• Journal of Preventive Veterinary Medicine
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• v.42 no.4
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• pp.171-176
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• 2018

A study of the tissue depletion of florfenicol (FFC) administered orally to pigs at a dose of 0.05 kg/ton feed for 7 days was performed. Sixteen healthy cross swine were administered with FFC. Four treated animals were arbitrarily selected to be sacrificed 1, 3 and 5 days after the end of treatment. FFC residue concentrations in muscle, liver, kidney, and fat were determined using high-performance liquid chromatography (HPLC) with ultraviolet photometric detector at 230 nm. The correlation coefficient ($R^2$) of the calibration curve for florfenicol amine (FFCa) was > 0.997 and the limits of detection and quantification were 0.012 and $0.040{\mu}g/mL$, respectively. Recovery rates in swine edible tissues ranged from 79.1 to 93.5%. In the FFC-treated group, FFC residues at 3 days post-treatment were below the maximum residue limits (MRLs) in muscle, kidney and fat, and those at 5 days post-administration were below the MRLs in all edible tissues. These results suggest that the withdrawal period of FFC after the drug treatment might be 5 days, which is a sufficient amount of time for reduction of the FFC residues below the MRLs in all edible tissues.

• Korean Journal of Animal Reproduction
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• v.11 no.1
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• pp.16-21
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• 1987

We describe a simple, solid-phase chemiluminescence immunoassay for the meausrement of serum T4. An immunoglobulin G fraction of antibody to thyroxine was passively absorbed onto the walls of polystyrene tubes. The labeled antigen was thyroxine-aminobutylethylisoluminol. After the bindings reaction (37$^{\circ}C$ for 1 hour), the solution is removed by aspiration and the antibody-bound fraction was washed once with buffer. Sodium hydroxide (5mol/1,200${mu}ell$) was added and the mixture incubated for 30 minutes at 6$0^{\circ}C$. Luminescence was initiated by oxidation of the label with micropeeroxidase-hydrogen peroxide and the signal of light emission was intergrated for 10 sec. The light yield was inversely proportional to the concentration of T4 in the standard or sample. An evaluation of the method gave the following values sensitivity of calibration curve 7.5$\pm$2.8 nmol/l (mean$\pm$SD). The intra-assay precision (CV%) was 8.9, 7.3 and 5.4. The inter-assay precision (CV%) was 10.2, 8.1 and 7.1. When seum samples were assayed for T4, the results obtained by solid-phase CIA and the conventional RIA agreed well(n=3.5, r=0.954).

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.04a
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• pp.137-137
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• 2021

The study of total phenol (TP) content from 700 rice varieties was evaluated using the UV-Vis spectrophotometric method. The calibration curve of serial diluted gallic acid as a standard of this study showed the acceptable performances (R² = 0.999, mean accuracy 90%) and the mean of % relative standard deviation (%RSD: 0.07%) within the range of 7.8 to 1000 ppm concentrations. The mean value of total phenol content from 700 rice varieties was 2723.15 ㎍/g ranged from 55.48 ㎍/g to 9922.23 ㎍/g and the mean %RSD was 2.5%. Furthermore, this study aim was to analyze and profile individual phenolic compounds in the rice genetic resources to construct an integrative database for development of new rice variety with high functionality for health and understanding of phenolics characteristics in the rice grain. Herein, we analyzed selected 100 rice varieties based on high TP content and identified total 15 phenolic compounds by LC-ESI-MS/MS. Among selected 100 rice genetic resources, the phenolic metabolites consisted of higher amount of flavonoid (catechin) and phenolic acid mainly protocatechuic acid. Further research of more selected rice genetic resources would be continued to provide for an integrative phenolics profile of different rice genetic resources.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.165-180
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• 2015

Jurassic granite from Geochang was analysed with respect to the characteristics of the rock cleavage. The phases of distribution of microcracks were well evidenced from the enlarged photomicrographs(${\times}6.7$) of the thin section. In this study, the length - cumulative frequency diagrams were used for expressing the distribution characteristics of microcrack. The diagrams for the six directions were arranged in the magnitude of density(${\rho}$). These diagrams show an order of H2 < H1 < G2 < G1 < R2 < R1 from the related chart. Among six diagrams, the diagram for hardway 2(H2) occupies the lowermost region on the left. On the contrary, the diagram for rift 1(R1) occupies the uppermost region on the right. Curve patterns of the two diagrams change from uniform to exponential distribution type in accordance with the increased density. The overall distribution characteristics of the diagrams were well evidenced from the magnitude of the exponent(${\lambda}$) and length of line oa related to the exponential straight line. The magnitude of exponent governing the values of slope(${\theta}$) is inversely proportional to the values of microcrack parameters such as number(N), length(L) and density. On the contrary, length of line oa is directly proportional to the values of the above three parameters. Above microcrack parameters related to the order of arrangement of diagrams show an order of hardway(H1 + H2) < grain(G1 + G2) < rift(R1 + R2). The distribution characteristics of progressive variation are found among the six diagrams. The order of arrangement of the diagrams indicates a relative magnitude of the rock cleavage. Meanwhile, the parameters such as slope, exponent, density and length of line oa were arranged in an order of H2 < H1 < G2 < G1 < R2 < R1. The variation curves of a smooth quadratic function are shown from the related chart. From the correlation chart between density and the above parameters, a common regularity following power-law correlation function was derived. Finally, the analysis for the rock cleavage was conducted through the combination between the diagram and microcrack parameter. This type of combination contribute to the progressivity in evaluation for the rock cleavage.

• Analytical Science and Technology
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• v.20 no.4
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• pp.323-330
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• 2007

A simple and rapid HPLC method with fluorescence detection(FLD) for quantitation of penciclovir in human plasma using a monolithic column was developed and validated. Penciclovir and ganciclovir(internal standard, I.S.) were separated on a Chromolith column RP-18e ($4.6{\times}100mm$) with a mobile phase consisting of a mixture of (A) methanol/50 mM sodium phosphate buffer containing 200 mg/L sodium dodecyl sulfate (3/97, pH 2.5) and (B) methanol/50 mM sodium phosphate buffer containing 200 mg/L sodium dodecyl sulfate (50/50, pH 2.5) at a flow gradient of $1.6{\sim}4.0mL/min$. The retention times of penciclovir and internal standard were less than 4.0 min. Calibration curve was linear ($R^2=0.9994$) over a concentration range of $0.1{\sim}5{\mu}g/mL$. Intra-day precision, accuracy and inter-day precision were 1.36~8.55 %, 92.8~100.0 % and 0.93~5.62 %, respectively with a limit of quantitation at $0.1{\mu}g/mL$. The present HPLC-FLD method is sensitive, precise and accurate. The method described herein has been successfully used for the bioequivalence study of a famciclovir formulation product after oral administration to healthy Korean volunteers.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.420-429
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• 2023

GC-MS/MS using liquid-liquid extraction (LLE) and C18 cartridges was used to identify and quantify levels of chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin and permethrin in bulk raw milk. A calibration curve spanning 10 ng/mL to 200 ng/mL was obtained with a satisfactory correlation coefficient of 0.99. The limits of detection (LOD) and limits of quantitation (LOQ) for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in the matrix ranged from 0.06 to 1.81 ng/mL and 0.19 to 6.04 ng/mL, respectively. The recoveries of 5 pesticides from spiked samples at 37.5-125 ng/mL ranged from 86.1 to 102.1%. The measurement of uncertainty of the GC-MS/MS method for these five pesticides was developed based on the analytical process and quantification. An analysis method that is easier and faster than the method specified in the Korean food standards codes for analyzing these five pesticides in raw material milk was developed. Moreover, the analytical method for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in bulk raw milk by GC-MS/MS was established.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.491-499
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• 1996

Background : Pleural effusion is a common disease in clinical practice but its effect on pulmonary function and altered pulmonary mechanics after removal of effusion are not still largely understood. Previous studies have shown that there is little or a relatively small improvement in pulmonary function and arterial blood oxygenation after therapeutic thoracentesis. The present study was designed to assess the effect on pulmonary function of pleural effusion and to test whether there was a significant improvement in pulmonary function and arterial oxygenation after thoracentesis and to observe long tenn effect after thoracentesis. Method : We examined flow-volume curve, body box and arterial blood gas analysis according to severity of effusion, present symptom, and symptom duration. Then, we measured changes of pulmonary function after thoracentesis and observed longterm effect after thoracentesis. Result: 1) Pleural effusion cause restrictive pulmonary insufficiency. Not only functional impairment of small airway but also large airway is provoked. 2) MMFR, FEV1, Raw, POz are earlier improved than FVC and TLC after thoracentesis and patients without complication have mild restrictive pulmonary insufficiency after longterm observation. 3) FVC, FEV1, & TLC are similarly restricted as severity of pleural effusion and po, is relatively decreased. 4) Cases with symptom duration 1 week or less and cases with dyspnea have more severe pulmonary insufficiency than others. 5) The flow volume curves show a relatively greater improvement in flow rates at large lung volumes than small airway. 6) Significant relationship is shown between first thoracentesis amount and changes of FEV1, FVC, TLC. Conclusion: Pleural effusion cause restrictive pulmonary insufficiency and not only functional impairment of small airway impairment but also large airway is provoked. Then, Pulmonary function is progressively improved after thoracentesis and remained mild restrictive pulmonary insufficiency after recovery.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.324-331
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• 2007

Age and growth of the robust tonguefish, Cynoglossus robustus were estimated using scale of 353 fish specimens from February, 2004 to December, 2005 in the Southern Sea of Korea. Marginal increment of the scale formed annual rings from October to November at the beginning of autumn season. In the relationship between total length and body weight, a multiplicative error structure was assumed because variability in growth increased as a function of the length, and the estimated equation was $BW=0.0013TL^{3.399}$ ($R^2=0.916$). The relative growth as body weight at total length has significant difference between females and males (p<0.05). For describing growth of the robust tonguefish, C. robustus a von Bertalanffy growth model was adopted. The von Betalanffy growth curve had a additive error structure and the growth parameters estimated from Walford method were $L_{\infty}=43.77cm$, K=0.186/year and $t_0=-2.295year$. Growth at age of females and males shows no significant difference (P>0.05).

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.69-78
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• 1967

Kim, Jong Hyup, (Div. of Biology, Atomic Energy Research Institute.) Studies on the Cellular Metabolism in Microorganisms as influenced by Gamma-irradiation(II). On respiration rate and dehydrogenase activity of yeast cells irradiated by gamma ray from cobalt-60. 1. Oxygen uptake rate of the gamma irraiated yeast cells had been measured with Warburg's manometer, and the $O_{2}$-uptake was compared with those of normal cells. The rate of endogetious respiration increases in its $O_2$-uptake at 150, 000 rentgen dose, and at higher rentoen doses it was decreased. Exogenous respiration begin to decrease in its O_2$-uptake at 5, 000r. doses of irradiation, further decrease with increasing of doses unproportionally. 2. It appears that plasma-membrane and nuclear membrane of yeast cells have changed and denatured by gamma-irradiation, as exogenous respiration of glucose had been decreased at a dose of 200, 000r's irradiation. 3. The activity of glucose, alcoholic, lactic, succinic and glutamic deliydrogenase (G.D.H., A.D.H., L.D.H., S.D.11., and GL.D.H.) in the gamma irradaited cells had been assayed by T.T.C.(Triphenyl tetrazolium chloride) method and spectrophotometry, the obtained results were compared with those of normal cells. 4. At a dose of and 10, 000 rentgens' irradiation of gamma ray, the activty of each debydrogenase (G.D.H., A.D.H., L.D.H., ) shows a sharp and highest peak in optical absorbalicy, but each abtivity of S.D.H and Gl.D.H shows its' maximum peak at a dose of 30, 000r. 5. The curve of each dehydrogenase activity was found to be rhythmical according to dose-rate of gamma irradiation. 6. Comparing with activity of debydrogenase each other, the maximum peak in optical absorbency can be arranged according to order as follows; glucose > alcoholoic > lactic > glutamic > succinic, this order is identical to the order of breakdown utility in respiration of normal yeast cells. 7. The activity of dehydrogenase experimented exhibit a resistance against gamma irradiation at lethal dose of cells, and the activity of dehydrogenase are found to be much resistant than those of respiratory system. We may assume that the membrane substrate of mitochondria or cytoplasm had been destructed by gamma-irradiation much more than that of dehydronase system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1791-1795
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• 2014

The objective of this study was to compare two extraction methods for determination of vitamin K1 (phylloquinone) in vegetables. In addition, analytical method validation parameters such as accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and linearity were calculated to ensure the method's validity. Vitamin K1 was quantified by reversed-phase HPLC using post-column derivatization and fluorescence detection ($Ex{\lambda}=243nm$, $Ex{\lambda}=430nm$). Higher analytical values were observed using solvent extraction compared to those from the enzyme extraction method. The results from the method validation showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9994. The LOD and LOQ were 0.1335 and 0.2784 ng/injection volume ($50{\mu}L$), respectively. The inter-day precision and inter-day precision were 2.0% and 2.1%, respectively. Overall recovery was close to 100% (n=5). The phylloquinone contents ranged from 9.42 to $1,212.57{\mu}g/100g$. Our study provides reliable data on the phylloquinone contents in commonly consumed vegetables in Korea.