• The Korean Journal of Nuclear Medicine
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• v.28 no.2
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• pp.220-226
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• 1994

This study was performed to evaluate the clinical applicability of the reverse transcription polymerase chain reaction (RT-PCR ) kit of HCV-RNA using biotinylated and radioiodinated primers. Study subjects were 118 patients with positive anti-HCV. HCV-RNA in patient's serum was extracted by guanidium thiocyanate method. After first amplification, the product was reamplified by primers labelled with biotin and I-125. The final amplification product was defected by counting the radioactivity after incubation in avidin coated tubes. In 51 samples, the test was repeated for evaluation of reproducibility. This new method was also compared with conventional RT-PCR methods in 34 samples from patients with chronic liver disease. The results were as follows ; 1) HCV-RNA was positive in 85(97%)of 88 patients with chronic liver disease, and in 23 (73%) of 30 patients with normal liver function. 2) In comparison with conventional method, HCV-RNA was detected in 32(94%) of 34 patients with new method, whereas in 27(79%) of the same group with conventional method. 3) Repeated test with new method in 52 samples demonstrated 82% of concordant result. In conclusion, new method with biotinylated and radioiodinated primers was more sensitive than conventional method. However, great care must be taken for quality control because there were considerable interassay variation and possiblity of false positivity and false negativity.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.70-74
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• 2011

Purpose: In the Nuclear Medicine department of Asan Medical Center, radioactive waste has been disposed of by using several disposal boxes designed for nuclear waste. However, some quantity of radioactivity has been detected occasionally due to some radiologists' carelessness not only from radioactive waste, but also from medical waste such as uncontrolled radioactive waste related to patients, poly gloves or saline solution bottles from radiopharmaceuticals laboratory. Thus, this study is going to suggest a solution to maintain the medical wastes made from controlled areas that can be below maximum permissible surface dose limits by finding the cause of radioactive contamination. Materials and methods: This study was taken place in 17 different places-2 medical wastebaskets in the waiting room, 2 medical wastebaskets in the PET room, 5 medical wastebaskets in the in vitro laboratory and 6 medical wastebaskets in the radiopharmaceuticals laboratory of the East building, 2 medical wastebaskets in the waiting room of the New building of Nuclear Medicine Department in Asan Medical Center from April to August 2010. Mean radioactivity and its standard deviation of each place have been found by measuring surface contamination of medical wastebaskets and backgrounds twice a week, totaling 30 times. An independent t-test of SPSS (Ver. 12.0) statistic program has been used for statistical analysis. Swabs, saline solution bottles and poly gloves collected from each place also measured 30 times, respectively. Results: This study analyzed medical waste and the backgrounds of each place by using survey meter detectors that significant differences of five places did not exist, but existed statistically in twelve places (p<0.05). Also, swabs, saline solution bottles and poly gloves collected from each radioactive waste partly exceed the legal dose limit as a result of measuring by a gamma counter. Conclusion: Backgrounds and the surface doses of radioactive disposal box in all 17 places measured by the survey meter did not exceed the legal dose limit; however, it obviously showed that there were prominent differences in 12 places. Assuming that the cause of the differences was swabs, saline solution bottles and gloves, we examined them by gamma counter, and the results showed remarkably high doses of radioactivity. Consequently, swabs and poly gloves which are normally disposed in the general medical waste box should be disposed in the radioactive waste box furnished by radiopharmaceuticals laboratory. Also, saline solution discharged from radioactive pharmaceutical places is considered as radioactive liquid waste so that it should be disposed of by the septic tank specifically designed for radioactive liquid.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.25-28
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• 2011

Purpose: The aim of study is to find accuracy of pocket dosimeter in measuring exposed dose in compared with survey meter and to compare exposed dose according as Nuclear medicine exams. Materials and Method: First, radiation dose to point source(185 MBq,370 MBq, ${\ldots}$, 1665 MBq, 1850 MBq) were measured in using a pocket dosimeter and a survey meter. Second, radiation dose to 12 patients injected $^{18}F$-FDG 370 MBq were measured in using a pocket dosimeter and a survey meter. Third, radiation dose to 10 patients injected $^{99m}Tc$-DPD 925 MBq were measured in using a pocket dosimeter and a surveymeter. Result: The average is $70.12{\pm}39.36{\mu}Sv/h$ in measurement of point source with Surveymeter and $5{\pm}3.06{\mu}Sv$ in measurement of point source with Pocket dosimeter. The average is $25.04{\pm}6.16{\mu}Sv/h$ in measurement of PET/CT patients with Surveymeter and $2.41{\pm}0.51{\mu}Sv$ in measurement of PET/CT with Pocket dosimeter. The average is $8.58{\pm}0.96{\mu}Sv/h$ in measurement of Bone Scan patients with Surveymeter and $1{\mu}Sv$ in measurement of Bone Scan patients with Pocket dosimeter. Significant difference found between Survey meter value and Pocket dosimeter value in all experimentation (p<0.001). Conclusion: Accoring to rusult Wearing Pocket dosimeter is usefulnee in manerage of exposed dose in nucler medicine exams.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.251-257
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• 2009

The effects of temperature variations during storage on the quality characteristics of muskmelons (Cucumis melo L.) were investigated. In samples stored at $4^{\circ}C$ and $10^{\circ}C$, weight losses were almost 2.9- and 3.4-fold higher, respectively, compared to samples stored at $0^{\circ}C$. Soluble solids slightly increased except in the samples stored at $10^{\circ}C$, but acidity decreased over the entire storage period. Firmness decreased with storage time, but the samples stored at $0^{\circ}C$ had a lesser decrease in firmness than the samples stored at other temperatures. Water loss from the muskmelon stalk was most inhibited, and vitamin C content was maintained for the longest period, with storage at $4^{\circ}C$. Mineral contents (Ca, Na, Fe, Mg, K) were best maintained in muskmelon samples stored at $10^{\circ}C$ for 15 days, but levels had decreased by 30 days. Microbiological quality was not appreciably different at any storage temperature at 18 days; however, samples stored at $4^{\circ}C$ and $10^{\circ}C$ had deteriorated by 25 days. The results of sensory evaluations indicated that taste was best retained in samples stored at $10^{\circ}C$ for 15 days, although changes in taste were evident at all storage temperatures. When the samples were stored over 22 days at $10^{\circ}C$, retention of texture and overall acceptability were more inferior compared to samples stored at $0^{\circ}C$ and $4^{\circ}C$. These results suggest that storage at $4^{\circ}C$ can be used to reduce deterioration in muskmelons without significant loss of their quality attributes.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.238-244
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• 2009

This survey was conducted as a surveillance program following the establishment of safety guidelines for agricultural products in Korea. Concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) were measured in 421 samples using a mercury analyzer or ICP-MS. The average levels of Pb in mg/kg were 0.021 for rice, 0.020 for corn, 0.028 for soybeans, 0.034 for red beans, 0.025 for sweet potatoes, 0.021 for potatoes, 0.019 for Chinese cabbage, 0.031 for spinach, 0.021 for Welsh onions, and 0.011 for radishes. The average levels of Cd in mg/kg were 0.021 for rice, 0.002 for corn, 0.020 for soybeans, 0.006 for red beans, 0.008 for sweet potatoes, 0.011 for potatoes, 0.007 for Chinese cabbage, 0.035 for spinach, 0.006 for Welsh onions, and, 0.006 for radishes. The average levels of As in mg/kg were 0.103 for rice, 0.005 for corn, 0.007 for soybeans, 0.005 for red beans, 0.005 for sweet potatoes, 0.004 for potatoes, 0.007 for Chinese cabbage, 0.015 for spinach, 0.009 for Welsh onions and, 0.006 for radishes. Finally, the average levels of Hg in ${\mu}g/kg$ were 2.3 for rice, 0.2 for corn, 0.6 for soybeans, 1.4 for red beans, 0.1 for sweet potatoes, 0.3 for potatoes, 0.5 Chinese cabbage, 2.1 for spinach, 0.5 for Welsh onions, and 0.2 for radishes. Based on the Korean public nutrition report 2005, these levels (or amounts) are calculated only at 2.6% for Pb, 8.7% for Cd, 1.2% for Hg of those presented in provisional tolerable weekly intake (PTWI) which has been established by FAO/WHO. Therefore, the levels presented here are presumed to be adequately safe.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.376-381
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• 2013

In this study, we monitored total mercury and methylmercury concentrations in tuna, billfish, and deep-sea fish distributed in Seoul city. With the acquired data, we carried out statistical analysis and an exposure assessment for intake. The mean concentrations (mg/kg) of total mercury and methylmercury were $0.32{\pm}0.31/0.20{\pm}0.20$ for tuna, $0.43{\pm}0.48/0.20{\pm}0.17$ for patagonian toothfish, $0.99{\pm}0.72/0.51{\pm}0.40$ for billfish and $1.20{\pm}0.70/0.95{\pm}0.51$ for sharks, respectively. We found that sharks, billfish, patagonian toothfish, and tuna were more contaminated with total mercury and methylmercury, in sequence, and that 66% of the total mercury concentration consisted of methylmercury, on average. Although the estimated weekly intakes of methylmercury from commercial deep-sea fish were lower than the weekly intakes recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), we identified that the total mercury and methylmercury concentrations in tuna, billfish, and deep-sea fish continued to increase with the passage of time. Therefore, we confirmed the necessity of continuous monitoring and comprehensive analysis for general safety.

• Journal of Life Science
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• v.22 no.8
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• pp.1114-1119
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• 2012

Bacteria are frequently contaminated during the collection and processing procedures of boar semen. Of the contaminants, Stenotrophomonas (S.) maltophilia is a Gram-negative bacterium that is widely distributed in a variety of habitats. Although PCR assays have been developed for the detection of S. maltophilia, they cross-react with some species of Xanthomonas. In this study, we designed a primer set for the detection of S. maltophilia in order to target the chiA (GenBank accession no. NC_010943) gene. The specific PCR products were amplified from S. maltophilia only, not from other tested strains that are frequently found in semen. The detection limit of the PCR was $1.5{\times}10^3$ CFU/ml with pure-cultured S. maltophilia and $1.5{\times}10^4$ CFU/ml with S. maltophilia spiked in semen. Twenty-six (5.9%) S. maltophilia were isolated from 440 semen samples. The PCR results exhibited 98.9% agreement with a comparison of S. maltophilia isolation. Also, the sensitivity and specificity of the PCR were 100% and 98.7%, respectively. In the antimicrobial susceptibility test, S. maltophilia isolates were highly susceptible to enrofloxacin and florfenicol, while the majority of them were resistant to amoxicillin/clavulanic acid, apramycin, ceftiofur, penicillin, and spectinomycin. These results indicated that the PCR using the chiA gene was proven to be reliable and effective for the detection of S. maltophilia with high levels of sensitivity and specificity.

• Journal of Life Science
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• v.23 no.8
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• pp.1025-1031
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• 2013

From a 95% ethanolic extract of H. diffusa, four marker compounds (HD1~HD4) were isolated, which were relatively unique and exist in comparably high contents. The structures of marker compounds were identified as digitolutein (1), 2-hydroxy-3-methylanthraquinone (2), (E/Z)-6-O-p-coumaroyl scandoside methyl ester (4:1 mixture) (3), and (E/Z)-6-O-p-methoxycinnamoyl scandoside methyl ester (4:1 mixture) (4), respectively, on the basis of $^{13}C$ and $^1H$-NMR analyses. The calibration curves of marker compounds showed high linearity, as their correlation coefficient ($R^2$) were in the range of 0.9991~0.9999. In addition, the limit of detection (LOD) and the limit of quantification (LOQ) were $0.03{\sim}0.07{\mu}g/ml$ and $0.099{\sim}0.231{\mu}g/ml$, respectively. The intra-day/inter-day precision and accuracy were 0.23~2.00%/0.25~1.16% and 94.60~108.44%/94.73-110.23%, respectively. The optimal HPLC conditions for the simultaneous quantification of HD1~HD4 were as follows: stationary phase; Merck Chromolith RP-18e ($100{\times}4.6mm$, $5{\mu}m$), column temp.; room temperature, UV detection at 280 nm, flow rate; 2.0 ml/min, injection volume; $10{\mu}l$, mobile phase; start with the mixture of 80% solvent A ($H_2O$ containing 0.5% acetic acid) and 20% solvent B (methanol containing 0.5% acetic acid) and gradually decrease solvent A to 40% in 9 min., then retain this condition to 18 min. Under the HPLC condition, the four marker compounds 1~4 were successfully separated without any interference of other constituents. The results obtained in this study are expected to be helpful for the development of nutraceutics and natural medicines and for the quality control of this plant.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.187-196
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• 2000

This paper describes a simple method that uses differences among Carlson's (1977) trophic state index (TSI) values based on total phosphorus (TP), chlorophyll a (CHL) and Secchi depth (SD) to draw inferences regarding the factors that are limiting to phytoplankton growth and the composition of lake seston. Examples are provided regarding seasonal and spatial patterns in a large subtropical lake (Lake Okeechobee, Florida, USA) and inter- and intra-lake variations from a multilake data set developed from published studies. Once an investigator has collected routine water quality data and established TSI values based on TP, CHL, and SD, a number of inferences can be made. Additional information can be provided where it also is possible to calculate a TSI based on total nitrogen (TN). Where TSI (CHL)<>TSI (SD), light attenuating particles are large (large filaments or colonies of algae), and the phytoplankton may be limited by zooplankton grazing. Other limiting conditions are inferred by different relationships between the TSI values. Results of this study indicate that the analysis is quite robust, and that it generally gives good agreement with conclusions based on more direct methods (e.g., nutrientaddition bioassays, zooplankton size data, zooplankton removal experiments). The TSI approach, when validated periodically with these more costly and time-intensive methods, provides an effective, low cost method for tracking long-term changes in pelagic structure and function with potential value in monitoring lake ecology and responses to management.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.203-211
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• 2015

Forest vegetation of Hwangjangsan (1,077.3 m) in Woraksan National Park is classified into mountain forest vegetation. Mountain forest vegetation is subdivided into deciduous broad-leaved forest, mountain valley forest, coniferous forest, riparian forest, afforestation and other vegetation. Including 55 communities of mountain forest vegetation and 4 communities of other vegetation, the total of 59 communities were researched; mountain forest vegetation classified by physiognomy classification are 28 communities deciduous broad-leaved forest, 12 communities of mountain valley forest, 3 communities of coniferous forests, 2 communities of riparian forest, 10 afforestation and 4 other vegetation. As for the distribution rate for surveyed main communities, Quercus mongolica and Quercus variabilis communities account for 65.928 percent of deciduous broad leaved forest, Fraxinus rhynchophylla - Quercus mongolica community takes up 41.459 percent of mountain valley forest, Pinus densiflora community holds 86.100 percent of mountain coniferous forest holds. In conclusion, minority species consisting of Quercus mongolica, Pinus densiflora, Quercus variabilis, Fraxinus rhynchophylla, and Quercus serrata are distributed as dominant species of the uppermost part in a forest vegetation region in Woraksan National Park. In addition, because of vegetation succession and climate factors, numerous colonies formed by the two species are expected to be replaced by Quercus mongolica, Quercus variabilis, and Fraxinus rhynchophylla which are climax species in the area.