• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.303-311
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• 1986

This work was designed as basic studies on the development of diet for the treatment of obesity. The effect of alginic acid which is the major component of brown algae was investigated by comparing with agar, cellulose, carboxymethylcellulose (CMC), chitin, and lignin as dietary fibers. These dietary fibers ($10\%$) supplemented to basic diet were fed ad libitum to Sprague Dawley rat for 4 weeks, and the inhibitory effects on obesity were evaluated by measuring body weight gain and feed efficiency, the content of glucose and cholesterol in serum, lipase activity in serum, lipid content in liver, adipose tissue around epididymis and ovarium, and Lee index etc. Among the inhibitory effect of these dietary fibers on obesity, lignin was the most effective (p<0.001), followed by Na-alginate (p<0.01) for body weight gain, but lignin was the most effective, followed by CMC, and followed by Na-alginate for feed efficiency (p<0.001). In the inhibitory effects on lipid accumulation in liver and adipose tissue around epididymis and ovarium, lignin and Na-alginate group among these dietary fibers were more effective than others, but there was no significant difference between male and female. The inhibitory effect on obesity evaluated by Lee index was effective in the order of Na-alginate>lignin>CMC>chitin>cellulose (p<0.001). The decreasing effects of lipid content in liver by dietary fibers were found in the order of agar>CMC>cellulose>Na-alginate>chitin>lignin (p<0.001). Glucose content in serum was significantly decreased in cases of CMC, lignin and Na-alginate, whereas a slight difference was found in chitin, but cholesterol content in serum was decreased for all dietary fibers examined except cellulose group. The increasing effect of lipase activity in plasma was found in cases of Na-alginate and chitin, while cellulose, CMC and lignin groups were decreased.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.108-114
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• 2015

Single - and combined effects of a domestic freshwater bivalve Unio douglasiae (7.6~8.6 cm in shell length) and zooplankton Daphnia magna (1~2 mm in body size) were examined to understand whether they inhibit the growth of harmful cyanobacterial bloom (i.e. Microcystis aeruginosa) in a eutrophic lake. The experiments were triplicated with twelve glass aquaria (40 L in volume); three aquaria without mussel and zooplankton, served as a control, three zooplankton aquaria (Z, density=40 indiv. $L^{-1}$), three mussel aquaria (M, density=0.5 indiv. $L^{-1}$), and three mussel plus zooplankton aquarium (ZM, density=40 indiv.Z $L^{-1}$ plus 0.5 indiv.M/L), respectively. Algal growth inhibition (%) calculated as a difference in the concentration of chlorophyll-a (Chl-a) before and after treatment. Chl-a in all aquaria decreased with the time, while a greatest algal inhibition was seen in the ZM aquaria. After 24 hrs of incubation, Chl-a concentration at the mid-depth (ca. 15 cm) in ZM aquaria reduced by 90.8% of the control, while 63.2% and 79.8% in Z and M aquaria, respectively. Interestingly, during the same period, the surface Chl-a was diminished by 51.9% and 65.4% relative to the control in Z and ZM aquaria, while 27.4% of initial concentration decreased in M aquarium, respectively. These results suggest that 1) this domestic freshwater filter-feeding bivalve plays a significant role in the control of cyanobacterial bloom (M. aeruginosa), and 2) the combination with zooplankton and mussel has a synergistic effect to diminish them, compared to the single treatment of zooplankton and mussel.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.402-411
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• 2008

Grazing effects of two freshwater shellfish, Unio douglasiae (UNIO) and Cipangoplaudina chinese malleata (CCM), on the hibernal diatom communities in eutrophic water was examined in a laboratory. Two animals having different feeding types used in the study were collected from Keum River (Boryeong, Korea), acclimatized in the artificial management system in a laboratory over at least one month, and starved in a laboratory for 2 days before the experiment. Experimental waters, which dominated by Synedra ulna-Scenedesmus sp. (ca. 80%), was collected from eutrophic lake, Lake Ilgam (Seoul) in Feb., 19, 2008 at AM 10:00, and used in the study after the filtration with 1 mm Nylon mesh. Feeding experiments were largely divided into three kinds of animal treatments; five densities of UNIO (U0, U1, U2, U3, U4) and CCM (C0, C1, C2, C3, C4), and four combined densities of two shellfish (M0, M1, M2, M3). U0 and C0 were control (no addition of UNIO or CCM), U1 or C1 (each animal density at 0.5 ind. $L^{-1}$), U2 or C2 (1.0 ind. $L^{-1}$), U3 or C3 (1.5 ind. $L^{-1}$), and U4 or C4 (2.0 ind. $L^{-1}$), respectively. Four combined treatments were consisted of M0 (no animals), M1 (U1+C3), M2 (U2+C2), and M3 (U4+C1), respectively. Under the presence of animal, the concentration of Chl-a and algal abundance were clearly decreased with the increase of UNIO density and the treated time, while in combined group a strong decrease of algal density showed with the increase of UNIO density. Total phytoplankton density shifted as the similar patterns to that of Chl-a concentration (r=0.6527, p<0.0001), however, there showed the differences following a species. There were strong decreases of dominant species Synedra ulna, Scenedesmus sp., Ankistrodesmus falcatus in UNIO treatment group, Diatoma vulgare in combined group, while Cryptomonas ovata in high density of CCM increased about 20% in algal density. Grazing rates (GRs) based on the concentration of Chl-a was depend on the kind of shellfish and treatment time; a strong feeding of CCM showed in the initial stage, and four hours later, UNIO and combined group with high UNIO density showed the high GRs. Interestingly, faeces production of shellfish was highest in combined group with high density of CCM, while their size over 60 ${\mu}m$ was much higher in production magnitude than that less 60 ${\mu}m$. Collectively, these results suggest that two domestic shellfish and its combined treatment have a strong potential as an effective biological controller of diatom bloom in cold eutrophic waters.

• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.265-272
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• 2004

Biological characteristics of anodic electrolyzed water were investigated in this study. Linear DNAs which were incubated at $4^\circ{C}$ and $25^\circ{C}$ for 10 mins in the anodic electrolyzed water were degraded about 40% and 50%, respectively. But the DNA was amplified pretty well without any degradation through polymerase chain reaction in the presence of anodic electrolyzed water. Protein degradation hardly occurred in the distilled water during entire incubation time of 7 days, while protein began to be degraded from 4 days in the anodic electrolyzed water. Rice seeds could germinate in the distilled water and anodic electrolyzed water with the same germination ratio, however, the anodic electrolyzed water inhibited the growth of roots and total length of rice seedlings in the soil. Anodic electrolyzed water did not affect the growth curve and cell number of marine alga significantly. The anodic electrolyzed water inhibited the browning of potato by inactivating 50% of polyphenol oxidase activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.212-217
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• 2015

Ships and marine structures have a lot of problems in their high maintenance and operating cost by biofouling. A biofouling occurrs by the adhesion of marine microorganism, algae and bacteria. In this study, the aim is to prevent or to reduce the biofouling phenomena through silver nano-particle coating on artificial light-weight aggregates and geopolymer. The antibacterial activity on them is tested according to ASTM E2149-2013a. The test results showed, it is estimated that silver nano-particles removed 99.99 % of bacteria. Specimens were set up in the sea side of field test area in Korea Institute of Ocean Science and Technology (KIOST) and have been observed for five months. The anti-biofouling effect and difference in weight change rate have been detected two months later after the installation. Because silver nanoparticles inhibit bacterial growth and kill the cells by destroying bacterial membranes, silver nano-particle coating on artificial lightweight aggregates is a well-suited and eco-friendly method for preventing biofouling in the sea up to 5 months.

• Journal of Life Science
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• v.28 no.10
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• pp.1170-1178
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• 2018

The anti-inflammatory effect of brown alga Ecklonia cava is well known, and several phlorotannins have also been reported. In this study, major active components for anti-allergy and anti-inflammation were identified by NMR and MS analysis, and the levels of effectiveness were compared. Six major phlorotannins-phloroglucinol, eckol, eckstolonol, triphlorethol-A, phlorofucofuroeckol A, and dieckol-were isolated from the ethyl acetate fraction of E. cava. In order to analyze the major active substances in E. cava, antioxidant, anti-inflammatory, and anti-allergic effects were evaluated for the six separate substances. Antioxidant capacities of each phlorotannin were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, where phlorofucofuroeckol A and triphlorethol-A had the highest radical scavenging capacity in respective radical scavenging assays. Phlorofucofuroeckol A exhibited the highest inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells among phlorotannins tested. Dieckol inhibited the release of ${\beta}-hexosaminidase$, a marker for the release of histamine in mast cells, in a dose-dependent manner in antigen-stimulated RBL-2H3 mast cells. Additionally, no cytotoxicities were observed at 1 and $2{\mu}g/ml$ in both phlorofucofuroeckol A and dieckol. These results suggest that phlorofucofuroeckol A and dieckol may play a key role in allergic inflammatory reactions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.451-459
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• 2005

The protective effects of ethanol extracts from 5 seaweeds on the mutagenic and cytotoxic damage were evaluated. They were separately extracted using ethanol from dried samples at room temperature, and freeze-dried. The inhibition effects on the mutagenicity in Salmonella assay by Ames test and cancer cell inhibitory effect in HeLa cell, MCF-7 cell and SNU -638 cell by MTT assay were assayed. Seaweed fusiforme, sea tangle and green laver showed strong inhibitory effect against 2-nitrofluorene, sodium azide- or 2-anthramine-induced mutagenicities in Salmonella Typhimurium TA 98 and TA 100 at the level of 2.5 mg ethanol extract per plate. Cancer cell inhibitory effect was shown with all of the seaweed extracts. Green laver, sea mustard, sea tangle and seaweed fusiforme showed strong cytotoxicity against HeLa and MCF-7 cells, with inhibiting by $92\~93\%$ and $89\~92\%$, respectively. These data show that 5 seaweeds tested in this study might be potent functional foods for cancer prevention, and consumption of these seaweeds in adequate amount is recommended.

• ALGAE
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• v.19 no.4
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• pp.349-352
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• 2004

We examined MeOH extracts of the marine plants from Korea for their inhibitory activities on rat lens aldose reductase in vitro. Among the MeOH extracts tested, the extracts of Enteromorpha prolifera, Ecklonia cava, Pelvetia siliquosa and Salicornia herbacea exhibited a rat lens aldose reductase inhibition (IC$_{50}$: 3.04, 8.84, 11.42 and 4.99 $\mu$g-ml$^{-1}$, respectively) in vitro.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.724-726
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• 2005

본 논문에서는 직렬보상된 430 km 길이의 초고압 선로를 EMTP를 이용하여 모델링하고 부하차단시에 직렬 보상량과 차단 부하크기에 따른 발생하는 과전압을 예측계산 하였다. 이러한 결과로부터 과전압발생을 허용범위 이내로 억제할 수 있는 조류한계와 직렬보상량을 산출하였다.

• Journal of Environmental Science International
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• v.11 no.9
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• pp.979-985
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• 2002

Laboratory experiments were conducted to investigate the effect of ceramic-treated water on the inhibition of algal growth. The growth of Scenedesmus quadricauda and Chlorella vulgaris was enhanced by the ceramic-treated water in Allen medium containing high concentration of nutrients, but inhibited in natural water containing low concentration of nutrients. The growth of Oscillatoria tenuis and Microcystis aeruginosa was inhibited in both Allen medium and natural water. When comparing the effects of ceramic-treated water 1 (NC1) and 2 (NC2), the growth of O. tenuis and M. aeruginosa was somewhat enhanced by NC1, whereas inhibited by NC2. Therefore, it is suggested that NC2 can be more effective than NC1 in controlling the algal growth.