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Driving style recognition using machine learning and smartphones

Bin Jamal Mohd Lokman EH, Goh VT, Yap TTV, Ng H

F1000Res, 2022;11:57.
PMID: 37082303 DOI: 10.12688/f1000research.73134.1

Background: The lack of real-time monitoring is one of the reasons for the lack of awareness among drivers of their dangerous driving behavior. This work aims to develop a driver profiling system where a smartphone's built-in sensors are used alongside machine learning algorithms to classify different driving behaviors. Methods: We attempt to determine the optimal combination of smartphone sensors such as accelerometer, gyroscope, and GPS in order to develop an accurate machine learning algorithm capable of identifying different driving events (e.g. turning, accelerating, or braking). Results: In our preliminary studies, we encountered some difficulties in obtaining consistent driving events, which had the potential to add "noise" to the observations, thus reducing the accuracy of the classification. However, after some pre-processing, which included manual elimination of extraneous and erroneous events, and with the use of the Convolutional Neural Networks (CNN), we have been able to distinguish different driving events with an accuracy of about 95%. Conclusions: Based on the results of preliminary studies, we have determined that proposed approach is effective in classifying different driving events, which in turn will allow us to determine driver's driving behavior.
Stimulating mechanism of corn oil on biomass and polysaccharide production of Pleurotus tuber-regium mycelium

Hu YH, Ge MD, Sun DN, Chen L, Cheung PCK, You CP, et al.

Int J Biol Macromol, 2021 Dec 30;201:93-103.
PMID: 34973980 DOI: 10.1016/j.ijbiomac.2021.12.149

Hyperbranched polysaccharides (HBPSs) are the main components in cell wall and exopolysaccharide (EPS) of Pleurotus tuber-regium. To enhance the yield of these macromolecules, corn oil at 4% addition exhibited the best effect for production of mycelial biomass at 20.49 g/L and EPS at 0.59 g/L, which was 2.56 folds and 1.90 folds of the control, respectively. The treated hyphae were much thicker with smooth surface, while its cell wall content (43.81 ± 0.02%) was 1.96 times of the control (22.34 ± 0.01%). Moreover, a large number of lipid droplets could be visualized under the view of confocal laser scanning microscopy (CLSM). RNA-seq analysis revealed that corn oil could enter the cells and result in the up-regulation of genes on cell morphology and membrane permeability, as well as the down-regulation on expression level of polysaccharide hydrolase and genes involved in the MAPK pathway, all of which probably contribute to the increase of polysaccharides production.
Ocular leptospirosis in four patients: A diagnostic dilemma

Ng HR, Cheong MY, Mustapha M

Med J Malaysia, 2021 07;76(4):569-572.
PMID: 34305121

Leptospirosis is a zoonotic disease that is caused by the pathogenic spirochetes of the genus Leptospira. The infection occurs worldwide and is particularly more common in the tropics. However, it is becoming a neglected reemerging global health disease due to rapid urbanisation. This disease has a wide range of clinical manifestations from flu-like illness to pneumonia, acute kidney injury, etc. But many uncommon clinical findings are being reported as well. In this paper, we report four patients who presented initially with uveitic features who turned out serologically positive for Leptospira after extensive investigations.
25S rDNA genotyping and multi-locus sequence typing of Candida albicans of pathogenic and commensal origins in the Klang Valley, Malaysia

Illyaaseen Z, Ngeow YF, Yap SF, Ng HF

Malays J Pathol, 2021 Apr;43(1):55-61.
PMID: 33903306

Candida albicans is an important opportunistic fungal pathogen capable of causing fatal systemic infections in humans. Presently in Malaysia, there is little information available on the genetic diversity of this organism and trends in behavioural characteristics. In this project, three genotyping methods: 25S rDNA genotyping, Alternative Lengthening of Telomerase (ALT) sequence typing and Multi-Locus Sequence Typing (MLST) were applied to study the genetic diversity of strains from infected hospital in-patients and asymptomatic individuals in the community. The results showed that, with the 25S rDNA genotyping, as in other parts of the world, the most common genotype was type A which accounted for approximately 70% of the 111 isolates tested. Further typing with the ALT sequence showed type 3 to be the most common in the isolates tested. MLST analysis revealed many possibly novel sequence types, as well as a statistically significant association between pathogenicity and a group of closely related isolates, most of which were from hospital samples. Further work on genotypes associated with enhanced virulence will help to clarify the value of genotyping for clinical and epidemiological investigations.
Production, structure and morphology of exopolysaccharides yielded by submerged fermentation of Antrodia cinnamomea

Chen L, Wang Z, Zhang B, Ge M, Ng H, Niu Y, et al.

Carbohydr Polym, 2019 Feb 01;205:271-278.
PMID: 30446105 DOI: 10.1016/j.carbpol.2018.10.070

Carbon and nitrogen sources in culture medium of Antrodia cinnamomea were optimized to eliminate the interference of exterior macromolecules on exopolysaccharide (EPS) yield by submerged fermentation. The results suggested that culture medium containing 50 g/L of glucose and 20 g/L of yeast extract as the optimal carbon and nitrogen sources could produce 1.03 g/L of exopolysaccharides. After purification, two heteropolysaccharides (AC-EPS1 and AC-EPS2) were obtained and characterized to provide the basic structure information. As the main component of the produced EPS, AC-EPS2 (accounting for 89.63%) was mainly composed of galactose (87.42%) with Mw (molecular weight) and R.M.S. (root-mean-square) radius of 1.18 × 105 g/mol and 25.3 nm, respectively. Furthermore, the spherical and flexible chain morphologies of EPS were observed in different solvents by TEM. The structural and morphological information of purified EPS were significant for further study on their structure-activity relationship and related applications.
Fulltext An updated hip fracture projection in Asia: The Asian Federation of Osteoporosis Societies study

Cheung CL, Ang SB, Chadha M, Chow ES, Chung YS, Hew FL, et al.

Osteoporos Sarcopenia, 2018 Mar;4(1):16-21.
PMID: 30775536 DOI: 10.1016/j.afos.2018.03.003

OBJECTIVES: Hip fracture is a major public health problem. Earlier studies projected that the total number of hip fracture will increase dramatically by 2050, and most of the hip fracture will occur in Asia. To date, only a few studies provided the updated projection, and none of them focused on the hip fracture projection in Asia. Thus, it is essential to provide the most up to date prediction of hip fracture in Asia, and to evaluate the total direct medical cost of hip fracture in Asia.
METHODS: We provide the updated projection of hip fracture in 9 Asian Federation of Osteoporosis Societies members using the most updated incidence rate and projected population size.
RESULTS: We show that the number of hip fracture will increase from 1,124,060 in 2018 to 2,563,488 in 2050, a 2.28-fold increase. This increase is mainly due to the changes on the population demographics, especially in China and India, which have the largest population size. The direct cost of hip fracture will increase from 9.5 billion United State dollar (USD) in 2018 to 15 billion USD in 2050, resulting a 1.59-fold increase. A 2%-3% decrease in incidence rate of hip fracture annually is required to keep the total number of hip fracture constant over time.
CONCLUSIONS: The results show that hip fracture remains a key public health issue in Asia, despite the available of better diagnosis, treatment, and prevention of fracture over the recent years. Healthcare policy in Asia should be aimed to reduce the burden of hip fracture.
Fulltext Non-evaporative method to remove high boiling point solvent (ethyl lactate) from palm oil extract at atmospheric conditions

Kua, Y. L., Gan, S., Morris, A., Ng, H. K.

International Food Research Journal, 2018;25(101):97-103.
MyJurnal

Ethyl lactate was demonstrated as a green and efficient agrochemical solvent to concentrate phytonutrients such as carotenes and tocols in palm oil. However, the removal of this solvent from the extract is difficult and expensive due to its very high boiling point and low volatility. Heating at high temperature in an effort to evaporate the solvent is undesirable even under reduced pressure as the extracted phytonutrients are heat-sensitive compounds. In this paper, a non-evaporative method using only water was proposed for the first time to remove the solvent at atmospheric conditions based on its solubility difference instead of the vapour pressure difference. The proposed method was proved to be more effective, faster and cheaper as compared to conventional approaches such as rotary evaporation, freeze drying and vacuum drying.
Multistage optimizations of slow pyrolysis synthesis of biochar from palm oil sludge for adsorption of lead

Lee XJ, Lee LY, Hiew BYZ, Gan S, Thangalazhy-Gopakumar S, Kiat Ng H

Bioresour Technol, 2017 Dec;245(Pt A):944-953.
PMID: 28946195 DOI: 10.1016/j.biortech.2017.08.175

This research investigated the removal of lead (Pb(2+)) by a novel biochar derived from palm oil sludge (POS-char) by slow pyrolysis. Multistage optimizations with central composite design were carried out to firstly optimize pyrolysis parameters to produce the best POS-char for Pb(2+) removal and secondly to optimize adsorption conditions for the highest removal of Pb(2+). The optimum pyrolysis parameters were nitrogen flowrateof30mLmin(-1), heating rateof10°Cmin(-1), temperatureof500°C and timeof30min. The optimum Pb(2+) adsorption conditions were concentrationof200mgL(-1), timeof60min, dosageof0.3g and pH of 3.02. The various functional groups within POS-char played a vital role in Pb(2+) uptake. Regeneration was demonstrated to be feasible using hydrochloric acid. Adsorption equilibrium was best described by Freundlich model. At low concentration range, adsorption kinetic obeyed pseudo-first-order model, but at high concentration range, it followed pseudo-second-order model. Overall, the results highlighted that POS-char is an effective adsorbent for Pb(2+) removal.
Evaluation of visual outcomes after toric intraocular lens implantation

Ng HR, Goh CH, Ngim YS, Juliana J

Med J Malaysia, 2017 12;72(6):356-359.
PMID: 29308773 MyJurnal

PURPOSE: To evaluate postoperative visual acuity, refractive status and rotational stability of toric intraocular lens (IOL) in correcting pre-existing corneal astigmatism.
METHODS: A total of 69 patients with topographic corneal astigmatism of 1.0 Diopter (D) and above who underwent cataract surgery between June 2015 and December 2016 were included in this retrospective observational study. All preoperative toric IOL calculations were performed using immersion biometry. Appropriate formula to calculate toric IOL power was applied (SRK/T, Holladay 1 or Hoffer Q formula). All patients undergone similar uncomplicated phacoemulsification with implantation of AcrySoft IQ SN6AT toric IOL of different powers. Visual outcome, refractive status and axis of lens were evaluated at six weeks postoperatively. Ethical approval from the Ministry of Health Medical Research Ethics Committee was obtained prior to commencement of study.
RESULTS: The mean refractive astigmatism decreased from 1.69 D ±1.10 (SD) to 0.81 D ± 0.40 (SD) at six weeks postoperatively. The mean postoperative spherical equivalent was at -0.37 D ±0.64 (SD). Mean LogMAR for uncorrected and corrected distance visual acuity in six weeks postoperative patients was at 0.29 ±0.16 (SD) and 0.12 ±0.12 (SD) respectively. Intraoperative to 6 weeks of postoperative comparison of IOL axis alignment showed low levels of rotation (mean 3.21 ±2.52 degrees).
CONCLUSION: Cataract surgery with implantation of toric IOL was stable and effective in improving pre-existing regular corneal astigmatism.
Fulltext An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes

Fattah NFA, Ng HM, Mahipal YK, Numan A, Ramesh S, Ramesh K

Materials (Basel), 2016 Jun 06;9(6).
PMID: 28773573 DOI: 10.3390/ma9060450

Solid polymer electrolyte (SPE) composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl) imide [EMI-BTI] and graphene oxide (GO) was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC). The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP)-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD) and thermogravimetric analysis (TGA) studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge-discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g(-1), which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.
Fulltext Poly(Acrylic acid)⁻Based Hybrid Inorganic⁻Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application

Liew CW, Ng HM, Numan A, Ramesh S

Polymers (Basel), 2016 May 18;8(5).
PMID: 30979292 DOI: 10.3390/polym8050179

Nanocomposite polymer electrolyte membranes (NCPEMs) based on poly(acrylic acid)(PAA) and titania (TiO₂) are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO₂.The highest ionic conductivity of (8.36 ± 0.01) × 10-4 S·cm-1 is obtained with addition of 6 wt % of TiO₂ at ambient temperature. The complexation between PAA, LiTFSI and TiO₂ is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) studies. Electrical double layer capacitors (EDLCs) are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV) and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g-1 (or equivalent to 29.54 mF·cm-2) with excellent electrochemical stability.
Fulltext Development of vision based multiview gait recognition system with MMUGait database

Ng H, Tan WH, Abdullah J, Tong HL

ScientificWorldJournal, 2014;2014:376569.
PMID: 25143972 DOI: 10.1155/2014/376569

This paper describes the acquisition setup and development of a new gait database, MMUGait. This database consists of 82 subjects walking under normal condition and 19 subjects walking with 11 covariate factors, which were captured under two views. This paper also proposes a multiview model-based gait recognition system with joint detection approach that performs well under different walking trajectories and covariate factors, which include self-occluded or external occluded silhouettes. In the proposed system, the process begins by enhancing the human silhouette to remove the artifacts. Next, the width and height of the body are obtained. Subsequently, the joint angular trajectories are determined once the body joints are automatically detected. Lastly, crotch height and step-size of the walking subject are determined. The extracted features are smoothened by Gaussian filter to eliminate the effect of outliers. The extracted features are normalized with linear scaling, which is followed by feature selection prior to the classification process. The classification experiments carried out on MMUGait database were benchmarked against the SOTON Small DB from University of Southampton. Results showed correct classification rate above 90% for all the databases. The proposed approach is found to outperform other approaches on SOTON Small DB in most cases.
Fulltext An experimental and modelling study of selected heavy metals removal from aqueous solution using Scylla Serrata as biosorbent

Aris A. Z., Ismail F. A., Ng, H. Y., Praveena, S. M.

Pertanika Journal of Science & Technology, 2014;22(2):553-566.
MyJurnal

This study was conducted using crab shells as a biosorbent to remove Cu and Cd with different initial concentrations of 1, 5, 10, 15, and 20 mg/L in a biosorption treatment process. Crab shells were selected as biosorbents due to their abundance in the environment and ready availability as waste products from the market place. This study aimed to determine the ability of Scylla Serrata shells to remove Cu and Cd in an aqueous solution, as well as to provide a comparison of the removal rate between the two metals. The data were incorporated into hydrochemical software, PHREEQC, to investigate the chemical speciation distribution of each heavy metal. The shells of S. serrata were found to have a significant (p< 0.05) ability to remove Cu and Cd following the treatment. After six hours of treatment, the crab shells had removed 60 to 80% of both metals. However, the highest removal percentage was achieved for Cu with up to 94.7% removal rate in 5 mg/L initial Cu concentration, while 85.1% of Cd was removed in 1 mg/L initial solution, respectively. It can be concluded that the shells of S. serrata could remove Cu and Cd better with significant results (p
Tuberculosis in captive Asian elephants (Elephas maximus) in Peninsular Malaysia

Ong BL, Ngeow YF, Razak MF, Yakubu Y, Zakaria Z, Mutalib AR, et al.

Epidemiol Infect, 2013 Jul;141(7):1481-7.
PMID: 23414617 DOI: 10.1017/S0950268813000265

A cross-sectional study was conducted from 10 January to 9 April 2012, to determine the seroprevalence of tuberculosis (TB) of all captive Asian elephants and their handlers in six locations in Peninsular Malaysia. In addition, trunk-wash samples were examined for tubercle bacillus by culture and polymerase chain reaction (PCR). For 63 elephants and 149 elephant handlers, TB seroprevalence was estimated at 20.4% and 24.8%, respectively. From 151 trunkwash samples, 24 acid-fast isolates were obtained, 23 of which were identified by hsp65-based sequencing as non-tuberculous mycobacteria. The Mycobacterium tuberculosis-specific PCR was positive in the trunk-wash samples from three elephants which were also seropositive. Conversely, the trunk wash from seven seropositive elephants were PCR negative. Hence, there was evidence of active and latent TB in the elephants and the high seroprevalence in the elephants and their handlers suggests frequent, close contact, two-way transmission between animals and humans within confined workplaces.
Fulltext Lack of association between RANTES-28, SDF-1 gene polymorphisms and systemic lupus erythematosus in the Malaysian population

Lian LH, Kee BP, Ng HL, Chua KH

Genet. Mol. Res., 2011;10(4):2841-50.
PMID: 22095608 DOI: 10.4238/2011.November.17.2

Regulated on activation, normal T-cell expressed and secreted (RANTES) and stromal cell-derived factor 1 (SDF-1) are members of the CC- and CXC-chemokine families, respectively. Both genes have been postulated to be involved in the pathogenesis of systemic lupus erythematosus (SLE). We analyzed position 28 of the RANTES gene promoter region, as well as the SNP observed in the 3' UTR of the SDF-1 gene at position 801, in 130 patients presenting SLE at the Malaya University Medical Centre. Screening of 130 healthy volunteer controls using RFLP was also performed. RANTES-28 polymorphism analysis showed no significant (P = 0.3520) relationship, even though homozygous C/C was more frequent in SLE patients (OR = 1.4183) and heterozygous C/G was more frequent in healthy controls (OR = 0.7051). There were no significant (P = 0.2650) associations between A/A (OR = 0.783), G/G (OR = 1.5914) and G/A (OR = 0.8289) genotypes in the SDF-1 gene polymorphism with SLE. We conclude that there is no significant association of RANTES-28 and SDF-1 gene polymorphisms and occurrence of SLE in Malaysia.
Application of vegetable oils in the treatment of polycyclic aromatic hydrocarbons-contaminated soils

Yap CL, Gan S, Ng HK

J Hazard Mater, 2010 May 15;177(1-3):28-41.
PMID: 20006435 DOI: 10.1016/j.jhazmat.2009.11.078

A brief review is conducted on the application of vegetable oils in the treatment of PAH-contaminated soils. Three main scopes of treatment strategies are discussed in this work including soil washing by oil, integrated oil-biological treatment and integrated oil-non-biological treatment. For each of these, the arguments supporting vegetable oil application, the applied treatment techniques and their efficiencies, associated factors, as well as the feasibility of the techniques are detailed. Additionally, oil regeneration, the environmental impacts of oil residues in soil and comparison with other commonly employed techniques are also discussed.
Fulltext Immunohistochemical study of p16 INK4A and survivin expressions in cervical squamous neoplasm

Tan GC, Norlatiffah S, Sharifah NA, Razmin G, Shiran MS, Hatta AZ, et al.

Indian J Pathol Microbiol, 2010 Jan-Mar;53(1):1-6.
PMID: 20090212 DOI: 10.4103/0377-4929.59173

Cervical cancer is the second most common cancer affecting Malaysian women. Despite the implementation of pap smear screening, many women are still diagnosed only in the advanced stage of cervical cancer. This could partly be due to failure of detection of its precursor lesions; hence the need to search for novel biomarkers to assist in the screening and diagnosis of cervical neoplasia. This study aims to determine the expression of p16INK4A and survivin as possible predictive biomarkers in cervical squamous neoplasm.
Fulltext Extraction techniques for polycyclic aromatic hydrocarbons in soils

Lau EV, Gan S, Ng HK

Int J Anal Chem, 2010;2010:398381.
PMID: 20396670 DOI: 10.1155/2010/398381

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.
Remediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs)

Gan S, Lau EV, Ng HK

J Hazard Mater, 2009 Dec 30;172(2-3):532-49.
PMID: 19700241 DOI: 10.1016/j.jhazmat.2009.07.118

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic micropollutants which are resistant to environmental degradation due to their highly hydrophobic nature. Concerns over their adverse health effects have resulted in extensive studies on the remediation of soils contaminated with PAHs. This paper aims to provide a review of the remediation technologies specifically for PAH-contaminated soils. The technologies discussed here include solvent extraction, bioremediation, phytoremediation, chemical oxidation, photocatalytic degradation, electrokinetic remediation, thermal treatment and integrated remediation technologies. For each of these, the theories are discussed in conjunction with comparative evaluation of studies reported in the specialised literature.
Fulltext The correlation between cytopenia and esophageal varices in patients with liver cirrhosis

Gue CS, Yap CK, Ng HS

Med J Malaysia, 2004 Dec;59(5):604-8.
PMID: 15889562

This retrospective study analysed the case records of 200 patients in the Department of Gastroenterology, Singapore General Hospital from February 2000 to January 2001 who had liver cirrhosis and underwent gastroscopy for the detection of varices. The aim of this study was to determine any relationship between leucopenia, thrombocytopenia and the occurrence of esophageal varices in a cirrhotic population. Our results showed that the diagnostic yield of varices grade 2 and 3 was 6.3% if platelet count was > 150,000/mm3, 25% if platelet count was 100,000 to 150,000/mm3, 38.9% if platelet count was 50,000-99,000/mm3 and 100% if platelet count was <50,000/mm3. Similarly, the diagnostic yield of varices grade 2 and 3 was 19.4% if total white count was > 4,000/mm3, 66.7% if total white count was 3,000- 4,000/mm3 and 94.8% if total white count was < 3,000/mm5. We conclude that thrombocytopenia and leucopenia can be used to stratify risk for occurrence of esophageal varices in cirrhotic patients and gastroscopy will have a high yield for varices when platelet count is < 150,000/mm3 or total white is < 4,000/mm.

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