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Evaluation of varian ix clinical linear accelerator performance based on daily quality assurance using quickcheck phantom
No full textThis study aims to evaluate the performance consistency of the Varian iX Clinical Linear
Accelerator (LINAC) by analysing radiation output parameters using the PTW
QUICKCHECK Phantom during daily quality assurance (QA) procedures at Hospital
Pakar Universiti Sains Malaysia (HPUSM). The parameters measured include central axis
dose (CAX), beam flatness, symmetry in the gantry-target (GT) and left-right (LR)
directions, and beam quality factor (BQF) for photon (6 MV) and electron beams (6, 9,
12, and 15 MeV). Data were collected over a three-month period from January to March
2025. All measurements were taken using a 10 × 10 cm² field size with 100 MU delivered
at a dose rate of 300 MU/min. Repeated measurements were conducted in cases of reading
errors, and any invalid data were excluded from the analysis. The results showed that all
radiation output parameters remained within the tolerance limits recommended by AAPM
TG-142 (±3%), indicating excellent output stability and machine performance. This
confirms the suitability of the QUICKCHECK device as a reliable and efficient tool for
routine daily QA in radiotherapy settings
Forensic discrimination of naturally and artificially aged paper using atr-ftir spectroscopy and chemometric techniques
No full textAging is a natural process that alters the chemical and physical properties of materials including papers, often complicating its analysis in forensic and preservation contexts. This study aimed to analyse paper samples aged under different conditions (air-drying, oven-drying, and UV exposure) using ATR-FTIR spectroscopy and chemometrics analysis to distinguish naturally aged paper from artificially aged samples. Fresh paper samples were stained using four staining agents (coffee, tea, black vinegar, and dark soy sauce) by dabbing the liquid staining agents onto the paper with cotton wool to ensure uniform application. The stained samples were then subjected to three different aging conditions: air-drying at room temperature for 30 days, oven-drying at 60°C for 1 day, and UV exposure for approximately 4.3 hours to simulate 30 days of natural aging. The fresh, unstained paper served as the baseline for comparison. ATR-FTIR analysis revealed significant spectral changes across the different groups, particularly in the regions corresponding to O–H, C–H, and C=O stretching vibrations, as well as in the fingerprint region (1500–60
Mobile application gigiku sihat to improve dietary habit and oral hygiene among children aged 4 to 6 years and dietary and oral health knowledge, attitude and practice among parents: a community intervention study in Kelantan
No full textMaintaining good oral health in children involves a combination level of parental knowledge, attitude, and persistent behavioral routines towards children’s nutrient and oral health. The ability of smartphone to overcome barriers in conventional education method is needed since more parents depend on it nowadays. In order to improve dietary habits and oral health, app of Gigiku Sihat (GS) was developed targeted to parents of preschool children. Aim of this study was to evaluate the effectiveness of mHealth apps Gigiku Sihat for improving dietary habits and oral health among 4- to 6-year-olds children at KEMAS preschool in Tumpat and Pasir Mas, Kelantan and their parents’ nutrition and oral health knowledge, attitude, and practice (KAP). A cluster randomized trial was done. During the study period, participants in the intervention group (IG) used GS installed in their mobile device, while the control group (CG) received TIP TOP which was delivered once during the first visit. The sample size was 60 for each IG and CG. Primary outcome measures including parental nutrition and oral health KAP and children’s cariogenic food frequency (CFF) were evaluated through validated self-administered questionnaires, and OH status was determined through clinical examination using Simplified Oral Hygiene Index (OHI-S). Measurement of variables were done at baseline, 4- (Evaluation 1) and 8-weeks (Evaluation 2) post-intervention. Descriptive analysis, independent t-test, and repeated measures ANOVA were performed with significance level set at p<0.05. A total of 116 parent-child pairs (IG:56, CG:60) completed the study. Both groups have more girls compared to boys. Majority of parents in both groups aged 30-39 years old (IG:73.2%, CG:53.3%); had finished secondary school as their highest education level (IG:48.2%, CG:66.7%); were housewife or not working (IG:41.1%, CG:68.3%); had less than 6 family members (IG:62.5%, CG:55%) and had monthly household income of RM1,000 - RM1,999 (IG: 32.1%, CG:45.0%). Most of parents in IG (35.7%) had spent RM500-RM599 monthly for food, while most of parents in CG (31.7%) had monthly expenditure of RM700-RM799. The main water supply for both groups was from AKSB (pipe water) (IG:69.6%, CG:73.3%). At Evaluation 1, IG showed significantly lower mean CFF score in the categories of biscuits (p=0.017), crisps (p=0.024, 0.003), soya bean-based milk (p=0.007) and sugared drinks /condensed milk (p=0.042). At Evaluation 2, significantly lower mean CFF scores was also observed in IG for traditional kuih (p=0.006), chocolate (p<0.001), crisps (p=0.003), sweets (p=0.047), processed fruits (p=0.002), soya bean-based milk (p<0.001) and sugared drinks /condensed milk (p=0.004). There was a significantly lower OHI-S score (p=0.023) and higher attitude score (p=0.041) at Evaluation 2 in IG as compared to CG. There was no significant difference in parental knowledge and practice scores between the IG and CG. GS was effective in improving parental attitude score, children’s oral health, as well as some categories of CFF of the preschool children. Mobile application, dietary habits, oral hygiene, KAP, preschool and parents
Multivariate chemometrics using r in forensic classification of certain animal hairs
No full textAnimal hairs are one of the trace evidence that could be encountered at a crime scene, though due to their minute size, they could be overlooked by forensic investigators. Conventional methodologies for analysis of animal hair samples usually are more focused on DNA and microscopy analysis of the animal hairs, which would require expertise of the forensic investigators and consume a good fraction of time to be completed. This study utilizes rapid and non-destructive analytical technique, namely Attenuated Total Reflectance Fourier Transform-Infrared (ATR-FTIR) spectroscopy accompanied by multivariate chemometrics using R in RStudio for classification of animal hair samples of seven different animals. The multivariate chemometrics used in this study are Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE), and Linear Discriminant Analysis (LDA), which were employed to generate a visual interpretation of the results. 3D plotting was implemented on PCA, t-SNE and LDA for better separation of the clusters, which illustrates a significant difference of the clusters for pig hair samples from the other type of animals. The current work demonstrated a rapid and non-destructive method for classification of animal hair samples in forensic investigation with the implementation of chemometrics using an open-source RStudio statistical softwar
Detection of 9-bp deletion in COII/tRNALys intergenic region of mitochondrial DNA among murut ethnic group
No full textThe 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
An investigation of physical activity level, sedentary time and bone mineral density in relation to sclerostin level in postmenopausal women with type 2 diabetes mellitus
No full textPeople with type 2 diabetes (T2D) have been associated with an increased risk of fractures at any skeletal site due to the poorer quality of the bone, despite having greater bone mineral density when compared to osteoporotic and normal non-T2D people. Studies showed that postmenopausal women with fragility fractures have high sclerostin levels compared to those without fractures, while physical activities (PA) were inversely related to sclerostin levels. In this study, different levels of PA (sedentary, moderate, vigorous PA and MVPA) levels were objectively measured to assess their influence on sclerostin levels in T2D postmenopausal women. This cross-sectional study involved 71 postmenopausal T2D women, aged 59.5±4.1 years from the Diabetic Clinic, Hospital Pakar Universiti Sains Malaysia. Health history of postmenopausal and T2D duration, also other chronic diseases were obtained, followed by calcium intake (mg/day) using a validated food frequency questionnaire. Anthropometry measurements were recorded and fasting blood glucose (mmol/L), HbA1c (%) and sclerostin (pmol/L) were obtained via blood assay. Using dual-energy X-ray absorptiometry (DEXA), bone mineral density (BMD, kg/cm2), T-score (SD), body fat (%), total lean mass (%), and appendicular lean mass index (ALMI, kg/m2) were derived. Participants wore an accelerometer for a week during waking hours where those with a minimum of 10-h wear/day and for a minimum of four days of valid data were analysed. Accelerometer data were analysed using the GGIR package
for R-software. Using SPSS version 27, descriptive output, correlation and multivariable regression analyses and outcomes were obtained. Overall, eight women (11%) were newly identified as having osteoporosis with average T-scores -3.3±0.6 SD. From our correlation analysis, duration of T2D, years (r = 0.50), ALMI, kg/m2 (r = 0.14) and average MVPA, min/day (r = -0.4) were significantly related to sclerostin levels (p<0.05). Sedentary (339.3±83.6 min/day), light (205.2±37.1 min/day), moderate (32.0±17.2 min/day) and vigorous PA (0.4±0.9min/day) were not correlated to sclerostin levels. The multivariable regression model predicted as much as 33% (F = 5.63, p<0.003) of sclerostin outcomes are influenced by the duration of T2D diagnosed (β= 1.070, p=0.009) and MVPA (β = -0.292, p = 0.056) while controlling for appendicular ALMI, kg/m2 (β= -0.010, p= 0.990). In conclusion, the duration of diagnosed T2D influenced the sclerostin levels, which may impair bone formation while accounting for appendicular muscle. More in-depth investigations are needed to understand these results of possible MVPA influence on sclerostin in T2D postmenopausal women
Developing individualised therapy for colistin through application of pharmacokinetic model tailored for critically ill Malaysian patients utilizing the HPLC-FLD
No full textColistin is an antibiotic used as a last option to treat bacterial infections. Due to its toxicity, colistin is administered in the form of an inactive prodrug, colistin methanesulfonate sodium (CMS). The conversion of CMS to colistin in vivo varies greatly, leading to variations in plasma colistin concentration and pharmacokinetic parameters in critically ill patients. A novel analytical method is necessary for any pharmacokinetic studies to succeed. Colistin has a narrow therapeutic window and needs to be monitored for dose optimisation. Therefore, this study aimed to develop personalised medicine for colistin using a pharmacokinetic model for Malaysian critically ill patients. The Human Research Ethics Committee of Universiti Sains Malaysia and the Malaysian Ministry of Health Research Ethical Committee approved the study. The high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method was developed and validated to measure colistin in human serum. This validated method was then used to analyse serum from critically ill patients receiving CMS. Colistin population pharmacokinetics was modelled with a nonparametric approach using Pmetrics software. The constructed pharmacokinetic model of colistin was then applied to optimise individual patient therapeutic drug doses. Linear calibration curves were obtained for colistin concentrations of 0.3 to 8 μg/mL, with good fit (r2 = 0.9993). This analytical method accurately measured the amount of colistin in serum, with no significant hydrolysis of CMS into colistin in vitro observed during the procedure. The accuracy ranged from 98% to 100%. In most patients, the trough concentration was higher than the recommended average steady-state concentration (2 μg/mL) and may be associated with nephrotoxicity. The Non-Parametric Adaptive Grid algorithm within Pmetrics software was used to develop a colistin pharmacokinetic model using meta-analysis data from 15 pharmacokinetic studies, and external validation of the final model was performed in 25 subjects (Malaysian and meta-analysis data). A two-compartment model with first-order elimination best describes colistin pharmacokinetics. Model validation was assessed by using a plot of observed versus individual predicted colistin concentration, and an R-squared of 0.974 was obtained in the validation group. The colistin pharmacokinetic model was then implemented for individual patient therapeutic drug dose optimisation. Applying a model-informed approach, focusing on personalised medicine, may help achieve precise dose individualisation
Enhancing piezoelectric effect performance in piezoelectric beam design.
No full textThe utilisation of piezoelectric materials in beam structures has garnered significant attention due to their ability to convert mechanical vibrations into electrical energy. This piezoelectric effect has paved the way for the development of energy harvesters using cantilevered beam structures, incorporating one or two piezoelectric layers mounted on a substrate This project seeks to investigate the influence of different piezoelectric layer materials on the voltage output of such beam structures. The primary focus is on the modelling and simulation analysis of cantilevered beam designs, considering a various of piezoelectric materials. In this paper, we dive into two types of simulation PEH cantilever beam: unimorph and bimorph model. The simulations were done in Ansys workbench software, in which modal analysis, harmonic response and voltage generation were set up and run for both types, and the results were validated from previous paper. It is shown that bimorph have a better result in voltage generation, so the simulation proceeds in bimorph with improvised model to determine the highest voltage generation on eight piezoelectric materials which are PZT-5H, PZT-5A, PZT-8. PZT-4, PZT-26, Lithium Niobate, Lithium Tantalate and Lithium Tetraborate. Since the deformation of the models with different piezoelectric materials have different in frequency obtained, a certain frequency within range for all materials were selected to compare the result. Lithium Niobate have the highest voltage obtained at 196Hz with 5681 millivolts followed by PZT-5A and Lithium Tantalate with 3906 millivolts and 150 millivolts respectively. The outcome of the simulation analysis was generated and interpreted graphically, which shows the model deformation, voltage and the frequency response for all the beams with same weight of load, force and dimensions
Investigating the effect of brain break exercise videos on mental stress, personality, mental hardiness, social support and physical activity among college students in Jiangxi province, China
No full textCollege students, as a distinct cohort, are navigating the transition between
campus and social life, facing pressures such as interpersonal dynamics, academic
demands, financial constraints, employment expectations, and daily stress. Managing
psychological well-being in universities is a pressing concern. Engaging in physical
activity, such as Brain Breaks exercise videos, has been shown to have a positive
impact on mental health by reducing stress levels. This study primarily aims to validate
the uBioMacpa Pro stress measurement tool among Chinese college students. Studies
indicated that individual characteristics like personality traits, hardiness, social support,
and physical activity profoundly influence mental stress levels. Thus, the subsequent
objectives were to explore the relationships between these factors and mental stress,
and to evaluate the effect of Brain-breaks exercise video intervention on the study
variables among Chinese college students in Shangrao City, Jiangxi Province. The
study was conducted in two phases, Phase 1 involved reliability and validity tests of
the uBioMacpa Pro and a cross-sectional study, with 60 students involved in the
reliability test, 200 in the validity test, and 890 in the cross-sectional study.
Additionally, 80 students with mental stress from Phase 1 participated in Phase 2,
which was a randomized controlled trial. In phase 2, 80 students were randomly
College students, as a distinct cohort, are navigating the transition between
campus and social life, facing pressures such as interpersonal dynamics, academic
demands, financial constraints, employment expectations, and daily stress. Managing
psychological well-being in universities is a pressing concern. Engaging in physical
activity, such as Brain Breaks exercise videos, has been shown to have a positive
impact on mental health by reducing stress levels. This study primarily aims to validate
the uBioMacpa Pro stress measurement tool among Chinese college students. Studies
indicated that individual characteristics like personality traits, hardiness, social support,
and physical activity profoundly influence mental stress levels. Thus, the subsequent
objectives were to explore the relationships between these factors and mental stress,
and to evaluate the effect of Brain-breaks exercise video intervention on the study
variables among Chinese college students in Shangrao City, Jiangxi Province. The
study was conducted in two phases, Phase 1 involved reliability and validity tests of
the uBioMacpa Pro and a cross-sectional study, with 60 students involved in the
reliability test, 200 in the validity test, and 890 in the cross-sectional study.
Additionally, 80 students with mental stress from Phase 1 participated in Phase 2,
which was a randomized controlled trial. In phase 2, 80 students were randoml
