• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.51-57
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• 1989

A series of four sodium ${\alpha}-sulfo$ fatty vinyl ester oligomers including sodium ${\alpha}-sulfo$ lauric acid vinyl ester oligomer, sodium ${\alpha}-sulfo$ myristic acid vinyl ester oligomer, sodium ${\alpha}-sulfo$ palmitic acid vinyl ester oligomer and sodium ${\alpha}-sulfo$ stearic acid vinyl ester oligomer were examined for surface activities such as surface tension, foaming power, foam stability, emulsifying power, dispersion effect, solubilization of orange OT. The critical micelle concentration(CMC) was also evaluated. Consequently, these sodium ${\alpha}-sulfo$ fatty acid vinyl ester oligomers were shown to have a good cohesive power and dispersion effect.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.92-95
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• 2014

In this work we have synthesized ZnS:Mn nanocrystals (NCs) using a simple one step thermochemical method. $Zn(NO_3)_2$ and $Na_2S_2O_3$ were used as the precursors and $Mn(NO_3)_2$ was the source of impurity. Thioglycolic acid (TGA) was used as the capping agent and the catalyst of the reaction. The structure and optical property of the NCs were characterized by means of X- ray diffraction (XRD), HRTEM, UV-visible optical spectroscopy and photoluminescence (PL). X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses demonstrated cubic phase ZnS:Mn NCs with an average size around 3 nm. Synthesized NCs exhibited band gap of about 4 eV. Photoluminescence spectra showed a yellow-orange emission with a peak located at 585 nm, demonstrating the Mn incorporation inside the ZnS particles.

• English & American cultural studies
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• v.18 no.4
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• pp.1-31
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• 2018

It is needless to say that America's indiscriminate artillery and chemical attacks have worsened the conditions of Vietnam's tropical rain forests, causing war-torn combat troops and civilians to suffer more from the participation and aftermath of the Vietnam war. Around two decades after the Vietnam War, American and Vietnamese writers dealing with the destruction of the human and nature of the Vietnam War and the following traumatic experience commonly report the horrors of inhumane warfare, but some differences among them appear in the reception of the ecocide consciousness. For American writers who had been involuntarily involved or who had stayed in the back area as interpreters and counter-intelligence force, the Vietnam War was often a kind of exotic "addicted adventure" which their American hometown could not provide. But apart from overcoming postwar post-traumatic stress by writing of healing which was shared with American war writers, Vietnamese writers have been able to overcome the scars of war as the communal memorial, which Jonathan Shay emphasized as the necessary comforting ritual by community members showing the sign of honor and care. On the other hand, American war writers were on the side of "separate peace," as Jeong stressed, and the Vietnam War to them was more racist like the case of "body count." Nevertheless, it is fortunate that the hideous experience of war could turn them all into the creativity pool, just as the 5,000 square mile of bomb creators have been used as the postwar fish ponds.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.598-604
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• 2013

This study was designed to evaluate the usability of the following citrus peel extracts (CPEs): Citrus sinensis (orange), C. unshiu (mandarin orange), C. limon (lemon), and C. paradise (grapefruit) as natural antibrowning agents. Overall, 0.1% of the CPEs were effective in reducing the browning of apple slices. The appearance of apple slices dipped in C. limon peel extracts (LPE) were found to be excellent and their Hunter L and ${\Delta}E$ values were similar to the values obtained when apple slices were dipped in ascorbic acid. The pH values of the different CPEs were not significantly different from each other, but were higher than that of ascorbic acid. LPE was found to possess the highest total phenolic content, flavonoid content, DPPH radical scavenging activity, and copper ($Cu^{2+}$) chelating activity. All these results suggest that citrus peel extracts, especially lemon peel extract, can be used as natural antibrowning agents.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.378-381
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• 2014

A new pathogen was isolated from zoysiagrass-planted park of Jeju island in 2014. Symptoms appeared a type of irregular patches occurring brownish leaf blight, followed by stem and crown rot. The symptom was very similar to that of large patch caused by Rhizoctonia solani, a well-known devastating zoysiagrass disease. The isolate showed thin orange-colored mycelia and screlotia were formed on the medium based on cultural characteristics. The causal agent of the disease was finally identified as Waitea circinata by analysis of ribosomal DNA. On the inoculation test, Waitea circinatae showed strong pathogenicity to the zoysiagrass. The mycelia were obviously observed in the inoculated tissues. This is the first report of Waitea ring patch caused by Waitea circinata on zoysiagrass.

• Environmental Mutagens and Carcinogens
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• v.21 no.1
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• pp.51-56
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• 2001

Kimchi is a major Korean traditional fermented food, as a supplying source of vitamin and minerals which is prepared with various vegetables and condiments such as red pepper, garlic and salted fish etc. There are many types of Kimchi depending on the ingredients and preparation methods used. To investigate the clastogenicity and anticlastogenicity of Baechu (Chinese cabbage) Kimchi and Buchu (leek, Allium odorum) Kimchi in mouse, it was performed acridine orange supravital staining of micronucleus (AOSS-MN) assay using mouse peripheral reticulocytes. Baechu Kimchi and Buchu Kimchi were cultivated by organic agricultural technique, and Kimchi samples were prepared by methanol extraction and lyophilization. First of all, it was studied the clastogenicity of two Kimchi samples themselves (250-1,000 mg/kg) after oral adminstration in mouse. And also to study the anticlastogenic effect of oral administration of Kimchi samples, mitomycin C (MMC, 1 mg/kg, i.p.) was used as micronucleus inducing agent in this study. Dosing scheme was performed as simultaneous (co-treatment), 3 hr before (pre-treatment) and 3 hr after (post-treatment) with MMC treatment. Two Kimchi samples in the range of 250-1,000 mg/kg did not reveal any clastogenic effect in AOSS-MN assay in mouse. They also revealed anticlastogenic effects in post-treatment of Baechu Kimchi (1,000 mg/kg), and in pre-treatment of Buchu Kimchi (500 and 1,000 mg/kg) with statistical significance. The anticlastogenic effect revealed 1 and 6 hr after treatment of Baechu Kimchi, and Buchu Kimchi with 3 and 6 hr pretreatment. Consequently, it is suggested that antimutagenic and anticlastogenic mechanisms of Baechu and Buchu Kimchi in vivo attributed to sipindle formation and kinetic behavior of mutagens such as absorption and metabolism etc.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.40-44
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• 2018

An isolate capable of inhibiting the growth of gram-positive bacteria was obtained from the soil of Mushim stream, Cheongju. The isolate was identified as Pseudomonas otitidis PS by 16S rRNA gene sequence analysis. P. otitidis PS produced antibiotics as a secondary metabolite when cultured in 1% soybean meal with 0.5% glucose. The maximum yield was about 0.1%. The antibiotic substance of P. otitidis PS extracted using ethyl acetate displayed a minimum inhibitory concentration of $2{\mu}g/ml$ for Staphylococcus aureus KCTC 1261. The antibiotic substance produced an orange halo on chrome azurol S agar due to siderophore activity. Growth inhibition was decreased when the iron was depleted. Since the antibiotic activity was lost upon the addition of the reducing agent ascorbic acid or during anaerobic culture, it was considered that antibiotic of P. otitidis PS strain exerts its bactericidal effect by the generation of reactive oxygen species.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7943-7957
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• 2015

Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7473-7478
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• 2014

Cholangiocarcinoma (CCA) is a fatal cancer with poor prognosis and less than 10% of CCA patients can be offered surgical cure. Conventional chemotherapy results in unfavorable outcomes. At present, plant-derived compounds are gaining interest as potential cancer therapeutics, particularly for treatment-refractory cancers. In this study, antitumor activity of tiliacorinine, the major alkaloid isolated from a tropical plant, on CCA was first demonstrated. Antiproliferative effects of tiliacorinine on human CCA cell lines were investigated using SRB assays. Acridine orange/ethidium bromide staining, flow cytometric analysis and DNA laddering assays were used for apoptotic determination. Apoptosis-related proteins were verified by Western blotting and antitumor activity of tiliacorinine in vivo was demonstrated in CCA xenografted mice. Tiliacorinine significantly inhibited proliferation of human CCA cell lines with $IC_{50}$ $4.5-7{\mu}M$ by inducing apoptosis through caspase activation, upregulation of BAX, and downregulation of $Bcl_{xL}$ and XIAP. Tiliacorinine considerably reduced tumor growth in CCA xenografted mice. These results demonstrated antitumor effects of tiliacorinine on human CCA in vitro and in vivo. Tiliacorinine may be an effective agent for CCA treatment.

• BMB Reports
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• v.38 no.4
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• pp.391-398
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• 2005

3-hydrogenwadaphnin (3-HK) is a new daphnane-type diterpene ester isolated from Dendrostellera lessertii with strong anti-tumoral activity in animal models and in cultures. Here, prolonged effects of this new agent on proliferation and viability of several different cancerous cell lines were evaluated. Using [$^3H$]thymidine incorporation, it was found that the drug inhibited cell proliferation and induced G1/S cell cycle arrest in leukemic cells 24 h after a single dose treatment. The cell viability of Jurkat cells was also decreased by almost 10%, 31% and 40% after a single dose treatment (7.5 nM) at 24, 48 and 72 h, respectively. The drug-treated cells were stained with acridine orange/ethidium bromide to document the chromatin condensation and DNA fragmentation. These observations were further confirmed by detection of DNA laddering pattern in the agarose gel electrophoresis of the extracted DNA from the treated cells. Treatment of K562 cells with the drug at 7.5, 15 and 30 nM caused apoptosis in 25%, 45% and 65% of the cells, respectively. Exogenous addition of $25-50\;{\mu}M$ guanosine and/or deoxyguanosine to the cell culture of the drug-treated cells restored DNA synthesis, released cell arrest at G1/S checkpoint and decreased the apoptotic cell death caused by the drug. These observations were not made using adenosine. However, the drug effects on K562 cells were potentiated by hypoxanthine. Based on these observations, perturbation of GTP metabolism is considered as one of the main reasons for apoptotic cell death by 3-HK.