Publications by authors named "Woosung Choi"

Anode materials storing large-scale lithium ions gradually decrease electrochemical performance due to severe volume changes during cycling. Therefore, there is an urgent need to develop anode materials with high electrochemical capacity and durability, without deterioration arising due to the volume changes during the electrochemical processes. To date, mesoporous materials have received attention as anode materials due to their ability to mitigate volume expansion, offer a short pathway for Li transport, and exhibit anomalous high capacity.

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Magnetic fields have been used to uniformly align the lyotropic chiral nematic (cholesteric) liquid crystalline (LC) phase of biopolymers to a global orientation and optical appearance. Here, we demonstrate that, in contrast, weak and patterned magnetic field gradients can create a complex optical appearance with the variable spatial local organization of needle-like magnetically decorated cellulose nanocrystals. The formation of optically patterned thin films with left- and right-handed chiral and achiral regions is observed and related to local magnetic gradient-driven vortices during LC suspension flow.

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Enhancing corporate accountability in areas such as environment, social, and governance (ESG) has solidified its role in the discussion on improving corporate resilience and growth. ESG management activities not only augment corporate sustainability and risk control but also influence the professional roles and personal lives of members through their perceived ESG. Historically, most ESG research has centered on the interrelation of corporate ESG endeavors and outcomes, while studies focusing on the influence of perceived ESG on members have been sparse.

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Article Synopsis
  • Environmentally friendly crosslinked polymer networks (EF-DCPNs) have dynamic characteristics that allow for easy degradation, reprocessing, and self-healing but suffer from mechanical instability due to their bonds.
  • EF-DCPNs combine high mechanical strength with the ability to degrade and recycle, making them promising alternatives for practical applications.
  • The review covers the synthesis, properties, and uses of EF-DCPNs, discussing various types of dynamic bonds and highlighting future research opportunities in the field.
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Owing to the development of Information and Communication Technology (ICT) and the inevitability of telecommuting in the COVID-19 environment, the boundary between working and non-working hours has become blurred. mWork, that is, ICT-based off-hour work, which has increased through the pandemic, affects employees' work attitudes, such as presenteeism. Hence, we designed a study to investigate the antecedents and mechanisms of employee presenteeism from the perspective of the conservation of resources theory.

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Background: The COVID-19 pandemic has significantly affected societies worldwide, including the medical healthcare system and trauma care. This study explores the impact of COVID-19 infection on trauma patients in South Korea, a country with effective pandemic management.

Methods: A retrospective cohort study of 4206 trauma patients from June 2020 to May 2022 was conducted.

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Article Synopsis
  • South Korea implemented a nationwide tele-emergency consultation network linking urban and rural hospitals to improve emergency medical services.
  • The study analyzed tele-emergency cases from May 2015 to December 2018, focusing on the types of consultations and the impact on unnecessary patient transportation (RUT).
  • Results indicated that image interpretation was the most common consultation type for trauma, with the system significantly reducing RUT, particularly in non-severe cases and non-island rural areas.
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Background: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known.

Methods: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs.

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  • Iron oxide anodes for lithium-ion batteries are gaining popularity due to their low cost, safety, and high capacity.
  • These nanostructured anodes can exhibit a phenomenon called negative fading, where their capacity increases during use, but the exact cause is still unclear.
  • Recent research using advanced techniques has shown that this negative fading is linked to improvements in a surface layer derived from the electrolyte, which enhances both the structural stability and overall performance of the anode materials.
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Innovation is now a feature of daily life. In a rapidly changing market environment and amid fierce competition, organizations pursue survival and growth through innovation, and the key driver of innovation is the creativity of employees. Because the value of creativity has been emphasized, many organizations are looking for effective ways to encourage employees to be creative at work.

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Article Synopsis
  • Organizations are facing increased uncertainty and must rapidly adapt to changes, which requires employees to engage in innovative behavior for improved performance.
  • The study investigates how leader-member exchange (LMX), self-efficacy, and perceived organizational support relate to fostering innovative behavior among employees.
  • Findings indicate that LMX boosts innovative behavior through enhanced self-efficacy, and that higher perceived organizational support strengthens this relationship.
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  • * The study analyzes the presence and precipitation of various impurities, including toxic elements like F, Cl, and S, in regenerated and purified NMC precursors using the hydroxide co-precipitation method.
  • * A new concept called yield of precipitation (YOP) is introduced to evaluate how well different elements precipitate, helping to categorize impurities and offering a quality control framework for the lithium-ion battery recycling industry.
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  • Metal halide perovskite nanocrystals (PNCs) are gaining attention for their unique properties and potential uses in technologies like photovoltaics and optoelectronics.
  • Combining these PNCs with polymers creates nanocomposites that enhance stability and flexibility while retaining their beneficial optoelectronic characteristics.
  • The text outlines recent advancements in making these nanocomposites, explores their interesting properties, discusses various applications like LEDs and lasers, and suggests future research directions and challenges in this field.
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In this study, four different MnO polymorphs are synthesized with a controlled morphology of hollow porous structures to systematically investigate the influences of polymorphs in conversion-based material. As the structure of these materials transforms into nanosized metal and maintains an extremely low-crystalline phase during cell operation, the effects of polymorphs are overlooked as compared to the case of insertion-based materials. Thus, differences in the ion storage behaviors among various MnO polymorphs are not well identified.

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To advance current Li rechargeable batteries further, tremendous emphasis has been made on the development of anode materials with higher capacities than the widely commercialized graphite. Some of these anode materials exhibit capacities above the theoretical value predicted based on conventional mechanisms of Li storage, namely insertion, alloying, and conversion. In addition, in contrast to conventional observations of loss upon cycling, the capacity has been found to increase during repeated cycling in a significant number of cases.

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Article Synopsis
  • Recent studies show that traditionally inactive metal nanoparticles, like ruthenium, actually participate in lithium-ion battery reactions through catalytic and interfacial effects.
  • A study prepared ≈5 nm ruthenium nanoparticles as an anode, aiming to understand the unusual lithium storage mechanisms that do not involve typical redox reactions but instead cause lattice expansion.
  • The findings reveal that smaller nanoparticles can enhance lithium adsorption by enabling charge redistribution at the surface, highlighting their significance in the dynamic behavior of rechargeable lithium batteries.
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Lipid rafts (LRs) play crucial roles in complex physiological processes, modulating innate and acquired immune responses to pathogens. The transmembrane C-type lectins human dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and its mouse homolog SIGN-R1 are distributed in LRs and expressed on splenic marginal zone (MZ) macrophages. The DC-SIGN-C1q or SIGN-R1-C1q complex could mediate the immunoglobulin (Ig)-independent classical complement pathway against .

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Amine-containing solids are promising adsorbents for CO capture, but they suffer from irreversible poisoning by the highly acidic SO in flue gas. Here, we demonstrate a facile strategy to inhibit SO poisoning. We first prepared an amine-containing adsorbent by impregnating polyethyleneimine (PEI) into porous silica.

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Due to the increased availability of digital human models, the need for knowing human movement is important in product design process. If the human motion is derived rapidly as design parameters change, a developer could determine the optimal parameters. For example, the optimal design of the door panel of an automobile can be obtained for a human operator to conduct the easiest ingress and egress motion.

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We prepare three-dimensional honeycomb-like CuCoO nanosheet arrays supported by Ni foam via electrochemical codeposition of cobalt and copper hydroxides on Ni foam followed by thermal oxidation. The codeposition with Cu changes the morphology of the cobalt hydroxide deposit to form honeycomb-like nanostructures, significantly decreasing the onset potential for oxygen evolution. The CuCoO anode displays an exceptionally low overpotential of 290 mV at a current density of 10 mA cm in 1 M KOH, and an anion-exchange membrane water electrolysis cell employing the above anode achieves a current density of 100 mA cm at 1.

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Substantial efforts have been made to increase the CO working capacity of amine adsorbents for an efficient CO capture. However, the more important metric for assessing adsorbents is the regeneration heat required for capturing a fixed amount of CO. In this work, we synthesized polyethyleneimine (PEI)/SiO adsorbents functionalized with various epoxides.

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Amine-containing solids have been investigated as promising adsorbents for CO capture, but the low oxidative stability of amines has been the biggest hurdle for their practical applications. Here, we developed an extra-stable adsorbent by combining two strategies. First, poly(ethyleneimine) (PEI) was functionalized with 1,2-epoxybutane, which generates tethered 2-hydroxybutyl groups.

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Poly(ethyleneimine) (PEI)/silica has been widely studied as a solid adsorbent for post-combustion CO capture. In this work, a highly macroporous silica (MacS), synthesized by secondary sintering of fumed silica, is compared with various mesoporous silicas with different pore structures as a support for PEI. The silicas with large pore diameter and volume enabled high CO adsorption kinetics and capacity, because pore occlusion by the supported PEI was minimized.

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Background: Multiple myeloma (MM) is characterized by a neoplastic proliferation of plasma cells primarily in the bone marrow. Bisphosphonates (BP) are used as supportive therapy in the management of MM. This study aimed to analyze the incidence, risk factors, and clinical outcomes of medication-related necrosis of the jaw (MRONJ) in MM patients.

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Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.

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