• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.550-553
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• 2000

Optimum temperature for paralytic shellfish poison (PSP) detoxofication of Enterobacter sp. CW-6 isolated from sea water and changes of contents and ingredients composition of PSP during bacterial detoxification process were investigated. Enterobacter sp. CW-6 detoxicated $61.5{\~}67.7{\%}\;and\;87.4{\~}96.8{\%}$ of initial PSP toxicity ($25.0{\~}28.5\;nmole/g$) after $5{\~}12$ days at 30 and $35^{\circ}C$, identified as optimal growth temperature, respectively. The detoxification rate of Enterobacter sp. CW-6 for crude PSP with initial concentration of 38.2 nmole/g after 8 and 12 days at $30^{\circ}C$ in the Marine broth was 88.4 and $92.7{\%}$, respectively. During bacterial detoxification process using crude toxin solution, temporary increasement of STX group was detected and identified that was derived from GTX2, 3 group. The detoxification rate of Enterobaoter sp. CW-6 on purified GTX1 and 4 with initial concentration 47 nmole/g and 37 nmole/g were more than $90{\%}$ after 12 days in the marine broth at $30^{\circ}C$. Enterobacter sp. CW-6 also showed a detoxification activity on purified GTX2 and 3, and the detoxification rate for the initial concentration 25.6 nmole/g after 12 days was $66.4{\%}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.49-54
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• 2006

Cultured cells of the toxic Alexandrium tamarense were fed to four mussel species, Mytilus coruscus, M. edulis, M. galloprovincialis and Septifer vulgatus, to examine the interspecies and interlocality differences in the ability to accumulate paralytic shellfish poisoning (PSP) toxins. Toxin content of A. tamarense cells varied during culture period. In contrast, toxin composition in the cell (C1,2, GTX1-4 and neoSTX) was constantly stable. In feeding experiment, the four mussel species collected from Geoje intoxicated after uptake of A. tamarense. Toxin content ($average{\pm}SD\;{\mu}g$ STXeq/100 g) of M. coruscus, M. edulis, M. galloprovincialis and Septifer vulgatus were $1,660{\pm}79,\;3,914{\pm}2,242,\;5,626{\pm}1,620\;and\;958{\pm}163$, respectively. Toxin profiles included C1,2, GTX1,4 and neoSTX as the major components, and dcGTX2,3, GTX2,3, neoSTX and STX as the minor ones. Toxin accumulation of three mussel species collected from Pohang, Geoje and Anmyon-do showed interspecies and interlocality differences. Toxin content ($average{\pm}SD\;{\mu}g$ STXeq/100 g) were $91{\pm}4,\;151{\pm}14,\;39{\pm}3$ in M coruscus, $189{\pm}1,\;231{\pm}11,\;206{\pm}15$ in M edu/is and $214{\pm}28,\;326{\pm}30,\;291{\pm}26$ in M. galloprovincialis in order of Anmyon-do, Geoje and Pohang.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.137-142
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• 2013

To understand critical aspects of paralytic shellfish poisoning (PSP) in a chief area of bivalve production in Korea, seasonal variation in PSP toxins in bivalves collected from Jinhae Bay, Korea in 2009 was surveyed by the pre-column high-performance liquid chromatography oxidation method. We also confirmed the profiles of major bivalves such as oysters Crassostrea gigas and mussels Mytilus galloprovincialis in Jinhae Bay. PSP toxins in the bivalves showed remarkable seasonal variation. PSP toxin levels were detected from April to May in 2009, and the highest total toxin levels at all stations were recorded in May. The major toxins in bivalves were gonyautoxin [GTX] 1&4 and C 1&2; in oysters GTX 2&3 were also detected as major components. GTX 1&4, which showed the highest PSP toxin levels at each station, accounted for the highest proportions of toxin components in mussels and oysters (64.5-71.3% and 41.4-42.4%, respectively). It was also confirmed that the highest toxicity (in ${\mu}g$ saxitoxin [STX] eq/g) was derived from GTX 1&4. The highest total toxicity (in ${\mu}g$ STX eq/g) was approximately 2-8-fold higher in mussels than in oysters collected from the same station. PSP toxin levels in bivalves differed significantly according to the sample collection station. However, the profiles of toxins in the bivalves did not show significant differences during the survey period according to sample collection station. This study shows that PSP toxin levels in some samples from Jinhae Bay were above the regulatory limit in Korea during a specific period in spring.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.212-218
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• 2006

Changes of paralytic shellfish poison (PSP) contents, toxicity and toxin composition with pH and storing periods at different temperature in toxic blue mussel, Mytilus edulis, were tested by using fluorometric HPLC method. Toxicity at pH 3 was the highest as 14.1 MU/g $(100\%)$ and showed 12.9 MU/g $(92.1\%)$ at pH 5, 9.0 MU/g $(63.8\%)$ at pH 7, 3.6 MU/g $(25.5\%)$ at pH 9 and 0.8 MU/g $(5.7\%)$ at pH 10 which suggested PSP was unstable at alkaline conditions. The decrease in toxicity during storage days was depend on pH and temperature. The toxicity markedly decreased until during the first S day storage $(19.9\~65.3\%)$ at all pH (3, 5, 7, 9) and temperature (30, 5, $-20^{\circ}C$), but, slightly decreased after then till to 30 days. C group toxin (C1 and C2) was the major components and other toxins such as GTX 1,2,3,4, STX and dcSTX were detected. Among the 8 toxins, GTX1,4, dcSTX and STX were firstly decreased according to the decreasing the toxicity at all processing conditions. The toxicity in blue mussel (14.1 MU/g) were able to remove by heating over 10 minutes at pH higher than 7.

• Journal of Food Hygiene and Safety
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• v.15 no.4
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• pp.287-292
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• 2000

The toxicity and toxin composition between blue mussel, Mytilus edulis and oyster, Crassostrea gigas collected at Woepori in Ko je island in South Coast of Korea in 1996 and 1997 were compared. The highest toxicity score was about 10 times higher in blue mussel than oyster (blue mussel, 8,670 $\mu\textrm{g}$; oyster, 860$\mu\textrm{g}$ in 1996, blue mussel, 5,657 $\mu\textrm{g}$/100g in 1997). The blue mussel also retained its toxicity for slightly longer period than oyster. In the both shellfish, PSP was composed almost exclusively of C toxicity (Cl and C2, 20~65%) and gonyautoxins (GTXl, 2, 3, and 4, 38~78%). In the early period of toxin accumulation, the ratio of 11$\beta$-epimer toxins (C2, GTX4) whose amount was 25~56 mole% (5th March to 12th April in 1996) and 25~80 mole% (18th March to 7th April in 1997), were higher than that of 11-epimer toxins (Cl, GTX2) whose amount was 41~57 mol%(27th May to 3rd June in 1996) and 25~56 mole% (29th April to 12th May in 1997), became higher than that of 11-epimer toxins. The toxin compositions in the both samples changed on a daily basis, presumably owing to metabolism of the toxin in the bivalves.

• Journal of The Korean Society of Clinical Toxicology
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• v.10 no.1
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• pp.37-40
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• 2012

Honey is produced by bees from nectar collected from nearby flowers. Sometimes, honey produced from the Rhododendron species is contaminated by Grayanotoxin (GTX) in Nepal and other countries. There have been reports of GTX intoxication, also known as 'mad honey disease', from honey produced in countries other than Korea. The importation of wild honey has been prohibited by the Korean Food and Drug Administration since 2005, yet it is still distributed within Korea by the occasional tourist. We report a case of GTX intoxication from contaminated honey which included the symptoms of nausea, vomiting, general weakness, dizziness, blurred vision, hypotension and sinus bradycardia. By means of infusion with normal saline and atropine sulfate, the patient's condition fully recovered within 8 hours of hospital admission, and she was discharged without any complications.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.159-164
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• 2013

The mouse bioassay and high performance liquid chromatography (HPLC) post-column oxidation method are different methods of quantifying paralytic shellfish poisoning toxins. In this study, we compared their ability to accurately quantify the toxicity levels in two types of field sample (oysters and mussels) with different toxin profiles for routine regulatory monitoring. A total of 72 samples were analyzed by both methods, 44 of which gave negative results, with readings under the limit of detection of the mouse bioassay ($40{\mu}g/100g$ saxitoxin [STX] eq). In 14 oysters, the major toxin components were gonyautoxin (GTX) 1, -2, -3, -4, -5, decarbamoylgonyautoxin-2 (dcGTX2), and decarbamoylsaxitoxin (dcSTX), while 14 mussels tested positive for dcSTX, GTX2, -3, -4, -5, dcGTX2, neosaxitoxin (NEO), STX, and dcSTX. When the results obtained by both methods were compared in two matrices, a better correlation ($r^2=0.9478$) was obtained for mussels than for oysters ($r^2=0.8244$). Additional studies are therefore needed in oysters to investigate the differences in the results obtained by both methods. Importantly, some samples with toxin levels around the legal limit gave inconsistent results using HPLC-based techniques, which could have a strong economic impact due to enforced harvest area closure. It should therefore be determined if all paralytic shellfish poisoning toxins can be quantified accurately by HPLC, and if the uncertainties of the method lead to doubts regarding regulatory limits.

• Explosives and Blasting
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• v.39 no.3
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• pp.24-34
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• 2021

Electronic detonators are widely used in various construction sites due to accurate delay time. Including the cases with exceeded noise and vibration from site using electric/non-electric detonator, electronic detonators are used to improve blast fragmentation or to reduce the cost of secondary partial blasting. Furthermore, the number of cases using electronic detonators are increased for reduction of the cost and construction period by maximizing operations efficiency. This case study is about applying electronic detonators on large section station, tunnel construction site which is the part of urban area GTX A project. Although it was initially planned to utilize non-electric detonators, damage was inflicted on safety-thing. We have considered blasting method using electronic detonators as solution of this problem. By applying electronic detonators, we not only satisfied environmental regulations but also prevented nearby safety-thing from getting damaged. In addition, we were able to shorten the construction period than the initial plan by conducting single simultaneous blasting on large section station, in order to ensure safe and efficient construction.

• Database Research
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• v.34 no.3
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• pp.28-44
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• 2018

In a database system, the most expensive operation among relational operations is a join operation. Generally, CPU-based join operations uses parallel processing with either 1 core or 16 cores at most, which does not significantly improve the function. On the other hand, GPGPU(General-Purpose computing on Graphics Processing Units) allows parallel processing through thousands of processing units, greatly reducing the time required to perform join operations. Parallelization of the operation using GPGPU uses NVIDIA's CUDA SDK. In this paper, we implement parallelization of the join operation using GPGPU and compare the performances. The used join operations are Nested Loop Join (NLJ), Sort Merge Join (SMJ) and Hash Join (HJ), and GPGPU equipment uses TITAN Xp, GTX 1080 Ti and GTX 1080. We measure and compare the performance of join operations based on CPU and GPGPU. We compare this performance with the performance of the previous study on the join operation based on GPGPU. The results of experiment show that the performance based on GPGPU is 6~328 times faster than the one based on CPU.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.144-150
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• 1992

Paralytic shellfish toxins in mussels Mytilus edulis and dinoflagellate Alexandrium tamarene from Jinhae Bay, south coast of Korea were investigated. The mussels collected in March-April, 1989 showed toxicities of 7.5 MU/g of whole meat(31-88 MU/g of the digestive gland) , and those collected in 1990 showed toxicity level of 1.9-9.9 MU/g of whole meat by the standard mouse bioassay. Analysis of toxins by high performance liquid chromatography revealed the presence of gonyautoxin 1-4$(48-76\%)$ gonyautoxin 8 and epi-gonyautoxin $8(C1-C2,\;14-39\%)$, saxitoxin$(1-10\%)$, neosaxitoxin$(l-7\%)$ and trace amount of decarbamoylgonyautoxin 2 and 3(dcGTX2, dcGTX3) in the mussels of 1989. While, Mussels collected in 1990 contained a significantly larger proportion of neosaxitoxin $(44-50\%)$ than did those of 1989. A. tamarense isolated in April 1989 produced the same toxins in culture with slightly higher proportion of Cl, C2, dcGTX2 and dcGTX3 than in the mussels. The difference was within a range of toxin change during accumulation by shellfish and during sample preparation for analysis. It was thus concluded that the dinoflagellate was the cause of toxins in the mussels.