Repository@USM
Welcome to closed access digital repository of Universiti Sains Malaysia (USM).
This repository contains multiple types of scholarly materials, especially USM theses and exam papers.
To access the full text, please log in with your USM email account.
Research outputs
6400
Projects
0
People
0
Recent Additions
- PublicationThe proportion and factors associated with diabetic retinopathy among type 2 diabetes mellitus patients in Perak from 2018-2022(2025-06)Introduction: Diabetic retinopathy (DR) remains a leading and preventable cause of vision loss among individuals with Type 2 Diabetes Mellitus (T2DM), posing a significant public health challenge both globally and in Malaysia. In Perak, the increasing burden of diabetes underscores the need for local data to inform targeted screening and management strategies. This study aimed to determine the proportion and identify factors associated with DR among T2DM patients in Perak between 2018 and 2022. Methodology: A cross-sectional study design was employed using secondary data from the National Diabetes Registry (NDR) of Perak. Adults aged 18 years and above with Type 2 Diabetes Mellitus diagnosed between January 2018 and December 2022 were included. After applying inclusion and exclusion criteria, 1160 patients were selected via simple random sampling. Data on sociodemographic characteristics, clinical parameters, comorbidities and treatment details were extracted and analysed using SPSS version 29. Simple and multiple logistic regression analyses were conducted to identify independent factors associated with Diabetic Retinopathy. Results: Among the 1160 Type 2 Diabetes Mellitus patients sampled, the overall proportion of Diabetic Retinopathy was 25.4%. Notably, there was a declining trend in Diabetic Retinopathy proportion from 31.4% in 2018 to 13.8% in 2022. The mean age of patients was 55.3 years and 59.0% were female. Multivariable logistic regression identified several independent risk factors for Diabetic Retinopathy which includes increasing age (Adj OR 1.04; 95% CI: 1.02, 1.05), longer duration of diabetes (Adj OR 1.20, 95% CI: 1.07, 1.35), poor HbA1c control (Adj OR 1.10, 95% CI: 1.01, 1.19), nephropathy (Adj OR 4.54, 95% CI: 2.88, 7.24), hypertension (Adj OR 1.72; 95%CI 1.21, 2.47) and insulin therapy (Adj OR 2.5; 95% CI 1.66, 3.77). The findings are consistent with both local and international literature, reinforcing the importance of these modifiable and non-modifiable risk factors Conclusion: The study reveals a significant reduction in Diabetic Retinopathy prevalence among Type 2 Diabetic Mellitus patients in Perak, reflecting improvements in diabetes management, regular retinal screening and public health interventions. However, the persistence of traditional risk factors highlights the ongoing need for integrated and multidisciplinary care, regular screening and prioritisation of high-risk individuals. The findings support the strengthening of preventive strategies and resource allocation to further reduce the burden of vision-threatening diabetic complications in Perak and similar settings
- PublicationCharacterization of acoustic parameters of resonant /m/ and /n/ sounds for the development of objective indicators of resonant voice therapy(2025-10)Resonant voice therapy (RVT) is an evidence-based intervention for voice disorders, often initiated with nasal sounds such as /m/ and /n/. Resonant voice (RV) is usually verified through auditory and tactile feedback under a speech-language therapist’s (SLT) guidance, but these perceptual methods are limited outside clinical settings. The present study aimed to identify objective acoustic parameters that could indicate RV and support tangible feedback tools for self-guided practice. Ninety participants (45 females, 45 males) contributed data for /m/, and 83 (41 females, 42 males) for /n/. After RV training, each provided three 6-second recordings of RV and typical voice (TV). The middle 3 seconds were analyzed in Praat to extract fundamental frequency (F0), formants (F1–F4), F0 standard deviation (F0SD), perturbation measures, cepstral peak prominence (CPPFull, CPPVoice), harmonic-to-noise ratio (HNR), and mean intensity. Significant differences (p < 0.05, medium effect size) were found in APQ3 and DDA for females, as well as in mean intensity for males. Mean intensity consistently distinguished RV from TV, with significantly higher values in RV. Compared to the /n/ sound, the /m/ sound presented with lower value perturbation measures and F0SD and higher value for CPP and HNR, though not significant. Formant analyses revealed significant F2 and F3 differences in males, while female results were less consistent. These findings demonstrate the potential of acoustic parameters to differentiate RV from TV. Consistent patterns across multiple measures, some statistically supported, highlight their promise as objective indicators and their utility in developing tangible feedback tools to enhance RVT practice
- PublicationAntiviral activities of tualang honey against chikungunya virus-infected human fibroblast-like synoviocytes (HFLS)(2025-11)Chikungunya is a mosquito-borne viral disease caused by chikungunya virus (CHIKV), primarily transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. The illness is characterised by fever, polyarthralgia, myalgia, rash and headache. In chronic chikungunya, arthralgia can persist for months or even years. Although a vaccine called IXCHIQ exists, it is not widely used and current treatment options focus on symptom relief. This study aimed to investigate the in vitro antiviral activity of Tualang honey against CHIKV infection in human fibroblast-like synoviocytes (HFLS) cells. The potential anti-CHIKV activity of different concentrations of Tualang honey at various incubation periods was evaluated through pre-treatment and post-treatment assays. Additionally, the modes of action were further investigated using virucidal, anti-adsorption, and anti-entry assays. The maximum non-toxic dose (MNTD) of honey in HFLS cells was found to be 50 mg/mL although for subsequent antiviral assays ≤ 20 mg/mL concentrations were used. The viral inhibitory effect was evaluated using plaque assays to measure viral titres and quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) to quantify RNA copy numbers. Tualang honey exhibited minimal to excellent prophylactic activity during the pre-treatment assay, reducing viral titres by 29.21% to 94.87% and RNA copy numbers by 12.90% to 69.80%. Significant inhibition (p < 0.05) of CHIKV viral titres was observed following pre-treatment with 10 and 15 mg/mL for 6 and 12 hours before infection, respectively. Interestingly, the anti-CHIKV effects of Tualang honey in HFLS cells were more prominent during pre-treatment compared to post-treatment. Post-treatment with Tualang honey resulted in minimal to strong inhibition, reducing CHIKV viral titres by 6.67% to 72.46% and RNA copy numbers by 10.87% to 29.21%. The greatest inhibition was observed following post-treatment with 15 mg/mL concentration at 4 hour post infection (hpi), although these effects were not statistically significant. Notably, Tualang honey exhibited a virucidal effect, with up to an 80.50% reduction in CHIKV viral titres. Significant virucidal activity (p < 0.05) was observed when 15 and 20 mg/mL of honey were incubated with 2 X 10³ pfu of CHIKV. Furthermore, Tualang honey demonstrated both anti-adsorption and anti-entry effects, with the latter being more pronounced, reducing viral titres by up to 90.45% compared to 66.89% for anti-adsorption. In conclusion, this study demonstrates that Tualang honey possesses anti-CHIKV activities and exerts its effects through broad modes of action. Further research is required to confirm its clinical applicability and fully elucidate its mechanisms of action
- PublicationInternal And External Factors Effects On Institutional And Retail Investors’ Herding Behaviour In The Gcc Financial Markets(2024-10)In this regard the study aims to analyse the impact of type of investors (institutional investors share and country of origin) in affecting herding behaviour; impact of external factors (political instability, global financial crisis, and oil shocks) and internal factors (PE Ratio and Market Capitalization) on herding behaviour.
- PublicationSegregation Of Microsatellite Markers, Fertility AND Pathogenicity On Hylocereus undatus (Dragon Fruits) In The Interspecific Hybrid Between Fusarium fujikuroi And Fusarium proliferatum(2023-10)The main objective of this research is to further characterize the interspecific hybrids. Continuing from the previous research, several progenies have been selected and extend the information regarding those hybrids such as pathogenicity test, fertility test and molecular approach using microsatellite marker.
Most viewed
- ItemSimulation of preventive and corrective maintenance schedule in reducing machine stoppage and downtime(2017-06)Maintenance approaches or strategies has been studied since many decades ago and nowadays it varies from the complex mathematical approach to improved and simplified yet effective time-based strategies. However, simulation of maintenance strategies is an intermittent field of research thus current maintenance strategies simulation model created a benchmark to imitate the methodology of implement maintenance strategies in real production. Currently, the major drawback of most of the published researchers is in the application of only single machine, single maintenance strategies or multiple machines of the same type working in parallel which does not reflect the real and complex manufacturing system. Thus, this project is conducted to create a model of maintenance strategies integrated with a dynamic manufacturing system. The system consists of five different machines and each cycle time of machines differ considering the shift time of maintenance team and spare part availability. The work has been conducted using WITNESS 14 Manufacturing Performance Edition software. The model was developed to imitate a Surface Mounted Technology (SMT) production system by considering the changeover time, minor and major breakdown, corrective maintenance (CM) as well as preventive maintenance (PM) scheduling. The aim is to study the effect of maintenance strategies towards the machine downtime. The SMT line was simulated and evaluated based on the availability of individual machines via discrete event simulation system. Presuming that each machine has different degradation level, which follows a Weibull distribution, the maintenance scheduling strategies were planned based on First Come First Serve (FCFS) basis if the same type of maintenance strategies is due on different machines but prior to CM. The findings of this project demonstrated that a daily PM schedule can improve the system availability by 30% while increasing the availability of machine up to 90%.
- ItemPhotocatalytic Degradation Of Phenol By Silica Gel-Supported Titania Nanotubes(2012)TiO2 nanotubes and immobilized TiO2 nanotubes were successfully synthesized by a hydrothermal method and binding method. The produced photocatalysts were characterized by the Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM) and X-ray diffraction (XRD). The photocatalytic activities of the photocatalysts were evaluated through the photocatalytic degradation of aqueous phenol solution in a batch reactor. TiO2 nanotubes produced at 130 °C for 3 h showed the highest degradation rate of phenol compared with the other samples prepared at 130 °C for 1 h, 5 h and 7 h, complete degradation being achieved in 130 min. Special focus was given in order to determine the optimum composition of each component (catalyst, support and binder) in the immobilization of TiO2 nanotubes. The highest efficiency of phenol degradation was achieved when the ratios of TiO2 nanotubes: silica gel: colloidal silica was 1:2:20. For the comparison, TiO2 nanotubes and immobilized TiO2 nanotubes showed higher photocatalytic activity as compared with pure TiO2. The photocatalytic performance of TiO2 nanotubes and immobilized TiO2 nanotubes achieved 100 % and 98.0 % respectively, of phenol degradation, whereas pure TiO2 attained only 77.0 % degradation. The photocatalytic activity of the immobilized TiO2 nanotubes was slightly decreased after four cycles for phenol degradation. The loss in percentage of photocatalytic degradation was less than 2 % even after four cycles. The results for the studied operating parameters were: the presence of the anions were found to inhibit the photocatalytic degradation of phenol in the order of SO4 2- > Cl- > HCO3 -; the optimal medium pH was found to be pH 5.5 (natural pH); the air flow rate gave an optimum value of 0.3 L/min; the phenol degradation efficiency decreased as initial phenol concentration increased. Response surface methodology (RSM) based on the central composite design (CCD) was used to optimize and predict the interactions between process variables by reducing the numbers and the times for the experimental runs. Finally, the reaction kinetics of phenol degradation by the immobilized TiO2 nanotubes obeyed well with the Langmuir-Hinshelwood model. The values of the reaction rate constant, k and the adsorption constant, K obtained were found to be 0.9324 mg/L.min and 0.0121 L/mg, respectively.
- ItemEvaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers(Universiti Sains Malaysia, 2019-06)Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever (TF) that causes millions of infections and 1% of mortality worldwide. TF is highly endemic in Southeast Asia and sub-Saharan Africa. Certain individuals with TF may not recover fully and can become carriers that do not show any symptoms of the disease. The carriers can then spread the disease when they come into contact with food and water. Antibodies against S. Typhi HlyE are elevated among patients with TF compared to healthy individuals, while antibodies against YncE were reported to be elevated among carriers of S. Typhi. Rapid and accurate methods to diagnose individuals with TF or who are carriers are crucial to manage the disease. In this study, recombinant HlyE and YncE antigens were found to be useful for the identification of individuals with TF and those who are possible carriers. Firstly, recombinant HlyE and YncE were expressed and purified. Next, rHlyE and rYncE ELISAs were developed to enable quantitative screening of many samples simultaneously to identify those with elevated IgM, IgG and IgA antibodies against the antigen. A total of 425 serum samples (acute typhoid patients, carriers, food handlers, other febrile, and healthy individuals) were screened with the ELISAs.The rHlyE-IgG, -IgA and -IgM ELISAs demonstrated a sensitivity of 70%, 80% and 11% respectively to detect acute typhoid patients, and with a combined sensitivity of 83%.The rYncE ELISA identified 16 possible carriers based on their antibody profiles. Taken together, this study showed that HlyE antigen could be used to identify individuals with TF while the YncE antigen may be used to identify possible carriers, but further validation is required.
- PublicationFactors Affecting The Use Of Gamification In Online Learning Environment Among School Teachers In The Kingdom Of Saudi Arabia(2023-05)The use of technology and e-learning systems in classrooms can have a significant impact on students’ learning. Not to be left behind, the Saudi government launched the ‘Future Gate’ project to implement technology in secondary schools in which gamification is applied in this e-learning platform. However, what are the factors that might influence its acceptance and utilization among the school teachers? Specifically, this study examined the effects of performance expectancy, effort expectancy, social influence, hedonic motivation, facilitating conditions, and habit on teachers’ behavioural intention to use gamification in teaching and learning activities in the Future Gate platform. It also investigated the impact of age, gender, and experience on these variables. In addition, the study evaluated the effects of task and technology characteristics and how they influence teachers’ perception of Task-Technology Fit (TTF) and the teachers’ behavioural intention to use gamification. This study utilised SEM-Partial Least Square (PLS-SEM) to analyse the relationships between the constructs identified from the literature review. A total of 328 secondary school teachers participated in this study from seven districts in Saudi Arabia.
- ItemNurses' knowledge and practice regarding prevention of surgical site infection (SSI) in Hospital Universiti Sains Malaysia (USM)(Pusat Pengajian Sains Perubatan, Universiti Sains Malaysia, 2021-06)Surgical site infection is an infection that occur 30 days after surgery and cause many effects such as increasing risk of death, increasing hospital stay and financial constraints for patient and health care system. A cross sectional study has been conducted to determine nurses’ knowledge and practice regarding prevention of SSI in Hospital USM. This study also examined the difference of knowledge and practice between general surgery and orthopaedic nurses. Pearson Chi-square was used to determine the association between clinical working experience with knowledge and practice towards prevention of SSI. A total of 66 nurses, 34 nurses were from surgical and 32 nurses from orthopaedic wards were recruited through proportional sampling. Data were collected September 2019 until June 2020 using self-administered questionnaires and analysed using SPSS version 26.0 for Window. Ethical approval was obtained from Human Research Ethics Committee (HREC), Universiti Sains Malaysia. The mean age of the participants was 31 years old. The results revealed staff nurses were having poor knowledge level (M=16.18, SD= 2.745) regarding prevention of SSI. Meanwhile for level of practice, nurses were found to be having good practice towards prevention of SSI (M=67.82, SD=6.44). There was no significant difference in knowledge between general surgery and orthopaedic nurses (p=0.467). While, there was significant difference in practice between general surgery and orthopaedic nurses (p=0.013). There was no association to be found between clinical working experience with knowledge (p=0.834) and practice (p=0.197) regarding prevention of SSI. It showed that nurses need more exposure towards SSI and its prevention for them to identify, assess and implementing the correct practice. As a conclusion, it is shown that knowledge and practice towards SSI is important as the results shows that nurses in Hospital USM had insufficient knowledge. A workshop or course training should be implemented to enhance their knowledge.