Displaying publications 1 - 20 of 24 in total

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  1. Musa H, Kasim FH, Gunny AAN, Gopinath SCB, Chinni SV, Ahmad MA
    Int J Biol Macromol, 2019 Jul 15;133:1288-1298.
    PMID: 31055112 DOI: 10.1016/j.ijbiomac.2019.05.003
    A report on the de novo Whole Genome Sequence (WGS) of Marinobacter litoralis SW-45, a moderately salt-tolerant bacterium isolated from the seawater in Malaysia is presented. The strain has a genome size of 3.45 Mb and is capable of producing halophilic lipase, protease and esterase enzymes. Computational prediction of non-coding RNA (ncRNA) genes in M. litoralis SW-45 was performed using standalone software known as the non-coding RNA characterization (nocoRNAc). In addition, a phylogenetic tree showing the evolutionary relationship between the strain and other members of the genus Marinobacter was constructed using 16SrRNA sequence information. A total of 385 ncRNA transcripts, 1124 terminator region, and 2350 Stress Induced Duplex Destabilization sites were predicted. The current WGS shotgun project has provided the relevant genetic information that may be useful for the strain's improvement studies. This manuscript gives the first description of M. litoralis with a complete genome.
  2. Ahmad MA, Singh DKA, Mohd Nordin NA, Hooi Nee K, Ibrahim N
    PMID: 31888293 DOI: 10.3390/ijerph16245144
    Virtual reality (VR) games has the potential to improve patient outcomes in stroke rehabilitation. However, there is limited information on VR games as an adjunct to standard physiotherapy in improving upper limb function. This study involved 36 participants in both experimental (n = 18) and control (n = 18) groups with a mean age (SD) of 57 (8.20) and 63 (10.54) years, respectively. Outcome measures were the Fugl-Meyer assessment for upper extremities (FMA-UE), Wolf motor function test (WMFT), intrinsic motivation inventory (IMI), Lawton of instrumental activities of daily living (IADL), and stroke impact scale (SIS) assessed at pre-post intervention. The experimental group had 0.5 h of upper limb (UL) VR games with 1.5 h of standard physiotherapy, and the control group received 2 h of standard physiotherapy. The intervention for both groups was performed once a week for eight consecutive weeks. The results showed a significant time-group interaction effect for IMI (p = 0.001), Lawton IADL (p = 0.01) and SIS domain of communication (p = 0.03). A significant time effect was found in FMA-UE (p = 0.001), WMFT (p = 0.001), Lawton IADL (p = 0.01), and SIS domains; strength, ADL and stroke recovery (p < 0.05). These results indicated an improvement in UL motor ability, sensory function, instrumental ADL, and quality of life in both groups after eight weeks of intervention. However, no significant (p > 0.05) group effect on all the outcome measures was demonstrated. Thus, replacing a portion of standard physiotherapy time with VR games was equally effective in improving UL function and general health compared to receiving only standard physiotherapy among stroke survivors.
  3. Arifin K, Ali MXM, Abas A, Ahmad MA, Ahamad MA, Sahimi AS
    J Safety Res, 2023 Sep;86:376-389.
    PMID: 37718065 DOI: 10.1016/j.jsr.2023.07.017
    INTRODUCTION: The electrical utility industry, which plays a vital role in sustaining other sectors, contributes to high occupational accident rates in the utility industries. The high accident rate shows that there has been insufficient effort made to control unsafe actions and conditions in the workplace. This study aims to examine the influence of hazard control and prevention as leading indicators of safety behaviors and outcomes in coal-fired power plants in Malaysia.

    METHODS: This quantitative research was conducted by distributing survey questionnaires randomly to five coal-fired power plants in Peninsular Malaysia. A total of 340 respondents were involved in this research. Partial least squares structural equation modeling (PLS-SEM) analysis was performed using SmartPLS to validate and examine the relationship of the proposed model.

    RESULTS: The results validate the construct of hazard control and prevention consisting of planning, action, managing, and verifying, while the safety outcomes construct consists of occupational accidents, fatal accidents, near misses, and lost time injuries. The results indicate that hazard control and prevention significantly relate to safety compliance, safety participation, safety motivation, and safety knowledge. Moreover, safety outcomes were influenced negatively by hazard control and prevention through safety compliance.

    CONCLUSION: The model provides a better understanding of the influence of hazard control and prevention on safety behavior and outcomes.

    PRACTICAL APPLICATIONS: The model can be used as guidance for practitioners and researchers in planning and implementing hazard control and prevention to improve health and safety in the workplace.

  4. Ahmad MA, Rashid ZA, Alzahrani AA, El-Harbawi M
    Heliyon, 2022 Nov;8(11):e11610.
    PMID: 36444264 DOI: 10.1016/j.heliyon.2022.e11610
    In this article, the prediction of fatality accident rate at methanol (MeOH) plant was studied using different assessment methods. The prediction method was performed and simulated using HYSYS, ALOHA, MARPLOT, and MATLAB software. Recent studies for pressure variation up to 442 bar in MeOH synthesis by carbon dioxide (CO2) hydrogenation showed that three times more MeOH was produced than in conventional plants, with 90% CO2 conversion and 95% MeOH selectivity. However, safety concerns were noted when MeOH production was operated at pressures above 76-500 bar. Therefore, a safety assessment of the pressures between 76 and 500 bar was performed to predict the fatality rate at the MeOH plant. Adaptive Neuro-Fuzzy Inference System (ANFIS) was compared with a conventional analysis by using the consequence method to predict the fatality rate. First, 26 input parameters were simulated in HYSYS, ALOHA, and MARPLOT software by using the consequence method. Then, the input parameters were reduced to six, namely, pressure, mass, volume, leakage size, wind speed, and wind direction, for prediction using ANFIS tool in MATLAB. This study aimed to highlight the accuracy of the fatality rate prediction by using the ANFIS method. In this manner, accurate prediction of fatality rate for MeOH plant incidents was achieved. The prediction values for the ANFIS method was validated using the standard error of the regression. The percent error measurement obtained the lowest regression of 0.0088 and the lowest percent error of 0.02% for Hydrogen (H2) Vapor Cloud Explosion (VCE) ident. Therefore, the ANFIS method was found to be a simpler and alternative prediction method for the fatality rate than the conventional consequence method.
  5. Suid MH, Ahmad MA
    ISA Trans, 2021 Dec 16.
    PMID: 34991880 DOI: 10.1016/j.isatra.2021.11.037
    Automatic Voltage Regulator (AVR) is fabricated to sustain the voltage level of a synchronous generator spontaneously. Several control strategies have been introduced into the AVR system with the aim of gaining a better dynamic response. One of the most universally utilized controllers is the Proportional-Integral-Derivative (PID) controller. Despite the PID controller having a relatively high dynamic response, there are still further possibilities to improve in order to obtain more appropriate responses. This paper designed a sigmoid-based PID (SPID) controller for the AVR system in order to allow for an accelerated settling to rated voltage, as well as increasing the control accuracy. In addition, the parameters of the proposed SPID controller are obtained using an enhanced self-tuning heuristic optimization method called Nonlinear Sine Cosine Algorithm (NSCA), for achieving a better dynamic response, particularly with regards to the steady-state errors and overshoot of the system. A time-response specifications index is used to validate the proposed SPID controller. The obtained simulation results revealed that the proposed method was not only highly effective but also greatly improved the AVR system transient response in comparison to those with the modern heuristic optimization based PID controllers.
  6. Ahmad MA, Ajit Singh DK, Chua WQ, Abd Rahman NNA, Mohd Padzil FA, Hendri ENM
    Jurnal Sains Kesihatan Malaysia, 2018;16(101):171-177.
    MyJurnal
    Knee osteoarthritis (OA) is a common chronic joint disease that results in pain and disability in many people. Cultural practice may influence patients’ views about their condition, its related issues and management. The aim of our study was to explore the perspective about knee OA and its related issues among Malaysian patients with knee OA. Twelve patients diagnosed with knee OA (8 females and 4 males) attending physiotherapy sessions at a University Hospital, mean age (SD): 67.1(9.4) years and median visual analog scale score of 5/10 participated in this qualitative study. One to one in-depth interviews were conducted, audio recorded and later transcribed verbatim. Three main themes were identified from the transcribed data; knee pain and its’ related issues (reason and aggravating factors of knee pain, coping strategies), impact of knee pain (impact on daily activities and emotions) and physiotherapy management (effects and expectations of physiotherapy, compliance and adherence towards home exercises). Most participants expressed that their knee pain was aggravated by certain movements that had an effect on their daily activities namely squatting. The findings also suggested that physiotherapy management was perceived as secondary prevention rather than a cure. Findings from this study provides information about the perceptions and related issues of patients with knee OA. This information may help health professionals in tailoring patient-centered care and provide better management.
    Study site: Physiotherapy department, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
  7. Ajit Singh DK, Ngu ACY, Ahmad MA, Mohd Padzil FA, Hendri ENM, Kamsan SS
    Jurnal Sains Kesihatan Malaysia, 2018;16(101):229-230.
    MyJurnal
    Knee osteoarthritis (KOA) is a major cause of disability and significantly reduce quality of life (QOL). There is limited information about knee associated problems and functional mobility among Malaysian adults with KOA. The aim of our study was to examine knee associated problems and functional mobility among this population. Forty-five (45) adults with KOA with mean age of 65.02 ± 8.083 were recruited from Hospital Canselor Tuanku Muhriz, UKM. Knee associated problems and functional mobility were measured using Knee injury and Osteoarthritis Outcome Scores (KOOS) and Timed-Up and Go (TUG) test respectively. The mean score and standard deviation for TUG test was 11.44 ± 2.69 seconds. Median scores (with interquartile ranges [IQR]) for the KOOS subscale domains were; Symptoms: 80.56, (69.44 to 91.67); Pain: 71.43 (50 to 78.57); Functional Activities of Daily Living: 82.3 (67.65 to 86.76); Sports and Recreation Function: 30 (20 to 60); and Knee-Related Quality of Life: 50 (25 to 75). Generally, participants’ TUG test performance showed that time taken to complete the test was higher than the reference values (7.14 to 8.43 seconds) identified among Malaysian community dwelling older adults with low to high risk of falls. The KOOS scores in adults with KOA in our study is similar to previous reports with Sport and Recreation Function and QOL domains been the most affected. It is important to improve functional mobility and balance in order to decrease falls risk and optimise sport and recreation function and QOL among adults with KOA.
    Study site: Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
  8. Salmiati, Ujang Z, Salim MR, Md Din MF, Ahmad MA
    Water Sci Technol, 2007;56(8):179-85.
    PMID: 17978446
    This study aimed to produce polyhydroxyalkanoates (PHAs) from organic wastes by mixed bacterial cultures using anaerobic-aerobic fermentation systems. Palm oil mill effluent (POME) was used as an organic source, which was cultivated in a two-step-process of acidogenesis and acid polymerization. POME was operated in a continuous flow anaerobic reactor to access volatile fatty acids (VFAs) for PHAs production. During fermentation, VFA concentration was produced in the range of 5 to 8 g/L and the COD concentration reduced up to 80% from 65 g/L. The VFA from anaerobic fermentation was then utilised for PHA production using a mixed culture in availability of aerobic bioreactor. Production of PHAs was recorded high when using a high volume of substrates because of the higher VFA concentration. Even though the maximum PHA content was observed at only 40% of the cell dried weight (CDW), their production and performance are significant in mixed microbial culture.
  9. Fahmi MZ, Aung YY, Ahmad MA, Kristanti AN, Sakti SCW, Arjasa OP, et al.
    Nanotheranostics, 2023;7(3):281-298.
    PMID: 37064612 DOI: 10.7150/ntno.80030
    The fluorescent imaging and drug delivery utilizing carbon dots nanomaterials (CDs) have attracted tremendously due to their unique optical ability and outstanding biocompatibility. Herein, we reported a new design of chalcone-loaded carbon dots (Chalcone-APBA-CDs) to serve chalcone transport onto cancer cells and enhance the CDs bioimaging and antitumor activity. The boronic acid was directly introduced to carbon dots (CDs) via pyrolysis process to drive CDs specifically to the cancer cell, and chalcone was mediated on CDs by ultrasonication to perform facile release of the drug delivery model. The successfully synthesized Chalcone-APBA-CDs were proved by their chemical structure, fluorescent activities, in vitro and in vivo analyses, and drug release systems using different pH. In addition, flow cytometry and confocal fluorescent imaging proved CDs' cellular uptake and imaging performance. In vitro analyses further proved that the Chalcone-APBA-CDs exhibited a higher toxicity value than bare CDs and efficiently inhibited the proliferation of the HeLa cells depending on their dose-response. Finally, the performance of Chalcone-APBA-CDs on cancer healing capability was examined in vivo with fibrosarcoma cancer-bearing mice, which showed a remarkable ability to reduce the tumor volume compared with saline (control). This result strongly suggested that the Chalcone-APBA-CDs appear promising simultaneously as cancer cell imaging and drug delivery.
  10. Al Azzam KM, Abdallah HH, Halim HN, Ahmad MA, Shaibah H
    Sci Pharm, 2015 06 22;83(4):683-98.
    PMID: 26839848 DOI: 10.3797/scipharm.1501-15
    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = -14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = -5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems.
  11. Zubair M, Aziz HA, Ihsanullah I, Ahmad MA, Al-Harthi MA
    Environ Res, 2022 Feb 07.
    PMID: 35143802 DOI: 10.1016/j.envres.2022.112861
    In this research work, a novel hybrid composite consisting of biochar (B), layered double hydroxide (CuFe) and chitosan (CS) (B-CuFe-CS) was produced using an ultrasonication-assisted co-precipitation method. The resultant composite was employed for adsorptive removal of Eriochrome black T (EBT) from water. Physicochemical characterization indicated that the B-CuFe-CS containing 10 wt % CS exhibited a heterogeneous structure with better crystallographic and textural characteristics. The B-CuFe-CS with abundant surface functionalities (-CO, -C-O, -OH, -NO3, and MMO), facilitates faster and enhanced removal of the EBT. The kinetic results showed better fitting to the pseudo-second order model, and equilibrium was achieved within 30 min. Equilibrium data was well explained by Langmuir and Redlich Peterson isotherm models (R2 > 0.98), indicating the EBT removal onto B-CuFe-CS followed monolayer adsorption. The maximum adsorption capacity was 806.4 mg/g, which was higher than pristine B-CuFe (476.19 mg/g) and many other adsorbents. The spectroscopic analysis (FTIR and XPS) and experimental results suggested that EBT adsorption is mainly governed by electrostatic, chemical and anion-exchange interactions. It is evident from these results that coupling B-CuFe composite with bio-filler (chitosan) resulted in an efficient bio-adsorbent to effectively purify dye-contaminated water streams.
  12. Ahmad MA, Yusof A, Hamid MSA, Zulkifli Amin FH, Kamsan SS, Ag Daud DM, et al.
    J Res Health Sci, 2023 Mar;23(1):e00569.
    PMID: 37571940 DOI: 10.34172/jrhs.2023.104
    BACKGROUND: Home-based exercise (HBE) and patient education (EDU) have been reported as beneficial additions to usual knee osteoarthritis (KOA) rehabilitation. However, previous trials mostly examined the effects of HBE and EDU separately. Thus, this study aimed to evaluate the effects of a structured combined HBE and EDU program in addition to usual KOA rehabilitation on pain score, functional mobility, and disability level.

    STUDY DESIGN: A parallel-group, single-blinded randomized controlled trial.

    METHODS: Eighty adults with KOA were randomly allocated to experimental (n=40) and control (n=40) groups. All participants underwent their usual physiotherapy care weekly for eight weeks. The experimental group received a structured HBE+EDU program to their usual care, while the control group performed home stretching exercises to equate treatment time. The Knee Injury and Osteoarthritis Outcome Score (KOOS) for the disability level, visual analogue scale (VAS) for pain, and timed up-and-go test (TUG) for mobility were measured pre-post intervention.

    RESULTS: After eight weeks, the experimental group demonstrated significant improvements in the KOOS (all subscales), pain VAS, and TUG scores compared to baseline (P<0.001); meanwhile, only KOOS (activities of daily living and sports subscales) was significant in the control group. Relative to the control, the experimental group presented higher improvements (P<0.001) by 22.2%, 44.1%, and 15.7% for KOOS, pain VAS, and TUG, respectively.

    CONCLUSION: Integrating the HBE+EDU program into usual KOA rehabilitation could reduce pain and disability, while it improved functional mobility. The finding of this study suggests a combination of a structured HBE and EDU program to be considered as part of mainstream KOA management.

  13. Herawan SG, Ahmad MA, Putra A, Yusof AA
    ScientificWorldJournal, 2013;2013:545948.
    PMID: 24027443 DOI: 10.1155/2013/545948
    Activated carbons are regularly used the treatment of dye wastewater. They can be produced from various organics materials having high level of carbon content. In this study, a novel Pinang frond activated carbon (PFAC) was produced at various CO₂ flow rates in the range of 150-600 mL/min at activation temperature of 800°C for 3 hours. The optimum PFAC sample is found on CO₂ flow rate of 300 mL/min which gives the highest BET surface area and pore volume of 958 m²/g and 0.5469 mL/g, respectively. This sample shows well-developed pore structure with high fixed carbon content of 79.74%. The removal of methylene blue (MB) by 95.8% for initial MB concentration of 50 mg/L and 72.6% for 500 mg/L is achieved via this sample. The PFAC is thus identified to be a suitable adsorbent for removing MB from aqueous solution.
  14. Adeel M, Lee JY, Zain M, Rizwan M, Nawab A, Ahmad MA, et al.
    Environ Int, 2019 06;127:785-800.
    PMID: 31039528 DOI: 10.1016/j.envint.2019.03.022
    BACKGROUND: Rare earth elements (REEs) are gaining attention due to rapid rise of modern industries and technological developments in their usage and residual fingerprinting. Cryptic entry of REEs in the natural resources and environment is significant; therefore, life on earth is prone to their nasty effects. Scientific sectors have expressed concerns over the entry of REEs into food chains, which ultimately influences their intake and metabolism in the living organisms.

    OBJECTIVES: Extensive scientific collections and intensive look in to the latest explorations agglomerated in this document aim to depict the distribution of REEs in soil, sediments, surface waters and groundwater possibly around the globe. Furthermore, it draws attention towards potential risks of intensive industrialization and modern agriculture to the exposure of REEs, and their effects on living organisms. It also draws links of REEs usage and their footprints in natural resources with the major food chains involving plants, animals and humans.

    METHODS: Scientific literature preferably spanning over the last five years was obtained online from the MEDLINE and other sources publishing the latest studies on REEs distribution, properties, usage, cycling and intrusion in the environment and food-chains. Distribution of REEs in agricultural soils, sediments, surface and ground water was drawn on the global map, together with transport pathways of REEs and their cycling in the natural resources.

    RESULTS: Fourteen REEs (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Th and Yb) were plighted in this study. Wide range of their concentrations has been detected in agricultural soils (<15.9-249.1 μg g-1) and in groundwater (<3.1-146.2 μg L-1) at various sites worldwide. They have strong tendency to accumulate in the human body, and thus associated with kidney stones. The REEs could also perturb the animal physiology, especially affecting the reproductive development in both terrestrial and aquatic animals. In plants, REEs might affect the germination, root and shoot development and flowering at concentration ranging from 0.4 to 150 mg kg-1.

    CONCLUSIONS: This review article precisely narrates the current status, sources, and potential effects of REEs on plants, animals, humans health. There are also a few examples where REEs have been used to benefit human health. However, still there is scarce information about threshold levels of REEs in the soil, aquatic, and terrestrial resources as well as living entities. Therefore, an aggressive effort is required for global action to generate more data on REEs. This implies we prescribe an urgent need for inter-disciplinary studies about REEs in order to identify their toxic effects on both ecosystems and organisms.

  15. Rozano L, Abdullah Zawawi MR, Ahmad MA, Jaganath IB
    Adv Bioinformatics, 2017;2017:5124165.
    PMID: 28932239 DOI: 10.1155/2017/5124165
    The inhibition of dipeptidyl peptidase-IV (DPPIV) is a popular route for the treatment of type-2 diabetes. Commercially available gliptin-based drugs such as sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin were specifically developed as DPPIV inhibitors for diabetic patients. The use of Gynura bicolor in treating diabetes had been reported in various in vitro experiments. However, an understanding of the inhibitory actions of G. bicolor bioactive compounds on DPPIV is still lacking and this may provide crucial information for the development of more potent and natural sources of DPPIV inhibitors. Evaluation of G. bicolor bioactive compounds for potent DPPIV inhibitors was computationally conducted using Lead IT and iGEMDOCK software, and the best free-binding energy scores for G. bicolor bioactive compounds were evaluated in comparison with the commercial DPPIV inhibitors, sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin. Drug-likeness and absorption, distribution, metabolism, and excretion (ADME) analysis were also performed. Based on molecular docking analysis, four of the identified bioactive compounds in G. bicolor, 3-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, and trans-5-p-coumaroylquinic acid, resulted in lower free-binding energy scores when compared with two of the commercially available gliptin inhibitors. The results revealed that bioactive compounds in G. bicolor are potential natural inhibitors of DPPIV.
  16. Ahmad MA, Moganan M, A Hamid MS, Sulaiman N, Moorthy U, Hasnan N, et al.
    Life (Basel), 2023 Jul 06;13(7).
    PMID: 37511894 DOI: 10.3390/life13071519
    BACKGROUND: Low-level (LLLT) and high-intensity laser therapy (HILT) can be beneficial additions to knee osteoarthritis (KOA) rehabilitation exercises; however, it is still being determined which electrophysical agent is more effective.

    AIM: To compare the effects of LLLT and HILT as adjuncts to rehabilitation exercises (LL + EX and HL + EX) on clinical outcomes in KOA.

    METHODS: Thirty-four adults with mild-to-moderate KOA were randomly allocated to either LL + EX or HL + EX (n = 17 each). Both groups underwent their respective intervention weekly for twelve weeks: LL + EX (400 mW, 830 nm, 10 to 12 J/cm2, and 400 J per session) or HL + EX (5 W, 1064 nm, 19 to 150 J/cm2, and 3190 J per session). The laser probe was placed vertically in contact with the knee and moved in a slow-scan manner on the antero-medial/lateral sides of the knee joint. Participants' Knee Injury and Osteoarthritis Outcome Score (KOOS), Numerical Pain Rating Scale (NPRS), active knee flexion, and Timed Up-and-Go test (TUG) were assessed.

    RESULTS: Post intervention, both groups showed improvements in their KOOS, NPRS, active knee flexion, and TUG scores compared to baseline (p < 0.01). The mean difference of change in KOOS, NPRS, and active knee flexion scores for the HL + EX group surpassed the minimal clinically important difference threshold. In contrast, the LL + EX group only demonstrated clinical significance for the NPRS scores.

    CONCLUSIONS: Incorporating HILT as an adjunct to usual KOA rehabilitation led to significantly higher improvements in pain, physical function, and knee-related disability compared to LLLT applied in scanning mode.

  17. Ahmad MA, Yahya WJ, Ithnin AM, Hasannuddin AK, Bakar MAA, Fatah AYA, et al.
    Environ Sci Pollut Res Int, 2018 Aug;25(24):24266-24280.
    PMID: 29948709 DOI: 10.1007/s11356-018-2492-2
    Non-surfactant water-in-diesel emulsion fuel (NWD) is an alternative fuel that has the potential to reduce major exhaust emissions while simultaneously improving the combustion performance of a diesel engine. NWD comprises of diesel fuel and water (about 5% in volume) without any additional surfactants. This emulsion fuel is produced through an in-line mixing system that is installed very close to the diesel engine. This study focuses mainly on the performance and emission of diesel engine fuelled with NWD made from different water sources. The engine used in this study is a direct injection diesel engine with loads varying from 1 to 4 kW. The result shows that NWD made from tap water helps the engine to reduce nitrogen oxide (NOx) by 32%. Rainwater reduced it by 29% and seawater by 19%. In addition, all NWDs show significant improvements in engine performance as compared to diesel fuel, especially in the specific fuel consumption that indicates an average reduction of 6%. It is observed that all NWDs show compelling positive effects on engine performance, which is caused by the optimum water droplet size inside NWD.
  18. Ahmad MA, Lim YH, Chan YS, Hsu CY, Wu TY, Sit NW
    Acta Pharm, 2022 Jun 01;72(2):317-328.
    PMID: 36651512 DOI: 10.2478/acph-2022-0013
    This study was conducted to evaluate the chemical composition and biological activities of the leaf extracts of Syzygium myrtifolium Walp. (Myrtaceae). The results indicate that the leaf extracts of S. myrtifolium contain various classes of phytochemicals (alkaloids, anthraquinones, flavonoids, phenolics, saponins, tannins and triterpenoids) and possess antioxidant, antibacterial, antifungal and antiviral activities. Ethyl acetate, ethanol, methanol, and water extracts exhibited significantly higher (p < 0.05) oxygen radical absorbance capacity and ferric-reducing antioxidant power than the hexane and chloroform extracts. However, all extracts exhibited stronger inhibitory activity against four tested species of yeasts (minimal inhibitory concentration: 0.02-0.31 mg mL-1) than against six tested species of bacteria (minimal inhibitory concentration: 0.16-1.25 mg mL-1). The ethanolic extract offered the highest protection of Vero cells (viability > 70 %) from the cytopathic effect caused by the Chikungunya virus while the ethyl acetate extract showed significant replication inhibitory activity against the virus (p < 0.001) using the replicon-enhanced green fluorescent protein reporter system.
  19. Ahmad MA, Razali A
    MyJurnal
    Factory and Machinery Act (Noise Exposure) Regulation 1989 (FMA [Noise] 1989) has been implemented in Malaysia for nearly 30 years, but noise-induced hearing loss (NIHL) cases is still rising. Fault tree analysis is a top-down approach to analyzing incidences of 'failures', starting with establishing the single top event that will eventually cause NIHL, followed by identification of the contributing factors to the top event which are the immediate or basic events. Through its visual, structural and deductive approach; FTA is able to depict the temporal sequence of events and their interactions in a formal and logical hierarchy. Materials and Methods: Employees with permanent standard threshold shifts (PSTS) underwent further assessment confirming the presence of NIHL. A single common fault tree was constructed based on six cases of PSTS. The top event is the PSTS. Intermediate and basic events were identified and mapped with relevance to the provisions in the FMA (noise) 1989 indicating how failed control measures have resulted in the PSTS cases.Results: The constructed fault tree with its branches illustrated how breach or non-compliance of FMA (Noise) 1989 resulted in the eventual top event (NIHL). Conclusion: FTA provides a standardized perspective of errors within the system in preventing NIHL.
  20. Musa H, Kasim FH, Gunny AAN, Gopinath SCB, Ahmad MA
    3 Biotech, 2019 Aug;9(8):314.
    PMID: 31406636 DOI: 10.1007/s13205-019-1845-y
    Initially, a new moderate halophilic strain was locally isolated from seawater. The partial 16S rRNA sequence analysis positioned the organism in Marinobacter genus and was named 'Marinobacter litoralis SW-45'. This study further demonstrates successful utilization of the halophilic M. litoralis SW-45 lipase (MLL) for butyl ester synthesis from crude palm fruit oil (CPO) and kernel oil (CPKO) in heptane and solvent-free system, respectively, using hydroesterification. Hydrolysis and esterification of enzymatic [Thermomyces lanuginosus lipase (TLL)] hydrolysis of CPO and CPKO to free fatty acids (FFA) followed by MLL-catalytic esterification of the concentrated FFAs with butanol (acyl acceptor) to synthesize butyl esters were performed. A one-factor-at-a-time technique (OFAT) was used to study the influence of physicochemical factors on the esterification reaction. Under optimal esterification conditions of 40 and 45 °C, 150 and 230 rpm, 50% (v/v) biocatalyst concentration, 1:1 and 5:1 butanol:FFA, 9% and 15% (w/v) NaCl, 60 and 15 min reaction time for CPO- and CPKO-derived FFA esterification system, maximum ester conversion of 62.2% and 69.1%, respectively, was attained. Gas chromatography (GC) analysis confirmed the products formed as butyl esters. These results showed halophilic lipase has promising potential to be used for biosynthesis of butyl esters in oleochemical industry.
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