• Journal of Veterinary Science
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• v.23 no.2
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• pp.24.1-24.10
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• 2022

Background: Small interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia. Objectives: The main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus. Methods: The effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells. Results: The siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene. Conclusions: These findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus.

• Structural Engineering and Mechanics
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• v.88 no.5
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• pp.501-519
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• 2023

This paper introduces a new hybrid structural connection joint that combines shear walls with section steel beams, fundamentally resolving the construction complexity issue of requiring pre-embedded connectors in the connection between shear walls and steel beams. Initially, a quasi-static loading scheme with load-deformation dual control was employed to conduct low-cycle repeated loading experiments on five new connection joints. Data was acquired using displacement and strain gauges to compare the energy dissipation coefficients of each specimen. The destruction process of the new connection joints was meticulously observed and recorded, delineating it into three stages. Hysteresis curves and skeleton curves of the joint specimens were plotted based on experimental results, summarizing the energy dissipation performance of the joints. It's noteworthy that the addition of shear walls led to an approximate 17% increase in the energy dissipation coefficient. The energy dissipation coefficients of dog-bone-shaped connection joints with shear walls and cover plates reached 2.043 and 2.059, respectively, exhibiting the most comprehensive hysteresis curves. Additionally, the impact of laminated steel plates covering composite concrete floors on the stiffness of semi-rigid joint ends under excessive stretching should not be disregarded. A comparison with finite element analysis results yielded an error of merely 2.2%, offering substantial evidence for the wide-ranging application prospects of this innovative joint in seismic performance.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.2
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• pp.119-128
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• 2016

In a performance-based design, the structural safety is estimated from pre-defined damage states and corresponding damage indices. Both damage states and damage indices are well defined for above-ground structures, but very limited studies have been performed on underground structures. In this study, we define the damage states and damage indices of a cut-and-cover box tunnel which is one of typical structures used in metro systems, under a seismic excitation from a series of inelastic frame analyses. Three damage states are defined in terms of the number of plastic hinges that develop within the structure. The damage index is defined as the ratio of the elastic moment to the yield moment. Through use of the proposed index, the inelastic behavior and failure mechanism of box tunnels can be simulated and predicted through elastic analysis. In addition, the damage indices are linked to free-field shear strains. Because the free-field shear strain can be easily calculated from a 1D site response analysis, the proposed method can be readily used in practice. Further studies are needed to determine the range of shear strains and associated uncertainties for various types of tunnels and site profiles. However, the inter-linked platform of damage state - damage index - shear wave velocity - shear strain provides a novel approach for estimating the inelastic response of tunnels, and can be widely used in practice for seismic designs.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.567-576
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• 2017

In a performance-based design, the structural safety is estimated from pre- defined damage states and corresponding damage indices. Both damage states and damage indices are well defined for above-ground structures, but very limited studies have been performed on underground structures. In this study, we define the damage states and damage indices of a cut-and-cover box tunnel which is one of typical structures used in metro systems, under a seismic excitation from a series of inelastic frame analyses. Three damage states are defined in terms of the number of plastic hinges that develop within the structure. The damage index is defined as the ratio of the elastic moment to the yield moment. Through use of the proposed index, the inelastic behavior and failure mechanism of box tunnels can be simulated and predicted through elastic analysis. In addition, the damage indices are linked to free-field shear strains. Because the free-field shear strain can be easily calculated from a 1D site response analysis, the proposed method can be readily used in practice. Further studies are needed to determine the range of shear strains and associated uncertainties for various types of tunnels and site profiles. However, the inter-linked platform of damage state - damage index - shear wave velocity - shear strain provides a novel approach for estimating the inelastic response of tunnels, and can be widely used in practice for seismic designs.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.1014-1032
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• 2020

This work aimed to investigate the psychobiotic effects of six bacterial strains on the mind and behavior of male Wistar rats. The probiotic (PRO) group (n=7) were rats pre-treated with antibiotics for 7 days followed by 14-day probiotic administration, antibiotics (ANT) group (n=7) were rats treated with antibiotics for 21 days without probiotics. The control (CON) group (n=7) were rats that received sham treatment for 21 days. The six bacterial strains with probiotic properties were mostly isolated from Thai fermented foods; Pedicoccus pentosaceus WS11, Lactobacillus plantarum SK321, L. fermentum SK324, L. brevis TRBC 3003, Bifidobacterium adolescentis TBRC 7154 and Lactococcus lactis subsp. lactis TBRC 375. The probiotics were freeze-dried into powder (6×10⁹ CFU/5 g) and administered to the PRO group via oral gavage. Behavioral tests were performed. The PRO group displayed significantly reduced anxiety level and increased locomotor function using a marble burying test and open field test, respectively and significantly improved short-term memory performance using a novel object recognition test. Antibiotics significantly reduced microbial counts in rat feces in the ANT group by 100 fold compared to the PRO group. Probiotics significantly enhanced antioxidant enzymatic and non-enzymatic defenses in rat brains as assessed using catalase activity and ferric reducing antioxidant power assay, respectively. Probiotics also showed neuroprotective effects with less pyknotic cells and lower frequency of vacuolization in cerebral cortex. This multi-strain probiotic formulation from Thai fermented foods may offer a potential to develop psychobiotic-rich functional foods to modulate human mind and behaviors.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.507-512
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• 2005

This research focuses on the development and application of a method for the detection of m-toluate in soils using a genetically engineered bioluminescent bacteria, Pseudomonas putida mt-2 KG1206. KG1206 produces light by direct (m-toluate and benzoate) and indirect (toluene analogs) inducers. For detection of m-toluate in soil system, 9.9 mL strain was amended with 0.1 mL soil ethanol extractant. A high correlation ($r^2>0.97$) was observed between bioluminescence and m-toluate concentration. The unknown concentrations of m-toluate in soil samples were pre-determined using a method developed based on bioluminescence activity of strain with extracted inducers. Values between by LC analysis and bioluminescence activity show moderate statistical results. These results demonstrate the feasibility of recombinant bioluminescent microorganism, engineered to generate a quantifiable bioluminescence signal in response to specific pollutants, may serve as combined sensing and reporting tools in environmental monitoring.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3068-3084
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• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to experimentally assess the damage and vibrations of NPP buildings subjected to aircraft crash. In present Part I, two shots of reduce-scaled model test of aircraft impacting on NPP building were carried out. Firstly, the 1:15 aircraft model (weighs 135 kg) and RC NPP model (weighs about 70 t) are designed and prepared. Then, based on the large rocket sled loading test platform, the aircraft models were accelerated to impact perpendicularly on the two sides of NPP model, i.e., containment and auxiliary buildings, with a velocity of about 170 m/s. The strain-time histories of rebars within the impact area and acceleration-time histories of each floor of NPP model are derived from the pre-arranged twenty-one strain gauges and twenty tri-axial accelerometers, and the whole impact processes were recorded by three high-speed cameras. The local penetration and perforation failure modes occurred respectively in the collision scenarios of containment and auxiliary buildings, and some suggestions for the NPP design are given. The maximum acceleration in the 1:15 scaled tests is 1785.73 g, and thus the corresponding maximum resultant acceleration in a prototype impact might be about 119 g, which poses a potential threat to the nuclear equipment. Furthermore, it was found that the nonlinear decrease of vibrations along the height was well reflected by the variations of both the maximum resultant vibrations and Cumulative Absolute Velocity (CAV). The present experimental work on the damage and dynamic responses of NPP structure under aircraft impact is firstly presented, which could provide a benchmark basis for further safety assessments of prototype NPP structure as well as inner systems and components against aircraft crash.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.257-264
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• 1997

Purpose: We performed this study to find out short period humoral immunogenicity and safety of 47 passaged Oka strain live attenuated varicella vaccine(1,400PFU) in 12 months to 15 years aged healthy children. Methods: Ninety nine healthy chidren, who have no histories of varicella vaccination, recent chicken pox illness and contact, allergy to other vaccines and underlying severe diseases, were involved in this study from April 1997 to August 1997. 5ml blood were collected before vaccination and after vaccination from all vaccinees to measure varicella membrane antibody by FAMA, and varicella IgG antibody by EIA. And immediate reactions within 30 minutes after vaccination, local and systemic reactions within 3 days after vaccination and vaccine induced systemic illness during 6 weeks postvaccination period were observed in all vaccinees to identify side effects of study vaccine. Results: 1) 49 seronegative and 50 seropositive vaccinees were identified in both prevaccination serologic tests. 2) Serologic responses after vaccination measured by the FAMA in seronegative group showed that the mean GMT level revealed 64.0, and seroconversion rate was 97.9%. And serologic responses after vaccination measured by the FAMA in seropositive group showed that the mean GMT level(242.2) was markedly elevated comparing with the mean GMT level(9.2) of pre vaccination. 3) The results of EIA in seronegative group revealed that postvaccination mean GMT was 435.2(prevaccination GMT; 78.7), and 100% seroconversion rate. Also, the results of EIA in seropositve group showed that the mean GMT level(769.9) of postvaccination was almostly two fold hihger than the mean GMT level(419.7) of prevaccination. 4) Observed local reactions like injection sites redness, pain, hardness and itching sense were mild and disappeared within 3 days, also shorterm systemic reactions like irritability, lethargy, poor appetites and rash were not remarkable. And there were no remarkable side effects due to vaccine during study period in all vaccinees. Conclusion: We confirmed that 47 paasaged Oka strain live attenuated varicella vaccine has high shorterm humoral immunogenicity and safety. However, we need more detail and longterm humoral and cell mediated immunogenicity studies of this vaccine including clinical field trials.

• Journal of Ginseng Research
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• v.27 no.1
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• pp.37-42
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• 2003

For study about introduce of gene connected with disease and transformation system of gingseng, chitinase gene cloned from soybene and disease resistant gene were carried out for expression and transformation of plant using Agrobacterium. The disease resistance gene(DR-49), 35S-35S-AMV, has been constructed. The disease resistance gene and chitinase gene were introduced into the binary vector pRD 400, which were mobilized into Agrobacterium tumefaciens faciens strain MP 90 and LBA 4404 harboring disarmed Ti-plasmid. As a result of induce transformants using ginseng embryo and petiole, multi shoots were formed on MS medium supplemented 1 mg/ι 2,4-D and 0.5 mg/ι kinetin. Also transformation by cotyledonwas effective on MS medium supplemented 1 mg/ι 2,4-D and 0.5 mg/ι kinetin, transformation percent of disease resistant gene and chitinase gene were showed 18%, 14% respectively. As transformed tissue is under pre-embryoid condition, normal shoot is required through the process of matured embryo.