• Journal of Korean society of Dental Hygiene
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• v.14 no.5
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• pp.641-648
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• 2014

Objectives : The purpose of this study is to investigate the attitude toward English learning in the dental hygiene students. Methods : A self-reported questionnaire was filled out by the 498 dental hygiene students in Seoul, Gyeonggi, Gangwon and Chungcheong Province. The questionnaire consisted of motive of English learning, confidence and interest. Data were analyzed by SPSS 19.0 program. Results : Approximately 85 percent of the students had strong motivation for English learning. Test-based English learning generally discouraged the students(61.8%). The students found that listening and speaking was the best way of learning English(44.6%). Most of the students were very interested in English but the cramming method of learning made them tired(p<0.05). Conclusions : Self-directed learning is the best way of learning English to the students. The curriculum should consist of actual listening and speaking practices instead of test-based study.

• The korean journal of orthodontics
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• v.48 no.5
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• pp.316-325
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• 2018

Objective: The aim of this systematic multiscale analysis was to evaluate the effects of thermoforming on the physical and mechanical properties of thermoplastic materials used to fabricate transparent orthodontic aligners (TOAs). Methods: Specimens were fabricated using four types of thermoplastic materials with different thicknesses under a thermal vacuum. Transparency, water absorption and solubility, surface hardness, and the results of three-point bending and tensile tests were evaluated before and after thermoforming. Data were analyzed using one-way analysis of variance and Student's t-test. Results: After thermoforming, the transparency of Duran and Essix A+ decreased, while the water absorption ability of all materials; the water solubility of Duran, Essix A+, and Essix ACE; and the surface hardness of Duran and Essix A+ increased. The flexure modulus for the 0.5-mm-thick Duran, Essix A+, and eCligner specimens increased, whereas that for the 0.75-/1.0-mm-thick Duran and eClginer specimens decreased. In addition, the elastic modulus increased for the 0.5-mm-thick Essix A+ specimens and decreased for the 0.75-mm-thick Duran and Essix ACE and the 1.0-mm-thick Essix ACE specimens. Conclusions: Our findings suggest that the physical and mechanical properties of thermoplastic materials used for the fabrication of TOAs should be evaluated after thermoforming in order to characterize their properties for clinical application.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.316-324
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• 2017

Purpose: Gulbi is a salted and dried yellow corvenia that is popular in Korea. In this study, yellow corvenia was vacuum-dried under two different conditions, average temperatures of $48^{\circ}C$ for 12 and 15 h and $54^{\circ}C$ for 9 and 12 h. Quality characteristics of vacuum-dried Gulbi against fresh corvenia were investigated. Methods: Moisture content, water activity, salt concentration, pH, acidity, volatile basic nitrogen (VBN), thiobarbituric acid-reactive substances (TBARS), and fatty acid composition of Gulbi were evaluated. Results: Moisture contents of fresh corvenia and four types of vacuum-dried Gulbi were 67.37, 31.51, 13.62, 35.17, and 10.05%, respectively. The pH values were in the range of pH 6.70-6.98. The VBN values of Gulbi vacuum-dried at the higher temperature range were greater than those of Gulbi at the lower temperature range. The TBARS of Gulbi increased after vacuum drying (p<0.05). Palmitic acid, palmitoleic acid, oleic acid, and docosahexaenoic acid were the main fatty acids of Gulbi. Conclusion: These results indicate that the quality of vacuum-dried Gulbi is dependent on the drying conditions including temperature and time.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.496-503
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• 2018

Background: Korean ginseng (Panax ginseng) plays an anti-inflammatory role in a variety of inflammatory diseases such as gastritis, hepatitis, and colitis. However, inflammation-regulatory activity of the calyx of the P. ginseng berry has not been thoroughly evaluated. To understand whether the calyx portion of the P. ginseng berry is able to ameliorate inflammatory processes, an ethanolic extract of P. ginseng berry calyx (Pg-C-EE) was prepared, and lipopolysaccharide-activated macrophages and HEK293 cells transfected with inflammation-regulatory proteins were used to test the anti-inflammatory action of Pg-C-EE. Methods: The ginsenoside contents of Pg-C-EE were analyzed by HPLC. Suppressive activity of Pg-C-EE on NO production, inflammatory gene expression, transcriptional activation, and inflammation signaling events were examined using the Griess assay, reverse transcription-polymerization chain reaction, luciferase activity reporter gene assay, and immunoblotting analysis. Results: Pg-C-EE reduced NO production and diminished mRNA expression of inflammatory genes such as cyclooxygenase-2, inducible NO synthase, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. This extract suppressed luciferase activity induced only by nuclear factor-${\kappa}B$. Interestingly, immunoblotting analysis results demonstrated that Pg-C-EE reduced the activities of protein kinase B (AKT)1 and AKT2. Conclusion: These results suggest that Pg-C-EE may have nuclear-factor-${\kappa}B$-targeted anti-inflammatory properties through suppression of AKT. The calyx of the P. ginseng berry is an underused part of the ginseng plant, and development of calyx-derived extracts may be useful for treatment of inflammatory diseases.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.514-518
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• 2004

Many methods are used in the measurement of antioxidative capacity. These meth­ods require very complex procedures and pretreatment. Our suggestions for research will be simple and accurate methods for obtaining many kinds of samples, especially colored samples such as natural product extracts for measuring antioxidative capacities. For oxidation-reduction potential (ORP) system value, we examined the relationships between the ORP-pH system and the ORAC, FRAP methods. To evaluate ORP System value, we calculated the absolute slope/intercept from the linear regression of each standard material at different concentrations and ORP-pH system, and compared the correlations with ORAC and FRAP values.

• KSBB Journal
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• v.27 no.2
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• pp.131-135
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• 2012

To develop potential cosmetic ingredients with antimicrobial and antioxidant activities of 4 Korean bamboo species (P. bambusoides, P. nigra var. henonis, P. pubescens and Sasa coreana) using three different extraction methods-water, ethanol and supercritical fluid extraction. Antimicrobial activities and DPPH assay have been examined. Among the antimicrobial activities against two test strains, Escherichia coli and Staphylococcus aureus, ethanol extracts of 3 bamboo trees, P. bambusoides, P. nigra var. henonis, and P. pubescens, showed stronger than those of supercritical extracts. However, 4 bamboo supercritical extracts showed dose-dependent increase in antioxidant activity by DPPH assay. These results suggest that water fraction of bamboo extracts may be useful for the cosmetic ingredient with low cytotoxicity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.387-394
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• 2000

The relationship between Man and yeast has been a successful and enduring one. The characteristics of yeast have made it an ideal tool in scientific research and as such, it has been used extensively. In this review some of the advantages, methods and applications of yeasts in the biosensor field are outlined. In doing so, we propose a eukaryotic alternative to the current battery of bacteria-based microbial biosensors.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.270-273
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• 2001

The fluorescence sensor is utilized to monitor the complex fluorescence patterns of intra- and extracellular components in cultivation processes. Especially biogenic fluorophores such as proteins and peptides (tryptophan, phenylalanine), coenzymes (FAD, NAD(P)H) and vitamins (riboflavin, pyridoxine) within cells are detected by a fluorescence sensor. In this work a 2-dimensional fluorescence sensor has been used to monitor a production process of itaconic acid by Aspergillus terreus and the on-line monitored spectra data can be con-elated to off-line data measured by a few methods.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.604-605
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• 2003

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.564-564
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• 2005