• Journal of Veterinary Science
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• 제22권4호
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• pp.52.1-52.8
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• 2021

Background: The normal vertebral anatomy of Korean raccoon dogs and their variants require research attention as a prerequisite for identifying pathologies and anomalies. Objectives: This retrospective study aimed at describing the vertebral formula and congenital vertebral anomalies in Korean raccoon dogs (Nyctereutes procyonoides koreensis). Methods: Radiographs of 82 raccoon dogs (42 males, 40 females) acquired from May 2013 to June 2020 in the Gangwon Wildlife Medical Rescue Center were reviewed to evaluate the cervical, thoracic, and lumbar vertebrae of the spine. Results: Normal morphology of all vertebrae was observed in 50 of the 82 raccoon dogs, and the vertebral formula was cervical 7, thoracic 13, and lumbar 7. Congenital vertebral anomalies were found in 32 raccoon dogs: transitional vertebrae (TV) in 31 and block vertebrae in 2. Two raccoon dogs had 2 types of vertebral anomalies: one had TV and block vertebra, and the other had 2 types of TV. Twenty-nine raccoon dogs had thoracolumbar TV (TTV) and 3 had lumbosacral TV. TTV was morphologically classified into 4 different types: unilateral extra-rib in 5 raccoon dogs, bilateral extra-ribs in 14, bilateral elongated transverse processes in 4, and an asymmetric mixed formation of extra-rib with elongated transverse process in 6. Conclusions: This study showed that TTV is common in Korean raccoon dogs, and that the vertebral formula is relatively diverse. The bilateral extra-ribs type TTV is the most common variant, which is almost similar to normal rib to be confused the radiographic evaluation.

• 마이크로전자및패키징학회지
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• 제25권4호
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• pp.35-40
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• 2018

다양한 디바이스 응용분야에 블록공중합체가 사용되기 위해, 블록공중합체의 형상을 제어하기 위한 간단하면서도 실용적인 합성방법이 필요하다. 하지만 콜로이드성의 형판을 사용하는 기존의 방식은 공정이 복합하고 비용이 많이 발생하여, 고순도의 코어-쉘 나노입자를 대량생산하기에 적합하지 않다. 본 논문에서 PS-b-PDMS 블록공중합체를 담금어닐링하여, 20 nm 이하크기를 가지는 PS가 봉입된 코어-쉘 구조의 $SiO_x$나노입자를 합성하였다. 또한, 어닐링 공정에 사용되는 헵테인과 에탄올의 혼합비율이 자기조립된 PS-b-PDMS 블록공중합체 나노입자의 형상에 어떠한 영향을 미치는지 분석하였으며, 최적의 담금어닐링 조건에서 나노입자가 worm-like구조로 변화하는 것을 확인하였다. 이러한 파우더 합성법은 다른 용매기반의 블록공중합체 합성방법에 응용이 가능할 것으로 생각되며, 새로운 가이드라인을 제공할 것으로 예상된다.

• 대한건축학회논문집:계획계
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• 제34권7호
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• pp.99-106
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• 2018

The purpose of this study is to examine adaptation types of urban tissue in Ipjeong-dong area, Seoul. Ipjeong-dong area has urban tissue those were made during Joseon dynasty and this is remaining even in the present time. This area was originally urban hanok residential districts till late 1950s. However, it has changed into machinery manufacture business area after demolition of Cheonggyechon shantytown. After several workshops and stores moved in this area, manufacturer and merchants required for more spaces due to lack of room for machinery. To place more workshops in the block, lot alteration were happened and accessibility to workshops inside the block were required. Adaptive road network which is main form of adaptative urban tissue were made to adapt in this kind of poor urban condition. To research about adaptive urban tissue making, distribution were explored and comparison tasks between various cadastral map of 1940, 1964, 1970s and 2017 were conducted. From these tasks, certain types of adaptive urban tissues and characteristics of these elements were found. First of all, forms of adaptive road depend on the surrounded environment. Connecting internal building corridor with original road system is categorized as Type A. Altering a portion of the buildings to make adaptive roads is categorized as Type B. Second, there were two types of formation of adaptive road. Type 1 is for adaptive road which is independent gesture from original road network. Type 2 is for adaptive road which is altering the form of original road network by lengthening or connecting two different dead-end roads.

• Geomechanics and Engineering
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• 제29권2호
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• pp.113-131
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• 2022

A rockburst is a common disaster in deep-tunnel excavation engineering, especially for high-geostress areas. An anomalously low friction effect is one of the most important inducements of rockbursts. To elucidate the correlation between an anomalously low friction effect and a rockburst, we establish a two-dimensional prediction model that considers the discontinuous structure of a rock mass. The degree of freedom of the rotation angle is introduced, thus the motion equations of the blocks under the influence of a transient disturbing force are acquired according to the interactions of the blocks. Based on the two-dimensional discontinuous block model of deep rock mass, a rockburst prediction model is established, and the initiation process of ultra-low friction rockburst is analyzed. In addition, the intensity of a rockburst, including the location, depth, area, and velocity of ejection fragments, can be determined quantitatively using the proposed prediction model. Then, through a specific example, the effects of geomechanical parameters such as the different principal stress ratios, the material properties, a dip of principal stress on the occurrence form and range of rockburst are analyzed. The results indicate that under dynamic disturbance, stress variation on the structural surface in a deep rock mass may directly give rise to a rockburst. The formation of rockburst is characterized by three stages: the appearance of cracks that result from the tension or compression failure of the deformation block, the transformation of strain energy of rock blocks to kinetic energy, and the ejection of some of the free blocks from the surrounding rock mass. Finally, the two-dimensional rockburst prediction model is applied to the construction drainage tunnel project of Jinping II hydropower station. Through the comparison with the field measured rockburst data and UDEC simulation results, it shows that the model in this paper is in good agreement with the actual working conditions, which verifies the accuracy of the model in this paper.

• Journal of Periodontal and Implant Science
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• 제53권6호
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• pp.429-443
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• 2023

Purpose: The aim of this study was to determine 1) the bone-regenerative effect of porcine bone block materials with or without collagen matrix incorporation, 2) the effect of a collagen barrier, and 3) the effect of adding recombinant human bone morphogenetic protein-2 (rhBMP-2) to the experimental groups. Methods: Four treatment modalities were applied to rabbit calvaria: 1) deproteinized bovine bone mineral blocks (DBBM), 2) porcine bone blocks with collagen matrix incorporation (PBC), 3) porcine bone blocks alone without collagen matrix incorporation (PB), and 4) PBC blocks covered by a collagen membrane (PBC+M). The experiments were repeated with the addition of rhBMP-2. The animals were sacrificed after either 2 or 12 weeks of healing. Micro-computed tomography (micro-CT), histologic, and histomorphometric analyses were performed. Results: Micro-CT indicated adequate volume stability in all block materials. Histologically, the addition of rhBMP-2 increased the amount of newly formed bone (NB) in all the blocks. At 2 weeks, minimal differences were noted among the NB of groups with or without rhBMP-2. At 12 weeks, the PBC+M group with rhBMP-2 presented the greatest NB (P<0.05 vs. the DBBM group with rhBMP-2), and the PBC and PB groups had greater NB than the DBBM group (P>0.05 without rhBMP-2, P<0.05 with rhBMP-2). Conclusions: The addition of rhBMP-2 enhanced NB formation in vertical augmentation using bone blocks, and a collagen barrier may augment the effect of rhBMP-2.

• 암석학회지
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• 제14권3호
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• pp.157-168
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• 2005

계명산층 및 주변 지역의 쌍봉형 조성을 나타내는 변성화산암 중에서 주로 조면암 조성을 나타내는 암석들에 대하여 연구하였다. 일부 암석은 매우 높은 철 함량을 보이며, 대부분 매우 높은 희토류 및 고장력 원소의 함량을 갖는다. 대부분 현저한 Eu(-) 이상치를 보이며 이는 장석의 분별에 기인한 것으로 설명된다. 주목할만한 Nb(-) 이상치가 나타나지 않는 것은 이들의 생성에 지각물질이 개입되지 않았음을 나타내는 것으로 이들의 생성환경에 있어 도호환경이나 대륙지각의 재용융과 같은 과정은 배제될 수 있음을 의미한다. 비유동적인 고장력원소인 Nb와 Y를 이용한 지구조판별도에서 계명산층의 변성조면암은 판내부환경에 도시되며, 높은 Ga 함량과 같은 전형적인 A-형 마그마의 특성을 잘 보여준다. 또한 Eby(1992)의 기준으로 Al형 영역에 속함과 750Ma의 생성시기(Lee et al., 1998)를 참조할 때 이들은 신원생대 초대륙 로디니아의 분열과 관련한 열곡대에서 만들어진 맨틀기원의 판내부 마그마작용 산물임을 시사한다. 이는 옥천변성대 중에서 적어도 계명산층과 문주리층의 일부가 신원생대의 시기에는 남중국의 Cathaysia 블록과 연결되었을 가능성을 강력히 시사한다.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.47-67
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• 1996

The purpose of this study was to observe the effect of $Biocoral^R$ graft and bioglass 45S5 graft in combination with ePTFE membrane in periodontal osseous defects for new bone formation. Nine healthy dogs were used. Under general anesthesia, 3-wall defects were created on the mesial and distal surfaces of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars. To induce periodontitis, a silicone rubber, $Provil^R$ light body, was injected under pressure into the defects. Ninety days later, $Provil^R$was removed and followed by thorough root planing. The followings were then applied in the mesial and distal defects of the maxillary right canines, the mesials of the maxillary right second premolars, the distals of the mandibular right canines and the mesials of the mandibular right third premolars by random selections : 1) ePTFE membrane only application, 2) $Biocoral^R$ graft, 3) $Biocoral^R$ graft and ePTFE membrane application, 4)Bioglass 45S5 graft, 5) Bioglass 45S5 graft and ePTFE membrane application. The membranes were removed 1 month later. The dogs were sacrified at 1, 2 and 3 months following the graft, and block sections were made, demineralized, embedded, stained and examined by light microscope and transmission electron microscope. On the sections from teeth treated with ePTFE membrane only, the defect demonstrated extensive connnective tissue and alveolar bone regeneration. The $Biocoral^R$ graft group demonstrated extensive bone regeneration compared with ePTFE membrane only group. In the $Biocoral^R$ graft plus ePTFE membrane group, regeneration of new alveolus and crest occurred within the defect. As the experimental period lengthened, bone regeneration was increased and bone bridge was formed among the graft particles. The but bioglass 45S5 graft group demonstrated extensive bone regeneration but the amount of new bone was less than that of the $Biocoral^R$ graft group. For the bioglass 45S5 graft plus ePTFE membrane group, the amount of new bone was also increased. As the experimental period lengthened, bone regeneration was increased. Multinucleated giant cells, fibroblasts and macrophages were observed. As the bone formation was increased, the number of such cells was decreased. In conclusion, the $Biocoral^R$ was found better than the bioglass 45S5 for new bone formation, and the use of ePTFE membrane alone or with $Biocoral^R$/bioglass 45S5 can be supported as potential methods of promoting bone formation.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.191-198
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• 2008

Purpose: Guided bone regeneration(GBR) has emerged as a treatment in the management of osseous defects associated with dental implants. But several studies have reported different degrees of success of guided bone regeneration, depending upon the type of barrier selected, presence or absence of an underlying graft material, types of graft material, feasibility of technique, and clinician's preference. The aim of the present study was to evaluate bone formation following dental implant placement with augmentation materials at dehiscence defects in dogs. Material and Methods: Standardized buccal dehiscence defects($3{\times}5\;mm$) were surgically 2 Mongrel dog's mandibles, each 8 SLA surface, 8 anodizing surface implants. Each buccal dehiscence defect received flap surgery only(no treatment, control), $Cytoflex^{(R)}$ membrane only, Resolut $XT^{(R)}$ membrane only, Resolut $XT^{(R)}+Osteon^{TM}$. Animals were sacrificed at 8 weeks postsurgery and block sections were harvested for histologic analysis. Resuts: All experimental group resulted in higher bone formation than control. Resolut $XT^{(R)}+Osteon^{TM}$ group resulted appeared highest defect resolution. There was no difference between SLA and anodizing surface, nonresorbable and resorbable membrane. Conclusion: GBR results in rapid and clinically relevant bone closure on dehiscence defects of the dental implants.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권6호
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• pp.481-491
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• 2005

Purpose: The aim of the present study is to evaluate the effect of autogenous bone and allograft material coverd with a bioresorbable membrane on bone regeneration after a simultaneous installation of implant. Materials and methods: Twelve healthy rabbits, weighing about $3{\sim}4$ kg, were used in this experiment. Following impalnt(with 3.25 mm diameter and 8 mm length) site preparation by surgical protocol of $Oraltronics^{(R)}$, artificial bony defect, 5mm sized in height and depth, was created on femoral condyle using trephine drill(with 5 mm diameter and 5 mm length). Then implant was inserted. In the experimental group A, the bony defect was filled with autogenous particulated bone and coverd with $Lyoplant^{(R)}$ resorbable membrane. In the experimental group B, the bony defect was filled with allograft material(Orthoblast $II^{(R)}$) containing demineralized bone matrix and covered with $Lyoplant^{(R)}$. In the control group, without any graft materials, the bony defect was covered with $Lyoplant^{(R)}$. The experimental group A and B were divided into each 9 cases and control group into 3 cases. The experimental animals were sacrificed at 3, 6 and 8 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E staining and then, measured BIC and bone density with KAPPA Image $Base^{(R)}$ system. Results: As a result of this experiment, bone formation and active remodeling process were examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. Especially bone to-implant contact fraction ranged from 12.7% to 43.45% in the autogenous bone group and from 9.02% to 29.83% in DBM group, at 3 and 8 weeks. But, bone density ranged from 15.67% to 23.17% in the autogenous bone group and from 25.95% to 46.06% in DBM group at 3 and 6 weeks, respectively. Although the bone density of DBM group was better than that of autogenous bone group at 3 and 6weeks, the latter was better than the former at 8 weeks, 54.3% and 45.1%, respectively. Therefore these results showed that DBM enhanced the density of newly formed bone at least initially.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권6호
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• pp.353-359
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• 2013

Purpose: Extensive research is actively ongoing for development of an ideal bone substitute that meets the gold standard. Tooth was selected as a donor site for evaluation of potentials in bone substitutes based on its similar chemical compositions to alveolar bone. Previous studies have evaluated inorganic components of autogenous tooth bone graft material (AutoBT) and osteoconductivity. In continuation from the previous studies, the current study was conducted for analysis of organic components and evaluation of osteoinductivity of AutoBT. Methods: Forty-six extracted teeth were collected from actual patients (Korea Tooth Bank, R&D Institute). Extracted teeth were processed into AutoBT and implanted in dorsal subcutaneous muscular tissues of 15 athymic mice. Biopsy samples were harvested at two, five, and eight weeks. The Bradford assay, sodium dodecyl sulphate polyacrylamide gradient gel, and western blotting were performed for investigation of organic contents of AutoBT. Results: Histology analyses showed signs of new bone formation as early as two weeks. Results of the Bradford assay indicated the existence of noncollagenous proteins (NCP). 0.29% (2.89 mg/g) of proteins were extracted by weight in the root portion of AutoBT; 0.02% (0.029 mg/g) and 1.79% (17.93 mg/g) of proteins were measured by weight in crown and block-form of AutoBT, respectively. However, recombinant human bone morphogenetic protein-2 was not observed in AutoBT. Conclusion: Within the limitation of the current study, AutoBT induced new bone formation by NCP embedded in dentin.