• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1672-1678
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• 2009

We studied the effects of aged total petroleum hydrocarbons (aged TPH) on the survival of allochthonous diesel-degrading Rhodococcus sp. strain YS-7 in both laboratory and field investigations. The aged TPH extracted from a crude-oil-contaminated site were fractionized by thin-layer chromatography/flame ionization detection (TLC/FID). The three fractions identified were saturated aliphatic (SA), aromatic hydrocarbon (AH), and asphaltene-resin (AR). The ratio and composition of the separated fractions in the aged TPH were quite different from the crude-oil fractions. In the aged TPH, the SA and AH fractions were reduced and the AR fraction was dramatically increased compared with crude oil. The SA and AH fractions (2 mg/l each) of the aged TPH inhibited the growth of strain YS-7. Unexpectedly, the AR fraction had no effect on the survival of strain YS-7. However, crude oil (1,000 mg/l) did not inhibit the growth of strain YS-7. When strain YS-7 was inoculated into an aged crude-oil-contaminated field and its presence was monitored by fluorescent in situ hybridization (FISH), we discovered that it had disappeared on 36 days after the inoculation. For the first time, this study has demonstrated that the SA and AH fractions in aged TPH are more toxic to an allochthonous diesel-degrading strain than the AR fraction.

• 자연과학논문집
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• 제10권1호
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• pp.39-47
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• 1998

본 실험은 대식세포 화학주성과 세포내 칼슘과 F-actin 증가에 대한 인삼사포닌 분획의 영향을 알아보기 위하여 수행되었다. 여러 가지 인삼사포닌 분획을 처리한 복강 대식세포는 대조군에 비해 화학주성이 28.4-71% 증가하였다. 세포내에 유리된 칼슘의 양은 65%까지 증가하였으며, NBD- phallacidin을 처리한 세포에서 F-actin의 양은 10% 증가하였다. 칼슘이나 PMA로 활성화시키고 사포닌 분획을 처리하였을 때, F-actin의 양은 현저하게 증가하였으며 이러한 현상은 2분까지 지속되었다. 이러한 결과로 보아 인삼사포닌 분획이 chemoattractant로 작용할 수 있을 것으로 생각된다.

• 한국식품저장유통학회지
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• 제17권1호
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• pp.131-138
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• 2010

연을 새로운 기능성 식품의 재료로 활용하기 위하여 잎과 뿌리로 구분한 후 항산화 및 항암활성을 측정한 결과는 다음과 같다. 총 플라보노이드와 총 페놀릭 화합물은 백련 잎에서 각각 12.84 mg/g 및 24.33 mg/g으로 높게 나타났다. 연의 부위별 DPPH radical 소거활성을 측정한 결과 분획물의 농도가 증가함에 따라 DPPH radical 소거활성이 증가하는 경향을 보였으며, 특히 백련잎의 부탄올 분획물에서 가장 높은 DPPH radical 소거활성을 보였다. 환원력도 분획물의 농도가 증가함에 따라 환원력이 증가하는 경향을 보였으며, 환원력 또한 백련잎의 부탄올 분획물에서 가장 높게 나타났다. Linoleic acid를 이용한 자동산화 억제활성을 실험한 결과 다른 분획물에 비하여 잎의 부탄올 분획물에서 가장 높은 과산화 억제활성을 나타내었고, tyrosinase 저해 활성 역시 잎의 부탄올 분획물에서 가장 높은 활성을 보였다. 연의 부위별 아질산염 소거활성을 측정한 결과 분획물의 농도가 증가함에 따라 아질산염 소거활성 역시 증가하는 경향을 보였으며, 특히 백련과 홍련잎 부탄올 분획물을 1mg/mL의 농도로 첨가하였을 때 각각 95.61%와 92.15%의 높은 아질산염 소거활성을 보였다. 폐암세포와 결장암세포에 대한 생육억제활성을 측정한 결과 백련과 홍련잎의 부탄올 분획물에서 가장 높은 생육억제활성을 보였다.

• 한국조리학회지
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• 제24권2호
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• pp.103-111
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• 2018

The objectives of the present study were to examine the antioxidant activity of autofocusing fractions from egg white protein hydrolysates and obtain higher antioxidant peptide fraction, which could be applied to the food model system. Alkaline protease hydrolysate of egg white protein exerted higher antioxidant activities than other protein hydrolysates and were fractionated on the basis of the amphoteric nature of sample peptides by preparative isoelectric focusing without toxic solvents and reagents, which is termed autofocusing. Neutral and basic fractions showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the acidic fractions. The acidic and neutral fractions showed higher hydroxyl (OH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) values than the basic fractions. The acidic fractions showed higher metal chelating activity than basic fractions. Antioxidant activities of some autofocusing fractions except for ORAC showed higher compared to the crude hydrolysate. These results suggest that peptides fractions from egg white protein are effective antioxidant, and that autofocusing could be useful to increase antioxidant activity for application to food system.

• Ocean and Polar Research
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• 제33권3호
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• pp.255-263
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• 2011

The aim of this investigation was to evaluate antioxidant activity of crude extracts from the halophyte Vitex rotundifolia, their solvent fractions, and isolated compounds (1-3). Antioxidant capacity was determined by measuring DPPH radical, and authentic $ONOO^-$ and $ONOO^-$ generated from 3- morpholinsydnonimine (SIN-1) in vitro as well as degree of occurrence of intracellular ROS, NO and GSH in mouse macrophage Raw 264.7 cells. From comparative analysis, MeOH extract, n-BuOH, and 85% aq. MeOH solvent fractions showed significant antioxidant effect in DPPH radical and $ONOO^-$ assay systems. Activity-guided purification of n-BuOH and 85% aq. MeOH fractions led to the isolation of flavonoids 1-3. Among them, compound 1 exhibited excellent antioxidant effect in all bioassay systems tested. On the other hand, compounds 2 and 3 revealed potent inhibitory effect against $ONOO^-$ generated from SIN-1, comparable with the positive control penicillamine.

• KSBB Journal
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• 제30권6호
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• pp.275-282
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• 2015

Dried samples of Ligustrum japonicum were extracted twice: with methylene chloride and with methanol (MeOH), respectively. The combined crude extracts were successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by liquid-liquid partition. Antioxidant activities of crude extract and its solvent fractions were evaluated by measuring authentic $ONOO^-$, and $ONOO^-$ generated from 3-morpholinsydnonimine (SIN-1) as well as degree of occurrence of intracellular ROS in HT 1080 cells, and genomic DNA oxidation. The 85% aq.MeOH and n-BuOH fractions exhibited the good antioxidant activity. Further purification of the 85% aq.MeOH fracition led to the isolation of Oleanolic acid (1), Maslinic acid (2), and Ursolic acid (3). All compounds showed the significant antioxidant effects in all assay systems.

• 한국식생활문화학회지
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• 제24권6호
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• pp.749-755
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• 2009

We investigated the chemical components of red onion powder dried using the low temperature vacuum method and the inhibitory effects of solvent extracts of the dried red onion powder on the growth of HT-1080 human fibrosarcoma and HT-29 human colon cancer cells and $H_2O_2$-induced oxidative stress. The moisture content of the dried red onion powder was 17.95%, while the vitamin C content was 96 mg/100 g and the total phenols content was 39.1 mg/mL. The inhibitory effects of acetone with methylene chloride (A+M) and methanol (MeOH) extracts of the red onion powder on the growth of HT-1080 and HT-29 cancer cells increased in a dose dependent manner (p<0.05). The inhibitory effect was greater on the growth of HT-29 cells, while the A+M extracts had a higher inhibitory effect than the MeOH extracts. Treatment with the hexane, 85% aq. methanol, butanol and water fractions of the extract led to significant inhibition of the growth of both cancer cell lines (p<0.05). Among the fractions, the hexane and 85% aq. methanol fractions showed a greater inhibitory effect. To determine the protective effect on $H_2O_2$-induced oxidative stress, a DCFH-DA (dichlorodihydrofluorescin diacetate) assay was conducted. All fractions, including the crude extracts of dried red onion, appeared to lead to a significant reduction in the levels of intracellular reactive oxygen species (ROS), and these reductions occurred in a dose dependent fashion (p<0.05). Among the fractions, the 85% methanol fraction showed the greatest protective effect on the production of lipid peroxides.

• East Asian mathematical journal
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• 제34권2호
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• pp.203-217
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• 2018

This study examined preservice elementary teachers' patterns and tendencies in thinking of drawn models of multiplication with fractions. In particular, it investigated preservice elementary teachers' work in a context where they were asked to select among drawn models for symbolic expressions illustrating multiplication with non-whole number fractions including a mixed number. Preservice teachers' interpretations of fraction multiplication used in interpreting different types of drawn models were analysed-both quantitatively and qualitatively. Findings and implications are discussed and further research is suggested.

• 대한수학교육학회지:학교수학
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• 제11권4호
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• pp.723-743
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• 2009

본 논문은 제7차 및 개정 수학과 교육과정에서 제시한 분수의 곱셈과 나눗셈 지도 내용을 바탕으로 관련 내용을 다루는 현행 수학교과서와 익힘책을 상세하게 분석하였다. 우선 전반적인 지도 내용과 관련하여 지도시기의 적절성, 지도계열의 연계성, 차시구성의 적절성을 탐색한 후, 구체적으로 교과서의 내용 전개를 감안하여 각 연산별로 제시된 문장제의 유형과 빈도, 활용된 시각적 모델의 유형과 빈도, 계산방법과 원리의 형식화 과정을 세부적으로 분석하였다. 이를 통해 현재 개발 중인 수학교과용 도서의 기초 자료 및 구체적인 시사점을 제공하고자 한다.

• Fisheries and Aquatic Sciences
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• 제19권7호
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• pp.29.1-29.6
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• 2016

In the present study, we investigated to the antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of the northern shrimp (Pandalus borealis) by-products (PBB) hydrolysates prepared by enzymatic hydrolysis. The antioxidant and ACE inhibitory activities of five enzymatic hydrolysates (alcalase, protamex, flavourzyme, papain, and trypsin) of PBB were evaluated by the 2, 2'-azino-bis [3-ethylbenzothiazoline-6-sulfonic acid] ($ABTS^+$) radical scavenging and superoxide dismutase (SOD)-like activities, reducing power and Li's method for ACE inhibitory activity. Of these PBB hydrolysates, the protamex hydrolysate exhibited the most potent ACE inhibitory activity with $IC_{50}$ value of $0.08{\pm}0.00mg/mL$. The PBB protamex hydrolysate was fractionated by two ultrafiltration membranes with 3 and 10 kDa (below 3 kDa, between 3 and 10 kDa, and above 10 kDa). These three fractions were evaluated for the total amino acids composition, antioxidant, and ACE inhibitory activities. Among these fractions, the < 3 kDa and 3-10 kDa fractions showed more potent $ABTS^+$ radical scavenging activity than that of > 10 kDa fraction, while the > 10 kDa fraction exhibited the significant reducing power than others. In addition, 3-10 kDa and > 10 kDa fractions showed the significant ACE inhibitory activity. These results suggested that the high molecular weight enzymatic hydrolysate derived from PBB could be used for control oxidative stress and prevent hypertension.