• 대한소아치과학회지
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• 제47권4호
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• pp.438-445
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• 2020

우상치는 수직적으로 긴 치수강과 근첨부에 위치하는 치수저를 특징으로 가지는 발육성 형태 이상이다. 이 연구의 목적은 어린이의 유구치에서 우상치의 유병률과 특징을 알아보기 위한 것이다. 이 연구는 2005년부터 2018년까지 연세대학교 치과대학병원 소아치과에 내원하여 파노라마 방사선 사진을 촬영한 만 5세에서 10세 사이의 환자 2,473명을 대상으로 시행되었으며 총 19,784개의 유구치가 평가되었다. 우상치의 유병률은 약 5.7%었고 남아에서 더 호발하였다. 또한 상악에서 6.3%, 하악에서 93.6%로 하악에서 현저히 높은 유병률을 보였다. 좌우에 따른 유병률의 차이는 나타나지 않았다. 우상치의 세부 유형으로 Daito의 방법을 적용하여 Hypertaurodontism, Mesotaurodontism, Hypotaurodontism으로 분류하였으며 각 유병률은 11.9%, 78.2%, 7.8%로 Mesotaurodontism이 가장 높은 유병률을 보였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.588-593
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• 2006

Cyst is pathologic disease develops in hard tissue as well as soft tissue, which is lined by epithelium filled with liquid, semi-liquid, or air. Origins and symptoms of the cyst are various according to region, and symptoms are malocclusion, diversion of root, tooth mobility, periapical swelling, discoloration and lesion expansion, because the odontogenic cysts begin in the numerous rests of odontogenic epithelium. But almost cysts produce no symptoms unless secondary infection occurs. Treatment of small cysts may include extraction, endodontic therapy, and apical surgery. Treatment of a large cysts usually involves surgical removal (enucleation), Marsupialization(a method of decompression) or combination of two before mentioned. Bone graft is done for helping of bone defect healing at the same time of enucleation This clinical research from January 2000 to December 2005, analyzed by the age, sex, classification, size, region, treatment method, whether or not of bone graft of cyst in the jaw in Daegu Catholic University Hospital.

• Journal of Species Research
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• 제1권1호
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• pp.4-34
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• 2012

Parastenocaris koreana sp. nov. is described based on examination of numerous adult specimens of both sexes from several localities in Korea. Scanning electron micrographs are used to examine intra- and interpopulation variability of micro-characters, in addition to light microscopy. The new species is most closely related to the Japanese P. biwae Miura, 1969, which we redescribe based on newly collected material from the Lake Biwa drainage area. The two species differ in size, relative length of the caudal rami, shape of the anal operculum, shape of the genital double somite, relative length of the inner distal process on the female fifth leg, as well as relative length of the apical setae on the second, third, and fourth legs exopods in both sexes. Detailed examinations of three disjunct populations of P. koreana reveal also some geographical variation, especially in the surface ornamentation of somites, which may indicate some population structuring or even cryptic speciation. Lack of intraspecific variability in the number and position of sensilla on somites, as well as their potential phylogenetic significance, is a novel discovery. Both species examined here belong to the brevipes group, which we redefine to include 20 species from India (including Sri Lanka), Australia, East Asia, Northern Europe, and North America. A key to species of this group is also provided. In order to test the monophyly of the redefined brevipes group with highly disjunct distribution, as well as relationship between different species, a cladistics analysis is performed based on 39 morphological characters and with help of three outgroup taxa. Six equally parsimonious cladograms are generated, all of which show that the ingroup is well defined by at least three synapomorphies. Reconstructed phylogeny questions the previously suggested hypothesis about the origin of this group in South East Asia, with one Australian species showing the most basal position. We speculate that the present distribution of this group may be a combination of ancient vicariance and subsequent dispersal, with a possible origin in the Gondwanaland, in the rift valley between Australia and India.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• Journal of Chest Surgery
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• 제26권6호
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• pp.470-474
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• 1993

A clinical evaluation was performed on 56 patients[ 60 cases ] of open thoracotomy in spontaneous pneumothorax who were admitted and treated at department of Thoracic and Cardiovascular Surgery, Chung Ang University, Yong San Hospital during the past 3 years from March 1990 to February 1993. The results were as follows. 1. The sex ratio was male predominence [ M:F = 7:1 ]. 2. The most common age group were 2nd, 3rd decades. 3. The most common chief complaints were dyspnea and chest pain [46.3% ]. 4. The etiologic factors of spontaneous pneumothorax were primary spontaneous pneumothorax [ 78.3%], secondary tuberculosis [ 18.3%], and others [ 3.4% ]. 5. The site of spontaneous pneumothorax was 50% in right, 40% in left, and 10% in both. 6. The state of activity on attack was almost in the usual life [ 98.3% ]. 7. Average height was 172.5 $\pm$ 5.39 cm in male and 164.0 $\pm$ 3.51 cm in female, average weight was 59.1 $\pm$ 7.06 kg in male and 52.0 $\pm$ 4.97 kg in female. 8. The common indications of open thoracotomy were recurrence [ 34.4% ] and persistent air leakage [ 17.8% ]. 9. The operative procedures were bullectomy [ 73.3% ], partial resection [ 11.7% ], lobectomy [ 11.7% ], and others [ 3.3% ]. 10. The most frequent location of bulla or bleb were apical segment of RUL [ 43.3 % ] and apicoposterior segment of LUL [ 40.0% ]. 11. The number of visible bulla or bleb were mainly 1 to 5, and size was about 1 to 3 cm.

• International Journal of Industrial Entomology and Biomaterials
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• 제23권1호
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• pp.107-113
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• 2011

Infection effect of $Nosema$ $bombyics$ on the midgut of silkworm $Bombyx$ $mori$ and subsequent appearance of spores and the performance of larvae was studied. Autopsy of larvae showed white pustules on the surface of midgut at 5 days of post infection (pi). At later stage, important organs like midgut, silk gland and gonads reduced in size and all these organs showed white pustules. Light microscope observation of pustules revealed enormous spores. Spore multiplication was at a faster rate in young larvae. Infection of the adult larvae resulted in pebrinized pupa and moths. Larval weight, cocoon weight and cocoon shell ratio reduced as the post infection period increased. Transverse sections of midgut showed $N.$ $bombycis$ infection limited to a few columnar cells at 3-5 days of pi. At 7 days pi, cell volume increased, cells were swollen and elongated. Heavily infected cells looked like sacks filled with parasite and the apical region of certain cells were bulging into the gut lumen. Later at 8-9 days of pi, spores or its developing stages leaked into the lumen either freely or enclosed within the globules of host cytoplasm. Besides columnar cells, development of $N.$ $bombycis$ was observed in the regenerative cells and rarely in goblet cells. Development of $N.$ $bombycis$ was also observed in both longitudinal and circular muscles at the late pi period. The histopathological changes, deformities and spore production time in the host were all influenced by the spore dosage and age of the host.

• 대한수의학회지
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• 제34권2호
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• pp.219-227
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• 1994

The development of abomasum in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light, scanning and transmission electron microscopy. The results obtained were summarized as follows ; 1. The abomasum wall appeared to be differentiated into the epithelium, lamina propria, muscle layer, and serosa at 60 days of gestation. The epithelium was stratified columnar and these nuclei were located near the apical two thirds portion of the cell at 60 days of gestation, and then transformed into simple columnar epithelium with the flat basal nuclei. 2. The inner circular and outer longitudinal muscle layers were observed at 90 days of gestation and the blood vessels had become quite well developed as various arterioles, venules and capillaries of different size during this age. 3. Gastric pits were seen at 90 days of gestation and continued gradually to increase depth during gestation. 4. The mucous, parietal and chief cells appeared in epithelium at 90 days of gestation and continued gradually to increase in number during gestation. In 120 days fetuses and neonates, muscle layer had become very thickeness. 5. Scanning electron microscopically, the inner surface of the abomasum already consisted of wavy spiral folds which had many fine wrinkles at 60 days of gestation. In 90 day old fetuses, each spiral fold was enlarged and its surface was tended to be split into many straight longitudinal ridges and among these ridge were found shallow grooves, At 120 days, the subdivided swellings of ridges were progressively complicated in shape. In the neonates, the inner surface was flat and holed with many gastric pits. 6. Transmission electron microscopically, the epithelium was straified columnar and these nuclei were irregular shape at 60 days fetus. The parietal, chief and mucous cells were observed in 90 day old fetuses and continued gradually to increase in number during gestation. 7. The development of the abomasum was relatively slow at early stages, it was accelerated greatly in the last of gestation.

• 구강회복응용과학지
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• 제22권1호
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• pp.75-87
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• 2006

The purpose of this study was to investigate the effects of prostheses misfit, cantilever on the stress distribution in the implant components and surrounding bone using three dimensional finite element analysis. Two standard 3-dimensional finite element models were constructed: (1) 3 ITI implant supported, 3-unit fixed partial denture and (2) 3 ITI implant supported, 3-unit fixed partial denture with a distal cantilever. variations of the standard finite element models were made by placing a $100{\mu}m$ or $200{\mu}m$ gap between the fixture, the abutment and the crown on the second premolar and first molar. Total 14 models were constructed. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the distal marginal ridge of the distal molar. von Mises stresses were recorded and compared in the crowns, abutments, crestal compact bones, and trabecular bones. The results were obtained as follows: 1. In the ITI implant system, cement-retained prostheses showed comparatively low stress distributions on all the implant components and fixtures regardless of the misfit sizes under vertical loading. The stresses were increased twice under oblique loading especially in the prostheses with cantilever, but neither showed the effects of misfit size. 2. Under the oblique loading and posterior cantilever, the stresses were highly increased in the crestal bones around ITI implants, but effects of misfit were not shown. Although higher stresses were shown on the apical portion of trabecular bones, the effects by misfit were little and the stresses were increased by the posterior cantilever. 3. When the cement loss happened in the ITI implant supported FPD with misfit, the stresses were increased in the implant componets and supporting structures.

• Restorative Dentistry and Endodontics
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• 제43권3호
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• pp.30.1-30.12
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• 2018

Objectives: To evaluate sealing ability of root canals obturated with bioceramic-impregnated gutta percha cone (BCC) or gutta percha (GP), with bioceramic sealer (BCS) or AH Plus (AH; Dentsply-Maillefer), in roundly-prepared canals using matched single-cone technique, based on bacterial leakage test, and to analyze obturation quality using micro-computed tomography (CT) analysis. Materials and Methods: Ninety-two distobuccal roots of maxillary molars were prepared using nickel-titanium files to apical size 40/0.06. The roots were divided into 4 groups (n = 20) that were obturated with a master cone and sealer: GP/AH, BCC/AH, GP/BCS, and BCC/BCS. Bacterial leakage model using Enterococcus faecalis was used to evaluate sealing ability for 60-day period. Obturated samples from each group (n = 4) were analyzed using micro-CT. Results: All groups showed bacterial leakage at 20%-45% of samples with mean leakage times of 42-52 days. There were no significant differences in bacterial leakage among the groups. Micro-CT showed minimal gaps and voids in all groups at less than 1%. Conclusions: In roundly-prepared canals, the single cone obturation with BCC/BCS was comparable to GP/AH for bacterial leakage at 60 days.

• BMB Reports
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• 제40권1호
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• pp.58-64
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• 2007

Similar to the other known structures of Bacillus thuringiensis Cry $\delta$-endotoxins, the crystal structure of the 65-kDa activated Cry4Ba toxin comprises three domains which are, from the N- to C-terminus, a bundle of $\alpha$-helices, a three-$\beta$-sheet domain, and a $\beta$-sandwich. To investigate the properties of the C-terminal domain III in isolation from the rest of the toxin, the cloned Cry4Ba-domain III was over-expressed as a 21-kDa soluble protein in Escherichia coli, which cross-reacted with anti-Cry4Ba domain III monoclonal antibody. A highly-purified domain III was obtained in a monomeric form by ion-exchange and size-exclusion FPLC. Circular dichroism spectroscopy indicated that the isolated domain III fragment distinctly exists as a $\beta$-sheet structure, corresponding to the domain III structure embodied in the Cry4Ba crystal structure. In vitro binding analysis via immuno-histochemical assay revealed that the Cry4Ba-domain III protein was able to bind to the apical microvilli of the susceptible Stegomyia aegypti larval midguts, albeit at lower-binding activity when compared with the full-length active toxin. These results demonstrate for the first time that the C-terminal domain III of the Cry4Ba mosquito-larvicidal protein, which can be isolated as a native folded monomer, conceivably participates in toxin-receptor recognition.