• 한국정밀공학회지
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• 제17권1호
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• pp.145-152
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• 2000

X-ray diffraction method detects change of crystal lattice distance under material surface using diffraction angle 2$\theta$. This technique can be applied to the behavior on slip band and micro crack due to material degradation. The relation between half-value breadth and number of cycle has three stages which constitute rapid decrease in initial number of cycles, slight decrease in middle number of cycles and rapid decrease in final number of cycles. The ratio of half-value breadth takes a constant value on B/B$_{0}$-N diagram with loading condition except early part of fatigue life. The ratio of half-value breadth B/B$_{0}$ with respect to number of cycle to failure N$_{f}$ has linear behavior on B/B$_{0}$-log N$_{f}$ diagram. Therefore, in this paper the estimation of fatigue life by average gradient method has much less estimated mean error than the estimation of fatigue life by log B/B$_{0}$-log N/N$_{f}$ relation.elation.ation.

• International Journal of Precision Engineering and Manufacturing
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• 제3권2호
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• pp.78-86
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• 2002

In general, X-ray diffraction method detects the changes of crystal lattice under material surface using the angle of diffraction 2$\theta$. This technique which deals with in the presented paper can be applied to a behavior on the slipped band or the micro crack cause to material degradation. The relation between half-value breadth and cycle numbers shows three stages, which consist of rapid decrease in the initial cycle, slight decrease in the middle cycle, and then rapid decrease in the final cycle. The ratio of half-value breadth has a constant value on B/B$\_$0/ - N diagram under the loading condition except early part of fatigue life. The ratio of half-value breadth B/B$\_$0/ - log N$\_$f/ with respect to number of cycle to failure N$\_$f/ has linear behavior on B/B$\_$0/ - log N$\_$f/ diagram. Therefore, the evaluation of fatigue life by the average gradient has much less mean error than the estimation of fatigue life by log B/B$\_$0/ - log N/N$\_$f/ relation.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.262-266
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• 2014

In this paper, we consider the problem of determining the confidence level in zero-failure reliability sampling plans when the life distribution is Weibull distribution with a shape parameter m and a scale parameter ${\eta}$. We introduce zero-failure reliability sampling plans for Weibull distribution and investigate some characteristics of zero-failure reliability sampling plans. Finally, We propose new guideline for determining the confidence level in zero-failure reliability sampling plans for assuring $B_x-life$.

• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.25-29
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• 2016

B형 간염 바이러스는 간경변증과 간세포암의 원인이 되는 간섬유화를 유발한다. 하지만 현재까지 그와 관련한 자세한 메커니즘은 밝혀지지 않았기에 본 연구에서 이를 알아보고자 하였다. 실험 결과, B형 간염 바이러스에서 발현되는 HBx 단백질에 의해 vimentin, fibronectin, slug, snail, NOX4가 증가되는 것을 확인하였다. NOX4에 의한 활성산소가 snail, slug 발현을 유도하고 섬유화 과정을 촉진할 수 있기 때문에 NOX4의 발현을 유도하는 HBx가 간섬유화를 조절, 유도하는 것을 확인하였다.

• BMB Reports
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• 제54권3호
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• pp.176-181
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• 2021

Bcl-x, a member of the Bcl-2 family, plays a key role in apoptosis. Alternative splicing of Bcl-x pre-mRNA through alternative 5' splice-site selection produces an anti-apoptotic mRNA isoform that includes exon 2b and a pro-apoptotic Bcl-x mRNA isoform that excludes exon 2b. Here we used Bcl-x minigene and identified SRSF2 and SRSF6 as two regulatory factors of 5' splice-site selection of Bcl-x pre-mRNA. We selected binding clusters closer to 5' splice-sites from multiple potential binding sites of SRSF2 and SRSF6 to perform loss of functions analysis through site-directed mutagenesis. Our results demonstrated that these mutations did not abolish regulatory functions of SRSF2 or SRSF6, indicating that a single binding motif or a cluster was not a functional target of these proteins in Bcl-x pre-mRNA splicing. Random deletion mutagenesis did not disrupt the role of SRSF2 and SRSF6. Importantly, mutagenesis of 5' splice-site to a conserved or a weaker score demonstrated that the weaker strength of the target 5' splice-site or higher strength of the other 5' splice-site strength limited the role of SRSF2 and SRSF6 in 5' splice-site activation.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2004년도 추계학술발표회
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• pp.94-95
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• 2004

• Molecules and Cells
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• 제20권3호
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• pp.361-363
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• 2005

Plasmid Achromobacter secretion (PAS) factor is a putative secretion factor that induces the secretion of periplasmic proteins. PAS factor from Vibrio vulnificus was crystallized at 294 K by the hanging drop vapor-diffusion method. It was isolated as a monomer during the purification procedures. The native crystal belongs to the F222 space group with unit cell parameters a = 56.1, b = 74.4, $c=80.0{\AA}$, ${\alpha}={\beta}={\gamma}=90^{\circ}$. The crystal was soaked in cryoprotectant containing 1 M NaBr for 1 h for MAD phasing. The diffraction limit of the Br-MAD data set was $1.9{\AA}$ using synchrotron X-ray irradiation at beam line BL-18B at the Photon Factory, Japan.

• 한국응용곤충학회지
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• 제37권2호
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• pp.187-191
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• 1998

새로운 Bacillus thuringiensis NT0423균주를 이용한 배양체계를 확립하고 대량생산을 위한 새로운 배양배지를 개발하였다 대두박과 밀기울의 다양한 성분비로 구성된 5종의 SW 배지는 기존의 인공합성배지인 GYS나 LB B. huringiensis 의 성장과 포자형성면에서 훨씬 우수한 결과를 보였고, 그중 대두박과 밀기율이 3:2의 비율로 구성된 SW32배지에서 전체 세포수가 3.9$\times$${10}^{8}$CFU/ml에 달했고, 대부분의 세포가 빠르게 포자를 형성하여 (3.7$\times$${10}^{8}$CFU/ml)가장 효율적이었다. 배양에 따른 배지의 pH는 최저 6.2에서 최고 7.3까지 변화하여 성장에 크게 영향을 미치지 않았고, 전체 배양액에서 대두박과 밀기울이 차지하는 비율이 4%일 경우, ml당 4.2$\times$${10}^{8}$CFU/ml의 포자가 형성되어 B. thuringiensis 의 성장에 가장 유리하였다. 교반플라스크와 5ι의 소규모 발효기를 이용한 B. thuringiensis 의 배양조건 확립에 의해 각각 최대 1$\times$${10}^{9}$CFU/ml과 5$\times$${10}^{10}$CFU/ml에 해당하는 많은 양의 균체를 회수할 수 있다.

• 식물분류학회지
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• 제37권1호
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• pp.1-15
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• 2007

제비꽃속 42집단에 대한 계통 유연관계를 알아보기 위하여 엽록체 DNA의 matK 유전자와 atpB-rbcL intergenic spacer 지역에 대한 염기서열을 분석하였다. MatK 분석에서는 노랑제비꽃절과 장백제비꽃절이 독립된 clade를 형성하였으며, 진정제비꽃절의 5개 아절은 paraphyletic하게 분리되었다. AtpB-rbcL 분석에서는 노랑제비꽃절이 단계통을 형성하였지만, 장백제비꽃절은 잔털제비꽃을 제외한 제비꽃아절 분류군들이 포함되어 있는 clade의자매군을 형성하였고, 진정제비꽃절은 paraphyletic한 분계조로 분리되어, matK 유전자와는 장백제비꽃절과 잔털제비꽃의 위치에 차이를 보였다. 두 가지 유전자의 염기서열 자료를 유합하여 분석한 결과는 제비꽃속 분류군들이 크게 3개의 분계조로 유집되는 것으로 나타났다. 즉, 기본염색체 수가 x=6인 노랑제비꽃절과 장백제비꽃절은 아욱제비꽃아절과 낚시제비꽃아절(x=10)에 속하는 분류군들이 포함된 clade의 자매군을 형성하면서 분리되었고, 잔털제비꽃은 진정제비꽃절의 콩제비꽃아절과 고깔제비꽃아절(x=10 또는 12)의 분류군들과 함께 분계조를 이루었으며, 잔털제비꽃을 제외한 제비꽃아절 (x=12)의 19개 집단도 하나의 clade를 형성하였다. 그러나 outgroup으로 부터 clade 각각의 기원에 대해서는 선행된 ITS와 trnL-F 지역에 의한 결과와는 일치하지 않는 것으로 나타났다.

• The Plant Pathology Journal
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• 제32권4호
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• pp.290-299
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• 2016

Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are $20^{\circ}C$ and the pathogen suffers mortality above $32^{\circ}C$. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August), the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%). To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.