• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.471-477
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• 1998

Taq DNA polymerase from Thermus aquaticus is very useful in the polymerase chain reaction. Taq DNA polymerase is classified in the pol I family, represented by E. coli DNA polymerase I. The three-dimensional structural alignment of 3'-5'exonuclease domains from the pol I family DNA polymerases explains why Taq DNA polymerase does not carry out proofreading in polymerase chain reactions. Three sequence motifs, Exo I, II, and III, must exist to carry out 3'-5'exonuclease activity for proof- reading by a 3'-5'exonuclease reaction, but these are abolished in Taq DNA polymerase. The key catalytic module in 3'-5'exonuclease is two metal ions chelated by four active-site carboxylic amino acids. Taq DNA polymerase was mutagenized to construct the catalytic module in the active site. The circular dichroism technique supported the formation of the catalytic module, and the radioactive assay showed that the 3'-5'exonuclease activity doubled in the mutant Taq DNA polymerase.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.219-225
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• 1996

This study was performed to investigate the inhibition mechanism of cancer cell proof iferation caused by the petroleum-ether extract of ginseng against human rectum (HRT-18), colon (HT-29), llepatoma (Hep G2) and prostate (LNCaP) cancer cells and monkey kidney cells (Vero 76). Cells were treated with the petroleum-ether extract of ginseng (50 to 200 $\mu\textrm{g}$/ml) in G1 or S phase of the cell cycle, and proliferation and protein kinase C activity were measured. The petroleum-eth or extract of ginseng inhibited proliferation of HRT-18, HT-29, Hep G2 and LNCaP when treated in Gl phase, but not in S phase. This result shows that the ginseng extract arrests the cell cycle in G1 phase, resulting in the inhibition of cell proliferation. At the same concentrations, treatment of the ginseng extract in G1 phase decreased protein kinase C activity, while the treatment in S phase had no effect. This reault suggests that protein kinase C might be involved in the inhibition of the cell cycle and proliferation of cancer cells caused by the petroleum-ether extract of ginseng.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.100-108
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• 2016

The purpose of this study is to present a business strategy plan to increase organizational effectiveness of small and medium-sized enterprises. The research investigated in the level of human resource activity, such as recruitment, education, evaluation, compensation and development for the employees and executives who are working at small and medium-sized enterprises where located in Busan and Gyongnam province. With this, the research carried out actual proof analysis on the level of human resource activity effects on organization effectiveness like job satisfaction and organizational commitment. The following implications can be acquired from the result of multiple regression analysis on the 201 employees of small and medium enterprises. First, small and medium-sized enterprises should carry out human resource management activities and improve research and development capacity to enhance organization effectiveness. Second, in order to improve job satisfaction of the members of small and medium-sized enterprises, the management should concentrate on recruitment activity and reward maintenance management activity and come up with strategies to enhance learning ability and external network ability. Third, in order to enhance organizational commitment of the members of small and medium-sized enterprises, recruitment activity, training activity, and reward maintenance management activity should be carried out and the management should come up with strategies to enhance learning ability and external network ability. In this research, the objective was only to find out antecedents of organization effectiveness, but considering that causality might arise among the antecedents, in the studies hereafter, the verification on the structural relationship of various factors will be needed.

• Korea Journal of Hospital Management
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• v.19 no.3
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• pp.11-28
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• 2014

This study, targeting Korean tertiary hospitals and general hospitals, aims to analyze how value chain model in health and medical institution suggested by Duncan and else influences on hospital management. A survey was conducted to verify the actual proof analysis of this study model. 880 questionnaires were distributed to entire 88 hospitals and 739 copies were returned from 76 hospitals. This study mainly consists of three steps to analyze the effect value chain activity has on management performance of general hospitals. For the first step, we analyzed the effects service delivery activity has on management performance. For the second step, we analyzed the effects service support activity has on management performance and for the third, we analyzed the effects interaction between service delivery activity and service support activity has on management performance. The main results of this study are as follows. First, in terms of the management performance of scale, the factors which influenced on daily charge of outpatient were service activity before treatment, at the moment of treatment and value chain activity, while more important factors in daily charge of inpatient were organizational culture, organizational structure and value chain activity. In terms of management performance of quality, the factors which influenced on the first medical examination rate of outpatient were service activity before, at the moment of and after treatment, while activity at the moment of treatment, organizational structure, and value chain activity which is interaction were more important factors in average length of stay. In terms of non-financial performance, the management performance factors which influenced on job satisfaction were service activity at the moment of, after the treatment and value chain activity, while organizational culture, strategy resources and value chain activity which is interaction were more important factors in job commitment. Secondly, all the service support activity, service delivery activity and value chain activity had statistically significant effect on management performance. Among the three factors, service support activity had relatively high effect than others.

• BMB Reports
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• v.50 no.8
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• pp.391-392
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• 2017

Overexpression of mammalian 2-Cys peroxiredoxin (Prx) enzymes is observed in most cancer tissues. Nevertheless, their specific roles in colorectal cancer (CRC) progression has yet to be fully elucidated. Here, a novel molecular mechanism by which PrxII/Tankyrase (TNKS) interaction mediates survival of adenomatous polyposis coli (APC)-mutant CRC cells was explored. In mice with an inactivating APC mutation, a model of spontaneous intestinal tumorigenesis, deletion of PrxII reduced intestinal adenomatous polyposis and thereby increased survival. In APC-mutant human CRC cells, PrxII depletion hindered PARP-dependent Axin1 degradation through TNKS inactivation. $H_2O_2-sensitive$ Cys residues in the zinc-binding domain of TNKS1 was found to be crucial for PARsylation activity. Mechanistically, direct binding of PrxII to ARC4/5 domains of TNKS conferred vital redox protection against oxidative inactivation. As a proof-of-concept experiment, a chemical compound targeting PrxII inhibited the growth of tumors xenografted with APC-mutation-positive CRC cells. Collectively, the results provide evidence revealing a novel redox mechanism for regulating TNKS activity such that physical interaction between PrxII and TNKS promoted survival of APC-mutant colorectal cancer cells by PrxII-dependent antioxidant shielding.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2015-2020
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• 2012

Oleanolic acid (OA) is a naturally occurring triterpenoid in food materials and is a component of the leaves and roots of Olea europaea, Viscum album L., Aralia chinensis L. and more than 120 other plant species. There are several reports validating its antitumor activity against different cancer cells apart from its hepatoprotective activity. However, antitumor activity against skin cancer has not beed studied well thus far. Hence the present study of effects of OA against HaCaT (immortalized keratinocyte) cells - a cell-based epithelial model system for toxicity/ethnopharmacology-based studies - was conducted. Radical scavenging activity ($DPPH{\cdot}$) and FRAP were determined spectrophotometrically. Proliferation was assessed by XTT assay at 24, 48 and 72 hrs with exposure to various concentrations (12.5-200 ${\mu}M$) of OA. Apoptotic induction potential of OA was demonstrated using a cellular DNA fragmentation ELISA method. Morphological studies were also carried out to elucidate its antitumor potential. The results revealed that OA induces apoptosis by altering cellular morphology as well as DNA integrity in HaCaT cells in a dose-dependent manner, with comparatively low cytotoxicity. The moderate toxicity observed in HaCaT cells, with induction of apoptosis, possibly suggests greater involvement of programmed-cell death-mediated mechanisms. We conclude that OA has relatively low toxicity and has the potential to induce apoptosis in HaCaT cells and hence provides a substantial and sound scientific basis for further validation studies.

• Herbal Formula Science
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• v.20 no.2
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• pp.65-82
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• 2012

Objectives : The aim of this study was verification of the anti-oxidative and anti-inflammatory effects of Odukhwan(ODH) and Sasinhwan(SSH) in mouse macrophage, RAW264.7 cells. Methods : To investigate the anti-oxidative effect and scavenging activities of DPPH radical, superoxide anions, nitric oxide and peroxynitrite were measured. Cytotoxic activity of extract of ODH and SSH on RAW264.7 cells was measured using MTS assay. To proof the reductive activity of intracellular oxidation, DCFH-DA assay was performed. The nitric oxide(NO) production was measured and pro-inflammatory cytokines and $PGE_2$ were measured by ELISA kit. The levels of inducible nitric oxide synthase(iNOS), cyclooxygenase-2(COX-2) and nuclear NF-${\kappa}B$ p65 expression were detected by western blot. Results : After those analyses, we bring to a conclusion as follows. Both herbal formulations scavenged DPPH radical and nitric oxide. But ODH had no scavenging activity of superoxide anions and SSH had low scavenging activity in peroxynitrite. And the results indicated that ODH and SSH inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of IL-$1{\beta}$ and IL-6 production in RAW264.7 cells. They also have suppression effects of LPS-induced NF-${\kappa}B$ activation. Conclusions : ODH and SSH have anti-oxidative and anti-inflammatory effects and they may be a part of database for development of new anti-oxidative and anti-inflammatory drugs.

• Natural Product Sciences
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• v.13 no.4
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• pp.311-316
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• 2007

In this study, the twenty-four ethyl acetate extracts of twenty-two medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for ${\alpha}$-amylase and protein tyrosine phosphatase 1B (PTP1B) enzymes inhibitory activity in vitro. The results indicated that, twelve materials (50.0%) showed moderate to strong inhibitory activity in ${\alpha}$-amylase inhibitory activity with $IC_{50}$ values ranging from 2.5 to $48.8{\mu}g/mL$; meanwhile, ten extracts (41.6%) could demonstrate PTP1B activity with $IC_{50}$ values less than $30.5{\mu}g/mL$. Some plants presented interesting activities against both of ${\alpha}$-amylase and PTP1B enzymes such as Catharanthus roseus, Carthamus tinctorius, Momordica charantia, Gynostemma pentaphyllum, Glycyrrhiza glabra, Smilax glabra, Psidium guajava (leave), and Rehmannia glutinosa. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• School Mathematics
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• v.4 no.3
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• pp.401-413
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• 2002

The Pythagorean theorem is one of the most important theorem which appeared in school mathematics. Allowing our pupils to rediscover it in classroom, we must know how this theorem was discovered and proved. Further, we should recompose that historical knowledge to practical program which might be suitable to them So, firstly this paper surveyed the history of mathematics on discovering the Pyth-agorean theorem. This theorem was known to many ancient civilizatons: There are evidences that Babylonian and Indian had the knowledges on the relationship among the sides of a right triangle. In Zhoubi suanjing, which was ancient Chinese text book, was the proof of the Pythagorean theorem in special case. And then this paper proposed a teaching program that is composed following five tasks : 1) To draw up squares on geo-board that are various in size and shape, 2) To invent squares that are n-times bigger than a given square, 3) Discovering the Pyth-agorean theorem through the previous activity, 4) To prove the Pythagorean theorem in special case, 5) To prove the Pythagorean theorem in general case.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.75-80
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• 2004

The study analyzes about brand image's effect and change when customers purchase product. Purpose of this study suggests how to influence that brand image come up to product purchase to cosmetic customer . Consumers compare with product and trademark when they select product. Consumers evaluate dissatisfaction and satisfaction about goods that they choose through comparison and analysis. Find the factor that decides consumer's choice. Give weight by the scores of each factor's relative importance. The purpose of this study is find various requirement of consumers and present efficient marketing activity through theoretical verification and actual proof analysis .