• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.170-178
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• 2011

The purpose of this study was to assess the prevalence of periodontopathic bacteria and resistance determinants from oral biofilm of children. Subgingival dental plaque was isolated from 87 healthy children, and PCR was performed to determine the presence of 5 periodontal pathogens including P. gingivalis, T. forsythia, T. denticola, F. nucleatum, A. actinomycetemcomitans, and nine resistance genes including tet(Q), tet(M), ermF, aacA-aphD, cfxA, $bla_{SHV}$, $bla_{TEM}$, vanA, mecA. 1. The prevalence of F. nucleatum, T. forsythia. and P. gingivalis was 95.4%, 55.2%, and 40.2%, respectively. In addition. the prevalence of A. actinomycetemc omitans was 5.7%, while T. denticola was 3.4%. 2. In analysis of antibiotic resistance determinants. cfxA, $bla_{TEM}$ and tet(M) were detected in all the samples tested. It was also found that the prevalence of tet(Q) showing tetracycline resistance. $bla_{SHV}$ associated with resistance to ${\beta}$-lactams, ermF exhibiting erythromycin resistance, and, vanA resulting vancomycin resistance was 88.5%, 29.9% 87.4%, and 48.5%, respectively. The aacA-aphD gene showing resistance to aminoglycosides and mecA gene harboring methicillin resistance exhibited the lowest prevalence with 9.2%. 3. In a correlation analysis between periodontopathic pathogens and antibiotic resistance determinants, it was found that there was a significant correlation between T. forsythia and $bla_{SHV}$. Also, P. gingivalis and vanA showed a correlation. Finally, tet(Q) and ermF showed a significant correlation (phi: 0.514) while mecA and vanA also showed a correlation(phi: 0.25).

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.102-107
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• 2009

In clinical pediatric dentistry, we have many chances to encounter the white spot like incipient enamel lesions on the mesial surfaces of the 1st molars with direct vision, especially just after the 2nd primary molars were exfoliated. But it was thought highly desirable to assess if these lesions are properly and effectively managed yet. This study aims at surveying the prevalence of incipient lesions on the mesial surfaces of the 1st molars in children through direct observation and examining the suitability of adhesive sealing on them as a pilot trial in searching for their proper management. 1. Among the 124 mesial surfaces of the 1st molars examined, 34% were sound, 53% had incipient carious lesions and 13% had cavitated lesions. 2. In the sectional views of the specimens, 20% showed microleakage after thermo-cycling and it was thought not recommendable as a permanent method. Therefore in order to effectively fight against the incipient caries lesions in children‘s permanent teeth, it was thought proper not to rely on any one method, but to perform reinforcing oral hygiene and promotion of remineralization in combination with therapeutic sealing which is stronger in short-term sealing effect. Although therapeutic sealing has been considered as the core in minimally invasive concept to treat the white spot lesions, its long-term clinical trials have not been suggested. Continuous research is strongly required for making this approach to acquire permanent nature, especially in regards of proper pretreatment and high molecular materials deeply penetrable into enamel.

• Child Health Nursing Research
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• v.20 no.3
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• pp.159-167
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• 2014

Purpose: The purpose of this study was to investigate factors associated with sexual debut among Korean middle school students. Methods: From the database of the Eighth Korea Youth Risk Behavior Web-based Survey (KYRBS), the researchers selected 37,297 middle school students aged 12-15 years. Data were analyzed using $x^2$ test and multiple logistic regression with the SPSS WIN 18.0 program. Results: The proportion of middle school students who had a sexual debut was 2.1% of boys and 1.5% of girls. In multiple regression analysis, economic status, experience of part time work, smoking, drug use and depression were associated with an increased proportion of sexual intercourse for both boys and girls. Living with parents, drinking alcohol and suicidal ideation were associated with sexual debut for boys only. By contrast, formal sexual education was associated with a reduced risk of sexual debut. Conclusion: The results of this study show the factors associated with sexual debut among Korean middle school students. Gender-related interventions should be taken into consideration in school sexual education programmes, because of differences in related factors according to gender.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.37-44
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• 2013

Sodium hypochlorite and ethylene diamine tetra acetic acid are substances usually used during endodontic treatment. Several studies found that the bonding was negated with certain irrigants and some of the used irrigants have demineralizing and chealating effects, so it was advocated to omit the etching step in etch and rinse adhesive systems. The purpose of this in vitro study was to evaluate the influence of NaOCl & EDTA on the bonding strength of ethanol wet bonding. Thirty human molars were selected and mesiodistally sectioned into halves, thus providing sixty specimens. The specimens were randomly assigned to 4 groups(n=15) according to the irrigant regimen used : (1) irrigated with distilled water for 10min (control); (2) irrigated with 5.25% NaOCl(10min), flushed with 5.25% NaOCl(1min) (3) irrigated with 5.25% NaOCl, flushed with 17% EDTA (4) irrigated with 5.25% NaOCl, flushed with 17% EDTA. Each group was acid-etched with 37% phosphoric acid(except group 4) and had their dentin surfaces dehydrated with ethanol solutions : 50%, 70%, 80%, 95%, 3x100%, 30s for each application. After dehydration, a primer( 50% all bond 3 resin + 50% ethanol) was used, followed by the adhesive(ALL-BOND 3 RESIN) application. Resin composite build-ups were then prepared using an incremental technique. Specimens were sectioned into beams and submitted to a tensile load using a Micro Tensile Tester(Bisco Inc.). The data were statistically analyzed using one-way ANOVA and Tukey HSD at p<0.5 level. There was no significant difference on G1(control) and G2(irrigated with NaOCl only ). (p>0.05). G3(flushed with EDTA) showed significantly high tensile bonding strength compared to the G2 (p<0.05). G4( treated with EDTA but no acid-etching) was significantly lower value than G3. (p<0.05) Although there was no significant difference, 5.25% NaOCl seemed to have an adverse effect on the bonding strength of ethanol wet bonding. The flushing with EDTA after NaOCl irrigation prevents the decrease of bonding strength. The use of 17% EDTA as a final flush can enhance the bonding strength but EDTA flushing can't substitute for a acid-etching.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.46-50
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• 1983

In order to find out the possibility of utilizing red pepper seed as food resources of fats and proteins, a series of studies were conducted. The red pepper seed contained 27.6% of crude fat and 22.2% of crude protein. The lipid fractions obtained by silicic acid column chromatography were mainly composed of 95.4% neutral lipid, where as compound lipid were 4.6%. Among the neutral lipid separated by thin layer chromatography, triglyceride was 85.6%, sterol ester 4.9%, free fatty acids 3.4%, diglyceride 2.5%, sterol 2.2% and monoglyceride 1.1%, respectively. The predominant fatty acids of red pepper seed oil were linoleic acid (57.1-75.4%), palmitic acid (13.9-21.3%) and oleic acid (8.0-15.1%), especially glycolipid contained 1.7% of linolenic acid and small amount of myristic acid and arachidic acid. The salt soluble protein of red pepper seed was highly dispersible in 0.02M sodium phosphate buffer containing 1.0M $MgSO_4$, and the extractability of seed protein was about 25.0%. Glutamic acid and arginine were major amino acids of red pepper seed protein. The electrophoretic analysis showed 6 bands in seed protein, and the collection rate of the main protein fraction purified by sephadex G-100 and G-200 was about 62.2%. Glutamic acid (19.9%) was major amino acid of the main protein, followed by glycine and alanine. The molecular weight of the main protein was estimated to be 93,000.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.11
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• pp.1458-1464
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• 2007

This study was conducted to develope a new type of ready-to-eat smoked Sebastes schlegeli product with high acceptability and extended shelf-life. A Sebastes schlegeli was salted at 4% salt concentration for 6 hr at $4^{\circ}C$. The cold smoking conditions for the salted Sebastes schlegeli consisted of drying for 2 hr at $22{\sim}24^{\circ}C$ followed by smoking for 2 hr at $22{\sim}24^{\circ}C$. The warm smoking conditions for the salted Sebastes schlegeli consisted of drying for 2 hr at $22{\sim}24^{\circ}C$, smoking for 2 hr at $22{\sim}24^{\circ}C$, and smoking again for 30 min at $47{\sim}50^{\circ}C$. The rancidity of the smoked Sebastes schlegeli did not change after 1 year storage at $-20^{\circ}C$ by monitoring the iodine value, peroxide value, and acid value. The number of viable cells in the cold and warm smoked samples were counted as $7.4{\times}10^5$ and $6.2{times}10^5$ CFU/g, respectively. Viable cells were not detected after 1 year of storage at $-20^{\circ}C$. The sensory evaluations of the processed Sebastes schlegeli showed that elastic texture increased with smoking as compared to with salting. There were no significant differences between cold and warm smoking in terms of sweetness, elastic texture, color, and smoke flavor. However, for overall acceptability, preference were in the oder of cold smoked, warm smoked, and salted.

• Economic and Environmental Geology
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• v.22 no.4
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• pp.327-339
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• 1989

Cassiterite, tantalite, columbite and tantalian rutile are found as accessory minerals in Soonkyoung tin-bearing pegmatites. These minerals occur as finely disseminated specks of up to micro-size in diameter and coarse grain size varying from 0.5-50mm in albite, muscovite and quartz assemblage. Cassiterite geneally shows a moderate to intense pleochroism, having a color brownish yellow to deep reddish brown. The substitution of $Ta^{+5}$, $Nb^{+5}$, $Ti^{+4}$ and Fe* for $Sn^{+4}$ in cassiterite ranges 0.01-0.10 mol%. The zoned cassiterite give a higher Ta/Nb ratios in margin than the ratios in core. This is due to the preferential $Ta^{+5}$ affinity to lower temperature during the crystallization of cassiterite. Tantalite-columbite and tantalian rutile occur in cassitertie with exsolution texture and/or infiltrate into the micro-fissures of cassiterite with micro quartz vein. The compositions of tantalite-columbite show the wide ranges of $Ta_2O_5$ : 14-46 wt.%, $Nb_2O_5$ : 60-28 wt. % and FeO*: 10.15 wt.%. The variation of chemical composition in tantalit-columbite exhibits the decreasing trends of $Mn^{+2}/M^{+2}+Fe^*$ with $Ta^{+5}/Ta^{+5}+Nb^{+5}$ increasing. These trends of vatiations indicate that the Ta/Nb fractionation are enhanced by higher Ta-complex activity in late stage of pegmatite consolidation and lower activity of F in agreements with the F-and Li-micas not to be developed in Soonkyoung tin-bearing pegmatite.

• Economic and Environmental Geology
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• v.46 no.5
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• pp.375-390
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• 2013

The Kenticha rare-element (Ta-Li-Nb-Be) mineralized zone is located in ophiolitic fold and thrust complex of southern Ethiopia and was firstly discovered by joint exploration program of Ethiopia-Soviet in 1980s. It includes Dermidama, Kilkele, Shuni Hill, Kenticha, and Bupo pegmatites from south to north. The Kenticha pegmatite intruded parallel to NS-striking serpentinite and talc-chlorite schist, and is exposed approximately 2 km length and 400-700 m width. The Kenticha pegmatite is internally zoned and subdivided into lower quartz-muscovite-albite granite, intermediate muscovite-quartz-albite-microcline pegmatite, and upper spodumene-quartz-albite pegmatite, based on their mineral assemblage. The major, trace elements (e.g., Rb, Li, Nb, Ta, and Ga), and element ratios (e.g., K/Rb, Nb/Ta, Mg/Li, and Al/Ga) suggest that the fractionation and solidification of pegmatite have progressed from the lower towards upper pegmatite. In contrast, unlike general magmatic fractionation, Mg/Li ratios of the Kenticha pegmatite tend to be increased towards the upper pegmatite. It may result from post-magmatic hydrothermal alteration and/or interaction with upper ultramafic rock. Rare-element mineralization in Kenticha pegmatite concentrates on the upper pegmatite, which contains up to 3.0 wt % $Li_2O$, 3,780 ppm Rb, 111 ppm Cs, 1,320 ppm Ta, and 332 ppm Nb. Ore minerals in Kenticha pegmatite mostly include tantalite, spodumene, and lepidolite, and tantalite has an association with coarser quartz-spodumene and relatively fine sacchroidal albite. The tantalite is classified into Mn-tantalite as a function of $Mn^*[Mn/(Mn+Fe)]$ and $Ta^*[Ta/(Ta+Nb)]$ values. Its compositions ($Mn^*$, $Ta^*$, and Nb/Ta) between coarse and fine tantalites are different and the former is strongly enriched in Ta and depleted in Nb compared to latter one. In conclusion, rare-element mineralization in the Kenticha pegmatite may has occurred in the latest stage of magmatic fractionation.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.250-256
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• 1982

A series of studies were conducted to find out the possibility of utilizing grape seed as resources of food fats and proteins, and the results of the studies are as follows: The grape seed contained 25.1%, of crude fat and 12.0% of crude protein. The lipid, fractions obtained by silicic acid column chromatography were mainly composed of about 95.5% neutral lipid, whereas compound lipid was only 4.5% level. Among the neutral lipid by thin layer chromatography, triglyceride was 91.89%, sterol ester, sterol, diglyceride and free fatty acid were 3.24%, 2.87%, 1.20% and 0.80%, respectively The predominant fatty acids of total and neutral lipids were linoleic acid $(69.72{\sim}71.72%)$ and oleic acid $18.09{\sim}19.46%)$, but those of glycolipid and phospolipid were linoleic acid $(31.49{\sim}38.18%)$, oleic acid $(20.20{\sim}35.27%)$ and palmitic acid $(26.80{\sim}39.98%)$. The major fatty acids of triglyceride separated from neutral lipid were oleic acid (43.08%), linoleic acid (38.42%) and palmitic acid (11.60%). The salt soluble protein of grape seed was highly dispersible in 0.02M sodium phosphate buffer containing about 1.0M $MgSO_4$, and the extractability of seed protein was 31%. Glutamic acid was the major amino acid in salt soluble protein, followed by arginine and aspartic acid. The electrophoretic analysis showed 3 bands in grape seed protein, and the collection rate of the main protein fraction purified by Sephadex G-100 and G-200 was 82%. Glutamic acid, aspartic acid and arginine were the major amino acids of the main grape seed protein. The molecular weight for the main protein of the grape seed was estimated to be 81,000.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.72-84
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• 2008

This study was carried out to provide proper management plans for small portable water supply system in the Nonsan area through water quality monitoring, hydrogeochemical investigation and multivariate statistical analyses. Nonsan area is a typical rural area heavily depending on small water supply system for portable usage. Geology of the area is composed of granite dominantly along with metasedimentary rocks, gneiss and volcanic rocks. The monitoring results of small portable water supply system showed that 13-21% of groundwaters have exceeded the groundwater standard for drinking water, which is 5 to 8 times higher than the results from the whole country survey (2.5% in average). The major components exceeding the standard limits are nitrate-nitrogen, turbidity, total coliform, bacteria, fluoride and arsenic. High nitrate contamination observed at southern and northern parts of the study area seems to be caused by cultivation practices such as greenhouses. Although Ca and $HCO_3$ are dominant species in groundwater, concentrations of Na, Cl and $NO_3$ have increased at the granitic area indicating anthropogenic contamination. The groundwaters are divided into 2 groups, granite and metasedimentary rock/gneiss areas, with the second principal component presenting anthropogenic pollution by cultivation and residence from the principal components analysis. The discriminant analysis, with an error of 5.56% between initial classification and prediction on geology, can explain more clearly the geochemical characteristics of groundwaters by geology than the principal components analysis. Based on the obtained results, it is considered that the multivariate statistical analysis can be used as an effective method to analyze the integrated hydrogeochemical characteristics and to clearly discriminate variations of the groundwater quality. The research results of small potable water supply system in the study area showed that the groundwater chemistry is determined by the mixed influence of land use, soil properties, and topography which are controlled by geology. To properly control and manage small water supply systems for central and local governments, it is recommended to construct a total database system for groundwater environment including geology, land use, and topography.