Pusat Pengajian Sains Perubatan - Tesis

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Chemical profiling of erasable and non-erasable black gel pen inks using atr-ftir spectroscopy and chemometrics techniques
(2026-02)
Inn, Chee Jia
Ink analysis is a key component of forensic document examination, aiding forensic document experts in detecting physical or chemical alterations, fabrication, or tampering of documents, particularly in cases involving forgery, authentication, or other offenses related to written and printed evidence. Gel pens are commonly encountered in questioned documents, and differentiating erasable and non-erasable inks is forensically important. The aim of this study is to chemically profile and discriminate 10 different brands of erasable and 10 different brands of non-erasable black gel pen inks using ATR-FTIR spectroscopy combined with chemometric analysis. Pen ink samples from erasable and non-erasable gel pens were firstly analysed using ATR-FTIR at wavelength of 4000 cm-1 to 600 cm-1. Fingerprint region of spectral data which between 1500 cm-1 to 600 cm-1 were then processed using Principal Component Analysis (PCA) for pattern recognition. Linear Discriminant Analysis (LDA) was applied to classify the inks into their respective groups. ATR-FTIR spectroscopy provided information on the functional groups present in black pen inks but demonstrated limited discriminatory capability when used alone to distinguish between erasable and non-erasable samples. PCA showed clear clustering between erasable and non-erasable inks. The first three principal components (PCs) of PCA achieved 98.4% of total variance data of pen ink samples (PC1 89.2%, PC2 8.2% and PC3 1.0%). This percentage indicates an excellent data representation, showing that PCA successfully retained almost all meaningful variation in the pen ink samples with minimal information loss. LDA showed strong discriminative performance, with 95.0% correct classification in the original data and 90.0% accuracy under leave-one-out cross-validation, indicating good model stability and predictive ability. The coupling of ATR-FTIR spectroscopy with chemometric techniques of PCA and LDA markedly improves the discrimination and classification of gel pen inks by extracting meaningful chemical patterns from complex spectral data, thereby providing a robust, non-destructive, and forensically reliable approach for questioned document examination.
The association between social media engagement, body image concern and eating behaviour among undergraduate health science students in Universiti Sains Malaysia
(2026-01)
Ali, Munira Adleena Mohd
The rapid growth of social media has influenced body image and eating habits among university students. The purpose of this study was to investigate the relationship between eating habits, body image concerns, and social media use among undergraduate health science students at Universiti Sains Malaysia (USM), Kubang Kerian. Simple random sampling was used in a cross-sectional quantitative design with 285 students. The Social Media Engagement Questionnaire (SMEQ), Body Self-Image Questionnaire–Short Form (BSIQ-SF) and Eating Attitudes Test-26 (EAT-26) were used to gather data. The findings showed a significant negative correlation between social media engagement and body image concern (r= -0.309, p= 0.001), and positive correlation between social media engagement and eating behavior (r= 0.172, p=0.004). A stronger negative correlation was observed between body image concern and eating behavior (r= -0.481, p= 0. 001). These results emphasize how crucial it is to encourage positive body image and healthy social media use to reduce the risk of unhealthy eating habits among university students.
Validation of the malay version for the subtypes of antisocial behaviour questionnaire (STAB) among secondary school students in Kelantan, Malaysia
(2022)
Zain, Wan Nor Ain Alyaa Wan
Background: Most antisocial behaviours started since a young age and are perpetrated with simply rule-breaking and delinquent behaviour in school or at home. Among the most established tools available to measure this antisocial behaviour is the Subtypes of Antisocial Behaviour Questionnaire (STAB). This STAB Questionnaire was developed as a simpler and shorter inventory with highlight on social aggression in addition to overt/physically aggressive and covert/rule breaking factors in antisocial behaviour study analysis. To date, information regarding the psychometric properties of this scale when used in the local context is still lacking especially among the schooling age group. Therefore, there is a need to validate the Malay version of the STAB (M-STAB), so that further research can be conducted to explore on subtypes of antisocial behaviour among secondary school students in Kelantan and their associated factors. Objective: The study aimed to validate the Malay version of the Subtypes of Antisocial Behaviour Questionnaire (M-STAB). Method: A cross-sectional study involving 387 participants from 13 to 17 years old, was conducted from August 2020 until November 2020 in eight secondary schools in the district of Kelantan. Participants were selected via a multistage sampling method. M-STAB was initially translated from English into Malay language using forward and backward translation procedures by 2 experts. The finalised version of M-STAB was harmonised and pre-tested on 10 participants. Study participants who assented to the study and obtained parental consent then completed the final version of the M-STAB questionnaire and a socio-demographic questionnaire. The validity of the M-STAB questionnaire was evaluated using confirmatory factor analysis (CFA) for construct validity. This is because, the adopted scales with sufficient empirical and theoretical evidence can be taken directly to CFA. The reliability of the M-STAB questionnaire was evaluated by composite reliability (Raykov’s rho) for construct reliability. Result: In this study, the final model of M-STAB most fitting the data comprised of 3 factors with 32 items, retaining all items from the original English version scale. These 3 factors consist of 10 items of physical aggression factor with a factor loading range of 0.45-0.70, 11 items of social aggression factor with a factor loading range of 0.38-0.66 and 11 items of rule breaking factor with a factor loading range of 0.02-0.56. The overall findings revealed good fit indices (RMSEA=0.03, CFI=0.92., TLI=0.91, SRMR=0.07). Composite reliability scales were also acceptable and satisfactory (physical aggression = 0.82, social aggression = 0.82, rule breaking = 0.55). Conclusion: The study revealed that a 3-factor model with 32 items of the Malay Version of STAB has good psychometric properties. The scale is valid and reliable to measure the subtypes of antisocial behaviour among secondary school students in Kelantan. However, utilisation of these questionnaire among other regions in Malaysia need to be used with caution.
Clinical outcomes of single stage posterior-only debridement and instrumentation in the management of spinal tuberculosis
(2022)
Tohkainathan, Thanabala
Introduction Spinal tuberculosis is the most common form of extra-pulmonary tuberculosis. Anti-tuberculous chemotherapy has been the standard treatment for spinal TB. However, surgical management is recommended to control the progression of kyphosis and improve the neurological impairment associated with this disease. Various surgical methods have been advocated. But the posterior approach surgery has gained popularity due to its reported low complication rate. In this study, we report the clinical outcomes of single stage posterior only approach for debridement and instrumentation for treatment of spinal tuberculosis. Methodology In this retrospective study, we analysed 27 patients with thoraco-lumbar TB treated in our centre from 2003 to 2019 with single‑stage posterior only debridement and instrumentation. Preoperative and postoperative kyphosis angle, ASIA neurological grading, C‑reactive protein (CRP), erythrocyte sedimentation rate (ESR) and visual analog scale (VAS) score were compared. Correction in kyphosis including loss of kyphosis angle, neurological recovery, resolution of infection and pain relief at one year follow‑up was assessed. The data was analysed using SPSS version 24. Numerical variables were presented as mean and standard deviation while categorical variables were presented as frequency and percentage. The numerical variables were assessed using skewness and kurtosis. Results 15 male and 12 female patients with mean age of 51 years were treated. All patients had two contiguous vertebral segment involvement. The preoperative average rise in ESR was 74.78  SD 23.68 mm/h which significantly dropped down to 25.46  SD 19.49 mm/h at one year follow-up. The average preoperative rise in CRP was 80.89  50.26 mg/L which returned to 16.55  10.01 at one year follow‑up. There was significant improvement of VAS from 6.96 ±1.29 preoperatively to 1.37 ± 0.57 at one year follow-up. Preoperatively, the mean kyphosis angle was 17.75 ± 10.49 and corrected postoperatively to 9.87 7.47 with an average correction of 7.88 6.99 (45.37%). At one year follow-up, the mean loss of correction was of 2.22 2.15(32.38%). No patients recorded any neurological deterioration with 100% neurological recovery observed at one year follow-up Conclusion The results of this study show improvements in kyphotic correction, neurological recovery, VAS score as well as resolution of infection.
Profile, risk factor, genotype, and outcome of staphylococcus aureus catheter related blood stream infection in Hospital Universiti Sains Malaysia
(2022)
Jye, Tey Nian
Background: Apart from being a common organism causing CRBSI, S. aureus also causes complicated CRBSI. The objective of this study was to detect S. aureus virulence gene isolated from complicated CRBSI cases and its association with development of complicated CRBSI. The profile of CRBSI, the risk factors and outcome associated with having S. aureus CRBSI were also reviewed. Method: A cross sectional study involve retrospective record review of CRBSI cases was carried out from January 2019 till December 2021. Total of 139 CRBSI cases was reviewed over the study period. Patient clinical data, risk factors and outcome of S. aureus CRBSI were analyzed. Descriptive statistics were used for profile of CRBSI, while multiple logistic regression was use for analysis of risk factors, and Pearson chi square were used for analysis of outcome for S. aureus CRBSI. Nineteen latest sample of S. aureus CRBSI were selected and subjected for molecular PCR to detect the presence of the gene Cna, Chp and Cap8. The association between development of complicated S. aureus CRBSI and virulence gene were analyzed using Pearson Chi Square. Result: S. aureus was the predominant agent (31%, n=43) causing CRBSI. The risk factor for S. aureus CRBSI was having CKD or ESRF (P value <0.001). The incidence of complicated CRBSI was 37%. The most common virulence genes among those 19 samples were Cap8 (89.5 %, n-17), followed by Cna (47.4%, n=9) and lastly Chp (26.3%, n=5). The 3 virulence gene was not found to be statistically significant with the development of complicated CRBSI. S. aureus CRBSI were associated with higher mortality (P value 0.035). Conclusion: S. aureus was the predominant agent for CRBSI. The incidence of complicated S. aureus CRBSI was 37%, and the most common virulence gene was Cap8. CKD or ESRF were the comorbid associated with development of S. aureus CRBSI.

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