• Natural Product Sciences
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• v.27 no.4
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• pp.234-239
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• 2021

Masclura tricuspidata, also called as Cudrania tricuspidata, is one of the most common Moraceae family plants in East Asia. Its trivial name follows mulberry due to the similar morphology. Investigation of the bioactive constituents of M. tricuspidata leaves yielded a new xanthone derivative along with twenty known compounds through various chromatographic techniques. A new compound was defined as mascluraxanthone (3), a prenylated xanthone glucoside on the basis of 1D and 2D NMR and MS data. Twenty known compounds were identified as four xanthone derivatives (1-2 and 4-5), two flavans (6-7), six flavanol derivatives (8-13), a flavonone (14) and seven flavonol derivatives (15-21). Among the isolated compounds, flavanol and flavonoid derivatives with 3',4'-OH groups showed antioxidant and anti-tyrosinase activities. Conclusively, the leaves of M. tricuspidata are rich in aromatic compounds including xanthones and flavonoids. In addition, these constituents showed antioxidant and anti-tyrosinase potentials, which might be useful for oxidative stress related diseases.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1299-1306
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• 2022

Six ansamycin derivatives were isolated from the culture broth of Streptomyces sp. KCB17JA11, including four new hygrolansamycins A-D (1-4) and known congeners divergolide O (5) and hygrocin C (6). Compounds 1-5 featured an unusual six-membered O-heterocyclic moiety. The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The structures of 1-4 were elucidated using NMR and HRESIMS experiments, and the absolute configuration was established by the Mosher's method. Compound 2 exhibited mild cytotoxicity against five cancer cell lines with IC₅₀ values ranging from 24.60 ± 3.37 µM to 49.93 ± 4.52 µM.

• Microbiology and Biotechnology Letters
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• v.50 no.4
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• pp.465-476
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• 2022

The importance of beneficial microorganisms, particularly probiotics, that coexist in the human body, is being increasingly recognized. Probiotics are representative health functional foods that provide health benefits to humans through the production of various metabolites, including short-chain fatty acids. However, the health benefits are strain-specific, and the use of each probiotic strain should follow guidelines that assure its safety. Accurate identification of the strain should be managed through genetic and phenotypic analyses of the strain. Besides, the functionality of probiotics should be disclosed in vitro and in vivo so that they can be used as legal functional ingredients (i.e., individual standards). In this review, we deal with the guidelines, including the technical factors related to probiotic strains. The common health effects of probiotic strains include proliferation of beneficial bacteria, control of harmful bacteria, and facilitation of bowel activities. Probiotics with various functionalities (e.g., body fat and cholesterol reduction, vaginal health, and improvement of skin's immune system) have been investigated as "individual standards of raw materials for health functional foods" provided by MFDS. In the future, various biotechnologies including synthetic biology can be applied to produce customized probiotics to improve human health.

• Mycobiology
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• v.50 no.5
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• pp.345-356
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• 2022

The fungal distribution, diversity, and load were analyzed in the geographically segregated island groundwater systems in Korea. A total of 79 fungal isolates were secured from seven islands and identified based on the internal transcribed spacer (ITS) sequences. They belonged to three phyla (Ascomycota, Basidiomycota, and Chlorophyta), five classes, sixteen orders, twenty-two families, and thirty-one genera. The dominant phylum was Ascomycota (91.1%), with most fungi belonging to the Cladosporium (21.5%), Aspergillus (15.2%), and Stachybotrys (8.9%) genera. Cladosporium showed higher dominance and diversity, being widely distributed throughout the geographically segregated groundwater systems. Based on the diversity indices, the genera richness (4.821) and diversity (2.550) were the highest in the groundwater system of the largest scale. As turbidity (0.064-0.462) increased, the overall fungal count increased and the residual chlorine (0.089-0.308) had low relevance compared with the total count and fungal diversity. Cladosporium showed normal mycelial growth in de-chlorinated sterilized samples. Overall, if turbidity increases under higher fungal diversity, bio-deterioration in groundwater-supplying facilities and public health problems could be intensified, regardless of chlorine treatment. In addition to fungal indicators and analyzing methods, physical hydrostatic treatment is necessary for monitoring and controlling fungal contamination.

• Journal of Information Science Theory and Practice
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• v.10 no.spc
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• pp.96-111
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• 2022

With the rapid development of the Fourth Industrial Revolution and digital transformation, scientific and technological innovation measures are being devised to overcome Korea's low-growth, high-cost structure. Accordingly, by examining the R&D investment evaluation system of R&D PIE (R&D Platform for Investment and Evaluation), which has been promoted by the Korean government in response to the Fourth Industrial Revolution, from the perspective of R&D transformation, this study aims to explore a new path for a sustainable national science and technology innovation system following digital transformation. In particular, from the perspective of R&D PIE, a MLP (Multi-level Perspective), which had been conducted as an abstract theoretical study, was attempted with specific cases and analysis for each of the three layers: niche, landscape, and regime. In conclusion, R&D PIE was intended to elevate the abstract R&D investment evaluation system to a platform that leads innovation in the digital space of the Fourth Industrial Revolution. In addition, it was confirmed that the R&D PIE could be replaced or enhanced as a platform for innovation in response to the Fourth Industrial Revolution, thereby providing an alternative to job creation and an escape from economic crisis.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.475-476
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• 2021

일반적으로 대학생들은 연간 약 50만원이 소요되는 전공 서적 구매비용에 부담감이 있는 것으로 조사된다. 이러한 대학생들을 위해 비교적 저렴한 교재용 전자책 서비스를 전문적으로 제공해 주는 애플리케이션이 없다. 본 논문에서는 대학생들을 위한 전공 및 교양 교재를 대상으로 대여를 포함한 전자책 제공 서비스가 가능한 모바일 앱을 설계한다. 제시하는 서비스 앱은 교재용 전자책을 대상으로 온라인 서점, 출판사, 도선관 등으로부터 전자책 정보를 수집하여 사용자에게 제공하고, 이를 대상으로 대여 또는 구매가 가능한 서비스를 제공한다. 제공되는 전자책 파일은 불법 배포를 방지하기 위해 DRM 방식을 사용하여 전용 뷰어를 통해 제공되어지도록 설계한다. 개발되는 앱을 통해서 대학생이 겪는 문제 중 하나인 교재비용 경감과 더불어, 종이책 생산을 줄임으로써 지구환경 보존에 기여할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.151-154
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• 2021

Rust is a promising system programming language that made its debut in 2010. It was developed to address the security problems in C/C++. It features a property called ownership, on which it relies to mitigate memory attacks. For this and its many other features, the language has consistently gained popularity and many companies have begun to seriously consider it for production uses. However, Rust also supports safe and unsafe regions under which the foreign function interface (FFI), used to port to other languages, falls. In the unsafety region, Rust surrenders most of its safety features, allowing programmers to perform operations without check. In this study, we analyze the security issues that arise due to Rust's safety/unsafety property, especially those introduced by Rust FFI.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.145-150
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• 2022

In this study, we investigated the influence of galangin on vascular contractibility and to determine the mechanism underlying the relaxation. Isometric contractions of denuded aortic muscles were recorded and combined with western blot analysis which was performed to measure the phosphorylation of phosphorylation-dependent inhibitory protein of myosin phosphatase (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) and to evaluate the effect of galangin on the RhoA/ROCK/CPI-17 pathway. Galangin significantly inhibited phorbol ester-, fluoride- and thromboxane mimetic-induced vasoconstrictions regardless of endothelial nitric oxide synthesis, suggesting its direct effect on vascular smooth muscle. Galangin significantly inhibited the fluoride-dependent increase in pMYPT1 and pCPI-17 levels and phorbol 12,13-dibutyrate-dependent increase in pERK1/2 level, suggesting repression of ROCK and MEK activity and subsequent phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that galangin-induced relaxation involves myosin phosphatase reactivation and calcium desensitization, which appears to be mediated by CPI-17 dephosphorylation via not PKC but ROCK inactivation.

• Korean Journal of Pharmacognosy
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• v.54 no.2
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• pp.53-60
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• 2023

Athyrium acutipinnulum, called as Ulleungdo ladyfern (Seom-go-sa-ri), is a native plant of South Korea. A. acutipinnulum has been consumed as foods and also traditionally used for the treatment of epilepsy, gonorrhea and nerve disorder. The methanolic extract and EtOAc soluble fraction of A. acutipinnulum showed the antioxidant activity. Fractionation using various chromatographic techniques resulted in the isolation of 13 compounds. The structures were elucidated on the basis of spectroscopic methods as seven phenolic compounds, methyl 2-hydroxy-3-phenylpropanoate (1), protocatechualdehyde (2), caffeic acid (3), trans-p-coumaric acid (4), (-)-4-E-caffeoyl-L-threonic acid (5), 5-O-caffeoyl shikimic acid (6) and 5-O-caffeoyl quinic acid (7), three flavonoids, quercetin 3-O-β-glucoside (8), naringenin-7-O-β-glucoside (9) and sutchenoside A (10), two steroids, ponasterone A (11) and ecdysone (12) and a coumarin, esculetin (13). Among them, compounds 5 and 10 were first reported from Athyrium spp and compounds 2, 5, 6 and 7 showed the antioxidant activity.

• Korea Trade Review
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• v.47 no.1
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• pp.43-61
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• 2022

The purpose of this study is to classify the types of local market knowledge and knowledge sources in reverse knowledge transfer and analyze their relevance. To do so, first, we searched for papers related to the types of local knowledge published in 9 international business academic journals between 1988 and 2020, and derived four types of local market knowledge. Second, in order to classify the source of knowledge, we searched for papers related to network types published in 9 international business academic journals between 1988 and 2020, and divided them into 4 types to derive characteristics. Third, by examining the types of local market knowledge that can be obtained according to network types, a conceptual model was developed between them, and the suitability between local market knowledge and sources of knowledge was revealed through empirical analysis. Through empirical research on what kind of knowledge can be obtained depending on the knowledge sources, various business and academic implications can be provided to many companies.