Displaying all 15 publications

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  1. Moradi M, Rezazadeh J, Ismail AS
    Sensors (Basel), 2012;12(4):4352-80.
    PMID: 22666034 DOI: 10.3390/s120404352
    Underwater Wireless Sensor Networks (UWSNs) provide new opportunities to observe and predict the behavior of aquatic environments. In some applications like target tracking or disaster prevention, sensed data is meaningless without location information. In this paper, we propose a novel 3D centralized, localization scheme for mobile underwater wireless sensor network, named Reverse Localization Scheme or RLS in short. RLS is an event-driven localization method triggered by detector sensors for launching localization process. RLS is suitable for surveillance applications that require very fast reactions to events and could report the location of the occurrence. In this method, mobile sensor nodes report the event toward the surface anchors as soon as they detect it. They do not require waiting to receive location information from anchors. Simulation results confirm that the proposed scheme improves the energy efficiency and reduces significantly localization response time with a proper level of accuracy in terms of mobility model of water currents. Major contributions of this method lie on reducing the numbers of message exchange for localization, saving the energy and decreasing the average localization response time.
  2. Ismail AS, Taharin R, Embong Z
    Int Med Case Rep J, 2012;5:33-7.
    PMID: 23754920 DOI: 10.2147/IMCRJ.S29960
    Here, a case of vision threatening blepharokeratoconjunctivitis that responded well to topical cyclosporin is reported. A 9-year-old Malay girl with a history of bilateral blepharokeratoconjunctivitis was regularly treated with lid scrubbing using diluted baby shampoo, fusidic acid gel, and topical steroids as well as an intermittent course of oral doxycycline for the past year. She developed acute onset bilateral eye redness associated with poor vision in her right eye. Both eyes showed marked diffuse hyperemic conjunctiva with corneal vascularization. The presence of corneal vascularization obscured the visual axis in the right eye. The condition did not improve with regular intensive lid hygiene using diluted baby shampoo, fusidic acid gel, and topical steroids. She was started on topical cyclosporin A 0.5% every 6 hours. There was a dramatic regression of corneal vascularization after 3 days on topical cyclosporin, with marked improvement in visual acuity. This is a single case in which cyclosporin improved the status of the ocular surface. A large cohort study is required to justify its effectiveness in treating blepharokeratoconjunctivitis and to test its potential as an alternative immunosuppressive agent in comparison to conventional corticosteroids.
  3. Al-Shargabi MA, Shaikh A, Ismail AS
    PLoS One, 2016;11(9):e0161873.
    PMID: 27583557 DOI: 10.1371/journal.pone.0161873
    Optical burst switching (OBS) networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS) for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS' QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR) scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate) ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50-60%, 30-40%, and 10-20% for high, normal, and low traffic loads respectively.
  4. Ismail AS, Jawaid M, Naveen J
    Materials (Basel), 2019 Jun 28;12(13).
    PMID: 31261821 DOI: 10.3390/ma12132094
    This study aims to investigate the void content, tensile, vibration and acoustic properties of kenaf/bamboo fiber reinforced epoxy hybrid composites. The composites were made using the hand lay-up method. The weight ratios of kenaf/bamboo were 30:70, 50:50 and 70:30. Further, kenaf and bamboo composites were fabricated for the purpose of comparison. The hybridization of woven kenaf/bamboo reduced the void content. The void contents of hybrid composites were almost similar. An enhancement in elongation at break, tensile strength and modulus of hybrid composites was observed until a kenaf/bamboo ratio of 50:50. Kenaf/bamboo (50:50) hybrid composite displays the highest elongation at break, tensile strength and modulus compared to the other hybrid composites which are 2.42 mm, 55.18 MPa and 5.15 GPa, respectively. On the other hand, the highest natural frequency and damping factors were observed for Bamboo/Kenaf (30:70) hybrid composites. The sound absorption coefficient of composites were measured in two conditions: without air gap and with air gap (10, 20, 30 mm). The sound absorption coefficient for testing without air gap was less than 0.5. Introducing an air gap improved the sound absorption coefficient of all composites. Hence, hybrid kenaf/bamboo composites exhibited less void content, as well as improved tensile, vibration and acoustic properties.
  5. Abdul Aziz AM, Ismail AS, Yaakub A
    Cureus, 2022 Oct;14(10):e30572.
    PMID: 36415408 DOI: 10.7759/cureus.30572
    Background Optic disc swelling (ODS) is a pathological condition with a variety of causes, including optic neuritis (ON), anterior ischemic optic neuropathy, and papilledema. Determining the causes of ODS is critical due to the possibilities of vision- or life-threatening diseases, such as space-occupying lesions. This study aimed to investigate the clinical profile of unilateral and bilateral ODS in Penang Hospital, Malaysia. Methodology This retrospective, descriptive study was conducted in Penang Hospital. Medical records of patients who were diagnosed with ODS from June 2018 until June 2020 in Penang Hospital Eye Emergency Clinic were reviewed. We excluded patients who defaulted on subsequent three months of follow up and those with pseudo-ODS. Results ODS was diagnosed in 43 patients who were all included in the study. Majority were females 55.8% (n = 24), with age ranging from 16 to 78 years. ON contributed most (41.9%, n = 18), followed by non-arteritic anterior ischemic optic neuropathy (NA-AION) (34.9%, n = 15), and papilledema (9.3%, n = 4). Other causes (14%, n = 6) included diabetic papillitis (n = 1), hypertensive retinopathy (n = 1), and central retinal vein occlusion (n = 4). Poor mean initial visual acuity was seen in patients with ON (1.07 ± 0.68) and NA-AION (1.33 ± 0.67). ON showed better final visual outcomes compared to NA-AION at the one-year follow-up. Conclusions ON and NA-AION were identified as the two most common causes of ODS in Penang Hospital for both unilateral and bilateral presentations. Most cases presented with poor initial visual acuity. After one year of follow-up, good visual recovery was seen in ON cases compared to other cases. These results were comparable with studies conducted in other Asian counties.
  6. Ismail AS, Osman NB, Patrick DO
    ACS Omega, 2022 Dec 20;7(50):46037-46050.
    PMID: 36570314 DOI: 10.1021/acsomega.2c03434
    Pelletization from nonwoody biomass has gained a lot of attention due to its potential to secure biomass feedstock supply and pricing. Studies have been conducted to produce biopellets from different parts of Napier grass plant. In this study, two different species of Napier grass were used. Two pressure points and five different times were varied accordingly. Proximate, ultimate, and Fourier transform infrared spectroscopy (FTIR) analyses were performed to assess chemical properties. Statistical analysis of the collected data validated and supported the discussion. The produced pellets of Napier grass exhibited good energy density comparable to those in the literature based on gross calorific values. The pellet density demonstrated a significant effect with time, pressure, and feedstock ratios. The pellet durability test showed comparable characteristics to another biomass pellet. Both Pakchong Napier grass (PNG) and wild Napier grass (WNG) biopellet densities obtained were higher than 0.650 g/cm3, and the durability was higher than 95%. This signifies that the pellet can withstand repeated transfer during handling without breakage.
  7. Ismail AS, Jawaid M, Hamid NH, Yahaya R, Hassan A
    Molecules, 2021 Feb 03;26(4).
    PMID: 33546097 DOI: 10.3390/molecules26040773
    Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.
  8. Alanazi HO, Abdullah AH, Qureshi KN, Ismail AS
    Ir J Med Sci, 2018 May;187(2):501-513.
    PMID: 28756541 DOI: 10.1007/s11845-017-1655-3
    INTRODUCTION: Information and communication technologies (ICTs) have changed the trend into new integrated operations and methods in all fields of life. The health sector has also adopted new technologies to improve the systems and provide better services to customers. Predictive models in health care are also influenced from new technologies to predict the different disease outcomes. However, still, existing predictive models have suffered from some limitations in terms of predictive outcomes performance.

    AIMS AND OBJECTIVES: In order to improve predictive model performance, this paper proposed a predictive model by classifying the disease predictions into different categories. To achieve this model performance, this paper uses traumatic brain injury (TBI) datasets. TBI is one of the serious diseases worldwide and needs more attention due to its seriousness and serious impacts on human life.

    CONCLUSION: The proposed predictive model improves the predictive performance of TBI. The TBI data set is developed and approved by neurologists to set its features. The experiment results show that the proposed model has achieved significant results including accuracy, sensitivity, and specificity.

  9. Azmi SZ, Latif MT, Ismail AS, Juneng L, Jemain AA
    Air Qual Atmos Health, 2010 Mar;3(1):53-64.
    PMID: 20376168
    Over the last decades, the development of the Klang Valley (Malaysia), as an urban commercial and industrial area, has elevated the risk of atmospheric pollutions. There are several significant sources of air pollutants which vary depending on the background of the location they originate from. The aim of this study is to determine the trend and status of air quality and their correlation with the meteorological factors at different air quality monitoring stations in the Klang Valley. The data of five major air pollutants (PM(10), CO, SO(2), O(3), NO(2)) were recorded at the Alam Sekitar Sdn Bhd (ASMA) monitoring stations in the Klang Valley, namely Petaling Jaya (S1), Shah Alam (S2) and Gombak (S3). The data from these three stations were compared with the data recorded at Jerantut, Pahang (B), a background station established by the Malaysian Department of Environment. Results show that the concentrations of CO, NO(2) and SO(2) are higher at Petaling Jaya (S1) which is due to influence of heavy traffic. The concentrations of PM(10) and O(3,) however, are predominantly related to regional tropical factors, such as the influence of biomass burning and of ultra violet radiation from sunlight. They can, though, also be influenced by local sources. There are relatively stronger inter-pollutant correlations at the stations of Gombak and Shah Alam, and the results also suggest that heavy traffic flow induces high concentrations of PM(10), CO, NO(2) and SO(2) at the three sampling stations. Additionally, meteorological factors, particularly the ambient temperature and wind speed, may influence the concentration of PM(10) in the atmosphere.
  10. Mohd Khair SZN, Ismail AS, Embong Z, Mohamed Yusoff AA
    J Ophthalmic Vis Res, 2019 5 23;14(2):171-178.
    PMID: 31114654 DOI: 10.4103/jovr.jovr_210_17
    Purpose: To determine the mutational analyses of familial exudative vitreoretinopathy (FEVR)-causing genes in Malay patients with retinopathy of prematurity (ROP) to obtain preliminary data for gene alterations in the Malay community.

    Methods: A comparative cross-sectional study involving 86 Malay premature babies (ROP = 41 and non-ROP = 45) was performed from September 2012 to December 2014. Mutation analyses in (FEVR)-causing genes (NDP, FZD4, LRP5, and TSPAN12) were performed using DNA from premature babies using polymerase chain reaction (PCR) and direct sequencing. Sequencing results were confirmed with PCR-Restriction Fragment Length Polymorphism (RFLP).

    Results: We found variants of FZD4, LRP5, and TSPAN12 in this study. One patient from each group showed a non-synonymous alteration in FZD4, c.502C>T (p.P168S). A synonymous variant of LRP5 [c.3357G>A (p.V1119V)] was found in 30 ROP and 28 non-ROP patients. Two variants of TSPAN12, c.765G>T (p.P255P) and c.*39C>T (3'UTR), were also recorded (29 and 21 in ROP, 33 and 26 in non-ROP, respectively). Gestational age and birth weight were found to be significantly associated with ROP (P value < 0.001 and 0.001, respectively).

    Conclusion: Analysis of data obtained from the ROP Malay population will enhance our understanding of these FEVR-causing gene variants. The c.3357G>A (p.V1119V) variant of LRP5, and c.765G>T (p.P255P) and c.*39C>T variants of TSPAN12 could be common polymorphisms in the Malay ethnic group; however, this requires further elucidation. Future studies using larger groups and higher numbers of advanced cases are necessary to evaluate the relationship between FEVR-causing gene variants and the risk of ROP susceptibility in Malaysian infants.

  11. Chong WK, Khoo Kah Kuen K, Mun-Wei L, Ismail AS, Yaakub A
    Cureus, 2022 Nov;14(11):e31726.
    PMID: 36569731 DOI: 10.7759/cureus.31726
    Simultaneous infections of tuberculosis and toxoplasmosis are uncommon in immunocompetent patients. We report a case of a 30-year-old male who presented with right eye redness and blurring of vision for one month. The visual acuities were hand movement and Snellen 20/30 in the right and left eyes, respectively. Panuveitis and scleritis were found in the right eye, together with dense vitritis and a large choroidal lesion that extended from the inferonasal to the superotemporal quadrants. B-scan ultrasonography of the right eye showed a choroidal detachment with scleral thickening and subtenon fluid. His IgM anti-Toxoplasma antibody was detected, and his QuantiFERON Gold testing was positive. Magnetic resonance imaging (MRI) of the orbit revealed an enhancing intraocular mass at the lateral and inferior aspects of the right globe. The diagnosis of right eye sclerouveitis with presumed tuberculosis and toxoplasmosis co-infections was made. He was treated with a course of oral azithromycin and anti-tubercular therapy along with systemic prednisolone and a topical steroid. The treatment reduced the inflammation; however, the patient suffered from a sequela of chronic uveitis with prolonged hypotony. Medical treatment alone may be insufficient in treating severe infective sclerouveitis, hence surgical intervention might be warranted to provide favorable clinical outcomes.
  12. Tee KR, Ismail AS, Ang YH, Hishamuddin HH, Paul VJ, Aizuddin AN, et al.
    Int J Environ Res Public Health, 2022 Oct 11;19(20).
    PMID: 36293589 DOI: 10.3390/ijerph192013010
    This study aimed to determine the prevalence of anxiety and burnout, and the coping mechanisms among clinical year undergraduate medical students in Universiti Kebangsaan Malaysia (UKM) during the coronavirus disease 2019 (COVID-19) pandemic. In total, 378 clinical year undergraduate medical students in UKM participated in this cross-sectional study from May to July 2021. A self-administered questionnaire consisting of questions on the participant's sociodemographic data and items from the DASS-21, CBI, and Brief-COPE was distributed. Chi-square and Spearman's correlation tests were used to calculate the correlation coefficient between both anxiety and burnout, and coping mechanisms. The prevalence of anxiety and burnout were 44.2% and 22.2%, respectively. There was a significant difference in the percentage of students with extremely severe anxiety in the presence and absence of burnout, 23.8% vs. 4.8% (p < 0.001). Among the three coping mechanisms, avoidant coping had a significant positive moderate correlation with both the presence of anxiety (r = 0.3966, p < 0.001) and the presence of burnout (r = 0.341, p < 0.001). Meanwhile, coping that was neither approach nor avoidant had a positive weak correlation with the presence of burnout (r = 0.176, p = 0.001). The prevalence of anxiety and burnout was concerning. Increased anxiety and burnout among students may negatively impact aspects of their personal, professional, and academic lives. Early recognition and preventive measures should be emphasised to prevent negative ramifications.
  13. Tablit S, Krache R, Amroune S, Jawaid M, Hachaichi A, Ismail AS, et al.
    J Mech Behav Biomed Mater, 2024 Apr;152:106438.
    PMID: 38359736 DOI: 10.1016/j.jmbbm.2024.106438
    Arundo donax L. is investigated in this study as a suitable reinforcing agent for PLA/PP waste blend 3D printing filament. To improve the compatibility of the fibre and polymer, the Arundo fibre was chemically modified using alkali and silane treatment. Untreated and treated fibres were extruded with Polymer blends before being 3D printed. Effect of chemical treatment on thermal, mechanical, and morphological properties of the composites was investigated. The tensile, Izod impact, and water absorption of the 3D printed specimens were also tested. The Alkali treated (ALK) and combination of alkali and silane treatment (SLN) composites displayed good results. Tensile strength and modulus of the materials increased, as well as their maintained stability in the Izod impact test, demonstrating that the incorporation of ArF did not result in a loss in performance. SEM examination supported these findings by confirming the creation of beneficial interfacial contacts between the matrix and fibre components, as demonstrated by the lack of void between the matrix and the fibre surface. Furthermore, the alkali treatment of the ArF resulted in a considerable reduction in water absorption inside the biocomposite, with a 64% reduction seen in ALK composite comparison to the untreated composite (Un). After the 43-day assessment period.
  14. Mohd Ali MR, Lih Huey L, Foo PC, Goay YX, Ismail AS, Mustaffa KMF, et al.
    Biomed Res Int, 2019;2019:9451791.
    PMID: 31355287 DOI: 10.1155/2019/9451791
    Melioidosis and leptospirosis, caused by two different bacteria, Burkholderia pseudomallei and Leptospira spp., are potentially fatal infections that share a very similar spectrum of clinical features and cause significant mortality and morbidity in humans and livestock. Early detection is important for better clinical consequences. To our knowledge, there is no diagnostic tool available to simultaneously detect and differentiate melioidosis and leptospirosis in humans and animals. In this study, we described a duplex TaqMan probe-based qPCR for the detection of B. pseudomallei and Leptospira spp. DNA. The performance of the assay was evaluated on 20 B. pseudomallei isolates, 23 Leptospira strains, and 39 other microorganisms, as well as two sets of serially diluted reference strains. The duplex qPCR assay was able to detect 0.02 pg (~ 4 copies) Leptospira spp. DNA and 0.2 pg (~ 25.6 copies) B. pseudomallei DNA. No undesired amplification was observed in other microorganisms. In conclusion, the duplex qPCR assay was sensitive and specific for the detection of B. pseudomallei & Leptospira spp. DNA and is suitable for further analytical and clinical evaluation.
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