• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.1-8
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• 2011

Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.63-69
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• 2007

Compositional components such as isoflavone, protein, oil, fatty acid, and free sugar in Korean vegetable soybeans were examined with four cultivars including Hwaeomputkong, Keunolkong, Mirang, and Danmi 2. In the isoflavone, Mirang cultivar showed the highest content ($967.1{\mu}g/g$), whereas Keunolkong was the lowest content ($535.9{\mu}g/g$). The malonylglucosides were the predominant isoflavone type followed by the glucoside, aglycone, and acetyl glucoside forms, respectively. In the protein content, Hwaeomputkong was the lowest (41.7%) and Danmi 2 was the highest (45.9%). The oil contents were 11.5 to 21.2% and Mirang cultivar was the lowest. The fatty acid compositions of the oil extracts exhibited that linoleic acid was the highest (33.6-42.5%), followed by oleic, palmitic, linolenic, and stearic acids. Whereas, oleic acid ($46.7{\pm}2.0%$) was more than linoleic acid ($33.6{\pm}1.3%$) in Mirang cultivar. In the free sugar contents, Hwaeomputkong cultivar showed the highest level and sucrose ($5.52{\pm}0.49%$) appeared to be most prevalent in vegetable soybeans.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1583-1591
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• 2020

CRISPR/Cpf1 has emerged as a new CRISPR-based genome editing tool because, in comparison with CRIPSR/Cas9, it has a different T-rich PAM sequence to expand the target DNA sequence. Single-base editing in the microbial genome can be facilitated by oligonucleotide-directed mutagenesis (ODM) followed by negative selection with the CRISPR/Cpf1 system. However, single point mutations aided by Cpf1 negative selection have been rarely reported in Corynebacterium glutamicum. This study aimed to introduce an amber stop codon in crtEb encoding lycopene hydratase, through ODM and Cpf1-mediated negative selection; deficiency of this enzyme causes pink coloration due to lycopene accumulation in C. glutamicum. Consequently, on using double-, triple-, and quadruple-base-mutagenic oligonucleotides, 91.5-95.3% pink cells were obtained among the total live C. glutamicum cells. However, among the negatively selected live cells, 0.6% pink cells were obtained using single-base-mutagenic oligonucleotides, indicating that very few single-base mutations were introduced, possibly owing to mismatch tolerance. This led to the consideration of various target-mismatched crRNAs to prevent the death of single-base-edited cells. Consequently, we obtained 99.7% pink colonies after CRISPR/Cpf1-mediated negative selection using an appropriate single-mismatched crRNA. Furthermore, Sanger sequencing revealed that single-base mutations were successfully edited in the 99.7% of pink cells, while only two of nine among 0.6% of pink cells were correctly edited. The results indicate that the target-mismatched Cpf1 negative selection can assist in efficient and accurate single-base genome editing methods in C. glutamicum.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.239.2-239.2
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• 2011

치과재료의 개발은 치과 치료 기술에 있어서 가장 중요한 요소이며, 현재 일반화되고 있는 치과 치료 기술 중 하나가 임플란트 시술이다. 임플란트의 기술 개발은 주로 임플란트 나사의 표면개질을 통한 기능개선에 초점을 ��추어 진행되어지고 있다. 본 연구에서는 Ti 임플란트 표면상에 양극산화법을 적용하여 다양한 지름 및 기공 크기를 갖는 $TiO_2$ 나노튜브를 제조하여 전자빔 조사를 통한 표면개질시 그 특성에 관한 연구를 수행하였다. 특히 전자빔 조사가 Ti/$TiO_2$ 나노튜브 표면상에 존재 가능한 조골세포의 성장 특성에 미치는 영향을 연구하였다. 양극산화법을 이용한 Ti/$TiO_2$ 나노튜브는 전해질로서 HF와 $NH_4F$를 사용하였으며, 20-80 V의 인가 전압하에서 내경 약 80 nm, 외경 약 124 nm 및 길이 약 280 nm-14 ${\mu}m$의 비교적 균질한 지름 및 분포를 갖는 Ti/$TiO_2$ 나노튜브를 제조하였다. 전자빔 조사는 EB-Tech (대전, 한국)의 electron-beam accelerator(Model ELV-4)를 이용하였으며, 1.0 MeV의 빔 에너지로 총 흡수선량이 50 kGy, 500 kGy 및 5,000 kGy로 조사하였다. 전자빔을 조사하기 전 후 Ti/$TiO_2$ 나노튜브 표면상에 조골세포주(Osteoblast cell)의 배양시간의 변화에 따른 효과를 연구한 결과 배양 전 후 전자빔 조사선량의 증가에 따라 조골세포의 흡착률이 증가함을 확인할 수 있었다. 특히 HF전해질을 이용한 $TiO_2$ 나노튜브의 경우 5,000 kGy 조사선량의 전자빔을 조사한 후 조골세포 흡착률이 약 160% 증가하는 결과를 얻을 수 있었다. 전자빔 조사 전 후 조골세포 흡착률의 변화원인은 전자빔 조사 유무에 따른 $Ti^{3+}$와 $Ti^{4+}$의 변화에 기인함을 규명하였다. 이러한 결과는 향후 임플란트용 Ti/$TiO_2$ 나노튜브의 표면 개질시 전자빔의 유용성을 제시한다고 할 수 있다.

• The Journal of Society for e-Business Studies
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• v.10 no.2
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• pp.133-150
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• 2005

Electronic Trade is dramatically changing classical international trade paradigms. In particular, under the new economic environment, the ability to utilize and Information Technologies such as Electronic Data Interchange, Web-based EDI, ebXML, web service, Internet are emerging as an important factor in deciding the competitiveness of export business. The primary purpose of this study is (1) to investigate motivation factors and performance factors of electronic trade, (2) to show the relationship between motivation factors and the level of the utilization of e-trade, (3) to reveal the relationship between the level of the utilization and performance factors of e-trade. Analysis of survey questionnaire of Korean middle and small companies indicates the following : (1) motivation factors such as cost factor, education and promotion and the search of new market, have positive effect on the level of utilization of e-trade. (2) the level of utilization of e-trade has positive effect on the performance factors such as cost factor, the search of new market, the improvement of task process.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.379-385
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• 2007

This study was aimed to investigate the estrogenic activity of Di-(2-ethylhexyl) adipate (DEHA) using immatured type uterotrophic assay. SD rats were treated with DEHA (40, 200, 1000mg/kg/day), estradiol-3-benzoate (EB) $(1{\mu}g/kg/day)$ as positive control on the assay. In immatured-type uterotrophic assay, relative organ weights of kidney and reproductive organs such as ovary at high-dose group were significantly increased compared to those of vehicle control group. DEHA did not influence the levels of serum FSH and LH, and uterine morphological changes such as luminal epithelial height, myometrial thickness and numbers of uterine gland, and BrdU indices. In these results, there was no significant variation by DEHA treatment, suggesting that DEHA appears not to be a endocrine disrupter with estrogenic activity.

• The Journal of Korean Association of Computer Education
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• v.7 no.3
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• pp.111-121
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• 2004

One of the cooperative learning models, the cooperative learning of structural approach which is very simple and easily applicable accomplishes teaching-learning through combining learning contents and organic connections of various structures. This work proposes a cooperative teaching-learning model for the structural approach, designs and implements a web-based cooperative system supporting it. The model provides a concrete frame which can apply to a subject learning thus could effectively support cooperative learning. Furthermore, it classifies learning into three types such as knowledge learning, investigation, and function mastering and presents a structure application model for each so as to apply different structures according to learning materials and types. We implemented a system that performs cooperative learning on the basis of these models, applied to a class, and analyzed the effect of it.

• Information Systems Review
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• v.8 no.3
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• pp.21-38
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• 2006

The major objectives of this study are to identify the key organizational factors that facilitate and/or inhibit the IS outsourcing in Korean hospitals, and to analyze the differences between adopter & non-adopters and successful ones and not-successful ones. In order to achieve the research objectives, we derived comprehensive lists of potential facilitators and inhibitors from the past research, and conducted a field survey on 135 hospitals in metropolitan area. The analysis results suggest that organizational, financial and strategic factors are the most important facilitators, while organizational, psychological, vendor-related and environmental factors are the most important inhibitors. In addition, it was found that factors differentiating adopters and non-adopters are organizational factor(facilitator) and environmental factor(inhibitor) while strategic factor is a differentiating one between successful hospitals and unsuccessful ones.

• Journal of the Korean School Mathematics Society
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• v.15 no.1
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• pp.53-80
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• 2012

This study was designed to find the characteristics of mathematical errors and discourse in simultaneous equations and inequalities for migrant students from North Korea. 5 sample students participated, who attended in an alternative school for the migrant students from North Korea at the study in Seoul, Korea. A total of 8 lesson units were performed as an extra curriculum activity once a week during the 1st semester, 2011. The results indicated that students showed technical errors, encoding errors, misunderstood symbols, misinterpreted language, and misunderstood Chines characters of Koreans and the discourse levels improved from the zero level to the third level, but the scenes of the third level did not constantly happen. Nevertheless, the components of discourse, explanation & justification, were activated and as a result, evaluation & elaboration increased in ERE pattern on communication.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3533-3536
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• 2014

Background: Breast cancer is one of the most common cancers in women in the world. Health-related quality of life (HRQL) at treatment endpoint in cancer clinical trials is widely considered to be increasingly important. The aim of this review was to provide a literature-based assessment of the validity, reliability and responsiveness of breast cancer-specific HRQL instruments in women breast cancer patients. Materials and Methods: The databases consulted were Medline, PubMed, and Embase. The inclusion criteria required studies to: (1) involve use of HRQL measures; (2) cover women with breast cancer under standard treatment (surgery, radiation therapy, chemotherapy, hormone therapy, and targeted therapy); (3) involve the validity, reliability, or responsiveness of HRQL; (4) deal with validation of breast cancer-specific HRQL instruments. Results: A total of 16 studies were identified through the literature search that met the 4 inclusion criteria. Some seven instruments were assessed among these 16 studies: EORTC QLQ-BR23, FACT-B, FACT-ES, HFRDIS, LSQ-32, QLICP-BR, and SLDS-BC. EORTC QLQ-BR23, FACT-B, LSQ-32, QLICP-BR, and SLDS-BC are more general breast cancer-specific HRQL instruments. FACT-EB is the endocrine subscale combined with FACT-B in order to measure the side effects and putative benefits of hormonal treatment administered in breast cancer patients. HFRDIS is the HRQL measure focusing on hot flash concerns. Conclusions: This paper provides an overall understanding on the currently available breast cancer-specific HRQL instruments in women breast cancer patients.