• Journal of Marine Life Science
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• v.3 no.1
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• pp.31-37
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• 2018

We investigated natural habitat of seagrass and created replacement habitat to monitor for restoration of the habitat which is expected to be damaged at Cheonseong harbor in Busan. Depth of water for natural seagrass habitat at Cheonseong harbor was 1.2~3.1 m and the water temperature was 7.4℃, salt concentration was 29.1 psu and pH was 8.05 in January, 2013. The density of seagrass was 167.1±16.4 shoots m^-2, the total length was 48.5±18.1 cm, the height of sheath was 9.1±2.8 cm and the width of leaf was 4.8±1.1 cm, respectively. We transplanted in December 2014 and monitored the habitat during 9 months after transplanted. In the beginning, the density of seagrass was decreased to 8.5 shoots patch^-1 in January and was increased to 19.0 shoots patch^-1 in April. The total height were 73.3±2.9~121.3±6.1 cm, the length of sheath were 9.6±0.6-21.0±1.2 cm, the width of leaf were 5.7±0.1~6.8±0.2 mm. It showed that all values were increased steadily until July and was decreased rapidly in August. Flowering shoot, which was not observed in the beginning of transplanting, started to be spotted in March and was continued to be seen during the monitoring period. We were able to observe seedling of germinated seagrass in seeds in the replacement habitat next year.

• Journal of Life Science
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• v.33 no.7
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• pp.593-604
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• 2023

The ocean accounts for over 70% of the Earth's surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.606-614
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• 2023

This study was conducted to optimize the size of olive flounder Paralichthys olivaceus (OF) as a material of sikhae and to investigate the quality characteristics. The results on the protease activity of OF meat, protein and ash contents of the bone, and yields and hardness of fish bone during fermentation time suggest that the suitable fish weight for sikhae was less than 250 g. The proximate compositions of the OF sikhae fermented under optimum condition (fermentation for 9 days at 15℃), were 73.0% moisture, 12.0% crude protein, 1.3% crude fat and 2.4% ash. The salinity, titration acidity and amino acid nitrogen contents per 100 g sikhae were 1.7 g, 2.46 g, and 311.3 mg, respectively. The lactic acid bacteria concentration in the sikhae were 8.84 log CFU/g, which were higher than those (5.78-6.62 log CFU/g) of 5 kind of commercial flounder sikhae. The functional properties, such as ACE inhibitory activity (69.0%), antioxidative activity (69.3%), α-glucosidase inhibitory activity (22.7%), xanthine oxidase inhibitory activity (88.2%), and nitrite scavenging activity (96.4%) of the sikhae were superior to those of 5 kind of commercial flounder sikhae.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.1
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• pp.51-60
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• 2024

Hi Air Korea and Hanwha ocean are currently developing an Onboard Carbon dioxide Capture System (OCCS) to absorb CO₂ emitted from ship's engine using a sodium hydroxide(NaOH) solution, and converting the resulting salt into a solid form through a chemical reaction with calcium oxide (CaO). The system process involves the following steps; 1)The reaction of CO₂ gas absorption in water, 2)The reaction between carbonic acid (H₂CO₃) and NaOH solution to produce carbonate or bicarbonate, and 3)The reaction between carbonate or bicarbonate and CaO to form calcium carbonate (CaCO₃). And ultimately, the solid material, CaCO₃, is separated and discharged using a separator. The OCCS has been installed on an ship and the test results have confirmed significant reduction effects of CO₂ in the ship's exhaust gas. A portion of the exhaust gas emitted from the engine was transferred to the OCCS using a blower. The flow rate of the transferred gas ranged from 800 to 1384 m³/hr, and the CO₂ concentration in the exhaust gas was 5.1 vol% for VLSFO, 3.7 vol% for LNG and a 12 wt% NaOH solution was used. The results showed a CO₂ capture efficiency of approximately 42.5 to 64.1 vol% and the CO₂ capture rate approximately 48.4 to 52.2kg/hr. Additionally, to assess the impact of the discharged CaCO₃on the marine ecosystem, we conducted "marine ecotoxicity test" and performed Computational Fluid Dynamics (CFD) analysis to evaluate the dispersion and dilution of the discharged effluent.

• Analytical Science and Technology
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• v.37 no.3
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• pp.143-154
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• 2024

In this study, we improved the vitamin C test method and reviewed data on the adjustable range of chromatography conditions for quantification. First, we adjusted the mobile phase conditions such as solvent composition, salt concentration, pH and column temperature and in particular, it was confirmed through an improved test method that the peak derived from the buffer solution could be clearly separated from the target component, vitamin C by adjusting the pH. The retention time of vitamin C was partially changed by adjusting the column diameter, length and particle size but the number of theoretical plates indicated similar values and did not affect the separation and quantitative analysis of the target component. The flow rate according to the column specifications was derived from the equation proposed by the U.S. FDA (Food and Drug administration) and the Korean MFDS (Ministry of Food and Drug Safety), and evaluation of the applicability to vitamin complexes showed high selectivity for vitamin C even with altered stationary phase conditions and flow rates. In conclusion, vitamin C can be optimally separated and detected by changing the chromatographic method conditions and it was confirmed that the mobile and stationary phase conditions of liquid chromatography can be slightly adjusted in case the assay method uses an isocratic elution.

• Applied Biological Chemistry
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• v.11
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• pp.1-27
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• 1969

More than thirty kinds of sea food pickles have been eaten in Korea. Out of these salted yellow tail pickle, salted clam pickle, salted oyster pickle, and salted cuttlefish pickle were employed for the analysis of their components, identification of main fermenting microbes, and determination of enzyme characteristics concerned. Also studied was the effect of enzymic action of microbes, which are concerned with the fermenting of pickles, on the production of flavorous 5'-mononucleotides and amino acids. The results are summarized as follows: 1. Microflora observed in the pickles are: (a) Total count of viable cells after 1-2 months of pickling was found to be $10^7$ and that after 6 months decreased to $10^4$. (b) Microbial occurence in the early stage of pickling was observed to be 10-20% Micrococcus spp., 10-20% Brevibacterium spp., 0-30% Sarcina spp., 20-30% Leuconostoc spp., ca 30% Bacillus spp., 0-10% Pseudomonas spp., 0-10% Flavobacterium spp., and 0-20% yeast. (c) Following the early stage of pickling, mainly halophilic bacteria such as Bacillus subtilis, Leuconostoc mesenteroides, Pediococcus halophilus and Sarcina litoralis, were found to exhibit an effect on the fermentation of pickle and their enzyme activities were in direct concern in fermentation of pickles. (d) Among the bacteria participating in the fermentation, Sarcina litoralis 8-14 and 8-16 strains were in need of high nutritional requirement and the former was grown only in the presence of purine, pyrimidine and cystine and the latter purine, pyrimidine and glutamic acid. 2. Enzyme characteristics studied in relation to the raw materials and the concerned microbes isolated are as follows: (a) A small amount of protease was found in the raw materials and 30-60% decrease in protease activity was demonstrated at 7% salt concentration. (b) Protease activity of halophilic bacteria, Bacillus subtilis 7-6, 11-1, 3-6 and 9-4 strains, in the complete media decreased by 10-30% at the 7% salt concentration and that of Sarcina litoralis 8-14 and 8-16 strains decreased by 10-20%. (c) Proteins in the raw materials were found to be hydrolyzed to yield free amino acids by protease in the fermenting microbes. (d) No accumulation of flavorous 5'-mononucleotides was demonstrated because RNA-depolymerase in the raw materials and the pickles tended to decompose RNA into nucleoside and phosphoric acid. (e) The enzyme produced in Bacillus subtilis 3-6 strain isolated from the salted clam pickles, was ascertained to be 5'-phosphodiesterase because of its ability to decompose RNA and thus accumulating 5'-mononucleotide. (f) It was demonstrated that the activity of phosphodiesterase in Bacillus subtilis 3-6 strain was enhanced by some components in the corn steep liquor and salted clam pickle. The enzyme activity was found to decrease by 10-30% and 40-60% at the salt concentration of 10% and 20%, respectively. 3. Quantitative data for free amino acids in the pickles are as follows: (a) Amounts of acidic amino acids such as glutamic and aspartic acids in salted clam pickle, were observed to be 2-10 times other pickles and it is considered that the abundance in these amino acids may contribute significantly to the specific flavor of this food. (b) Large amounts of basic amino acids such as arginine and histidine were found to occur in salted yellow tail pickle. (c) It is much interesting that in the salted cuttlefish pickle the contents of sulfur-containing amino acids were exceedingly high compared with those of others: cystine was found to be 17-130 times and methionine, 7-19 times. (d) In the salted oyster pickle a high content of some essential amino acids such as lysine, threonine, isoleucine and leucine, was demonstrated and a specific flavor of the pickle was ascribed to the sweet amino acids. Contents of alanine and glycine in the salted oyster pickle were 4 and 3-14 times as much as those of the others respectively. 4. Analytical data for 5'-mononucleotides in the pickles are as follows: (a) 5'-Adenylic acid and 3'-adenylic acid were found in large amounts in the salted yellow tail pickle and 5'-inosinic acid in lesser amount. (b) 5'-Adenylic acid, especially 3'-adenylic acid predominated in amount in the salted oyster pickle over that in the other pickles. (c) The salted cuttlefish pickle was found to contain only 5'-adenylic acid and 3'-adenylic acid. It has become evident from the above fact that clam and the invertebrate lack of adenylic deaminase and contain high content of adenylic acid. Thus, they were demonstrated to be the AMP-type. (d) 5'-Inosinic acid was contained in the salted yellow tail pickle in a significant concentration, and it might be considered to be IMP-type. 5. Comparative data for flavor with regard to the flavorous amino acids and the contents of 5'-mononucleotides are: (a) A specific flavor of salted yellow tail pickle was ascribed to the abundance in glutamic acid and aspartic acid, and to the existence of a small amount of flavorous 5'-inosinic acid. The combined effect of these components was belived to exhibit a synergistic action in producing a specific fiavor to the pickle. (b) A specific flavor of salted clam pickle has been demonstrated to be attributable to the richness in glutamic acid and aspartic acid rather than to that of 5'-mononucleotides.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.110-123
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• 2008

The use of CCA as a wood preservative was recently inhibited due to its environmental pollution and human harmfulness. Instead of CCA, copper azole (CuAz) and alkaline copper quaternary (ACQ) have been used as alternative wood preservatives, but the price of the preservatives is much more expensive than that of CCA. As a substitute for high-priced CuAz and ACQ, environmentally friendly wood preservatives were formulated with okara, which is an organic waste from the production of tofu. Prior to formulating the preservatives, okara was hydrolyzed by three levels of sulfuric acid concentration (1, 2.5 and 5%) to easily penetrate the effective components of the preservatives into wood blocks. Final preservative solutions were formulated with the hydrolyzed okara and metal salts, such as copper sulfate, copper chloride and borax. The preservatives were treated into wood blocks by vacuum-pressure method to measure the treatability of the preservatives, and the treated wood blocks were placed in hot water for three days to measure the leachability of the preservatives. The effective components of the preservatives might be successfully penetrated into wood blocks through the uses of hydrolyzed okara and ammonia water. However, the leached amount of effective components was increased as the concentration of acid used for the hydrolysis of okara increased. The treatability and leachability of the preservatives were not affected by hydrolysis temperature but negatively affected by the addition of borax. Based on the results above, the optimal conditions for formulating okara-based wood preservatives cost-effectively and environmentally might be 1% acid hydrolysis of okara and the use of $CuCl_2$ as a metal salt. In addition, the treatability and leachability of okara-based wood preservatives were superior or no differences comparing with those of CuAz. Therefore, it is concluded that okara-based wood preservatives might have a potential to be used as an environmentally friendly wood preservative.

• The Korean Journal of Pharmacology
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• v.28 no.1
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• pp.81-89
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• 1992

Enuresis is a common voiding disorder among children. There are several therapeutic regimens for the disorder available today; behavioral therapies, psychotherapy, bladder training, sleep interruption, hypnosis and drug therapy. Recently, the efficacy of drug therapy has been acknowledged, particularly of antidepressants. Among the tricyclic antidepressants, imipramine is most frequently employed for the treatment of enuresis. Present study was undertaken to investigate the mechanism of imipramine on the contractility of urinary bladder in relation to the calcium modulation using isolated strips of rat detrusor urinae. 1. The electric fileld stimulation-induced contraction was abolished by imipramine, but partially inhibited by atropine. 2. Imipramine reduced the basal tone and diminished the phasic activity of detrusor muscle concentration-dependently, which was similar to that of diltiazem, a calcium channel blocker. 3. Imipramine suppressed the maximal responses and shifted the concentration-response curves of bethanechol and ATP to right. 4. Imipramine inhibited the calcium-induced recovery of tension in calcium-free physiologic salt solution (PSS) with a mode of action similar to that of diltizaem. 5. A23187, a calcium ionophore recovered the basal tone which had been reduced by imipramine in normal PSS. 6. In calcium-free PSS, A23187 could recover the abolished basal tone with the pretreatment of imipramine, but it exerted a partial recovery with the pretreatment of TMB-8, an inhibitor of intracellular calcium release. Based on these results, it is suggested that the inhibitory action of imipramine on the detrusor muscle exerted in part by blockade of the muscarinic and purinergic receptors, and interference with the influx of extracellular calcium, but not with the release of intracellular stored calcium, is involved in its mechanism of action.

• Journal of the Korean GEO-environmental Society
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• v.16 no.4
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• pp.13-22
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• 2015

The combined impact of Dissolved Organic Matter (DOM) fouling and inorganic ($CaSO_4,Ca_3(PO_4)_2$) scaling on the retention of TNT (2, 4, 6-Trinitrotoluene), RDX (Hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine) and HMX (1, 3, 5, 7-Tetranitro-1, 3, 5, 7-tetrazocane) explosive contaminants by nano-filtration membrane were studied, since organic fouling and salt scaling are the major limitations for membrane filtration. Results reported here indicate that DOM fouling layer with a humic acid does not necessarily lead to an immediate loss of permeate flux but can result in a severe impact on the flux loss when both humic acid and inorganic scaltants were presented simultaneously. The $Ca_3(PO_4)_2$ mixed with humic acid showd most sever flux loss (42%) compared to that of only humic acid presence (8%). It could be a result that the scaling formation of the NF membrane was dominated by cake layer formation of DOM and it was along with pore blocking by the formation of crystals inside the porous active matrix of the NF membrane. In addition, these results indicated that the membrane selectivity of the explosives retention trended correlated with respect to increasing explosives size (listed by MW) based on greater steric interactions and followed the order (MW, g $mol^{-1}$; removal, %): HMX (296.15; 83%) ${\gg}$ RDX (222.12; 49%) ≋ TNT (227.13; 32%). Because the scaling and fouling layer could lead to a additional cake-enhanced concentration polarisation effect, the retention of explosives with the presence of humic acid in the feed solution and inorganic scaling formation on top of an organic fouling layer do not differ substantially retention from that of pure DI feed and NaCl solution.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.152-161
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• 2020

This study determined the removal ofrates for three types of pesticides which were spiked from Chonggak radish during the preparation of chonggak kimchi. When Chonggak radish (leaves) were brined with 10% salt solution and rinsed with water, the removal rate of the three pesticides was 43.8%, 41.9% and 89.8% for diazinon, diniconazole and dimethomorph, respectively. When Chonggak kimchi (leaves) were prepared and fermented for 4 weeks at 4℃, the removal rate of the three pesticides was 82.4%, 77.2% and 98.9% for diazinon, diniconazole and dimethomorph, respectively. Pesticide residues in chonggak radish (roots) were removed by up to 54.7-85.1% of initial concentration through brining and washing. During the fermentation of chonggak kimchi (roots) for 4 weeks at 4℃, the amount of pesticide residues was decreased by 94.0%, 91.8% and 90.0% of initial concentration for diazinon, diniconazole and dimethomorph, respectively. The highest relative removal rate by percentage for the three pesticides asreached 66.5% by salting chonggak radish (leaves). On the other hand, the highest relative removal rate by percentage of pesticides was shown during fermentation, reaching 51.8% and 55.8% for diazinon and diniconazole, respectively, in Chonggak kimchi (roots). As a result of examining the differences ofbetween the three pesticide removal rates rates according to temperature while fermentedduring fermentation of Chonggak kimchi with three pesticides for 4 weeks at 0℃ and 4℃, diazinon pesticide removal was has a high pesticide removal rate of 2.7-10.8% from fermented Chonggak kimchi (roots) at 4℃ compared to 0℃. In the other pesticides, the difference in removal rate of the pesticideresidual pesticides residues by aging temperature was found to be insignificant.