• Current Optics and Photonics
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• v.2 no.5
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• pp.474-481
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• 2018

We propose a polarization phase-shifting technique to investigate the thickness of $Ta_2O_5$ thin films deposited on BK7 substrates, using a modified Sagnac interferometer. Incident light is split by a polarizing beam splitter into two orthogonal linearly polarized beams traveling in opposite directions, and a quarter-wave plate is inserted into the common path to create an unbalanced phase condition. The linearly polarized light beams are transformed into two circularly polarized beams by transmission through a quarter-wave plate placed at the output of the interferometer. The proposed setup, therefore, yields rotating polarized light that can be used to extract a relative phase via the self-reference system. A thin-film sample inserted into the cyclic path modifies the output signal, in terms of the phase retardation. This technique utilizes three phase-shifted intensities to evaluate the phase retardation via simple signal processing, without manual adjustment of the output polarizer, which subsequently allows the thin film's thickness to be determined. Experimental results show that the thicknesses obtained from the proposed setup are in good agreement with those acquired by a field-emission scanning electron microscope and a spectroscopic ellipsometer. Thus, the proposed interferometric arrangement can be utilized reliably for non-contact thickness measurements of transparent thin films and characterization of optical devices.

• The Journal of Internal Korean Medicine
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• v.34 no.2
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• pp.178-191
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• 2013

Objectives : In this study, we made an effort to investigate the protective mechanism of Ukgan-san (UGS) extracts on hypoxia-induced C6 glial cell death. Methods : The cell viability was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MMT) assay and cell morphological changes were analysed with microscope after staining with crystal violet (CV). Reactive oxygen species (ROS) formation was assessed by flow cytometer after staining with 2'7'-dichlorofluorescein diacetate (DCF-DA). We also analyzed expression of hypoxia-inducible factor-1 alpha (HIF-$1{\alpha}$) and p53, processing of procaspase-3 and procyclic acidic repetitive protein (PARP) by western blot method. Results : We estimated the elevated cell viability by UGS extract on $CoCl_2$-induced C6 glial cells. UGS attenuated $CoCl_2$-induced ROS formation in C6 glial cells and also showed a protective activity compared to antioxidants and exhibited abrogation of LDH-released by $CoCl_2$. UGS suppressed the typical apoptotic cell death markers, caspase-3 and PARP activation. UGS inhibited $CoCl_2$-induced HIF-1${\alpha}$ expression which is known as a major regulator for hypoxia-induced cell death, and suppressed p53 expression. Conclusions : These results suggest that UGS extract contains protective constituents for hypoxia-induced C6 glial cell death.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1137.2-1245
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• 2001

The ${\gamma}$-irradiated medicinal herbs were examined the genotoxicological safety to consider the possibility of application of the irradiation technology for hygienic purpose. The three medicinal herbs -Glycyrrhigae Radix, Aurantii nobilis Pericarpium and Bupleuri Radix- were irradiated with ${\gamma}$ -rays at the practical dosage of 10 kGy. The hot water extracts of the irradiated herbs were examined in two short-term in vitro tests: (1) Ames test in Salmonella typhimurium TA98 and TA100, (2) Micronucleus test in cultured Chinese hamster ovary(CHO) cells. In the Salmonella reversion assays both with and without metabolic activation, the number of revertant colonies was not increased with each extract from the irradiated herbs, compared with negative controls. No significant difference in formation of the colonies was observed between non-irradiated and 10 kGy-irradiated herbs. These results indicated that no mutagenicity of the irradiated herbs was detected. In the micronucleus tests in cultured CHO cells, the incidences of micronucleus were not increased with irradiated herbs, and no significant difference in the incidences was observed between non-irradiated and irradiated herbs. These results indicated that no cytogenetic toxicity of the irradiated herbs was detected. The results of the two in vitro tests suggest that the irradiated herbs do not show mutagenic effects and cytogenetic toxicity. Further tests of in vivo genotoxicity and chronic toxicity are needed to determine the safety of the herbs irradiated with ${\gamma}$ -rays at practical doses.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.643-649
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• 2004

Pork was cooked using three kinds of instrument [electric pill (EG) for 5min., microwave oven (MW) for 6min. and reheated using a MW] and then extracted with $80\%$ methanol. The Ames test was performed on the methanol extracts, employing the S. typhimurium tester strain, TA100. The methanol extract of cooked pork showed high mutagenicity ion the 5.0 mg/plate without the S9 mix, but a higher mutagenicity was induced with the S9 mix With increasing refrigeration $(4^{\circ}C)$ and freezing $(-18^{\circ}C)$ periods the extracts showed higher mutagenicities and TBA values, and the same results where shown with reheating. Correlations of the mutagenicity (-S9 mix) and rancidity of the pork cooked by EG, according to storage at and $-18^{\circ}C$ and reheated by MW (1 min), were r=0.85, 0.86, 0.98 and 0.83, respectively. When the MW was used for reheating, the refrigeration storage (r=0.98) showed a higher correlation coefficient than for that stored frozen (r=0.83). From the structure of cooked pork, as observed by SEM, many vapor pathways were viewed in the pork reheated using themicrowave oven.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7C
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• pp.675-686
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• 2005

In this paper, we propose an efficient face region detection technique for the content-based video summarization. To segment video, shot changes are detected from a video sequence and key frames are selected from the shots. We select one frame that has the least difference between neighboring frames in each shot. The proposed face detection algorithm detects face region from selected key frames. And then, we provide user with summarized frames included face region that has an important meaning in dramas or movies. Using Bayes classification rule and statistical characteristic of the skin pixels, face regions are detected in the frames. After skin detection, we adopt the projection method to segment an image(frame) into face region and non-face region. The segmented regions are candidates of the face object and they include many false detected regions. So, we design a classifier to minimize false lesion using CART. From SGLD matrices, we extract the textual feature values such as Inertial, Inverse Difference, and Correlation. As a result of our experiment, proposed face detection algorithm shows a good performance for the key frames with a complex and variant background. And our system provides key frames included the face region for user as video summarized information.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1426-1432
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• 2000

The effects of raw anchovy, salted raw anchovy (20% salt+anchovy), 6- and 12-month fermented anchovy (20% salt added) on the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenicities were evaluated using Salmonella assay and the SOS chromotest. The methanol extracts from raw, salted and the fermented anchovy (FA) sample increased the revertants of Salmonella typhimurium TA100 at the level of $0.125{\sim}5\;mg/plate$ in Ames test. The salted raw anchovy extract induced the largest number of the revertants. All the FA extracts had comutagenic effect on the MNNG. Twelve-month FA juice exerted the lowest comutagenic activity among the FA samples. The comutagenicity of 12-month FA was due to the synergistic effect of salt and histidine which teem in FA. Thus the Ames test using histidine requiring mutant, S. typhimurium, is not appropriate to determine the mutagenicity of FA which is rich in histidine. In SOS chromotest using E coli, raw, salted and fermented anchovy extracts did not show any mutagenicity in the absence of MNNG. The raw and fermented anchovy samples blocked the SOS response of E. coli PQ37 induced by MNNG, while raw salted anchovy increased the SOS induction factor. Twelve-month FA juice showed higher antimutagenic effects than 6-month FA samples (both solid and liquid). The ripened (12-month) FA along with raw anchovy in the SOS chromotest exhibited antimutagenic activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.581-586
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• 1998

The present study was conducted to prepare seaweed extracts suppressing mutagenic activity of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine ( PhIP ) ana 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx) derived from cooked meat produce. The tumor initiation activity of PhIP and MeIQx was assayed with Ames method using Salmonella typhimurium TA98 in the presence of S-9 mixtures before and after addition of methanol-solubles of seaweed, such as, Phaeophyta; Undaria pinnatifida, Ecklonia stolonifera Ecklonia cava, Laminaia japonica Sargassum fulvellum, Sargassum hornezi, Sargassum miyabei, Sargassum thunbergii, Agarum cribrosum and Hizikia fusifomis, Rhodophpei Porphyra yezoensis, Grateloupia eiliptiut Lomentraria catenata, Ploemium telfairiae and Glarilaria verrucosa, Chlorophyta; Codium fragile, Enteromorpha compresa and Ulva pertusa. Among seaweed tested, Phaeophyta was shown the higher desmutagenic activity than Rhodophyta and Chlorophyta. E. stolonifera, E. cava and S. miyabei, among Phaeophyta exerted the stronger desmutagenic activity (above $90\%$/2 mg). The ethyl acetate, diethyl ether and chlomform extracts except water extracts from E. stolonifera exhibited a high desmutagenic activity. The ethyl acetate extract of E. stolonifera which showed highest activity was fractionated with Sephadex LH20 column chromatography to give active fraction A-7, which showed desmutagenicity of $90\%$/mg against PhIP and $80\%$/mg against MeIQx. The active fraction had the absorbance at 207.7 and 232nm.

• Journal of Life Science
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• v.20 no.10
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• pp.1532-1537
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• 2010

This study compared the inhibitory effects of methanol extracts from yellow and black soybeans (black soybean, Seomoktae and Seoritae) on mutagenicity using the Ames test and growth of human cancer cells (AGS human gastric adenocarcinoma, HT-29 human colon cancer, Hep 3B hepatocellular carcinoma cells). In the Ames test system using Salmonella typhimurium TA100, aflatoxin $B_1$ ($AFB_1$)-induced mutagenicity was significantly inhibited by treatments with the methanol extracts from either yellow or black soybeans in a dose dependent manner (p<0.05). The methanol extracts from various black soybeans tended to have a greater inhibitory effect compared to those from yellow soybeans. As for N-methyl-N'-nitro-N-nitrosoguamidine (MNNG)-induced mutagenicity, the methanol extracts (5 mg/assay) from black soybean, Seomoktae and Seoritae showed 51%, 61% and 53% inhibitory rates, respectively, indicating that Seomoktae, a type of black soybean, had a stronger antimutagenic activity against mutagens (both $AFB_1$ and MNNG). Methanol extracts from black soybeans showed an inhibitory rate of greater than 50% on the growth of human cancer cells (AGS, HT-29 and Hep 3B) and the inhibition was more effective in the methanol extract from Seomoktae. Our results suggested that the methanol extracts from black soybeans showed stronger inhibitory effects on mutagenicity and growth of cancer cells than those from yellow soybean. It is concluded that intake of black soybean can be recommended for improving health.