• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.118-121
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• 2005

Methanol extracts were prepared from loquat leaves (2 kg) and successively fractionated with hexane, chloroform, ethyl acetate, butanol, and water solvents. The ethyl acetate fraction exhibited the highest antioxidative and, antimicrobial activities. Therefore, the ethyl acetate fraction was purified and a chemical structure was identified by $^1H$ and $^{13}C-NMR$ spectra, FT-IR and EI/MS spectroscopies. The isolated antioxidative and antimicrobial substance was identified as epicatechin.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.50-58
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• 2022

BACKGROUND: Little is known regarding right ventricular (RV) remodeling immediately after Tetralogy of Fallot (TOF) repair. We sought to describe myocardial deformation by cardiac magnetic resonance imaging (CMR) after TOF repair and investigate associations between these parameters and early post-operative outcomes. METHODS: Fifteen infants underwent CMR without sedation as part of a prospective pilot study after undergoing complete TOF repair, prior to hospital discharge. RV deformation (strain) was measured using tissue tracking, in addition to RV ejection fraction (EF), volumes, and pulmonary regurgitant fraction. Pearson correlation coefficients were used to determine associations between both strain and CMR measures/clinical outcomes. RESULTS: Most patients were male (11/15, 73%), with median age at TOF repair 53 days (interquartile range, 13,131). Most patients had pulmonary stenosis (vs. atresia) (11/15, 73%) and 7 (47%) received a transannular patch as part of their repair. RV function was overall preserved with mean RV EF of 62% (standard deviation [SD], 9.8). Peak radial and longitudinal strain were overall diminished (mean ± SD, 33.80 ± 18.30% and -15.50 ± 6.40%, respectively). Longer hospital length of stay after TOF repair was associated with worse RV peak radial ventricular strain (correlation coefficient (r), -0.54; p = 0.04). Greater pulmonary regurgitant fraction was associated with shorter time to peak radial RV strain (r = -0.55, p = 0.03). CONCLUSIONS: In this small study, our findings suggest presence of early decrease in RV strain after TOF repair and its association with hospital stay when changes in EF and RV size are not yet apparent.

• Journal of Soil and Groundwater Environment
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• v.17 no.5
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• pp.20-30
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• 2012

In case of analyzing PAHs (EPA 16 compounds) in oil-contaminated soils, the lump of peaks may occur because of the aliphatic and polar compounds in oil. This phenomenon is due to the lower accuracy of the analysis. To solve this problem, evaluation of application of silicagel-alumina multi-layer fraction was performed using standard substances and oil-contaminated soils. As a result of application of silicagel-alumina multi-layer fraction cleanup method using standard substances, recovery rates of surrogate standards (5 compounds including Naphthalene-d8) were 83~100% and those of target standards were 75~129%. These were to meet the target values (60~130%) in this study. When used 4% water-silicagel column analyze PAHs in oil-contaminated soils, Some problems were generated for quantitative analysis of PAHs; concentration of PAHs was underestimated due to an upward baseline of internal standard (recovery rate: less than 60%) and overestimated by the lump of peaks which were not purified (the biggest recovery rate: more than 400%). On the other hand, in case of silicagel-alumina multi-layer fraction cleanup method, recovery rate of surrogate standards were 61~101.6%. Therefore this cleanup method was considered a valid method to improve accuracy of analysis of PAHs in oil-contaminated soils.

• Journal of Soil and Groundwater Environment
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• v.20 no.2
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• pp.47-54
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• 2015

The objective of this study was to optimize the experimental conditions for bioleaching of arsenic (As) using Herbaspirillum sp. GW103 and to understand the interaction between bacteria and As during bioleaching. Five variables, temperature, time, CaCO₃, coconut oil cake, and shaking rate, were optimized using response surface methodology (RSM) based Box-Behnken design (BBD). Maximum (73.2%) bioleaching of As was observed at 30℃, 60 h incubation, 1.75% CaCO₃, 3% coconut oil cake, and 140 rpm. Sequential extraction of bioleached soil revealed that the isolate Herbaspirillum sp. GW103 significantly reduced 28.6% of water soluble fraction and increased 38.8% of the carbonate fraction. The results of the study indicate that the diazotrophic bacteria Herbaspirillum sp. could be used for bioleaching As from mine soil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1197-1204
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• 2012

As an effort to develop functional food ingredients and to discover the biological activity, the total phenolic content, total flavonoid content, DPPH and ABTS radical scavenging activity, SOD-like activity, ferric reducing antioxidant power (FRAP), and $Fe^{2+}$ chelating of Aster scaber were measured using a 70% ethanol extract and various solvent fractions. As a result, the total phenolic concent was highest in an ethyl acetate fraction of 141.9 mg GAE eq/g and the total flavonoid content was 105.6 mg QUE eq/g. The DPPH radical scavenging activity was highest in an ethyl acetate fraction of 97.1% at a concentration of 1,000 ${\mu}g/mL$ (p<0.05). The ABTS radical scavenging activity showed a 86.9% ethyl acetate fraction and a 57.9% butanol fraction at a concentration of 125 ${\mu}g/mL$, and higher than that of positive control (${\alpha}$-tocopherol and BHT) (p<0.05). The SOD-like activity showed 42.8% in an ethyl acetate at a concentration of 1,000 ${\mu}g/mL$. The ethyl acetate fraction showed the highest value of FRAP at 1051.9 ${\mu}M$ and a concentration of 1,000 ${\mu}g/mL$ (p<0.05). The $Fe^{2+}$chelating was highest in the 70.1% chloroform fraction at a concentration of 500 ${\mu}g/mL$ (p<0.05). There is the highest correlation between DPPH radical scavenging activity and FRAP (r=0.981) as compared to other antioxidant assays (p<0.01). With these results, we confirmed that the ethyl acetate fraction of Aster scaber has great antioxidant potential. So it can be expected to be developed into a specific functional food ingredient.

• Herbal Formula Science
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• v.19 no.2
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• pp.109-118
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• 2011

Objectives : The Lycoris squamigera Maxim has been used traditionally for treatment of various diseases. However, the studies on the effect of Lycoris squamigera Maxim have not been carried out. In the present study, extract of Lycoris squamigera Maxim were tested for their anti-inflammatory and anti-oxidation effect. Methods : The anti-inflammatory effect of the various solvent extract was studied in lipopolysaccharide (lps)-treated mouse macrophage cells. RAW 264.7 cells were pre-incubated with Lycoris squamigera Maxim extracts for 4h and treated with $1\;{\mu}g/m{\ell}$ lps for 18h, and then the anti-inflammatory effects of extracts were determined. The anti-oxidation effect of extracts measured by DPPH method, reductive potential test, total phenolics test. Results : Extracted root's ethyl acetate layer showed a significant decrease in nitric oxide. And that layer (root's ethyl acetate extract) was showed decrease in TNF-${\alpha}$ concentration dependently. Separated from Root's ethyl acetate extract was fraction 1 has $0.1{\sim}5\;{\mu}M$ range, fraction 2 has $0.1{\sim}10\;{\mu}M$ range did not showed cytotoxicity. Anti-oxidation result as DPPH test showed the best was root ethyl acetate extract. Redusing power was made a comparison between fractions and standard. They were showed similar value. Fraction's total phenol containing result was better then standard. Conclusions : These results suggest that these extracts can be used as anti-inflammatory, anti-axidation materials.

• Composites Research
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• v.30 no.5
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• pp.310-315
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• 2017

In this study, we have investigated microstructure, mechanical properties and wear characteristic of aluminum metal matrix composites with a high volume fraction and uniformly dispersed SiC particles which produced by a liquid pressing process. The volume fraction of bimodal SiC/Al7075 composite was 12% higher than that of the monomodal SiC/Al7075 composite and a compressive strength is increased about 200 MPa. As a result of the abrasion test, the wear width and depth of the bimodal SiC/Al7075 composite were $285.1{\mu}m$ and $0.45{\mu}m$, respectively. The coefficient of friction of bimodal SiC/Al7075 was 0.16.

• Education of Primary School Mathematics
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• v.19 no.1
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• pp.19-30
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• 2016

This study examined pre-service teachers' pedagogical content knowledge of fraction division in a context where they were asked to write a story problem for a symbolic expression illustrating a whole number divided by a proper fraction. Problem-posing is an important instructional strategy with the potential to create meaningful contexts for learning mathematical concepts, especially when real-world applications are intended. In this study, story problems written by 135 elementary pre-service teachers were analyzed with respect to mathematical correctness. error types, and division models. Patterns and tendencies in elementary pre-service teachers' knowledge of fraction division were identified. Implicaitons for teaching and teacher education are discussed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.303-309
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• 2016

The human skins had a lot of changes as aging. The synthesis of collagens and elastic fibers were reduced and the expression of matrix metalloproteinase (MMPs) was increased in the dermis. These changes have been known to be responsible for skin wrinkle formation. In this study, we tried to develop pre-indicator of inner skin aging, and investigated the effect of the cream product containing Gynostemma pentaphyllum gypenoside fraction (Gynostemma pentaphyllum gypenoside cream). 21 ~ 34 years old 52 Korean female volunteers without crow's feet were chosen for this clinical study. The starting point of inner skin aging was confirmed through dermal density measurement, even though outside skin wrinkles were not observed. In addition, 4 and 8 weeks treatment of G. pentaphyllum gypenoside cream significantly increased age-related reduction of dermal density. These results suggest that the evaluation of dermal density can be used as pre-indicator of skin aging. Furthermore, G. pentaphyllum gypenoside fraction is a potential anti-wrinkle agent for prevention and treatment of skin aging.

• Composites Research
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• v.34 no.2
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• pp.88-95
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• 2021

VARTM (Vacuum-assisted resin transfer molding) process is a low-cost process technology and affiliated with OoA (Out of Autoclave). Besides, it has been widely used in various fields. However, because of its lower quality than the autoclave process, it isn't easy to apply the VARTM process to the aerospace industry, which requires high reliability. The main problem of the VARTM process is the loss of mechanical properties due to the low fiber volume fraction and high void content in comparison to the autoclave. Therefore, many researchers have studied to reduce void and increase fiber volume fraction. This study examines whether the method of controlling atmospheric pressure could increase the fiber volume fraction and reduce void during the resin impregnation process. Reliability evaluation was confirmed by compressive strength test, fiber volume fraction analysis, and optical microscopy. As a result, it was confirmed that increasing the atmospheric pressure step by step in the VARTM process of impregnating the preform with resin effectively increases the fiber volume fraction and reduces void.