Publications by authors named "JunKyu Park"

The amphibian chytrid fungus, (), has been implicated as an agent of acute declines in amphibian populations worldwide. East Asian amphibians have been coexisting with for long periods and thus are considered resistant; among the many is the Japanese tree frog, . Our study focused infection effects on reproductive behaviors and physiological parameters in as a function of better understanding the chronic effect of the disease on long-term population viability.

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The pervasive distribution of microplastics (MPs) in aquatic ecosystems presents a significant threat to wildlife, with amphibians being particularly vulnerable due to their complex life cycles and ecological roles. This study investigates physiological and ecological impacts of aquatic MP exposure on juvenile black-spotted pond frogs (Pelophylax nigromaculatus), focusing on juvenile frog stage, history of life after metamorphosis. MP examinations in the intestine and body revealed accumulation primarily in the gastrointestinal tracts without evidence of systemic distribution.

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Studies have demonstrated the therapeutic effects of plants. This study was undertaken to reveal the antihypertensive properties of leaf ethanolic extract (LEL). Aorta segments of Sprague-Dawley rats were used to study the vasodilatory effect of LEL, and the mechanisms involved were evaluated by treating specific inhibitors or activators that affect the contractility of blood vessels.

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Article Synopsis
  • * Twenty patients were enrolled, and results after 8 months showed minimal in-stent late lumen loss (0.7 mm) and complete stent strut coverage, indicating successful healing.
  • * There were no adverse cardiovascular events reported within the same period, suggesting that the new stent design is safe and effective in treating coronary artery disease.
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(TJ) fruit, is a herb that is traditionally used for erectile dysfunction (ED). Given the shared mechanisms of ED and hypertension through vascular smooth muscle, we hypothesized that TJ would be effective in vasodilation and blood pressure reduction. This study confirmed the authenticity of TJ samples via DNA barcoding and quantified the main active compound, torilin, using HPLC.

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This study examines how temperature influences the response of Japanese tree frogs (Dryophytes japonicus) to microplastic (MP) pollution, assessing whether temperature can regulate the harmful effects of MPs on their life history and the dispersal of MPs across habitats. This analysis aims to understand the ecological and physiological ramifications of MP pollution. Our results demonstrated an ontogenetic transfer of MP particles across amphibian metamorphosis, possibly allowing and facilitating the translocation of MPs across ecosystems.

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The incidence of cardiovascular diseases, such as high blood pressure, is increasing worldwide, owing to population aging and irregular lifestyle habits. Previous studies have reported the vasorelaxant effects of bark methanol extract. However, various solvent extracts of bark and their vascular relaxation mechanisms have not been sufficiently studied.

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Previous studies have revealed the medicinal and therapeutic effects of . However, no studies have focused on the antihypertensive effects of . Therefore, we aimed to determine the vasorelaxant and hypotensive effects of 50% ethanolic extract (GCE).

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Gut microbiota impact host physiology, though simultaneous investigations in ectothermic vertebrates are rare. Particularly, amphibians may exhibit more complex interactions between host physiology and the effects of gut microbiota due to the combination of seasonal changes and complex life histories. In this study, we assessed the relationships among food resources, gut bacterial communities, and host physiology in frogs (Phelophylax nigromaculatus), taking into account seasonal and life history variations.

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(L.) Cusson, a member of the family, is rich in coumarins, such as imperatorin and osthole. fruit (CM) has a broad range of therapeutic potential that can be used in anti-bacterial, anti-cancer, and sexual dysfunction treatments.

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Eustachian tube balloon dilatation (ETBD) has shown promising results in the treatment of ET dysfunction (ETD); however, recurrent symptoms after ETBD frequently occur in patients with refractory ETD. The excessive pressure of balloon catheter during ETBD may induce the tissue hyperplasia and fibrotic changes around the injured mucosa. Sirolimus (SRL), an antiproliferative agent, inhibits tissue proliferation.

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Hypertension is the crucial modifiable risk factor for cardiovascular diseases, and efforts to identify functional foods that are effective for hypertension control are increasing. The nutgall tree (NT, Mill.) is used in traditional medicine and food because of its medicinal value.

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Biliary strictures are characterized by the narrowing of the bile duct lumen, usually caused by surgical biliary injury, cancer, inflammation, and scarring from gallstones. Endoscopic stent placement is a well-established method for the management of biliary strictures. However, maintaining optimal mechanical properties of stents and designing surfaces that can prevent stent-induced tissue hyperplasia and biofilm formation are challenges in the fabrication of biodegradable biliary stents (BBSs) for customized treatment.

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Natural compounds, known for diverse pharmacological properties, have attracted attention as potential sources for hypertension treatment. Previous studies have revealed the hypotensive effect and vascular relaxation of prunetin, a natural compound derived from . However, the potential blood pressure-lowering and vasorelaxant effects of sakuranetin, another representative compound found in plants belonging to the genus , have remained unexplored.

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The gut microbiota maintains a deeply symbiotic relationship with host physiology, intricately engaging with both internal (endogenous) and external (exogenous) factors. Anurans, especially those in temperate regions, face the dual challenges of significant external influences like hibernation and complex internal variances tied to different life histories. In our research, we sought to determine whether different life stages (juvenile versus adult) of the Japanese wrinkled frog (Glandirana rugosa) lead to distinct shifts in gut bacterial communities during winter (hibernation) and its subsequent transition to spring.

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Hypertension is one of the most common chronic diseases, and its prevalence is increasing worldwide. (Siebold & Zucc.) Blume, known as grayblue spicebush (GS), has been used as food and for medicinal purposes; however, studies about its hypotensive or vasorelaxant effects are lacking.

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Blood-contacting devices must be designed to minimize the risk of bloodstream-associated infections, thrombosis, and intimal lesions caused by surface friction. However, achieving effective prevention of both bloodstream-associated infections and thrombosis poses a challenge due to the conflicting nature of antibacterial and antithrombotic activities, specifically regarding electrostatic interactions. This study introduced a novel biocompatible hydrogel of sodium alginate and zwitterionic carboxymethyl chitosan (ZW@CMC) with antibacterial and antithrombotic activities for use in catheters.

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The hibernation of amphibians can offer a unique window into overwintering adaptation processes and host-gut microbiota interactions through changes in metabolic availability and homeostasis. We attempted to identify differences in the physiology and gut microbiome during and after hibernation in Japanese wrinkled frogs (Glandirana rugosa), an aquatic overwintering amphibian. After hibernation, the high alpha and beta diversity of the gut bacterial community appears to reflect the more diverse and complex environmental conditions.

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This paper proposes fault diagnosis methods aimed at proactively preventing potential safety issues in robot systems, particularly human coexistence robots (HCRs) used in industrial environments. The data were collected from durability tests of the driving module for HCRs, gathering time-series vibration data until the module failed. In this study, to apply classification methods in the absence of post-failure data, the initial 50% of the collected data were designated as the normal section, and the data from the 10 h immediately preceding the failure were selected as the fault section.

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Article Synopsis
  • Drynaria rhizome is a herbal remedy from East Asia known for its bone-strengthening properties, but its effects on obesity and bone health are complex due to the role of visceral fat in osteoporosis.
  • A study on high-fat diet-induced obese mice showed that supplementation with Drynaria rhizome extract (DRE) led to weight loss without affecting food intake.
  • DRE improved lipid metabolism by regulating key transcription factors and decreasing fat accumulation in the liver and fat pads, suggesting it could be a beneficial natural product for both bone health and obesity management.
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Background: Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models.

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Hypertension requires proper management because of the increased risk of cardiovascular disease and death. For this purpose, functional foods containing tannins have been considered an effective treatment. Sanguisorbae radix (SR) also contains various tannins; however, there have been no studies on its vasorelaxant or antihypertensive effects.

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Analysis of physiological responses can be used to assess population health, identify threat factors, and understand mechanisms of stress. In addition to this, conservation physiologists have sought to establish potential management strategies for environmental change and evaluate the effectiveness of conservation efforts. From past to present, the field of conservation physiology is developing in an increasingly broader context.

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Tadpoles present an intriguing model system for studying the regulation and selection of gut microbiota. They offer a unique perspective to enhance our understanding of host-microbiota interactions, given their capacity to alter the dynamics of the gut microbial community by interacting with multiple environmental factors within a complex life cycle. In this study, we comprehensively investigated variations in growth rate and gut bacterial community in relation to temperature differences during the complex process of amphibian metamorphosis.

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Article Synopsis
  • - The study investigates the invasion of five hornet species, focusing on the yellow-legged hornet (Vespa velutina) in South Korea, emphasizing their gut bacteria and dietary habits as factors in their invasion success.
  • - Findings show that all species have similar food sources, but V. velutina and V. mandarinia exhibited higher levels of beneficial gut bacteria, potentially aiding their ability to break down dietary fiber and produce necessary nutrients.
  • - The research highlights the significance of gut microbiota in the success of invasive species, with implications for better management and control strategies against these environmental threats.
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