• Applied Microscopy
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• v.30 no.3
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• pp.311-319
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• 2000

The gill morphology and ultrastructure of the fleshy shrimp, Penaeus chinensis were investigated by light and electron microscopy. Fleshy shrimp has dendrobranchiate gills. Gill has a longitudinal septum dividing them into afferent and efferent channel. Each gill lamella is covered by multi-layered thin cuticle of different electron density. The lamella basal cell is squamous and contains cytoplasm of electron dense. Simple epithelial layer consists of squamous epithelium contained large nucleus. The lamella pillar structures are characterized by the axial microtubules and lateral membrane interdigitations Secretory cells of AB-PAS negative are multicellular gland. In active gland each cell boundary is not apparent and the cytoplasm contains smooth endoplasmic reticula, mitochondria, membrane-bounded secretory vesicles of low electron density and granular resettes. In inactive gland each cell boundary is apparent and the cytoplasm is occupied with numerous small granules of electron dense. The well-developed rough endoplasmic reticula and Golgi apparatus are observed in the unicellular gland of alcian blue positive.

• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.185-192
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• 1986

Upon germination, a conidium was septated in accordance with number of germ tubes. The percentages of ppressorial formation were not different between the resistant cultivars (Kumchang NO. 2 and Hongilpum) and the susceptible cultivars (Haneulcho and Saegochu). Appressorial form was various such as round, elliptic or star-shapped. The maximum number of appressoria was shown at 12 hours after inoculation. By 24 hours fter inoculation, hypersensitive tiny brown lesions were observed on the leaves and fruits of the resistant cultivars. Epidermal cells under cuticle layer of the resistant Kumchang NO. 2 fruit showed severe plasmolysis, while on the susceptible cultivars, the lession was largely extended to following incubation. Subcuticular infection hyphae were profusely colonized in the disintegrated tissues. Acervuli and setae on the stromatic structure ere formed at 96 hours. The infected seed coat was not only severely collapsed, but also infection hyphae were observed on the disintegrated seed coat, resulting severe plasmolysis of nucellus and embryo.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.31-35
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• 2004

This experiment was performed to observe morphological changes in rice leaf tissue caused by a successive UV-B radiation. Effect of UV-B radiation on the structural alteration of tissue was not visually found, however, Photosynthate containing phosphate was sharply reduced in proportion with an increase of UV-B radiation. Fundamental components of cuticle layer were being degraded after 6 h of UV-B radiation compared to the control. UV-B-induced mesophyll cell appeared altered because of water stress, the shape of chloroplast appeared to be considerably shrunk and chloroplast thylakoid membranes were severely destructed. Primary cell wall of UV-B-stressed tissue was entirely scattered or disappeared, and the secondary cell wall due to lignin synthesis and deposition resulted in being thickened, almost 2-times, compared with the control.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.569-572
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• 2013

Dirofilariasis is a rare disease in humans. We report here a case of a 48-year-old male who was diagnosed with pulmonary dirofilariasis in Korea. On chest radiographs, a coin lesion of 1 cm in diameter was shown. Although it looked like a benign inflammatory nodule, malignancy could not be excluded. So, the nodule was resected by video-assisted thoracic surgery. Pathologically, chronic granulomatous inflammation composed of coagulation necrosis with rim of fibrous tissues and granulations was seen. In the center of the necrotic nodules, a degenerating parasitic organism was found. The parasite had prominent internal cuticular ridges and thick cuticle, a well-developed muscle layer, an intestinal tube, and uterine tubules. The parasite was diagnosed as an immature female worm of Dirofilaria immitis. This is the second reported case of human pulmonary dirofilariasis in Korea.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.330-337
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• 1993

A bacterium, pathogenic to Nilaparvata lugens Stal. causing high mortality in 3~5 days, were selected and identified as Serratuz marcescens biotype A2a which is not a nosocomlally infective strain. In order to determine the characters of Serratia marcesce'1lS associated with insect pathogenicity, Tn5 mutagenesis was carried out by conjugating with E. coli pJB4J1. Transconjugants were plate-assayed for missing chitinase, protease and DNase activity. A protease negative mutant was selected for missing JOseet pathogenicity. SEM and TEM revealed the presence of bacterial cells in the epithelial tissue of inner abdomal tissue of the hypodermic layer of abdomen. Such a colonization was limmited to the subjacent tissue inside the intacL cuticular epidermis. These observation supported our result of pathogenicity tests of transconjugants.

• Journal of Convergence for Information Technology
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• v.10 no.5
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• pp.216-223
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• 2020

We investigated the morphology of the scalp hair shaft from the base to the distal end of the newborn hair and the ratio of the longitudinal axis diameter of the scale exposed to the surface of the hair to the diameter of the hair by scanning electron microscopy(SEM). Neonatal hair was observed to taper from the area adjacent to the scalp toward the end of the hair. In this study, as the thickness of the hair increases, the ratio of the long axis diameter of the exposed scale becomes relatively small, but the long axis diameter of the exposed scale on the surface of the hair is similar in length regardless of the thickness of the hair. In conclusion, it was confirmed that the major axis diameter of the scales exposed to the surface of fine or thick hair does not change significantly.

• Applied Microscopy
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• v.37 no.3
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• pp.175-183
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• 2007

The Drosophila retinal cell is widely used to study cell development and cell signaling processes. In the past decades, conventional chemical fixation had been used to study the structure of retinal cells in Droscphila. Rapid freezing methods are superior to chemical fixation methods due to their fixation speed. Some Drosophila tissues, such as the eyes, should not be freezed due to their surrounding cuticle layer. Therefore, in the case of the Drosophila retina, the benefits of high pressure freezing and freeze substitution (HPF-FS) had not been verified. In this study, a retinal cell from Drosophila melanogaster had been studied by using the HPF-FS method. Compared to chemical fixation, the preservation of the cytoplasm in the HPF-FS sample was improved on the whole. The HPF-FS cell membranes were smoother than that of chemical fixation. In addition, HPF-FS preserved the mitochondria structures very well. These results of the present study suggest that HPF-FS is superior to other fixation methods for the preservation of the retinal cell structure.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.1-8
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• 1993

This study was conducted to find the potential of polyethylene wrapping, ethylene scrubber, and Prolong as postharvest application in oriental pear, 'Niitaka'. Polyethylene film($30{\mu}m$) wrapping greatly reduced weight loss during storage for 80 to 110 days but the occurrence of dark skin browning became severe because of high humidity in polyethylene bags. Also, in long term storage of 110 days, parts of fruit developed uneven skin disorder or rupturing of cuticle layer. Ethylene scrubber reduced uneven skin disorder but no beneficial effect was found on the prevention of core breakdown. This indicates that the ethylene scrubber probably be effective when applied dicrectly to the storage room. The immediate application of Prolong to harverted fruit was confirmed not to be useful as postharvest treatment in 'Niitaka' pears.

• Journal of Plant Biology
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• v.37 no.3
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• pp.309-316
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• 1994

To make regional comparisons of water status of pitch pine, the temporal changes of water status in pitch pine were investigated at different areas; urban Seoul (heavily polluted area), surburb of Seoul (lightly polluted area), and rural area (control). The effects of air pollutants, acid rain and chemical properties of soil on water deficit in pitch pine were also investiaged. Water content of needles growing at polluted areas were usually lower than that at unpolluted area. Water saturation deficit of needles growing at polluted areas were usually higher than that at unpolluted area especially in dry season. These results indicated that water in needles growing at polluted areas were usually more deficient than that at unpolluted area, and were more deficient in April than other months. At polluted areas, the older the needles were, the more quickly transpirated the water in the needle was. At unpolluted areas, however, water in old needles was not so quickly transpirated as those at polluted areas. Water potential of needles of pitch pine seedlings treated with simulated acid rain (SAR) of pH 3.5 decreased more quickly than that of needles treated with SAR of pH 5.6. Loss of water through epicuticular layer was greater in the following order: magnesium deficiency＋100 $\mu$M aluminium>100$\mu$M aluminium>magnesium deficiency>control. In addition to Mg deficiency and Al toxicity, growth decline of pitch pine widely occurring in polluated Seoul could to a large extent be due to cuticle degredation and abnormal vertical distribution of fine roots, which lead to water stress, particularly in dry seasons.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.1-7
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• 2014

The possibility of using hyphomycete fungi as suitable biocontrol agents against greenhouse whitefly has led to the isolation of various insect pathogenic fungi. Among them is Beauveria bassiana, one of the most studied entomopathogenic fungi. The objective of this study was to use B. bassiana M130 as an insecticidal agent against the greenhouse whitefly. M130 isolated from infected insects is known to be a biocontrol agent against greenhouse whitefly. Phylogenetic classification of M130 was determined according to its morphological features and 18S rRNA sequence analysis. M130 was identified as B. bassiana M130 and showed chitinase (342.28 units/ml) and protease (461.70 units/ml) activities, which were involved in the invasion of the host through the outer cuticle layer, thus killing them. The insecticidal activity was 55.2% in petri-dish test, 84.6% in pot test, and 45.3% in field test. The results of this study indicate that B. bassiana has potential as a biological agent for the control of greenhouse whitefly to replace chemical pesticides.