• Journal of Ginseng Research
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• v.43 no.2
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• pp.261-271
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• 2019

Background: Protopanaxatriol (PPT) is an aglycone of ginsenosides, which has high medicinal values. Production of PPT from natural ginseng plants requires artificial deglycosylation procedures of ginsenosides via enzymatic or physicochemical treatments. Metabolic engineering could be an efficient technology for production of ginsenoside sapogenin. For PPT biosynthesis in Panax ginseng, damarenediol-II synthase (PgDDS) and two cytochrome P450 enzymes (CYP716A47 and CYP716A53v2) are essentially required. Methods: Transgenic tobacco co-overexpressing P. ginseng PgDDS, CYP716A47, and CYP716A53v2 was constructed via Agrobacterium-mediated transformation. Results: Expression of the three introduced genes in transgenic tobacco lines was confirmed by Reverse transcription-polymerase chain reaction (RT-PCR). Analysis of liquid chromatography showed three new peaks, dammarenediol-II (DD), protopanaxadiol (PPD), and PPT, in leaves of transgenic tobacco. Transgenic tobacco (line 6) contained $2.8{\mu}g/g$ dry weight (DW), $7.3{\mu}g/g$ DW, and $11.6{\mu}g/g$ DW of PPT, PPD, and DD in leaves, respectively. Production of PPT was achieved via cell suspension culture and was highly affected by auxin treatment. The content of PPT in cell suspension was increased 37.25-fold compared with that of leaves of the transgenic tobacco. Transgenic tobacco was not able to set seeds because of microspore degeneration in anthers. Transmission electron microscopy analysis revealed that cells of phloem tissue situated in the center of the anther showed an abnormally condensed nuclei and degenerated mitochondria. Conclusion: We successfully achieved the production of PPT in transgenic tobacco. The possible factors deriving male sterility in transgenic tobacco are discussed.

• Genes and Genomics
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• v.40 no.12
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• pp.1363-1371
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• 2018

One of the main concerns in biology is extracting sophisticated features from DNA sequence for gene interaction determination, receiving a great deal of researchers' attention. The epigenetic modifications along with their patterns have been intensely recognized as dominant features affecting on gene expression. However, studying sequenced-based features highly correlated to this key element has remained limited. The main objective in this research was to propose a new feature highly correlated to epigenetic modifications capable of classification of genes. In this paper, classification of 34 genes in PPAR signaling pathway associated with muscle fat tissue in human was performed. Using different statistical outlier detection methods, we proposed that 5-mers highly correlated to epigenetic modifications can correctly categorize the genes involved in the same biological pathway or process. Thirty-four genes in PPAR signaling pathway were classified via applying a proposed feature, 5-mers strongly associated to 17 different epigenetic modifications. For this, diverse statistical outlier detection methods were applied to specify the group of thoroughly correlated genes. The results indicated that these 5-mers can appropriately identify correlated genes. In addition, our results corresponded to GeneMania interaction information, leading to support the suggested method. The appealing findings imply that not only epigenetic modifications but also their highly correlated 5-mers can be applied for reconstructing gene regulatory networks as supplementary data as well as other applications like physical interaction, genes prioritization, indicating some sort of data fusion in this analysis.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.114-118
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• 2011

Even though the carbon paste electrode bound with mineral oil is useful for research about the characteristics of enzymes, it remains far from practical uses because the lack of mechanical hardness limits its practical use. When the rubber liquefied in toluene was used as a binder of carbon powder in lab, it is confirmed that the mechanical robustness of the electrode is guaranteed. In order to confirm whether it shows quantitative electrochemical behaviors or not, its kinetic parameters, e.g. the symmetry factor (${\alpha}=0.28$), the exchange current density ($i_0=4.06{\mu}A/cm^2$), the capacity of the double layer ($C_d=2.11{\times}10^{-3}F$), the Michaelis constant ($K_M=2.45{\times}10^{-3}M$), and the time constant (${\tau}_B=0.077sec$) were investigated. Our experimental observations prove that the chloroprene rubber is a promising binder for the practical use of a carbon paste electrode.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.186-195
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• 2022

Objective : To explore the histological feature of the cervical disc degeneration in patients with degenerative ossification (DO) and its potential mechanisms. Methods : A total of 96 surgical segments, from cervical disc degenerative disease patients with surgical treatment, were divided into ossification group (group O, n=46) and non-ossification group (group NO, n=50) based on preoperative radiological exams. Samples of disc tissues and osteophytes were harvested during the decompression operation. The hematoxylin-eosin staining, Masson trichrome staining and Safranin O-fast green staining were used to compare the histological differences between the two groups. And the distribution and content of transforming growth factor (TGF)-β1, p-Smad2 and p-Smad3 between the two groups were compared by a semi-quantitative immunohistochemistry (IHC) method. Results : For all the disc tissues, the content of disc cells and collagen fibers decreased gradually from the outer annulus fibrosus (OAF) to the central nucleus pulposus (NP). Compared with group NO, the number of disc cells in group O increased significantly. But for proteoglycan in the inner annulus fibrosus (IAF) and NP, the content in group O decreased significantly. IHC analysis showed that TGF-β1, p-Smad2, and p-Smad3 were detected in all tissues. For group O, the content of TGF-β1 in the OAF and NP was significantly higher than that in group NO. For p-Smad2 in IAF and p-Smad3 in OAF, the content in group O were significantly higher than group NO. Conclusion : Histologically, cervical disc degeneration in patients with DO is more severe than that without DO. Local higher content of TGF-β1, p-Smad2, and p-Smad3 are involved in the disc degeneration with DO. Further studies with multi-approach analyses are needed to better understand the role of TGF-β/Smads signaling pathway in the disc degeneration with DO.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.422-428
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• 2023

Ultrafast ultrasound imaging has been applied to various imaging approaches, including shear wave elastography, ultrafast Doppler, and super-resolution imaging. However, these methods are still challenging in real-time implementation for three Dimension (3D) or portable applications because of their massive data rate required. In this paper, we proposed an adaptive quantization method that effectively reduces the data rate of large Radio Frequency (RF) data. In soft tissue, ultrasound backscatter signals require a high dynamic range, and thus typical quantization used in the current systems uses the quantization level of 10 bits to 14 bits. To alleviate the quantization level to expand the application of ultrafast ultrasound imaging, this study proposed a depth-sectional quantization approach that reduces the quantization errors. For quantitative evaluation, Field II simulations, phantom experiments, and in vivo imaging were conducted and CNR, spatial resolution, and SSIM values were compared with the proposed method and fixed quantization method. We demonstrated that our proposed method is capable of effectively reducing the quantization level down to 3-bit while minimizing the image quality degradation.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.256-263
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• 2022

Skin cancer is one of the most common diseases in the world, and the incidence rate in Korea has increased by about 100% over the past five years. In the United States, more than 5 million people are diagnosed with skin cancer every year. Skin cancer mainly occurs when skin tissue is damaged for a long time due to exposure to ultraviolet rays. Melanoma, a malignant tumor of skin cancer, is similar in appearance to Atypical melanocytic nevus occurring on the skin, making it difficult for the general public to be aware of it unless secondary signs occur. In this paper, we propose a skin cancer lesion edge detection algorithm and a deep learning model, CRNN, which performs skin cancer lesion classification for early detection and classification of these skin cancers. As a result of the experiment, when using the contour detection algorithm proposed in this paper, the classification accuracy was the highest at 97%. For the Canny algorithm, 78% was shown, 55% for Sobel, and 46% for Laplacian.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.127-135
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• 2023

Accurate segmentation of histopathology whole slide images (WSIs) is a crucial task for disease diagnosis and treatment planning. However, conventional automated segmentation algorithms may not always be applicable to WSI segmentation due to their large size and variations in tissue appearance, staining, and imaging conditions. Recent advances in interactive segmentation, which combines human expertise with algorithms, have shown promise to improve efficiency and accuracy in WSI segmentation but also presented us with challenging issues. In this paper, we propose a novel interactive segmentation method, ZoomISEG, that leverages multi-resolution WSIs. We demonstrate the efficacy and performance of the proposed method via comparison with conventional single-scale methods and an ablation study. The results confirm that the proposed method can reduce human interaction while achieving accuracy comparable to that of the brute-force approach using the highest-resolution data.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.58-69
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• 2024

To evaluate the adhesive characteristics of mixed cross-laminated timber (CLT) using domestic softwoods structural lumber proposed by KS F 3020 and yellow poplar, penetration depth of adhesive and thickness of bonding line were analyzed based on the results of boiling water soaking delamination. 3 Types of adhesives and 2 types of major layer were divided into a 5 ply CLT using yellow popular as minor layer. The bonding performance of the mixed CLT as structural members was evaluated based on the KS F 2081. The thickness of bonding line between layers of the mixed CLT was measured with a scanning electron microscope, and the adhesive penetration depth in the layer members was measured with an optical microscope. As a result of boiling water soaking delamination test of mixed CLT, the CLT specimens using PRF and PUR adhesives met the requirements of KS F 2081. It was verified that the penetration path of the adhesive in the layes was mainly through the tracheid cell in the case of Japanese larch and Korean red pine layers, and through the vessel and radial tissue in yellow popular layers. The penetration depth of the adhesive was the highest for the PRF adhesive under the same pressing time conditions, and the thickness of the bonding line was in inverse proportion to the penetration depth in the case of the PUR adhesive.

• Journal of Adhesion and Interface
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• v.24 no.3
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• pp.105-111
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• 2023

Recently, there has been a growing interest in low biofouling coatings for various industrial applications including precious metal and jewelry applications. Contaminations including cells and bacteria of the metallic substrates (i.e., accessories, earring, and piercings) may irritate the contacted tissue surfaces or induce an abnormal reaction. In this study, catechol-conjugated polyethylene glycol (PEG-C) was synthesized as low bio-fouling coating materials inspired by mussel-adhesion. PEG-C-coated copper-zinc alloy surfaces showed excellent cell viability and significant inhibitions of protein and cell adhesions to metal surfaces. Thus, PEG-C coating methods and PEG-C-coated metallic substrates can be usefully exploited for versatile industrial applications, particularly for precious metal and jewelry industries.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.10.1-10.17
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• 2024

In this review, we will explore the intricate roles of cytokines and vascular endothelial growth factors in autoimmune diseases (ADs), with a particular focus on rheumatoid arthritis (RA) and multiple sclerosis (MS). AD is characterized by self-destructive immune responses due to auto-reactive T lymphocytes and Abs. Among various types of ADs, RA and MS possess inflammation as a central role but in different sites of the patients. Other common aspects among these two ADs are their chronicity and relapsing-remitting symptoms requiring continuous management. First factor inducing these ADs are cytokines, such as IL-6, TNF-α, and IL-17, which play significant roles in the pathogenesis by contributing to inflammation, immune cell activation, and tissue damage. Secondly, vascular endothelial growth factors, including VEGF and angiopoietins, are crucial in promoting angiogenesis and inflammation in these two ADs. Finally, placental growth factor (PlGF), an emerging factor with bi-directional roles in angiogenesis and T cell differentiation, as we introduce as an "angio-lymphokine" is another key factor in ADs. Thus, while angiogenesis recruits more inflammatory cells into the peripheral sites, cytokines secreted by effector cells play critical roles in the pathogenesis of ADs. Various therapeutic interventions targeting these soluble molecules have shown promise in managing autoimmune pathogenic conditions. However, delicate interplay between cytokines, angiogenic factors, and PlGF has more to be studied when considering their complementary role in actual pathogenic conditions. Understanding the complex interactions among these factors provides valuable insights for the development of innovative therapies for RA and MS, offering hope for improved patient outcomes.