• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.365-369
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• 2012

Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae treated with mannose for 20 cycles exhibited larger vacuoles occupying the most area of the amoebic cytoplasm in comparison with the control group amoebae and glucose-treated amoebae. Mannose-selected amoebae exhibited lower levels of binding to Chinese hamster ovary (CHO) cells. Exogenous mannose inhibited >50% inhibition of amoebae (control group) binding to CHO cells. Moreover, exogenous mannose inhibited amoebae (i.e., man-treated) binding to CHO cells by <15%. Mannose-selected amoebae exhibited significantly decreased cytotoxicity to CHO cells compared with the control group amoebae, 25.1% vs 92.1%. In phagocytic assay, mannose-selected amoebae exhibited significant decreases in bacterial uptake in comparison with the control group, 0.019% vs 0.03% (P<0.05). Taken together, it is suggested that mannose-selected A. castellanii trophozoites should be severely damaged and do not well interact with a target cell via a lectin of MBP.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.38-50
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• 1998

Laser cutting tests were conducted to investigate the laser cutting characteristics of solid woods such as 25mm-thick white oak(Quercus acutissima) and maple(Acer mono), and wood-based panels such as 15mm-thick medium density fiberboard and particleboard. Test variables were laser power, cutting speed, grain direction, and moisture content. Specific cutting energy was measured and the qualities of cut surface were estimated in constant laser power. Specific cutting energy of white oak was larger than that of maple, and specific cutting energy of medium density fiberboard was smaller than that of particleboard. For both white oak and maple, specific cutting energy of green wood was smaller than that of air-dried wood because weight loss of moisture evaporation in green wood was larger than that in air-dried wood. In laser-cut surface, wood cells were not deformed and damaged, but in circular saw-cut surface fibers were pushed out and cut, and wood cells were deformed severely. However, mechanical surface roughness of saw-cut surface was smoother than that of laser-cut surface because of the existence of undeformed cell cavity in laser-cut surface.

• Archives of Reconstructive Microsurgery
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• v.25 no.1
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• pp.12-14
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• 2016

In cases of replantation, accurate closure of all structures, including bone, tendons, arteries, nerves, and veins is essential. Among these, the vein is a weaker structure and is damaged severely in most amputation cases. After fixation of bone, repair of tendons, nerves, and arteries, surgeons often experience difficulty in performing venous anastomoses. We found that in such cases, venous anastomosis is easy to perform using an additional incision after closure of the original wound. In a 33-year-old male patient with amputation of all four fingers at the metacarpophalangeal joint level, venous anastomoses were performed with dorsal veins using additional incisions after completion of the fixation of bones and repair of all other structures and closure of the skin due to surgical site tension.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.83-91
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• 1994

Stem tissues of tomato plants (cv. Kwanyang) inoculated with Phytophthora capsici were examined by light and electron microscopy to compare early cytological differences between comaptible and incompatible interactions of tomatoes with the fungus. Twenty four hours after inoculation, the compatible isolate S 197 colonized severely the epidermis, cortex, and xylem vessels of stem tissue, whereas only few fungal cells colonized the stem tissues inoculated with the incompatible isolate CBS 178.26. Fragmented plasma membrane, distorted chloroplast, degraded cell wall, remnants of host cytoplasm were early ultrastructural features of the damaged host cell observed both in the compatible and incompatible interaction, a number of vesicles were distributed in the space between fungal cell walls and plasma membrane. The degradation of host cell walls by P. capsici was more pronounced in the compatible than the incompatible interactions. The incompatible interactions of tomato cells with P. capsici were characterized by formation of host cell wall apposition in the cortical parenchyma cells, indicating that the apposition of electron-dense material from the host cell walls may function as a plant defense reaction to the fungus. The fungal cells encased by wall appositions had abnormal cytoplasm and separated plasma membranes. The haustorium which formed from the fungal hyphae did not further penetrate through the host wall apposition and cytoplasmic aggregation, especially in the incompatible reactions. In contrast, the haustorium of the compatible isolate S 197 was not encased by wall appositions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.235-242
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• 2004

Bridge Management System (BMS) requires a more objective condition assessment over the lifespan of a given bridge. Thus, a quantitative assessment model of resistance capacity was developed here to meet the requirement for deteriorated concrete bridges. The model focuses on damage mechanisms of concrete bridges deteriorated by traffic loads and environment factors such as chloride and carbonation attacks. Also, it was applied to a typical concrete slab bridge which was severely damaged due to both load and environmental conditions. It was shown that the proposed quantitative model simulates well the deterioration level considering the two damage criteria.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.6-10
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• 2005

Optimal extraction conditions such as pressures, temperatures, and modifiers on glycyrrhizin extraction from licorice were investigated using supercritical $CO_2\;(SC-CO_2)$ at 3 mL/min flow rate. Morphology of licorice tissue, after glycyrrhizin extraction, was examined by SEM, and absolute density ($g/cm^3$) measurement and glycyrrhizin content were determined by HPLC. Pure $SC-CO_2$ had no effect on glycyrrhizin extraction, but recovery of glycyrrhizin ($32.66{\pm}0.77%$) was enhanced when water was used as modifier. The highest recovery was $97.22{\pm}2.17%$ when 70% (v/v) aqueous methanol was added to 15% (v/v) $SC-CO_2$ at 50 MPa and $60^{\circ}C$. Under optimal extraction conditions, 30 MPa pressure and $60^{\circ}C$ heating temperature, glycyrrhizin recovery reached maximum ($102.67{\pm}1.13%$) within 60 min. Licorice tissue was severely damaged by excessive swelling, and absolute density of licorice residues was highest when aqueous methanol was used as a modifier.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.5
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• pp.353-360
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• 1990

The bacterium Edwardsiella tarda was injected into healthy snakeheads (Channa argus) in order to prove the causative agent of ascite. The bacterium dominantly isolated from 2 cultured ascite snakeheads was injected into fish by the dose of $5\times10^6$ CFU/ 0.25ml, but the same dose of $0.65\%$ physiological saline was injected into the each control. The injected fish was divided into 4 groups such as intraperitoneal, intramuscle, control intra-peritoneal and control intramuscle according to their injection points. Each was composed of 10 healthy snakeheads respectively. Ascites and haemorrhagic ulcers became distinct 5 days after injection, but controls did not show any abnormal symptoms during the experimental period. Edwardsiella tarda was reisalated out of the injected fish's ascite, liver, kidney, spleen and haemorrhagic ulcer on the skin. Regardless of the injecting methods, liver was necrotized more severely than any other internal organ, but both the glomeruli of kidney and spleen were considerably damaged. Necrosis of muscle and a number of leucocytes were observed at the ulcerous region of the intramuscular injected fish. It is concluded that judging from the above results the Edwardsiella tarda is a causative agent to cause ascite in snakehead.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.176-185
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• 2007

This study investigated native Rubus coreanus community in Korea(Ulleung island and Jeju island excepted). The quadrates were located in the middle of the native Rubus coreanus habitats. As the result of the research, the patter of native habitats were found to be divided into mountain roadsides, second-transition rents, severely damaged rents in the mountain, strictly protected regions, and environmentally harsh regions. The research revealed 218 taxa in total, in which 71 families, 165 genera, 18 varieties,1 forma and 199 species were checked in the flora of the native Rubu coreanus habitats. In this flora, the perennial plants appeared in as much as 80.74% proportion and appearance-frequency of the compositae was highest, accounting for 7.80%.

• Mycobiology
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• v.42 no.4
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• pp.391-396
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• 2014

In the past two decades, European ash trees (Fraxinus spp.) have been severely damaged due to ash dieback disease, which is caused by the fungal species Hymenoscyphus fraxineus (Chalara fraxinea in the anamorphic stage). Recent molecular phylogenetic and population genetic studies have suggested that this fungus has been introduced from Asia to Europe. During a fungal survey in Korea, H. fraxineus-like apothecia were collected from fallen leaves, rachises, and petioles of Korean ash and Manchurian ash trees. The morphological and ecological traits of these materials are described with the internal transcribed spacer rDNA sequence comparison of H. fraxineus strains collected from Korea, China and Japan.

• Transactions of Materials Processing
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• v.22 no.4
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• pp.183-188
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• 2013

Scroll compressors are widely used in air conditioning systems and in automobiles due to their low pressure loss, minimal vibrations, and light-weight. Open-die forging with back pressure is used to forge the rotating scroll, and it requires special care since the forging die can be severely damaged at the fixed end of the spiral cavity similar to a fracture of a cantilever beam. To overcome the inevitable weakness of the forging die due to such damage, an innovative design is necessary. In this study, structural analysis using the finite element method was conducted to determine the reason for the fracture of the forging die. A novel design to avoid stress concentrations and vertical deflection, causing serious damage to the die, is suggested.