Publications by authors named "Hyeok-Chan Kwon"

Sucrose functions as a signaling molecule in several metabolic pathways as well as in various developmental processes. However, the molecular mechanisms by which sucrose regulates these processes remain largely unknown. In the present study, we demonstrate that sucrose promotes flowering by mediating the stability of a regulatory protein that represses flowering in rice.

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Background: Systemic lupus erythematosus (SLE) is a chronic inflammatory disease primarily affecting young females. SLE can invade any organ, and various forms of splenic invasion have been reported. Manifestations include splenomegaly and splenic infarction, rupture, and calcification.

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Objective: Methotrexate (MTX) is an anchor drug for most patients with rheumatoid arthritis (RA); however, its use may be limited depending on renal function. Therefore, this study aimed to examine the discrepancy in the estimated glomerular filtration rate (eGFR) using conventional serum creatinine (SCr)-, cystatin C-, and MTX-associated toxicities in patients with RA.

Methods: In total, 436 patients were enrolled, and eGFR was evaluated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on both cystatin C and SCr levels.

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Objective: We investigated the prevalence of metabolic syndrome (MetS) in all or nonobese patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and compared it with age- and gender-matched controls. Also, we assessed the effect of variables at diagnosis on the risk of cardiovascular disease (CVD) in all or nonobese AAV patients.

Methods: In this study, 173 AAV patients and 344 controls were included and MetS was defined by the National Cholesterol Education Program Adults Treatment Panel III criteria.

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Background: We investigated and compared the initial clinical features at diagnosis and the poor outcomes during follow-up in Korean patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) based on sex.

Methods: The medical records of 223 immunosuppressive drug-naïve patients with AAV were reviewed. Age, body mass index (BMI), smoking history, AAV subtypes, ANCA positivity, clinical manifestations, Birmingham vasculitis activity score (BVAS), five-factor score (FFS), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at diagnosis were collected.

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We previously reported that fibrosis-4 (FIB-4) was associated with poor outcomes of microscopic polyangiitis (MPA) and granuloma with polyangiitis (GPA). We also investigated the potential of FIB-5, a novel index, in predicting all-cause mortality and end-stage renal disease (ESRD) during follow-up in patients with MPA and GPA without substantial liver diseases. Clinical and laboratory data at diagnosis were collected by reviewing the medical records of 180 patients with MPA and GPA.

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Purpose: We investigated whether antineutrophil cytoplasmic antibody (ANCA) positivity is associated with vascular manifestations at diagnosis of Behçet's disease (BD) and poor outcomes during follow-up.

Materials And Methods: We retrospectively reviewed the medical records of 1060 patients with BD. Among them, 808 patients could be diagnosed with BD based on the revised version of the International Criteria for Behçet's Disease (ICBD) in 2014 (2014 ICBD criteria) and 588 patients could be diagnosed with BD based on the International Study Group (ISG) criteria proposed in 1990 (1990 ISG criteria).

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Background/aims: Measures of body composition, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA), are considered important prognostic factors in chronic diseases. The association of these measures with auto-inflammatory disorders, such as anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), remains unclear. We investigated the clinical significance of VAT, SAT, and SMA in patients with AAV.

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To resolve the inherent trade-off issue between responsivity and detectivity in FACsPbI perovskite photodetectors, this paper proposes a novel strategy using multifunctional self-combustion additives (urea and ammonium nitrate). During the early stages of crystallization, urea allows for the formation of a strong Lewis complex-derived low-dimensional intermediate phase; this suppresses the formation of perovskite nuclei, while ammonium ions assist the preferred grain growth along the [110] direction. During the high-temperature annealing steps, a self-combusting exothermic reaction occurs between urea as a fuel and NHNO as an oxidizer, through which a locally supplied heat facilitates the removal of residual urea and byproducts.

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Purpose: There has been no extensive study to compare the efficacy between rituximab originator (Mabthera®) and its biosimilar (Truxima®) for microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). Here, we investigated the clinical effects of rituximab on poor outcomes of MPA and GPA in Korean patients, and compared those between Mabthera® and Truxima®.

Materials And Methods: We retrospectively reviewed the medical records of a total of 139 patients, including 97 MPA patients and 42 GPA patients.

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Mannose-binding lectin (MBL) is a soluble pattern-recognition molecule, which plays a crucial role in the innate immune system and the activation of lectin complement pathway. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disease affecting the small vasculatures and is characterized by the alteration of innate and adaptive immunity and complement activation. In this study, we investigated whether serum MBL is associated with disease activity of AAV, which was measured by ELISA.

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Background: No study has provided evidence of the clinical significance of the antineutrophil cytoplasmic antibody (ANCA) in patients with Takayasu arteritis (TAK). Therefore, we investigated the frequency of ANCA positivity and its clinical implications in patients with TAK.

Methods: We retrospectively reviewed the medical records of 121 patients with established TAK, who had results for ANCA status at diagnosis.

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Current evidence suggests that high uric acid levels are associated with accelerated renal damage. However, the clinical impact of serum uric acid level on patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) is unknown. We aimed to evaluate the impact of hyperuricemia on such patients.

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Flexible perovskite solar cells (PSCs) have attracted significant interest as promising candidates for portable and wearable devices. Copper nanowires (CuNWs) are promising candidates for transparent conductive electrodes for flexible PSCs because of their excellent conductivity, flexibility, and cost-effectiveness. However, because of the thermal/chemical instability of CuNWs, they require a protective layer for application in PSCs.

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Background: Chronic paranasal sinusitis (CPS) has been known as a surrogate marker for granulomatosis with polyangiitis (GPA). We investigated whether CPS at diagnosis may have an influence on the classification and outcomes of microscopic polyangiitis (MPA).

Methods: We retrospectively reviewed the medical records of 106 immunosuppressive drug-naïve patients with MPA.

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All-inorganic cesium lead triiodide (CsPbI ) perovskite is considered a promising solution-processable semiconductor for highly stable optoelectronic and photovoltaic applications. However, despite its excellent optoelectronic properties, the phase instability of CsPbI poses a critical hurdle for practical application. In this study, a novel stain-mediated phase stabilization strategy is demonstrated to significantly enhance the phase stability of cubic α-phase CsPbI .

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Solar-energy conversion by photoelectrochemical (PEC) devices is driven by the separation and transfer of photogenerated charge carriers. Thus, understanding carrier dynamics in a PEC device is essential to realizing efficient solar-energy conversion. Here, we investigate time-resolved carrier dynamics in emerging low-cost SbSe nanostructure photocathodes for PEC water splitting.

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Organic-inorganic hybrid perovskite solar cells (PSCs) have recently attracted tremendous attention because of their excellent efficiency and the advantage of a low-cost fabrication process. As a transparent electrode for PSCs, the application of copper nanowire (CuNW)-network was limited because of its thermal/chemical instability, despite its advantages in terms of high optical/electrical properties and low-cost production. Here, the copper-nickel core-shell nanowire (Cu@Ni NW)-based composite electrode is proposed as a bottom window electrode for PSCs, without the involvement of a high-cost precious metal and vacuum process.

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Organometal halide perovskite materials have become an exciting research topic as manifested by intense development of thin film solar cells. Although high-performance solar-cell-based planar and mesoscopic configurations have been reported, one-dimensional (1-D) nanostructured perovskite solar cells are rarely investigated despite their expected promising optoelectrical properties, such as enhanced charge transport/extraction. Herein, we have analyzed the 1-D nanostructure effects of organometal halide perovskite (CHNHPbICl ) on recombination and charge carrier dynamics by utilizing a nanoporous anodized alumina oxide scaffold to fabricate a vertically aligned 1-D nanopillared array with controllable diameters.

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Organic-inorganic hybrid perovskite solar cells (PSCs) are considered promising materials for low-cost solar energy harvesting technology. An electron transport layer (ETL), which facilitates the extraction of photogenerated electrons and their transport to the electrodes, is a key component in planar PSCs. In this study, a new strategy to concurrently manipulate the electrical and optical properties of ETLs to improve the performance of PSCs is demonstrated.

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Copper nanowires (CuNWs) have been applied to hybrid perovskite solar cells (PSCs) as a window electrode. By sandwiching the CuNW network between aluminum-doped zinc oxide and adopting a poly(ethylenimine) buffer layer, the compatibility between the CuNWs and the perovskite layer could be dramatically improved. PSCs containing the CuNW-based composite electrode exhibited an average power conversion efficiency of 8.

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We demonstrated crystallization retardation of CHNHPbI thin film during single coating of precursor solution by simple addition of NaCl. NaCl was codissolved into a precursor mixture solution containing PbI and methylammonium iodide (MAI). Dissolved NaCl interacted with the PbI in solution and produced a stable intermediate phase, which was converted to a full-coverage uniform perovskite absorber layer via reaction with MAI during a single spin-coating.

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Secretory leukocyte peptidase inhibitor (SLPI) plays a role in proliferation and differentiation via the autocrine and paracrine systems. SLPI's expression is well-documented in the reproductive tract, but it remains unclear whether it is active during early embryonic development. In this study, the expression and role of Slpi in the early embryo were evaluated.

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We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films.

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