• Korean Journal of Microbiology
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• v.28 no.1
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• pp.47-54
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• 1990

In order to investigate physiological characteristics of fusants by interspecific protoplast fusion of the genus Cellulomonas, protoplasts of Cellulomonas flavigena NCIB 12901 and Cellulomonas bibula NCIB 8142 were fused and cell wall regenerated. To give gene maker, C. bibula was treated with 500 ug/ml NTG for 1 hr and arginine requiring auxotrophic mutants were isolated. Protoplasts of the genus Cellulomonas were obtained by treatment with $600{\mu}{\textrm{g}}$/ml lysozyme, and 0.5M sorbitol was optimal for osmotic stabilizer on protoplast fromation. Protoplast fusion was enhanced by 40% PEG)M.W.6,000) containing 25 mM $CaCl_{2}$ at $30^{\circ}C$ for 30 min and fusion frequency between C. bibula and C. flavigena was $5\times 10^{-4}$. Processes of protoplast formation, cell wall regeneration and protoplast fusion were obsdrved by scanning electron microscope. By comparing enzyme activities of cellulase, exocellobiohydrolase, .betha.-glucosidase of the parent strains of Cellulomonas with those of thier mutants and fusants, fusants with increased enzyme activity were obtained. By the studies on nutritional requirement, antibiotic resistance, cellulolytic enzyme activities, type of peptidoglycan and motility of two mutants and fusants, fusants were proved to be recombinant of both mutant strains.

• Archives of Plastic Surgery
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• v.35 no.6
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• pp.743-747
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• 2008

Purpose: Malignant changes of Marjolin's ulcer arising from chronic burn scar are rare. The majority of them are squamous cell carcinoma and basal cell carcinoma. Malignant fibrous histiocytoma is a deep seated pleomorphic sarcoma, which occurs principally as a mass of the extremities, abdominal cavity, or retroperitoneum in adults. Methods: We report a 58-year-old male patient who was admitted due to $3.5{\times}5cm$ chronic ulceration of anterior chest wall on the center of old burn scar. His scar had been occurred by boiling oil and treated with conservative treatment 45 years ago. Preoperative punch biopsy showed suspicious malignant changes and contrast enhanced chest CT showed well-defined, irregular shape enhancing lesion on anterior chest wall without intrathoracic metastasis. Results: The tumor was widely excised and defect was covered with skin graft without infection, necrosis and any other complication. The pathologic findings are compatible with malignant fibrous histiocytoma(storiform - pleomorphic type). The patient underwent 3 cycles of chemotheraphy. Although distant metastasis to the lung developed 6 months later and the patient died 9 month later, there was no local reoccurrence. Conclusion: Aggressive and early excision is needed because malignant fibrous histiocytoma has characteristics of high malignancy with a propensity for early and distant spread. Furthermore, the patient's education about disease entity and postoperative regular follow-up for local recurrence or metastasis is very important. To prevent malignancy from secondly healing burn scar, early skin graft is recommended for patients with deep second degree burn.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1529-1535
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• 1999

This study was done for the extraction of carotenoid from Phaffia rhodozyma in combination with PEF and other methods. PEF treatment conditions were $30{\sim}80\;kV/cm,\;100{\sim}1000\;Hz\;and\;100{\sim}1000\;{\mu}s$. In order to increase permeability of yeast cell wall, various methods such as freezing-thawing, mechanical treatment, solvents, permeabilizing agents, and yeast cell wall lytic enzyme were used before PEF treatment. The combination of PEF $(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ and conventional methods such as solvent and freezing-thawing pre-treatment had no effects on the extraction of carotenoid pigments. The extent of extracted carotenoid by the PEF $treatment(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ combined with yeast cell wall lytic enzyme and mechanical pre-treatment increased 52% and 69.8% more than the sum of that by each treatment, respectively. Permeabilizing agents, especially Tween 20 and capric acid, enhanced the extraction efficiency of carotenoid pigments from P. rhodozyma cells. These results indicated the feasibility for the continuous extracting carotenoid pigments from P. rhodozyma by PEF combined with other permeabilizing methods.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.484-489
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• 2004

Bifidobacterium species isolated from infant feces were fractionated into cell wall, cytosol, and extracellular preparations of culture broth, and each fraction was examined for Peyer's patch-mediated bone marrow cell proliferation activity in vitro. Cell wall preparation of B. bifidum SL-21 (CWP) showed the highest bone marrow cell proliferating activity dose dependently, and enhanced production of cytokines, such as hematopoietic growth factor (GM-CSF), IL-2, and IL-6, in culture supernatant of Peyer's patch cells, After treatment with lysozyme, CWP was fractionated, among which intermediate molecular-weight fraction (30-50 kDa) showed significantly high bone marrow cell proliferating activity. These results suggest CWP of B. bifidum SL-21 effectively activates lymphocytes in Peyer's patch, and several cytokines, possibly playing important role in enhancement of systemic immune system, were produced by activated lymphocytes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.10a
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• pp.15-20
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• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.240-249
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• 2009

HRSG(Heat Recovery Steam Generator) building is large enclosed structure included various heat sources. This building needs to appropriately keep internal air temperature for worker's safety and operability of control devices. In this study, ventilation analysis is performed to find proper ventilation method for temperature control. Ventilation analysis is applied to entire internal space of the building with standard $k-{\varepsilon}$ model and enhanced wall treatment because of large size of the structure. And the ventilation method is considered natural and forced convection with two louver structures which has damper or not. Louver structure affect directly air circulation in near HRSG and lower region of the building. Forced ventilation provides strong inertial force which cause upward airflow. From the analysis, it is found that design requirement for internal air temperature can be satisfied by forced ventilation method with louver structure without damper.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.386-392
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• 2010

The multiphase simulation of a liquid jet in a lab-scale ramjet combustor with a plain orifice type injector was studied with a commercial CFD tool, a FLUENT program. The objectives of the current study are to analysis the breakup characteristics of a hexane liquid jet in a cross flow and to derive the correlation between flow conditions and drag force coefficients in a test section. From the result of a numerical simulation, we concluded that a DPM and Realizable $k-{\varepsilon}$ model with an enhanced wall treatment were available to simulate the multiphase flow simulation. And the calculated distribution of a hexane vapor concentration was well-matched with experimental results.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.186-192
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• 2021

The roots of Korean ginseng (Panax ginseng) have a long history of usage as a medicinal drug. Ginsenosides, a group of triterpenioid saponins in ginseng, have been reported to show important pharmacological effects. Many studies have attempted to identify the ginsenoside synthesis pathways of P. ginseng and to increase crop productivity. Recent studies have shown that exogenous gibberellin (GA) treatments promote storage root secondary growth by integration of the modulating cambium stem cell homeostasis with a secondary cell wall-related gene network. However, the dynamic regulation of ginsenoside synthesis-related genes and their contents by external signaling cues has been rarely evaluated. In this study, we confirmed that GA treatment not only enhanced the secondary growth of P. ginseng storage roots, but also significantly enriched the terpenoid biosynthesis process in RNA-seq analysis. Consistently, we also found that the expression of most genes involved in the ginsenoside synthesis pathways, including those encoding methylerythritol-4-phosphate (MEP) and mevalonate (MVA), and the saponin content in both leaves and roots was increased by exogenous GA application. These results can be used in future development of biotechnology for ginseng breeding and enhancement of saponin content.

• Korean Journal of Materials Research
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• v.28 no.2
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• pp.108-112
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• 2018

The present study demonstrates the effect of raw powder on the pore structure of porous W-Ni prepared by freeze drying of camphene-based slurries and sintering process. The reduction behavior of $WO_3$ and $WO_3-NiO$ powders is analyzed by a temperature programmed reduction method in Ar-10% H2 atmosphere. After heat treatment in hydrogen atmosphere, $WO_3-NiO$ powder mixture is completely converted to metallic W without any reaction phases. Camphene slurries with oxide powders are frozen at $-30^{\circ}C$, and pores in the frozen specimens are generated by sublimation of the camphene during drying in air. The green bodies are hydrogen-reduced at $800^{\circ}C$ and sintered at $1000^{\circ}C$ for 1 h. The sintered samples show large and aligned parallel pores to the camphene growth direction, and small pores in the internal wall of large pores. The strut between large pores, prepared from pure $WO_3$ powder, consists of very fine particles with partially necking between the particles. In contrast, the strut densification is clearly observed in the Ni-added W sample due to the enhanced mass transport in activation sintering.

• Korean Journal of Medicinal Crop Science
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• v.16 no.5
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• pp.349-355
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• 2008

Anticancer and immuno-modulatory activities of methanol extracts from different parts, bark, wood and leaf, of Cornus macrophylla Wall. were investigated in this study. All extracts at a concentration of 1.0mg/ml showed relativity low cytotoxicities on human normal kidney cell (HEK293) by approximately 25%. Bark extract of C. macrophylla showed the highest anticancer activity on human lung cancer cell line (A549) and human breast cancer cell line (MCF-7) by 57.4% and 58.7%, respectively, at a concentration of 1.0mg/ml. All extracts enhanced the growth of human B and T cells, showing 38.7% and 65.9% increase compared to control, respectively, by 5 days incubation with bark extract. The secretions of interleukin 6 (IL6) and tumor necrosis factor alpha (TNF-$\alpha$) from human B and T cells were significantly increased by extracts, especially bark extract. B or T cell medium, which contains cytokines (IL 6 and TNF-$\alpha$) secreted by bark extract treatment for 5 days, time-dependently enhanced the growth of NK-92MI cells with the maximal effect at 5th day of incubation. These results suggest that C. macrophylla, especially bark, has the potential for anticancer and immuno-modulatory activities.