Publications by authors named "Young-Heon Kim"

Article Synopsis
  • - The study introduces a highly sensitive gas sensor for detecting nitrogen monoxide (NO) using a hybrid structure made of palladium nanoparticles (Pd NPs) and porous titanium oxide (TiO), achieving excellent performance at room temperature (∼30°C).
  • - The TiO@Pd 50 hybrid shows impressive results, such as a 175.42% response to 100 ppm NO, a low detection limit of ∼82 ppb, and rapid response times (48s/72s) when exposed to UV light, along with reliability under varying temperatures and humidity levels.
  • - This research highlights the effective mechanisms behind the sensor's performance, including improved surface area, charge carrier management, and a Schottky junction
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We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases.

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Photocuring kinetics in photopolymerization-based three-dimensional (3D) printing processes have gained significant attention because they determine the final dimension accuracy of the printed structures. In this study, the curing kinetics of liquid-light-curable resins, including water-dispersed graphene oxide (GO) and ultraviolet (UV)-cured acrylic resins, were investigated during digital light processing (DLP) 3D printing. Various stable composites of water-dispersed GO and UV-cured acrylic resin were prepared to fabricate 3D structures for cure-depth measurements.

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Complex oxide heterointerfaces contain a rich playground of novel physical properties and functionalities, which give rise to emerging technologies. Among designing and controlling the functional properties of complex oxide film heterostructures, vertically aligned nanostructure (VAN) films using a self-assembling bottom-up deposition method presents great promise in terms of structural flexibility and property tunability. Here, the bottom-up self-assembly is extended to a new approach using a mixture containing a 2Dlayer-by-layer film growth, followed by a 3D VAN film growth.

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We investigate interacting disordered zigzag nanoribbons at low doping, using the Hubbard model to treat electron interactions within the density matrix renormalization group and Hartree-Fock method. Extra electrons that are inserted into an interacting disordered zigzag nanoribbon divide into anyons. Furthermore, the fractional charges form a new disordered anyon phase with a highly distorted edge spin density wave, containing numerous localized magnetic moments residing on the zigzag edges, thereby displaying spin-charge separation and a strong non-local correlation between the opposite zigzag edges.

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In the era of "big data," the cognitive system of the human brain is being mimicked through hardware implementation of highly accurate neuromorphic computing by progressive weight update in synaptic electronics. Low-energy synaptic operation requires both low reading current and short operation time to be applicable to large-scale neuromorphic computing systems. In this study, an energy-efficient synaptic device is implemented comprising a Ni/Pb(Zr Ti )O (PZT)/0.

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The nucleation and crystallization of Bi particles on two matrices, crystalline bismuth sulfide (-BiS) and amorphized bismuth titanium oxide (-BiTiO), were studied by using in situ transmission electron microscopy (TEM) analysis. The atomic structures of the Bi particles were monitored by acquiring high-resolution TEM images in real time. The Bi particles were grown on -BiS and -BiTiO via a two-step nucleation mechanism; dense liquid clusters were clearly observed at the initial stage of nucleation, and the coalescence of clusters was frequently observed during the growth.

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Understanding the dynamic thermal behavior of nanomaterials based on their unique physical and chemical properties is critical for their applications. In this study, the thermal behavior of single-crystalline InAs nanowires in an amorphous AlOshell was investigated by conductingheating experiments in a transmission electron microscope. Two different thermodynamic patterns were observed during theheating experiments: (1) continuous vaporization and condensation simultaneously at temperatures lower than 838.

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Evaluating the stability of semiconductor photocatalysts is critical in the development of efficient catalysts. The morphological and microstructural behaviors of nanorod-shaped BiS semiconductors in aqueous solution were studied using a liquid cell transmission electron microscopy (TEM) technique. The rapid decomposition of BiS in water was observed under electron beam irradiation during TEM.

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Article Synopsis
  • * This research explored how SOX2 levels change in colorectal cancer cells after exposure to radiation, finding that the resistant tumors showed increased SOX2 and CD44 expression, which is linked to their aggressive behavior.
  • * Targeting the PI3K/AKT pathway was effective in reducing SOX2-driven CSC properties and resistance in irradiated colorectal cancer cells, suggesting SOX2 may serve as a valuable target for new therapies.
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Background: Recent DNA/RNA sequencing and other multi-omics technologies have advanced the understanding of the biology and pathophysiology of AD, yet there is still a lack of disease-modifying treatments for AD. A new approach to integration of the genome, transcriptome, proteome, and human interactome in the drug discovery and development process is essential for this endeavor.

Methods: In this study, we developed AlzGPS (Genome-wide Positioning Systems platform for Alzheimer's Drug Discovery, https://alzgps.

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An in-depth understanding of thermal behavior and phase evolution is required to apply heterostructured nanowires (NWs) in real devices. The intermediate status during the vaporization process of InAs NWs in an AlO shell was studied by conducting quenching during heating experiments, using a transmission electron microscope. The formation of As clusters in the amorphous AlO shell was confirmed by analyzing the high-angle annular dark field images and energy-dispersive X-ray spectra.

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The microstructural evolutions in self-catalyzed GaAs nanowires (NWs) were investigated by using in situ heating transmission electron microscopy (TEM). The morphological changes of the self-catalyst metal gallium (Ga) droplet, the GaAs NWs, and the atomic behavior at the interface between the self-catalyst metal gallium and GaAs NWs were carefully studied by analysis of high-resolution TEM images. The microstructural change of the Ga-droplet/GaAs-NWs started at a low temperature of ∼200 °C.

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Backgroud: Exposure to high-dose radiation, such as after a nuclear accident or radiotherapy, elicits severe intestinal damage and is associated with a high mortality rate. In treating patients exhibiting radiation-induced intestinal dysfunction, countermeasures to radiation are required. In principle, the cellular event underlying radiation-induced gastrointestinal syndrome is intestinal stem cell (ISC) apoptosis in the crypts.

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Intestinal organoids have recently emerged as an in vitro model relevant to the gut system owing to their recapitulation of the native intestinal epithelium with crypt-villus architecture. However, it is unclear whether intestinal organoids reflect the physiology of the in vivo stress response. Here, we systemically investigated the radiation response in organoids and animal models using mesenchymal stem cell-conditioned medium (MSC-CM), which contains secreted paracrine factors.

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Recently, III-nitride semiconductor nanostructures, especially InGaN/GaN quantum well nanorods (NRs), have been established as a promising material of choice for nanoscale optoelectronics and photoelectrochemical (PEC) water-splitting applications. Due to the large number of surface states, III-nitride NRs suffer from low quantum efficiency. Therefore, control of the surface states is necessary to improve device performance in real-time applications.

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In this work, for the first time, we have made InN/InO core-shell heterostructure by hydrogen plasma treatment. InN nanorods (NRs) were grown by using plasma-assisted molecular beam epitaxy, and hydrogen plasma treatment was performed by using reactive ion etching at room temperature. From x-ray photoemission spectroscopy studies, it was observed that the bonding partner of In changes from N to O and N 1s completely disappeared in the hydrogenated InN NRs.

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Three-dimensional (3D) homo/heterogeneous DNA nanostructures were studied with low-voltage scanning transmission electron microscopy (LV-STEM). Four types of 3D DNA nanostructures were designed and fabricated by the origami method including newly proposed protocols. The low-energy electron probe and optimized dark-field STEM detector enabled individual unstained DNA nanostructures to be clearly imaged by the single acquisition without the averaging process.

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Although radiotherapy plays a crucial in the management of pelvic tumors, its toxicity on surrounding healthy tissues such as the small intestine, colon, and rectum is one of the major limitations associated with its use. In particular, proctitis is a major clinical complication of pelvic radiotherapy. Recent evidence suggests that endothelial injury significantly affects the initiation of radiation-induced inflammation.

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Stretchable electrodes, which are essential components of next-generation electronic devices, should be highly conductive under multiaxial tensile strain, durable under repetitive stretching, and patternable for integrating stretchable devices. Herein, a lubricant-added stretchable conductive composite of a polydimethylsiloxane-based elastomer containing silver flakes is reported. The added lubricant minimizes changes in conductivity during stretching and maximizes elastic durability by reducing friction.

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Although chemo- or radiotherapy is usually performed in patients with colorectal cancer, the response is highly variable in locally rectal cancer. Therefore, additional studies are needed on predictable markers and the molecular mechanisms of chemo- and radiotherapy. Y box binding protein 1 (YB1) is an oncoprotein that is aberrantly expressed in many cancers, including colorectal cancer.

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A single-crystalline BiS nanowire array (BiSNWA) is synthesized by an in situ hydrothermal reaction on the surface of a BiMoO film. As no additional source of Bi is provided during the process, the BiMoO layer acts as the Bi source for the synthesis of BiS nanowires. The fabricated BiMoO/BiSNWA electrode exhibited an increased photoelectrochemical (PEC) sulfite oxidation activity, which is attributed mainly to the effective interface obtained by the in situ hydrothermal growth, compared to other BiS electrodes.

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Recurrence and chemoresistance in colorectal cancer remain important issues for patients treated with conventional therapeutics. Metformin and phenformin, previously used in the treatment of diabetes, have been shown to have anticancer effects in various cancers, including breast, lung and prostate cancers. However, their molecular mechanisms are still unclear.

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Hyaluronic acid synthase 2 (HAS2) is suggested to play a critical role in malignancy and is abnormally expressed in many carcinomas. However, its role in colorectal cancer (CRC) malignancy and specific signaling mechanisms remain obscure. Here, we report that HAS2 was markedly increased in both CRC tissue and malignant CRC cell lines.

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Sublimation is an interesting phenomenon that is frequently observed in nature. The thermal behavior of InAs NWs with As-face polarity and the [1[combining macron]1[combining macron]1[combining macron]] growth direction of the zinc blende structure were studied by using in situ transmission electron microscopy (TEM). In this study, the anisotropic morphological and atomistic evolution of InAs nanowires (NWs) was observed during decomposition.

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