• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.439-445
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• 2006

Purpose : ${\alpha}$-Galactosylceramide (${\alpha}$-GalCer)-stimulated human $V{\alpha}24$ natural killer T (NKT) cells exert antitumor activity against some leukemia in a CD1d dependent and TCR-mediated manner, but could not kill CD1d - negative neuroblastoma (NB) cells. There are few reports about the direct antitumor effect of highly secreted cytokines by these cells on activation. In this study, using a cell-free supernatant (SPN) collected from plate bound hCD1d/${\alpha}$ GalCer tetramers-stimulated NKT cells, we examined whether they could be helpful in the immunotherapeutic treatment of NB. Methods : Cells were cultured in IMDM. The cytokines produced by NKT cells were measured with Cytometric Bead Array (CBA) analysis. Cell viability was evaluated by calcein-AM fluorescence with digital image microscopy scanning (DIMSCAN). The percentage of specific apoptosis was calculated by flow cytometric detection of apoptosis using annexin V and 7-AAD. Results : The activated NKT cells secreted high levels of IL-2, INF-${\gamma}$, TNF-${\alpha}$. The SPN was significantly cytotoxic against four out of eight tested NB cell lines, through mainly apoptosis as evidenced by annexin-V staining and inhibition with the pretreatment of pancaspase blocker. This apoptosis was significantly inhibited when anti-TNF-${\alpha}$ and anti-IFN-${\gamma}$ neutralizing mAbs were used separately and it was completely abolished when the two mAbs were combined. Conclusion : IFN-${\gamma}$ and TNF-${\alpha}$ produced by NKT cells could exert synergistically direct antitumor activity through apoptosis on some NB cell lines.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.187-195
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• 2015

The gas explosions in offshore installations are known to be very severe according to its geometry and environmental conditions such as leak locations and wind directions, and a dynamic response of structures due to blast loads depends on the load profile. Therefore, a parametric study has to be conducted to investigate the effects of the dynamic response of structural members subjected to various types of load shapes. To do so, a series of CFD analyses was performed using a full-scale FPSO topside model including detail parts of pipes and equipments, and the time history data of the blast loads at monitor points and panels were obtained by the analyses. In this paper, we focus on a structural dynamic response subjected to blast loads changing the magnitude of positive/negative phase pressure and time duration. From the results of linear/nonlinear transient analyses using single degree of freedom(SDOF) and multi-degree-of freedom(MDOF) systems, it was observed that dynamic responses of structures were significantly influenced by the magnitude of positive and negative phase pressures and negative time duration.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.197-205
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• 2015

Offshore structures for the gas production are exposed to the risk of gas leaks, and gas explosions can result in fatal damages to the primary structures as well as secondary structures. To minimize the damage from the critical accidents, the study of the dynamic response of structural members subjected to blast loads must be conducted. Furthermore, structural dynamic analysis has to be performed considering relationships between the natural frequency of structural members and time duration of the explosion loading because the explosion pressure tends to increase and dissipate within an extremely short time. In this paper, the numerical model based on time history data were proposed considering the negative phase pressure in which considerable negative phase pressures were observed in CFD analyses of gas explosions. The undamped single degree of freedom(SDOF) model was used to characterize the dynamic response under the blast loading. A blast wall of FPSO topside was considered as an essential structure in which the wall prevents explosion pressures from the process area to utility and working areas. From linear/nonlinear transient analyses using LS-DYNA, it was observed that dynamic responses of structures were influenced by significantly the negative time duration.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.273-286
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• 2019

A derelict bridge called WoljungGyo was restored in Gyeongju, the capital city of ancient Silla. WoljungGyo was originally built in 760AD, and later rebuilt in 1280AD during the Goryeo Kingdom. The bridge lasted in working condition for at least 520 years. The bridge was uncovered to the remains of both abutments and four piers, with only one or two steps remaining. One of the foundation for piers showed evidence of partial settlement. The cause of the partial settlement is important for the successful restoration of the bridge so that an extensive investigation was carried out, which includes layer stratification by boring, 2-D stiffness profiling by surface-wave tests, and large scaled-plate load test for evaluating capacity. In addition to the field studies in the Woljunggyo bridge, 3-D finite element analysis was also conducted. Based on the results of the site investigation and the numerical analysis, it was concluded that the further ground improvement to build the piers was not necessary so that the gravels were placed and leveled underneath the existing pier stones to compensate partial settlement before the restoration.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.124-132
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• 2010

This study evaluated the effects of gamma ray and electron beam (E-beam) to improve the safety of spices for meat processing. The spices (garlic powder, curry powder, turmeric powder, black pepper, white pepper, oregano, parsley, laurel leaf powder, basil, and rosemary) were irradiated by gamma ray and E-beam at 0, 2, 4, 6, 8, and 10 kGy. Total bacterial populations were then enumerated on total plate count agar, and bacteria isolated from the samples were identified by polymerase chain reaction (PCR). In addition, $D_{10}$ values for Bacillus cereus and Staphylococcus aureus inoculated in spices was determined, and the Ames test was conducted for genotoxicity analysis. The contaminated total bacterial populations in spices ranged from 1.5 to 3.8 Log CFU/g, and most of identified bacteria were Bacillus spp., and Staphylococcus spp. However, the bacterial populations decreased below the detection limit (2 Log CFU/g) after irradiation at 4 kGy except for parsley, which required 6 kGy in gamma ray and 8 kGy in E-beam to decrease total bacterial populations below detection limit. $D_{10}$ values were also higher (p<0.05) in E-beam treated samples than gamma-ray treated samples. No genotoxicity was observed in both conditions with and without metabolic activation. These results indicate that gamma ray (>4 kGy and <6 kGy) could be more useful to improve food safety of meat processing spices compared to E-beam.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.234-240
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• 2013

This test was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). In preliminary tests, both E. coli and S. typhimurium working culture suspension number (N value) was $4.0{\times}10^8$ CFU/mL. And all of the colony numbers on the carriers exposed the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of bacteria recovered on the control-carriers (T value) was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the reduction number of S. typhimurium and E. coli (d value) was 5.26 and 5.64 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results of this study, Fumagari OPP$^{(R)}$ has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.51-57
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• 2013

In order to know the shear performances of a bolted connection in reinforced glulam depending upon the combination of textile glass fiber, a tensile-type shear test was conducted. Textile glass fiber was used as a reinforcement, whose glass fiber arrangement was a plain weaving type or a diagonal cloth type. Reinforced glulam was made up of 5 plies and it was produced by inserting and laminating the plies between laminas depending upon a changed insert position and combination form of textile glass fiber. Tensile-type shear test specimens were a steel plate insert-type and joined at end-distance 7D with bolts whose diameter 12 or 16 mm. In textile glass fiber reinforced glulam, whose volume ratio was 1%, the yield shear strength of a 12 mm bolted connection increased by 10% when a test specimen had reinforced internal layers than when external layers were reinforced. As for textile glass fiber reinforced glulam, whose volume ratio was 2%, the yield shear strength of a 12 mm bolted connection increased significantly by about 22% compared to the bolted connection of non-reinforced glulam, and the yield shear strength of a 16 mm bolted connection was improved by about 20% compared to the bolted connection of non-reinforced glulam.

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.220-230
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• 2004

This study was conducted of Korean native plants to screen herbicidal activity which could be used for the development of new natural herbicides. Ninety-eight plants were collected from Wan Island, Chollanamdo in Korea and their methanol extracts were obtained. Herbicidal activities of the methanol extracts were determined by seed bioassay using canola (Brassica napus L.) seedlings. Among ninety-eight species, twenty plants were highly herbicidal ($GR_{50}<1,000\;{\mu}g\;g^{-1}$): Abies holophylla MAXIM., Ailanthus altissima (MILL.) SWINGLE, Anthemis nobilis L., Aralia elata SEEM., Artemisia iwayomogi KITAMURA, Asarum sieboldii MIQ., Brassica campestris subsp. napus var. nippo-oleifera MAKINO, Clematis terniflora DC., Crataegus scabrida SARG., Gnaphalium affine D. DON, Jasminum nudiflorum LINDL., Kalopanax pictus (THUNE.) NAKAI, Machilus japonica S. et Z., Myrica rubra S. et Z., Osmunda japonica THUNB., Phytolacca esculenta V. Houtte, Platanus occidentalis L., Quisqualis indica L., Rubus hirsutus THUNB., Yucca smalliana FERN. Fifty plants were shown moderate herbicidal activity $(1,000\;{\mu}g\;g^{-1}, however, twenty-eight plants were not shown any herbicidal activity.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.65-70
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• 2023

Nanoimprint lithography (NIL) has attracted much attention due to its process simplicity, excellent patternability, process scalability, high productivity, and low processing cost for pattern formation. However, the pattern size that can be implemented on metal materials through conventional NIL technologies is generally limited to the micro level. Here, we introduce a novel hard imprint lithography method, extreme-pressure imprint lithography (EPIL), for the direct nano-to-microscale pattern formation on the surfaces of metal substrates with various thicknesses. The EPIL process allows reliable nanoscopic patterning on diverse surfaces, such as polymers, metals, and ceramics, without the use of ultraviolet (UV) light, laser, imprint resist, or electrical pulse. Micro/nano molds fabricated by laser micromachining and conventional photolithography are utilized for the nanopatterning of Al substrates through precise plastic deformation by applying high load or pressure at room temperature. We demonstrate micro/nanoscale pattern formation on the Al substrates with various thicknesses from 20 ㎛ to 100 mm. Moreover, we also show how to obtain controllable pattern structures on the surface of metallic materials via the versatile EPIL technique. We expect that this imprint lithography-based new approach will be applied to other emerging nanofabrication methods for various device applications with complex geometries on the surface of metallic materials.

• Membrane Journal
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• v.15 no.2
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• pp.114-120
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• 2005

The purpose of this study is to obtain practical information about membrane coupled $ A_2O$ system for muncipal wastewater treatment. A flat-plate microfiltration (MF) module with a pore size $0.25\;{\mu}m$ was submerged into the aeration basin and treated water was filtrated through the membrane by continuous suction with low pressure. The system was operated with synthetic wastewater to find operational parameters of internal recycle ratio and maximum MLSS showing best water quality and long-term stability. The internal recycle was defined as type 1 for aerobic to anoxic tank and type 2 for anoxic to anaerobic tank, respectively When the flux was maintained at $0.015\;m^3/m^2/hr$ (15 LMH) with 2Q type 1 internal recycle ratio, the optimal operational setting were 10 internal recycle ratio for type 2 and maximum MLSS of 11,000 mg/L among tested conditions. At this condition, removal efficiencies of BOD, CODcr, T-N and T-P showed $97.3\%,\;94.2\%,\;64.0\%,\;63.0\%$, respectively.