• Journal of Nutrition and Health
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• 제15권4호
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• pp.277-289
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• 1982

Because of a high degree of unsaturation of perilla seed oil vitamin E deficiency can be produced in chicks by using this particular oil diet. It is therefore convenient to use this oil for elucidating more detailed function (s) of vitamin E. The present study was undertaken to investigate the nutritional and pathological aspects both of high PUFA and of low vitamin E in the diet eventually to elucidate the function(s) of vitamin E. The present study examines the relationships between PUFA, vitamin E and Se in the experimental diets by measuring vitamin E levels both in serum and in liver and activities of SGPT and SGOT and by examining electron micrographs of the chick hepatocytes. Vitamin E concentrations in serum and liver responded to dietary treatments. Serum levels of vitamin E were more affected than those in liver, the values of groups IV(15% fat,- Vit.E) and V(15% fat,-Vit E,-Se) were significantly lower than those of groups I (5% fat) and 111 (15% fat) with P/S ratio of 1. The activities of SGOT and SGPT were found not to be different significantly among different diet groups. Electron microscopic observations of the chick hepatocyte revealed degeneration of mitochondria and appearance of vesicles in the cytoplasm of groups fed diets high in PUFA and deficient in vitamin E alone or deficient in both vitamin E and Se. In the same group pyknotic nuclei and deterioration of the sinusoidal border, showing diminution in microvilli were also observed. More detailed studies concerning biochemical aspects should be carried out by using radioisotopes both in the in vitro and in vivo systems and morphological study should have a focus on the changes in nucleus which seems already suggestive in the present observation.

• Spatial Information Research
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• 제23권4호
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• pp.79-89
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• 2015

본 연구는 GIS를 이용하여 미시적 수준에서 교통현상을 시뮬레이션 할 수 있는 미시적 수준의 교통모형을 설계 및 구현하는데 목적이 있다. 이를 위해 차량이 GIS 도로 중심선 자료를 차선, 이동속도 등이 반영된 도로 네트워크 자료로 인식하는 방법론을 개발하였으며, 운전자의 주행 행태를 반영하기 위해 환경인식모형, 차두시간분포모형, 차량추종모형 및 차로변경모형으로 행태모형을 설계 및 구현했다. 모형의 정확도 평가는 종로구의 자하문길을 대상으로 관측자료와 예측 자료를 비교하였으며, 그 결과 시간대별 이동 속도를 매우 정확하게 예측한 것을 확인할 수 있었다. 본 연구를 통해 구현된 GIS 기반의 미시적 수준의 교통모형은 교통 탄소 배출량 분석, 교통류 평가 및 도시기반시설 입지 계획등의 다양한 분야에 효과적으로 기여할 수 있을 것으로 판단된다.

• 한국가금학회지
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• 제46권4호
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• pp.263-269
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• 2019

IBV는 전세계적으로 양계산업에 문제시되고 있는 호흡기성 질병으로 육계 및 산란계의 생산성에 큰 영향을 미치고 있다. 본 연구는 2018년도에 분리된 3개의 IBV의 병원성을 확인하였다. 동물실험을 통해서 염증정도, 섬모소실도 그리고 폐사율의 결과를 바탕으로 2018년도 분리주인 QX-like IBV형은 병아리에게서 충분한 병원성을 지닌 것을 확인하였다.

• 대한수의학회지
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• 제29권4호
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• pp.531-540
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• 1989

A new sudden death in rabbits appeared in China and Korea in 1984 and 1985, respectively, and was recognized to be an acute infectious disease caused by a virus. The disease was reported as a "new viral disease," and thereafter, a tentative name of "viral hemorrhagic disease", "hemorrhagic pneumonia" or "viral hemorrhagic pneumonia" has been described in the case reports. But authors had called the viral disease "rabbit viral hepatitis" due to picornavirus infection, because the principal lesion of the disease was an acute hepatitis. The purpose of this report is to describe the electron microscopic findings on the livers in experimentally infected rabbits. All the livers of the affected rabbits were shown to have degenerative changes of a type that is characteristic of acute hepatitis. In the liver cells, there were dilation of rER and mitochondria, vacuole formation of various sizes, and appearances of many virus-like particles in the vicinity of rER, granular bodies and crystalline arrays of viral particles in the cytoplasm with necrotic changes of the nucleus. Clusters of virus-like particles and viral crystals appeared in the cytoplasm of sinusoid endothelial cells and Kupffer's cells with morphological changes of organelles. Also viral crystals were demonstrated in the cytoplasm of macrophages among the liver cells. On the whole, the liver cells had many virus-like particles and a few crystalline arrays of viral particles. Therefore, this implies that the liver cells are the main site of the viral replication in inducing the viremia. It was concluded that the liver was the primary target organ of this viral disease, and the pathological and the ultrastructural evidence suggest that the virus may be belong to genus enterovirus.

• 대한수의학회지
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• 제42권2호
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• pp.153-162
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• 2002

For the induction of arthropathy, 5% hydrogen peroxide($H_2O_2$) was injected for 5 weeks into the intraarticular space of the New Zealand white rabbits to damage articular cartilage. Alginic acid of low molecular weight (2%) made from macromolecular alginate treated with enzyme was administered into articular space at the dose of 5 mg/kg twice a week for 3 and 6 weeks using 1 ml syringe and 26 G needle. Saline was injected for the control. Tissues surrounding the articulation were obtained for the measurements of superoxide dismutase(SOD) activity as a major antioxidant enzyme and malondialdehyde (MDA) as a lipid peroxidation level. Histopathologic examination on the surface of articular cartilage was carried out. Data showed that injection of hydrogen peroxide for 5 weeks had led to the induction of free radical damage and of articular cartilage change as confirmed by microscopic observation. The application of hydrogen peroxide caused a gradual increase in the SODs and MDA. These patterns were similar after 3 and 6 weeks of alginate treatment. Furthermore, microscopic examinations revealed that hydrogen peroxide caused flaking, fibrillation, fissuring, denudation, and hypocellularity in the articular surfaces. In conclusion, lipid peroxidation was demonstrated in the articular cartilage by the administration of hydrogen peroxide in the rabbit model. This lipid peroxidation could be caused by oxygen free radicals. The histologic and enzymatic correlations on lipid peroxidation in the articulation have provided a better understanding of arthropathy. It is possible to take advantage of these findings to evaluate effective alginate dosage more efficiently.

• 한국터널지하공간학회 논문집
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• 제15권4호
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• pp.375-385
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• 2013

본 논문에서는 천매암을 중심으로 저변성퇴적암류에 속하는 암석을 대상으로 암석학적 특징과 풍화도의 상관성에 대하여 분석하였다. 현장 지질조사를 통하여 암석의 풍화도를 결정하였고, 구성암석의 강도 값을 추정하기 위하여 슈미트해머 테스트를 실시하였다. 9개 시료의 현미경 박편 관찰을 통하여 주구성광물의 부피비와 엽리의 간격을 측정하였다. 암석시료의 현미경 분석 결과에 의하면 풍화도가 낮을수록 풍화에 강한 석영성분이 많고, 풍화도가 높을수록 풍화에 약한 운모성분이 많은 것으로 나타났다. 또한 엽리 간격이 좁을수록 강도는 낮고 풍화도는 높은 것으로 나타났다.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.847-863
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• 1999

The present study was performed to evaluate the effect of EDTA on diseased root surfaces with regard to the removal of the smear layer, exposure of dentinal tubule openings, and demineralization of the peritubular dentin. 20 periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning was carried out with 3%, 17%, and 24% EDTA solution for 20 sec., 3 min., and 5 min. respectively. Then, the specimens were rinsed with tap water for 5 min. and processed for scanning electron microscopic observation. The following results were obtained. 1. In control group which was conditioned with cotton pellets soaked with saline for 3 min., the surface showed an amorphous irregular coating. The tubule orifices seemed to be com-pressed in the direction of the curette strokes. 2. In test group which was conditioned with EDTA solution, the number of opening dentinal tubules and the extent of the dentinal tubule opening increased with time irrespective of the concentration of EDTA solution. 3. In the group which was conditioned with EDTA solution for 20 sec., the smear layer was not completely removed. 4. If the time of root conditioning is above 3 min., collagen-like fibers covering the circum tubular dentin surface were shown even in the group which was conditioned with 3% EDTA solution. In conclusion, EDTA solution was a very effective root conditioning agent like low pH root conditioning agents which had various disadvantages. Therefore, using EDTA solution, more successful periodontal regeneration could be obtained.

• Journal of Yeungnam Medical Science
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• 제20권2호
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• pp.142-151
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• 2003

To induce bone formation at ectopic site by tissue engineering and gene therapy, we transplanted collagen sponges containing rhBMP-7 transduced HEK 293 cells in the hypodermis of nude mice. Bone formation was investigated by histological and electron microscopic method at 3, 6, and 9 weeks after transplantation. At 9 weeks after transplantation, eosinophilic bony tissue was observed in the implanted collagen sponge and was confirmed as bone tissue by Von Kossa stain. In the transmission electron microscopic observation, the cells in newly formed bone tissue had eccentrically located nucleus and well developed rough endoplasmic reticulum (rER). Therefore, the cells were evaluated as osteoblasts. Those results suggest that it is possible to form a bone tissue in the ectopic site by transplantation of rhBMP-7 transduced HEK 293 cells. This will be contributed to push more advanced gene therapy for bone formation. However, the HEK 293 cell is unable to apply to the clinical gene therapy. Therefore it is worth to find more compatible cells for clinical application. In addition, collagen sponge is considered as an excellent scaffold and/or carrier for gene therapy and a good biomaterial for tissue engineering.

• Applied Microscopy
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• 제29권3호
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• pp.315-321
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• 1999

12주령 랫트의 정상 비골골절의 치유과정을 이해하고, 난소적출 후 비골골절의 치유과정과 난소적출 후 비골골절의 치유에 미치는 $1\alpha$, 25 dihyoxycholecalciferol의 영향을 알아보고자 실험을 실시한 결과 다음과 같은 결론을 얻었다. 비골의 골절은 골절유발 후 5주에 성숙된 신생골 조직으로 충만되어 조직형태학적으로 완전한 치유가 이루어졌다. 난소적출 후 골절의 치유는 정상골절의 치유보다 지연되었으나, $1\alpha$, 25 dihydroxycholecalciferol 투여 결과 골절유발 후 5주에 성숙된 신생골 조직으로 골절단이 충만되어 정상상태의 골절과 비슷하게 치유가 되었다. 이상의 결과를 종합해보면 랫트의 난소를 적출하여 여성호르몬의 결핍을 유발하면 난소적출 후 7주에는 골다공증이 발생되고, 골다공증은 정상상태의 골절에 비하여 약 1주일 이상 골절의 치유를 지연시켰으며, $1\alpha$, 25 dihydroxycholecalciferol을 투여하였을 경우 정상상태의 골절치유와 비슷한 경과를 나타내어 $1\alpha$, 25 dihydroxycholecalciferol은 골다공증성 골절의 치료에 있어서 효과있는 치료제라는 결론을 내릴 수 있었다.

• Journal of Periodontal and Implant Science
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• 제32권4호
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• pp.697-709
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• 2002

The present study was performed to evaluate the effect of citric acid on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, titanium plasma-sprayed surface, and sand-blasted, large grit, acid etched surface were utilized. Implant surface was rubbed with pH 1 citric acid for $\frac{1}{2}$ min., 1 min., 1 $\frac{1}{2}$ min., 2 min., and 3min, respeaively in the test group and implant surface was not treated in the control group. Then, the specimens were processed for scanning electron microscopic observation. The following results were obtained. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two groups. 2. In titanium plasma-sprayed surfaces, round or amorphous particles were deposited irregularly. The irregularity of titanium plasma-sprayed surfaces conditioned with pH 1 citric acid was lessened and the cracks were increased relative to the application time of pH 1 citric acid. 3. Sand-blasted, large grit, acid etched surfaces showed the macro/micro double roughness. The application of pH 1 citric acid didn't change the characteristics of the sand-blasted, large grit, acid etched surfaces. In conclusion, the application of pH 1 citric acid to titanium plasma-sprayed surface is improper. And pure titanium machined surface implants and sand-blasted, large grit, acid etched surface implants can he treated with pH 1 citric acid for peri-implantitis treatment if the detoxification of these surfaces could be evaluated.