• Applied Biological Chemistry
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• 제30권4호
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• pp.293-299
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• 1987

Bradyrhizobium japonicum ROKS 26 균주를 glycine및 Iysozyme을 처리하여 spheroplast를 형성시킨 후 Agrobacterium tumefaciens에서 분리한 Ti plasmid를 분리하여 형질전환 시키고 octopine 영양 요구성에 의하여 transformants를 분리하였다. 그 결과 Ti plasmid가 도입된 transformants의 형질전환율은 $1{\times}10^{-7}$ 정도 되었다. 얻어진 transformant의 plasmid를 조사한 결과 도입된 Ti plasmid 존재가 확인되었으며, 2차원 전기영동법으로 균체 단백질을 분석한 결과 수용세포인 Bredyrhizobium japonicum ROKS 26과 transformant간의 단백질 구성 차이도 화인되었다. 또한 transformant의 근류 형성력을 조사한 결과 본래의 근류의근류형성력을 가지고 있었으나, crown gall형성에 있어서는 Agrobacterium tumefaciens 15955에 의한 gall보다는 크기에 있어 차이가 있었다.

• 대한소아치과학회지
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• 제25권2호
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• pp.268-276
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• 1998

낭종은 환자의 연령, 낭종의 종류 및 위치에 따라 치료방법을 선택하는 것이 바람직하며, 환자의 연령이 어린 경우에는 조대술을 통하여 낭종에 이환된 치아를 가능한 보존시키는 것이 바람직한 것으로 생각된다. 낭종에 포함되었던 치아는 조대술로 낭종을 제거후에 생리적인 맹출이 이루어지는 것을 관찰할 수 있었으며 기능도 정상적으로 수행하는 것으로 판단된다. 그러나, 조대술을 이용하여 시술한 후에는 맹출된 치아에 병리조직이 잔존되어 재발의 가능성이 있으므로 주기적인 관찰이 요구될 것으로 생각된다.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.116-122
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• 2000

On the instrumented root canal wall, amorphous, irregular smear layer can be observed with Scanning Electron Microscope(SEM). The purpose of this study was to evaluate the effect of the presence or absence of smear layer on the adhesion of Staphylococcus aureus to the dentin of the root canal. Human incisors, extracted within 7 days, with no caries, no fracture, no calcification of canal, were selected. After cutting crown portion at cemento-enamel junction, root canal preparation was done by modified crown-down technique using Profile and Gates - Glidden Drill. During canal preparation, 10ml physiologic saline solution(group1&3) or 10ml 3.5% NaOCl(group2&4) was used as irrigation solution. And 10ml physiologic saline solution(group1&3) or 10ml 0.5M EDTA(group2&4) was applicated for final flush. After vertical sectioning and ethylene oxide gas sterilization, samples(group1&2) were immersed into BHIYHM broth inoculated with Staphylococcus aureus (ATCC 31153) and incubated for 3hrs at $37^{\circ}C$. All samples were prepared for and observed with SEM(JEOL JSM840S). The data were analyzed by Mann-Whitney rank sum test. The conclusions are as follows ; 1. Smear layer covers entire root canal surface after root canal preparation. 2. Smear layer has been removed away and the entrances of dentinal tubules have opened widely, when applying 0.5M EDTA and 3.5% NaOCl. 3. A significantly higher number of bacteria were adhered to the root canal dentin without smear layer(p<0.0001). 4. Smear layer produced during root canal preparation impedes bacterial adhesion and colonization to dentin matrix, therefore inhibits canal reinfection.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.219-237
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• 1998

Numerous bone graft materials have been used in Periodontics, in an attempt to reach the main goal of periodontal therapy, i.e. the regeneration of periodontal tissue lost due to destructive periodontal diseases. The present study investigates the effect of composite graft of DFDB and Calcium sulfate with and without Calcium sulfate barrier in Periodontal 1-wall intrabony defects in dogs. Following the initiation of general anesthesia by I.V. administration of 40mg/Kg of Pentobabital, second premolar was extracted and full thickness flap elevated. The crown portion of premolars was removed. Exposed root canals were sealed with Caviton and covered completely with flap. After the healing period of 8 weeks, the surgical sites were re-opened and 1-wall intrabony defects were created, and treated with flap operation alone(control group), with composit graft of 80% DFDB and 20% Calcium sulfate(Experimental group 1), with composite graft of DFDB and calcium sulfate with calcium sulfate membrane( Experimental group 2). Healing response was histologically observed after 8 weeks and the results were as follows : 1. New bone formation was 70 % in the control group, 93 % in the Experimental group I, 89 % in the Experimental group II. There was a no differences between Experimental groups. 2. New cementum formation was not significantly different between control and two Experimental groups. 3. The length of connective tissue adhesion was 30 % in the control, 7% in the Experimental group I and 11 % in the Experimental group II. 4. After 8weeks, calcium sulfate was completely resorbed, while DFDB particle remained. These results suggest that the use of composite graft of allogenic DFDB and Calcium sulfate with and without Calcium sulfate barrier in periodontal 1 wall intrabony defects have little effect on connective tissue adhesion, but has beneficial effect on new alveolar bone and new cementum formation, and prevent downgrowth of epithelium and connective tissue effectively.

• 한국조경학회지
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• 제35권1호
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• pp.1-8
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• 2007

The purpose of this study is to suggest the minimum distance needed between landscape trees and apartment buildings. in order for the trees to grow soundly and maintain constant growth. Therefore, this study investigated and analyzed the present conditions of the green-spaces contiguous to apartment buildings and the trees inside the apartment complex. The following general problems were identified : (1) the tree growth conditions, (2) the planting intervals, and (3) the planting methods in the apartment complexes. The method of this study was to survey areas, measure the trees and analyze the results. Ten apartment complexes located in Seoul were randomly selected for this study. To analyze the greens contiguous to the building of each apartment complex, the greens were divided into three types, including the front greens, the side greens, and the rear greens. The study surveyed the width of all contiguous greens and the distance from trees to my given building. Four representative sites were specifically investigated to measure the crown widths, heights, and diameters of the trees. These investigations were carried out over 3 months from August to December 2006. According to the results of the study, it was found that the greens are narrower in width and the more closer to a building. The study identified a correlation between the tree and the passage of time after the completion of construction of an apartment complex, showing that the malformation of the trees worsened as time passed. As a result of measuring the right crown and left crown width with the tree trunk as the center, a broad difference was found between coniform trees and trees that tend to branch out more. For example, the ratio of the width of the Acer palmatum is 1:6. However, the ratio of the Metasequoia glyptostroboide is 1:1.7. Based on the overall analysis, it was concluded that the maintained minimum width must be greater than one meter over the green space according to the 'Landscape Standard 2000'. However, that is only applicable to cases such as apartment buildings that present no obstacles. In conclusion having greens placed within one meter of width to a building is not an appropriate environment for the healthy growth of trees. To create sound green spaces, sustainable, long-term growth rate and size should be considered. It is necessary to prepare new standards for the computation of planting trees and the measurement of square landscapes. Wall greenery and shrubberies could be an alternative in the case of a narrow-width green space.

• 한국터널지하공간학회 논문집
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• 제25권1호
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• pp.13-26
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• 2023

최근 급속한 도시화, 인구 과밀화로 지하공간의 개발이 활발해지면서 지하공간의 공사에 따른 지반거동에 대한 관심이 높아지고 있다. 인구밀집도가 크고 건물도 많은 대도시에서의 지표침하는 구조물에 큰 영향을 주고 붕괴의 위험이 있을수 있기에 지하공사로 인한 지반거동에 대한 분석은 필수적으로 진행되어야 한다. 지금까지 터널 굴착 시 지표의 침하 양상과 터널의 변형에 관한 연구가 많이 이루어져 왔으나, 실제 지형 정보를 반영하여 분석을 진행한 경우는 거의 없다. 따라서 본 연구에서는 FLAC 3D를 활용하여 실제지형과 평면지형에서의 지반거동의 차이를 분석하였다. 지형은 부산의 OO~OO 지하고속도로 구간의 OO역 인근의 지형으로 적용하였으며, 상행선과 하행선을 각각의 Case로 나누어 지형과 터널의 위치에 따라 3차원 수치해석을 수행하였다. 그 결과 지반침하는 산악지형과 같이 표고가 높을수록 크게 발생한다는 것을 확인할 수 있었으며, 터널의 천단침하는 지형 정보를 고려하여 수치해석을 진행하였을 때, 같은 지점에서 지형을 고려하지 않은 경우와 최대 약 10 mm의 차이를 보였으며, 내공변위의 경우 천단침하와 지반침하에 비해 민감도가 적은 것을 알 수 있었다. 수치해석을 통해 현장을 잘 모사하기 위해서는 지형을 고려하는 것뿐만 아니라 상부 구조물을 해석에 반영시켜야 하기 때문에 수치해석에 사용할 건물 데이터에 대한 연구가 진행되어야 할 것이다. 본 연구에서 제시된 GIS 기반 지형 정보를 고려한 수치해석은 터널 굴착공사로 인한 상부 구조물의 거동을 파악하기 위해 더 정확한 지반침하 데이터를 얻는데 활용될 수 있을 것으로 판단된다.

• 복식
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• 제60권7호
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• pp.117-130
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• 2010

The four walls of mural paintings in Afrasiab, Samarkand, have discovered: the indian-concept east wall, the west with the paintings of envoys from a number of countries bringing in King's letters or gifts, the south describing traditional ceremony celebrating the new year, the north with a picture of a Chinese princess on board beside hunting scenes. Overall, Sogdians in Afrasiab mural paintings of 7th century had following costume codes: a very short haircut or the Turkic queue, a rather-narrow-sleeved caftan with round-neck, a belt and boots. The west wall showed various costume style of a set of envoys from countries. First, a Turkic envoy had 3-6 rows of long plaits, wearing a caftan with two lapels and a belt - interestingly, Sogdian and Turkic nobles didn't wear pochettes. Second, a Chaganiyan had a hairband on his short hair, and his colorful round-neck caftan is decorated with animal-patterned medallions and a golden belt. Third, a Chach wore a jewelled hairband, putting gaiters on his pants. Forth, a Chinese was in putou with a round-neck caftan, and with a belt and sword around his waist. Lastly, also appeared a Koguryo envoy in white putou with a double-bird-feathered crown on top, wearing a long-sleeved yellow v-neck top, a belt, narrow-cuffed pants and boots. Identical to the Sogdian statues excavated in various regions of China are the appearance of big eyes and nose -similar to the warrior stone in Korea- a hairband, and a pochette down from the waist line. During this period, white and red were considered as prevailing colors for clothing: red and yellow among Turks. The costumes of characters in Afrasiab mural paintings were preferably made with the animal-patterned, sophiscated samite Zandanachi of Sogdiana.

• Applied Microscopy
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• 제23권1호
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• pp.91-108
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• 1993

The relationship of cartilage canals to initial osteogenesis of primary ossification center of developing vertebrae in human fetuses ranging from 50mm to 260mm in crown rump length was studied by light and electron microscopy. The cartiage canals of the thoracic vertebrae were first observed at 60mm fetus. Cartilage canals were identified as vascular channels arising from perichondrium surfaces. A number of cartilage canals were observed around the primary center of ossification at 80mm fetus. At 120mm fetus, cartilage canals of the bodies of vertebra were increased. Eventually the canals were eroded from the main medullary cavity and remained at only peripheral regions of growth cartilage. Superficial, intermediate, and deep canals were identified by the characteristics of cartilage cells. Fibroblasts, undifferentiated mesenchymal cells, and vacuolated macrophages were observed adjacent to the matrix of resting cartilage cells in the superficial canal. Fibroblasts and mesenchymal cells were densely packed at the tip of canal, giving an epithelial appearance to the clustered cell in the intermediate canal. Vacuolated macrophages were in contact with matrix of hypertrophied cartilage. The thick-walled vessels in the intermediate and deep canals consisted of typical endothelial cells, but in the newly formed vessels contained mesenchymal cells and fibroblasts incorporated into the vessel wall. During lengthening of cartilage canal, the matrix of cartilage cells were invaded by newly formed capillaries and vacuolated macrophages. At the deep canal, the lateral wall of the canal terminated in matrix containing calcified cartilage. The mesenchymal cells began to differentiate into osteoblasts adjacent to the calcified matrix. The results indicate that the connective tissue cells within the cartilage canals proliferate and differentiate into osteoblasts at the site of primary ossification center.

• Restorative Dentistry and Endodontics
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• 제25권3호
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• pp.321-337
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• 2000

Dental caries, one of the most frequent dental disease, become larger because it can be thought as a simple disease. Further more, it can progress to unexpected root canal therapy with fabrication of crown that needs reduction of tooth structure. Base is required in a large caries and ZOE, ZPC, glass ionomer are used frequently as base material. They, with restorative material, can affect the longevity of the restoration. In this study, we assume that the mandibular 1st molar has deep class I cavity. So, installing the 3 base material, 3 kinds of fillings were restored over the base as follows; 1) amalgam only, 2) amalgam with ZPC, 3) amalgam with ZOE, 4) amalgam with GI cement, 5) gold inlay with ZPC, 6) gold inlay with GI cement, 7) composite resin only, 8) composite resin with GI cement. After develop the 3-dimensional model for finite element analysis, we observe the distribution of stress and temperature with force of 500N to apical direction at 3 point on occlusal surface and temperature of 55 degree, 15 degree on entire surface. The analyzed results were as follow : 1. Principal stress produced at the interface of base, dentin, cavity wall was smallest in case of using GI cement as base material under the amalgam. 2. Principal stress produced at the interface of base, dentin, cavity wall was smaller in case of using GI cement as a base material than ZPC under gold inlay. 3. Composite resin-filled tooth showed stress distributed over entire tooth structure. In other words, there was little concentration of stress. 4. ZOE was the most effective base material against hot stimuli under the amalgam and GI cement was the next. In case of gold inlay, GI cement was more effective than ZPC. 5. Composite resin has the small coefficient of thermal conductivity. So, composite resin filling is the most effective insulating material.

• 대한치과보철학회지
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• 제44권1호
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• pp.10-19
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• 2006

Statement of problem : The various kinds of properties of post and core may affect the stress distribution to the root of endodontically treated teeth Purpose: To evaluate the influence of various kinds of properties of post and core to the stress distribution to the root of endodontically treated teeth. Material and methods: Mandibular first premolar, prepared by general shape of post and core with gold crown, was used to two dimensional axisymmetric modeling for finite element analysis. Then property values of 8 different kinds of post and core was substituted for each. Finally, stress distribution shown areas around the root of post and core was analysed after applying 50N of vortical and oblique load. Results: 1. Stress value of oblique load was much higher than the maximum stress value of vertical load. 2. Under oblique load, very concentrated stress was located on post periapical area and variations in stress were very severe. Contrary to this, stress distribution was relatively uniform in vertical load. 3. Post materials with higher elastic modulus showed relatively more apically focused stress, and post materials with lower elastic modulus showed stress focused on cervical area on the axial wall of post. 4. Stress change according to the properties of core was shown only in the cervical area of post and below core as the higher elastic modulus, then increased in stress. 5. Post and core with medium value of elastic modulus showed relatively uniform stress distribution. Conclusions: Post materials with higher elastic modulus showed relatively more apically focused stress, and post materials with lower elastic modulus showed stress focused on cervical area on the axial wall of post. Stress change according to the properties of core was shown only in the cervical area of post and below core.