• Korean Journal of Microbiology
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• v.48 no.4
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• pp.240-245
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• 2012

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that causes serious infection, particularly in immunocompromised patients. Also, P. aeruginosa possessing carbapenem-resistant metallo-${\beta}$-lactamases (MBL) has been reported with increasing frequency in Korea. We therefore analyzed the level of multidrug-resistant clinical P. aeruginosa isolated from a secondary hospital in Korea in 2010. A total of 92 isolates of P. aeruginosa were collected from Sahmyook Medical Center in 2010. Susceptibility to antimicrobial agents was determined by analysis of the minimum inhibitory concentration test; the inhibitor-potentiated disk diffusion (IPD) test was performed for MBL detection. RAPD-PCR was used for genotyping to rapidly characterize P. aeruginosa strains isolated from clinical patients. The percentages of non-susceptible isolates were as follows: 40.2% to ceftazidime, 58.7% to meropenem, 56.5% to gentamicin, 46.7% to tobramycin, 62.0% to ciprofloxacin and 97.8% to chloramphenicol. The 29 multidrug-resistant strains were screened by the IPD test: of the 21 PCR-positive isolates, 19 were IPM-1 producers and 2 were VIM-2 producers. Among the 19 IMP-1-producing P. aeruginosa isolates, 16 isolates showed similar patterns, and three different banding patterns were observed. The proportion of IMP-1-producing multidrug-resistant P. aeruginosa from clinical isolates steadily increased in this secondary hospital in Korea in 2010. This study provides information about the antimicrobial-resistant patterns and genotype of multidrug-resistant P. aeruginosa isolated from clinical isolates in Korea, 2010.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.5-18
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• 2018

The field trial was performed to evaluate the rice growth and yield in direct seeding cultivation with iron-coated rice seeds. The required time for seed emergence was for 9~11days in the tested direct seeding methods. That was 1~2days earlier in direct seeding with pregerminated seeds than that of direct seeding with iron-coated seeds. The seedling establishment was highest in water seeding with iron-coated seeds but there was not significant difference in terms of statistical analysis. The rice plant height was taller in water seeding with broadcasting method than that of wet hill-seeding methods and in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The tiller number in the rice plant was the highest in machine transplanting at 30days after direct seeding(June 17) and in water seeding with iron-coated seeds at 45days after seeding(DAS) and 60DAS. The tiller number of 75 and 90DAS in the tested rice cultivation methods being with 352~405/m² was not significantly different in terms of statistical analysis. The heading time was not different in rice direct seeding methods but 2 day earlier in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The culm length was the highest in water seeding with iron-coated seeds and the panicle length was the longest in wet hill-seeding with pregerminated seeds. The panicle number per m² was highest in water seeding with iron-coated seeds but not significant difference among the tested rice cultivation methods. The water seeding with iron-coated seeds resulted in the highest spikelet number per m² and the heaviest grain weight of brown rice. Percentage of ripened kernel was the highest in wet hill-seeding with iron-coated seeds. But there were not significant among the tested rice cultivation methods. The milled rice yield in direct seeding methods was 3~21% higher than that in machine transplanting. Water seeding with iron-coated seeds recorded the highest milled rice yield being with 6.86t/ha.The occurrence of sheath blight was high according to machine transplanting>wet hill-seeding>water seeding. Weed occurrence was the highest in water seeding with pregerminated seeds. Weedy rice occurred not in machine transplanting but occured 0.6~0.7% in direct seeding methods with pregerminated seeds and 0.1% in direct seeding with iron-coated seeds.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.516-526
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• 2004

Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.67-76
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• 2000

An experiment was conducted to evaluate the effects of lime, zeolite, and rock phosphate as coating materials and coated seed size on germination, establishment, and early growth of pasture species at the experimental livestock farm, Yonam College of Agriculture in 1997. Germinating energy and germination of coated tall fescue and orchardgrass seeds were lower than those of non-coated seeds. Coated seed of tall fescue with 70% lime and 15% rock phosphate was the best in germination. The germination of small size seed (< ${\varnothing}2$ mm) was better than those of medium (> ${\varnothing}2$ mm and < ${\varnothing}2$ mm) and large size seeds (> ${\varnothing}2$ mm). Germination of coated orchardgrass seed with 55% lime and 30% rock phosphate treatment was higher than that of other coated seeds, and germination of small size seed was higher than those of medium and large size seeds (p<0.05). Germination energy and germination of coated alfalfa and birdsfoot trefoil seeds were lower than those of non-coated seeds. Germination of coated alfalfa seed with 70% lime and 15% rock phosphate, and 45% lime and 55% rock phosphate was higher compared with other coated seeds. Germination of medium size seed was higher than those of small and large size seeds (p<0.05). Among coated birdsfoot trefoil seed, 45% lime and 40% rock phosphate treatment resulted in higher germinating energy and germination than other treatments. There was no significant difference in establishment and early growth of coated tall fescue and orchardgrass seeds. However, tall fescue and orchardgrass coated with 45 % lime and 40% phosphate rock showed higher establishment and early growth. There was also no significant difference in establishment and early growth of coated alfalfa among the treatments. Among coated treatments, establishment and early growth of alfalfa coated with 75% lime and 10% rock phosphate were the highest and showed 46.4% and $72.6\;g/\textrm{m}^2$, respectively. Establishment and early growth of coated birdsfoot trefoil with 55% lime and 30% rock phosphate were the highest among coated birdsfoot trefoil seed (p<0.05) and recorded 46.4% and $44.6\;g/\textrm{m}^2$, respectively. Results of this study indicate that the germination of coated grass and legume seed may be improved by increasing the percentage of rock phosphate and decreasing that of lime. With regard to seed size, the germination of pasture species with small seed size (< ${\varnothing}2$ mm) may be better than medium and large size seeds except alfalfa. Establishment and early growth of grasses can be also improved by increasing the percentage of rock phosphate and decreasing that of lime.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.61-71
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• 1989

The purposes of this study were to investigate the genetic variations by backcrossing in commercial chickens. Backcrossing was carried out successively back to parent stock (P.S). Heritabilities and genetic correlation coefficients were estimated to verify the genetic variations. The data obtained from a breeding programme with commercial chickens (I strain) were collected from 1955 to 1987 at Poultry Breeding Farm, Seoul National University. Data came from a total of 1230 female offspring. The results obtained are summarized as follows： 1. The general performance ($Mean\pmStandard deviation$) of each trait was $663.94\pm87.11$g for 8 weeks body weight, $1579.1\pm155.43$g for 20 weeks body weight, $2124.1\pm215.3$g for 40 weeks body weight, $2269.1\pm242.94$g for 60 weeks body weight, $168.43\pm12.94$ day for a9e at sexual maturity (SM), $214.52\pm29.82$ eggs , for total egg number to 60 weeks of age (TEN), $61.45\pm3.48$ g for average weight (AEW), $13180.7\pm1823.22$ g for total egg mass to 60 weeks of age(TEM). All traits, except 10 weeks body weight and AEW, were significant for the degrees of backcross (p＜0.01). 2. The pooled estimates of heritabilities derived from the sire, dam and combined variance components were 0.47~0.52 for age at sexual maturity (SM), 0.07~0.37 for total egg number (TEN), 0.40~0.54 for average egg weight (AEW), 0.18~0.27 for total egg mass (TEM). High heritability estimates were found for SM and AEW. TEN and TEM were estimated to be a lowly heritable traits. Heritability estimates from dam components were higher than those from sire components. These differences might be due to non-additive genetic effect and maternal effect. 3. The estimates of heritabilities and standard errors derived from combined variance components for different degrees of backcross were $0.47\pm0.11$ (BCO), $0.42\pm0.16$ (BC1), $0.51\pm0.29$ (BC2) for TEN, $0.59\pm0.20$ (BCO), $0.43\pm0.17$ (BC1), $0.35\pm0.18$ (BC2) for AEW, $0.28\pm0.12$(BC0), $0.20\pm0.11$(BC1), $0.18\pm0.14$ (BC2) for TEM. Heritability estimates for AEW and TEM were decreased by backcrossing while those for SM and TEN remained constant. Since backcrossing contributes to increased homozygosity, the genetic variation of the traits (AEW and TEM) decreased . 4. The pooled estimates of genetic correlation coefficients were -0.55 between SM and TEN, 0.20 between SM and AEW, -0.29 between TEN and AEW, 0.82 between TEM and TEN, 0.31 between TEM and AEW, -0.42 between TEM and SM. The genetic correlation between TEM and TEN was higher than that between TEM and AEW, and it was suggested that egg mass was strongly affected by egg number. Also, age at sexual maturity(SM) contributes to egg mass(TEM). 5. When backcrossing was carried out successively, the genetic correlation between TEM and TEN increased (BC0：0.79, BC1：0.82, BC2：0.91) but those between TEM and SM decreased (BC0：-0.54, BC1：-0.36, BC2：-0.09) with successive backcrosses.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.60-77
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• 1973

The non-enzymatic browning phenomenons of red ginseng were studied to identify these compounds which function as the factors for browning. The samples were classified into five divisions; Fresh ginseng, blanched ginseng, sun dried red ginseng, dehydrated red ginseng, and browning accelerated red ginseng respectively, and the various compounds in each of them were analyzed quantitatively and investigated the compounds which were thought to function for browning during the drying and the dehydration processes; the results were as follows. 1. The chemical compositions among five divisions did not show any difference except a) total and reducing sugars, b) total acids, c) water soluble extracts; a) and b) were decreased during the drying process, c) was decreased about 6-7% in red ginseng divisions. 2. Sixteen free amino acids; asp., thr., ser., glu., gly., ala., val., cys., met., ileu., leu., tyr., phe., lys., his., and arg, were identified in each division. Among them the arg, was extremly high. All of the essential amino acids were contained, while generally these amino acids were decreased in drying period and their rates were smaller in dehydrated red ginseng than in sun dried red ginseng. 3. Three kinds of sugars; fructose, glucose and sucrose were identified and other four kinds of unidentified sugars were seperated. The content of sucrose was 80% and all kind of sugars were generally less in red ginseng divisions than in the other two divisions. The decreasing rate of sngars was higher in the sun dried red ginseng than in the dehydrated red ginseng. Especially the decreasing rate of the reducing sugars was high as compared with that of sucrose. 4. Almost all the ascorbic acid was decomposed during the blanching whereas there could'nt be shown any change of the ascorbic acid content during the period of drying. 5. Eleven kinds of volatile acids; acetic acid, propionic acid, acrylic acid, iso-butyric acid, n-butyric acid, isovaleric acid, n-valeric acid, isoheptylic acid, n-heptylic acid, and an unknown volatile acid were identified. They showed a little decrease during the period of blanching perhaps on account of their volatility whereas they were increased in drying period. 6. Six kinds of non-volatile acids; citric acid, malic acid, ${\alpha}-ketoglutaric$ acid, succinic acid, pyruvic acid and glutaric acid were identified. The content of them were decreased during the drying procedures in red ginseng but only that of succinic acid was increased. 7. Three kinds of polyphenols; 3-caffeyl quinic acid, 4-caffeyl quinic acid, 5-caffeyl quinic acid and an unknown polyphenol were identified. The content of them showed considerable decrease during the drying procedures, especially in sun drying. 8. The intensity of the browning in each divisior was as follows; browning accelerated red ginseng> sun dried red ginseng> dehydrated red ginseng. 9. In the process of red ginseng preparation, a. certain relationship could be found between the decreasing rates of amino acids, reducing sugars, polyphenols and the intensity of browning. Therefore the browning phenomenon may be concluded that nonenzymatic browning reactions of the amino-carbonyl reaction and autoxidation of polyphenols are the most important processes, furthermore, as their reactions could be controlled it is thought to be possible to accelerate effectively browning within a relatively short period.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.2
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• pp.125-132
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• 1990

The authors carried out an experiment to investigate the responsive behavior of sea eel, Astroconger myriaster(BREVOORT) to chemical stimuli. The experimental tank was made in doughnut type by using FRP plates. The channel of tank was divided into three concentric troughs by using perforated plastic plates. The inside trough was used as influent part, the outside one as effluent part, and the middle one as the testing trough in which testing fish may be swimmable. The influent part was radially portioned into 12 sections so as to be 30 degrees of central angle. But a basin of any section in testing trough was diverged in the range of 45 degrees of central angle. The the testing trough are radially divided into eight zones. Water is supplied at the rate of 6.3l per minute from the central water tank set as high as 50cm in the center of doughnut, passed across the influent part, testing trough, effluent part and finally discharged by overflow pipes. The chemical substance to stimulate the sea eel was extracted from mackerel, shad and krill which are used as bait for fishing. The chemical substance was injected into any one of 12 hoses which supplies water from central water tank to the influent part at the rate of 2ml per minute. Sea eels used for the experiment were caught by pot in the coast of Chung-mu and accustomed to the tanks for 5 days before applying them to the experiment. The result obtained are as follows: 1. The rate of time length of sea eel's staying in the stimulated zone, as the extracts of mackerel, shad and krill were given to it, was observed as 7.9%, 30.9% and 11.4% respectively. It means that the extract from shad was the most effective of three in attracting sea eel. 2. To compare the effect of freshness of bait fish, the extracts were prepared from shad just killed, form the 24 hour-lapsed one and from the 48 hour-lasped one after killed. The rate of time length of sea eel's staying in the stimulated zone was 30.9%, 17.1% and 11.3% respectively. It means that the freshness is much effective in attracting olfactory fishes like sea eel.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.340-349
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• 2011

This study examined the roles of autolytic enzymes and microorganisms in the ripening process of salted Alaska pollack tripe made with various concentrations of salt i.e, 7.5% and 20% by weight. Salted Alaska pollack tripe treated with antibiotic agents for the inhibition of microbial growth and a control were prepared experimentally, and changes in chemical composition and viable cell counts were investigated, individually, during the ripening process. Just after the preparation of the low salt Alaska pollack tripe made with 7.5% salt, viable bacterial cells occurred at a level of $10^5$ CFU/g. In the control, bacterial counts increased rapidly to $10^7$ CFU/g by the 14th day of ripening. However, in the sample treated with antibiotic agents, counts were decreased to a level of $10^4$ CFU/g by the 3rd day of ripening and increased gradually to $10^6$ CFU/g by the 5th day of ripening, and then the same value was maintained there-after. Just after the preparation of the high salt Alaska pollack tripe made with 20% salt, viable bacterial cells occurred at a level of $10^3$ CFU/g. In both the samples treated with antibiotic agents and the control, bacterial counts decreased rapidly to $10^0$ CFU/g by the 45th day of ripening and increased gradually there-after. The content of amino type nitrogen was 76.3 mg% just after the preparation of the low salt Alaska pollack tripe made with 7.5% salt. Amino type nitrogen content was increased to 283.5 mg% by the 5th day of proper ripening in the control, but it was increased to 208.0 mg% in the sample treated with antibiotic agents. The difference in amino type nitrogen content was 75.5 mg/100 g. The content of amino type nitrogen was 57.2 mg% just after the preparation of the high salt Alaska pollack tripe made with 20% salt. Amino type nitrogen content was increased to 198.3 mg by the 60th day of proper ripening in the control, but it was increased to 162.0 mg% in the sample treated with the antibiotic agents. The difference in amino type nitrogen content was 36.3 mg/100 g. The contents of VBN and TMA-N were 102.1 mg% and 20.5 mg%, respectively, at the 7th day of ripening in the low salt Alaska pollack tripe made with 7.5% salt. The content of VBN was 60.0 mg% and TMA-N was not detected at the 21st day of ripening in the sample treated with antibiotic agents. The control sample was spoiled by the 7th day of ripening but the sample treated with antibiotic agents was not spoiled by the 21st day of ripening. On the other hand, VBN content was 37.2 mg% and TMA-N was not detected at the 90th day of ripening in the high salt Alaska pollack tripe made with 20% salt, and the control sample was not spoiled.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.125-135
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• 2006

The purpose of this study was to measure and compare the level of frictional resistance generated from three currently used ceramic brackets; 1, Crystaline $V^{(R)}$, Tomy International Inc., Tokyo, Japan; 2, $Clarity^{(R)}$, 3M Unitek, Monrovia, CA, USA; 3, $Inspire^{(R)}$, Ormco, Orange, CA, USA; with composite resin brackets, Spirit, Ormco, Orange, CA, USA; and conventional stainless steel brackets, Kosaka, Tomy International Inc., Tokyo, Japan used as controls. In this experiment, the resistance to sliding was studied as a function of four angulations $(0^{\circ},\;5^{\circ},\;10^{\circ}\;and\;15^{\circ})$ using 2 different orthodontic wire alloys: stainless steel (stainless steel, SDS Ormco, Orange, CA, USA), and beta-titanium (TMA, SDS Ormco, Orange, CA, USA). After mounting the 22 mil brackets to the fixture and $.019{\times}.025$ wires ligated with elastic ligatures, the arch wires were slid through the brackets at 5mm/min in the dry state at $34^{\circ}C$. Silica-insert ceramic brackets generated a significantly lower frictional force than did other ceramic brackets, similar to that of stainless steel brackets. Beta-titanium archwires had higher frictional resistance than did stainless steel, and all the brackets showed higher static and kinetic frictional force as the angulation increased. When the angulation exceeded $5^{\circ}$, the active configuration emerged and frictional force quickly increased by 2.5 to 4.5-fold. The order of frictional force of the different wire-bracket couples transposed as the angle increased. The silica-insert ceramic bracket is a valuable alternative to conventional stainless steel brackets for patients with esthetic demands.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.275-282
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• 2017

This study was conducted to investigate the effect of dietary silicate based complex mineral (SCM) on the performance of broiler chicks. Four hundred fifty one day old Cobb ${\times}$ Cobb broiler chicks were fed with commercial diets at 0%, 0.05%, 0.10%, 0.15% and 0.20% SCM with five replicates for five weeks. Weight gain, feed intake and feed conversion were measured weekly, and blood composition, immunity and meat quality were evaluated at the end of experiment. During overall period weight gain in chicks fed diet containing 0.1% SCM was significantly increased as compared with that of control (p<0.05). Feed intake showed no consistency among the treatments. Feed conversion appeared to increase in the chickens fed with SCM addition diets during prestarter period. Albumin, glucose and other blood parameters related to chicken health tended to improve at the level of 0.05% SCM addition treatments. Drip loss in breast meat was significantly decreased in more than 0.05% SCM addition (p<0.05). The expression of IL-2 (Interleukin-2) in blood increased significantly in the chickens fed with SCM of 0.05% or 0.10% level than other treatments (p<0.05). The optimum SCM concentration for commercial dietary supplementation for improving broiler performance and other health-related parameters was 0.10%.