Displaying publications 1 - 20 of 51 in total

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  1. Ahmad Saffian H, Talib MA, Lee SH, Md Tahir P, Lee CH, Ariffin H, et al.
    Polymers (Basel), 2020 Aug 15;12(8).
    PMID: 32824275 DOI: 10.3390/polym12081833
    Mechanical strength, thermal conductivity and electrical breakdown of polypropylene/lignin/kenaf core fiber (PP/L/KCF) composite were studied. PP/L, PP/KCF and PP/L/KCF composites with different fiber and lignin loading was prepared using a compounding process. Pure PP was served as control. The results revealed that tensile and flexural properties of the PP/L/KCF was retained after addition of lignin and kenaf core fibers. Thermal stability of the PP composites improved compared to pure PP polymer. As for thermal conductivity, no significant difference was observed between PP composites and pure PP. However, PP/L/KCF composite has higher thermal diffusivity. All the PP composites produced are good insulating materials that are suitable for building. All PP composites passed withstand voltage test in air and oil state as stipulated in IEC 60641-3 except PP/L in oil state. SEM micrograph showed that better interaction and adhesion between polymer matrix, lignin and kenaf core fibers was observed and reflected on the better tensile strength recorded in PP/L/KCF composite. This study has successfully filled the gap of knowledge on using lignin and kenaf fibers as PP insulator composite materials. Therefore, it can be concluded that PP/Lignin/KCF has high potential as an insulating material.
  2. Ahmad Saffian H, Hyun-Joong K, Md Tahir P, Ibrahim NA, Lee SH, Lee CH
    Materials (Basel), 2019 Dec 05;12(24).
    PMID: 31817323 DOI: 10.3390/ma12244043
    In this study, the effects of lignin modification on the properties of kenaf core fiber reinforced poly(butylene succinate) biocomposites were examined. A weight percent gain (WPG) value of 30.21% was recorded after the lignin were modified with maleic anhydride. Lower mechanical properties were observed for lignin composites because of incompatible bonding between the hydrophobic matrix and the hydrophilic lignin. Modified lignin (ML) was found to have a better interfacial bonding, since maleic anhydrides remove most of the hydrophilic hydrogen bonding (this was proven by a Fourier-transform infrared (FTIR) spectrometer-a reduction of broadband near 3400 cm-1, corresponding to the -OH stretching vibration of hydroxyl groups for the ML samples). On the other hand, ML was found to have a slightly lower glass transition temperature, Tg, since reactions with maleic anhydride destroy most of the intra- and inter-molecular hydrogen bonds, resulting in a softer structure at elevated temperatures. The addition of kraft lignin was found to increase the thermal stability of the PBS polymer composites, while modified kraft lignin showed higher thermal stability than pure kraft lignin and possessed delayed onset thermal degradation temperature.
  3. Ai JY, Kuan G, Juang LY, Lee CH, Kueh YC, Chu IH, et al.
    Int J Environ Res Public Health, 2022 Nov 22;19(23).
    PMID: 36497548 DOI: 10.3390/ijerph192315472
    Sleep is a crucial factor in healthy aging. However, most middle-aged adults experience high levels of sleep disorders. While previous findings have suggested exercise training could benefit the quality of sleep, the effects of multi-component exercise on sleep quality are less examined. Accordingly, the current study aimed to assess the effectiveness of a multi-component exercise program on the quality of sleep among middle-aged adults. Twenty-four middle-aged adults were randomly assigned either to a multi-component exercise (MCE) group or a control group. The participants in the MCE group attended a 90-min session per week for 12 weeks. The control group was instructed to maintain their daily routine for 12 weeks. The primary outcome was the sleep quality evaluated by the Pittsburgh Sleep Quality Index (PSQI). The secondary outcome was physical fitness, including muscular strength and endurance, balance, and flexibility. Regarding sleep quality, the global mean score (p = 028), sleep disturbances (p = 011), and sleep efficiency (p = 035) of the PSQI scores were significantly reduced in the MCE group after the 12-week intervention. Regarding physical fitness, the flexibility of the MCE group improved significantly after the intervention (p = 028), yet, no significant change was observed in the control group. Additionally, the muscular strength of the control group declined significantly after the 12-week period (p = 034). Our results revealed the effectiveness of the MCE intervention in improving sleep quality and physical fitness in middle-aged adults. Further studies using larger sample sizes, objective measures of sleep quality, different types of exercise training, as well as different populations, are warranted to extend our current findings.
  4. Aisyah HA, Paridah MT, Sapuan SM, Ilyas RA, Khalina A, Nurazzi NM, et al.
    Polymers (Basel), 2021 Feb 02;13(3).
    PMID: 33540731 DOI: 10.3390/polym13030471
    Over the last decade, the progressive application of natural fibres in polymer composites has had a major effect in alleviating environmental impacts. Recently, there is a growing interest in the development of green materials in a woven form by utilising natural fibres from lignocellulosic materials for many applications such as structural, non-structural composites, household utilities, automobile parts, aerospace components, flooring, and ballistic materials. Woven materials are one of the most promising materials for substituting or hybridising with synthetic polymeric materials in the production of natural fibre polymer composites (NFPCs). These woven materials are flexible, able to be tailored to the specific needs and have better mechanical properties due to their weaving structures. Seeing that the potential advantages of woven materials in the fabrication of NFPC, this paper presents a detailed review of studies related to woven materials. A variety of factors that influence the properties of the resultant woven NFRC such as yarn characteristics, fabric properties as well as manufacturing parameters were discussed. Past and current research efforts on the development of woven NFPCs from various polymer matrices including polypropylene, polylactic acid, epoxy and polyester and the properties of the resultant composites were also compiled. Last but not least, the applications, challenges, and prospects in the field also were highlighted.
  5. Aisyah HA, Paridah MT, Khalina A, Sapuan SM, Wahab MS, Berkalp OB, et al.
    Polymers (Basel), 2018 Nov 28;10(12).
    PMID: 30961245 DOI: 10.3390/polym10121320
    The effects of different fabric materials namely weave designs (plain and satin) and fabric counts (5 × 5 and 6 × 6) on the properties of laminated woven kenaf/carbon fibre reinforced epoxy hybrid composites were evaluated. The hybrid composites were fabricated from two types of fabric, i.e., woven kenaf that was made from a yarn of 500tex and carbon fibre, by using vacuum infusion technique and epoxy resin as matrix. The panels were tested for tensile, flexural, and impact strengths. The results have revealed that plain fabric is more suitable than satin fabric for obtaining high tensile and impact strengths. Using a fabric count of 5 × 5 has generated composites that are significantly higher in flexural modulus as compared to 6 × 6 which may be attributed to their structure and design. The scanned electron micrographs of the fractured surfaces of the composites demonstrated that plain woven fabric composites had better adhesion properties than satin woven fabric composites, as indicated by the presence of notably lower amount of fibre pull out.
  6. Ayu RS, Khalina A, Harmaen AS, Zaman K, Mohd Nurrazi N, Isma T, et al.
    Sci Rep, 2020 01 24;10(1):1166.
    PMID: 31980742 DOI: 10.1038/s41598-020-58278-y
    In this study, it focused on empty fruit brunch (EFB) fibres reinforcement in polybutylene succinate (PBS) with modified tapioca starch by using hot press technique for the use of agricultural mulch film. Mechanical, morphological and thermal properties were studied. Mechanical analysis showed decreased in values of modulus strength for both tensile and flexural testing for fibres insertion. Higher EFB fibre contents in films resulted lower mechanical properties due to poor fibre wetting from insufficient matrix. This has also found evident in SEM micrograph, showing poor interfacial bonding. Water vapour permeability (WVP) shows as higher hydrophilic EFB fibre reinforcement contents, the rate of WVP also increase. Besides this, little or no significant changes on thermal properties for composite films. This is because high thermal stability PBS polymer show its superior thermal properties dominantly. Even though EFB fibres insertion into PBS/tapioca starch biocomposite films have found lower mechanical properties. It successfully reduced the cost of mulch film production without significant changes of thermal performances.
  7. Ayu RS, Khalina A, Harmaen AS, Zaman K, Jawaid M, Lee CH
    Polymers (Basel), 2018 Oct 25;10(11).
    PMID: 30961112 DOI: 10.3390/polym10111187
    In this study, polybutylene succinate (PBS) was blended with five types of modified tapioca starch to investigate the effect of modified tapioca starch in PBS blends for food packaging by identifying its properties. Tensile and flexural properties of blends found deteriorated for insertion of starch. This is due to poor interface, higher void contents and hydrolytic degradation of hydrophilic starch. FTIR results show all starch/PBS blends are found with footprints of starch except OH stretching vibration which is absent in B40 blends. Besides, Broad O⁻H absorption in all specimens show that these are hydrogen bonded molecules and no free O⁻H bonding was found. SEM testing shows good interfacial bonding between PBS and starch except E40 blends. Therefore, poor results of E40 blends was expected. In TGA, a slightly weight loss found between 80 to 100 °C due to free water removal. Apart from this, insertion of all types of starch reduces thermal stability of blend. However, high crystallinity of starch/PBS blend observed better thermal stability but lower char yield. Starch A and B blends are suggested to be used as food wrap and food container materials while starch D blend is suitable for grocery plastic bags according to observed results.
  8. Azib FN, Lee CH, Mohd Yusof NM, Yusuf N, Mohd Fuad NF, Saharuddin NS, et al.
    MyJurnal
    1st UMS INTERNATIONAL NURSING CONFERENCE IN CONJUNCTION WITH 11TH INTERNATIONAL NURSING STUDENTS’ FORUM
    A view into the future of nursing: Nursing Transformation towards IR-4.0, Held at the Faculty of Medicine and Health Sciences,, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia, On 6-8th March 2020
    Introduction: Delayed wound healing and a hefty cost of treatment poses a burden to those undergoing treatment for Diabetic wound care. An alternative wound product to speed up wound healing may address this problem. Honey has been recognized around the world for its efficacy as treating wounds, eczema, and inflammation while cinnamon has a variety of biological functions including anti-diabetic, anti-microbial, and anti-inflammatory. As both cinnamon and honey possess different properties in wound healing, it is hypothesized that combining both products can accelerate wound healing. This study is to compare the efficacy of pure honey, pure cinnamon and honey-cinnamon commixture in diabetic wound healing.
    Methods: Three volunteers were selected from Kitamura clinic, Pontianak, Indonesia participated in this study. Each of them was given a different wound product which were pure honey (subject 1), pure cinnamon extract (subject 2), and honey-cinnamon commixture (subject 3). The wound bed percentage, size, and characteristics were recorded and compared. Results: Usage of pure cinnamon was discontinued during the second visit due to its drying effect. Subjects 1 and 3 both presented with an increase in granulation and reduction in sloughing of cells and biofilm. However, subject 3 showed faster wound contraction and reduction in maceration as compared to subject 1.
    Conclusion: Pure cinnamon extract should not be used as a standalone wound product due to its drying properties. However, topical co-administration of honey and Cinnamon cassia extract has a synergistic interaction effect, improves wound healing in diabetic individuals and is recommended as a new topical herbal drug production for treating of the diabetic wound. Further studies on the therapeutic concentration of honey-cinnamon commixture should be conducted.
  9. Chan KH, Lee CH, Sharif SZ, Hayati F, Sallapan S
    Ann Med Surg (Lond), 2020 Dec;60:438-441.
    PMID: 33251002 DOI: 10.1016/j.amsu.2020.11.035
    Background: Metastatic neuroendocrine tumours (NETs) to the breast are very rare entities.

    Case presentation: A 26-year-old lady presented with anterior neck swelling with symptoms of superior vena cava syndrome for 6 months. Imaging study revealed a mediastinal mass which was preceded with core biopsy which was consistent with high-grade small cell NETs. Despite second-line adjuvant chemotherapy and radiotherapy, her disease became advanced which was confirmed via restaging scan. There were bilateral breast lesions discovered during the scan which was deemed to be metastatic NETs histologically. Despite prompt initiation of treatment, she succumbed 1 year after the radiotherapy due to disease progression.

    Conclusion: High suspicion of an index is needed for diagnosis when patients with known primary NETs present with suspicious breast lesions. Triple assessment is mandatory, however histopathology assessment and immunohistochemistry staining are the mainstay of diagnosis.

  10. Chan MY, Tan K, Tan HC, Huan PT, Li B, Phua QH, et al.
    Pharmacogenomics, 2012 Apr;13(5):533-42.
    PMID: 22462746 DOI: 10.2217/pgs.12.24
    AIM, MATERIALS & METHODS: We investigated the functional significance of CYP2C19*2, *3, *17 and PON1 Q192R SNPs in 89 consecutive Asian patients on clopidogrel treatment and the prevalence of functionally significant polymorphisms among 300 Chinese, Malays and Asian Indians.
  11. Chan MY, Efthymios M, Tan SH, Pickering JW, Troughton R, Pemberton C, et al.
    Circulation, 2020 10 13;142(15):1408-1421.
    PMID: 32885678 DOI: 10.1161/CIRCULATIONAHA.119.045158
    BACKGROUND: Heart failure (HF) is the most common long-term complication of acute myocardial infarction (MI). Understanding plasma proteins associated with post-MI HF and their gene expression may identify new candidates for biomarker and drug target discovery.

    METHODS: We used aptamer-based affinity-capture plasma proteomics to measure 1305 plasma proteins at 1 month post-MI in a New Zealand cohort (CDCS [Coronary Disease Cohort Study]) including 181 patients post-MI who were subsequently hospitalized for HF in comparison with 250 patients post-MI who remained event free over a median follow-up of 4.9 years. We then correlated plasma proteins with left ventricular ejection fraction measured at 4 months post-MI and identified proteins potentially coregulated in post-MI HF using weighted gene co-expression network analysis. A Singapore cohort (IMMACULATE [Improving Outcomes in Myocardial Infarction through Reversal of Cardiac Remodelling]) of 223 patients post-MI, of which 33 patients were hospitalized for HF (median follow-up, 2.0 years), was used for further candidate enrichment of plasma proteins by using Fisher meta-analysis, resampling-based statistical testing, and machine learning. We then cross-referenced differentially expressed proteins with their differentially expressed genes from single-cell transcriptomes of nonmyocyte cardiac cells isolated from a murine MI model, and single-cell and single-nucleus transcriptomes of cardiac myocytes from murine HF models and human patients with HF.

    RESULTS: In the CDCS cohort, 212 differentially expressed plasma proteins were significantly associated with subsequent HF events. Of these, 96 correlated with left ventricular ejection fraction measured at 4 months post-MI. Weighted gene co-expression network analysis prioritized 63 of the 212 proteins that demonstrated significantly higher correlations among patients who developed post-MI HF in comparison with event-free controls (data set 1). Cross-cohort meta-analysis of the IMMACULATE cohort identified 36 plasma proteins associated with post-MI HF (data set 2), whereas single-cell transcriptomes identified 15 gene-protein candidates (data set 3). The majority of prioritized proteins were of matricellular origin. The 6 most highly enriched proteins that were common to all 3 data sets included well-established biomarkers of post-MI HF: N-terminal B-type natriuretic peptide and troponin T, and newly emergent biomarkers, angiopoietin-2, thrombospondin-2, latent transforming growth factor-β binding protein-4, and follistatin-related protein-3, as well.

    CONCLUSIONS: Large-scale human plasma proteomics, cross-referenced to unbiased cardiac transcriptomics at single-cell resolution, prioritized protein candidates associated with post-MI HF for further mechanistic and clinical validation.

  12. Gan SW, Ong LS, Lee CH, Lin YS
    J Genet Psychol, 2020 08 13;181(6):458-469.
    PMID: 32787705 DOI: 10.1080/00221325.2020.1803196
    This paper examined the role of loneliness in mediating the relation between social support and life satisfaction among Chinese young adults within the Malaysian context. Young adults (N = 275; Mage = 22.41; SD = 1.76; 57.5% females) completed self-administered questionnaires on the scales of perceived social support, loneliness and life satisfaction. The results of Structural Equation Modeling (SEM) showed a partial mediation effect of loneliness on the relation between social support and life satisfaction. The integration of the bottom-up theory of subjective well-being and social cognitive theory is included to explain the mediating process. The results revealed that perceived social support can relate to a lower level of loneliness, which could eventually lead to higher levels of young adults' life satisfaction. Overall, the findings highlighted the importance of social support as well as their loneliness as a mediating pathway in promoting Malaysian Chinese young adults' life satisfaction. Interventions are also suggested to optimize life satisfaction as a whole.
  13. Grismer LL, Wood PL, Lee CH, Quah ES, Anuar S, Ngadi E, et al.
    Zootaxa, 2015 Apr 20;3948(1):1-23.
    PMID: 25947760 DOI: 10.11646/zootaxa.3948.1.1
    An integrative taxonomic analysis is used to identify and describe two new species of the agamid genus Bronchocela (Kuhl) from Peninsular Malaysia: an upland species B. shenlong sp. nov. from Bukit Larut, Perak in the Bintang Mountain Range and Parit Falls, Cameron Highlands, Pahang in the Titiwangsa Mountain Range and an insular species, B. rayaensis sp. nov., from Pulau Langkawi, Kedah off the northwest coast on the border with Thailand. Both species are diagnosed from each other and all other species of Bronchocela on the basis of body shape, scale morphology, and color pattern. The analysis also demonstrates the remarkable genetic similarity of B. cristatella (Kuhl) throughout 1120 km of its range from northern Peninsular Malaysia to western Borneo despite its highly variable coloration and pattern. The two new species are appended to a rapidly growing list of newly described lizard species (60 to date) from Peninsular Malaysia tallied within the last decade.
  14. Huang PC, Lee CH, Griffiths MD, O'Brien KS, Lin YC, Gan WY, et al.
    J Eat Disord, 2022 Nov 21;10(1):177.
    PMID: 36414956 DOI: 10.1186/s40337-022-00701-y
    BACKGROUND: Weight-related stigma has negative physiological and psychological impacts on individuals' quality of life. Stigmatized individuals may experience higher psychological distress and therefore increase the potential risk to develop obesity and/or food addiction. The present study examined the associations and mediated effect between perceived weight stigma, weight-related self-stigma, and psychological distress in explaining food addiction among Taiwanese university students.

    METHODS: All participants (n = 968) completed an online survey which included the Perceived Weight Stigma Questionnaire, Weight Self-Stigma Questionnaire, Depression, Anxiety, Stress Scale-21, and Yale Food Addiction Scale Version 2.

    RESULTS: After controlling for demographic variables, significant associations were found in the paths from (1) perceived weight stigma to weight-related self-stigma ([Formula: see text] = 0.23), psychological distress ([Formula: see text] = 0.35), and food addiction ([Formula: see text] = 0.23); (2) weight-related self-stigma to psychological distress ([Formula: see text] = 0.52) and food addiction ([Formula: see text] = 0.59); and (3) psychological distress to food addiction ([Formula: see text] = 0.59) (all p-values 

  15. Khoo SC, Ma NL, Peng WX, Ng KK, Goh MS, Chen HL, et al.
    Chemosphere, 2022 Jan;286(Pt 1):131477.
    PMID: 34303046 DOI: 10.1016/j.chemosphere.2021.131477
    Global solid waste is expected to increase by at least 70% annually until year 2050. The mixture of solid waste including food waste from food industry and domestic diaper waste in landfills is causing environmental and human health issues. Nevertheless, food and diaper waste containing high lignocellulose can easily degrade using lignocellulolytic enzymes thereby converted into energy for the development and growth of mushroom. Therefore, this study explores the potential of recycling biomass waste from coffee ground, banana, eggshell, tea waste, sugarcane bagasse and sawdust and diaper waste as raw material for Lingzhi mushroom (Ganoderma lucidum) cultivation. Using 2% of diaper core with sawdust biowaste leading to the fastest 100% mushroom mycelium spreading completed in one month. The highest production yield is 71.45 g mushroom; this represents about 36% production biological efficiency compared to only 21% as in commercial substrate. The high mushroom substrate reduction of 73% reflect the valorisation of landfill waste. The metabolomics profiling showed that the Lingzhi mushroom produced is of high quality with a high content of triterpene being the bioactive compounds that are medically important for treating assorted disease and used as health supplement. In conclusion, our study proposed a potential resource management towards zero-waste and circular bioeconomy for high profitable mushroom cultivation.
  16. Klionsky DJ, Abdelmohsen K, Abe A, Abedin MJ, Abeliovich H, Acevedo Arozena A, et al.
    Autophagy, 2016;12(1):1-222.
    PMID: 26799652 DOI: 10.1080/15548627.2015.1100356
  17. Le TT, Lim V, Ibrahim R, Teo MT, Bryant J, Ang B, et al.
    Eur Heart J Cardiovasc Imaging, 2021 05 10;22(6):670-679.
    PMID: 32255186 DOI: 10.1093/ehjci/jeaa040
    AIMS: Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. We previously developed the remodelling index (RI) that incorporated left ventricular (LV) volume and wall-thickness in a single measure of advanced hypertrophy in hypertensive patients. This study examined the prognostic potential of the RI in reference to contemporary LVH classifications.

    METHODS AND RESULTS: Cardiovascular magnetic resonance was performed in 400 asymptomatic hypertensive patients. The newly derived RI (EDV3t, where EDV is LV end-diastolic volume and t is the maximal wall thickness across 16 myocardial segments) stratified hypertensive patients: no LVH, LVH with normal RI (LVHNormal-RI), and LVH with low RI (LVHLow-RI). The primary outcome was a composite of all-cause mortality, acute coronary syndromes, strokes, and decompensated heart failure. LVHLow-RI was associated with increased LV mass index, fibrosis burden, impaired myocardial function and elevated biochemical markers of myocardial injury (high-sensitive cardiac troponin I), and wall stress. Over 18.3 ± 7.0 months (601.3 patient-years), 14 adverse events occurred (2.2 events/100 patient-years). Patients with LVHLow-RI had more than a five-fold increase in adverse events compared to those with LVHNormal-RI (11.6 events/100 patient-years vs. 2.0 events/100 patient-years, respectively; log-rank P 

  18. Lee BW, Park JG, Ha TKQ, Pham HTT, An JP, Noh JR, et al.
    J Nat Prod, 2019 08 23;82(8):2201-2210.
    PMID: 31393125 DOI: 10.1021/acs.jnatprod.9b00224
    Melicope pteleifolia has long been consumed as a popular vegetable and tea in Southeast Asian countries, including Malaysia and southern mainland China, and is effective in the treatment of colds and inflammation. In the search for active metabolites that can explain its traditional use as an antipyretic, six new phloroacetophenone derivatives (3-8) along with seven known compounds (1, 2, and 9-13) were isolated from the leaves of M. pteleifolia. Their chemical structures were confirmed by extensive spectroscopic analysis including NMR, IR, ECD, and HRMS. All compounds isolated from the leaves of M. pteleifolia (1-13) have a phloroacetophenone skeleton. Notably, the new compound 8 contains an additional cyclobutane moiety in its structure. The bioactivities of the isolated compounds were evaluated, and compounds 1, 6, and 7 inhibited tumor necrosis factor-α-induced prostaglandin E2. Moreover, the major constituent, 3,5-di-C-β-d-glucopyranosyl phloroacetophenone (1), was found to be responsible for the antipyretic activity of M. pteleifolia based on in vivo experiments.
  19. Lee CH, Chiang SL, Ko AM, Hua CH, Tsai MH, Warnakulasuriya S, et al.
    Addiction, 2014 Jul;109(7):1194-204.
    PMID: 24650227 DOI: 10.1111/add.12530
    Betel-quid (BQ) contains biologically psychoactive ingredients; however, data are limited concerning the symptoms and syndrome of BQ dependence among chewers. The aims of this study were to evaluate the ingredients-associated BQ dependence syndrome and country-specific chewing features and behaviour for BQ dependence among chewers from six Asian communities.
  20. Lee CH, Kuo CN, Chen HL, Chen CY
    Nat Prod Res, 2013;27(11):988-91.
    PMID: 22691063 DOI: 10.1080/14786419.2012.695369
    This review describes the morphological, phytochemical and pharmacological properties of Cinnamomum subavenium (Lauraceae). The plant grows wild in southern Mainland China, Burma, Cambodia, Taiwan, Malaysia and Indonesia. This plant is recorded as having long been used to treat carcinomatous swelling, stomach ache, chest pain, abdominal pain, hernia, diarrhoea, rheumatism, nausea and vomiting. This article enumerates an overview of phytochemical and pharmacological aspects that is useful to researchers for further exploration for the necessary development of this potential herb.
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