Displaying publications 1 - 20 of 56 in total

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  1. Fulltext 2 μm passively mode-locked thulium-doped fiber lasers with Ta2AlC-deposited tapered and side-polished fibers
    Ahmad H, Azri MFM, Ramli R, Samion MZ, Yusoff N, Lim KS
    Sci Rep, 2021 Oct 28;11(1):21278.
    PMID: 34711908 DOI: 10.1038/s41598-021-99928-z
    In this work, mode-locked thulium-doped fiber lasers operating in the 2 µm wavelength region were demonstrated using tantalum aluminum carbide (Ta2AlC)-based saturable absorbers (SAs) utilizing the evanescent wave interaction. The Ta2AlC MAX Phase was prepared by dissolving the Ta2AlC powder in isopropyl alcohol and then deposited onto three different evanescent field-based devices, which were the tapered fiber, side-polished fiber, and arc-shaped fiber. Flame-brushing and wheel-polishing techniques were used to fabricate the tapered and arc-shaped fibers, respectively, while the side-polished fiber was purchased commercially. All three SA devices generated stable mode-locked pulses at center wavelengths of 1937, 1931, and 1929 nm for the tapered, side-polished, and arc-shaped fibers. The frequency of the mode-locked pulses was 10.73 MHz for the tapered fiber, 9.58 MHz for the side-polished fiber, and 10.16 MHz for the arc-shaped fiber. The measured pulse widths were 1.678, 1.734, and 1.817 ps for each of the three SA devices. The long-term stability of the mode-locked lasers was tested for each configuration over a 2-h duration. The lasers also showed little to no fluctuations in the center wavelengths and the peak optical intensities, demonstrating a reliable, ultrafast laser system.
  2. Fulltext 56 nm Wide-Band Tunable Q-Switched Erbium Doped Fiber Laser with Tungsten Ditelluride (WTe2) Saturable Absorber
    Ahmad H, Albaqawi HS, Yusoff N, Yi CW
    Sci Rep, 2020 Jun 17;10(1):9860.
    PMID: 32555280 DOI: 10.1038/s41598-020-66664-9
    A wide-band and tunable Q-switched erbium-doped fiber (EDF) laser operating at 1560.5 nm with a tungsten ditelluride (WTe2) saturable absorber (SA) is demonstrated. The semi-metallic nature of WTe2 as well as its small band gap and excellent nonlinear optical properties make it an excellent SA material. The laser cavity uses an 89.5 cm long EDF, pumped by a 980 nm laser diode as the linear gain while the WTe2 based SA generates the pulsed output. The WTe2 based SA has a modulation depth, non-saturable loss and saturation intensity of about 21.4%, 78.6%, and 0.35 kW/cm2 respectively. Stable pulses with a maximum repetition rate of 55.56 kHz, narrowest pulse width of 1.77 µs and highest pulse energy of 18.09 nJ are obtained at the maximum pump power of 244.5 mW. A 56 nm tuning range is obtained in the laser cavity, and the output is observed having a signal to noise ratio (SNR) of 48.5 dB. The demonstrated laser has potential for use in a large number of photonics applications.
  3. Fulltext A minireview of CYP2C9 and CYP2C19 single nucleotide polymorphisms (SNPs) among Malaysian populations
    Rosdi R.A., Yusoff S., Mohd Yusoff N., Ismail R., Tan, C.S., Musa N.
    Journal of Biomedical and Clinical Sciences, 2017;2(1):47-52.
    MyJurnal
    It has been recognized extensively that studies of pharmacogenetics provide massive examples of causal relationship between genotypes and drug effectiveness to account for interindividual phenotypic variations in drug therapy. In most cases, cytochrome P450 (CYP) polymorphisms are one of the major variables that affecting those drug plasma concentration, drug detoxification and drug activation in humans. Thus, understanding of CYP polymorphisms can be crucially valuable in order to allow early and more accurate drug dosage prediction and improve the drug response accordingly. Despite the high level of homologous amino acid sequences, CYP2C9 and CYP2C19 genes are among the most important CYP genes which metabolize a wide range of clinically therapeutic drugs. Several critical reviews have been published relating to the aforementioned genes. However, this minireview aims to systematically merge reported studies on the SNPs frequencies of both genes concentrating only on Malaysian population. It is hoped that, the minireview can be an opener for new opportunities to reevaluate the evidence on the prevalence of CYP2C genes as a potential genetic factor influencing a particular drug efficacy and safety among Malaysian. Such evaluation can be developed to the next level of early prediction of better and specific drug treatment, thereby improving the drug response while helping the government in minimising the drug expenditures.
  4. A RUNX1/ETO-SKP2-CDKN1B axis regulates expression of telomerase in t (8;21) acute myeloid leukemia
    Moses EJ, Azlan A, Khor KZ, Mot YY, Mohamed S, Seeni A, et al.
    Cell Mol Life Sci, 2023 Feb 23;80(3):70.
    PMID: 36820913 DOI: 10.1007/s00018-023-04713-y
    The fusion oncoprotein RUNX1/ETO which results from the chromosomal translocation t (8;21) in acute myeloid leukemia (AML) is an essential driver of leukemic maintenance. We have previously shown that RUNX1/ETO knockdown impairs expression of the protein component of telomerase, TERT. However, the underlying molecular mechanism of how RUNX1/ETO controls TERT expression has not been fully elucidated. Here we show that RUNX1/ETO binds to an intergenic region 18 kb upstream of the TERT transcriptional start site and to a site located in intron 6 of TERT. Loss of RUNX1/ETO binding precedes inhibition of TERT expression. Repression of TERT expression is also dependent on the destabilization of the E3 ubiquitin ligase SKP2 and the resultant accumulation of the cell cycle inhibitor CDKN1B, that are both associated with RUNX1/ETO knockdown. Increased CDKN1B protein levels ultimately diminished TERT transcription with E2F1/Rb involvement. Collectively, our results show that RUNX1/ETO controls TERT expression directly by binding to its locus and indirectly via a SKP2-CDKN1B-E2F1/Rb axis.
  5. Aerosol-based delivery of fibroblast cells for treatment of lung diseases
    Kardia E, Yusoff NM, Zakaria Z, Yahaya B
    J Aerosol Med Pulm Drug Deliv, 2014 Feb;27(1):30-4.
    PMID: 23409833 DOI: 10.1089/jamp.2012.1020
    Cell-based therapy has great potential to treat patients with lung diseases. The administration of cells into an injured lung is one method of repairing and replacing lost lung tissue. However, different types of delivery have been studied and compared, and none of the techniques resulted in engraftment of a high number of cells into the targeted organ. In this in vitro study, a novel method of cell delivery was introduced to investigate the possibility of delivering aerosolized skin-derived fibroblasts.
  6. Amperometric determination of L-cysteine using a glassy carbon electrode modified with palladium nanoparticles grown on reduced graphene oxide in a Nafion matrix
    Yusoff N, Rameshkumar P, Mohamed Noor A, Huang NM
    Mikrochim Acta, 2018 04 03;185(4):246.
    PMID: 29616348 DOI: 10.1007/s00604-018-2782-x
    An amperometric sensor for L-Cys is described which consists of a glassy carbon electrode (GCE) that was modified with reduced graphene oxide placed in a Nafion film and decorated with palladium nanoparticles (PdNPs). The film was synthesized by a hydrothermal method. The PdNPs have an average diameter of about 10 nm and a spherical shape. The modified GCE gives a linear electro-oxidative response to L-Cys (typically at +0.6 V vs. SCE) within the 0.5 to 10 μM concentration range. Other figures of merit include a response time of less than 2 s, a 0.15 μM lower detection limit (at signal to noise ratio of 3), and an analytical sensitivity of 1.30 μA·μM-1·cm-2. The sensor displays selectivity over ascorbic acid, uric acid, dopamine, hydrogen peroxide, urea, and glucose. The modified GCE was applied to the determination of L-Cys in human urine samples and gave excellent recoveries. Graphical abstract Spherical palladium nanoparticles (PdNPs) on reduced graphene oxide-Nafion (rGO-Nf) films were synthesized using a hydrothermal method. This nanohybrid was used for modifying a glassy carbon electrode to develop a sensor electrode for detecting L-cysteine that has fast response (less than 2 s), low detection limit (0.15 μM), and good sensitivity (0.092 μA μM-1 cm-2).
  7. An analysis of genetic association in opioid dependence susceptibility
    Nagaya D, Zahari Z, Saleem M, Yahaya BH, Tan SC, Yusoff NM
    J Clin Pharm Ther, 2018 Feb;43(1):80-86.
    PMID: 28656735 DOI: 10.1111/jcpt.12585
    WHAT IS KNOWN: Drug addiction is a novelty-seeking personality trait that is associated with the candidate genes OPRD1 (opioid delta receptors), OPRK1 (opioid kappa receptors) and PDYN (prodynorphin). However, associations between single nucleotide polymorphisms (SNPs) rs1042114 (80G>T) of the OPRD1 gene, rs702764 (843 A>G) of the OPRK1 gene, and rs910080 (3' UTR _743T>C), rs1997794 (5' UTR -381A>G) and rs1022563 (3' UTR) of the PDYN gene and novelty seeking remain controversial as reported results have not been reproducible.

    OBJECTIVE: The goal of this study was to determine the frequencies of SNPs rs1042114, rs702764, rs1997794, rs1022563 and rs910080 in the Malaysian population and to study their association with opioid dependence in Malaysian Malays.

    METHODS: A total of 459 Malay male with opioid dependence and 543 healthy male (controls) subjects were included in this study. SNPs were genotyped using the TaqMan SNP genotyping assay. Statistical analysis was performed using Golden Helix SVS software suite to identify the distribution of allele and genotype frequencies, and SNP-SNP interactions were also analysed in this study.

    RESULTS AND DISCUSSION: SNP rs1042114 in the OPRD1 gene is strongly associated with opiate addiction (P=.0001). In individuals homozygous for this risk allele, the likelihood of opiate addiction is increased by a factor 1.62 (95% confidence interval (CI) 1.412-1.875). Polymorphic alleles at SNP rs702764 of OPRK1 were not associated with opioid dependence. A significant association between opioid dependence and SNP rs910080 of PDYN (P=.0217) was detected, but there was no association for SNPs rs199774 and rs1022563. A significant interaction was also identified between homozygous wild-type genotype TT of rs702764 with the risk genotypes TG/GG of rs1042114 (odds ratio (OR)=2.111 (95% CI 1.227-3.631), P=.0069) and with the risk genotypes GA/AA of rs910080 (OR=1.415 (95% CI 1.04-1.912), P=.0239).

    WHAT IS NEW AND CONCLUSION: The results indicate that SNPs rs1042114 and rs910080 contribute to vulnerability to opioid dependence in the Malaysian Malay population. These results will help us to understand the effect of the SNPs and the SNP-SNP interaction on opioid dependence and may assist in efforts to screen vulnerable individuals and match them with individually tailored prevention and treatment strategies.

  8. Cellulitis: An unusual manifestation of Neisseria meningitidis infection
    Muhd Yusoff NH, Zainol Rashid Z, Sulong A, Shafiee MN, Ismail Z
    Malays J Pathol, 2019 Dec;41(3):351-354.
    PMID: 31901921
    INTRODUCTION: Neisseria meningitidis infections often cause severe meningitis as well as bacteraemia. However, cellulitis in meningococcal diseases have rarely been described. Here, we report a case of right lower limb cellulitis caused by N. meningitidis.

    CASE REPORT: A 69-year-old woman presented with fever and lower limb swelling. She had diabetes mellitus, hypertension, dyslipidaemia and a history of surgical resection of vulvar carcinoma. N. meningitidis was isolated from her blood culture.

    DISCUSSION: This report provides additional evidence in support of N. meningitidis as a cause of cellulitis.

  9. Combination of Multiple Ligation-Dependent Probe Amplification and Illumina MiSeq Amplicon Sequencing for TSC1/TSC2 Gene Analyses in Patients with Tuberous Sclerosis Complex
    Ismail NF, Rani AQ, Nik Abdul Malik NM, Boon Hock C, Mohd Azlan SN, Abdul Razak S, et al.
    J Mol Diagn, 2017 03;19(2):265-276.
    PMID: 28087349 DOI: 10.1016/j.jmoldx.2016.10.009
    Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder characterized by tumor growth in multiple organs and caused by mutations in either TSC1 or TSC2 genes. Because of their relatively large genomic sizes, absence of hotspots, and common type of mutations, mutation detection in TSC1 and TSC2 genes has been challenging. We devised a combination of multiple ligation-dependent probe amplification (MLPA) and amplicon sequencing (AS) to simplify the detection strategy, yet we come up with reasonably high detection rate. Thirty-four Malaysian patients diagnosed with TSC were referred to Human Genome Center, Universiti Sains Malaysia. We used a combination of MLPA to detect large copy number changes and AS to detect smaller mutations. TSC1 pathogenic or likely pathogenic mutations were found in 6 patients (18%) and TSC2 in 21 patients (62%), whereas 6 patients (18%) show no mutations and 1 patient (2%) showed only TSC2 missense variant with uncertain significance. Six of the mutations are novel. Our detection strategy costs 81% less and require 1 working week less than the conventional strategy. Confirmatory sequencing using Sanger method on a few representative mutations showed agreement with results of the AS. Combination of MLPA and Illumina MiSeq AS provides a simplified strategy and reasonably high detection rate for TSC1/TSC2 mutation, which suggested application of the strategies into clinical molecular diagnostics.
  10. Commemorating the 40-Year Journey of the School of Medical Sciences, Universiti Sains Malaysia
    Ismail SB, Hassan R, Baharuddin KA, Sulaiman AR, Jaalam K, Wan Hitam WH, et al.
    Malays J Med Sci, 2019 Mar;26(2):1-7.
    PMID: 31447603 DOI: 10.21315/mjms2019.26.2.1
    The School of Medical Sciences of Universiti Sains Malaysia (USM) is the launching pad for this journal. From the school's humble beginning at the USM Main Campus in Pulau Pinang, Malaysia, it has grown in stature at its current location in the USM Health Campus, Kubang Kerian, Kelantan, Malaysia. Commemorating its 40th anniversary, this editorial aims to recollect, although not exhaustively, the wealth of returns for the USM, as well as for the nation, which the school has managed to deliver in that period. Resolute to its vision and mission, this article highlights the outstanding accomplishments in various core aspects of the school's academic, research and professional growth as we continually strive to train globally competitive and compassionate medical graduates, medical specialists and scientists, skilled to serve nation's needs and broader markets worldwide. Currently guided by the Malaysian Higher Education Blueprint (2015-2025), the school shall remain ingenious in its duties in the many more years to come, as we head for a world-class trajectory.
  11. Fulltext Cosmos caudatus Kunth. extract reduced number of microflora in oyster mushroom (Pleurotus ostreatus)
    Yusoff, N. A. H., Sanuan, F. M., Rukayadi, Y.
    International Food Research Journal, 2015;22(5):1837-1842.
    MyJurnal
    Nowadays consumer is more demand on natural foodstuff instead of synthetic product due to their concern on health. The objective of this study is to investigate the effect of C. caudatus extract on the number of microflora in oyster mushroom at different concentration of C. caudatus extract and exposure time using dilution method. The results showed that the number of microorganisms (Log10 CFU/g) in oyster mushroom in term of Total Plate Count (TPC), Bacillus cereus, Escherichia coli and Staphylococcus aureus were 6.13 ± 0.04, 6.15 ± 0.09, 5.97 ± 0.04, and 6.46 ± 0.00, respectively. The effect of C. caudatus extract on microflora in oyster mushroom at concentrations of 0.00%, 0.05%, 0.5%, and 5.0% with exposure time of 0, 5, 10, and 15 min demonstrated that the reduction number of microflora in oyster mushroom was dependent on the concentration of C. caudatus extract and exposure times. The number of TPC (Log10 CFU/g) in oyster mushroom was significantly reduced after treated with C. caudatus extract at concentration of 0.05% for 15 min; 6.13 ± 0.04 reduced to 2.62 ± 0.07. Moreover, B. cereus (Log10 CFU/g) in oyster mushroom was significantly reduced by treatment of C. caudatus extract at concentration of 0.05% for 5 min; 6.15 ± 0.09 reduced to 3.77 ± 0.15. Meanwhile, the number of E. coli (Log10 CFU/g) in oyster mushroom was significantly reduced at concentration of 0.05% for 10 min; 5.97 ± 0.04 reduced to 3.21 ± 0.13. Lastly, the survival number of S. aureus in oyster mushroom was significantly reduced after treated with C. caudatus extract at concentration of 0.05% for 15 min; 6.46 ± 0.00 reduced to 4.83 ± 0.07. In conclusion, C. caudatus extract has potentiality to be developed as natural sanitizer for rinsing raw food materials such as oyster mushroom.
  12. Fulltext Dengue virus type 2 (DENV2)-induced oxidative responses in monocytes from glucose-6-phosphate dehydrogenase (G6PD)-deficient and G6PD normal subjects
    Al-Alimi AA, Ali SA, Al-Hassan FM, Idris FM, Teow SY, Mohd Yusoff N
    PLoS Negl Trop Dis, 2014 Mar;8(3):e2711.
    PMID: 24625456 DOI: 10.1371/journal.pntd.0002711
    Dengue virus is endemic in peninsular Malaysia. The clinical manifestations vary depending on the incubation period of the virus as well as the immunity of the patients. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Malaysia where the incidence is 3.2%. It has been noted that some G6PD-deficient individuals suffer from more severe clinical presentation of dengue infection. In this study, we aim to investigate the oxidative responses of DENV2-infected monocytes from G6PD-deficient individuals.
  13. Fulltext Dental patient knowledge about the effects of smoking and attitudes about the role of dentists in smoking cessation
    Yahya NA, Saub R, Nor MM, Yusoff N
    Southeast Asian J. Trop. Med. Public Health, 2017 Mar;48(2):473-84.
    PMID: 29642311
    Dentists can offer their patients who smoke tobacco assistance with smoking cessation. We conducted this study to assess dental patient knowledge about the effects of smoking and perceptions and attitudes regarding the role of dentists in smoking cessation counselling. We conducted this study to inform tobacco cessation programs that could potentially include dentists. We conducted a cross-sectional study using a self-administered questionnaire among 375 patients. The mean age of subjects was 33.4 years; females comprised 51.5%. Participants were divided into 3 groups: those who never smoked (n = 263, 70.7%), smokers (n = 92, 24.7%), and ex-smokers (n = 17, 4.5%). Significantly more participants (p = 0.046) who never smoked (92.9%) knew smoking can cause bad breath than smokers(86.9%). Significantly more participants (p = 0.002) who never smoked (74.8%) knew smoking can cause periodontal disease than smokers (57.6%). Significantly
    more participants (p < 0.001) who never smoked (84.5%) knew smoking can cause
    oral cancer than smokers (66.7%). Significantly more participants (p < 0.001) who never smoked (86.7%) knew smoking can cause lung cancer than smokers (69.7%). Significantly more participants who never smoked (85.5%) felt dentists should be interested in the smoking status of their patients (p = 0.004) than smokers (72.6%). Significantly more participants (p = 0.08) who never smoked (69.6%) stated dentists should give smoking cessation advice than smokers/ex-smokers (59.0%). Smoker/ex-smokers had less knowledge about the effects of smoking on oral and general health than non-smokers. Both smokers/ex-smokers and non-smokers felt dentists should provide smoking cessation advice.
  14. Design and validation of a bi-axial loading bioreactor for mechanical stimulation of engineered cartilage
    Yusoff N, Abu Osman NA, Pingguan-Murphy B
    Med Eng Phys, 2011 Jul;33(6):782-8.
    PMID: 21356602 DOI: 10.1016/j.medengphy.2011.01.013
    A mechanical-conditioning bioreactor has been developed to provide bi-axial loading to three-dimensional (3D) tissue constructs within a highly controlled environment. The computer-controlled bioreactor is capable of applying axial compressive and shear deformations, individually or simultaneously at various regimes of strain and frequency. The reliability and reproducibility of the system were verified through validation of the spatial and temporal accuracy of platen movement, which was maintained over the operating length of the system. In the presence of actual specimens, the system was verified to be able to deliver precise bi-axial load to the specimens, in which the deformation of every specimen was observed to be relatively homogeneous. The primary use of the bioreactor is in the culture of chondrocytes seeded within an agarose hydrogel while subjected to physiological compressive and shear deformation. The system has been designed specifically to permit the repeatable quantification and characterisation of the biosynthetic activity of cells in response to a wide range of short and long term multi-dimensional loading regimes.
  15. DietPal: a Web-based dietary menu-generating and management system
    Noah SA, Abdullah SN, Shahar S, Abdul-Hamid H, Khairudin N, Yusoff M, et al.
    J Med Internet Res, 2004 Jan 30;6(1):e4.
    PMID: 15111270
    Attempts in current health care practice to make health care more accessible, effective, and efficient through the use of information technology could include implementation of computer-based dietary menu generation. While several of such systems already exist, their focus is mainly to assist healthy individuals calculate their calorie intake and to help monitor the selection of menus based upon a prespecified calorie value. Although these prove to be helpful in some ways, they are not suitable for monitoring, planning, and managing patients' dietary needs and requirements. This paper presents a Web-based application that simulates the process of menu suggestions according to a standard practice employed by dietitians.
  16. Dose-Dependent Effect of Wedelia trilobata Essential Oil (EO) on Lettuce (Lactuca sativa L.) with Multivariate Analysis
    Azlan Azizan K, Izzairy Zamani A, Azlan Nor Muhammad N, Khairudin K, Yusoff N, Firdaus Nawawi M
    Chem Biodivers, 2022 Mar;19(3):e202100833.
    PMID: 34962057 DOI: 10.1002/cbdv.202100833
    Understanding metabolite changes and underlying metabolic pathways that may be affected in target plants following essential oils (EOs) exposure is of great importance. In this study, a gas chromatography-mass spectrometry (GC/MS) based metabolomics approach was used to determine the metabolite changes in lettuce (Lactuca sativa L.) shoot and root after exposure to different concentrations of W. trilobata EO. Multivariate analyses of principal component analysis (PCA) and orthogonal partial least-discriminant analysis (OPLS-DA) corroborated that shoot and root of lettuce responded differently to W. trilobata EO. In EO-exposed shoot samples, an increase in the levels of malic acid, glutamine, serine, lactose and α-glucopyranose affected important metabolism pathways such as glycolysis, fructose and mannose metabolism and galactose metabolism. The findings suggest that lettuce may be up-regulating these metabolites to increase tolerance against W. trilobata EO. In EO-exposed root samples, changes in fatty acid biosynthesis, elongation, degradation, phenylalanine, tyrosine and tryptophan metabolism were linked to a decrease in lyxose, palmitic acid, octadecanoic acid, aspartic acid, phenylalanine and myo-inositol. These results indicate that W. trilobata EO could cause alterations in fatty acid compositions and lead to inhibition of roots growth. Together, these findings provide insight into the metabolic responses of lettuce upon W. trilobata EO exposure, as well as potential mechanisms of action of W. trilobata EO as bio-herbicides.
  17. Fulltext Drivers of green purchasing behaviour: a systematic review and a research agenda
    Yusoff N, Alias M, Ismail N
    F1000Res, 2023;12:1286.
    PMID: 38196406 DOI: 10.12688/f1000research.140765.1
    Background: Green purchasing is an important aspect of sustainable consumption, which decreases society's environmental effect. Although numerous research has been conducted to investigate the determinants of green buying behaviour, there has been a lack of effort in comprehensively analysing these findings. The purpose of this study is to examine the available literature on the factors that influence green purchasing behaviour. Methods: The review focused on empirical research published in peer-reviewed English-language publications between 2017 and 2021 in Web of Science and Scopus. The research took place from May to June 2021. Mixed Methods Appraisal Tool (MMAT) is used to assess the risk of bias in systematic literature reviews. Results: 41 articles were included, with significant focus on the retailing sector. Most of these studies were centred in Asian countries, primarily China and India. The Theory of Planned Behaviour was the most prominent, appearing 15 times, followed by the Theory of Reasoned Action (seven times). Analysis identified five main themes and 15 sub-themes related to green purchase behaviour drivers. These themes were categorized by occurrence: People (34 papers), marketing (13), knowledge (12), environment (12), and influence (nine). The dominant driver was people (34 studies), encompassing sub-themes including motivation (three), perception (eight), behavioural (13), and psychographic characteristics (10). Conclusions: This study has given an overview of the present status of green purchasing behaviour, which serves as a foundation for future studies and guidance for policymakers and practitioners. However, it does not include unpublished materials and non-English papers. Secondly, it focuses on articles from two databases within the last five years which doesn't encompass all article types, prompting the need for future exploration. Thirdly, extending the review's time frame could unveil more pronounced GPB patterns. Lastly, although all eligible papers were assessed based on criteria, the chance of overlooking some papers is acknowledged.
  18. Electrocatalytic Reduction of Hydrogen Peroxide and Its Non-Enzymatic Electrochemical Detection Using Silver Nanoparticles Anchored on Reduced Graphene Oxide
    Ikhsan NI, Rameshkumar P, Yusoff N, Huang NM
    J Nanosci Nanotechnol, 2019 Nov 01;19(11):7054-7063.
    PMID: 31039858 DOI: 10.1166/jnn.2019.16630
    Silver-reduced graphene oxide (Ag-rGO) nanohybrid was synthesized by applying a slight modification to the Turkevich method using trisodium citrate as a reducing and stabilizing agent to catalyze the non-enzymatic electrochemical detection of hydrogen peroxide (H₂O₂). Spherical silver nanoparticles (AgNPs) with an average particle size of 2.2 nm surfaced on reduced graphene oxide (rGO) sheets. Cyclic voltammograms (CV) obtained from glassy carbon (GC) electrode coated with Ag-rGO nanohybrid (4 mM) exhibited a peak at an overpotential of -0.52 V, with a larger faradaic current for the reduction of H₂O₂. Using the modified electrode for the linear sweep voltammetry (LSV) detection of H₂O₂, the detection limit and sensitivity were determined to be 4.8 μM (S/N ═ 3) and 0.0262 μA μM-1, respectively. The sensor appeared selective and stable towards H₂O₂ in the presence of possible interference, and it also demonstrated good recoveries of H₂O₂ concentration in real water samples.
  19. Fulltext Enrolment and retention of people who inject drugs in the Needle & Syringe Exchange Programme in Malaysia
    Chandrasekaran S, Kyaw NTT, Harries AD, Yee IA, Ellan P, Kurusamy T, et al.
    Public Health Action, 2017 Jun 21;7(2):155-160.
    PMID: 28695090 DOI: 10.5588/pha.17.0003
    Setting: Needle and Syringe Exchange Programme (NSEP) implemented by non-governmental organisations in Malaysia. Objectives: To determine enrolment, characteristics and retention in the NSEP of people who inject drugs (PWID) between 2013 and 2015. Design: Retrospective cohort study. Results: There were 20 946 PWID, with a mean age of 38 years. The majority were male (98%) and of Malay ethnicity (92%). Follow-up data were available for 20 761 PWID. Annual retention of newly enrolled PWID for each year was respectively 85%, 87% and 78% for 2013, 2014 and 2015, although annual enrolment over these years declined from 10 724 to 6288 to 3749. Total person-years (py) of follow-up were 27 806, with loss to follow-up of 40 per 100 py. Cumulative probability of retention in NSEP was 66% at 12 months, 45% at 24 months and 26% at 36 months. Significantly higher loss to follow-up rates were observed in those aged 15-24 years or ⩾50 years, females, transgender people and non-Malay ethnic groups. Conclusion: Annual retention of new PWID on NSEP was impressive, although enrolment declined over the 3 years of the study and cumulative loss to follow-up was high. A better understanding of these programmatic outcomes is required.
  20. Ergonomic evaluation of postural stress in school workshop
    Hashim AM, Dawal SZ, Yusoff N
    Work, 2012;41 Suppl 1:827-31.
    PMID: 22316824 DOI: 10.3233/WOR-2012-0249-827
    The objective of this study is to compare the evaluation of postural analysis between a self-report questionnaire and physical assessments methods for students aged 13 to 15 years old in school workshop. 336 students were volunteered as participants to fill in the questionnaire and being observed in the workshop. Total of 104 positions were selected and analyzed while students performing their tasks. Questionnaire data was examined to specify the prevalence of postural stress symptoms. The relationship of postural stress by physical assessment methods (RULA and REBA methods) was defined to identify the risk level of students' working posture. From the results, comparison of four factors categorized from total of 22 questions among ages, the mean values were lower for 13 years old students meaning that they were faced higher posture problems while using the workstation. The obtained results from both physical assessment methods and questionnaire analysis have identified 13 years old students faced higher risk exposure. Analysis results emphasized the fact that self-reports questionnaire method has almost accurate as postural evaluation methods to identify physical risks in workplace. The result also shows that an intervention is needed to overcome the posture problems.
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