• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.1
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• pp.1-10
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• 2013

Dental erosion is a complex disease of multifactorial etiology with high risk of loss of tooth structure, which still has not been appropriate interest. The aim of this study was to assess the prevalence and risk indicators of dental erosion in Korean school children. A cross-sectional survey was performed on 664 children aged 8~9 years. Data concerning gender, types of caregiver, dietary habits, oral hygiene habits and parental knowledge were obtained from a questionnaire, which was answered by the parents of the children. Association between erosion and the factors were statistically analyzed with chi-squared test and independent t-test at a significance level of 0.05. Dental erosion was present in 242 children. In carbonated drinks, dental erosion was significantly associated with preference, frequency of consumption and the ingestion method (p < 0.05). In fruit juices, dental erosion was significantly associated with preference and frequency of consumption (p < 0.05), but no significant associations were found with the ingestion method (p > 0.05). There were no significant associations between dental erosion and gender, type of caregiver, oral hygiene habits and parental knowledge (p > 0.05). In conclusion, it was considered that motivation to be followed by practice is important as well as education for prevention of dental erosion.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.242-253
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• 2020

Purpose: The aim of this study was to compare the accuracy of dies fabricated using 3D printing system to conventional method and to evaluate overall volumetric changes by arranging the superimposed surfaces. Materials and Methods: A mandibular right first molar from a dental model was prepared, scanned and fabricated with composites of polyetherketoneketone (PEKK). Master dies were classified into 4 groups. For the conventional method, the impression was taken with polyvinylsiloxane and the impression was poured with Type IV dental stone. For the 3D printing, the standard die was scanned and converted into models using three different 3D printers. Each of four methods was used to make 10 specimens. Scanned files were superimposed with the standard die by using 3D surface matching software. For statistical analysis, Kruskal-Wallis test and Mann-Whitney U test were done (P < 0.05). Results: Compared to the standard model, the volumetric changes of dies fabricated by each method were significantly different except the models fabricated by conventional method and 3D printer of Stereolithography (P < 0.05). The conventional dies showed the lowest volumetric change than 3D printed dies (P < 0.05). 3D printed dies fabricated by Stereolithography showed the lowest volumetric change among the different 3D printers (P < 0.05). Conclusion: The conventional dies were more accurate than 3D printed dies, though 3D printed dies were within clinically acceptable range. Thus, 3D printed dies can be used for fabricating restorations.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.193-199
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• 2005

To obtain the residual organochlorine pesticides in the ginseng, the methods of multi-analysis for BHC's isomer, DDT's isomer and other organochlorine pesticides by GC-ECD are surveyed. The relative retention time for $\alpha-BHC,\;\beta-BHC,\;\delta-BHC\;and\;\gamma-BHC$ is 1.000, 1.025, 1.034 and 1.056, respectively. The relative retention time for o,p-DDE, p,p-DDE, o,o-DDD, o,p-DDT, o,p-DDD, and p,p-DDT is 1.199, 1.230, 1.242, 1.286, 1.329 and 1.333, respectively. The BHC isomers, DDT's isomer and other organochlorine pesticides are separated with multianalysis condition. The qualified defection concentration for $\alpha-BHC$, Quintozene, Aldrin, Captan, $\alpha-Endosulfan$, and Dieldrin is 0.95ng/g, 0.27ng/g, 1.04ng/g, 0.63ng/g, 0.55ng/g and 0.62ng/g, respectively. The qualified defection concentration for Fenhexamid, Endrin, $\beta-Endosulfan$, o,p-DDT, Endosulfan-sulfate is 5.71ng/g, 0.61ng/g, 0.48ng/g, 0.44ng/g and 0.51ng/g, respectively. BHC, Aldrin, Dieldrin, Endrin and DDT, which were Korea Food & Drug Administration advisory pesticides, are not detected in soil environment. Also it's residual organochlorine pesticides are not polluted in the ginseng on Sangju Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.242-244
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• 1975

Taxonomical evaluation of P. nuntia var. vallata and P. nuntia var. brevicirris Grube was checked. On the basis of the number of paragnaths and its arrangement pattern it is suggested that these two varieties are no longer valid, and they are synonym of Perinereis nuntia(Savigny, 1818).

• Biomedical Science Letters
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• v.23 no.2
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• pp.73-79
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• 2017

Pulse pressure is an independent risk factor for cardiovascular disease. The aim of the present study was to assess the association between pulse pressure and metabolic syndrome in Korean men. The study subjects were 8,439 adults aged 40 to 64 years, who underwent health screening examination from January 2012 to December 2014 at the Health Promotion Center of one hospital in Gyeonggi-do for general health check-up. They include the metabolic syndrome absent group (Absent, n=3,078), the pre-metabolic syndrome group (Pre-MetS, n=4,242) and the metabolic syndrome group (MetS, n=1,119). Progressive increase in pulse pressure was demonstrated for increasing components of the metabolic syndrome (P<0.001). The pulse pressure according to the degree of the metabolic syndrome was higher in the pre-MetS and MetS groups compared to the Absent group (P<0.001). Systolic and diastolic blood pressure, total cholesterol, triglyceride, fasting glucose, and abdominal obesity positively correlated with pulse pressure (P<0.001).

• Journal of Chest Surgery
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• v.19 no.2
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• pp.238-242
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• 1986

The prognosis of patients with VSD and pulmonary hypertension is at least partially related to the reversibility of pulmonary hypertension after surgery. To predict postoperative pulmonary arterial pressure, immediate postbypass values were compared with preoperative hemodynamic data in 18 surgically closed VSD patients aged 6 to 80 months. The following results were obtained. 2] There was a good correlation between preoperative PP/PS and postoperative PP/PS in patients aged over 24 months [r=0.685, p<0.05], and in patients whose QP/QS were over 2.0 [r=0.686, p<0.01]. 3] There was also a good correlation between pump time and postoperative PP in total patients [r=0.697, p<0.005]. 4] Direct correlations were found between preoperative PP/PS and immediate postbypass PP/PS in patients aged over 24 months and in patients whose QP/QS>2.0, but the effect of CPB would participate in some degree. So it may be necessary to reevaluate their relationship after the effect of CPB have been disappeared.

• The Korean Journal of Food And Nutrition
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• v.13 no.3
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• pp.242-248
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• 2000

수산물 가공시 흘러나오는 폐수 중에 함유되어 있는 수용성 단백질을 chitosan에 흡착시키기 위하여 albumin과 hemoglobin, albumin-myoglobin 혼합단백질을 이용하여 chitosan과의 흡착 및 chitosan 제조조건에 따른 흡착효과와 chitosan의 수용성 단백질 흡착에 미치는 인자를 살펴본 결과는 다음과 같다. Chitosan위 탈아세틸화 조건을 60, 70, 80%로 달리하여, albumin, hemoglobin, albumin-myoglobin 혼합용액에 적용했을때 chitosan의 탈아세틸화도가 높을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. 초음파 처리에 의하여 chitosan의 분자량이 작을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. pH변화에 따른 chitosan과 수용성 단백질의 흡착률은 albumin 및 albumin-myoglobin 혼합용액에서는 pH 4.0에서, hemoglobin용액에서는 pH 7.0에서 흡착률이 높게 나타났다 chitosan과 수용성단백질과의 흡착에서 반응시간은 albumin및 albumin-myoglobin 혼합용액에서는 4시간, hemoglobin용액에서는 3시간까지 흡착률이 증가하였고, 그 이후의 시간이 경화하여도 흡착률의 증가는 거의 보이지 않았다. 수용성 단백질 용액에 NaCl 농도를 0.1M에서 1.0M로 증가시켜 첨가했을때 염의 농도가 높을수록 chitosan과 단백질 사이의 흡착이 잘 일어나지 않았다.

• Journal of Plant Biology
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• v.29 no.4
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• pp.233-242
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• 1986

In order to pursue some physiological studies on organogenesis in ginseng tissue culture, ginseng root explants were cultured on a modified MS medium containing NAA and kinetin. The activities of peroxidase and some enzymes were investigated and their isoenzyme patterns were also observed. The activity of peroxidase decreased by 20% in one week's culture and increased thereafter by 80% in culturing for 7 weeks compared with the control group. Glucose-6-phosphate dehydrogenase activity increased by 400% after culturing for 5 weeks and increased during the days preceeding root formation. The activities of glutamate dehydrogenase and acid phosphatase also increased during the culture. After 3 weeks' culture, new peroxidase isozyme (pH 7.6) appeared and 7 weeks' culture, another new peroxidase isozyme (pH unidentified) appeared. These patterns were also identified by using FPLC. After 7 weeks' culture, a new esterase isozyme of pH 8.5 appeared and isozyme patterns of acid phosphatase were quite changed compared with the isozyme patterns of tissue cultured for 5 weeks. In so far as these new isoenzymes appear distinctively after 7 weeks' culture, root differentiation is supposed to be induced after 7 weeks' culture.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.242-245
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• 1997

Co single layer and Co/Ti used to form a CoSi$_2$ contact. We fabricated the n+/p diodes with this CoSi$_2$ contact as diffusion source of As. The diodes wish CoSi$_2$ formed by Co/ri bilayer had more Bo7d electrical characteristics than CoSi$_2$ formed by Co single layer. This shows that the flatness of interface which is a parameters to affect the diodes\` electrical characteristics. And the electrical characteristics of diodes are more good when the second thermal activation processing temperature was low as much as 50$0^{\circ}C$ than the temperature high over than 80$0^{\circ}C$, it was thought as that the silicide was degradated at high temperature.

• Journal of Forest and Environmental Science
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• v.28 no.4
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• pp.242-246
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• 2012

The variation in random amplified polymorphic DNA (RAPD) markers were examined for Xanthoceras sorbifolium Bunge seeds from three plantations (Inner Mongolia [IM], Liaoning [LN], and Shandong [SD] province) in China. Mean genetic variation was measured by polymorphism percentage (42.10%) and expected heterozygosity (He=1.27). Among three populations, Shandong showed the highest values both in polymorphism percentage and heterozygosity (p=57.89; Ho=1.58; and He=1.37). Total genetic diversity value, based on the total loci, was estimated as total genetic diversity of the species (Ht)=0.27 and mean within-population genetic diversity (Hs)=0.16. UPGMA cluster analysis showed the genetic closeness between Inner Mongolia and Liaoning population, but that Shandong seems to be the separate population.