• 한국발생생물학회지:발생과생식
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• 제14권4호
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• pp.215-223
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• 2010

배아줄기세포를 이용한 형질전환동물의 제조는 유전자의 기능 연구에 필수적이다. 특히 유전자 파괴 생쥐는 유전자의 기능 연구뿐만 아니라 사람 질병 연구에 중요한 모델이 되어 왔다. 유전자 적중법(gene targeting)과 유전자 함정법(gene trapping)은 ES 세포에서 녹아웃(knockout) 생쥐를 제조하는 대표적인 방법이다. 20여 년 전 유전자 적중법과 함정법이 최초로 개발된 이후에 이 기술은 많은 변화를 거쳤다. 특히 상동재조합에 기초한 전통적 유전자 적중법은 대량 제조기반의 조건부 유전자 적중법의 개발로 이어졌고, 유전자 적중법 및 유전자 함정법의 장점 요소의 조합은 유전자를 파괴하는 범위를 넓혔고, 유전자 적중을 더욱 효율적으로 만들었다. 이런 기술은 특정 유전자를 표적으로 하는 다양한 종류의 돌연변이 형질전환동물을 제조할 수 있게 하여 포스트게놈 시대에 요구되는 전체 유전체의 기능 연구를 더욱 효과적으로 진행시켜 줄 것이다.

• Archives of Pharmacal Research
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• 제26권11호
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• pp.892-897
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• 2003

Anticancer drugs have serious side effects arising from their poor malignant cells selectivity, Since insulin receptors highly express on the cytomembrane of some kind of tumor cells, using insulin as the vector was expected to reduce serious side effects of the drugs. The objective of this study was to evaluate the tumor targeting effect of the newly synthesized mitoxantrone-insulin conjugate (MIT-INS) with the drug loading of 11.68%. In vitro stability trials showed MIT-INS were stable in buffers with different pH (2-8) at $37^{\circ}C$ within 120 h (less than 3% of free MIT released), and were also stable in mouse plasma within 48 h (less than 1 % of free MIT released). In vivo study on tumor-bearing mice showed that, compared with MIT [75.92 $\mu g \cdot$ h/g of the area under the concentration-time curve (AUC) and 86.85 h of mean residence time (MRT)], the conjugates had better tumor-targeting efficiency with enhanced tumor AUC of 126.53 1l9 h/g and MTR of 151.95 h. The conjugate had much lower toxicity to most other tissues with targeting indexes ($TI^c$) no larger than 0.3 besides good tumor targeting efficiency with $TI^c$ of 1.67. The results suggest the feasibility to promote the curative effect in ca.ncer chemotherapy by using insulin as the vector of anti-cancer drugs.

• Journal of Plant Biotechnology
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• 제42권3호
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• pp.154-160
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• 2015

The plant breeding technology was developed with genetic engineering. Many researchers and breeders have turned from traditional breeding to molecular breeding. Genetically modified organisms (GMO) were developed via molecular breeding technology. Currently, molecular breeding technologies facilitate efficient plant breeding without introducing foreign genes, in virtue by of gene editing technology. Gene targeting (GT) via homologous recombination (HR) is one of the best gene editing methods available to modify specific DNA sequences in genomes. GT utilizes DNA repair pathways. Thus, DNA repair systems are controlled to enhance HR processing. Engineered sequence specific endonucleases were applied to improve GT efficiency. Engineered sequence specific endonucleases like the zinc finger nuclease (ZFN), TAL effector nuclease (TALEN), and CRISPR-Cas9 create DNA double-strand breaks (DSB) that can stimulate HR at a target site. RecQl4, Exo1 and Rad51 are effectors that enhance DSB repair via the HR pathway. This review focuses on recent developments in engineered sequence specific endonucleases and ways to improve the efficiency of GT via HR effectors in plants.

• Archives of Pharmacal Research
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• 제29권7호
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• pp.598-604
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• 2006

In many conventional drug delivery systems in vogue, failure to deliver efficient drug delivery at the target site/organs; is evident as a result, less efficacious pharmacological response is elicited. Microspheres can be derived a remedial measure which can improve site-specific drug delivery to a considerable extent. As an application, Lung-targeting Ofloxacin-loaded gelatin microspheres (GLOME) were prepared by water in oil emulsion method. The Central Composite Design (CCD) was used to optimize the process of preparation, the appearance and size distribution were examined by scanning electron microscopy, the aspects such as in vitro release characteristics, stability, drug loading, loading efficiency, pharmacokinetics and tissue distribution in albino mice were studied. The experimental results showed that the microspheres in the range of $0.32-22\;{\mu}m$. The drug loading and loading efficiency were 61.05 and 91.55% respectively. The in vitro release profile of the microspheres matched the korsmeyer’s peppas release pattern, and release at 1h was 42%, while for the original drug, ofloxacin under the same conditions 90.02% released in the first half an hour. After i.v. administration (15 min), the drug concentration of microspheres group in lung in albino mice was $1048\;{\mu}g/g$, while that of controlled group was $6.77\;{\mu}g/g$. GLOME found to release the drug to a maximum extent in the target tissue, lungs.

• 식물조직배양학회지
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• 제27권5호
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• pp.407-409
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• 2000

Outer envelope membrane proteins of chloroplasts encoded by the nuclear genome are transported without the N-terminal transit peptide. Here, we investigated the targeting mechanism of AtOEP7, an Arabidopsis homolog of small outer envelope membrane proteins in vivo. AtOEP7 was expressed transiently in protoplasts or stably in transgenic plants as fusion proteins with GFP. In both cases AtOEP7:GFP was targeted to the outer envelope membrane when assayed under a fluorescent microscope or by Western blot analysis. Except the transmembrane domain, deletions of the N- or C-terminal regions of AtOEP7 did not affect targeting although a region closed to the C-terminal side of the transmembrane domain affected the targeting efficiency. Targeting experiments with various hybrid transmembrane mutants revealed that the amino acid sequence of the transmembrane domain determines the targeting specificity The targeting mechanism was further studied using a fusion protein, AtOEP7：NLS：GFP, that had a nuclear localization signal. AtOEP7：NLS：GFP was efficiently targeted to the chloroplast envelope despite the presence of the nuclear localization signal. Taken together, these results suggest that the transmembrane domain of AtOEP7 functions as the sole determinant of targeting specificity and that AtOEP7 may be associated with a cytosolic component during translocation to the chloroplast envelope membrane.

• Reproductive and Developmental Biology
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• 제38권2호
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• pp.71-77
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• 2014

The specific genetic modification in porcine somatic cells by gene targeting has been very difficult because of low efficiency of homologous recombination. To improve gene targeting, we designed three kinds of knock-out vectors with ${\alpha}1,3$-galactosyltransferase gene (${\alpha}1,3$-GT gene), DT-A/pGT5'/neo/pGT3', DT-A/NLS/pGT5'/neo/pGT3' and pGT5'/neo/ pGT3'/NLS. The knock-out vectors consisted of a 4.8-kb fragment as the 5' recombination arm (pGT5') and a 1.9-kb fragment as the 3' recombination arm (pGT3'). We used the neomycin resistance gene (neo) as a positive selectable marker and the diphtheria toxin A (DT-A) gene as a negative selectable marker. These vectors have a neo gene insertion in exon 9 for inactivation of ${\alpha}1,3$-GT locus. DT-A/pGT5'/neo/pGT3' vector contain only positive-negative selection marker with conventional targeting vector. DT-A/NLS/pGT5'/neo/pGT3' vector contain positive-negative selection marker and NLS sequences in upstream of 5' recombination arm which enhances nuclear transport of foreign DNA into bovine somatic cells. pGT5'/neo/pGT3'/NLS vector contain only positive selection marker and NLS sequence in downstream of 3' recombination arm, not contain negative selectable marker. For transfection, linearzed vectors were introduced into porcine ear fibroblasts by electroporation. After 48 hours, the transfected cells were selected with $300{\mu}g/ml$ G418 during 12 day. The G418-resistant colonies were picked, of which 5 colonies were positive for ${\alpha}1,3$-GT gene disruption in 3' PCR and southern blot screening. Three knock-out somatic cells were obtained from DT-A/NLS/ pGT5'/neo/pGT3' knock-out vector. Thus, these data indicate that gene targeting vector using nuclear localization signal and negative selection marker improve targeting efficiency in porcine somatic cells.

• 농업생명과학연구
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• 제44권1호
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• pp.69-80
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• 2010

본 연구는 착색단고추의 유통실태를 분석하고 운영효율성을 측정하여 유통경로별 유통효율성을 비교분석한 것이다. 수출시장 (일본)의 경우에는 개별농가가 직접수출대행업체와의 계약을 통해 수출하는 것 (유형 III)이 영농조합법인 (유형 I:수출농단결성)과 지역농협을 통한 공동출하 (유형 II)의 경우보다 운영효율성이 높은것으로 분석되었다. 내수시장의 경로에서는 도매시장을 통한 경로가 가장 효율적인 것으로 분석되었는데 이는 도매시장을 통해 유통되는 물량은 대형유통업체와 계통판매되는 물량보다 비표준화된 물량이 많으므로 품질면에서 차이가 나지만 내수시장균형가격이 비교적 높게 형성됨으로써 품질에 상응하는 가격이 형성되지 않고 있는 실정이다. 그리고 유형IV의 경우는 유형 V, VI유형보다 유통비용 투입에 대한 산출수준이 비교적 유리한 것으로 나타났다.

• 기술혁신연구
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• 제15권1호
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• pp.235-250
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• 2007

The Korean Government has recently been pushing ahead with a variety of programs to support regional innovation. This paper examines whether the variety of regional innovation programs of the government are efficiently managed and effectively functioning in regions. To make the assessment, questionnaire surveys were executed targeting innovation actors in fourteen regions and evaluated the efficiency of government regional programs. Key points of assessment were the appropriateness of the program organization and the efficiency of program management for the effectiveness of program results. It was found that the appropriateness of the program organization and the efficiency of program management were related positively to performance of programs, but the performance of regional innovation programs overall was not high. Some problems were found in program organization and program management such as the overlapping of program objectives and functions, the inadequate synergy among programs, insufficient reflection of the needs of industry in planning, the overlapping investment in facilities and equipment, and low effectiveness of evaluation.

• Journal of the Korean Data and Information Science Society
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• 제20권6호
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• pp.1129-1143
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• 2009

인터넷 쇼핑몰은 그 특성상 직접 상품을 살펴보기 힘들고 판매자와의 상호작용이 어렵다. 그래서 소비자들은 인터넷상품 구매 시 의사결정에 확신이 부족하거나 절차를 간소화하기 위하여 상품 평이나 추천을 고려한다. 추천의 정교화 및 성과를 높이기 위하여 수 많은 연구가 진행되었으나, 이러한 연구들은 목적을 선정하지 않고 상품간, 사용자간, 협업적 연관성을 바탕으로 진행되어 비슷한 유형을 나열하는 것에 그치고 있다. 그러므로 목적성을 가지는 기업의 캠페인에 바로 적용하기에는 어려움이 존재하였고, 부가적으로 정보를 가공하여 로지스틱회귀모형 등 모형 작업을 실시하는 것이 일반적이었다. 본 논문에서 제안하는 목적성을 고려한 추천은 개인마다 점수를 부여하여 개인화에 따른 추천이 가능토록 하였으며, S주식회사 쇼핑몰의 이메일 캠페인에 적용하여 개봉율, 클릭율, 구매율에 대하여 그 우수성을 증명하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.52.2-52.2
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• 2011

Flat form technology for constructing anticancer loaded multi-walled carbon nanotubes (mwCNTs) was introduced in this study. Conventional anticancer drugs, such as MTX (Methotrexate), cisplatin, DOX (Doxorubicin hydrochloride), DAU (Daunorubicin) and EPI (epirubicin) were bio-conjugated with folic acid (FA) for selective targeting tumor cells. Loading efficiencies of the used anticancer drugs on mwCNTs have shown different order of bindings depending on the molecular bind affinity of NH (amine) formation on mwCNTs. MTT assays have shown increased selective target efficiency of FA conjugated mwCNTs on breast cancer cell growth inhibition. All results collectively indicated promising application of mwCNTs as a smart inorganic nanomaterial for selective targeting drug delivery vehicle at tumor tissues.