• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.360-372
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• 2020

Objective: Specific genomic sites can be recognized and permanently modified by genome editing. The discovery of endonucleases has advanced genome editing in pigs, attenuating xenograft rejection and cross-species disease transmission. However, off-target mutagenesis caused by these nucleases is a major barrier to putative clinical applications. Furthermore, off-target mutagenesis by genome editing has not yet been addressed in pigs. Methods: Here, we generated genetically inheritable α-1,3-galactosyltransferase (GGTA1) knockout Yucatan miniature pigs by combining transcription activator-like effector nuclease (TALEN) and nuclear transfer. For precise estimation of genomic mutations induced by TALEN in GGTA1 knockout pigs, we obtained the whole-genome sequence of the donor cells for use as an internal control genome. Results: In-depth whole-genome sequencing analysis demonstrated that TALEN-mediated GGTA1 knockout pigs had a comparable mutation rate to homologous recombination-treated pigs and wild-type strain controls. RNA sequencing analysis associated with genomic mutations revealed that TALEN-induced off-target mutations had no discernable effect on RNA transcript abundance. Conclusion: Therefore, TALEN appears to be a precise and safe tool for generating genomeedited pigs, and the TALEN-mediated GGTA1 knockout Yucatan miniature pigs produced in this study can serve as a safe and effective organ and tissue resource for clinical applications.

• 한국해양공학회지
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• 제29권3호
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• pp.241-248
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• 2015

A subsea pipeline for oil/gas transportation or gas injection is subjected to extreme variations in internal pressure and temperature, which can involve a strain rate effect on the pipeline material. This paper describes the flow stress characteristics of a pipeline material called API 5L X52N PSL2, using and experimental approach. High-speed tensile tests were carried out for two metal samples taken from the base and weld parts. The target temperature was 100℃, but two other temperature levels of –20℃and 0℃ were taken into account. Three strain rates were also considered for each temperature level: quasi static, 1/s, and 10/s. Flow stress data were proposed for each temperature level according to these strain rates. The dynamic hardening behaviors of the base and weld metals appeared to be nonlinear on the log-scale strain rate axis. A very high material constant value was required for the Cowper-Symonds constitutive equation to support the experimental results.

• 한국해양바이오학회지
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• 제1권2호
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• pp.84-90
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• 2006

Vibrio fluvialis의 opp gene cluster내에 존재하는 oppABCDF 유전자를 allelic exchange 방법에 의해서 각각의 유전자가 deletion된 mutant를 제조하였다. 각각의 유전자가 deletion된 mutant의 확인은 PCR과 Southern hybridization으로 결정하였다. 각 mutant들을 BHI 배지에서 생육을 비교한 결과 배양후 4시간 이전까지는 wild strain이 모든 mutant들에 비해서 생육이 좋았으나 4시간 이후부터는 같은 수준의 생육을 보여주었다. Biofilm 생산을 비교한 결과 ${\Delta}oppA$ mutant에서 가장 높은 생산성을 보여주었다. ${\Delta}oppC,D,F$ mutant들의 biofilm 생산은 ${\Delta}oppA$ mutant 보다는 낮았으나 wild strain보다는 높은 biofilm 생산성을 보여주었다.

• 한국식품과학회지
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• 제34권6호
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• pp.1134-1139
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• 2002

Campylobacter, Arcobacter, Helicobacter는 분류학적으로 동일한 rRNA superfamily Ⅵ로 식중독 이외에도 위궤양, 위암, 유산 및 신경 장애를 유발한다. Campylobacter, Arcobacter, Helicobacter를 오염된 식품 등에서 선택적으로 검출하기 위해 PCR, multiplex-PCR, RFLP(restriction fragment length polymorphism)의 기법을 이용하였다. Campylobacter, Arcobacter, Helicobacter의 16S rRNA를 target으로 하는 CHA primer를 사용하여 동일한 PCR product의 검출할 수 있었다. C. jejuni와 C.coli를 A. butzleri와 H. pylori로부터 선택적으로 검출하기 위해 fla A gene을 target으로 하는 pg3, p50을 사용하였으며, A. butzleri는 23S rRNA를 target으로 하는 Arco2, Butz를 이용했다. 또한 H. pyloyi는 isocitrate dehydrogenase gene을 target으로 하는 icd1, icd2를 사용하였고, C. jejuni는 ceuE gene을 target으로 하는 JEJ1, JEJ2를 이용하여 효과적으로 분리검출이 이루어졌다. 또한 제한효소 Dde I 을 사용하여 PCR-RFLP를 통해 C. jejuni, C. coli를 A. butzleri, H. pylori로부터 분리할 수가 있었다. 따라서 이러한 primer를 이용하여 C. jejuni, C. coli, A. butzleri, H. pylori가 함께 오염되었을 때 각각 균주의 선택적인 검출이 가능할 것이다.

• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.666-669
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• 2010

A target bacterial strain of interest for use in Red-based recombineering may already encode resistance to antibiotic markers used with current Red recombination tools, such that the resistance cannot be removed. Such cases include those where markers are needed to maintain an unstable genetic element co-resident in the strain or those where the genetic source of resistance is not known. We report the availability of PCR templates with FRT-flanked mutagenesis cassettes and plasmids encoding Red recombination functions that contain marker combinations not currently available on widely disseminated lambda Red molecular reagents. The functionality of these convenient alternative tools is demonstrated.

• 한국안전학회지
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• 제16권1호
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• pp.9-17
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• 2001

The purpose of this research is to analyze the impact resposes(impulsive stress and strain etc.) of anisotropic materials subjected to the low-velocity impact. For this purpose, a beam finite element program based on modified higher-order beam theory for anisotropic materials are developed and used to simulate the dynamic behaviors [contact force, displacement of ball and target, strain(stress) response histories] according to the changes of material property, stacking sequence, velocity and dimension etc.. Test materials for simulation are composed of $[0^{\circ}/45^{\circ}/0^{\circ}/-45^{\circ}/0^{\circ}]_{2s} and [90^{\circ}/45^{\circ}/90^{\circ}/-45^{\circ}/90^{\circ}]_{2s}$ stacking sequences. Finally, the results of this simulation are compared with those of wave propagation theory and then the impact responses and wave propagation phenomena are investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.265-268
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• 2006

Performed fatigue strength analysis for Hub to get the targeted service life of 20 years. ANSYS is used to analysis. The major structure of bearing which connect the hub and blades is modeled using the element of LINK10. To represent the stiffness of LINK10 element, initial strain and diameter of LINK10 element is applied. Prior to calculating the fatigue damages, the influence matrix is extracted from the unit loads. The target service life of 20 years is achieved from the Analysis results.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1824-1828
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• 2016

AcrR, the toxic-compounds-response regulator, regulates motility in microorganisms, presumably to escape from toxic environments. In this study, the genome-wide target genes of AcrR were investigated in a ΔacrR mutant strain by microarray analysis. In the absence of AcrR, the transcription of most flagella/motility genes was highly increased. In addition, flagella formation was increased in this mutant strain. Motility assays revealed that AcrR modulates swimming motility, but not swarming.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.131-137
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• 2003

Proper door effort, required force to open or close a vehicle door, is an essential door design factor for the safety of passengers and pedestrians. Section shape of the door checker arm is the most influential design parameter for achieving a door effort design target. In this research. an analysis procedure to predict door effort using a simplified plane strain finite element model wes investigated for two passenger cars, for which mechanism of checker systems were: different. The variation of checker arm force to be required during moving on arm in opening and closing direction was estimated through analysis, and the result was transformed to the door effort with respect to door opening angle by considering door characteristics. Also, the self·closing force due to door weight was theoretically calculated and added to the door effort from checker arm force. Finally the estimated results of door effort were compared with test results.

• Computers and Concrete
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• 제8권1호
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• pp.111-123
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• 2011

Severe element distortion problem is observed in finite element mesh while performing numerical simulations of high velocity steel projectiles penetration/perforation of concrete targets using finite element method (FEM). This problem of element distortion in Lagrangian formulation of FEM can be resolved by using element erosion methodology. Element erosion approach is applied in the finite element program by defining failure parameters as a condition for element elimination. In this study strain parameters for both compression and tension at failure are used as failure criteria. Since no direct method exists to determine these values, a calibration approach is used to establish suitable failure strain values while performing numerical simulations of ogive-nose steel projectile penetration/perforation into concrete target. A range of erosion parameters is suggested and adopted in concrete penetration/perforation tests to validate the suggested values. Good agreement between the numerical and field data is observed.