• 생약학회지
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• 제48권3호
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• pp.208-212
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• 2017

In this study, analysis of active compounds that are believed to be highly relevant to antioxidant activity was carried out on the methanol extract and its solvent fractions of Corni fructus. The DPPH radical scavenging activity for the comparison of antioxidant activity was higher in order of aqueous fraction > methanol extract > ethyl acetate fraction > n-hexane fraction. It is similar to the order of total polyphenol contents in the samples. As a result of LC-MS analysis, phenolic acid compounds such as caffeic acid, gallic acid and chlorogenic acid and lognin, which is known as a representative active ingredient of Corni fructus, were identified as active compounds. And the antioxidative activity and the total polyphenol content of the extracts and solvent fractions were found to be related to the contents of the compounds. Particularly, it was confirmed that phenolic acid such as caffeic acid contributes to the antioxidative activity of the aqueous fraction of Corni fructus methanol extract.

• 생약학회지
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• 제48권1호
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• pp.46-50
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• 2017

This study was conducted to investigate the antioxidative activities and tyrosinase inhibition effects of fractions from the distilled water extract of Inonotus obliquus. Moreover, GC-MS based analysis with trimethylsilyl (TMS) derivatization was carried out for active compound in the extract of I. obliquus. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate fraction was 0.393 mg/ml as a result of the most effective than other fractions. Meanwhile, aqueous fraction showed higher effect in tyrosinase inhibitoty activity. In GC-MS based analysis with TMS derivatization, 7 compounds including syringic acid, vanillic acid and protocatechuic acid were observed in ethyl acetate fraction, and oxalic acid is the main compound in aqueous fraction. As a result, it was confirmed that oxalic acid in aqueous fraction from the distilled water extract of I. obliquus was a compound showing tyrosinase inhibition effect.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.145-151
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• 1999

Apolipoprotein B-100 (apo B-100) is an important component in plasma low density lipoproteins (LDL). It function as the ligand for the LDL receptor in peripheral cells. The LDLs are removed from the circulation by both high-affinity receptor-mediated and receptor-independant pathways. LDLs are heterogeneous in their lipid content, size and density and certain LDL subspecies increase risk of atherosclerosis due to differences in the conformation of apo B in the particle. In the present study , surface and core peptide fraction of Apo B-100 have been characterized by comparing peptide-mapping and fluorescence spectroscopy. Surface fragments of apo B-100 were generated by digestion of LDL with either trypsin , pronase, or pancreatin elastase. Surface fractions were fractionated on a Sephadex G-50 column. The remaining core fragments were delipidated and redigested with the above enzymes, and the resulting core peptides were compared with surface peptides. Results from peptide-mapping by HPLC showed pronase-digestion was more extensive than trypsin -digestion to remove surface peptide fraction from LDL. Fluorescence spectra showed that core fractions contained higher amount of tryptophan than surface fractions, and it indicated that core fraction wa smore hydrophobic than surface fractions. A comparison of the behavior of the core and surface provided informations about the regions of apo B-100 involved in LDL metabolism and also about the structural features concerning the formation of atherosclerosis.

• 한국수산과학회지
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• 제56권2호
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• pp.196-203
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• 2023

We investigated the nutritional characteristics and antioxidant effects of sea mustard Undaria pinnatifida fractions from Gultongmeori in Taejongdae, Youngdo, Busan. Based on dry weight, the moisture, crude protein, crude lipid, crude ash, and crude fiber contents were 34.98%, 11.55%, 0.43%, 17.82%, and 3.45%, respectively. To evaluate the antioxidant effect, we used radical scavenging (DPPH and ABTS), reactive oxygen species (ROS) production measurement, and DNA oxidation assays. Total flavonoid and phenol contents were higher in the n-hexane fraction than in other fractions. The n-hexane fraction was more effective at scavenging free radicals than other fractions as assessed using DPPH and ABTS assays (P<0.05). The ROS production assay showed that all sea mustard fractions decreased H₂O₂ induced cellular ROS production compared to that seen in the control (P<0.05); however, the n-hexane fraction reduced cellular ROS production to a greater extent than the other fractions. Furthermore, the n-hexane fraction from Gultongmeori significantly inhibited genomic DNA oxidation. These results indicate that the antioxidant effect of sea mustard is associated with its high flavonoid and phenol content. This study proposes that processed food products supplemented with sea mustard can be developed as functional foods to promote health in the local population.

• 한국환경농학회지
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• 제26권3호
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• pp.210-216
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• 2007

The cadmium (Cd) and zinc (Zn) contamination of soils and cultivated crop plants by zinc smelting activities was studied. In the study area of the vicinity of ${\triangle}{\triangle}$ zinc smelting factory in Korea, soils and corn plants were sampled at corn harvesting stage and analyzed Cd and Zn concentration as well as Cd and Zn fraction and chemical properties in soils. At 600 m radius of studied area, Cd and Zn were highly accumulated in the surface soils (0 - 20 cm) showed greater than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with corresponding values 1.7 and 407 mg $kg^{-1}$, respectively. The leaf part gave higher Cd concentration with the corresponding value of 9.5 mg $kg^{-1}$ as compared to the stem and grains pare (1.6 and 0.18 mg $kg^{-1}$), respectively. Higher Zn concentration was also obtained from the leaf part of the corn plant which gave the value of 1,733 mg $kg^{-1}$. The stem and grain part gave corresponding values of 547 and 61 mg $kg^{-1}$. The order of the mean Cd concentration in fractions is F3 (oxidizable fraction) > F2 (reducible fraction) > F4 (residual fraction) > F1 (exchangeable + acidic fraction). A highly positive correlation is observed between F2 and concentration of Cd and Zn in both plant pare, leaf and grain. Highly positive correlations are shown in the pH exchangeable Ca and Mg, and CEC when correlated with Cd and Zn bound to F4 fractions. To reduce Cd and Zn uptake by corn plant in an arable land heavily contaminated with Cd and Zn as affected by smelting factory, an efficient and effective soil management to increase soil pH and CEC is thus recommended.

• 대한수학교육학회지:학교수학
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• 제14권1호
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• pp.45-64
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• 2012

본 정성 연구에서는 교사들의 등분제 분수 나눗셈에 대한 지식을 분석하였다. 자료 수집은 13명의 교사들이 참여한 분수, 소수, 비례 등에 대한 주제를 다룬 40시간의 교사교육 프로그램으로부터 수집되어 일부분이 활용되었으며, 교사들의 등분제 분수 나눗셈 지식을 세밀하게 분석하기 위해 두 가지 지식 요소들 (단위에 대한 지식, 분할 조작)을 분석틀로 사용하였다. 그 결과, 제수와 피제수가 서로소인 등분제 나눗셈 문제 상황을 다루는 능력이 두 지식 요소의 사용여부와 수준에 따라 다르게 나타났다. 두 단계의 단위 구조만을 가지고 추론한 교사의 경우 한 사람의 몫을 주어진 단위로 정확하게 나타낼 수 없었다는 점에서 제한점을 보였으며, 세 단계의 단위 구조를 가지고 추론한 교사는 다양한 분할 조작과 참조 단위의 활용으로 보다 유연하게 문제 상황에 대처할 수 있음을 보여주었다.

• 한국세라믹학회지
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• 제51권5호
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• pp.453-458
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• 2014

SiC and its composites have been considered for use as nuclear fuel cladding materials of pressurized light water reactors. In this study, a $SiC_f$/SiC composite as a constituent layer of SiC triplex fuel cladding was fabricated using a chemical vapor infiltration (CVI) process in which tubular SiC fiber preforms were prepared using a filament winding method. To enhance the matrix density of the composite layer, winding patterns, deposition temperature, and gas input ratio were controlled. Fiber arrangement and porosity were the main parameters influencing densification behaviors. Final density of the composites decreased as the SiC fiber volume fraction increased. The CVI process was optimized to densify the tubular preforms with high fiber volume fraction at a high $H_2$/MTS ratio of 20 at $1000^{\circ}C$; in this process, surface canning of the composites was effectively retarded.

• 보존과학연구
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• 통권31호
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• pp.89-102
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• 2010

This study evaluated the activity of biocidal compounds isolated from natural products and confirmed applicable possibility as conservative agents for orgainic cultural heritages damaged by biological degradation. we used methanol extracts of 11 Korean trees and 17 medicinal plants as natural resources. Among these extracts, Phellodendron amurense was investigated on antifungal activity against Coniophora puteana, Lentinus lepideus, Tyromyces palustris and Aspergillus niger. Asarum sieboldii was investigated on insecticidal activity against adult of Lasioderma serricorne. First, the extract of Phellodendron amurense was partitioned into hexane, dichloromethan and ethylacetate fraction. Among them, the ethylacetate fraction had the most significant antifungal activity. In addition, Asarum sieboldii essential oil showed an effective antifungal and insecticidal activity. As a result, the extract of Phellodendron amurense and Asarum sieboldii essential oil could be useful for conservation of organic cultural heritage against biological deterioration by wood rot fungi and Lasioderma serricorne.

• 대한약침학회지
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• 제16권3호
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• pp.23-29
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• 2013

Objectives: Dyslipidemia in diabetes mellitus is a significant risk factor for the development of cardiovascular complications. The aim of this study was to evaluate the effect of the ethyl-acetate fraction of an ethanolic extract from Streospermum suaveolens on lipid metabolism in streptozotocin (STZ)-induced diabetic rats. Methods: Diabetes was induced by intraperitonial injection of STZ (50 mg/kg). Diabetic rats were treated with an ethyl-acetate fraction orally at doses of 200 and 400 mg/kg daily for 14 days. On the $15^{th}$ day, serum lipid profiles, such as total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL), were estimated in experimental rats. The atherogenic (AI) and the coronary risk (CRI) indices were also evaluated. Results: The ethyl-acetate fraction at doses of 200 and 400 mg/kg significantly (P < 0.001) and dose-dependently reduced serum cholesterol, triglycerides and LDL, but increased HDL towards near normal levels as compared to diabetic control rats. The fraction also significantly (P < 0.001) lowered the atherogenic index (AI) and coronary risk index (CAI) in a dose-dependent manner. Conclusion: The present study demonstrated that the ethyl-acetate fraction of Stereospermum suaveolens exhibits a potent antihyperlipidemic activity in hyperglycemic rats and suggests that the plant may have therapeutic value in treating the diabetic complication of hyperlipidemia.

• 한국식품저장유통학회지
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• 제12권5호
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• pp.496-500
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• 2005

홍경천(Rhodiola dumulosa)을 기능성 식품소재로 개발하기 위하여 홍경천(뿌리)을 80% 메탄올로 열수 추출하여 용매 분획한 후 이들에 대한 항산화, 암세포 성장 억제 및 대식세포의 면역활성 등과 같은 기능성을 조사하였다. 홍경천 메탄올 추출물의 헥산, 에틸 아세테이트, 부탄올, 메탄올 및 물 분획물의 수소공여능은 100 ${\mu}g/mL$의 농도에서 각각 28.30, 53.21, 35.48, 42.64 및 21.14% 로서 에틸아세테이트 분획물이 가장 높았으며, 이는 합성 항산화제인 BHT와 비슷한 항산화 효과를 나타내었다. A549 및 SW480 와 같은 암세포에 용매 분획물 1, 10 및 100 ${\mu}g/mL$의 농도로 48시간 처리한 결과 에틸아세테이트 분획물이 다른 분획물에 비하여 암세포주의 성장을 강하게 억제하였으며, 그 활성은 농도 의존적으로 나타났다. 또한 100 ${\mu}g/mL$의 농도로 48시간 동안 에틸아세테이트 분획물을 암세포에 처리시 처리구에서의 암세포는 뚜렷한 세포수의 감소와 함께 심한 형태학적 변화가 관찰되었다. 대식세포주(RAW 264.7)에 1, 10 및 50 ${\mu}g/mL$의 농도로 용매 분획물을 처리한 후 NO의 생성량을 측정한 결과 10 μg/mL 이상의 농도에서 메탄올 분획물에서 NO 생성을 강하게 유도하였다. 따라서 본 결과는 홍경천의 기능성 식품소재로의 활용 가능성을 시사한다.