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Antiproliferative effect of selected zingiberaceae species against human oral cancer cells / Muhammad Amirul Amil
No full textOral squamous cell carcinoma (OSCC) is a prevalent and highly challenging form of oral cancer that poses significant health burdens worldwide. Current treatment options for OSCC are limited and often associated with adverse side effects. Therefore, there is an urgent need to explore alternative therapeutic approaches. Natural compounds derived from medicinal plants have gained significant attention for their promising prospects as effective and safe antiproliferative agents. This study aims to investigate the in vitro antiproliferative effects of essential oils and extracts obtained from Curcuma aeruginosa, Curcuma mangga, Curcuma xanthorrhiza, Kaempferia galanga, and Zingiber zerumbet on OSCC cells. The essential oil of the rhizomes obtained by hydrodistillation were subjected to chemical analyses using a combination of GC/MS and GC-FID analytical techniques. Substantial percentages of identified compounds were found, such as β- myrcene (79.77%) in the essential oil of C. mangga, followed by zerumbone (48.39%), ethyl-cinnamate (40.14%), and β-curcumene (34.90%) in the essential oils of Z. zerumbet, C. xanthorrhiza, and K. galanga, respectively. The essential oils and extracts of the Zingiberaceae species were evaluated for their antiproliferative effects against OSCC namely H103 and ORL-204 cancer cells; and hGF a noncancerous human gingival fibroblast cells using the MTT assay. Notably, the hexane fractionated extract of C. mangga (IC50 = 10.72 μg/mL), ethyl acetate fractionated extract of C. xanthorrhiza (IC50 = 4.99 μg/mL), and Z. zerumbet’s fractionated extract in hexane and essential oil (IC50 = 1.93 and 8.29 μg/mL, respectively) displayed significant antiproliferative activity on H103 cancer cells. Moreover, the crude methanol extract of C. mangga (IC50 = 5.04 μg/mL), ethyl acetate fractionated extract of C. xanthorrhiza (IC50 = 3.07 μg/mL), and the hexane fractionated extract as well as the essential oil of Z. zerumbet (IC50 = 1.13 and 8.21 μg/mL, respectively), demonstrated potent inhibition against the proliferation of ORL-204 cells. Based on the observed low IC50 value of the essential oil of Z. zerumbet in the MTT viability assay, subsequent investigations were conducted to explore the cell death pathway and the underlying mechanisms of ORL-204 cells treated with the essential oil of Z. zerumbet. These investigations encompassed in vitro morphological examinations, assessment of mitochondrial membrane potential, detection of caspases (caspase-3, -8, and -9), analysis of DNA fragmentation-TUNEL, and cell cycle analysis. Consistently, these assays confirmed the occurrence of apoptosis within the ORL-204 cells upon treatment with the essential oil of Z. zerumbet, suggesting its ability to induce programmed cell death and inhibit cell proliferation. Altogether, the findings of this study highlight the antiproliferative effects of the essential oil of Z. zerumbet on OSCC cells and its ability to induce programmed cell death through both extrinsic and intrinsic pathways. These results suggest that the essential oil of Z. zerumbet has the capacity to become a valuable antiproliferative agent in the future treatment of oral cancer, opening up possibilities for further research and development of novel therapeutic approaches
Elemen landskap perkhidmatan dalam pemilihan restoran halal Korea: Kajian dalam kalangan belia Muslim di Lembah Klang / Aisyah Muhamad Talmizi
No full textLandskap perkhidmatan memainkan peranan penting bagi menjaga imej restoran serta menarik perhatian pengunjung untuk mengunjungi sesebuah restoran, sama ada berdasarkan landskap perkhidmatan fizikal ataupun landskap perkhidmatan sosial. Restoran halal Korea yang menekankan kedua-dua dimensi ini akan berjaya menarik perhatian para pengunjung. Namun, kecenderungan sesetengah restoran halal Korea untuk meletakkan papan tanda “no pork” dan “no alcohol”, menempatkan pekerja bertudung di barisan hadapan serta menonjolkan kebersihan restoran dilihat boleh mengelirukan pengunjung Muslim perihal status kehalalan restoran tersebut. Maka, kajian ini dijalankan bagi merungkai isu ini dengan menetapkan tiga objektif kajian. Pertama, meneliti konsep landskap perkhidmatan dalam konteks pemilihan restoran halal Korea. Kedua, menganalisis elemen landskap perkhidmatan fizikal terhadap pemilihan restoran halal Korea dalam kalangan belia Muslim di Lembah Klang. Ketiga, menganalisis elemen landskap perkhidmatan sosial terhadap pemilihan restoran halal Korea dalam kalangan belia Muslim di Lembah Klang. Bagi mencapai objektif pertama, kajian perpustakaan telah dijalankan. Hasil penelitian literatur menemukan bahawa landskap perkhidmatan terdiri daripada landskap perkhidmatan fizikal dan landskap perkhidmatan sosial. Terdapat empat elemen bagi landskap perkhidmatan fizikal, iaitu ambien, susun atur dan perhiasan, kemudahan serta papan tanda dan simbol, manakala terdapat dua elemen bagi landskap perkhidmatan sosial iaitu penampilan pekerja dan pelanggan lain serta jumlah pelanggan (kesesakan sosial). Bagi mencapai objektif kajian yang kedua dan ketiga, kajian kuantitatif yang menggunakan kaedah tinjauan telah dilaksanakan. Hasil analisis soal selidik terhadap 384 responden kajian yang terdiri daripada belia Muslim di Lembah Klang menemukan beberapa dapatan utama. Dari segi landskap perkhidmatan fizikal, dapatan menunjukkan bahawa elemen papan tanda dan simbol sangat diambil kira oleh belia Muslim dalam pemilihan restoran halal Korea dengan nilai purata min 3.08. Di bawah elemen ini, logo halal JAKIM merupakan item terpenting (nilai min 3.33). Dari segi landskap perkhidmatan sosial pula, jumlah pelanggan (kesesakan sosial) mencatat nilai purata min tertinggi (3.06). Jumlah pengunjung Muslim yang ramai dilihat dapat menarik belia Muslim untuk berkunjung ke restoran halal Korea. Dapatan kajian ini memberi input kepada pihak restoran halal Korea agar terus mengekalkan logo halal yang dimiliki kerana ia mempunyai daya tarikan yang tersendiri. Bagi belia Muslim pula, mereka perlu mengutamakan logo halal JAKIM berbanding landskap perkhidmatan yang lain dalam memilih restoran yang terjamin halal. Selain itu, pihak JAKIM perlu memainkan peranan bagi mempromosikan sijil halal serta mempergiatkan lagi pemantauan agar pihak restoran tidak mengambil kesempatan dengan menggunakan landskap perkhidmatan yang menggambarkan status halal untuk mengaburi mata pengunjung Muslim khususnya
Development and characterization of nanostructured lipid carrier loaded with flavonoid from selected local plant extracts for topical anti inflammatory application / Sharifah Sarah Shazwani
No full textTopical drug delivery has a long history, dating back to ancient times, and has continuously evolved in modern medicine. It is now widely used, particularly in over-the-counter formulations. However, conventional topical preparations have encountered various issues. Consequently, scientific literature has started exploring alternative drug delivery systems, such as nanostructured lipid carriers (NLCs). NLCs offer benefits like improved bioavailability and efficacy of active ingredients like flavonoids by enhancing solubility, absorption pathways, stability, and improved occlusive effects on skin. In this study, flavonoid-rich extracts from local plants were loaded into NLCs and analyzed for particle size, zeta potential, morphology, encapsulation efficiency, and in-vitro release. These loaded-NLCs were then incorporated into a gel base, and the resulting formulation underwent evaluation for rheological properties, texture profile, drug release, and fitting into kinetic models. The NLCs were formulated using stearic acid, a mixture of medium-chain triglycerides (MCT) and oleic acid, tween 20, and span 20 through the hot-homogenization method. The optimized NLCs exhibited a particle size of 294.30±7.08 nm, a PDI of 0.23±0.01, and a zeta potential of -35.0±0.1 mV, with formulation SR8 being the optimal choice. Statistical analysis confirmed a strong fit for mean particle size, PDI, and zeta potential. MCT incorporation led to size reduction, demonstrating formulation adjustability. HPLC analysis revealed successful optimization of the aglycone Quercetin content in the extracts with approximately 200% increments in its content after the acid-reflux hydrolysis treatment. Additionally, the nitric oxide (NO) scavenging activity of the extracts was notable with approximately 50% to 54% efficacy in relative to the standard Quercetin compound. Encapsulation efficiency of the extract-loaded NLC also exceeded 90% at an optimal concentration of 0.6% to 2%. NLC with a 0.4% concentration of specific content demonstrated consistent particle size and was selected for further testing. Morphological evaluation confirmed stability and uniform particle distribution. Rheological analysis and gel studies validated optimal consistency and stability for topical use, with NLC-loaded gels exhibiting solid-like behavior and increased viscosity relative to the applied strain. Temperature-induced structural changes were observed during heating and cooling. In-vitro release studies emphasized controlled release properties, with loaded-NLCs fitting well into first-order kinetic models. Both loaded-gel and loaded-NLC gel favored Higuchi and Korsmeyer-peppas drug release kinetic models, respectively. Overall, this research covers various aspects, including flavonoid extraction, HPLC analysis, NO assay, NLC development, NLC optimization via Box-Behnken Analysis, loaded NLC characterization, NLC gel evaluation, and their applications. It underscores the significance of proper extraction techniques, demonstrates enhanced quercetin efficacy through acid hydrolysis, and confirms quercetin glycosides' anti-inflammatory properties via the NO assay. NLC development involves lipid and surfactant selection, BBD optimization ensures desired NLC properties, and physical evaluation validates gel stability and application. Morphological assessments demonstrate successful NLC integration in the gel matrix, enhancing stability and efficacy, while in-vitro studies emphasize controlled release. Kinetic models effectively describe release profiles for various carriers
Direct laser writing of optical waveguides in transparent materials using a high repetition rate femtosecond laser / Ng Kok Bin
No full textDirect laser writing (DLW) is an advanced nanofabrication technology where high-power laser is tightly focused into a transparent material to induce modifications. Arbitrary structure can be produced by moving the sample across the laser focal spot in the 3-D space. During the fabrication process, several laser writing parameters are manipulated depending on the material properties, desired structure, dimensions, and applications. Among the many types of lasers, high repetition rate femtosecond laser (>100 kHz) has attracted much attention due to its unique interactions with the transparent material. DLW with high repetition rate laser typically gives rise to the heat accumulation effect. The pulse energy is deposited to the material faster than the thermal energy can dissipate between the arrival of successive pulses. This causes thermal energy to build up at the laser focal spot, leading to intense heat accumulation effect. In this work, the interaction between the heat accumulation effect with different transparent materials is investigated. The first study involves the waveguide fabrication in soda lime glass with a 100 kHz femtosecond laser at 515 nm. The waveguide produced has a core index of 4.7 x 10-3, among the highest recorded value compared with the waveguide written in borosilicate glass and fused silica glass. However, the fabricated waveguide exhibits high propagation loss of 2.5 dB/cm and coupling loss of 2.8 dB due to the non-uniformity of the core refractive index and the ellipticity mismatch, respectively. Further work is necessary to improve the performance of the waveguide. The second study involves laser ablation of CR-39 using 80 MHz femtosecond laser at 800 nm. The result shows that continuous modification is impossible when the laser is focused inside the material due to the inherent characteristics of thermoset plastics. However, straight trenches were successfully ablated when the laser is focused on the surface of the CR-39. The study highlights that the surface ablation efficiency is influenced by the dynamic interplay between the plasma iv
shielding effects and beam profile distortion at the laser focal spot. The third study involves the laser-induced polymerization in SU-8 for optical waveguide fabrication. Straight channel waveguide was first fabricated in the SU-8 film using an 80 MHz femtosecond laser operating at 780 nm. The processing window for complete polymerization is obtained in terms of the laser fluence, which is in the range of 1.8 – 10 kJ/cm2. Thermal damage observed during the suspended waveguide writing suggesting that beam truncation effect is involves during the fabrication of 3D waveguide, where the variation of the voxel dimension at different focal position changes the local intensity of the laser. This study demonstrates the potential of SU-8 in the creation of 3D optical waveguide for future photonics integrated circuit applications. As a conclusion, the experimental works included in this dissertation provide valuable insights of the interaction between high repetition rate femtosecond laser with various transparent materials, which in turns benefit future research not only in the field of direct laser writing, but also applications in the diverse field of femtosecond laser interactions with materials
Risk factors of development of Post Mastectomy Pain Syndrome (PMPS) and its impact on the psychological symptoms in patient with PMPS / Chua Kah Yee
No full textBackground: Post-mastectomy pain syndrome (PMPS) is a common complication following breast cancer surgery, characterized by persistent neuropathic pain. Objective: To determine the prevalence of PMPS, identify its risk factors, and assess its impact on psychological symptoms in affected patients. Method: The study successfully recruited 202 patients with complete medical records. Inclusion criteria comprised women diagnosed with breast cancer who underwent surgery at PPUM in 2022, while exclusion criteria included patients who declined study consent, were unreachable, or faced communication barriers. These patients were assessed for PMPS according to the IASP definition. For those with PMPS, pain characteristics were documented, pain intensity was measured using the numeric rating scale (NRS), and psychological symptoms were evaluated using the Hospital Depression and Anxiety Score (HADS). Univariate and multivariate logistic regression analyses were conducted to identify PMPS risk factors. Results: Among the 202 patients, 14 (7%) reported PMPS, with pain predominantly described as mild or moderate intensity localized in the ipsilateral breast or chest wall, often characterized as throbbing. Risk factors for PMPS encompassed younger age, increased weight, high BMI, neoadjuvant chemotherapy, sentinel lymph node biopsy (SLNB), and axillary lymph node dissection (ALND), all exhibit p-values < 0.05. Among patients with PMPS, two experienced mild depression, one experienced mild anxiety, and one experienced moderate anxiety. Conclusion: PMPS significantly impacts patient morbidity, psychological well-being, and quality of life. Identifying potential risk factors for PMPS is crucial for implementing early multimodal and multidisciplinary approaches to prevent or alleviate this condition
Materialism, over-indebtedness and financial fragility: An empirical study of Malaysian civil servants / Amien Arief Jamaluddin
No full textThe rapid increase of household debt in the advanced and developing countries over the past decade is detrimental to economic growth in the long run. Excessive borrowing at the micro-level not only reduces household consumption and standard of living, but at the same time increases household exposure to financial fragility and default. Despite the alarming statistics, several other studies suggested that the raise in household debt is supported by the new entry and the financially sound borrowers which imply an optimistic economic environment.
Based on contradictory past evidence, this micro-level study aims to investigate household debt and financial fragility by examining socio-economic characteristics with a specific focus on household life cycle, debt service ratio (DSR) level, and household materialistic values. By utilising a multi-staged sampling procedure this cross-sectional study focuses on Malaysian civil servants as its population sample. The selection of these specific groups is due to their larger total debt accumulation and higher DSR level compared to the Malaysian average. A binary logistic regression model is employed to analyse the probability of being over-indebted and financially fragile. Further examination on the likelihood of being financially fragile is conducted by utilising ordered logistic estimation to assess the level of reliability and robustness of the main findings.
It is found that nearly 7 out of 10 Malaysian civil servants are over-indebted and almost 3 out of 10 are financially fragile. While the study identified a moderate level of financially fragile civil servants, the non-financially fragile which represents 47% of households are facing some form of financial constraint. Despite this, analysis on household perceived financial condition shows that 65.1% are financially sound indicating household’s ability to keep a fair amount of income as precautionary savings. The contradiction gap between the actual and perceived financial position is likely to be contributed by the constant use of the accumulated savings to finance additional expenditures that lead to insufficient long-term savings as well as the sense of financial stability due to future income expectation, and guaranteed pension remuneration during retirement.
Apart from household life cycle, level of income and debt, as well as gender and number of dependents, household level of materialistic orientation are proved to be the key determinants to household financial position. It is suggested that higher attachment to material possession lead to higher non-debt expenditure, decreases household ability to save, and increases the probability of being financially fragile.
Several short-term and long-term policy responses are proposed to ease the demand for debt as well as reduce household attachment to material possessions. These include reviewing the civil servant housing and cost of living allowances for households in the urban area, tightening the lending and borrowing procedure, particularly for personal loan applications as well as introducing the mandatory debt management program for newly recruited public employees
Ultra-high frequency antenna sensor with self identification and ambient noise reduction for partial discharge detection in open substations / S. M. Kayser Azam
No full textThe occurrence of partial discharge (PD) in high voltage (HV) insulation can lead to equipment failure and is detectable in the ultra-high frequency (UHF) range. UHF antennas are increasingly popular as PD sensors, but existing models face challenges in early PD signal detection, ambient noise reduction, and PD identification, especially in open substations. Current UHF sensors rely on expensive amplifiers and additional filters, making data processing error-prone and cumbersome. Identifying the exact PD-affected equipment early on has also been unresolved by recent RFID tag-assisted systems. This research introduces a novel standalone UHF antenna sensor that addresses these challenges. Based on a planar monopole antenna (PMA), the sensor was developed systematically from this fundamental design. First, a preliminary investigation sensor (PIS) is created as a reference to characterize PD detection under various conditions. Next, a primary sensor (PS) is designed to enable early PD detection, forming the final identifying sensor (IDS) basis. The IDS follows a design hierarchy, incorporating a noise-cancelling sensor (NCS) with a novel notch element called a complementary intermingled resonator (CICR) to reduce ambient noise. A novel notch element concentration (NEC) mechanism is introduced to enable self-identification through multi-resonating bits. The IDS prototype reduces sensor size by over 35.35% and improves the average realized gain by more than 48.93% compared to existing UHF antenna sensors. It achieves high sensitivity at 271.10 dBi/m² and a Figure of Merit of 1.809 dB, higher than other antenna sensors. Operating within 0.78–1.38 GHz, the IDS targets the most PD-affected frequency range. Without additional filters, it reduces the in-band noise of GSM-900 during PD detection, lowering the noise floor to 2.5 mV. The IDS provides multi- resonating 6-bit identification codes with 1-bit noise reduction, outperforming RFID tags. Experimental results validate the IDS's standalone operation, demonstrating superior performance in early PD signal detection, ambient noise reduction, and PD event identification in open substations
Pitch realisation and creaky phonation of Malaysian Mandarin tones / Yong Zhien Bao
No full textMandarin has become a global language with many different varieties around the world, but the phonology of many Mandarin varieties such as Malaysian Mandarin remains understudied. This study seeks to examine pitch realisation and creaky phonation of Malaysian Mandarin citation tones and non-final tones produced by young Chinese speakers from Kuala Lumpur or Selangor. A total of 10 participants (5 male, 5 female) ranging from 19 to 30 years old were recruited. Elicitation was done through a picture-guessing game to obtain a more natural pronunciation. Pitch data was processed using Praat while creaky phonation was identified auditorily and acoustically. The results show that Malaysian Mandarin tones are unique in certain aspects. In terms of pitch realisation, unlike other varieties where Tone 1 and Tone 4 are both high tones, Malaysian Mandarin citation Tone 1 is a mid falling-level tone dividing the tonal space in half. The high-falling citation Tone 4 occupies the high level while citation Tone 2 and 3 resides at the lower halve of the tonal space. The mid-dipping citation Tone 2 and low-falling citation Tone 3 in Malaysian Mandarin are similar to Singapore and Taiwanese Mandarin but the former dips much lower. Non-final tones are similar to citation tones in pitch realisation except the initial F0 of Tone 1 and 4 are higher possibly due to anticipatory dissimilation. Tone 3 sandhi occurs in most cases of T3T3, resulting non-final tone resembles Tone 2 in pitch height and contour. Phonation-wise, citation Tone 3 and Tone 4 have similar likelihood of creakiness unlike Beijing Mandarin where Tone 3 is creakier. Tone 2 in both citation and non-final form is sometimes characterised by medial vowel laryngealisation which accentuates its dipping contour. Citation tones are more susceptible to creakiness than non-final tones likely due to the effects of prosodic boundary. Overall, this study contributes to research on the phonological interrelationship of pitch and phonation
Counter memorial practices in contemporary Singaporean and Malaysian Historiographical Art / Adam Jay Robert
No full textThis dissertation argues that contemporary Singaporean and Malaysian
historiographical artworks, although engaging with the recovery or forgotten or
silenced histories in the official state canon, practise counter-memorial methods that
do not create clear binaries (hegemonic/marginalised, state/oppressed, etc.). Instead,
they connect and maintain multiple fragments of histories, subjects and narratives
within a complex network. This dissertation therefore applies Veronica Tello’s
counter-memorial concept and method to examine the complex network of
connections created by historiographical artworks like Ho Tzu Nyen’s One or Several
Tigers (2017), Erika Tan’s The Forgotten Weaver (2017-2019), Wong Hoy Cheong’s
Doghole (2010) and Mark Teh’s Baling (2015-2018).
By examining artistic historiography from a larger field of engagement within
contemporary society, this dissertation argues that these artworks act as active tools
that map out interlocking connections between multiple subjects, histories and spaces
to create new possibilities in reimagining identity and nationhood within the global
contemporary world. The thesis hopes to emphasise the significance of historical
artworks as a platform that proposes alternative narratives of history that are more
plural and inclusive
Sound quality classification of wood used for Sarawak traditional musical instrument- Sape / Wong Tee Hao
No full textSape, a traditional musical instrument in Malaysia, is meticulously handcrafted through a complex process. Each Sape, crafted by various makers, differs in size, materials, and design, leading to variations in their quality. Despite individual methods employed by Sape makers to assess quality during production, a standardized guideline for quality inspection remains absent. This research aims to delineate the primary factors influencing Sape quality, employing both qualitative and quantitative methodologies. Initial stages involved gathering insights from seasoned Sape makers and players through questionnaires and focus group discussions, revealing material as the foremost quality determinant in the Sape. Subsequently, the focus shifted to investigating common woods used in Sape construction, specifically Adau, Tapang, and Merbau, representing light, medium, and heavy hardwood categories, respectively. Rectangular wood samples simulating Sape soundboards were created, and sound data was recorded through flexural vibration tests. Expert evaluations of the sound quality were conducted via listening tests. Utilizing MATLAB's MIRToolbox, 18 acoustic properties were extracted from the wood samples. Statistical analyses were employed to identify the most reliable quality ratings. To address dataset imbalances, Synthetic Minority Oversampling Technique was used, enhancing dataset quality before training 40 machine learning classification algorithms. Among these, the Gaussian-kernel Support Vector Machine stood out, achieving remarkable performance with 88.18% validation and 93.37% test accuracies. This model was employed to build a MATLAB-based Sape sound quality classifier. Utilizing the Shapley Additive Explanations interpretation method, the analysis emphasized the importance of selected features in predicting wood acoustic quality, highlighting "Spectral Roll-off 85%" as the most crucial predictor of sound quality. Finally, a user-friendly Graphical User Interface was developed to aid Sape makers in assessing wood quality objectively, enhancing the process of selecting high-quality Sape instruments