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Characterization of Umbilical Cord-derived Stem Cells during Expansion in Vitro (탯줄유래 줄기세포의 계대배양에 따른 특성 변화의 분석)

  • Park, Se-Ah;Kang, Hyun-Mi;Heo, Jin-Yeong;Yoon, Jin-Ah;Kim, Hae-Kwon
    • Clinical and Experimental Reproductive Medicine
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    • v.36 no.1
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    • pp.23-34
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    • 2009
  • Objectives: Mesenchymal stem cells (MSC) comprise a promising tool for cellular therapy. It is known that long-term in vitro culture of human bone marrow and adipose tissue derived-MSCs lead to a reduction of life span and a change of stem-like characters. The aim of our study was to examine whether stem cell properties of human umbilical cord-derived stem cells (HUC) could be affected by in vitro expansion. Methods: HUC were isolated from human umbilical cord and cultured for 10 passages in vitro. Morphology and population doubling time (PDT) were investigated, and changes of stem cell properties were examined using RT-PCR and immunocytochemistry during serial subcultures. Results: Morphology and PDT of HUC began to change slightly from the 7th passage (p7). Expression level of nestin and vimentin mRNAs increased along with the culture period from p4 until p10. In contrast, expression level of SCF mRNA decreased during the same culture period. Expression level of Oct-4 and HNF-4${\alpha}$ mRNAs was not significantly changed throughout the culture period until p10. Expression level of BMP-4, FGF-5, NCAM and HLA-ABC mRNAs appeared to increase as the culture continued, however, the difference was not significant. Immunocytochemical studies showed that HUC at p3, p6 and p9 positively were stained with antibodies against SSEA-3 and SSEA-4 proteins. Interestingly, staining intensity of HUC for ICAM-1 and HLA-ABC gradually increased throughout the culture period. Intensity against thy-1 and fibronectin antibodies increased at p9 while that against TRA-1-60 and VCAM-1 antibodies began to decrease at p6 until p9. Conclusions: These results suggest that HUC change some of their stem cell characteristics during in vitro culture. Development of culture system might be needed for the maintenance of characteristics.

A Study on the Improvement of the Existing Technology Valuation Solutions;focused on high technology based start-up company (현행 기술가치 평가모형의 개선 방안에 관한 연구;신기술 창업기업의 경우를 중심으로)

  • Yang, Tai-Shik;Min, Kyung-Se
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.2 no.2
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    • pp.93-120
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    • 2007
  • To promote the commercialization of high technology based start-up company, it is essential to activate technology trading for the Innovative Small & Medium companies which eager to acquire technology competitiveness through technology trading and facilitate financial system which provide Small & Medium companies with technology commercialization money. This study focus on enhancing credibility of technology valuation solutions through the improvement of the existing technology valuation solutions. The existing technology valuation solutions in practice have deficiency in reasonable valuation because of subjective technology factor's calculation. And the commercialization risk of high technology based start-up companies cannot be fully reflected in the existing valuation solutions. The high risk of technology commercialization acts as a hurdle in the facilitation of providing money for the start-up companies. The improved new model will have more acceptable objectivity and reasonably reflect the commercialization risk of start-up companies. The new model has two distinctive features compared to existing solutions. The new model newly adopts commercialization success factor which reflects the risk of high technology based start-up company. And the new model excludes technology factor which is controversial among interested parties. The exclusion of technology factor will improve the objectivity of technology valuation and the adoption of commercialization success factor will solicit investor and capitalist who concern the high risk of technology based start-up companies. In conclusion, the improved new model is expected to activate technology trading and facilitate the money market through which high technology based start-up companies raise commercialization money.

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Simultaneous Determination of UV Absorbers Migrated from Polyethylene and Polypropylene Food Packaging Materials into Food Simulants by HPLC-UVD (HPLC-UVD를 이용한 폴리에틸렌, 폴리프로필렌 기구 및 용기·포장 유래 자외선흡수제 동시분석법)

  • Choi, Heeju;Choi, Jae Chun;Bae, In-Ae;Lee, Chanyong;Park, Se-Jong;Kim, MeeKyung
    • Journal of Food Hygiene and Safety
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    • v.32 no.5
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    • pp.434-442
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    • 2017
  • The UV light in sunlight breaks down the chemical bonds in a polyolefin polymer through a process called photodegradation, ultimately causing cracking, chalking, colour changes, and loss of physical properties such as impact strength, tensile strength, elongation, and others. UV absorbers are used to prevent or terminate the oxidation of plastics by UV light. They are receptive to UV radiation and dissipate the energy harmlessly as heat. Benzotriazoles and benzophenones are used mainly in polyolefins such as polyethylene and polypropylene. In this study, we have developed a method for the analysis of 12 UV absorbers, which are Uvinul 3000, Cyasorb UV 24, Uvinul 3040, Tinuvin 312 and P, Seesorb 202, Chimassorb 81, Tinuvin 329, 234, 326, 328 and 327, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The UV absorbers in food simulants were determined by reversed-phase high performance liquid chromatograph-ultraviolet detector with 310 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.049~0.370 mg/L), and limits of quantification (0.149~1.120 mg/L). The recoveries of UV absorbers spiked to four food simulants ranged from 70.05% to 110.13%. The developed method would be used as a reliable tool to determine concentrations of the migrated UV absorbers.

Discrimination of Korean Apple Cultivars Using Combination of RAPD-SCAR Markers (RAPD-SCAR 마커 조합을 이용한 국내 육성 사과 품종 판별)

  • Cho, Kang-Hee;Heo, Seong;Kim, Hyun-Ran;Kim, Jeong-Hee;Shin, Il-Sheob;Han, Sang-Eun;Kim, Se-Hee;Kim, Dae-Hyun
    • Horticultural Science & Technology
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    • v.28 no.5
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    • pp.828-835
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    • 2010
  • Conventional methods for identification of apple cultivars are based on the evaluation of sets of morphological characteristics, however, closely related cultivars often cannot be distinguished by morphological traits. This study was conducted to develop DNA markers for discrimination of the apple cultivars bred in Korea. Thirty random primers generated eighty-three random amplified polymorphic DNA (RAPD) markers from thirty-one Korean bred and introduced apple cultivars. Fifty-two RAPD fragments were cloned and sequenced for conversion into sequence characterized amplified region (SCAR) markers. Among them only seventeen SCAR markers resulted in the amplification of single major bands the same size as the RAPD fragment cloned. Several combinations of six (AN11_433, AN08_566, A408_592, AK17_653, AO04_711, AO04_779 or AW15_368, AN11_433, A408_592, AK17_653, AO04_711, AO04_779, or AL1_427, AN11_433, AN08_566, A408_592, AK17_653, AO04_779) to seven (AL1_427, AN11_433, AN08_566, A408_592, AK17_653, AM16_708, AO04_779 or A330_424, AN11_433, AG14_502, AN08_566, A408_592, AK17_653, AO04_779 or A330_424, AN11_433, AK14_564, A408_592, AK17_653, AM16_708, AT14_789) SCAR markers provided enough polymorphism to identify sixteen Korean apple cultivars among thirty-one tested cultivars. Therefore, application of the seventeen SCAR markers was sufficient to identify the thirty-one tested apple cultivars. These markers could be utilized as a reliable tool for cultivar discrimination of Korean apples.

Analysis of Chemistry Teaching-Learning Programs for the Gifted in Science Used in Middle School Gifted Classes (중학교 영재학급에서 사용 중인 화학영역의 과학영재 교수-학습 프로그램의 분석)

  • Cho, Yun-Hyang;Kim, Dong-Jin;Hwang, Hyun-Sook;Park, Se-Yeol;Yang, Kyoung-Eun;Park, Kuk-Tae
    • Journal of Gifted/Talented Education
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    • v.21 no.2
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    • pp.485-510
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    • 2011
  • This study aimed to analyze the appropriateness of chemistry teaching-learning programs for the gifted in science in middle school gifted classes and to propose improvements. For this study, 5 chemistry teaching-learning 4-6 hour programs developed for science gifted classes by Korea Education Development Institute (KEDI) and 3 chemistry teaching-learning programs developed for science gifted classes by three middle schools in K province were selected. A standard model for gifted education programs was used as tool for analyzing the program targets, program contents, teaching-learning methods, and assessment items. The results showed that all chemistry teaching-learning programs for the gifted in science presented well attainable objectives in the program targets. However, most program targets did not offer differentiated objectives from the general education. Program contents of KEDI stresses intensified education, and also presented a high ratio of sub-elements of creativity, which can enhance gifted creativity. On the other hand, program contents developed by three middle schools focused on acceleration in advancement, and presented low ratio of creativity sub-elements, which could be insufficient in enhancing gifted creativity. Differentiated and personalized, integrated science and interscience, updated research contents were hardly found in programs developed by KEDI and three middle schools. However, teaching-learning methods were composed to fit the learning objectives in the teaching process and the procedures, and were made to self-directed learning. There were no assessment for the feedback after class. Therefore, teaching-learning programs for the gifted in science should be developed further in order to fulfill the objectives of gifted education and gifted characteristics. Also, it is necessary to construct infrastructure to carry out the developed teaching-learning programs.

Generation of a Mammalian Gene Expression Vector Using Bovine Viral Diarrhea Virus (Bovine Vira1 Diarrhea Virus를 이용한 포유동물세포 발현벡터의 개발)

  • 이영민
    • Korean Journal of Microbiology
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    • v.38 no.2
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    • pp.86-95
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    • 2002
  • As a result of genome projects, the research to elucidate the function of a protein of interest has recently been well-recognized. In order to facilitate functional genomics, a useful mammalian gene expression vector is required. Using an infectious CDNA clone of BVDV pNADLclns-, we have developed a mammalian gene expression vector. In this study, a replication-competent full-length infectious CDNA clone containing puremycin acetyltransferase (pac) gene (pNADLclns-/pac) was successfully generated. The viral RNA replication and viral protein NS3 synthesis were examined by detecting metabollically $^{32}P$-labelled genomic viral RNA and immunoblotting with a mouse anti-NS3 antibody. To generate viral replicon as an expression vector, we examine if the viral structural genes (C, E0, El, E2) are required for viral replication by deletion analysis. As a result, all of the structural proteins are dispensable for viral replication per se, but essential for infectious viral particle formation. Based on our deletion analysis, we have generated a replication-competent BVDV viral replicon (pNADLclns-/pac/${\Delta}S$), whose structural genes are all deleted. In addition to NADLclns- /pac/${\Delta}S$, NADLclns-/ luc/${\Delta}S$ viral replicon containing luciferase gene as a reporter was constructed and fecund to be replication-compotent in HeLa and BHK cells as well as MDBK cells. Therefore, BVDV viral replicon developed in our study will be a useful tool to express a protein of interest in various mammalian cells.

A Study on the Influence of Affct Based Trust and Cognition Based Trust on Word-of-Mouth Behaviors -Focusing on Friendship Network and Advice Network- (정서기반신뢰와 인지기반신뢰가 구전행동에 미치는 영향 연구 -친교네트워크와 조언네트워크를 중심으로-)

  • Bae, Se-Ha;Kim, Sang-Hee
    • Management & Information Systems Review
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    • v.32 no.5
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    • pp.193-231
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    • 2013
  • As developed IT, Word-of-Mouth(WOM) used varied terms as buzz marketing and viral marketing, and impressed that importance. Despite introduced new marketing tool on managers and professionals, online word-of-mouth including SNS lack of study on social network what based viral in marketing. In social network, patterns of relationship between individuals influence each other individual behaviors. Therefore this research grouped friendship-network and advice-network by characteristics, studied on trust of information source that antecedents of word-of-mouth in network. This study examined that affect- and cognition based trust affect WOM acceptance as WOM behaviors and examined effect of type of product as moderating variable. Additional this literature studied that WOM acceptance affect WOM recommend. To find the Influence of Trust on Word-of-Mouth Behaviors, a survey has done 206 samples(undergraduate students). The results of this study are as following : First, type of trust different friendship network and advice network. Affect-based trust is outstanding in friendship network than in advice network, while cognition-based trust stands out in advice network than another. Second, affect- and cognition based trust positive affect WOM acceptance. Contrary to expectations, what is preconceived trust in network have a similar effect for WOM acceptance regardless of type of trust. Third, WOM acceptance positive affect WOM recommend. Fourth, affect based trust affect WOM acceptance of hedonic product rather than utilitarian product. Upon especially in friendship network terms, affect-based trust has a more effect on WOM acceptance than cognition-based trust. This study has many implications. First, it is important that trust what have an influence WOM acceptance grouped affect- and cognition based trust. Second, it confirmed that trust is antecedents of positive WOM. Third, it is important that network grouped friendship network and advice-network by trust. Fourth, it gave managerial implications that they have to supply WOM through which network by type of product. We This study classified network and trust based on previous study. Then it examined relations between WOM behaviors. Further research could do enrich various things for example various age group, valence of message, quality of information.

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Study on Oneself Developed to Apparatus Position of Measurement of BMD in the Distal Radius (자체 개발한 보조기구로 원위 요골의 골밀도 측정 자세 연구)

  • Han, Man-Seok;Song, Jae-Yong;Lee, Hyun-Kuk;Yu, Se-Jong;Kim, Yong-Kyun
    • Journal of radiological science and technology
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    • v.32 no.4
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    • pp.419-426
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    • 2009
  • Purpose : The aim of this study was to evaluate the difference of bone mineral density according to distal radius rotation and to develop the supporting tool to measure rotation angles. Materials and Methods : CT scanning and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 20 males. Twenty healthy volunteers without any history of operations, anomalies, or trauma were enrolled. The CT scan was used to evaluate the cross sectional structure and the rotation angle on the horizontal plane of the distal radius. The rotational angle was measured by the m-view program on the PACS monitor. The DXA was used in 20 dried radii of cadaveric specimens in pronation and supination with five and ten degrees, respectively, including a neutral position (zero degrees) to evaluate the changes of BMD according to the rotation. Results : The mean rotation angle of the distal radius on CT was 7.4 degrees of supination in 16 cases (80%), 3.3 degrees of pronation in three cases (15%), and zero degree of neutral in one case (9%), respectively. The total average rotation angle in 20 people was 5.4 degrees of supination. In the cadaveric study, the BMD of the distal radius was different according to the rotational angles. The lowest BMD was obtained at 3.3 degrees of supination. Conclusion : In the case of the measurement of BMD in the distal radius with a neutral position, the rotational angle of the distal radius is close to supination. Pronation is needed for the constant measurement of BMD in the distal radius with the rotation angle measuring at the lowest BMD and about five degrees of pronation of the distal radius is recommended.

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A Study on the Experience Design and Practical Use of Experience by On- and Off-Line Environment (온 오프라인 환경에 따른 경험의 활용과 경험디자인에 관한 연구)

  • Yoon, Se-Kyun;Kim, Tae-Kyun;Kim, Min-Su
    • Archives of design research
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    • v.18 no.3 s.61
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    • pp.5-14
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    • 2005
  • In the past, consumers sought utilitarian and defensive consumption in an attempt to move to a balanced state. However, today's consumers go beyond this to consume more for hedonic and creative reasons if not for sheer pleasure. There is an obvious shift from the type of consumption that satisfies basic desires through the characteristics, convenience and quality of goods and services to an era of 'experiential consumption,' in which consumers pursue distinctive value systems and way of life along with a total 'experience' provided by such goods and services. Such a sign of the times has given birth to the experience design that aims at maximizing the strategic use of experiences in design. Research on this subject is gradually increasing. The research and application peformed even without the proper understanding about the concepts and purposes of experience design, however, is likely to deviate from the true nature in its process or method. Also, they are likely to cause rather than solve problems. Accordingly, this study examined the meaning of experience from a spatial aspect, focusing on areas that recognize the experience as economically valuable, making the most of it substantively. The main concept of experience practical used on-line is enhancement of the usability of a medium by reflecting the experience of users accustomed to both off-line and on-line environments and materializing the environment doser to and more familiar with the users, thus allowing them to comfortably use the medium. This is to allow the users to feel more comfortable. The experience practical used pertaining to off-line is a tool to fulfill the sensitivity of users, with efforts to create new, future-oriented consumer values. This, based on the understanding of consumer behavior, seeks to maximize the consumption experience of consumers by providing a combination of sensual and sensitive experiences as well as to enhance the existing experiences by permitting users to create new, extended experiences from the fixed characteristics of products. Furthermore, it aims to provide consumers with the hedonic experience of play through the joy, fun and uniqueness of alternate experiences.

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Current Trend of European Competition Damage Actions (유럽 경쟁법상 손해배상 청구제도의 개편 동향과 그 시사점)

  • Lee, Se-In
    • Journal of Legislation Research
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    • no.53
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    • pp.525-551
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    • 2017
  • This Article discusses the current trend of European competition damage actions focused on the recent Damage Directive and its transposition by the United Kingdom and Germany. The relevant Directive was signed into law in November 2014, and it requires the EU Member States to adopt certain measures to support competition damage actions. The required measures and principles by the Directive include right to full compensation, rebuttable presumption of harm, extensive disclosure of evidence, use of pass-on for defense and indirect purchaser suits. Although many Member States did not meet the deadline to transpose the Directive, the end of 2016, it is reported that 23 Member States have now, as of September 2017, made enactments according to the Directive. When we look at the transposition done by the United Kingdom and Germany, the revisions on their competition laws closely follow the contents of the Directive. However, it will take quite a long time before the amended provisions apply to actual cases since most of the new provisions apply to the infringement that take place after the date of the amendment. A similar situation regarding application time may happen in some other Member States. Furthermore, even if the terms of the competition laws of the Member States become similar following the Directive, the interpretations of the laws may differ by the courts of different countries. EU also does not have a tool to coordinate the litigations that are brought in different Member States under the same facts. It is true that the EU made a big step to enhance competition damage actions by enacting Damage Directive. However, it needs to take more time and resources to have settled system of competition private litigation throughout the Member States. Korea has also experienced increase in competition damage actions during the last fifteen years, and there have been some revisions of the relevant fair trade law as well as development of relevant legal principles by court decisions. Although there are some suggestions that Korea should have more enactments similar to the EU Directive, its seems wiser for Korea to take time to observe how EU countries actually operate competition damage actions after they transposed the Directive. Then, it will be able to gain some wisdom to adopt competition action measures that are suitable for Korean legal system and culture.