• Fisheries and Aquatic Sciences
• /
• 제20권11호
• /
• pp.28.1-28.17
• /
• 2017

Members of the phylum Echinodermata, commonly known as echinoderms, are exclusively marine invertebrates. Among the Echinodermata, sea cucumber belongs to the family Holothuroidea. The sea cucumber Stichopus (Apostichous) japonicus (Selenka) is an invertebrate animal inhabiting the coastal sea around Korean, Japan, China, and Russia. Sea cucumber has a significant commercial value, because it contains valuable nutrients such as vitamins and minerals. They possess a number of distinctive biologically and pharmacologically important compounds. In particular, the body wall of sea cucumber is a major edible part. It consists of peptide, collagen, gelatin, polysaccharide, and saponin, which possess several biological activities such as anti-cancer, anti-coagulation, anti-oxidation, and anti-osteoclastogenesis. Furthermore, the regenerative capacity of sea cucumber makes it a medically important organism. This review presents the various biological activities and biomedical potential of sea cucumber S. japonicus.

• Ocean and Polar Research
• /
• 제43권4호
• /
• pp.245-253
• /
• 2021

Surirella atomus Hustedt 1955, surirelloid diatom, were obtained from Hampyeong Bay, Mu-an, in the west coast of Korea. We describe the first record of S. atomus in Korea and report its ultrastructure and molecular characteristics for the first time. For molecular analysis, rbcL gene and cob gene were sequenced. This species is very small in size, making it difficult to observe its morphological features under a light microscope. Even with a scanning electron microscope, it has no unique structure in the valve. It is morphologically very simple. This rare species was known as a marine benthic species. However, it appears to be widely distributed in marine, freshwater, and brackish environments according to the literature documenting this species. In terms of phylogeny, S. atomus has been tentatively linked to Petrodictyon gemma, but the phylogenetic placement of S. atomus seems to be still uncertain, in a manner that is similar to S. febigeri. However, morphological observations derived from this study suggest that this species belongs to the genus Surirella.

• Nutrition Research and Practice
• /
• 제11권1호
• /
• pp.3-10
• /
• 2017

BACKGROUND/OBJECTIVES: Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. MATERIALS/METHODS: CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-${\kappa}B$, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer. RESULTS: The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells ($IC_{50}$ value: $95.7{\mu}g/mL$). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-${\alpha}$ and IL-$1{\beta}$, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-${\kappa}B$ p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan. CONCLUSIONS: Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2000년도 Proceeding of International Symposium NAVAIDS 2001
• /
• pp.21-26
• /
• 2000

This paper gives a general introduction on the development of Chinese marine aids to navigation. It also briefs some modern technology applied in this field. In the paper, an outlook is described for the development of our marine navaids in the next five-year period.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2001년도 Proceeding of International Symposium
• /
• pp.2-1-2-6
• /
• 2001

This paper gives a general introduction on the development of Chinese marine aids to navigation. It also briefs some modern technology applied in this field. In the paper, an outlook is described for the development of our marine navaids in the next five-year periods.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제8권3호
• /
• pp.219-227
• /
• 2016

Numerical simulation based on the Reynolds Averaged Naviere-Stokes (RANS) Computational Fluid Dynamics (CFD) method had been carried out with the commercial code ANSYS CFX. The structured grid and SST $k-{\omega}$ turbulence model had been adopted. The impact of non-condensable gas (NCG) on cavitation performance had been introduced into the Schnerr and Sauer cavitation model. The numerical investigation of cavitating flow of marine propeller E779A was carried out with different advance ratios and cavitation numbers to verify the numerical simulation method. Tip clearance effects on the performance of pumpjet propulsor had been investigated. Results showed that the structure and characteristics of the tip leakage vortex and the efficiency of the propulsor dropped more sharply with the increase of the tip clearance size. Furthermore, the numerical simulation of tip clearance cavitation of pumpjet propulsor had been presented with different rotational speed and tip clearance size. The mechanism of tip clearance cavitation causing a further loss of the efficiency had been studied. The influence of rotational speed and tip clearance size on tip clearance cavitation had been investigated.

• 한국수산과학회지
• /
• 제43권5호
• /
• pp.391-399
• /
• 2010

This study was conducted to improve the antioxidative activity of instant noodles containing enzymatic extracts from Ecklonia cava (EEC). EEC has relatively better antioxidative activity than extracts from other indigenous plants in Jeju Island. The EEC (2.5 mg/mL) had 82.5% for the hydroxy radical, 78.4% for the DPPH radical, and 64.9% for the superoxide anion radical scavenging activities, and 65.2% for the cell viability (100 ${\mu}g/mL$). According to the texture of the dough, the DPPH free radical scavenging of uncooked instant noodles, sensory evaluation of cooked instant noodles, and turbidity of the cooking drip, the optimal EEC concentration was 1.8% for the instant noodles. The major amino acids in the instant noodles with EEC were glutamic acid (24.2%), proline (10.2%), valine (10.0%), and isoleucine (12.3%). The zinc and iron in the instant noodles were enhanced by adding 1.5-1.8% EEC. The antioxidant activity of instant noodles with EEC was 75.4% for the hydroxy radical, 74.1% for the DPPH radical, and 51.2 % for the superoxide anion radical scavenging activities.

• 한국해양생명과학회지
• /
• 제3권1호
• /
• pp.9-21
• /
• 2018

This study investigated cytogenetic and hematological and histological characteristics between diploid and spontaneous triploid on Cyprinidae (Crucian carp, Carassius auratus; crucian carp, C. cuvieri and common carp, Cyprinus carpio) in four major rivers of Korea. In our results, DNA contents of triploid Cyprinidae were 50% more than those of diploid Cyprinidae. Also, erythrocyte size of triploid Cyprinidae was 50% larger than those of diploid Cyprinidae. In all sampling rivers, sex ratios of C. auratus were biased to female, and especially, triploid groups of C. auratus were all female groups (p<0.05). In principle, sex ratios of C. cuvieri and common carp were equivalent between male and female.

• 한국해양공학회지
• /
• 제36권6호
• /
• pp.364-379
• /
• 2022

Coastal communities have been vulnerable to extreme coastal flooding induced by hurricanes and tsunamis. Many studies solely focused on the overland flow hydrodynamic and loading mechanisms on individual inland structures or buildings. Only a few studies have investigated the effects of flooding mitigation measures to protect the coastal communities represented through a complex series of building arrays. This study numerically examined the performance of flood-mitigation measures from tsunami-like wave-induced overland flows. A computational fluid dynamic model was utilized to investigate the performance of mitigation structures such as submerged breakwaters and seawalls in reducing resultant forces on a series of building arrays. This study considered the effects of incident wave heights and four geometrically structural factors: the freeboard, crest width of submerged breakwaters, and the height and location of seawalls. The results showed that prevention structures reduced inundation flow depths, velocities, and maximum forces in the inland environment. The results also indicated that increasing the seawall height or reducing the freeboard of a submerged breakwater significantly reduces the maximum horizontal forces, especially in the first row of buildings. However, installing a low-lying seawall closer to the building rows amplifies the maximum forces compared to the original seawall at the shoreline.

• 수산해양기술연구
• /
• 제55권4호
• /
• pp.327-334
• /
• 2019

The feeding habits of the bighead croaker Collichthys niveatus were studied using 745 specimens collected by bottom trawl net in the West Sea, Korea, in April and October of 2016, 2017 and 2018. The size of C. niveatus ranged from 4.8 to 16.0 cm in total length. The stomach contents analysis indicated that C. niveatus consumed mainly euphausiids and copepods. C. niveatus consumed mainly euphausiids and copepods in all size classes. The dietary compositions of C. niveatus was not significantly different among size classes (One-way ANOVA, P > 0.05). As body size of C. niveatus increased, the mean weight of prey per stomach (mW/ST) tended to increase.