• Restorative Dentistry and Endodontics
• /
• v.26 no.4
• /
• pp.332-340
• /
• 2001

Flowable composite resin has lower filler content, increased flow, and lower modules of elasticity. It is suggested that flowable composite resin can be bonded to the tooth structure intimately and absorb or dissipate the stress. Therefore, it may be advantageous to use flowable composite resin for the base material of class II restoration and for the class V restoraton. The purpose of this study was to evaluate the microleakage and shear bond strength of four flowable composite resins (Aeliteflo, Flow-It, Revolution, Ultraseal XT Plus) compared to Z100 using Scotchbond Multi Purpose dentin bonding system. To evaluate the microleakage, notch-shaped class V cavities were prepared on buccal and lingual surfaces of 80 extracted human premolars and molars on cementum margin. The teeth were randomly divided into non-thermocycling group (group 1) and thermocycling group (group 2) of 40 teeth each. The experimental teeth of each group were randomly divided onto five subgroups of eight samples (sixteen surfaces). The Scotchbond Multi-Purpose and composite resin were applied for each group following the manufacturer's instructions. the teeth of group 2 were thermocycled five hundred times between 5$^{\circ}C$ and 55$^{\circ}C$. The teeth of group 2 were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, and sectioned longitudinally with a diamond saw. The dye penetration on each of the specimen were observed with a stereomicioscope at $\times$20 magnification. To evaluate the shear bond strength, 60 teeth were divided into five groups of twelve teeth each. The experimental teeth were ground horizontally below the dentinoenamel junction, so that no enamel remained. After applying Scotchbond Multi-Purpose on the dentin surface, composite resin was applied in the shape of cylinder. The cylinder was 4mm in diameter and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. After shear bond strength measurement, mode of failure was evaluated with a stereomicroscope at $\times$30 magnification. All data were statistically analyzed by One Way ANOVA and Student-Newman-Keuls method. The correlation between microleakage and shear bond strength was analyzed by linear regression. The results of this study were as follows ; 1. In non-thermocycling group, the leakage value of Z100 was significantly lower than those of flowable composite resins at the enamel and dentin margin, margin, except that Revolution showed the lower leakage value than that of Z100 at the dentin margin (p<0.05). 2. In thermocycling group, the leakage values of Z100 and Ultraseal XT Plus were lower than those of other subgroup at the enamel and dentin margin, except that Flow-It showed the lower leakage value than that of Ultraseal XT Plus at the dentin margin (p<0.05). 3. The leakage value of Z100 and Ultraseal XT Plus in thermocycling group were not higher than that in non-thermocycling group at the enamel margin. The leakage value of Z100 in thermocycling group was not higher than that in non-thermocycling group at the dentin margin (p<0.05). 4. As for the shear bond strength measurement, there were no statistically significant differences among groups (p<0.05). The shear bond strengths given in descending order were as follows: Z100(16.81$\pm$2.98 MPa), Flow-It(14.8$\pm$4.43 MPa), Aeliteflo(14.34$\pm$3.69 MPa), Revolution(13.46$\pm$4.23 MPa), Ultraseal XT Plus(12.83$\pm$3.16 MPa). 5. Failure modes of all specimens were adhesive failures. 6. There was no correlation between microleakage and shear bond strength.

• Korean Journal of Plant Resources
• /
• v.30 no.1
• /
• pp.38-49
• /
• 2017

The objective of this research was to develop Near-Infrared Reflectance Spectroscopy (NIRS) model for amylose and protein contents analysis of large accessions of rice germplasm. A total of 511 accessions of rice germplasm were obtained from National Agrobiodiversity Center to make calibration equation. The accessions were measured by NIRS for both brown and milled brown rice which was additionally assayed by iodine and Kjeldahl method for amylose and crude protein contents. The range of amylose and protein content in milled brown rice were 6.15-32.25% and 4.72-14.81%, respectively. The correlation coefficient ($R^2$), standard error of calibration (SEC) and slope of brown rice were 0.906, 1.741, 0.995 in amylose and 0.941, 0.276, 1.011 in protein, respectively, whereas $R^2$, SEC and slope of milled brown rice values were 0.956, 1.159, 1.001 in amylose and 0.982, 0.164, 1.003 in protein, respectively. Validation results of this NIRS equation showed a high coefficient determination in prediction for amylose (0.962) and protein (0.986), and also low standard error in prediction (SEP) for amylose (2.349) and protein (0.415). These results suggest that NIRS equation model should be practically applied for determination of amylose and crude protein contents in large accessions of rice germplasm.

• Korean Journal of Plant Resources
• /
• v.33 no.2
• /
• pp.73-79
• /
• 2020

This study was conducted to evaluate the appropriateness cultivation of R. glutinosa by plug seedling. Cultivation by direct seeding (DS) and plug seedling (PS) of R. glutinosa was conducted in each of the Pyeongchang and Eumseong areas. As a result, locally, for the Eumseong area, aerial parts in leaf length, leaf width and number of leaves per plant were better than for the Pyeongchang area. In the cultivation method, leaf width and number of leaves per plant were better with PS cultivation than with DS cultivation. Locally, rhizome yield of underground parts in the Eumseong area was better than that in the Pyeongchang area, but the rhizome yield with DS cultivation in the Eumseong area and PS cultivation in the Pyeongchang area were statistically the same. The fresh rhizome yield for DS in Eumseong, PS in Eumseong, DS in Pyeongchang and PS in Pyeongchang was 1,253 kg/10a, 1,376 kg/10a, 923 kg/10a and 1,256 kg/10a, respectively. Finally, the catalpol content for DS in Eumseong, PS in Eumseong, DS in Pyeongchang and PS in Pyeongchang was 3.67%, 2.03%, 2.96% and 1.60%, respectively. From these results, it can be seen that the R. glutinosa PS cultivation method can increase the rhizome yield.

• Journal of Korean Home Economics Education Association
• /
• v.19 no.4
• /
• pp.57-74
• /
• 2007

The purpose of this study was to investigate differences in adolescent's academic motivation, which is composed of intrinsic learning motivation and extrinsic learning motivation, by family strengths and parent's expectation styles. The subject of this study were 508 students who were selected at random from second, and third grade of middle school in Daegu. Factor analysis and MANOVA were employed for data analysis and Scheff test for post - hoc analysis. The main findings of this study were as follows: First, there were significant differences in learning motivation of adolescents according to the degree of family strengths. More specifically, adolescents who perceived their family strengths to be high had higher intrinsic learning motivation than adolescents who perceived their family strengths to be middle and low. Second, there were significant differences in intrinsic learning motivation of adolescents according to the parent's academic expectation styles. Adolescents who perceived their parent's academic expectation styles paternal support-maternal support, paternal pressure-maternal support, and paternal support-maternal pressure showed higher intrinsic learning motivation than adolescents who perceived their parent's academic expectation styles paternal pressure-maternal pressure. Third, there were significant differences in intrinsic learning motivation of adolescents according to the parent's academic expectation styles and the degree of family strengths. In adolescents group who perceived their family strengths to be low, adolescents who perceived their the parent's academic expectation styles to be paternal support-maternal support, paternal pressure-maternal support and paternal support-maternal pressure had higher intrinsic learning motivation than adolescents who perceived their the parent's academic expectation styles to be paternal pressure-maternal pressure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.5
• /
• pp.636-643
• /
• 2009

This research was to find out what impacts do selection attributes of Jeju local folklore food by Jeju tourists provide on their behaviors. Multiple regression analysis was carried out using statistics package of SPSS+/WIN 12.0 to find out impacts of selection attribute factors of Jeju local folklore food on customers' satisfaction, re-visit, and intention by word of mouth. As the results, for factors with statistically meaningful impacts at the level of meaningfulness (p<0.05); level of satisfaction showed regression coefficient of 0.476 and t value of 5.198 in essential factors; auxiliary factors showed regression coefficient of 0.232 and t value of 2.808; and sensual (five senses) factors showed regression coefficient of 0.165 and t-value of 2.013. Also, for re-visit, essential factors showed impacts with regression coefficient of 0.413 and t-value of 3.540; factors of menu composition showed regression coefficient of 0.228 and t-value of 3.118; and auxiliary factors showed regression coefficient of 0.218 and t-value of 2.643. In positive word of mouth factors, auxiliary factors showed impacts with regression coefficient of 0.273 and t-value of 2.555; sensual (five senses) factors showed regression coefficient of 0.264 and t-value of 2.238; essential factor showed regression coefficient of 0.237 and t-value of 2.230 and factors of menu composition showed regression coefficient of 0.161 and t-value of 2.167. Therefore, in customer behaviors (customer satisfaction, re-visit, and positive word of mouth) regarding Jeju local folklore food by tourists who visited Jeju, local folklore and cultures did not impact on customer behaviors; also, it can suggested this thesis is meaningful as a study proving that the best marketing is focus on essential substances of food as indicated in existing researches.

• Tuberculosis and Respiratory Diseases
• /
• v.60 no.6
• /
• pp.638-644
• /
• 2006

Backgrounds: This study investigated whether or not a polymorphism in the gene encoding the surfactant protein A(SP-A) has any bearing on the individual susceptibility to the development of chronic obstructive pulmonary disease(COPD) in a genetically homogenous Korean population. Methods: The genotypes of 19 COPD patients and 20 healthy neonates as controls were tested using a polymerase chain reaction followed by restriction fragment length polymorphism analysis for the SP-A gene. Results: The specific frequencies of the 6A2 and 6A18 alleles of SP-A1 and the 1A2 allele of SP-A2 were much higher in the COPD group than control group (p<0.05). However, the frequencies of the 6A3 and 6A4 alleles of SP-A1 and the 1A0 allele of SP-A2 in the COPD group were significantly lower than the control group. In the COPD group, the frequencies of the +50 locus genotypes GG of SP-A1 and the +9 locus genotypes CC of SP-A2 were 85.0% and 60.6%, respectively, and 19.7% and 24.8% in the control group, respectively. The frequencies of the polymorphic genotypes or alleles showed a statistically significant difference between the COPD group and the control group (P<0.05). Conclusion: A genetic polymorphism in SP-A is associated with the development of COPD in the Korean population.

• Restorative Dentistry and Endodontics
• /
• v.31 no.4
• /
• pp.300-311
• /
• 2006

The purpose of this study is to evaluate prospectively the effect of different bonding systems and retention grooves on the clinical performance of resin restorations in non-carious cervical lesions (NCCLs). Thirty-nine healthy adults who had at least 2 NCCLs in their premolar areas were included in this study. One hundred and fifty teeth were equally assigned to six groups: (A) Scotchbond Multi-Purpose (SBMP, 3M ESPE, St. Paul, MN, USA, 4th generation bonding system) without retention grooves; (B) SBMP with retention grooves; (C) BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5th generation bonding system) without retention grooves; (D) BC Plus with retention grooves; (E) Adper Prompt (3M ESPE, Seefeld, Germany, 6th generation bonding system) without retention grooves; (F) Adper Prompt with retention grooves. All cavities were filled with a hybrid composite resin. Denfil (Vericom Co., Anyang, Gyeonggido, Korea) by one operator. Restorations were evaluated at baseline and at 6-month recall, according to the modified USPHS (United States Public Health Service) criteria. Additionally, clinical photographs were taken and epoxy resin replicas were made for SEM evaluation. At 6-month recall, there were some differences in the number of alpha ratings among the experimental groups. But, despite the differences in the number of alpha ratings, there was no significant difference among the 3 adhesive systems (p < 0.05). There was also no significant difference between the groups with or without mechanical retention (p < 0.05). Follow-ups for longer periods than 6 months are needed to verify the clinical performance of different bonding systems and retention grooves.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.452-458
• /
• 2019

Coix lacryma-jobi var. ma-yuen (Rom. Caill.) Stapf (CL), which contains riboflavin and coixol, has traditionally been used to treat cancer and arthritis. However, no method for the simultaneous determination of riboflavin and coixol in CL sprouts has been established. In this study, we established and validated a high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the identification and quantification of two reference markers, riboflavin and coixol, in CL sprout extracts. CL sprouts (whole sprouts and leaves) were subjected to extraction with 70% ethanol at room temperature and at 80 ℃ under reflux conditions. The two extractions were validated with respect to specificity, accuracy, precision, and linearity. The content of the two reference markers was highest in leaves extracted under reflux conditions (riboflavin, 8.23 ± 0.32 mg/g; coixol, 5.95 ± 0.04 mg/g). We also investigated the antioxidant activity of the extracts via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) scavenging assays. The results indicated that extracts obtained from sprouts under reflux conditions had the strongest antioxidative effects (DPPH half maximal inhibitory concentration [IC₅₀], 68.9 ± 4.1 g/mL; and ABTS, IC₅₀, 34.9 ± 0.1 g/mL). These results can serve as baseline data for the simultaneous determination of the two reference marker compounds, riboflavin and coixol, and development of functional food materials using CL sprouts.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.639-643
• /
• 2002

Water quality, bacterial phase and fish growth rate were analyzed in the process of artificial seed production of flounder (Paralichtys oliraceus) larvae to investigate the water quality in rearing tank using Ultra Filtration System (UES). Sand Filtration System (SFS) and Ultra Filtration System (Ins) were set up in the experimental group. For the analysis of water quality, pH, salinity, DO, SS, COD, $NH_{4}^{+},\;NO_{2}^{-},\;NO^-,\;DIN$ (dissolved inorganic nitrogen) and DU (dissolved inorganic phosphate) were measured. There was no data difference between SFS group and UES group in most analysis items, but the UEs group showed low salinity and low 55 values, such that salinity was $33.5\%_{\circ}$ in SES group and $30.2\%_{\circ}$ in WS group and 55 was 15.5 mL/L in SES group and 7.0 mL/L for UPS group. For changes in bacterial phase and TBC (Total Bacterial Counts), in SES group, 6$\times$10^{5}CFU/mL in seawater decreased to the ratio of about 116, and TBC, Genus Vibrio and bacteria in the Genus Acinetobacter and Genus Micrococcus sharply increased after nine days, while stable bacterial phase was maintained low in UES group during the experiment except for Genus Ajteromonas. In the growth of the larvae, fish length was 17.0 mm (SGR 14.0) in the SES group and 18.8 mm (SGR 14.3) in the UFS group. It is concluded that when water is supplied for artificial seed production with WS, stabilization of water quality condition and inhibition of bacterial multiplication are possible. When production environment becomes stable, stable growth of fish becomes possible by reduction of environmental stress.

• Korean Journal of Organic Agriculture
• /
• v.22 no.3
• /
• pp.457-468
• /
• 2014

This study was conducted to investigate the effect of mixed-sowing of legume forage and applying of cattle manure on the productivity of rye in order to produce the organic roughage to be effectively reducing the environmental contamination and to provide Hanwoo rearing farmer with safe organic animal products. The present study also aimed to evaluate optimal applying level of cattle manure and carrying capacity of Korean native cattle (Hanwoo) per unit area. The annual amount of crude protein (CP) of rye in Gyeongju were higher than those of in Gyeongsan and Yeongju, and the mixed-sowing of forage pea was the highest (p<0.05) compared with the single-sowing. The amount of CP were increased proportionately corresponded to the applying level of fermented cattle manure, and found significantly (p<0.05) high at the level of 100 and 150 kg/ha groups. With feed value of forage, CP was tended to be higher in the mixed-sowing of legume than the single-sowing of rye at the wintering experimental sites of legume, and in particular the forage peas was higher (p<0.05) than other crops. Carrying capacity of organic Hanwoo (head/ha) was higher (p<0.05) in Gyeongju (3.28 head) than that in Gyeongsan (1.94) and Yeongju (1.50). The carrying capacity in the single-sowing of rye also was lower than that in the mixed-sowing of legume, and the forage peas was the highest among the mixed-sowing groups (p<0.05). Overall, the present results showed that it would be recommended to take into account the wintering for mix-sowing of legume. The fermented cattle manure may be applied for legume in the wintering unavailable regions. In addition, the applying the fermented cattle manure at the level of 100~150kg/ha and the mix-sowing of legume with forage peas may increase the productivity per unit area and feed value including CP for improving carrying capacity of organic Hanwoo.