• 암석학회지
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• 제19권1호
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• pp.31-49
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• 2010

한반도 남부 원생대 하동회장암체 내에는 주변 회장암의 암상과 무관하게 대략 남북방향으로 단속적으로 철-티탄 광체들이 출현한다. 이들 광체의 야외산상과 변형사를 밝히기 위하여 야외기재학적 특징과 주변 지질구조 분석 그리고 주요 암석과 광체 내 티탄철석에 대한 박편관찰과 전자현미분석을 실시하였다. 이번 연구의 대상 광체는 맥상과 층상 광체로 구분된다. 맥상 광체는 회장암체가 정치 고화된 이후에 관입하였음이 확실시되며, 층상 광체는 후기의 강력한 우수향 연성 전단작용에 의해 상대적으로 규모가 큰 맥상 광체가 압쇄암화 되고 전단엽리와 평행하게 전위된 결과로 해석된다. 철-티탄 광체는 청룡리, 월횡리, 종화리, 자양리와 백운리의 순서로 남에서 북으로 갈수록 후기 우수향 연성 전단변형을 많이 받았으며, 광체 내 티탄철석의 함량은 감소하는 특징을 보인다. 광체 내 티탄철석은 야외산상과 후기 전단변형의 정도와 무관하게 유사한 화학조성을 가지며, $TiO_2$ 함량이 52~55 wt.% 내외로 자철석으로 용리되지 않은 순수한 티탄철석의 화학조성을 보여준다. 야외 지질구조 자료들을 분석하면, 하동회장암체는 마그마의 분화작용으로 만들어진 누적 엽리의 생성 이후에 북북동-남남서 습곡, 철-티탄 광체의 관입, 북북서~북북동 우수향 연성 전단작용, 북서~북북서 좌수향 아취성 전단작용, 그리고 북북동~북동 방향의 염기성 마그마의 관입의 순서로 변형된 것으로 판단된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권5호
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• pp.435-439
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• 2011

Ameloblastoma is an aggressive benign odontogenic epithelial tumour that may arise from the enamel organ, remnants of dental lamina, or the lining of an odontogenic cyst. It is usually categorized into solid or multicystic, unicystic, and peripheral types. Treatment ofameloblastomas include conservative methods such as marsupialisation, enucleation, and curettage; and radical treatments such as marginal or segmental resection. Radical treatments have resulted in lower recurrence rates; however, may also encounter esthetic, functional, and reconstructive problems. Unicystic ameloblastoma has been considered less aggressive and a lower recurrence tendency. Thus, many authors have recommended conservative treatment in cases of unicystic ameloblastoma. An 11 year-old boy presented with displaced second and third molars by luminal unicystic ameloblastoma in the mandible. Cyst enucleation, curettage, and third molar extraction were done. No signs of recurrence or esthetic problems such as facial asymmetry were seen radiologically and clinically, up to 8 years 2 months postoperatively.

• 한국어류학회지
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• 제17권4호
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• pp.241-247
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• 2005

왕종개 Iksookimia longicorpa의 공기호흡에 관한 호흡체계를 조사하기 위해 표피 (epidermis)와 소화관 (intestinal tract)를 관찰하였다. 표피는 작은 점액세포 (mucous cell)와 곤봉세포 (club cell)로 이루어진 두 종류의 선세포 (gland cell)을 가진다. 점액세포는 대부분 acid sulfomucin으로 구성되었으나 곤봉상세포는 점액물질에 대한 어떠한 반응도 보이지 않았다. 기저층에는 작은 림파구를 포함하는 lymphocytes가 존재하며, 다량의 모세혈관이 기저층 바로 아래부분에 존해하고 있다. 장( intestinal tract)은 거의 일직선형태이며, 크게 장(intestine)과 직장(rectum)으로 구성된다. 이러한 장은 점액층 (mucosa), 점막하층 (laminal propria-submucosa), 근육층 (musculary), 장막 (serosa) 층으로 구성되었다. 이러한 장은 짧은 fold와 얇은 벽으로 구성되었으며, 점막층은 acid sulfomucin의 점액을 가지고 있다. 공기호흡하는 어류들의 변형된 공기호흡 기관의 특징들과 비교해 볼 때 왕종개는 하천의 가뭄으로 인해 용존산소가 부족할 경우 장에서는 이루어지지않고 표피에서만 공기를 흡입하는 것으로 생각된다.

• 대한소아치과학회지
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• 제26권1호
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• pp.157-161
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• 1999

1. Periphelal odontoma는 매우 드문 질환으로 확진을 위해서는 생검이 필수적이다. 2. Peripheral odontoma는 치은의 종창을 동반하며 서서히 성장하는 임상적 특징을 가진다. 3. 골내 치아종과 마찬가지로 peripheral odontoma의 치료로는 완전한 외과적 절제가 추천되고 예후 또한 양호하다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제25권4호
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• pp.311-323
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• 1999

The osteonectin is a sort of glycoprotein which is secreted in human tissues. The osteonectin is generally detected in number of normal or neoplastic human tissues in vivo, but hasn't been studied the role of osteonectin in developing human teeth and odontogenic tumors. We evaluated degree of the expression of osteonectin immunohistochemically in 20 cases of developing tooth germ which growth from fetus 5 to 38 weeks, and total 51 odontogenic tumors whitch has taken from routine biopsy, such as 10 ameloblastomas, 5 cases of adenomatoid odontogenic tumors and odontomas and odontogenic fibromas, 4 cases of cementomas and calcifying epithelial odontogenic cyst and odontogenic keratocyst and dentigerous cysts and periapical cysts, and 3 cases of ameloblastic fibromas and myxomas. The results were as follows: 1. The osteonectin on the bud stage of tooth germ was strongly expressed in the epithelial dental lamina and in the outer dental epithelium on the early bell stage, and also strongly expressed in the inner dental epithelium on the late bell stage of tooth germs. 2. In ameloblastoma, the osteonectin was strongly expressed in the epithelial tumor component and especially in the acanthomatous types. 3. In both of calcifying epithelial odontogenic tumor and adenomatoid odontogenic tumors, the osteonectin was moderately expressed on the duct like spindle cells and epithelial tumor cells around calcification areas. 4. In odontogenic tumors originated from epithelial-mesenchymal tissues, the osteonectin was moderately expressed on the epithelial tumor components and in odontogenic cysts, it was expressed in ghost cells and calcification areas only. These were summaried the osteonectin may be strongly related to the developing tooth germ and odontogenic tumors and could be regulated hard tissue of human tooth in morphogenesis and involved with calcification mechanism in development odontogenic tumors.

• 한국수의병리학회지
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• 제3권1호
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• pp.35-44
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• 1999

The morphologic changes of small intestinal epithelium in pigs diagnosed as porcine epidemic diarrhea(PED} by virus isolation and immunohistochemistry were studied through light microscope and transmissible electron microscope. On semi-thin section, the histologic findings showed severe villous atrophy and fusion with hyperplasia of cuboidal epithelium in the villi, inflammatory cell infiltration in lamina propria, and increased mitotic figures in the crypt. The structural changes were mostly restricted to the cytoplasm of affected absorptive epithelium of villi. 3 types of epithelial changes were found; degenerated virus-affected cells, undifferentiated cuboidal cells, and normal columnar cells. On electron microscopy, round to spherical viral particles of 50∼l00nm in diameter were found within the dilated vesicles and endoplasmic reticulums of degenerated cells, which had decreased their cytoplasmic electron density due to dilated and missing organelles(e.g. mitochondria, ERs, etc.). Microvilli were shortened and sparse, leaving denuded terminal web of the villous epithelial cells. Fat globules were often found within slightly degenerated enterocytes. On the tip of villi, severely damaged cells were exfoliated and replaced by undifferentiated cuboidal cells We found distinct ultrastructural changes in the jejunal epithelium confirming PED virus infection is involved in malabsorptive diarrhea.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.682-690
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• 2015

The bonding performance of two types of wood adhesives, namely phenol-resorcinol-formaldehyde (PRF) resin and melamine-urea-formaldehyde (MUF) resin for glued laminated timber manufactured by high frequency (HF) heating was evaluated. The HF heating system consists of HF oscillator with dielectric heating system for curing adhesives, and hydraulic press system for clamping glued laminated timber. The designed frequency and output power of the HF system was as 5 MHz and 60 kW, respectively. To verify dielectric heating mechanism under HF oscillation, the heat loss factors of laminae and adhesives were measured. The results show that it is possible to selectively heat adhesives for their curing due to the remarkably higher loss factor of the adhesives than those of wood laminae. The temperature of adhesive in the bonding line reached up to the set temperature within a few seconds by high frequency oscillating, which advanced the curing of adhesive afterwards. The bonding performance, such as shear strength of bonding line, water soaking delamination, and boiling water soaking delamination of PRF resin met the requirement of Korean Standard (KS), however the MUF resin did not meet the KS requirement of boiling water soaking delamination. These results indicate that the HF heating system is successful to manufacture glued laminated timbers with PRF resins to meet the bonding requirements.

• Smart Structures and Systems
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• 제9권6호
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• pp.505-534
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• 2012

The present work deals with second order statistics of post buckling response of piezoelectric laminated composite cylindrical shell panel subjected to hygro-thermo-electro-mechanical loading with random system properties. System parameters such as the material properties, thermal expansion coefficients and lamina plate thickness are assumed to be independent of the temperature and electric field and modeled as random variables. The piezoelectric material is used in the forms of layers surface bonded on the layers of laminated composite shell panel. The mathematical formulation is based on higher order shear deformation shell theory (HSDT) with von-Karman nonlinear kinematics. A efficient $C^0$ nonlinear finite element method based on direct iterative procedure in conjunction with a first order perturbation approach (FOPT) is developed for the implementation of the proposed problems in random environment and is employed to evaluate the second order statistics (mean and variance) of the post buckling load of piezoelectric laminated cylindrical shell panel. Typical numerical results are presented to examine the effect of various environmental conditions, amplitude ratios, electrical voltages, panel side to thickness ratios, aspect ratios, boundary conditions, curvature to side ratios, lamination schemes and types of loadings with random system properties. It is observed that the piezoelectric effect has a significant influence on the stochastic post buckling response of composite shell panel under various loading conditions and some new results are presented to demonstrate the applications of present work. The results obtained using the present solution approach is validated with those results available in the literature and also with independent Monte Carlo Simulation (MCS).

• Journal of Veterinary Science
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• 제22권3호
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• pp.31.1-31.12
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• 2021

Background: Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. Objectives: We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. Methods: In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. Results: The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. Conclusions: In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.

• Applied Microscopy
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• 제33권1호
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• pp.25-39
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• 2003

큰발웃수염박쥐 (Myotis macrodactylus)의 세정관 정상피의 분화과정과 미세구조적 특징들은 알아보기 위하여 광학 및 전자현미경을 이용하여 조사하였다. 정자형성 과정은 4월부터 9월까지로 나타났다. 정자형성세포의 미세 구조적 특징에 있어서, A형 (Ad, Ap)의 정원세포는 기저막 위에 위치하며, Sertoli cell에 의해 둘러싸여져 있고, 대부분의 세포는 타원형이다. Ad형은 Ap형 보다 핵과 세포질의 전자밀도가 높은 것이 특징적인 반면에, B형의 정원세포는 구형의 세포로서 A형 정원세포 보다 세포가 크며, Ap형과 마찬가지로 세포질이 밝고, 거의 핵소체가 핵막에 인접되어 있다. 정모세포는 크고 구형이지만, 제 1 정모세포가 제 2 정모세포보다 다소 크다. 정자변태는 골지, 두모, 첨체, 성숙 및 이탈기로 구분하였고, 세포구조물의 특징들에 의해 각각 전 후기로 다시 세분하여 전과정을 9 (기)로 나누었다. 핵질의 변화는 골지후기부터 서서히 응축하기 시작하여, 이탈기에서 완전한 핵을 형성하였다. 정자꼬리의 형성시기는 골지전기에서 형성하기 시작하여 이탈기에서 완성되었다. 동면직전 10월부터 동면기 (11월, 12월, 이듬해 1, 2, 3월)까지는 정자형성 세포의 퇴화과정이 일어났다. 즉 미분화 정자형성 세포들은 세르톨리 세포의 식작용에 의해 포식되어졌는데 이는 동면을 위한 에너지 효율적 이용과 번식조절을 위한 적응 메카니즘이라 여겨진다.