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MICROLEAKAGE AND SHEAR BOND STRENGTH OF FLOWABLE COMPOSITE RESIN (Flowable Composite Resin의 미세변연누출 및 전단결합강도)

  • 박성준;오명환;김오영;이광원;엄정문;권혁춘;손호현
    • Restorative Dentistry and Endodontics
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    • v.26 no.4
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    • pp.332-340
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    • 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.

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Distribution Patterns and Ecological Characters of Paulownia coreana and P. tomentosa in Busan Metropolitan City Using MaxEnt Model (MaxEnt 모형을 활용한 부산광역시 내 오동나무 및 참오동나무의 분포 경향과 생태적 특성)

  • Lee, Chang-Woo;Lee, Cheol-Ho;Choi, Byoung-Ki
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.2
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    • pp.87-97
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    • 2017
  • Paulownia species has long been recognized in Korean traditional culture and the values of the species have been researched in various focuses. However, studies on distribution and ecological characteristics of the species are still needed. This study aimed to identify distribution trends and ecological characteristics of two Paulownia species in Busan metropolitan city using the MaxEnt model. The MaxEnt model was established based on the environmental factors such as positioning information of the Paulownia species, topography, climate and degree of anthropogenic disturbance potentiality (ADP), which was collected in the on-site research. The study verified that the accuracy of the model was appropriate as the AUC value of Paulownia coreana and P. tomentosa was 0.809, respectively. In terms of the distribution trends of the two Paulownia species in the research area depending on the distribution model, they were both mainly distributed in downtown where built-up area and bare ground were densely concentrated. The potential distribution area of the two species was identified as $137.4km^2$ for P. coreana and $135.0km^2$ for P. tomentosa. The distribution probability was high in Jung-gu, Dongrae-gu, Busanjin-gu and Yeonje-gu. As a result of the analysis on contribution of the environmental factors, it was turned out that the degree of anthropogenic disturbance potentiality (ADP) contributed to distribution of P. coreana and P. tomentosa by about 50%, and the contribution of the environmental factors had a positive correlation with the degree of ADP. The elevation had a negative correlation with both the two species, which was considered because the species must compete more with native species in natural habitats as the altitude above sea level rises. The research findings demonstrated numerically that the distribution of P.coreana and P. tomentosa depended on artificial activities, and indicated the relevance with the Korean traditional landscape. These findings are expected to provide meaningful information in using, preserving and restoring Paulownia species.

A Study of Garlic-Yackwa Development 1. Quality Characteristics of Garlic-Yackwa Substituted with Different Amounts of Garlic Juice (마늘약과의 개발에 관한 연구 1. 마늘즙 대체량을 달리한 마늘약과의 품질특성)

  • 문숙임
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.8
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    • pp.1285-1291
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    • 2003
  • This study was carried out to find optimum substitution amounts of garlic juice for the purpose of garlic-Yackwa development. Five experimental groups containing 0 t.s, 1/2 t.s, 1 t.s, 1 and 1/2 t.s, and 2 t.s of garlic juice per 1 cup of flour were compared with basic group containing 2 t.s of ginger juice per 1 cup of flour (ginger-Yackwa), by Hunter's colorimetry, texture profile analysis and sensory evaluation. In Hunter's color value, Yackwa, substituted garlic juice from 1/2 t.s to 2 t.s per 1 cup of flour for ginger juice, were lower than ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the lower tendancy of L and a values. The b value of garlic-Yackwa containing from 0 t.s to 2 t.s of garlic juice was higher than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancy of b value. In the texture characteristics, hardness, adhesiveness, springiness and chewiness of all garlic-Yackwa were significantly lower than those of ginger-Yackwa. Cohesiveness of garlic-Yackwa containing from 1 t.s to 2 t.s of garlic juice was significantly higher than that of ginger-Yackwa. Gumminess of Yackwa with garlic juice was higher ($1_{1/2}$ t.s, 2 t.s) than that of ginger-Yackwa, or lower (0 t.s∼l t.s) than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancies of hardness, cohesiveness and gumminess, while springiness and chewiness showed vice versa. In sensory evaluation, the higher amounts of garlic juice in garlic-Yackwa showed the better color, appearance, flavor, taste and overall acceptability. Especially garlic-Yackwa with 2 t.s of garlic juice showed the best color, appearance, taste, overall acceptability among them. Garlic-Yackwa with 2 t.s of garlic juice evaluated the best, while ginger-Yackwa evaluated the worst. In conclusion, these results indicated that 2 t.s of garic juice per 1 cup of flour could be very useful as a substitute for ginger juice in developing garlic-Yackwa.

Parents' Perception and Satisfaction of School Food Materials and Supplier -Performance in Mokpo, Korea- (학교급식 식재료 및 공급업체에 대한 학부모들의 인식 및 만족도 -목포지역 중심으로-)

  • Lee, Seok-In;Kang, Pyong-Yon;Jung, Hyun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.11
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    • pp.1741-1749
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    • 2015
  • The purpose of this study was to investigate parents' perception and satisfaction of school food materials and supplier performance in Mokpo. To achieve these research objectives, a questionnaire was distributed to parents at 66 schools, and a total of 589 were used in the final analysis. The results of this study were as follows. First, satisfaction of school foodservice, showed the following scores: overall was 3.75, quality of food materials was 3.84, reliability of food suppliers was 3.80, education was 3.53, and information was 3.50. Second, 38.5% of parents participated in receiving school materials. Exactly 80.6% of parents showed intentions to participate. The most difficult thing for receiving materials was comparing quality of food materials (46.3%). Third, the most important factor cited for school food supplier was quality (62.3%) and sanitation and safety (24.1%). Forth, most parents were positive about the possibility of replacing foods used at school with environment friendly products. Local foods were cited for use in school foodservice (92.2%). The reasons were good quality (39.9%) and contribution to the local community (28.5%). In conclusion, parent's perception of school foodservice should increase to improve food material quality of school foodservice. Institutions for certifying are needed to offer high quality food materials at school foodservice and improved communication and education tool between the school and parents.

Ectomycorrhizal Development and Growth of Pinus thunbergii Seedlings Inoculated with Pisolithus tinctorius(KJ-1) in Copper Treated Soil (Cu를 처리(處理)한 토양(土壤)에서 Pisolithus tinctorius균(菌)을 접종(接種)한 곰솔유묘(幼苗)의 외생균근발달(外生菌根發達)과 생장(生長))

  • Oh, Kwang In;We, Kye Moon
    • Journal of Korean Society of Forest Science
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    • v.85 no.2
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    • pp.329-339
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    • 1996
  • This study is to investigate the effect of mycorrhizal development, growth, nutrient absorption of P. thunbergii seedlings inoculated with Pisolithus tinctorius(Pt. KJ-1) in relation to toxic materials in soil. The concentrations on copper solution applied to the soils were 0, 40, 120, 260, 430ppm. The results are summarized as follows : 1. The germination of P. thunbergii with Pt. increased greater than without ectomycorrhizal fungi. Mycorrhizal development showed a significant decreasing trend at high concentration, and tolerant Cu test with Pt. in agar plate media showed a decreasing trend at a high level. 2. P. thunbergii seedlings inoculated with Pt. showed that the shoot length was significantly promoted at 40, 120ppm copper levels, and that of noninoculated seedlings had the lowest effect in 430ppm copper level. 3. The outer shape of ectomycorrhizal root tips after inoculating Pt. on P. thunbergii seedlings appeared as a monopodial type, a fern-like type, and a cluster-like type at 0ppm, 40ppm levels, but only monopodial type came out at 260ppm, 430ppm copper levels. 4. Root length, no. of juvenile leaves, total length of juvenile leaves, total dry weight, no. of needles and total length of needles of P. thunbergii with Pt. increased greater than those of noninoculated seedling. Growth response of P. thunbergii seedling inoculated with Pt. increased significantly at 40ppm, 120ppm Cu levels. 5. As a result of analysis of growth medium, pH, Na, CEC increased at higher Cu level, and total nitrogen, organic matters, available phosphorous, K, Ca and Mg decreased at 40ppm, 120ppm Cu levels. As a result of an analysis about a copper within soils, it appeared having high Cu-concentration at 0ppm level of an inoculated Pt. and high Cu-concentration in noninoculated Pt. than in inoculated Pt. at higher level. 6. As a result of an analysis of shoot, N, P, and K-concentration were higher in noninoculated seedlings than in inoculated seedlings, and Cu-concentration was higher in inoculated seedlings than in noninoculated seedlings. The analysis of root resulted in a high N-concentration at 40ppm, 120ppm levels, in a high P-concentration in inoculated seedlings and in a high Cu-concentration in noninoculated seedlings. Cu-concentration was significantly higher at root than at shoot.

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Effects of Added Harvey Powder on the Quality of Yulmoo Kimchi (톳가루의 첨가가 열무김치의 품질에 미치는 영향)

  • Moon, Sung-Won;Lee, Myung-Ki
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.435-443
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    • 2011
  • In this study, we evaluated the effects of harvey powder on the fernentation of Yulmoo Kimchi, by measuring sensory, physicochemical, and microbiological properties during fermentation up to 31 days. The Yulmoo Kimchi, with various levels [0, 0.1, 0.2, 0.3, 0.4% (w/w)] of harvey powder, was fermented at $10^{\circ}C$. The product containing the control evidenced the highest scores for appearance and smell. Taste, carbonated taste, texture and overall acceptability were highest in the 0.1% harvey powder and control. During fermentation, titratable acidity increased while pH gradually decreased. Reducing sugar showed no difference at initial fermentation and then steadily decreased. Total vitamin C was gradually decreased during fermentation and reduced sharply after 10 days, and then almost maintained. Total polyphenol content was the highest in the 0.3% harvey powder on day 0 and maintained in all samples thereafter. Antioxidant effect of the Yulmoo Kimchi with 0.1% harvey powder was shown to be the highest. Also, the time required to achieve maximum levels of lactic acid bacteria, as determined by log numbers of cells and total viable cells, were more delayed in the experimental groups with added harvey powder than in the controls. Our results indicated that the Yulmoo Kimchii with below 0.1% added harvey powder was acceptable.

Chemical Composition and Antioxidative Activity of Kiwifruit in Different Cultivars and Maturity (제주산 참다래의 품종 및 숙도에 따른 화학성분과 항산화 활성)

  • Oh, Hyun-Jeong;Jeon, Si-Bum;Kang, Hye-Young;Yang, Young-Jun;Kim, Seong-Cheol;Lim, Sang-Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.343-349
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    • 2011
  • The chemical composition and antioxidative activity of kiwifruit varieties in Jeju, such as Jecy Gold (Actinidia chinensis var. 'Jecy Gold'), Halla Gold (A. chinensis var. 'Halla Gold'), Jecy Sweet (A. deliciosa var. 'Jecy Sweet') and Hwabuk 94 (A. deliciosa var. 'Hwabuk 94') were investigated. The crude protein, crude lipid, and pH showed no differences among variety and maturity whereas the moisture contents showed differences among the variety and maturity. Jecy Sweet in mature stage showed the highest values in soluble solid, crude protein, crude lipid, and crude ash. The changes in chemical components of kiwifruit by maturity stage were as follows: during ripening, the glucose and the fructose contents increased considerably with the decrease of sucrose content. Potassium, phosphorus, sodium, and magnesium were estimated as the major minerals in kiwifruit and Jecy Sweet contained the highest amounts of potassium and magnesium. At maturity stage, ascorbic, malic and lactic acid were increased with the decrease of citric acid content. The polyphenol contents were 26.81~56.10 ${\mu}g/g$ and 8.64~26.45 ${\mu}g/g$, respectively, in immature and mature fruits. During ripening, the polyphenol content was decreased. The DPPH radical scavenging activity of methanol extracts were 84.47~89.37% and 43.94~76.96% at 500 ppm, respectively, in immature and mature fruits. The immature varieties of kiwifruit have a high DPPH radical scavenging activity. Therefore the chemical composition and physiological activity of kiwifruit was affected by variety and maturity.

Effects of Persimmon (Diospyros kaki Thunb) Syrup Extracted from Persimmon and Persimmon By-products on Blood Glucose Level (감(Diospyros kaki Thunb) 또는 감부산물에서 추출한 감시럽의 혈당수치에 미치는 영향)

  • Yoo, Ki-Hwan;Kim, Seok-Jin;Jeong, Jong-Moon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.682-688
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    • 2011
  • The purpose of this study was to measure the blood glucose level and glycemic index (GI) in response to persimmon (Diospyros kaki Thunb) syrup extracted from persimmon and extract of persimmon by-products. Major component analyses of persimmon syrup I (PSI, 95:5 mixture of purified persimmon syrup and non-purified persimmon syrup) and persimmon syrup II (PSII, 50:50 mixture ratio of purified persimmon syrup and non-purified persimmon syrup) were $0.3{\pm}0.1$ and $0.6{\pm}0.2$ mg/g for total polyphenolic compounds and $70.6{\pm}0.6$ and $66.6{\pm}1.6%$ for total carbohydrates, respectively. Blood glucose responses of PSI and PSII were determined using both normal ICR mice and streptozotocin (STZ)-induced diabetic male Sprague-Dawley (SD) rats. Further, oral glucose tolerance test (OGTT) was performed on diabetic rats to assess the effects of the experimental diets. Blood glucose response and OGTT showed that blood glucose levels were significantly lower in mice and diabetic rats fed PSI and PSII compared to those fed diets of sugar, maple syrup, or honey. The GIs of healthy volunteers in response to PSI and PSII were calculated to be 51.9 and 35.7, respectively. On the contrary, the GIs of healthy volunteers fed diets including sugar, maple syrup, or honey were 52.6, 20.0, and 93.0, respectively. These results suggest that persimmon syrup can be used for both the treatment of diabetics and healthy people due to its beneficial effects on blood glucose level.

Anti-obesity Effects of Black Bean Chungkugjang Extract in 3T3-L1 Adipocytes and Obese Mice Induced by High Fat Diet (검은콩 청국장 추출물이 3T3-L1 지방세포와 고지방식이를 급여한 마우스의 항비만효과에 미치는 영향)

  • Jang, Young-Sun;Jeong, Jong-Moon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.9
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    • pp.1235-1243
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    • 2011
  • In this study, we investigated the antioxidative activity (scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and superoxide anion radical) and anti-obesity effects of black bean chungkugjang extract (BBCE). DPPH free radical-scavenging activity and superoxide anion radical-scavenging activity ($SC_{50}$ value) of BBCE were $162.7{\pm}2.8$ ppm, and $205.62{\pm}3.6$ ppm, respectively. The anti-obesity effects of BBCE were investigated by measuring Oil Red O staining in 3T3-L1 adipocytes. BBCE reduced the content of Oil Red O dye in 3T3-L1 adipocytes. We also examined the effects of BBCE on adiposity, serum lipid, and leptin levels in obese mice fed a high-fat diet. Mice were fed the BBCE experimental diets for 7 weeks, after which they were sacrificed. ICR male mice were randomly divided into three groups, one normal diet group (ND group) and two high fat diet groups with or without BBCE supplementation (HFD group and HFD-BBCE group). The results showed that weight gain and the food efficiency ratio significantly decreased upon addition of BBCE compared to those of the HFD group. Further, white adipose tissue weights of epididymal, mesenteric, and retroperitoneal areas in the HFD-BBCE group were reduced to 34.8%, 7.1%, and 40.6%, respectively, compared to that of the HFD group. The serum levels of triglycerides, total cholesterol, LDL-cholesterol, and leptin in the HFD-BBCE group were significantly lower than those of the HFD group. Based on these results, it can be concluded that BBCE may have beneficial effects on reducing fat mass and serum lipid content.

Placement of Insecticides in the Root Zone of the Plants for Rice Insect Control (살충제 수도근부주변처리의 해충 방제효과)

  • Choi S. Y.;Lee H. R.;Ryu J. K.
    • Korean journal of applied entomology
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    • v.16 no.3 s.32
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    • pp.155-161
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    • 1977
  • During 1976 the effects of insecticide placement in the root zone of the rice plants were evaluated for control of rice insect pests in the screenhouse and in the paddy field at Suweon. The methods of insecticide placement included the use of encapsuled formulation and injection of liquid formulation. In screen house experiments, the root' zone placement of carbofuran was highly effective up to 30 days after treatment against the striped rice borers (Chilo sujppressalis) and up to 17 days after treatment against the small brown planthopper(Laodelphax xtriatellus) and the brown planthopper (Nilaparvata lugens), while the root-zone placement of omethoate and disyston were ineffective. In field experiments, the injection in every other row by the liquid applicator designed at IRRI was less effective for control of the striped "'rice borers and the small brown planthoppers than the caupsule placement. The single root·zone placement of liquid carbofuran, however, seemed to be equal in 'effectiveness to two broadcast applications of carbofuran and diazinon. In the plots treated at 5 days after transplanting, incidence of the dead hearts by the striped rice borers was much lower than in the plots treated at the 18 days after transplanting.

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