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Fulltext Motorcycle Conspicuity Issues and Intervention: A Systematic Review

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.
Fulltext Favourable response to splenectomy in familial myelodysplastic syndrome

Abdul-Wahab J, Naznin M, Suhaimi A, Amir-Hamzah AR

Singapore Med J, 2007 Jul;48(7):e206-8.
PMID: 17609817

Familial myelodysplastic syndrome occurring at a young age is a very rare childhood haematological malignancy. Two siblings, aged three and 18 years, from a consanguineous marriage, presented with pancytopenia and was subsequently diagnosed to have myelodysplastic syndrome. Both remained clinically stable throughout the illness. Splenectomy appeared to have fully corrected the cytopenia in one of them.
Fulltext Transcatheter Closure of Patent Ductus Arteriosus: The Penang Hospital's Experience

Amir Hamzah AR, Tiow CA, Koh GT, Sharifah AM

Med J Malaysia, 2011 Mar;66(1):19-21.
PMID: 23765137

Transcatheter closure of small and moderate sizes of Patent Ductus Arteriosus (PDA) is a standard and well accepted form of treatment. The aim of this study is to describe the experience of transcatheter closure of PDA in Penang Hospital. All patients who underwent transcatheter closure of PDA at our institution between 20th January 2006 and 27th June 2008 were retrospectively identified and studied. There were a total of 66 patients who had undergone transcatheter closure of PDA during this period which comprised of 24 male and 42 female. The PDA was closed by Amplatzer Duct Occluder (ADO) in 31 patients, Gianturco coil in 29 patients and other types of devices in 6 patients. There were 4 patients (6%) who had developed acute complication during the procedure (3 of them developed coil embolization and 1 had bleeding from puncture site). The PDA was successfully close in 95.5% of the study population without any residual PDA shunting. All the patients were alive but 5 of them (4.5%) have some abnormalities (2 has mild left pulmonary stenosis, 3 has small residual). Comparison between ADO and Gianturco coil revealed no significant difference in the outcome. Transcatheter closure of PDA has proven to be safe and effective with good midterm outcome. There was no significant difference between Amplatzer Ductal Occluder and Gianturco coil in term of the outcome.
Analyzing the relationships between travel mode indicators and the number of passenger transport fatalities at the city level

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.
Fulltext Prevalence of Smoke-Free Zone Compliance among Schools in Indonesia: A Nationwide Representative Survey

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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Partner's engagement in community-based health promotion programs: a case study of professional partner's experiences and perspectives in Iran

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.
Fulltext Modeling the Impact of Phonon Scattering with Strain Effects on the Electrical Properties of MoS2 Field-Effect Transistors

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.
Fulltext Semi-analytical modelling and evaluation of uniformly doped silicene nanotransistors for digital logic gates

Chuan MW, Wong KL, Riyadi MA, Hamzah A, Rusli S, Alias NE, et al.

PLoS One, 2021;16(6):e0253289.
PMID: 34125874 DOI: 10.1371/journal.pone.0253289

Silicene has attracted remarkable attention in the semiconductor research community due to its silicon (Si) nature. It is predicted as one of the most promising candidates for the next generation nanoelectronic devices. In this paper, an efficient non-iterative technique is employed to create the SPICE models for p-type and n-type uniformly doped silicene field-effect transistors (FETs). The current-voltage characteristics show that the proposed silicene FET models exhibit high on-to-off current ratio under ballistic transport. In order to obtain practical digital logic timing diagrams, a parasitic load capacitance, which is dependent on the interconnect length, is attached at the output terminal of the logic circuits. Furthermore, the key circuit performance metrics, including the propagation delay, average power, power-delay product and energy-delay product of the proposed silicene-based logic gates are extracted and benchmarked with published results. The effects of the interconnect length to the propagation delay and average power are also investigated. The results of this work further envisage the uniformly doped silicene as a promising candidate for future nanoelectronic applications.
Fulltext Device performances analysis of p-type doped silicene-based field effect transistor using SPICE-compatible model

Chuan MW, Riyadi MA, Hamzah A, Alias NE, Mohamed Sultan S, Lim CS, et al.

PLoS One, 2022;17(3):e0264483.
PMID: 35239699 DOI: 10.1371/journal.pone.0264483

Moore's Law is approaching its end as transistors are scaled down to tens or few atoms per device, researchers are actively seeking for alternative approaches to leverage more-than-Moore nanoelectronics. Substituting the channel material of a field-effect transistors (FET) with silicene is foreseen as a viable approach for future transistor applications. In this study, we proposed a SPICE-compatible model for p-type (Aluminium) uniformly doped silicene FET for digital switching applications. The performance of the proposed device is benchmarked with various low-dimensional FETs in terms of their on-to-off current ratio, subthreshold swing and drain-induced barrier lowering. The results show that the proposed p-type silicene FET is comparable to most of the selected low-dimensional FET models. With its decent performance, the proposed SPICE-compatible model should be extended to the circuit-level simulation and beyond in future work.
Toward understanding Malaysian fishermen's decision making on the use of fishing technology: a mental model approach

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.
Cloning of high activity xylanase gene from Bacillus pumilus PJ19

Hamzah A, Abdulrashid N

J. Biochem. Mol. Biol. Biophys., 2002 Oct;6(5):365-9.
PMID: 12385974

The xylanase gene from Bacillus pumilus PJ19 amplified by polymerase chain reaction (PCR) was cloned into pCRII vector and transformed into Escherichia coli strain INValphaF'. Starting from an ATG as an initiator codon, an open reading frame coding for 202 amino acids was obtained. The recombinant xylanase sequence showed a 96% homology with the xylanase sequence from B. pumilus IPO strain and had an estimated molecular weight of 22,474. Xylanase activity expressed by E. coli INValphaF' harboring the cloned gene was located primarily in the cytoplasmic fraction.
Genetic analysis of a red tilapia (Oreochromis spp.) population undergoing three generations of selection for increased body weight at harvest

Hamzah A, Thoa NP, Nguyen NH

J Appl Genet, 2017 Nov;58(4):509-519.
PMID: 28980200 DOI: 10.1007/s13353-017-0411-8

Quantitative genetic analysis was performed on 10,919 data records collected over three generations from the selection programme for increased body weight at harvest in red tilapia (Oreochromis spp.). They were offspring of 224 sires and 226 dams (50 sires and 60 dams per generation, on average). Linear mixed models were used to analyse body traits (weight, length, width and depth), whereas threshold generalised models assuming probit distribution were employed to examine genetic inheritance of survival rate, sexual maturity and body colour. The estimates of heritability for traits studied (body weight, standard length, body width, body depth, body colour, early sexual maturation and survival) across statistical models were moderate to high (0.13-0.45). Genetic correlations among body traits and survival were high and positive (0.68-0.96). Body length and width exhibited negative genetic correlations with body colour (- 0.47 to - 0.25). Sexual maturity was genetically correlated positively with measurements of body traits (weight and length). Direct and correlated genetic responses to selection were measured as estimated breeding values in each generation and expressed in genetic standard deviation units (σG). The cumulative improvement achieved for harvest body weight was 1.72 σG after three generations or 12.5% per generation when the gain was expressed as a percentage of the base population. Selection for improved body weight also resulted in correlated increase in other body traits (length, width and depth) and survival rate (ranging from 0.25 to 0.81 genetic standard deviation units). Avoidance of black spot parent matings also improved the overall red colour of the selected population. It is concluded that the selective breeding programme for red tilapia has succeeded in achieving significant genetic improvement for a range of commercially important traits in this species, and the large genetic variation in body colour and survival also shows that there are prospects for future improvement of these traits in this population of red tilapia.
Fibrous Hamartoma of the Chest Wall: A Benign Tumour that Mimics a Malignant Entity

Hamzah AA, Mallhi TH, Khan AH, Adnan AS, Khan YH

West Indian Med J, 2015 Dec 16.
PMID: 27617795 DOI: 10.7727/wimj.2015.330
Rare middle ear anomaly in a patient with Turner's syndrome

Hamzah AR, Jalaluddin MA, Raman R

Ann Otol Rhinol Laryngol, 1999 Mar;108(3):253-4.
PMID: 10086617

A patient with Turner's syndrome presented with a rare anomaly of absent oval window, inferiorly placed facial nerve, and abnormal stapes. To our knowledge, this is the first report of this combination of malformations.
Kaempferitrin from the leaves of Hedyotis verticillata and its biological activity

Hamzah AS, Lajis NH, Sargent MV

Planta Med, 1994 Aug;60(4):388-9.
PMID: 7938277
Youth hedonistic behaviour: moderating role of peer attachment on the effect of religiosity and worldview

Hamzah SR, Suandi T, Krauss SE, Hamzah A, Tamam E

Int J Adolesc Youth, 2014 Oct 2;19(4):419-433.
PMID: 25431513

This study was carried out on the moderating effect of peer attachment on the relationships between religiosity and worldview, and on how hedonistic behaviour among Malaysian undergraduate students is shaped by such influences. With regard to peer attachment, the study focused on the influences of communication, trust and alienation among youth. Bronfenbrenner's theory of human ecology and Armsden and Greenberg's attachment model were used as the framework. Drawing on a quantitative survey of 394 Malaysian university students (M age = 21.0, SD = 0.40), structural equation modelling and path analysis revealed a significant relationship between worldview and hedonistic behaviour. Peer attachment moderated the relationships between religiosity and religious worldview. The results further showed that the unique moderating effect of the lower level of attachment with peers is positively related to the hedonistic behaviour. Implications from the findings are discussed.
Fulltext The Impact of Emotional Solidarity on Residents' Attitude and Tourism Development

Hasani A, Moghavvemi S, Hamzah A

PLoS One, 2016;11(6):e0157624.
PMID: 27341569 DOI: 10.1371/journal.pone.0157624

In many countries, especially one such as Malaysia, tourism has become a key factor in economic development, and the industry heavily relies on feedback from local residents. It is essential to observe and examine the perceptions of residents towards tourists and tourism development for better planning in realizing successful and sustainable tourism development. Therefore, this research measured the relationship between residents' welcoming nature, emotional closeness, and sympathetic understanding (emotional solidarity) towards tourists and their respective attitudes towards supporting tourism development. To test the proposed research model, we collected data using a questionnaire survey from 333 residents in rural areas in Malaysia. We used the structural equation modelling technique (Amos) to evaluate the research model, and the results revealed that the residents' willingness (welcoming nature) to accept tourists is the strongest factor that effects the residents' attitudes towards supporting tourism development. However, there was no significant relationship between residents' emotional closeness and their sympathetic understanding towards tourists with their attitude and support towards tourism development. Welcoming nature, emotional closeness, and sympathetic understanding are able to predict 48% of residents' attitudes towards tourism development and 62% of their support towards tourism development.
Fulltext An Analytical Conductance Model for Gas Detection Based on a Zigzag Carbon Nanotube Sensor

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.
Fulltext Quality of Life in Rural Communities: Residents Living Near to Tembeling, Pahang and Muar Rivers, Malaysia

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.
Fulltext Benzylidene derivatives of andrographolide inhibit growth of breast and colon cancer cells in vitro by inducing G(1) arrest and apoptosis

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.

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