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Regenerative Endodontic Treatment of Infected Immature Permanent Teeth with Dens Invaginatus : A Report of Two Cases (치내치를 동반한 감염된 미성숙 영구치의 재생형 근관치료)

  • Shin, Gayoung;Lee, Kwanghee;An, Soyoun;Song, Jihyun;Heo, Narang;Ra, Jiyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.42 no.2
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    • pp.188-196
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    • 2015
  • Endodontic management of an immature permanent tooth with dens invaginatus poses a challenge to efficient treatment planning for the clinicians. Because it is difficult to shape, disinfect, and seal the canal space effectively, teeth with complex root canal structures often require particularly extensive and thorough treatment approaches. The purpose of this case report was to share clinical insight from the results of short-term follow-ups after regenerative endodontic treatment with a dens invaginatus. Two immature maxillary lateral incisors with Oehlers type I and III dens invaginatus and infected necrotic pulp were treated using regenerative endodontic procedures. For the type III dens invaginatus case, an unusual approach toward redesigning the complex internal structure was taken, in order to have sufficient infection control and sealing. Cone-beam computed tomography (CBCT) and a surgical operating microscope were used to aid visualization and treatment. As a result, regenerative endodontic treatment appears to be effective for managing immature permanent teeth with complex dens invaginatus, and can lead not only to clinical and radiographic resolution, but also increased thickness of the dentinal walls.

Spatiotemporal change in ectomycorrhizal structure between Tricholoma matsutake and Pinus densiflora symbiosis (송이와 소나무간의 공생관계(共生關係)에서 외생균근(外生菌根)의 시(時)-공간적(空間的) 구조변화(構造變化))

  • Koo, Chang-Duck;Kim, Je-Su;Park, Jae-In;Ka, Kang-Hyeon
    • Journal of Korean Society of Forest Science
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    • v.89 no.3
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    • pp.389-396
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    • 2000
  • To determine whether the Tricholoma matsutake (pine mushroom, Songyi) is symbiotic or parasitic to Pinus densiflora, structural change in their natural ectomycorrhizas were examined. The mycorrhizal samples were collected at three progressional points in the natural hypogeous colony(shiro) : colony front edge, near the fruiting point and 20cm back. The fine roots in the colonies were typical ectomycorrhizas with fungal mantle and Hartig net. However, the T. matsutake mycorrhizas had unique characteristics compared to other types of ectomycorrhizas. That is, spatially the fungal mantle and Hartig net of the T. matsutake mycorrhizas continued to develop along the growing tip, while temporally those structures declined to shrink changing to black brown in the older part of the roots behind the actively growing tip portion. However, there was no mark that the fungal hyphae penetrated into either the cortical cells, endodermal cell layers or stele. The apical tips of the blackened roots remained alive to form new mycorrhizas with other fungi later. Therefore, we conclude that the mycorrhiza of T. matsutake+P. densiflora is rather a dynamic symbiosis that changes its position spatiotemporally as the root grows than either a simple parasitism or symbiosis.

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Regulation of cementoblast differentiation and mineralization using conditioned media of odontoblast (상아모세포의 조건배지를 이용한 백악모세포의 분화와 석회화 조절)

  • Moon, Sang-Won;Kim, Hye-Sun;Song, Hyun-Jung;Choi, Hong-Kyu;Park, Jong-Tae;Kim, Heung-Joong;Jang, Hyun-Seon;Park, Joo-Cheol
    • Journal of Periodontal and Implant Science
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    • v.36 no.2
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    • pp.385-396
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    • 2006
  • For the regeneration of periodontal tissues, the microenvironment for new attachment of connective tissue fibers should be provided, At this point of view, cementum formation in root surface plays a key role for this new attachment. This study was performed to figure out which factor promotes differentiation of cementoblast Considering anatomical structure of tooth, we selected the cells which may affect the differentiation of cementoblast - Ameloblast, OD11&MDPC23 for odontoblasts, NIH3T3 for fibroblsts and MG63 for osteoblasts. And OCCM30 was selected for cementoblast cell line. Then, the cell lines were cultured respectively and transferred the conditioned media to OCCM30. To evaluate the result, Alizarin red S stain was proceeded for evaluation of mineralization. The subjected mRNA genes are bone sialoprotein(BSP), alkaline phosphate(ALP) , osteocalcin(OC), type I collagen(Col I), osteonectin(SPARC ; secreted protein acidic and rich in cysteine). Expression of the gene were analysed by RT-PCR, The results were as follows: 1. For alizarin red S staining, control OCCM30 didn't show any mineralized red nodules until 14 days. But red nodules started to appear from about 4 days in MDPC-OCCM30 & OD11-OCCM30. 2. For results of RT-PCR, ESP mRNAs of control-OCCM30 and others were expressed from 14 days, but in MDPC23-OCCM30 & OD11-OCCM30 from 4 days. Like this, the gene expression of MDPC23-OCCM30 & OD11-OCCM30 were detected much earlier than others. 3. For confirmation of odontoblast effect on cementoblast, conditioned media of osteoblasts(MG63) which is mineralized by producing matrix vesicles didn't affect on the mineralized nodule formation of cementoblasts(OCCM30). This suggest the possibility that cementoblast mineralization is regulated by specific factor in dentin matrix protein rather than matrix vesicles. Therefore, we proved that the dentin/odontoblast promotes differentiation/mineralization of cementoblasts. This new approach might hole promise as diverse possibilities for the regeneration of tissues after periodontal disease.

Establishing Effective Screening Methodology for Novel Herbicide Substances from Metagenome (신규 제초활성 물질 발굴을 위한 메타게놈 스크리닝 방법 연구)

  • Lee, Boyoung;Choi, Ji Eun;Kim, Young Sook;Song, Jae Kwang;Ko, Young Kwan;Choi, Jung Sup
    • Weed & Turfgrass Science
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    • v.4 no.2
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    • pp.118-123
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    • 2015
  • Metagenomics is a powerful tool to isolate novel biocatalyst and biomolecules directly from the environmental DNA libraries. Since the metagenomics approach bypasses cultivation of microorganisms, un-cultured microorganisms that are majority of exists can be the richest reservoir for natural products discovery. To discover novel herbicidal substances from soil metagenome, we established three easy, simple and effective high throughput screening methods such as cucumber cotyledon leaf disc assay, microalgae assay and seed germination assay. Employing the methods, we isolated two active single clones (9-G1 and 9-G12) expressing herbicidal activity which whitened leaf discs, inhibited growth of microalgae and inhibited root growth of germinated Arabidopsis seeds. Spraying butanol fraction of the isolated active clones' culture broth led to growth retardation or desiccation of Digitalia sanguinalis (L) Scop. in vivo. These results represent that the screening methods established in this study are useful to screen herbicidal substances from metagenome libraries. Further identifying molecular structure of the herbicidal active substances and analyzing gene clusters encoding synthesis systems for the active substances are in progress.

Evaluation on the impact of Lowest Bid Contracts on Site Operations in times of Severe Economic Downturn (건설경기 침체기의 최저가 낙찰제 건설현장의 운영 실태분석과 개선 방안 도출)

  • Koo, Bon-Sang;Jang, Hyoun-Seung
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.6
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    • pp.146-153
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    • 2009
  • The year 2008 was a hard year for Korea's construction companies. The real estate downturn resulted in halting new construction and stopping existing work, and inflation of global oil prices caused price hikes in rebar and concrete materials. As a solution to reducing the budget, the newly appointed government announced plans to increase low cost bid contracts from 10 billion to 30 billion won. When such economical and political factors negatively impact the construction market, projects based on low cost contracts are the hardest hit. Many problems already inherent in low cost bid contracts become accentuated. Consequently, this provides an opportune time to actually study and analyze the issues in these projects. This paper introduces the findings made from investigating four projects struggling to make ends meet in the year 2008. Results show that flow of cash (i.e., liquidity), or lack thereof, was the root cause which in turn was hampered by failed mechanisms for design changes, material inflation. Attributing cash flow risk to the bottom of the production structure (i.e., small business subcontractors) was also a problem within the industry. Contractors need a better way to prepare against material price fluctuations, and owners need to assist in expediting payment during times of extreme downturn.

Optimal Design of Generalized Process-storage Network Applicable To Polymer Processes (고분자 공정에 적용할 수 있는 일반화된 공정-저장조 망구조 최적설계)

  • Yi, Gyeongbeom;Lee, Euy-Soo
    • Korean Chemical Engineering Research
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    • v.45 no.3
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    • pp.249-257
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    • 2007
  • The periodic square wave (PSW) model was successfully applied to the optimal design of a batch-storage network. The network structure can cover any type of batch production, distribution and inventory system, including recycle streams. Here we extend the coverage of the PSW model to multitasking semi-continuous processes as well as pure continuous and batch processes. In previous solutions obtained using the PSW model, the feedstock composition and product yield were treated as known constants. This constraint is relaxed in the present work, which treats the feedstock composition and product yield as free variables to be optimized. This modification makes it possible to deal with the pooling problem commonly encountered in oil refinery processes. Despite the greater complexity that arises when the feedstock composition and product yield are free variables, the PSW model still gives analytic lot sizing equations. The ability of the proposed method to determine the optimal plant design is demonstrated through the example of a high density polyethylene (HDPE) plant. Based on the analytical optimality results, we propose a practical process optimality measure that can be used for any kind of process. This measure facilitates direct comparison of the performance of multiple processes, and hence is a useful tool for diagnosing the status of process systems. The result that the cost of a process is proportional to the square root of average flow rate is similar to the well-known six-tenths factor rule in plant design.

Storage and Retrieval of XML Documents Without Redundant Path Information (경로정보의 중복을 제거한 XML 문서의 저장 및 질의처리 기법)

  • Lee Hiye-Ja;Jeong Byeong-Soo;Kim Dae-Ho;Lee Young-Koo
    • The KIPS Transactions:PartD
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    • v.12D no.5 s.101
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    • pp.663-672
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    • 2005
  • This Paper Proposes an approach that removes the redundancy of Path information and uses an inverted index, as an efficient way to store a large volume of XML documents and to retrieve wanted information from there. An XML document is decomposed into nodes based on its tree structure, and stored in relational tables according to the node type, with path information from the root to each node. The existing methods using path information store data for all element paths, which cause retrieval performance to be decreased with increased data volume. Our approach stores only data for leaf element path excluding internal element paths. As the inverted index is made by the leaf element path only, the number of posting lists by key words become smaller than those of the existing methods. For the storage and retrieval of U data, our approach doesn't require the XML schema information of XML documents and any extension of relational database. We demonstrate the better performance of on approach than the existing approaches within the scope of our experiment.

Formation of Genetic Tumor and Characteristics of Teratoma Shoot from Tobacco Interspecific Reciprocal Hybrids (연초종간 상호교잡에 의한 Genetic Tumor의 유도 및 Teratoma Shoot의 특성)

  • 양덕춘;윤의수;최광태;이정명
    • Korean Journal of Plant Tissue Culture
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    • v.25 no.2
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    • pp.135-139
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    • 1998
  • Reciprocal interspecific hybrids between N. glauca(2n=24) and N. langsdorffii(2n=18) were obtained by intercrossing. One hundred percent of F1 seeds was produced from intercrossing of N. glauca × N. langsdorffii, whereas the frequency of F1 hybrid seed formation from N. langsdorffii × N. glauca was very low. However, all the hybrid seeds were germinated well and then grown to normal plantlets. All the plants of F1 hybrids have chromosome number of interspecific hybrids (2n=21). From observation of morphological characteristic, the structure of petrol, leaf, flower, and the morphology of pollen have characteristics of F1 hybrid. Spontaneous tumors (genetic tumor) were formed from each F1 hybrid; the genetic tumor arose at the reproductive phase when the maternal type of F1 hybrid came from N. glauca, while the genetic tumor arose only after reproductive phase when the maternal type of F1 hybrid came from N. langsdorffii. The genetic tumor actively proliferated on hormone-free medium and produced numerous teratoma shoots. In addition, normal leaf or stem explants of F1 hybrid produced calli on hormone-free medium after 15 days of culture, the calli produced new numerous teratoma shoots after 30 days. The frequency of teratoma shoot formation from rnterspecific hybrid was higher in the N. glauca × N. langsdorffii than in the N. langsdorffii × N. glauca. Root development from the teratoma shoots was hardly obtained. Teratoma shoots without roots in vitro can form genetic tumor at the vegetative growth phase after tissue culture.

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Geographical Distribution and Ecology in Microhabitats of the Rare Species, Pulsatilla tongkangensis Y.N. Lee et T.C. Lee (희귀종인 동강할미꽃(Pulsatilla tongkangensis Y.N. Lee et T.C. Lee)의 지리적 분포와 미소생육지의 생태)

  • Oh, Hyun-Kyung;Lee, Kyungeun;Lee, Yonghak;Choung, Yeonsook
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.74-82
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    • 2014
  • A perennial plant species of Ranunculaceae, Pulsatilla tongkangensis is a very rare species only found in limestone vegetation of South Korea. It is not only rare but also has great value as a horticultural resource, thus resulting in serious problems of overexploitation and habitat disturbance. For the conservation of the rare species and its development as a resource, the study was conducted with the following three aims: first, to investigate any new geographical distribution of the species; second, to identify the site condition and vegetation structure of its habitat; and third, to compare the ecology of P. tongkangensis in other microhabitats such as rock, slope and ridge area. A new distribution was found in limestone vegetation at Danyang-gun, Chungcheongbuk-do. It was, therefore, confirmed that the distribution of P. tongkangensis exactly coincides with the area of distribution of limestone, indicating a possibility that the species might be a calcicole. 87% of the microhabitats found in rocks. Compared to P. tongkangensis, at ridges or slopes, number of P. tongkangensis plants were few in rocks. It is possibly due to the lack of microhabitats that could settle in rocky areas. Once established on rocks, however, plants grew large enough to flower with higher number of leaves and flowers per plant, resulting in higher flowering rate on rocky areas. Cracks in/between rocks are likely to be safe places for the plants with favorable light conditions, abundant fine particles to root down and reduced competition for resources. Yet, further research is necessary in terms of determining whether the species is indeed a calcicole, whether other limiting factors work in its establishment stage, and genetic diversity exists in the population.

Comparative Study of Infection Effects with AMF (Arbuscular-Mycorrhizal Fungi) Isolated from Upland Plants (밭 작물에서 분리한 균근균의 접종 효과 비교)

  • Kim, Seak-Jin;Kim, Ji-Hyun;Kim, Jin-Kyung;Chang, Kwang-Jin;Choi, Jang-Nam
    • Korean Journal of Plant Resources
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    • v.27 no.2
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    • pp.194-201
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    • 2014
  • This study was carried out to investigate the characteristics and infection effects of AMF with soil samples collected at some sites in Gyeonggi province, Korea. AMF spore and characteristics of infection structure in upland plant root were observed as wet sieving and staining method, growth of Capsicicum annum was compared between treatment and non treatment. AMF spores isolated from each soil sample were ellipse or circle type and the colors were soft yellow and white. The colonization rate of AMF with soil infection of Zea mays roots was 13.3~83.3%, the rate of infected soil collected from Z. mays was higher on average. When compared to the growth of C. Annum with control after infection on C. annum, it wasn't showing many differences in fresh weight, dry weight and height, but the yield of fruit of C. annuum showed double than the control group.