Institut Perubatan & Pergigian Termaju - Tesis

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    The Effects Of Nannochloropsis Sp. Methanolic Extract On Prevention Of Dna Damage In L929 Cells
    (2023-01)
    Zainoddin, Ahmad Hazwan
    Nannochloropsis and Spirulina are some of microalgae species that have been found to have a wide range of biological activities such as antioxidant and anti-DNA damage properties. Unfortunately, there is still lack of study on the effect of both microalgae especially Nannochloropsis species. Hence, this study was carried out to determine the effect of Nannochloropsis sp. extract on prevention of DNA damage in L929 cell line. The phytochemicals of both microalgae were extracted using 100% methanol. The extractions were then screened with HPLC to detect the presence of targeted compounds. HPLC analysis revealed that Nannochloropsis sp. methanolic extracts had caffeic acid, p-Coumaric acid, naringenin and hesperetin while Spirulina sp. methanolic extract had caffeic acid, quercetin and naringenin. The extracts were then tested for Total Phenolic Content (TPC) and Total Flavonoid Content (TFC). Results revealed that the extracts for both TPC and TFC for Nannochloropsis sp. were higher than Spirulina sp. with 58.43 mg GAE/g and 19.64 mg GAE/g, and 79.87 mg QE/g and 11.19 mg QE/g respectively. The study was then proceeded by evaluating the antioxidant activities of the microalgae extracts using DPPH-HPLC analysis. Nannochloropsis sp. methanolic extract exhibit greater percentage of DPPH inhibition compared to Spirulina sp. extract. A negative correlation existed between TPC and TFC with the EC50 of DPPH antioxidant inhibition activity. In this study, Spirulina sp. and Nannochloropsis sp. showed moderate toxicity toward L929 cell lines with IC50 1.701 mg/mL and 1.134 mg/mL respectively. In DNA damage analysis with Nannochloropsis sp., the result revealed that the methanolic extract are able to prevent and reduce DNA damage activity. Thus, microalgae can be proposed as one of alternative form in medical and pharmaceutical industry.
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    Investigation On The Radiation Dose Distribution In High Dose Rate (Hdr) Gynaecological Brachytherapy Treatment Using Monte Carlo Calculation
    (2025-07)
    Azahari, Ahmad Naqiuddin
    This study addresses the research gap by evaluating the influence of tissue heterogeneity and geometric factors on dose distribution, while exploring alternative methods for more accurate dose verification. The purpose of this study was to evaluate dosimetric accuracy in endometrial HDR brachytherapy through experimental and simulation approaches. Specifically, the study aimed to: (1) assess suitable materials for phantom development representing organs at risk (OARs), (2) investigate dose distribution using the constructed phantom, (3)validate Monte Carlo (MC) modelling against experimental measurements, and (4)estimate tissue inhomogeneity correction factors to complement the TG-43 formalism.
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    Identification Of Brain-derived Neurotrophic Factor (Bdnf) Val66met Gene Polymorphism As A Biomarker On Cognitive Performance Of Aging Brain In Response To An 8-week Of Exergames Training
    (2023-09)
    Ismail, Noor Azila
    The BDNF Val66Met gene polymorphism is a plausible factor for the changes in cognitive performance of the aging brain with Met carriers showed a greater impairment in cognitive ability. Therefore, study 1 examined the distribution of BDNF Val66Met gene polymorphism in the aging population and its association with cognitive performance. 206 older adults aged 55 – 80 years were enrolled in the study and divided based on their Mini Mental State Examination (MMSE) score: control group (MMSE > 26; n = 103) and case group (MMSE £ 26; n = 103). The results showed that the distribution of BDNF Val66Met gene polymorphism was significantly different between the studied groups. Conversely, the BDNF genotype was associated with a twofold risk of cognitive impairment. Therefore, Study 2 was conducted to examine the effect of the BDNF Val66Met gene polymorphism on cognitive performance in the aging brain in response to 8 weeks of exergames training. 42 participants from the case group in study 1 were subjected to 3 groups with different training methods for 30 minutes, 3 days per week for 8 weeks: exergames (training with Ring Fit Adventure for Nintendo Switch; n = 14), conventional training (similar training without exergames; n = 14), and control group (no training; n = 14). The results showed that neuropsychological test scores had significant differences between the studied groups. fMRI analysis showed that more brain areas with greater activation were detected in the exergames group as compared to the conventional group. With respect to BDNF genotype, a repeated measure of ANOVA revealed that cognitive performance was better in the ValVal genotypes on MoCA scores, and hippocampal volume tended to improve after the exergames intervention. In addition, the Met allele was associated with an improvement in neuropsychological test scores in response to both types of exercise training. Although the intervention did not produce overall improvements, there were interesting trends in the data for the ValVal genotype after exergames training. This demonstrates that exergames training appears to be an appealing and promising means of concurrent physical-cognitive training in the aging population.
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    Elucidation Of Circular Rna (Circ007667 And Circ037236) Roles In Colorectal Cancer Pathogenesis
    (2024-10)
    Wang, Fang
    Colorectal cancer (CRC) ranks as the third most frequently diagnosed cancer worldwide and the fourth leading cause of cancer-related deaths. Circular RNAs (circRNAs) are unique RNA molecules with a closed-loop structure, lacking 5′ to 3′ polarity and a poly-adenylated tail. Despite their potential, the role of circRNAs in CRC remains poorly understood. This study investigates the roles of circ007667 and circ037236 in CRC, exploring their potential as molecular targets for intervention.
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    Neurophysiological Characteristics Of Inhibitory Control Deficit Among Individuals With And Without Internet Gaming Disorder
    (2024-11)
    Yu, Junjian
    In mid-2018, the world health organisation (who) highlighted that gaming behaviour can cause significant distress or impair functioning in various aspects of life. Internet gaming disorder (igd) is a form of internet addiction characterized by losing control over gaming, leading to neglect of other interests and daily activities. Currently, the lack of systematic research paradigms to study igd and its inhibitory control abilities limits the understanding of impaired inhibitory control in igd patients. Moreover, no studies have compared different types of inhibitory control (distractor interference inhibitory control and prepotent response inhibitory control) to determine their distinct behavioural and neurophysiological characteristics in igd. To address this research gap, the current study examines the inhibitory control functions in individuals with igd using questionnaire surveys, cognitive experiments, and erp experiments. The study participants were selected from 817 university students in china. The questionnaire survey, a cross-sectional study, used the igd-20 and dsm-v to diagnose igd and assess relevant sociodemographic and psychological factors. The findings indicate that individuals with igd are younger, predominantly male, have less education, longer gaming history, and spend more time gaming daily. They also exhibit poorer impulse control, stronger cravings, higher risk-taking, compulsive behaviour, and reduced self-control and attention abilities.