• Food Science and Biotechnology
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• v.18 no.2
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• pp.449-455
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• 2009

The antioxidant properties of water extracted polysaccharides (PW), 1%(w/v) NaOH extracted polysaccharides (PN1), and 5%(w/v) NaOH extracted polysaccharides (PN5) were assessed in this paper. PW showed good capability of scavenging $H_2O_2$, anti-lipid peroxidation, reduction power, and scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH). The maximum values were all observed at the dose of 1 mg/mL sample. As far as the antioxidant activities of PN1 were concerned, the capability of scavenging superoxide radical, chelating metal, and total antioxidation showed higher than those of PN5. When polysaccharide concentration was 1 mg/mL, the 3 index described above were attached 71.8%, 51.6%, and $446.3{\mu}M$ Trolox equivalent, respectively. With respect to PN5, higher capabilities of scavenging hydroxyl free radicals were obtained while the peak of 84.8% was observed at the concentration of 1.0 mg/mL. Moreover, the concentration-dependent influences were characterized in all cases.

• YAKHAK HOEJI
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• v.55 no.3
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• pp.234-239
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• 2011

Glycycoumarin, a 3-arylcoumarine isolated from Glycyrrhizae radix (a family of Leguminosae), is reported to have anti-bacterial activity. However, its antifungal activity is still unknown. In this present study, the antifungal activity of glycycoumarin (GLM) against Candida albicans, a polymorphic fungus was investigated. Possible mechanism such as blocking of the hyphal induction was also analyzed. By the in-vitro susceptibility analysis, GLM showed anticandidal activity, resulting in an almost complete inhibition of the fungal growth at a concentration of 320 ${\mu}g/ml$, which was equivalent to the efficacy of fluconazole at the same dose. In the murine model of disseminated candidiasis GLM enhanced resistance of mice against the disseminated disease (P<0.05), resulting in 60% protection of GLM-treated mice group during a period of 21-day observation. As for its mechanism of the antifungal activity, GLM blocked hyphal production, one of the important of virulence factors by the fungus, from the yeast form of C. albicans (P<0.01). These data indicate that GLM may contribute to the perspectives that focus on the development of a novel agent with antifungal activity specific for C. albicans infection.

• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.273-280
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• 2014

The spectrum weighted responses of various detectors were calculated to provide guidance on the proper selection and use of survey instruments on the basis of their energy response characteristics on the neutron fields. To yield the spectrum weighted response, the detector response functions of 17 neutron-measuring devices were numerically folded with each of the produced calibration neutron spectra through the in-house developed software 'K-SWR'. The detectors' response functions were taken from the IAEA Technical Reports Series No. 403 (TRS-403). The reference neutron fields of 21 kinds with 2 spectra groups with different proportions of thermal and fast neutrons have been produced using neutrons from the $^{241}Am$-Be sources held in a graphite pile, a bare $^{241}Am$-Be source, and a DT neutron generator. Fluence-average energy ($E_{ave}$) varied from 3.8 MeV to 16.9 MeV, and the ambient-dose-equivalent rate [$H^*(10)/h$] varied from 0.99 to 16.5 mSv/h.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.145-151
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• 2011

The purpose of this study is to know some changes of resolution and image if we remove scattered ray using lead plate when doing lumbar lateral projection. Using 3 DR system(2 FD types, 1 CCD type) equipments and 2 film system equipments, we gain the image whether the phantom of abdomen equivalent sticking resolution chart has lead plate or not, whether we do collimation or not. Also, we use ion chamber, measure radiation exposure rate and change to entrance surface dose from it. we gain that images in the greatest condition of taking in clinic. 5 people in this group decoded resolution with our eyes, measured thickness of images and compared them from each equiments. Resolution has difference to size of collimation in DR FD type. Also there is no difference the original image with the new image which we abbreviated mAs. In DR CCD type, resolution didn't have difference whether lead plate is or not and whether we do collimation or not. In film type, existing or nonexisting of lead plate didn't influence on resolution. Lead plate makes the quality of image higher due to reducing scattered ray, it doesn't influence on resolution.

• Nuclear Engineering and Technology
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• v.31 no.5
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• pp.512-521
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• 1999

A feasibility study was performed to design an epithermal neutron beam for BNCT using the neutron of 2.45 MeV on the average produced from $^2H(d,n)^3$He reaction induced by plasma focus in the z-pinch instead of the conventional accelerator-based $^3H(d, n)^4$He neutron generator. Flux and spectrum were analyzed to use these neutrons as the neutron source for BNCT. Neutronic characteristics of several candidate materials in this neutron source were investigated Using MCNP Code, and $^7LiF$ ; 40%Al + 60%$AIF_3$, and Pb Were determined as moderator, filter, and reflector in an epithermal neutron beam design for BNCT, respectively. The skin-skull-brain ellipsoidal phantom, which consists of homogeneous regions of skin-, bone-, or brain-equivalent material, was used in order to assess the dosimetric effect in brain. An epithermal neutron beam design for BNCT was proposed by the repeated work with MCNP runs, and the dosimetric properties (AD, AR, ADDR, and Dose Components) calculated within the phantom showed that the neutron beam designed in this work is effective in tumor therapy. If the neutron source flux is high enough using the z-pinch plasma, BNCT using the neutron source produced from $^2H(d,n)^3$He reaction will be very feasible.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.756-762
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• 2003

In the current study, our research focused on the estrogenic activity of isoflavonoids, mainly genistein, biochanin A and daidzein. Genistein enhanced the reporter gene expression of MCF-7-ERE-Luc cells, at a concentration as low as 10 nM, with a concentration of 100 nM the achieved gene expression effects were similar to those of 10 pM 17$\beta$-estradiol. Based on the estrogenic activities of biochanin A and daidzein, hydroxyl groups at the 4 and 5 positions are needed for the maximal effect of the genistein. The estrogenic effects of these isoflavonoids were inhibited by the concomitant treatment with tamoxifen. The data showed that the estrogenic effects of isoflavonoids were mediated through estrogen receptors. When the isoflavonoids were tested as mixtures, the estrogenic effects were lower than the arithmetic sum of those induced by each individual isoflavonoid. The estrogenic potency of each isoflavonoid was presented at EC50 levels with a 17$\beta$-estradiol equivalent concentration (EEQ) based on the dose response of each chemical. The EC50s and EEQs of genistein, biochanin A and daidzein were 4.15, 0.89 and 0.18 $\mu$M, and 15.0, 5.12 and 1.83 $\mu$ M/M, respectively. Our data clearly demonstrated that the pERE-luciferase reporter gene assay was suited for the sensitive and quantitative measurement, and large scale screening, of the estrogenicity of chemicals in vitro.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.2121-2132
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• 2018

Abnormal melanin synthesis results in several hyperpigmentary disorders such as freckles, melanoderma, age spots, and other related conditions. In this study, we investigated the anti-melanogenic effects of an extract from the microalgae Chlamydomonas reinhardtii (CE) and potential mechanisms responsible for its inhibitory effect in B16F10, normal human epidermal melanocyte cells, and human skin-equivalent models. The CE extract showed significant dose-dependent inhibitory effects on ${\alpha}$-melanocyte-stimulating, hormone-induced melanin synthesis in cells. Additionally, the CE extract exhibited suppressive effects on the mRNA and protein expression of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2. The CE extract also inhibited the phosphorylation of protein kinase A and extracellular signal-related kinase, which function as upstream regulators of melanogenesis. Using a three-dimensional, reconstructed pigmented epidermis model, the CE-mediated, anti-pigmentation effects were confirmed by Fontana-Masson staining and melanin content assays. Taken together, CE extract can be used as an anti-pigmentation agent.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.275-283
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• 2019

Rare isotope beam facilities require shielding data in early stage of their design. There is much less shielding data on neutrons from the reactions between heavy ion beams and matter than the data on neutrons produced by protons. The purpose of the present work is to produce and thus increase the amount of shielding data on neutrons generated by high-energy heavy ion beams based on the RAON in-flight fragment facility. Calculations were performed with the computational Monte Carlo codes PHITS and MCNPX. The secondary neutron source terms were evaluated at 550 MeV/u for Ca, Kr, and Sn and at 400 MeV/u for U ions on a graphite target. Source terms and attenuation lengths were obtained by fitting the ambient dose equivalent inside an ordinary concrete shield.

• Journal of Environmental Science International
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• v.28 no.4
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• pp.393-401
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• 2019

The present study were conducted to determine physiological activities and antioxidant effects [2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, reducing power, Ferric Reducing Antioxidant Power (FRAP) and Fe2+ (ferrous ion) chelating capacity] of 70% methanol, chloroform:methanol, 2:1 volume ratio (CM) and ethyl acetate extract of turmeric (Curcuma longa L.). Bioactive compound of tannin $0.125{\pm}0.007mg$ Catechin Equivalent (CE)/g dry weight. Turmeric extracts yield were 70% methanol 16.54%, CM 5.64% and ethyl acetate 4.14%, respectively. Antioxidant activity of the samples exhibited a dose-dependent increase. Results showed that extraction solvent had significant effects on total flavonoid content and antioxidant effects of ethyl acetate. But ferrous ion-chelating capacity of 70% methanol extract was higher than CM and ethyl acetate extract. From the results of this study, turmeric can be utilized as a valuable and potential nutraceutical for the functional food industry.

• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.160-169
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• 2021

Background: Dual-energy X-ray images (DEI) can distinguish or improve materials of interest in a two-dimensional radiographic image, by combining two images obtained from separate low and high energies. The concepts of DEI performance describing the performance of double-exposure DEI systems in the Fourier domain been previously introduced, however, the performance of double-exposure DEI itself in terms of various parameters, has not been reported. Materials and Methods: To investigate the DEI performance, signal-difference-to-noise ratio, modulation transfer function, noise power spectrum, and noise equivalent quanta were used. Low- and high-energy were 60 and 130 kVp with 0.01-0.09 mGy, respectively. The energy-separation filter material and its thicknesses were tin (Sn) and 0.0-1.0 mm, respectively. Noise-reduction (NR) filtering used the Gaussian-filter NR, median-filter NR, and anti-correlated NR. Results and Discussion: DEI performance was affected by Sn-filter thickness, weighting factor, and dose allocation. All NR filtering successfully reduced noise, when compared with the dual-energy (DE) images without any NR filtering. Conclusion: The results indicated the significance of investigating, and evaluating suitable DEI performance, for DE images in chest radiography applications. Additionally, all the NR filtering methods were effective at reducing noise in the resultant DE images.