• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.61-66
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• 1989

포플라 세포(細胞)의 Sucrose gradient 원심분리(遠心分離)에 나타난 세포(細胞)분획은 6개의 band 및 침전으로 분리(分離) 되었다. Peroxidase의 활성변화(活性變化)는 휴면기(休眼期)에 높아졌으며, 자발적(自發的) 휴면(休眠)이 타파되면서 낮아지기 시작하였다. 휴면기(休眠期)에 급격히 높아진 Peroxidase 활성(活性)은 Peroxidative 활성(活性)을 지닌 세포내(細胞內) Microbody에 존재(存在)하는 것으로 사료된다. Catalase의 활성(活性)은 11월(月), 12 월(月) 1월(月)의 휴면기(休眼期)에 활성(活性)이 낮았으며. IAA의 농도는 휴면초기(休眼初期)에 감소하기 시작하여, 12월(月)에 최저(最低)가 되었다. 자연휴면(自然休眠)이 타파된 1월(月)부터는 IAA 농도가 증가하기 시작하여 4월(月)의 발아기(發芽期)까지 계속되었다. 이와같은 Peroxidase, Catalase를 비롯한 IAA의 변화(變化)는 봄철의 발아(發芽) 및 재생장(再生長)과 가을철 휴면조절(休眠調節)에 영향을 미치는 것으로 사료된다.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.915-922
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• 2001

Effects of thermal exposure and rejuvenation treatment on the microstructural evolution and the stress-rupture properties of IN738LC have been investigated. The role of precipitates on the stress-rupture properties has been analyzed through microstructural observations. Thermal exposure at $982^{\circ}C$ for 1000 hours gave rise to precipitation of $\sigma$ phase and coarsening of r'. The microstructural degradation with thermal exposure at $982^{\circ}C$ deteriorated stress rupture properties of the alloy. All the existing phases except MC carbides have completely dissolved into the matrix with homogenization treatment at $1200^{\circ}C$ for 2 hours. Microstructure and stress-rupture properties of the thermal exposed specimens have been successfully rejuvenated by the proposed treatment.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.71-77
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• 1997

With the aim of improving periodontal regeneration efficacy, as a biodegradable local drug delivery device, drug releasing chitosan beads were prepared. Chitosan beads were prepared through the formation of intermolecular or intramolecular ionic interaction bewteen chitosan and sodium tripolyphosphate and were loaded with flurbiprofen. The mean diameter of the beads was $250\;{\mu}m$. Drug loading efficiency was improved by regulating the pH of tripolyphosphate solution. The drug release kinetics mainly depended upon the hydrophobic properties of the flurbiprofen, that is, the release of flurbiprofen showed initial burst with rapid release for the first day followed by a levelling off of the release rate. However, the release rate could be controlled by the formulation factor including the pH, concentration of the tripolyphosphate solution, gelation time, drug contents. From these results, flurbiprofen loaded chitosan beads were anticipated as biodegradable local drug delivery devices for periodontal regeneneration.

• Proceedings of the Botanical Society of Korea Conference
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• 1993.07a
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• pp.1-36
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• 1993

It is possible to regenerate plants from calli, single cells and protoplasts of numerous species via organogenasis or embryogenesis in cell and tissue culture systems. Also such regeneration of plants can directly occur from cells of explants. However certain plant species has not been yet provided cultures suitable for plant regeneration from cells or tissues. For example, we have to confirm the regenerability of plant from cells before preparing transformed cells for application. Even more, it is very important to notice that regenerated plants in cell and tissue cultures often show structural abnormality. The mojority of those plants is functionally disordered and eventually cases degenerated. One of such examples is vitreous plants which are manifested mainly in the leaves and manifesteds to a lesser extent in the stems and roots. Regenerants in suspension cultures show more frequent vitrification than on gelled media so that relative humidity and water potential are the key factors involved in abnormal morphogenesis in vitro. The other is that somatic embryos formed in media containing BAP or high concentration of sucrose show frequently cotyledon aberrancy such as polycotyledon and born type cotyledon. The embryos with aberrant cotyledon of Codonopsis lanceolata could not germinate or regenerate into plants in many cases. In contrast, the polycotyledon embryos of Aralia cordata germinated in higher percentage than two cotyledonary embryos, but horn type cotyledonary embryos rarely germinated. The major cause of poor germination is the abnormal development of plumule apex meristem.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.561-571
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• 1994

The comparative study on the predominant cultivable periodontopathic bacteria were done 2 weeks after the application of the e-PTFE membrane and collagen membrane in the controlled tissue regeneration procedures. The purpose of the present study also included the antibiotic susceptibility test (ciprofloxacin, tetracycline, clindamycin) of these cultured organisms. 0.1% chlorhexidine mouthwash (10ml twice/day for 6 weeks) and systemic doxycycline (200mg/day for 2 weeks) were administered for supragingival and subgingival plaque control respectively. Four clinical isolates of A.a. from 2 patients were found to be resistant to tetracycline which were susceptible to clindamycin and ciprofloxacin. One isolate of W.r. and two unidcntified microorganisms were resistant only to clindamycin and one isolate of NID BPB and E.c. and two isolates of unidentified microorganisms were resistant only to ciprofloxacin. Overall susceptibility of tested microorganisms to ciprofloxacin, tetracycline and clindamycin were 85%, 77% and 89% respectively. The results indicated no significant differences in the percentage of cultivable periodontopathic bacteria between the two membranes, and also the microorganisms resistant to tetracycline after systemic administration of doxycycline turned out to be susceptible to either ciprofloxacin or clindamycin.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.329-333
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• 2001

Callus and shoot formation from medicinal crop, Lycium chinense Mill. cv. 'Cheongyang', as influenced by various media, explant sources and plant growth regulators were investigated. The rate of shoots formation, number of shoots, and fresh weight of shoots were the best on MS medium followed by B$_{5}$, WPH, and SH. Callus induction was more effective in leaf than internode segments, and was the best on MS medium containing 0.5 mg/L NAA with 0.2 mg/L BA. Effects of plant growth regulators in shoot formation were more effective in BA than TDA combined with NAA. Shoot formation from callus induced in leaf and internode segments was the best on MS medium containing 0.01 mg/L NAA with 0.2 mg/L BA.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.374-380
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• 2006

With the aim of inducing mutation in fern Cyrtomium caryoptideum var. coreanum, rhizome segments of In vitro-grown cultures were treated with chemical mutagens such as EMS, NMU and colchicine. Based on regeneration ratios, sensitivities for each treatments were assessed and also optimum treatment condition of each mutagens was explored. Optimum concentration for EMS treatment was considered to be 20 to 50mM and for NMU 5 to 10mM. NMU was found to be more effective in inducing chlorophyll and morphological variations than EMS. The RAPD were performed to check the genetic modification of phenotypical variants. As a result, polymorphic DNA band patterns between wild type and variants were observed by two 10-mer primers.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.245-249
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• 2003

This study was carried out to establish a regeneration system from leaf explant of purple sweetpotato(Ipomoea batatas L.) The optimal concentrations of plant growth regulators for callus induction and shoot formation were determined. The optimal combination for callus formation was 1$\mu$M 2,4-D 5$\mu$M BM, and highest yield of embryogenic calli were observed on Murashige and Skoog basal medium containing 0.5$\mu$M 2,4-D under light condition after 4weeks of culture. Embryogenec callus was subcultured on medium supplemented with 5$\mu$M ABA for 4 days. Subsequently, regeneration of adventitious shoots occurred when these embryogenic calli were transferred onto medium with 3∼6$\mu$M gibberellic acid. Regenerated shoots were developed into normal plantlets.

• The Journal of the Korean dental association
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• v.55 no.12
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• pp.828-840
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• 2017

In recent years, many researchers and clinicians found interest in regenerative medicine using induced pluripotent stem cells (iPSCs) with biomaterials due to their pluripotency, which is able to differentiate into any type of cells without human embryo, which of use is ethically controversial. However, there are limitations to make iPSCs from adult somatic cells due to their low stemness and donor site morbidity. Recently, to overcome above drawbacks, dental tissue-derived iPSCs have been highlighted as a type of alternative sources for their high stemness, easy gathering, and their complex (ectomesenchymal) origin, which easily differentiate them to various cell types for nerve, vessel, and other dental tissue regeneration. In other part, utilizing biomaterials for regenerative medicine using cell is recently highlighted because they can modulate cell adhesion, proliferation and (de)differentiation. Therefore, this paper will convey the overview of advantages and drawbacks of dental tissue-derived iPSCs and their future application with biomaterials.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.136-136
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• 2011

최근, 수자원의 효율적 이용을 위하여 농업용수로를 파이프라인으로 시공하는 지구가 증가하는 추세에 있다. 한편으로는 간척지를 복합농업단지, 시설원예, 신재생에너지단지 등 다각적으로 이용하는 정책을 추진하고 있다. 이에 따라, 농업용수 공급시스템도 개수로에서 관수로로 설계하는 추세에 있다. 농업분야에서 관수로를 활용하기 시작한 것은 ‘80년대 중반부터이나 그간 관수로 설계기준의 부재, 시범사업의 실패 등으로 인하여 보급이 지연되어 왔다. 일반적으로 관수로 설계는 노선선정, 관조직 구성, 관경산정, 관망해석, 도면작성 등 일련의 과정을 거쳐야 완성된다. 이 설계과정에서 관경산정 및 관망해석은 고도의 설계 노하우가 없으면 활용이 어려운 설계기술이다. 이번에 개발한 관수로 설계지원시스템은 관수로 설계 전문가가 처리해야할 일련의 설계작업을 AUTO CAD상에서 일관성 있게 처리할 수 있도록 개발한 것이 특징이다. 관수로설계지원시스템은 수치지도상에서 등고선 좌표, 표고 등을 자동 추출하여 사업계획서 및 종단도를 작성할 수 있으며, 관망심볼을 이용하여 시스템상에서 관망조직을 구성할 수 있으며, 다양한 안에 대한 노선검토, 관경산정, 관망해석과 관두께, 매설심도 등 구조해석이 가능하다. 그리고, 농업용 관수로의 제수밸브 등 부대시설에 대한 표준도를 D/B로 작성하여 설계도 작성시 참고할 수 있도록 개발하였다. 관수로설계지원시스템은 매뉴얼대로 처리하면 관망해석에 대한 전문지식이 없어도 설계에 활용이 가능하다.