• Food Science and Biotechnology
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• v.16 no.6
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• pp.1041-1045
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• 2007

Heated onion juice was partitioned using the solvents hexane, chloroform, ethyl acetate, and butanol. The ethyl acetate fraction showed the strongest scavenging effect on the ABTS radical. The antioxidant activities of the ethyl acetate fraction from raw and heated onion (120, 130, and $140^{\circ}C$) were evaluated using radical scavenging assays. Radical and nitrite scavenging activities were higher in heated onion than raw onion, and the higher the temperature of heat treatment, the greater the radical and nitrite scavenging activities. Heated onion ($140^{\circ}C$, 2 hr) was more effective than raw onion, having higher DPPH radical scavenging (5.7-fold), hydroxyl radical scavenging (6.4-fold), superoxide radical scavenging (2.3-fold), hydrogen peroxide scavenging (11.8-fold), and nitrite scavenging (4.3-fold) activities. Onion increased its physiologically active materials after heating, and in this regard, heated onion can be used as biological material for the manufacture of health foods and supplements.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.52-58
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• 2014

Structurally, herboxidiene contains the tetrahydropyran acetic acid moiety and a side chain including a conjugated diene, and has been isolated from Streptomyces chromofuscus ATCC 49982. Its production was significantly elevated nearly 13.5-fold (0.74 g/l) in a medium supplemented with glycerol (medium No. 6A6), and was more efficacious (1.08 g/l; 19.8-fold) in fed-batch fermentation at 36 h in medium No. 6A6, from Streptomyces chromofuscus. For further enhancement, regulatory genes metK1-sp and afsR-sp from Streptomyces peucetius were overexpressed using an expression vector, pIBR25, and similarly ACCase from Streptomyces coelicolor and two genes, metK1-sp and afsR-sp, were also overexpressed using an integration vector, pSET152, under the control of the strong $ermE^*$ promoter in Streptomyces chromofuscus. Only the recombinant strains S. chromofuscus SIBR, S. chromofuscus GIBR, and S. chromofuscus AFS produced more herboxidiene than the parental strain in optimized medium No. 6A6 with an increment of 1.32-fold (0.976 g/l), 3.85-fold (2.849 g/l), and 1.7-fold(1.258 g/l) respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.38-43
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• 1994

To investigate the effects of krill and cadmium on lipid composition of plasma in cholesterol-fed rats, male Sprague-Dawley rats were raised for 4 weeks with 8 experimental diets. The cholesterol, ${\beta}-lipoprotein$, phospholipid and triglyceride concentration of plasma in rats fed krill diets containing below 5%9w/w) krill were not significant differences in comparison with those of control diet. The ingestion of cadmium caused a significant increase in free cholesterol 91.6-fold), triglyceride 91.6-fold), ${\beta}-lipoprotein$(1.4-fold) and total cholesterol (1.3-fold) level, and then HDL-cholesterol concentration of cadmium diet was 1.6-fold lower than that of control diet. The krill supplement of cadmium diet rather resulted in a increase in total cholesterol, free cholesterol, ${\beta}-lipoprotein$ and triglyceride concentration of plasma.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.176-181
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• 2008

This study analyzed the some of the physiological activities of 70% ethanol extracts of specialty rough rice ('Goami2', 'Keunnunbyeo', and 'Heugkwangbyeo' rough rice cultivars) before and after germination. The physiological activities of the extracts were analyzed for their inhibition of linoleic acid peroxidation, hydrogen peroxide radical scavenging activity, superoxide dismutase-like activity, xanthine oxidase inhibitory activity, and nitrite scavenging effects. The most active rough rice cultivar was 'Heugkwangbyeo' and germinated 'Heugkwangbyeo' rough rice was more effective than ungerminated rough rice, having higher inhibition activity of linoleic acid peroxidation (1.2-fold), hydrogen peroxide radical scavenging activity (1.4-fold), superoxide dismutase-like activity (1.2-fold), and xanthine oxidase inhibitory activity (1.1-fold). The nitrite scavenging effect was increased after germination (2.1-fold) and decreased as pH increased. According to the results obtained in this study, 70% ethanol extracts from germinated 'Heugkwangbyeo' rough rice can be used for industrial applications such as the functional food materials.

• Biomedical Science Letters
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• v.28 no.1
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• pp.25-33
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• 2022

The imbalance of oxidative stress due to the excessive production of reactive oxygen species (ROS) leads to the pathogenesis of liver disease. To prevent this, the role of antioxidant mechanisms is important. Antioxidant studies have been reported on the Filipendula glaberrima Nakai. However, studies applied to HepG2 cells, which are human liver cells, have not yet been conducted. In this study, 70% ethanol extract of Filipendula glaberrima Nakai (FGE) was prepared and antioxidant activity was investigated. It was confirmed whether FGE pretreatment could reduce hydrogen peroxide-induced oxidative stress in HepG2 cells. The increase in gene expression of antioxidant biomarkers and the scavenging ability of ROS were measured, and Hoechst 33342 staining was used to know the inhibitory effect of the apoptosis. As a result, FGE significantly increased SOD (2.6-fold), CAT (4.4-fold), MT-1A (3.1-fold), GPx (4-fold), and G6PD (2.4)-fold compared to the H₂O₂-treated group. FGE directly inhibited ROS production from 13.4 to 3.6 (the fluorescence mean of DCF-DA) and also reduced apoptotic cells from 45% to 10% (Hoechst 33342 staining) at 2.5 ㎍/mL. These results demonstrate the excellent antioxidant activity of FGE and show that it can be used as a functional food to prevent liver disease.

• Microbiology and Biotechnology Letters
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• v.52 no.2
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• pp.122-134
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• 2024

Levan is a functional fructooligosaccharide that belongs to the class of fructans and displays a range of physiological and dietary benefits. Levansucrase, classified as a fructosyltransferase, catalyzes the synthesis of levan fructans through the transfer of d-fructosyl residues from sucrose. Recombinant levansucrase exhibits a significantly high level of expression and activity in E. coli, however, its industrial applicability is limited due to its relatively poor thermal stability. In this study, we generated six single mutants by targeting either the high flexibility regions (242-250) or the 382Glu residue within the -TEAP- motif, and further developed two double mutants featuring concurrent mutations encompassing both regions. We expressed multiple levansucrase mutant proteins in E. coli DH5α using site-directed mutagenesis and measured the enzymatic activity and thermal stability of each mutant by levan formation reactions. The E246Y mutant displayed half-time 5.02-fold and 1.89-fold higher at 55℃ and 56℃, respectively, when compared to the WT, whereas the E382L mutant exhibited a 1.06-fold enhancement in half-time at 55℃. Furthermore, E246Y/E382L exhibited 1.95-fold and 1.86-fold higher thermal stability at 55℃ and 56℃, respectively. These findings suggest the potential for the developed thermally stable levansucrases to be applied in industrial settings, highlighting the effectiveness of our targeted mutagenesis approach.

• Honam Mathematical Journal
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• v.37 no.2
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• pp.221-233
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• 2015

The notion of a mighty (vague) filter in a BE-algebra is introduced, and the relation between a (vague) filter and a mighty (vague) filter are given. We investigate an equivalent condition for a (vague) filter to be mighty, and state an extension property for mighty filter. Also we define the notion of an n-fold mighty filter which is an extended notion of a mighty filter in a BE-algebra. Characterizations of an n-fold mighty filter are given. Extension property for an n-fold mighty filter are provided.

• Bulletin of the Korean Mathematical Society
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• v.55 no.1
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• pp.165-173
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• 2018

In this paper we obtain the bounds of the third Hankel determinants for the classes $\mathcal{S}^*({\alpha})$ of starlike functions of order ${\alpha}$ and $\mathcal{K}({\alpha}$) of convex functions of order ${\alpha}$. Moreover,we derive the sharp bounds for functions in these classes which are additionally 2-fold or 3-fold symmetric.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.1
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• pp.51-53
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• 2003

Amyotrophic lateral sclerosis Is an unusual pattern of distal muscular atrophy with permanent bulbar sign. Vocal fold paralysis and velopharyngeal insufficiency(VPI) due to soft palate paralysis Is occasionally associated with distal muscular atrophy. Recently we experienced a case of amyotrophic lateral sclerosis whose symptom was initially expressed with hoarseness and VPI. So we report a case with review of literature.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.177-178
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• 2005

The load/unload behavior of the hard disk drive slider is studied in terms of the air bearing static characteristics. The numerical continuation methods are applied to calculate suspension force - equilibrium position curve. The critical preloads of the femto size slider are analyzed. The hi-stability conditions are depicted on the skew angle - preload diagram. The perturbation method is used to check the stability of the solution branches.