• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.123-123
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• 2019

Xanthone is a kind of polyphenolic compounds that contain a distinctive chemical structure with a tricyclic aromatic ring found in a few higher plant families e.g. gentian root. This compound had a variety of biological activity, for instance antioxidant, antibacterial, anti-inflammatory, and anticancer effects. However, the effect of xanthone on mast cell-mediated allergic inflammation and its associated mechanism have not been elucidated. Therefore, the aim of this study was to elucidate the anti-allergic inflammatory effects and the underlying molecular mechanism of xanthone in PMACI-stimulated human mast cells-1 (HMC-1). In this result, xanthone treatment decreased the production of histamine, pro-inflammatory cytokines such as tumor necrosis factor-a (TNF-${\alpha}$), IL-6, and IL-8 and expressions of TSLP in PMACI-stimulated HMC-cells. In addition, xanthone significantly suppressed the phosphorylation of MAPKs and the activation of NF-${\kappa}B$ signal pathway in activated mast cells. Furthermore, xanthone inhibited the activation of caspase-1, an IL-$1{\beta}$ converting enzyme, in PMACI-stimulated HMC-1 cells. These findings provide evidence that xanthone could be a potential therapeutic agent for allergy-related inflammatory disorders.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.355-364
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• 2018

When focusing using an ultrasonic transducer array, a main lobe is formed in the focal region of an ultrasound field, but side lobes also arise around the focal region due to the leakage. Since the side lobes cannot be completely eliminated in the focusing process, they are responsible for subsequent ultrasound image quality degradation. To improve ultrasound image quality, a signal processing strategy to reduce side lobes is definitely in demand. To this end, quantitative determination of main and side lobes is necessary. We propose a theoretically and actually error-free method of exactly discriminating and separately computing the main lobe and side lobe parts in ultrasound image by computer simulation. We refer to images constructed using the main and side lobe signals as the main and side lobe images, respectively. Since the main and side lobe images exactly represent their main and side lobe components, respectively, they can be used to evaluate ultrasound image quality. Defining the average brightness of the main and side lobe images, the conventional to side lobe image ratio, and the main to side lobe image ratio as image quality metrics, we can evaluate image characteristics in speckle images. The proposed method is also applied in assessing the performance of side lobe suppression filtering. We show that the proposed method may greatly aid in the evaluation of medical ultrasonic images using computer simulations, albeit lacking the use of actual experimental data.

• Molecules and Cells
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• 제44권5호
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• pp.335-341
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• 2021

Zinc is an essential micronutrient with crucial roles in multiple facets of biological processes. Dysregulated zinc homeostasis impairs overall immune function and resultantly increases susceptibility to infection. Clinically, zinc supplementation is practiced for treatment of several infectious diseases, such as diarrhea and malaria. Recent focus on zinc as a beneficial element for immune system support has resulted in investigation of the immunomodulatory roles of zinc in a variety of immune cells. Besides its classical role as a cofactor that regulates the structural function of thousands of proteins, accumulating evidence suggests that zinc also acts, in a manner similar to calcium, as an ionic regulator of immune responses via participation as an intracellular messenger in signaling pathways. In this review, we focus on the role of zinc as a signaling molecule in major pathways such as those downstream of Toll-like receptors-, T cell receptor-, and cytokine-mediated signal transduction that regulate the activity and function of monocytes/macrophages and T cells, principal players in the innate and adaptive immune systems.

• ETRI Journal
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• 제42권6호
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• pp.837-845
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• 2020

The objective of this study was to implement an in vitro exposure system for 28 GHz to investigate the biological effects of fifth-generation (5G) communication. A signal source of 28 GHz for 5G millimeter-wave (MMW) deployment was developed, followed by a variable attenuator for antenna input power control. A power amplifier was also customized to ensure a maximum output power of 10 W for high-power 28-GHz exposure. A 3-dB uniformity over the 80 mm × 80 mm area that corresponds to four Petri dishes of three-dimensional cell cultures can be obtained using a customized choke-ring-type antenna. An infrared camera is employed for temperature regulation during exposure by adjusting the airflow cooling rate via real-time feedback to the incubator. The reported measurement results confirm that the input power control, uniformity, and temperature regulation for 28-GHz exposure were successfully accomplished, indicating the possibility of a wide application of the implemented in vitro exposure system in the fields of various MMW dose-response studies.

• Molecules and Cells
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• 제45권4호
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• pp.231-242
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• 2022

The neuromuscular junction (NMJ), which is a synapse for signal transmission from motor neurons to muscle cells, has emerged as an important region because of its association with several peripheral neuropathies. In particular, mutations in GARS that affect the formation of NMJ result in Charcot-Marie-Tooth disease and distal hereditary motor neuropathy. These disorders are mainly considered to be caused by neuronal axon abnormalities; however, no treatment is currently available. Therefore, in order to determine whether the NMJ could be targeted to treat neurodegenerative disorders, we investigated the NMJ recovery effect of HDAC6 inhibitors, which have been used in the treatment of several peripheral neuropathies. In the present study, we demonstrated that HDAC6 inhibition was sufficient to enhance movement by restoring NMJ impairments observed in a zebrafish disease model. We found that CKD-504, a novel HDAC6 inhibitor, was effective in repairing NMJ defects, suggesting that treatment of neurodegenerative diseases via NMJ targeting is possible.

• 한국식생활문화학회지
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• 제37권3호
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• pp.248-255
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• 2022

Spinach (Spinacia oleracea L.), a green leafy vegetable, is well known as a functional food due to its biological activities. Vascular calcification is associated with several disease conditions including atherosclerosis, diabetes, and chronic kidney disease (CKD), and is known to raise the risk of cardiovascular diseases related morbidity and mortality. However, there are no previous studies that have investigated the effects of fermented spinach exract (FSE) against aortic and its underlying mechanisms. Therefore, this study investigated the effects and action of possible mechanisms of FSE on inorganic phosphate (PI)-induced vascular calcification in ex vivo mouse aortic rings. PI increased vascular calcification through calcium deposition in ex vivo aortic rings. FSE inhibited calcium accumulation and osteogenic key marker, runt-related transcription factor 2 (Runx2), and bone Morphogenetic Protein 2 (BMP-2) protein expression in ex vivo aortic rings. And, FSE inhibited PI-induced extracellular signal-regulated kinase (ERK) and p38 phosphorylation in ex vivo aortic rings. These results show that FSE can prevent vascular calcification which may be a crucial way for the prevention and treatment of vascular disease association with vascular calcification.

• 대한의용생체공학회:의공학회지
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• 제44권3호
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• pp.218-224
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• 2023

This study aimed to analyze the coordination of muscle and muscle fatigue between biceps, lateral deltoid, and anterior deltoid during dumbbell side lateral raise using bio-signal. One male subject performed dumbbell side lateral raise with 3% of 1RM dumbbell at the rate of 30bpm until failure (8 minutes). While performing, ECG were recorded to observe the participant's performance. EMG were recorded from biceps, lateral deltoid, and anterior deltoid for observing coordination and fatigue. ECG were analyzed in time and frequency domain to observe Heart rate, normLF, normHF. Changes in heart rate, normLF, and normHF indicate that the sympathetic nervous system is activated, while changes in median frequency (MDF) indicate the occurrence of muscle fatigue. Moreover, the coordination relationship of muscle changed. The correlation of MDF between each muscles indicated that lateral deltoid is associated with biceps and anterior deltoid. These results showed that our study can contribute to improving understanding of muscle fatigue and muscle coordination relationships.

• Genomics & Informatics
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• 제21권1호
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• pp.6.1-6.8
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• 2023

Glaucoma is the second leading cause of irreversible blindness, and primary open-angle glaucoma (POAG) is the most common type. Due to inadequate diagnosis, treatment is often not administered until symptoms occur. Hence, approaches enabling earlier prediction or diagnosis of POAG are necessary. We aimed to identify novel drugs for glaucoma through bioinformatics and network analysis. Data from 36 samples, obtained from the trabecular meshwork of healthy individuals and patients with POAG, were acquired from a dataset. Next, differentially expressed genes (DEGs) were identified to construct a protein-protein interaction (PPI) network. In both stages, the genes were enriched by studying the critical biological processes and pathways related to POAG. Finally, a drug-gene network was constructed, and novel drugs for POAG treatment were proposed. Genes with p < 0.01 and |log fold change| > 0.3 (1,350 genes) were considered DEGs and utilized to construct a PPI network. Enrichment analysis yielded several key pathways that were upregulated or downregulated. For example, extracellular matrix organization, the immune system, neutrophil degranulation, and cytokine signaling were upregulated among immune pathways, while signal transduction, the immune system, extracellular matrix organization, and receptor tyrosine kinase signaling were downregulated. Finally, novel drugs including metformin hydrochloride, ixazomib citrate, and cisplatin warrant further analysis of their potential roles in POAG treatment. The candidate drugs identified in this computational analysis require in vitro and in vivo validation to confirm their effectiveness in POAG treatment. This may pave the way for understanding life-threatening disorders such as cancer.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제65차 동계학술대회논문집 30권1호
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• pp.291-292
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• 2022

현 사회는 효율성과 편리함을 목적으로 수고를 덜어주는 기계 및 장치, 시스템들을 연구하고 개발하고 있다. 이를 목적으로, 개발되는 시스템에 가장 적합한 대상이 누구인지 파악하는 것도 중요한 요소 중 하나이다. 따라서, 본 프로젝트는 대부분의 사람들에게는 쉬운 행동이지만 신체적 한계로 어려움을 겪는 분들을 대상으로 초점을 맞췄다. 특정한 입력을 인식하여 그 입력에 따라 자동으로 책장을 한 페이지씩 넘겨주는 출력 시스템을 제안한다. 호흡, 손가락 기울기, 버튼 등의 센서에서 감지된 움직임을 통해 최소한의 동작으로 아두이노 기반의 자동화 프로그램 이행을 목표로 하고 있다. 생체 동작 신호 수집을 위한 비접촉 및 웨어러블 센서로 구성되며 수신받은 데이터를 기반으로 각각의 모터에 전송하여 담당하는 작동을 한다. 자동화 및 모션 감지 기술 프로토타입을 제시한다.

• 대한의용생체공학회:의공학회지
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• 제45권1호
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• pp.37-42
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• 2024

In this study, we explored the possibility of using sympathetic skin response (SSR), a type of electrodermal activity (EDA), as a method of evaluating a subject's responsiveness to physical or psychological stimulation. To provide physical and psychological stimulation, walking on an acupressure plate and a roller coaster virtual reality experience wearing an HMD (head mounted display) were used. Walking on an acupressure plate significantly increased the SSR signal compared to walking on the bare floor. Additionally, it was observed that the SSR response significantly increased while the subject was wearing an HMD and experiencing a roller coaster compared to the resting state of sitting on a chair. The SSR response to physical or psychological stimulation increased in all subjects, but the degree of reactivity differed. These experimental results suggested that sympathetic skin response (SSR) is a useful tool as a biosignal that can be used to evaluate the human body's responsiveness to physical stimulation or psychological stimulation using virtual reality.