• Korean journal of applied entomology
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• v.32 no.3
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• pp.291-299
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• 1993

Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d;et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1486-1491
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• 2010

Recently, the frequency and magnitude of the earthquake have increased. The structural safety of the public facilities such as bridges and tunnels etc. which were not concerned for earthquake resistant design are increased. Fiber reinforcement polymer that has been frequently studied for seismic retrofit has advantage as seismic reinforcement material, but it has disadvantage of the brittleness. Therefore, the investigation of safety and seismic reinforcement are required. In this study, new FRP-ductile material layered composites proposed to seismic performance reinforced of subway tunnel. Tensile test of FRP-ductile material layered composites showed that Maximum tensile force of FRP-ductile using Aluminum is similar to existing FRP reinforcement material and maximum strain was increased. In case of application of domestic subway tunnel which need ductility, layered composites of FRP-Aluminum is estimated effectively for increase of seismic performance.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.233-239
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• 2003

We have developed a reliable and high-frequency genetic transformation and regeneration system via somatic embryogensis of Eleutherococcus sessiliflorus. Embryogenic callus obtained from seed were co- cultivated with Agrobacterium tumefaciens strain EHA101/pIG121Hm harboring genes for intron-$\beta$-glucoronidase(GUS), kanamycin and hygromycin resistance. Following co-cultivation, two types of samples(fine embrogenic calli and early globular embryo clusters) were cultivated on Murashige and Skoog(MS) medium containing 1 mg/L2.4-D for 3day in dark. Transient expression of GUS gene was found to be higher in the early globular embryo clusters than in the embryogenic calli. Also, co-cultivated period affected expression of GUS gene; the best result was obtained when globular embryo clusters were co-cultivated with Agrobacterium for 3 days. Subsequently, this callus transferred to selective MS medium containing 1mg/L2.4-D, 50mg/L kanamycin or/and 30mg/L hygromycin and 300mg/L cefortaxime. These embryogenic calls were subcultured to the same selection medium at every 2 weeks intervals. Approximately 24.5% of the early globular embryos co-cultivated with Agrobacterium for 3days produced kanamycin or/and hygromycin-resistant calli. Transgenic somatic embryos were converted into plantlets in half strength MS medium supplemented with 3mg/L GA$_3$ kanamycin and were confirmed by GUS histochemical assay and polymerase chain reaction analysis. Genomic Southem blot hybridization confirmed the incorporation of NPT II gene into the host genome.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.53-60
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• 2011

Artemisinin is effective against both chloroquine-resistant and -sensitive strains of Plasmodium species. However, the low yield of artemisinin from cultivated and wild plants is a serious limitation to the commercialization of this drug. Optimization of artemisinin yield either in vivo or in vitro is therefore highly desirable. To this end, we have overexpressed the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR) gene (hmgr) from Catharanthus roseus L. in Artemisia annua L. and analyzed its influence on artemisinin content. PCR and Southern blot analyses revealed that the transgenic plants showed stable integration of the foreign hmgr gene. The reverse transcriptase-PCR results suggested that the hmgr was expressed at the transcriptional level in transgenic lines of Artemisia annua L., while the high-performance liquid chromatography analysis showed that artemisinin content was significantly increased in a number of the transgenic lines. Artemisinin content in one of the A. annua transgenic lines was 38.9% higher than that in non-transgenic plants, and HMGR enzyme activity in transgenic A. annua L. was also higher than that in the non-transgenic lines.

• Steel and Composite Structures
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• v.8 no.1
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• pp.1-18
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• 2008

Observations from experiments and real fire indicate that restrained steel beams have better fire-resistant capability than isolated beams. Due to the effects of restraints, a steel beam in fire condition can undergo very large deflections and the run away damage may be avoided. In addition, axial forces will be induced with temperature increasing and play an important role on the behaviour of the restrained beam. The factors influencing the behavior of a restrained beam subjected to fire include the stiffness of axial and rotational restraints, the load type on the beam and the distribution of temperature in the cross-section of the beam, etc. In this paper, a simplified model is proposed to analyze the performance of restrained steel beams in fire condition. Based on an assumption of the deflection curve of the beam, the axial force, together with the strain and stress distributions in the beam, can be determined. By integrating the stress, the combined moment and force in the cross-section of the beam can be obtained. Then, through substituting the moment and axial force into the equilibrium equation, the behavior of the restrained beam in fire condition can be worked out. Furthermore, for the safety evaluation and repair after a fire, the behaviour of restrained beams during cooling should be understood. For a restrained beam experiencing very high temperatures, the strength of the steel will recover when temperature decreases, but the contraction force, which is produced by thermal contraction, will aggravate the tensile stresses in the beam. In this paper, the behaviour of the restrained beam in cooling phase is analyzed, and the effect of the contraction force is discussed.

• Steel and Composite Structures
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• v.22 no.4
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• pp.875-888
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• 2016

The proper selection of materials for the intended use of the structural member is of particular interest. The paper deals with determining both the mechanical properties at different temperatures and the behavior in tensile creep as well as fatigue testing of tensile stressed specimens made of low alloy 42CrMo4 steel delivered as annealed and cold drawn. This steel is usually used in engineering practice in design of statically and dynamically stressed components. Displayed engineering stress - strain diagrams indicate the mechanical properties, creep curves indicate the material creep behavior while experimental investigations of fatigue may ensure the fatigue limit determination for considered stress ratio. Also, hardness testing provides an insight into material resistance to plastic deformation. Experimentally obtained results regarding material properties were: tensile strength (735 MPa / $20^{\circ}C$, 105 MPa / $680^{\circ}C$), yield strength (593 MPa / $20^{\circ}C$, 76 MPa / $680^{\circ}C$). Fatigue limit in the amount of 532.26 MPa, as maximum stress at stress ratio R = 0.25 at ambient temperature was calculated on the basis of experimentally obtained results. Regarding the creep resistance it is visible that this steel can be treated as creep resistant at high temperatures (including $580^{\circ}C$) when applied stress is of low level (till 0.2 of yield stress).

• Journal of Microbiology
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• v.34 no.4
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• pp.320-326
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• 1996

To analyze the effects of host versus plasmid on survival of 2, 4-degrading bacteria in environmental samples, strains Pseudomonas cepacia/pJP4, Alcaligenes JMP228/pJP4, P. cepacia/p712, and Alcaligenes JMP228/p712 were separately inoculated into samples of field soil, paddy soil, lake water, and river water, and then the changes of their populations were measured. The strains used contained a 2, 4-D degradative plasmid, either pJP4 conferring fast-growing property to the host or p712 conferring slow-growing property, and were resistant to antibiotics such that the inoculated strains could be enumerated against the indigenous microbial populations. In sterile environmental samples, these strains were stably maintained at the levels used for inoculation, except in sterile paddy soil where Alcaligenes JMP228 strains died drapidly. In natural soil samples for four strains declined steadily with time, but in naturla water samples their polulations fell rapidly at the early phase and then remained almost constant. When the environmentla samples were treated with 2, 4-D, P. cepacia/pJP4 and P. cepacia/p712 maintained significant numbers, while Alcaligenes JMP228/pJP4 and Alcaligenes JMP228/p712 declined significantly in most of the samples. The results indicated that the survivability of genetically modified microorganisms could vary depending on the environments and that their abundance in the environments under s2, 4-D selection was markedly influenced by the nature of the 2, 4-D degradative plasmid as well as type of the host strain.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.118-126
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• 2003

In the present study, the residual stresses can have a significant on the life of structural engineering components. Residual stresses are created by the surface treatment such as shot peening or deep rolling. The objective of this experimental investigation is to study the influence of friction and wear characteristics due to residual stress under dry sliding condition. Friction and wear data were obtained with a specially designed tribometer. Test specimens were made of SUP9(leaf spring material) after they were created residual stress by shot peening treatment. Residual stress profiles were measured at surface by means of the X-ray diffraction. Sliding tests were carried out different contact pressure and same sliding velocity 0.035m/s(50rpm). Leaf spring assembly test used to strain gauge sticked on leaf spring specimen in order to measure interleaf friction of leaf spring. Therefore, we were obtained hysteresis curve. As the residual stresses of surfaces increased, coefficient of friction and wear volume are decreased, but the residual stresses of surfaces are high, and consequently wear volume do not decreased. Coefficient of friction obtained from leaf spring assembly test is lower than that obtained from sliding test. From the results, structural engineering components reduce coefficient of friction and resistant wear in order to have residual stresses themselves.

• Plant Biotechnology Reports
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• v.3 no.2
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• pp.167-174
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• 2009

To identify genes involved in rice Pi5-mediated disease resistance to Magnaporthe oryzae, we compared the proteomes of the RIL260 rice strain carrying the Pi5 resistance gene with its susceptible mutants M5465 and M7023. Proteins were extracted from the leaf tissues of both RIL260 and the mutant lines at 0, 24, and 48 h after M. oryzae inoculation and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis identified eight proteins that were differently expressed between the resistant and susceptible plants (three down- and five up-regulated proteins in the mutants). The down-regulated proteins included a triosephosphate isomerase (spot no. 2210), a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (no. 3611), and an unknown protein (no. 4505). In addition, the five up-regulated proteins in the mutants were predicted to be a fructokinase I (no. 313), a glutathione S-transferase (no. 2310), an atpB of chloroplast ATP synthase (no. 3616), an aminopeptidase N (no. 3724), and an unknown protein (no. 308). These results suggest that proteomic analysis of rice susceptible mutants is a useful method for identifying novel proteins involved in resistance to the M. oryzae pathogen.

• Korean Journal of Veterinary Research
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• v.52 no.3
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• pp.169-176
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• 2012

Probiotics colonize the intestines and exert an antibacterial effect on pathogens. Therefore, probiotics could be used as a preventive agent against lethal infections. To isolate probiotic microorganisms, 116 bacterial strains were isolated from healthy cow's milk and were subjected to Gram-stain, morphology and biochemical analyses, Vitek analysis, and 16S rRNA analysis. One of the strains identified as Bacillus (B.) thuringiensis 87 was found to grow very well at pH 4.0~7.0 and to be resistant to high concentrations of bile salts (0.3~0.9% w/v). B. thuringiensis was susceptible to the antibiotics used in the treatment of bovine mastitis, yet it exhibited an antimicrobial effect against Staphylococcus (S.) aureus 305. Moreover, it protected mice from experimental lethal infections of E. coli O55, Salmonella typhimurium 01D, and S. aureus 305 through a significant induction of interferon-${\gamma}$, even at four-week post-administration of B. thuringiensis. Although oral administration of B. thuringiensis 87 did not provide significant protection against these lethal challenges, these results suggest that B. thuringiensis 87 could be a feasible candidate as a probiotic strain.