Publications by authors named "Kwang Soup Song"

The biosynthesis of nanoparticles is a crucial research area aimed at developing innovative, cost-effective, and eco-friendly synthesis techniques for various applications. Herein, we synthesized copper oxide nanoparticles (CuNPs) using Couroupita guianensis flower extract via a simple green synthesis method. These green CuNPs demonstrate promising antimicrobial activity and anticancer activity against A549 nonsmall cell lung cancer (NSCLC) cells.

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In this study, we report the development of a novel CuO(3 wt%)/CoFeO nanocubes (NCs) photocatalyst through simple co-precipitation and wet impregnation methods for the efficient photocatalytic degradation of triclosan (TCS) pollutants. Initially, rod-shaped bare CoFeO was synthesized using a simple co-precipitation technique. Subsequently, CuO was loaded in various percentages (1, 2, and 3 wt%) onto the surface of bare CoFeO nanorods (NRs) via the wet impregnation method.

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Advancement in bioinspired alloy nanomaterials has a crucial impact on fuel cell applications. Here, we report the synthesis of PtPd alloy nanoclusters via the hydrothermal method using Piper longum extract, representing a novel and environmentally friendly approach. Physicochemical characteristics of the synthesized nanoclusters were investigated using various instrumentation techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, and High-Resolution Transmission electron microscopy.

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Ion-sensitive field-effect transistors (ISFETs) detect specific ions in solutions that enable straightforward, fast, and inexpensive sensors compared to other benchtop equipment. However, a conventional reference electrode (RE) such as Ag/AgCl is limited on the miniaturization of the sensor. We introduce reduced graphene oxide (rGO), which serves as a new RE, when fluorinated (F-rGO) using fluorothiophenol through the π-π interaction.

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The monitoring of Na ions distributed in the body has been indirectly calculated by the detection of Na ions in urine. We fabricated a two-dimensional (2D) Na ion sensor using a graphene ion-sensitive field-effect transistor (G-ISFET) and used fluorinated graphene as a reference electrode (FG-RE). We integrated G-ISFET and FG on a printed circuit board (PCB) designed in the form of a secure digital (SD) card to fabricate a disposable Na ion sensor.

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A reference electrode is necessary for the working of ion-sensitive field-effect transistor (ISFET)-type sensors in electrolyte solutions. The Ag/AgCl electrode is normally used as a reference electrode. However, the Ag/AgCl reference electrode limits the advantages of the ISFET sensor.

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The understanding of cardiac arrhythmia under genetic mutations has grown in interest among researchers. Previous studies focused on the effect of the D172N mutation on electrophysiological behavior. In this study, we analyzed not only the electrophysiological activity but also the mechanical responses during normal sinus rhythm and reentry conditions by using computational modeling.

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Electrical stimulation therapy is a promising method for treating neurological diseases. This method induces the activity and differentiation of nerve cells by the direct or indirect transmission of an electrical signal through biomedical electrodes. We demonstrated the efficacy of a graphene sheet as a bioelectrode to differentiate neurites from hippocampal neuron, through electrical stimulation.

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Background: The heart wall exhibits three layers of different thicknesses: the outer epicardium, mid-myocardium, and inner endocardium. Among these layers, the mid-myocardium is typically the thickest. As indicated by preliminary studies, heart-wall layers exhibit various characteristics with regard to electrophysiology, pharmacology, and pathology.

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The detection of alpha-fetoprotein (AFP) in plasma is important in the diagnosis of hepatocellular carcinoma (HCC) in humans. We developed a biosensor to detect AFP in HCC patient plasma and in a phosphate buffer saline (PBS) solution using a graphene field-effect transistor (G-FET). The G-FET was functionalized with 1-pyrenebutyric acid -hydroxysuccinimide ester (PBASE) for immobilization of an anti-AFP antibody.

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Brain-computer interface (BCI) studies based on electroencephalography (EEG) measured around the ears (ear-EEGs) have mostly used exogenous paradigms involving brain activity evoked by external stimuli. The objective of this study is to investigate the feasibility of ear-EEGs for development of an endogenous BCI system that uses self-modulated brain activity. We performed preliminary and main experiments where EEGs were measured on the scalp and behind the ears to check the reliability of ear-EEGs as compared to scalp-EEGs.

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Background And Aims: Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model.

Methods: In this study, we combined a three-dimensional finite element electromechanical model of ventricles, which is based on human ventricular morphology captured by magnetic resonance imaging (MRI) with a lumped model of the circulatory system and continuous flow LVAD function in order to construct an integrated model of an LVAD implanted-cardiovascular system.

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This study hypothesized that a left ventricular assist device (LVAD) shortens the electromechanical delay (EMD) by mechanical unloading. The goal of this study is to examine, by computational modeling, the influence of LVAD on EMD for four heart failure (HF) cases ranging from mild HF to severe HF. We constructed an integrated model of an LVAD-implanted cardiovascular system, then we altered the Ca transient magnitude, with scaling factors 1, 0.

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Valvular insufficiency affects cardiac responses and the pumping efficacy of left ventricular assist devices (LVADs) when patients undergo LVAD therapy. Knowledge of the effect of valvular regurgitation on the function of LVADs is important when treating heart failure patients. The goal of this study was to examine the effect of valvular regurgitation on the ventricular mechanics of a heart under LVAD treatment and the pumping efficacy of an LVAD using a computational model of the cardiovascular system.

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Intra-aortic balloon pump (IABP) is normally contraindicated in significant aortic regurgitation (AR). It causes and aggravates pre-existing AR while performing well in the event of mitral regurgitation (MR). Indirect parameters, such as the mean systolic pressure, product of heart rate and peak systolic pressure, and pressure-volume are used to quantify the effect of IABP on ventricular workload.

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Background: A left ventricular assist device (LVAD) is normally contraindicated in significant aortic regurgitation (AR) and requires intraoperative valve repair or exclusion. Nevertheless, AR can coexist with an LVAD, so a valid question when asked might still be of clinical significance. The purpose of this study is to analyze the effects of valve regurgitation on the pumping efficacy of continuous and pulsatile LVADs with a computational method.

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Atrial fibrillation (AF) is related to mutations at the genetic level. This includes mutations in genes that encode KCNQ1, a subunit of the I Ks channel. Here, we investigate the mechanism of gain-of-function in I Ks towards the occurrence of AF.

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The unique properties of graphene have earned much interest in the fields of materials science and condensed-matter physics in recent years. However, the biological applications of graphene remain largely unexplored. In this study, we investigated the conditions and viability of a cell culture exposed to graphene onto glass and SiO2/Si, using a human nerve cell line, SH-SY5Y.

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We have introduced pH sensors fabricated on diamond thin films through modification of the surface-terminated atom. We directly modified the diamond surface from hydrogen to amine or oxygen with ultraviolet (UV) irradiation under ammonia gas. The quantified amine site based on the spectra obtained by X-ray photoelectron spectroscopy (XPS) is 26% (2.

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Charge detection biosensors have recently become the focal point of biosensor research, especially field-effect-transistors (FETs) that combine compactness, low cost, high input, and low output impedances, to realize simple and stable in vivo diagnostic systems. However, critical evaluation of the possibility and limitations of charge detection of label-free DNA hybridization using silicon-based ion-sensitive FETs (ISFETs) has been introduced recently. The channel surface of these devices must be covered by relatively thick insulating layers ( SiO2, Si3N4, Al2O3, or Ta2O5) to protect against the invasion of ions from solution.

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Here, we report a novel method of micropatterning oligonucleotides via aromatic groups as linkers on partially amino-terminated diamond and the inherence on subsequent hybridization. The covalent immobilization of probe oligonucleotides and characterization of immobilized probe oligonucleotides with carboxylic compounds were investigated by X-ray photoelectron spectroscopy (XPS). To confirm the effects of linker flexibility in a low amino group on diamond for probe oligonucleotides, three kinds of dicarboxylic compound--adipic acid, terephthalic acid, and trimesic acid--were used for immobilization of probe oligonucleotides, like linkers; and these oligonucleotides were hybridized with target oligonucleotides labeled with Cy 5 on the micropatterned diamond surface.

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We report a novel method of one-step direct amination on polycrystalline diamond to produce functionalized surfaces for DNA micropatterning by photolithography. Polycrystalline diamond was exposed to UV irradiation in ammonia gas to generate amine groups directly. After patterning, optical microscopy confirmed that micropatterns covered with an Au mask were regular in size and shape.

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We have investigated the electrolyte-solution-gate field effect transisitors (SGFETs) used hydrogen terminated (H-terminated) or partially oxygen terminated (O-terminated) polycrystalline diamond surface in the Cl- and Br- ionic solutions. The H-terminated channel SGFETs are insensitive to pH values in electrolyte solutions. The threshold voltages of the diamond SGFETs shift according to the density of Cl- and Br- ions about 30 mV/decade.

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