• Progress in Medical Physics
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• v.27 no.1
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• pp.31-36
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• 2016

The paper discusses radiation dose of dual energy CT on which copper modulation layer, is mounted in order to improve diagnostic performance of the dual energy CT. The radiation dose is estimated using MCNPX and its results are compared with that of the conventional dual energy CT system. CT X-ray spectra of 80 and 120 kVp, which are usually used for thorax, abdominal, head, and neck CT scans, were generated by the SPEC78 code and were used for the source specification 'SDEF' card for MCNPX dose modeling. The copper modulation layer was located 20 cm away from a source covering half of the X-ray window. The radiation dose was measured as changing its thickness from 0.5 to 2.0 mm at intervals of 0.5 mm. Since the MCNPX tally provides only normalized values to a single particle, the dose conversion coefficients of F6 tally for the modulation layer-based dual energy CBCT should be calculated for matching the modeling results into the actual dose. The dose conversion coefficient is $7.2*10^4cGy/output$ that is obtained from dose calibration curve between F6 tally and experimental results in which GAFCHORMIC EBT3 films were exposed by an already known source. Consequently, the dose of the modulation layer-based dual energy cone beam CT is 33~40% less than that of the single energy CT system. On the basis of the results, it is considered that scattered dose produced by the copper modulation layer is very small. It shows that the modulation layer-based dual energy CBCT system can effectively reduce radiation dose, which is the major disadvantage of established dual energy CT.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.451-458
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• 2004

No comprebensive forage quality of annual legumes harvested and cured in spring has been conducted in Korea. Therefore, this experiment was carried out to gain information on the quality of crimson clover (Trifolium incarnatum L.), bolta baIansa clover(Trifolium ba/anansae L.), and persian c1over(Trifolium resupinatum L.) during field curing in spring. The dry matter content of crimson clover at harvest was 24.7%, while bolta balansa and persian clovers had 20.4 and 18.8%, respectively. The moisture content of persian clover was low at the final curing day. But All species took 4 days to reach moisture content under 20%Tedding frequency did not affect moisture content, but consisten trends were also observed during the field curing. Persian clover tended to show a higher leaf-stem ratio than crimson and bolta balansa clovers on dry matter basis. Crude protein of persian clover(19.5%) was higher than other legumes. The percentage of erode protein was decreased from 17.8 to 16.5% as tedding frequency often did. Neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents of persian clover were lower than those of other legumes. From the comparison among tedding frequency, NDF and ADF contents of three times were higher than those of one and two times. Relative feed value(RFV) of persian clover hay was the highest(178) and classified as Grade Prime in forage quality standard. Crimson and bolta balansa clovers in the RFV were also high quality as Grade 1 in forage quality standard. The RFV of legume hay was decreased from 150 to 140 as tedding frequency often did Results of the experiment indicate that hay quality of persian clover was higher than other clovers. And this is due to high leaf and stem content, hollow stem and late maturity stage. Then tedding frequency in annual legume can be teded by two times for quality.

• Analytical Science and Technology
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• v.27 no.3
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• pp.172-180
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• 2014

Fenpyrazamine which is a pyrazole fungicide class for controlling gray mold, sclerotinia rot, and Monilinia in grapevines, stone fruit trees, and vegetables has been registered in republic of Korea in 2013 and the maximum residue limits of fenpyrazamine is set to grape, peach, and mandarin as 5.0, 2.0, and 2.0 mg/kg, respectively. Very reliable and sensitive analytical method for determination of fenpyrazamine residues is required for ensuring the food safety in agricultural products. Fenpyrazamine residues in samples were extracted with acetonitrile, partitioned with dichloromethane, and then purified with silica-SPE cartridge and eluted with hexane and acetone mixture. The purified samples were determined by HPLC-UVD and confirmed with LC-MS and quantified using external standard method. Linear range of fenpyrazamine was between $0.1{\sim}5.0{\mu}g/mL$ with the correlation coefficient (r) 0.999. The average recovery ranged from 71.8 to 102.7% at the spiked level of 0.05, 0.5, and 5.0 mg/kg, while the relative standard deviation was between 0.1 and 7.3%. In addition, limit of detection and limit of quantitation were 0.01 and 0.05 mg/L, respectively. The results revealed that the developed and validated analytical method is possible for fenpyrazamine determination in agricultural product samples and will be used as an official analytical method.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.797-808
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• 2016

The experiment of grape leafroller (Herpetogramma luctuosalis) was carried out at Okcheon area from 2007 to 2009 and 2015. The grape leafroller had been occurred at a campbell early' organic vineyard in Okcheon. It's larva was rolling the leaf of grape and ate the leaf. So the leaf of grape decreased. In organic vineyards, adult grape leafroller' generation rate per year showed the first peak in mid-June, the second peak in early -August and the third in mid-September. The larva showed the first peak in early July and the second peak in late August-early September. The grape leaf roller had three generations per year. And it took $60.9{\pm}1.09days$ from egg to adult in growth chamber (VS-91G09M-1300) which the relative humidity conditions was $60{\pm}10%$, temperature $25{\pm}2^{\circ}C$ and photoperiod 16L:8D (The egg : $12{\pm}0days$, larvae : $22.2{\pm}0.22days$, pupa : $10.6{\pm}0.75days$ and adult : $16.1{\pm}0.45days$). It was conducted to find out the effect of microbial pesticide treatments to control H. luctuosalis. The 4 microbial pesticides (Bacillus thurigiensis) were treated twice on the grape leaves in June 11 and 21 at an organic vineyard in Okcheon. On 10 days after last treatment, the control value of all microbial pesticides were more than 95%. When the dates of spraying to the grape leaves were on May 22, June 12 and July 2 each, the effects of microbial pesticide were 73.9%, 93.5% and 43.6% respectively. As a result, it was effective that Bt was sprayed to grape leaves on mid and late June for controling the H. luctuosalis in organic vineyard. And microbial pesticide Bt was thought to be useful to control the grape leafroller in organic vineyard.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.361-366
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• 2009

The purpose of this study was to assess the genetic variation and establish the relationship amongst breeds and strains using 7 chicken specific microsatellite markers. A total of 317 DNA samples from four Korean native chicken (KNC) strains (KR: Korean Native Red chicken strain, KY: Korean Native Yellow chicken strain, KL: Korean Native Black chicken strain, KO: Ogol chicken strain) and three introduced endemic chicken breeds (LE: Leghorn chicken breed, RI: Rhode Island Red chicken breed, CO: Cornish chicken breed). The size of microsatellite markers was decided using GeneMapper Software (v.4.0) after being analyzed using an ABI 3130 Genetic Analyzer. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The lowest distance (0.074) was observed between the KY and KL breeds and the highest distance (0.779) between the KL and LE breeds. The KNC strains (KR, KY, KL) have comparatively near genetic distance each other. On the other side, each individual was not ramified to different groups and were spread evenly in phylogenetic dendrogram about all the KNC of each strain populations. But the endemic breed populations (LE, RI, CO) were ramified to different groups. The microsatellite polymorphism data were shown to be useful for assessing the genetic relationship between Korean native strains and other foreign breeds.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.169-175
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• 2012

Five kinds of selective media, such as mannitol salt agar (MSA), Baird-Parker agar (BPA), Baird-Parker supplemented with rabbit plasma fibrinogen (BPA+RPF), CHROMagar Staphylococcus aureus (CSA), and Petrifilm Staph Express count system (Petrifilm), were compared to recommend the optimum selective media for isolation of Staphylococcus aureus from agricultural products. Seventy four target and non target bacteria were inoculated on five selective media to analyze sensitivity and specificity. In the recovery test of injured S. aureus cells, S. aureus was exposed to acid (1% lactic acid for 10 min), heat ($60^{\circ}C$ for 90s), and cold ($-20^{\circ}C$ for 1h) conditions. And artificially contaminated agricultural products (iceberg lettuce, green pepper, and cherry tomato) was enumerated on five selective media. The sensitivity of BPA+RPF, CSA, Petrifilm, MSA, and BPA were 100%, 100%, 100%, 90.5%, 90.5%, respectively. In addition, the specificity of BPA+RPF, CSA, MSA, BPA and Petrifilm were 100%, 100%, 84.6%, 75.0%, 67.3%, respectively. However, no difference among five selective media was observed in recovery on injured S. aureus cell and enumeration from agricultural products. This results suggest that BPA+RPF and CSA are the optimum media for detection of S. aureus from agricultural products.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.351-360
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• 2002

The Korean fresh pork loins in vacuum packaged were obtained from three different Korean export companies and investigated for microbiological and sensory properties. The fresh pork loins were stored at 2$^{\circ}C$ for 50 days and analyzed with an interval of 5$\sim$10 days. The results were as follows: The overall numbers of total plate counts and coliform bacteria were higher in swab method than in meat sampling method. The total plate counts in the loins from the company I were maintained low levels ($\prec$10$^5$ cfu/$cm^2$ or $\prec$10$^5$ cfu/g) for entire storage periods(50 days at 2$^{\circ}C$), whereas the loins from the company III had high levels when they were compared to the domestic standard for the allowance limit. The samples from the company III showed that total plate counts were over 106 after about 30 days when determined by meat sampling method and total plate counts were over 106 after 15 days when determined by swab method. The overall numbers of coliform bacteria were also significantly lowest in the samples from the company I, whereas they were highest in the company III. Therefore, all meat companies will have to make an effort to prevent bacterial contamination in each stage such as slaughtering, marketing and consumer in order to ensure the production of safe meat and the extension of shelf-life. For fresh products, scores of intramuscular fat were higher in samples form the companies II and III than those from the company I when visibly evaluated with the standard. There were no significant differences in scores of meat color, drip and fresh meat flavor. However, the samples from the company I had the lowest score of off-flavor and highest score of overall acceptability. For cooked products, there were no significant differences in meat flavor, off-flavor, juiciness and overall acceptability.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.1-9
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• 1977

The effects of extracellular calcium concentrations and several concentration of Aconiti tuber butanol fraction, norepinephrine, ouabain on the force of isometric contraction of isolated atrial preparations obtained from rabbits were determined at $11{\sim}14$ different frequencies of contraction. Qualitatively similar results were obtained in all preparations. In most preparations, rested-state contraction was induced at the range of $120{\sim}400$ seconds stimulation interval. Over the range of intervals from 120 to 10 seconds negative inotropic effect of activation (NIEA) was predominant, so the steady-state contractile force progressively declined. At the intervals of 3 seconds, changes in the cumulated negative and positive isotropic effect of activation (PIEA) practically cancelled each other under steady-state conditions. At the interval from 3 seconds to 0.25 seconds, the additional cumulation of PIEA was greater than that of the NIEA. When the intervals between contractions were shorter than 0.25 seconds, the cumulation of the NIEA was again predominant. The positive inotropic effect of cardiac glycoside resulted at least in large part from increase in the rested-state contraction. No significant effect on the PIEA was found. The decay of the NIEA was apparently greatly accelerated in the presence of high concentration of ouabain, but this may also be a reflection of their action on the state determining the strength of the rested-state contraction. In the case of extracellular calcium concentration increment, the similar results with the ouabain treatment were obtained. Norepinephrine produced more powerful inotropic effect at shorter stimulation interval than long. The rested-state contraction and the decay of the NIEA were not significantly altered in the presence of norepinephrine, but cumulated PIEA and the amount of PIEA produced by each contraction were significantly increased. Aconiti tuber butanol fraction showed similar results with that of norepinephrine. The increment of contractile force at various contraction frequency were dose-responsive in the presence of Aconiti tuber butanol fraction. It is suggested that the positive inotropic effect of Aconiti tuber butanol fraction at various contraction frequency may be due to increase of the cumulation of PIEA and the amount of PIEA produced by each beat.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.306-320
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• 2018

Emission inventory is the essential component for improving the performance of air quality forecasting system. This study evaluated the simulated daily mean $PM_{2.5}$ concentrations in South Korea and China for 1-year period (Sept. 2016~Aug. 2017) using air quality forecasting system which was applied by the emission inventory of E2015 (predicted CAPSS 2015 for South Korea and KORUS 2015 v1 for the other regions). To identify the impacts of emissions on the simulated $PM_{2.5}$, the emission inventory replaced by E2010 (CAPSS 2010 and MIX 2010) were also applied under the same forecasting conditions. These results showed that simulated daily mean $PM_{2.5}$ concentrations had generally suitable performance with both emission data-sets for China (IOA>0.87, R>0.87) and South Korea (IOA>0.84, R>0.76). The impacts of the changes in emission inventories on simulated daily mean $PM_{2.5}$ concentrations were quantitatively estimated. In China, normalized mean bias (NMB) showed 5.5% and 26.8% under E2010 and E2015, respectively. The tendency of overestimated concentrations was larger in North Central and Southeast China than other regions under both E2010 and E2015. Seasonal differences of NMB were higher in non-winter season (28.3% (E2010)~39.3% (E2015)) than winter season (-0.5% (E2010)~8.0% (E2015)). In South Korea, NMB showed -5.4% and 2.8% for all days, but -15.2% and -11.2% for days below $40{\mu}g/m^3$ to minimize the impacts of long-range transport under E2010 and E2015, respectively. For all days, simulated $PM_{2.5}$ concentrations were overestimated in Seoul, Incheon, Southern part of Gyeonggi and Daejeon, and underestimated in other regions such as Jeonbuk, Ulsan, Busan and Gyeongnam, regardless of what emission inventories were applied. Our results suggest that the updated emission inventory, which reflects current status of emission amounts and spatio-temporal allocations, is needed for improving the performance of air quality forecasting.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.263-267
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• 2007

Parabens are used in nearly all types of cosmetics and toiletries because they are formulated well and have broad spectrum of activity, interness, low costs and excellent chemical stability in relation to pH. 2-phenoxyethanol and chlorphenesin are common preservatives which are usually used in combination with parabens in cosmetics. Toxicity of parabens is generally low but application of parabens to damaged or broken skin has resulted in sensitization. Moreover, the possibility of their estrogenic potential, anesthetic effects and reproductive toxicity has been reported. Consequently there are some regulations in use of parabens. And the maximum permitted concentrations of chlorphenesin and 2-phenoxyethanol in cosmetic products are authorized by the same reasons. So it is important to control and estimate the amount of parabens in products. In this article, we proposed a valid method for the simultaneous determination of 8 preservatives including parabens in a short time using ultra performance liquid $chromatography^{TM}\;(UPLC^{TM})$. Separation of eight components was achieved in less than 10 min and resolutions were reasonable (USP resolution ${\geqq}\;2$). And limit of detection and quantification were evaluated. The method was suitably validated for specificity, linearity, precision (repeatability, intermediate precision) and accuracy for assay (recovery) based on International conference on harmonisation (ICH) guideline. The method was applicable to analysis of preservatives in cosmetic products.