MyMedR

Displaying publications 281 - 300 of 474 in total

Abstract:

Sort:

Fulltext DETERMINATION OF REACTIVE BLACK 5 (RB5) BY DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRIC TECHNIQUE

Nur Syamimi Zainudin, Nur Aqilah Abdul Rahman

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):73-79.
MyJurnal

Dyes are aromatic organic compound which have an affinity towards the substrate to which they are being applied to. The presence of dyes in wastewater samples is not safe for human even at low level. The presence of dyes in wastewater which are discharged from textile industry must be analysed. Hence, a precise, fast, accurate, simple and inexpensive analytical method with low detection limit is needed for the determination of dyes in wastewaters. The differential pulse anodic stripping voltammetric (DPASV) technique using bare glassy carbon electrode (GCE) as a working electrode and phosphate buffer at pH 4.2 as a supporting electrolyte has been proposed for Reactive Black 5 (RB5) determination. Several experimental voltammetric parameters were being optimized for obtaining a maximum response before analytical validation of the proposed technique being carried out. The optimum parameters were initial potential (Ei) = +0.3 V, end potential (Ef) = +1.0 V, scan rate (v) = 0.04 V/s, accumulation time (tacc) = 50 s, accumulation potential (Eacc) = 0.4 V and pulse amplitude = 0.075 V. The well-defined anodic peak appeared at 0.77972 V. The response was linear from 0.5 to 1.25 mg/L (R2=0.9986) with LOD of 0.050 mg/L. The relative standard deviation (RSD) achieved were 0.08 %, 0.62 % and 0.50 %, respectively for three consecutive days. The % recovery range achieved was from 89.71 % to 111.15 %. It can be concluded that the proposed technique is precise, accurate, inexpensive, fast and has a potential to be an alternative analytical technique for RB5 analysis. The proposed method will in the future be tested for the amount of RB5 in the wastewater samples from textile industry.

Matched MeSH terms: Electrodes
Improved peroxide biosensor based on Horseradish Peroxidase/Carbon Nanotube on a thiol-modified gold electrode

Kafi AKM, Naqshabandi M, Yusoff MM, Crossley MJ

Enzyme Microb Technol, 2018 Jun;113:67-74.
PMID: 29602389 DOI: 10.1016/j.enzmictec.2017.11.006

A new 3-dimensional (3D) network of crosslinked Horseradish Peroxidase/Carbon Nanotube (HRP/CNT) on a thiol-modified Au surface has been described in order to build up the effective electrical wiring of the enzyme units with the electrode. The synthesized 3D HRP/CNT network has been characterized with cyclic voltammetry and amperometry which results the establishment of direct electron transfer between the redox active unit of HRP and the Au surface. Electrochemical measurements reveal that the high biological activity and stability is exhibited by the immobilized HRP and a quasi-reversible redox peak of the redox centre of HRP was observed at about -0.355 and -0.275V vs. Ag/AgCl. The electron transfer rate constant, KSand electron transfer co-efficient α were found as 0.57s-1and 0.42, respectively. Excellent electrocatalytic activity for the reduction of H2O2was exhibited by the developed biosensor. The proposed biosensor modified with HRP/CNT 3D network displays a broader linear range and a lower detection limit for H2O2determination. The linear range is from 1.0×10-7to 1.2×10-4M with a detection limit of 2.2.0×10-8M at 3σ. The Michaelies-Menten constant Kapp M value is estimated to be 0.19mM. Moreover, this biosensor exhibits very high sensitivity, good reproducibility and long-time stability.

Matched MeSH terms: Electrodes
Fulltext MODIFIED SCREEN-PRINTED ELECTRODE FOR DETERMINATION OF IMIDACLOPRID IN WATER SAMPLES: A PRELIMINARY STUDY

AZRILAWANI AHMAD, NUR ANIS ZAFIRAH ZAINORDIN, NUR AMIRA JAAFAR

UMT Journal of Undergraduate Research, 2019;1(2):41-50.
MyJurnal

A preliminary assessment of a simple and rapid electrochemical method was carried out to analyse imidacloprid (IMI) in water samples using cyclic voltammetry (CV) based on modified screen-printed gold electrode (SPGE). Self-assembled monolayer (SAM) was optimized using 11-mercaptoundecanoic acid (11-MUA) with several parameters such as scan rates, type of supporting electrolyte, and pH of the supporting electrolyte. The modified SPGE showed high suppressed current against the potential due to the formation of a monolayer on the electrode surface. Surface morphology of the electrode was analysed using Scanning Electron Microscopy (SEM) confirming that 11-MUA was present on the modified SPGE. The water samples were collected from GM Peladang, Kuala Terengganu and two locations at Universiti Malaysia Terengganu. Method detection limit was expressed as limit of detection (LOD) and limit of quantification (LOQ) for modified SPGE which were calculated at 3.784 and 12.613 mg/L in water samples, respectively. This study showed that the reduction peak current observed on the modified electrode was lower compared with oxidation peak current. Hence, gold is unsuitable for IMI detection.

Matched MeSH terms: Electrodes
Fulltext Surface Electromyography (sEMG) Activity of Masticatory Muscle (Masseter and Temporalis) with Three Different Types of Orthodontic Bracket

Nishi SE, Rahman NA, Basri R, Alam MK, Noor NFM, Zainal SA, et al.

Biomed Res Int, 2021;2021:6642254.
PMID: 33969121 DOI: 10.1155/2021/6642254

Objective: This pre-post study is aimed at determining the effects of masticatory muscle activity (masseter and temporalis) measured via sEMG between conventional, self-ligating, and ceramic bracket after six months of orthodontic treatment.
Methods: A total of eighteen (18) malocclusion patients were identified. Malocclusion patients were subdivided into 3 groups based on the bracket selection (conventional, self-ligating, and ceramic bracket) with 6 patients for each group. sEMG of muscles were done using a two-channel electromyography device, where pregelled and self-adhesive electrodes (bilateral) were applied. Chewing and clenching of masseter and temporalis muscle activity were recorded for 20 s pre and 6 months of orthodontic treatment using sEMG (frequency 60 Hz). The data were analysed by using repeated measures ANOVA in IBM SPSS Statistics Version 24.0.
Results: Chewing and clenching for masseter muscle showed no significant difference (P > 0.05) in sEMG activity of three types of the brackets. However, for temporalis muscle, there was a significant difference found in sEMG activity during chewing (P < 0.05) and clenching (P < 0.05) between these three brackets.
Conclusion: The activity of temporalis muscle showed significant changes in chewing and clenching, where the conventional group demonstrated better muscle activity pre and at six months of fixed appliances.

Matched MeSH terms: Electrodes
A novel application of simple submersible yeast-based microbial fuel cells as dissolved oxygen sensors in environmental waters

Christwardana M, Yoshi LA, Setyonadi I, Maulana MR, Fudholi A

Enzyme Microb Technol, 2021 Sep;149:109831.
PMID: 34311895 DOI: 10.1016/j.enzmictec.2021.109831

In this study, yeast microbial fuel cells (MFCs) were established as biosensors for in-situ monitoring of dissolved oxygen (DO) levels in environmental waters, with yeast and glucose substrates acting as biocatalyst and fuel, respectively. Diverse environmental factors, such as temperature, pH and conductivity, were considered. The sensor performance was first tested with distilled water with different DO levels ranging from 0 mg/L to 8 mg/L and an external resistance of 1000 Ω. The relationship between DO and current density was non-linear (exponential). This MFC capability was further explored under different environmental conditions (pH, temperature and conductivity), and the current density produced was within the range of 0.14-34.88 mA/m2, which increased with elevated DO concentration. The resulting regression was y = 1.3051e0.3548x, with a regression coefficient (R2) = 0.71, indicating that the MFC-based DO meter was susceptible to interference. When used in environmental water samples, DO measurements using MFC resulted in errors ranging from 6.25 % to 15.15 % when compared with commercial DO meters. The simple yeast-based MFC sensors demonstrate promising prospects for future monitoring in a variety of areas, including developing countries and remote locations.

Matched MeSH terms: Electrodes
Fulltext Inhibitory effects of cardamonin on compound action potentials in frog sciatic nerves and the possible involvement of opioidergic pathway

Sambasevam, Yogesvari, Wong, Siong Jiun, Farihah Hanani Ghazali, Ammar Izzati Amir Ramadan, Mohd Roslan Sulaiman, Mohd Khairi Hussain, et al.

Life Sciences, Medicine and Biomedicine, 2017;1(1):18-24.
MyJurnal

Introduction: Active compounds derived from plants are able to inhibit nerve conduction. Cardamonin, a naturally occurring chalcone, manifests anti-nociceptive, anti-inflammatory and anti-neuropathy properties. Consequently, cardamonin may potentially inhibit nerve action potential, whereby, it affects the nerve conduction. Compound action potential is the sum of the activity which is measured from a nerve trunk. Objective: The experiment was carried out to investigate the inhibitory effect of cardamonin on compound action potentials and its possible mechanism of action on frog sciatic nerve. Methodology: LabTutor software was used to record compound action potentials in frog sciatic nerve. Sciatic nerve was isolated from the frog and soaked in Ringer’s solution. Stimulating electrodes were used to stimulate the nerve and recording electrodes were used to record compound action potentials. Compound action potential of the nerve were recorded before and after treatments [vehicle, cardamonin (0.5, 1 & 2 mg/ml) & morphine (3mg/ml)]. Participation of opioid system was investigated by pre-treating the nerve with naloxone and followed by cardamonin. All the data were recorded and analysed via LabTutor software. The data were analysed by using Two-way ANOVA followed by Bonferonni’s post hoc test with significant value at P < 0.05. Results: The outcomes showed that all the doses of cardamonin significantly reduced the peak amplitude of compound action potential in frog sciatic nerves. Besides, co-treatment of naloxone and cardamonin significantly (P < 0.001) reversed the effect of cardamonin on peak amplitude of compound action potential, suggesting the involvement of opioid receptors to inhibit nerve conduction. Conclusion: Cardamonin reduces the nerve signal conduction via activation of opioid receptors to modulate pain and contribute to the analgesic effects.

Matched MeSH terms: Electrodes
Fulltext Bimodal Data Fusion of Simultaneous Measurements of EEG and fNIRS during Lower Limb Movements

Al-Quraishi MS, Elamvazuthi I, Tang TB, Al-Qurishi M, Adil SH, Ebrahim M

Brain Sci, 2021 May 27;11(6).
PMID: 34071982 DOI: 10.3390/brainsci11060713

Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) have temporal and spatial characteristics that may complement each other and, therefore, pose an intriguing approach for brain-computer interaction (BCI). In this work, the relationship between the hemodynamic response and brain oscillation activity was investigated using the concurrent recording of fNIRS and EEG during ankle joint movements. Twenty subjects participated in this experiment. The EEG was recorded using 20 electrodes and hemodynamic responses were recorded using 32 optodes positioned over the motor cortex areas. The event-related desynchronization (ERD) feature was extracted from the EEG signal in the alpha band (8-11) Hz, and the concentration change of the oxy-hemoglobin (oxyHb) was evaluated from the hemodynamics response. During the motor execution of the ankle joint movements, a decrease in the alpha (8-11) Hz amplitude (desynchronization) was found to be correlated with an increase of the oxyHb (r = -0.64061, p < 0.00001) observed on the Cz electrode and the average of the fNIRS channels (ch28, ch25, ch32, ch35) close to the foot area representation. Then, the correlated channels in both modalities were used for ankle joint movement classification. The result demonstrates that the integrated modality based on the correlated channels provides a substantial enhancement in ankle joint classification accuracy of 93.01 ± 5.60% (p < 0.01) compared with single modality. These results highlight the potential of the bimodal fNIR-EEG approach for the development of future BCI for lower limb rehabilitation.

Matched MeSH terms: Electrodes
Electrocatalytic Reduction of Hydrogen Peroxide and Its Non-Enzymatic Electrochemical Detection Using Silver Nanoparticles Anchored on Reduced Graphene Oxide

Ikhsan NI, Rameshkumar P, Yusoff N, Huang NM

J Nanosci Nanotechnol, 2019 Nov 01;19(11):7054-7063.
PMID: 31039858 DOI: 10.1166/jnn.2019.16630

Silver-reduced graphene oxide (Ag-rGO) nanohybrid was synthesized by applying a slight modification to the Turkevich method using trisodium citrate as a reducing and stabilizing agent to catalyze the non-enzymatic electrochemical detection of hydrogen peroxide (H₂O₂). Spherical silver nanoparticles (AgNPs) with an average particle size of 2.2 nm surfaced on reduced graphene oxide (rGO) sheets. Cyclic voltammograms (CV) obtained from glassy carbon (GC) electrode coated with Ag-rGO nanohybrid (4 mM) exhibited a peak at an overpotential of -0.52 V, with a larger faradaic current for the reduction of H₂O₂. Using the modified electrode for the linear sweep voltammetry (LSV) detection of H₂O₂, the detection limit and sensitivity were determined to be 4.8 μM (S/N ═ 3) and 0.0262 μA μM-1, respectively. The sensor appeared selective and stable towards H₂O₂ in the presence of possible interference, and it also demonstrated good recoveries of H₂O₂ concentration in real water samples.

Matched MeSH terms: Electrodes
Reclamation of Hexavalent Chromium from Electroplating Effluents by Electroextraction

Revathi M, Sivagaami Sundari G, Ahmed Basha C, Alam M, Sagadevan S, Ahmad N

J Nanosci Nanotechnol, 2020 10 01;20(10):6547-6554.
PMID: 32385012 DOI: 10.1166/jnn.2020.18562

This investigation aims at the reclamation of Cr(VI) from synthetic electroplating industrial effluent by electroextraction process namely electrochemical ion exchange (EIX). An electrochemical ion exchange reactor of desired dimensions was fabricated with the help of ion-permeable membranes, stainless steel cathode and PbO₂ coated Ti expanded mesh anode. The performance of the reactor was studied in batch recirculation mode, continuous flow mode at different experimental conditions. The influence of various experimental factors, for instance, initial metal ion concentration (20, 300, 1000 mg/L of Cr(VI)), applied voltages (2.5 V, 5 V, 7.5 V, 10 V) and flow rates of the process stream (2, 4, 6, 8, 10, 12 and 14 ml/min) on removal/reclamation efficiency was deliberated. For comparison purposes, an electrodialysis process was conducted at the same optimal conditions. It was found that the EIX process with three compartments has more removal efficiency at optimum experimental conditions than the electrodialysis process. The continuous flow process of the reactor with 300 mg/L of Cr(VI) as inlet concentration has studied to predict the breakeven point of the reactor. It was noted that Cr(VI) ion concentration in the treated wastewater is almost zero up to the discharge of 20 liters of treated rinse water.

Matched MeSH terms: Electrodes
Hemoglobin Immobilization on Multiporous Nanofibers of SnO₂ and Chitosan Composite for Hydrogen Peroxide Sensing

Kafi AKM, Alim S, Jose R, Yusoff MM

J Nanosci Nanotechnol, 2019 04 01;19(4):2027-2033.
PMID: 30486943 DOI: 10.1166/jnn.2019.15465

A multiporous nanofiber (MPNFs) of SnO₂ and chitosan has been used for the immobilization of a redox protein, hemoglobin (Hb), onto the surface of glassy carbon electrode (GCE). The multiporous nanofiber of SnO₂ that has very high surface area is synthesized by using electrospinning technique through controlling the tin precursor concentration. Since the constructed MPNFs of SnO₂ exposes very high surface area, it increases the efficiency for biomolecule-loading. The morphology of fabricated electrodes is examined by SEM observation and the absorbance spectra of Hb/(MPNFs) of SnO₂ are studied by UV-Vis analysis. Cyclic Voltammetry and amperometry are employed to study and optimize the performance of the resulting fabricated electrode. After fabrication of the electrode with the Hb and MPNFs of SnO₂, a direct electron transfer between the protein's redox centre and the glassy carbon electrode was established. The modified electrode has showed a couple of redox peak located at -0.29 V and -0.18 V and found to be sensitive to H₂O₂. The fabricated electrode also exhibited an excellent electrocatalytic activity towards the reduction of H₂O₂. The catalysis currents increased linearly to the H₂O₂ concentration in a wide range of 5.0×10-6-1.5×10-4 M. Overall experimental results show that MPNFs of SnO₂ has a role towards the enhancement of the electroactivity of Hb at the electrode surface. Thus the MPNFs of SnO₂ is a very promising candidate for future biosensor applications.

Matched MeSH terms: Electrodes
An electrochemical sensor based on gold nanoparticles-functionalized reduced graphene oxide screen printed electrode for the detection of pyocyanin biomarker in Pseudomonas aeruginosa infection

Rashid JIA, Kannan V, Ahmad MH, Mon AA, Taufik S, Miskon A, et al.

Mater Sci Eng C Mater Biol Appl, 2021 Jan;120:111625.
PMID: 33545813 DOI: 10.1016/j.msec.2020.111625

Multidrug resistant Pseudomonas aeruginosa (P. aeruginosa) is known to be a problematic bacterium for being a major cause of opportunistic and nosocomial infections. In this study, reduced graphene oxide decorated with gold nanoparticles (AuNPs/rGO) was utilized as a new sensing material for a fast and direct electrochemical detection of pyocyanin as a biomarker of P. aeruginosa infections. Under optimal condition, the developed electrochemical pyocyanin sensor exhibited a good linear range for the determination of pyocyanin in phosphate-buffered saline (PBS), human saliva and urine at a clinically relevant concentration range of 1-100 μM, achieving a detection limit of 0.27 μM, 1.34 μM, and 2.3 μM, respectively. Our developed sensor demonstrated good selectivity towards pyocyanin in the presence of interfering molecule such as ascorbic acid, uric acid, NADH, glucose, and acetylsalicylic acid, which are commonly found in human fluids. Furthermore, the developed sensor was able to discriminate the signal with and without the presence of pyocyanin directly in P. aeruginosa culture. This proposed technique demonstrates its potential application in monitoring the presence of P. aeruginosa infection in patients.

Matched MeSH terms: Electrodes
Bioelectrofuel Synthesis by Nanoenzymes: Novel Alternatives to Conventional Enzymes

Singh L, Rana S, Thakur S, Pant D

Trends Biotechnol, 2020 05;38(5):469-473.
PMID: 31932067 DOI: 10.1016/j.tibtech.2019.12.017

Recent bioinspired efforts of designing novel nanoenzyme-based electrocatalysts are driven by the urgency of making bioelectrofuels more affordable and efficient. Unlike natural enzymes, nanoenzyme-modified electrodes with large surface areas enclose numerous biomimicking active sites to facilitate enhanced microbial growth followed by increased reactant-to-bioelectrofuel conversion.

Matched MeSH terms: Electrodes
Composite of medium-chain-length polyhydroxyalkanoates-co-methyl acrylate and carbon nanotubes as innovative electrodes modifier in microbial fuel cell

Sirajudeen AAO, Annuar MSM, Subramaniam R

Biotechnol Appl Biochem, 2021 Apr;68(2):307-318.
PMID: 32314420 DOI: 10.1002/bab.1928

A microbial fuel cell is a sustainable and environmental-friendly device that combines electricity generation and wastewater treatment through metabolic activities of microorganisms. However, low power output from inadequate electron transfer to the anode electrode hampers its practical implementation. Nanocomposites of oxidized carbon nanotubes and medium-chain-length polyhydroxyalkanoates (mcl-PHA) grafted with methyl acrylate monomers enhance the electrochemical function of electrodes in microbial fuel cell. Extensive polymerization of methyl acrylate monomers within mcl-PHA matrix, and homogenous dispersion of carbon nanotubes within the graft matrix are responsible for the enhancement. Modified electrodes exhibit high conductivities, better redox peak and reduction of cell internal resistance up to 76%. A stable voltage output at almost 700 mV running for 225 H generates maximum power and current density of 351 mW/m2 and 765 mA/m2 , respectively. Superior biofilm growth on modified surface is responsible for improved electron transfer to the anode hence stable and elevated power output generation.

Matched MeSH terms: Electrodes
Flow-through chloroquine sensor and its applications in pharmaceutical analysis

Saad B, Zin ZM, Jab MS, Rahman IA, Saleh MI, Mahsufi S

Anal Sci, 2005 May;21(5):521-4.
PMID: 15913140

Poly (vinyl chloride) membrane electrodes that responded selectively towards the antimalarial drug chloroquine are described. The electrodes were based on the use of the lipophilic potassium tetrakis(4-chlorophenyl)borate as ion-exchanger and bis(2-ethylhexyl)adipate (BEHA), or trioctylphosphate (TOP) or dioctylphenylphosphonate (DOPP) as plasticizing solvent mediator. All electrodes produced good quality characteristics such as Nernstian- and rapid responses, and are minimally interfered with by the alkali and alkaline earth metal ions tested. The membranes were next applied to a flow-through device, enabling it to function as flow-injection analysis (FIA) detector. The performance of the sensor after undergoing the FIA optimization was further evaluated for its selectivity characteristics and lifetime. Results for the determination of chloroquine in synthetic samples that contained common tablet excipients such as glucose, starch, and cellulose, and other foreign species such as cations, citric acid or lactic acid were generally satisfactory. The sensor was also successfully used for the determination of the active ingredients in mock tablets, synthetic fluids and biological fluids. The sensor was applied for the determination of active ingredients and the dissolution profile of commercial tablets was also established.

Matched MeSH terms: Electrodes
Multi-stacking from two sample streams in nonaqueous microchip electrophoresis

Thang LY, See HH, Quirino JP

Anal Chem, 2016 Sep 26.
PMID: 27669824

The translation of stacking techniques used in capillary electrophoresis (CE) to microchip CE (MCE) in order to improve concentration sensitivity is an important area of study. The success in stacking relies on the generation and control of the stacking boundaries which is a challenge in MCE because the manipulation of solutions is not as straightforward as in CE with a single channel. Here, a simple and rapid on-line sample concentration (stacking strategy) in a battery operated nonaqueous MCE device with a commercially available double T-junction glass chip is presented. A multi-stacking approach was developed in order to circumvent the issues for stacking in nonaqueous MCE. The cationic analytes from the two loading channels were injected under field-enhanced conditions and were focused by micelle-to-solvent stacking. This was achieved by the application of high electric fields along the two loading channels and a low electric field in the separation channel, with one ground electrode in the reservoir closest to the junction. At the junction, the stacked zones were re-stacked under field-enhanced conditions and then injected into the separation channels. The multi-stacking was verified under a fluorescence microscope using Rhodamine 6G as the analyte, revealing a sensitivity enhancement factor (SEF) of 110. The stacking approach was also implemented in the nonaqueous MCE with contactless conductivity detection of the anticancer drug tamoxifen as well as its metabolites. The multi-stacking and analysis time was 40 s and 110 s, respectively, the limit of detections was from 10 to 35 ng/mL, and the SEFs were 20 to 50. The method was able to quantify the target analytes from breast cancer patients.

Matched MeSH terms: Electrodes
Fulltext An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions

Naderipour A, Asuhaimi Mohd Zin A, Bin Habibuddin MH, Miveh MR, Guerrero JM

PLoS One, 2017;12(2):e0164856.
PMID: 28192436 DOI: 10.1371/journal.pone.0164856

In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method.

Matched MeSH terms: Electrodes
Fulltext Characterization of Textile-Insulated Capacitive Biosensors

Ng CL, Reaz MB

Sensors (Basel), 2017 Mar 12;17(3).
PMID: 28287493 DOI: 10.3390/s17030574

Capacitive biosensors are an emerging technology revolutionizing wearable sensing systems and personal healthcare devices. They are capable of continuously measuring bioelectrical signals from the human body while utilizing textiles as an insulator. Different textile types have their own unique properties that alter skin-electrode capacitance and the performance of capacitive biosensors. This paper aims to identify the best textile insulator to be used with capacitive biosensors by analysing the characteristics of 6 types of common textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile) while evaluating their impact on the performance of a capacitive biosensor. A textile-insulated capacitive (TEX-C) biosensor was developed and validated on 3 subjects. Experimental results revealed that higher skin-electrode capacitance of a TEX-C biosensor yields a lower noise floor and better signal quality. Natural fabric such as cotton and linen were the two best insulating materials to integrate with a capacitive biosensor. They yielded the lowest noise floor of 2 mV and achieved consistent electromyography (EMG) signals measurements throughout the performance test.

Matched MeSH terms: Electrodes
Fulltext Sensitivity and specificity of vestibular evoked myogenic potential elicited by different tone bursts to diagnose peripheral vestibular disordered

Zuraida Zainun, Mohd Normani Zakaria, Din Suhaimi Sidek, Zalina Ismail

Malaysian Journal of Medicine and Health Sciences, 2014;10(2):9-17.
MyJurnal

Peripheral vestibular disorder (PVD) is serious and common. Clinically, giving an accurate diagnosis of PVD can be challenging. Vestibular evoked myogenic potential (VEMP) is an objective test to evaluate the integrity of vestibular organs, particularly saccule and/or inferior vestibular nerve. This study was performed to determine the sensitivity and specificity of VEMP using different stimuli. Fourty normal and 65 PVD subjects who fulfilled the inclusion criteria were recruited. While sitting comfortably, VEMP waveforms were recorded with active electrode on sternocleidomastoid muscle and negative electrode on upper forehead. Tone bursts (500, 750 and 1000 Hz) were delivered via headphones at 90 dBnHL and 5/s presentation rate. VEMP parameters for each stimulus (amplitude and latency of P1 and N1 peak) were analyzed accordingly. Receiver operating characteristic (ROC) was performed to determine the sensitivity and specificity of VEMP at different test frequencies. N1 amplitude of 750 Hz stimulus produced the most ideal sensitivity (65% on right and 63% on left) and specificity (83% on right and 78% on left). The importance of using a few tone bursts in VEMP test in order to minimize the false negative in cases might be encountered in clinics as the certain tone burst had inadequate sensitivity in detecting PVD cases. The 750 Hz stimulus produced the most ideal VEMP with adequate values of sensitivity and specificity, at least in this study.

Matched MeSH terms: Electrodes
Fulltext Template-assisted growth of nanostructured functional materials

Kok, Kuan Ying, Nur Ubaidah Saidin, Ng, Inn Khuan, Suhaila Hani Ilias, Choo, Thye Foo

Journal of Nuclear and Related Technologies, 2012;2012(2):66-72.
MyJurnal

Template-assisted growth is an important nanoelectrochemical deposition technique for synthesizing one-dimensional (1-D) nanostructures with uniformly well-controlled shapes and sizes. A good template with well-defined dimensions is imperative for realizing this task. Porous anodic alumina (PAA) has been a favorable candidate for this purpose as it can be tailor-made with precise pore geometries, such as pore length and diameter as well as inter-pore distances, via the anodisation of pure aluminium. This paper reports the fabrication of PAA templates and electrochemical synthesis of functional nanostructures in the form of nanowires using PAA templates as scaffolds. Axial heterostructured and homogeneous nanowires formed by engineering materials configuration via composition and/or layer thickness variations were fabricated for different functionalities. X-ray diffraction and imaging techniques were used to elucidate the microstructures, morphologies and chemical compositions of the nanowires produced. Due to their large surface area-to-volume ratios, and therefore high sensitivities, these functional nanostructures have useful applications as critical components in nanosensor devices and various areas of nanotechnology. Potential applications include as hydrogen gas sensors in nuclear power plant for monitoring structural integrity of reactor components and containment building, as well as environmental monitoring of air pollution and leakages of toxic gases and chemicals.

Matched MeSH terms: Electrodes
Sustainable green technology on wastewater treatment: The evaluation of enhanced single chambered up-flow membrane-less microbial fuel cell

Thung WE, Ong SA, Ho LN, Wong YS, Ridwan F, Oon YL, et al.

J Environ Sci (China), 2018 Apr;66:295-300.
PMID: 29628097 DOI: 10.1016/j.jes.2017.05.010

This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell (UFML-MFC) in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the performance under different operational conditions which affect the chemical oxygen demand (COD) reduction and power generation, including the increase of KCl concentration (MFC1) and COD concentration (MFC2). The results showed that the increase of KCl concentration is an important factor in up-flow membrane-less MFC to enhance the ease of electron transfer from anode to cathode. The increase of COD concentration in MFC2 could led to the drop of voltage output due to the prompt of biofilm growth in MFC2 cathode which could increase the internal resistance. It also showed that the COD concentration is a vital issue in up-flow membrane-less MFC. Despite the COD reduction was up to 96%, the power output remained constrained.

Matched MeSH terms: Electrodes

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links