• Title/Summary/Keyword: natural regeneration

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Regeneration of Cardiovascular Tissues using Tissue Engineering and Mesenchymal Stem Cells

  • Kim, Byung-Soo
    • Proceedings of the Korean Society of Life Science Conference
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    • 2003.10a
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    • pp.28-37
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    • 2003
  • Tissue engineering and stem cells show potentials to restore lost or malfunctioning human tissues or organs. Another cell source for tissue engineering of cardiovascular tissues is stem cell. This study reports the development of cardiovascular tissues using tissue engineering and mesenchymal stem cells. The blood vessels and heart valves were fabricated by culturing mesenchymal stem cells on biodegradable synthetic or natural matrices. Bone marrow was isolated from dogs or rats and mesenchymal stem cells were cultured. The cells were seeded onto biodegradable synthetic or natural matrices and implanted in dogs. Histological and immunohistochemical analyses were performed to examine the regenerated cardiovascular tissues. Histological and immunohistochemical analyses showed the complete regeneration of blood vessels and heart valves. Fluorescent labeling of cells prior to implantation and fluorescence examination of the regenerated tissues revealed that the implanted cells reconstituted the cardiovascular tissues. This study demonstrates the potential of tissue engineering and mesenchymal stem cells for the regeneration of functional cardiovascular tissues or organs.

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Gap characteristics and natural regeneration in Mt. Makiling rainforest, the Philippines

  • Kim, Hyun-Ji;Kim, Tae-Geun;Kim, Eun-Hee;Castillo, Manuel L.;Cho, Do-Soon
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.157-165
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    • 2011
  • This study was conducted to determine the characteristics of gaps and natural regeneration of trees on Mt. Makiling, the Philippines. Canopy gaps in or around two 1-ha permanent plots and on 3-km line transects were investigated. Most of the gaps studied were formed or affected by Typhoon Milenyo, which hit the study site in September 2006. The most frequent mode of gap maker death was snap-off, whereas uprooting was relatively less important. The most frequent gap maker was balobo (Diplodiscus paniculatus) followed by magabuyo (Celtis luzonica) and katmon (Dillenia philippinensis). In contrast, the most frequent gap filler was magabuyo (C. luzonica). At the sapling layer, the most important species was magabuyo (C. luzonica), but there was a high proportion of lianas and palms. Most of the gaps had leaf area index (LAI) values between 3 and 5. A clear trend of a decrease in gap size and an increase in LAI was observed for 2 years from 2007 to 2009. New seedlings emerged very abundantly during the same time period. The rapid changes in the gaps were partially due to the excellent capability of tropical trees to resprout after the crown or stem was damaged by the typhoon. This study on gap dynamics may contribute to a better understanding of the natural regeneration process of trees in tropical rainforests.

Phytosociological Position of the Natural Regeneration of the Gallery Forest at the SAO BARTOLOMEU River in Brazil (브라질 SAO BARTOLOMEU강(江) 유역(流域)에 자생(自生)하는 천연갱신임분(天然更新林分)의 식물사회학적(植物社會學的) 위치(位置))

  • Imana-Encinas, Jose;Woo, Jong-Choon;Kleinn, Christoph
    • Journal of Forest and Environmental Science
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    • v.10 no.1
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    • pp.1-7
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    • 1994
  • A survey of the natural regeneration of the gallery forest at the Sao Bartolomeu river, Federal District - Brazil it was carry out. Plots of $100m^2$ let established the composition of the trees succession of one hectare. 4262 plants distributed in four classes according to the height were found. The phytosociological value of the classes was respectively 3,3 2,4 2,0 2,3 and through of them it was possible to identify the phytosociological position of the species. The results of the calculations of the relative index of the natural regeneration and value of importance shows that the most important species are Cheiloclinium cognatum A.C. Smith, Piptadenia communis Benth., Faramea cyanea M. Arg., Xylopia sericea St. Hil., Copeifera lansdorfii Desf., Cupania vernalis Camb., Matayba guianensis Aublet, Virola sebifera Aublet, Ocotea densiflora Meissn and Didimopanax morototoni (Aublet) Dcne et Pl.

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A Study on the Berlin Waterfront Development for Urban Regeneration -Focused on the case of Wasserstadt Berlin-Oberhavel, Berlin, Germany-

  • Park, Jong-Ki
    • KIEAE Journal
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    • v.17 no.3
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    • pp.23-34
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    • 2017
  • Purpose: The purpose of this study is to explore the relationship between suburban waterfront und urban regeneration strategies. Specifically, This paper investigates how urban design strategies for suburban waterfront has been conceptualized and realized in a case-based research study of the regeneration of suburban waterfront in Berlin, Germany. Since Germany's reunification, Berlin was faced a wide variety of challenges and has been transformed into a new capital city. First of all, Wasserstadt Berlin-Oberhavel was a key development task for the urban regeneration in Berlin. The Wasserstadt Berlin-Oberhavel project with over 207 hectares will provide new residential urban areas, office spaces, educational facilities and cultural facilities. In details, 3,640 apartments with 12,700 units and around 4,800 jobs will be created. Method: The study consists of five sections. The first and second section are divided into two stages:"waterfront definition in urban design" and "urban design strategy in waterfront". The third section explores the waterfront development process of Wasserstadt Berlin-Oberhavel. The fourth section aims to investigate the strategies for urban regeneration as well as waterfront development. Finally, the fifth provides some of the key policy challenges for Urban Regeneration in suburban waterfront area. Result: The results showed that urban regeneration strategies in suburban waterfront have a substantial impact on all two dimensions: relationship between waterfront and urban context, relationship between waterfront and natural environment.

Plant Regeneration Derived from Leaf Disk Cultures in Purple Sweetpotato (자색고구마의 잎 조직배양을 통한 식물체 재생)

  • Park, Hyae-Jeong;Ahn, Young-Sup;Jeong, Byeong-Choon;Park, Hyeon-Yong
    • 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.

Myocardial tissue engineering using electrospun nanofiber composites

  • Kim, Pyung-Hwan;Cho, Je-Yoel
    • BMB Reports
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    • v.49 no.1
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    • pp.26-36
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    • 2016
  • Emerging trends for cardiac tissue engineering are focused on increasing the biocompatibility and tissue regeneration ability of artificial heart tissue by incorporating various cell sources and bioactive molecules. Although primary cardiomyocytes can be successfully implanted, clinical applications are restricted due to their low survival rates and poor proliferation. To develop successful cardiovascular tissue regeneration systems, new technologies must be introduced to improve myocardial regeneration. Electrospinning is a simple, versatile technique for fabricating nanofibers. Here, we discuss various biodegradable polymers (natural, synthetic, and combinatorial polymers) that can be used for fiber fabrication. We also describe a series of fiber modification methods that can increase cell survival, proliferation, and migration and provide supporting mechanical properties by mimicking micro-environment structures, such as the extracellular matrix (ECM). In addition, the applications and types of nanofiber-based scaffolds for myocardial regeneration are described. Finally, fusion research methods combined with stem cells and scaffolds to improve biocompatibility are discussed. [BMB Reports 2016; 49(1): 26-36]

Pine Forest Soil Characteristics and Major Soil Impact Factors for Natural Regeneration

  • Kim, Min-Suk;Kim, Yong-Suk;Min, Hyun-Gi;Kim, Jeong-Gyu;Koo, Namin
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.3
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    • pp.179-186
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    • 2017
  • This study was conducted to identify characteristics of domestic pine forest soils and to elucidate major soil influencing factors for natural regeneration. We analyzed the physico-chemical characteristics of the soil samples collected from 23 pine forests and confirmed the similar results with the forest soil characteristics. Soil pH, organic matter content, total nitrogen, exchangeable Ca, silt content, and exchangeable Al were selected as the major soil factors among the exposed soils through 10 days of pine seedlings exposure and cultivation experiments and statistical analysis. Multiple regression analysis showed that soil pH had a positive effect on specific root length (SRL) of red pine seedlings and exchangeable Al was a significant factor affecting negative change in SRL. Taken together, the reduction of exchangeable Al by soil pH adjustment would be helpful for natural regeneration by restoring the forest and improving the fine root and root integrity of pine seedlings. Therefore, soil pH and exchangeable Al could be recommended as a major soil factor to be carefully considered in the monitoring and management of soil in pine forests that need to be renewed in the future.

Urban Regeneration Considerated on Safety Vulnerability of Port Hinterland Residential Area - Focused on Dong-Gu and Nam-Gu of Busan Metropolitan City - (항만배후 주거지역의 안전 취약성을 고려한 도시재생 - 부산광역시 동구와 남구를 대상으로 -)

  • Park, Kang Ah;Kim, Jong Gu;Park, Min Ah
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.5
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    • pp.761-769
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    • 2018
  • Urban safety has not been substantially considered in urban regeneration projects, although there is increasing interest in safety issues lately. However, there is limited research on the safety of port hinterland residential areas. Therefore, this study 1)selects appropriate safety indicators, and 2)identifies the most vulnerable sites in Dong-gu and Nam-gu in Busan using ArcGIS. 3)Lastly, our study asks residents of the selected sites to examine their awareness of the urban regeneration projects occurring in the vicinity. The respondents are fairly well aware of the ongoing urban regeneration projects, the effect of which on the improvement of safety are thought to be negative. The weakest point they indicated was accidents regarding aged buildings, and they also care more about life safety than natural hazard. These findings must be taken into account in the next urban regeneration projects in the Dong-gu and Nam-gu area.

Photocatalytic Systems of Pt Nanoparticles and Molecular Co Complexes for NADH Regeneration and Enzyme-coupled CO2 Conversion

  • Kim, Ellen;Jeon, Minkyung;Kim, Soojin;Yadav, Paras Nath;Jeong, Kwang-Duk;Kim, Jinheung
    • Rapid Communication in Photoscience
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    • v.2 no.2
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    • pp.42-45
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    • 2013
  • Natural photosynthesis utilizes solar energy to convert carbon dioxide and water to energy-rich carbohydrates. Substantial use of sunlight to meet world energy demands requires energy storage in useful fuels via chemical bonds because sunlight is intermittent. Artificial photosynthesis research focuses the fundamental natural process to design solar energy conversion systems. Nicotinamide adenine dinucleotide ($NAD^+$) and $NADP^+$ are ubiquitous as electron transporters in biological systems. Enzymatic, chemical, and electrochemical methods have been reported for NADH regeneration. As photochemical systems, visible light-driven catalytic activity of NADH regeneration was carried out using platinum nanoparticles, molecular rhodium and cobalt complexes in the presence of triethanolamine as a sacrificial electron donor. Pt nanoparticles showed photochemical NADH regeneration activity without additional visible light collector molecules, demonstrating that both photoactivating and catalytic activities exist together in Pt nanoparticles. The NADH regeneration of the Pt nanoparticle system was not interfered with the reduction of $O_2$. Molecular cobalt complexes containing dimethylglyoxime ligands also transfer their hydrides to $NAD^+$ with photoactivation of eosin Y in the presence of TEOA. In this photocatalytic reaction, the $NAD^+$ reduction process competed with a proton reduction.