• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.13 no.1
• /
• pp.17-27
• /
• 1983

The author observed the effects of /sup 60/Co irradiation on the development and subcellular structure of tongue tissue of the fetal rats. The lower left abdomen of mothers were exposed to radiation on 15½th day of gestation with 300R. The fetuses were removed on the 6hr, 14hr, 24hr, 48hr and 72hr after irradiation and the light microscopic and electron microscopic observations of the lingual epithelium, lamina propria and muscle layer were carried out. The results were as follows: 1. The irradiated fetuses showed the retardation of filiform papillae formation. 2. Epithelial cells revealed fusion and myelination of mitochondria, large autolysosomes, increased lipid droplets, retardation of tonofilaments and desmosome formation. 3. In the lamina propria, undifferentiated cells showed bleb formation of nuclear membrane, pyknosis and fragmentation of nucleus, edema of cytoplasm I and nucleus, increased auto-lysosomes, dilatation of cell membrane and cell necrosis. Also, collagenous fibril formation was inhibited by irradiation. 4. In the muscle layer, growth of myotubes was inhibited. Myotubes showed swelling of mitochondria, loss of mitochondrial cristae, autolysosomes, retardation of myofibril formation, and large vacuoles. Undifferentiated cells adjacent myotube contained pyknotic nucleus and autolysosomes. 5. Among the various tissues of tongue, it seems that mesenchymal cells were most radiosensitive.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.13 no.1
• /
• pp.97-105
• /
• 1983

For the assessment of changes in the bone architecture of the maxilla and mandible in renal osteodystrophy, 31 chronic renal failure patients who were undergoing hemodialysis therapy were selected. They were evaluated through clinical oral examination, radiographic and biochemical examination. The results were as follows: 1. In 17 cases (54.8%), there were evidences of bony change in jawbone. 2. The most common dental radiographic finding was decreased bone density (14 cases, 45.2%). 3. The second most common dental radiographic finding was total or partial loss of lamina alveolar dura (11 cases, 35.5%). 4. The third most common dental radiographic finding was total or partial loss of inferior canal wall (8 cases, 25.8%). 5 cases showed evidences of bony change only in jawbone, and 5 cases only in hand, and 12 cases in both. 6. Serum creatinine, urea nitrogen and alkaline phosphatase values in hemodialysis group were much higher than in control group. 7. There were statistically significant correlation between bone density and lamina dura, and inferior alveolar canal wall.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.24 no.1
• /
• pp.7-21
• /
• 1994

Fifty-two cases of traumatic bone cysts in 50 patients were analysed clinically and radiologically. The obtained results were as follows; 1. Women showed a slightly higher incidence than did men (56% of patients) and the average age proved to be 18.6 years. 2. The majority of the cases were asymptomatic. being detected incidentally. and over the half of the cases occurred in the mandibular symphyseal region. 3. All cases were unilocular and the largest diameter of the lesions varied from 1 to 10㎝, mean 3㎝. 4. Some degree of marginal condensation was present in 28 cases and 23 cases presented pencil-sketch appearance. 5. Many anatomical cortical plates (especially, mandibular inferior cortex and lamina durae) consisted of the margin of the lesions partly. 6. Erosive change of the mandibular inferior cortex was caused by 12 cysts, but cortical expansion only by 3 cysts including 2 cases of buccal expansion. 7. The lesion enveloped the roots of the adjacent teeth in 27 cases and scalloping was present between roots in 17 cases. 8. Lamina dura of the teeth was destroyed by only 1 cyst, and in 1 case root resorption was noticed. But there was no divergence of the roots of teeth.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.1
• /
• pp.41-52
• /
• 2001

In this paper the analysis of laminate composite folded plates with arbitrary angle connection like box girder is studied by finite strip method Total stiffness of laminated plate is obtained by integration of the stiffness in each layer or lamina through laminate thickness and total stiffness in each layer or lamina through laminate thickness and total tiffness matrix is obtained by substitutionto equilibrium equation derived from the minimum total potential energy theorem. The assumed displacement functions for a finite strip method in plate or box girder analysis are combinations of one-way polynomial functions in the transverse direction and harmonic functions in the span-wise direction. Finite strip method with the merits of the simplification in modeling and the reduction of analytical time is accurate in the analysis of laminate composite folded plates shaped like box firders.

• Composites Research
• /
• v.30 no.1
• /
• pp.7-14
• /
• 2017

In this paper, the inter-lamina shear strength (ILSS) of multi-wall carbon nanotube (MWNT) reinforced carbon fiber reinforced plastics (CFRP) and thin-ply composites were verified under low earth orbit (LEO) space environment. CFRP, MWNT reinforced CFRP, thin-ply CFRP and MWNT reinforced thin-ply CFRP were tested after aging by using accelerated ground simulation equipment. The used ground simulation equipment can simulate high vacuum ($2.5{\times}10^{-6}torr$), atomic oxygen (AO, $9.15{\times}10^{14}atoms/cm^2{\cdot}s$), ultraviolet light (UV, 200 nm wave length) and thermal cycling ($-70{\sim}100^{\circ}C$) simultaneously. The duration of aging experiment was twenty hours, which is an equivalent duration to that of STS-4 space shuttle condition. After the aging experiment, ILSS were measured at room temperature ($27^{\circ}C$), high temperature ($100^{\circ}C$) and low temperature ($-100^{\circ}C$) to verify the effect of operation temperature. The MWNT and thin-ply shows good improvement of ILSS at ground condition especially with the thin-ply. And after LEO exposure large degradation of ILSS was observed at MWNT added composite due to the thermal cycle. And the degradation rate was much higher under the high temperature condition. But, at the low temperature condition, the ILSS was largely recovered due to the matrix toughening effect.

• Journal of Nutrition and Health
• /
• v.29 no.2
• /
• pp.166-176
• /
• 1996

Effect of fish oil feeding was investigated on morphological changes of thoracic aora in female rats after bilateral oophorectomy(OVX). Fifty four healthy female rats of Spraque-Dawley strain, were divided into sham group, OVX group and , OVX and fish oil feeding, group. Experimental animals were sacrificed at the end first, eighth week and sixteenth week after operation, thoracic aorta blood sample were collected. The results obtained were as follows ; 1) Total cholesterol and LDL-cholesterol contents in serum were significantly higher in the sham and OVX groups than fish oil feeding group. Serum HDL-cholesterol levels among three exjperimentnal group were lowest in the OVX group. 2) In the sham operation group, as experimental period prologed the endothelial cells were distorted round shape and enlarged, and the subendothelial layer was widened in tunical intima. The elastic lamina were disrupted in tunica group. In the fish oil feeding group, the endothelial cells and subendothelial layer in tunica intima, and the elastic lamina in tunica media were intance. From the present results, it was suggested that fish oil feeding may prevent the atherosclerotic changes in thoracic aorta and serum cholesterol induced by oophhorectomy in the rats.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.4
• /
• pp.313-315
• /
• 2010

Osteochondromas are common, benign tumors in the long bones, but osteochondromas are rare in the vertebrae. Most vertebral osteochondromas arise from the cervical or upper thoracic spine. However, lumbar osteochondromas have rarely been reported. In this report, a rare case of a lumbar osteochondroma arising from the spondylolytic L3 lamina in a 57-year-old woman is presented. She also had a ruptured disc and lumbar canal stenosis at L4-5-S1. The osteochondroma was completely removed and a posterior lumbar interbody fusion and instrumentation were performed. Considering the rarity of osteochondromas in the lumbar vertebrae, especially the L3 vertebra, it is possible that the pre-existing lumbar spondylolysis or spondylolisthesis was one of the factors affecting the occurrence or progression of the osteochondroma.

• Composites Research
• /
• v.12 no.1
• /
• pp.28-36
• /
• 1999

Thermal stress-induced failure in the free edge region of various thin carbon/epoxy composite laminates(1mm thick) has been investigated using the three-dimensional finite-element stress analysis, ultrasonic C-scan and microscopic observations. High thermal in-plane and interlaminar stresses were predicted in the interior layer near the free edge boundaries of the laminates. In the interior lamina, not in the skin lamina, of the thin laminates with lay-up of $[0_2/90_2]_s,\;[45_2/-45_0]_s,\;[0_2/60_2]_s$ treated by liquid $N_2$ immersion, many transverse matrix cracks took place due to thermal stress concentration, which agreed qualitatively with the above predictions.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.9 no.1
• /
• pp.17-21
• /
• 1998

Benign vocal fold lesions such as polyps, nodules and edema are known to be caused by vocal trauma such as voice misuse and/or abuse. Even though these lesions are known to be caused by the same etiology, phonotrauma, they show widely different clinical features and different responses to voice therapy. Previous studies suggested that benign vocal fold lesions represent disturbance in the balance of the extracellular matrix(ECM) constituents of the vocal folds. Collagen is one of the major constituents of ECM. Among collagens, fibrillar collagens are most important ones for maintaining the structural integrity. On the basis of gross morphology, vocal polyps wert divided into angiomatous one and edematous one, and nodules were divided into conical one and sessile one. In these four groups, the pattern of distribution of various fibrillar collagens(type 1, 2, 3, 5) was studied by immunohistochemical staining using paraffin embedded tissues. Within each group, differences among collagen subtypes were insignificant. In edematous polyp, collagens were sparsely dispersed in lamina propria by diffuse edema. In angiomatous polyp, collagens were displaced into submucosal layer by hemorrhagic space. In nodules, collagens were stained compactly in lamina propria. Quite different distributions of fibrillar collagens between polyps and nodules are thought to suggest that vocal polyps and nodules are totally different disorders in their pathophysiology.

• Korean Journal of Veterinary Research
• /
• v.60 no.3
• /
• pp.155-161
• /
• 2020

From 2006 to 2009, 50 pigs suspected of enteritis associated with porcine circovirus type 2 (PCV-2) (EAPC) were collected. Gross and histopathologic examinations and immunohistochemistry (IHC) were performed on the small intestine of 50 pigs. The pigs with EAPC were concentrated in grower pigs (68%), and diarrhea (84%) was the most common clinical sign. Grossly, the walls of the small intestine were thickened, and mesenteric lymph nodes were enlarged. The histopathologic features in the small intestine with EAPC were characterized by lymphoid depletion, histiocytic infiltration, and formation of basophilic grape-like inclusion bodies and multinucleated giant cells in gut-associated lymphatic tissue (GALT) and lamina propria. According to IHC, PCV-2 antigens were more intense and distributed widely in GALT (98%) than lamina propria (82%) of the small intestine. Co-infection with other enteric pathogens was detected in 26 pigs (52%). Twenty-four pigs (48%) were confirmed to be a PCV-2 single infection. Collectively, infected PCV-2 in the small intestine may induce an immunosuppressive status of individuals and then allow secondary co-infections in the digestive system. This study shows that PCV-2 can induce diarrhea and enteric lesions in pigs without a co-infection of other enteric pathogens.