Publications by authors named "JiWon Ahn"

Raman spectroscopy has emerged as a pivotal analytical instrument, valued for its nondestructive capabilities and its capacity to provide essential material-specific insights. However, the excessive costs associated with commercially available Raman instruments present a barrier to their accessibility for many academic institutions and broader usage. Herein, we introduce an affordable and accessible approach to constructing a versatile Raman instrument capable of accommodating both spectroscopic and microscopic analyses.

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Waste from non-degradable packaging materials poses a serious environmental risk and has led to interest in developing sustainable bio-based packaging materials. Sustainable packaging materials have been made from diverse naturally derived materials such as bamboo, sugarcane, and corn starch. In this study, we made a sustainable packaging film using chitosan extracted from the biomass of yellow mealworm () shell waste.

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Immunogenic cell death (ICD) holds the potential for in situ tumor vaccination while concurrently eradicating tumors and stimulating adaptive immunity. Most ICD inducers, however, elicit insufficient immune responses due to negative feedback against ICD biomarkers, limited infiltration of antitumoral immune cells, and the immunosuppressive tumor micro-environment (TME). Recent findings highlight the pivotal roles of stimulators of interferon gene (STING) activation, particularly in stimulating antigen-presenting cells (APCs) and TME reprogramming, addressing ICD limitations.

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Article Synopsis
  • - Various edible polymers, including SHE, were tested as coatings for potatoes to determine their effectiveness in extending shelf life through a combination of edible coatings and UV-C irradiation treatments.
  • - SHE was found to be the best coating material due to its superior moisture and light barrier properties, effectively preventing greening, respiration, and sprouting of potatoes.
  • - Although SHE itself lacked antimicrobial properties, when used alongside UV-C irradiation, it significantly enhanced the quality and shelf life of the potatoes postharvest.
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Article Synopsis
  • Advances in adeno-associated virus (AAV)-based gene therapy are highlighting the need for proper efficacy and toxicity evaluations for retinal disease treatments.
  • Human pluripotent stem cells (hPSCs) can be transformed into retinal organoids, providing a practical test platform that mimics the human retina for assessing AAV transduction efficiency.
  • The study suggests a detailed protocol for creating retinal organoids and testing AAV effectiveness, aiming to enhance the development of gene therapies for retinal conditions.
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(1) Background: The purposes of this study were to develop a physical fitness evaluation program for new firefighters, to investigate whether there is a quality difference in performing CPR for cardiac arrest patients according to physical strength, and to provide basic data to improve CPR quality. (2) Methods: The subjects of this study were fire trainees who were appointed as firefighters for the first time in G province from 3 March 2021 to 25 June 2021. The age of the subjects was 25-29 years old, and their experience of working as a firefighter was less than three months.

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Hepatic stellate cells (HSCs) play an important role in liver fibrosis; however, owing to the heterogeneity and limited supply of primary HSCs, the development of in vitro liver fibrosis models has been impeded. In this study, we established and characterized a novel human HSC line (LSC-1), and applied it to various types of three-dimensional (3D) co-culture systems with differentiated HepaRG cells. Furthermore, we compared LSC-1 with a commercially available HSC line on conventional monolayer culture.

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Given the advantage of being able to be extracted by a minimally invasive method, blood is regarded as a suitable cell source for reprogramming to establish induced pluripotent stem cells (iPSCs). Therefore, iPSCs established from patient derived peripheral blood mononuclear cells (PBMCs) is widely used to develop disease modeling to elucidate disease development. Here, PBMCs from a healthy man were reprogrammed into iPSCs using the Sendai virus.

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Herein, we describe the direct synthesis of pyrrolo[1,2-α]quinoxaline oxidative coupling between methyl arene and 1-(2-aminophenyl) pyrroles. Oxidation of the benzylic carbon of the methyl arene was achieved by di--butyl peroxide in the presence of an iron catalyst, followed by conversion to an activated aldehyde . Oxygen played a crucial role in the oxidation process to accelerate benzaldehyde formation.

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Herein, we describe novel iron-catalyzed transfer hydrogenation between alcohols and 1-(2-nitrophenyl)pyrroles for the synthesis of pyrrolo[1,2-α]quinoxalines. The tricarbonyl (η-cyclopentadienone) iron complex catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding aldehydes and aniline were generated . The resulting Pictet-Spengler-type annulation/oxidation completed the quinoxaline structure formation.

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Herein, we describe the iron(III)-catalyzed oxidative coupling of alcohol/methyl arene with 2-amino phenyl ketone to synthesize 4-quinolone. Alcohols and methyl arenes are oxidized to the aldehyde in the presence of an iron catalyst and di--butyl peroxide, followed by a tandem process, condensation with amine/Mannich-type cyclization/oxidation, to complete the 4-quinolone ring. This method tolerates various kinds of functional groups and provides a direct approach to the synthesis of 4-quinolones from less functionalized substrates.

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Ethnopharmacological Relevance: Melissa officinalis L. (Labiatae; lemon balm) is a traditional medicinal plant with hypoglycemic and hypolipidemic effects; however, how it imparts its beneficial effects remains unclear. We thus hypothesized that the herbal extract ALS-L1023, isolated from Melissa officinalis, inhibits obesity and diabetes, and tested our hypothesis using Otsuka Long-Evans Tokushima fatty (OLETF) rats, which are an established animal model of type 2 diabetes.

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Interference is a pivotal issue of a non-dispersive infrared (NDIR) sensor and analyzer. Therefore, the main contribution of this study is to introduce a potential method to compensate for the interference of the NDIR analysis. A potential method to compensate for the interference of a nitric oxide (NO) NDIR analyzer was developed.

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Our previous studies demonstrated that peroxisome proliferator-activated receptor α (PPARα) activation reduces weight gain and improves insulin sensitivity in obese mice. Since excess lipid accumulation in non-adipose tissues is suggested to be responsible for the development of insulin resistance, this study was undertaken to examine whether the lemon balm extract ALS-L1023 regulates hepatic lipid accumulation, obesity, and insulin resistance and to determine whether its mechanism of action involves PPARα. Administration of ALS-L1023 to high-fat-diet-induced obese mice caused reductions in body weight gain, visceral fat mass, and visceral adipocyte size without changes of food consumption profiles.

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Although primary human hepatocytes (PHHs) are the gold standard in drug efficacy and metabolism studies, long-term survival of PHHs and maintenance of their hepatic function are still challenging. In this study, we focused on the effect of the initial microenvironment on upregulation and long-term preservation of hepatic function of PHHs encapsulated within biodegradable hydrogel systems. PHHs were encapsulated in RGD-functionalized hybrid hydrogels with various degrees of degradability, and their hepatic functionality was analyzed.

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Ethnopharmacological Relevance: Melissa officinalis L. (Labiatae; lemon balm) has traditionally been used as a medicinal herb to treat stress, anxiety, and insomnia. Current reports suggest that not only chronic stress stimulates angiogenesis, but angiogenesis also regulates adipogenesis and obesity.

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Unlabelled: Ethnopharmacologic relevance: Gyeongshingangjeehwan 18 (GGEx18) is a polyherbal composition derived from Ephedra sinica Stapf (Ephedraceae), Laminaria japonica Aresch (Laminariaceae), and Rheum palmatum L. (Polygonaceae) that is used as an antiobesity drug in Korean clinics. Its constituents are traditionally known to combat obesity, dyslipidemia, and insulin resistance.

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Spheroids, a widely used three-dimensional (3D) culture model, are standard in hepatocyte culture as they preserve long-term hepatocyte functionality and enhance survivability. In this study, we investigated the effects of three operation modes in 3D culture - static, orbital shaking, and under vertical bidirectional flow using spheroid forming units (SFUs) on hepatic differentiation and drug metabolism to propose the best for mass production of functionally enhanced spheroids. Spheroids in SFUs exhibited increased hepatic gene expression, albumin secretion, and cytochrome P450 3A4 (CYP3A4) activity during the differentiation period (12 days).

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Tumor cells overexpress amino acid transporters to meet the increased demand for amino acids. PQ loop repeat-containing (PQLC)2 is a cationic amino acid transporter that might be involved in cancer progression. Here, we show that upregulation of PQLC2 is critical to gastric cancer (GC) development in vitro and in vivo.

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Background/objectives: Ascorbic acid is a known cofactor in the biosynthesis of carnitine, a molecule that has an obligatory role in fatty acid oxidation. Our previous studies have demonstrated that obesity is regulated effectively through peroxisome proliferator-activated receptor α (PPARα)-mediated fatty acid β-oxidation. Thus, this study aimed to determine whether ascorbic acid can inhibit obesity and nonalcoholic fatty liver disease (NAFLD) in part through the actions of PPARα.

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Ethnopharmacological Relevance: The herbal composition Gyeongshingangjeehwan 18 (GGEx18), composed of Rheum palmatum L. (Polygonaceae), Laminaria japonica Aresch (Laminariaceae), and Ephedra sinica Stapf (Ephedraceae), is used as an antiobesity drug in Korean clinics. The constituents of GGEx18 have traditionally been reported to inhibit obesity and related metabolic diseases such as insulin resistance and dyslipidemia.

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Unlabelled: Current in vitro liver models provide three-dimensional (3-D) microenvironments in combination with tissue engineering technology and can perform more accurate in vivo mimicry than two-dimensional models. However, a human cell-based, functionally mature liver model is still desired, which would provide an alternative to animal experiments and resolve low-prediction issues on species differences. Here, we prepared hybrid hydrogels of varying elasticity and compared them with a normal liver, to develop a more mature liver model that preserves liver properties in vitro.

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Unlabelled: Alternative cell sources, such as three-dimensional organoids and induced pluripotent stem cell-derived cells, might provide a potentially effective approach for both drug development applications and clinical transplantation. For example, the development of cell sources for liver cell-based therapy has been increasingly needed, and liver transplantation is performed for the treatment for patients with severe end-stage liver disease. Differentiated liver cells and three-dimensional organoids are expected to provide new cell sources for tissue models and revolutionary clinical therapies.

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Shikonin derivatives exert powerful cytotoxic effects including induction of apoptosis. Here, we demonstrate the cytotoxic efficacy of shikonin in vivo in xenograft models, which did not affect body weight as well as its reduction of cell viability in vitro using several non-small cell lung cancer (NSCLC) cell lines. We found that inhibition of AKT by shikonin activated the forkhead box (FOX)O3a/early growth response protein (EGR)1 signaling cascade and enhanced the expression of the target gene Bim, leading to apoptosis in lung cancer cells.

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