Displaying publications 61 - 72 of 72 in total

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  1. Chen LH, Shen HT, Chang WH, Khalil I, Liao SY, A Yehye W, et al.
    Nanomaterials (Basel), 2020 Oct 07;10(10).
    PMID: 33036455 DOI: 10.3390/nano10101985
    Graphene (Gr)/gold (Au) and graphene-oxide (GO)/Au nanocomposites (NCPs) were synthesized by performing pulsed-laser-induced photolysis (PLIP) on hydrogen peroxide and chloroauric acid (HAuCl4) that coexisted with Gr or GO in an aqueous solution. A 3-month-long aqueous solution stability was observed in the NCPs synthesized without using surfactants and additional processing. The synthesized NCPs were characterized using absorption spectroscopy, transmission electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray diffraction to prove the existence of hybrid Gr/Au or GO/Au NCPs. The synthesized NCPs were further evaluated using the photocatalytic reaction of methylene blue (MB), a synthetic dye, under UV radiation, visible light (central wavelength of 470 nm), and full spectrum of solar light. Both Gr/Au and GO/Au NCPs exhibited photocatalytic degradation of MB under solar light illumination with removal efficiencies of 92.1% and 94.5%, respectively.
    Matched MeSH terms: Lighting
  2. Ting SL, Saimon R, Rahman MM, Safii R, Ho SL, John N, et al.
    Med J Malaysia, 2020 11;75(6):649-654.
    PMID: 33219172
    BACKGROUND AND OBJECTIVE: Physical and behavioural problems from extended usage of electronic devices are issues among primary school children. This study is aimed to investigate the prevalence of physical and behavioural complaints arising from the electronic device usage and to identify the potential factors that predicted the complaints.

    METHODS: This was a primary school-based cross-sectional study using multistage cluster sampling, conducted at Bau district in Sarawak, Malaysia in 40 primary schools. A questionnaire was used to collect information of usage pattern in insufficient lighting, timing and position. The physical and behavioural complaints were traced. Data analysis was performed using SPSS version 22. A p-value < 0.05 with 95% CI was considered as statistically significant.

    RESULTS: About 52.8% of the 569 students used digital devices in a bright room, 69.8% in the day time and 54.4% in sitting position. The physical complaints were headache (32.9%), neck, shoulder and back pain (32.9%) followed by by eye strain (31.8%). Regarding behavioural problems, 25.7% of the students had loss of interest in study and outdoor activities (20.7%), skipped meals (19.0%) and arguments/disagreements with parents (17.9%). After logistic regression analysis, the lying position (OR=1.71, 95% CI: 1.096, 2.688) and darkroom lighting (OR=2.323 95% CI: 1.138, 4.744) appeared to be potential predictors of the complaint.

    CONCLUSION: One-quarter of the students studied experienced physical complaints, and one-fifth had behavioural problems associated with the use of electronic devices. Lying position and darkroom lighting are the potential predictors of complaints. Therefore, we suggest that the children should use electronic devices in the sitting position with adequate room lighting.

    Matched MeSH terms: Lighting
  3. Anuar, I., Mohamad Jauhari, J., Mohd Riduan, A.
    MyJurnal
    Background: Level of comfort in working environment can contribute to increase level of health, emotion during working, level of safety, quality and productivity of work. A study of physical factors (heat, noise and lighting) is important to determine the level of comfort during working. This study was carried out to study those physical factors upon comfort level during working among Casting Shop workers in a car manufacturing factory.

    Methods: Instruments for the physical monitoring including Questemp°36 Thermal Environment Monitor, Sound Level Meter and Lux Meter were used at seven measured areas. The information about the level of comfort during working was collected using questionnaires among 65 respondents by random sampling method.

    Results: Measured data showed there were four measured areas which Wet Bulb Globe Temperature indoor (WBGTi) value are above the standard limit recommended by ACGIH, three measured areas recorded noise level above the standard limit recommended by Factories and Machineries (Noise Exposure) 1989, while there was no measured area recorded lighting reading below the standard limit recommended by MS ISO 8995:2005. Result from questionnaire found that the majority of the workers did not feel comfortable towards the heat and noise level in their workplace while most of the respondents felt comfortable towards lighting level in their workplace. Mean of WBGTi reading and lighting reading have a significant difference (p
    Matched MeSH terms: Lighting
  4. Roslizar A, Alghoul MA, Bakhtyar B, Asim N, Sopian K
    ScientificWorldJournal, 2014;2014:310539.
    PMID: 25485294 DOI: 10.1155/2014/310539
    Buildings are among the largest consumers of energy. Part of the energy is wasted due to the habits of users and equipment conditions. A solution to this problem is efficient energy usage. To this end, an energy audit can be conducted to assess the energy efficiency. This study aims to analyze the energy usage of a primary school and identify the potential energy reductions and cost savings. A preliminary audit was conducted, and several energy conservation measures were proposed. The energy conservation measures, with reference to the MS1525:2007 standard, were modelled to identify the potential energy reduction and cost savings. It was found that the school's usage of electricity exceeded its need, incurring an excess expenditure of RM 2947.42. From the lighting system alone, it was found that there is a potential energy reduction of 5489.06 kWh, which gives a cost saving of RM 2282.52 via the improvement of lighting system design and its operating hours. Overall, it was found that there is a potential energy reduction and cost saving of 20.7% when the energy conservation measures are earnestly implemented. The previous energy intensity of the school was found to be 50.6 kWh/m(2)/year, but can theoretically be reduced to 40.19 kWh/mm(2)/year.
    Matched MeSH terms: Lighting
  5. Payani S, Law TH
    Int J Inj Contr Saf Promot, 2020 Jun;27(2):188-196.
    PMID: 32019438 DOI: 10.1080/17457300.2020.1724159
    Fatal motorcycle crashes are a persistent problem in Southeast Asia. In many respects, road safety experts have acknowledged conspicuity issue as one of the main causes of such accidents. To mitigate this deficiency, daytime running headlights (DRHs) law has been documented among the widely exercised countermeasures. The present study aimed to explore socio-psychological factors shaping intentions towards use of DRHs among Malaysian motorcyclists, because compliance level with this rule has remained constant since 1996 (80%). For this purpose, a model was constructed through the Theory of Planned Behaviour (TPB) to evaluate factors affecting motorcyclists' intentions towards compliance with DRHs law. A series of statistical analyses were performed to explain the effect of these factors and to predict degree of compliance with this rule. The model applied on a sample of university students (N = 398) demonstrated that the TPB components could significantly predict motorcycle riders' behaviours and degree of compliance with DRHs law. Moreover, it would be of assistance to policy-makers to recognize groups of motorcyclists more likely to cause an increase in traffic accidents. In general, regular educational campaigns were recommended to raise awareness regarding consequences of not using DRHs and also to nurture factors influencing motorcyclists' attitudes towards DRHs.
    Matched MeSH terms: Lighting/legislation & jurisprudence*
  6. Rahman HA, Che Ani AI, Harun SW, Yasin M, Apsari R, Ahmad H
    J Biomed Opt, 2012 Jul;17(7):071308.
    PMID: 22894469 DOI: 10.1117/1.JBO.17.7.071308
    The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm; 0.775 mV/mm and 0.4 mm; 0.5109 mV/mm and 0.5 mm; and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.
    Matched MeSH terms: Lighting/instrumentation*
  7. Ahmed AB, Rao AS, Rao MV, Taha RM
    ScientificWorldJournal, 2012;2012:897867.
    PMID: 22629221 DOI: 10.1100/2012/897867
    Gymnema sylvestre (R.Br.) is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA). The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L) and KN (0.5 mg/L). Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w) was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w). Maximum GA production (58.28 mg/g d.w) was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors.
    Matched MeSH terms: Lighting/methods*
  8. Mohd Ridah LJ, A Talib N, Muhammad N, Hussain FA, Zainuddin N
    Asian Pac J Cancer Prev, 2017 10 26;18(10):2781-2785.
    PMID: 29072413
    Introduction: p16 gene plays an important role in the normal cell cycle regulation. Methylation of p16 has been reported to be one of the epigenetic events contributing to the pathogenesis of diffuse large B-cell lymphoma (DLBCL) which occurring at varying frequency. DLBCL is an aggressive and high-grade malignancy which accounts for approximately 30% of all non-Hodgkin lymphoma cases. However, little is known regarding the epigenetic alterations of p16 gene in DLBCL cases in Malaysia. Therefore, the objective of this study was to examine the status of p16 methylation in DLBCL. Methods: A total of 88 formalin-fixed paraffin-embedded DLBCL tissues retrieved from two hospitals located in the east coast of Malaysia, namely Hospital Tengku Ampuan Afzan (HTAA) Pahang and Hospital Universiti Sains Malaysia (HUSM) Kelantan, were chosen for this study. DNA specimens were isolated and subsequently subjected to bisulfite treatment prior to methylation specific-PCR. Two pairs of primers were used to amplify methylated and unmethylated regions of p16 gene. The PCR products were then separated using agarose gel electrophoresis and visualised under UV illumination. SPSS version 12.0 was utilised to perform all statistical analysis. Result: p16 methylation was detected in 65 of 88 (74%) samples. There was a significant association between p16 methylation status and patients aged >50 years old (p=0.04). Conclusion: Our study demonstrated that methylation of p16 tumor suppressor gene in our DLBCL cases is common and significantly increased among patients aged 50 years and above. Aging is known to be an important risk factor in the development of cancers and we speculate that this might be due to the increased transformation of malignant cells in aging cell population. However, this has yet to be confirmed with further research and correlate the findings with clinicopathological parameters.
    Matched MeSH terms: Lighting
  9. Khim TP, Sanggar V, Shan TW, Peng KC, Western JS, Dicksit DD
    J Conserv Dent, 2018 10 9;21(5):562-568.
    PMID: 30294122 DOI: 10.4103/JCD.JCD_115_18
    Introduction: Among the various causes of tooth discoloration after root canal treatment, percolation of sealer remnants into the dentinal tubules of the pulp chamber is the most common cause.

    Objectives: The aim of this study is to evaluate the efficacy of dentin bonding agent (DBA) in preventing coronal discoloration caused by four different root canal sealers- MTA Fillapex, Sealapex, Zical and Z. O. B seal at different time intervals by measuring chromatic alterations using digital images analysis method.

    Methodology: Ninety mandibular premolars were collected and sectioned at 1 mm below the cementoenamel junction. Standard access cavity preparations of dimensions (depth-3 mm, width-0.8 mm, and length-3 mm) were prepared with a No. 245 bur through the cervical access. Following the standard irrigation protocol, specimens were then randomly divided into nine groups (four groups without DBA [1-4] +4 groups with DBA [5-8] +1 negative control [9]). In Groups 1-4, four different root canal sealers (MTA Fillapex, Sealapex, Zical, and Z.O.B seal) were applied to the walls of the pulp chamber. For Groups 5-8, the samples were etched with 37% phosphoric acid and DBA application was done before the respective root canal sealer application. The cervical access in all specimens was sealed using glass ionomer cement. Digital photographs were taken under standard lighting and environmental conditions at different time intervals: preprocedural, postprocedural, and after 1, 2, 3, and 4 months. These images were analyzed using Adobe Photoshop CS6 from which laboratory values and subsequently Delta E values were obtained.

    Results: Statistical analysis performed using repeated measures ANOVA and post hoc Tukey's tests show that the groups with DBA application had significantly lower mean Delta E values (P < 0.05) compared to the groups without DBA application.

    Conclusion: DBAs applied to the dentinal walls of the pulp chamber before obturation can effectively reduce the sealer-induced coronal discoloration.

    Matched MeSH terms: Lighting
  10. Mallick Z, Siddiquee AN, Haleem A
    J Hum Ergol (Tokyo), 2008 Dec;37(2):57-66.
    PMID: 19227193 DOI: 10.11183/jhe1972.37.57
    The last 20 years have seen a tremendous growth in the field of computing with special reference to mobile computing. Ergonomic issues pertaining to this theme remains unexplored. With special reference to readability in mobile computing, an experimental research was conducted to study the gender effect on human performance under the impact of vibration in a human computer interaction environment. Fourteen subjects (7 males and 7 females) participated in the study. Three independent variables, namely gender, level of vibration and screen text/background colour, were selected for the experimental investigation while the dependent variable was the number of characters read per minute. The data collected were analyzed statistically through an experimental design for repeated measures. Results indicated that gender as an organismic variable, the level of vibration and screen text/background colour revealed statistically significant differences. However, the second order interaction was found to be statistically non-significant. These findings are discussed in light of the previous studies undertaken on the topic.
    Matched MeSH terms: Lighting
  11. Cyranoski D, Law YH, Ong S, Phillips N, Zastrow M
    Nature, 2018 06;558(7711):502-510.
    PMID: 29950631 DOI: 10.1038/d41586-018-05506-1
    Matched MeSH terms: Lighting/instrumentation*
  12. Boo NY, Chee SC, Rohana J
    Acta Paediatr, 2002;91(6):674-9.
    PMID: 12162601
    A randomized controlled study was carried out on 96 preterm infants (< 37 wk) with birthweight less than 2000 g admitted to a neonatal intensive care unit. The aim was to compare the weight gain between preterm infants exposed to 12 h cyclical lighting (intensity of light: 78.4 +/- 24.7 lux, mean +/- SD) and those exposed to a continuously dim environment (5.9 +/- 1.9 lux). The exclusion criteria were infants with major congenital malformations or who needed continuous lighting for treatment procedure and care. From day 7 of life until discharge, 50 infants were randomized to receive 12 h cyclical lighting and 46 infants to a continuously dim environment. There was no significant difference in the mean birthweight (12 h lighting vs continuously dim: 1482 vs 1465 g, p = 0.8), mean gestational age (31.6 vs 31.4 wk, p = 0.6), median duration of hospital stay (28.5 vs 28.5 d, p = 0.8), mean age to regain birthweight (13.0 vs 12.9 d, p = 0.3), mean weight gained by day 14 (27.6 vs 36.2 g, p = 1.0), median weight gain per day (11.9 vs 12.2 g, p = 0.9) or median body weight on discharge (1800 vs 1800 g, p = 0.4) between the two groups of infants.

    CONCLUSION: Exposing preterm infants to either 12 h cyglical lighting or continuously dim environment did not have any significant effect on their weight gain during the neonatal period.

    Matched MeSH terms: Lighting
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