Browse publications by year: 2019

  1. Ngernna S, Rachaphaew N, Thammapalo S, Prikchoo P, Kaewnah O, Manopwisedjaroen K, et al.
    Am J Trop Med Hyg, 2019 12;101(6):1397-1401.
    PMID: 31595871 DOI: 10.4269/ajtmh.19-0063
    Although human infections of Plasmodium knowlesi have been found throughout Southeast Asia, most cases originated from Malaysian Borneo. In Thailand, P. knowlesi malaria was considered extremely rare. However, during October 2017-September 2018, there was a surge in the number of reported P. knowlesi cases. Here, a series of six cases of P. knowlesi malaria found during this period in Songkhla and Narathiwat provinces of southern Thailand are presented. All cases were confirmed by polymerase chain reaction. The unprecedented case number in the affected area is a warning sign of an increasing P. knowlesi burden in the south of Thailand.
    MeSH terms: Adult; Antimalarials/therapeutic use; Female; Humans; Malaria/diagnosis*; Malaria/drug therapy; Male; Middle Aged; Thailand; Travel; Plasmodium knowlesi/drug effects; Plasmodium knowlesi/pathogenicity*; Young Adult
  2. Naje AS, Ajeel MA, Ali IM, Al-Zubaidi HAM, Alaba PA
    Water Sci Technol, 2019 Aug;80(3):458-465.
    PMID: 31596257 DOI: 10.2166/wst.2019.289
    In this work, landfill leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The influence of rotating anode speed on the removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landfill leachate was investigated. The influence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance.
    MeSH terms: Electrocoagulation; Electrodes; Waste Disposal, Fluid/methods*; Water Pollutants, Chemical*; Biological Oxygen Demand Analysis
  3. Azuan NH, Khairunniza-Bejo S, Abdullah AF, Kassim MSM, Ahmad D
    Plant Dis, 2019 Dec;103(12):3218-3225.
    PMID: 31596688 DOI: 10.1094/PDIS-10-18-1721-RE
    Basal stem rot (BSR), caused by the Ganoderma fungus, is an infectious disease that affects oil palm (Elaeis guineensis) plantations. BSR leads to a significant economic loss and reductions in yields of up to Malaysian Ringgit (RM) 1.5 billion (US$400 million) yearly. By 2020, the disease may affect ∼1.7 million tonnes of fresh fruit bunches. The plants appear symptomless in the early stages of infection, although most plants die after they are infected. Thus, early, accurate, and nondestructive disease detection is crucial to control the impact of the disease on yields. Terrestrial laser scanning (TLS) is an active remote-sensing, noncontact, cost-effective, precise, and user-friendly method. Through high-resolution scanning of a tree's dimension and morphology, TLS offers an accurate indicator for health and development. This study proposes an efficient image processing technique using point clouds obtained from TLS ground input data. A total of 40 samples (10 samples for each severity level) of oil palm trees were collected from 9-year-old trees using a ground-based laser scanner. Each tree was scanned four times at a distance of 1.5 m. The recorded laser scans were synched and merged to create a cluster of point clouds. An overhead two-dimensional image of the oil palm tree canopy was used to analyze three canopy architectures in terms of the number of pixels inside the crown (crown pixel), the degree of angle between fronds (frond angle), and the number of fronds (frond number). The results show that the crown pixel, frond angle, and frond number are significantly related and that the BSR severity levels are highly correlated (R2 = 0.76, P < 0.0001; R2 = 0.96, P < 0.0001; and R2 = 0.97, P < 0.0001, respectively). Analysis of variance followed post hoc tests by Student-Newman-Keuls (Newman-Keuls) and Dunnett for frond number presented the best results and showed that all levels were significantly different at a 5% significance level. Therefore, the earliest stage that a Ganoderma infection could be detected was mildly infected (T1). For frond angle, all post hoc tests showed consistent results, and all levels were significantly separated except for T0 and T1. By using the crown pixel parameter, healthy trees (T0) were separated from unhealthy trees (moderate infection [T2] and severe infection [T3]), although there was still some overlap with T1. Thus, Ganoderma infection could be detected as early as the T2 level by using the crown pixel and the frond angle parameters. It is hard to differentiate between T0 and T1, because during mild infection, the symptoms are highly similar. Meanwhile, T2 and T3 were placed in the same group, because they showed the same trend. This study demonstrates that the TLS is useful for detecting low-level infection as early as T1 (mild severity). TLS proved beneficial in managing oil palm plantation disease.
    MeSH terms: Lasers; Plant Stems/microbiology; Remote Sensing Technology
  4. Khalid NA, Rajandas H, Parimannan S, Croft LJ, Loke S, Chong CS, et al.
    3 Biotech, 2019 Oct;9(10):364.
    PMID: 31588388 DOI: 10.1007/s13205-019-1892-4
    Empty fruit bunch (EFB) and palm oil mill effluent (POME) are the major wastes generated by the oil palm industry in Malaysia. The practice of EFB and POME digester sludge co-composting has shown positive results, both in mitigating otherwise environmentally damaging waste streams and producing a useful product (compost) from these streams. In this study, the bacterial ecosystems of 12-week-old EFB-POME co-compost and POME biogas sludge from Felda Maokil, Johor were analysed using 16S metagenome sequencing. Over ten phyla were detected, with Chloroflexi being the predominant phylum, representing approximately 53% of compost and 23% of the POME microbiome reads. The main bacterial lineage found in the compost and POME was Anaerolinaceae (Chloroflexi) with 30% and 18% of the total gene fragments, respectively. The significant differences between compost and POME communities were abundances of Syntrophobacter, Sulfuricurvum and Coprococcus. No methanogens were identified due to the bias in general 16S primers to eubacteria. The preponderance of anaerobic species in the compost and high abundance of secondary metabolite fermenting bacteria is due to an extended composting time, with anaerobic collapse of the pile due to the tropical heat. Predictive functional profiles of the metagenomes using 16S rRNA marker genes suggest that the presence of enzymes involved in degradation of polysaccharides such as glucoamylase, endoglucanase and arabinofuranosidase, all of which were strongly active in POME. Eubacterial species associated with cellulytic methanogenesis were present in both samples.
    MeSH terms: Anaerobiosis; Cellulase; Eubacterium; Glucan 1,4-alpha-Glucosidase; Fruit; Hot Temperature; Malaysia; RNA, Ribosomal, 16S; Sewage; Bioreactors; Chloroflexi; Metagenome; Biofuels
  5. Khairul-Anuar MA, Mazumdar P, Lau SE, Tan TT, Harikrishna JA
    3 Biotech, 2019 Oct;9(10):371.
    PMID: 31588395 DOI: 10.1007/s13205-019-1898-y
    Isolation of high-quality RNA from Dendrobium flowers is challenging because of the high levels of pigment, polysaccharides, and polyphenols. In the present study, an efficient CTAB method for RNA extraction from the pigment-rich flowers of Dendrobium was optimised. The optimised method yielded high quantities of RNA (10.1-12.9 µg/g). Spectrophotometric values of A260/280 in the range of 2.2 to 2.4 and A260/230 values of 2.0 suggested that the isolated RNA was free of polyphenols, polysaccharides, and protein contaminants. RNA integrity numbers determined by microfluidics were in the range of 7.9-8.9 indicative of intact RNA. In the improved method, the addition of 3 M NaCl and 3% PVP-10 in the extraction buffer, followed by an incubation period of 45 min at 65 °C, eliminated most of the polysaccharides, polyphenolic compounds, and denatured protein. Extraction with phenol:chloroform:isoamyl alcohol (125:24:1) effectively removed pigments from the aqueous phase, while the precipitation of RNA with lithium chloride minimised the co-precipitation of protein, DNA, and polysaccharide and resulted in the extraction of high quality of RNA. The suitability of the RNA for downstream processing was confirmed via RT-PCR amplification of Chalcone synthase gene from cDNA prepared from RNA isolated from different developmental stages of the flower of a Dendrobium hybrid. The present method will be highly useful for the isolation of RNA from pigment, polyphenol, and polysaccharide-rich plant tissues.
    MeSH terms: Pentanols; Chloroform; Phenols; RNA; Sodium Chloride; Lithium Chloride; DNA, Complementary; Phenol; Reverse Transcriptase Polymerase Chain Reaction; Dendrobium; Microfluidics; Polyphenols
  6. Momtaz YA, Hamid TA, Bagat MF, Hazrati M
    Curr Aging Sci, 2019;12(1):62-66.
    PMID: 31589113 DOI: 10.2174/1874609812666190614104328
    INTRODUCTION: Although diabetes through several possible mechanisms such as increased microvascular pathology and inefficiency of glucose utilization during cognitive tasks can be associated with cognitive impairment, there is inconclusive evidence that shows elderly diabetic patients under therapy have higher cognitive function compared to their non-diabetics counterparts. The present study was conducted to elucidate the association between diabetes and cognitive function in later life.

    METHODS: Data for this study, consisting of 2202 older adults aged 60 years and above, were taken from a population-based survey entitled "Identifying Psychosocial and Identifying Economic Risk Factor of Cognitive Impairment among Elderly. Data analysis was conducted using the IBM SPSS Version 23.0.

    RESULTS: The mean of MMSE was found to be 22.67 (SD = 4.93). The overall prevalence of selfreported diabetes was found to be 23.6% (CI95%: 21.8% - 25.4%). The result of independent t-test showed diabetic subjects had a higher mean score of MMSE (M = 23.05, SD =4 .55) than their counterparts without diabetes (M = 22.55, SD = 5.04) (t = -2.13 p

    MeSH terms: Aged; Aged, 80 and over; Aging/psychology*; Cognition/physiology; Cognition Disorders/diagnosis*; Cognition Disorders/epidemiology*; Diabetes Mellitus, Type 2/diagnosis; Diabetes Mellitus, Type 2/epidemiology*; Female; Humans; Malaysia/epidemiology; Male; Middle Aged; Neuropsychological Tests; Surveys and Questionnaires; Socioeconomic Factors; Comorbidity; Prevalence; Multivariate Analysis; Linear Models; Risk Assessment; Independent Living
  7. Yan CZY, Austin CM, Ayub Q, Rahman S, Gan HM
    FEMS Microbiol Lett, 2019 09 01;366(17).
    PMID: 31589302 DOI: 10.1093/femsle/fnz211
    The Malaysian and global shrimp aquaculture production has been significantly impacted by acute hepatopancreatic necrosis disease (AHPND) typically caused by Vibrio parahaemolyticus harboring the pVA plasmid containing the pirAVp and pirBVp genes, which code for Photorhabdus insect-related (Pir) toxin. The limited genomic resource for V. parahaemolyticus strains from Malaysian aquaculture farms precludes an in-depth understanding of their diversity and evolutionary relationships. In this study, we isolated shrimp-associated and environmental (rearing water) V. parahaemolyticus from three aquaculture farms located in Northern and Central Malaysia followed by whole-genome sequencing of 40 randomly selected isolates on the Illumina MiSeq. Phylogenomic analysis and multilocus sequence typing (MLST) reveal distinct lineages of V. parahaemolyticus that harbor the pirABVp genes. The recovery of pVA plasmid backbone devoid of pirAVp or pirABVp in some V. parahaemolyticus isolates suggests that the toxin genes are prone to deletion. The new insight gained from phylogenomic analysis of Asian V. parahaemolyticus, in addition to the observed genomic instability of pVa plasmid, will have implications for improvements in aquaculture practices to diagnose, treat or limit the impacts of this disease.
    MeSH terms: Animals; Animal Diseases/microbiology*; Animal Diseases/epidemiology; Malaysia; Phylogeny; Genetic Variation*; Vibrio Infections/veterinary*; Vibrio parahaemolyticus/genetics*; Vibrio parahaemolyticus/isolation & purification; Water Microbiology; Computational Biology/methods; Genomics*; Penaeidae/microbiology*; Multilocus Sequence Typing; Phylogeography
  8. Steiner JD, Cheng H, Walsh J, Zhang Y, Zydlewski B, Mu L, et al.
    ACS Appl Mater Interfaces, 2019 Oct 16;11(41):37885-37891.
    PMID: 31589393 DOI: 10.1021/acsami.9b14729
    Elemental doping represents a prominent strategy to improve interfacial chemistry in battery materials. Manipulating the dopant spatial distribution and understanding the dynamic evolution of the dopants at the atomic scale can inform better design of the doping chemistry for batteries. In this work, we create a targeted hierarchical distribution of Ti4+, a popular doping element for oxide cathode materials, in LiNi0.8Mn0.1Co0.1O2 primary particles. We apply multiscale synchrotron/electron spectroscopy and imaging techniques as well as theoretical calculations to investigate the dynamic evolution of the doping chemical environment. The Ti4+ dopant is fully incorporated into the TMO6 octahedral coordination and is targeted to be enriched at the surface. Ti4+ in the TMO6 octahedral coordination increases the TM-O bond length and reduces the covalency between (Ni, Mn, Co) and O. The excellent reversibility of Ti4+ chemical environment gives rise to superior oxygen reversibility at the cathode-electrolyte interphase and in the bulk particles, leading to improved stability in capacity, energy, and voltage. Our work directly probes the chemical environment of doping elements and helps rationalize the doping strategy for high-voltage layered cathodes.
    MeSH terms: Electrodes; Electrons; Interphase; Oxides; Oxygen; Electric Power Supplies; Rationalization; Spectrum Analysis; Synchrotrons
  9. Chumnumwat S, Lu ZH, Sukasem C, Winther MD, Capule FR, Abdul Hamid AAAT, et al.
    Public Health Genomics, 2019;22(3-4):132-139.
    PMID: 31587001 DOI: 10.1159/000502916
    Pharmacogenomics (PGx) is increasingly being recognized as a potential tool for improving the efficacy and safety of drug therapy. Therefore, several efforts have been undertaken globally to facilitate the implementation process of PGx into routine clinical practice. Part of these efforts include the formation of PGx working groups working on PGx research, synthesis, and dissemination of PGx data and creation of PGx implementation strategies. In Asia, the Southeast Asian Pharmacogenomics Research Network (SEAPharm) is established to enable and strengthen PGx research among the various PGx communities within but not limited to countries in SEA; with the ultimate goal to support PGx implementation in the region. From the perspective of SEAPharm member countries, there are several key elements essential for PGx implementation at the national level. They include pharmacovigilance database, PGx research, health economics research, dedicated laboratory to support PGx testing for both research and clinical use, structured PGx education, and supportive national health policy. The status of these essential elements is presented here to provide a broad picture of the readiness for PGx implementation among the SEAPharm member countries, and to strengthen the PGx research network and practice in this region.
  10. Ng KT, Sarode D, Lai YS, Teoh WY, Wang CY
    Paediatr Anaesth, 2019 12;29(12):1163-1172.
    PMID: 31587414 DOI: 10.1111/pan.13752
    BACKGROUND: Ketamine is believed to reduce the incidence of emergence agitation in children undergoing surgery or procedure. However, recent randomized controlled trials reported conflicting findings.

    AIMS: To investigate the effect of ketamine on emergence agitation in children.

    METHODS: Databases of MEDLINE, EMBASE, and CENTRAL were systematically searched from their start date until February 2019. Randomized controlled trials comparing intravenous ketamine and placebo in children were sought. The primary outcome was the incidence of emergence agitation. Secondary outcomes included postoperative pain score, duration of discharge time, and the adverse effects associated with the use of ketamine, namely postoperative nausea and vomiting, desaturation, and laryngospasm.

    RESULTS: Thirteen studies (1125 patients) were included in the quantitative meta-analysis. The incidence of emergence agitation was 14.7% in the ketamine group and 33.3% in the placebo group. Children receiving ketamine had a lower incidence of emergence agitation, with an odds ratio being 0.23 (95% confidence interval: 0.11 to 0.46), certainty of evidence: low. In comparison with the placebo, ketamine group achieved a lower postoperative pain score (odds ratio: -2.42, 95% confidence interval: -4.23 to -0.62, certainty of evidence: very low) and lower pediatric anesthesia emergence delirium scale at 5 minutes after operation (odds ratio: -3.99, 95% confidence interval: -5.03 to -2.95; certainty of evidence: moderate). However, no evidence was observed in terms of incidence of postoperative nausea and vomiting, desaturation, and laryngospasm.

    CONCLUSION: In this meta-analysis of 13 randomized controlled trials, high degree of heterogeneity and low certainty of evidence limit the recommendations of ketamine for the prevention of emergence agitation in children undergoing surgery or imaging procedures. However, the use of ketamine is well-tolerated without any notable adverse effects across all the included trials.

    PROSPERO REGISTRATION: CRD42019131865.

    MeSH terms: Adolescent; Anesthesia Recovery Period; Anesthesia, General/adverse effects*; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Ketamine/adverse effects; Ketamine/therapeutic use*; Pain, Postoperative/drug therapy; Randomized Controlled Trials as Topic; Anesthetics, Inhalation/adverse effects*; Postoperative Nausea and Vomiting/drug therapy; Emergence Delirium/drug therapy*
  11. Putsathit P, Neela VK, Joseph NMS, Ooi PT, Ngamwongsatit B, Knight DR, et al.
    Vet Microbiol, 2019 Oct;237:108408.
    PMID: 31585650 DOI: 10.1016/j.vetmic.2019.108408
    Information on the epidemiology of C. difficile infection (CDI) in South-East Asian countries is limited, as is data on possible animal reservoirs of C. difficile in the region. We investigated the prevalence and molecular epidemiology of C. difficile in piglets and the piggery environment in Thailand and Malaysia. Piglet rectal swabs (n = 224) and piggery environmental specimens (n = 23) were collected between 2015 and 2016 from 11 farms located in Thailand and Malaysia. All specimens were tested for the presence of C. difficile with toxigenic culture. PCR assays were performed on isolates to determine the ribotype (RT), and the presence of toxin genes. Whole genome sequencing was used on a subset of isolates to determine the evolutionary relatedness of RT038 (the most prevalent RT identified) common to pigs and humans from Thailand and Indonesia. C. difficile was recovered from 35% (58/165) and 92% (54/59) of the piglets, and 89% (8/9) and 93% (13/14) of the environmental specimens from Thailand and Malaysia, respectively. All strains from Thailand, and 30 strains from Malaysia (23 piglet and 7 environmental isolates) were non-toxigenic. To our knowledge, this is the first and only report with a complete lack of toxigenic C. difficile among piglets, a feature which could have a protective effect on the host. The most common strain belonged to RT038 (ST48), accounting for 88% (51/58) of piglet and 78% (7/9) of environmental isolates from Thailand, and all 30 isolates tested from Malaysia. Piglet RT038 isolates from Thailand and Malaysia differed by only 18 core-genome single nucleotide variants (cgSNVs) and both were, on average, 30 cgSNVs different from the human strains from Thailand and Indonesia, indicating a common ancestor in the last two decades.
    MeSH terms: Animals; Clostridium Infections/microbiology; Clostridium Infections/epidemiology; Clostridium Infections/veterinary*; Environmental Microbiology; Housing, Animal; Malaysia/epidemiology; Swine; Swine Diseases/microbiology*; Thailand/epidemiology; Genetic Variation; Prevalence; Clostridium difficile/genetics*; Molecular Epidemiology
  12. Chen KJ, Chou HD, Teh WM
    Ophthalmol Retina, 2019 10;3(10):887.
    PMID: 31585711 DOI: 10.1016/j.oret.2019.05.023
    MeSH terms: Candida/isolation & purification*; Candidiasis/diagnosis*; Candidiasis/microbiology; Chorioretinitis/diagnosis*; Chorioretinitis/microbiology; Female; Humans; Middle Aged; Retina/pathology*; Eye Infections, Fungal/diagnosis*; Eye Infections, Fungal/microbiology; Immunocompromised Host*; Tomography, Optical Coherence/methods*
  13. Mohd A, Zainal N, Tan KK, AbuBakar S
    Sci Rep, 2019 10 04;9(1):14336.
    PMID: 31586088 DOI: 10.1038/s41598-019-50674-3
    Zika virus (ZIKV) infection is a serious public health concern. ZIKV infection has been associated with increased occurrences of microcephaly among newborns and incidences of Guillain-Barré syndrome among adults. No specific therapeutics or vaccines are currently available to treat and protect against ZIKV infection. Here, a plant-secreted phytoalexin, resveratrol (RES), was investigated for its ability to inhibit ZIKV replication in vitro. Several RES treatment regimens were used. The ZIKV titers of mock- and RES-treated infected cell cultures were determined using the focus-forming assay and the Zika mRNA copy number as determined using qRT-PCR. Our results suggested that RES treatment reduced ZIKV titers in a dose-dependent manner. A reduction of >90% of virus titer and ZIKV mRNA copy number was achieved when infected cells were treated with 80 µM of RES post-infection. Pre-incubation of the virus with 80 µM RES showed >30% reduction in ZIKV titers and ZIKV mRNA copy number, implying potential direct virucidal effects of RES against the virus. The RES treatment reduced >70% virus titer in the anti-adsorption assay, suggesting the possibility that RES also interferes with ZIKV binding. However, there was no significant decrease in ZIKV titer when a short-period of RES treatment was applied to cells before ZIKV infection (pre-infection) and after the virus bound to the cells (virus internalization inhibition), implying that RES acts through its continuous presence in the cell cultures after virus infection. Overall, our results suggested that RES exhibited direct virucidal activity against ZIKV and possessed anti-ZIKV replication properties, highlighting the need for further exploration of RES as a potential antiviral molecule against ZIKV infection.
    MeSH terms: Zika Virus Infection/drug therapy*; Zika Virus Infection/virology; Zika Virus/drug effects*; Zika Virus/physiology; Animals; Cercopithecus aethiops; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Humans; RNA, Messenger/metabolism; RNA, Viral/isolation & purification; RNA, Viral/metabolism; Vero Cells; Virus Replication/drug effects*; Viral Load; Cell Line, Tumor; Virus Attachment/drug effects; Virus Internalization/drug effects
  14. Loh SC, Othman AS, Veera Singham G
    Sci Rep, 2019 10 04;9(1):14296.
    PMID: 31586098 DOI: 10.1038/s41598-019-50800-1
    Hevea brasiliensis remains the primary crop commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. Here, we described the transcriptional events related to jasmonic acid (JA)- and linolenic acid (LA)-induced secondary laticifer differentiation (SLD) in H. brasiliensis clone RRIM 600 based on RNA-seq approach. Histochemical approach proved that JA- and LA-treated samples resulted in SLD in H. brasiliensis when compared to ethephon and untreated control. RNA-seq data resulted in 86,614 unigenes, of which 2,664 genes were differentially expressed in JA and LA-induced secondary laticifer harvested from H. brasiliensis bark samples. Among these, 450 genes were unique to JA and LA as they were not differentially expressed in ethephon-treated samples compared with the untreated samples. Most transcription factors from the JA- and LA-specific dataset were classified under MYB, APETALA2/ethylene response factor (AP2/ERF), and basic-helix-loop-helix (bHLH) gene families that were involved in tissue developmental pathways, and we proposed that Bel5-GA2 oxidase 1-KNOTTED-like homeobox complex are likely involved in JA- and LA-induced SLD in H. brasiliensis. We also discovered alternative spliced transcripts, putative novel transcripts, and cis-natural antisense transcript pairs related to SLD event. This study has advanced understanding on the transcriptional regulatory network of SLD in H. brasiliensis.
    MeSH terms: Cyclopentanes/chemistry; Latex/metabolism*; Organophosphorus Compounds/chemistry; Plant Proteins/genetics; Plant Proteins/metabolism*; Transcription Factors/genetics; Transcription Factors/metabolism*; Genes, Plant; alpha-Linolenic Acid/chemistry; Gene Expression Regulation, Plant; Hevea/genetics; Hevea/metabolism*; Oxylipins/chemistry
  15. Myzabella N, Fritschi L, Merdith N, El-Zaemey S, Chih H, Reid A
    Int J Occup Environ Med, 2019 10;10(4):159-173.
    PMID: 31586381 DOI: 10.15171/ijoem.2019.1576
    BACKGROUND: The palm oil industry is the largest contributor to global production of oils and fats. Indonesia and Malaysia are the largest producers of palm oil. More than a million workers are employed in this industry, yet there is a lack of information on their occupational health and safety.

    OBJECTIVE: To identify and summarize occupational hazards among oil palm plantation workers.

    METHODS: A search was carried out in June 2018 in PubMed, Web of Science, Scopus, and Ovid. Relevant publications were identified by a systematic search of four databases and relevant journals. Publications were included if they examined occupational hazards in oil palm plantation workers.

    RESULTS: 941 publications were identified; of these, 25 studies were found eligible to be included in the final review. Of the 25 studies examined, 19 were conducted in Malaysia, 2 in Costa Rica, and one each in Ghana, Indonesia, Myanmar, Papua New Guinea, and Cameroon. Oil palm plantation workers were found to be at risk of musculoskeletal conditions, injuries, psychosocial disorders, and infectious diseases such as malaria and leptospirosis. In addition, they have potential exposure to paraquat and other pesticides.

    CONCLUSION: In light of the potential of palm oil for use as a biofuel, this is an industry with strong growth potential. The workers are exposed to various occupational hazards. Further research and interventions are necessary to improve the working conditions of this already vast and growing workforce.

    MeSH terms: Agricultural Workers' Diseases/epidemiology; Myanmar/epidemiology; Cameroon/epidemiology; Costa Rica/epidemiology; Ghana/epidemiology; Humans; Indonesia/epidemiology; Malaysia/epidemiology; Papua New Guinea/epidemiology; Pesticides/toxicity; Plant Oils/adverse effects; Comorbidity; Food Safety
  16. Chean KY, Abdulrahman S, Chan MW, Tan KC
    Int J Occup Environ Med, 2019 10;10(4):203-215.
    PMID: 31586385 DOI: 10.15171/ijoem.2019.1657
    BACKGROUND: Despite its excellent psychometric properties, St George's Respiratory Questionnaire (SGRQ) has not been previously used in measuring respiratory quality of life (RQoL) among traffic police and firefighters who are at risk of poor respiratory health by virtue of their occupations.

    OBJECTIVE: To assess and compare the RQoL of the occupationally exposed (firefighters and traffic police) and the occupationally unexposed populations in Penang, Malaysia.

    METHODS: We recruited male traffic police and firefighters from 5 districts of Penang by convenient sampling during June to September 2018. Participants completed the SGRQ. Scores (symptoms, activity, impacts, total) were derived using a scoring calculator. Higher scores indicate poorer RQoL. Univariate and multivariate linear regression models were fitted to explore the relationship of the independent predictive factors with participants' RQoL.

    RESULTS: We recruited 706 participants---211 firefighters, 198 traffic police, and 297 from general population. Smokers had significantly higher scores than non-smokers in all SGRQ domains. Regardless of smoking status, the "occupationally exposed group" had higher symptoms score than the "occupationally unexposed group," who had higher activity and impact scores. Smoking status, comorbidity status and monthly income were significant independent predictors of SGRQ total score.

    CONCLUSION: In comparison with the general population, firefighters and traffic police reported poorer RQoL; smoking further deteriorated their respiratory health. There is a need to strengthen preventive health measures against occupational disease and smoking cessation among firefighters and traffic police.

    MeSH terms: Adolescent; Adult; Cross-Sectional Studies; Humans; Malaysia/epidemiology; Male; Middle Aged; Occupational Diseases/epidemiology; Occupations/statistics & numerical data*; Quality of Life*; Surveys and Questionnaires; Respiration Disorders/etiology; Respiration Disorders/epidemiology*; Smoking/adverse effects; Smoking/epidemiology; Case-Control Studies; Occupational Exposure/statistics & numerical data; Police/statistics & numerical data*; Inhalation Exposure/adverse effects; Inhalation Exposure/statistics & numerical data*; Young Adult; Firefighters/statistics & numerical data*
  17. Tamadon A, Pons DJ, Clucas D, Sued K
    Materials (Basel), 2019 Oct 01;12(19).
    PMID: 31581446 DOI: 10.3390/ma12193215
    One of the difficulties with bobbin friction stir welding (BFSW) has been the visualisation of microstructure, particularly grain boundaries, and this is especially problematic for materials with fine grain structure, such as AA6082-T6 aluminium as here. Welds of this material were examined using optical microscopy (OM) and electron backscatter diffraction (EBSD). Results show that the grain structures that form depend on a complex set of factors. The motion of the pin and shoulder features transports material around the weld, which induces shear. The shear deformation around the pin is non-uniform with a thermal and strain gradient across the weld, and hence the dynamic recrystallisation (DRX) processes are also variable, giving a range of observed polycrystalline and grain boundary structures. Partial DRX was observed at both hourglass boundaries, and full DRX at mid-stirring zone. The grain boundary mapping showed the formation of low-angle grain boundaries (LAGBs) at regions of high shear as a consequence of thermomechanical nature of the process.
    MeSH terms: Aluminum; Biological Transport; Computers; Electrons; Microscopy; Motion; Shoulder; Welding; Friction; Plant Structures
  18. Fatahi S, Kord-Varkaneh H, Talaei S, Mardali F, Rahmani J, Ghaedi E, et al.
    Nutr Metab Cardiovasc Dis, 2019 11;29(11):1168-1175.
    PMID: 31582198 DOI: 10.1016/j.numecd.2019.07.011
    BACKGROUND AND AIM: Although some earlier studies have indicated the effect of phytosterol (PS) supplementation on serum lipoprotein(a) (Lp(a)) and free fatty acid (FFA) concentration, findings are still conflicting. We aimed to assess the impact of PS supplementation on serum Lp(a) and FFA concentration through a systematic review and meta-analysis of available RCTs.

    METHODS AND RESULTS: We performed a systematic search of all available RCTs conducted up to 21 February 2019 in the following databases: PubMed, Scopus, and Cochrane. The choice of fixed- or random-effect model for analysis was determined according to the I2 statistic. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Pooling of 12 effect sizes from seven articles revealed a significant reduction of Lp(a) levels following PS supplementation (MD: -0.025 mg/dl, 95% CI: -0.045, -0.004, p = 0.017) without significant heterogeneity among the studies (I2 = 0.0%, p = 0.599). Also, PS supplementation significantly lowered FFA (MD: -0.138 mg/dl, 95% CI: -0.195, -0.081, p = 0.000) without significant heterogeneity among the studies (I2 = 0.0%, p = 0.911). The results for meta-regression and sensitivity analysis were not significant.

    CONCLUSION: The meta-analysis suggests that oral PS supplementation could cause a significant reduction in serum Lp(a) and FFA.

    MeSH terms: Adult; Hypolipidemic Agents/adverse effects; Hypolipidemic Agents/therapeutic use*; Fatty Acids, Nonesterified/blood*; Female; Humans; Male; Middle Aged; Phytosterols/adverse effects; Phytosterols/therapeutic use*; Biomarkers/blood; Down-Regulation; Randomized Controlled Trials as Topic; Treatment Outcome; Lipoprotein(a)/blood*; Dyslipidemias/blood; Dyslipidemias/diagnosis; Dyslipidemias/drug therapy*
  19. Abdullah NA, Radzi SNF, Asri LN, Idris NS, Husin S, Sulaiman A, et al.
    Biodivers Data J, 2019;7:e35679.
    PMID: 31582889 DOI: 10.3897/BDJ.7.e35679
    Riparian areas hold vast number of flora and fauna with exceptional contributions to the ecosystem. A study was conducted in Sungai Sepetang, Sungai Rembau and Sungai Chukai to identify the insect community in a riparian zone of Peninsular Malaysia. Sampling was conducted in six consecutive months from December 2017 to May 2018 during both day and night using sweep nets. Twenty sampling stations (S1-S20) had been assembled along the riverbanks with an average distance of 200 m between each station. The 17,530 collected insects were from 11 orders and consisted of Diptera, Coleoptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Orthoptera, Blattodea, Thysanoptera, Mantodea and Odonata. The three most abundant orders were Diptera (33.84%; 5933 individuals), Coleoptera (28.82%; 5053 individuals) and Hemiptera (25.62%: 4491 individuals). The collected insect community consisted of different guilds such as the scavenger, predator, herbivore, pollinator and parasitoid. Sungai Sepetang and Sungai Rembau were dominated by mangrove flora, Sonneratia caseolaris (Myrtales: Lythraceae), while Sungai Chukai was dominated by Barringtonia racemosa. There was a significant difference (p < 0.05) in the composition of insects between the three rivers though clustering analysis showed that the insect communities in Sungai Sepetang and Sungai Rembau were 100% similar compared to Sungai Chukai which consisted of a totally different community. There is a significant negative correlation between abundance of insects with salinity and wind speed at Sungai Chukai and Sungai Sepetang.
    MeSH terms: Animals; Cockroaches; Diptera; Hemiptera; Hymenoptera; Lepidoptera; Malaysia; Orthoptera; Wind; Ecosystem; Mantodea; Lythraceae; Barringtonia; Rivers; Salinity; Pollination; Herbivory; Thysanoptera; Odonata
  20. Ghazali SM, Huey TC, Cheong KC, Li LH, Fadhli M, Yusoff M, et al.
    Tob Induc Dis, 2019;17:22.
    PMID: 31582933 DOI: 10.18332/tid/102728
    INTRODUCTION: Exposure to secondhand smoke (SHS) has been proven to be detrimental to health. However, there is little information on SHS exposure among Malaysian adolescents. This study aims to assess the magnitude of and factors associated with SHS exposure among school-going adolescents in Malaysia.

    METHODS: We performed secondary analysis on data from 25461 respondents of the Global School Health Survey in Malaysia. Descriptive analyses and multivariable logistic regression were performed to determine factors associated with SHS exposure.

    RESULTS: Respondents were adolescents of mean age 14.84 (SD=1.45) years, 50.2% of which were male and 49.8% female. Approximately four in ten respondents were exposed to SHS in the past week (41.5%). SHS exposure was significantly higher among respondents who smoked than among non-smokers (85.8% vs 35.7%, p<0.001). The likelihood of exposure to SHS was higher among smoking adolescents (Adjusted OR=1.66, 95% CI: 1.07-2.56) and non-smoking adolescents (AOR=3.15, 95% CI: 1.48-4.71) who had at least one smoking parent/guardian regardless of their own smoking status. Male adolescents had higher risk of SHS exposure compared to their female counterparts (current smoker AOR=1.66, 95% CI: 1.07-2.56; non-smoker AOR=1.50, 95% CI: 1.12-2.00) and increased with age, regardless of their smoking status.

    CONCLUSIONS: Our findings suggest that prevalence of exposure to SHS among school-going adolescents in Malaysia is high. Parents should be advised to stop smoking or abstain from smoking in the presence of their children. Education programmes are recommended to increase awareness on avoidance of SHS as well as smoking cessation interventions for both adolescents and their parents.

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