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- PublicationPremature mortality from cardiovascular disease: global burden and country-specific estimate through review study, trend analysis, prediction modelling, and causal inference study(2024-12)Cardiovascular disease (CVD) is a leading cause of premature mortality worldwide, with its burden growing in recent years. Despite considerable research into CVD, there are noticeable gaps in addressing premature mortality associated with it. For example, there is insufficient information on global research activity and pool estimation of the global burden of premature CVD mortality from existing literature. Additionally, within-country estimates of this burden and country-specific CVD risk profiles are lacking. Therefore, this thesis aims to comprehensively analyze and understand various aspects of premature CVD mortality, including global research activities, estimating the global burden of CVD related to premature mortality, examining country-specific trends and risk profiles for premature CVD mortality, and constructing causal pathways for premature CVD mortality. This thesis consists of five interrelated studies aimed at addressing all research objectives. The first study summarizes the global publication information related to premature mortality through bibliometric analysis. The bibliometric analysis shows that premature mortality research has increased substantially in the past decade; however, there have been disparities in research output between high-income countries (HICs) and low-middle-income countries (LMICs), emphasizing the need for collaborative efforts in LMICs. In the second study, consisting of two parts: Study 2a, a systematic review concentrating on premature CVD mortality using the Years of Life Lost (YLL) indicator, followed by study 2b, a subsequent meta-analysis based on the age-standardized mortality rate (ASMR) indicator. Studies 2a and 2b underscore the persistent burden of premature CVD mortality, particularly in LMICs and among men, emphasizing the importance of targeted interventions and public health strategies. The third study involves trend analysis utilizing Malaysia country-specific mortality data from Dapartment of Statistics Malaysia employing a joinpoint regression model. This study reveals a persistent increasing trend of premature CVD mortality rates in Malaysia over the past decades, underscoring the ongoing burden in the country. In study four, a modeling study is conducted to assess the premature CVD risk profile by applying various survival models. This study utilizes data from Malaysia's National Health and Morbidity Survey (NHMS) conducted in 2006, 2011, and 2015, linked with mortality records through 2021. The semi-parametric and parametric survival models both highlight the considerable impact of socioeconomic status and modifiable risk factors on premature CVD mortality in Malaysia. Finally, the fifth study entails a causal inference study systematically demonstrating the construction of a Directed Acyclic Graph (DAG) model for premature CVD mortality. This study introduces a new approach integrating evidence synthesis and expert opinion using the Fuzzy Delphi method to construct the DAG model, followed by testing the model with available data. This step demonstrates a step-by-step process for constructing a causal model, offering a systematic, practical, and transparent approach, contributing to DAG methodology. In summary, through meticulous methodologies, the findings of this thesis contribute to the growing body of literature on premature mortality from CVD and provide valuable insights and frameworks for informing public health strategies and guiding future research endeavours in tackling premature CVD mortality.
- PublicationStigma, anxiety, depression, social support and quality of life in young women with breast cancer undergoing chemotherapy: a predictive model(2024-12)Young women diagnosed with breast cancer (BC) are increasing annually, and they are prone to mental health problems, which significantly reduce their quality of life (QoL). Social support is crucial for enhancing the QoL in patients with BC. However, the relationship between stigma, anxiety, depression, social support, and QoL in young women with BC undergoing chemotherapy remains unclear. This study aims to examine the relationship between stigma, anxiety, depression, social support, and QoL among young women with BC undergoing chemotherapy. This cross-sectional study was done in the First Affiliated Hospital of Guangxi Medical University, China, from December 2022 to October 2023. The research instruments were the Functional Assessment of Cancer Therapy-Breast (FACT-B), the Social Support Rating Scale (SSRS), the Social Impact Scale (SIS), and the Hospital Anxiety Depression Scale (HADS). SPSS 26.0 and AMOS28.0 software were used for statistical analyses. Data were analysed using descriptive, univariate, correlation analysis, structural equation model (SEM) and multiple linear regression (MLR). 196 women with BC aged ≤ 40 were included in the study. The mean QoL score of participants was at a moderate level, 98.01 (SD = 16.97). The findings indicated participants' QoL was associated with education level (p = 0.010), residence (p = 0.004), surgery type (p = 0.021), current chemotherapy cycle (p = 0.002) and postoperative time (p = 0.020). Stigma (r = −0.590), anxiety (r = −0.344), and depression (r = −0.236) were negatively correlated with the QoL among young women with BC. However, there was a positive correlation between social support and QoL (r = 0.416). In addition, social support significantly mediated the impact of stigma (β = −0.214, p = 0.016) and depression (β = −0.084, p = 0.030) on the QoL. However, social support did not significantly mediate the relationship between anxiety and QoL (β = 0.054, p = 0.105). 41.3% of the variance in QoL among young women with BC was explained by stigma, anxiety, and social support. In conclusion, a significant interaction exists among stigma, social support, anxiety, depression, and QoL in young women with BC undergoing chemotherapy. This finding highlights the importance of assessing the psychological challenges faced by young women with BC as part of routine care. Furthermore, it underscores the need for the future development and implementation of mental health support programs tailored to young women with BC undergoing chemotherapy.
- PublicationDari Daerah Ke Kerajaan : Sejarah Politik Perlis, 1841-1957(2000)Dua objektif tesis ini ialah untuk membina sejarah penubuhan sebuah kerajaan Melayu bernama Perlis dan untuk menggalurkan pertumbuhannya dari sebuah unit politik yang baru di alam politik Melayu yang berjuang bagi hak mengekalkan kewujudannya sehingga sebuah entiti berautonomi di dalam Persekutuan Tanah Melayu. Penemuan-penemuannya menawarkan empat sumbangan utama. Paling penting ia telah mendedahkan satu bahagian di dalam sejarah Malaysia yang paling sedikit dikenali, iaitu sejarah negeri Perlis. Kedua, dalam menggalurkan sejarah Perlis dari permulaannya sebagai sebuah daerah Kedah sehingga menjadi sebuah kerajaan baru pada 1841, tesis ini telah cuba mendedahkan pelbagai ketidaktepatan berkenaan kelahirannya yang wujud dalam pensejarahan setakat ini lalu menetapkan tarikh penubuhannya yang didapati lebih betul dan tepat. Ketiga, dan sehubungan dengan itu, kajian ini telah memperbetulkan beberapa tanggapan umum yang utama berkenaan sejarah Malaysia dan sejarah Kedah. Sedangkan kebanyakan pemberontak berjuang demi menaiki takhta yang ada atau demi melawan British dan Siam dan apabila gagal terpaksa meninggalkan kampung halaman, pemberontak dalam kajian ini, yakni Syed Hussein bin Syed Harun Jamalullail, telah berjuang demi membina sebuah takhta dan wangsa pemerintah yang baru bagi dirinya. Sememangnya ia bukan berjuang semata-mata untuk berdiri di belakang Sultan tetapi untuk mendapatkan kemerdekaan daripadanya.
- PublicationIn vitro antioxidative evaluation of plukenetia volubilis aqueous extract in ovarian aging process(2025-01)Ovarian aging is the aging process related to the decline in ovarian cellular function primarily driven by oxidative stress which affects hormonal production, resulting in reduced fertility and hormonal dysfunction in women. Although there are many medications have been developed to increase fertility and reproductive hormones such as clomiphene citrate and gonadotropins, they can cause short- and long-term effects on women. Plukenetia volubilis (Sacha Inchi) is a plant that originated from Northwestern Brazil and Peru and has proven to contain high antioxidant contents such as tocopherols and phenolic compounds. Therefore, our study aims to evaluate the antioxidative potential of P. volubilis aqueous extract in combating oxidative stress during the ovarian aging process using in vitro models. This study assesses the total phenolic content of P. volubilis aqueous extract via total phenolic content (TPC) assay, its radical scavenging ability via DPPH assay, and its protective effects on granulosa cells (COV434) subjected to oxidative stress via MTT assay. Ascorbic acid is used as a standard antioxidant to compare the results. As a result, the TPC assay confirms the presence of significant phenolic content in the extract where the phenolic contents increase as the concentration increases from 0.2 mg/ml to 15 mg/ml. Next, The DPPH assay shows the increase of DPPH radical scavenging with the IC50 value of 2.27 mg/ml. P. volubilis aqueous extract also shows a significant radical scavenging activity when compared to ascorbic acid (p = 0.009). Additionally, the MTT assay reveals the significant protective effects of the extract against hydrogen peroxide-induced oxidative stress in COV434 cells when compared to ascorbic acid (p = 0.089) with the EC50 value of 23.82 mg/ml. This is proven by increasing cell viability when treated with P. volubilis aqueous extract. Overall, the findings successfully underscore the promise of P. volubilis as a natural antioxidant to mitigate oxidative stress-related ovarian aging
- PublicationAssesment of monocyte phagocytosis in the presence of synovial-fluid-derived exosomes from osteoarthritis patients(2025-01)Osteoarthritis (OA) is a degenerative joint disease characterised by cartilage degradation, inflammation, and joint dysfunction, and monocytes play an important role in its pathogenesis via phagocytosis and inflammatory regulation. This study investigated the effect of synovial fluid-derived exosomes from OA patients on monocyte phagocytic activity. Synovial fluid (SF) was harvested from OA patients undergoing total knee arthroplasty, and exosomes were isolated by ultracentrifugation. Monocytes from healthy donor were cultured for 24 and 48 hours at different exosome concentrations (1:10, 1:20, and 1:40). Then, pHrodo™ Green E. coli conjugates were used to measure monocyte phagocytosis, which was quantified by flow cytometry. The findings demonstrated a significant increase in monocyte phagocytic activity upon exosome treatment, indicating a modulatory effect. These findings provide insight into the interaction between exosomes and monocyte in OA pathogenesis, underlining the possibility of exosome-based treatments to manage this degenerative illness
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- PublicationDesign of a retrofit inferarm cruthes(2008-04-01)The walking stick is a great aid when the person had an accident and his walking is impaired. It provides steadiness and stability, allowing the user to get around pretty well. By the way, for a person that unable to walk, the easiest way to help them to get around is using a wheelchair. It would help them hanging around easily with no burden to walk. But, wheelchair is not able to use in all aspect. For example, the user can't use the wheelchair to go up the staircase. Furthermore, if a person always sits on the wheelchair s without exercise, the bones of legs will get weaker. The main objective of this project is to design a crutch that can assist the disable or leg's injury person to climb up the staircase. It would help to prevent further damage or accidents when the user climbs up the staircase. Besides, the user is able to maintain proper posture, relieves damaging. stress, and reduces the overall chance of injury when climbing staircase. The project has completed with 3D solid modeling of the designed crutches with SolidWork 2007. Furthermore. COSMOS analysis was done on the critical parts of the designed crutches to make sure the factor of safety required was achieved.
- ItemMST 564 - Statistical Reliability - Oktober 2004(Universiti Sains Malaysia, 2004-10)
- ItemEffects Of Repetitive Uncontrolled Temperature Exposure On The Quality Of Packed Red Blood Cells(Universiti Sains Malaysia, 2019)Packed Red Blood Cells (PRBC) must be transfused within 30 minutes upon removal from blood refrigerator and the PRBC should not be hold in the ward where the storage temperature is not controlled. Untransfused blood which returned to the blood bank shall be discarded unless it is kept in an appropriate condition and temperature. Intermittent storage outside allowable temperature range often leads to destruction of the PRBC unit. This was a cross sectional study performed to determine the PRBC warming rates and the quality of PRBC upon repetitive exposure to uncontrolled temperature after 30 minutes and 4 hours. In this study four PRBC units (228 mL ± 37mL) collected from eligible volunteer subjects were equivalently split into two units, producing eight smaller units PRBC (±130mL) which then assigned into two groups; control and experimental group. Eight units of PRBC from both control and experimental group were tested on day 1, day 7, day 14 and day 35 of storage for haemoglobin level, haematocrit, haemolysis rate, potassium, lactate dehydrogenase (LDH), pH and sterility. The PRBC warming rate upon exposure to uncontrolled temperature were monitored and recorded. All PRBCs achieved desired quality requirement from national guideline from day 1 to day 35 for haematocrit, haemolysis rate, and sterility. However, none of the PRBC units met the standard requirement (>45g/unit) for haemoglobin starting day 14 to day 35. No significant changes observed for all PRBC’s quality over repetitive exposure to uncontrolled temperature in 35 days in experimental group (P<0.05). There was also no evidence of bacterial contamination in PRBC at the end of their shelf life.
- ItemSynthesis And Characterization Of Black Silicon By Silver-Assisted Chemical Etching For Solar Cell(Universiti Sains Malaysia, 2021-03)Crystalline silicon (c-Si) suffers from poor light absorption due to its indirect band gap and high reflection from its surface (about 35% in the visible region). This problem can be solved by texturing the surface of c-Si wafer to reduce its broadband reflection. Black silicon (b-Si) or nanotextured c-Si, has a huge potential for applications in solar cell due to its superior broadband light absorption within 300-1100 nm wavelength region. In this work, two-step metal-assisted chemical etching (MACE) is used to synthesize b-Si by combining low-annealing temperature of silver (Ag) film and short duration of etching of the c-Si wafer. For the b-Si fabrication, p-type (100) c-Si wafers are deposited with 15 nm Ag film using radio frequency (RF) sputtering process. Subsequently, the Ag film is annealed at low temperatures (200-230ᵒC) for 40 min in nitrogen (N2) ambient, producing Ag nanoparticles (NPs). Then, the c-Si wafers with the Ag NPs are etched in a solution containing hydrofluoric acid:hydrogen peroxide:deionized water (HF:H2O2:DI H2O) for a short duration (35-180 s). Effects of etching time, etchant volume ratio and annealing temperature towards surface morphological and optical properties by using atomic force microscope (AFM), field emission scanning electron microscope (FESEM) and UV-Vis-NIR (within 300-1100 nm wavelength region) of b-Si are then investigated. From the investigation, the b-Si with the lowest broadband reflection is produced by annealing at 230ᵒC for 40 min and etched for 70 s using HF:H2O2:DI H2O (1:5:10 by volume). The lowest reflection of the b-Si wafer is 3% at wavelength of 600 nm, with weighted average reflection (WAR) of 8%. The b-Si demonstrates average width and height of about 50-100 nm and 300-400 nm respectively for the nanotextures. For solar cell fabrication, the b-Si is diffused with phosphoric acid (H3PO4) and 2-butanol using temperatures between 850 to 950oC for 20 min to form front n+ emitter. The emitter is characterized using Hall effect measurement. Ag and aluminium (Al) are thermally evaporated on the front and rear surfaces respectively to form electrical contacts. From current-voltage measurement, the b-Si solar cells demonstrate short-circuit current density (Jsc) of 20 mA/cm2, open-circuit voltage (Voc) of 423 mV and fill factor (FF) of 25.4%. This corresponds to conversion efficiency (η) of 5.2%. On the other hand, the planar c-Si reference solar cells exhibit Jsc of 7 mA/cm2, Voc of 390 mV and FF of 21.7%. The low conversion efficiency of the solar cells is contributed by high shading loss due to the front metal fingers and poor quality of p-n junction formation.
- ItemMAT 122 - Persamaan Pembezaan - Mac 2005(Universiti Sains Malaysia, 2005-03)