• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.578-585
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• 2010

The purpose of this research was to estimate dietary sodium exposure and to determine the sodium contents of school lunches in Incheon and Gangwon. In this study, we collected 1,334 samples from 8 elementary schools and 8 middle schools for 15 days. The average lunch intakes at the elementary and middle schools were $381.2{\pm}73.8g$ and $460.4{\pm}81.5g$, respectively. The sodium contents of main dishes, side dishes, and desserts were $49.7{\pm}105.6$ mg/100 g, $517.2{\pm}409.2$ mg/100 g, and $135.4{\pm}195.5$ mg/100 g, respectively. The average sodium intakes through lunch at the elementary and middle schools were $863.0{\pm}291.1$ mg and $1,052.1{\pm}323.4$ mg, and average potassium intakes were $571.1{\pm}193.0$ mg and $655.8{\pm}198.4$ mg, respectively. The results of this study show that sodium intake from school lunches is about 47% of the recommended daily intake (RDI, 2,000 mg per day) established by the WHO. Therefore, it is recommended that sodium exposure be continuously monitored.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.150-157
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• 2002

One of the latest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not dry but left moist before application of the bonding primer Ideally the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically, contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during cavity preparation. The aim of this study was to evaluate the effect of contamination by hemostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were removed soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive papers on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows : Group 1: Dentin surface was not etched and not contaminated by hemostatic agents. Group 2: Dentin surface was not etched but was contaminated by Astringedent$^{\circledR}$(Ultradent product Inc., Utah, U.S.A.) Group 3: Dentin surface was not etched but was contaminated by Bosmin$^{\circledR}$(Jeil Pharm, Korea.). Group 4: Dentin surface was not etched but was contaminated by Epri-dent$^{\circledR}$(Epr Industries, NJ, U.S.A.). Group 5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6: Dentin sorface was etched and contaminated by Astringedent$^{\circledR}$. Group 7 : Dentin surface was etched and contaminated by Bosmin$^{\circledR}$. Group 8: Dentin surface was etched and contaminated by Epri-dent$^{\circledR}$. Group 9: Dentin surface was contaminated by Astringedent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 10: Dentin surface was contaminated by Bosmin$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. Group 11 : Dentin surface was contaminated by Epri-dent$^{\circledR}$. The contaminated surface was rinsed by water and dried by compressed air. After surface conditioning, F2000$^{\circledR}$ was applicated on the conditoned dentin surface The teeth were thermocycled in distilled water at 5$^{\circ}C$ and 55$^{\circ}C$ for 1,000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the knife-edge shearing rod of the Universal Testing Machine(Zwick Z020, Zwick Co., Germany) running at a cross head speed or 1.0 mm/min. Group 2 showed significant decrease in shear bond strength compared with group 1 and group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.121-129
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• 2007

The purpose of this study was to assess the antibacterial effect of sodium dichloroisocyanurate (NaDCC), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) on Enterococcus faecalis and to evaluate and to compare the time-dependant antimicrobial effect of NaDCC with NaOCl and CHX in the root canal in vitro before and after instrumentation. Extracted Human single teeth were prepared by serial instrumentation technique. The samples were autoclaved and contaminated for 3 days with E. faecalis monocultures. The teeth were then divided into 4 groups Each group was irrigated and inserted with 2% NaOCl, 2% NaDCC, 2% CHX and steri)ized saline. After 6, 12, 24, 72h, and 1 week incubation, sterilized paper point was inserted into the root canal. Paper points containing root canal contents were then placed on the agar plate. And then each root cana) was prepared with #4 and #5 GG (Gates-Glidden) drill. The debris were collected in the sterilized microtube and the plates were incubated at $37^{\circ}C$ in an increased $CO_2$ atmosphere. After 24h incubation the growth of bacteria around the paper points were measured. NaOCl and NaDCC solution shows similar antimicrobial effect for E. faecalis at 6, 12, 24, 72h and 1 week. In centrol group, irrigated with sterilized saline, no antimicrobial effect was observed. The results are in agreement with other investigators, who have shown the bactericidal property and possibility of NaDCC as a root canal irrigation solution. Thus it seems that NaDCC solutions can be clinically applied into the root canal within 1 week after dilution.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.257-262
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• 2012

This study was conducted to verify the performance of the solar water circulation apparatus that was installed in a semi-closed sea area of Tongyeong to improve the water quality through removing thermocline and oxygen depleted water mass, and to prevent the occurrence of red tides caused by eutrophication. From 8 weeks of experiments, we found that the thermocline in the semi-closed sea area has been removed gradually after installation of the apparatus. The initial temperature of surface and bottom was $27.9^{\circ}C$ and $23.8^{\circ}C$, respectively and it was changed to $22.1^{\circ}C$ in both depth. In case of DO concentration, there was a big gap between surface (5.49 mg/L) and bottom (2.61 mg/L) and was an oxygen depleted water mass in the bottom area at initial. However DO concentration in bottom layer has increased gradually after operation (6.19 mg/L) and the oxygen depleted water mass has removed. Due to the effects of seasonal variation and the operation of the solar water circulation apparatus for 8 weeks, COD concentration decreased from 5.61 mg/L to 2.36 mg/L in surface area, and from 6.08 mg/L to 1.73 mg/L in bottom area. Dissolved inorganic nitrogen concentration also decreased from 0.135 mg/L to 0.050 mg/L in surface area, and from 0.076 mg/L to 0.051 mg/L in bottom area. This research was conducted from July to September, and it might be possible that the variation of water quality was affected by both seasonal variation and the operation of the water circulation apparatus. Hence a further research is required to verify the performance of the water circulation apparatus itself and to monitor dissolved inorganic nitrogen and phosphorous concentrations as well as Chl-a.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.133-142
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• 2009

In order to understand the present environmental condition and future impingement of Changjiang(Yangtze River) outflow upon the adjacent seas after the scheduled completion of the Sanxia (Three Gorges) Dam in 2009, we tried to estimate the mixing ratios among surface waters of three end-members: Changjiang Water (CW), Kuroshio Water (KW), and East China Sea Water (ECSW) using $^{228}Ra/^{226}Ra$ activity ratio and salinity as tracers. Water samples were collected from 32 stations in November 2005 (R/V Tamgu 3), from 20 stations in July 2006 (R/V Ocean 2000) and from 17 stations in August 2006 (R/V Ieodo) in the northern part of the East China Sea. Radium isotopes in ~300 liters of surface seawater were extracted onboard by filtering through manganese impregnated acrylic fibers and following coprecipitation as $Ba(Ra)SO_4$. Activities of radium isotopes were determined by a high purity germanium detector. Results show that the fraction of CW was in the range of 1-23% in the study area, while KW was in the range of 0-30 % and ECSW 58-100 %. The eastward plume of Changjiang outflow, commonly observed in satellite images during summer and also displayed by the eastward-decreasing CW fraction in this study, could be attributed to Ekman transport caused by the SE monsoon prevailing in this region during summer. Results of this study showed that in the drought season, there was a little or no fraction of CW in the study area. Concentration of dissolved inorganic nitrogen (DIN) showed strong positive relationship with the fraction of CW, suggesting Changjiang as the major source of nitrogen. The mixing curve of DIN indicates the removal of nitrate by biological uptake during the mixing of CW with ambient seawater in the study area.

• Journal of Korean Home Economics Education Association
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• v.15 no.4
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• pp.115-132
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• 2003

The purpose of this study is aimed at giving proof that helps the elementary practical arts education system accomplish as the effects are turned out experimentally. Two classes of the sixth grade of J elementary school in Dae-gu have been selected in order to be experimented. One was chosen as an experimental group, the other was done as a comparative group. The creative-problem-solving learning-model was applied to the experimental group, and the traditional way of teaching was applied to the comparative group. For four classes of the sixth grades, ‘chapter 8: Making with recycled materials’ was proceeded as the content. Then. tests about the way of environmental awareness and creativity were carried out twice. After that, the results of pre and after-test in the comparative and experiment groups were compared using the t-test method. Following the analysis of the data collected in this study. the following major observations were obtained: First, children who were educated the creative problem-solving in a practical arts education achieved higher scores than before. Therefore, it turns out that the CPS method is an effective way to improve the environmental awareness in children. It showed that it included lots of daily habits connected with daily life and it made the intention to carry out the environment-preservation stronger and children´s attitude towards the environment improved. Moreover, making with recycled materials was used to solve an environmental problem, affecting in a positive way in our life. It also made the positive recognition about the environment. Second. the application of the creative problem-solving class of the practical arts education can make positive results to children. It helped children to have more interest in the environment around them. Children´s fluency, flexibility and originality in their ideas were improved as much as possible while they were solving problems. Consequently, the application of the creative problem-solving class model of elementary practical arts environmental education lets children expand environment consciousness and creativity.

• Journal of Nutrition and Health
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• v.43 no.1
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• pp.12-25
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• 2010

This study was carried out to evaluate the bioavailabilities and the digestibilities of oligopeptide chelated (peptide-Ca), anchovy bone (anchovy-Ca) and methionine hydroxyl analogue (MHA-Ca) calcium compared to those of calcium carbonate in rats. In exp1, $CaCO_3$, were added to the basal diet at level of 0, 30 and 60% calcium of the AIN-93G diet. In test groups, peptide-Ca, anchovy-Ca and MHA-Ca, were added to the basal diet to provide calcium at the level of 40% of AIN-93G. In exp1, the bioavailabilities were evaluated from the regression equation of the ratios of theological/ actual calcium intakes of each dietary treatment. In exp2, urine and feces was to evaluate the true- and apparent digestibility and apparent retention. In exp1, Ca-60% group had higher bone mineral density (BMD), bone mineral content (BMC) and bone breaking strength (BBS) than those of the other standard groups. The bone weight and ash content of the peptide-Ca and anchovy-Ca groups were significantly higher than those of the MHA-Ca. Bone calcium content were not significantly different from the test group. The bioavailability of the MHA-Ca group was shown higher BMD (71%), BS (38%) and BBS (27%) compared to another control group. But the regression coefficient for BMD, BS and BBS were lower compare with that of bone ash and BMC. In exp2, the true- and apparent digestibility of test groups were shown to over 90%. Peptide-Ca was not significantly different from other test group, but digestibility and retention were higher compare to other test groups. In conclusion, peptide-Ca, anchovy-Ca and MHA-Ca improved Ca bioavailability in the rats. The compounds were higher Ca digestibility compared with those of $CaCO_3$. It is assumed that difference of digestibility for test groups may be correlated to the bioavailability of test groups in BMD, BMC, BS, BBS and bone ash respectively.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.839-850
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• 2008

This study describes the demographic and diet-related psychosocial correlates of nutrition label use, and examines the relationship between label use and diet. Self-reported dada from a population-based cross-sectional survey of 2073 Korean women aged 20 to 60 years were collected to identify demographic and health-related characteristics, belief on diet-disease relationship, awareness on importance of healthy eating practice and diet quality associated with label use. Label users, who are in the stage of action and maintenance (31.6%), were more likely to have belief on nutrient-disease relationship (in sodium, cholesterol, sugar and trans fat) and were more likely to have higher awareness of the importance of healthy eating practice compared with label nonusers, who are in the stage of precontemplation, contemplation and preparation. Label users were more likely to have higher dietary quality compared with label nonusers [odds ratio (OR) = 2.01; 95% confidence interval (CI): 1.66, 2.44](P < 0.001). Also, label use appeared to be associated with the consumption of diets that were higher vegetables and fruits, and lower in cholesterol. The findings of this study suggests that reading nutrition labels on food packages may improve food choices and enable healthful dietary practices.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.776-785
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• 2008

Maternal stress was one of the common symptoms that pregnant women could have experienced during pregnant period. The purpose of this study was to investigate the relation of maternal stress with maternal nutrients intake and pregnancy outcome. Subjects were 248 pregnant women and were recruited at two hospitals in Seoul area. Individual stress levels were divided by the stress scores (total 41 scores), as low stressed group (< 12) and high stressed group (${\geqq}12$). The social characteristics, nutrient intake, anthropometric measurements and pregnancy outcome were compared between low stressed group (LSG) and high stressed group (HSG) to recognize risk factor of maternal stress. We found that subjects experience stress by various factors which were concern about newborn (40.4%), concern about health (28.8%), economic difficulties (13.2%), depress (10.1%), family relationship (2.9%), concern of house work (2.5%), human relationship (2%). In HSG, unemployed rate (p < 0.05) and pre-pregnancy BMI (p < 0.05) were higher than in LSG. Family size in HSG was larger than that in LSG (p < 0.01). Doing regular exercise with the light activity level was significantly higher in LSG (p < 0.05). The nutrient intake in LSG was slightly higher than that in HSG, but not statistically significant. Pregnancy outcome was not significantly affected by the maternal stress. In conclusion, the risk of maternal stress may be related with a life style during pregnancy. Therefore, life style for maternal stress control, such as weight control and regular exercise is recommended to prevent maternal stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.178-184
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• 1992

The changes in contents of chlorophyll and free proline in the seedling leaves of ten rice cultivars as affected by salt stress were checked in order to obtain the basic information on the judgement of the degrees of salt injury. The difference in salt injury among the cultivars was clearly observed about 25 days after 6% salt treatment. Chlorophyll content was decreased in both Gayabyeo and Taebaegbyeo for 14 days after different salt treatment as salt concentration was increased and the decreased tendency was much higher in Taebaegbyeo than in Gayabyeo over 0.4% salt concentration. Chlorophyll content in Gayabyeo after 0.6% salt treatment was decreased slowly, while in Taebaegbyeo, deminished very rapidly as time progressed, therefore it decreased by about 16% in Gayabyeo and 67% in Taebaebyeo compared to the control at 20 days, respectively. The relationship between chlorophyll content and the degrees of salt injury in ten rice cultivars showed significant negative correlation at 10 day after 0.6% salt treatment. Free proline content in Gayabyeo was increased gradually for 14 days after different salt treatment as salt became higher, while in Taebaebyeo, it was increased rapidly under 0.6% but rather decreased under 0.8% salt concentration. Particularly, it was much higher Taebaegbyeo than in Gayabyeo under salt concentration from 0.4 to 0.6%. Free proline content in Gayabyeo after 0.6% salt treatment was increased from 15 days, on the other hand in Taebaegbyeo, it was increased from 5 days, but rather decreased from 20 days, and it was 6 times higher in Taebaegbyeo than in Gayabyeo at 10 days. There was significant positive correlation between free proline content and the degrees of salt injury in ten rice cultivars at 10 days after 0.6% salt treatment. From the above results, chlorophyll and free proline content may be used as an indicative character of intensity of salt stress as well as varietal difference in resistance to salt stress in the seedling stage.