Displaying publications 1 - 20 of 170 in total

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  1. Raya SA, Saaid IM, Mohd Aji AQ, A Razak AA
    RSC Adv, 2022 Oct 27;12(48):30952-30961.
    PMID: 36349040 DOI: 10.1039/d2ra04816g
    The production of crude oil is always accompanied by water production, which may create severe separation problems. It is important to understand the stabilization mechanism and parameters contributing to the formation of emulsion, specifically the synergy mixing of surfactants. These factors have not been studied primarily in previous studies. The main objective of the current work was to assess the influence of synergy mixing of nonionic surfactants, sorbitan monooleate (hexitol) and polysorbate 80 (glycol), which are mainly affecting the stability of oil-in-water emulsions. Several factors, such as the mixing rate, mixing time, and aging time of the studied emulsions were also investigated. Response surface methodology (RSM), and central composite design (CCD) were employed to design the experiments. Emulsion stability was measured through a static bottle test over a range of time (1-7 days) at a temperature of 60 °C. A model was established with a coefficient of determination value at 0.8814 and the highest emulsion stability achieved was 42.83%. The least water separation was observed at 0.5 v/v% hexitol, 1.5 v/v% glycol, 15 000 rpm mixing rate in 5 minutes, and seven-day ageing time to achieve ∼41.56% emulsion stability. The minimum emulsion stability of ∼25.0% was observed using 0.5 v/v% of sorbitan monooleate and polysorbate 80 at 5000 rpm of mixing rate in 15 min and under seven days of observation. The results also revealed that the mixing time and ageing time do not affect the stability of the prepared emulsions. Hexitol, mixing rate, synergy mixing of nonionic surfactants and polysorbate 80, and mixing speed significantly influence emulsion stability. The R 2 value of 88.14% verified that the model is well-fitted and the optimal values for the input variables were successfully obtained using RSM.
  2. Mat Eil Ismail MS, Sharifudin MA, Shokri AA, Ab Rahman S
    Singapore Med J, 2016 Mar;57(3):138-43.
    PMID: 26996450 DOI: 10.11622/smedj.2016055
    INTRODUCTION: Physiotherapy is an important part of rehabilitation following arthroplasty, but the impact of preoperative physiotherapy on functional outcomes is still being studied. This randomised controlled trial evaluated the effect of preoperative physiotherapy on the short-term functional outcomes of primary total knee arthroplasty (TKA).
    METHODS: 50 patients with primary knee osteoarthritis who underwent unilateral primary TKA were randomised into two groups: the physiotherapy group (n = 24), whose patients performed physical exercises for six weeks immediately prior to surgery, and the nonphysiotherapy group (n = 26). All patients went through a similar physiotherapy regime in the postoperative rehabilitation period. Functional outcome assessment using the algofunctional Knee Injury and Osteoarthritis Outcome Score (KOOS) scale and range of motion (ROM) evaluation was performed preoperatively, and postoperatively at six weeks and three months.
    RESULTS: Both groups showed a significant difference in all algofunctional KOOS subscales (p < 0.001). The mean score difference at six weeks and three months was not significant in the sports and recreational activities subscale for both groups (p > 0.05). Significant differences were observed in the time-versus-treatment analysis between groups for the symptoms (p = 0.003) and activities of daily living (p = 0.025) subscales. No significant difference in ROM was found when comparing preoperative measurements and those at three months following surgery, as well as in time-versus-treatment analysis (p = 0.928).
    CONCLUSION: Six-week preoperative physiotherapy showed no significant impact on short-term functional outcomes (KOOS subscales) and ROM of the knee following primary TKA.
    KEYWORDS: algofunctional Knee Injury and Osteoarthritis Outcome Score; functional outcome; prehabilitation; preoperative physiotherapy; total knee arthroplasty
  3. Uddin K, Juraimi AS, Ismail MR, Hossain A, Othman R, Abdul Rahim A
    ScientificWorldJournal, 2012;2012:905468.
    PMID: 22666166 DOI: 10.1100/2012/905468
    The demand for salinity-tolerant turfgrasses is increasing due to augmented use of effluent or low-quality water (sea water) for turf irrigation and the growing turfgrass industry in coastal areas. Experimental plants, grown in plastic pots filled with a mixture of river sand and KOSAS(R) peat (9 : 1), were irrigated with sea water at different dilutions imparting salinity levels of 0, 8, 16, 24, 32, 40, or 48 dS m⁻¹. Salinity tolerance was evaluated on the basis of leaf firing, shoot and root growth reduction, proline content, and relative water content. Paspalum vaginatum was found to be most salt tolerant followed by Zoysia japonica and Zoysia matrella, while Digitaria didactyla, Cynodon dactylon "Tifdwarf," and Cynodon dactylon "Satiri" were moderately tolerant. The results indicate the importance of turfgrass varietal selection for saline environments.
  4. Wong KC, Jayapalan JJ, Subramanian P, Ismail MN, Abdul-Rahman PS
    PMID: 36915983 DOI: 10.1002/arch.22008
    Mutation in the Drosophila melanogaster lethal giant larvae (lgl), a tumor suppressor gene with a well-established role in cellular polarity, is known to results in massive cellular proliferation and neoplastic outgrowths. Although the tumorigenic properties of lgl mutant have been previously studied, however, little is known about its consequences on the proteome. In this study, mass spectrometry-based label-free quantitative proteomics was employed to investigate the changes in the head and intestinal tissues proteins of Drosophila melanogaster, due to lgl mutation and following treatment with melatonin. Additionally, to uncover the time-influenced variations in the proteome during tumorigenesis and melatonin treatment, the rhythmic expression of proteins was also investigated at 6-h intervals within 24-h clock. Together, the present study has identified 434 proteins of altered expressions (p 
  5. Sibuar AA, Zulkafflee NS, Selamat J, Ismail MR, Lee SY, Abdull Razis AF
    PMID: 35055550 DOI: 10.3390/ijerph19020731
    Rice is one of the major crops as well as the staple food in Malaysia. However, historical mining activity has raised a concern regarding heavy metal contamination in paddy plants, especially in Perak, a state with major tin mining during the late nineteenth century. Therefore, the objective of this study is to investigate the heavy metals (As, Cd, Pb, Cu, Cr) contamination in paddy soils and paddy plants in three districts in Perak. The content of heavy metals was determined using ICP-MS, while the absorption and transferability of heavy metals in the paddy plants were investigated through enrichment (EF) and translocation (TF) factors. Principal component analysis (PCA) was employed to recognize the pattern of heavy metal contaminations in different sampling areas. Health risk assessment was performed through calculation of various indices. The quantification results showed that root contained highest concentration of the studied heavy metals, with As exhibiting the highest concentration. The EF results revealed the accumulation of As, Cu, and Cr in the rice grains while PCA showed the different compositional pattern in the different sampling areas. The health risk assessment disclosed both noncarcinogenic and carcinogenic risks in the local adults and children. Overall, findings from this study show that heavy metal contamination poses potential health risks to the residents and control measure is required.
  6. Zulkafflee NS, Mohd Redzuan NA, Hanafi Z, Selamat J, Ismail MR, Praveena SM, et al.
    PMID: 31795132 DOI: 10.3390/ijerph16234769
    Rice ingestion is one of the major pathways for heavy metal bioaccumulation in human. This study aimed to measure the heavy metal content of paddy soils and its bioavailability in paddy grain in order to assess the health risk. In total, 10 rice samples (50 g each) of paddy plants were harvested from the Selangor and Terengganu areas of Malaysia to assess the bioavailability of heavy metal (As, Cd, Cu, Cr, and Pb) using the in vitro digestion model of Rijksinstituut voor Volksgezondheid en Milieu. The bioavailability of heavy metal concentrations in rice samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings showed the bioavailability of heavy metal concentrations was decreased in the order Cr > Cu > Pb > As > Cd. Chromium was found to be the most abundant bioavailable heavy metal in cooked rice, which was the result of its high content in paddy soil. Hazard Quotient values for the bioavailability of the heavy metal studied were less than one indicating no non-carcinogenic health risks for adults and children. Meanwhile, the total Lifetime Cancer Risk exceeded the acceptable value showing a potential of carcinogenic health risk for both adults and children. The application of in vitro digestion model in assessing bioavailability of heavy metal produces a more realistic estimation of human health risks exposure. However, a regular monitoring of pollution in Selangor and Terengganu areas is crucial since the exposure of heavy metals through rice consumption poses the potential non-carcinogenic and carcinogenic health risk to the local residents.
  7. Zakaria Z, Zulkafflee NS, Mohd Redzuan NA, Selamat J, Ismail MR, Praveena SM, et al.
    Plants (Basel), 2021 May 26;10(6).
    PMID: 34073642 DOI: 10.3390/plants10061070
    Rice is a worldwide staple food and heavy metal contamination is often reported in rice production. Heavy metal can originate from natural sources or be present through anthropogenic contamination. Therefore, this review summarizes the current status of heavy metal contamination in paddy soil and plants, highlighting the mechanism of uptake, bioaccumulation, and health risk assessment. A scoping search employing Google Scholar, Science Direct, Research Gate, Scopus, and Wiley Online was carried out to build up the review using the following keywords: heavy metals, absorption, translocation, accumulation, uptake, biotransformation, rice, and human risk with no restrictions being placed on the year of study. Cadmium (Cd), arsenic (As), and lead (Pb) have been identified as the most prevalent metals in rice cultivation. Mining and irrigation activities are primary sources, but chemical fertilizer and pesticide usage also contribute to heavy metal contamination of paddy soil worldwide. Further to their adverse effect on the paddy ecosystem by reducing the soil fertility and grain yield, heavy metal contamination represents a risk to human health. An in-depth discussion is further offered on health risk assessments by quantitative measurement to identify potential risk towards heavy metal exposure via rice consumption, which consisted of in vitro digestion models through a vital ingestion portion of rice.
  8. Ismail MA, Deris S, Mohamad MS, Abdullah A
    PLoS One, 2015;10(5):e0126199.
    PMID: 25961295 DOI: 10.1371/journal.pone.0126199
    This paper presents an in silico optimization method of metabolic pathway production. The metabolic pathway can be represented by a mathematical model known as the generalized mass action model, which leads to a complex nonlinear equations system. The optimization process becomes difficult when steady state and the constraints of the components in the metabolic pathway are involved. To deal with this situation, this paper presents an in silico optimization method, namely the Newton Cooperative Genetic Algorithm (NCGA). The NCGA used Newton method in dealing with the metabolic pathway, and then integrated genetic algorithm and cooperative co-evolutionary algorithm. The proposed method was experimentally applied on the benchmark metabolic pathways, and the results showed that the NCGA achieved better results compared to the existing methods.
  9. Haque M, Sa B, Majumder MAA, Islam MZ, Othman NSAB, Lutfi SNNB, et al.
    Ann Afr Med, 2018;17(4):183-188.
    PMID: 30588931 DOI: 10.4103/aam.aam_57_17
    BACKGROUND: Empathy is one of the cardinal components for physician-patient relationships, optimal outcomes in patient care, improved patient satisfaction, greater adherence to therapy, and lower malpractice liability. It is also considered an essential quality for health-care professionals to practice medicine. The aim of the present study was to assess the empathy level of medical students of Universiti Pertahanan Nasional Malaysia (UPNM) National Defense University of Malaysia, Kuala Lumpur, Malaysia.

    METHODS: This was a cross-sectional study conducted in 2017 which recruited medical students of UPNM. The Empathy Quotient, a self-reported questionnaire, was utilized for data collection. The total empathy score of the questionnaire is 80.

    RESULTS: Majority of the respondents were male (60.9%), year-V students (26.6%), Malay (70.5%), and cadet officer (69.6%). The overall mean score achieved by the respondents was 36.76 ± 9.18, and 74.4% of the respondents scored more than 30. The empathy scores of the students were significantly affected by the gender (t = 2.371; df = 205; P < 0.05), year of study (F = 2.553; df = 4/202; P < 0.05), and examination grades (F = 3.488; df = 2/204; P < 0.05). The findings showed that female students are more empathetic than their male counterparts. Further, the post hoc Tukey test analysis revealed that Year-V students are more empathetic than their junior counterparts and students who got highest grade are more empathetic.

    CONCLUSIONS: To improve the empathy level of the UPNM medical students, appropriate educational strategies and interventions should be designed and implemented in the curriculum to inculcate, maintain, and enhance empathy.

  10. Ismail MA, Tamchek N, Hassan MR, Dambul KD, Selvaraj J, Rahim NA, et al.
    Sensors (Basel), 2011;11(9):8665-73.
    PMID: 22164098 DOI: 10.3390/s110908665
    This paper reports the design, characterization and implementation of a fiber Bragg grating (FBG)-based temperature sensor for an insulted-gate Bipolar transistor (IGBT) in a solar panel inverter. The FBG is bonded to the higher coefficient of thermal expansion (CTE) side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorized into three characterization temperature regions between 26 °C and 90 °C. The region from 41 °C to 90 °C shows the highest sensitivity, with a value of 14 pm/°C. A new empirical model that considers both temperature and strain effects has been developed for the sensor. Finally, the FBG-bimetal temperature sensor is placed in a solar panel inverter and results confirm that it can be used for real-time monitoring of the IGBT temperature.
  11. Zuikafly SNF, Ahmad H, Ismail MF, Abdul Rahman MA, Yahya WJ, Abu Husain N, et al.
    Micromachines (Basel), 2023 May 14;14(5).
    PMID: 37241671 DOI: 10.3390/mi14051048
    We investigate the dynamics of high energy dual regime unidirectional Erbium-doped fiber laser in ring cavity, which is passively Q-switched and mode-locked through the use of an environmentally friendly graphene filament-chitin film-based saturable absorber. The graphene-chitin passive saturable absorber allows the option for different operating regimes of the laser by simple adjustment of the input pump power, yielding, simultaneously, highly stable and high energy Q-switched pulses at 82.08 nJ and 1.08 ps mode-locked pulses. The finding can have applications in a multitude of fields due to its versatility and the regime of operation that is on demand.
  12. Ismail MA, Harun SW, Zulkepely NR, Nor RM, Ahmad F, Ahmad H
    Appl Opt, 2012 Dec 20;51(36):8621-4.
    PMID: 23262603 DOI: 10.1364/AO.51.008621
    We demonstrate a simple and low cost mode-locked erbium-doped fiber laser (EDFL) operating in the nanosecond region using a single-walled carbon nanotube (SWCNT)-based saturable absorber (SA). A droplet of SWCNT solution is applied on the end of a fiber ferrule, which is then mated to another clean connector ferrule to construct an SA. Then the SA is integrated into a ring EDFL cavity for nanosecond pulse generation. The EDFL operates at around 1570.4 nm, with a soliton-like spectrum with small Kelly sidebands, which confirms the attainment of the anomalous dispersion. It produces a soliton pulse train with a 332 ns width, repetition rate of 909.1 kHz, an average output power of 0.31 mW, and energy of 0.34 nJ at the maximum pump power of 130.8 mW.
  13. Jamaluddin J, Kamarudin N, Ismail MH, Ahmad SA
    J Environ Manage, 2023 Apr 20;340:117977.
    PMID: 37086558 DOI: 10.1016/j.jenvman.2023.117977
    Suitable extraction technique and the least cost while reducing the environmental impact is the primary concern in timber transportation planning in undulate topography. Two types of extraction machines with unique characteristics to be applied in timber harvest area in Malaysia is combined for timber harvesting with the aim each machine will extract timber suitable to their ability. A Bees Algorithm (BA) was proposed to find an optimum TTP for timber extraction, forest road, and landing locations with grid cell-sized 10 m × 10 m and attributed with fixed and variable costs. The result shows the log fisher (1351 timbers) as a preferable extraction technique with total cost of RM 86,551.73 than the crawler tractor (206 timbers); the timber extraction route is 2630 m for the log fisher and 9860 m for the crawler tractor with total cost of RM 10,453.03. The model finds a suitable timber extraction technique and estimates the extraction costs. Further studies are required to compare the BA with other optimization methods for better results.
  14. Chew, Poh Ling, Noor Hayati Mohd Isa, Siti Nor Azreen Abdul Manap, Ismail Mohd Ghauth, Aisah Md Yunus
    MyJurnal
    Demodex sp. merupakan ektoparasit kulit dan dikenali sebagai tungau folikel yang selalu didapati pada manusia pada semua peringkat umur, kaum dan kumpulan geografi. Objektif kajian ini adalah untuk menentukan prevalens infestasi Demodex sp. di kalangan orang dewasa berumur antara 20 hingga 29 tahun di kawasan Lembah Klang dan menentukan kaitan infestasi ektoparasit ini dengan jantina dan masalah jerawat. Kajian ini merupakan kajian pertama penentuan prevalens infestasi Demodex sp. di Malaysia. Seramai 350 orang subjek telah dikaji yang mana pemilihan sampel dilakukan secara pensampelan rawak berstrata. Pengambilan spesimen dilakukan secara kikisan kulit pada kawasan muka iaitu dahi, hidung, pipi dan dagu. Spesimen dititiskan dengan medium Hoyer dan pemerhatian dijalankan di bawah mikroskop cahaya. Borang soal selidik diedarkan untuk mengetahui kehadiran jerawat pada kulit muka. Hasil kajian mendapati prevalens keseluruhan infestasi Demodex sp. adalah 18.9% dan lelaki menunjukkan infestasi lebih tinggi (25.7%) berbanding perempuan (12.0%) manakala tiada perbezaan bermakna antara masalah jerawat dan infestasi Demodex sp. Kesimpulannya, infestasi Demodex sp. hadir di kalangan satu perlima dari subjek dengan lelaki didapati lebih bermasalah.
  15. Awajan AM, Ismail MT, Al Wadi S
    PLoS One, 2018;13(7):e0199582.
    PMID: 30016323 DOI: 10.1371/journal.pone.0199582
    Many researchers documented that the stock market data are nonstationary and nonlinear time series data. In this study, we use EMD-HW bagging method for nonstationary and nonlinear time series forecasting. The EMD-HW bagging method is based on the empirical mode decomposition (EMD), the moving block bootstrap and the Holt-Winter. The stock market time series of six countries are used to compare EMD-HW bagging method. This comparison is based on five forecasting error measurements. The comparison shows that the forecasting results of EMD-HW bagging are more accurate than the forecasting results of the fourteen selected methods.
  16. Malumfashi ML, Ismail MT, Ali MKM
    Bull Malays Math Sci Soc, 2022;45(Suppl 1):395-424.
    PMID: 35698582 DOI: 10.1007/s40840-022-01316-x
    The economic production quantity (EPQ) model for delayed deteriorating items considering two-phase production periods, exponential demand rate and linearly increasing function of time holding cost is proposed to solve a production problem similar to the one caused by the Covid-19 pandemic. Without shortages, the necessary and sufficient conditions for optimality of this model are characterized through a theorem and lemmas while a solution methodology based on differential calculus is adopted. This paper determines the best replenishment cycle length corresponding to the optimal total variable cost and production quantity of imperfect production industry. To illustrate this model, a numerical experiment is conducted. The results demonstrate that a higher carrying charge decreases the production quantity and a longer demanding period decreases the total variable cost of an industry with a distracted production period. Finally, managerial insights are discussed using sensitivity analysis and future research directions are exposed.
  17. How Jin Aik D, Ismail MH, Muharam FM, Alias MA
    PLoS One, 2021;16(5):e0252111.
    PMID: 34019599 DOI: 10.1371/journal.pone.0252111
    The Cameron Highlands has experienced multiple land encroachment activities and repeated deforestation, leading to extensive land-use and land-cover change (LULCC) during the past six decades. This study aims to determine the LULCC against topography in Cameron Highlands between 2009 and 2019 by using geospatial techniques to analyze Landsat 7 (ETM+) and 8 (OLI/TIRS), ASTER GDEM and MODIS imaging sensors. The results showed a decline of 35.98 km2 in primary forests over ten years across the Cameron Highlands, while agricultural lands and urban areas flourished by a rise of 51.61 km2 and 11.00 km2 respectively. It can be noted that the elevation most affected is between 1000 and 1500 m, across all classes. Further results showed the expansion of both agriculture and urban development onto slopes above 35°, leading to an instability of soil structure. In a comparison of the base years of 2009 with 2019, mean LST results have shown temperatures rising by 7.5°C, while an average between 3 and 4°C across the region is recorded. The results obtained provide new information for government bodies and land planners to coordinate their actions without further jeopardizing the environment of the Cameron Highlands.
  18. Alenezy AH, Ismail MT, Jaber JJ, Wadi SA, Alkhawaldeh RS
    PLoS One, 2022;17(12):e0278835.
    PMID: 36490280 DOI: 10.1371/journal.pone.0278835
    This research employs the gradient descent learning (FIR.DM) approach as a learning process in a nonlinear spectral model of maximum overlapping discrete wavelet transform (MODWT) to improve volatility prediction of daily stock market prices using Saudi Arabia's stock exchange (Tadawul) data. The MODWT comprises five mathematical functions and fuzzy inference rules. The inputs are the oil price (Loil) and repo rate (Repo) according to multiple regression correlation, and the Engle and Granger Causality test Engle RF, (1987). The logarithm of the stock market price (LSCS) in Tadawul reflects the output variable. The correlation matrix reveals that there is no collinearity between the input variables, and the causality test demonstrates that the input variables significantly influence the outcome variable. According to the multiple regression, there is a substantial negative influence between Loil and LSCS but a significant positive effect between Repo and output. For the 80% dataset under ME (0.000005), MAE (0.003214), and MAPE (0.064497), the MODWT-LA8 (ARIMA(1,1,0) with drift) for the LSCS variable performs better than other WT functions. In the novel hybrid model MODWT-FIR.DM, each function's approximation coefficient (LSCS) is applied with input variables (Loil and Repo). We evaluate the performance of the proposed model (MODWT-LA8-FIR.DM) using different statistical measures (ME, RMSE, MAE, MPE) and compare it to two established models: the original FIR.DM and other MODWT-FIR.DM functions for forecasting 20% of datasets. The outcomes show that the MODWT-LA8-FIR.DM performs better than the traditional models based on lower ME (3.167586), RMSE (3.167638), MAE (3.167586), and MPE (80.860849). The proposed hybrid model may be a potential stock market forecasting model.
  19. Jaber AM, Ismail MT, Altaher AM
    ScientificWorldJournal, 2014;2014:708918.
    PMID: 25140343 DOI: 10.1155/2014/708918
    This paper mainly forecasts the daily closing price of stock markets. We propose a two-stage technique that combines the empirical mode decomposition (EMD) with nonparametric methods of local linear quantile (LLQ). We use the proposed technique, EMD-LLQ, to forecast two stock index time series. Detailed experiments are implemented for the proposed method, in which EMD-LPQ, EMD, and Holt-Winter methods are compared. The proposed EMD-LPQ model is determined to be superior to the EMD and Holt-Winter methods in predicting the stock closing prices.
  20. Tan SC, Ismail MP, Duski DR, Othman NH, Ankathil R
    Cancer Genet, 2017 02;211:18-25.
    PMID: 28279307 DOI: 10.1016/j.cancergen.2017.01.004
    This study aimed to investigate the association between FAS c.-671A>G polymorphism and cervical cancer risk in a case-control setting, followed by a meta-analysis of the published literatures. The case-control study involved genotyping of the polymorphism in 185 histopathologically confirmed cervical cancer patients and 209 cancer-free female controls utilizing PCR-RFLP technique, followed by logistic regression analyses. Meta-analysis was then conducted under homozygous, heterozygous, dominant, recessive and allele contrast models to combine data from 12 studies which consisted of 2798 cases and 3039 controls. Our case-control analysis revealed a significant association of the variant allele (G) and the homozygous variant genotype (GG) of the FAS polymorphism with an increased risk of cervical cancer. Subgroup analysis by ethnicity further confirmed the risk association in Malays (P  0.05). However, results of meta-analysis suggested a lack of association between the polymorphism and cervical cancer risk in all the five genetic models analyzed. In conclusion, while the FAS c.-671A>G polymorphism may serve as a biomarker for cervical cancer risk prediction among the Malays, there is a limited usability of the polymorphism as a cervical cancer risk biomarker in other populations.
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