Browse publications by year: 2018

  1. Habib MAH, Gan CY, Abdul Latiff A, Ismail MN
    Biochem. Cell Biol., 2018 12;96(6):818-824.
    PMID: 30058361 DOI: 10.1139/bcb-2018-0020
    The natural rubber latex extracted from the bark of Hevea brasiliensis plays various important roles in modern society. Post-translational modifications (PTMs) of the latex proteins are important for the stability and functionality of the proteins. In this study, latex proteins were acquired from the C-serum, lutoids, and rubber particle layers of latex without using prior enrichment steps; they were fragmented using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and electron-transfer dissociation (ETD) activation methods. PEAKS 7 were used to search for unspecified PTMs, followed by analysis through PTM prediction tools to crosscheck both results. There were 73 peptides in 47 proteins from H. brasiliensis protein sequences derived from UniProtKB were identified and predicted to be post-translationally modified. The peptides with PTMs identified include phosphorylation, lysine acetylation, N-terminal acetylation, hydroxylation, and ubiquitination. Most of the PTMs discovered have yet to be reported in UniProt, which would provide great assistance in the research of the functional properties of H. brasiliensis latex proteins, as well as being useful biomarkers. The data are available via the MassIVE repository with identifier MSV000082419.
    MeSH terms: Amino Acid Sequence/physiology; Latex/metabolism*; Latex/chemistry; Peptides/metabolism; Phosphorylation; Plant Proteins/genetics; Plant Proteins/metabolism*; Protein Processing, Post-Translational/physiology; Hevea/metabolism*; Hevea/chemistry; Proteomics/methods
  2. Abubakar BM, Salleh FM, Shamsir Omar MS, Wagiran A
    Pharm Biol, 2018 Dec;56(1):368-377.
    PMID: 30058427 DOI: 10.1080/13880209.2018.1479869
    CONTEXT: Eurycoma longifolia Jack (Simaroubaceae) commonly known as Tongkat Ali is one of the most important plants in Malaysia. The plant extracts (particularly roots) are widely used for the treatment of cough and fever besides having antimalarial, antidiabetic, anticancer and aphrodisiac activities.

    OBJECTIVES: This study assesses the extent of adulteration of E. longifolia herbal medicinal products (HMPs) using DNA barcoding validated by HPLC analysis.

    MATERIALS AND METHODS: Chloroplastic rbcL and nuclear ITS2 barcode regions were used in the present study. The sequences generated from E. longifolia HMPs were compared to sequences in the GenBank using MEGABLAST to verify their taxonomic identity. These results were verified by neighbor-joining tree analysis in which branches of unknown specimen are compared to the reference sequences established from this study and other retrieved from the GenBank. The HMPs were also analysed using HPLC analysis for the presence of eurycomanone bioactive marker.

    RESULTS: Identification using DNA barcoding revealed that 37% of the tested HMPs were authentic while 27% were adulterated with the ITS2 barcode region proven to be the ideal marker. The validation of the authenticity using HPLC analysis showed a situation in which a species which was identified as authentic was found not to contain the expected chemical compound.

    DISCUSSION AND CONCLUSIONS: DNA barcoding should be used as the first screening step for testing of HMPs raw materials. However, integration of DNA barcoding with HPLC analysis will help to provide detailed knowledge about the safety and efficacy of the HMPs.

    MeSH terms: Chromatography, High Pressure Liquid/methods; Drug Contamination*; Plant Extracts/genetics*; Plant Extracts/isolation & purification*; Plants, Medicinal/genetics*; Plant Roots; Eurycoma/genetics*; DNA Barcoding, Taxonomic/methods*
  3. Hasan MS, Tan JK, Chan CYW, Kwan MK, Karim FSA, Goh KJ
    J Orthop Surg (Hong Kong), 2018 7 31;26(3):2309499018789529.
    PMID: 30058437 DOI: 10.1177/2309499018789529
    BACKGROUND: Drugs used in anesthesia can affect somatosensory evoked potential (SSEP) monitoring, which is used routinely for intraoperative monitoring of spinal cord integrity during spinal surgery.

    OBJECTIVE: The objective of this study was to determine whether combined total intravenous anesthesia (TIVA) technique with propofol/remifentanil is associated with less SSEP suppression when compared to combined volatile agent desflurane/remifentanil anesthesia during corrective scoliosis surgery at a comparable depth of anesthesia.

    DESIGN: It is a randomized controlled trial.

    SETTING: The study was conducted at the Single tertiary University Hospital during October 2014 to June 2015.

    PATIENTS: Patients who required SSEP and had no neurological deficits, and were of American Society of Anesthesiologist I and II physical status, were included. Patients who had sensory or motor deficits preoperatively and significant cardiovascular and respiratory disease were excluded. A total of 72 patients were screened, and 67 patients were randomized and allocated to two groups: 34 in desflurane/remifentanil group and 33 in TIVA group. Four patients from desflurane/remifentanil group and three from TIVA group were withdrawn due to decrease in SSEP amplitude to <0.3 µV after induction of anesthesia. Thirty patients from each group were analyzed.

    INTERVENTIONS: Sixty-seven patients were randomized to receive TIVA or desflurane/remifentanil anesthesia.

    MAIN OUTCOME MEASURES: The measurements taken were the amplitude and latency of SSEP monitoring at five different time points during surgery: before and after the induction of anesthesia, at skin incision, at pedicle screw insertion, and at rod insertion.

    RESULTS: Both anesthesia techniques, TIVA and desflurane/remifentanil, resulted in decreased amplitude and increased latencies of both cervical and cortical peaks. The desflurane/remifentanil group had a significantly greater reduction in the amplitude ( p = 0.004) and an increase in latency ( p = 0.002) of P40 compared with the TIVA group. However, there were no differences in both amplitude ( p = 0.214) and latency ( p = 0.16) in cervical SSEP between the two groups.

    CONCLUSIONS: Compared with TIVA technique, desflurane/remifentanil anesthesia caused more suppression in cortical SSEP, but not in cervical SSEP, at a comparable depth of anesthesia.

    MeSH terms: Adolescent; Adult; Analgesics, Opioid/administration & dosage*; Child; Drug Therapy, Combination; Evoked Potentials, Somatosensory/drug effects*; Female; Humans; Male; Scoliosis/surgery*; Propofol/administration & dosage*; Monitoring, Intraoperative; Anesthetics, General/administration & dosage*; Young Adult; Consciousness Monitors
  4. Virk NA, Rehman A, Abbasi MA, Siddiqui SZ, Rashid U, Iqbal J, et al.
    Pak J Pharm Sci, 2018 Jul;31(4(Supplementary)):1501-1510.
    PMID: 30058542
    N-(Substituted)-5-(1-(4-methoxyphenylsulfonyl)piperidin-4-yl)-4H-1,2,4-triazol-3-ylthio) acetamide were synthesized by following conventional as well as microwave assisted protocol through five consecutive steps under the impact of various reaction conditions to control the reaction time and the yield of product. Starting from 4-methoxybenzenesulfonyl chloride and ethyl isonipecotate, product 3 was obtained which was converted into product 4 by treating with hydrazine hydrate. In step 3, the product 4 was refluxed with methyl isothiocyanate and KOH to yield compound 5 which was finally treated with variety of N-substituted acetamides to yield an array of different new compounds (8a-k). These synthesized compounds were evaluated for their inhibition potential against bovine carbonic anhydrase (bCA-II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Compound 8g demonstrated good activity against bCA-II, AChE and BChE with IC50 values of 8.69 ± 0.38 μM, 11.87±0.19 μM and 26.01±0.55 μM respectively. SAR studies assisted with molecular docking were carried out to explore the mode of binding of the compounds against the studied enzymes.
    MeSH terms: Animals; Cattle; Chemistry, Pharmaceutical/methods*; Cholinesterase Inhibitors/chemical synthesis*; Cholinesterase Inhibitors/pharmacology; Microwaves*; Structure-Activity Relationship; Triazoles/chemical synthesis*; Triazoles/pharmacology; Protein Structure, Secondary; Molecular Docking Simulation/methods*
  5. Aziz A, Agamuthu P, Fauziah SH
    Waste Manag Res, 2018 Oct;36(10):975-984.
    PMID: 30058954 DOI: 10.1177/0734242X18790360
    Landfill leachate contain persistent organic pollutants (POPs), namely, bisphenol A (BPA) and 2,4-Di-tert-butylphenol, which exceed the permissible limits. Thus, such landfill leachate must be treated before it is released into natural water courses. This article reports on investigations about the removal efficiency of POPs such as BPA and 2,4-Di-tert-butylphenol from leachate using locust bean gum (LBG) in comparison with alum. The vital experimental variables (pH, coagulant dosage and stirring speed) were optimised by applying response surface methodology equipped with the Box-Behnken design to reduce the POPs from leachate. An empirical quadratic polynomial model could accurately model the surface response with R2 values of 0.928 and 0.954 to reduce BPA and 2,4-Di-tert-butylphenol, respectively. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were performed on treated flocs for further understanding. FTIR analysis revealed that the bridging of pollutant particles could be due to the explicit adsorption and bridging via hydrogen bonding of a coagulation mechanism. SEM micrographs indicated that the flocs produced by LBG have a rough cloudy surface and numerous micro-pores compared with alum, which enabled the capture and removal of POPs from leachate. Results showed that the reduction efficiencies for BPA and 2,4-Di-tert-butylphenol at pH 7.5 were 76% and 84% at LBG dosage of 500 mg·L-1 and 400 mg·L-1, respectively. Coagulant dosage and pH variation have a significant effect on POPs reduction in leachate. Coagulation/flocculation using LBG could be applied for POPs reduction in leachate as a pre-treatment prior to advanced treatments.
    MeSH terms: Benzhydryl Compounds; Flocculation; Phenols; Water Pollutants, Chemical*
  6. Saswati, Adão P, Majumder S, Dash SP, Roy S, Kuznetsov ML, et al.
    Dalton Trans, 2018 Aug 21;47(33):11358-11374.
    PMID: 30059099 DOI: 10.1039/c8dt01668b
    The synthesis and characterization of an oxidovanadium(iv) [VIVO(L)(acac)] (1) and of two dioxidovanadium(v) [VVO2(L')] (2) and [VVO2(L)] (2a) complexes of the Schiff base formed from the reaction of 4-(p-fluorophenyl) thiosemicarbazone with pyridine-2-aldehyde (HL) are described. The oxidovanadium(iv) species [VIVO(L)(acac)] (1) was synthesized by the reaction of VIVO(acac)2 with the thiosemicarbazone HL in refluxing ethanol. The recrystallization of [VIVO(L)(acac)] (1) in DMF, CH3CN or EtOH gave the same product i.e. the dioxidovanadium(v) complex [VVO2(L)] (2a); however, upon recrystallization of 1 in DMSO a distinct compound [VVO2(L')] (2) was formed, wherein the original ligand L- is transformed to a rearranged one, L'-. In the presence of DMSO the ligand in complex 1 is found to undergo methylation at the carbon centre attached to imine nitrogen (aldimine) and transformed to the corresponding VVO2-species through in situ reaction. The synthesized HL and the metal complexes were characterized by elemental analysis, IR, UV-Vis, NMR and EPR spectroscopy. The molecular structure of [VVO2(L')] (2) was determined by single crystal X-ray crystallography. The methylation of various other ligands and complexes prepared from different vanadium precursors under similar reaction conditions was also attempted and it was confirmed that the imine methylation observed is both ligand and metal precursor specific. Complexes 1 and 2 show in vitro insulin-like activity against insulin responsive L6 myoblast cells, higher than VIVO(acac)2, with complex 1 being more potent. In addition, the in vitro cytotoxicity studies of HL, and of complexes 1 and 2 against the MCF-7 and Vero cell lines were also done. The ligand is not cytotoxic and complex 2 is significantly more cytotoxic than 1. DAPI staining experiments indicate that an increase in the time of incubation and an increase of concentration of the complexes lead to the increase in cell death.
    MeSH terms: Ethanol; Aldehydes; Carbon; Dimethyl Sulfoxide; Electron Spin Resonance Spectroscopy; Humans; Ligands; Methylation; Nitrogen; Magnetic Resonance Spectroscopy; Pyridines; Schiff Bases; Staining and Labeling; Thiosemicarbazones; Vanadium; Molecular Structure; Cell Death; Crystallography, X-Ray; Myoblasts; Coordination Complexes; Insulins; MCF-7 Cells
  7. Hamid MSA
    Wounds, 2018 Jul;30(7):186-190.
    PMID: 30059343
    INTRODUCTION: Despite limited clinical evidence, platelet-rich plasma (PRP) is currently used for the treatment of various soft tissue injuries, but optimal use of PRP has yet to be determined. In many instances, PRP is prepared using commercial devices that lack standardized preparation techniques and consistent quality of the PRP produced.

    OBJECTIVE: The aim of this study is to explore a simple, easy, economical method of PRP preparation that is practical for clinical use.

    MATERIALS AND METHODS: This cross-sectional study was conducted at the Sports Medicine Clinic at the University of Malaya Medical Centre, Malaysia. Participants were healthy postgraduate students and staff at the Sports Medicine Department. The PRP was prepared using a single centrifugation technique. Leukocyte and platelet levels were compared with that of a whole blood baseline and a commercial preparation kit.

    RESULTS: The PRP produced using this technique contained significantly higher mean platelet (1725.0 vs. 273.9 x 109/L) and leukocyte (33.6 vs. 7.7 x 109/L) levels compared with whole blood. There was no significant difference in the mean platelet and leukocyte levels between the PRP produced in this study and by a commercial PRP system.

    CONCLUSIONS: A single-centrifugation protocol using readily available materials in a typical clinical setting could produce PRP of comparable quality to those of a commercial PRP production system.

    MeSH terms: Adult; Centrifugation/economics; Centrifugation/methods*; Cost-Benefit Analysis; Cross-Sectional Studies; Female; Humans; Male; Sports Medicine/economics*; Sports Medicine/methods*; Soft Tissue Injuries/economics; Soft Tissue Injuries/therapy*; Platelet-Rich Plasma*; Young Adult
  8. Javanmardi A, Ibrahim Z, Ghaedi K, Khan NB, Benisi Ghadim H
    PLoS One, 2018;13(7):e0200482.
    PMID: 30059506 DOI: 10.1371/journal.pone.0200482
    This paper investigated the seismic retrofitting of an existing cable-stayed bridge through the use of a seismic isolation system. The bridge is situated in a high seismic zone. During the Saguenay earthquake 1988, one of the anchorage plates of the bridge supports failed. Herein, several configurations of seismic isolation system were considered to identify an appropriate solution for the seismic retrofitting of the bridge in both the longitudinal and transverse directions. A three-dimensional model of the bridge was created, and its seismic behavior studied through nonlinear dynamic time-history analysis. The comparative performance study among the five retrofitting configurations showed that the partial seismic isolation of the bridge led to an enhancement of the seismic response of the bridge in one direction only. However, the overall seismic response of the cable-stayed bridge substantially improved in the longitudinal and transverse directions in cases where the isolation systems were utilized between the supports and the deck-tower connection of the bridge.
    MeSH terms: Canada; Construction Materials; Disasters*; Equipment Design; Motion; Steel*; Nonlinear Dynamics; Earthquakes*; Structure Collapse/prevention & control*
  9. Takaoka H, Low VL, Srisuka W, Ya'cob Z, Saeung A
    J Med Entomol, 2018 Oct 25;55(6):1453-1463.
    PMID: 30060220 DOI: 10.1093/jme/tjy109
    Seven populations of Simulium parahiyangum Takaoka & Sigit (Diptera: Simuliidae), a geographically widespread nominal species of black fly in Southeast Asia, were morphologically and molecularly studied. Three morphoforms based on male and pupal morphological features, and two primary lineages based on the COI gene sequence analysis were recognized. Morphoform 1 (lineage 1) from Sarawak, Malaysia, is identified as S. parahiyangum sensu stricto and morphoform 2 (lineage 2) from Thailand and Vietnam, and morphoform 3 (lineage 1) from Peninsular Malaysia are each regarded as distinct species, although morphoform 3 is partially homosequential for the COI gene with morphoform 1. Morphoforms 2 and 3 are described as Simulium ngaoense sp. nov. and Simulium sazalyi sp. nov., respectively. Overall, S. parahiyangum is not a single geographic generalist but a composite of multiple species.
    MeSH terms: Animals; Asia, Southeastern; Electron Transport Complex IV/genetics; Female; Larva/anatomy & histology; Male; Terminology as Topic; Phylogeny; Pupa/anatomy & histology; Simuliidae/anatomy & histology; Simuliidae/classification*; Simuliidae/genetics; DNA Barcoding, Taxonomic
  10. Nur Dini Jamil, Adekunle Qudus Adeleke
    MyJurnal
    This paper assessed the relationship between team competency and design risk
    management among Kuantan construction industries. Similarly, a survey was
    conducted among 10 local and national construction industries in Kuantan with a
    stratified random sampling. The returned questionnaires yielded 10 responses which
    was used for data analysis. Five point Likert scale categories of risk management from
    the previous studies was used and statistical analysis affirmed that there is positive
    relationship between team competency and design risk management among Kuantan
    construction industries.
    MeSH terms: Paper; Surveys and Questionnaires; Risk; Risk Management; Construction Industry
  11. Nurushshahirah Sabodin, Adekunle Qudus Adeleke
    MyJurnal
    This paper examined the significant relationship between government regulation and
    construction waste management among Malaysian construction industries. Survey
    was conducted among 10 contractors registered G7, using proportionate stratified
    random sampling, out of which 10 questionnaire were collected for data analysis with
    five point Likert scale categories of waste management from previous studies,
    statistical analysis affirmed a significant positive relationship between government
    regulation and construction waste management in Malaysian construction industries
    through Statistical Package for the Social Sciences.
    MeSH terms: Government; Paper; Surveys and Questionnaires; Social Sciences; Waste Management; Government Regulation; Construction Industry
  12. Ahmed, Ibrahim Galadima, Abdurrahman Abubakar, Sulaiman Mohammed, Abdulkarim Ali Deba
    MyJurnal
    Phytoremediation is considered as a cost-effective and environmentally friendly
    technique for decontaminating environments that have been contaminated with
    heavy metal ions. The technique describes the use of plants and their concomitant
    microbes to mitigate environmental contaminations. However, conventional
    remediation techniques like chemical, thermal and physical treatment methods are
    too costly, and may end of causing more contamination to the environment.
    Phytoremediation practice provides a major information on the utilization of plants
    and their materials in decontaminating polluted environments. Heavy metals and
    other organic contaminants are among the most precarious substances released into
    the environment which have an eminent level of toxicity and sturdiness of both
    aquatic and terrestrial organisms. The review aimed at providing a broad
    understanding of utilizing various plants and their materials in decontaminating
    polluted environments with heavy metals and other organic contaminants. It also
    provided the general methods used in treating the aforementioned contaminants in
    an environment. The review further discussed the classes of phytoremediation like
    phytoextraction, phytovolatilisation, phytostabilization, phytotransformation,
    phytodegradation and phytofiltration. The generalized advantages and disadvantages
    of phytoremediation were ultimately highlighted.
    MeSH terms: Biodegradation, Environmental; Ions; Plants; Metals, Heavy
  13. David Olugbenga Taiwo, Nooraini Yusoff, Norsiah Abdul Aziz
    MyJurnal
    Housing is ranked second as a basic human need after food. Generally, there is
    inadequate housing both in the rural and urban centres in most of the developing
    countries. The issue of housing quality seems to be common in the rural areas
    whereas the major housing problem in urban areas is more of insufficient supply
    from which the people can make choices. In any preference and choice situation,
    certain underlying motivational factors make it possible for an individual to evaluate
    available alternatives. Preferences and choices are dynamic operational activities
    individuals make based on changing circumstances and situations. The study
    examines housing choices and preferences within the Nigerian housing delivery
    systems. The study employed quantitative method of data collection. A total of 434
    questionnaires were distributed to selected households in the South West,
    geopolitical zone of Nigeria. The analysis was based on 359 retrieved questionnaires
    that represented 82.7 percent response rate. Descriptive statistics, relative
    importance index and regression analysis was used for the analysis. Using relative
    importance index, the study found out that 41 percent of the respondents preferred
    3 bedroom flat with a relative importance index of 0.74, followed by 2 bedrooms flat
    with RII of 0.64, self-contain with RII of 0.61. The study also revealed that the state of
    the national economy plays a prominent role in individual’s housing preferences and
    choices and increasingly a large number of Nigerians find housing to be beyond the
    family budget. The authors are also of the opinion that policy measures that
    incorporate the design of low-cost social housing and the creation of conducive
    environment for developers such as the granting of tax break and provision of
    subsidy may promote a better housing delivery system. Consideration of user
    preferences for housing is a requirement to meeting and satisfying housing needs.
  14. Nur A'shirah Mohd Azman, Adekunle Qudus Adeleke
    MyJurnal
    This paper assessed the effect of time overruns on apartment building among
    Kuantan Malaysian construction industries. A survey was conducted among 10
    construction industries in Kuantan Pahang. Using proportionate stratified random
    sampling, out of which 10 questionnaires were distributed for data analysis. Using
    five point Likert scale categories from previous studies, statistical analysis affirmed a
    significant positive relationship between time overruns and apartment building
    among Kuantan Malaysian construction industries.
    MeSH terms: Paper; Surveys and Questionnaires; Specimen Handling; Construction Industry
  15. Nur Syafiqah Abdul Malik, Adekunle Qudus Adeleke
    MyJurnal
    This paper assessed the significant relationship between organizational culture and
    material risk among Kuantan Malaysian construction industries. Survey was
    conducted among 10 registered G7 contractors operating in Kuantan construction
    industry. Proportionate stratified random sampling was used out of which 10
    questionnaires were distributed for pilot study. Methodologically, this research is
    perhaps the first to assess the relationship between organizational culture and
    material risk among Malaysian construction industries with five point Likert scale
    categories of material risk from previous studies. Statistical analysis affirmed a
    significant positive relationship between organizational culture and material risk
    among Malaysian construction industries through Statistical Package for Social
    Sciences (SPSS).
    MeSH terms: Pilot Projects; Surveys and Questionnaires; Research; Risk; Organizational Culture; Construction Industry
  16. Mohamed Khatif Tawaf, Doris Asmani Mat Yusof, Shahrul Nizam Mohamad, Diana Che Lat, Mohd For Mohd Amin
    MyJurnal
    Rock with moderate strengths (20 to 70 MPa) effectively excavated by ripping
    method which is considered as shallow excavation or surface striping method.
    Disputed between client and contractor often occur due to the lack of proper
    assessment to determine the rippabality of hard material. Practically, rippability of in
    situ rock is assessed based on field ripping test that being conducted using actual
    ripper dozer which is time-consuming and expensive. Therefore the assessment of
    rippability of rock based on specific laboratory tests able to resolve the conflict that
    occurs on ripping method. The correlation between specific energy with surface
    hardness and tensile strength is chose as the material properties to assess in order to
    determine the rippability of rock in this study. Few samples of Sandstone undergone
    several laboratory tests such as laboratory ripping test, Brazilian's test and Schmitt
    hammer test in order to obtain the required parameters in this study. The average
    tensile strength (σT) obtained was 4.62MPa with a range of value from 3.19 to 7.50
    MPa whilst the average rebound number (R) obtained for Sandstone was 26.6 with a
    range between 19.0 and 34.0. The specific energy (SE) obtained indicates an average
    value of 3.95 MJ/m3
    with a range value between 1.73MJ/m3
    and 6.45 MJ/m3
    . The
    correlation of R and σT with SE shows a relatively good relationship. Parameters of R
    and σT are acceptable and reliable for assessing rippability of Sandstone based on the
    value of regression coefficient (R2) which is consistence above 0.8 for both
    correlation between SE, R and σT.
  17. Nur Fazlina Abdul Rahman, Adekunle Qudus Adeleke
    MyJurnal
    In this paper, the influence of effective communication in construction risk
    management among Kuantan Malaysian construction industries was assessed. Then a
    survey was conducted on pilot test among 10 local construction industries in Kuantan
    Malaysian, using stratified random sampling, out of which 10 questionnaires were
    collected for data analysis. Methodologically, this research is perhaps the first to
    study the influence of effective communication on construction risk management
    among Kuantan Malaysian construction industries. Using the five point Likert scale
    categories of risk management from previous studies. Pearson Correlation anaylysis
    output results affirmed that there is a strong positive relationship between effective
    communication and construction risk management among Kuantan construction
    industries.
    MeSH terms: Communication; Surveys and Questionnaires; Research; Risk; Risk Management; Construction Industry
  18. Mohamed Ibrahim J. Ibrahim, Mohd Zuhri Mohamed Yusoff
    MyJurnal
    This study presents an investigation about the effect of size variation on mechanical
    performance of square core interlocking structures, by using finite element analysis
    (FEA). The material used in this study is flax fibre reinforced polypropylene (PP)
    composite. Abaqus software was used for modelling and visualizing number of six
    interlocking honeycomb structures with different cell sizes and heights. In the first
    analysis, Abaqus/standard was performed on the perfect models by applying quasistatic
    loading to identify the imperfection shape and obtaining the buckling Eigenmodes
    for the models, then the Eigen-modes from abaqus/standard were imported
    to abaqus/explicit to run post-buckling analysis and simulate the overall imperfection
    behaviour of models. The numerical results from the finite element analysis
    simulation were used to plot load-displacement curve to each model. The area under
    the load-displacement curve represents the total absorbed energy, energy absorption
    per unit mass indicates the specific energy absorption, and the highest value of
    specific energy absorption represents the optimum size. The findings demonstrated
    that the square interlocking structure exhibits good energy absorption performance
    in some geometrical cases, and also revealed that the natural fibre composites have
    unique energy absorption capability under quasi-static loads.
    MeSH terms: Computers; Dietary Fiber; Polypropylenes; Software; Flax; Finite Element Analysis; Cell Size; Laxatives
  19. Siyal AA, Shamsuddin MR, Khan MI, Rabat NE, Zulfiqar M, Man Z, et al.
    J Environ Manage, 2018 Oct 15;224:327-339.
    PMID: 30056352 DOI: 10.1016/j.jenvman.2018.07.046
    The world water resources are contaminated due to discharge of a large number of pollutants from industrial and domestic sources. A variety of a single and multiple units of physical, chemical, and biological processes are employed for pollutants removal from wastewater. Adsorption is the most widely utilized process due to high efficiency, simple procedure and cost effectiveness. This paper reviews the research work carried out on the use of geopolymer materials for the adsorption of heavy metals and dyes. Geopolymers possess good surface properties, heterogeneous microstructure and amorphous structure. The performance of geopolymers in the removal of heavy metals and dyes is reported comparable to other materials. The pseudo-second order kinetics and Langmuir isotherm models mostly fit to the adsorption data suggesting homogeneous distribution of adsorption sites with the formation of monolayer adsorbate on the surface of geopolymers. Adsorption of heavy metals and dyes onto geopolymers is spontaneous, endothermic and entropy driven process. Future research should focus on the enhancement of geopolymer performance, testing on pollutants other than heavy metals and dyes, and verification on real wastewater in continuous operation.
    MeSH terms: Adsorption; Coloring Agents/isolation & purification*; Coloring Agents/chemistry; Kinetics; Water Pollutants, Chemical; Metals, Heavy/isolation & purification*; Metals, Heavy/chemistry; Waste Water
  20. Mohd S, Ghazali MI, Yusof N, Sulaiman S, Ramalingam S, Kamarul T, et al.
    Cell Tissue Bank, 2018 Dec;19(4):613-622.
    PMID: 30056604 DOI: 10.1007/s10561-018-9711-4
    Air-dried and sterilized amnion has been widely used as a dressing to treat burn and partial thickness wounds. Sterilisation at the standard dose of 25 kGy was reported to cause changes in the morphological structure as observed under the scanning electron microscope. This study aimed to quantify the changes in the ultrastructure of the air-dried amnion after gamma-irradiated at several doses by using atomic force microscope. Human placentae were retrieved from mothers who had undergone cesarean elective surgery. Amnion separated from chorion was processed and air-dried for 16 h. It was cut into 10 × 10 mm, individually packed and exposed to gamma irradiation at 5, 15, 25 and 35 kGy. Changes in the ultrastructural images of the amnion were quantified in term of diameter of the epithelial cells, size of the intercellular gap and membrane surface roughness. The longest diameter of the amnion cells reduced significantly after radiation (p 
    MeSH terms: Air; Amnion/radiation effects*; Amnion/ultrastructure*; Desiccation*; Dose-Response Relationship, Radiation; Female; Gamma Rays*; Humans; Pregnancy; Surface Properties; Microscopy, Atomic Force*
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