Displaying publications 301 - 320 of 409 in total

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  1. Fulltext Dual Properties of Polyvinyl Alcohol-Based Magnetorheological Plastomer with Different Ratio of DMSO/Water
    Hapipi NM, Mazlan SA, Ubaidillah U, Abdul Aziz SA, Choi SB, Nordin NA, et al.
    Sensors (Basel), 2021 Nov 22;21(22).
    PMID: 34833835 DOI: 10.3390/s21227758
    Polyvinyl alcohol (PVA)-based magnetorheological plastomer (MRP) possesses excellent magnetically dependent mechanical properties such as the magnetorheological effect (MR effect) when exposed to an external magnetic field. PVA-based MRP also shows a shear stiffening (ST) effect, which is very beneficial in fabricating pressure sensor. Thus, it can automatically respond to external stimuli such as shear force without the magnetic field. The dual properties of PVA-based MRP mainly on the ST and MR effect are rarely reported. Therefore, this work empirically investigates the dual properties of this smart material under the influence of different solvent compositions (20:80, 40:60, 60:40, and 80:20) by varying the ratios of binary solvent mixture (dimethyl sulfoxide (DMSO) to water). Upon applying a shear stress with excitation frequencies from 0.01 to 10 Hz, the storage modulus (G') for PVA-based MRP with DMSO to water ratio of 20:40 increases from 6.62 × 10-5 to 0.035 MPa. This result demonstrates an excellent ST effect with the relative shear stiffening effect (RSTE) up to 52,827%. In addition, both the ST and MR effect show a downward trend with increasing DMSO content to water. Notably, the physical state of hydrogel MRP could be changed with different solvent ratios either in the liquid-like or solid-like state. On the other hand, a transient stepwise experiment showed that the solvent's composition had a positive effect on the arrangement of CIPs within the matrix as a function of the external magnetic field. Therefore, the solvent ratio (DMSO/water) can influence both ST and MR effects of hydrogel MRP, which need to be emphasized in the fabrication of hydrogel MRP for appropriate applications primarily with soft sensors and actuators for dynamic motion control.
  2. Fulltext Cell viability and electrical response of breast cancer cell treated in aqueous graphene oxide solution deposition on interdigitated electrode
    Ramli MM, Rosman AS, Mazlan NS, Ahmad MF, Halin DSC, Mohamed R, et al.
    Sci Rep, 2021 10 19;11(1):20702.
    PMID: 34667216 DOI: 10.1038/s41598-021-00171-3
    Breast cancer is one of the most reported cancers that can lead to death. Despite the advances in diagnosis and treatment procedures, the possibility of cancer recurrences is still high in many cases. With that in consideration, researchers from all over the world are showing interest in the unique features of Graphene oxide (GO), such as its excellent and versatile physicochemical properties, to explore further its potential and benefits towards breast cancer cell treatment. In this study, the cell viability and electrical response of GO, in terms of resistivity and impedance towards the breast cancer cells (MCF7) and normal breast cells (MCF10a), were investigated by varying the pH and concentration of GO. Firstly, the numbers of MCF7 and MCF10a were measured after being treated with GO for 24 and 48 h. Next, the electrical responses of these cells were evaluated by using interdigitated gold electrodes (IDEs) that are connected to an LCR meter. Based on the results obtained, as the pH of GO increased from pH 5 to pH 7, the number of viable MCF7 cells decreased while the number of viable MCF10a slightly increased after the incubation period of 48 h. Similarly, the MCF7 also experienced higher cytotoxicity effects when treated with GO concentrations of more than 25 µg/mL. The findings from the electrical characterization of the cells observed that the number of viable cells has corresponded to the impedance of the cells. The electrical impedance of MCF7 decreased as the number of highly insulating viable cell membranes decreased. But in contrast, the electrical impedance of MCF10a increased as the number of highly insulating viable cell membranes increased. Hence, it can be deduced that the GO with higher pH and concentration influence the MCF7 cancer cell line and MCF10a normal breast cell.
  3. Effect of modified Otago exercises on postural balance, fear of falling, and fall risk in older fallers with knee osteoarthritis and impaired gait and balance: A secondary analysis
    Mat S, Ng CT, Tan PJ, Ramli N, Fadzli F, Rozalli FI, et al.
    PM R, 2018 03;10(3):254-262.
    PMID: 28827207 DOI: 10.1016/j.pmrj.2017.08.405
    BACKGROUND: Osteoarthritis (OA) is considered an established risk factor for falls. Published studies evaluating secondary falls prevention strategies among individuals with OA are limited.
    OBJECTIVE: To evaluate the effect of a personalized home-based exercise program to improve postural balance, fear of falling, and falls risk in older fallers with knee OA and gait and balance problems.
    DESIGN: Randomized controlled trial.
    SETTING: University of Malaya Medical Centre.
    PARTICIPANTS: Fallers who had both radiological OA and a Timed Up and Go (TUG) score of over 13.5 seconds.
    MAIN OUTCOME MEASURE: Postural sway (composite sway) was quantified with the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB) under 4 different sensory conditions: eyes open on firm surface, eyes closed on firm surface, eyes open on unstable foam surface, and eyes closed on unstable foam surface. Participants were asked to stand upright and to attempt to hold their position for 10 seconds for each test condition. The average reading for all conditions were calculated.
    METHODS: Participants randomized to the intervention arm received a home-based modified Otago Exercise Program (OEP) as part of a multifactorial intervention, whereas control participants received general health advice and conventional treatment. This was a secondary subgroup analysis from an original randomized controlled trial, the Malaysian Falls Assessment and Intervention Trial (MyFAIT) (trial registration number: ISRCTN11674947). Posturography using a long force plate balance platform (Balancemaster, NeuroCom, USA), the Knee injury and Osteoarthritis Outcome Score (KOOS) and the short-form Falls Efficacy Scale-International (short FES-I) were assessed at baseline and 6 months.
    RESULTS: Results of 41 fallers with radiological evidence of OA and impaired TUG (intervention, 17; control, 24) were available for the final analysis. Between-group analysis revealed significant improvements in the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB), Limits of Stability (LOS), and short FES-I scores by the intervention group compared to the control group at 6 months. No significant difference in time to first fall or in fall-free survival between the intervention and control groups was found.

    CONCLUSION: Home-based balance and strength exercises benefited older fallers with OA and gait and balance disorders by improving postural control, with no observable trend in reduction of fall recurrence. Our findings will now inform a future, adequately powered, randomized controlled study using fall events as definitive outcomes.

    LEVEL OF EVIDENCE: I.
  4. ISSR marker-assisted genetic diversity analysis of Dioscorea hispida and selection of the best variety for sustainable production
    Nudin NFH, Ali AM, Ngah N, Mazlan NZ, Mat N, Ghani MNA, et al.
    C. R. Biol., 2017 Aug;340(8):359-366.
    PMID: 28888550 DOI: 10.1016/j.crvi.2017.08.003
    Plant breeding is a way of selection of a particular individual for the production of the progeny by separating or combining desired characteristics. The objective of this study was to justify different characteristics of Dioscorea hispida (Ubi gadong) varieties using molecular techniques to select the best variety for sustainable production at the farmer's level. A total of 160 germplasms of Ubi gadong were collected from different locations at the Terengganu and Kelantan states of Malaysia. Forty eight (48) out of 160 germplasms were selected as "primary" selection based on yield and other qualitative characters. Selected collections were then grown and maintained for ISSR marker-assisted genetic diversity analysis. Overall plant growth and yield of tubers were also determined. A total of 12 ISSR markers were tested to justify the characteristics of Ubi gadong varieties among which three markers showed polymorphic bands and on average 57.3% polymorphism were observed representing the highest variation among germplasms. The ISSR marker based on UPGMA cluster analysis grouped all 48 D. hispida into 10 vital groups that proved a vast genetic variation among germplasm collections. Therefore, hybridization should be made between two distant populations. The D. hispida is already proved as the highest starch content tuber crops and very rich in vitamins with both micro and macro minerals. Considering all these criteria and results from marker-assisted diversity analysis, accessions that are far apart based on their genetic coefficient (like DH27 and DH71; DH30 and DH70; DH43 and DH62; DH45 and DH61; DH77 and DH61; DH78 and DH57) could be selected as parents for further breeding programs. This will bring about greater diversity, which will lead to high productive index in terms of increase in yield and overall quality and for the ultimate target of sustainable Ubi gadong production.
  5. Fulltext Effects of Aging and Tocotrienol-Rich Fraction Supplementation on Brain Arginine Metabolism in Rats
    Mazlan M, Hamezah HS, Taridi NM, Jing Y, Liu P, Zhang H, et al.
    Oxid Med Cell Longev, 2017;2017:6019796.
    PMID: 29348790 DOI: 10.1155/2017/6019796
    Accumulating evidence suggests that altered arginine metabolism is involved in the aging and neurodegenerative processes. This study sought to determine the effects of age and vitamin E supplementation in the form of tocotrienol-rich fraction (TRF) on brain arginine metabolism. Male Wistar rats at ages of 3 and 21 months were supplemented with TRF orally for 3 months prior to the dissection of tissue from five brain regions. The tissue concentrations of L-arginine and its nine downstream metabolites were quantified using high-performance liquid chromatography and liquid chromatography tandem mass spectrometry. We found age-related alterations in L-arginine metabolites in the chemical- and region-specific manners. Moreover, TRF supplementation reversed age-associated changes in arginine metabolites in the entorhinal cortex and cerebellum. Multiple regression analysis revealed a number of significant neurochemical-behavioral correlations, indicating the beneficial effects of TRF supplementation on memory and motor function.
  6. Fulltext A Logical Framework (MYGERYFS) for Hospital Foodservice to Prevent Malnutrition Among Geriatric Patients in Hospitals, Malaysia: Protocol for a Feasibility Study
    Omar N, Shafiee SI, Nor'hisham SH, Ibrahim Z, Jamaluddin R, Rahamat S, et al.
    JMIR Res Protoc, 2023 Jan 31;12:e42496.
    PMID: 36719732 DOI: 10.2196/42496
    BACKGROUND: Geriatric malnutrition in hospitals is common and can be affected by many things, including poor satisfaction toward hospital foodservice. Hospital foodservice plays an important role in a patient's recovery process by providing adequate nutrients. On top of that, patients' foodservice satisfaction can easily be afflicted by the quality of food served and the overall foodservice experience. Furthermore, malnutrition can occur from poor foodservice quality, especially among geriatric patients.

    OBJECTIVE: This study aims to assess the effectiveness of the Malaysian Geriatric Patients' Hospital Foodservice Protocol (MYGERYFS).

    METHODS: The protocol comprises 3 phases. Phase One is a cross-sectional study that took place at public hospitals with geriatric wards in the Klang Valley. Univariate data from Phase One were analyzed descriptively. Pearson correlation and chi-square were conducted to find factors associated with foodservice satisfaction. Phase Two involves the collaboration of health care professionals in the geriatric field. In Phase Three, a feasibility study will be conducted to determine the feasibility of the MYGERYFS protocol in a hospital among 60 geriatric patients. These patients will be randomized into control and intervention groups, respectively. Intervention care will be done to ensure the safety of the protocol.

    RESULTS: Data collection for Phase One of the study has been completed. A total of 233 geriatric respondents with the mean age of 71.39 (SD 7.99) years were gathered. Approximately 51.5% (n=120) of the respondents were female, while 48.5% (n=113) were male, with a mean BMI of 24.84 (SD 6.05) kg/m2. Their mean energy and protein intakes were 1006.20 kcal (SD 462.03 kcal) and 42.60 (SD 22.20) grams, respectively. Based on the Mini Nutritional Assessment, older patients who scored 12-14 (normal) were 27.9% (n=65), those who scored 8-11 (at risk) were 54.9% (n=128), and those who scored 0-7, which is the lowest (malnutrition), were 17.2% (n=40) of the study population. Hence, most patients were at risk of malnutrition. Although a majority of the patients claimed to have good foodservice satisfaction 26.2% (n=61), they also experienced at least 3 barriers during mealtimes. It was found that dietary intake and mealtime barriers were significantly associated with the respondent's foodservice satisfaction. Data for Phase Two and Phase Three are yet to be collected and analyzed.

    CONCLUSIONS: This study protocol could potentially benefit the hospital foodservice system and aid in improving geriatric nutritional status.

    TRIAL REGISTRATION: ClinicalTrials.gov NCT04858165; https://clinicaltrials.gov/ct2/show/NCT04858165.

    INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/42496.

  7. Fulltext Zinc status in public health: exploring emerging research trends through bibliometric analysis of the historical context from 1978 to 2022
    Mohamad NS, Tan LL, Ali NIM, Mazlan NF, Sage EE, Hassan NI, et al.
    Environ Sci Pollut Res Int, 2023 Mar;30(11):28422-28445.
    PMID: 36680719 DOI: 10.1007/s11356-023-25257-5
    The current study aims to provide a roadmap for future research by analyzing the research structures and trends in scholarly publications related to the status of zinc in public health. Only journal articles published between 1978 and 2022 are included in the refined bibliographical outputs retrieved from the Web of Science (WoS) database. The first section announces findings based on WoS categories, such as discipline heterogeneity, times cited and publications over time, and citation reports. The second section then employs VoSViewer software for bibliometric analysis, which includes a thorough examination of co-authorship among researchers, organizations, and countries and a count of all bibliographic databases among documents. The final section discusses the research's weaknesses and strengths in zinc status, public health, and potential future directions; 7158 authors contributed to 1730 papers (including 339 with publications, more than three times). "Keen, C.L." is a researcher with the most publications and a better understanding of zinc status in public health. Meanwhile, the USA has been the epicenter of research on the status of zinc in public health due to the highest percentage of publications with the most citations and collaboration with the rest of the world, with the top institution being the University of California, Davis. Future research can be organized collaboratively based on hot topics from co-occurrence network mapping and bibliographic couplings to improve zinc status and protect public health.
  8. Fulltext Mycobacterium Tuberculosis and Avium Complex Investigation among Malaysian Free-Ranging Wild Boar and Wild Macaques at Wildlife-Livestock-Human Interface
    Lekko YM, Che-Amat A, Ooi PT, Omar S, Ramanoon SZ, Mazlan M, et al.
    Animals (Basel), 2021 Nov 13;11(11).
    PMID: 34827984 DOI: 10.3390/ani11113252
    Wild animals are considered reservoirs, contributing to the transmission of emerging zoonotic diseases such as tuberculosis (TB). A cross-sectional study was conducted by opportunistic sampling from fresh carcasses of free-ranging wild boar (n = 30), and free-ranging wild macaques (n = 42). Stained smears from these tissues were tested for acid-fast bacilli (AFB) with Ziehl-Neelsen staining. Mycobacterial culture was conducted using Lowenstein-Jensen media and Middlebrook 7H11 agar media. Polymerase chain reaction (PCR) was performed through the detection of the 16S rRNA gene, with multiple sets of primers for the detection of Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium complex (MAC). In wild boars, 30% (9/30; 95% Confidence Interval: 16.7-47.9%) of examined samples showed gross tuberculosis-like lesions (TBLLs). Multiple nodular lesions that were necrotic/miliary with cavitation were found in the submandibular lymph nodes, tonsils, lungs, kidney and liver, while single nodular lesions were found in the mediastinal lymph nodes, spleen and mesenteric lymph nodes. Conventional PCR on the submandibular lymphoid tissues of wild boar (nine samples with TBLLs and three non-TBLL samples) showed that 75% (9/12) were positive for Mycobacterium bovis (95% CI: 46.8-91.1), and 91% (CI: 64.6-98.5) were positive for Mycobacterium avium. For macaques, 33.3% (10/30) were positive for M. avium (95% CI: 19.2-51.2) but negative for MTBC.
  9. Fulltext Temperature Dependent on Mechanical and Rheological Properties of EPDM-Based Magnetorheological Elastomers Using Silica Nanoparticles
    Rashid RZA, Yunus NA, Mazlan SA, Johari N, Aziz SAA, Nordin NA, et al.
    Materials (Basel), 2022 Mar 31;15(7).
    PMID: 35407889 DOI: 10.3390/ma15072556
    Temperature is one of the most influential factors affecting the performance of elastomer matrix in magnetorheological elastomer (MRE). Previous studies have utilized silica as a reinforcing filler in polymer composite and as a coating material in MRE to improve the thermal stability of the base material. However, the usage of silica as an additive in the thermal stability of MRE has not been explored. Thus, in this study, the effect of silica as an additive on the temperature-dependent mechanical and rheological properties of ethylene propylene diene monomer (EPDM)-based MREs was investigated by using 30 wt.% carbonyl iron particles (CIPs) as the main filler, with different contents of silica nanoparticles (0 to 11 wt.%). The microstructure analysis was examined by using field-emission scanning electron microscopy (FESEM), while the thermal characterizations were studied by using a thermogravimetric analyzer and differential scanning calorimetry. The tensile properties were conducted by using Instron Universal Testing Machine in the absence of magnetic field at various temperatures. Meanwhile, the rheological properties were analyzed under oscillatory loadings in the influence of magnetic field, using a rotational rheometer at 25 to 65 °C. The results revealed that the temperature has diminished the interfacial interactions between filler and matrix, thus affecting the properties of MRE, where the tensile properties and MR effect decrease with increasing temperature. However, the presence of silica capable improved the thermal stability of EPDM-based MRE by enhancing the interactions between filler and matrix, thus reducing the interfacial defects when under the influence of temperature. Consequently, the incorporation of silica nanoparticles as an additive in EPDM-based MRE requires more exploration, since it has the potential to sustain the properties of MRE devices in a variety of temperature conditions. Thus, the study on the temperature-dependent mechanical and rheological properties of MRE is necessary, particularly regarding its practical applications.
  10. Fulltext Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites
    Mat Yazik MH, Sultan MTH, Jawaid M, Abu Talib AR, Mazlan N, Md Shah AU, et al.
    Polymers (Basel), 2021 Feb 25;13(5).
    PMID: 33669149 DOI: 10.3390/polym13050700
    The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E'), loss modulus (E"), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.
  11. Fulltext The Effect of Microparticles on the Storage Modulus and Durability Behavior of Magnetorheological Elastomer
    Johari MAF, Mazlan SA, Nordin NA, Ubaidillah U, Aziz SAA, Nazmi N, et al.
    Micromachines (Basel), 2021 Aug 11;12(8).
    PMID: 34442570 DOI: 10.3390/mi12080948
    This paper presents the effect of the micro-sized particles on the storage modulus and durability characteristics of magnetorheological elastomers (MREs). The initial phase of the investigation is to determine any associations among the microparticles' weight percent fraction (wt%), structure arrangement, and the storage modulus of MRE samples. In order to carry out this, both isotropic and anisotropic types of MRE samples consisting of the silicone rubber matrix and 50, 60, 70, 75, and 80 wt% microparticles of carbonyl iron fractions are prepared. It is identified from the magneto-rheometer that the increase in storage modulus and decrease in linear viscoelastic region limit are observed in varying consistency depending on wt% and particle arrangement. The consistency of this dependency feature is highlighted by superimposing all of the graphs plotted to create the proposed the samples' behavior model. In response to increasing magnetic stimulation, a sample of 70 wt% microparticles with an isotropic arrangement is found to be significant and stable. The experimentally defined fraction is then used for the durability test as the second phase of the investigation. During this phase, the durability evaluation is subjected to stress relaxation for an extended period of time. After undergoing durability testing, storage modulus performance is decreased by 0.7-13% at various magnetic stimulation levels. This result directly indicates that the storage modulus characteristics of different forms of MRE are sensitive to the different iron particle fractions' and microparticles' alignment. Therefore, important treatments to alter the storage modulus can be undertaken before the practical implementation to accommodate any desired performance of MRE itself and MRE application systems.
  12. Strategies to improve the stability of amorphous solid dispersions in view of the hot melt extrusion (HME) method
    Al-Japairai K, Hamed Almurisi S, Mahmood S, Madheswaran T, Chatterjee B, Sri P, et al.
    Int J Pharm, 2023 Nov 25;647:123536.
    PMID: 37865133 DOI: 10.1016/j.ijpharm.2023.123536
    Oral administration of drugs is preferred over other routes for several reasons: it is non-invasive, easy to administer, and easy to store. However, drug formulation for oral administration is often hindered by the drug's poor solubility, which limits its bioavailability and reduces its commercial value. As a solution, amorphous solid dispersion (ASD) was introduced as a drug formulation method that improves drug solubility by changing the molecular structure of the drugs from crystalline to amorphous. The hot melt extrusion (HME) method is emerging in the pharmaceutical industry as an alternative to manufacture ASD. However, despite solving solubility issues, ASD also exposes the drug to a high risk of crystallisation, either during processing or storage. Formulating a successful oral administration drug using ASD requires optimisation of the formulation, polymers, and HME manufacturing processes applied. This review presents some important considerations in ASD formulation, including strategies to improve the stability of the final product using HME to allow more new drugs to be formulated using this method.
  13. Fulltext TaqMan real-time PCR for detection of pathogenic Leptospira spp. in canine clinical samples
    Rahman MSA, Khor KH, Khairani-Bejo S, Lau SF, Mazlan M, Roslan MA, et al.
    J Vet Res, 2023 Jun;67(2):187-195.
    PMID: 38143826 DOI: 10.2478/jvetres-2023-0024
    INTRODUCTION: Canine leptospirosis has always been a differential diagnosis in dogs presenting with clinical signs and blood profiles associated with kidney and/or liver disease. The conventional polymerase chain reaction (PCR) provides diagnoses, but real-time PCR-based tests provide earlier confirmation and determine the severity of infection, especially in the acute stage, allowing early detection for immediate treatment decisions. To our knowledge, real-time PCR has not been routinely adopted for clinical investigation in Malaysia. This study evaluated TaqMan real-time PCR (qPCR) assays diagnosing leptospirosis and compared their applicability to clinical samples from dogs with kidney and/or liver disease against a conventional PCR reference.

    MATERIAL AND METHODS: The qPCR assays were validated using existing leptospiral isolates. Whole blood and urine samples were analysed using a conventional PCR, LipL32(1) and LipL32(2) qPCRs and a microscopic agglutination test. The sensitivity and specificity of the qPCRs were determined.

    RESULTS: The LipL32(1) qPCR assay had more diagnostic value than the LipL32(2) qPCR assay. Further evaluation of this assay revealed that it could detect as low as five DNA copies per reaction with high specificity for the tested leptospiral strains. No cross-amplification was observed with other organisms. Analysing the clinical samples, the LipL32(1) qPCR assay had 100.0% sensitivity and >75.0% specificity.

    CONCLUSION: The LipL32(1) qPCR assay is sensitive, specific and has the potential to be applied in future studies.

  14. Morphological features of magnetorheological elastomer degradation under a natural weathering environment
    Johari MAF, Mazlan SA, Abdul Aziz SA, Zaini N, Nordin NA, Ubaidillah U, et al.
    Sci Rep, 2024 Jan 12;14(1):1155.
    PMID: 38212384 DOI: 10.1038/s41598-024-51736-x
    It is well known in the field of materials science that a substance's longevity is significantly influenced by its environment. Everything begins with the initial contact on a material's surface. This influence will then deteriorate and have an extended negative impact on the strength of the material. In this study, the effect of natural weathering in tropical climates on magnetorheological elastomer (MRE) was investigated through microstructural evaluation to understand the aging behavior of the environmentally exposed MRE. To understand and elucidate the process, MREs made of silicone rubber and 70 wt% micron-sized carbonyl iron particles were prepared and exposed to the natural weathering of a tropical climate for 90 days. The MRE samples were then mechanically tensile tested, which revealed that Young's modulus increased, while elongation at break decreased. Surface degradation due to weathering was suspected to be the primary cause of this condition. Using scanning electron microscopy (SEM), the degradation of MRE was investigated as a function of morphological evidence. Upon examination through SEM, it was noted that the weathering effects on the morphology of the exposed samples showed distinct characteristics on the degraded surfaces of the MRE, including numerous microvoids, cavities, and microcracks. While these features were not prominent for the MRE itself, they bear resemblance to the effects observed in similar materials like rubber and elastomer. An atomic force microscope (AFM) is used to investigate the surface topography and local degradation conditions. This observation revealed a distinctive degradation characteristic of the MRE in connection to natural weathering in tropical climates. The surface damage of the MRE samples became severe and inhomogeneous during the environmental aging process, and degradation began from the exposed MRE surface, causing the mechanical characteristics of the MRE to significantly change.
  15. Fulltext Effect of Cellulose Nanocrystals Extracted from Oil Palm Empty Fruit Bunch as Green Admixture for Mortar
    Mazlan D, Krishnan S, Din MFM, Tokoro C, Khalid NHA, Ibrahim IS, et al.
    Sci Rep, 2020 04 14;10(1):6412.
    PMID: 32286486 DOI: 10.1038/s41598-020-63575-7
    This paper aims to examine the effect of cellulose nanocrystals (CNCs) derived from oil palm empty fruit bunch fiber (EFB) incorporating cement mortar on its structural performances. Cellulose nanocrystals (CNCs) were extracted from α-cellulose extracted from EFB using an acid hydrolysis process with a concentration of acid used was 64% w/v under the temperature of 45 °C for 60 minutes. The Cellulose nanocrystals (CNCs) were mixed into the cement mortar ranging from 0 to 0.8% w/w and its mechanical properties were determined. The developed CNCs mortar was characterized for their compressive and flexural properties as well as microstructure. The influence of CNCs concentration, curing method, dispersion of CNCs on mortar's mechanical performance was thoroughly examined to find out the optimum condition. Overall results revealed that an addition of 0.4% cellulose nanocrystals has shown to increase the compressive and flexural strength to 46% and 20%, respectively cured under the wrapping method. The hydration of cementitious composites also improved significantly with the addition of CNCs by the formation of highly crystalline of portlandite observed under the XRD test. This present work demonstrates the importance of palm oil empty fruit bunch waste as a sustainable resource of cellulose nanocrystals admixture to achieve structural strength of cement mortar and promotes green technologies in construction.
  16. Preliminary detection of mites and coccidia with their zoonotic potential in meat-farmed rabbits in three districts in Selangor, Malaysia
    Mohamad-Radzi NN, Che-Amat A, Aziz NAA, Babjee SMA, Mazlan M, Hamid NFS, et al.
    J Parasit Dis, 2021 Mar;45(1):169-175.
    PMID: 33746402 DOI: 10.1007/s12639-020-01291-9
    Mites infestation and gastrointestinal parasites including coccidia are common problems reported in pets, petting farms and farmed practices. Sarcoptes sp. and Cheyletiella sp. could be a potential zoonosis from rabbits to human. Detection of mites and coccidia with their zoonotic potential in meat-farmed rabbits from three (3) commercial farms in Selangor were investigated. Tape impression, fur pluck, skin scraping and ear swab tests were used for mites detection and faecal samples was used for coccidia examination by using McMaster's technique and the identification of Eimeria spp. was further analysed by sporulation technique. The overall prevalence of mites and Eimeria spp. (oocysts) in rabbits were 51.85% ± 0.38 (standard deviation; S.D.) and 76.47% ± 0.42 respectively. Sarcoptes scabiei was the most frequent mite found (25.92% ± 0.44), followed by Cheyletiella parasitovorax and Psoroptes cuniculi. Nine Eimeria spp. were identified and the oocysts of E. perforans shows the highest prevalence (64.71% ± 3.97) followed by E. exigua, E. coecicola, E. magna, E. flavescens, E. irresidua, E. intestinalis, E. media and E. stiedai. There was a significant difference (p = 0.013) where large-scale farm has a higher prevalence of coccidia than small scale farms apparently due to the excessive stocking density as coccidia are easily transmitted among rabbits through ingestion of sporulated oocysts. In conclusion, mites and coccidia are commonly present in the commercial rabbit farms, thus control and preventive measures should be executed to reduce the incidence of parasites. The zoonotic mites Sarcoptes scabiei and Cheyletiella parasitovorax detected in this study could be regarded as a public health concern especially when handling the rabbit.
  17. Fulltext Thermal Aging Rheological Behavior of Magnetorheological Elastomers Based on Silicone Rubber
    Aziz SAA, Mazlan SA, Ubaidillah U, Mohamad N, Choi SB, Che Aziz MA, et al.
    Int J Mol Sci, 2020 Nov 27;21(23).
    PMID: 33260840 DOI: 10.3390/ijms21239007
    Engineering rubber composites have been widely used as main components in many fields including vehicle engineering and biomedical applications. However, when a rubber composite surface area is exposed to heat or sunlight and over a long-term accelerated exposure and lifecycle of test, the rubber becomes hard, thus influencing the mechanical and rheological behavior of the materials. Therefore, in this study, the deterioration of rheological characteristics particularly the phase shift angle (δ) of silicone rubber (SR) based magnetorheological elastomer (MRE) is investigated under the effect of thermal aging. SR-MRE with 60 wt% of CIPs is fabricated and subjected to a continuous temperature of 100 °C for 72 h. The characterization of SR-MRE before and after thermal aging related to hardness, micrograph, and rheological properties are characterized using low vacuum scanning electron microscopy (LV-SEM) and a rheometer, respectively. The results demonstrated that the morphological analysis has a rough surface and more voids occurred after the thermal aging. The hardness and the weight of the SR-MRE before and after thermal aging were slightly different. Nonetheless, the thermo-rheological results showed that the stress-strain behavior have changed the phase-shift angle (δ) of SR-MRE particularly at a high strain. Moreover, the complex mechanism of SR-MRE before and after thermal aging can be observed through the changes of the 'in-rubber structure' under rheological properties. Finally, the relationship between the phase-shift angle (δ) and the in-rubber structure due to thermal aging are discussed thoroughly which led to a better understanding of the thermo-rheological behavior of SR-MRE.
  18. Fulltext Rice Husk Ash/Silicone Rubber-Based Binary Blended Geopolymer Coating Composite: Fire Retardant, Moisture Absorption, Optimize Composition, and Microstructural Analysis
    Mohd Basri MS, Yek TH, A Talib R, Mohamed Amin Tawakkal IS, Kamarudin SH, Mazlan N, et al.
    Polymers (Basel), 2021 Mar 23;13(6).
    PMID: 33806990 DOI: 10.3390/polym13060985
    Geopolymer coating using rice husk ash (RHA) as the aluminosilicate source has shown excellent fire retardant properties. However, incorporation of rice husk ash into the geopolymer matrix increased water absorption properties of the polymer composite. As such, silicone rubber (SiR) was introduced to improve the moisture absorption and fire retardant properties of the composite. Additionally, the less efficient one-factor-at-a-time (OFAT) approach was conventionally used in past studies on the RHA-based geopolymer composite. In understanding the optimum value and significant effect of factors on the fire retardant and moisture absorption properties of the binary blended geopolymer coating composite, the use of statistical analysis and regression coefficient model (mathematical model) was considered essential. The objectives of this study are to identify the significant effect of factors on moisture absorption and fire retardant properties, to determine the optimum composition, and to study the microstructure of the rice husk ash/silicone rubber (RHA/SiR)-based binary blended geopolymer coating composite. The RHA/AA and SiR/Ge ratios were chosen as factors, and the response surface methodology (RSM) was employed to design experiments and conduct analyses. Fire retardant and moisture absorption tests were conducted. A scanning electron microscope (SEM) was used to observe the microstructure of geopolymer samples. The RHA/alkaline activator (AA) and SiR/Ge ratios were shown to have a significant effect on the responses (temperature at equilibrium and moisture absorption). The high ratio of RHA/AA and SiR/Ge resulted in a lower temperature at equilibrium (TAE) below 200°C and at moisture absorption below 16%. The optimum formulation for the geopolymer coating composite can be achieved when the RHA/AA ratio, SiR/Ge ratio, and sodium hydroxide concentration are set at 0.85, 0.70, and 14 M, respectively. SEM micrographs of samples with good fire retardant properties showed that the char residue of the geopolymer composite coating, which is a layer of excess silicone rubber, is porous and continuous, thus providing a shielding effect for the layer of geopolymer underneath. The sample with good moisture absorption showed the formation of a thin outer layer of silicone rubber without any cracks. The unreacted SiR formed a thin layer beneath the geopolymer composite matrix providing a good moisture barrier.
  19. Fulltext The Effect of Graphite Additives on Magnetization, Resistivity and Electrical Conductivity of Magnetorheological Plastomer
    Zaini N, Mohamad N, Mazlan SA, Abdul Aziz SA, Choi SB, Hapipi NM, et al.
    Materials (Basel), 2021 Dec 06;14(23).
    PMID: 34885641 DOI: 10.3390/ma14237484
    Common sensors in many applications are in the form of rigid devices that can react according to external stimuli. However, a magnetorheological plastomer (MRP) can offer a new type of sensing capability, as it is flexible in shape, soft, and responsive to an external magnetic field. In this study, graphite (Gr) particles are introduced into an MRP as an additive, to investigate the advantages of its electrical properties in MRPs, such as conductivity, which is absolutely required in a potential sensor. As a first step to achieve this, MRP samples containing carbonyl iron particles (CIPs) and various amounts of of Gr, from 0 to 10 wt.%, are prepared, and their magnetic-field-dependent electrical properties are experimentally evaluated. After the morphological aspect of Gr-MRP is characterized using environmental scanning electron microscopy (ESEM), the magnetic properties of MRP and Gr-MRP are evaluated via a vibrating sample magnetometer (VSM). The resistivities of the Gr-MRP samples are then tested under various applied magnetic flux densities, showing that the resistivity of Gr-MRP decreases with increasing of Gr content up to 10 wt.%. In addition, the electrical conductivity is tested using a test rig, showing that the conductivity increases as the amount of Gr additive increases, up to 10 wt.%. The conductivity of 10 wt.% Gr-MRP is found to be highest, at 178.06% higher than the Gr-MRP with 6 wt.%, for a magnetic flux density of 400 mT. It is observed that with the addition of Gr, the conductivity properties are improved with increases in the magnetic flux density, which could contribute to the potential usefulness of these materials as sensing detection devices.
  20. Fulltext Physical properties of banana pseudo-stem woven fabric treated with softening agent
    Wan Syazehan Ruznan, Suraya Ahmad Suhaimi, Nazzuha Pairan, Aimi Umairah Mazlan, Anis Naziihah Azrain, Intan Shahirah Md Rosli, et al.
    Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(2):76-83.
    MyJurnal
    Fibres from banana’s stem are abundantly available in Malaysia. This study focused on the production
    of woven fabric from banana pseudo-stem fibres. Yarn made of 100% banana stem and 100% cotton
    yarn were produced. Two types of retting techniques were conducted, which are water retting and
    retting using softening agent. The fibres were spun and weaved into plain weave fabric. All specimens
    were evaluated for yarn twist, yarn evenness, yarn linear density and selected fabric physical
    properties. The results obtained showed that banana stem fabric treated with softening agent has lower
    area density and higher thickness. Weft sample retted in softening agent has higher bending length and
    flexural rigidity than sample retted in water. This might be due to the decrement of yarn’s stiffness,
    which eases the insertion of yarn during shedding process. Weft sample retted in water has lower
    bending length due to coarser yarn and tends to break easily. It is found that retting banana stem fibres
    with softening agent affect the yarn linear density, area density, fabric stiffness properties and flexural
    rigidity of the fabric.
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