Browse publications by year: 2019

  1. Looi CK, Chung FF, Leong CO, Wong SF, Rosli R, Mai CW
    J Exp Clin Cancer Res, 2019 Apr 15;38(1):162.
    PMID: 30987642 DOI: 10.1186/s13046-019-1153-8
    BACKGROUND: Pancreatic cancer is one of the most lethal type of cancers, with an overall five-year survival rate of less than 5%. It is usually diagnosed at an advanced stage with limited therapeutic options. To date, no effective treatment options have demonstrated long-term benefits in advanced pancreatic cancer patients. Compared with other cancers, pancreatic cancer exhibits remarkable resistance to conventional therapy and possesses a highly immunosuppressive tumor microenvironment (TME).

    MAIN BODY: In this review, we summarized the evidence and unique properties of TME in pancreatic cancer that may contribute to its resistance towards immunotherapies as well as strategies to overcome those barriers. We reviewed the current strategies and future perspectives of combination therapies that (1) promote T cell priming through tumor associated antigen presentation; (2) inhibit tumor immunosuppressive environment; and (3) break-down the desmoplastic barrier which improves tumor infiltrating lymphocytes entry into the TME.

    CONCLUSIONS: It is imperative for clinicians and scientists to understand tumor immunology, identify novel biomarkers, and optimize the position of immunotherapy in therapeutic sequence, in order to improve pancreatic cancer clinical trial outcomes. Our collaborative efforts in targeting pancreatic TME will be the mainstay of achieving better clinical prognosis among pancreatic cancer patients. Ultimately, pancreatic cancer will be a treatable medical condition instead of a death sentence for a patient.

    MeSH terms: Clinical Studies as Topic; Combined Modality Therapy; Humans; Immunotherapy; Macrophages/drug effects; Macrophages/immunology; Macrophages/metabolism; Pancreatic Neoplasms/immunology*; Pancreatic Neoplasms/metabolism; Pancreatic Neoplasms/pathology; Pancreatic Neoplasms/therapy*; T-Lymphocytes/drug effects; T-Lymphocytes/immunology; T-Lymphocytes/metabolism; Biomarkers, Tumor; Lymphocytes, Tumor-Infiltrating/drug effects; Lymphocytes, Tumor-Infiltrating/immunology; Lymphocytes, Tumor-Infiltrating/metabolism; Immunocompromised Host*; Treatment Outcome; Immunomodulation/drug effects*; Molecular Targeted Therapy; Tumor Microenvironment/drug effects*; Tumor Microenvironment/immunology*; Cancer-Associated Fibroblasts/drug effects; Cancer-Associated Fibroblasts/immunology; Cancer-Associated Fibroblasts/metabolism
  2. Chong SS, Hoh SY, Huang SM
    Asian J Surg, 2019 Nov;42(11):957-962.
    PMID: 30987945 DOI: 10.1016/j.asjsur.2019.01.015
    BACKGROUND: Hemithyroidectomy has a known but less predictable sequelae of hypothyroidism. Presence of anti-thyroid antibody is known, well studied risk factor. Other postulated risk factors include higher pre-operative TSH level and lower ratio of post-operative thyroid remnant to the patient's weight. We reviewed our data to address the above mentioned risk factors.

    METHOD: This was a retrospective study done in National Cheng Kung University Hospital, Taiwan from 2015 to 2017. 125 patients underwent hemithyroidectomy, but 24 patients were excluded due to autoimmune thyroiditis, which was determined as the exclusion criteria. Standard panel of blood investigations were taken in each clinic visit before and after operation. A neck ultrasound was done 2 months post-operatively to assess the thyroid remnant. Chi-square test was used for categorical data analysis. Independent student t-test was used for continuous data with parametric distribution and Mann-Whitney U test for non parametric data. p 2.0 uIU/mL was a risk factor as Chi square test showed p 

    MeSH terms: Adolescent; Adult; Aged; Aged, 80 and over; Female; Follow-Up Studies; Humans; Hypothyroidism/etiology*; Hypothyroidism/epidemiology; Male; Middle Aged; Postoperative Complications; Retrospective Studies; Risk Factors; Taiwan; Thyroidectomy/adverse effects*; Thyroidectomy/methods; Thyroiditis, Autoimmune; Time Factors; Incidence; Chi-Square Distribution; Young Adult
  3. Naveen J, Jawaid M, Zainudin ES, Thariq Hameed Sultan M, Yahaya R
    Materials (Basel), 2019 Apr 16;12(8).
    PMID: 30988270 DOI: 10.3390/ma12081249
    This research investigated the effect of adding different wt.% (0, 0.25, 0.50, and 0.75) of GNP (graphene nanoplatelets) to improve the mechanical and moisture resistant properties of Kevlar (K)/cocos nucifera sheath (CS)/epoxy hybrid composites. The laminates were fabricated with different K/CS weight ratios such as 100/0 (S1), 75/25 (S2), 50/50 (S3), 25/75 (S4), and 0/100 (S5). The results revealed that the addition of GNP improved the tensile, flexural, and impact properties of laminated composites. However, the optimal wt.% of GNP varies with different laminates. A moisture diffusion analysis showed that the laminates with a 0.25 wt.% of GNP content efficiently hindered water uptake by closing all the unoccupied pores inside the laminate. Morphological investigations (SEM and FE-SEM (Field Emission Scanning Electron Microscope)) proved that the addition of GNP improved the interfacial adhesion and dispersion. Structural (XRD and FTIR) analyses reveals that at 0.25 wt.% of GNP, all the hybrid composites showed a better crystallinity index and the functional groups presents in the GNP can form strong interactions with the fibers and matrix. A statistical analysis was performed using One-way ANOVA, and it corroborates that the mechanical properties of different laminates showed a statistically significant difference. Hence, these GNP-modified epoxy hybrid composites can be efficiently utilized in load-bearing structures.
  4. Woo WK, Dzaki N, Thangadurai S, Azzam G
    Sci Rep, 2019 Apr 15;9(1):6096.
    PMID: 30988367 DOI: 10.1038/s41598-019-42369-6
    CTP synthase (CTPSyn) is an essential metabolic enzyme, synthesizing precursors required for nucleotides and phospholipids production. Previous studies have also shown that CTPSyn is elevated in various cancers. In many organisms, CTPSyn compartmentalizes into filaments called cytoophidia. In Drosophila melanogaster, only its isoform C (CTPSynIsoC) forms cytoophidia. In the fruit fly's testis, cytoophidia are normally seen in the transit amplification regions close to its apical tip, where the stem-cell niche is located, and development is at its most rapid. Here, we report that CTPSynIsoC overexpression causes the lengthening of cytoophidia throughout the entirety of the testicular body. A bulging apical tip is found in approximately 34% of males overexpressing CTPSynIsoC. Immunostaining shows that this bulged phenotype is most likely due to increased numbers of both germline cells and spermatocytes. Through a microRNA (miRNA) overexpression screen, we found that ectopic miR-975 concurrently increases both the expression levels of CTPSyn and the length of its cytoophidia. The bulging testes phenotype was also recovered at a penetration of approximately 20%. However, qPCR assays reveal that CTPSynIsoC and miR-975 overexpression each provokes a differential response in expression of a number of cancer-related genes, indicating that the shared CTPSyn upregulation seen in either case is likely the cause of observed testicular overgrowth. This study presents the first instance of consequences of miRNA-asserted regulation upon CTPSyn in D. melanogaster, and further reaffirms the enzyme's close ties to germline cells overgrowth.
    MeSH terms: Animals; Cell Differentiation; Cytoskeleton/metabolism*; Drosophila melanogaster/enzymology*; Isoenzymes/metabolism; Male; Spermatocytes/cytology*; Testis/cytology*; Carbon-Nitrogen Ligases/metabolism*; Drosophila Proteins/metabolism; MicroRNAs/genetics*; Cell Proliferation; Stem Cell Niche
  5. Lim CC, Woo PCY, Lim TS
    Sci Rep, 2019 Apr 15;9(1):6088.
    PMID: 30988390 DOI: 10.1038/s41598-019-42628-6
    Antibody phage display has been pivotal in the quest to generate human monoclonal antibodies for biomedical and research applications. Target antigen preparation is a main bottleneck associated with the panning process. This includes production complexity, downstream purification, quality and yield. In many instances, purified antigens are preferred for panning but this may not be possible for certain difficult target antigens. Here, we describe an improved procedure of affinity selection against crude or non-purified antigen by saturation of non-binders with blocking agents to promote positive binder enrichment termed as Yin-Yang panning. A naïve human scFv library with kappa light chain repertoire with a library size of 109 was developed. The improved Yin-Yang biopanning process was able to enrich monoclonal antibodies specific to the MERS-CoV nucleoprotein. Three unique monoclonal antibodies were isolated in the process. The Yin-Yang biopanning method highlights the possibility of utilizing crude antigens for the isolation of monoclonal antibodies by phage display.
    MeSH terms: Antibodies, Viral/immunology; Antibodies, Viral/isolation & purification*; Antigens, Viral/immunology*; Feasibility Studies; Humans; Immunoglobulin kappa-Chains/immunology; Immunoglobulin kappa-Chains/isolation & purification; Nucleocapsid Proteins/immunology*; Single-Chain Antibodies/immunology; Single-Chain Antibodies/isolation & purification; Cell Surface Display Techniques/methods*; Bioprospecting/methods*; Middle East Respiratory Syndrome Coronavirus/immunology*
  6. Hammad MA, Syed Sulaiman SA, Aziz NA, Mohamed Noor DA
    J Res Med Sci, 2019;24:15.
    PMID: 30988683 DOI: 10.4103/jrms.JRMS_100_18
    Background: Statins are recommended for cardiovascular protection for people with diabetes (high-risk groups). This study aimed to evaluate the gap between the guidelines of statin utilization and clinical practice among outpatients with type 2 diabetes regarding the patient's age and gender, to assess if this preventive drug is being satisfactorily utilized or not.

    Materials and Methods: In this cross-sectional study, patients aged <40 or >75 years, pregnant patients, and patients with type 1 diabetes, human immunodeficiency virus, or liver cirrhosis were excluded. Demographics, laboratory parameters, and prevalence of exposure to statin therapy were evaluated. This study was guided by the 2013 American College of Cardiology/American Heart Association cholesterol guidelines. IBM SPSS software was used for data management.

    Results: The study cohort involved 576 patients, with age being 58.3 ± 8.9 years. There were 50.5% of females and 49.5% of males. Overall 81.1% of patients aged 58.8 ± 8.8 years were statin users and 18.9% of patients aged 56.2 ± 9 years were statin nonusers. About 83.2% of females and 78.9% of males were prescribed statins. Statin medications included simvastatin 79.2%, atorvastatin 11.6%, lovastatin 5.8%, rosuvastatin 2.1%, and pravastatin 1.3%. Statin users' and nonusers' adherence was 56.5%, and 41.3% (P = 0.004), respectively. The adherence to medication plan of females and males was 55.7% and 51.6%, respectively (P = 0.004).

    Conclusion: Patients with diabetes who are at high risk of cardiovascular events, exposure to statin treatment is significantly less than perfect position both in females and males. Nearly one-fifth of the patients with type 2 diabetes are not using statins despite therapeutic necessities.

  7. Muhamad SA, Muhammad NS, Ismail NDA, Mohamud R, Safuan S, Nurul AA
    Exp Ther Med, 2019 May;17(5):3867-3876.
    PMID: 30988772 DOI: 10.3892/etm.2019.7416
    Asthma is a chronic inflammatory disorder in the airways that involves the activation of cells and mediators. Lignosus rhinocerotis (Cooke) Ryvardan or Tiger Milk mushroom is a medicinal mushroom that is traditionally used to treat inflammatory diseases including asthma. In this study, the protective effects of intranasal administration of L. rhinocerotis extract (LRE) in ovalbumin (OVA)-induced airway inflammation mouse model were investigated. Mice were sensitized by intraperitoneal (i.p) injection on days 0 and 14, followed by a daily challenge with 1% OVA from days 21 to 27. Following OVA challenge, LRE and dexamethasone were administered via intranasal and i.p. injection respectively. On day 28, the level of serum immunoglobulin (Ig)E, differential cell counts and T-helper (Th) 2 cytokines in bronchoalveolar lavage fluid (BALF) fluid, cell subset population in lung-draining lymph nodes (LNs), leukocytes infiltration and mucus production in the lungs of the animals was measured. Results demonstrated that intranasal administration of LRE significantly suppressed the level of inflammatory cell counts in BALF as well as populations of CD4+ T-cells in lung draining LNs. Apart from that, LRE also significantly reduced the level of Th2 cytokines in BALF and IgE in the serum in OVA-induced asthma. Histological analysis also demonstrated the amelioration of leukocytes infiltration and mucus production in the lungs. Overall, these findings demonstrated the attenuation of airway inflammation in the LRE-treated mice therefore suggesting a promising alternative for the management of allergic airway inflammation.
    MeSH terms: Administration, Intranasal; Agaricales; Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cell Count; Dexamethasone; Immunoglobulin E; Inflammation; Lung; Lymph Nodes; Mucus; Ovalbumin; CD4-Positive T-Lymphocytes; Cytokines; Mice
  8. Ong MH, Wong HK, Tengku-Muhammad TS, Choo QC, Chew CH
    Mol Biol Rep, 2019 Jun;46(3):2631-2641.
    PMID: 30989556 DOI: 10.1007/s11033-019-04661-6
    The prevalence of atherosclerosis has increased significantly in the recent years due to sedentary lifestyle and high-fat diet. However, the association between saturated fat intake and the increased risk for atherosclerotic cardiovascular diseases remains heavily debated. Lauric acid belongs to the saturated fatty acid group and its unique medium chain fatty acid properties are proven to be beneficial to humans in many ways. Thus, the aim of this project is to investigate the effect of lauric acid on the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) genes-ADAMTS-1, ADAMTS-4, and ADAMTS-5-in macrophages. These genes encode for proteases that participate in the extracellular matrix remodeling and they play important roles in the vulnerability of atherosclerotic plaque. Here, we show that the treatment of 20 µM of lauric acid successfully reduced both transcriptional and translational expressions of these genes in THP-1 differentiated macrophages after 24-h incubation. Further cell signaling experiments using a panel of kinase inhibitors and phosphorylated antibodies proved that lauric acid down-regulated ADAMTS-1 by reducing the activation of PI3K and JNK at Tyr458 and Tyr185, respectively. Finally, JNK1 siRNA knockdown assay confirmed that ADAMTS-1 was regulated through JNK pathway, and lauric acid interfered with this pathway to down-regulate ADAMTS-1 expression. Although preliminary, this present study indicates that lauric acid has the potential to stabilize atherosclerotic plaque and may prevent thrombosis by interfering with the ADAMTS-1 expression through PI3K/JNK pathways.
    MeSH terms: Humans; Lauric Acids/pharmacology*; Macrophages/drug effects*; Macrophages/metabolism; Metalloendopeptidases/metabolism; Signal Transduction; Down-Regulation/drug effects; Gene Expression; Matrix Metalloproteinase 3/metabolism; Phosphatidylinositol 3-Kinases/metabolism; MAP Kinase Signaling System/drug effects*; Atherosclerosis/metabolism*; ADAMTS1 Protein/biosynthesis; ADAMTS1 Protein/genetics; ADAMTS1 Protein/metabolism*
  9. Yau MQ, Emtage AL, Chan NJY, Doughty SW, Loo JSE
    J Comput Aided Mol Des, 2019 05;33(5):487-496.
    PMID: 30989574 DOI: 10.1007/s10822-019-00201-3
    The recent expansion of GPCR crystal structures provides the opportunity to assess the performance of structure-based drug design methods for the GPCR superfamily. Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA)-based methods are commonly used for binding affinity prediction, as they provide an intermediate compromise of speed and accuracy between the empirical scoring functions used in docking and more robust free energy perturbation methods. In this study, we systematically assessed the performance of MM/PBSA in predicting experimental binding free energies using twenty Class A GPCR crystal structures and 934 known ligands. Correlations between predicted and experimental binding free energies varied significantly between individual targets, ranging from r = - 0.334 in the inactive-state CB1 cannabinoid receptor to r = 0.781 in the active-state CB1 cannabinoid receptor, while average correlation across all twenty targets was relatively poor (r = 0.183). MM/PBSA provided better predictions of binding free energies compared to docking scores in eight out of the twenty GPCR targets while performing worse for four targets. MM/PBSA binding affinity predictions calculated using a single, energy minimized structure provided comparable predictions to sampling from molecular dynamics simulations and may be more efficient when computational cost becomes restrictive. Additionally, we observed that restricting MM/PBSA calculations to ligands with a high degree of structural similarity to the crystal structure ligands improved performance in several cases. In conclusion, while MM/PBSA remains a valuable tool for GPCR structure-based drug design, its performance in predicting the binding free energies of GPCR ligands remains highly system-specific as demonstrated in a subset of twenty Class A GPCRs, and validation of MM/PBSA-based methods for each individual case is recommended before prospective use.
    MeSH terms: Humans; Protein Binding; Protein Conformation; Thermodynamics; Drug Design; Receptors, G-Protein-Coupled/metabolism; Receptors, G-Protein-Coupled/chemistry*; Molecular Dynamics Simulation; Molecular Docking Simulation
  10. Stucki G, Pollock A, Engkasan JP, Selb M
    Eur J Phys Rehabil Med, 2019 Jun;55(3):384-394.
    PMID: 30990004 DOI: 10.23736/S1973-9087.19.05808-8
    Rehabilitation aims to optimize functioning of persons experiencing functioning limitations. As such the comparative evaluation of rehabilitation interventions relies on the analysis of the differences between the change in patient functioning after a specific rehabilitation intervention versus the change following another intervention. A robust health information reference system that can facilitate the comparative evaluation of changes in functioning in rehabilitation studies and the standardized reporting of rehabilitation interventions is the International Classification of Functioning, Disability and Health (ICF). The objective of this paper is to present recommendations that Cochrane Rehabilitation could adopt for using the ICF in rehabilitation studies by: 1) defining the functioning categories to be included in a rehabilitation study; 2) specifying selected functioning categories and selecting suitable data collection instruments; 3) examining aspects of functioning that have been documented in a study; 4) reporting functioning data collected with various data collection instruments; and 5) communicating results in an accessible, meaningful and easily understandable way. The authors provide examples of concrete studies that underscore these recommendations, whereby also emphasizing the need for future research on the implementation of specific recommendations, e.g. in meta-analysis in systematic literature reviews. Furthermore, the paper outlines how the ICF can complement or be integrated in established Cochrane and rehabilitation research structures and methods, e.g. use of standard mean difference to compare cross-study data collected using different measures, in developing core outcome sets for rehabilitation, and the use of the PICO model.
    MeSH terms: Rehabilitation Research/standards*; Activities of Daily Living/classification*; Disabled Persons/rehabilitation*; Humans; Outcome Assessment (Health Care)*; International Classification of Functioning, Disability and Health*
  11. Mohamad Marzuki MF, Yaacob NA, Bin Yaacob NM, Abu Hassan MR, Ahmad SB
    JMIR Hum Factors, 2019 Apr 16;6(2):e12103.
    PMID: 30990454 DOI: 10.2196/12103
    BACKGROUND: Participation in colorectal cancer screening is still low among Malaysians despite the increasing trend of incidence, with more than half of the new cases being detected in the advanced stages. Knowledge improvement might increase screening participation and thus improve the chances of disease detection. With the advancement of communication technology, people nowadays prefer to read from their mobile phone using a Web browser or mobile apps compared with the traditional printed material. Therefore, health education and promotion should adapt this behavior change in educating the community.

    OBJECTIVE: This study aimed to document the process of designing and developing a mobile app for community education on colorectal cancer and assess the usability of the prototype.

    METHODS: The nominal group technique (NGT) was used for the content development of the mobile app. NGT involving community educationists and clinicians combined with community representatives as the target users identified relevant health information and communication strategies including features for a user-friendly mobile app. The prototype was developed using framework Ionic 1, based on the Apache Cordova and Angular JS (Google). It was published in the Google Play store. In total, 50 mobile phone users aged 50 years and above and who had never been diagnosed with any type of cancer were invited to download and use the app. They were asked to assess the usability of the app using the validated Malay version of System Usability Scale Questionnaire for the Assessment of Mobile Apps questionnaire. The One-sample t test was used to assess the usability score with a cut-off value of 68 for the usable mobile app.

    RESULTS: The Colorectal Cancer Awareness Application (ColorApp) was successfully developed in the local Malay language. The NGT discussion had suggested 6 main menus in the ColorApp prototype, which are Introduction, Sign and Symptoms, Risk Factors, Preventive Measures, Colorectal Cancer Screening Program, and immunochemical fecal occult blood test kit. A total of 2 additional artificial intelligence properties menus were added to allow user-ColorApp interaction: Analyze Your Status and ColorApp Calculator. The prototype has been published in the Google Play store. The mean usability score was 72 (SD 11.52), which indicates that ColorApp is a usable mobile app, and it can be used as a tool for community education on colorectal cancer.

    CONCLUSIONS: ColorApp mobile app can be used as a user-friendly tool for community education on colorectal cancer.

    MeSH terms: Artificial Intelligence; Health Education; Language; Malaysia; Occult Blood; Surveys and Questionnaires; Risk Factors; Colorectal Neoplasms; Incidence; Early Detection of Cancer; Mobile Applications; Web Browser
  12. Hassan RA, Heng LY, Ahmad A, Tan LL
    PLoS One, 2019;14(4):e0214580.
    PMID: 30990847 DOI: 10.1371/journal.pone.0214580
    A potentiometric whole cell biosensor based on immobilized marine bacterium, Pseudomonas carrageenovora producing κ-carrageenase and glycosulfatase enzymes for specific and direct determination of κ-carrageenan, is described. The bacterial cells were immobilized on the self-plasticized hydrogen ion (H+)-selective acrylic membrane electrode surface to form a catalytic layer. Hydrogen ionophore I was incorporated in the poly(n-butyl acrylate) [poly(nBA)] as a pH ionophore. Catalytic decomposition of κ-carrageenan by the bienzymatic cascade reaction produced neoagarobiose, an inorganic sulfate ion and a proton. The latter was detectable by H+ ion transducer for indirect potentiometric quantification of κ-carrageenan concentration. The use of a disposable screen-printed Ag/AgCl electrode (SPE) provided no cleaning requirement and enabled κ-carrageenan detection to be carried out conveniently without cross contamination in a complex food sample. The SPE-based microbial biosensor response was found to be reproducible with high reproducibility and relative standard deviation (RSD) at 2.6% (n = 3). The whole cell biosensor demonstrated a broad dynamic linear response range to κ-carrageenan from 0.2-100 ppm in 20 mM phosphate buffer saline (PBS) at pH 7.5 with a detection limit at 0.05 ppm and a Nernstian sensitivity of 58.78±0.87 mV/decade (R2 = 0.995). The biosensor showed excellent selectivity towards κ-carrageenan compared to other types of carrageenans tested e.g. ι-carrageenan and λ-carrageenan. No pretreatment to the food sample was necessary when the developed whole cell biosensor was employed for direct assay of κ-carrageenan in dairy product.
    MeSH terms: Algorithms; Bacterial Proteins/metabolism; Carrageenan/analysis*; Culture Media; Electrodes; Hydrogen; Ions; Kinetics; Potentiometry/methods*; Pseudomonas/metabolism*; Time Factors; Reproducibility of Results; Biosensing Techniques*; Linear Models; Cells, Immobilized/metabolism; Limit of Detection
  13. Sharin Ab Ghani, Idris Mohd Yusoff
    MyJurnal
    As the lighting load constituted amount of power in electricity system, improving of efficiency in lighting technology would make a beneficial to consumer, energy provider and environment. Consequently, majority of home lighting manufacturers were competing each other by improving and claiming their product as the best energy efficient lighting product. Knowledge or exposure regarding to lighting technology especially on energy efficiency, power quality and economy are an important issues to give awareness to user before buy or use the lighting product. Therefore in this research study, three types of lighting product such as energy saving incandescent lighting, compact fluorescent lighting (CFL) and solid state lighting (LED) were compared. Comparative parameters were collected from data provided by lighting manufacturer and experimental data conducted in laboratory using power quality meter and lux meter. Hence, these study discussed in term of economy, power and light quality and energy efficiency of the tested lighting product. At the end of this study, the best home lighting technology is determined successfully.
    MeSH terms: Electricity; Household Articles; Light; Lighting; Incandescence
  14. Hazura Haroon, Abdul Aziz Abu Mansor, Hanim Abdul Razak, Siti Khadijah Idris, Anis Suhaila Mohd Zain, Fauziyah Salehuddin
    MyJurnal
    An investigation of bending loss characteristics of a Polymer Optical Fiber is presented experimentally. Loss of optical power in an optical fiber due to bending has been investigated for a wavelength of 650 nm. Variations of bending loss with different lengths have been measured, with a number of radii of curvature. Bending Loss equations for short length POF is proposed, which shows the dependence of bending loss on the curvature radii. The equations can be an initial reference or aid in predicting the loss contributes by the polymer optical fiber.
    MeSH terms: Fiber Optic Technology; Polymers; Refractometry; Optical Fibers
  15. Goh CF, Moffat JG, Craig DQM, Hadgraft J, Lane ME
    Mol Pharm, 2019 01 07;16(1):359-370.
    PMID: 30525649 DOI: 10.1021/acs.molpharmaceut.8b01027
    Drug crystallization on and in the skin has been reported following application of topical or transdermal formulations. This study explored novel probe-based approaches including localized nanothermal analysis (nano-TA) and photothermal microspectroscopy (PTMS) to investigate and locate drug crystals in the stratum corneum (SC) of porcine skin following application of simple ibuprofen (IBU) formulations. We also conducted in vitro skin permeation studies and tape stripping. The detection of drug crystals in the SC on tape strips was confirmed using localized nano-TA, based on the melting temperature of IBU. The melting of IBU was also evident as indicated by a double transition and confirmed the presence of drug crystals in the SC. The single point scans of PTMS on the tape strips allowed collection of the photothermal FTIR spectra of IBU, confirming the existence of drug crystals in the skin. The combined methods also indicated that drug crystallized in the SC at a depth of ∼4-7 μm. Future studies will examine the potential of these techniques to probe crystallization of other commonly used actives in topical and transdermal formulations.
    MeSH terms: Animals; Crystallization/methods*; Epidermis/metabolism*; Ibuprofen/metabolism; Ibuprofen/chemistry; Skin Absorption; Swine; Microspectrophotometry/methods*; Spectroscopy, Fourier Transform Infrared
  16. Tan KH, Chen YW, Van CN, Wang H, Chen JW, Lim FS, et al.
    ACS Appl Mater Interfaces, 2019 Jan 09;11(1):1655-1664.
    PMID: 30561192 DOI: 10.1021/acsami.8b17758
    The ability of band offsets at multiferroic/metal and multiferroic/electrolyte interfaces in controlling charge transfer and thus altering the photoactivity performance has sparked significant attention in solar energy conversion applications. Here, we demonstrate that the band offsets of the two interfaces play the key role in determining charge transport direction in a downward self-polarized BFO film. Electrons tend to move to BFO/electrolyte interface for water reduction. Our experimental and first-principle calculations reveal that the presence of neodymium (Nd) dopants in BFO enhances the photoelectrochemical performance by reduction of the local electron-hole pair recombination sites and modulation of the band gap to improve the visible light absorption. This opens a promising route to the heterostructure design by modulating the band gap to promote efficient charge transfer.
    MeSH terms: Attention; Electrolytes; Electrons; Light; Metals; Neodymium; Recombination, Genetic; Solar Energy; Water; Physical Phenomena
  17. Khyasudeen MF, Nowakowski PJ, Tan HS
    J Phys Chem B, 2019 02 14;123(6):1359-1364.
    PMID: 30657672 DOI: 10.1021/acs.jpcb.9b00099
    We use two-dimensional electronic spectroscopy to measure the ultrafast correlation dynamics between the Q x and Q y transitions in chlorophyll molecules. We derive a variation to the center line slope method to quantify the frequency fluctuation cross-correlation function, C xy( Tw). Compared with the frequency fluctuation correlation function of the Q y transition, we observe that there is only a minimal correlation between the Q x and Q y transition, even at the ultrashort timescale of ∼100 fs, which then decays to zero in a time scale of ∼2 ps.
    MeSH terms: Energy Transfer; Porphyrins/chemistry*; Photoelectron Spectroscopy
  18. Olesen AP, Amin L, Mahadi Z, Ibrahim M
    Account Res, 2019 04;26(3):157-175.
    PMID: 30982340 DOI: 10.1080/08989621.2019.1607312
    The purpose of this study is to highlight the experiences of individuals who participate in the Responsible Conduct of Research (RCR) training program held at various universities in Malaysia. In response to a mailing request sent to 40 individuals who had undertaken a RCR training program, 15 participants agreed to be interviewed. The results of the study showed that the three main reasons for participating in the training were as follows: anticipation for knowledge gained; personal experience with research misconduct; and establishing a new network of researchers. In terms of the positive effects gained from undertaking the training, the participants highlighted an increased awareness of the issues and problems related to research misconduct; the need to promote integrity in research conduct; a change in the way they conduct their research; and a change in the way they confront and address misconduct. The findings of this study should be valuable for policy makers and those involved in the management of research programs and ethics, as it demonstrated the importance of RCR training in equipping researchers with the necessary knowledge to conduct research responsibly, and to avoid research misconduct.
    MeSH terms: Female; Humans; Interviews as Topic; Malaysia; Male; Research Personnel/psychology*; Universities; Ethics, Research/education*; Qualitative Research
  19. Lall P, Saifi R, Baggio D, Schoenberger SF, Choo M, Gilbert L, et al.
    Asia Pac J Public Health, 2019 04;31(3):227-237.
    PMID: 30983376 DOI: 10.1177/1010539519841294
    Malaysia currently has an estimated hepatitis C virus (HCV) prevalence of 1.3% with an infected population of 384,000. Fishermen in Malaysia are at risk of HCV infection due to injection drug use and disproportionately high rates of incarceration. This study used quantitative data from Project WAVES, a large-scale mixed methods project charting environmental drivers of risk-taking behaviors among a respondent-driven sample of 406 fishermen in Malaysia. Over a quarter of participants (27.9%) reported injecting drugs in the past month; 49.8% of the sample tested positive for HCV. Respondents who had previously been arrested displayed increased odds of being HCV-positive (adjusted odds ratio = 4.79, confidence Interval = 2.46-9.35). Participants who reported being in lock-up displayed close to 6-fold odds of being HCV-infected (adjusted odds ratio = 5.49, confidence interval = 2.77-10.90, P < .001). These findings underscore the need for policies and structural interventions targeting the negative effects of aggressive incarceration contributing to the burden of HCV among high-risk communities.
    MeSH terms: Adolescent; Adult; Fisheries*; Hepatitis C/epidemiology*; Humans; Malaysia/epidemiology; Male; Middle Aged; Prisoners/statistics & numerical data; Risk Factors; Substance Abuse, Intravenous/epidemiology; Prevalence; Young Adult
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