoluble complexes with proteins and are able to protect them from degradation, which could lead to rumen bypass proteins. Depending on their degrees of polymerization (DP) and molecular weights, CT fractions vary in their capability to bind proteins. In this study, purified condensed tannins (CTs) from a Leucaena leucocephala hybrid were fractionated into five different molecular weight fractions. The structures of the CT fractions were investigated using 13C-NMR. The DP of the CT fractions were determined using a modified vanillin assay and their molecular weights were determined using Q-TOF LC-MS. The protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay. The DP of the five CT fractions (fractions F1-F5) measured by the vanillin assay in acetic acid ranged from 4.86 to 1.56. The 13C-NMR results showed that the CT fractions possessed monomer unit structural heterogeneity. The number-average molecular weights (Mn) of the different fractions were 1265.8, 1028.6, 652.2, 562.2, and 469.6 for fractions F1, F2, F3, F4, and F5, respectively. The b values representing the CT quantities needed to bind half of the maximum precipitable bovine serum albumin increased with decreasing molecular weight--from fraction F1 to fraction F5 with values of 0.216, 0.295, 0.359, 0.425, and 0.460, respectively. This indicated that higher molecular weight fractions of CTs from L. leucocephala have higher protein-binding affinities than those with lower molecular weights.
    MeSH terms: Fabaceae/chemistry*; Molecular Weight; Magnetic Resonance Spectroscopy; Proanthocyanidins/chemistry*
  6. Chan PL, Rose RJ, Abdul Murad AM, Zainal Z, Low ET, Ooi LC, et al.
    PLoS One, 2014;9(6):e99774.
    PMID: 24927412 DOI: 10.1371/journal.pone.0099774
    The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR). With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels.
    MeSH terms: Genes, Plant/genetics*; Gene Expression Regulation, Plant; Oligonucleotide Array Sequence Analysis; Arecaceae/genetics*; Arecaceae/physiology; Real-Time Polymerase Chain Reaction/methods*
  7. Aisha MD, Nor-Ashikin MN, Sharaniza AB, Nawawi HM, Kapitonova MY, Froemming GR
    Exp Cell Res, 2014 Aug 1;326(1):46-56.
    PMID: 24928274 DOI: 10.1016/j.yexcr.2014.06.003
    Exposure of Normal Human Osteoblast cells (NHOst) to a period of hypothermia may interrupt their cellular functions, lead to changes in bone matrix and disrupt the balance between bone formation and resorption, resulting in bone loss or delayed fracture healing. To investigate this possibility, we exposed NHOst cells to moderate (35 °C) and severe (27 °C) hypothermia for 1, 12, 24 and 72 h. The effects of hypothermia with respect to cell cytoskeleton organization, metabolic activity and the expression of cold shock chaperone proteins, osteoblast transcription factors and functional markers, were examined. Our findings showed that prolonged moderate hypothermia retained the polymerization of the cytoskeletal components. NHOst cell metabolism was affected differently according to hypothermia severity. The osteoblast transcription factors Runx2 and osterix were necessary for the transcription and translation of bone matrix proteins, where alkaline phosphatase (Alp) activity and osteocalcin (OCN) bone protein were over expressed under hypothermic conditions. Consequently, bone mineralization was stimulated after exposure to moderate hypothermia for 1 week, indicating bone function was not impaired. The cold shock chaperone protein Rbm3 was significantly upregulated (p<0.001) during the cellular stress adaption under hypothermic conditions. We suggest that Rbm3 has a dual function: one as a chaperone protein that stabilizes mRNA transcripts and a second one in enhancing the transcription of Alp and Ocn genes. Our studies demonstrated that hypothermia permitted the in vitro maturation of NHOst cells probably through an osterix-dependent pathway. For that reason, we suggest that moderate hypothermia can be clinically applied to counteract heat production at the fracture site that delays fracture healing.
    MeSH terms: Alkaline Phosphatase/genetics; Alkaline Phosphatase/metabolism*; Calcification, Physiologic*; Cell Differentiation; Cells, Cultured; Cytoskeleton/metabolism; Flow Cytometry; Humans; Hypothermia*; Mitochondria/metabolism; Osteoblasts/cytology; Osteoblasts/metabolism*; RNA, Messenger/genetics; Transcription Factors/genetics; Transcription Factors/metabolism*; Blotting, Western; Osteocalcin/genetics; Osteocalcin/metabolism*; Reverse Transcriptase Polymerase Chain Reaction; Cell Proliferation; Core Binding Factor Alpha 1 Subunit/genetics; Core Binding Factor Alpha 1 Subunit/metabolism*; Real-Time Polymerase Chain Reaction
  8. Fouz N, Amid A, Hashim YZ
    Appl Biochem Biotechnol, 2014 Aug;173(7):1618-39.
    PMID: 24928548 DOI: 10.1007/s12010-014-0947-6
    The contributing molecular pathways underlying the pathogenesis of breast cancer need to be better characterized. The principle of our study was to better understand the genetic mechanism of oncogenesis for human breast cancer and to discover new possible tumor markers for use in clinical practice. We used complimentary DNA (cDNA) microarrays to compare gene expression profiles of treated Michigan Cancer Foundation-7 (MCF-7) with recombinant bromelain and untreated MCF-7. SpringGene analysis was carried out of differential expression followed by Ingenuity Pathway Analysis (IPA), to understand the underlying consequence in developing disease and disorders. We identified 1,102 known genes differentially expressed to a significant degree (p<0.001) changed between the treatment. Within this gene set, 20 genes were significantly changed between treated cells and the control cells with cutoff fold change of more than 1.5. These genes are RNA-binding motif, single-stranded interacting protein 1 (RBMS1), ribosomal protein L29 (RPL29), glutathione S-transferase mu 2 (GSTM2), C15orf32, Akt3, B cell translocation gene 1 (BTG1), C6orf62, C7orf60, kinesin-associated protein 3 (KIFAP3), FBXO11, AT-rich interactive domain 4A (ARID4A), COPS2, TBPL1|SLC2A12, TMEM59, SNORD46, glioma tumor suppressor candidate region gene 2 (GLTSCR2), and LRRFIP. Our observation on gene expression indicated that recombinant bromelain produces a unique signature affecting different pathways, specific for each congener. The microarray results give a molecular mechanistic insight and functional effects, following recombinant bromelain treatment. The extent of changes in genes is related to and involved significantly in gap junction signaling, amyloid processing, cell cycle regulation by BTG family proteins, and breast cancer regulation by stathmin1 that play major roles.
    MeSH terms: Antineoplastic Agents/pharmacology*; Breast Neoplasms/pathology*; Bromelains/pharmacology*; Humans; Recombinant Proteins/pharmacology*; Gene Expression Profiling*; Cell Proliferation/drug effects; Genes, Neoplasm/genetics; MCF-7 Cells
  9. Teh AH, Lee SM, Dykes GA
    Appl Environ Microbiol, 2014 Sep;80(17):5154-60.
    PMID: 24928882 DOI: 10.1128/AEM.01493-14
    Campylobacter jejuni is one of the most frequent causes of bacterial gastrointestinal food-borne infection worldwide. This species is part of the normal flora of the gastrointestinal tracts of animals used for food production, including poultry, which is regarded as the primary source of human Campylobacter infections. The survival and persistence of C. jejuni in food processing environments, especially in poultry processing plants, represent significant risk factors that contribute to the spread of this pathogen through the food chain. Compared to other food-borne pathogens, C. jejuni is more fastidious in its growth requirements and is very susceptible to various environmental stressors. Biofilm formation is suggested to play a significant role in the survival of C. jejuni in the food production and processing environment. The aims of this minireview were (i) to examine the evidence that C. jejuni forms biofilms and (ii) to establish the extent to which reported and largely laboratory-based studies of C. jejuni biofilms provide evidence for biofilm formation by this pathogen in food processing environments. Overall existing studies do not provide strong evidence for biofilm formation (as usually defined) by most C. jejuni strains in food-related environments under the combined conditions of atmosphere, temperature, and shear that they are likely to encounter. Simple attachment to and survival on surfaces and in existing biofilms of other species are far more likely to contribute to C. jejuni survival in food-related environments based on our current understanding of this species.
    MeSH terms: Animals; Environmental Microbiology*; Food Microbiology*; Campylobacter jejuni/growth & development; Campylobacter jejuni/physiology*; Biofilms/growth & development*; Microbial Viability
  10. Rothan HA, Bahrani H, Shankar EM, Rahman NA, Yusof R
    Antiviral Res, 2014 Aug;108:173-80.
    PMID: 24929084 DOI: 10.1016/j.antiviral.2014.05.019
    Chikungunya virus (CHIKV) outbreaks have led to a serious economic burden, as the available treatment strategies can only alleviate disease symptoms, and no effective therapeutics or vaccines are currently available for human use. Here, we report the use of a new cost-effective approach involving production of a recombinant antiviral peptide-fusion protein that is scalable for the treatment of CHIKV infection. A peptide-fusion recombinant protein LATA-PAP1-THAN that was generated by joining Latarcin (LATA) peptide with the N-terminus of the PAP1 antiviral protein, and the Thanatin (THAN) peptide to the C-terminus, was produced in Escherichia coli as inclusion bodies. The antiviral LATA-PAP1-THAN protein showed 89.0% reduction of viral plaque formation compared with PAP1 (46.0%), LATA (67.0%) or THAN (79.3%) peptides alone. The LATA-PAP1-THAN protein reduced the viral RNA load that was 0.89-fold compared with the untreated control cells. We also showed that PAP1 resulted in 0.44-fold reduction, and THAN and LATA resulting in 0.78-fold and 0.73-fold reductions, respectively. The LATA-PAP1-THAN protein inhibited CHIKV replication in the Vero cells at an EC50 of 11.2μg/ml, which is approximately half of the EC50 of PAP1 (23.7μg/ml) and protected the CHIKV-infected mice at the dose of 0.75mg/ml. We concluded that production of antiviral peptide-fusion protein in E. coli as inclusion bodies could accentuate antiviral activities, enhance cellular internalisation, and could reduce product toxicity to host cells and is scalable to epidemic response quantities.
    MeSH terms: Animals; Antiviral Agents/pharmacology; Antiviral Agents/therapeutic use*; Cercopithecus aethiops; Chikungunya virus/drug effects*; Chikungunya virus/physiology; Disease Models, Animal; Escherichia coli/genetics; Mice, Inbred ICR; Microbial Sensitivity Tests; Viral Plaque Assay; Recombinant Fusion Proteins/genetics; Recombinant Fusion Proteins/pharmacology; Recombinant Fusion Proteins/therapeutic use; Spider Venoms/genetics; Spider Venoms/pharmacology; Spider Venoms/therapeutic use*; Vero Cells; Virus Replication/drug effects; Gene Expression; Treatment Outcome; Viral Load; Antimicrobial Cationic Peptides/genetics; Antimicrobial Cationic Peptides/pharmacology; Antimicrobial Cationic Peptides/therapeutic use*; Ribosome Inactivating Proteins, Type 1/genetics; Ribosome Inactivating Proteins, Type 1/pharmacology; Ribosome Inactivating Proteins, Type 1/therapeutic use*; Chikungunya Fever/drug therapy; Chikungunya Fever/prevention & control*
  11. Osahor AN, Tan CY, Sim EU, Lee CW, Narayanan K
    Anal Biochem, 2014 Oct 1;462:26-8.
    PMID: 24929088 DOI: 10.1016/j.ab.2014.05.030
    When recombineering bacterial artificial chromosomes (BACs), it is common practice to design the ends of the donor molecule with 50 bp of homology specifying its insertion site. We demonstrate that desired recombinants can be produced using intermolecular homologies as short as 15 bp. Although the use of shorter donor end regions decreases total recombinants by several fold, the frequency of recombinants with correctly inserted donor molecules was high enough for easy detection by simple polymerase chain reaction (PCR) screening. This observation may have important implications for the design of oligonucleotides for recombineering, including significant cost savings, especially for high-throughput projects that use large quantities of primers.
    MeSH terms: Base Sequence; Escherichia coli/genetics; Genetic Engineering/methods*; Plasmids/genetics; Sequence Homology, Nucleic Acid*; Telomere/genetics; Chromosomes, Artificial, Bacterial/genetics*; Homologous Recombination*
  12. Castaño-Rodríguez N, Kaakoush NO, Pardo AL, Goh KL, Fock KM, Mitchell HM
    Hum Immunol, 2014 Aug;75(8):808-15.
    PMID: 24929142 DOI: 10.1016/j.humimm.2014.06.001
    Gastric cancer (GC) is a progressive process initiated by Helicobacter pylori-induced inflammation. Initial recognition of H. pylori involves Toll-like receptors (TLRs), central molecules in the host inflammatory response. Here, we investigated the association between novel polymorphisms in genes involved in the TLR signalling pathway, including TLR2, TLR4, LBP, MD-2, CD14 and TIRAP, and risk of H. pylori infection and related GC.
    MeSH terms: Acute-Phase Proteins/genetics; Acute-Phase Proteins/immunology; Aged; Carrier Proteins/genetics; Carrier Proteins/immunology; China; Female; Humans; Male; Membrane Glycoproteins/genetics; Membrane Glycoproteins/immunology; Middle Aged; Polymorphism, Genetic; Stomach Neoplasms/complications; Stomach Neoplasms/genetics*; Stomach Neoplasms/immunology; Stomach Neoplasms/microbiology; Signal Transduction; Gene Expression; Case-Control Studies; Helicobacter pylori/physiology; Helicobacter Infections/complications; Helicobacter Infections/genetics*; Helicobacter Infections/immunology; Helicobacter Infections/microbiology; Receptors, Interleukin-1/genetics; Receptors, Interleukin-1/immunology; Antigens, CD14/genetics; Antigens, CD14/immunology; Genetic Predisposition to Disease*; Toll-Like Receptor 2/genetics*; Toll-Like Receptor 2/immunology; Toll-Like Receptor 4/genetics*; Toll-Like Receptor 4/immunology; Lymphocyte Antigen 96/genetics; Lymphocyte Antigen 96/immunology
  13. Sow SL, Khoo G, Chong LK, Smith TJ, Harrison PL, Ong HK
    World J Microbiol Biotechnol, 2014 Oct;30(10):2645-53.
    PMID: 24929362 DOI: 10.1007/s11274-014-1687-z
    In a previous study, notable differences of several physicochemical properties, as well as the community structure of ammonia oxidizing bacteria as judged by 16S rRNA gene analysis, were observed among several disused tin-mining ponds located in the town of Kampar, Malaysia. These variations were associated with the presence of aquatic vegetation as well as past secondary activities that occurred at the ponds. Here, methane oxidizing bacteria (MOB), which are direct participants in the nutrient cycles of aquatic environments and biological indicators of environmental variations, have been characterised via analysis of pmoA functional genes in the same environments. The MOB communities associated with disused tin-mining ponds that were exposed to varying secondary activities were examined in comparison to those in ponds that were left to nature. Comparing the sequence and phylogenetic analysis of the pmoA clone libraries at the different ponds (idle, lotus-cultivated and post-aquaculture), we found pmoA genes indicating the presence of type I and type II MOB at all study sites, but type Ib sequences affiliated with the Methylococcus/Methylocaldum lineage were most ubiquitous (46.7 % of clones). Based on rarefaction analysis and diversity indices, the disused mining pond with lotus culture was observed to harbor the highest richness of MOB. However, varying secondary activity or sample type did not show a strong variation in community patterns as compared to the ammonia oxidizers in our previous study.
    MeSH terms: Bacterial Proteins/genetics; Malaysia; Methane/metabolism*; Methylococcaceae/classification*; Methylococcaceae/genetics; Methylococcaceae/isolation & purification*; Mining*; Molecular Sequence Data; Phylogeny; Tin*; Sequence Analysis, DNA; Geologic Sediments/microbiology; Evolution, Molecular; Ponds/microbiology*
  14. Aketarawong N, Isasawin S, Thanaphum S
    BMC Genet, 2014;15:70.
    PMID: 24929425 DOI: 10.1186/1471-2156-15-70
    Bactrocera dorsalis s.s. (Hendel) and B. papayae Drew & Hancock, are invasive pests belonging to the B. dorsalis complex. Their species status, based on morphology, is sometimes arguable. Consequently, the existence of cryptic species and/or population isolation may decrease the effectiveness of the sterile insect technique (SIT) due to an unknown degree of sexual isolation between released sterile flies and wild counterparts. To evaluate the genetic relationship and current demography in wild populations for guiding the application of area-wide integrated pest management using SIT, seven microsatellite-derived markers from B. dorsalis s.s. and another five from B. papayae were used for surveying intra- and inter-specific variation, population structure, and recent migration among sympatric and allopatric populations of the two morphological forms across Southern Thailand and West Malaysia.
    MeSH terms: Animals; Bayes Theorem; Genetics, Population*; Genotype; Malaysia; Male; Models, Genetic; Thailand; Genetic Variation*; Sequence Analysis, DNA; Microsatellite Repeats; Principal Component Analysis; Tephritidae/genetics*; Gene Flow*; Sympatry
  15. Hassan S, Duclaux L, Lévêque JM, Reinert L, Farooq A, Yasin T
    J Environ Manage, 2014 Nov 1;144:108-17.
    PMID: 24929502 DOI: 10.1016/j.jenvman.2014.05.005
    The adsorption from aqueous solution of imidazolium, pyrrolidinium and pyridinium based bromide ionic liquids (ILs) having different alkyl chain lengths was investigated on two types of microporous activated carbons: a fabric and a granulated one, well characterized in terms of surface chemistry by "Boehm" titrations and pH of point of zero charge measurements and of porosity by N2 adsorption at 77 K and CO2 adsorption at 273 K. The influence of cation type, alkyl chain length and adsorbate size on the adsorption properties was analyzed by studying kinetics and isotherms of eight different ILs using conductivity measurements. Equilibrium studies were carried out at different temperatures in the range [25-55 °C]. The incorporation of ILs on the AC porosity was studied by N2 adsorption-desorption measurements at 77 K. The experimental adsorption isotherms data showed a good correlation with the Langmuir model. Thermodynamic studies indicated that the adsorption of ILs onto activated carbons was an exothermic process, and that the removal efficiency increased with increase in alkyl chain length, due to the increase in hydrophobicity of long chain ILs cations determined with the evolution of the calculated octanol-water constant (Kow). The negative values of free energies indicated that adsorption of ILs with long chain lengths having hydrophobic cations was more spontaneous at the investigated temperatures.
    MeSH terms: Adsorption; Bromides/chemistry*; Cations/chemistry; Charcoal/chemistry; Heterocyclic Compounds/chemistry; Kinetics; Solvents/chemistry*; Temperature; Thermodynamics; Water Pollutants, Chemical/chemistry*; Ionic Liquids/chemistry*
  16. Hashim S, Alajerami YS, Ramli AT, Ghoshal SK, Saleh MA, Abdul Kadir AB, et al.
    Appl Radiat Isot, 2014 Sep;91:126-30.
    PMID: 24929526 DOI: 10.1016/j.apradiso.2014.05.023
    Lithium potassium borate (LKB) glasses co-doped with TiO2 and MgO were prepared using the melt quenching technique. The glasses were cut into transparent chips and exposed to gamma rays of (60)Co to study their thermoluminescence (TL) properties. The TL glow curve of the Ti-doped material featured a single prominent peak at 230 °C. Additional incorporation of MgO as a co-activator enhanced the TL intensity threefold. LKB:Ti,Mg is a low-Z material (Z(eff)=8.89) with slow signal fading. Its radiation sensitivity is 12 times lower that the sensitivity of TLD-100. The dose response is linear at doses up to 10(3) Gy. The trap parameters, such as the kinetics order, activation energy, and frequency factor, which are related to the glow peak, were determined using TolAnal software.
    MeSH terms: Borates; Gamma Rays; Glass; Kinetics; Lithium; Potassium; Radiation Tolerance; Software; Titanium; Lithium Compounds; Tartrate-Resistant Acid Phosphatase
  17. Tey LS, Zhu S, Ferreira L, Wallis G
    Accid Anal Prev, 2014 Oct;71:177-82.
    PMID: 24929822 DOI: 10.1016/j.aap.2014.05.014
    Level crossings are amongst the most complex of road safety issues, due to the addition of rail infrastructure, trains and train operations. The differences in the operational characteristics of different warning devices together with varying crossing, traffic or/and train characteristics, cause different driver behaviour at crossings. This paper compares driver behaviour towards two novel warning devices (rumble strips and in-vehicle audio warning) with two conventional warning devices (flashing light and stop sign) at railway level crossings using microsimulation modelling. Two safety performance indicators directly related to collision risks, violation and time-to-collision, were adopted. Results indicated the active systems were more effective at reducing likely collisions compared to passive devices. With the combined application of driving simulation and traffic microsimulation modelling, traffic safety performance indicators for a level crossing can be estimated. From these, relative safety comparisons for the different traffic devices are derived, or even for absolute safety evaluation with proper calibration from field investigations.
    MeSH terms: Accidents; Accidents, Traffic/statistics & numerical data*; Adolescent; Adult; Aged; Automobile Driving/statistics & numerical data*; Computer Simulation; Environment Design/statistics & numerical data*; Female; Humans; Male; Middle Aged; Railroads*; Regression Analysis; Young Adult
  18. Lim SP, Pandikumar A, Lim YS, Huang NM, Lim HN
    Sci Rep, 2014;4:5305.
    PMID: 24930387 DOI: 10.1038/srep05305
    This paper reports a rapid and in-situ electrochemical polymerization method for the fabrication of polypyrrole nanoparticles incorporated reduced graphene oxide (rGO@PPy) nanocomposites on a ITO conducting glass and its application as a counter electrode for platinum-free dye-sensitized solar cell (DSSC). The scanning electron microscopic images show the uniform distribution of PPy nanoparticles with diameter ranges between 20 and 30 nm on the rGO sheets. The electrochemical studies reveal that the rGO@PPy has smaller charge transfer resistance and similar electrocatalytic activity as that of the standard Pt counter electrode for the I₃(-)/I(-) redox reaction. The overall solar to electrical energy conversion efficiency of the DSSC with the rGO@PPy counter electrode is 2.21%, which is merely equal to the efficiency of DSSC with sputtered Pt counter electrode (2.19%). The excellent photovoltaic performance, rapid and simple fabrication method and low-cost of the rGO@PPy can be potentially exploited as a alternative counter electrode to the expensive Pt in DSSCs.
    MeSH terms: Electrodes; Electrons; Graphite; Oxidation-Reduction; Platinum; Polymers; Pyrroles; Nanoparticles; Nanocomposites; Electrochemical Techniques; Polymerization
  19. Nikzad S, Tan SG, Yong Seok Yien C, Ng J, Alitheen NB, Khan R, et al.
    J Med Primatol, 2014 Dec;43(6):433-44.
    PMID: 24930735 DOI: 10.1111/jmp.12130
    The genetic diversity and structure of long-tailed macaques (Macaca fascicularis) in Peninsular Malaysia, a widely used non-human primate species in biomedical research, have not been thoroughly characterized.
    MeSH terms: Animals; Macaca fascicularis/genetics*; Malaysia; Genetic Variation*; Polymerase Chain Reaction
  20. Jaafar SA, Latif MT, Chian CW, Han WS, Wahid NB, Razak IS, et al.
    Mar Pollut Bull, 2014 Jul 15;84(1-2):35-43.
    PMID: 24930738 DOI: 10.1016/j.marpolbul.2014.05.047
    This study was conducted to determine the composition of surfactants in the sea-surface microlayer (SML) and atmospheric aerosol around the southern region of the Peninsular Malaysia. Surfactants in samples taken from the SML and atmospheric aerosol were determined using a colorimetric method, as either methylene blue active substances (MBAS) or disulphine blue active substances (DBAS). Principal component analysis with multiple linear regressions (PCA-MLR), using the anion and major element composition of the aerosol samples, was used to determine possible sources of surfactants in atmospheric aerosol. The results showed that the concentrations of surfactants in the SML and atmospheric aerosol were dominated by anionic surfactants and that surfactants in aerosol were not directly correlated (p>0.05) with surfactants in the SML. Further PCA-MLR from anion and major element concentrations showed that combustion of fossil fuel and sea spray were the major contributors to surfactants in aerosol in the study area.
    MeSH terms: Aerosols/chemistry*; Colorimetry/methods; Environmental Monitoring/methods*; Malaysia; Surface-Active Agents/chemistry*
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