• Korean Journal of Plant Tissue Culture
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• 제21권1호
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• pp.23-28
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• 1994

This study was rimed out to examine the difference in the cell vitality between mesophyII protoplast (MP) and paraveinal mesophyII protoplast (PVMP) of Nicotiana tabaccum 'Xanti', Petunia hybrida 'Blue Star' and Chrysanthemum morifolium 'Baeckwang' by using urea permeability technique. The effects of various enzyme solutions and incubation time, NAA and thidiazron on plant regeneration from isolated protoplasts were also investigated. The vibratome technique was used for protoplast isolation and urea permeability test because the fresh living, thin tissue stripes (50 ${\mu}{\textrm}{m}$ of thickness) could be obtained with minimal damage with the vibratome. For the three plants examined, the urea permeability on the tested tissue stripes was relatively higher in PVMP than in MP by about Ks = 2.0 $\times$ 10$^{-5}$ cm/sec. The treatment of an enzyme mixture of 1.5% cellulase R-10, 1% Driselase, 0.5% Macerozyme R-10, and 0.5% Pectinase for 4 to 8 h was effective on the isolation of PVMP. The highest frequency of callus formation and plant regeneration from the isolated protoplasts was obtained with NAA 2 mg/L and thidiazuron 0.01 mg/L. Furthermore, the results demonstrated that cell devision and plantlet regeneration was more frequent in the PVMP than in the MP of the same leaf or plant We, therefore, conclude that UM is an excellent experimental material for the callus formation and regeneration from isolated protoplasts.

• Journal of Dental Rehabilitation and Applied Science
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• 제24권3호
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• pp.311-316
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• 2008

Calcium phosphate cement (CPC) has been used as bone substitute successfully due to good biocompatibility and osteoconductivity. One of the important mechanical characteristics of CPC is flowablility, which can be evaluated by measuring rheological parameters. However, there have been few studies that measured rheological properties of CPC. The purpose of this study was to evaluate the rheological properties of CPC paste mixed with 2 kinds of setting solutions, 2% hydroxyprophyl methylcellulose (HPMC) and 35% polyacrylic acid (PAA). The CPC used was dicalcium phosphate dihydrate (DCPD). Rheological properties of CPC paste were measured using rheometer. The statistical analysis was carried out with Mann-whitney test with Bonferronis collection. CPC with both setting solutions showed shear thinning behavior. CPC with 2% HPMC showed signigicantly higher complex viscosity than CPC with 35% PAA(p<0.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• 제12권10호
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• pp.4378-4384
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• 2011

In order to evaluate the anti-oxidative capabilities of Angelica dahurica Radix ethanol extract (ADEE), we analyzed the contents of polyphenol and flavonoid compounds and the electron donating ability from ADEE. For animal experimentation, the test agent was topically applied to the artificial tanning spots which were induced by 1,500 mJ/$cm^2$ of ultraviolet B radiation on the backs of brown guinea pigs weighing approximately 450~500g. The test agent of $30{\mu}{\ell}$ was applied (6areas per group) twice a day, five days a week, for five weeks. On completion of the experiment, the animals were sacrificed under anesthetization, and the artificial tanning spots were obtained by biopsy punch and stained with H&E to observe the histological change in the epidermis and dermis. As a result, the contents of polyphenol and flavonoid compounds in ADEE were 20.7mg/g and 19.5mg/g respectively. As the for electron-donating capability of ADEE, it was observed that ADEE displays a dose-dependent antioxidative capacity of 14.8% and 19.8% at the concentration of 500 and 1000 ${\mu}g/m{\ell}$ respectively. Tissue staining with H&E revealed that the epidermis of the control group was slightly thicker than that of the other groups. However no inflammation or any other undesirable effect on the skin tissue due to ADEE was observed. These results indicate that ADEE is of value as a natural antioxidant.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권12호
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• pp.768-777
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• 2017

The efforts to improve river levee maintenance technologies have accelerated globally in a bid to deal with the flood damage resulting from the changes to the climate and flood events. This paper, in line with such tendency, proposes an evaluation system of a river levee safety map to maintain the river levee in an efficient manner. The concept of a river levee safety map is aimed at maximizing the maintenance efficiency for a manager to indicate the safety index, including the current river levee sliding, piping, and visual inspection on a GIS map. To develop such an evaluation system, a safety index covering the sliding, piping, and visual inspection are designated through the data and document examination and the rational guideline to classify each index into three grades, A, B, and C, is proposed. Based on the guideline proposed, the sliding and piping characteristics in terms of safety depending on the change to the flood water level duration time at the test section (Nam river) were evaluated by numerical analysis. As a result, both the protected landside and riverside satisfied the requirements for Grade A in terms of sliding, and when it comes to piping, the grade declined to C because the flood water level duration time increased at R2. As a planning study to propose a river levee safety map evaluation system, a further advanced study, standardization of the river levee data, and improvement of the existing system and laws are required.

• Korean Journal of Community Nutrition
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• 제14권5호
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• pp.590-599
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• 2009

The purpose of this study was to analyze the relationship of nutritional status measured by the body composition and dietary nutrients intakes with calcaneal broadband ultrasound attenuation in college students. Total of 886 (462 male and 424 female) students who received health examination in May 2007 participated in this research. Participants bone status was measured by a quantitative ultrasound method and t-score was calculated via WHO guideline. For body composition measurements, body fat, height and weight were measured and BMI was calculated. Dietary data were collected by a 24-hour recall method. Based on Asia-Pacific standard of WHO, BMI was divided into 3 groups; UW (BMI < 18.5), NW + OW (18.5 $\leqq$ BMI < 25) and Obese group (25 $\leqq$ BMI). Among male students, 2.4% belong to the UW group, 45.0% to the NW+OW group and 52.6% belong to the obese group, bwhile 10.4% of female students belong to the UW group, 71.9% to the NW + OW group and 17.7% of female students belong to the Obese group. Differences among male and female students were statistically significant (p < 0.001). Students with higher BMI showed significantly higher bone health status. Male students did not show any significant differences in nutrients intakes by BMI groups while female students showed the higher intakes of energy, protein, pyridoxin, phosphorus, iron and zinc among NW + OW group than other groups (p < 0.05). The qualitative and quantitative evaluation of diet by BMI groups did not show any significant differences in both male and female students. The result of the multiple regression analyses showed that the body fat and bone status was negatively related while energy intake was positively related with the bone status. These results revealed that bone health status was positively affected by BMI but not by body fat. In conclusion, among those who are at their twenties, the period when the bone density becomes maximized, body fat may negatively affect bone health unlike during other life cycle stages.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제12권
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• pp.31-36
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• 1972

These studies were carried out to find out the proper plant spacing and the optimum amount of nitrogen for maximum yield, on the occasion of early planting with creen vegetable (soybean for cook with rice) at the low temperature in early spring. The plant spacing were applied in 5 levels (50cm$\times$5cm, 50cm$\times$10cm, 40cm$\times$10cm, 30cm$\times$10cm and 30cm$\times$20cm) and the amount of nitrogen were applied in 4 levels (non, standard, twice and triple-amount), The triple super phosphate and potassium chloride were applied only in standard amount. The promotion of flowering was practised by the short-day treatment for 10 days (11 hr. a day). The variety examined was the early maturing one, HOKKAI # 1. and the results are as follow. 1. The plant spacing for maximum yield by the promotion of branch, pod and garin per a plant recognized the fact that there were 2 levels (50cm$\times$10cm and 30cm$\times$20cm planting method) and the maximum yield by the promotion of pod and grain per area showed the fact that there were 2 levels (50cm$\times$5cm and 30cm$\times$10cm planting method) in narrow planting method. 2. The optimum amount of nitrogen applied for maximum yield of pod and grain per area recognized w hat was sufficient as standard amount.

• Journal of the Korean Chemical Society
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• 제45권5호
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• pp.481-490
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• 2001

The purpose of this study was to find out the problems on the fractional distillation experiments in the middle school science textbooks based on the 6th curriculum and to suggest an efficient experiment method for the middle school students. The first step was the classification of the experiments in 8 science textbooks according to heating apparatus and liquid mixtures. The second step was doing each experiment 3 times followed by the experimental process in the textbooks. The third step was developing the alternative experiments for solving the problems found in the second step. The heating method used in the alternative experiments were direct heating, oil bath, and heating mantle. The results of the second step showed that the direct heating experiment of branched round flask was more close to the theoretical prediction than the experiment of water bath heating of branched test tube. Also the direct heating experiment of thermally insulated branched round flask was better than the result of the experiment which was not insulated. The results of the third step showed that the experiment using heating mantle regulated heating power by observing the temperature of distillate gave the closest result to the theoretical prediction. From the above results, it is concluded that the experiment using branched test-tube with water bath heating is not adequate for the fractional distillation and an alternative experiment using insulated branched round flask with heating mantle regulated heating power during experiment is recommended.

• Journal of Korean Society of Environmental Engineers
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• 제39권6호
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• pp.348-355
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• 2017

Human activities have resulted in soil pollution problems to us. Human and ecological risk assessment have been suggested as an efficient environmental management strategy for protecting human and ecosystems from soil pollution. However, Korean environmental policy is currently focused on human protection, and fundamental researches for ecology protection are required for institutional frameworks. In this study, we developed a schematic frame of Korean soil ecological risk assessment, and suggested the basic information for its application. This study suggested a soil ecological risk assessment scheme consisting of 4 steps for derivation of Predicted-No-Effect-Concentration (PNEC): 1) ecotoxicity data collection and reliability determination, 2) data standardization, 3) evaluation of data completeness for PNEC calculation, and 4) determination of ecological-risk. The reliability determination of ecotoxicity data was performed using Reliability Index (RI), and the classification of domestic species, acute/chronic, toxicity endpoint, and soil properties was used for data cataloging. The PNEC calculation methodology was determined as low-reliability, middle-reliability, and high-reliability according to their quantitative and qualitative levels of ecotoxicity data. This study would be the introductory plan research for establishment of Korean soil ecological risk assessment, and it can be a fundamental framework to further develop guidelines of Korean environmental regulation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• 제3권4호
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• pp.193-202
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• 1998

Water quality of Masan-Jinhae Bay was monitored from January 1996 to August 1997. The monitoring focused on the spatial and vertical gradients and seasonal changes of eutrophication parameters such as nutrients, DO and water transparency. Flagellate phytoplanktons persistently bloomed from April to October with monospecific or mixed algal blooms and dynamic algal successions were observed in this area. Algal blooms were highly correlated with salinity drops and made the water less transparent. Stratification of oxygen content was persistent through summer and oligo-oxygenation was developed in the bottom waters. Nutrient gradients were consistently maintained through the depth in summer and through spatial distribution from inner Masan Bay to outer Jinhae Bay in winter. Except the rainfall seasons, water quality was under the influence of the waste waters discharged from watershed around the Masan Bay. The waste waters would act as the primary factor for the water quality deterioration of the bay. Literature data for eutrophication were gathered and analyzed to review the water quality trends of the Masan and Jinhae bays since 1970. Annual mean COD and phosphate concentration consistently increased from 1975 to 1990 and decreased or dropped after 1991. The sediment of inner part of Masan Bay was dredged from 1991 to 1994 as a decontamination process and it is assumed that the dredging has weakened more or less the deterioration trend of the water quality of the bay.

• Journal of Food Hygiene and Safety
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• 제23권4호
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• pp.324-329
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• 2008

An analytical method for the simultaneous determination of nine quinolones (QNs) namely, marbofloxacin, norfloxacin(IS), ciprofloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine in flatfish and egg was developed and validated using liquid chromatography with fluorescence detection (LC-FD). The samples were extracted using a traditional liquid-liquid extraction process; deproteinization was accomplished by the addition of trichloroacetic acid and acetonitrile (ACN), and defatting was performed with hexane. Chromatographic separation was achieved on a reverse phase C8 column with gradient elution using a mobile phase of 200 mM ammonium acetate buffer (pH 4.5) and ACN. The proposed method was validated according to the CODEX guideline. Mean recoveries of QNs from flatfish and egg were 89.6-106.5% with relative standard deviations (RSDs) below 15% at three different concentrations of 50, 100 and $500{\mu}g/kg$. Linearity was obtained with a correlation coefficient ($r^2$) of 0.9989-1.0000. The LOD for the investigated QNs was $1-16{\mu}g/kg$ depending on flatfish and egg. The present method can be applied simultaneously to determine QNs in muscle of flatfish and egg.