MyMedR

Displaying all 7 publications

Abstract:

Sort:

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 Understanding Development of Malnutrition in Hemodialysis Patients: A Narrative Review

Sahathevan S, Khor BH, Ng HM, Gafor AHA, Mat Daud ZA, Mafra D, et al.

Nutrients, 2020 Oct 15;12(10).
PMID: 33076282 DOI: 10.3390/nu12103147

Hemodialysis (HD) majorly represents the global treatment option for patients with chronic kidney disease stage 5, and, despite advances in dialysis technology, these patients face a high risk of morbidity and mortality from malnutrition. We aimed to provide a novel view that malnutrition susceptibility in the global HD community is either or both of iatrogenic and of non-iatrogenic origins. This categorization of malnutrition origin clearly describes the role of each factor in contributing to malnutrition. Low dialysis adequacy resulting in uremia and metabolic acidosis and dialysis membranes and techniques, which incur greater amino-acid losses, are identified modifiable iatrogenic factors of malnutrition. Dietary inadequacy as per suboptimal energy and protein intakes due to poor appetite status, low diet quality, high diet monotony index, and/or psychosocial and financial barriers are modifiable non-iatrogenic factors implicated in malnutrition in these patients. These factors should be included in a comprehensive nutritional assessment for malnutrition risk. Leveraging the point of origin of malnutrition in dialysis patients is crucial for healthcare practitioners to enable personalized patient care, as well as determine country-specific malnutrition treatment strategies.
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 Superior Interaction of Electron Beam Irradiation with Carbon Nanotubes Added Polyvinyl Alcohol Composite System

Bee ST, Ooi Ker Qi N, Sin LT, Ng HM, Lim JV, Ratnam CT, et al.

Polymers (Basel), 2021 Dec 10;13(24).
PMID: 34960885 DOI: 10.3390/polym13244334

This work was conducted to investigate the effect of carbon nanotube (CNT) on the mechanical-physico properties of the electron beam irradiated polyvinyl alcohol (PVOH) blends. The increasing of CNT amount up to 1.5 part per hundred resin (phr) has gradually improved tensile strength and Young's modulus of PVOH/CNT nanocomposites due to effective interlocking effect of CNT particles in PVOH matrix, as evident in SEM observation. However, further increments of CNT, amounting up to 2 phr, has significantly decreased the tensile strength and Young's modulus of PVOH/CNT nanocomposits due to the CNT agglomeration at higher loading level. Irradiation was found to effectively improve the tensile strength of PVOH/CNT nanocomposites by inducing the interfacial adhesion effect between CNT particles and PVOH matrix. This was further verified by the decrement values of d-spacing of the deflection peak. The increasing of CNT amounts from 0.5 phr to 1 phr has marginally induced the wavenumber of O-H stretching, which indicates the weakening of hydrogen bonding in PVOH matrix. However, further increase in CNT amounts up to 2 phr was observed to reduce the wavenumber of O-H stretching due to poor interaction effect between CNT and PVOH matrix. Electron beam irradiation was found to induce the melting temperature of all PVOH/CNT nanocomposite by inducing the crosslinked networks.
Is malnutrition a determining factor of health-related quality of life in hemodialysis patients? A cross-sectional design examining relationships with a comprehensive assessment of nutritional status

Ng HM, Khor BH, Sahathevan S, Sualeheen A, Chinna K, Gafor AHA, et al.

Qual Life Res, 2021 Nov 08.
PMID: 34748139 DOI: 10.1007/s11136-021-03018-6

PURPOSE: To identify relationships between health-related quality of life (HRQOL) and nutritional status in hemodialysis (HD) patients.
METHOD: Secondary data from a cross-sectional survey was utilized. HRQOL was assessed for 379 HD patients using the generic Short Form 36 (SF-36) and disease-specific Kidney-Disease Quality of Life-36 (KDQOL-36). Malnutrition was indicated by malnutrition inflammation score (MIS) ≥ 5, and presence of protein-energy wasting (PEW). The individual nutritional parameters included the domains of physical status, serum biomarkers, and dietary intake. Multivariate associations were assessed using the general linear model.
RESULTS: MIS ≥ 5 was negatively associated with SF-36 scores of physical functioning (MIS
Validity of Ultrasound Imaging in Measuring Quadriceps Muscle Thickness and Cross-Sectional Area in Patients Receiving Maintenance Hemodialysis

Sahathevan S, Khor BH, Yeong CH, Tan TH, Meera Mohaideen AK, Ng HM, et al.

JPEN J Parenter Enteral Nutr, 2021 02;45(2):422-426.
PMID: 32384179 DOI: 10.1002/jpen.1867

BACKGROUND: Muscle wasting, prevalent in maintenance hemodialysis (HD) patients diagnosed with protein-energy wasting, represents an assessment challenge in the outpatient HD setting. Quadriceps muscle thickness (QMT) and cross-sectional area (CSA) assessment by ultrasound (US) is a potential surrogate measure for muscle wasting. We aimed to determine the validity of US to measure QMT and CSA against the gold standard-computed tomography (CT).
METHODS: Twenty-six patients on HD underwent US and CT scans on the same day, postdialysis session. QMT for rectus femoris (RF) and vastus intermedius (VI) muscles was taken at the midpoint (MID) and two-thirds (2/3) of both thighs and CSA of the RF muscle (RFCSA ), respectively. Correlation between US and CT measurements was determined by intraclass correlation coefficient (ICC) and Bland-Altman plot.
RESULTS: ICC (95% CI) computed between US and CT was 0.94 (0.87-0.97), 0.97 (0.93-0.99), 0.94 (0.87-0.97), 0.94 (0.86-0.97), and 0.92 (0.83-0.97) for RFMID , VIMID, RF2/3, VI2/3 , and RFCSA , respectively (all P < 0.001). Bland-Altman analysis indicated no bias in agreement between both methods.
CONCLUSION: The US imaging offers a valid and quick bedside assessment approach to assess muscle wasting in HD patients.
Response to "Intraclass Correlation Coefficient and Reliability of Muscle Mass Measurements"

Sahathevan S, Khor BH, Yeong CH, Tan TH, Meera Mohaideen AK, Ng HM, et al.

JPEN J Parenter Enteral Nutr, 2021 07;45(5):872-873.
PMID: 34165200 DOI: 10.1002/jpen.2206