Pusat Pengajian Sains Kesihatan - Tesis

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A study on fibre identification and characterization of various headscarf fabrics
(2025-02)
Fahmi, Shazwina Ayna Mohd
This study focuses on the identification and characterisation of fibres from six types of headscarf fabrics, mainly cotton, silk, polyester, lycra, viscose, and moss crepe as potential sources of trace evidence in forensic investigations. Fibre evidence, often transferred during physical contact, plays a crucial role in linking suspects, victims, and crime scenes. Morphological tests revealed that distinct weave patterns and yarn structures significantly influence fabric behaviour, such as porosity and density, aiding in the differentiation of fabric types. Both cotton and viscose exhibited plain weaves, but cotton had a less porous fabric structure than viscose. Polyester and lycra showed dense synthetic structures. Burning tests identified fibres based on their combustion behaviour, residue formation, and odour. Lycra however shows uniqueness in the absence of hard beads although it is synthetic fibre. Moss crepe and viscose displayed mixed traits, confirming their partially synthetic origins. Solubility tests further validated fibre compositions by observing their reactions to various chemical solvents, demonstrating distinct dissolution behaviours influenced by chemical structure and environmental factors. Most fibres did not dissolve in 75% and 60% sulphuric acid, and none dissolved in formic acid, while most fibres dissolved in high-temperature 50% sodium hydroxide solutions. In conclusion, this study successfully classified and identified the six types of fibres using comprehensive fibre identification methods, enhancing their value as trace evidence in forensic applications
Allelic variations in the edar gene and their influence on hair types in Malaysian populations
(2025-02)
Boon, Wendy Tan Lee
Ectodysplasin A Receptor (EDAR) is a tumor necrosis factor receptor (TNFR) that is involved in the development of ectodermal tissues, including hair follicles. The single nucleotide polymorphism (SNP) rs3827760, which encodes EDAR:p.(Val370Ala), is a missense mutation in the EDAR gene that pleiotropically influences phenotypic traits such as hair type, particularly in East Asian populations. However, the genotype distribution and correlation of this SNP with hair type among Malaysian ethnic groups remain largely unexplored. Thus, this study aimed to determine the allelic variation of SNP rs3827760 in the Malaysian population among the Malay, Chinese, and Indian ethnic groups. DNA samples (buccal swabs) were collected from 30 participants, with 10 individuals from each ethnic group, and extracted using a silica-based solid-phase extraction (SPE) method. Polymerase chain reaction (PCR) was performed using the custom EDAR primers, followed by agarose gel electrophoresis, DNA quantification, cycle sequencing, and ethanol precipitation (purification). Sanger sequencing was conducted using the SeqStudio™ Genetic Analyzer, and the chromatograms were analyzed with Chromas and Jalview software to identify nucleotide variations at the SNP loci rs3827760, rs146567337, and rs12623957. A chi-square test was performed to determine the statistical significance of the association between the SNPs and ethnicity or hair type. The analysis showed that SNP rs3827760 was significantly correlated with both ethnicity (P-value <0.001) and hair type (P-value = 0.011). The ancestral allele (allele A) was strongly associated with Indian (curly hair) individuals, while the derived allele (allele G) was strongly associated with Chinese (straight hair) individuals. Malay individuals with straight or wavy hair exhibited a mix of all three genotypes. SNP rs146567337 showed no significant association with ethnicity (P-value = 0.155) or hair type (P-value = 0.432). SNP rs12623957 was not significantly related to ethnicity (P-value = 0.058) but was correlated with hair type (P-value = 0.017). Therefore, SNP rs3827760 in the EDAR gene was the most strongly correlated genetic factor for hair types and ethnicity in this study
An evaluation using fdi criteria to compare full-ceramic crowns, composite resin fillings, ceramic inlays and onlays in posterior teeth after endodontic treatment
(2025-09)
Shiwei, Che
Restoring endodontically treated posterior teeth is a critical challenge due to structural compromises following root canal treatment. This study evaluates the clinical performance of full-ceramic crowns (FCC), composite resin (CR) fillings, and ceramic inlays/onlays in posterior teeth using the World Dental Federation (FDI) criteria. A prospective cohort study was conducted involving 150 patients (194 posterior teeth), assessing functional outcomes such as fracture resistance, marginal adaptation, wear, and patient satisfaction over a mean follow-up period of 58.14 months (SD = 2.93). Statistical analysis revealed significant differences (p < 0.05) in long-term success rates among the three groups, with FCC demonstrating superior durability and marginal adaptation, while CR fillings provided a minimally invasive, cost-effective option with higher wear and marginal deterioration over time. Ceramic inlays/onlays offered a balance between structural conservation and durability, making them suitable for cases with moderate tooth structure loss. Patient satisfaction scores, as measured by the FDI criteria, were highest in the FCC group (mean score: 1.2 ± 0.4), followed by the ceramic inlays/onlays group (1.4 ± 0.5) and the CR fillings group (1.8 ± 0.6), with differences statistically significant (p < 0.05). These findings provide evidence-based recommendations for restorative material selection, emphasizing the need for personalized treatment planning based on clinical conditions and patient needs
Analytical investigation of corrosive agents in relation to cotton textile damage assessment
(2025-02)
Khairi, Siti Nur Aiefika
Acid attacks cases occur commonly with the ill intention to hurt the victim by utilising corrosive substances that are easily obtained and cheap. Clothing fabrics are one of the surfaces that are in contact with the corrosive agents used making identification of the corrosive substances vital to provide clue in connecting the perpetrator to the crime. Therefore, this study investigates the chemical characterization of corrosive agents and the relation to textile damage. Relationships of corrosive substance samples with cotton textile were studied over time interval of every 5 minutes in spend of 15 minutes. The tear area and absorption area occurred to the cotton textile were taken into account as the effect. Lab graded acids and commercial products were included in the analytical investigation, whereby pH measurements and chemical characterization of the corrosive substance samples by using ATR-FTIR spectroscopy was performed. Resulting in observation of the acidity trends of the samples through the pH measurement. In addition, the chemical characteristics of the samples was achieved through principal component analysis, clustering the samples according to selected features of each sample unique chemical characteristics. These findings provide implications for acid attack cases in identifying corrosive substances evidence. Furthermore, identifying the corrosive substance by utilising analytical instrument and observation the relationship between corrosive substances with cotton textile in contact
Anti cancer effect of paddy husk extracts in human salivary gland epidermoid cancer cells in vitro model
(2024-02)
Al-Azazi, Entesar Ahmed Abdullah
Global agriculture produces millions of tons of waste yearly. Paddy husk is an inedible agriculture waste obtained during the process of rice milling. Studies reported that it has chemopreventive potential due to the presence of related phytochemicals. The aim of this study is to elucidate the presence of anti-cancer related phytochemicals from paddy husk extract and evaluate its inhibitory and anti-proliferative effects against human submaxillary salivary gland epidermoid carcinoma cells (HTB-41). Two types of solvent for paddy husk extract have been used; water and aqueous methanol. The phytochemical constituents of paddy husk extracts were identified using GC-MS. The inhibitory activity and cytotoxicity analysis was calculated using Trypan Blue Exclusion Assay (TBEA). Apoptosis and cell cycle analysis were evaluated by flow cytometer, and cell morphology post treatment was analysed ultrastructurally, while Western blot was performed for proteomic analysis. Our results showed presence of vitamin E and other phytochemicals in paddy husk extracts. Both water and aqueous methanol extracts demonstrated inhibitory activity on HTB- 41 cells where IC50 dose of water extract (400 μg/ml) managed to reduce cell viability to 53.0 % and IC50 dose of aqueous methanol extract (200 μg/ml) managed to reduce cell viability to 51.12 % without exhibiting any significant cytotoxic effects. Apoptosis analysis revealed that water and aqueous methanol extracts induce apoptosis effect on HTB-41 as supported with microscopic findings of cell shrinkage, membrane blebbing and apoptotic bodies, meanwhile, Hoechst 33342 staining showed nuclear shrinkage and fragmentation. Flow cytometry analysis demonstrated that paddy husk extracts promote a significant amount of apoptotic cellular population from 76.00% (untreated) to 47.86% (paddy husk water extract) and 43.13% (paddy husk aqueous methanol) and arresting the cells at S-phase from 19.90% (control) to 36.90 % (paddy husk aqueous methanol extract) and 27.86 % (paddy husk water extract). Western blot analysis reveals that apoptosis was induced through caspase 3-mediated intrinsic pathway. Pro-apoptotic and tumour suppressor proteins; Bax, p27kip1 expressed higher (P <0.05), while anti-apoptotic protein, Bcl-2 downregulated after treatment (P <0.01). This leads to increase of caspase 9 expression which in turn activate caspase 3 and 7 leading to cell apoptosis. In conclusion, the presence of phytochemicals in paddy husk especially in aqueous methanol extract successfully showed better inhibitory and anti-proliferative effects on the human submaxillary salivary gland epidermoid carcinoma cells (HTB-41), while it acted in a tumour-selective manner by not inducing any significant changes on human gingival fibroblast cell (HGF-1).
Automated detection and evaluation of ischemic stroke on ct brain imaging using machine learning techniques
(2025-06)
Sharuddin, Nur Amirah Atikah
This study investigates the application of machine learning algorithms for the detection of ischemic stroke using CT brain images. Stroke, particularly ischemic stroke, remains a leading cause of death and disability globally. The early detection and diagnosis of ischemic stroke are crucial for minimizing long-term damage and improving patient outcomes. Traditional methods of diagnosis rely on the expertise of radiologists, which can be time-consuming and prone to inter-observer variability. This research aims to develop an automated system for ischemic stroke detection by leveraging machine learning techniques such as Support Vector Machine (SVM), K-Nearest Neighbours (KNN), and Random Forest (RF), applied to CT brain images. The study uses a dataset consisting of 397 ischemic stroke CT images and 25 normal brain scans. A series of preprocessing steps, including resizing, normalization, and noise reduction, were performed on the CT images to ensure they were suitable for machine learning analysis. Relevant features were extracted from the images, such as intensity, texture, and shape, which were then used to train the machine learning models. The performance of the models was evaluated using metrics such as accuracy, precision, recall, F1-score, and AUC. The Random Forest model achieved the highest accuracy at 92.76%, with an AUC of 0.973, outperforming both the KNN and SVM models. The KNN model achieved an accuracy of 93.93% with an AUC of 0.940, while the SVM model achieved an accuracy of 87.87% with an AUC of 0.984. Additionally, the training time for each model was recorded: SVM took 0.0152 seconds, KNN took 0.0114 seconds, and Random Forest took 0.2083 seconds. The results demonstrate that machine learning models, particularly Random Forest and KNN, can provide accurate and consistent stroke detection, offering potential for rapid and reliable clinical application, with KNN being the fastest in training time.
Bloodstain pattern analysis: examining the effect of wind blow on passive bloodstain pattern dropped from different heights
(2025-02)
Sheng, Chia
Bloodstain pattern analysis serves vitally in crime scene investigation by reconstructing the bloodshed events and providing information on the assailant, victim and crime nature. Passive bloodstain pattern enables the estimations of blood source’s height which could potentially correlate with the height of assailant or victim. However, a bloodletting crime occurring at outdoor environment introduces uncontrollable and unpredictable external factors such as wind blow which can interfere with the usual behaviour of blood leaving the body, hindering the correct interpretation of bloodstain evidence. Additionally, limited research has been done on the effect of wind blow on passive bloodstain pattern, especially when incorporating with different heights of blood source. This study aims to examine the effects of wind velocity and height of blood drop fall on the position shift and physical characteristics of passive blood drop stain, as well as how prolonged exposure to wind blow affect the stain’s physical appearance. In this study, a single drop of blood was gently dispensed from the pipette tip using a micropipette onto a smooth white floor tile under each combination of wind velocity category and fall height. The data obtained were statistically analysed using multiple linear regression. The findings showed that wind velocity and its combined effect with fall height caused increase in the horizontal (x) position shift for up to 15.70 cm but had no significant effect on the vertical (y) position shift. The shrinkage observed on majority of the bloodstains obliterated their original physical characteristics, hence no relationship was found between wind velocity and height of fall with width, length, width-to-length ratio, number of spines, number of satellite stains, angle of impact, and glancing angle. The bloodstain’s shape was found to be not distorted from sphericity much and no directionality was revealed on the stain when blood drop fell passively from 60 cm height across different categories of wind velocity. To conclude, this study demonstrates the unpredictable and distortable passive blood drop stain at outdoor environment and suggests careful consideration of wind blow and height of blood drop fall effects by the investigators when dealing with bloodstain evidence, especially at actual outdoor crime scenes
Children with autism at zayed higher organization for-people of determination, Abu Dhabi
(2025-09)
Odat, Abeer Ali Ahmad Al
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder causing social communication impairments, restricted interests, and repetitive behaviors. A global prevalence of one in every 100 children presents lifelong challenges for affected families. Parents often experience psychological stress due to caregiving issues, inadequate support systems, and societal stigma, especially in Arab countries. This study aims to assess the levels of anxiety, depression, and coping strategies as well as determining factors associated with depression, anxiety, and coping strategies among parents of autism spectrum disorder (ASD) children at the Zayed Higher Organization for People of Determination, Abu Dhabi. This cross-sectional study involved 200 parents of children with autism spectrum disorder (ASD), recruited through convenience sampling. Data was collected by inviting available and willing parents of children with ASD at the Zayed Higher Organization in Abu Dhabi to participate in the study by completing an online self-administered questionnaire. The data was collected using a validated online self-administered questionnaire consisting of the hospital anxiety and depression scale (HADS) to measure anxiety and depression and the Ways of Coping Questionnaire (WOC) to measure coping methods. Data were analyzed using SPSS version 27 with a chi-square test for categorical data. The results show that the majority of the respondents had moderate anxiety levels n=72 (36%) and high depression levels (48.5%), and most of the respondents were moderate-level copers (81.3%). There was no significant association between the respondents' coping levels and their levels of depression and anxiety. The analysis identifies several factors that are significantly associated with anxiety levels: education level (p = 0.011), employment (p = 0.028), marital status (p = 0.022), number of children (p = 0.001), and children’s sex (p = 0.028). In addition to the children age/year (p = 0.010). Depression levels are associated with marital status (p = 0.035) and the children’s method of education (p = 0.002). For coping levels, the factors associated are the respondent's age (p = 0.019), marital status (p = 0.009), and the children’s method of education (p = 0.002). In addition, Income (p = <0.001) and Children age (p = <0.001). In conclusion, understanding the experiences and concerns of parents can guide the provision of services that help parents identify needs related to the challenges of raising children with autism. It suggests that nursing professionals, psychoeducation, collaboration between practitioners and families, and future research should involve a large population and awareness-raising programs. The practical implications of these findings highlight the need for targeted psychological support, counseling services, and family-centered interventions, especially for parents with limited education, low income, and those managing older children. Healthcare professionals, particularly nurses, should be trained to provide culturally sensitive psychoeducation and early emotional support. Workplace flexibility, accessible educational resources for children with ASD, and marital support programs may help improve parental well-being. Future research should involve larger, more diverse populations and support awareness-raising programs at the community and institutional levels
Comparison among Butterworth, hann and gaussian filter in accurate activity quantification of m99 tc SPECT/CT imaging
(2025-06)
Salimmi, Nadhrah
This study focuses on evaluating the accuracy of activity quantification in 99mTc Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) imaging achieved through three different filters which is Butterworth, Gaussian and Hann filters with different parameters. The primary objective is to determine the optimal filter with optimal parameter for accurate quantification of 99mTc activity in SPECT/CT imaging. Quantitative imaging with 99mTc SPECT/CT faces challenges such as noise, resolution limitations and partial volume effects. Therefore, filters are applied to improve resolution and reduce noise for better diagnostic accuracy. The study utilizes NEMA 2007/IEC 2008 phantoms filled with 99mTc, using the GE Discovery NM/CT 670 Pro SPECT/CT system and tumor-to-background ratios (TBR) of 5:1 and 10:1. The experiment involved scanning with three filter parameters and performing a thorough comparison of the results using the recovery coefficient (RC) to evaluate filter performance across different sphere sizes. The sensitivity calibration was performed first using an activity concentration (AC) of 30 kBq/ml to establish the calibration factor (CF) for 99mTc SPECT activity quantification which is a crucial step in ensuring the accuracy of the diagnostic results. Then, image reconstruction and quantification were carried out using QMetrix software and the Xeleris workstation to facilitate detailed analysis. Based on the findings, Butterworth filter with a cut-off frequency (COF) of 0.5 provided the most optimal performance across various spherical diameters and yielded the smallest average quantification error when applied with Partial Volume Correction (PVC).
Detection and effects of methamphetamine on the lifecycle of sarcophagidae in Malaysia
(2025-02)
Lian, Yong Zi
Forensic investigations often face challenges when determining the time and cause of death, especially in cases where remains are found in advanced decomposition. Forensic entomology, the study of insects that colonize decomposing remains, has become a crucial tool in forensic investigations, providing valuable insights into the post-mortem interval (PMI) and the cause of death. A more specialized field, forensic entomotoxicology, focuses on using insects to detect drugs and other chemical substances in decomposing tissues. Insects, particularly larvae, play a significant role in PMI estimation as they accumulate substances from decomposing bodies, offering a more sensitive method for detecting toxins with fewer interferences from decomposition by-products. The rising prevalence of methamphetamine (MA) abuse has led to numerous overdose deaths, where bodies are typically discovered after several days of decomposition. This delay complicates forensic investigations. To address this, forensic entomotoxicological analysis using insects is increasingly being used to detect the presence of drugs such as MA in decomposing tissues. In this study, pig liver mince was used to simulate the decomposition process and attract necrophagous insects, particularly Sarcophagidae. The liver was minced with two concentrations of MA (5 ng/mg and 10 ng/mg) to examine its impact on the lifecycle and morphology of Sarcophagidae. Samples were collected at various developmental stages for GC-FID analysis to detect MA presence. The results demonstrated that MA exposure delayed the lifecycle of Sarcophagidae, with insects exposed to 10 ng/mg MA taking 26 days to complete their lifecycle compared to 25 days for the 5 ng/mg MA-treated and control groups. Additionally, MA exposure resulted in a dose-dependent increase in the size and weight of larvae and pupae. However, adult flies from the MA-treated groups were slightly lighter compared to the control group. Notably, MA was detected in 3rd instar larvae at both concentrations and in adult flies at higher concentration, suggesting that the 3rd instar larvae are the most suitable stage for toxicological analysis
Detection of 9-bp deletion in COII/tRNALys intergenic region of mitochondrial DNA among murut ethnic group
(2025-02)
Najah Farahin Nadiah Azman
The 9-base-pair (bp) deletion in the COII/tRNALys intergenic region of the mitochondrial DNA (mtDNA) has been an important marker for haplogroup B classification in population group studies especially in Southeast Asia. However, no genetic data from 9-bp deletion was available for indigenous groups in Sabah including the Murut ethnic group due to the lack of population genetic studies done in these groups. The objective of this research is to fill in the research gap by investigating the presence or absence of 9-bp deletion of the COII/tRNALys intergenic region of mtDNA among the Murut ethnic group. A total of 100 unrelated Murut individuals participated in this research and were PCR amplified using a specific primer to generate 211 bp for absence of 9-bp deletion and a DNA band at 202 bp indicates the presence of 9-bp deletion. The finding shows 45% of Murut individuals were identified with 9-bp deletion and 55% were absence of 9-bp deletion. This outcome suggests that the Murut individual shows a considerably higher percentage of 9-bp deletion than other populations such as Papua New Guinea and Malaysian Han. In conclusion, typing of the COII/tRNALys intergenic region was able to provide information about the haplogroup structure among Murut individuals because the deletion at this region was used to confirm for haplogroup B
Detection of lead, cadmium and nickel in children’s plastic toys using atomic absorption spectroscopy (AAS)
(2025-02)
Hashim, Hazirah
Exposure to heavy metals present in plastic toys which can pose significant health risks to children is a growing concern particularly through mouthing behaviours like chewing, licking and sucking. The contents of three heavy metals (Pb, Cd and Ni) were analysed in six children’s plastic toys samples by using atomic absorption spectrosocpy (AAS). The plastic toy samples were prepared using dry ashing method and digested with nitric acid and hydrogen peroxide. The analysis showed that all six plastic toy samples contained Cd (0.2026 - 3.5519 mg/kg), five out of six samples contained Ni (0.5581 - 6.8927 mg/kg) and only one sample contained Pb (3.4529 mg/kg). All heavy metal concentrations were below the permissible limits specified in the EN71-3:2019 set by the European Union (EU). Leaching of Pb, Cd and Ni from plastic toy samples was conducted on the plastic toy samples under two different temperature conditions: room temperature and 50°C. Samples exposed to 50°C for four hours exhibited increased levels of Pb, Cd and Ni compared to unheated samples, demonstrating that elevated temperatures facilitated heavy metal leaching from plastic toys. Despite this, the leaching rates remained within the EU limits. These findings emphasised the potential risks of storing plastic toys in high-temperature environments, such as inside vehicles under direct sunlight for extended periods. While the tested toys were deemed safe for children, proper storage practices were strongly recommended
Detection of microplastics in bottled drinking water
(2025-02)
Noor, Farah Mohd
as a significant concern, particularly regarding its potential implications for product safety and consumer health. This study aimed to evaluate the leaching of MPs under different conditions, including temperature variations at room temperature (25 ± 2°C) and peak temperature (60 ± 2°C), mechanical stress at two shaking speeds (30 RPM and 60 RPM), and repeated usage of drinking bottled water. Additionally, the study characterized the morphology of the leached MPs. Results revealed that peak temperatures and increased mechanical stress significantly enhanced MPs release, with peak leaching observed at 60°C and 60 RPM. Repeated use further amplified the release, indicating that thermal and mechanical degradation play critical roles in the fragmentation of MP particles. The most commonly observed MP shapes were pellets, fibers, and filaments, with transparent MPs dominating across all tests, reflecting the material of the bottles. This study highlighted the awareness to the consumer on the critical impact of thermal, mechanical stress and repeated use of drinking bottled water through temperature test at two different temperatures (25 ± 2 and 60 ± 2°C), shaking test at 30 RPM and 60 RPM, and the reusability test, on the release of MPs from single-use bottled drinking water.
Detection of microplastics in commercial bottled mineral water
(2025-02)
Olong, Nurannisah
Microplastic ranging in size from 1 μm to 5 mm are contaminants in bottled mineral water, raised significant health concerns. This study aims to detect the presence of microplastics in commercially bottled mineral water. A total of 18 local bottled mineral water were used as sample in this study. Six samples were analysed using temperature test, in which the three samples were exposed to room temperature (25°C ± 2°C) and another three were exposed to peak temperature (60°C ± 2°C). Another 12 samples were undergoing shaking test. In shaking test, the samples were exposed to two different temperatures (room and peak temperature) and speeds (30 and 60 RPM). Each three samples were exposed to room temperature at 30 RPM, peak temperature at 30 RPM, room temperature 60 RPM, and peak temperature at 60 RPM. After temperature and shaking test were completed, the samples underwent reusability test where they underwent their respective tests for three repeated uses. To observe the presence of microplastic particles, the samples were filtered through nylon-66 membrane filter 0.45-micron pore size. The microplastics were observed under a stereomicroscope to determine the quantity, shape, and colour of microplastic particles. The results highlighted that samples that were exposed to high thermal stress (60°C ± 2°C) and mechanical stress (30 and 60 RPM) leached more microplastics. In terms of the microplastic shape, fragment, fibre, filament, and film were presented in the samples and predominantly by fragment microplastics. The colour of microplastics detected in the samples were transparent, green, and dark grey with transparent colour predominantly. Repeated use of bottles did not lead to an increase in microplastic leaching. Instead, the number of microplastic particles detected varied inconsistently in each bottle. To conclude, this study may raise awareness among consumers to take necessary precautions to minimise the potential microplastics contamination in their bottled mineral water
Determination of chemical attribution substances in methamphetamine tablets by gas chromatography-mass spectrometry
(2025-02)
Zabidi, Mohammad Zawawis Mohammad
Methamphetamine abuse is a significant global concern. Chemical attribution substances (CAS) in methamphetamine tablets, including adulterants, diluents, and impurities, play a crucial role in forensic investigations by providing insights into manufacturing methods and trends in adulteration. However, routine forensic analyses typically focus on identifying and quantifying the primary drug component in seized methamphetamine tablets, with less emphasis on detecting CAS. Therefore, this study was aimed to identify and characterise CAS in seized illicit methamphetamine tablets using gas chromatography-mass spectrometry (GC-MS) to establish chemical profiles and assess trends in adulteration. In this study, a total of 161 methamphetamine tablets, seized by the Royal Malaysian Police in Kelantan state, were analysed using GC-MS. These samples were extracted with methanol followed by chromatographic separation and mass spectrometric identification. The presence of methamphetamine and caffeine were detected in all tested samples. The methamphetamine-to-caffeine ratio was found to be varied across samples, indicating inconsistencies in manufacturing processes and possible differences in source or synthesis methods. Most samples fell within the ratio range of 0.6 to 0.65 with 39 samples, representing 24.22% of the total samples. To conclude, this study could contribute to forensic drug intelligence by aiding in determining methamphetamine tablet sources and manufacturing trends. Establishing CAS profiles could enhance forensic investigations by linking illicit drug samples to specific production routes, supporting law enforcement efforts in combating drug trafficking
Development and validation of a quality of life scale for primary caregivers of children with cerebral palsy in Malaysia
(2025-09)
Wei, Kelvin Ying @ Tang Shee
The quality of life (QoL) among primary caregivers of children with cerebral palsy (CP) is a critical concern, influencing both caregiver well-being and overall family dynamics. Understanding the factors that shape caregivers’ QoL is essential for developing effective support interventions. Yet, there are limited validated tools to assess caregiver QoL in the local context. This study aimed to develop and validate a culturally relevant QoL measure for primary caregivers of children with CP in Malaysia, conducted in three phases. Phase 1 involved a baseline quantitative study assessing primary caregiver QoL, Phase 2 focused on scale development, and Phase 3 validated the scale through exploratory factor analysis (EFA). Participants were recruited using key informant sampling in Phase 1 and purposive sampling in Phases 2 and 3, with a cross-sectional study design applied. In Phase 1, 159 primary caregivers (Mean age = 42.8 years, SD = 8.4) who attended health screening camps in Kelantan, Johor, and Sarawak participated. Their QoL was assessed using the Pediatric Quality of Life Inventory™ Family Impact Module (PEDSQL FIM) and analysed through descriptive analysis, single linear regression, and multiple linear regression. Results indicated that primary caregivers who attending health screening camps generally had good health-related QoL, family functioning, and overall QoL, with maternal education level and family income identified as key factors influencing all three. In Phase 2, a new Malay-language QoL scale was developed through literature review expert input, and in-depth interviews with eighteen local primary caregivers (Mean age = 39.3 years, SD = 7.28), identifying eight key themes: physical constraint, emotional distress, financial hardship, child’s difficult behavior, social support, acceptance, beliefs, and initiative for the child’s development. Items were generated and compiled into a draft scale, which underwent content validation by seven experts and pre-testing with 15 caregivers. In Phase 3, a hundred Malaysian primary caregivers (Mean age = 44.9 years, SD = 11.1) participated in the study. The newly developed scale, named the Primary Caregiver Quality of Life (PCQoL) scale, was tested for construct validity through EFA, concurrent validity through correlations with related constructs, and reliability via Cronbach’s alpha. The final 28-item version, covering eight domains, demonstrated strong validity and reliability in assessing QoL in the Malaysian primary caregiver context. This study provides valuable insights for healthcare providers to improve the QoL of primary caregivers of children with CP
Development of dna aptamers against bipd antigen of burkholderia pseudomallei for diagnostic applications
(2025-09)
Selvam, Kasturi
Melioidosis is an infectious disease caused by Burkholderia pseudomallei (B. pseudomallei). A major challenge in diagnosing this disease arises from the limitations of the gold standard method, which is often time-consuming and lacks sufficient sensitivity. Therefore, this study aimed to develop DNA aptamers targeting the Burkholderia invasion protein D (BipD) antigen for melioidosis diagnostic applications. The recombinant BipD protein was expressed and purified to serve as the target for DNA aptamer isolation through systematic evolution of ligands by exponential enrichment (SELEX). Three potent aptamers were isolated based on their high frequency. All these selected aptamers were evaluated for their binding affinity to the recombinant BipD protein, followed by specificity testing against lysates from other Gram-negative bacteria, including Salmonella Typhi, Shigella flexneri, Escherichia coli and Klebsiella pneumoniae, through an enzyme-linked oligonucleotide assay (ELONA). AptBipD1 exhibited the highest binding affinity, with a dissociation constant (Kd) of 0.91 ± 0.08 μM, which was lower than AptBipD13 and AptBipD50. All three aptamers demonstrated strong specificity for B. pseudomallei compared to other tested bacteria. Binding analyses were performed through computational methods such as molecular docking and molecular dynamics (MD) simulations. Computational analysis revealed that AptBipD1 exhibited the highest predicted binding free energy of -22.8 kcal/mol and greater stability upon binding with BipD protein, as well as the binding site located away from its 5' and 3' ends. This finding suggests that immobilising this aptamer at either end would not affect its binding characteristics. An electrochemical aptasensor was developed by immobilising the most promising aptamer onto screen-printed gold electrodes. AptBipD1-based electrochemical aptasensor demonstrated high specificity for B. pseudomallei over other bacterial strains. This sensor achieved a limit-of-detection (LoD) of 3.4 ± 0.03 ng/mL and limit-of-quantification (LoQ) of 59.2 ± 0.03 ng/mL in buffer, and a LoD of 3.5 ± 0.06 ng/mL and LoQ of 63.2 ± 0.06 ng/mL in spiked serum. The electrochemical aptasensor developed using AptBipD1, which had high binding affinity and specificity, demonstrated low LoD and LoQ in both buffer solution and serum spiked with protein. This indicates its potential for rapid and accurate detection of the BipD protein, making it suitable for diagnostic purposes in melioidosis
Development of dna aptamers for hemolysin e antigen of salmonella enterica serovar typhi towards diagnostic application
(2025-09)
Mohamad, Ahmad Najib
The rapid and accurate diagnosis of typhoid fever using specific biomarkers is essential for enhancing treatment outcomes and preventing disease transmission. This study aimed to develop a DNA aptamer-based detection system for Salmonella enterica serovar Typhi (S. Typhi), focusing on the hemolysin E (HlyE) antigen. Using Systematic Evolution of Ligands by EXponential enrichment (SELEX), DNA aptamers targeting the HlyE antigen were isolated and evaluated for binding affinity and specificity through enzyme-linked oligonucleotide assay (ELONA). Following SELEX, 11 aptamers were identified, and three (AptHlyE97, AptHlyE11 and AptHlyE45) were selected for further characterization. Their dissociation constants (Kd) fell within the nanomolar range, with AptHlyE97 showing the highest binding affinity at 83.6 nM, followed by AptHlyE11 at 102.2 nM and AptHlyE45 at 119.3 nM. Specificity tests demonstrated that these aptamers could effectively distinguish S. Typhi HlyE from other bacteria, including Salmonella Paratyphi A (P<0.001), Salmonella Paratyphi B (P<0.001), Shigella flexneri (P<0.001), Klebsiella pneumoniae (P<0.001) and Escherichia coli (P<0.001). Molecular docking analysis further supported these findings, with AptHlyE97 displaying the highest binding energy (-15.5 kcal/mol). Molecular dynamics simulations confirmed the aptamer-antigen stability, with a root-mean-square deviation (RMSD) of ~2.0 Å during 100 ns simulations. AptHlyE97 was subsequently used to develop an electrochemical aptasensor as a proof-of-concept diagnostic tool. The aptasensor was constructed by immobilizing AptHlyE97 onto a screen-printed gold electrode (Au-SPE) via thiol conjugation, with potassium ferricyanide and ferrocyanide employed for signal detection. The aptasensor demonstrated excellent diagnostic performance, achieving 100% sensitivity and 85.7% specificity in serum sample testing. Additionally, it exhibited a strong linear response with a limit of detection (LoD) of 0.158 ng/mL. This study presents a novel aptamer specific against HlyE antigen of S. Typhi and aptamer-based diagnostic platform for the efficient and selective detection of S. Typhi HlyE antigen. The high sensitivity, specificity and low detection limit of the developed aptasensor highlight its potential for advancing point-of-care diagnostics, particularly in resource-limited settings. This innovation lays a solid foundation for improving typhoid fever detection and management, offering a promising tool for community-level disease monitoring and control
Discrimination between beers with different best before dates using gas chromatography with mass spectrometry
(2025-02)
The quality of beer is influenced by various factors, including its best-before dates, which may impact its flavour, aroma, and chemical composition. This study aimed to discriminate between beer samples from different best-before dates and different brands using liquid-liquid extraction followed by gas chromatography with mass spectrometry (LLE/GC-MS). In this study, beer samples from the brand Carlsberg® were selected to represent different time points with varying best-before dates to compare for their GC profiles. Additionally, four beer samples originated from different brands, namely Carlsberg®, Asahi®, Heineken® and Tiger® were also analysed and compared for their compositional differences. The GC-MS method was optimised for solvent selection, dissolution ratio, and injection volume to maximize detection sensitivity and accuracy, followed by the analyses of beer samples. Key findings through GC-MS revealed that beers with varying best-before dates exhibited distinct differences in their chemical profiles. Overall, 35 organic compounds were identified from Carlsberg® beer sample using the proposed method. Specific profiles for each beer set and from different brands were observed and visualised through principal component analysis. To conclude, this study has successfully determined the chemical profiles of beers with different best-before dates and of different brands, allowing for forensic discrimination of stale beer samples
Discrimination of food wrappers using atr-ftir spectroscopy and chemometrics
(2025-02)
Hairunnizam, Leia Susannah
Food wrappers are frequently encountered in daily life and at crime scenes but are often overlooked as trace evidence. Their chemical composition and physical characteristics can provide crucial information in forensic investigations. Nonetheless, the potential evidentiary value of food wrappers in forensic applications remains unexplored. Hence, this study evaluated the use of Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy combined with chemometrics analysis to discriminate food wrappers from 15 different brands across three categories: junk food, chocolates, and candy. ATR-FTIR spectroscopy enabled rapid and non-destructive chemical analysis but revealed that many wrappers had similar polymer compositions within the same category, making differentiation challenging. Principal Component Analysis (PCA) alone was also insufficient for effective brand discrimination, as clustering primarily followed polymer type. Integration of PCA with Linear Discriminant Analysis (PCA-LDA) significantly improved classification accuracy, achieving 93.3% and 98.5% correct classification rates for the outer and inner wrapper layers, respectively. A blind test further validated the model’s reliability where all unknown samples were correctly classified. These findings highlighted the potential of ATR-FTIR spectroscopy combined with chemometrics as a powerful forensic tool for distinguishing food wrappers. By enabling the discrimination between specific brands, this method demonstrated the evidential value of food wrappers, supporting its use as corroborative trace evidence in forensic investigations

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