• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.30-38
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• 2016

The objective of this study was to investigate the useful components and potential antioxidant activities of 30 marine algae, collected from Jeju Island in Korea. The contents of bioacitve substance of extracts from marine algae, such total polyphenol and carbohydrate, were determined. The extract of Distromium decumbens had the highest amount of total polyphenol content (21.27%), and that of Gracilaria incurvata Okamura had the highest amount of total carbohydrate content (10.18%). The antioxidant activities of extracts obtained from algae were tested through the evaluation of DPPH radical and hydroxyl radical scavenging activity. The extracts of Distromium decumbens, Sargassum hemiphyllum (Turner) C.Agardh, Sargassum serratifolium (C. Agardh) C. Agardh and Acrosorium yendoi Yamada were found to have more than 80% DPPH radical scavenging activity and that of Dictyota okamurae (Dawson) $H{\ddot{o}}tning$, Schnetter, et Prud'homme van Reine, Myagropsis myagroides (Martens ex Turner) Fensholt, Sargassum serratifolium (C. Agardh) C. Agardh and Cladophora wrightiana Harvey showed more than 50% hydroxyl radical scavenging activity. These results suggest that algae collected from Jeju Island would be good raw materials for antioxidant.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.248-257
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• 2016

The international collaboration on marine biodiversity increases in the proportion of the world's scientific papers produced with more than one international author, 2006-2010. The number of scientific papers from 2006 to 2010 describing "marine new species (or spec. nov., n. sp.)" published 401 (international ranking : $13^{th}$) by S. Korea, 824 ($7^{th}$) by China, 1,249($5^{th}$) by Japan, 1,282($3^{rd}$) by Austrailia, and 3,679 ($1^{st}$) by United States. The papers having an international co-authorship account for 52.0% by S. Korea, 79.0% by China, 67.0% by Japan, 81.0% by Australia at the same period. The proportion of national publication output produced in collaboration with other countries differs proportionately between countries. In S. Korea, the overall numbers of international collaboration were not growing significantly. Both in Japan and China, an overall numbers of international collaboration increased well in accordance with the proportion of national output with international collaboration.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.460-462
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• 2018

Flagellimonas eckloniae DOKDO $007^T$, isolated from the rhizosphere of the marine algae Ecklonia kurome collected from Dokdo Island, South Korea, is a marine Flavobacteria belonging to the family Flavobacteriaceae. The genome consists of 4,132,279 bp, 3,527 coding sequences with 37.85% G + C contents and two contigs in one scaffold chromosome. This strain contains a gene encoding proteorhodopsin, as well as other retinal biosynthesis genes, allowing it to utilize sunlight as an energy source. The strain contained only few segment of flagellar constructing gene cluster and this is not consistent with genus name Flagellimonas, therefore, revision of the genus name is required.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.93-103
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• 2023

eDNA, an abbreviation for environmental DNA, means DNA derived from organisms inhabiting in a specific environment. The utilization of eDNA extracted from environmental samples allows for efficient and accurate monitoring of organisms inhabiting the respective environment. Specifically, eDNA obtained from seawater samples can be used to analyze marine biodiversity. After collecting seawater samples and extracting eDNA, metagenome analysis enables the taxonomic and diversity analysis among marine organisms inhabiting the sampled area. This review proposed an overall process of marine biodiversity analysis by utilizing eDNA from seawater. Currently, the application of eDNA for analyzing marine biodiversity in domestic setting is not yet widespread. This review can contribute to establishment of marine eDNA research methods in Korea, providing valuable assistance in standardizing the use of eDNA in marine biodiversity studies.

• Animal Systematics, Evolution and Diversity
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• v.35 no.4
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• pp.200-203
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• 2019

A new marine sponges, Mycale (Carmia) ieoensis n. sp., of the family Mycalidae was collected SCUBA diving in June 2017 from Ieodo Ocean Research Station, Korea. M. (C.) ieoensis n. sp. is encrusting to irregular massive type, yellow in life. This new species is similar to M. nullarosette Hoshino, 1981 in color and growth form but it differs in spicule size and sigma shape. Spicule size of M. (C.) ieoensis n. sp. smaller than that M. nullarosette. Also, M. (C.) ieoensis n. sp. has two size toxa, but M. nullarosette is not. The new species are compared to other Mycale species from the Korean region, and similar species from elsewhere.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.47-51
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• 2016

Three specimens of Abudefduf septemfasciatus were collected firstly from tidal pools on the southern and northern coasts of Jeju Island, Korea in August 2015. This species is characterized by black blotches on the upper origin of the pectoral fin, upper caudal peduncle and a dorsal fin between the second and fourth spines, predorsal scales beyond to above the middle of the eye, 12~13 soft dorsal and anal fin rays, and 20 lateral-line scales. This species is distinguishable from Abudefduf sordidus by soft dorsal and anal fin rays, location of caudal peduncle blotch, and location of the dorsal fin blotch. The newly proposed Korean name is "Il-gop-jul-ja-dom".

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.463-464
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• 2018

Tamlana sp. UJ94 isolated from seawater can degrade alginate. To identify the genomic basis of this activity, the genome was sequenced. The genome was composed of 4,116,543 bp, 3,609 coding sequences, and 35.2 mol% G + C content. A BLASTp search predicted the presence of 9 alginate lyases as well as 6 agarases, 5 amylases, 4 carrageenases, 1 cellulase, 4 pectate lyases, and 7 xylanases, indicating its ability to degrade diverse polysaccharides. The genome of strain UJ94 is a source of polysaccharide-degrading enzymes for bioconversion processes.

• Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.181-187
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• 2023

The control of intestinal α-amylase and α-glucosidase is an effective therapeutic strategy for prevention of post-prandial hyperglycemia associated with diabetes mellitus. The objective of this study was to evaluate the anti-diabetes activities of Korean edible seaweed against α-amylase and α-glucosidase, two carbolytic enzymes involved in serum glucose regulation. Of the 41 species initially screened, Cladophora wrightiana var. minor, Eisenia bicyclis, Ecklonia cava, Ishige foliacea, and Ishige okamurae exhibited the strongest inhibitory activities from brown seaweeds. Asparagopsis taxiformis showed the strongest inhibitory effects from red seaweeds. The results of this study suggest that the crude brown seaweed extracts (C. wrightiana var. minor, E. bicyclis, E. cava, I. foliacea, and I. okamurae) and crude red seaweed extracts (A. taxiformis) may have beneficial effects suppressing the rise in postprandial hyperglycemia through the inhibition of α-amylase and α-glucosidase.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.389-401
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• 2024

In recent decades, numerous instances of blockages have been reported in coastal nuclear power plants globally, leading to serious safety accidents such as power reduction, manual or automatic power loss, or shutdown of nuclear power units. Loss or shortage of cooling water may compromise the reliability of the cooling water system, thus threatening the operational safety of power plants and resulting in revenue reduction. This study provides a comprehensive review of the current state of cooling water system safety in coastal nuclear power plants worldwide and the common challenges they face, as well as the relevant research on cooling water system safety issues. The research overview and progress in investigation methods, outbreak mechanisms, prevention and control measures, and practical cases of blockages were summarized. Despite existing research, there are still many shortcomings regarding the pertinence, comprehensiveness and prospects of related research, and many problems urgently need to be solved. The most fundamental concern involves understanding the list of potential risks of blockages and their spatially distributed effects in surrounding waters. Furthermore, knowledge of the biological cycles and ecological habits of key organisms is essential for implementing risk prevention and control and for building a scientific and effective monitoring system.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.1-9
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• 2002

Copepods play an important role as a primary consumer in the various aquatic ecosystems. Most of marine benthic copepods belong to the Order Harpacticoida, and are known over 3,000 species in the world. Research on the biodiversity of the benthic copepods are important in the development of the new bio-resources, and the genetic resources. The importances and the prospects of biodiversity research on the mavins benthic copepods are discussed.