University of Malaya

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    A new experience of auditory brainstem implantation in Malaysia

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    Auditory brainstem implantation (ABI) is the only solution to restore hearing when cochlear nerves are disrupted together with the pathologies where bilateral cochleae do not provide a suitable location for cochlear implantation. We reported first two successful auditory brainstem implantation cases in patients with neurofibromatosis Type II (NF2) with bilateral acoustic neuroma causing bilateral profound sensorineural hearing loss in Malaysia. A good candidate selection, dedicated surgeons and rehabilitation team as well as strong family support are the crucial factors in achieving the best possible surgical, audiological and speech outcomes

    Actual safety performance of the Malaysian offshore oil platforms: Correlations between the leading and lagging indicators

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    Introduction: This study establishes the correlations between performance of a set of key safety factors and the actual lagging performance of oil platforms in Malaysia, hence the relevance of the key safety factors in evaluating and predicting the safety performance of oil and gas platforms. The key factors are crucial components of a safety performance evaluation framework and each key safety factor corresponds to a list of underlying safety indicators. Method: In this study, participating industrial practitioners rated the compliance status of each indicator using a numbering system adapted from the traffic light system, based on the actual performance of 10 oil platforms in Malaysia. Safety scores of the platforms were calculated based on the ratings and compared with the actual lagging performance of the platforms. Safety scores of two platforms were compared with the facility status reports’ findings of the respective platforms. Results: The platforms studied generally had good performance. Total recordable incident rates of the platforms were found to show significant negative correlations with management and work engagement on safety, compliance score for number of incident and near misses, personal safety, and management of change. Lost time injury rates, however, correlated negatively with hazard identification and risk assessment. The safety scores generally agreed with findings of the facility status reports with substandard process containment found as a contributor of hydrocarbon leaks. Conclusions: This study proves the criterion validity of the safety performance evaluation framework and demonstrates its usability for benchmarking and continuous improvement of safety practices on the Malaysian offshore oil and gas platforms. Practical applications: This study reveals the applicability of the framework and the potential of extending safety reporting beyond the few conventional lagging safety performance indicators used. The study also highlights the synergy between correlating safety factors to streamline safety management on offshore platforms

    In situ reactive extraction of Jatropha curcas L. seeds assisted by ultrasound: Preliminary studies

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    Esterification is required to reduce the high free fatty acid (FFA) content of crude Jatropha oil to below 3% prior to transesterification. In this study, raw decorticated Jatropha seeds were employed as the feedstock in in situ reactive extraction assisted by ultrasound in the presence of sulfuric acid (H2SO4) as a catalyst. Extraction efficiency, esterification efficiency, and fatty acid methyl ester (FAME) yield were optimized as a function of ultrasonic pulse mode, amplitude, and H2SO4 amount. The optimum extraction efficiency of 83.96%, esterification efficiency of 71.10%, and FAME yield of 38.58% were achieved at a pulse mode of 5 s on/2 s off, an ultrasonic amplitude of 60%, and an H2SO4 amount of 5 mL in reaction time of 150 min

    Fully automated segmentation of the left ventricle in cine cardiac MRI using neural network regression

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    Background: Left ventricle (LV) structure and functions are the primary assessment performed in most clinical cardiac MRI protocols. Fully automated LV segmentation might improve the efficiency and reproducibility of clinical assessment. Purpose: To develop and validate a fully automated neural network regression-based algorithm for segmentation of the LV in cardiac MRI, with full coverage from apex to base across all cardiac phases, utilizing both short axis (SA) and long axis (LA) scans. Study Type: Cross-sectional survey; diagnostic accuracy. Subjects: In all, 200 subjects with coronary artery diseases and regional wall motion abnormalities from the public 2011 Left Ventricle Segmentation Challenge (LVSC) database; 1140 subjects with a mix of normal and abnormal cardiac functions from the public Kaggle Second Annual Data Science Bowl database. Field Strength/Sequence: 1.5T, steady-state free precession. Assessment: Reference standard data generated by experienced cardiac radiologists. Quantitative measurement and comparison via Jaccard and Dice index, modified Hausdorff distance (MHD), and blood volume. Statistical Tests: Paired t-tests compared to previous work. Results: Tested against the LVSC database, we obtained 0.77 ± 0.11 (Jaccard index) and 1.33 ± 0.71 mm (MHD), both metrics demonstrating statistically significant improvement (P < 0.001) compared to previous work. Tested against the Kaggle database, the signed difference in evaluated blood volume was +7.2 ± 13.0 mL and –19.8 ± 18.8 mL for the end-systolic (ES) and end-diastolic (ED) phases, respectively, with a statistically significant improvement (P < 0.001) for the ED phase. Data Conclusion: A fully automated LV segmentation algorithm was developed and validated against a diverse set of cardiac cine MRI data sourced from multiple imaging centers and scanner types. The strong performance overall is suggestive of practical clinical utility. Level of Evidence: 3. Technical Efficacy: Stage 2. J. Magn. Reson. Imaging 2018

    Phase derivative thermo-spatiogram for distributed temperature sensing based on chirped grating-Michelson Interferometer

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    A novel thermometric measurement based on chirped fiber Bragg grating (CFBG) and Michelson Interferometer is proposed. The interrogation technique is based on the linear relation between the temperature and the phase derivative function of the grating, which is determined through Fourier transformation of the output spectrum. The Michelson interferometer configuration offers the flexibility in adjusting the position of coupling coefficient curve in the spatiogram, enabling the interrogation to be done at a shorter optical spectrum record length which can reduce the interrogation time and computation load

    Links between bacteria derived from penguin guts and deposited guano and the surrounding soil microbiota

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    Penguins are an important indicator of marine ecosystem health and a major contributor of nutrients to terrestrial ecosystems in Antarctica. Their stomach microbiota is influenced by both the prey consumed and their foraging environment in the sea. As penguins feed at sea and breed on land, they might be expected to transfer microbes (e.g. prey-associated and marine bacteria) as well as nutrients from their stomachs while regurgitating food or in their guano to the surrounding terrestrial environment. However, most research attention to date has focused separately on the penguin gut microbiota (via cloacal/guano samples) and the terrestrial soil microbiota, and any relationship between them has yet to be established. Here, we analysed the bacterial communities in stomach regurgitates and cloacal swabs from the same individual birds, freshly deposited guano and rookery soils of two Pygoscelis penguins that breed sympatrically on Signy Island (South Orkney Islands, maritime Antarctic) using a high-throughput DNA sequencing method. Our data do not support the hypothesis that bacteria transferred from penguin guts and/or deposited guano make a significant contribution to the communities of the surrounding terrestrial microbial ecosystem. In both penguin species, composition of bacterial communities differed between the four sample types, with Jaccard similarities ranging between 10 and 36%. Assemblages of the dominant and co-occurring bacterial communities in rookery soils were either significantly negatively correlated or not correlated with the three other sample types. Sample-specific communities were also identified in this study, contributing around 63% of the identified diversity overall

    On the behaviour of mid-connection in off-centre bracing system

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    This paper presents theoretical and experimental investigations on the behaviour of mid-connections in an off-centre bracing system. This braced system is preferred by architects because of the eccentricity introduced by the diagonal brace members, which allows a wider area of opening in the frame panel. Assumptions when designing the system in two dimensions has led to severe damage of structures based on observations of the recent Bam earthquake. In this regard, the assumption of mid-connection of the brace elements has a significant effect on the behaviour, stability and lateral buckling load resistance of the system. In order to investigate the effect of mid-connection types on the behaviour of the system, two possible implementations of this connection were considered. Based on the slope-deflection method and equilibrium equation at the connection point, the stiffness matrix was obtained to calculate the lateral buckling load of the system. In addition, to validate the theoretical calculation and practical consideration of the system, two frames of one-third scale were fabricated and tested. A good agreement between the experimental results and the theoretical calculations was obtained

    Bakuchiol is an effective antimicrobial agent in maintaining oral health of the elderly adults

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    Aging leads to hyposalivation, which in turn alters the normal oral microflora. Candida species often becomes a predominant inhabitant due to changes in the physiology and functions of the oral fluid and tissues. This study aimed to determine the antimicrobial activity of active compound bakuchiol on candidal population of the elderly adults. The action mechanism of bakuchiol may suggest its potential as an effective agent for the maintenance of oral health in this target group

    The association between obesity and dengue severity among pediatric patients: A systematic review and meta-analysis

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    Background: Severe dengue infection often has unpredictable clinical progressions and outcomes. Obesity may play a role in the deterioration of dengue infection due to stronger body immune responses. Several studies found that obese dengue patients have a more severe presentation with a poorer prognosis. However, the association was inconclusive due to the variation in the results of earlier studies. Therefore, we conducted a systematic review and meta-analysis to explore the relationship between obesity and dengue severity. Methods: We performed a systematic search of relevant studies on Ovid (MEDLINE), EMBASE, the Cochrane Library, Web of Science, Scopus and grey literature databases. At least two authors independently conducted the literature search, selecting eligible studies, and extracting data. Meta-analysis using random-effects model was conducted to compute the pooled odds ratio with 95% confidence intervals (CI). Findings: We obtained a total of 13,333 articles from the searches. For the final analysis, we included a total of fifteen studies among pediatric patients. Three cohort studies, two case-control studies, and one cross-sectional study found an association between obesity and dengue severity. In contrast, six cohort studies and three case-control studies found no significant relationship between obesity and dengue severity. Our meta-analysis revealed that there was 38 percent higher odds (Odds Ratio = 1.38; 95% CI:1.10, 1.73) of developing severe dengue infection among obese children compared to non-obese children. We found no heterogeneity found between studies. The differences in obesity classification, study quality, and study design do not modify the association between obesity and dengue severity. Conclusion: This review found that obesity is a risk factor for dengue severity among children. The result highlights and improves our understanding that obesity might influence the severity of dengue infection

    Modified mesoporous HMS supported Ni for deoxygenation of triolein into hydrocarbon-biofuel production

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    A series of modified hexagonal mesoporous silica (HMS) supported by various Ni loading (5 wt% Ni, 10 wt% Ni, 40 wt% Ni and 100 wt% Ni) have been synthesized and systematically characterized. The resultant Ni catalysts improved the performance of the deoxygenation (DO) of triolein at a reaction temperature of 380 °C in a simple glass batch reactor under a solvent-free condition and are hydrogen-free. The incorporation of Ni loading into the HMS framework casued the catalytic activity to increase when compared to that of HMS. Surprisingly, 10 wt% Ni/HMS catalyst exhibited the highest conversion. It was observed that 10 wt% Ni loading was highly dispersed on the HMS which is capable of achieving 92.5% and 95.2% of conversion and selectivity, respectively. This is due to the synergistic effect of Si-O-Ni bonding and high dispersion of NiO on HMS. In this respect, the nature of catalyst support such as pore size and the high surface areas of HMS play an important role in enhancing the catalytic performance of DO reaction. This study has revealed that Ni/HMS catalyst is a promising catalyst that can be applied to the development of sustainable biofuel from non-edible oil

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