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Fulltext Impact of ZnO nanoparticles as additive on performance and emission characteristics of a diesel engine fueled with waste plastic oil

Suhel A, Abdul Rahim N, Abdul Rahman MR, Bin Ahmad KA, Khan U, Teoh YH, et al.

Heliyon, 2023 Apr;9(4):e14782.
PMID: 37064486 DOI: 10.1016/j.heliyon.2023.e14782

Neat waste plastic oil (WPO) application as a fuel in engines reduces BTE and increases deleterious emissions of CO, UHC, NOx, and smoke due to the presence of insufficient oxygen and unbreakable hydrocarbon chains in WPO. Present investigation was performed to evaluate the impact of ZnO nanoparticles on the performance and emission characteristics of a diesel engine operated with the waste plastic oil (WPO20) blend. The objective of doping ZnO nanoparticles with WPO20 was to enhance the oxidation reaction and heat transfer rate between fuel droplets during combustion, which aids in completing the combustion. The sol-gel technique was adopted to successfully synthesize the ZnO nanoparticles using zinc acetate (Zn(CH3CO2)2.2H2O) and sodium hydroxide (NaOH) precursors. The structure and morphology of resulted particles were studied by XRD and FESEM tests. Both results indicate the stable formation of ZnO, and exhibit the crystallinity nature, spherical surface, and size consistency. The synthesized ZnO nanoparticles were infused in WPO20 blend in the amounts of 50, 100, and 150 ppm with the aid of the ultrasonication technique. Engine test was conducted with diesel fuel, WPO20 blend, and nano-infused fuels at a constant speed of 1500 rpm under various loads. The disparities in performance and emission characteristics were examined and compared with pure diesel fuel. The findings demonstrated that adding nanoparticles to WPO20 significantly lowers the smoke, CO, UHC, and NOx emissions and simultaneously improves the BTE and decreases the BSFC of the diesel engine. Optimum results were obtained for 100 ppm concentration of ZnO nanoparticles. Reduction of smoke by 11.86%, CO by 5.7%, UHC by 28%, and NOx by 14.93%, along with the enhancement of BTE by 2.47%, were noticed at maximum load with 100 ppm particles. Based on the test results, it is concluded that ZnO nanoparticles can be used as a suitable additive in WPO blends to improve the overall engine characteristics. Further scope of the present work is to study the effect of organic nanoparticles with WPO on engine behaviour, the detailed combustion of nanoparticles infused WPO, and the nanoparticles doped WPO on engine wear and corrosion.
Fulltext Proof-of-concept for incorporating mechanistic insights from multi-omics analyses of polymyxin B in combination with chloramphenicol against Klebsiella pneumoniae

Hanafin PO, Abdul Rahim N, Sharma R, Cess CG, Finley SD, Bergen PJ, et al.

CPT Pharmacometrics Syst Pharmacol, 2023 Mar;12(3):387-400.
PMID: 36661181 DOI: 10.1002/psp4.12923

Carbapenemase-resistant Klebsiella pneumoniae (KP) resistant to multiple antibiotic classes necessitates optimized combination therapy. Our objective is to build a workflow leveraging omics and bacterial count data to identify antibiotic mechanisms that can be used to design and optimize combination regimens. For pharmacodynamic (PD) analysis, previously published static time-kill studies (J Antimicrob Chemother 70, 2015, 2589) were used with polymyxin B (PMB) and chloramphenicol (CHL) mono and combination therapy against three KP clinical isolates over 24 h. A mechanism-based model (MBM) was developed using time-kill data in S-ADAPT describing PMB-CHL PD activity against each isolate. Previously published results of PMB (1 mg/L continuous infusion) and CHL (Cmax : 8 mg/L; bolus q6h) mono and combination regimens were evaluated using an in vitro one-compartment dynamic infection model against a KP clinical isolate (108 CFU/ml inoculum) over 24 h to obtain bacterial samples for multi-omics analyses. The differentially expressed genes and metabolites in these bacterial samples served as input to develop a partial least squares regression (PLSR) in R that links PD responses with the multi-omics responses via a multi-omics pathway analysis. PMB efficacy was increased when combined with CHL, and the MBM described the observed PD well for all strains. The PLSR consisted of 29 omics inputs and predicted MBM PD response (R2 = 0.946). Our analysis found that CHL downregulated metabolites and genes pertinent to lipid A, hence limiting the emergence of PMB resistance. Our workflow linked insights from analysis of multi-omics data with MBM to identify biological mechanisms explaining observed PD activity in combination therapy.
Fulltext Bacterial Metabolomics: Sample Preparation Methods

Mohd Kamal K, Mahamad Maifiah MH, Abdul Rahim N, Hashim YZH, Abdullah Sani MS, Azizan KA

Biochem Res Int, 2022;2022:9186536.
PMID: 35465444 DOI: 10.1155/2022/9186536

Metabolomics is a comprehensive analysis of metabolites existing in biological systems. As one of the important "omics" tools, the approach has been widely employed in various fields in helping to better understand the complex cellular metabolic states and changes. Bacterial metabolomics has gained a significant interest as bacteria serve to provide a better subject or model at systems level. The approach in metabolomics is categorized into untargeted and targeted which serves different paradigms of interest. Nevertheless, the bottleneck in metabolomics has been the sample or metabolite preparation method. A custom-made method and design for a particular species or strain of bacteria might be necessary as most studies generally refer to other bacteria or even yeast and fungi that may lead to unreliable analysis. The paramount aspect of metabolomics design comprises sample harvesting, quenching, and metabolite extraction procedures. Depending on the type of samples and research objective, each step must be at optimal conditions which are significantly important in determining the final output. To date, there are no standardized nor single designated protocols that have been established for a specific bacteria strain for untargeted and targeted approaches. In this paper, the existing and current developments of sample preparation methods of bacterial metabolomics used in both approaches are reviewed. The review also highlights previous literature of optimized conditions used to propose the most ideal methods for metabolite preparation, particularly for bacterial cells. Advantages and limitations of methods are discussed for future improvement of bacterial metabolomics.
Fulltext Anemia among Men in Malaysia: A Population-Based Survey in 2019

Awaluddin SM, Shahein NA, Che Abdul Rahim N, Mohd Zaki NA, Nasaruddin NH, Saminathan TA, et al.

Int J Environ Res Public Health, 2021 Oct 17;18(20).
PMID: 34682667 DOI: 10.3390/ijerph182010922

This study aimed to determine the prevalence of anemia and factors associated with anemia among men in Malaysia. The researchers used data from the 2019 National Health and Morbidity Survey (NHMS). The hemoglobin levels of men aged 15 years and above who gave their consent was measured using the HemoCue® Hb 201+ System©. The majority of them (87.2%) were men aged 15-59 years, referred to as the younger age group in this study. The prevalence of anemia among men was 12.6% (95% confidence interval (CI): 10.9, 14.5). The prevalence was higher among older men (30.7%; 95% CI: 26.6, 35.1) than younger men (10.0%; 95% CI: 8.2, 12.2). Anemia among men was associated with older age (adjusted odds ratios (aOR) = 3.1; 95% CI: 2.1, 4.4) and those with diabetes (aOR = 1.5; 95% CI: 1.2, 2.1) via a logistic regression analysis. In conclusion, older men were more affected by anemia than younger men in this study. Anemia among older men in Malaysia is at the level of moderate to severe public health significance. The likelihood of developing anemia is increased among older men with diabetes compared to older men without diabetes. These often-overlooked issues among men need to be detected and treated early in order to prevent complications and improve their quality of life.
Fulltext Exploring the rise of telehealth services in Malaysia: A retrospective study

Loo JS, Yow HY, Ten YY, Govindaraju K, Megat Mohd Zubairi MH, Oui HC, et al.

Digit Health, 2023;9:20552076231216275.
PMID: 38025110 DOI: 10.1177/20552076231216275

BACKGROUND: Telehealth services have gained popularity in Malaysia, providing convenient consultations during the COVID-19 pandemic. However, there is limited research on their usage, user demographics and prescribed medications. This study aims to fill that gap by investigating telehealth service utilisation in community pharmacies and identifying trends in common diagnoses and medications prescribed.
METHODS: A retrospective observational study was conducted using a telehealth services database in Malaysian community pharmacies. Consultation records from January 2019 to December 2021 were extracted using a data collection form. The study identified the service usage over time, demographic profiles of users and the most common diagnoses and prescribed medications. Diagnoses were classified using the International Classification of Disease, 10th Revision (ICD-10), and medications were classified using the Anatomical Therapeutic Chemical (ATC) system.
RESULTS: The study included 835,826 telehealth service records, with 88.8% being assisted consultations with e-prescriptions and 11.2% direct consultations. The user population consisted of primarily Malaysians (96.9%), with a mean age of 50 ± 21 years. Both telehealth services saw an increase in unique users over the 3-year study period. There was a moderate correlation between active COVID-19 cases and monthly user count. Assisted consultations were more widely used than direct consultations.
CONCLUSION: This study found an increased usage of telehealth services and its potential to remain as a healthcare system feature in community pharmacies. Further investigation into the impact on medication safety, quality and healthcare delivery is warranted.
Fulltext Adaptation of an in vitro one-compartment pharmacodynamic chemostat for testing efficacy of ceftazidime against Burkholderia pseudomallei outside a BSL3 facility

Zamri HF, Mohd Ali MR, Sha'ari AII, Mohd Mazalan NH, Ahmad N, Nor Amdan NA, et al.

MethodsX, 2025 Jun;14:103167.
PMID: 39897649 DOI: 10.1016/j.mex.2025.103167

Non-clinical pharmacokinetic-pharmacodynamic (PKPD) models are crucial in the initial design of drug-dosage regimens and in drug development but has rarely been employed for testing high-risk organisms due to stringent handling procedures. Burkholderia pseudomallei is classified as a Tier 1 select agent with international guidelines recommending this organism to be handled within a biosafety level 3 (BSL3) facility. Unfortunately, BSL3 facilities are not widely available in low-resource settings. This paper describes a detailed guide for setting up an in vitro pharmacodynamic infection model specific for testing B. pseudomallei outside BSL 3 laboratory. Briefly in this study,•All procedures involving active handling of live B. pseudomallei cultures were performed strictly inside a class II BSC in BSL-2 plus negative airflow laboratory.•The model was set to simulate B. pseudomallei-bacteremia treated with ceftazidime, a 1st-line anti-melioidosis drug with an approximate 2-hour half-life. Model validation was performed by simulating ceftazidime half-life.•For the pharmacodynamic study, ceftazidime was given as bolus injections at 8-hour intervals into the central culture chamber containing actively growing B. pseudomallei.
Fulltext In-vitro diagnosis of single and poly microbial species targeted for diabetic foot infection using e-nose technology

Yusuf N, Zakaria A, Omar MI, Shakaff AY, Masnan MJ, Kamarudin LM, et al.

BMC Bioinformatics, 2015;16:158.
PMID: 25971258 DOI: 10.1186/s12859-015-0601-5

Effective management of patients with diabetic foot infection is a crucial concern. A delay in prescribing appropriate antimicrobial agent can lead to amputation or life threatening complications. Thus, this electronic nose (e-nose) technique will provide a diagnostic tool that will allow for rapid and accurate identification of a pathogen.
Placenta microRNA profile of patient with Obstetric Antiphospholipid Syndrome

Mohamad MA, Ahmad Asnawi AW, Suhiman MS, Sathar J, Hayati AR, Abdul Rahim NS, et al.

Malays J Pathol, 2023 Dec;45(3):425-440.
PMID: 38155384

The onset of obstetric antiphospholipid syndrome (APS) occurs when antiphospholipid antibodies act upon the placenta. During pregnancy, APS exhibits traits such as vascular thrombosis, inflammation, and hindered trophoblast implantation. The involvement of microRNA expression has been proposed as a genetic factor contributing to the syndrome's development. MicroRNAs play a role in regulating gene expression in various cellular processes, including the formation of placental tissue. Therefore, additional research is needed to explore the control of placental miRNA in APS. In this study, we aimed to profile miRNA expressions from placenta tissue of patients with APS. Differentially expressed miRNAs were determined for its targeted genes and pathways. Agilent microarray platform was used to measure placental microRNA expressions between normal placental tissue and those obtained from patients with APS. Differentially expressed miRNAs were detected using GeneSpring GX software 14.2 and sequences were mapped using TargetScan software to generate the predicted target genes. Pathway analysis for the genes was then performed on PANTHER and REACTOME software. Selected miRNAs and their associated genes of interest were validated using qPCR. Microarray findings revealed, 9 downregulated and 21 upregulated miRNAs expressed in placenta of patients with APS. Quantitative expressions of 3 selected miRNAs were in agreement with the microarray findings, however only miR-525-5p expression was statistically significant. Pathway analysis revealed that the targeted genes of differentially expressed miRNAs were involved in several hypothesised signalling pathways such as the vascular endothelial (VE) growth factor (VEGF) and inflammatory pathways. VE-cadherin, ras homolog member A (RHOA) and tyrosine kinase receptor (KIT) showed significant downregulation while Retinoblastoma gene (RET), Dual specificity protein phosphatase 10 (DUSP10) and B-lymphocyte kinase (BLK) genes were significantly upregulated. These preliminary findings suggest the involvement of miRNAs and identified novel associated genes involvement in the mechanism of obstetric APS, particularly through the alteration of vascular-associated regulators and the inflammatory signalling cascade.
Factors contributing to food insecurity among older persons in Malaysia: Findings from the National Health and Morbidity Survey (NHMS) 2018

Salleh R, Man CS, Ahmad MH, Palaniveloo L, Zulkafly N, Ab Halim SA, et al.

Geriatr Gerontol Int, 2020 Dec;20 Suppl 2:73-78.
PMID: 33370860 DOI: 10.1111/ggi.14006

AIM: Older persons are vulnerable to food insecurity. Therefore, this study aimed to determine the prevalence of food insecurity and associated factors among older persons in Malaysia.
METHODS: This is a cross-sectional study with two-stage stratified random sampling. In total, 3977 older persons participated in this study. Face-to-face interviews were conducted using a mobile device to obtain information about socio-demographic background, food insecurity, non-communicable diseases, social support and living arrangements. Descriptive and multiple complex sample logistic regression analyses were performed for data analysis.
RESULTS: The overall prevalence of food insecurity among older persons was 10.4%. Older persons from rural areas with no or only primary and secondary education, income less than RM 2000 (USD 477.57), at risk of malnutrition and not receiving very high social support were more likely to be food-insecure.
CONCLUSION: Approximately, one-tenth of Malaysian older adults were classified as food-insecure; particularly those living in rural areas from lower socio-economic status, not receiving very high social support and malnourished were more likely to be at risk. A specific nutrition program, such as meals on wheels and food vouchers, should be targeted toward older persons who are at risk to improve their malnutrition status. Geriatr Gerontol Int 2020; 20: 73-78.
Fulltext Novel Polymyxin Combination with the Antiretroviral Zidovudine Exerts Synergistic Killing against NDM-Producing Multidrug-Resistant Klebsiella pneumoniae

Lin YW, Abdul Rahim N, Zhao J, Han ML, Yu HH, Wickremasinghe H, et al.

Antimicrob Agents Chemother, 2019 04;63(4).
PMID: 30670431 DOI: 10.1128/AAC.02176-18

Polymyxins are used as a last-line therapy against multidrug-resistant (MDR) New Delhi metallo-β-lactamase (NDM)-producing Klebsiella pneumoniae However, polymyxin resistance can emerge with monotherapy; therefore, novel strategies are urgently needed to minimize the resistance and maintain their clinical utility. This study aimed to investigate the pharmacodynamics of polymyxin B in combination with the antiretroviral drug zidovudine against K. pneumoniae Three isolates were evaluated in static time-kill studies (0 to 64 mg/liter) over 48 h. An in vitro one-compartment pharmacokinetic/pharmacodynamic (PK/PD) model (IVM) was used to simulate humanized dosage regimens of polymyxin B (4 mg/liter as continuous infusion) and zidovudine (as bolus dose thrice daily to achieve maximum concentration of drug in broth [Cmax] of 6 mg/liter) against K. pneumoniae BM1 over 72 h. The antimicrobial synergy of the combination was further evaluated in a murine thigh infection model against K. pneumoniae 02. In the static time-kill studies, polymyxin B monotherapy produced rapid and extensive killing against all three isolates followed by extensive regrowth, whereas zidovudine produced modest killing followed by significant regrowth at 24 h. Polymyxin B in combination with zidovudine significantly enhanced the antimicrobial activity (≥4 log10 CFU/ml) and minimized bacterial regrowth. In the IVM, the combination was synergistic and the total bacterial loads were below the limit of detection for up to 72 h. In the murine thigh infection model, the bacterial burden at 24 h in the combination group was ≥3 log10 CFU/thigh lower than each monotherapy against K. pneumoniae 02. Overall, the polymyxin B-zidovudine combination demonstrates superior antimicrobial efficacy and minimized emergence of resistance to polymyxins.

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