• The Korea Journal of Herbology
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• v.22 no.2
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• pp.109-114
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• 2007

Objectives : A morphological classification among Sinomenium acutum, Cocculus trilobus and Aristolochia fangchi was made through microscopic observation. Method : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Result : 1. Fiber bundles of pericycle in S. acutum are like a crescent moon, stone cells were found among fiber bundles, and starch grain and raphides of calcium oxalate were included in parenchyma. 2. C. trilobus has the fiber bundle of pericycle resembling a crescent moon, but does not have the raphidesof calcium oxalate. 3. A. fangchi has the raphides of calcium oxalate, but does not have the fiber bundles of pericycle. 4. Stems and roots of S. acutum arc mostly similar, but only stems have the pith. Conclusion :' C. trilobus and A. fangchi can be distinguished from each other by the fiber bundles of pericycle and the raphides of calcium oxalate.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.24-34
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• 1995

The purpose of this study was to compare effects of demineralization of citric acid and tetracycline HCI on periodontally involved root surface. Twelve periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning with citric acid and tetracycline HCI were carried and the teeth were processed scanning electron microscopic observation.The results were as follows: The scaled root surface was covered by much debris and calculus. The effect of demineralization of citric acid and tetracycline HCI was more reduced on scaling group than root planing group, because of hypermineralization of cementum surface and demineralization effect on root surface of tetracycline HCI showed tendency to reduction. The root planed group displayed more smooth root surface than scaling group, the surface was covered by smear layer, thus no exposure of dentinal tubule opening and collagen fiber, especially after root planing, citric acid and tetracycline HCl treated group showed exposure of dentinal tubule and collagen fiber, thus it was thought that new connective tissue attachment could be acquired.

• BMB Reports
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• v.30 no.3
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• pp.167-172
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• 1997

The yeast Saccharomyces cerevisiae, mutant CH117, shows a drug-hypersensitivity (dhs) to cycloheximide, bleomycin, actinomycin D, 5-fluorouracil. nystatin, nigericin and several other antibiotics. CH 117 was also temperature-sensitive (ts). being unable to grow at $37^{\circ}C$ and secreted more invertase and acid phosphatase into the medium than the parent yeast. CH117 grows very slowly and the cell shape is somewhat larger and more sensitive to zymolyase than the wild type cells. Light microscopic and electron microscopic observation also revealed abnormality of the mutant cell wall. These characteristics indicate that CH117 has a defect in an essential component of the cell surface and that the cell wall which performs barrier functions has become leaky in the mutant. We screened a genomic library of wild type yeast for clones that can complement the mutation of CH117. A plasmid, pCHX1, with an insert of 3.6 kilobases (kbs) could complement the dhs and ts of CH117. Deletion and subcloning of the 3.6 kb insert showed that a gene for the complementation of mutant phenotypes was located in 1.9 kbs Puvll-Hindlll fragment.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.125-129
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• 1993

An acute fatal infectious disease in rabbits has been outbroken in Korea since 1985. This disease has been characterized as an acute hepatitis caused by viruses. However, viral pathogenesis in rabbit viral hepatitis leading to sudden death remain unclear. This report dealt with the electron microscopic findings on the spleen of experimentally infected rabbits, because spleen is one of the affected organs which have high titer of virus by a haemagglutination test. A typical crystalline array of virus was not found in the splenic cells of infected rabbits with acute hepatitis. Virus-like particles were seen within the phagosome of macrophages of the spleen. Ultrastructural changes in the spleen were severe with the lapse of time after inoculation. From these results, virus-like particles in the spleen were supposed to be phagocytosed by macrophage during viremia, while active replication of virus occurred in the liver. It was concluded that sudden death in this viral disease was caused by hepatic coma and/or circulatory disturbance.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.24-33
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• 1987

This study was executed to investigate scanning electron microscopic characteristics of Korean Rhus lacquer coats. With the unrefined coat, distilled water, sodium hydroxide, acetic acid, ethyl alcohol, cold-check test, and accelerated weathering were performed after refining treatment. These treated lacquer coats were discussed through observation by scanning electron microscope and the obtained results were summarized as follows: 1. Compared with unrefined coat, the refined coat of Korean Rhus lacquer showed more even surface with regular distribution of dispression. 2. Korean Rhus lacquer coat heated at $120^{\circ}C$ for 3 hours revealed no observable difference irrespective of refining and unrefining. 3. Korean Rhus lacquer coat treated by distilled water, sodium hydroxide, acetic acid. ethyl alcohol, cold-check test. and ultraviolet radiation showed significant characteristics compared with untreated coat. Especially. large deformation and checkings were observed by cold-check test and ultraviolet radiation respectively. 4. The Korean Rhus lacquer coat radiated by ultraviolet ray showed 0.11 duller and 1.41 brighter than non-radiated coat through color difference calculator.

• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.457-466
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• 1992

An 11 years old Irish Setter bitch was euthanlzed and necropsied because of clinical findings such as severe purulent nasal discharge and formation of large tumor mass, 8 ${\times}$8cm in size, in the abdominal cavity. A complete unilateral mastectomy had been carried out twice 14 and 22 months before necropsy. The surgically removed masess of the mammary glands had been diagnosed as malignant mixed tumor in each time. Grossly, tumor masses were observed in nasal cavity, infralumbar lymph node, lung, abdominal cavityn and brain. Microscopic findings of the surgically removed masses consisted of tumor epithelial cells, tumor hyaline cartilage-like structures and abundant connective tissues. The mass of the lymph node had similar microscopic features to those of the original malignant mixed tumor of the mammary glands. The tumor osseous tissue and osteoid were observed in the abdominal cavity, lung, and brain. Myoepithelial cells were frequently found on association with the metastatic tumors. From the results, it was concluded that malignant mixed tumor of the mammary glands metastasized to the infralunbar lymph node, abdominal cavity, lung and brain. In addition, the observation in this study supported two theories at the same time that the bone in malignant mixed tumor arises by endochondral ossification of the cartilage formed by the myoepithelial cells and arises by intramembranous ossification of stromal connective tissue or transformed myeopithelial cells. Solid carcinoma of the nasal epielia and granulosa cell tumor were also diagnosed in a mass of the nasal cavity and of the ovaries respectively.

• Biomedical Science Letters
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• v.25 no.4
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• pp.367-371
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• 2019

In this study, the author observed the fungal characteristics of T. verrucosum which is commonly known as the cattle ringworm fungus in the farms of Hoengseong, Gangwon-do. After isolating 20 strains of T. verrucosum from cattle, they were cultured on SDA, PDA media and the fungal characteristics were concluded through visual observation of the colonies, microscopic findings, hair perforation test and urease test. The size of the colonies cultured on SDA media at 37 C was on an average 5 mm at 1 week, 33 mm at 2 weeks, 42 mm at 3 weeks and 58 mm after 4 weeks. Observing the characteristics of the colonies, 17 strains of T. album showing central bold radial folds, 2 strains of T. ochraceum having l throughout the colonies and 1 strain of T. discoides with rapid growth rate and gray-white cotton patterns were found. On microscopic observations of the cultured colonies on SDA, PDA media, macroconidia and microconidia were not found in T. verrucosum and hyphae and chlamydospore were only seen in T. album types. Out of 20 strains of T. verrucosum, hair perforation test was positive on only 3 strains and urease test was positive on all of the 20 strains.

• Journal of Microbiology
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• v.37 no.1
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• pp.27-34
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• 1999

Two fractions with unusual antifungal activity that suppress asexual sporulation of several fungi were obtained from culture filtrate of Pseudomonas aeruginosa and were partially purified through the repeated silicagel flash column chromatographies. The sporulation-suppressive actions of these fractions in Aspergillus nidulans, Rhizopus stolonifer, and Coprinus cinereus, were analyzed by light and electron microscopes. The germination ability of the spores produced in the presence of these fractions were also checked to determine the persistent effects of these antifungal substances on the next generation. Light microscopic observation of developing sporangia of R. stolonifer grown in the presence of both fractions revealed that the significant number of sporangia failed to reach maturity, and frequently, uncontrolled growths of hyphae and rhizoids from the sporangiophores were found. In A. nidulans addition of these fractions appeared to cause different classes of morphological abnormality in conidia development, which included aborted formation of conidiogenous cells from the apex of conidiophores and enhanced hyphal growths either at the tip or middle of the conidiophores. Germination abilities of spores obtained from the cultures grown in the presence of antifungal fractions were 40∼60% in Aspergillus, 50∼80% in Coprinus (thallic spores), and 30∼40% in Rhizopus compared to those of normal spores.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.417-424
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• 2019

Melanose, caused by Diaporthe citri, is one of severe diseases in citrus, a major economic resource in Jeju island. To reduce the usage amount of organic synthetic fungicide, bio-sulfur was tested as an alternative chemical to control citrus melanose in the present study. Direct antifungal activity of bio-sulfur against D. citri was determined through in vitro experiment using artificial nutrient media. Disease severity of melanose on bio-sulfur pretreated citrus leaves was lower than that on untreated ones. To illustrate the mechanism of disease suppression by bio-sulfur, infection structures were observed with a fluorescent microscope and a scanning electron microscope. In fluorescent microscopic observation, most conidia rarely germinated. In addition, hyphal growth on leaves pretreated with bio-sulfur was inhibited compared to that on untreated ones. In scanning electron microscope images of bio-sulfur pretreated leaves, surfaces of most conidia were shrunk while hyphae were morphologically changed and frequently branched. Such microscopic observations were also found for leaves pretreated with a commercial fungicide Dithianon. These results suggest that bio-sulfur may be used to control citrus melanose as an environment friendly alternative to organic synthetic fungicides

• Applied Microscopy
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• v.52
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.