• Journal of Life Science
• /
• v.32 no.3
• /
• pp.256-262
• /
• 2022

Oxysterols are oxygenated metabolites of cholesterol generated by serial enzymatic reactions during bile acid synthesis. Similar to cholesterol, oxysterols move rapidly to the intracellular region and modulate various cellular processes, such as immune cell responses, lipid metabolism, and cholesterol homeostasis. Different nuclear transcription factors, such as glucocorticoid, estrogen, and liver X receptors, can be modulated by oxysterols in multiple tissues. The most abundant oxysterol, 27-hydroxycholesterol (27-OHC), is a well-known selective modulator that can either activate or suppress estrogen receptor activity in a tissue-specific manner. The contribution of 27-OHC in atherosclerosis development is apparent because a large amount of it is found in atherosclerotic plaques, accelerating the transformation of macrophages into foam cells that uptake extracellular modified lipids. According to previous studies, however, there are opposing opinions about how 27-OHC affects lipid and cholesterol metabolism in metabolic organs, including the liver and adipose tissue. In particular, the effects of 27-OHC on lipid metabolism are entirely different between in vitro and in vivo conditions, suggesting that understanding the physiology of this oxysterol requires a sophisticated approach. This review summarizes the potential effects of 27-OHC in atherosclerosis and metabolic syndromes with a special discussion of its role in metabolic tissues.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.7
• /
• pp.843-856
• /
• 2023

The global surge in maritime traffic has resulted in an increased number of ship collisions, leading to significant economic, environmental, physical, and human damage. The causes of these maritime accidents are multifaceted, often arising from a combination of crew judgment errors, negligence, complexity of navigation routes, weather conditions, and technical deficiencies in the vessels. Given the intricate nuances and contextual information inherent in each incident, a methodology capable of deeply understanding the semantics and context of sentences is imperative. Accordingly, this study utilized the SentenceBERT model to analyze maritime safety tribunal decisions over the last 20 years in the Busan Sea area, which encapsulated data on ship collision incidents. The analysis revealed important keywords potentially responsible for these incidents. Cluster analysis based on the frequency of specific keyword appearances was conducted and visualized. This information can serve as foundational data for the preemptive identification of accident causes and the development of strategies for collision prevention and response.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.365-376
• /
• 2020

Immature embryogenesis is a useful process in wheat tissue culture, including transgenic technology, because of its high regeneration efficiency compared to that in other tissues. However, it is a very labor-intensive and time-restrictive method, because the preparation of immature embryos is limited to the optimal time after flowering. In this experiment, 'Speed Breeding', a breeding technique that accelerates breeding generation advancement by extending the photoperiod, was applied to the wheat variety 'Bobwhite'. A controlled growth room was constructed by adjusting the photoperiod (22-hour light/2-hour dark) using LED lights at temperature of 22℃. After vernalization of the Bobwhite seeds at 4℃ for 4 weeks, the seedlings were grown in a controlled growth room and a greenhouse to compare the heading date. In both conditions, calli were induced from immature embryos on the 11^th day after flowering. After 4 weeks, the calli were transferred to a regeneration medium. Regeneration efficiencies under greenhouse conditions and Speed Breeding conditions were determined as 45.05% and 43.18%, respectively. Antioxidant enzyme activity and reference gene expression analysis were performed to confirm the presence of stress due to an extremely long-day photoperiod. As a result, the antioxidant enzyme activity was not distinguished from that of the greenhouse condition. The reference gene expression analysis revealed that the PsaA and CDC genes were highly expressed under the Speed Breeding condition. However, expression of PsbA was similar expression in both conditions. These results will provide useful information for the application of immature embryogenesis to the wheat transformation system.

• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.347-354
• /
• 2007

Commercialization of genetically modified (GM) plants will be required the assessment of risks associated with the release of GM plants that should include a detailed risk assessment of their impacts in human health and the environment. Prior to GM plant release, applicants should provide the information on GM crops for approval. We carried out this study to provide the molecular data for risk assessment of the GM Chinese cabbage plants with insect-resistance gene, modified CryIAc, which we obtained by Agrobacterium-transformation. From the molecular analysis with GM Chinese cabbage, we confirmed the transgene copy number and stability, the expression of the transgene, and integration region sequences between the transgene and the Chinese cabbage genome. Based on the unique integration DNA sequences, we designed specific primer set to detect GM Chinese cabbage and set up the GM cabbage detection method by qualitative PCR analysis. Qualitative analysis with GM Chinese cabbage progenies analysis was revealed the same as the result of herbicide treatment. Our results provided the molecular data for risk assessment analysis of GM Chinese cabbage and demonstrated that the primer set proposed could be useful to detect GM Chinese cabbage.

• Journal of Plant Biotechnology
• /
• v.39 no.4
• /
• pp.295-299
• /
• 2012

We performed in vitro assay and field trials to assess levels of changes in intrinsic properties and resistance against soft rot of the potato cv. Dejima upon the introduction of a soybean calmodulin 4 gene (SCaM4). Field trials with four lines overexpressing SCaM4 gene were conducted over two seasons, and harvested tubers were evaluated in bioassay for resistance to Pectobacterium carotovorum ssp. carotovorum. The SCaM4 transgenic potato lines inoculated with $10^8$ CFU/ml of P. carotovorum ssp. carotovorum showed enhanced resistance compared to control. Among the SCaM4 transgenic lines, the transgenic line SCaM4-4 exhibited the highest tolerance to soft rot in vitro assays, so did in field trials. In the field trial, the soft rot resistance of SCaM4-4 line was more than 5 times higher compared to that of control cultivar, Dejima. The major agronomic characteristics of the SCaM4 transgenic lines were not different from those of the nontransgenic 'Dejima'. The result demonstrated that the transformation of a calmodulin 4 gene was a successful strategy in development of potato cultivar enhanced to soft rot.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.20 no.2
• /
• pp.138-149
• /
• 2000

Various modeling techniques for ultrasonic wave propagation and scattering problems in finite solid media are presented. Elastodynamic boundary value problems in inhomogeneous multi-layered plate-like structures are set up for modal analysis of guided wave propagation and numerically solved to obtain dispersion curves which show propagation characteristics of guided waves. As a powerful modeling tool to overcome such numerical difficulties in wave scattering problems as the geometrical complexity and mode conversion, the Boundary Element Method(BEM) is introduced and is combined with the normal mode expansion technique to develop the hybrid BEM, an efficient technique for modeling multi mode conversion of guided wave scattering problems. Time dependent wave forms are obtained through the inverse Fourier transformation of the numerical solutions in the frequency domain. 3D BEM program development is underway to model more practical ultrasonic wave signals. Some encouraging numerical results have recently been obtained in comparison with the analytical solutions for wave propagation in a bar subjected to time harmonic longitudinal excitation. It is expected that the presented modeling techniques for elastic wave propagation and scattering can be applied to establish quantitative nondestructive evaluation techniques in various ways.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.12
• /
• pp.3011-3015
• /
• 2009

Structural and thermo-analytical studies were carried out to understand the phase formation kinetics of the single phase $Bi_5Ti_3FeO_{15}$ (BTFO) nanocrystals in $Bi_2O_3-Fe_2O_3-TiO_2$, during the polymerized complex (PC) synthesis method. The crystallization of Aurivillius phase $Bi_5Ti_3FeO_{15}$ layered perovskite was found to be initiated and achieved under the temperature conditions in the range of ${\sim}$800 to 1050$^{\circ}C$. The activation energy for grain growth of $Bi_5Ti_3FeO_{15}$ nanocrystals (NCs) was very low in case of NCs formed by PC (2.61 kJ/mol) than that formed by the solid state reaction (SSR) method (10.9 kJ/mol). The energy involved in the phase transformation of Aurivillius phase $Bi_5Ti_3FeO_{15}$ from $Bi_2O_3-Fe_2O_3-TiO_2$ system was ${\sim}$ 69.8 kJ/mol. The formation kinetics study of $Bi_5Ti_3FeO_{15}$ synthesized by SSR and PC methods would not only render a large impact in the nanocrystalline material development but also in achieving highly efficient visible photocatalysts.

• Journal of Intelligence and Information Systems
• /
• v.16 no.2
• /
• pp.33-54
• /
• 2010

The World Wide Web is transitioning from being a mere collection of documents that contain useful information toward providing a collection of services that perform useful tasks. The emerging Web service technology has been envisioned as the next technological wave and is expected to play an important role in this recent transformation of the Web. By providing interoperable interface standards for application-to-application communication, Web services can be combined with component based software development to promote application interaction both within and across enterprises. To make Web services for service-oriented computing operational, it is important that Web service repositories not only be well-structured but also provide efficient tools for developers to find reusable Web service components that meet their needs. As the potential of Web services for service-oriented computing is being widely recognized, the demand for effective Web service discovery mechanisms is concomitantly growing. A number of public Web service repositories have been proposed, but the Web service taxonomy generation has not been satisfactorily addressed. Unfortunately, most existing Web service taxonomies are either too rudimentary to be useful or too hard to be maintained. In this paper, we propose a Web service taxonomy generation framework that combines an artificial neural network based clustering techniques with descriptive label generating and leverages the semantics of the XML-based service specification in WSDL documents. We believe that this is one of the first attempts at applying data mining techniques in the Web service discovery domain. We have developed a prototype system based on the proposed framework using an unsupervised artificial neural network and empirically evaluated the proposed approach and tool using real Web service descriptions drawn from operational Web service repositories. We report on some preliminary results demonstrating the efficacy of the proposed approach.

• Journal of Internet Computing and Services
• /
• v.23 no.1
• /
• pp.77-86
• /
• 2022

The Republic of Korea is a country in which coastal surveillance is an imperative national task as it is surrounded by seas on three sides under the confrontation between South and North Korea. However, due to Defense Reform 2.0, the number of R/D (Radar) operating personnel has decreased, and the period of service has also been shortened. Moreover, there is always a possibility that a human error will occur. This paper presents specific guidelines for developing an AI learning model for the intelligent coastal surveillance system. We present a three-step strategy to realize the guidelines. The first stage is a typical stage of building an AI learning model, including data collection, storage, filtering, purification, and data transformation. In the second stage, R/D signal analysis is first performed. Subsequently, AI learning model development for classifying real and false images, coastal area analysis, and vulnerable area/time analysis are performed. In the final stage, validation, visualization, and demonstration of the AI learning model are performed. Through this research, the first achievement of making the existing weapon system intelligent by applying the application of AI technology was achieved.

• Journal of Life Science
• /
• v.32 no.12
• /
• pp.956-961
• /
• 2022

Plant Chloroplast have several advantages as an expression platform of biopharmaceuticals over conventional expression platforms such as mammalian cells, yeast and bacteria. First, plants do not serve as a host for mammalian infectious virus and have endotoxin like bacteria which can cause anaphylactic shock. In addition, high copy number of chloroplast genome allows for chloroplast transformants to reach the high level of expression of heterologous genes. Moreover, the integration of transgenes into specific region of chloroplast genomes makes chloroplast transformants unaffected by positional effect which can be frequently observed from nuclear transformants, resulting in loss of transgene expressions. Antimicrobial peptides (AMPs) are a kind of innate immunity which is found from bacteria to humans. Unlike conventional antibiotics, very less dosage of AMPs can have catastrophic effect on bacterial survival. Further, the repeated use of AMPs does not trigger the development of bacterial resistance. Moricin, one of the AMPs, was isolated from Bombyx mori, a silkworm moth. The C-terminal of moricin consists largely of basic amino acids, and the N-terminal has an α-helix structure. Moricin was chosen and expressed in a SUMO/SUMOase without leaving any unwanted amino acids which could potentially affect the anti-bacterial activity of the moricin. The transformation vector used in this study has already been created in this lab for the expression in both prokaryotic systems such as E. coli and chloroplast. The expressed moricin was purified using Ni columns and SUMOase, and the antibacterial activity of the purified moricin was confirmed using an agar diffusion assay.