2,865 results match your criteria: "Ulsan National Institute of Science and Technology (UNIST).[Affiliation]"

Seawater batteries (SWBs) have emerged as a next-generation battery technology that does not rely on lithium, a limited resource essential for lithium-ion batteries. Instead, SWBs utilize abundant sodium from seawater, offering a sustainable alternative to conventional battery technologies. Previous studies have demonstrated the feasibility of achieving high energy densities in SWB anodes using vertically aligned electrodes.

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Current in vitro models of 3D tumor spheroids within the microenvironment have emerged as promising tools for understanding tumor progression and potential drug responses. However, creating spheroids with functional vasculature remains challenging in a controlled and high-throughput manner. Herein, a novel open 3D-microarray platform is presented for a spheroid-endothelium interaction (ODSEI) chip, capable of arraying more than 1000 spheroids on top of the vasculature, compartmentalized for single spheroid-level analysis of drug resistance, and allows for the extraction of specific spheroids for further analysis.

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We report a CNT/eGaIn composite that suppresses dissolutive wetting on platinum, maintaining interconnect stability for up to 30 days. Minimizing CNT aggregation prevents gallium penetration, enhancing the reliability of liquid metal components in electronics.

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Tumor-derived extracellular vesicle (tEV)-associated RNAs hold promise as diagnostic biomarkers, but their clinical use is hindered by the rarity of tEVs among nontumor EVs. Here, we present EV-CLIP, a highly sensitive droplet-based digital method for profiling EV RNA. EV-CLIP utilizes the fusion of EVs with charged liposomes (CLIPs) in a microfluidic chip.

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We report the exfoliation of ultrathin gallium oxide (GaO) films from liquid metal balloons, formed by injecting air into droplets of eutectic gallium-indium alloy (eGaIn). These GaO films enable the selective adsorption of carbon nanotubes (CNTs) dispersed in water, resulting in the formation of a dense, percolating CNT network on their surface. The self-assembled CNT network on GaO provides a versatile platform for device fabrication.

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Organic anode materials have garnered attention for use in rechargeable Li-ion batteries (LIBs) owing to their lightweight, cost-effectiveness, and tunable properties. However, challenges such as high electrolyte solubility and limited conductivity, restrict their use in full-cell LIBs. Here, we report the use of highly crystalline Cl-substituted contorted hexabenzocoronene (Cl-cHBC) as an efficient organic anode for full-cell LIBs.

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eIF2α Phosphorylation-ATF4 Axis-Mediated Transcriptional Reprogramming Mitigates Mitochondrial Impairment During ER Stress.

Mol Cells

January 2025

Basic-Clinical Convergence Research Center, School of Biological Sciences, University of Ulsan, Ulsan 44610, Korea. Electronic address:

Eukaryotic translation initiation factor 2α (eIF2α) phosphorylation, which regulates all three unfolded protein response pathways, helps maintain cellular homeostasis and overcome endoplasmic reticulum (ER) stress through transcriptional and translational reprogramming. However, transcriptional regulation of mitochondrial homeostasis by eIF2α phosphorylation during ER stress is not fully understood. Here, we report that the eIF2α phosphorylation-activating transcription factor 4 (ATF4) axis is required for expression of multiple transcription factors (TFs) including nuclear factor erythroid 2-related factor 2 (Nrf2) and their target genes responsible for mitochondrial homeostasis during ER stress.

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The simultaneous removal reaction (SRR) is a pioneering approach for achieving the simultaneous removal of anthropogenic NO and CO pollutants through catalytic reactions. To facilitate this removal across diverse industrial fields, it is crucial to understand the trade-offs and synergies among the multiple reactions involved in the SRR process. In this study, we developed mixed metal oxide nanostructures derived from layered double hydroxides as catalysts for the SRR, achieving high catalytic conversions of 93.

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Lifetimes and Lifetime-Associated Spectra for Reversible Excited Two-State Reactions.

J Phys Chem A

January 2025

Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.

Photoinduced excited-state processes have been platforms for understanding the molecular mechanisms of many chemical and biological reactions. To elucidate associated chemical kinetics, time-resolved spectroscopic experiments have been performed tracking how the populations of reactants and products change during the reactions while reaction conditions such as the concentration of a reactant, temperature, and solvent properties change. Here, we simulate the lifetimes of a reactant and a product, and construct their lifetime-associated spectra with the various combinations of rate constants based on the analytical solutions of differential rate equations.

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Pine needle, pine bark, and soil samples were collected from various regions in South Korea, considering the suitability of vegetation samples as passive samplers. A total of 27 organochlorine pesticides (OCPs) were analyzed using a gas chromatograph/high-resolution mass spectrometer (GC/HRMS). The total concentrations of OCPs ranged between 650 and 3652 pg/g dw in soil, 215 and 1384 pg/g ww in pine needles, and 456 and 1723 pg/g ww in pine bark.

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Metabolic Engineering of Corynebacterium glutamicum for High-Level Production of 1,5-Pentanediol, a C5 Diol Platform Chemical.

Adv Sci (Weinh)

December 2024

Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea.

The biobased production of chemicals is essential for advancing a sustainable chemical industry. 1,5-Pentanediol (1,5-PDO), a five-carbon diol with considerable industrial relevance, has shown limited microbial production efficiency until now. This study presents the development and optimization of a microbial system to produce 1,5-PDO from glucose in Corynebacterium glutamicum via the l-lysine-derived pathway.

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Two-dimensional materials with a nanostructure have been introduced as promising candidates for SERS platforms for sensing application. However, the dynamic control and tuning of SERS remains a long-standing problem. Here, we demonstrated active tuning of the enhancement factor of the first- and second-order Raman mode of monolayer (1L) MoS transferred onto a flexible metallic nanotip array.

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Research on perovskite light-emitting diodes (PeLEDs) has primarily focused on modulating crystal growth to achieve smaller grain sizes and defect passivation using organic additives. However, challenges remain in controlling the intermolecular interactions between these organic additives and perovskite precursor ions for precise modulation of crystal growth. In this study, we synthesize two triphenylphosphine oxide (TPPO)-based multidentate additives: bidentate hexane-1,6-diyl-bis(oxy-4-triphenylphosphine oxide) (2-TPPO) and tetradentate pentaerythrityl-tetrakis(oxy-4-triphenylphosphine oxide) (4-TPPO).

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Water is pursued as an electrolyte solvent for its non-flammable nature compared to traditional organic solvents, yet its narrow electrochemical stability window (ESW) limits its performance. Solvation chemistry design is widely adopted as the key to suppress the reactivity of water, thereby expanding the ESW. In this study, an acetamide-based ternary eutectic electrolyte achieved an ESW ranging from 1.

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Polythiophene donors offer scalable and cost-effective solutions for the organic photovoltaic industry. A thorough understanding of the structure-property-performance relationship is essential for advancing polythiophene-based organic solar cells (PTOSCs) with high power conversion efficiencies (PCEs). Herein, we develop two polythiophene donors─PTTz-CN and PTTz-CN(T2)─to verify the energy loss-quantum efficiency relationship.

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Nanographenes and polycyclic aromatic hydrocarbons, both finite forms of graphene, are promising organic semiconducting materials because their optoelectronic and magnetic properties can be modulated through precise control of their molecular peripheries. Several atomically precise edge structures have been prepared by bottom-up synthesis; however, no systematic elucidation of these edge topologies at the molecular level has been reported. Herein, we describe rationally designed modular syntheses of isomeric dibenzoixenes with diverse molecular peripheries, including cove, zigzag, bay, fjord, and gulf structured.

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Among 2-dimensional (2D) non-layered transition-metal chalcogenides (TMCs), cobalt sulfides are highly interesting because of their diverse structural phases and unique properties. The unique magnetic properties of TMCs have generated significant interest in their potential applications in future spintronic devices. In addition, their high conductivity, large specific surface area, and abundant active sites have attracted attention in the field of catalysis.

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Proteins, inherently biocompatible and biodegradable, face a challenge in forming stable hydrogels without external chemical crosslinkers. Here, we construct a ring-shaped trimeric SpyTag-fused Proliferating Cell Nuclear Antigen Protein (ST-PCNA) as a core protein building block, and a dumbbell-shaped tandem dimeric SpyCatcher (SC-SC) as a bridging component. Self-crosslinked PCNA/SC-SC Protein (2SP) hydrogels are successfully formed by simply mixing the solutions of ST-PCNA and SC-SC, without chemical crosslinkers.

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Development of a comprehensive air risk index and its application to high spatial-temporal health risk assessment in a large industrial city.

Environ Pollut

December 2024

Department of Civil, Urban, Earth, and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea; Research and Management Center for Particulate Matter in the Southeast Region of Korea, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea. Electronic address:

Particulate matter (PM) contains various hazardous air pollutants (HAPs) that can adversely affect human health, highlighting the need for an integrated index to represent the associated health risks. In response, this study developed a novel index, the comprehensive air-risk index (CARI), for Ulsan, the largest industrial city in South Korea. This index integrates toxicity-weighted concentrations of polycyclic aromatic hydrocarbons (PAHs) and heavy metals using their inhalation unit risks.

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Electrolyte additive engineering enables the creation of long-lasting interfacial layers that protect electrodes, thus extending the lifetime of high-energy lithium-ion batteries employing Ni-rich Li[NiCoMn]O (NCM) cathodes. However, batteries face various limitations if existing additives are employed alone without an appropriate combination. Herein, the study reports the development of a molecular-engineered salt-type multifunctional additive, lithium bis(phosphorodifluoridate) triethylammonium ethenesulfonate (LiPENS), that leverages the different functionalities of phosphorous, nitrogen, and sulfur-embedded motifs, as well as the classical additive vinylene carbonate (VC), to construct protective interfacial layers.

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The influence of transboundary air pollutants originating from the Asian continent on South Korea has been a major concern. Although organochlorine pesticides (OCPs) have been banned for several decades, they continue to be detected in the Korean environment. However, studies on the long-range atmospheric transport (LRAT) of OCPs in South Korea, particularly in background areas, remain limited.

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The advent of next-generation nonfullerene acceptors (NFAs) has propelled major advances in organic solar cells (OSCs). Here we report an NFA design incorporating CF-terminated side chains having varying -(CH)-CF linker lengths ( = 1, 2, and 3) which introduce new intermolecular interactions, hence strong modulation of the photovoltaic response. We report a systematic comparison and contrast characterization of this NFA series with a comprehensive set of chemical/physical techniques versus the heavily studied third-generation NFA, Y6, revealing distinctive and beneficial properties of this new NFA series.

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Nationwide monitoring of polychlorinated naphthalenes in soils across South Korea: Spatial distribution, source identification, and health risk assessment.

Chemosphere

February 2025

Department of Civil, Urban, Earth, and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea; UNIST Environmental Analysis Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea. Electronic address:

Article Synopsis
  • The study reveals that even though the use of polychlorinated naphthalenes (PCNs) was banned long ago, they are still found in South Korean soils due to their persistence and emissions from industrial activities.
  • Industrial sites show significantly higher levels of PCNs compared to urban and suburban areas, with combustion sources being the primary contributor to contamination.
  • Monitoring data indicates that while cancer risks from PCNs are generally within acceptable limits, children are at a higher risk, suggesting the need for continued monitoring and assessment of these hazardous substances.
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Radical S-adenosyl methionine enzymes catalyze a diverse repertoire of post-translational modifications in protein and peptide substrates. Among these, an exceptional and mechanistically obscure example is the installation of α-keto-β-amino acid residues by formal excision of a tyrosine-derived tyramine unit. The responsible spliceases are key maturases in a widespread family of natural products termed spliceotides that comprise potent protease inhibitors, with the installed β-residues being crucial for bioactivity.

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To enhance the alkaline hydrogen evolution reaction (HER), it is crucial, yet challenging, to fundamentally understand and rationally modulate potential catalytic sites. In this study, we confirm that despite calculating a low water dissociation energy barrier and an appropriate H adsorption free energy (ΔG) at Ru-top sites, metallic Ru exhibits a relatively inferior activity for the alkaline HER. This is primarily because the Ru-top sites, which are potential H adsorption sites, are recessive catalytic sites, compared with the adjacent Ru-hollow sites that have a strong ΔG.

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