• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.201-207
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• 2017

Objective of this research was to investigate the influence of pre-plant nitrogen levels in root media on plug seedling growth of radish cv. Soksungbommu. To achieve the research purpose, a root medium, the mixture of perlite, coir dust, and peatmoss (volume percentage of 30:35:35) was formulated and the N levels incorporated during mixing were controlled to 0, 100, 250, 500, 750, 1,000, and $1,500mg{\cdot}L^{-1}$. Then, the seeds were sown into 72-cell plug trays in which the root medium was packed. The measurements of growth and analysis of tissue and root media were conducted 2 and 4 weeks after sowing. Elevation of pre-plant N levels raised EC and turned down pH of root media. But, as seedling grew, the pH rose and EC get lowered in all treatments. The EC as well as $NH_4-N$ and $NO_3-N$ concentrations of root media declined gradually until week 2, but those declined sharply between weeks 2 to 4. The seedling growth 2 weeks after sowing showed quadratic response to pre-plant N levels with the highest growth in $250mg{\cdot}L^{-1}$ treatment and lagging growth in the treatments of lower or higher N levels than $250mg{\cdot}L^{-1}$. The seedling growth 4 weeks after sowing showed also quadratic response with the highest growth in $500mg{\cdot}L^{-1}$ treatment. The tissue N contents were get higher and those of K, Ca, and Mg were get lower as pre-plant N levels were elevated. Above results suggest that lower than $250mg{\cdot}L^{-1}$ in pre-plant N levels is optimistic for growth of plug seedling and avoidance of toxic injury in very young stage.

• Biomedical Science Letters
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• v.3 no.1
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• pp.55-67
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• 1997

Considering many problems caused by the abuse of antibiotics recently, the appearance of antibiotic resistance bacteria is believed to help the cure of patients greatly. From Jan. 1st, 1996 to Dec. 31, 1996, 6135 strains were examined after being asked of and seperated from the clinical pathology departments of general hospitals, and the isolation frequency of identified bacteria and the susceptibility of antibiotics showed the following result. 1. The isolation frequency of strains was Escherichia coli, 1134 strains (18.4%), Pseudomonas aeruginosa, 856 strains (13.9%), coagulase negative Staphylococcus, 793 strains (12.89%), Staphylococcus aureus, 555 strains (9.02%), B. cepacia, 421 strains (6.84%), Enterobacter cloacae, 366 strains (5.95%), Enterobacter faecalis (4.86%), and Klebsiella pneumonia, 220 strains (3.85%). 2. The isolation rate of specimen was urine, 1, 969 strains, wound 1, 104 strains, sputum 701 strains, blood 643 strains, vaginal swab, 342 strains, and eye discharge, 192 strains, 40% of urine strains were E. coli 18％ of wound strains were B. cepacia, 43.7％ of sputum were P. aeruginosa, and in blood strains there were Enterobacter cloacae (25.8%), coagulase negative Staphylococcus (19.6%), and P. aeruginosa (8.7%). 3. The result of antibiotics susceptibility showed that, among gram negative bacilli, P. aeruginoas had resistance in almost all antibiotics except ceftazidme imipenem. But B. cepacia, the same glucose non-fermentation gram negative bacilli had more than 90％ of sensitivity in aztreonam, ceftazidime, ciproflxacin, piperacillin, trimethoprim/sulfa and had resistance in the others. Enterococcus faecalis showed more than 85% of sensitivity in penicillin-G, ampicillin, ciprofloxacin. 4. In the case of specimen antibiotics susceptibility, Enterobacter cloacae was lower in specimen isolated from blood than in those isolated from others and p. aeruginosa was low in specimen isolated from urine, which showed that there was difference in specimen antibiotics susceptibility. The result of this study shows that there happen many resisitances in antibiotics used frequently and some countermeasure is necessary because many bacteria began to show new resistance. Also it is desirable that the choice of antibiotics for infection diagnosis and its cure should be made after the inspection of antibiotics.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.445-456
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• 2002

The purpose of this study were to determine that dexamethasone(Dex) induces differentiation of periodontal ligament(PDL) cells to osteoblastic cells and to investigate expression of matrix Gla protein(MGP), which is one of bone matrix protein. The isolated human PDL cells and gingival fibroblasts were prepared and cultured. The fourth or sixth sub-passage cells were used in this experiments. control group, ascorbic acid and ${\beta}$-glycerophosphate treated group, ascorbic acid, ${\beta}$-glycerophosphate and l00nM Dex treated group, ascorbic acid, ${\beta}$-glycerophosphate, and 5 ${\mu}M$ Dex treated group were made for study. The results were as follows: Cellular morphological change of PDL cells according to time was investigated. At first, the cells exhibited confluent monolayer of spindle or polygonal appearance. The multilayer of cells were seen after 7 days of treatment. After 14 days, the cells lost polarity and were densely packed. The mineralized nodule formation was seen at 21 days in the only Dex treated PDL cell groups. In the gingival fibroblast groups and no Dex treated PDL cell groups, the mineralized nodule was not seen. The mineralized nodule formation of 5 ${\mu}M$ Dex treated group was higher than 100 nM Dex treated group. Alkaline phosphatase(ALP) activity was higher in the Dex treated PDL cell groups of 14 and 21 days than 0 and 7 days. MGP was expressed in the control and all experimental groups and the expression was constant at 0,7,14,21 day. The above results confirm that Dex is affected to differentiation of the PDL cells to osteoblastic or cementoblastic cells and has dose-dependent effect for mineralization. And, MGP is expressed in the PDL cells and is not affected to mineralization of PDL cells.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.219-228
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• 2015

To secure water resources, dams are normally constructed on the upper - middle part of streams, and it generates physical disturbances such as habitat alteration and stream fragmentation. Such construction can restrict movement of aquatic organisms, especially for freshwater fish which is one of top predator in aquatic ecosystem, and cause genetic fragmentation and community change. In this study, to investigate impact of habitat alteration after dam construction on freshwater fish, we monitored fish community changes, and compared fish fauna between dam reservoir and inflows. Additionally, movement characteristics and habitat boundaries of four species were identified by radio telemetry method. The study was conducted in the Gunwi Dam which was constructed in December 2010. Radio telemetry was applied to Pungtungia herzi, Zacco platypus (living lotic and lentic), Silurus asotus (lentic preferred species) and Zacco koreanus (lotic preferred species). The number of species was remarkably decreased (4 family, 10 species) comparing with before the dam construction (7 family, 15 species). Specifically, Coreoleuciscus splendidus, Niwaella multifasciata, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala that inhabit in the lotic environment were not collected in the study area. A total of 8 species were caught in both the dam reservoir and tributaries except 2 species (C. auratus and S. asotus). Sorenson's similarity between the reservoir and its tributaries was high (0.842). All of the radio tagged species stayed in the reservoir except S. asotus which moved to the tributary. These species mainly utilized the shallow littoral zone as a habitat. These results could be useful as a baseline data for efficient management of fishes in lakes.

• Research in Plant Disease
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• v.14 no.3
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• pp.193-200
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• 2008

Blending of eggshell powder into soil as ratio of 1:5, 1:10, 1:15, 1:20, and 1:25 did not affect seed germination rates of several crops including Chinese cabbage. The blending increased pH of distilled water and decreased the viability of resting spores of Plasmodiophora hrassicae. The ratio of non-viable resting spores in eggshell-blending water was over five times higher than in distilled water of the same pH. Chinese cabbage (cv. 'Norangbom') grew more in eggshell-blended soil than in non-treated soil, but other crops grew less. Leaf numbers and above ground growth of Norangbom increased to around 150% and 470%, respectively, in soil blended with $1:20{\sim}1:15$ of eggshell powder. Even though the optimum sizes of eggshell powder were $0.8{\sim}2.0mm$ for growth and smaller than 0.4 mm for inhibition of clubroot disease of Chinese cabbage, there was no statistical difference among the sizes. Soil pH was above 8.0 in all eggshell treatments without any statistical difference among them. Eggshell powder blending to 1:20 showed lower control efficacy, 58.5%, than registered fungicide 'Hokanna (flusulfamide)', 78.5%. However, Chinese cabbage of that blending ratio recorded the highest growth among the treatments. Therefore, blending of eggshell powder into clubroot-contaminated soil may make culture of Chinese cabbage possible by growth-increasing, even though eggshell powder could not inhibit clubroot disease entirely.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.470-478
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• 2017

This study was classified into two groups, normal season group and drought season group, by the cluster analysis using the weather and water quality data from 2012 to 2015, using SPSS 18 version. Also each cluster was classified into three spaces, Gangcheon, Yeoju and Ipoh weir. We performed the multiple regression analysis with each monthly data that concentration of Chl-a was more than algae warming level. 6 groups classified in time and space were analyzed by the correlation analysis between concentration of Chl-a and 3 weather, 11 water quality and discharge factors. We developed Chl-a prediction equations of each group with independent variables of the multiple regression analysis applying to the correlation result. The result of cluster analysis was that the period was divided into two groups, normal group(2012-2013) that total annual precipitation rate was normal and drought group(2014-2015) that total annual precipitation rate was less than 1,000 mm/hr, in time. The months that concentration of Chl-a was more than algae warming level in each group classified by cluster analysis were that the normal group was 3~8 and drought group was 3 and 6~10. The correlation result between Chl-a and weather, water quality and discharge factors for each 6 group was that relationships between Chl-a and water, discharge factors were high in the drought group more than in normal group at all weirs. This was influenced by velocity reduction and increasing HRT according to the intense drought. Weather, water quality and discharge factors that were high correlation with Chl-a were applied to independent variables of Chl-a prediction equations and each equations were developed. Among them, Each adjusted R square of Prediction equations for Chl-a in each group at Ipoh weir where is located in Namhan river downstream and is directly connected to Paldang dam were normal group = 0.920 and drought group = 0.818. It's showed the high linear.

• Science of Emotion and Sensibility
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• v.9 no.2
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• pp.111-118
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• 2006

The purpose of the study is to examine the effects of the positive menial stress, eustress, on autonomic nervous system(ANS) and human health. For this, we analyzed heart rate variability(HRV) parameters, the most promising markers of ANS function to assess the changes of emotional and physiological states of human body. We measured HRV Signal of World Cup group(281 male subjects: $29.8{\pm}5.6yr$., 187 female subjects: $29.0{\pm}5.4yr$.) in two stadiums at least an hour before the game during '2002 FIFA World Cup Korea/Japan' event. We also measured control group's(331 male subjects: $30.9{\pm}4.7 yr$., 344 female subjects: $30.2{\pm}5.2 yr$.) in the health promotion centers in two university hospitals at least a month before and after the world cup event period. Considering physiological differences between males and females, the data analysis was applied to 'male group' and 'female group' separately. As a result, some tendency was observed that is different from what we have known as the stress reaction. In general, all parameter values except that of mean heart rate tend to decrease under stressed condition. However, under eustressed condition, both heart rate and standard deviation of the Normal to Normal intervals(SDNN) were higher then those of normal condition(p<0.05). Especially, in case of female group, contrary to distressed condition, every frequency-domain powers showed tile higher value(p<0.05, p<0.001). Considering that decrease of HRV indicates the loss of one's health, the increase of SDNN and frequency parameters means that homeostasis control mechanism of ANS is functioning positively. Accordingly, induction of eustress from international sports event may affect positively to the people's health.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.349-353
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• 2013

This study was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Staphylococcus aureus (S. aureus). In this research, efficacy test of fumigant against S. aureus was carried out according to French standard NF T 72-281. S. aureus working culture suspension number (N value), all of the colony numbers on the carriers exposed with the fumigant (n1, n2, and n3), the number of bacterial test suspentions by pour plate method (N1), the number of bacterial test suspentions by filter membrane method (N2) and the mean number of bacteria recovered on the control-carriers (T value) were obtained from the preliminary test. In addition, the reduction number of S. aureus exposed with the fumigant (d value) was calculated using T value, the mean number of bacteria in recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). N value was $4.0{\times}10^8$ CFU/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, T value was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the d value was 6.43 logCFU/mL. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. The results indicated that Fumagari OPP$^{(R)}$ had an effective bactericidal activity against S. aureus, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.131-143
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• 1994

For maintenance of exposed implant in healthy state, it is necessary to treat the surface of implant fixture and provide the surface adjustable to surrounding tissues. Variable techniques have been introduced such as citric acid and air-abrasive system to treat the failed implant. Although when the rough surface of HA coated implant was exposed to oral environment, the surface treatment method with citric acid or air-abrasive system is effective for removal of bacterial endotoxin, it is unsuccessful to prevent plaque deposition due to difficulty in removal of rough surface of HA coated implant. Thus, in this study the method that removes bacterial endotoxin and makes smooch surface without alteration of surface characteristics was studied. HA coated disc manufactured by IMZ Co. Was treated with high speed diamond bur, low speed diamond bur, stone bur, rubber point, jetpolisher. And then its surface state was examined with profilometer and SEM to evaluate the surface smoothness, and its surface component was analyzed with EDX to evaluate wheter the surface characteristics were altered or not. As a result, following results were obtained. When the surface roughness of each implant disc was measured by profilometer, the group I showed a $R_{max}\;2.11{\mu}m$ and the group II, III, IV, V showed a $R_{max2}\;4.17{\mu}m$, $7.28{\mu}m$, $8.61{\mu}m$ and $39.44{\mu}m$ respectively. That is, surface smoothness was highest in the group I and it has been gradually decreased in the group II, III, IV and V. Under the SEM examination, the group I showed relatively smooth surface and the group II showed slightly rougher surface than the group I due to partially remaining HA particles while most HA particle was removed. The group III and IV showed rough topography due to HA particles that was not grinded, and HA coated surface in group V showed very irregular surface with deep groove and prominence. In cross-sectional view, the group I showed uniform surface, and the group III, IV showed rough surface due to remaining HA particles but the thickness of HA coating was remarkably reduced. The group II has similar pattern in group I, and the group V showed about $40{\mu}m$ thickness although it was not constant. By analysis of surface component with EDX, the group II in which the grinding was effective showed a small quantity of calcium and phosphorous and the group III, IV, in which the grinding was incomplete showed calcium and phosphorus peak. In all experimental group, no other than titanium, aluminum, calcium, phosphorus was observed.

• Journal of Aquaculture
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• v.11 no.4
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• pp.573-580
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• 1998

Red spotted grouper, Epinephelus akaara is distributed in the south and west coasts of Korea. The natural stocks of the fish are decreasing sharply year by uear because of reckless overfishing. This research was carried out to understand general informations on maturation, sex composition and sex-reversals of the fish. Annual fishing uields of red spotted grouper in the castal area of Byonsan Peninsular of Kora decreased over 10% from 1992 to 1994. The main fishing season was from May to July with fishing gear of Hand-lines. Gonadosomatic index (GSI) and condition factor were highest on early and late July, respectively, thus main spawning reriod was assumed from late July to early August. The relationship between total length (X) and body weight (Y) for wild adults was represented as a regression, Y=$0.0169X^{2.9705}$, ($r^2$=0.96). Frequency of sex of wild red spotted gouper showed that the number of female below 38cm in total length was more than that of male, and hermaphrodite mainly occurred from 28cm to 32cm in total length the frequency of male and female were almost same. Also hermaphrodite occurred mainly between 25~29cm. Sex reversal ration of the adults reared in a tank for a year with different sexual compositions revealted that the frequency of female reversed from male was more than that of male reversed from female at 1:1 and 1:2 stocking densities of female and male, respectively. Also, about 20% of female was reversed to male when all females were reared. And the size of the fish reversed to male was larger than that of non-reversed female.