Browse publications by year: 2018

  1. Tahlan S, Ramasamy K, Lim SM, Shah SAA, Mani V, Narasimhan B
    Chem Cent J, 2018 Dec 19;12(1):139.
    PMID: 30569392 DOI: 10.1186/s13065-018-0513-3
    BACKGROUND: The emergence of bacterial resistance is a major public health problem. It is essential to develop and synthesize new therapeutic agents with better activity. The mode of actions of certain newly developed antimicrobial agents, however, exhibited very limited effect in treating life threatening systemic infections. Therefore, the advancement of multi-potent and efficient antimicrobial agents is crucial to overcome the increased multi-drug resistance of bacteria and fungi. Cancer, which remains as one of the primary causes of deaths and is commonly treated by chemotherapeutic agents, is also in need of novel and efficacious agents to treat resistant cases. As such, a sequence of novel substituted benzamides was designed, synthesized and evaluated for their antimicrobial and anticancer activities.

    METHODOLOGY: All synthesized compounds were characterized by IR, NMR, Mass and elemental analysis followed by in vitro antimicrobial studies against Gram-positive (Staphylococcus aureus), Gram-negative (Salmonella typhi and Klebsiella pneumoniae) bacterial and fungal (Candida albicans and Aspergillus niger) strains by the tube dilution method. The in vitro anticancer evaluation was carried out against the human colorectal carcinoma cell line (HCT116), using the Sulforhodamine B assay.

    RESULTS, DISCUSSION AND CONCLUSION: Compound W6 (MICsa, st, kp = 5.19 µM) emerged as a significant antibacterial agent against all tested bacterial strains i.e. Gram-positive (S. aureus), Gram-negative (S. typhi, K. pneumoniae) while compound W1 (MICca, an = 5.08 µM) was most potent against fungal strains (A. niger and C. albicans) and comparable to fluconazole (MIC = 8.16 µM). The anticancer screening demonstrated that compound W17 (IC50 = 4.12 µM) was most potent amongst the synthesized  compounds and also more potent than the standard drug 5-FU (IC50 = 7.69 µM).

    MeSH terms: Anti-Infective Agents; Anti-Bacterial Agents; Aspergillus niger; Bacterial Infections; Benzamides; Candida albicans; Cause of Death; Cell Line; Fluorouracil; Humans; Klebsiella pneumoniae; Magnetic Resonance Spectroscopy; Rhodamines; Salmonella typhi; Staphylococcus aureus; Colorectal Neoplasms; Fluconazole; Drug Resistance, Multiple; Inhibitory Concentration 50
  2. Wan Asyraf WA, Mohd Shahrir MS, Asrul W, Norasyikin AW, Hanita O, Kong WY, et al.
    Reumatismo, 2018 Dec 20;70(4):241-250.
    PMID: 30570242 DOI: 10.4081/reumatismo.2018.1075
    Based on the recent evidence of association between hyperprolactinemia and systemic lupus erythematosus disease activity (SLEDAI), a study was conducted to analyze the association of hyperprolactinemia with lupus nephritis disease activity. In this cross-sectional study, the analysis was conducted on SLE patients who visited the University Kebangsaan Malaysia Medical Centre (UKMMC) Nephrology Clinic from August 2015 till February 2016. The disease activity was measured using the SLEDAI score, with more than 4 indicating active lupus nephritis. Basal resting prolactin level was analyzed in 43 patients with lupus nephritis, in 27.9% of them had raised serum prolactin. The median of serum prolactin level at 0 minutes was 19.91 ng/mL (IQR: 15.95-22.65 ng/ mL) for active lupus nephritis, which was significantly higher compared to the median of serum prolactin level of 14.34 ng/mL (IQR: 11.09-18.70 ng/mL) for patients in remission (p=0.014). The serum prolactin level positively correlated with SLEDAI (rhos: 0.449, p=0.003) and the UPCI level in lupus nephritis patients (rhos: 0.241, p=0.032). The results were reproduced when the serum prolactin was repeated after 30 minutes. However, the serum prolactin levels at 0 minutes were higher than those taken after 30 minutes (p=0.001). An assessment of serum IL-6 levels found that the active lupus nephritis patients had a higher median level of 65.91 pg/ mL (IQR: 21.96-146.14 pg/mL) compared to the in-remission level of 15.84 pg/mL (IQR: 8.38-92.84 pg/mL), (p=0.039). Further correlation analysis revealed that there was no statistical correlation between the interleukin (IL)-6 levels with serum prolactin, SLEDAI and other lupus nephritis parameters. An ROC curve analysis of serum prolactin at 0 minutes and serum prolactin after 30 minutes and IL-6 levels for prediction of SLE disease activity provided the cutoff value of serum prolactin at 0 minutes, which was 14.63 ng/mL with a sensitivity of 91.7% and specificity of 58.1% and AUC of 0.74 (p=0.015). This study concurred with the previous findings that stated that hyperprolactinemia is prevalent in SLE patients and correlated with clinical disease activity and UPCI level. The baseline of the fasting serum prolactin level was found to be a sensitive biomarker for the evaluation of lupus nephritis disease activity.
    MeSH terms: Adult; Cross-Sectional Studies; Female; Humans; Hyperprolactinemia/blood*; Hyperprolactinemia/complications*; Lupus Erythematosus, Systemic/blood*; Lupus Erythematosus, Systemic/complications*; Male; Prolactin/blood*; Interleukin-6/blood*
  3. Hasan HA, Abdulmalek E, Rahman MBA, Shaari KB, Yamin BM, Chan KW
    Chem Cent J, 2018 Dec 20;12(1):145.
    PMID: 30570683 DOI: 10.1186/s13065-018-0509-z
    BACKGROUND: Although the development of antibiotic and antioxidant manufacturing, the problem of bacterial resistance and food and/or cosmetics oxidation still needs more efforts to design new derivatives which can help to minimize these troubles. Benzimidazo[1,2-c]quinazolines are nitrogen-rich heterocyclic compounds that possess many pharmaceutical properties such as antimicrobial, anticonvulsant, immunoenhancer, and anticancer.

    RESULTS: A comparative study between two methods, (microwave-assisted and conventional heating approaches), was performed to synthesise a new quinazoline derivative from 2-(2-aminophenyl)-1H-benzimidazole and octanal to produce 6-heptyl-5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazoline (OCT). The compound was characterised using FTIR, 1H and 13C NMR, DIMS, as well as X-ray crystallography. The most significant peak in the 13C NMR spectrum is C-7 at 65.5 ppm which confirms the cyclisation process. Crystal structure analysis revealed that the molecule grows in the monoclinic crystal system P21/n space group and stabilised by an intermolecular hydrogen bond between the N1-H1A…N3 atoms. The crystal packing analysis showed that the molecule adopts zig-zag one dimensional chains. Fluorescence study of OCT revealed that it produces blue light when expose to UV-light and its' quantum yield equal to 26%. Antioxidant activity, which included DPPH· and ABTS·+ assays was also performed and statistical analysis was achieved via a paired T-test using Minitab 16 software with P 

    MeSH terms: Aldehydes; Anti-Infective Agents; Anti-Bacterial Agents; Anticonvulsants; Benzimidazoles; Cosmetics; Pharmaceutical Preparations; Fluorescence; Fungi; Heating; Hydrogen; Microwaves; Nitrogen; Quinazolines; Reaction Time; Software; Ultraviolet Rays; Spectroscopy, Fourier Transform Infrared; Crystallography, X-Ray; Carbon-13 Magnetic Resonance Spectroscopy
  4. Nazri A, Mazlan N, Muharam F
    PLoS One, 2018;13(12):e0208501.
    PMID: 30571683 DOI: 10.1371/journal.pone.0208501
    Rice is a staple food in Asia and it contributes significantly to the Gross Domestic Product (GDP) of Malaysia and other developing countries. Brown Planthopper (BPH) causes high levels of economic loss in Malaysia. Identification of BPH presence and monitoring of its abundance has been conducted manually by experts and is time-consuming, fatiguing and tedious. Automated detection of BPH has been proposed by many studies to overcome human fallibility. However, all studies regarding automated recognition of BPH are investigated based on intact specimen although most of the specimens are imperfect, with missing parts have distorted shapes. The automated recognition of an imperfect insect image is more difficult than recognition of the intact specimen. This study proposes an automated, deep-learning-based detection pipeline, PENYEK, to identify BPH pest in images taken from a readily available sticky pad, constructed by clipping plastic sheets onto steel plates and spraying with glue. This study explores the effectiveness of a convolutional neural network (CNN) architecture, VGG16, in classifying insects as BPH or benign based on grayscale images constructed from Euclidean Distance Maps (EDM). The pipeline identified imperfect images of BPH with an accuracy of 95% using deep-learning's hyperparameters: softmax, a mini-batch of 30 and an initial learning rate of 0.0001.
    MeSH terms: Adhesives; Animals; Asia; Developing Countries; Humans; Learning; Malaysia; Plastics; Oryza; Steel; Neural Networks (Computer); Gross Domestic Product
  5. Musa KI, Keegan TJ
    PLoS One, 2018;13(12):e0208594.
    PMID: 30571691 DOI: 10.1371/journal.pone.0208594
    BACKGROUND: Acute stroke results in functional disability measurable using the well-known Barthel Index. The objectives of the study are to describe the change in the Barthel Index score and to model the prognostic factors for Barthel Index change from discharge up to 3 months post-discharge using the random intercept model among patients with acute first ever stroke in Kelantan, Malaysia.

    METHODS: A total 98 in-hospital first ever acute stroke patients were recruited, and their Barthel Index scores were measured at the time of discharge, at 1 month and 3 months post-discharge. The Barthel Index was scored through telephone interviews. We employed the random intercept model from linear mixed effect regression to model the change of Barthel Index scores during the three months intervals. The prognostic factors included in the model were acute stroke subtypes, age, sex and time of measurement (at discharge, at 1 month and at 3 month post-discharge).

    RESULTS: The crude mean Barthel Index scores showed an increased trend. The crude mean Barthel Index at the time of discharge, at 1-month post-discharge and 3 months post-discharge were 35.1 (SD = 39.4), 64.4 (SD = 39.5) and 68.8 (SD = 38.9) respectively. Over the same period, the adjusted mean Barthel Index scores estimated from the linear mixed effect model increased from 39.6 to 66.9 to 73.2. The adjusted mean Barthel Index scores decreased as the age increased, and haemorrhagic stroke patients had lower adjusted mean Barthel Index scores compared to the ischaemic stroke patients.

    CONCLUSION: Overall, the crude and adjusted mean Barthel Index scores increase from the time of discharge up to 3-month post-discharge among acute stroke patients. Time after discharge, age and stroke subtypes are the significant prognostic factors for Barthel Index score changes over the period of 3 months.

    MeSH terms: Activities of Daily Living*; Adult; Age Factors; Aged; Female; Humans; Interviews as Topic; Malaysia; Male; Middle Aged; Patient Discharge; Prognosis; Retrospective Studies; Severity of Illness Index; Sex Factors; Linear Models; Stroke/pathology*; Stroke Rehabilitation
  6. Al-Saiagh W, Tiun S, Al-Saffar A, Awang S, Al-Khaleefa AS
    PLoS One, 2018;13(12):e0208695.
    PMID: 30571777 DOI: 10.1371/journal.pone.0208695
    Word sense disambiguation (WSD) is the process of identifying an appropriate sense for an ambiguous word. With the complexity of human languages in which a single word could yield different meanings, WSD has been utilized by several domains of interests such as search engines and machine translations. The literature shows a vast number of techniques used for the process of WSD. Recently, researchers have focused on the use of meta-heuristic approaches to identify the best solutions that reflect the best sense. However, the application of meta-heuristic approaches remains limited and thus requires the efficient exploration and exploitation of the problem space. Hence, the current study aims to propose a hybrid meta-heuristic method that consists of particle swarm optimization (PSO) and simulated annealing to find the global best meaning of a given text. Different semantic measures have been utilized in this model as objective functions for the proposed hybrid PSO. These measures consist of JCN and extended Lesk methods, which are combined effectively in this work. The proposed method is tested using a three-benchmark dataset (SemCor 3.0, SensEval-2, and SensEval-3). Results show that the proposed method has superior performance in comparison with state-of-the-art approaches.
    MeSH terms: Heuristics; Algorithms*; Computer Simulation; Humans; Language*; Pattern Recognition, Automated
  7. Zhang J, Chu R, Chen Y, Jiang H, Zeng Y, Zhang Y, et al.
    Nanotechnology, 2018 Dec 20.
    PMID: 30572323 DOI: 10.1088/1361-6528/aafa25
    Carbon-coated nickel cobaltate on nickel foam (C@NCO@NF) with stable pseudocapacitive lithium storage capacity was prepared via a two-step strategy. NiCo hydroxide were initially grown on Ni foam via electrodeposition. Subsequent glucose soaking and annealing converted the intermediate into C@NCO@NF. Carbon coating could significantly improve cycling stability and rate performance of the binder-free anode. The C@NCO@NF electrode could stably deliver a reversible capacity of 513 mAh∙g-1 after 500 cycles at a current density of 500 mA∙g-1. It could even stably cycle at a high current density of 5000 mA∙g-1 for 3000 times, with a reversible capacity of 115 mAh∙g-1. Kinetic analysis revealed that surface-controlled pseudo-capacitance play a dominate role in the lithium ion storage. Improved electrochemical performance is attributed to the synergetic effect of pseudo-capacitance and carbon coating.
  8. Nasir Mohamad, Shariff Halim, Mohd Ekhwan Toriman, Nor Hidayah Abu Bakar, Ahmad Zubaidi A. Latif
    MyJurnal
    Zamzam is holy water believed by Muslim to have remedial power for all kinds of diseases. It contains
    many electrolytes and the concentration of the electrolytes may be affected by the types of container
    used for its storage. This study was carried out to determine the difference in ions concentration of
    Zamzam water stored in plastic and glass containers, and to determine cytotoxicity effects of Zamzam
    water against U-87 cell line (human primary glioblastoma cell line). Ion Chromatography (IC) was used
    to analyze the concentration. The analyzed anions in the Zamzam water include bromide, chloride,
    phosphate, nitrite, nitrate, sulfate and fluoride whereas the cations were ammonium, lithium, potassium,
    sodium, calcium and magnesium. Subsequently, MTT assay was used to determine the cytotoxicity of
    Zamzam water on U-87 cell line. This study reveals that Zamzam water anions and cations
    concentration was not statistically significant neither in plastic nor glass container. In addition, the
    Zamzam water did not cause any toxicity on the U87 cell line. We postulate that types of container do
    not have much influence on the ion concentration of Zamzam water and it is non-toxic on U87 cell line.
    MeSH terms: Anions; Bromides; Cations; Cell Line; Chromatography; Fluorides; Glioblastoma; Humans; Islam; Lithium; Magnesium; Nitrates; Nitrites; Phosphates; Plastics; Potassium; Sodium; Sulfates; Water; Ammonium Compounds
  9. Zarina Mohamad, Fadhilah Ahmad, Ahmad Nazari Mohd Rose, Fatma Susilawati Mohamad, Mustafa Mat Deris
    MyJurnal
    In this work, a new model for federation data grid system called Sub-Grid-Federation was designed to
    improve access latency by accessing data from the nearest possible sites. The strategy in optimising
    data access was based on the process of searching into the area identified as ‘Network Core Area’
    (NCA). The performance of access latency in Sub-Grid-Federation was tested based on the
    mathematical proving and simulated using OptorSim simulator. Four case studies were carried out and
    tested in Optimal Downloading Replication Strategy (ODRS) and the Sub-Grid-Federation. The results
    show that Sub-Grid-Federation is 20% better in terms of access latency and 21% better in terms of
    reducing remotes sites access compared to ODRS. The results indicate that the Sub-Grid-Federation
    is a better alternative for the implementation of collaboration and data sharing in data grid system.
  10. Wan Muhamad Amir W. Ahmad, Mohamad Arif Awang Nawi, Mustafa Mamat
    MyJurnal
    This paper proposes the use of bootstrap, robust and fuzzy multiple linear regressions method in
    handling general insurance in order to get improved results. The main objective of bootstrapping is to
    estimate the distribution of an estimator or test statistic by resampling one's data or a model estimated
    from the data under conditions that hold in a wide variety of econometric applications. In addition,
    bootstrap also provides approximations to distributions of statistics, coverage probabilities of confidence
    intervals, and rejection probabilities of hypothesis tests that produce accurate results. In this paper, we
    emphasize the combining and modelling using bootstrapping, robust and fuzzy regression methodology.
    The results show that alternative methods produce better results than multiple linear regressions (MLR)
    model.
    MeSH terms: Biometry; Probability; Linear Models
  11. Nurnadiah Zamri, Syibrah Naim, Lazim Abdullah
    MyJurnal
    Over the past century there has been a dramatic increase in the number of road accidents in
    Malaysia. Hence, it is necessary to create a decision making method which can consider various
    preferences and criteria in order to identify the main causes of the accidents. This paper proposes an
    Interval Type-2 Fuzzy Technique for Order Preference by Similarity to Ideal Solution (IT2FTOPSIS)
    method which provides a comprehensive valuation from experts. This method is developed based on
    the aggregation of experts’ opinions on preferred causes of road accidents. The extended
    IT2FTOPSIS employs a linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy
    Number (IT2TrFN) and hybrid averaging approach (from an ambiguity and type-reduction methods) to
    formulate a collective decision environment. Three authorised personnel from three Malaysian
    Government agencies were interviewed where they were asked to rank the causes. The analysis
    shows that the linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy Number
    (IT2TrFN) and hybrid averaging approach are effective in measuring the uncertainties in the
    interviewees’ responses. Thus this paper concludes that the extended IT2FTOPSIS is more aligned
    with the users’ decisions compared to the earlier IT2FTOPSIS.
  12. Yusof Nurhayati, Ali Abdul Manaf, Abu Bakar Che Abdullah, Tang, John Yew Huat, Hassan Osman
    MyJurnal
    The aim of this study was to determine the effect of chitosan and chitosan oligosaccharides (COS),
    prepared by enzymatic hydrolysis with cellulase from Trichoderma reesei, Celluclast® on the growth of
    Bifidobacterium sp. The growth of the two bacteria strains were determined every 12 h for 48 h under
    anaerobic incubation at 37 °C in four MRS media containing lactose, COS, chitosan and inulin. The
    bacteria cell growth in substrate-added medium increased significantly after 48 h of incubation, except
    for the chitosan medium. COS was found to have a similar growth effect on B. bifidum ATCC 11863
    and B. breve ATCC 15700 when compared with inulin and lactose. The pH of medium containing
    COS, inulin and lactose fermented with B. bifidum ATCC 11863 and B. breve ATCC 15700 decreased
    rapidly after 12 h. B. bifidum ATCC 11863 showed the highest specific growth rate at 12 h. The results
    revealed that COS support the growth of probiotic bacteria, thus indicating that COS has the potential
    as new prebiotic source in the functional food industry.
  13. Azizah Endut, Fathurrahman Lananan, Ahmad Jusoh, Wan Norsani Wan Nik, Nora'aini Ali
    MyJurnal
    The current and escalating extent of soil degradation, water scarcity and environmental concern
    plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics
    is a concept relatively new to modern food production methods and can contribute to food security.
    This study was conducted to establish sustainable aquaculture systems that maximize benefits and
    minimize the accumulation of detrimental compounds and other types of negative impacts on both
    natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to
    evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth
    and yield of African catfish as well as water spinach. A special design of ARS was used to provide
    nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough,
    providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies
    of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen
    (TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO4
    3-
    ) were 82%, 89%,
    93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate
    (SGR) of African catfish were 1.08 and 3.34% day-1
    , respectively. The average water spinach
    production was 3.56 kg per m2
    . This study showed that ARS is a method of producing crop along with
    a healthy protein source and among the best alternatives for achieving economic and environmental
    sustainability.
    MeSH terms: Agriculture; Ammonia; Animals; Catfishes; Fisheries; Food; Food Supply; Nitrates; Nitrites; Nitrogen; Oxygen; Phosphates; Social Environment; Soil; Water; Aquaculture; Hydroponics; Spinacia oleracea; Biofuels; Nitrification; Waste Water
  14. Kampan NC, Xiang SD, McNally OM, Stephens AN, Quinn MA, Plebanski M
    Curr Med Chem, 2018;25(36):4785-4806.
    PMID: 28707587 DOI: 10.2174/0929867324666170712160621
    Interleukin 6 (IL-6), a well-known pro-inflammatory cytokine with pleiotropic activity is a central player in chronic inflammatory diseases including cancers. Therefore, blockade of the IL-6 signalling pathway has become a target for the therapy of diverse cancers such as multicentric Castleman's disease (CD), multiple myeloma and solid tumours including renal, prostate, lung, colorectal and ovarian cancers. Monoclonal antibodies against IL-6 (Siltuximab) and the IL-6 receptor (IL-6R) (Tocilizumab) have emerged as potential immunotherapies, alone or in combination with conventional chemotherapy. Human trials have demonstrated the ability to block IL-6 activity and in multicentric CD lead to durable clinical response and longer disease stabilisation. However, the efficacy of these treatments is still debatable for other cancers. New generation therapeutics in development such as Clazakizumab, Sarilumab, and soluble gp130-Fc have the additional features of improved binding affinity, better specificity with reduced adverse effects. A deeper understanding of the immunological basis of these agents, as well as of the challenges that are faced by immunotherapy-based products in clinical trials, will help select the most promising anti-IL-6/IL-6R therapies for large scale use. Concurrently, current research efforts to personalize treatments may help in the treatment of patients that would greatly benefit from IL-6 blocking therapies.
    MeSH terms: Animals; Antibodies, Monoclonal/immunology; Female; Humans; Immunotherapy; Inflammation/metabolism; Inflammation/therapy; Neoplasms/metabolism; Neoplasms/therapy*; Signal Transduction/drug effects; Interleukin-6/antagonists & inhibitors*; Interleukin-6/immunology; Receptors, Interleukin-6/antagonists & inhibitors*; Receptors, Interleukin-6/immunology
  15. Ghavamian A, Mustapha F, Baharudin BTHT, Yidris N
    Sensors (Basel), 2018 Dec 17;18(12).
    PMID: 30563013 DOI: 10.3390/s18124470
    This paper aims to provide an overview of the experimental and simulation works focused on the detection, localisation and assessment of various defects in pipes by applying fast-screening guided ultrasonic wave techniques that have been used in the oil and gas industries over the past 20 years. Major emphasis is placed on limitations, capabilities, defect detection in coated buried pipes under pressure and corrosion monitoring using different commercial guided wave (GW) systems, approaches to simulation techniques such as the finite element method (FEM), wave mode selection, excitation and collection, GW attenuation, signal processing and different types of GW transducers. The effects of defect parameters on reflection coefficients are also discussed in terms of different simulation studies and experimental verifications.
  16. Ahmad NA, Jumbri K, Ramli A, Abd Ghani N, Ahmad H, Lim JW
    Molecules, 2018 Dec 05;23(12).
    PMID: 30563037 DOI: 10.3390/molecules23123201
    The antiradical efficiency (AE) and kinetic behavior of a new ferulate-based protic ionic liquids (PILs) were described using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The reduction of the DPPH free radical (DPPH•) was investigated by measuring the decrease in absorbance at 517 nm. The time to reach steady state for the reaction of parent acid (ferulic acid) and synthesized PILs with DPPH• was continuously recorded for 1 h. Results revealed that the AE of 2-butylaminoethanol ferulate (2BAEF), 3-dimethylaminopropanol ferulate (3DMAPF) and 3-diethylaminopropanol ferulate (3DEAPF) PILs have improved compared to ferulic acid (FA) as the reaction class changes from low to medium. This attributed to the strong hydrogen abstraction occurred in the PILs. Furthermore, these PILs were found to have a good kinetic behavior compared to FA due to the high rate constant (k₂) (164.17, 242.84 and 244.73 M-1 s-1, respectively). The alkyl chain length and more alkyl substituents on the nitrogen atom of cation were believed to reduce the cation-anion interaction and speed up the hydrogen atom transfer (HAT) and electron transfer (ET) mechanisms; hence, increased rate constant was observed leading to a strong antioxidant activity of the synthesized PILs.
    MeSH terms: Biphenyl Compounds/antagonists & inhibitors; Biphenyl Compounds/chemistry*; Coumaric Acids/chemistry*; Dose-Response Relationship, Drug; Kinetics; Picrates/antagonists & inhibitors; Picrates/chemistry*; Molecular Structure; Free Radical Scavengers/pharmacology; Free Radical Scavengers/chemistry*; Ionic Liquids/chemistry*
  17. Al-Anazi M, Al-Najjar BO, Khairuddean M
    Molecules, 2018 Dec 05;23(12).
    PMID: 30563058 DOI: 10.3390/molecules23123203
    Human Epidermal Growth Factor Receptor-1 (EGFR), a transmembrane tyrosine kinase receptor (RTK), has been associated with several types of cancer, including breast, lung, ovarian, and anal cancers. Thus, the receptor was targeted by a variety of therapeutic approaches for cancer treatments. A series of chalcone derivatives are among the most highly potent and selective inhibitors of EGFR described to date. A series of chalcone derivatives were proposed in this study to investigate the intermolecular interactions in the active site utilizing molecular docking and molecular dynamics simulations. After a careful analysis of docking results, compounds 1a and 1d were chosen for molecular dynamics simulation study. Extensive hydrogen bond analysis throughout 7 ns molecular dynamics simulation revealed the ability of compounds 1a and 1d to retain the essential interactions needed for the inhibition, especially MET 93. Finally, MM-GBSA calculations highlight on the capability of the ligands to bind strongly within the active site with binding energies of -44.04 and -56.6 kcal/mol for compounds 1a and 1d, respectively. Compound 1d showed to have a close binding energy with TAK-285 (-66.17 kcal/mol), which indicates a high chance for compound 1d to exhibit inhibitory activity, thus recommending to synthesis it to test its biological activity. It is anticipated that the findings reported here may provide very useful information for designing effective drugs for the treatment of EGFR-related cancer disease.
    MeSH terms: Binding Sites; Chalcone/analogs & derivatives*; Chalcone/pharmacology; Chalcone/chemistry*; Humans; Hydrogen Bonding; Ligands; Molecular Conformation; Protein Binding; Structure-Activity Relationship; Drug Design*; Molecular Structure; Catalytic Domain; Cell Line, Tumor; Protein Kinase Inhibitors/pharmacology; Protein Kinase Inhibitors/chemistry*; Molecular Dynamics Simulation; Molecular Docking Simulation; ErbB Receptors/antagonists & inhibitors; ErbB Receptors/chemistry
  18. John CM, Mohamed Yusof NIS, Abdul Aziz SH, Mohd Fauzi F
    Int J Mol Sci, 2018 Dec 05;19(12).
    PMID: 30563117 DOI: 10.3390/ijms19123894
    Gestational diabetes mellitus (GDM) carries many risks, where high blood pressure, preeclampsia and future type II diabetes are widely acknowledged, but less focus has been placed on its effect on cognitive function. Although the multifactorial pathogenesis of maternal cognitive impairment is not completely understood, it shares several features with type 2 diabetes mellitus (T2DM). In this review, we discuss some key pathophysiologies of GDM that may lead to cognitive impairment, specifically hyperglycemia, insulin resistance, oxidative stress, and neuroinflammation. We explain how these incidents: (i) impair the insulin-signaling pathway and/or (ii) lead to cognitive impairment through hyperphosphorylation of τ protein, overexpression of amyloid-β and/or activation of microglia. The aforementioned pathologies impair the insulin-signaling pathway primarily through serine phosphorylation of insulin receptor substances (IRS). This then leads to the inactivation of the phosphatidylinositol 3-kinase/Protein kinase B (PI3K/AKT) signaling cascade, which is responsible for maintaining brain homeostasis and normal cognitive functioning. PI3K/AKT is crucial in maintaining normal cognitive function through the inactivation of glycogen synthase kinase 3β (GSκ3β), which hyperphosphorylates τ protein and releases pro-inflammatory cytokines that are neurotoxic. Several biomarkers were also highlighted as potential biomarkers of GDM-related cognitive impairment such as AGEs, serine-phosphorylated IRS-1 and inflammatory markers such as tumor necrosis factor α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), leptin, interleukin 1β (IL-1β), and IL-6. Although GDM is a transient disease, its complications may be long-term, and hence increased mechanistic knowledge of the molecular changes contributing to cognitive impairment may provide important clues for interventional strategies.
    MeSH terms: C-Reactive Protein; Diabetes Mellitus, Type 2; Female; Humans; Insulin Resistance; Pregnancy; Receptor, Insulin; Tumor Necrosis Factor-alpha; Diabetes, Gestational; tau Proteins; Leptin; Proto-Oncogene Proteins c-akt; Interleukin-1beta; Phosphatidylinositol 3-Kinase; Glycogen Synthase Kinase 3 beta
  19. Chen X, Yang B, Huang W, Wang T, Li Y, Zhong Z, et al.
    Int J Mol Sci, 2018 Dec 05;19(12).
    PMID: 30563128 DOI: 10.3390/ijms19123897
    Polyphenol oxidase (PPO) catalyzes the o-hydroxylation of monophenols and oxidation of o-diphenols to quinones. Although the effects of PPO on plant physiology were recently proposed, little has been done to explore the inherent molecular mechanisms. To explore the in vivo physiological functions of PPO, a model with decreased PPO expression and enzymatic activity was constructed on Clematis terniflora DC. using virus-induced gene silencing (VIGS) technology. Proteomics was performed to identify the differentially expressed proteins (DEPs) in the model (VC) and empty vector-carrying plants (VV) untreated or exposed to high levels of UV-B and dark (HUV-B+D). Following integration, it was concluded that the DEPs mainly functioned in photosynthesis, glycolysis, and redox in the PPO silence plants. Mapman analysis showed that the DEPs were mainly involved in light reaction and Calvin cycle in photosynthesis. Further analysis illustrated that the expression level of adenosine triphosphate (ATP) synthase, the content of chlorophyll, and the photosynthesis rate were increased in VC plants compared to VV plants pre- and post HUV-B+D. These results indicate that the silence of PPO elevated the plant photosynthesis by activating the glycolysis process, regulating Calvin cycle and providing ATP for energy metabolism. This study provides a prospective approach for increasing crop yield in agricultural production.
    MeSH terms: Photosynthesis*; Gene Silencing*; Proteomics*
  20. Mohd Razip Wee MF, Jaafar MM, Faiz MS, Dee CF, Yeop Majlis B
    Biosensors (Basel), 2018 Dec 05;8(4).
    PMID: 30563159 DOI: 10.3390/bios8040124
    Gallium Nitride (GaN) is considered as the second most popular semiconductor material in industry after silicon. This is due to its wide applications encompassing Light Emitting Diode (LED) and power electronics. In addition, its piezoelectric properties are fascinating to be explored as electromechanical material for the development of diverse microelectromechanical systems (MEMS) application. In this article, we conducted a theoretical study concerning surface mode propagation, especially Rayleigh and Sezawa mode in the layered GaN/sapphire structure with the presence of various guiding layers. It is demonstrated that the increase in thickness of guiding layer will decrease the phase velocities of surface mode depending on the material properties of the layer. In addition, the Q-factor value indicating the resonance properties of surface mode appeared to be affected with the presence of fluid domain, particularly in the Rayleigh mode. Meanwhile, the peak for Sezawa mode shows the highest Q factor and is not altered by the presence of fluid. Based on these theoretical results using the finite element method, it could contribute to the development of a GaN-based device to generate surface acoustic wave, especially in Sezawa mode which could be useful in acoustophoresis, lab on-chip and microfluidics applications.
    MeSH terms: Aluminum Oxide; Gallium; Models, Theoretical; Semiconductors; Silicon; Sound; Vibration; Finite Element Analysis; Microfluidics; Micro-Electrical-Mechanical Systems
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