• Radiation Oncology Journal
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• v.19 no.2
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• pp.163-170
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• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.339-350
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• 2007

Status on the spent nuclear fuel management policy and R&D plan of the major countries is surveyed. Also the prospect of the future R&D plan is suggested. Recently so-called fuel cycle nations, which have the reprocess policy of the spent fuel, announced new spent fuel management policy based on the advanced fuel cycle technology. The policy is focused to transmute highly radioactive material and material having a very long half-life, and to recycle the Pu and U contained in the spent fuel. In this way the radio-foxily of the spent fuel as well as the amount of the high level waste to be eventually disposed can greatly be reduced. Most of countries selected the wet process as a primary option for the treatment of the spent fuel since the advanced wet process, which is based on the existing PUREX process, looks more feasible as compared with the dry process. The wet process, however, is much more sensitive in terms of proliferation-resistance compared with the dry process. The pure Pu can easily be obtained by simply modifying the process. On the other hand the pure Pu can not be extracted in the dry process based on the high temperature molten salt process such as a pyroprocess. Even though the pyroprocess technology is very premature, it has a great merit. Thus it is necessary for Korea to have a long term strategy for pursuing a spent fuel treatment technology with a proliferation resistance and a great merit for the GEN-IV fuel cycles. Pyroprocess is one of the best candidates to satisfy these purposes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.98-107
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• 2015

Olive flounder contains rich amount of lysine which is required for children's growth. Moreover, it is good foodstuffs for elderly, convalescent and diabetics because of low lipid content and high digestibility. This study was investigated for the purpose of obtaining basic data which can be applied to the processing of olive flounder steak. Olive flounder 100 g were chopped, mixed with vegetable (onion 20%, celery 10%, carrot 15%, garlic 1% of chopped olive flounder meat) and ingredient (bread crumbs 20 g, onion 15 g, celery 10 g, egg 1 ea, tarragon 1/2 t, blanc sauce 20 g, fresh cream 20 mL, salt and pepper pinch). Mixed dough was molded into steak shape ($12{\times}7cm$) and was processed by two types of products, Steak-1 {Roasting for 2 minutes in a frying pan wrapped with olive oil and then vacuum packaging in polyethylene film ($20{\times}30{\times}0.05mm$), and then storage at $-20^{\circ}C$ for 7 days, next thawed and warmed by microwave for 2 minutes} and Steak-2 {vacuum-packaging in polyethylene film ($20{\times}30{\times}0.05mm$), and then storage at $-20^{\circ}C$ for 7 days, after thawed, roasted during 2 minutes in a frying pan wrapped with olive oil}. The factors such as pH, TBA value, amino-N, free amino acid, chemical composition, color value (L, a, b), texture profile, sensory evaluation and viable bacterial count of the olive flounder steak (Steak-1, Steak-2) were measured. From the result of sensory evaluation, Steak-2 showed a bit more high scores than Steak-1 but it was difficult to distinguish significant difference (color, odor, taste, texture and acceptance) between Steak-1 and Steak-2 products.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.277-284
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• 1998

The raw food waste of Korea contained markedly high sodium chloride and such high sodium chloride concentration in the soil is a factor limiting plant growth and impairing soil physicochemical properties. This study was carried out to assess the effect of NaCl-containing compost on the growth of lettuce(Lactuca satjva L.) and on the soil chemical properties. For the experiment, six treatments applying 0, 0.5, 1, 3, 6, and 9% NaCl-containing composts at the rate of $20Mg\;ha^{-1}$ were conducted established in a greenhouse. Growth measurements, chemical analysis of lettuce foliage, and soil chemical properties after the harvest were investigated. Lettuce yield in the treatments applied to composts over 3% NaCl was gradually reduced and mortality of lettuce as well as Na concent ration of lettuce foliage progressively increased with successively higher NaCl concentration of composts. With an increase of NaCl concentration of composts, the values of ESP and exchangeable sodium concentration in the surface soil were significantly increased. Especially, ESP of surface soil in the treatment incorporated with 9% NaCl-containing compost after the harvest attained by about 15, suggesting that sodification of surface soil under a greenhouse condition can occur when the compost over 9% NaCl is applied to soil. In conclusion, the application of over 3% NaCl-containing compost at the rates of $20Mg\;ha^{-1}$ can cause undesirable influences in plant growth and also the treatments of over 6% NaCl-containing composts can create conspicuous deteriorations in soil chemical properties in the current year.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.418-424
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• 2015

The content of ${\beta}$-carotene in agricultural foods, such as seasonings, tea, vegetables, cereals, nuts & seeds, oils & fats, and fruits, were quantitatively analyzed using reversed-phase HPLC with an UV/visible detector. Standard reference material (SRM) 2385 was used as a control material to validate measurement of ${\beta}$-carotene in this study. Recovery percentage and relative standard deviation of ${\beta}$-carotene in SRM 2385 were 102% and 1.73%, respectively. Vegetables and tea contained relatively high concentrations of ${\beta}$-carotene (young barley powder, $17,293.95{\mu}g/100g$; raw young barley, $2,755.15{\mu}g/100g$; dried green tea leaves, $13,671.85{\mu}g/100g$; green tea powder, $7,579.04{\mu}g/100g$). Contents of ${\beta}$-carotene in nuts & seeds as well as oils & fats ranged from $11.32{\mu}g/100g$ in almond products (roasted with salt) to $58.56{\mu}g/100g$ in perilla seed oil. Among 20 fruits, a high content of ${\beta}$-carotene was found in apricots (raw), which contained $2,280.35{\mu}g/100g$.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.2
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• pp.85-94
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• 1997

The study is aimed to find out the causes of rapidly increasing chloride (Cl$^{－}$) concentration of the Samyang 3rd pumping station originated from coastal springs of Cheju since January 1996. The study results show that it was caused by following complicated natural and anthropogenic effects. Due to severe draught in 1996 with total rainfall of only 41.7% of annual mean of the last 36 years (1991 to 1995), it creates firstly), significant decrease of the spring discharges as well decline of the groundwater level at the site . Sea water level was in general 4.4 cm to 12.4 cm higher than the groundwater level of the site during 2 to 3.8 hours at each high tide. Those higher potential head of sea water motivates the sea water intrusion into the fresh water lens through the permeable clinkers and fracture zones situated beneath the existing grouted zone which was installed to a maximum 10 m below the ground water surface, The repeated expansion and contraction of the fresh water lens occurred by periodic changes of the sea water level at high and low tide accelerates secondly the enlargement of the transition zone between the fresh and sea water at the site. The decrease of recharge amount by rainfall shortage creates thirdly the reverse flow at the interface of sea water and groundwater. The repeated groundwater extraction of 2790${\pm}$450 $m^3$d$^{－1}$ at the time of low tide, when the fresh water lens of the sire is under the contraction stare, makes additional drawdown of the ground water level and induces the upconing of salt water into the fresh water lens. The duration of spring discharge whose Cl concentration is less than 150 mg/1 at the low tide measured at the nearby springs was about two hours with discharge rate of 532 $m^3$d$^{－1}$ and after that Cl$^{－}$ concentration is increased up to more than 1900 mg/ι.eased up to more than 1900 mg/L.

• Journal of the Korean Society of Food Culture
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• v.18 no.4
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• pp.333-345
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• 2003

We conducted a survey on Japanese women's consciousness of food culture and their traditional food consumption by self filling-out questionnaire during January, 2000 for the period of a month, For the survey we selected 250 women residing in Kyoto, Japan. For the statistic work we used SAS package system, and t-test, $\cal{X}^2-test$ and Duncan's multiple range test were also used to verify the results significance. The purpose of this survey lies in gathering a basic data on the comparative direction of Korean and Japanese women's food culture in the future 1. Comparing the preferred food purchase place, In case of Korean women, traditional market was comparatively more preferred while Japanese women relatively preferred convenience store (p<0.001). 2. In case of Japanese women, they answered there is no difference from ordinary days on New Year's Day (71%) and Christmas (40%) while 38% answered they prepare food at home. 40% said they prepare food on parents-in-law's birthday, and 41% said no difference from ordinary days. 52% said they prepare food at home on husband's birthday. For their own birthday, 32% said yes to preparing food at home while 45% said no difference and 22.3% said eating out. For children's birthday 65% said preparing at home, 16.3% said no difference and 14.9% said eating out. 3. Comparing the conception on traditional food, Korean women answered 'complicated' (77%) most while 'simple' (5%) least, which indicates their demands for simplified recipes. In case of Japanese women, 'complicated' (44%) was most while 'scientific' (6%) was least which indicates their demands for scientific way of recipes. There were differences shown by age (p<0.001) and the older the more said 'simple' or 'logical' (p<0.01). 4. As the reason for the complicity of traditional food recipes, Koreans said 'too many hand skill' (60%) most while 'too many spices' (8%) least. For Japanese, 'various kind of the recipe' (55%) was most while 'too many hand skill' (7%) was least. There were significant differences shown by academic background (p<0.01) and income(p<0.01), and the lower the academic background, the more said 'too many spices' as the reason for the complicity in making traditional food. Generally, the lesser the income, the more tendency to say 'various kinds of the recipe'. 5. In case of Koreans, 'the recipe is difficult' (56%) was high while 'uninterested' (9%) was low in answer which showed differences by academic background (p<0.05), and in case of Japanese, 'no time to cook' (44%) was high while 'uninterested' (7%) was low. 6. The following is the reasons for choosing traditional food as a snack for children. In case of Koreans, they answered as 'traditional food' (34%), 'made from nutrious and quality materials' (27%), 'for education' (22%) and 'suites their taste' (17%) revealing 'traditional food' is highest. In case of Japanese, it was revealed in the order of 'made from nutrious and quality materials' (36.3%), 'traditional food' (25.2%), 'suites their taste' (22.6%), 'for education' (12.8%) and 7. Comparing the most important thing for the popularization of traditional food in the world, Koreans answered 'taste and nutrition' (45%) most while 'shape and color' (6%) least. In case of Japanese, 'taste and nutrition' (75%) was answered most while 'hygienic packaging' (4%) was least. Both considered 'taste and nutrition' as most important thing for the popularization of traditional food in the world. 8. In case of Koreans, they answered they learn how to make traditional food 'from mother' (47%), 'media' (18%), 'school' (15%), 'from mother-in-law' (14%), 'private cooking school' (4%) and 'close acquaintances' (2%). In case of Japanese, they said mostly learn 'from mother', but it was also shown that the lower the academic background the lesser the tendency of learning 'from mother' but 'from school' (p<0.001). 9. About the consumption of traditional fermented food, Koreans said they make kimchi (90%), pickled vegetables (39%), soy sauce (33%), bean paste (38%), salted fishery (12%) and traditional liquors (14%) at home while 67% for salted fishery and 48% for traditional liquors answered they buy rather than making at home. On the other hand, Japanese answered they mostly buy kimchi (60%), soy sauce (96%), bean paste(91%), natto(92%), salt fermented fish foods (77%) and traditional alcoholic beverage (88%) to eat. This difference was shown very distinct between Korean and Japanese women (p<0.001). 10. About the most important thing in food, Koreans answered in the order of 'liking and satisfaction' (33%), 'for health' (32%), 'for relieve hunger' (18%) and 'convenience' (17%). In case of Japanese, it was revealed in the order of 'for health' (61%), 'liking and satisfaction' (20%), 'to relieve hunger' (16%) and 'convenience' (3%). This shows that Japanese women take comparably more importance to health than Korean women. The conception of food was shown different between Korean and Japanese women (p<0.001), and Koreans showed level 4-5 of food culture while Japanese showed level 5.

• Journal of Life Science
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• v.19 no.8
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• pp.1039-1046
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• 2009

The cytochrome P450s (P450s) metabolizing natural products are among the most versatile biological catalysts known in plants, but knowledge of the structural basis for their broad substrate specificity has been limited. The activity of p-coumarate 3-hydroxylase (C3H) is thought to be essential for the biosynthesis of lignin and many other phenylpropanoid pathway products in plants however, all attempts to express and purify the protein corresponding C3H gene have failed. As a result, no conditions suitable for the unambiguous assay of the enzyme are known. The detailed understanding of the mechanism and substrate-specificity of C3Hdemands a method for the production of active protein on the milligram scale. We have developed a bacterial expression and purification system for the plant C3H, which allows for the quick expression and purification of active wild-type C3H via introduction of combinational mutagenesis. The modified cytochrome P450 C3H ($C3H_{mod}$) could be purified in the absence of detergent using immobilized metal affinity chromatography and size exclusion chromatography following extraction from isolated membranes in a high salt buffer and catalytically activated. This method makes the use of isotopic labeling of C3H for NMRstudies and X-ray crystallography practical, and is also applicable to other plant cytochrome P450 proteins.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.1008-1012
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• 2008

Nanoscale zero-valent iron(nZVI) is famous for its high reactivity originated from its high surface area and it has received considerable attentions as one of the latest innovative technologies for treating contaminated groundwater. Due to its fine powdery form, nZVI has limited filed applications. The efforts to overcome this shortcoming by immobilizing nZVI on a supporting material have been made. This study investigated the differences of resin-supported nZVI's characteristics by changing the preparation methods and evaluated its reactivity. The borohydride reduction of an iron salt was proceeded in ethanol/water solvent containing a dispersant and the synthesis was conducted in the presence of ion-exchange resin. The resulting material was compared to that prepared in a conventional way of using de-ionized water by measuring the phyrical and chemical characteristics. BET surface area and Fe content of nZVI-attached resin was increased from $31.63m^2/g$ and 18.19 mg Fe/g to $38.10m^2/g$ and 22.44 mg Fe/g, respectively, by switching the solution medium from water to ethanol/water with a dispersant. The reactivity of each material was tested using nitrate solution without pH control. The pseudo first-order constant of $0.462h^{-1}$ suggested the reactivity of resin-supported nZVI prepared in ethanol/water was increased 61 % compared to that of the conventional type of supported nZVI. The specific reaction rate constant based on surface area was also increased. The results suggest that this new supported nZVI can be used successfully in on-site remediation for contaminated groundwater.