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Cellular cytoskeletal changes after oxidant injury and possible healing assisted by thymoquinone, the main constituent of Nigella sativa / Mohd Suhaimi Draman
No full textA wide-ranging spectrum of stem cell research receives intensively growing attention since the last decade. It promises the cure for a lot of apparently incurable diseases (e.g., paralysis or spinal cord injury). One of them is in the cytoskeleton concerning cell death/cell injury. For instance, oxidative injury by hydrogen peroxide (H2O2) has been linked to triggering cell death especially programmed cell death or apoptosis in bone marrow stem cells. The cytoskeleton commonly plays a big role in protecting cells against oxidative damage and, itself is a target for oxidative stress-induced free radical damage. Thus, drugs that protect the cytoskeleton could be one of the ways to save the cells from dying. Thymoquinone compound, which has been suggested to have protective and healing function against injury caused by an oxidant agent, is one of the candidates. In the current study, rat bone marrow mesenchymal stem cells (rBMSCs) were cultured and treated with different concentrations of H2O2 (50 μM, 500 μM, and 5000 μM) to damage the cells. This treatment caused morphological changes in the cells reminiscent of necrotic and apoptotic cell death. The number of cells surviving after the treatment was counted by MTT assay. At the end of the experiment, the cells were fixed and immunocytochemistry for the F-actin, microtubules, and nucleus was each performed using Alexa Fluor-488 phalloidin, Cy3-labeled anti-β-tubulin monoclonal antibody, and 4′,6-diamidino-2-phenylindole (DAPI), respectively. Three-channel fluorescence microscopy along with phase-contrast images was obtained by using fluorescence microscope to obtain digitally merged images of the cytoskeleton and the nucleus. The cells were also treated with thymoquinone (TQ) with different concentrations (0.5 μM, 5 μM, 50 μM, and 500 μM) before and after H2O2 oxidative damage treatments (50 μM, 500 μM and 5000 μM) to observe the protective and healing effects on the cytoskeleton of the rBMSCs. H2O2 was observed to cause cell death of rBMSCs in a concentration-dependent manner. H2O2 induced morphological changes in the cytoskeleton of the cells were devastating as shown by immunocytochemistry of the F-actin and microtubules. The morphology of stress fibres of the F-actin was disrupted, and the microtubules appeared to be missing. The cell nuclei were shrunken, and this involved a big cell number. Pre-treatment with TQ appeared to partially prevent these changes in the cytoskeleton. However, higher concentrations of TQ appeared to be toxic to the cells. Therefore, the results demonstrated that these compounds at high concentrations were pro-oxidant, whereas at low dosage they acted as antioxidants. These results suggested that the active compounds which can found in Nigella sativa could help in preserving the bone marrow rBMSCs and, thus, could help in regeneration against several degenerative diseases
Critical success factors of Malaysian Armed Forces digital library system / Abdul Rahim Abdul Rahman
Get PDFDigital Library System (DLS) refers to an online database that collects, creates, stores, distributes, and preserves digital objects, including text, images, video, and audio over a network. The present study aims to understand the critical success factors affecting user satisfaction and their continuous usage intention behaviour. This study employed updated DeLone and McLean IS Success Model (ISSM) and incorporated additional construct, namely perceived instrumental support to predict the critical success factors of Malaysian Armed Forces Digital Library System (MAFDLS). This study employed survey questionnaires to examine the research model and hypotheses developed. Five hundred twenty-four usable responses from military members who have accessed and used the digital library system were analysed using SPSS 25 and PLS 3.2.9. Within the context of military setting, it appears that perceived quality experience and perceived instrumental support as critical factors that triggered user satisfaction, net benefits and continuous usage intention behaviour. The findings specifically support that user satisfaction and net benefits play as sequential mediating roles between the perceived quality experience and continuous usage intention. In this study, perceived instrumental support affects user satisfaction and continuous usage and plays a moderating role between perceived quality experiences and user satisfaction. Hence, it is safe to say that users who are not satisfied with the system due to imperfect perceived quality experience factors would experience low difficulties. This study's perceived quality factors were MAF digital library environment, information relevance, system accessibility, navigation, and interface design. If they receive necessary instrumental supports from Malaysian Armed Forces Digital Library (MAFDL), this would increase users' perceptions of perceived instrumental support factors (such as education and training; technical support and communication support). While it is vital to satisfy the users' needs and satisfaction, Malaysian Armed Forces Digital Library (MAFDL) needs to bear in mind that not all group of users are the same. This study found that the different group specifics (such as geographical locations, level of experience and type of usage) have model effect differences as evidence to support that different group specifics have different perceptions of the overall digital library system evaluation criteria unique needs and opinions. The findings also uncover the potential challenges and issues faced by users when using the system. The results were synthesised, which would assist the management by re-strategizing the overall service delivery system by improving WebOPAC, KnowledgeBased Taxonomy, and MAF e-resource embedded in the system. The researcher produced strategic, tactical, and operational planning for future digital library system improvements based on full sampling or re-sampling group findings. Thus, the various planning of various levels of Malaysian Armed Forces (MAF) libraries was translated into a management action plan that acted as key performance indicators. This management action plan ensures that the military-users' needs are met to achieve a higher level of satisfaction on quality and instrumental support factors. It also meant getting higher organisational and individual impacts that benefit the users in having the system and having higher overall service delivery. In the end, it also meant to improve the continuous usage intention behaviour as the proxy to success behaviour of Malaysian Armed Forces Digital Library System (MAFDLS) future usage
Facemask usage and disposal practices from safety and waste perspective / Abirami V. Veeramani
Get PDFCOVID-19 has sparked a worldwide emergency and prompted concerns about waste management due to the excessive face mask waste generated globally. Malaysia records over 10 million face masks binned daily and in average a person spends RM180/year on face masks since the pandemic outbreak. Therefore, this study aims to explore the current issues arising from face mask waste from safety and waste dimension in Malaysia. The main objectives of this study are to identify the face mask usage among Malaysian and provide the best safety and waste practices of face mask. Questionnaire and case study analysis have been conducted to collect the data in this study. The questionnaires were distributed to a random population to understand their current practices in wearing face masks, selection preferences and face mask waste management and knowledge level. The data was analyzed using SPSS analytical tool. The result shows that majority (73.3 %) of the respondent agreed choosing face mask that is comfort and fit to their face. Besides, 77.2% of responded agreed that the level of bacterial filtration efficiency (BFE) is important in mask selection. And, around 90 respondents agreed wearing double mask in public spaces. According to 52.8% respondents, N95 masks are most effective in providing protection against COVID-19. 65% respondents are not satisfied with available information of disposal of face masks. Finally, based on the results obtained through the analysis, a guidance was developed to assist users on end-to-end process to improve their management of face mask. Since many nations considering COVID-19 as an endemic phase and thus existence of face mask may prolong longer in usage, this research will assist in developing enhanced public knowledge on safe use and effective face mask waste management for all level of stakeholders
Synthesis and characterization of perovskite-based materials for memory device application / Gregory Thien Soon How
No full textThis project aims to study the resistive switching behaviour in memory devices using perovskites-based structures. A hybrid organic-inorganic lead halide perovskite was studied in this project, specifically methylammonium lead triiodide, CH3NH3PbI3 or MAPbI3 perovskite. The effect of the various counter electrodes in MAPbI3 perovskite was investigated by fabricating MAPbI3 perovskite on Indium Tin Oxide (ITO). Three commonly used electrodes which are Aluminium (Al), Silver (Ag), and Gold (Au) were thermally evaporated on top of the MAPbI3 perovskite layer. It was found that the ITO/MAPbI3/Al exhibits Resistive Random Access Memory (ReRAM) behaviour with SET voltage (VSET) of 4.5 V and RESET voltage (VRESET) of -1.3 V. On the other hand, ITO/MAPbI3/Ag and ITO/MAPbI3/Au reveals write-once-read-many (WORM) behaviour as ON process occurs at around 4.7 V and 4.0 V, respectively. Hence, it was proposed that the conductivity of iodide vacancies and the electrochemically active metal electrodes plays a role in determining ReRAM or WORM characteristics. Through this study, ReRAM based MAPbI3 perovskite memory device were selected by using TiO2 blend amounts of 0, 3, 5, and 10 mol% into the MAPbI3 layer. The ITO/MAPbI3-T5%/Al ReRAM device displays the highest improved VSET and VRESET values of 3.6 V and -1.1 V. This was owed to the refined grain size and film uniformity that aids in enhancing the mobility of iodide vacancies towards the ITO interface. Through this project, the importance of the electrode’s material in memory devices is crucial in varying resistive switching behaviour. Moreover, the novel design of a single layer TiO2 blend MAPbI3 perovskite opens new possibilities in simplifying ReRAM based devices
Establishing the minimally important clinical difference for the oral health impact profile in Malaysians provided with removable partial dentures / Siti Fauzza Ahmad
No full textFuture demand for a removable partial denture (RPD) remains as more adults retain their
natural teeth into old age. Partial tooth loss often leads to masticatory function
disturbances and negatively affects the quality of life (QoL). Prosthodontic rehabilitation
with RPD improves QoL; however, the statistically significant change with many Oral
Health-Related Quality of Life (OHRQOL) instruments, may not be clinically
meaningful. The Malaysian version of Oral Health Impact Profile, OHIP(M)-45
questionnaires has been validated and adapted; however, its clinical interpretability has
not been established. The smallest change in OHRQoL score perceived by a patient as
beneficial, following an intervention, is termed Minimal Important Difference (MID).
There are two methods to estimate the MID estimation; i) distribution-based approach
which compares changes in OHRQoL scores after intervention through statistical
parameters, ii) anchor-based approach which correlates the change with clinical
measures. This pre-post intervention study investigated the change in OHRQoL, partially
dentate subjects after RPD therapy and determined the MID for OHIP(M)45, using both
approaches. The association between subjective perception and clinical outcomes (bite
force and masticatory performance) were also determined. Subjects completed
OHIP(M)-45 questionnaires before and after the intervention. The OHIP(M)-45 score
ranges from 0-180 with a lower score indicating better OHRQoL. The clinical anchors,
Global Transitional Scale (GTS) questionnaire, bite force and masticatory performance
were used. Bite force was measured using a digital dynamometer while masticatory
performance using gravimetric sieving method, (mesh sizes ranging from 4.00mm to
0.425mm) with alginate pellet as a test food. Statistical analysis was performed using
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Paired t-test, Wilcoxon Signed Rank and Friedmann test for within and between
comparison while the relationship between subjective and objective measurements using
Linear Regression and Spearman Rho. A total of 118 subjects enrolled with mean age
58.3 (SD±10.4) years, number of teeth 16.0 (SD±6.6) and number of occluding pairs 4.8
(SD±3.8). A significant reduction of 40% in the prevalence of impact (p<0.001) was
observed with RPD therapy. The mean OHIP(M)-45 change score was 17.36 (95%CI
(13.53;21.20, ES=0.76, p<0.001) with high treatment effect in the domains of physical
pain (ES=0.78) and psychological discomfort (0.82) and low effect in social disability
domain (ES=0.30). The GTS measure showed that 13%-24% of subjects perceived a little
improvement in their QoL, mainly in chewing with a significant association (p<0.05).
The estimated MID was 11. A significant increase in bite force (p<0.05) and
improvement in masticatory performance (p<0.05) with the new dentures were observed,
and a significant association was found between them. However, they showed no
significant association with the change in OHIP(M)-45 scores. MID estimates using bite
force and masticatory performance as anchors were 19 and 21 OHIP units respectively.
In conclusion, RPD therapy improved subjects' OHRQoL, bite force and masticatory
performance. The OHIP(M)-45 instrument is found to be responsive and sensitive to
change, and the MID for OHIP(M)-45 for RPD therapy is established.
Keywords: OHRQoL, MID, removable partial denture, bite force, masticatory
performanc
Perceptions of paediatric surgeons on the selection & admission processes in Master of Paediatric Surgery : a qualitative study / Anand Sanmugam
No full textThe selection and intake criteria for the paediatric training surgery training
program (Master of Paediatric Surgery) has undergone changes. Changes were instituted
to ensure a more robust selection system to ensure that the best candidates were selected
into the program. However, there has not been any data to show that these changes have
resulted in selection of candidates that could graduate on time and possess the attributes
that predicted the development of competencies required. The aim of this study aim was
to explore the perspectives of senior paediatric surgeons on the Master of Paediatric
Surgery selection and intake process. The study used phenomenological qualitative
research approaches and was based on the constructivist paradigm. In-depth structured
interviews were conducted with senior paediatric surgeons in Malaysia with experience
in the selection process. The viewpoint of these respondents with regards to the selection
process before and after the introduction of the current selection process were sought. The
relevance, strength and weaknesses of individual selection criteria were analysed.
Opinions on areas of improvements in the current selection criteria were discussed as
well. Most respondents agreed that a structured selection system, prior general surgery
experience, involvement in scholarly activities and examinations were important in
assessing applicants for selection. Less emphasis should be placed on years in service.
Suggestions for improvement included improved applicant referee/supervisor
engagement and the introduction of psychometric testing. In conclusion, despite a more
structured, robust selection process of paediatric surgery trainees in Malaysia there is still
room for improvement
A qualitative study on the perception of undergraduate nursing students on online learning during the Covid-19 pandemic at a public university in Malaysia / Muhammad Hibatullah Romli
No full textThe COVID-19 pandemic and Movement Control Order have restricted learning
activities in traditional face-to-face classrooms. Subsequently, these learning activities
have shifted to full online learning, and these activities are conducted in the student’s own
environment namely dorm room and home. The present researcher conducted a meta-synthesis, and the result shows that full online learning is receiving resistance, however,
it begin to gain better reception. Past studies show that online learning is a potential
approach in allowing active and dynamic learning experience especially on the
acquisition of theoretical knowledge, despite having limitations to developing technical
skills. Therefore, the present study aimed to investigate the perception of undergraduate
nursing students on online learning during the COVID-19 pandemic.
A qualitative study involving focus group discussions and in-depth interviews was
conducted. Nursing students from one Malaysian public institution were recruited. Ethical
approval was obtained, and the participants were recruited via social media platform (i.e.,
WhatsApp, email). A total of twenty-one participated in four group and three individual
interviews. The sessions were conducted online via Zoom or Google Meet applications,
and these were recorded. The data were analyzed using thematic analysis with assistance
of QDA Miner Lite software. Trustworthiness on the findings were done via credibility
(giving the findings summary to the participants for feedback a.k.a. member-checking),
confirmability (discussion with researchers and note-takers) and transferability
(comprehensive representation to the targeted population).
Three themes with a total of ten sub-themes were generated: (i) Full online
learning has ramification on life (it’s about life; blurred division on education life and
personal life; non-conducive environment for learning; health and well-being; human is
an adaptable being while transition takes time), (ii) full online learning is a medium of
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teaching and learning delivery but with several concerns (the silver living of full online
learning; challenges associated with full online learning; coping strategy in handling full
online learning), and (iii) Foundation in teaching and learning is the key (role of the
educator; teaching and learning approaches; motivation and regulation).
Full online learning during this pandemic is a life event and a transition process
from conventional to digital learning. However, the importance of teaching concepts such
as educators’ quality, teaching and learning approaches, and supportive learning
environment remains intact and relevant; hence modification required to suits with online
learning needs. Based on the lessons learnt in dealing with full online learning during the
COVID-19 pandemic, these lessons learnt may also essential for both learners and
educators to be equipped with technology skills in embracing the national aspiration for
Industrial Revolution 4.0 and National Education Policy. A practice framework is
successfully developed from the present study. Further investigation such as replication
of the study to other populations may enhance the generalizability of the findings, while
experimental research of single-subject research design is suggested to assess the efficacy
of the practice framework
Development and evaluation of 1’-acetoxychavicol acetate-loaded nanostructured lipid carrier for prostate cancer therapy / Bavani Subramaniam
No full textPrevious studies have established 1’-acetoxychavicol acetate (ACA), a phytoconstituent extracted from the rhizomes of Alpinia conchigera Griff (Zingiberaceae), as an anti-cancer compound with cytotoxic properties on many cancer types. ACA has been demonstrated to induce apoptosis-mediated cell death by deregulation of the NF-ĸB signalling pathway on cancer cells, while minimally affecting normal cells. However, as with other natural products, ACA is a hydrophobic ester with poor rate of dispersion, lack of bioavailability and non-specific tumour targeting in vivo. To overcome these problems, a nanostructured lipid carrier (NLC) system was formulated to encapsulate ACA and improve the latter’s aqueous solubility. In addition, to encourage targeted delivery towards tumours, the NLC was modified with AMD3100 octahydrochloride, an antagonist of the CXCR4 receptor which is overexpressed on many cancer cell lines. Formulation and optimisation of the NLC has availed nanoparticles of ideal physico-chemical properties which include small particle size, low aggregation tendency, high homogeneity, high affinity towards the drug, long-term stability and sustained rate of drug release. In vitro studies on PC-3 prostate cancer cells have also demonstrated time-based cellular uptake in addition to significant cytotoxicity, anti-migration and anti-invasion properties of the modified ACA-NLC. Furthermore, the ACA-NLC formulations have exhibited significant anti-tumour efficacy in nude athymic (Nu/Nu) mice models. The lack of systemic toxicity such as loss in body weight and inflammation of major organs, suggest the safety of the lipid excipients towards the biological system. Post-in vivo immunohistochemistry analysis and cytokine quantification provided evidence that the NLCs downregulated NF-ĸB related tumour markers and pro-inflammatory cytokines. Therefore, this NLC system was found to have great potential in promoting the anti-tumour effects of ACA in prostate cancer therapy and can possibly be translated to other forms of cancer
Geometric morphometrics analysis of wing venation for identification of selected forensically important flies in Malaysia / Nur Ayuni Dayana Mohd Puaad
No full textEntomological evidence has become one of the elements in assisting the criminal
investigation. The presence of various insects at the crime scene or on the dead body
often giving clues on the manner of death particularly in suicide and homicide cases.
Flies for instance, are the most common and apparent insect at the murder scene and
frequently, a specific fly species would be present at the specific location and time.
From here, the estimation of post mortem interval will be made upon various criteria;
the time of death or the synchronisation between the locations of the murder and the
location of the body was found. Thus, it is very crucial to acquire the speciation
information of the fly as fast as we could to help the investigation processes. Hence, an
effective, economical and rapid method is needed for the identification of these insects.
This study was focused on using quantitative methods for species identification of the
flies through geometric morphometrics analysis. The analysis on the wings of the flies
was conducted by measuring the venation via landmark method. Fifteen forensically
important fly species in Malaysia from the Calliphoridae and Sarcophagidae families
were chosen from an archived collection as the subject of this analysis. The
measurement obtained from the geometric morphometrics analysis in the form of thinplate-
spline data were subjected to the Generalised Procrustes Analysis (GPA),
Principal Component Analysis (PCA) and Heat Map Analysis. From PCA, the
differences between both families and the distribution of fly species within
Calliphoridae family were quite obvious compared to Sarcophagidae family. Geometric
morphometrics analysis were also carried out on 36 crime scene sample, and 14 randomly chosen crime scene samples were sent for DNA sequence analysis for
verification. From this study, geometric morphometrics method was shown to have the
potential to become a useful identification and diagnostic tools for forensically
important fly species in Malaysia
Adoption of cleaner production concept in hawker centre / Lee Shei Ching
No full textHawker centres are commonly found in Malaysia and the facilities operations may
contribute to significant fraction of carbon footprint from food industries. In this work,
Cleaner Production (CP) audit was conducted at a hawker center to quantify the energy
usage, fuel and resources consumption, raw material usage and generation of waste. A
hawker centre located at Kepong, Kuala Lumpur was selected to identify the Cleaner
Production (CP) Strategy that aims to produce a greener hawker. According to the audit
finding, the normal operation of hawker centre generates 1.18kg CO2 per customer which
were contributed by 53% food waste, 28% LPG fuel consumption and 14% electricity
usage. The remaining are contributed by 6% of solid waste and 2% is by the wastewater
production and water usage. From the findings, a total of 30 CP options were identified
with 18 of it were suggested for cleaner production implementations based on
considerations of the cost and improvement in carbon emission reduction. Through the carbon footprint calculation, the implementation of the CP options cut the carbon emission from 1.18 kgCO2 to 0.82kgCO2 per customer which equivalent to 31% of reduction. The estimated investment cost required for the implementations of suggested CP options is sixteen thousand Ringgit Malaysia with payback period of 1 year and 3 months. Therefore, implementation of CP options was beneficial to reduce carbon
emission and produce a greener hawker