• Journal of Periodontal and Implant Science
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• v.27 no.2
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• pp.317-328
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• 1997

Since laser therapy has been applied to dentistry, many dental practitioners are very interested in laser therapy on various intraoral soft tissue lesions including gingival hyperplasia and aphthous ulcer. The purpose of the present study was to determine the therapeutic effect and the harmful effect of a pulsed-Nd:YAG laser irradiation on human gingival tissue. In twenty periodontal patients with gingival enlargement, the facial gingival surface of maxillary anterior teeth was randomly irradiated at various power of 1.0W(100mJ, 10Hz), 3.0W(100mJ, 30Hz) and 6.0W(l50mJ, 40Hz) for 60 seconds by contact delivery of a pulsed-Nd:YAG laser(EN.EL.EN060, Italy). Immediately after laser irradiation, the gingival tissues were surgically excised and prepared in size of 1mm3. Subsequently the specimens were processed for prefixation and postfixation, embedded with epon mixture, sectioned in $1{\mu}$ thickness, stained with uranyl acetate and lead citrate, and observed under transmission electron microscope(JEM 100 CXII). Following findings were observed; l. In the gingival specimens irradiated with l.OW power, widening of intercelluar space and minute vesicle formation along the widened intercellular space were noted at the epithelial cells adjacent to irradiated area. 2. In the gingival specimens irradiated with 3.0W power, the disruption of cellular membrane, aggregation of cytoplasm, and loss of intercellular space were observed at the epithelial cells adjacent to irradiated area. 3. In the gingival specimens irradiated with 6.0W power, the disruption of nuclear and cellular membrane was observed at the epithelial cells adjacent to irradiated area. The ultrastructural findings of this study suggest that surgical application of a pulsed-Nd:YAG laser on human gingival tissue may lead somewhat delayed wound healing due to damage of epithelial cells adjacent to irradiated area.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.1-5
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• 2012

This study was conducted to elucidate the cause of micro-cracking in the exocarp of 'Jinmi' peach (Prunus persica). through the microscopic observation of fruit skin development in 4 varieties such as 'Jinmi', 'Kanoiwa Hakuto', 'Kawanakajima Hakuto', and 'Yumyeong'. Micro-cracking was noted in 59.1% of 'Jinmi', 30.6% of 'Kanoiwa Hakuto', 21.5% 'Kawanakajima Hakuto' and 6.4% of 'Yumyeong', respectively. The development of intercellular spaces, which increased rapidly with the fruit development, was easily observed at 69 days after full bloom. Histological studies revealed that the number of outer epiderm cell layers of 'Jinmi' was smaller than that of the other three cultivars, and thinner than the 'Kawanakajima Hakuto' and 'Yumyeong'. Moreover, 'Jinmi' exhibited smaller and flatter shapes in the sub-epidermal cell layer than those of the 'Kawanakajima Hakuto' and 'Yumyeong' at harvest season. Therefore, these results suggest that micro-cracking of 'Jinmi' fruit skin was due to poor-developed outer epidermis and well-developed intercellular spaces just under exocarp as compared with other varieties.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.237-246
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• 1995

In this study, the callus was induced and regenerated from the immature embryo and ultrastructural characteristics of developmental stages in Citrus junos SIEB, were investigated. The yellowish callus was induced by 5 to 6 week of culture of citrus. In proliferation callus after 6 weeks of culture, large vacuole was formed by fusion between adjacent small ones. In the non-embryogenic callus cultured for 12weeks, re-differentiated cells of callus showed the large nucleus with globular nucleus and amyloplast with large size of starches. In the embryogenic callus cltured for 14-16 weeks, the active exocytosis occurred in cells, secretory vesicles appeared on cell membrane and small particles from cytoplasm were released to intercelluar space. In the embryogenic callus cultured for 24 weeks, a sperical type of chloroplast bounded on cytoplasm by double membrane and typical grana was dispersed equally among matrix. In the normal plantlet after 26 weeks of culture, a lot of vessels and companion cells apperaed in the leaf cell of plantlet. In the normal plantlet after 30 weeks of culture, the immature leaf showed many small companion cells, sieve tubes and central vacuole. Also, the secondary vacuole protruded into the central vacuole and elongated chloroplasts near plasma membrane. In the matured plant habituated on the soil, palisada tissue composed of orderly arranged cells contained the nucleus in the center of the cell and large vacuoles on either side of the nucleus.

• The Journal of Internal Korean Medicine
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• v.22 no.2
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• pp.145-160
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• 2001

Objectives : The purpose of this investigation is to evaluate the effect of Geupoongjibo-dan Extracts on Reversible Forebrain Ischemia in Mongolian Gerbils. Methods : The change rate of water content in cerebral tissues, the numercal change of the CA1 pyramidal neuron in the hippocampus, the change of delayed neuronal death(necrosis apoptosis) through light microscopy, the reactivity change of glycoprotein in neuronal membrane and the ultrastructural change of pyramidal neuron through electron microscopy caused by dalayed neuronal death were investigated. Results : 1. The change rate of water content in the normal group showed 78.90% on the third day, and 79.12% on the seventh day after an attack of ischemia. The rate in the control group showed 82.25% and 85.13%, respectively. The rate in the sample group showed a significant decrease: 81.72% and 83.66%. 2. Light microscopy revealed that the cells, continuous and systematic forms in the pyramidal cells of hippocampus, changed into discontinuous and unsystematic forms in the normal group when compared with the control group. The cells were less damaged in the sample group. 3. The mean of the numerical change of the CA1 pyramidal neurons in the hippocampus was 104 in the normal group. The mean of the control group was decreased to 27. The mean of the sample group was 44. 4. TUNEL staining examination reveals that the whole part of the hippocampus of the normal group had negative reactivity. As far as CA1 pyramidal neurons in the hippocampus, the control group had positive reactivity. The sample group was more positive than the control group. 5. Electron microscopy reveals that the ischemic injury of the control group had both necrotic and apoptotic morphology. The sample group was less necrotic, and more apoptotic morphology than the control group. 6. Lectin histochemisrical examination reveals that the normal group had positive reactivity to PNA and SBA in interneuron, and weak positive reactivity to WGA Con A LCA in intercelluar space. The reactivity to PNA and WGA decreased in the control group. The reactivity to PNA and WGA tended to increase in the sample group. Conclusions : The data shows that the effect of Geupoongjibo-dan Extracts on Reversible Forebrain Ischemia in MG is a significant result.