• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.46-54
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• 2005

To make the composite panels of wood particles and recycled plastics, the recycled polypropylene was used. In the composite panels the sizes of wood particles were 1/32", 1/4" and 1/2" mesh, and the composition ratios of the recycled plastics were 10%, 30%, 50% and 70%. The physical and mechanical properties of the composite panels were investigated. As the composition ratio of wood particle increases, the density increases, while it decreases at the same composition ratio because the size of wood particle increases. As the composition ratio of recycled polypropylene increases from 10% to 30%, both thickness swelling and water adsorption significantly decrease. As the composition ratio of recycled polypropylene increases, the modulus of rupture in bending strength increases, but the modulus of elasticity in bending strength decreases. SEM shows that the dissolved recycled polypropylene penetrates into tracheid and pit, and bonds mechanically to other wood particle and matrix to increase the bonding strength and improve the physical and mechanical properties of composite panel.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.4
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• pp.335-343
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• 2014

Regenerative endodontic treatment has the potential to heal a necrotic pulp, which can affect root development in immature teeth. However, several drawbacks and unfavorable outcomes are associated with regenerative endodontic treatment, of which the most significant is coronal discoloration due to the presence of minocycline in triple antibiotic paste and mineral trioxide aggregate (MTA). To prevent tooth discoloration following pulp treatment, the modified triple antibiotics (ciprofloxacin, metronidazole, clindamycin) were used as canal disinfectants and Retro MTA, a $ZrO_2$-containing calcium aluminate cement, was used to seal the canal. Following access cavity acquisition, the canal was copiously irrigated with 2.5% sodium hypochlorite. A modified triple antibiotic paste was then applied to the canal. Once the tooth was asymptomatic (after between 3 and 8 weeks), Retro MTA was carefully placed over the blood clot or a collagen plug. Follow-up radiographs revealed normal periodontal ligament space and root development. In two cases, successful regenerative endodontic treatment of the infected immature tooth, without discoloration, was achieved with disinfection using modified triple antibiotics and Retro MTA sealing.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.129-142
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• 2019

It is needed to regenerate declined industrial districts in downtown area through to invite new industry and to improve urban environment. The purpose of this paper was to make suggestions on the urban regeneration for the districts. I have taken a literature research and a site analysis with cases of 'the South Lake Union' in Seattle and 'Pearl District' in Portland, USA. The result of the analysis was as follows: (1) The land use was changed to mixed use of business-commerce-recreation. The building use was changed to facilities for work, play and live. (2) Infrastructures were improved for user oriented facilities such as pedestrian friendly street, public parks & open spaces, public transportation system, and life supporting facilities. (3) The place identity was enhanced through the preservation of urban structure-tissues, renovation of existing buildings, and preservation of historical heritages.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.2
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• pp.91-101
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• 2021

The interdental papilla area is a difficult area for connective tissue graft (CTG) due to its narrow space. So Regeneration of interdental papilla is very challenging work. It is very difficult when the teeth have contact with adjacent teeth, but if there was only 3mm of space between the teeth, CTG was not very difficult. Therefore, through the orthodontic force, a 3mm space between the teeth was intentionally created. The CTG was performed using a microblade, and only one vertical incision was performed off the gingival margin, and the graft was performed by inserting the grafts through here. After a period of maintenance, I was able to gather the teeth again with orthodontic force and regenerate the interdental papilla. I named this technique ELSA Technique (Enlargement of space - Labial graft - Squeezing - for Augmentation of papilla). If interdental papilla is lost due to periodontal disease, ELSA techniques can regenerate interdental papilla very efficiently.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.54-54
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• 2020

지구온난화에 따라 농업부문 신재생에너지의 중요성이 증대되고 있으며, 화본과 식물은 바이오에너지작물의 중요한 소재를 제공하고 있다. 화본과 식물의 기내대량증식연구의 일환으로 홍띠식물의 기내 재생 식물체의 유전적 안정성에 대한 기초자료를 제공할 목적으로 기내배양으로 재분화시킨 홍띠(Imperata cylindrica 'Rubra') 재분화 식물체 중 녹색체 재생식물체를 대상으로 ISSR 표지를 사용하여 유전적 안정성을 조사하였다. 재분화식물체는 MS (Murashige and Skoog, 1962)배지에 생장조절제를 첨가한 배지에서 배양하였다. 생장점 부위를 적출하여 캘러스를 유도하고(0.1 mg/L 2,4-D와 2 mg/L BA), 캘러스 증식(0.1 mg/L 2,4-D와 0.05 mg/L BA), 신초 재분화( 0.01 mg/L NAA와 2 mg/L BA) 후 MS배지에서 식물체를 양성하고 순화시켰다. 배양은 26±2℃, 25 µmol/m²/s, 14h/10h (day/night) 광조건 하에서 실시하였다. 재분화식물체는 홍띠 및 녹색 재분화식물체 2 종류로 나타났는데, 이는 생장점에서는 홍띠가 분화되었음에도 불구하고 생장점 주변조직에서 유래한 녹새체가 분화된 후 우세하게 자라서 녹색재생체가 우점하는 것으로 추정된다. ISSR 분석은 대조구로 모식물체 홍띠를(8개체), 재분화식물체는 녹색체 중, 1년간 노지포장에서 재배중인 녹색체(10개체)와 실험실내 화분에서 재배중인 시료를(10개체) 사용하였다. ISSR 밴드패턴을 비교한 결과, 재분화체는 실내포트 재배식물체 10.3%, 노지1년 재배식물체 8.3%로 대조구의 4.1%보다 유전적 다형성 비율이 2배 이상 높게 나타났다. 또한 재분화식물체들의 유전적 유사도를 평가하고 군집분석을 실시하였다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.7-15
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• 1993

Nitrogenous and non structural carbohydrate compounds in the remaining tissues of 10 weeks old alfalfa (Medicago sativa L.) grown in hydroponic culture, were analysed during 24 days of regrowth following shoot removal. The dry weights of the remaining organs were not significantly changed for 10 days following shoot removal. Compared with uncut plants, defoliation drastically depressed root growth, in particular that of taproot. During 6 days of regrowth, nitrogen contents in all remaning organs significantly decreased. Nitrogen loss in this period was pronounced in root system. Nitrogen contents in each organ after 24 days of regrowth in defoliated plant were recovered completely or exceeded initial level. Amino acid-N was the most readily available form of nitrogen while protein-N was the largest storage pool. The tap root contained about 51.0% and 33.4%, respectively, of the total starch and total ethanol-soluble sugar contents. The starch content of tap roots initially exceeded 40.7 mg. plant$^{-1}$ (day 0), and then declined to the minimum level on day 14. This result clearly showed that the tap root is the major storage site for metabolizable nitrogen (protein-N and amino acid-N) and carbohydrate(starch), and that the degradation of these researves occur much actively in the early period of regrowth.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.115-120
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• 1995

A method for cryopreservation of suspension cultured embryogenic cells derived from immature zygotic embryos of rice (Korean cultivars, Donggin-byeo and Taebaeg-byeo) was developed. The highest cell regrowth after storage in liquid nitrogen was obtained when Donggin-byeo cells were cryoprotected with a mixture of 2 M DMSO and 0.4 M sucrose and Taebaeg-byeo cells with a mixture of 0.64 M DMSO and 0.4 M sucrose at frequencies of 88% and 90%, respectively, Pretreatment in a high osmotic medium was not necessary. Upon transfer to $N_{6}$ medium suplemented with lmg/L NAA and 5 mg/L kinetin, the regenerated calli gave rise to numerous somatic embryos which subsequently underwent development into plantlets. Among approximately 100 plantlets, 25% of them were albinos.s.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.86.1-86.1
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• 2010

Cu2ZnSnSe4는 CIS 태양전지의 In 대체 물질계로 주목을 받고 있는 저가형 태양전지 재료로 장차 차세대 태양전지 재료로 응용이 기대되고 있다. 그러나 에너지 밴드갭이 0.9~1.1eV로 다소 낮아 태양전지 광흡수층 재료로 사용하기 위해서는 wide band gab화 처리가 필요하다. 본 연구에서는 CZTSe에 S를 첨가하여 에너지 밴드갭을 확장하고자 하며, S의 첨가가 CZTSe 박막의 특성에 미치는 영향에 대하여 조사하였다. 실험의 편의성을 도모하고자 펄스레이저 법을 사용하여 증착하였다. 박막 조성 제어에는 Cu, Zn, Sn, Se, S 분말을 볼밀로 분쇄, 혼합하여 균질 혼합상 프리커서를 제조하고 이를 Cold Isostatic Press(CIP) 성형하여 Source target을 사용하였다. Pulsed YAG-Laser를 사용하여 soda lime glass상에 증착하고 조성, 구조, 조직을 관찰하고 에너지 밴드갭, 광흡수계수, 면저항, 전하밀도 등 특성을 조사하였다.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.220-227
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• 2004

The number of patients with coronary artery disease and peripheral vascular disease are increasing, and the need of small diameter vessel is also increasing. We developed small diameter artificial vessel and experimented in vivo. We got allogenic valve from mongrel dogs, and removed all cells from the allogenic valve. Then, we seeded autologous bone marrow cells onto the decellularized scaffold. After implantation of artificial vessel into the canine carotid artery, we performed angiography regularly. In case of vessel occlusion or at 8 weeks after operation, we euthanized dogs, and retrieved the implanted artificial vessels. Control vessels were all occluded except one (which developed aneurysmal dilatation). But autologous cell seeded vascular graft were patent by 4 weeks in one, by 6 in one and by 8 weeks in two. Histologic examination of patent vessel revealed similar structure to native artery. Tissue-engineered vascular graft manufactured with decellularized allogenic matrix and autologous bone marrow cells showed that tissue engineered graft had similar structure to native artery.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.817-829
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• 2014

One of the main issues in tissue engineering has been the development of a three-dimensional (3D) structure, which is a temporary template that provides the structural support and microenvironment necessary for cell growth and differentiation into the target tissue. In tissue engineering, various biomaterials and their processing techniques have been applied for the fabrication of 3D structures. In particular, 3D printing technology enables the fabrication of a complex inner/outer architecture using a computer-aided design and manufacturing (CAD/CAM) system, and it has been widely applied to the fabrication of 3D structures for tissue engineering. Novel cell/organ printing techniques based on 3D printing have also been developed for the fabrication of a biomimetic structure with various cells and biomaterials. This paper presents a comprehensive review of the functional scaffold and cell-printed structures based on 3D printing technology and the application of this technology to various kinds of tissues regeneration.