Displaying publications 21 - 40 of 45 in total

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  1. Koh GT, Ai Mokthar S, Hamzah A, Kaur J
    Ann Pediatr Cardiol, 2009 Jul;2(2):159-61.
    PMID: 20808631 DOI: 10.4103/0974-2069.58320
    We report a case of transcatheter closure of patent ductus arteriosus using the new Amplatzer duct occluder II in an adult patient with interrupted inferior vena cava with azygous continuation via the femoral artery approach.
  2. Asadi-Shekari Z, Moeinaddini M, Sultan Z, Shah MZ, Hamzah A
    Traffic Inj Prev, 2016 08 17;17(6):650-5.
    PMID: 26890058 DOI: 10.1080/15389588.2015.1136739
    OBJECTIVE: A number of efforts have been conducted on travel behavior and transport fatalities at the neighborhood or street level, and they have identified different factors such as roadway characteristics, personal indicators, and design indicators related to transport safety. However, only a limited number of studies have considered the relationship between travel behavior indicators and the number of transport fatalities at the city level. Therefore, this study explores this relationship and how to fill the mentioned gap in current knowledge.

    METHOD: A generalized linear model (GLM) estimates the relationships between different travel mode indicators (e.g., length of motorway per inhabitants, number of motorcycles per inhabitant, percentage of daily trips on foot and by bicycle, percentage of daily trips by public transport) and the number of passenger transport fatalities. Because this city-level model is developed using data sets from different cities all over the world, the impacts of gross domestic product (GDP) are also included in the model.

    CONCLUSIONS: Overall, the results imply that the percentage of daily trips by public transport, the percentage of daily trips on foot and by bicycle, and the GDP per inhabitant have negative relationships with the number of passenger transport fatalities, whereas motorway length and the number of motorcycles have positive relationships with the number of passenger transport fatalities.

  3. Quah BS, Mazidah AR, Hamzah AM, Simpson H
    Asian Pac J Allergy Immunol, 2000 Mar;18(1):15-21.
    PMID: 12546053
    While many studies of the prevalence of wheeze have been conducted in schoolchildren, there have been few in pre-school children. Most children with asthma develop symptoms before the age of 5 years and many pre-school wheezers continue to wheeze in the early school years. Among the latter, those children who continue to wheeze at school age have poorer lung function than those who don't. It is thus appropriate to enquire more fully about wheeze in this age-group where its incidence is high and its relation with asthma less well defined. The objective of this study was to investigate the prevalences of wheeze, night cough and doctor diagnosed asthma in pre-school children. A cross-sectional study was conducted in five primary health clinics in the district of Kota Bharu from April to October 1998. Nurses from these clinics distributed Bahasa Malaysia questionnaires containing questions on asthma symptoms to preschool children aged 1-5 years during their home visits. The respondents were parent(s) or carer(s) of the child. The response rate was 100% and a total of 2,878 responses were analysed. The prevalence of symptoms and doctor diagnosed asthma were as follows: ever wheezed 9.4% (95% confidence interval (CI) 8.3-10.4%); current wheeze 6.2% (95% CI 5.2 to 7.0%); night cough 10.2% (95% CI 9.1 to 11.4%); and doctor diagnosed asthma 7.1% (95% CI 6.2 to 8.0%). There were no significant differences in prevalence between males and females, or among age groups. The prevalence of night cough in children with no history of wheeze was 6.9%. The cumulative and current prevalences of wheeze were similar to, and those of night cough and doctor-diagnosed asthma significantly lower than, those reported for Kelantan schoolchildren. These findings provide a baseline for assessing future symptoms trends, and perhaps also the validity of diagnosing asthma in this age group.
  4. Chin HC, Hamzah A, Alias NE, Tan MLP
    Micromachines (Basel), 2023 Jun 12;14(6).
    PMID: 37374820 DOI: 10.3390/mi14061235
    Molybdenum disulfide (MoS2) has distinctive electronic and mechanical properties which make it a highly prospective material for use as a channel in upcoming nanoelectronic devices. An analytical modeling framework was used to investigate the I-V characteristics of field-effect transistors based on MoS2. The study begins by developing a ballistic current equation using a circuit model with two contacts. The transmission probability, which considers both the acoustic and optical mean free path, is then derived. Next, the effect of phonon scattering on the device was examined by including transmission probabilities into the ballistic current equation. According to the findings, the presence of phonon scattering caused a decrease of 43.7% in the ballistic current of the device at room temperature when L = 10 nm. The influence of phonon scattering became more prominent as the temperature increased. In addition, this study also considers the impact of strain on the device. It is reported that applying compressive strain could increase the phonon scattering current by 13.3% at L = 10 nm at room temperature, as evaluated in terms of the electrons' effective masses. However, the phonon scattering current decreased by 13.3% under the same condition due to the existence of tensile strain. Moreover, incorporating a high-k dielectric to mitigate the impact of scattering resulted in an even greater improvement in device performance. Specifically, at L = 6 nm, the ballistic current was surpassed by 58.4%. Furthermore, the study achieved SS = 68.2 mV/dec using Al2O3 and an on-off ratio of 7.75 × 104 using HfO2. Finally, the analytical results were validated with previous works, showing comparable agreement with the existing literature.
  5. Abdul Khalid MS, Khamis NK, Abu Mansor MR, Hamzah A
    Iran J Public Health, 2021 Jan;50(1):24-34.
    PMID: 34178761 DOI: 10.18502/ijph.v50i1.5069
    Background: Conspicuity has been one of the key factors in motorcycle road crashes around the world. The inability and difficulty of other road users in detecting motorcycles either at day or at night have contributed to conspicuity related motorcycle crashes. This literature review attempts to understand the motorcycle conspicuity issues in road traffic. The review also analyses relevant types of conspicuity intervention in terms of its effectiveness in enhancing motorcycle conspicuity that had been discussed in past studies.

    Methods: Using specific keywords and search terms, relevant articles were screened, identified and analyzed systematically using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

    Results: Twenty-seven final articles were reviewed and found that almost every part of motorcycle and motorcyclist's conspicuity intervention have been covered in past studies. In terms of conspicuity aids, the majority of past studies discussed conspicuity enhancement in the frontal area, particularly on motorcycle daytime running headlight (DRH) color and configurations. Few other studies have discussed in other areas, particularly on rear running and brake light and motorcycle color. There were also numerous studies looking at motorcyclists' appearances in terms of their attire and helmet color.

    Conclusion: Motorcycle and motorcyclist's appearances are highly associated with the risk of motorcycle crashes. The most important part of enhancing motorcycle conspicuity is to ensure motorcycle appearance is always in contrast with the road traffic environment.

  6. Asyary A, Veruswati M, Arianie CP, Ratih TSD, Hamzah A
    Asian Pac J Cancer Prev, 2021 Feb 01;22(2):359-363.
    PMID: 33639648 DOI: 10.31557/APJCP.2021.22.2.359
    BACKGROUND: With the increasing prevalence of teenage or school-age smokers, schools have become the main focus of the Indonesian government in tobacco control, including through the smoke-free zone (SFZ) policy. This study aims to obtain information related to the implementation of SFZ policies in schools.

    METHODS: A nationally representative survey was employed in 900 elementary, junior high, and senior high schools that were located in 60 regions or 24 provinces of Indonesia. Each school's compliance with SFZ parameters was measured using a closed-ended questionnaire. The dataset was analyzed using frequency distribution, while the chi-square was performed to analyze the measurement effect of each parameter for SFZ compliance.

    RESULTS: Java Island is the region with the largest proportion of school units (10%) studied in this study, and the largest group of the schools are high schools (36.1%). In terms of SFZ compliance, 413 (45.9%) of schools had perfect compliance scores of 8, followed by 183 schools (20.3%) with a score of 7 and 107 (11.9%) with a score of 6. It was found that parameter 5, namely cigarette butts found in the school environment, had the largest proportion when a school did not apply SFZ. Cigarette butts were found in 261 (29.0%) schools. Cigarette butts found in schools contributed 7.8 times to not applying SFZ compared to schools where no cigarette cutters were found.

    CONCLUSION: Although the SFZ compliance rate in Indonesian schools is 66.2% at least on 7 of 8 existed parameters, this means most of schools still aren't fully complying with the regulations for SFZs. This recent evidence will help decisionmakers to enforce tobacco control, particularly among youth, which form the pillar of national development.
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  7. Mukred AM, Hamid AA, Hamzah A, Yusoff WM
    Pak J Biol Sci, 2008 Sep 01;11(17):2122-7.
    PMID: 19266926
    Addition of nitrogen sources as supplementary nutrient into MSM medium to enhance biodegradation by stimulating the growth four isolates, Acinetobacter faecalis, Staphylococcus sp., Pseudomonas putida and Neisseria elongata isolated from petroleum contaminated groundwater, wastewater aeration pond and biopond at the oil refinery Terengganu Malaysia was investigated. The organic nitrogen sources tested not only supported growth but also enhances biodegradation of 1% Tapis crude oil. All four isolates showed good growth especially when peptone was employed as the organic nitrogen compared to growth in the basal medium. Gas chromatography showed that more then 91, 93, 94 and 95% degradation of total hydrocarbon was observed after 5 days of incubation by isolates Pseudomonas putida, Neisseria elongate, Acinetobacter faecalis and Staphylococcus sp., respectively.
  8. Mukred AM, Abd-Hamid A, Hamzah A, Yusoff WM
    Pak J Biol Sci, 2008 Jul 01;11(13):1708-12.
    PMID: 18819623
    The bioremediation of polluted groundwater, wastewater aeration pond and biopond sites was investigated using bacteria isolated from these sites located at the oil refinery Terengganu Malaysia. Out of 62 isolates, only 16 isolates from groundwater (8) and wastewater aeration pond (3) and biopond (5) were chosen based on growth medium containing 1% (v/v) Tapis crude oil. Only four isolates; Acinetobacter faecalis, Staphylococcus sp., Pseudomonas putida and Neisseria elongata showed percentage biodegradation of crude oil more than 50% after 5 days using Mineral Salts Medium (MSM). The effect of physical parameters (temperature, pH and agitation) on growth by all four strains showed a maximum growth in MSM medium with 1% Tapis crude oil at 37 degrees C with pH 7 and agitation of 130 rpm.
  9. Hamzah A, Krauss SE, Shaffril HA, Suandi T, Ismail IA, Abu Samah B
    Int J Psychol, 2014 Oct;49(5):397-403.
    PMID: 25178962 DOI: 10.1002/ijop.12010
    The vast majority of Malaysia's fishermen are located in rural areas, specifically in the Western and Eastern coastal regions of Peninsular Malaysia and the Sabah and Sarawak central zones. In these areas, the fishing industry is relied upon as a major economic contributor to the region's residents. Despite the widespread application of various modern technologies into the fishing industry (i.e., GPS, sonar, echo sounder, remote sensing), and the Malaysian government's efforts to encourage their adoption, many small-scale fishermen in the country's rural areas continue to rely on traditional fishing methods. This refusal to embrace new technologies has resulted in significant losses in fish yields and needed income, and has raised many questions regarding the inputs to decision making of the fishermen. Drawing on multiple literatures, in this article we argue for the use of a mental model approach to gain an in-depth understanding of rural Malaysian fishermen's choices of technology adoption according to four main constructs--prior experience, knowledge, expertise and beliefs or values. To provide needed inputs to agricultural specialists and related policy makers for the development of relevant plans of action, this article aims to provide a way forward for others to understand dispositional barriers to technology adoption among fishermen who use traditional methods in non-Western contexts.
  10. Bahraminejad N, Ibrahim F, Riji HM, Majdzadeh R, Hamzah A, Keshavarz Mohammadi N
    Health Promot Int, 2015 Dec;30(4):963-75.
    PMID: 24934454 DOI: 10.1093/heapro/dau043
    Community-based health promotion requires effective participation and partnership of diverse and numerous stakeholders from community as well as external professional organizations. Although effective partnership of stakeholders is often the key for success of health promotion practice and research, but this has proved to be a complex and challenging task. This study is an exploratory study to identify professional stakeholder's perspectives and experiences toward the partner's engagement challenges in community-based participatory research conducted in Population Research Centers in Iran. A qualitative study design with in-depth semi-structured interviews as data collection method was chosen. Using purposeful sampling technique, policy-makers and managers (mainly academics) involved in community-based participatory research in these centers were invited to be interviewed. Data were collected to the point where no new information was forthcoming. All interviews were taped and transcribed. To provide answers for research questions, qualitative content analysis was employed to extract emerging main themes from numerous cods. Findings were categorized in three main themes as Partnership's relationship and trust issues, Partnership's individual issues and Partnership's system issues. Although community-based participatory research in Iran benefits from more than a decade history and some physical infrastructures, but it seems that public health experts and researchers and other partner organizations are lagging behind in terms of capacities and competencies required to effectively utilize the available structure and opportunities. Hence, capacity development, both among professional partners and community may be the main way forward to tackling the future challenges for strengthening community actions but should include both levels of individuals and systems.
  11. Wibowo A, Ahmat N, Hamzah AS, Low AL, Mohamad SA, Khong HY, et al.
    Fitoterapia, 2012 Dec;83(8):1569-75.
    PMID: 22982329 DOI: 10.1016/j.fitote.2012.09.004
    A new oligostilbenoid tetramer, malaysianol B (1), was isolated from the acetone extract of the stem bark of Dryobalanops lanceolata along with seven oligostilbenoids tetramers; hopeaphenol (2), stenophyllol A (3), nepalensinol B (4), vaticanol B (5) and C (6), upunaphenol D (7), and flexuosol A (8). The structures of the isolated compounds were established on the basis of their spectroscopic data evidence. The antibacterial activity of the isolated compounds was evaluated using resazurin microtitre-plate assay.
  12. Wibowo A, Ahmat N, Hamzah AS, Sufian AS, Ismail NH, Ahmad R, et al.
    Fitoterapia, 2011 Jun;82(4):676-81.
    PMID: 21338657 DOI: 10.1016/j.fitote.2011.02.006
    A new resveratrol trimer, malaysianol A (1), five known resveratrol oligomers: laevifonol (2), ampelopsin E (3), α-viniferin (4), ε-viniferin (5), diptoindonesin A (6), and bergenin (7) have been isolated from the acetone extract of the stem bark of Dryobalanops aromatica by combination of vacuum and radial chromatography techniques. Their structures were established on the basis of their spectroscopic evidence and comparison with the published data. The cytotoxic activity of the compounds was tested against several cell lines in which compound 4 was found to inhibit strongly the growth of HL-60 cell line.
  13. Idris K, Mohamed Shaffril HA, Md Yassin S, Abu Samah A, Hamzah A, Abu Samah B
    PLoS One, 2016;11(3):e0150741.
    PMID: 26974837 DOI: 10.1371/journal.pone.0150741
    The main aim of this study is to identify the quality of life (QoL) among communities residing near the Tembeling, Pahang and Muar Rivers in Malaysia. This quantitative study used a constructed questionnaire as main tool to collect data on the QoL of river communities. A total of 240 villagers were selected as respondents. The results indicated that the dimensions of settlement, safety, involvement and social relationships, as well as education scored highest, while dimensions of physical environment, financial and job security yielded moderate scores. Dimensions of infrastructure facilities yielded a low mean score. Recommendations are provided, in the hope that our results may be useful for strategies that could enhance QoL of these river communities.
  14. Saha K, Lajis NH, Israf DA, Hamzah AS, Khozirah S, Khamis S, et al.
    J Ethnopharmacol, 2004 Jun;92(2-3):263-7.
    PMID: 15138010
    Methanol extracts of seven Malaysian medicinal plants were screened for antioxidant and nitric oxide inhibitory activities. Antioxidant activity was measured by using FTC, TBA and DPPH free radical scavenging methods and Griess assay was used for the measurement of nitric oxide inhibition in lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-treated RAW 264.7 cells. All the extracts showed strong antioxidant activity comparable to or higher than that of alpha-tocopherol, BHT and quercetin in FTC and TBA methods. The extracts from Leea indica and Spermacoce articularis showed strong DPPH free radical scavenging activity comparable with quercetin, BHT and Vit C. Spermacoce exilis showed only moderate activity but other species were weak as compared to the standards. In the Griess assay Lasianthus oblongus, Chasalia chartacea, Hedyotis verticillata, Spermacoce articularis and Leea indica showed strong inhibitory activity on nitric oxide production in LPS and IFN-gamma-induced RAW 264.7 cells. Extracts from Psychotria rostrata and Spermacoce exilis also inhibited NO production but this was due to their cytotoxic effects upon cells during culture.
  15. Sim SK, Lau BL, Zaila SR, Hazira N, Aniqah NM, Panicker J, et al.
    Med J Malaysia, 2021 03;76(2):138-144.
    PMID: 33742619
    INTRODUCTION: Healthcare workers serve as the frontliners against the coronavirus 2019 disease (COVID-19) and this puts them most at risk of infection as they attend to numerous patients with unknown status. This study aimed to examine stress, anxiety, and depression among healthcare workers caring for COVID-19 patients in Sarawak General Hospital (SGH), Malaysia.

    MATERIALS AND METHODS: This cross-sectional observational study conducted in SGH during the pandemic with an online self-administered questionnaire composed of two parts, the socio-demographic characteristics, and the Depression Anxiety Stress Scale (DASS).

    RESULTS: A total of 105 healthcare workers responded to this study. A questionnaire in both Bahasa Melayu and English was used. The findings showed that all healthcare workers had mild anxiety, with the majority experiencing mild stress (57.1%), and almost half of the respondents experiencing mild depression (41%). Female subjects had a significant higher mean score in anxiety level and stress level compared to male subjects (10.0±3.20 vs. 8.6±2.93, p<0.05; 14.1±4.76 vs. 10.7±3.70, p<0.05, respectively). Staff who were transferred from other units to handle COVID-19 cases experienced more psychological symptoms. There were significant correlations between the depression, anxiety and stress levels among the healthcare workers and the number of children they had (r=0.739, p=0.001; r=0.642, p=0.001; r=1, p =0.001 respectively). However, the stress level among the healthcare workers was reversely correlated with their years of working experience (r=-0.199, p=0.042).

    CONCLUSION: This study identified some socio-demographic factors associated with increased levels of stress, anxiety and depression among the healthcare workers during pandemic, which may lay ground for future interventions.

  16. Hosseingholipourasl A, Hafizah Syed Ariffin S, Ahmadi MT, Rahimian Koloor SS, Petrů M, Hamzah A
    Sensors (Basel), 2020 Jan 08;20(2).
    PMID: 31936402 DOI: 10.3390/s20020357
    Recent advances in nanotechnology have revealed the superiority of nanocarbon species such as carbon nanotubes over other conventional materials for gas sensing applications. In this work, analytical modeling of the semiconducting zigzag carbon nanotube field-effect transistor (ZCNT-FET) based sensor for the detection of gas molecules is demonstrated. We propose new analytical models to strongly simulate and investigate the physical and electrical behavior of the ZCNT sensor in the presence of various gas molecules (CO2, H2O, and CH4). Therefore, we start with the modeling of the energy band structure by acquiring the new energy dispersion relation for the ZCNT and introducing the gas adsorption effects to the band structure model. Then, the electrical conductance of the ZCNT is modeled and formulated while the gas adsorption effect is considered in the conductance model. The band structure analysis indicates that, the semiconducting ZCNT experiences band gap variation after the adsorption of the gases. Furthermore, the bandgap variation influences the conductance of the ZCNT and the results exhibit increments of the ZCNT conductance in the presence of target gases while the minimum conductance shifted upward around the neutrality point. Besides, the I-V characteristics of the sensor are extracted from the conductance model and its variations after adsorption of different gas molecules are monitored and investigated. To verify the accuracy of the proposed models, the conductance model is compared with previous experimental and modeling data and a good consensus is observed. It can be concluded that the proposed analytical models can successfully be applied to predict sensor behavior against different gas molecules.
  17. Jada SR, Matthews C, Saad MS, Hamzah AS, Lajis NH, Stevens MF, et al.
    Br J Pharmacol, 2008 Nov;155(5):641-54.
    PMID: 18806812 DOI: 10.1038/bjp.2008.368
    BACKGROUND AND PURPOSE: Andrographolide, the major phytoconstituent of Andrographis paniculata, was previously shown by us to have activity against breast cancer. This led to synthesis of new andrographolide analogues to find compounds with better activity than the parent compound. Selected benzylidene derivatives were investigated for their mechanisms of action by studying their effects on the cell cycle progression and cell death.
    EXPERIMENTAL APPROACH: Microculture tetrazolium, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and sulphorhodamine B (SRB) assays were utilized in assessing the in vitro growth inhibition and cytotoxicity of compounds. Flow cytometry was used to analyse the cell cycle distribution of control and treated cells. CDK1 and CDK4 levels were determined by western blotting. Apoptotic cell death was assessed by fluorescence microscopy and flow cytometry.
    KEY RESULTS: Compounds, in nanomolar to micromolar concentrations, exhibited growth inhibition and cytotoxicity in MCF-7 (breast) and HCT-116 (colon) cancer cells. In the NCI screen, 3,19-(2-bromobenzylidene) andrographolide (SRJ09) and 3,19-(3-chloro-4-fluorobenzylidene) andrographolide (SRJ23) showed greater cytotoxic potency and selectivity than andrographolide. SRJ09 and SRJ23 induced G(1) arrest and apoptosis in MCF-7 and HCT-116 cells, respectively. SRJ09 downregulated CDK4 but not CDK1 level in MCF-7 cells. Apoptosis induced by SRJ09 and SRJ23 in HCT-116 cells was confirmed by annexin V-FITC/PI flow cytometry analysis.
    CONCLUSION AND IMPLICATIONS: The new benzylidene derivatives of andrographolide are potential anticancer agents. SRJ09 emerged as the lead compound in this study, exhibiting anticancer activity by downregulating CDK4 to promote a G(1) phase cell cycle arrest, coupled with induction of apoptosis.
  18. Xian TK, Omar NA, Ying LW, Hamzah A, Raj S, Jaarin K, et al.
    PMID: 23320039 DOI: 10.1155/2012/828170
    Background. Palm oil is commonly consumed in Asia. Repeatedly heating the oil is very common during food processing. Aim. This study is aimed to report on the risk of atherosclerosis due to the reheated oil consumption. Material and Methods. Twenty four male Sprague Dawley rats were divided into control, fresh-oil, 5 times heated-oil and 10 times heated-oil feeding groups. Heated palm oil was prepared by frying sweet potato at 180°C for 10 minutes. The ground standard rat chows were fortified with the heated oils and fed it to the rats for six months. Results. Tunica intima thickness in aorta was significantly increased in 10 times heated-oil feeding group (P < 0.05), revealing a huge atherosclerotic plaque with central necrosis projecting into the vessel lumen. Repeatedly heated oil feeding groups also revealed atherosclerotic changes including mononuclear cells infiltration, thickened subendothelial layer, disrupted internal elastic lamina and smooth muscle cells fragmentation in tunica media of the aorta. Conclusion. The usage of repeated heated oil is the predisposing factor of atherosclerosis leading to cardiovascular diseases. It is advisable to avoid the consumption of repeatedly heated palm oil.
  19. Taib AK, Johari Z, Abd Rahman SF, Mohd Yusoff MF, Hamzah A
    PLoS One, 2023;18(3):e0282370.
    PMID: 36897883 DOI: 10.1371/journal.pone.0282370
    In this study, computational simulations were used to investigate the performance of a carbon-doped boron nitride nanoribbon (BC2NNR) for hydrogen (H2) gas sensing at elevated temperatures. The adsorption energy and charge transfer were calculated when H2 was simultaneously attached to carbon, boron, and both boron and nitrogen atoms. The sensing ability was further analyzed considering the variations in current-voltage (I-V) characteristics. The simulation results indicated that the energy bandgap of H2 on carbon, boron, and both boron and nitrogen exhibited a marginal effect during temperature variations. However, significant differences were observed in terms of adsorption energy at a temperature of 500 K, wherein the adsorption energy was increased by 99.62% of that observed at 298 K. Additionally, the evaluation of charge transfer indicated that the strongest binding site was achieved at high adsorption energies with high charge transfers. Analysis of the I-V characteristics verified that the currents were considerably affected, particularly when a certain concentration of H2 molecules was added at the highest sensitivity of 15.02% with a bias voltage of 3 V. The sensitivity at 298 K was lower than those observed at 500 and 1000 K. The study findings can form the basis for further experimental investigations on BC2NNR as a hydrogen sensor.
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