• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.133-140
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• 1994

Recently, there are many considerations and studies on biological effects of radiations in radiation workers, as well as in accidentally or therapeutically irradiated persons. The most practical and reliable method of dosimetry for radiation accidents is the scoring of gross chromosomal aberrations in human lymphocytes (Ydr) as a biological dosimetry. By the way, although usual doses of $^{131}I$ administered therapeutically for thyroid cancer are ranging from 100 mCi to 200 mCi, there are differences of absorbed doses and Ydr, ranging from 0.004 to 0.04, on equally administered $^{131}I$ due to variations in metabolic characteristics, stage of tumors and physical status of subjects. In this study, We exert to obtain the dose-response relationships of $^{131}I$, as a good guide to evaluating acute effects of accidental irradiations and radiation induced leukemia or solid tumor, by in vitro induction of chromosomal aberrations. we studied the relationship between radiation dose (D) and the frequency of chromosomal aberrations (Ydr) obserbed in peripheral lymphocytes that were irradiated in vitro with $^{131}I$ at doses ranging from 0.05 to 6.00 Gy. By scoring cells with unstable chromosomal aberrations (dicentric chromosomes and ring chromosomes) we obtained this linear-quadratic dose response equation Ydr=0.064351 $D^2$-0.13143 D+0.045684 This dose-response relationship may be useful for evaluating acute and chronic $^{131}I$ induced biological effects.

• Korean Journal of Organic Agriculture
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• v.9 no.2
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• pp.101-115
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• 2001

Nitrogen applied as fertilizer for crop production is partly absorbed by plant , and the remaining nitrogen in soil might be leached out through complicated processes to the subsoil layer Especially, NO$_3$-N in leachate causes environmental pollution. The purpose of this study was focused on understanding of uptake of nutrients by plants, the behaviors of nutrients in soil and the possibility of leaching loss when nitrogen fertilizer and completely decomposed compost were applied. Lysimeters(Volume 0.15㎥, Diameter 62cm, Height 62.8cm) were installed for collecting leachate in the Jeju volcanic ash soils. Lysimeter study consisted of thirteen treatments : fallow, fallow with weeding, cropping without fertilizer and compost, three N fertilizer soil surface applications(16, 32, 64kg/10a), three N fertilizer and compost soil surface applications(16+800, 32+1600, 64+32kg/10a), two water dissolved N fertilizer applications(16, 32kg/10a), and low and high plant densities. N fertilizer was applied as urea. The growth of com(preceding crop) and potatoes(succeeding crop) and leaching loss were determined during the experimental period. The results obtained were summarized as follows ; With Increased N, pH of leachate tended to decrease and NO$_3$-N concentration of leachate increased. NO$_3$-N leaching loss was remarkably greater in soil from the bare plot without fertilization and the weed control than from plots with medium N rate and was least in the cropping plot without fertilization. NO$_3$-N concentration in leachates from the water dissolved N fertilizer application plots was 64% of that from the soil surface application plots. The concentration of Ca and K ions and the leaching loss of these ions were least from the cropping plot without fertilization and were greatest from bare plots(T1 and T2) without fertilization. The proportion of leaching and residual N in soil increased as N rate increased indicting that higher N rates increase the possibility of N leaching to subsoil layer The proportion of N leaching losses was lower at the low N rate and the high plant density. In future, fertilization prescription which can maximize fertilizer use efficiency and minimize the pollution of ground water will be needed for conserving the environments.

• Journal of Life Science
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• v.25 no.5
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• pp.548-556
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• 2015

Three groups of black seabream (Acanthopagrus schlegeli) were fed with treatment diets containing certain concentrations of conjugated linoleic acid (CLA) and carotenoids. The control group feed contained 0% CLA and 0% carotenoids, the CP10 group feed contained 1% CLA and 0.1% carotenoids, and the CP25 group feed contained 2.5% CLA and 0.1% carotenoids. The CP10 and CP25 groups demonstrated the enhanced growth and increased feed conversion efficiency of black seabream. The specific growth rates (SGRs) were 0.74, 0.81, and 0.97, while the feed conversion ratios (FCRs) were 2.65, 2.46, and 2.04 for the control, CP10, and CP25 groups, respectively. The total contents of high unsaturated fatty acid (HUFA) for the control, CP10, and CP25 groups were 41.0%, 41.7%, and 43.5%, respectively. CLA was deposited to the extent of 2.8% and 5.6% in the muscle, and 4.0% and 8.3% in the viscera of the CP10 and CP25 groups, respectively. Meanwhile, treatment with the viscera lipid extract (VLE) from CP25 fish evidently lowered 3T3-L1 adipocytes viability. The lipid extract from the muscle and viscera of black seabream contained ample amounts of beneficial substances, such as CLA, carotenoids, EPA, and DHA. CLA, which enriched black seabream muscle, could be categorized as a functional food and serve as a well-being food. Meanwhile, the fish oil from its viscera could serve as a high function supplement.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.343-349
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• 1995

Background : For biological dosimetry of radiation exposure, both observing hematologic change and calculating Ydr by chromosomal analysis as biological indicators are widely used. However, due to the lack of studies on biological dosimetry of radiation dose absorbed in the body such as in the cases of radioactive iodine therapy, the maximal and safe dose is not well known, nor is the extent to which the body can safely endure radiation exposure. Purpose : To investegate the practical applicability of hematologic changes and Ydr as an indicator for estimating radiation exposure, to patients with thyroid diseases after doses of radioactive iodine. Material and Methods : 5 patients with hyperthyroidism and 35 patients who have had thyroid cancer operation were under treatment with radioactive iodine, changes in number of lymphocytes were tracked and Ydr was calculated for more than 2 months by chromosomal analysis in peripheral lymphocytes. Results ; 1) The number of lymphocytes began to decrease 2 weeks after doses of radioactive iodine, and reached the nadir after 6 and 8 weeks, then gradually recovered. 2) The nadir count of lymphocytes was reversely correlated with the administered dosage of radioactive iodine. 3) Ydr was generally stable between 2 and 8 weeks. 4) The maximal value of Ydr was correlated with the administered dosage of radioactive iodine. 5) Ydr value at the 2nd week increased with augmented dosage of radioactive iodine. 6) Ydr value at the 2nd week was correlated with fall of lymphocyte count. Conclusion : Patients must be closely observed, because temporary bone marrow suppression and slight chromosomal aberration can be produced by even generally used dosages of radioactive iodine for diagnosis and therapy. Maximal percent fall of lymphocyte count, Ydr at the 2 week interval and maximal Ydr can be used as the biological predictor of administered dosage of radioactive iodine.

• Food Science and Preservation
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• v.19 no.5
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• pp.783-791
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• 2012

The purpose of the study was to provide baseline information that could encourage consumers and establish the direction of development for sprouts and leafy vegetables. A survey on the consumption and preference for sprouts and leafy vegetables of 823 people over 20 years of age in Seoul and Gyeonggi province was conducted. The preference for sprouts was higher in men ($3.75{\pm}0.96$) than in women ($3.64{\pm}0.84$), whereas the preference for leafy vegetables was higher in women ($4.06{\pm}0.74$) than in men ($3.88{\pm}0.90$). Based on age, the respondents in their 40s or above had high preferences for sprouts and leaf vegetables due to the importance that they accorded to health and nutrition (p<0.01). The sprouts and leafy vegetables were purchased mainly for their high nutritional value. The purchase frequency of once a month or more for leafy vegetables (82.7%) was higher than that for sprouts (57.1%). The consumers purchased sprouts and leafy vegetables mainly from a large discount store. The respondents in their 20s showed the highest percentage of purchasing from a local store whereas the older ones showed a high preference for traditional markets. The reason for the choice of the place of purchase was convenience. The freshness and price were important factors in the consumption of sprouts and leafy vegetables. In the case of leafy vegetables, the consumers preferred to buy them using the conventional weight measurement system rather than in small packages. On the other hand, mixed small packages were preferred for sprouts. The purchase frequency was correlated with the preferences, need for improvement and purchase intent for sprouts and leafy vegetables. The aspects that require improvement for producing high-quality sprouts and leafy vegetables were the nutritional and functional properties. To increase the consumption of sprouts and leafy vegetables, there is need for variations and improvement of the quality and safety of the products.

• Journal of Life Science
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• v.19 no.11
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• pp.1611-1616
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• 2009

This study was conducted to determine the characteristics in breeding of the little tern Sterna albifrons in Shinja-do and Doyo-Deung in Nakdong estuary. The data was obtained in the middle and late 1990's and in the mid 2000's, which were analysed for the breeding information of the little tern. In Shinja-Do, a total of 638 nests were observed in 1995, and the average numbers of eggs laid per nest were 2.48. In 2004 and 2005, 94 and 456 nests were observed, and the average number of eggs laid per nest was 2.16 and 2.53, respectively. There was a significant difference between the average numbers of eggs laid per nest for the 3 respective years. In Doyo-Deung, a total of 269 nests were observed in 1998, and the average number of eggs laid per nest was 2.16. In 2004 and 2005, 1,023 and 1,123 nests were observed, and the average numbers of eggs laid per nest were 2.33 and 2.52, respectively. There was a significant difference (p<0.001) between the average number of eggs laid per nest as well. Hatching success rate by nesting site in Shinja-Do was calculated in 1995. Type A nest (nest located on dry sand land) showed a 56.8% success rate, and type B nest (nest located on the land with dwarf grass), type C nest (nest located on moist land) and type D nest (nest located on the land with shells) showed 55.3%, 36.6% and 59.3% success rates, respectively. The average hatching success rate in Shinja-Do was 54.5%. The most crucial factor for hatching failure was flood, especially, for the type C nests. The hatching success rate by the nesting site in Doyo-Deung showed an average of 73.2%. It was high in type D nest (83.8%) and type A nest (75.9%), and low in type C nest (59.7%). Again, the most crucial factor for hatching failure was flood, especially, for the type C nests. Nakdong estuary has been through many changes over time, particularly in recent. Therefore, continuous efforts to keep it a breeding place for the little tern are urgently required, including overall management of land, protection of reef and sand, etc.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.66-72
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• 2009

The detection methods are required to monitor and diagnose the abnormality on the insulation condition inside a gas-insulated switchgear (GIS). Due to a good sensitivity to the products decomposed by partial discharges (PDs) in $SF_6$ gas, the development of a SWNT gas sensor is actively in progress. However, a few numerical studies on the diffusion mechanism of the $SF_6$ decomposition products by PD have been reported. In this study, we modeled $SF_6$ decomposition process in a chamber by calculating temperature, pressure and concentration of the decomposition products by using a commercial CFD program in conjunction with experimental data. It was assumed that the mass production rate and the generation temperature of the decomposition products were $5.04{\times}10^{-10}$ [g/s] and over 773 K respectively. To calculate the concentration equation, the Schmidt number was specified to get the diffusion coefficient functioned by viscosity and density of $SF_6$ gas instead rather than setting it directly. The results showed that the drive potential is governed mainly by the gradient of the decomposition concentration. A lower concentration of the decomposition products was observed as the sensors were placed more away from the discharge region. Also, the concentration increased by increasing the discharge time. By installing multiple sensors the location of PD is expected to be identified by monitoring the response time of the sensors, and the information should be very useful for the diagnosis and maintenance of GIS.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.451-461
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• 2009

The purpose of this study is to provide fundamental information for snack development contributing to physical growth of children with cerebral palsy. The study was conducted on the children with cerebral palsy of age 1 to 7 by investigating their food behavior, physical growth development, nutritional status, and snack intake. As a result of assessing physical growth by WLI (Weight-Length Index), the proportions of the children with cerebral palsy were the following: underweight 45.5%, normal 45.5%, overweight 6.0%, and obesity 3.0%. The mothers of the children with cerebral palsy mainly bought milk and dairy products for their children's snacks (43.5%) as well as fruits (33.3%). They wanted development of new snacks that helped growth development (50.5%), and preferred more development of the following snacks: Korean rice cakes (47.5%), biscuits (24.2%), bread (22.3%). The result of dietary intake showed that the percentage of RI in zinc and folic acid did not reach the RI in every age categories. The proportion of subjects with less than 75% of RI was 76.8% for the zinc and folic acid, and 52.4% for the calcium and iron. These results indicate that children with cerebral palsy had slower physical development and lesser nutrition intake than normal children. Hence, this study provided the basis to develop the snack for the malnutrition state children with cerebral palsy which helped their physical development. The shape of new snack considered was a rice cake which included zinc and folic acid that were insufficient in RI in children with cerebral palsy.

• The Korean Journal of Nuclear Medicine Technology
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• v.24 no.1
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• pp.33-38
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• 2020

Purpose Vitamin D is essential for maintaining bone health, controling cell proliferation or differentiation, strengthening immune function by controlling calcium metabolism in the body. Vitamin D deficiency can lead to increase the risk of rickets, osteoporosis, cardiovascular disease, diabetes and cancer. Especially, South Korea is one of the highest population proportion of vitamin D deficiency. Accurate determination of levels of 25-OH-VitD or 25-OH-VitD3 in blood serum is required for the diagnosis and treatment of vitamin D deficiency. In this study, radioimmunoassay of 25-OH-VitD and 25-OH-VitD3 was performed and compared to evaluate the effectiveness of Vitamin D radioimmunoassay. Materials and Methods Serum 25-OH-VitD and 25-OH-VitD3 levels were measured using radioimmunoassay. The interrelationship, reproducibility and population distribution rate were evaluated. In addition, the internal quality control was performed at Asan Medical Center from April 2017 to June 2019 and the result of external quality control (Interagency proficiency evaluation) of first and second half of 2018 hosted by the Korean Society of Nuclear Medicine Technology (KSNMT). Both tests were measured by same manufacturer's reagent. Results 25-OH-VitD showed a strong positive correlation on 97 samples, as 25-OH-VitD3 x 0.9 + 0.3 (R>0.9). In repeated measurement, the average Diff(%) value of the reproducibility evaluation of 25-OH-VitD and 25-OH-VitD3 were 7.7% and 7.4%, respectively. Population distribution results showed no statistically significant differences(p>0.05). The resultant value of internal quality control, which measured from April, 2017 to June 2019 in Blood test room of Nuclear Medicine at Asan Medical Center, showed average (CV%) 6.2% and 6.8%, respectively. As a result of the external quality control (interagency proficiency evaluation) Z value obtained under 2.0, as shown below; Conclusion The interrelationship, reproducibility, population distribution rate, internal quality control and external quality control between 25-OH-VitD and 25-OH-VitD3 radioimmunoassay shows superior outcome. Radioimmunoassay, which can be alone measured in the blood as 25-OH-VitD or 25-OH-VitD3, is considered suitable screening tests for the diagnosis of vitamin D deficiency.

• Journal of Animal Environmental Science
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• v.7 no.1
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• pp.1-12
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• 2001

This study was conducted to develope an automatic liquid feeder for early weaning piglets and to test the efficacy of the system. The liquid feeder consists of water heating and discharge unit, dry diet storing and discharge unit, mixing and discharge unit, mixed liquid feed-delivering unit, and the central control part which control each unit, feeding frequency and the amount of feeding. For investigating the possibility of practical use, a feeding trial was carried out using eighteen three way crossbred piglets weaned on 19 days of age for the experimental period of six weeks. Experimental diet was provided in liquid form using the automatic liquid feeder for the first three weeks and in dry form for the later three weeks. The water heating and discharge unit exactly supplied warm water by 27 $m\ell$/s, into the mixing unit. The dry diet storing and discharge unit supplied dry feed by 3.7g/s, into the mixing unit. Being compared with the standard growth rate suggested by NRC, average daily gain of the piglets during the first three weeks of liquid feeding was lower by 10%, while it was higher during three weeks of dry feeding and over the whole experimental period by 24 and 17%, respectively. Feed/gain was 1.09, 2.14 and 1.89 for the first 3 weeks, later 3 weeks, and whole period, respectively. Diarrhea was observed for three days from day 3 to day 7 after feeding liquid diet, but no pig died of it. In conclusion, a preliminary test for the newly developed an automatic liquid feeder using 19 days of age weaning piglets showed that the unit was successfully operated without any major problems. Piglets raised on a liquid diet through the unit developed grew less during the first three weeks, but their growth and feed intake were greatly improved thereafter, indicating the developed automatic liquid feeder may be practically used in swine industry.