• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.162-166
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• 2004

This study investigated tile effect of ozonation on indigenous microorganisms distributed in different size fractions of soil aggregates. Soil was ozonated from 0 to 300 minutes. The treated soils were fractionated into 3 groups (small, <53 $\mu$m; medium, 53-500 $\mu$m; and large, 2000-500 $\mu$m) and total heterotrophic bacteria in the soils were enumerated. Cell number decreased rapidly within 120 minute ozonation and showed slow decrease upon longer ozonation. Abundance of total heterotrophic bacteria in each fraction was in the following order regardless of ozonation time: small>medium>large fractions. Difference in microbial abundance among the fractions was smaller as ozonation time increased.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.52-59
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• 1987

The result of the screening of lectins on 28 species of marine shell fishes(mollusks) showed that 10 species (Tapes philippinarum, Cyclosunetta menstrualis, Neptunea arthritica cumingii, Omphalius pfeifferi carpenteri, Chlorostoma argyrostoma turbinatum, Chiorostoma argyrostoma lischkei, Semisulcosira corea, Neptunea polycosta, Babylonica japonica, Noverita didyma) were present hemagglutinating properties to human A, B, and O group, and animal blood erythrocytes. A new lectin from Tapes philippinarum. was isolated and partially characterized. The lectin was purified by (NH$_4$)$_2$SO$_4$ precipitation and ion exchange chromatography on DE 53 column. Six fractions were obtained from DE 53 column by salt gradient elution but only 0.3M, and 0.4M NaCl fraction had strong lectin activity. On its 0.3M NaCl fraction, purity was identified by polyacrylamide gel electrophoresis. This lectin was inhibited by N-acetyl-D-galactosamine. It seems that two kinds of lectin react as antigen by immunochemical studies.

• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.169-175
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• 1991

Pediococcus acidilactici strain M produced a bacteriocin which was proteinaceous, heat stable, and exhibited antimicrobial activity against lactic acid bacteria, variety of food spoilage and pathogenic bacteria. The antimicrobial activity was not caused by $H_2$$O_2$ and organic acid, and was remained between pHs of 4.0 to 9. Molecular weight of crude bacteriocin was approximately 2, 500. Phenotypic assignment after plasmid cruing experiment demonstrated that a 53.7 kilobase (kb) plasmid, designated as pSUC53, was responsible for the sucrose fermentation phenotype ($Suc^+$) and a 11.1 kb plasmid, designated as pBAC11, was associated with bacteriocin production phenotype ($Bac^+$). Neither of the two plasmids were linked to antibiotic resistance.

• Kyungpook Mathematical Journal
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• v.53 no.4
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• pp.541-552
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• 2013

This research is a continuation of a recent paper due to the first author in [9]. Different from previous results, we investigate the value distribution of difference polynomials of moromorphic functions in this paper. In particular, we are interested in the existence of zeros of $f(z)^n({\lambda}f(z+c)^m+{\mu}f(z)^m)-a$, where f is a moromorphic function, n, m are two non-negative integers, and ${\lambda}$, ${\mu}$ are non-zero complex numbers. However, the proof here is obviously different to the one in [9]. We also study difference polynomials of entire functions sharing a common value, which improves the result in [10, 13].

• Journal of the Korean Ceramic Society
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• v.53 no.5
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• pp.557-562
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• 2016

Pyrophyllite granule powders for thermal spray coating were successfully prepared through spray drying process. To produce a stable slurry, commercial pyrophyllite powder of $45{\mu}m$ in size was ball-milled for reduction of the size to $2{\sim}3{\mu}m$ and a dispersant was added to control the viscosity. Dense and spherical granules (average granule size : $59{\mu}m$) were prepared under conditions of 12,500 rpm for rotation velocity of the atomizer and 100 cps for slurry viscosity. The granules were then heat treated at $1,200^{\circ}C$ for proper handling strength and flow properties. The final granules had an apparent density of $0.725g/cm^3$ and a flow rate of 2.5 g/sec, which represent excellent properties to be used as the granule powder for thermal spray coatings.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.172-172
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• 2002

This study was carried out to develop the antitoxic compound about cytotoxicity of cadmium on NIH 3T3 fibroblasts. These cells divided into 3 groups: control groups (cadmium only) or MTT50 group (NIH 3T3 fibroblasts, 53.32 ${\mu}$M cadmium) and experimental group (53.32 ${\mu}$M quercitrin and 54.72 ${\mu}$M quercetin). (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.485-492
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• 2011

The influence of high temperature on mammary cell turnover during the dry period is still unclear. The objective of this study was to investigate mammary cell turnover and p53 protein expression in the mammary tissue under high temperature conditions. Mammary gland biopsy samples from 8 dairy cows were obtained at 7, 25, 40, and 53 d during the dry period in summer or spring (n = 4, each season). Cell cycle, cell turnover, and p53 protein expression were analyzed by flow cytometry. During the dry period in summer, the percentage of mammary epithelial cells in the G0/G1 phase was the highest, but those in the S and G2/M phases were lower. However, the proportion of cells in the different stages of the cell cycle was not significantly different among the different biopsy time points, except in the G2/M phase. Under different temperature conditions, the cells were significantly different in their apoptotic rate and proliferation index; moreover, the tendencies of these indicators to change significantly differed. In general, the samples under high temperature conditions showed significantly lower apoptotic rates and proliferation indices. Under high temperature conditions, the apoptotic rate and proliferation index were the lowest (2.17% and 3.26%, respectively) at day 40, and the highest at day 53 (3.67% and 4.61%, respectively). However, under normal temperature conditions, the values of these indicators were the lowest (7.60% and 5.54%, respectively) at day 7, and almost the highest at day 25 (12.85% and 6.47%, respectively). Moreover, p53 protein expression was significantly higher under high temperature conditions than under normal temperature conditions, except at day 25. The level of p53 protein was the lowest (13.10%) under high temperature conditions at day 25, but was the highest (26.07%) under normal temperature conditions. Our findings suggest that high temperature delayed the G2/M phase of the cell cycle and the cell turnover rate, but remarkably increased p53 protein expression. Thus, the results indicate that high temperature extends the recovery period of mammary epithelial cells.

• Bulletin of the Korean Mathematical Society
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• v.53 no.4
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• pp.1171-1184
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• 2016

We define a new connection on semi-Riemannian manifolds, which is called a symmetric connection of type (${\ell}$, m). Semi-symmetric connection and quarter-symmetric connection are two examples of this connection such that $({\ell},m)=(1,0)$ and $({\ell},m)=(0,1)$ respectively. In this paper, we study lightlike hypersurfaces of an indefinite Kaehler manifold endowed with a symmetric metric connection of type (${\ell}$, m).

• Clinical and Experimental Reproductive Medicine
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• v.23 no.1
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• pp.33-39
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• 1996

This objective of this experiment was to test the effect of EGF on GVBD and MII of nuclear maturation of pig immature oocytes in vitro. Experiment 1 examined to the effect of EGF on nuclear maturation of pig immature oocytes according to different maturational times. The percentage of GVBD of EGF 10mg/ml treated groups were significantly higher than untreated groups after 24hr (p < 0.001). Experiment 2 examined to the effect of duration of exposure of oocytes to EGF supplement in maturation medium. Nuclear maturation rates (M II) of EGF treated groups (during 0-24: 72.8% and 0-42hr: 84.8%) were significantly higher than 53.5 and 26.1% of EGF treated group (during 24-42hr) and untreated group (p < 0.001). Also, experiment 3 examined to the effect of EGF on nuclear maturation of CEOs or CFOs. Nuclear maturation rate (M II) 84.6% of EGF treated group of CEOs was significantly higher than 53.0, 27.6, and 44.2% of EGF treated group of CFOs and untreated groups of CEOs and CFOs (p < O.001). These results conclude that EGF alone can stimulate GVBD and M II of nuclear maturation in pig immature oocytes.

• Journal of Life Science
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• v.16 no.4
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• pp.589-597
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• 2006

Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase activities. There are several studies documenting molecular alterations leading to cell cycle arrest and induction of apoptosis by genistein as a chemopreventive agent in a variety of cancer cell lines; however, its mechanism of action and its molecular targets on human bladder carcinoma and leukemic cells remain unclear. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of T24 bladder carcinoma and U937 leukemic cells. Genistein significantly inhibited the cell growth and induced morphological changes, and induced the G2/M arrest of the cell cycle in both T24 and U937 cells with a relatively stronger cytotoxicity in U937. The G2/M arrest in T24 cells was associated with the inhibition of cyclin A, cyclin B1 and Cdc25C protein expression without alteration of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1). However, the inhibitory effects of genistein on the cell growth of U937 cells were connected with a marked inhibition of cyclin B1 and an induction of Cdk inhibitor p21 proteins by p53-independent manner. These data suggest that genistein may exert a strong anticancer effect and additional studies will be needed to evaluate the different mechanisms between T24 and U937 cells.