• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.117-124
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• 2009

The purpose of the study was to improve quality of high volume fly ash concrete. The study evaluated on the possibility of early quality improvement of high volume fly ash concrete with early strength gain admixture ('GA' below) developed by the preceding research. The study regarded applying naphthalene admixture ('NA' below) to mix proportion substituting FA 15 % to be plain. In the event of substituting FA 20, 25 and 30 %, the study compared engineering properties of concrete with plain by applying GA. Because of features of fresh concrete, fluidity falls down when GA is applied. Therefore, its use amount shall be increased. Only, in W/B 60 %, it was beneficial since slump loss was reduced about 35~70 mm than plain. The study could see that AE use should be increased proportionally since air content was reduced by coming from AE absorption operation of unburned coal content included in FA according to an increase in the amount of FA use. Reduction effect of bleeding could be anticipated since the amount of bleeding appeared at least in FA 20 %. Because of hardened concrete, time of setting appeared in the same level as plain when GA was applied. Therefore, it is judged that delay of setting can be reduced. In compressive strength, the study could check the same strength development as plain when GA was applied, having nothing to do with W/B and curing temperature. However, it is thought that we shall pay attention to GA use in the event of FA 30 % substitution. Freezing and melting resistance had less early value than plain. However, it is judged that there will be no problem of frost resistance since there is no a large difference between freezing and melting resistance and plain in overall. In accelerated neutralization, it was analyzed that a problem of weakening in neutralization appointed as a demerit when FA was applied in mass in proportion with GA use could be settled to some extent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.105-133
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• 1969

The stability of three major pigments in lavers, namely chlorophylls, carotenoids, and phy-cobilins, during processing and storage was studied. The results of the pigment retention in fresh lavers during storage at low temperatures, of heat lability during heat treatment, and of the pigment loss during storage are summarized as follows: 1. The contents of chlorophyll a, xanthophyll (lutein+zeaxanthin), and carotene ($\alpha-+\beta-carotene$) averaged 1,525, 627, and $409{\mu}g/g$ of dry samples respectively The comparative composition of four carotenoids, lutein, $\beta-carotene$, zeaxanthin, and $\alpha-carotene$, was 35.9, 33.7, 12.2, and $5.8\%$ respectively. 2. In storage of fresh lavers at room ternperature ($20-25^{\circ}C$), 2 to $5^{\circ}C$, and $-15^{\circ}C$, the pigments generally were retained more at 2 to $5^{\circ}C$ than others while carotene only showed more retention at $-15^{\circ}C$ than at 2 to $5^{\circ}C$. Phycocyanin tended to decrease more rapidly than phyco-erythrin at low temperatures. 3. In regard to heat treatment of both dried and wet materials at 40, 60, 80, $100^{\circ}C$ respectively, the pigments were more stable at lower temperatures than at higher temperatures in both cases of materials. Carotenoids were retained more in wet materials than in the sun dried. Xanthophylls showed higher heat stability than carotenes. Phycoerythrin was considered more heat labile than phycocyanin, particularly at higher temperatures. 4. In storage of heat treated lavers for 50 days at room temperature, the retention of pigments appeared differently in accordance with the temperatures of treatment The materials treated at $60^{\circ}C$ showed better relention of pigments than those treated at the other temperatures. Degradation rate of xanthopllylls, carotenes, and phycobilins was decreased in the materials treated at higher temperatures, showing a tendency of great pigment retention even for a long period storage. Chlorophyll il was retained more in sun dried materials whereas xanthophyll and carotene were retained more in the wet. 5. In order to maintain a higher pigment stability during storage, the materials must be treated at $60^{\circ}C$ in a dryer with rapid ventilation until the moisture level reaches about $6.0\%$. In case of treatment at a higher temperature than $60^{\circ}C$, they must be treated for a short period of time to minimize pigment degradation by heat. 6. The lavers treated with the solutions of pH around 7.8 showed a higher retention of chlorophyll a. When treated with the solutions of algal extracts such as agar and alginic acid, uniform layer of laver sheets and better surface gloss of dried layers were obtained.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.388-395
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• 1987

In order to obtain a regulatory mutant strain with high cellulase activity, a newly isolated Penicillium verrculosum, strain F-3 was used as parental strain since it was proved to be an efficient cellulase producer. A number of experiments were conducted to determine the optimum conditions to in-duce mutagenesis and isolate the desirable mutant strains. Out of several restriction compounds tested, 1.5% oxgall was found to be most effective to restrict the colony size by suppressing overgrowth. Derepression of catabolites was employed as a criterion in selecting mutant strains with high cellulase productivity. Production of cellulase by Penicillium venculosum F-3 was suppressed when cultured on the media with more than 1% of glucose or glycerol. It was found that either irradiation with UV light for 19 mins or treatment with nitrosoguanidine at 200$\mu\textrm{g}$/m1 for 60 mins, induced mutagenesis at desired level, when the survival rate of the spore was 0.2% and 48%, respectively. Three mutant strains of F-3, UV-9, UV-10, and NTG-3 that had the highest cellulase productivity were finally selected, based on filter paper degradation rate, size of clearing zone on the screening plate and cellulase activity in the medium containing cellulose powder. When the mutant strains were compared with parental strain F-3, on the KC-M-W medium containing cellulose powder, the filter paper activities of UV-9, UV-10, and NTG-3 were increased by 34%, 55%, and 41%, respectively. However, the assimilation of cellobiose octaacetate by UV-9 or NTG-3 was markedly reduced. When the mutant UV-10 was grown on cellobiose octaacetate medium (CCA-4) in shaking flasks, the cellulase activities of the mutant increased by 20 to 50% compared to the parental strain. Excreation of soluble protein from the mutant also elevated up to 30%. The mutant also constitutively produced both CMCase and $\beta$-glucosidase, though at relatively low level, in the presence of glucose or cellobiose as carbon sources.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.82-87
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• 2016

Enterotoxigenic Bacteroides fragilis (ETBF) produces enterotoxins known to be a virulence factor. Three isotypes of the B. fragilis toxin (BFT) gene have been identified: bft-1, bft-2, and bft-3. We investigated the presence of bft isotypes in clinical B. fragilis isolates and the antimicrobial resistance of BFT-negative and BFT-positive isolates. Overall, 537 B. fragilis isolates were collected from extraintestinal specimens over 8 years (2006~2013) from a university hospital in Korea. Samples were analyzed by multiplex PCR to identify the bft gene isotypes. Additionally, the antimicrobial susceptibility of 107 B. fragilis isolates (74 BFT-negative and 33 BFT-positive) was examined by the CLSI agar dilution method. PCR revealed a total bft gene detection rate of 30%, while 33% and 29% of blood and other extraintestinal isolates contained the gene, respectively. Among ETBF isolates, the most common isotype was bft-1 gene, followed by bft-2 and bft-3 (bft-1 77%, bft-2 14%, bft-3 9%). Resistance rates (%) for BFT-negative and positive isolates differed in response to various antimicrobial agents, with 3%, 5%, 1% and 38% of BFT-negative isolates and 3%, 6%, 3% an 42% of BFT-positive isolates being resistant to piperacillin-tazobactam, cefoxitin, imipenem, and clindamycin, respectively. Interestingly, neither BFT-negative nor positive isolates showed antimicrobial resistance to chloramphenicol and metronidazole. Overall, the proportion of ETBF from blood was similar to that of other extraintestinal sites and the bft-1 gene was the predominant isotype. Higher antimicrobial resistance rates were found in BFT-positive isolates than BFT-negative isolates, but these differences were not statistically significant.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.209-219
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• 1986

This study was designed to investigate the effects of various sources of dietary fats on the blood and liver cholesterol(CHOL) levels in young Single Comb White Leghorn male chicks, In experiment 1, corn oil, palm gil, tallow and fish oil were added individually at a level of 4% to semipurified type diets composed of isolated soyprotein and glucose as major components. The diets were fed ad libitum for a period of 15 days. In experiment 2, various fats such as corn oil, soybean oil, repeseed oil, palm oil, tallow, fish oil and hydrogenated fish oil(HFO) were added individually at a level of 11.4% to practical type diets primarily based on corn and soybean meal. Control diet contained 3% of corn oil. All these diets were formulated to contain equivalent amount of nutrients such as protein, vitamins and minerals on a basis of unit kcal of metabolizable energy. The third Experiment was to compare the effects of different levels of calorie/protein(C/P ratio) of diets on the performances and various biological parameters in the chicks. Control diet was the same as in experiment 2. Another diet was added with 11.14% corn oil(C/P ratio=146) and the other diet with 10% corn oil(C/P ratio=164), The diets in experiment 2 and 3 were fed ad libitum for 26 days. In the first experiment, the chicks fed the diet containing vegetable oils tended to grow faster and show better feed efficiency without significance than those fed diets added with animal fats. However, this tendency was not observed in the experiment 2. Birds consumed the diets added with fish oil appeared to have heavier liver weight and higher liver CHOL than the others(p〈0.05), No significant differences in the levels of blood CHOL and triacylglycerol(TG) were observed among the chicks of various dietary groups(Exp. 1). Weights of liver or heart were significantly heavier in the chicks consumed the diets added with HFO or fish oil, respectively(Exp. 2). However, chicks ingested diet containing fish oil appeared to have significantly lower plasma CHOL. No significant differences were observed in the levels of liver CHOL and plasma TG among the dietary groups. Birds consumed the diet with a wider C/P ratio resulted in higher liver TG levels in experiment 3(p〈0.05). Although no statistical differences were observed among the various dietary groups, chicks fed the diet with a wider C/P ratio tended to show higher levels of plasma CHOL, TG, liver CHOL and total liver lipids compared to those of the control group.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.286-294
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• 2004

Between 1997 and 1998 in Korea, 56 isolates of Escherichia coli were obtained from pig suffering diarrhea. Among those, 38 isolates that showed the hemolytic activity, antimicrobial resistance, and toxin production were studied. Among 38 isolates, thirty-six isolates $(94.7\%)$ were resistant to tetracycline, 27 isolates $(71.0\%)$ were resistant to ampicillin, 26 isolates $(68.4\%)$ were resistant to chloramphenicol, and 21 isolates $(55.2\%)$ were resistant to trimethoprim, while none was resistant to aztreonam, amikacin, and norfloxacin. Among these iso­lates, 21 isolates $(55.3\%)$ were multiple drug resistant to at least four different class antimicrobial agents. Extended spectrum $\beta-lactamase$ producing isolates were not detected in the double disk synergy test. In these hemolytic Escherichia coli, heat-stable enterotoxin $(89.5\%)$ was the most prevalent toxin, followed by vero­toxins $(47.4\%),$ and then heat-labile enterotoxin $(31.6\%).$ Except 8 isolates $(21.0\%)$ which produced ST only, 12 isolates $(31.6\%)$ produced ST and LT, 13 isolates $(34.2\%)$ produced ST, VT, and VTe, and 5 isolates $(13.2\%)$ produced VT and VTe. However, none produced all 4 types of toxin, simultaneously. The predominant serotype could not be determined by the agglutination method. Sixteen isolates $(42.1\%)$ were strongly adhered to T-24 bladder cell and 17 isolates $(44.7\%)$ were to Caco-2 intestinal cell. Especially, 11 strains $(28.9\%)$ were evaluated as strongly adhesive to both T-24 cells and Caco-2 cells. Genes for toxin and the antimicrobial resistance were transferred to clinical isolates of Escherichia coli from human urine by the filter mating method. Results suggest the possibility that antimicrobial resistance and toxin can be transferred from animals to humans by direct con­tact of resistant bacteria as well as gene transfer, although there was no correlation between toxin production, adherent activity, and antimicrobial resistance among hemolytic E. coli isolated from pig suffering diarrhea.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.119-127
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• 2015

To date, detection of microbial populations in dairy products has been performed using culture media, which is a time-consuming and laborious method. The recently developed chromogenic media could be more rapid and specific than classical culture media. However, the newly developed molecular-based technology can detect microbial populations with greater rapidity and sensitivity than the classical method involving culture media and chromogenic media. This molecular-based technology could provide various options for monitoring the characterization of different states of bacteria and cells. Thus, it could help upgrade the processing system of the dairy industry so as to maintain the safety and quality of dairy foods. Among the various newly developed molecular-based technologies, flow cytometry can potentially be used for monitoring microbiological populations in the dairy industry if official international standards are available for this purpose. When omics technology would have biomarker identification, it could be regarded as the rapid and sensitive analytical methods. Methods based on PCR, which has become a basic technique in microbiological research, can be developed and validated as alternative methods for quantification of dairy microorganisms. This review discusses methods for monitoring microbiological populations in dairy foods and the limitations of these studies, as well as the need for further research on such methods in the dairy industry.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.106-111
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• 2012

Purpose: The purpose of this study was to compare the effect of 3 chairside polishing methods and laboratory polishing methods on surface roughness and $C.$ $albicans$ adhesion of polyamide denture base. Materials and methods: Using contact profilometer, the surface of polyamide specimens ($25{\times}15{\times}2mm$) was studied after conventional polishing without finishing and after chiarside polishing with 2 chiarside polishing kits and chairside-pumice polishing following finishing with tungsten carbide bur. To evaluate the adhesion of $C.$ $albicans$, $C.$ $albicans$ suspension was overlayed on the test specimen. And the specimens were incubated for 2 hours. Imprint culture method was achieved and counted the colony on the agar plate. Polished polyamide were evaluated using a scanning electron microscope. The statistics were conducted using one-way ANOVA and in case of difference, Scheffe test and Tamhane's T2 test were used. Results: Surface roughness (Ra) of surfaces polished with 2 chairside polishing kits had higher than conventional polishing and pumice polishing. The highest roughness value was $0.32{\pm}0.10{\mu}m$, and the lowest was $0.02{\pm}0.00{\mu}m$. The adhesion of $C.$ $albicans$ on the specimens polished with chairside polishing group and pumice polishing group were increased than conventional polishing group ($P$<.01). Conclusion: Conventional laboratory polishing was found to produce the smoothest surface and the lowest adhesion of $C.$ $albicans$. Two groups polished with Chairside polishing kits were similar with respect to surface roughness. Surface of the specimen polished with pumice is significantly smoother than 2 chairside polishing groups, but the result of $C.$ $albicans$ adhesion is that group polished with pumice was similar with 2 chairside polishing groups ($P$>.01).

• Food Science and Preservation
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• v.18 no.5
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• pp.692-699
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• 2011

This study was conducted to investigate the physicochemical characteristics of yanggaeng prepared with pear juice and dried pear powder. The proximate composition and total polyphenol content, antioxidant activities, Hunter's color values, texture, sensory properties of pear yanggaeng variants [pear juice (PJ), pear juice and hot-air-dried pear powder (PJH), pear juice and freeze-dried pear powder (PJF) yanggaeng] were examined. The moisture content was highest (27.9%) in the control (C) yanggaeng, but the latter's energy and carbohydrate content were lower than in the pear yanggaeng variants. The differences between the pear yanggaeng variants were not significant.The total polyphenol content was highest in the 20.7 mg/100g PJF yanggaeng. The antioxidant activities of PJF yanggaeng were higher than those of the other pear yanggaeng varients. The Hunter color value results showed that the lightness (L) values were highest in C yanggaeng whereas the redness(a) and yellowness(b) values were highest in PJH yanggaeng. The springiness in texture was lowest in C yanggaeng and not significant in the others. The hardness and chewiness were highest in PJH and PJF yanggaeng, but adhesiveness was lowest therein. The results of the sensory test showed that PJF yanggaeng was the highest in flavor, color, taste, hardness, chewiness, and overal quality. Based on these results, it can be concluded that pear juice and freeze-dried pear powder yanggaeng has excellent physicochemical and antioxidant activities.

• The Korean Journal of Zoology
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• v.16 no.2
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• pp.79-96
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• 1973

In order to elucidate the effects of copper on Corassius carassius, the following were studied: 1) lactate dehydrogenase isozyme patterns by cellulose acetate electrophoresis, 2) LDH activity and copper effect on LDH enzyme system y spectrophotometry, 3) esterase isozyme patterns by agar thin layer electrophoresis, 4) hemoglobin patterns by starch gel electrophoresis, and 5) histological study. 1. There were two bands of LDH isozymes (LDH-3 and LDH-5) in the gill, three bands (LDH-2, LDH-4, and LDH-5) in the liver, and two bands (LDH-3 and LDH-4) in the muscle of the normal fish. The LDH-1 bond was not found in the above three tissues. When the fish were exposed to copper, LDH-3 appeared in the liver, LDH-5 in the muscle, but no new LDH band appeared in the gill. 2. The sepcific activities of the LDH were lowest in the gill and highest in the muscle of the normal fish, and they were gradually decreassed in the gill and highest in the muscle of the normal fish, and they were gradually decreased in the liver and mucle except in the gill from 1-day to 10-day exposure to copper. It indicates that LDH activities in the liver and muscle of the fish were inhibited by copper. 3. Through in vitro experiment, it is clear that the decrease of the LDH activities of the liver and muscle of the fish exposed to copper is mainly caused by the inhibition on the M-LDH in the fish. 4. The numbers of the esterase isozyme bands of the gill, liver, muscle, blood, brain, and kidney of the normal fish were 3, 6, 2, 2, 2, and 2 respectively, and these numbers were the same as those exposed to copper. The relative mobilities of the esterase bands in the gill, liver, blood, and kidney of the exposed group were different from those of the control. 5. There was one hemoglobin band on the anode in the normal fish. It seems that the nobility of hemoglobin band of the fish exposed to copper was slightly faster than that of the normal fish. 6. The normal gill lamellae of the fish consisted of centrally located pillar cells and a number of mucus cells. When the fish were exposed to copper, the epithelial layer was divorced first, disintegrated, and then destroyed completely. 7. The liver of the normal fish had prominent central veins, cords of hepatic cells, and sinusoids. When the fish were exposed to copper, numerous droplets of fat appeared in the cells around the central vein of the liver. It is assumed that the fatty droplets were accumulated by the lesion due to fatty metamorphosis of the liver caused by copper. 8. There was no histological difference between the muscle of the normal fish and that of the fish exposed to copper. 9. In the normal fish, the tubules of the kidney were surrounded by hemopoetic tissues. However, the kidney tissue of the fish exposed to copper received some damage on the proximal tubules. Since the tubule cells were reduced in height, the lumens of the tubules were enlarged. Consequently many proximal tubules exhibited some pink-stained granular casts and various stages of degeneration.