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Fulltext High-efficiency electromagnetic energy harvesting using double-elliptical metasurface resonators

Amer AAG, Othman N, Sapuan SZ, Alphones A, Salem AA

PLoS One, 2023;18(12):e0291354.
PMID: 38127949 DOI: 10.1371/journal.pone.0291354

This study introduces a metasurface (MS) based electrically small resonator for ambient electromagnetic (EM) energy harvesting. It is an array of novel resonators comprising double-elliptical cylinders. The harvester's input impedance is designed to match free space, allowing incident EM power to be efficiently absorbed and then maximally channelled to a single load through optimally positioned vias. Unlike the previous research works where each array resonator was connected to a single load, in this work, the received power by all array resonators is channelled to a single load maximizing the power efficiency. The performance of the MS unit cell, when treated as an infinite structure, is examined concerning its absorption and harvesting efficiency. The numerical results demonstrate that the MS unit cell can absorb EM power, with near-perfect absorption of 90% in the frequency range of 5.14 GHz to 5.5 GHz under normal incidence and with a fractional bandwidth of 21%. The MS unit cell also achieves higher harvesting efficiency at various incident angles up to 60o. The design and analysis of an array of 4x4 double elliptical cylinder MS resonators integrated with a corporate feed network are also presented. The corporate feed network connects all the array elements to a single load, maximizing harvesting efficiency. The simulation and measurement results reveal an overall radiation to AC efficiency of about 90%, making it a prime candidate for energy harvesting applications.
Fulltext Human pentastomiasis caused by Armillifer moniliformis in Malaysian Borneo

Latif B, Omar E, Heo CC, Othman N, Tappe D

Am J Trop Med Hyg, 2011 Nov;85(5):878-81.
PMID: 22049042 DOI: 10.4269/ajtmh.2011.11-0404

We report a case of visceral pentastomiasis caused by Armillifer moniliformis in a 70-year-old aboriginal farmer from rural Malaysian Borneo. The patient complained of upper abdominal pain, jaundice, and loss of weight. Radiological investigations and subsequent histopathological examination revealed an adenocarcinoma of the pancreas with an adjacent liver nodule containing a nymph of A. moniliformis. This report constitutes the first documented human pentastomid infection in the whole of Malaysia after nearly 40 years, and it is the third description from Malaysian Borneo. Cases of human and animal pentastomiasis in Malaysia are discussed.
Fulltext Identification and characterization of lignin depolymerization enzymes in Bacillus subtilis strain S11Y isolated from a tropical environment in Malaysia

Riyadi FA, Azman NF, Nadia Md Akhir F, Othman N, Hara H

J Gen Appl Microbiol, 2024 Mar 07;69(5):278-286.
PMID: 37612074 DOI: 10.2323/jgam.2023.08.003

Biological pretreatment using microbial enzymes appears to be the most promising pre-treatment technology for the breakdown of recalcitrant lignin structure. This research focuses on the identification and characterization of lignin-depolymerizing enzymes in Bacillus subtilis strain S11Y, previously isolated from palm oil wastes in Malaysia. The draft genome sequences of this highly lignin-depolymerizing strain revealed that the genome lacked any of the well-known dye-decolorizing peroxidase or catalase-peroxidase that are commonly reported to be involved in lignin depolymerization by bacteria, indicating that strain S11Y has distinct sets of potential lignin depolymerization genes. The oxidative stress-related enzymes Cu/Zn type-superoxide dismutase (Sod2) and a heme-containing monofunctional catalase (Kat2) were identified in the genome sequences that are of interest. Their lignin-depolymerizing ability were evaluated by treating Alkali lignin (AL) with each enzyme and their degradation ability were evaluated using gel-permeation chromatography (GPC), ultrahigh-pressure liquid chromatography-mass spectrometry (UHPLC/MS), and gas chromatography-mass spectrometry (GC/MS), which successfully proved lignin depolymerizing ability. Successful evaluation of lignin depolymerizing enzymes can be applicable for lignin pretreatment process in green energy production and generation of valuable chemicals in bio-refinery.
Fulltext Identification of FLT3 and NPM1 Mutations in Patients with Acute Myeloid Leukaemia

Mat Yusoff Y, Abu Seman Z, Othman N, Kamaluddin NR, Esa E, Zulkiply NA, et al.

Asian Pac J Cancer Prev, 2019 06 01;20(6):1749-1755.
PMID: 31244296 DOI: 10.31557/APJCP.2019.20.6.1749

Objective: The most frequent acquired molecular abnormalities and important prognostic indicators in patients
with Acute Myeloid Leukaemia (AML) are fms-like tyrosine kinase-3 gene (FLT3) and nucleophosmin-1 (NPM1)
mutations. Our study aims to develop a cost effective and comprehensive in-house conventional PCR method for
detection of FLT3-ITD, FLT3-D835 and NPM1 mutations and to evaluate the frequency of these mutations in patients
with cytogenetically normal (CN) AML in our population. Methods: A total of 199 samples from AML patients (95
women, 104 men) were included in the study. Mutation analyses were performed using polymerase chain reaction
(PCR) and gene sequencing. Result: Sixty-eight patients were positive for the mutations. FLT3-ITD mutations were
detected in 32 patients (16.1%), followed by FLT3-D835 in 5 (2.5%) and NPM1 in 54 (27.1%). Double mutations of
NPM1 and FLT3-ITD were detected in 23 cases (11.6%). Assays validation were performed using Sanger sequencing
and showed 100% concordance with in house method. Conclusion: The optimized in-house PCR assays for the
detection of FLT3-ITD, FLT3-D835 and NPM1 mutations in AML patients were robust, less labour intensive and cost
effective. These assays can be used as diagnostic tools for mutation detection in AML patients since identification of
these mutations are important for prognostication and optimization of patient care.
Identification of novel extracellular protein for PCB/biphenyl metabolism in Rhodococcus jostii RHA1

Atago Y, Shimodaira J, Araki N, Bin Othman N, Zakaria Z, Fukuda M, et al.

Biosci Biotechnol Biochem, 2016 May;80(5):1012-9.
PMID: 26828632 DOI: 10.1080/09168451.2015.1127134

Rhodococcus jostii RHA1 (RHA1) degrades polychlorinated biphenyl (PCB) via co-metabolism with biphenyl. To identify the novel open reading frames (ORFs) that contribute to PCB/biphenyl metabolism in RHA1, we compared chromatin immunoprecipitation chip and transcriptomic data. Six novel ORFs involved in PCB/biphenyl metabolism were identified. Gene deletion mutants of these 6 ORFs were made and were tested for their ability to grow on biphenyl. Interestingly, only the ro10225 deletion mutant showed deficient growth on biphenyl. Analysis of Ro10225 protein function showed that growth of the ro10225 deletion mutant on biphenyl was recovered when exogenous recombinant Ro10225 protein was added to the culture medium. Although Ro10225 protein has no putative secretion signal sequence, partially degraded Ro10225 protein was detected in conditioned medium from wild-type RHA1 grown on biphenyl. This Ro10225 fragment appeared to form a complex with another PCB/biphenyl oxidation enzyme. These results indicated that Ro10225 protein is essential for the formation of the PCB/biphenyl dioxygenase complex in RHA1.
Fulltext Immunohistochemical localization of RET rearrangements in a Malaysian papillary thyroid carcinoma population

Omar E, Othman NH

Med J Malaysia, 2003 Aug;58(3):461-2.
PMID: 14750392
Fulltext Impact of the COVID-19 pandemic on child malnutrition in Selangor, Malaysia: A pilot study

Rahman A, Othman N, Kuddus MA, Hasan MZ

J Infect Public Health, 2024 May;17(5):833-842.
PMID: 38547630 DOI: 10.1016/j.jiph.2024.02.019

BACKGROUND: Child malnutrition risk factors are globally recognized, but the specific impact of the COVID-19 pandemic on the prevalence of child malnutrition, considering socioeconomic burdens and changes in family lifestyles, remains underexplored. This study aims to identify the significance of COVID-19-related factors in relation to the prevalence of child malnutrition in Selangor, Malaysia.
METHODS: Purposive sampling was employed in this pilot study to select the households with under-5 children and, a structured questionnaire was developed to gather data. Chi-squared tests, logistic regression modelling and World Health Organisation AnthroPlus software-based visualization were used for analyses.
RESULTS: The present study's findings indicate that demographic and social factors, including 'Citizenship,' 'Type of House,' 'Number of Earning Members,' 'Father's Highest Educational Level,' and 'Number of Children in a Family,' have a statistically significant association with Wasting. Additionally, the mother's 'Highest Educational Level' is found to be linked to underweight prevalence. Within COVID-19 factors, "COVID-19 Impact on Employment/Business" demonstrated significance for both stunting and wasting. Multivariate analysis revealed disparities in childhood malnutrition by gender, age, and factors such as "COVID-19 impact on children's physical activity" and "COVID-19 impact on children's decrease in health over the last two weeks."
CONCLUSIONS: This study identified COVID-19 factors alongside sociodemographic variables with statistically significant relationships impacting childhood malnutrition in Selangor, Malaysia. The results underscored the substantial influence of the COVID-19 pandemic on child malnutrition prevalence. Decision-makers at family and community levels can benefit by considering these factors in their actions. However, the study's limitation lay in its dataset, urging larger-scale analyses to explore further sub-categories of the examined variables.
Fulltext Importance of screening for macroprolactin in all hyperprolactinaemic sera

Jamaluddin FA, Sthaneshwar P, Hussein Z, Othman N, Chan SP

Malays J Pathol, 2013 Jun;35(1):59-63.
PMID: 23817395 MyJurnal

Prolactin (PRL) exists in different forms in human serum. The predominant form is monomeric PRL (molecular mass 23 kDa) with smaller amounts of big PRL (molecular mass 50-60 kDa) and at times macroprolactin (molecular mass 150-170 kDa). Macroprolactin, generally considered to be biologically inactive, accounts for the major part of prolactin in some patients. Different immunoassays for prolactin differ in reactivity with this macromolecular complex.
Fulltext In Vitro Testing of Potential Entamoeba histolytica Pyruvate Phosphate Dikinase Inhibitors

Saidin S, Othman N, Noordin R

Am J Trop Med Hyg, 2017 Oct;97(4):1204-1213.
PMID: 28820699 DOI: 10.4269/ajtmh.17-0132

Adverse effects and resistance to metronidazole have motivated the search for new antiamoebic agents against Entamoeba histolytica. Control of amoeba growth may be achieved by inhibiting the function of the glycolytic enzyme and pyruvate phosphate dikinase (PPDK). In this study, we screened 10 compounds using an in vitro PPDK enzyme assay. These compounds were selected from a virtual screening of compounds in the National Cancer Institute database. The antiamoebic activity of the selected compounds was also evaluated by determining minimal inhibitory concentrations (MICs) and IC50 values using the nitro-blue tetrazolium reduction assay. Seven of the 10 compounds showed inhibitory activities against the adenosine triphosphate (ATP)/inorganic phosphate binding site of the ATP-grasp domain. Two compounds, NSC349156 (pancratistatin) and NSC228137 (7-ethoxy-4-[4-methylphenyl] sulfonyl-3-oxido-2, 1, 3-benzoxadiazol-3-ium), exhibited inhibitory effects on the growth of E. histolytica trophozoites with MIC values of 25 and 50 μM, and IC50 values of 14 and 20.7 μM, respectively.
Inactivation of fungal spores from clinical environment by silver bio-nanoparticles; optimization, artificial neural network model and mechanism

Noman E, Al-Gheethi A, Saphira Radin Mohamed RM, Talip B, Othman N, Hossain S, et al.

Environ Res, 2022 03;204(Pt A):111926.
PMID: 34461120 DOI: 10.1016/j.envres.2021.111926

The present study aimed to assess the efficiency of silver bio-nanoparticles (Ag-NPs) in inactivating of the Aspergillus fumigatus, A. parasiticus and A. flavus var. columnaris and A. aculeatus spores. The AgNPs were synthesized in secondary metabolic products of Penicillium pedernalens 604 EAN. The inactivation process was optimized by response surface methodology (RSM) as a function of Ag NPs volume (1-10 μL/mL); time (10-120 min); pH (5-8); initial fungal concentrations (log10) (3-6). The artificial neural network (ANN) model was used to understand the behavior of spores for the factors affecting inactivation process. The best conditions to achieved SAL 10-6 of the fungal spores were recorded with 3.46 μl/mL of AgNPs, after 120 min at pH 5 and with 6 log of initial fungal spore concentrations, at which 5.99 vs. 6.09 (SAL 10-6) log reduction was recorded in actual and predicted results respectively with coefficient of 87.00%. The ANN revealed that the timehas major contribution in the inactivation process compare to Ag NPs volume. The fungal spores were totally inactivated (SAL 10-6, 6 log reduction with 99.9999%) after 110 min of the inactivation process, 10 min more was required to insure the irreversible inactivation of the fungal spores. The absence of protease and cellulase enzymes production confirm the total inactivation of the fungal spores. FESEM analysis revealed that the AgNPs which penetrated the fungal spores leading to damage and deform the fungal spore morphology. The AFM analysis confirmed the total spore surface damage. The bands in the range of the Raman spectroscopy from 1300 to 1600 cm-1 in the inactivated spores indicate the presence of CH3, CH2 and the deformation of lipids released outside the spore cytoplasm. These finding indicate that the AgNPs has high potential as a green alternative inactivation process for the airborne fungal spores.
Increased radical scavenging activity of thymoquinone and l-ascorbic acid dual encapsulated in palmitoyl-chitosan nanoparticles in a human normal lung fibroblast, MRC-5 due to synergistic antioxidative effects

Othman N, Md Jamil SNA, Masarudin MJ, Jusoh RABM, Alamassi MN

RSC Adv, 2023 Sep 18;13(40):27965-27983.
PMID: 37736560 DOI: 10.1039/d3ra04326f

Less effective antioxidant supplementation in combating free radicals is often related to the lack of the formulation of carriers. The antioxidant may be one of the most powerful substances but is marred by poor uptake by cells when the carrier degraded and dissolved too rapidly. Nanoparticle (NP) systems are promising in overcoming the problem since they provide high surface area to enhance encapsulation and release efficiency. With the right selection of material, NP carriers could function as constructive antioxidant cargos. Generally, NPs carry only one active ingredient; this study, however, utilized chitosan nanoparticles (CNPs) and hydrophobically modified palmitoyl-chitosan nanoparticles (PCNPs) that were dual encapsulated with antioxidants of different polarities, namely, hydrophobic thymoquinone (TQ) and hydrophilic l-ascorbic acid (LAA) to evaluate their combination effects in scavenging free radicals. The antioxidants followed zero-order release kinetics with a controlled release manner for about 48 h. The interaction effects between TQ and LAA loaded in the NP systems were determined by classical isobologram (CI) values. The CI values were derived by a diphenyl picrylhydrazyl (DPPH) assay, a radical scavenging activity assay. Combined TQ and LAA had CI values of less than one, with a lower value in the PCNP system than in the CNP system. This indicates that the interaction between those antioxidants showed higher synergistic effects in PCNPs, which enhanced the DPPH radical scavenging activities. The antioxidative potential of compound(s) encapsulated in the PCNP carrier was further experimented by a reactive oxygen species (ROS) assay on a human normal lung fibroblast cell line (MRC-5) as lung is one of the organs with high accumulation of free radicals. About 48 h post treatment, the dual-loaded TQ and LAA in PCNPs showed the lowest ROS level in comparison to single-loaded antioxidants and bare antioxidant delivery. The hydrogen peroxide (H2O2) radical scavenging was influenced by both the controlled release property of the PCNP system and the synergy between TQ and LAA. In short, dual-loaded TQ and LAA in the hydrophobically modified PCNP had effectively depicted the capability of a single CS-based nanocarrier to hold more than one compound at a time to function as a potent radical scavenger.
Infections in post-tsunami victims

Othman N, Ismail IH, Yip R, Zainuddin Z, Kasim SM, Isa R, et al.

Pediatr Infect Dis J, 2007 Oct;26(10):960-1.
PMID: 17901807 DOI: 10.1097/INF.0b013e3181257234

Two tsunami survivors from Banda Acheh, Sumatra, presented with pyrexia of unknown origin and a nonresolving left-sided empyema, respectively. Both children had mixed infections of tuberculosis and melioidosis; Salmonella typhi was also present in the second patient. Mixed infections are common late sequela complications in post-tsunami victims.
Fulltext Influence of technology adoption on farmers' well-being: Systematic literature review and bibliometric analysis

Abdul-Majid M, Zahari SA, Othman N, Nadzri S

Heliyon, 2024 Jan 30;10(2):e24316.
PMID: 38312653 DOI: 10.1016/j.heliyon.2024.e24316

This study aimed at determining the effects of technology adoption on farmers' well-being. Specifically, we analysed and extended the current understanding of the topic by focusing on the concepts of technology adoption and well-being. The data were sourced from 30 papers that were selected based on specific criteria from the WoS and Scopus databases. They were acquired through a systematic search and quality appraisal process. The adopted technology can be grouped into sustainable agricultural practices and innovations, digital agriculture and information technology, precision farming and resource management, financial inclusion and agricultural transactions, remote sensing and satellite technology, and agricultural programs and initiatives. Most papers indicated that technology adoption improved farmers' well-being which was basically measured using productivity and income. The measure however lacked farmers' value judgments, such as happiness. Agricultural technology could have a mixed effect on farmers' well-being, depending on the type of technology adopted and the compatibility of farmers with technology in their agricultural practices. This study will assist researchers in developing an appropriate framework and strategy to improve farmers' welfare, which can alleviate poverty. These may further help policymakers identify the best technological innovations that can improve farmers' economic and social welfare, thereby facilitating the development of plans to meet farmers' needs and interests. Finally, the study suggested future research directions for researchers and academics.
Fulltext Integration of solar dryer technologies in high value herbal crops production for Malaysia: pathway for a sustainable future

Othman, N. F.,, Ya’acob, M. E., Abdul-Rahim, A.S., Mohd. Shahwahid, O., Hizam, H., Ramlan, M.F.

International Food Research Journal, 2016;23(101):51-55.
MyJurnal

This paper embarks on the evolution of green economy approach to support the increasing
food commodity expenses by adapting Solar Photovoltaic (PV) as the suitable renewable
energy technology for Natural Resource Management (NRM). The crops for cash trend and
continuously decreasing market price in solar technologies are highlighted with strong effort
by Malaysian Government through Renewable Energy (RE) policy and National Key Economy
Area (NKEA). Reviews on the benefits of solar dryer technologies in crop production and agrobusiness
are presented with highlights on high value herbal crops (HVHc) and some potentials
of high-performance solar dryer technology.
Integrative meta-analysis for the identification of hub genes in chemoresistant colorectal cancer

Abu N, Othman N, W Hon K, Nazarie WF, Jamal R

Biomark Med, 2020 05;14(7):525-537.
PMID: 32462912 DOI: 10.2217/bmm-2019-0241

Background: Finding a new target or a new drug to overcome chemoresistance is difficult due to the heterogenous nature of cancer. Meta-analysis was performed to combine the analysis of different microarray studies to get a robust discovery. Materials & methods: Herein, we analyzed three microarray datasets on combination of folinic acid, fluorouracil, and oxaliplatin drugs (FOLFOX) resistance that fit our inclusion/exclusion criteria and performed a meta-analysis using the OmiCC system. Results: We identified several deregulated genes and we discovered HNF4A as a hub gene. We performed functional validation and observed that by targeting HNF4A, HCT116 cells were more sensitive toward both oxaliplatin and 5-fluorouracil significantly. Conclusion: Our findings show that HNF4A could be a potential target in overcoming FOLFOX chemoresistance in colorectal cancer.
Fulltext Intraventricular angiolipoma

Lee HK, Ghani AR, Sayuthi S, Abdullah J, Mustaffa F, Othman N, et al.

Med J Malaysia, 2007 Oct;62(4):339-40.
PMID: 18551942 MyJurnal

We report a case of 50-year-old man who was presented with recurrent episodes of left sided hemiparesis. CT scan and MRI brain revealed a large intraventricular fatty lesion. Histopathological examination showed a picture of angiolipoma.
Fulltext Is the Degree of Hearing Loss Truly Dependent on the Site of Tympanic Membrane Perforation?

Zakaria M, Othman N, Lih AC

Oman Med J, 2016 Jan;31(1):83-4.
PMID: 26813114 DOI: 10.5001/omj.2016.17
Fulltext Isolation and characterization of Lignin-derived monomer degraders under acidic conditions from tropical peatland

Imran Firdaus Kamardan M, Atikah Binti Marsid E, Nadia Md Akhir F, Ali Muhammad Yuzir M, Othman N, Hara H

J Gen Appl Microbiol, 2022 Nov 10;68(3):117-124.
PMID: 35400678 DOI: 10.2323/jgam.2021.09.004

Tropical peatlands account for one of the largest carbon stores in the form of organic matter due to the accumulation of plant litter and waterlogged conditions. Recent anthropogenic disturbances, such as forest fires, agricultural conversion and drainage, in tropical peatlands have caused a vast amount of carbon to be released into the atmosphere, and microbial activities are impacted by these changes. A recent study showed that many phenol- and lignin-degrading bacteria prefer alkaline and neutral pH conditions, while tropical peatland conditions are acidic, possibly changing the mechanisms of the utilization of organic matter from peat soil. The purpose of this study was to isolate and characterize phenolic compound-degrading bacteria from tropical peatlands under acidic conditions due to the lack of information on how the biological processes of microorganisms occur in this unique habitat. Two isolates show the capability to utilize phenolic aldehydes based on building blocks of lignin that are abundant in tropical peatlands, including hydroxyphenyl, guaiacyl and syringyl units. The identification of these isolates by 16S rRNA gene sequence shows that strain S38 is similar to Stenotrophomonas sp., while strain S46 is similar to Burkholderia sp. Further characterization of these isolates shows their ability to degrade 4-hydroxybenzaldehyde and vanillin into phenolic acids within 24 hours of incubation and syringaldehyde within 7 days of incubation. In conclusion, these isolated bacteria show the ability to withstand the acidic environment of tropical peatlands and utilize lignin monomers through unknown metabolic pathways.
Job characteristics and staying engaged in work of nurses: Empirical evidence from Malaysia

Othman N, Nasurdin AM

Int J Nurs Sci, 2019 Oct 10;6(4):432-438.
PMID: 31728397 DOI: 10.1016/j.ijnss.2019.09.010

Objective: The purpose of this study is to examine the relationship between job characteristics (job autonomy, job feedback, skill variety, task identity, task significance) and work engagement of nurses in Malaysia.
Methods: A survey using self-administered questionnaires was used to collect data from a sample of 856 staff nurses working in eight public hospitals in Malaysia. A shortened nine-item version of the Utrecht Work Engagement Scale(UWES-9) was used to measure work engagement. The UWES-9 comprises three dimensions, which was measured with three items each: vigor, dedication, and absorption. Job characteristics (job autonomy, job feedback, skill variety, task identity, task significance) were measured with the corresponding subscales of the Job Diagnostic Survey. Each subscale consisted of three items. Hypotheses were tested using hierarchical regression analysis.
Results: Findings indicated that all the five demographic variables (age, marital status, education, organizational tenure, job tenure) were unrelated to work engagement. The results further revealed that job autonomy (β = 0.19, P  0.05), however, did not affect work engagement.
Conclusion: Job autonomy, job feedback, task identity, and task significance are important factors in predicting work engagement. The findings of this study highlighted the need to incorporate these core dimensions in nursing management to foster work engagement.
Kimura's disease: a report of three cases with a brief review of literature

Madhavan M, Othman NH, Singh MS, Indudharan R, Sharma HS, Shamsuddin AR

Acta Otorhinolaryngol Ital, 2000 Aug;20(4):284-9.
PMID: 11234448

Kimura's disease (KD) is an uncommon chronic inflammatory condition of unknown aetiology involving subcutaneous tissue, presenting as a tumor like lesion with a predilection for the head and neck region. Clinically it is often confused with parotid tumor with lymph node metastasis. It is difficult to diagnose before tissue biopsy. Fine needle aspiration cytology has only limited value. Unless the pathologists are aware of this entity, it might be misdiagnosed. Surgery, radiotherapy and steroid therapy have been tried but none is proved best and recurrence is common. Three cases of KD seen in our hospital and the problems encountered in them are presented.

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