• Environmental Mutagens and Carcinogens
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• v.26 no.2
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• pp.53-58
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• 2006

Normally, environmental toxicants are classified as endocrine disruptors if they interfere with regulation of cellular function by endogeneous steroids through inhibition of receptor binding and/or transcriptional activation. So, many studies have been performed about agonist/antagonist of hormone receptor to study mechanisms of endocrine disruptors. If toxicants affect steroid biosynthesis and/or degradation and alter hormone homeostasis, these also are classified as endocrine disruptors. But there are not many studies of the mechanisms of endocrine disruptors on the basis of alteration of steroid biosynthesis and/or degradation. Isolation and culture of Leydig cells from testis is one of methods for the steroidogenesis screening assays to evaluate a substance for altering steroidogenesis. Leydig cells were harvested using the method described by Klinefelter with modifications. Leydig cells were purified by perfusion of testis and incubation ($34^{\circ}C$, 80cycles/minute, 20 minutes) with collagenase (0.25 mg/kg), centrifugal elutriation, percoll gradient centrifugation and BSA multidensity gradient centrifugation. To confirm if this method is one of appropriate tools to evaluate a substance for altering steroidogenesis, ketoconazole, positive control was administered to purified Leydig cells. Ketoconazole ($10^{-8}M$ and above) significantly reduced testosterone production in purified Leydig cells. From above results, we suggest that this method for steroidogenesis screening assay appears to be a appropriate tool to detect suspected compounds for altering steroidogenesis.

• Ocean and Polar Research
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• v.41 no.4
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• pp.311-318
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• 2019

We analyzed the preliminary survey data (2014-2016) of macrobenthic community biomass (n = 112) from the wind farm area located in the southern part of the west coast of Korea and compared this data with data from the entire west coast (n = 369; 2006-2008). Modal classes from frequency distributions were 6 times higher in the latter (5 vs. 32 g/㎡). The mean and median values of the latter were 1.3 and 1.7 times higher (mean, 20.7 vs. 27.8 g/㎡; median, 17.1 vs. 29.5 g/㎡), and the maximum value was 3.4 times higher. Mood's median test showed significant difference at p-value = 0.01. We estimated the biomass-to-depth relationships from each data set by using Akaike Information Criterion and regarded the non-overlap of the 95% confidence intervals as indicating significant difference. The biomass was different from a 10 m depth below, and 3 times higher in the west coast at around 20 m compared with the maximum depth of the wind farm area. A local event of catastrophic sedimentation ranging from 1 to 2 m was observed in the wind farm during winter surveys. This could be a probable source of the lower biomass, but information on biomass seasonality and a natural experimental approach seem to be needed for the conduct of further studies. This study is meaningful in that it provided the background to assess future changes by understanding the lower level of benthic productivity in the area. We expect this study will contribute to the preparation of measures that can remove or mitigate the source of the lower biomass and improve the productivity of fishery resources in the area.

• Journal of Preventive Medicine and Public Health
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• v.38 no.2
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• pp.125-131
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• 2005

Injury has recently become a major world-wide health problem. Injury related deaths occur in many actively working young people and produce major social and economical losses. However health related specialists do not recognize the importance of injury and there have not been many studies related to this problem. This research studied the trends of injury related research in Korea, mortality rate and prevalence rate, socio-economical losses and control in Korea and out of the country, based on literature from Korea and without such as statistical yearly reports on causes of deaths and OECD health reports, as well as WHO web sites. Studies in Korea about injury were very few, with 9 in the 1960's, 5 in the 1980's, 4 in the 1990's and 5 in 2000's. Mortality rate of injury was higher in Korea than in England, USA or Japan, especially in car accidents, suicide and falls. In Korea, the yearly trends in mortality rates were highest in car accidents but those rates are falling, suicide is steadily rising, with highest rate in 2003. Falls is in second rank with no change in rates. In 2003, the ten causes of death in Korea were suicide in 5th rank, transport accidents in 7th rank, and falls in 10th rank. Considering age groups, in the teens, transport accidents were 1st rank, in the 20's and 30's, suicide was 1st rank, and although there were some differences, falls, drowning, assault, fire were in the top 10. Prevalence rates of injury could not be known, but in 2001, according to the National Health and Nutrition Survey, lifelong injury was 10%, and yearly major injury was 1.3%, major injury for two weeks was 0.1%, and minor injury was 10%. In other foreign countries, injury has become to be recognized as a major health related problem, and much programs are being set up to reduce injury related deaths and injuries. WHO is putting much effort in prevention of violence and transport accidents, and in the USA, Canada and Europe, there are injury surveillance systems. Recently, as suicide is increasing rapidly and providing much problems, each country are managing suicide prevention programs. In Korea, Ministry of Construction and Transportation is managing and guiding the policies for prevention of transport accidents. In September of 2004, the Ministry of Health and Welfare has set up a 5 year plan of suicide prevention.

• Journal of Life Science
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• v.14 no.5
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• pp.770-777
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• 2004

It has been previously reported that unacetylated a-tropomyosin(TM) produced in E. coli failed to bind to actin while acetylated muscle TM and Ala-Ser dipeptide fusion TM (AS-TM) bound well to actin. In order to determine the structural requirement of the amino terminus for high actin affinity, a recombinant tropomyosin (Ala-TM) that a single Ala residue was added to the amino terminus of Ala-TM was constructed, overexpressed, and purified from E. coli. Actin affinity of Ala-TM was 2.3$\times$$10^{6}$$M^{-1}$, whereas that of unacetylated TM was considerably lower than 0.1$\times$$10^{-6}$$M^{-1}$ indicating that addition of a single Ala residue to the amino terminus drastically increased, at least twenty times, actin affinity of TM. Ala-TM, however, bound to actin about three times weaker than acetylated TM and AS- TM, implying that the addition of an Ala residue was insufficient for complete restoration of high actin affinity. While Ala-TM, AS-TM, and muscle TM showed inhibition and activation of actomyosin Sl ATPase activity depending on myosin Sl concentration, the degree of inhibition and activation was different from each other. AS-TM exhibited the greatest inhibition of the ATPase at low Sl concentration, whereas the greatest activation of the ATPase was observed with muscle TM. These results, together with previous findings, strongly suggested that local structure of the amino terminus is the crucial functional determinant of TM.

• Journal of Life Science
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• v.22 no.1
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• pp.80-86
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• 2012

This study was conducted to improve quality of takju where natural honey is used to control the ripening fermentation and the amount of sediment derived from takju mash. A koji was prepared using rice starch and Aspergillus awamori var. kawachii. Takju mash was prepared by alcohol fermentation with Saccharomyces cerevisiae and a 3-step addition of steamed rice. The clean part of the mash (CPM) was separated from the sediment at $5^{\circ}C$ and 5% (w/v) of natural honey was added and then ripened for 23 days at 5, 10, or $15^{\circ}C$. Temperature, pH, acidity, and total sugar content showed no significant differences, but a 0.2 percent reduction in alcohol content occurred during storage. However, CPM ripened with honey had a comparatively higher score on sensory evaluation than did immature CPM with added honey added. Takju with 8% alcohol content was prepared by mixing the water from the mixed CPM ripened with honey together with 100, 50, and 25% of the frozen sediment. Several quality characteristics of the takju were checked over 37 days of fermentation at $10^{\circ}C$. The pH was sustained between 4.1 and 4.3, and changes in the number of viable yeast cells, acidity, total sugar amounts, and alcohol content showed similar patterns but differences in scale. Smaller amounts of sediment affected the stability of the takju. Mixing the CPM ripened with natural honey at low temperature moderately reduced the amount of sediment in the mash and resulted in a highly flavorful takju with an extended shelf life.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.684-690
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• 2006

Eriobotrya japonica has been used as a folk medicine for treatment of skin diseases, inflammation, coughing, phlegm, and ulcers in Korea and other Asian countries. In a search for possible bioactive agents from natural sources, we found that the methanolic extracts from various parts of E. japonica showed moderate antioxidative and antimicrobial activities in several in vitro bioassay systems. Additionally, the respective parts of E. japonica were irradiated at 20 kGy to investigate the effects of irradiation. Gamma irradiation of E. japonica extracts removed the deep greenish color without affecting its natural biological activities such as its antioxidative and antimicrobial properties. Based on these findings, the methanolic extracts of this plant source may be not affected by gamma irradiation as its bioactive constituents may be insensitive to this irradiation. Moreover, the methanolic extract of E. japonica may serve as a good natural resource for beneficial functions in food and other related industries.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.11-19
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• 2016

Field observation for oceanic conditions and paralarvae of the common squid, Todarodes pacificus in Korean waters were sampled with the Bongo net (diameter: 60 cm, mesh size: $333{\mu}m$) by using oblique tow method with the oceanographic research vessel (Tamgu 12 and Tamgu 20) around Korean waters (middle of the Yellow Sea, northern part of the East China Sea, East Sea) in 2013 and 2014 was carried out. The observation in the Yellow Sea and the northern part of the East China Sea was done in August, 2013 and in the East Sea it was repeated at seven times from June, 2013 to September, 2014. The paralarvae in August of 2013 was not found in the Yellow Sea and one paralarvae was found in the northern part of the East China Sea. In the East Sea, 39 paralarvae during whole observation period were found, mantle length of paralarvae was from 1.7 to 13.5 mm. Surface water temperature in the Yellow Sea was $30^{\circ}C$, and cold water mass lower than $10^{\circ}C$ was occupied in the deep layer than 30 m. In the northern part of the East China Sea, surface water temperature was $31^{\circ}C$, and higher water temperature above $20^{\circ}C$ was found in deeper than 50 m. In the East Sea, optimum temperature for survival, $15-24^{\circ}C$, was existed shallower than 75 m.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.108-117
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• 2017

Laver, Porphyra, is distinctive for its high content of proteins and polysaccharides such as porphyran and hemicellulose. The chemical properties of the polysaccharides extracted with different extraction methods such as hot water, dilute acid(pH 4.0) or alkali solution(2N NaOH) were examined to investigate the suitable extraction conditions for porphyran and hemicellulose from laver. For porphyran extraction, dilute acid solution was more preferable to hot water and alkali solution because of its higher 3,6-anhydrogalactose content and lower protein content. However, alkali solution was more suitable to extract the hemicellulose because of higher mannose content indicating the extraction of mannan. To decrease contamination of the polysaccharides with protein, the dried lavers were pretreated with enzymes (Protamex, Flavourzyme, Alcalase, Viscozyme) before hot water extraction. All enzyme pretreatments increased the yield of polysaccharides by compared with control (enzyme unpretreated) and Flavourzyme pretreatment was most effective to decrease protein contamination in the polysaccharide. All viscosities of porphyran solutions pretreated by enzymes were lower compared to the control porphyran solution and showed pseudoplastic behavior with yield stress. In case of alkali extraction of residues obtained after enzyme hydrolysis and hot water extraction, protease pretreatment increased the mannose contents in the polysaccharide while the xylose content was increased by Viscozyme pretreatment.

• The Journal of the Petrological Society of Korea
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• v.19 no.3
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• pp.199-208
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• 2010

The Cenozoic alkali basalts are distributed over Korea, both on central part as Bangnyeongdo, Ganseong, Pyeongtaek-Asan and Jogongni and also on southernmost part Jejudo. The ultramafic mantle xenoliths carried by Korean alkali basalts are spinel lherzolites. Garnet lherzolite that is more stable at the deeper level has not been reported so far, indicating that the lithospheric thickness under Korea does not reach deep enough to the stable zone of garnet lherzolite. The crustal evolution history of the Korean peninsula, at least some part of it, seemingly started since the Archean, it normally should have lithospheric thickness greater than 150 km. However, the mantle xenoliths carried by the Cenozoic alkali basalts indicate the maximum depth of origination in the much shallower range of 60-90 km. Such significantly thinner lithospheric thickness of the Korean peninsula than expected is quite similar to the case of North China Craton having lithospheric thickness of ca. 80 km in average, suggesting thinning of the lithospheric mantle in a depth scale of a few tens of kilometers during the past geologic time. The main causal events for such significant thinning of the lithospheric mantle can be continental collisional events of Paleoproterozoic and early Mesozoic similar to the case of North China Craton, which are also supported by Paleoproterozoic igneous and metamorphic events during the 1.9-2.0 Ga occurring all over the Korean peninsula and also early Mesozoic continental collisional event which has been discussed on lively arguments.

• Archives of design research
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• v.17 no.4
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• pp.69-78
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• 2004

This thesis is designed to investigate the relationship of Web Multimedia design. Web sites are needed to approach the lot of ways that increase the user intuitive lay over communicating information nowadays. In the digital era of today, multimedia is composed of such various elements as text, image, sound, animation, video. The method of the thesis is a research questions as this follow. First, the structuring element of the web site type was classified by a form and the contents in the web site. These types in this classified web site are HTML, flash and mixed type. Second, to study this thesis, we made up pose a questionnaire to students in the university as th method of random sampling. The goal of this survey is that user is how to understand about the web multimedia design. Results of analysis may be summarized as follows: 1) It was the image design in the NIKE web site that there would be evaluated the best design effected by flash, and it is finding that the NIDE web site will need more supporting Information, Interactive design through this studies. 2) It was information that there would be evaluated good design effect by text and image in SAMSUNG web site. Based on HTML, SAMSUNG need supporting motion image design by this studies. In conclusion, this thesis suggests that the each web medias should be constructed by the different web design component, according to information, Interactive, image design of web site.