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Perkembangan sosioekonomi masyarakat India di Selangor, 1884-1941 / Jaya Gannesan Sela Sundram
No full textKajian ini membincangkan perkembangan sosioekonomi masyarakat India di Selangor dengan memberikan penekanan terhadap aspek ekonomi, pendidikan dan kesihatan antara tempoh 1884 hingga 1941. Kehadiran orang India ke Selangor mempunyai kaitan dengan pengenalan ekonomi komersial terutamanya tanaman kopi dan getah. Pembukaan kawasan ladang getah yang dilakukan secara besar-besaran pada awal abad ke-20 telah membawa kepada peningkatan jumlah orang India di Selangor. Kajian ini mempunyai beberapa persoalan. Antaranya ialah sejauh mana penglibatan masyarakat India dalam pembangunan sosioekonomi di Selangor? Persoalan lain ialah apakah keadaan kesihatan dalam kalangan masyarakat India di Selangor? Antara objektif kajian adalah untuk membincangkan penglibatan masyarakat India dalam Pembangunan sosioekonomi di Selangor terutamanya perkembangan pendidikan dan kesihatan dalam kalangan masyarakat India di Selangor. Kajian ini menggunakan pendekatan analisis kualitatif dengan berdasarkan data dan maklumat yang diperoleh daripada kajian arkib dan perpustakaan. Sumber-sumber pertama seperti Fail Setiausaha Kerajaan Negeri Selangor, Fail Pejabat Tanah Jajahan (CO 273 dan CO 717), Laporan Tahunan Selangor mengikut jabatan serta dokumen rasmi kerajaan lain telah dirujuk dalam kajian ini. Mengikut data dan maklumat yang diperoleh, kajian ini membuktikan penglibatan orang India dalam pelbagai aspek sama ada ekonomi mahupun sosial. Kajian ini sangat penting dalam menonjolkan kehidupan masyarakat India di Selangor dalam tempoh kajian. Selain itu, kajian ini penting kerana mampu memperjelaskan aspek pekerjaan, pendidikan dan kesihatan orang India di Selangor secara terperinci. Antara hasil dapatan kajian ini ialah wujudnya kepelbagaian dalam melihat aktiviti ekonomi orang India di Selangor. Meskipun buruh ladang merupakan sektor utama, namun didapati, terdapat sektor-sektor lain yang turut melibatkan orang India. Ini bermakna kajian ini menolak pandangan sebelum ini yang meletakkan seolah-olah 100 peratus orang India di Selangor hanyalah sebagai buruh ladang semata. Dapatan lain pula menunjukkan kesukaran-kesukaran yang terpaksa dihadapi oleh kalangan orang India terutama dalam menghadapi ancaman pelbagai jenis penyakit berjangkit. Malahan tekanan mental yang besar juga menyebabkan ada di antara mereka yang mengambil keputusan membunuh diri.
Kata Kunci: Sejarah Selangor; Masyarakat India; Ekonomi; Pendidikan; Kesihata
Comparing 3D printed twin block appliance designs for class ii division 1 malocclusion on optimised fit, retention and compressive strength / Roselyn Mathew
No full textIntroduction: The Twin Block appliance (TBA) is a removable functional appliance used for skeletal Class II malocclusion in growing individuals. Its design has evolved with various modifications to improve patient acceptance and compliance. The advent of 3D printing technology in dentistry brings a shift towards to digital workflow. Currently, 3D printing TBA is new in the market with limited literature on effective designs. Thus, there is a need to explore 3D-printed Twin Block (3D-TBA) designs to accommodate the materials used in 3D workflow to ensure adequate fit and retention of the appliance. Objective: This study aims to propose key features for 3D-TBA designs based on best fit, retention, and compressive strength. Methods: This laboratory-based study assessed three designs for each dental arch, varying the incisal and occlusal coverage on two Class II Division 1 models (Model 1 and Model 2). The upper designs were extended palatally either to the cingulum plateau (U-D1), up to the gingival margin (U-D2) or further to cover a third incisal crowns (U-D3). The lower designs were extended either to the first permanent molar without any incisal coverage (L-D1), up to the second premolar with half incisal coverage (L-D2) or up to the second premolar with full incisal coverage (L-D3). Three ISO178 standard blocks of TR07 resin (Graphy, South Korea) and polymethyl-methacrylate (PMMA) were compared for flexural modulus and experts were consulted before design refinement. Each appliance was evaluated for fit and retention on their respective 3D-printed models, and compressive strength was measured using a universal testing machine (AG-X Series, Shimadzu, Japan). Results: PMMA exhibited a higher flexural modulus (2688.76 MPa; SD 1276.09) compared to Graphy TR-07 (41.70 MPA; SD 0.315). The fit of the 3D-TBA (U-D1 Model 1 and U-D3 Model 2) was inferior to the conventional TBA with significant differences in fit score (p = 0.010 and 0.001), respectively. No significant differences were found between the lower appliance of the 3D-TBA designs of study models 1 and 2 (p > 0.05). For the upper TBA, significant differences in retention scores were observed for U-D1 and U-D3 on Model 1 and all designs on Model 2 (p = 0.001). For the lower 3D-TBA, the retention scores in Model 1 did not exhibit statistical significance across all designs. However, in lower study Model 2, significant differences were found in L-D2 and L-D3 (p = 0.001 and 0.010, respectively). The Chi-square test revealed a statistically significant difference in compressive strengths (p < 0.001) for all designs in the upper and lower models, with the 3D-TBA having a greater compressive strength than the conventional TBA, regardless of their design. Conclusion: Design 2 on the upper arch (U-D2) and design 1 on the lower arch (L-D1) offered the best fit and retention. However, it is imperative to consider specific features of malocclusion before employing these designs. The 3D-TBA made from Graphy TR-07 resin exhibits superior compressive strength compared to the conventional PMMA-based TBA, enabling it to resist higher applied compressive forces before failure
Development of tea-waste impregnated with iron oxide nanoparticles for magnetic micro-solid phase extraction of non-steroidal anti-inflammatory drugs in water samples / Yagulan Muniandy
No full textThe presence of pharmaceutical compounds as well as their degradation products in the aquatic environment is of great concern. Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the major pharmaceutical products that may be present in environmental water samples. In this study, a simple method based on the magnetic micro-solid phase extraction (MMSPE) technique was developed for the determination of NSAIDs in water samples prior to the UV-Vis spectrophotometer analysis. A new tea waste-impregnated with magnetic nanoparticles (MNP-TW) was successfully synthesized by the chemical co-precipitation technique. The characterization studies were carried out by Brunauer–Emmett–Teller (BET), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX), vibrating-sample magnetometry (VSM) and thermogravimetric analysis (TGA). MNP-TW was utilized as an MSPE sorbent for the extraction and determination of ibuprofen (IBP), diclofenac (DCF) and naproxen (NAP) separately. Experimental variables affecting the extraction efficiency of NSAIDs such as sample pH, sorbent dosage, extraction time, ionic strength, the volume of sample, type of desorption solvent, desorption time and desorption volume were studied and optimized in detail. Under the optimal conditions, the calibration curves were linear for the concentration ranging between 30 and 700 μg L-1 with the coefficient of determination (R2) between 0.9964 to 0.9981. The limit of detection (LOD) was in the range from 10.30 to 11.70 μg L-1, the limit of quantification (LOQ) was in the range from 31.20 to 35.40 μg L-1 and the method exhibited excellent precision (RSD ≤ 4.83%), repeatability (RSD ≤ 4.66%) and relative recovery (86% - 115%). The green assessment was conducted, and the Analytical eco scale score obtained from this method would be 77 which shows this method is neatly a green analysis. The method presented the advantages of the study which show that the integration of MNP-TW and MMSPE with UV-Vis spectrophotometer provides a simple, sensitive, and rapid method for the extraction and determination of NSAIDs in water samples. The usage of tea waste in the extraction process presents many advantages, as it is biodegradable and versatile, and it contributes to an intelligent and sustainable economic strategy projected toward a circular economy approach
Fabrication of non-enzymatic copper oxide-based electrochemical sensor for glucose detection / Adam Tan Tiek Aun
No full textIn the present study, three non-enzymatic copper-based sensors namely Cu oxide, Cu Ag oxide, and lactate templated Cu oxide were developed for the detection of glucose. The Cu oxide was prepared by the electrochemical anodization of a clean copper foil. The Cu Ag oxide and lactate templated Cu oxide were prepared by the electrodeposition of Cu Ag or lactate templated Cu on to a carbon paste electrode, followed by electrochemical oxidation in 0.1 M NaOH. The parameters of the synthesis process of all three glucose sensors were screened using 2k factorial design of experiments, then optimized using a central composite design of experiments. Chronoamperometry was used to measure the current density at the glucose sensor as a function of glucose concentration in the electrolyte and the sensitivity to glucose is used as a measure of the performance. It was found that lactate templated Cu oxide prepared at optimum conditions has the highest average sensitivity of 522.77 μA cm-2 mM-1. On the other hand, the Cu Ag oxide prepared at optimum conditions has the lowest average sensitivity of 191.33 μA cm-2 mM-1. The Cu oxide prepared at optimum conditions has a good sensitivity of 422.91 μA cm-2 mM-1. The Cu oxide, Cu Ag oxide, and lactate templated Cu oxide were then characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The CV study shows that the oxidation of glucose on all three sensors is limited by kinetics. The EIS study shows that increasing the concentration of glucose in the electrolyte lowers the charge transfer resistance between the glucose molecule and the Cu oxide, Cu Ag oxide, and lactate templated Cu oxide. The FESEM images show the glucose sensors prepared at optimized parameters have better coverage of the backing current collector electrode with unique nanostructures that increase the surface area at which the glucose can be oxidized. EDX analysis show that Cu oxide, Cu Ag oxide, and lactate Cu oxide prepared at optimum parameters all have a notably higher ratio of O to Cu. XRD analysis shows the crystal planes of the species of Cu, Ag, and C. The Cu oxide, Cu Ag oxide, and lactate templated Cu oxide have also used to measure the sugar content of several soft drinks. All three tend to slightly overestimate the sugar content likely due to the soft drinks containing other oxidizable substances such as colouring. The stability of the Cu oxide, Cu Ag oxide, and lactate templated Cu oxide have also been checked by using to measure glucose once every day for ten days. All the sensors have a general downward trend and the average drop in current density after 10 days for Cu oxide electrode is 9.96 %, Cu Ag oxide is 27.10 %, and lactate templated Cu oxide is 31.36 %. The Cu oxide, Cu Ag oxide, and lactate templated Cu oxide was also subjected to a constant potential of 0.5 V for 12 hours in solution of 6.04 mM glucose in 0.1 M NaOH. This resulted in the current density steadily dropping and the average drop in current density after 12 hours for Cu oxide is 30 %, Cu Ag oxide is 40.28%, and lactate templated Cu oxide is 44.91 %
In silico studies of antiviral ligands derived from Ganoderma lucidum against dengue type 2 and zika viral proteins / Lim Wui Zhuan
No full textDengue and Zika infections are mainly transmitted through the bites of Aedes aegypti
mosquitoes. Without potential cures or clinically approved antivirals for both infections,
the Flaviviruses that cause these infectious diseases will continue to pose health risks,
especially to the nations of Asia, Africa and South America. For dengue, it is a
challenging process to find suitable treatment that can eradicate the infections
successfully, as there are multiple serotypes circulating in tropical and subtropical regions
around the world. In this study, the transcriptional changes caused by virus-host
interactions were presented through the identification of differentially expressed genes
(DEGs) and pathway analysis, to gain understanding of the pathogenicity of dengue virus
(DENV) and Zika virus (ZIKV). Based on the enriched pathways in DAVID, KEGG and
Reactome, the biological processes of DEGs in dengue and Zika patients were
concentrated in cell division and DNA replication. DEGs such as MCM2, MCM4, MCM6
and PCNA can serve as potential biomarkers of dengue infections. Surprisingly, a few
up-regulated DEGs in Zika datasets, namely OAS1, OAS2, OAS3 and DDX58, were
associated with other diseases such as measles, Epstein-Barr virus infection, and hepatitis
C. These antiviral interferon-stimulated genes suggested that ZIKA-infected patients
responded to Zika infection primarily by suppressing viral RNA replication. Since cell
cycle and genome replication were highlighted in the pathway analysis, the natural
compounds derived from the antler-shaped fruiting body of Ganoderma lucidum were
screened against the protease and envelope proteins of DENV and ZIKV, to find potential
antivirals that can disrupt the above pathways. Docking results showed that hesperetin
and naringenin were the best ligand candidates to bind at the catalytic site of NS2B-NS3 protease and the hydrophobic pocket of envelope protein, respectively. Their stable
docking conformations and favourable binding free energy showed potential to prevent
the viral replication and fusion processes. Naringenin was also able to target the same
hydrophobic pocket of Zika virus envelope protein, however its binding free energy after
100 ns of simulation was less favourable than the reference ligand. A longer simulation
time might be required to extend the convergence of the trajectories. This study can serve
as a reference for molecular biological experiments in future to confirm the function of
DEGs associated with dengue and Zika infections, as well as the roles of hesperetin and
naringenin in combating the diseases
Tunable and dual-wavelength passive Q-switched pulse generation with fiber-optic interferometers / Siti Fazilah Shaik Mohd Noor
No full textTunable and multi-wavelength Q-switched Erbium doped fiber laser (EDFLs) operating
in 1.5-micron region have gained tremendous interests in recent years due to their
important applications in many areas including material processing, optical
communication and biomedical. These lasers are normally realized by using an
interference filter in conjunction with saturable absorber (SA). The filter functions to
enable tunability and multi-wavelength operation while SA functions to initiate pulses by
passive means. Up to date, plenty of works have been reported on developing new SA
devices which have a good optical characteristic to produce high performance pulse lasers
and on finding new applications for various interference filters. This work was aimed to
explore the use of two types of fiber-optic interferometer: sagnac loop mirror (SLM) and
single-mode fiber (SMF) – multimode fiber (MMF) – single-mode fiber (SMF) or SMS
structure for demonstrating a tunable or dual-wavelength Q-switched EDFL using
graphene oxide (GO) and aluminum oxide (Al2O3) thin film as SA. Both GO and Al2O3,
thin films have been successfully fabricated by embedding in PVA thin film and
characterized with modulation depths of 24.1% and 3.5 %, respectively. Wavelength
tunable Q-switched EDFLs have been successfully demonstrated using the SLM in
figure-of-eight laser cavity as a tunable filter and GO or Al2O3, thin film as SA. For
instance, a stable passively Q-switched EDFL tunable by Sagnac interferometer operation
was realized with a GO. By tuning the temperature of SLM from 30oC to 70 oC, the central
wavelength of the Q-switched EDFL could be tuned continuously from 1566.3 nm to
1559.3 nm. At 1566.3 nm operation, the maximum repetition rate and minimum pulse
width was recorded at 41.5 kHz and 7.3 μs, respectively. A dual-wavelength Q-switched pulse generation has been successfully demonstrated in an EDFL cavity using GO SA
and SMS filter to operate at wavelengths of 1549.6 nm and 1558.6 nm. The maximum
pulse repetition rate and the shortest pulse width are obtained at 65.27 kHz and 2.9 μs,
respectively. At 225.1 mW pump power, the maximum output power and pulse energy
were obtained at 0.99 mW and 15.17 nJ, respectively. This study revealed the promising
potential of GO and Al2O3 based SA to be used in pulse generation. Both SLM and SMS
could also be used as filters for tunable or multi-wavelength laser generation. The
fabrication of the SAs and filters are simple, hence reducing the cost of the laser itself.
Simple and low-cost fiber lasers are required in various applications including medical
diagnostics and environmental sensing
Effect of particle size on β-glucan content, antioxidant and anti-inflammatory properties of Pleurotus floridanus / Wong Wei Yan
No full textCellular damage caused by high concentrations of free radicals can lead to chronic health problems. Pleurotus floridanus is an edible white oyster mushroom that contains high β-glucan with antioxidant and anti-inflammatory potential. In this study, β-glucan, total phenolic content, antioxidant and anti-inflammatory potential of hot water extract with different particles sizes which were <75 μm, 75-154 μm, 154-300 μm and 300-600 μm of the whole (AW) and sliced (AS) fruiting body of P. floridanus were analysed. All particle sizes of AS of P. floridanus extract have higher β-glucan content compared to AW. Results showed that β-glucan content increased as the particle size increased but no significant difference was observed. For the total phenolic content, particle size <75 μm of AW and AS of P. floridanus has the highest phenolic content. Antioxidant potential of P. floridanus extract was determined using DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power (FRAP) assays. Each particle size of AW and AS of P. floridanus displayed potent scavenging activities toward DPPH and ABTS radicals in a concentration dependent manner. Both DPPH and ABTS assays showed that smaller particle size has higher scavenging activity compared to larger particle sizes. For FRAP assay, although there were fluctuations in the result but all the particle size of AW and AS of P. floridanus extract possess the ability to reduce Fe3+ to Fe2+. Four samples (AW2, AW3, AS1 and AS2) with the highest antioxidant activity were selected for anti-inflammatory assay. The ability of AW2, AW3, AS1 and AS2 to inhibit NO production, NO radical scavenging activity, TNF-α and IL-10 production in LPS-stimulated RAW264.7 cells was evaluated. All four samples reduced NO and TNF-α but did not enhance IL-10 expression in LPS-stimulated RAW264.7 cells. It was also observed that the particle size <75-300 μm lacked anti-inflammatory activity. Therefore, it is suggested that the particle size <300 μm of P. floridanus hot water extract could be a good source of antioxidant and anti-inflammatory compounds to counteract the free radicals. These results demonstrate how the sieving process can boost the bioactive compounds found in P. floridanus powder. This understanding holds significance for the food and pharmaceutical sectors, as it enables the creation of products with specific particle size fractions, maximizing both functional and nutritional benefits
Innovative polyhydroxyalkanoates/perovskite/ surfactant composite film as an eco-friendly proton exchange membrane for water filtration / Nur Amirah Mohd Faizal
No full textThe focus of this project is to analyse the potential of Polyhydroxyalkanoate-Perovskite-Tween 80 (PHA-PV-T80) composites as a selective proton exchange membrane (SPEM) for water filtration. PHA-PV-T80 composites were prepared by initially synthesizing PHA from Pseudomonas putida BET001 via a batch fermentation process; then PHA was blended with distinct concentrations of perovskite and Tween 80 ranging from 0.01 – 0.0025 % (w/v) and 1.5 – 4.5 % (w/v), respectively. Ultrasonication was used to enhance the mixing process. The sonicated solution was cast onto a petri dish to be air-dried until it reached a constant weight. Mcl-PHA monomer constituents were identified using GCMS and 1H-NMR. The functional group changes, thermal properties, and surface morphology of PHA-PV-T80 composites were characterized using FTIR, TGA, and FESEM, respectively. Proton transport analysis was carried out to understand the efficiency of its transfer across the membrane surface by studying the flux (mol.min-1.cm-2) of each membrane. PHA-PV0.01%-T80 4.5% showed the highest flux among the investigated composites. Analysis of the apparent rate constant, k’, provided insights on the enhanced proton flux process in a specific membrane composite; compositing of surfactant with a larger hydrophilic head group in the PHA matrix, as opposed to increasing the perovskite amount, plays a greater role in the partitioning of water molecules on the membrane surface, hence facilitating proton flux
Analisis terhadap resolusi syariah dalam kewangan Islam oleh majlis penasihat syariah Bank Negara Malaysia berkaitan kad kredit / Aisyah Nasyeethah Azhari
No full textKad kredit ialah sekeping kad mewakili akaun pembiayaan pengguna dan digunakan sebagai metod pembayaran barang dan perkhidmatan serta membuat bayaran kemudian di bawah kontrak perjanjian. Di Malaysia, pada tahun 2023, terdapat lebih kurang 10.1 juta pengguna kad kredit. Oleh kerana kad kredit konvensional mengandungi ribā, institusi-insitusi kewangan Islam telah menghasilkan kad kredit Islam untuk menjadi alternatif kepada masyarakat Islam mengikut panduan dan kayu ukur dari Majlis Penasihat Syariah Bank Negara Malaysia (MPS BNM). Hal ini menimbulkan persoalan tentang bagaimana MPS membuat ijtihad dan keputusan untuk setiap isu yang berkaitan dengan kad kredit. Untuk menyelesaikan masalah ini, konsep berijtihad dalam kontrak syariah yang menghasilkan kad kredit perlu dikenalpasti. Kontrak-kontrak syariah yang
menimbulkan isu dan kontroversi di dalam Resolusi Syariah dalam Kewangan Islam MPS BNM juga perlu dibincangkan. Antara isu-isu yang terdapat di dalam resolusi ini adalah penggunaan bay’ al-‘īnah dan al-wadī ‘ah, kontrak ujrah, penggunaan takaful di dalam kad kredit, isu pemberian tunai semula (cashback) dan kontrak al-wakālah dan al-kafālāh dalam kad kredit. Proses dan langkah-langkah MPS membuat ijtihad dan keputusan syariah juga perlu dianalisis dengan cara membuat kajian kepustakaan dan lapangan, khususnya temu ramah ahli MPS. Antara kaedah yang yang digunakan oleh ahli MPS adalah ijtihad kolektif dan maqāṣid al-sharī‘ah dalam menetapkan keputusan. Hal ini menunjukkan bahawa kedua-duanya merupakan komponen penting dalam
proses terhasilnya kad kredit Islam
Chemical constituents and biological activities of Boesenbergia stenophylla, Polyalthia bullata and Prismatomeris glabra / Phoebe Sussana Primus
No full textThe chemical constituents from the rhizome of Boesenbergia stenophylla and the root of Polyalthia bullata and Prismatomeris glabra have been investigated. The extraction of the compounds was carried out using n-hexane, chloroform and ethanol followed by the isolation using chromatographic techniques such as column chromatography (CC), centrifugal thin layer chromatography (CTLC) and preparative thin layer chromatography (PTLC). Structural elucidations of the compounds were established through spectroscopic methods; 1D-NMR (1H,13C, DEPT-135), 2D-NMR (COSY, HSQC, HMBC), UV, IR and MS with comparison from the published data. 25 chemical compounds were successfully isolated from these three species. The B. stenophylla rhizome extract yielded three new compounds, stenophyllol A 458, stenophyllol B 459 and stenophyllol C 460 and five known compounds namely, (E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one 461, 5R-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenylheptan-3-one 462, 1,7-diphenylhept-4-en-3-one 463, 3,5,7-trihydroxyflavone 464, and oleic acid 465. Extraction and isolation on the root of Polyalthia bullata resulted in the isolation of eight chemical compounds, that is one new oxoaporhine alkaloid 5-methyl-liridine 466, six known alkaloids that is liriodenine 223, 11-methoxy-liriodenine 467, lysicamine 222, onychine 271, 5-hydroxy-6-methoxy-onychine 274, 8-methoxy-eupolauridine 237, and a methyl stearate 468. The investigation of the crude extract on the root of Prismatomeris glabra has resulted in the isolation of nine chemical compounds, which two of the compounds are new compounds with bisanthraquinone skeleton namely glabraquinone A 469 and glabraquinone B 470, six known anthraquinones, 1-hydroxy-2-methoxy-6-methyl-anthraquinone 471, 1,2-dimethoxy-7-methyl-anthraquinone 472, lucidin 379, nordamnacanthal 397, damnacanthal 398, 2-carboxaldehyde-3-hydroxy-anthraquinone396, and catechol diethyl ether 473. Compounds 459, 461, 463, 223, 469, 472, and 473were subjected to in vitro neuroblastoma cell viability assay using N2a cell line. Compounds 459, 461, and 223 displayed excellent in vitro anti-neuroblastoma activitywhich reduces the cell viability to 30%, 20%, 22%, respectively