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  1. IgA nephropathy in Malaysia
    Cheong I, Kong N, Segasothy M, Moras Z, Menon P, Suleiman AB
    Southeast Asian J. Trop. Med. Public Health, 1991 Mar;22(1):120-2.
    PMID: 1948252
    A total of 164 patients with IgA nephropathy were diagnosed at the Department of Medicine, Universiti Kebangsaan Malaysia and the Department of Nephrology, General Hospital, Kuala Lumpur between 1981-1988. This represented an incidence of 20.1% of all primary glomerulopathies seen in both units. The 3 major ethnic groups were equally affected with 59.7% occurring between the ages of 20-36 years. It was not uncommon in females. The high prevalence of hypertension, renal failure, heavy proteinuria at presentation and the increased chronicity index in the biopsy, suggest that IgA nephropathy is progressive disease leading to chronic renal failure.
  2. Fulltext MoS2/h-BN/Graphene Heterostructure and Plasmonic Effect for Self-Powering Photodetector: A Review
    Sundararaju U, Mohammad Haniff MAS, Ker PJ, Menon PS
    Materials (Basel), 2021 Mar 29;14(7).
    PMID: 33805402 DOI: 10.3390/ma14071672
    A photodetector converts optical signals to detectable electrical signals. Lately, self-powered photodetectors have been widely studied because of their advantages in device miniaturization and low power consumption, which make them preferable in various applications, especially those related to green technology and flexible electronics. Since self-powered photodetectors do not have an external power supply at zero bias, it is important to ensure that the built-in potential in the device produces a sufficiently thick depletion region that efficiently sweeps the carriers across the junction, resulting in detectable electrical signals even at very low-optical power signals. Therefore, two-dimensional (2D) materials are explored as an alternative to silicon-based active regions in the photodetector. In addition, plasmonic effects coupled with self-powered photodetectors will further enhance light absorption and scattering, which contribute to the improvement of the device's photocurrent generation. Hence, this review focuses on the employment of 2D materials such as graphene and molybdenum disulfide (MoS2) with the insertion of hexagonal boron nitride (h-BN) and plasmonic nanoparticles. All these approaches have shown performance improvement of photodetectors for self-powering applications. A comprehensive analysis encompassing 2D material characterization, theoretical and numerical modelling, device physics, fabrication and characterization of photodetectors with graphene/MoS2 and graphene/h-BN/MoS2 heterostructures with plasmonic effect is presented with potential leads to new research opportunities.
  3. Fulltext Recent Advances in Shape-Controlled Synthesis of Noble Metal Nanoparticles by Radiolysis Route
    Abedini A, Bakar AA, Larki F, Menon PS, Islam MS, Shaari S
    Nanoscale Res Lett, 2016 Dec;11(1):287.
    PMID: 27283051 DOI: 10.1186/s11671-016-1500-z
    This paper focuses on the recent advances on radiolysis-assisted shape-controlled synthesis of noble metal nanostructures. The techniques and protocols for producing desirable shapes of noble metal nanoparticles are discussed through introducing the critical parameters which can influence the nucleation and growth mechanisms. Nucleation rate plays a vital role on the crystallinity of seeds while growth rate of different seeds' facets determines the final shape of resultant nanoparticles. Nucleation and growth rate both can be altered with factors such as absorbed dose, capping agents, and experimental environment condition to control the final shape. Remarkable physical and chemical properties of synthesized noble metal nanoparticles by controlled morphology have been systematically evaluated to fully explore their applications.
  4. Fulltext Asymptomatic proteinuria and/or haematuria in 265 Malaysian adults
    Cheong IKS, Kong N, Segasothy M, Morad Z, Menon P, Suleiman AB
    Med J Malaysia, 1991 Jun;46(2):150-4.
    PMID: 1839419
    Two-hundred and sixty-five patients with asymptomatic proteinuria and/or haematuria were studied at the Department of Medicine, Universiti Kebangsaan Malaysia and Department of Nephrology, General Hospital Kuala Lumpur. They represented 25.4% of all the renal biopsies performed during the period 1980-88. All the three races were affected with 71.3% occurring between the ages of 20-39 years and 41.1% were detected during routine medical examination. Excluding those patients with lupus nephritis, IgA nephropathy was the commonest histological diagnosis (51.7%). The presence of severe and advanced histological changes in a significant number of biopsies emphasises the need for more effective screening and early referral of this group of patients.
  5. Fulltext Urea and creatinine detection on nano-laminated gold thin film using Kretschmann-based surface plasmon resonance biosensor
    Menon PS, Said FA, Mei GS, Berhanuddin DD, Umar AA, Shaari S, et al.
    PLoS One, 2018;13(7):e0201228.
    PMID: 30052647 DOI: 10.1371/journal.pone.0201228
    This work investigates the surface plasmon resonance (SPR) response of 50-nm thick nano-laminated gold film using Kretschmann-based biosensing for detection of urea and creatinine in solution of various concentrations (non-enzymatic samples). Comparison was made with the presence of urease and creatininase enzymes in the urea and creatinine solutions (enzymatic samples), respectively. Angular interrogation technique was applied using optical wavelengths of 670 nm and 785 nm. The biosensor detects the presence of urea and creatinine at concentrations ranging from 50-800 mM for urea samples and 10-200 mM for creatinine samples. The purpose of studying the enzymatic sample was mainly to enhance the sensitivity of the sensor towards urea and creatinine in the samples. Upon exposure to 670 nm optical wavelength, the sensitivity of 1.4°/M was detected in non-enzymatic urea samples and 4°/M in non-enzymatic creatinine samples. On the other hand, sensor sensitivity as high as 16.2°/M in urea-urease samples and 10°/M in creatinine-creatininase samples was detected. The enhanced sensitivity possibly attributed to the increase in refractive index of analyte sensing layer due to urea-urease and creatinine-creatininase coupling activity. This work has successfully proved the design and demonstrated a proof-of-concept experiment using a low-cost and easy fabrication of Kretschmann based nano-laminated gold film SPR biosensor for detection of urea and creatinine using urease and creatininase enzymes.
  6. Recent Advances in Surface Plasmon Resonance (SPR) Technology for Detecting Ovarian Cancer Biomarkers
    Kumar VR, Kampan NC, Abd Aziz NH, Teik CK, Shafiee MN, Menon PS
    Cancers (Basel), 2023 Nov 27;15(23).
    PMID: 38067311 DOI: 10.3390/cancers15235607
    Epithelial Ovarian Cancer (EOC) is a leading cause of cancer-related deaths among women, mainly due to a lack of early detection and screening methods. Advanced immunoassay techniques, such as Luminex and proximity extension assay (PEA) technology, show promise in improving EOC detection by utilizing highly sensitive and specific multiplex panels to detect multiple combinations of biomarkers. However, these advanced immunoassay techniques have certain limitations, especially in validating the performance characteristics such as specificity, sensitivity, limit of detection (LOD), and dynamic range for each EOC biomarker within the panel. Implementing multiplexing in point-of-care (POC) biosensors can enhance EOC biomarker detection, with Surface Plasmon Resonance (SPR) being a versatile option among optical biosensors. There is no study on multiplex SPR biosensors specifically tailored for diagnosing EOC. Recent studies have shown promising results in the single detection of EOC biomarkers using SPR, with LOD for cancer antigen 125 (CA125) at 0.01 U/mL-1 and human epididymis protein 4 (HE4) at 1pM. This study proposes a potential roadmap for scientists and engineers in academia and industry to develop a cost effective yet highly efficient SPR biosensor platform for detecting EOC.
  7. Fulltext First-Principles Studies for Electronic Structure and Optical Properties of Strontium Doped β-Ga2O3
    Kean Ping L, Mohamed MA, Kumar Mondal A, Mohamad Taib MF, Samat MH, Berhanuddin DD, et al.
    Micromachines (Basel), 2021 Mar 24;12(4).
    PMID: 33804978 DOI: 10.3390/mi12040348
    The crystal structure, electron charge density, band structure, density of states, and optical properties of pure and strontium (Sr)-doped β-Ga2O3 were studied using the first-principles calculation based on the density functional theory (DFT) within the generalized-gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE). The reason for choosing strontium as a dopant is due to its p-type doping behavior, which is expected to boost the material's electrical and optical properties and maximize the devices' efficiency. The structural parameter for pure β-Ga2O3 crystal structure is in the monoclinic space group (C2/m), which shows good agreement with the previous studies from experimental work. Bandgap energy from both pure and Sr-doped β-Ga2O3 is lower than the experimental bandgap value due to the limitation of DFT, which will ignore the calculation of exchange-correlation potential. To counterbalance the current incompatibilities, the better way to complete the theoretical calculations is to refine the theoretical predictions using the scissor operator's working principle, according to literature published in the past and present. Therefore, the scissor operator was used to overcome the limitation of DFT. The density of states (DOS) shows the hybridization state of Ga 3d, O 2p, and Sr 5s orbital. The bonding population analysis exhibits the bonding characteristics for both pure and Sr-doped β-Ga2O3. The calculated optical properties for the absorption coefficient in Sr doping causes red-shift of the absorption spectrum, thus, strengthening visible light absorption. The reflectivity, refractive index, dielectric function, and loss function were obtained to understand further this novel work on Sr-doped β-Ga2O3 from the first-principles calculation.
  8. Fulltext Visible and angular interrogation of Kretschmann-based SPR using hybrid Au-ZnO optical sensor for hyperuricemia detection
    Mustaffa SN, Md Yatim N, Abdul Rashid AR, Md Yatim N, Pithaih V, Sha'ari NS, et al.
    Heliyon, 2023 Dec;9(12):e22926.
    PMID: 38125452 DOI: 10.1016/j.heliyon.2023.e22926
    Uric acid is a waste product of the human body where high levels of it or hyperuricemia can lead to gout, kidney disease and other health issues. In this paper, Finite Difference Time Doman (FDTD) simulation method was used to develop a plasmonic optical sensor to detect uric acid with molarity ranging from 0 to 3.0 mM. A hybrid layer of gold-zinc oxide (Au-ZnO) was used in this Kretschmann-based Surface Plasmon Resonance (K-SPR) technique with angular interrogation at 670 nm and 785 nm visible optical wavelengths. The purpose of this study is to observe the ability of the hybrid material as a sensing performance enhancer for differentiating between healthy and unhealthy uric acid levels based on the refractive index values from previous study. Upon exposure to 670 nm wavelength, the average sensitivity of this sensor was found to be 0.028°/mM with a linearity of 98.67 % and Q-factor value of 0.0053 mM-1. While at 785 nm, the average sensitivity is equal to 0.0193°/mM with slightly lower linearity at 94.46 % and Q-factor value of 0.0076 mM-1. The results have proven the ability of hybrid material Au-ZnO as a sensing performance enhancer for detecting uric acid when compared with bare Au and can be further explored in experimental work.
  9. Fulltext Breastfeeding: crucially important, but increasingly challenged in a market-driven world
    Pérez-Escamilla R, Tomori C, Hernández-Cordero S, Baker P, Barros AJD, Bégin F, et al.
    Lancet, 2023 Feb 11;401(10375):472-485.
    PMID: 36764313 DOI: 10.1016/S0140-6736(22)01932-8
    In this Series paper, we examine how mother and baby attributes at the individual level interact with breastfeeding determinants at other levels, how these interactions drive breastfeeding outcomes, and what policies and interventions are necessary to achieve optimal breastfeeding. About one in three neonates in low-income and middle-income countries receive prelacteal feeds, and only one in two neonates are put to the breast within the first hour of life. Prelacteal feeds are strongly associated with delayed initiation of breastfeeding. Self-reported insufficient milk continues to be one of the most common reasons for introducing commercial milk formula (CMF) and stopping breastfeeding. Parents and health professionals frequently misinterpret typical, unsettled baby behaviours as signs of milk insufficiency or inadequacy. In our market-driven world and in violation of the WHO International Code for Marketing of Breast-milk Substitutes, the CMF industry exploits concerns of parents about these behaviours with unfounded product claims and advertising messages. A synthesis of reviews between 2016 and 2021 and country-based case studies indicate that breastfeeding practices at a population level can be improved rapidly through multilevel and multicomponent interventions across the socioecological model and settings. Breastfeeding is not the sole responsibility of women and requires collective societal approaches that take gender inequities into consideration.
  10. The epidemiology and clinical characteristics of myeloproliferative neoplasms in Malaysia
    Yap YY, Law KB, Sathar J, Lau NS, Goh AS, Chew TK, et al.
    Exp Hematol Oncol, 2018;7:31.
    PMID: 30564475 DOI: 10.1186/s40164-018-0124-7
    Background: The evolution of molecular studies in myeloproliferative neoplasms (MPN) has enlightened us the understanding of this complex disease consisting of polycythaemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The epidemiology is well described in the western world but not in Asian countries like Malaysia.

    Materials and methods: This retrospective national registry of MPN was conducted from year 2009 to 2015 in Malaysia.

    Results: A total of 1010 patients were registered over a period of 5 years. The mean age was 54 years with male predominance. The ethnic distribution revealed that Chinese had a relatively high weighted incidence proportion (43.2%), followed by Indian (23.8%), Malay (15.8%) and other ethnic groups (17.2%). The types of MPN reported were 40.4% of ET (n = 408), 38.1% of PV (n = 385), 9.2% of PMF (n = 93), 3.1% of hypereosinophilic syndrome (HES) (n = 31) and 7.9% of unclassifiable MPN (MPN-U) (n = 80). Splenomegaly was only palpable clinically in 32.2% of patients. The positive JAK2 V617F mutation was present in 644 patients with 46.6% in PV, 36.0% in ET, 9.0% in PMF, and 7.4% in MPN-U, and had significantly lower haemoglobin (p p p 

  11. Detection of SARS-CoV-2 in Environment: Current Surveillance and Effective Data Management of COVID-19
    Nadzirah S, Mohamad Zin N, Khalid A, Abu Bakar NF, Kamarudin SS, Zulfakar SS, et al.
    Crit Rev Anal Chem, 2024;54(8):3083-3094.
    PMID: 37358486 DOI: 10.1080/10408347.2023.2224433
    Since diagnostic laboratories handle large COVID-19 samples, researchers have established laboratory-based assays and developed biosensor prototypes. Both share the same purpose; to ascertain the occurrence of air and surface contaminations by the SARS-CoV-2 virus. However, the biosensors further utilize internet-of-things (IoT) technology to monitor COVID-19 virus contamination, specifically in the diagnostic laboratory setting. The IoT-capable biosensors have great potential to monitor for possible virus contamination. Numerous studies have been done on COVID-19 virus air and surface contamination in the hospital setting. Through reviews, there are abundant reports on the viral transmission of SARS-CoV-2 through droplet infections, person-to-person close contact and fecal-oral transmission. However, studies on environmental conditions need to be better reported. Therefore, this review covers the detection of SARS-CoV-2 in airborne and wastewater samples using biosensors with comprehensive studies in methods and techniques of sampling and sensing (2020 until 2023). Furthermore, the review exposes sensing cases in public health settings. Then, the integration of data management together with biosensors is well explained. Last, the review ended with challenges to having a practical COVID-19 biosensor applied for environmental surveillance samples.
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