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Fulltext Ultrathin Assembles of Porous Array for Enhanced H2 Evolution

Islam A, Hwa Teo S, Awual MR, Taufiq-Yap YH

Sci Rep, 2020 Feb 11;10(1):2324.
PMID: 32047187 DOI: 10.1038/s41598-020-59325-4

Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H2) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UV-visible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh-1 which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water.

Matched MeSH terms: Lighting
Fulltext Efficient Solar-Induced Photoelectrochemical Response Using Coupling Semiconductor TiO₂-ZnO Nanorod Film

Abd Samad NA, Lai CW, Lau KS, Abd Hamid SB

Materials (Basel), 2016 Nov 22;9(11).
PMID: 28774068 DOI: 10.3390/ma9110937

Efficient solar driven photoelectrochemical (PEC) response by enhancing charge separation has attracted great interest in the hydrogen generation application. The formation of one-dimensional ZnO nanorod structure without bundling is essential for high efficiency in PEC response. In this present research work, ZnO nanorod with an average 500 nm in length and average diameter of about 75 nm was successfully formed via electrodeposition method in 0.05 mM ZnCl₂ and 0.1 M KCl electrolyte at 1 V for 60 min under 70 °C condition. Continuous efforts have been exerted to further improve the solar driven PEC response by incorporating an optimum content of TiO₂ into ZnO nanorod using dip-coating technique. It was found that 0.25 at % of TiO₂ loaded on ZnO nanorod film demonstrated a maximum photocurrent density of 19.78 mA/cm² (with V vs. Ag/AgCl) under UV illumination and 14.75 mA/cm² (with V vs. Ag/AgCl) under solar illumination with photoconversion efficiency ~2.9% (UV illumination) and ~4.3% (solar illumination). This performance was approximately 3-4 times higher than ZnO film itself. An enhancement of photocurrent density and photoconversion efficiency occurred due to the sufficient Ti element within TiO₂-ZnO nanorod film, which acted as an effective mediator to trap the photo-induced electrons and minimize the recombination of charge carriers. Besides, phenomenon of charge-separation effect at type-II band alignment of Zn and Ti could further enhance the charge carrier transportation during illumination.

Matched MeSH terms: Lighting
Fulltext Soft bilateral filtering volumetric shadows using cube shadow maps

Ali HH, Sunar MS, Kolivand H

PLoS One, 2017;12(6):e0178415.
PMID: 28632740 DOI: 10.1371/journal.pone.0178415

Volumetric shadows often increase the realism of rendered scenes in computer graphics. Typical volumetric shadows techniques do not provide a smooth transition effect in real-time with conservation on crispness of boundaries. This research presents a new technique for generating high quality volumetric shadows by sampling and interpolation. Contrary to conventional ray marching method, which requires extensive time, this proposed technique adopts downsampling in calculating ray marching. Furthermore, light scattering is computed in High Dynamic Range buffer to generate tone mapping. The bilateral interpolation is used along a view rays to smooth transition of volumetric shadows with respect to preserving-edges. In addition, this technique applied a cube shadow map to create multiple shadows. The contribution of this technique isreducing the number of sample points in evaluating light scattering and then introducing bilateral interpolation to improve volumetric shadows. This contribution is done by removing the inherent deficiencies significantly in shadow maps. This technique allows obtaining soft marvelous volumetric shadows, having a good performance and high quality, which show its potential for interactive applications.

Matched MeSH terms: Lighting
Fulltext Feasibility of fiber optic displacement sensor scanning system for imaging of dental cavity

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*
An application of the theory of planned behaviour to understand compliance with daytime running headlights law among motorcycle riders

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*
Fulltext Production of gymnemic acid depends on medium, explants, PGRs, color lights, temperature, photoperiod, and sucrose sources in batch culture of Gymnema sylvestre

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*
Prevention of coronal discoloration induced by root canal sealer remnants using Dentin Bonding agent: An in vitro study

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
Fulltext Mobile computing with special reference to readability task under the impact of vibration, colour combination and gender

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
p16 Tumor Suppressor Gene Methylation in Diffuse Large B Cell Lymphoma: A Study of 88 Cases at Two Hospitals in the East Coast of Malaysia

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
Science stars of East Asia

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*
Randomized controlled study of the effects of different durations of light exposure on weight gain by preterm infants in a neonatal intensive care unit

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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