• Toxicological Research
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• 제31권2호
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• pp.151-156
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• 2015

5-Fluorouracil (5-FU) is commonly used for the therapy of colon cancer; however, acquired resistance to 5-FU is a critical barrier to successful treatment and the primary cause of chemotherapy failure. Epithelial-mesenchymal transition (EMT) is a process whereby cells undergo alterations in morphology and molecular characteristics promoting tumor progression and metastasis. Accumulating evidence shows that transition from epithelial to mesenchymal phenotype in cancer cells is associated with their resistance to chemotherapy. However, it is still poorly understood whether EMT is involved in acquired resistance to 5-FU. In this study, we developed an in vitro cell model, 5-FU-resistant HT-29 colon cancer cells, and characterized the differences in cellular morphology and molecular alterations between parental and resistant cells. In accord with mesenchymal-like morphology of 5-FU-resistant HT-29 cells, the expression of the mesenchymal marker fibronectin was significantly increased in these cells in comparision with that in the parental cells. Of interest, we also found a marked increase in the expression of EMT-inducing transcription factors Twist, Zeb1, and Zeb2. Finally, 5-FU-resistant cells showed enhanced migration in comparison with parental HT-29. Taken together, these results indicate that EMT could be associated with 5-FU resistance acquired by HT-29 cells. A specific role of each transcription factor found in this study will require further investigation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권6호
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• pp.17-28
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• 2010

As a preliminary survey to improve efficiency of well-based permeable reactive barrier system for groundwater remediation, this site-scale study was carried to identify the flowpaths and controlling factors of plume at a remediation site in Suwon City, Korea. A total of 22 monitoring wells were installed as a grid system in the $4m{\times}4m$ square area by 1-m interval. For the groundwater characterization, various tests were performed including water-level monitoring, water sampling & analysis, pumping and slug tests, and tracer tests. The aquifer appeared to be unconfined with hydraulic conductivities (K) ranging from $2.6{\times}10^{-4}cm/s$ to $9.5{\times}10^{-3}cm/s$. The average linear velocity of groundwater was estimated to be $2.94{\times}10^{-6}m/s$, and the longitudinal dispersivity of a conservative tracer to be $5.94{\times}10^{-7}m^2/s$. Groundwater plume moves preferentially through the high-K zones, and the relatively high ion concentrations along the low-K zones implying deterred groundwater flow. Consequently, the spatial variation of hydraulic conductivity caused by aquifer heterogeneity and anisotropy appears to be the most important factor to maximize the effect of plume treatment system for application of in-situ groundwater remediation techniques.

• 한국치위생학회지
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• 제6권3호
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• pp.175-185
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• 2006

This study got a conclusion following by questionnaire individual own recording law from Mokpo, Iksan, Gangneung to the objects to the academic 608 Dental Hygiene students whom had for consciousness investigations about employment overseas of some special college Dental Hygiene students. 1. Regarding the motivating factors to major in Dental Hygiene, most students(51.3%), particularly most freshmen(57.3%), have chosen this major because of more job opportunities than students with other majors. The most common source of information in choosing majors is the Internet(30.8%). 2. Many students have heard about overseas employment, particularly in case of juniors(82.5%). They want to work abroad if they are given the chances(70.6%), which indicates that the Dental Hygiene majors have much interest and positive attitude in overseas employment. 3. The most significant barrier to their overseas employment is the language, and thus the Dental Hygiene majors should improve their language abilities to be more involved in working abroad. 4. Showed the difference that an experience and light oil, the country where wanted to get a job at that tried to listen to relevance about employment of dental hygiene students by a school year abroad about these results, overseas employment noted. 5. While 'foreign language education must become activation' showed average highest, results to have seen relevance about employment time promotion plan overseas of dental hygiene students by a school year showed a difference by a school year.

• 디지털융복합연구
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• 제14권8호
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• pp.487-496
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• 2016

본 연구의 목적은 교육부의 대학평가에 의한 입학정원 감축과 체육계열학과의 취업교육에 관련된 연구사례의 부족 등의 이유로 전문적인 체육역량을 갖춘 융합인재 양성 및 체육전공의 입지를 확고히 할 수 있도록 체육계열학과의 취업준비 현황을 심층적으로 탐색하고 진로교육 방향을 제시하는데 있다. 체육계열 전공자들의 인식 수준에 따른 하위 요인과의 관계를 분석하기 위해 다변량분산분석과 대응일치분석 방법을 사용하였다. 연구결과를 통해 얻어진 결과는 다음과 같다. 첫째, 체육계열 대학생들의 학년별 적성과 소질을 고려하여 진로교육을 사전에 실시하는 것이 중요한 것으로 나타났다. 둘째, 진로를 준비하는데 있어서 취업장벽의 문제를 조속히 완화시켜주는 것이 중요한 것으로 나타났다. 셋째, 체육계열 전공과 관련된 취업직종의 확대와 기회의 제공에 다 같이 노력하는 것이 중요한 것으로 나타났다.

• 한국재료학회지
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• 제23권10호
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• pp.550-554
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• 2013

As continued scaling becomes increasingly difficult, 3D integration has emerged as a viable solution to achieve higher bandwidths and good power efficiency. 3D integration can be defined as a technology involving the stacking of multiple processed wafers containing integrated circuits on top of each other with vertical interconnects between the wafers. This type of 3D structure can improve performance levels, enable the integration of devices with incompatible process flows, and reduce form factors. Through silicon vias (TSVs), which directly connect stacked structures die-to-die, are an enabling technology for future 3D integrated systems. TSVs filled with copper using an electro-plating method are investigated in this study. DC and pulses are used as a current source for the electro-plating process as a means of via filling. A TiN barrier and Ru seed layers are deposited by plasma-enhanced atomic layer deposition (PEALD) with thicknesses of 10 and 30 nm, respectively. All samples electroplated by the DC current showed defects, even with additives. However, the samples electroplated by the pulse current showed defect-free super-filled via structures. The optimized condition for defect-free bottom-up super-filling was established by adjusting the additive concentrations in the basic plating solution of copper sulfate. The optimized concentrations of JGB and SPS were found to be 10 and 20 ppm, respectively.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.335-341
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• 2017

The complexity of the bacterial recombination system is a barrier for the construction of bacterial mutants for the further functional investigation of specific genes. Several protocols have been developed to inactivate genes from the genus Pseudomonas. Those protocols are complicated and time-consuming and mostly do not enable easy construction of multiple knock-ins/outs. The current study describes a single and double crossover-recombination system using an optimized vector-free allele-exchange protocol for gene disruption and gene replacement in a single species of the family Pseudomonadaceae. The protocol is based on self-ligation (circularization) for the DNA cassette which has been obtained by overlapping polymerase chain reaction (Fusion-PCR), and carries an antibiotic resistance cassette flanked by homologous internal regions of the target locus. To establish the reproducibility of the approach, three different chromosomal genes (ncRNA31, rpoN, rpoS) were knocked-out from the root-associative bacterium Pseudomonas stutzeri A1501. The results showed that the P. stutzeri A1501 mutants, which are free of any plasmid backbone, could be obtained via a single or double crossover recombination. In order to optimize this protocol, three key factors that were found to have great effect on the efficiency of the homologous recombination were further investigated. Moreover, the modified protocol does not require further cloning steps, and it enables the construction of multiple gene knock-in/out mutants sequentially. This work provides a simple and rapid mutagenesis strategy for genome editing in P. stutzeri, which may also be applicable for other gram-negative bacteria.

• 대한가정학회지
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• 제46권10호
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• pp.133-146
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• 2008

This study investgates the factors influencing the levels of consumer satisfaction and life satisfaction of resident foreigners in Korea. The data were collected through a structured self-administered survey and 545 foreigners who lived in Korea for more than 3 months, with age over 20 participated as respondents. A research framework was formulated based on the resource constraint hypothesis and the study investigated the impact of information resource(human, media and internet information source) and consumer resource(monthly income, language ability and consumer proficiency) on the levels of consumer satisfaction and life satisfaction. The results from data analysis can be summarized as follows; First, analysis of consumer problems of resident foreigners in Korea indicated that resident foreigners recognize a burden for residence cost, food expense and education fee. Most of resident foreigners in Korea are found to use small local shops most often indicating they may experience adverse market environment due to resource constraint such as language or psychological barrier, and most of the respondents answered that the most often used payment method was cash. Furthermore, resident foreigners in Korea responded that lack of language service, lack of information provision, inability to use certain goods and services are the common cause of consumer dissatisfaction, as well as price and quality problems. Second, the level of consumer satisfaction (2.96 in 4.0) is higher than the level of life satisfaction (2.63 in 4.0). Third, the level of life satisfaction is significantly influenced by Korean language ability and the level of consumer satisfaction. The level of consumer satisfaction is by the media information source usage and consumer claim experience. Fourth, the level of consumer satisfaction is found to be the variable with the strongest causal relationship with the level of life satisfaction.

• Journal of Information Technology Applications and Management
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• 제16권1호
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• pp.137-148
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• 2009

Knowledge management becomes the key point for organizations to survive and maintain competitive advantages in the knowledge economy era. E-learning plays a vital role for the organizational learning. How to share the experience of knowledge and the success of the knowledge management has great connection with the organizational culture. This study focuses on the factors of effective E-learning as well as its relation to the organizational culture. A successful e-learning system should not only aim at different statistical variables but emphasize on : course contents, variety of teaching methods and establishes a stable network environment. A stable E-learning platform and speedy bandwidth is a must to achieve the non-barrier communication and built an interactive learning environment. To achieve success in E-learning, it is not necessary to divide the organizational culture to strengthen the course content multiplication and plans the E-learning supervisory work by the sole responsibility unit. It should establish an ample teaching frequency width and platform and also must establish the appropriate study network frequency width and hardware equipment to achieve the best E-learning effect. The interaction in different organizational culture in adapting E-learning, those Ad-hoc and Marketing Culture, are mostly influence by the external environment and have more interactive content. Those in Clan and Hierarchy Culture are affected by traditional conception and lack of interaction. Meanwhile, under the cost consideration, Clan and Ad-hoc Culture on the dynamic side prefer to spend more cost on E-Learning while the stable side, Hierarchy and Marketing culture are willing to pay more expenses on E-Learning.

• 교육시설 논문지
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• 제22권1호
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• pp.25-36
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• 2015

Historically, college campuses have played a role of a city, and the development pattern of various forms and functions of cities was found in the growth stages of campuses as well. In this way, campuses developed in close relationships with our lives and such a characteristic can be confirmed in a number of cases in and out of the country. The strategic concept of such expansion is shown in the strategic classification through a master plan. This research examines concepts of major universities in the metropolitan area of Korea for promoting campus expansion and proposes implications through them. The results drawn from the research are as follows. Firstly, various developmental directions should be sought in aspects of planning, programming and economics for campus expansion with the complex application of such factors. Secondly, the multi-campus strategy of past localization era is changing into the concept of forming a global campus materializing itself as the planning strategy of internal campus. Thirdly, the physical barrier is being dissolved as a way to promote the relationship with local communities, and particularly, the management strategy of constructing new buildings in connection with local communities is the leading measure of materialization. Lastly, the development of underground space is actively carried out due to the limitation of ground physical space through which a role of establishing new campus order along with securing space is pursued.

• 한국컴퓨터정보학회논문지
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• 제18권10호
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• pp.225-234
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• 2013

본 연구는 최근 급변하고 있는 국내 항공운송시장에서 항공사 유지자산이 항공여행객들의 긍정적 배타적 행동의도에 미치는 영향력을 평가하고, 고객이탈을 최소화할 수 있는 유지기반의 주요 변인들을 도출하는데 목적이 있다. 먼저 실증분석을 위해 인천국제공항과 김포공항에서 국적항공사를 이용하는 내국인 항공여행객들을 대상으로 서베이를 실시하였고, 수집된 자료 480부에 대해 SPSS 통계패키지의 다중회귀분석을 실시하였다. 그 결과 항공사 충성도 프로그램, 특별우대와 인정프로그램, 커뮤니티 프로그램은 모두 긍정적 행동의도에 유의한 영향을 미쳤다. 그러나 배타적 행동의도에 대해서는 특별우대와 인정프로그램, 커뮤니티 프로그램만이 유의한 영향을 미치고 있었다. 연구결과는 특별우대와 인정프로그램, 커뮤니티 프로그램이 충성도 프로그램보다 항공사 전환 장벽으로서 더 높은 영향력을 가지고 있음을 시사한다. 본 연구는 심화된 경쟁시장에서 고객유지를 극대화할 수 있는 유지자산의 변인들을 도출하고 전략적 우선순위를 실증 규명하였다는 데에 연구의 학문적 실무적 의의를 가진다.