Publications by authors named "Youngcheol Lee"

The superheating process is a unique grain refining method found only in aluminum-containing magnesium alloys. It is a relatively simple method of controlling the temperature of the melt without adding a nucleating agent or refining agent for grain refinement. Although previous studies have been conducted on this process, the precise mechanism underlying this phenomenon has yet to be elucidated.

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  • This study examined how different levels of impurities affect grain structures in two types of AZ91 alloys: commercial-purity and high-purity.
  • The average grain size was significantly smaller in high-purity AZ91 (90 µm) compared to commercial-purity AZ91 (320 µm), with thermal analysis revealing less undercooling in the high-purity variety.
  • It was found that the high-purity AZ91 alloy contained more carbon (197 ppm) than the commercial version (104 ppm), which is linked to its production with high-purity magnesium, influencing the formation of finer grains due to Al-C particles acting as nucleants.
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The Special Issue "Molecular Mechanisms of Natural Products and Phytochemicals in Immune Cells and Asthma" in the includes original research and reviews on the molecular mechanisms of active, natural products (medicinal plants and animal ones) and phytochemicals in vitro and in vivo [...

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Background: Air pollution has led to an increased exposure of all living organisms to fine dust. Therefore, research efforts are being made to devise preventive and therapeutic remedies against fine dust-induced chronic diseases.

Methods: Research of the respiratory protective effects of KRG extract in a particulate matter (PM; aerodynamic diameter of <4 μm) plus diesel exhaust particle (DEP) (PM4+D)-induced airway inflammation model.

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In this study, we aimed to evaluate the anti-inflammatory effects and mechanisms of CP and OA treatments in LPS-stimulated lung epithelial cells on overall chemokines and their receptors using PCR arrays. In addition, we aimed to confirm those effects and mechanisms in LPS-stimulated lung macrophages on some chemokines and cytokines. In our study, CP treatments significantly inhibited the inflammatory mediators CCL2, CCL3, CCL4, CCL5, CCL6, CCL9, CCL11, CCL17, CCL20, CXCL1, CXCL2, CXCL3, CXCL5, CXCL7, CXCL10, TNF-α, and IL-6, while markedly suppressing NF-κB p65 nuclear translocation and the phosphorylations of PI3K p55, Akt, Erk1/2, p38, and NF-κB p65 in LPS-stimulated lung epithelial cells.

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  • The study investigates how adding TiB particles affects the eutectic Al + MgSi phases in aluminum alloys, leading to significant modifications.
  • Analysis using microscopic techniques showed that increased TiB content alters the shape, size, and distribution of these phases.
  • The research also proposes a new mechanism for the improved modification of MgSi phases by TiB, highlighting the role of TiB as nucleation sites in the aluminum matrix.
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  • Cicadae Periostracum (CP) is a traditional medicine used in Korea and China, known for its various health benefits including anti-inflammatory and antioxidant properties.
  • The study focused on evaluating the antiasthmatic effects of CP in a mouse model of asthma, finding that CP and oleic acid (OA) reduced inflammation and immune responses linked to asthma.
  • The research suggests that CP might help treat asthma by interfering with specific signaling pathways (GATA-3/Th2 and IL-17/RORγt) that contribute to the inflammatory process.
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The consequences of increased industrialization increased the risk of asthma and breathing difficulties due to increased particulate matter in the air. We aim to investigate the therapeutic properties of Hypericum ascyron L. extract (HAE) in airway inflammation and unravel its mechanism of action.

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  • Chronic obstructive pulmonary disease (COPD) is linked to harmful exposures like coal fly ash, diesel exhaust, and cigarette smoke, resulting in chronic bronchitis and lung problems.
  • In a mouse model, a herbal combination of Glycyrrhiza glabra (GG) and Arseniatus (AR) was tested, showing significant reduction in lung inflammation by decreasing neutrophils and several inflammatory markers.
  • The study suggests that this herbal mixture, particularly its active ingredients like glycyrrhizic acid and tilianin, could be a promising treatment for COPD by targeting inflammatory pathways.
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Atopic dermatitis (AD) is a chronic inflammatory skin disease in humans. In this study, we evaluated the effects of a mixture (NCM 1921) of omega-3 butter, omega-3 beef tallow oil, omega-3 lard oil, caprylic acid, lauric acid, choline, and Fe on AD in 1-chloro-2,4-dinitrobenzene (DNCB)-treated NC/Nga mice. NCM 1921 significantly ameliorated the macroscopic and microscopic signs and reduced skin thickness and mast cell incorporation in the skin lesions of mice with DNCB-induced AD.

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larvae (HD), a natural product from an insect resource, possesses many pharmacological properties, including anticoagulant, antitumor, anti-inflammatory, and analgesic activity. The major bioactive ingredients include oleic acid, palmitic acid, palmitoleic acid, linoleic acid, proline, and glutamic acid. Although HD is associated with immunoregulatory activities in allergic diseases, the therapeutic mechanisms of the action of HD in allergic diseases have not been investigated.

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Lemon verbena () has been used as a food spice, cosmetic, and in traditional medicine formulations to treat asthma and diabetes in South America and Southern Europe. Hibiscus flower ( L.) is used in traditional Chinese medicine in the form of a tea to treat hypertension and inflammation.

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18β-Glycyrrhetinic acid (18Gly), the major bioactive component of Glycyrrhizae Radix, possesses anti-ulcerative, anti-inflammatory, and other pharmacological properties. Although 18Gly is associated with immunoregulatory functions of allergic diseases, the pathophysiological mechanisms of 18Gly action in allergic inflammatory lung disease have not been examined. Moreover, there are no in vivo studies on the anti-asthmatic effects of 18Gly in allergic asthma.

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Nodakenin, a coumarin isolated from the roots of Angelicae gigas, is effective for treating function control disorders, bacterial infections, pain, diarrhea, vitamin E deficiency, and for relaxation of the uterus. The aim of this study was to investigate the antiallergic related inflammatory effects in phorbol-12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated human mast cells (HMC-1) or anaphylactic activity in a mouse model. Nodakenin inhibited the mRNA expression and production of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β in PMACI-stimulated HMC-1.

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Background: Chelidonine, a major bioactive, isoquinoline alkaloid ingredient in Chelidonium majus, exhibits anti-inflammatory and other pharmacological properties. However, its molecular mechanisms in asthma remain unclear. In this work we investigated chelidonine's effect and mechanism in airway inflammation in a mouse model of allergic asthma.

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Purpose: This study was conducted to determine the distributions of the polyp detection rate (PDR) and the adenoma detection rate (ADR) according to age by analyzing the polypectomy results.

Methods: A total of 10,098 patients who underwent a colonoscopy in 2013 were included in this study. Chi-square and logistic regression statistical analyses were performed using SPSS ver.

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The natural product oleanolic acid is commonly found in a variety of medicinal plants. It is a triterpenoid compound known for its anti-inflammatory effects as well as various other pharmacological properties. The aim of the current study was to use a mouse model of allergic asthma to investigate whether oleanolic acid has anti-asthmatic effects, and if so, to determine the mechanism of these effects.

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This paper proposes a smartphone-based network real-time kinematic (RTK) positioning and gravity-surveying application (app) that allows semi-real-time measurements using the built-in Bluetooth features of the smartphone and a third-generation or long-term evolution wireless device. The app was implemented on a single smartphone by integrating a global navigation satellite system (GNSS) controller, a laptop, and a field-note writing tool. The observation devices (i.

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Allergic asthma is a chronic airway disorder characterized by airway hyperresponsiveness to allergens, chronic airway inflammation, airway edema, increased mucus secretion, excess production of Th2 cytokines, and eosinophil accumulation in the lungs. Ursolic acid is known for its pharmacological effects, such as its anti-tumor, anti-inflammatory and antimicrobial activities. To investigate the anti-asthmatic effects and mechanism of ursolic acid, we studied the development of pulmonary eosinophilic inflammation and enhanced pause (Penh) in a mouse model of allergic asthma.

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  • Allergic asthma is a chronic lung condition marked by extreme reactions to allergens, leading to inflammation and increased mucus production, influenced by Th2 cytokine levels and eosinophils in the lungs.
  • The study explored the anti-asthmatic potential of Corni fructus (CF) using a mouse model, focusing on its impact on airway hyperreactivity and eosinophilic inflammation linked to allergic asthma.
  • Results indicated that CF treatment significantly reduced eosinophil infiltration and airway inflammation by lowering levels of specific Th2 cytokines (IL-5, IL-13) and OVA-specific IgE, suggesting it could be a beneficial therapy for asthma.
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  • Asthma features include airway inflammation, reversible airflow obstruction, and increased airway hyperresponsiveness (AHR), often linked to excess Th2 cytokines and eosinophils in the lungs.
  • The study examines the effects of hesperidin (HPN) on these asthma-related factors in a mouse model, specifically looking at its impact on cytokine production and immune responses.
  • Results indicate that HPN reduces eosinophil infiltration and allergic inflammation, while lowering the production of key cytokines and IgE, suggesting its therapeutic effectiveness against asthma through inhibition of GATA-3 transcription factor.
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Background And Objective: This study was aimed to analyse the curative effects of Pinellia ternata, Citrus reticulata, and their combination on airway hyperresponsiveness (AHR) to inhaled methacholine, pulmonary eosinophilic infiltration, Th2 cytokine production, and IgE and histamine production in a murine model of asthma.

Methods: For this purpose, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed intratracheally, intraperitoneally, and by aerosol allergen challenges for 12 weeks. We examined the development of pulmonary eosinophilic accumulation, control of Th2 cytokine, immunoglobulin E (IgE), and histamine productions in a murine model of asthma.

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Objectives: This study aimed to investigate the effect of piperine on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production, immunoglobulin E and histamine production in a murine model of asthma.

Methods: Asthma was induced in Balb/c mice by ovalbumin sensitization and inhalation. Piperine (4.

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The present study is performed to investigate the inhibitory effects of Radix Adenophorae extract (RAE) on ovalbumin-induced asthma murine model. To study the anti-inflammatory and antiasthmatic effects of RAE, we examined the development of pulmonary eosinophilic inflammation and inhibitory effects of T cells in murine by RAE and cyclosporine A (CsA). We examined determination of airway hyperresponsiveness, flow cytometric analysis (FACS), enzyme-linked immunosorbent assay (ELISA), quantitative real time (PCR), hematoxylin-eosin staining, and Masson trichrome staining in lung tissue, lung weight, total cells, and eosinophil numbers in lung tissue.

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The immune balance controlled by T helper 1 (Th1) and T helper 2 (Th2) is crucial for immunoregulation and its imbalance causes various immune diseases including allergic asthma. Therefore, diagnosis of Th1/Th2 balance in autoimmune diseases including asthma is essential for the application of immune balance regulating drugs. Th1/Th2 balance is not only controlled by Th1 cells and Th2 cells, but also by various regulatory factors including regulatory T cells, sexual factor, chemokines, transcription factors, signal transduction pathway (STAT6) etc.

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