• 한국항공우주학회지
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• 제36권5호
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• pp.407-419
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• 2008

본 연구에서는 축 대칭 원뿔 형상 위의 압축성 경계층의 천이 지점을 선형 안정성 이론과 -method를 이용하여 예측하였다. 축 대칭 좌표계에서의 압축성 유동 지배 방정식으로부터 압축성 원뿔 경계층의 선형 안정성 방정식을 얻었으며 안정성 방정식을 2차 정확도의 유한 차분법을 이용하여 계산하는 수치 프로그램을 개발하였다. 개발 된 코드로 원뿔 경계층의 안정성 특성 및 2차원 교란의 증폭률을 계산하고 실험결과와의 비교를 통해 검증을 수행하였다. 얻어진 교란의 증폭률을 활용하여 -method를 통해 천이지점 예측을 수행하였다. 풍동 시험 및 비행 시험 결과와의 비교를 통해 비행 조건에 있는 마하수 4와 8사이의 원뿔 경계층에 대한 본 연구의 천이지점의 예측 능력을 확인하였다. 또한 벽면 냉각이 경계층 내부 교란의 안정성 및 천이 지점에 미치는 영향을 분석하였다.

• 한국어병학회지
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• 제33권1호
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• pp.15-21
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• 2020

We found skin flukes in snubnose pompano (Trachinotus blochii) from a public aquarium and attempted clear identification of them to the species level by morphology and molecular analyses. Skin flukes were collected from snubnose pompano showing dyspnea, anorexia and mild hemorrhage on the skin. All the fish samples (n=2) were infected with the flukes on the skin, gill and eyes, covered with excessive mucus. The isolated worms were transferred for making slide specimen and PCR amplification targeting 18S rDNA, 28S rDNA, mitochondrial cytochrome c oxidase subunit 1 (mt cox1) and cytochrome b (Cytb) genes for further analyses. Morphology and measurements data of our slide specimen coincided with those of Neobenedenia girellae. The sequence data of 2 genes (28S rDNA and Cytb) and the phylogenetic trees revealed that our specimen consistently belonged to the N. girellae clade. For 18S rDNA and mt cox1 genes, there was no sequence of either of these 2 Neobenedenia species from the type host available in GenBank. This is the first record of N. girellae in snubnose pompano, but it is still unclear if the snubnose pompano is a natural host for N. girellae or not because N. girellae is known to have an unusual broad host range and the host-switching can occur particularly in captive conditions such as aquarium or aquaculture facilities.

• Smart Structures and Systems
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• 제22권1호
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• pp.41-55
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• 2018

Damping ratio and frequency have influence on dynamic serviceability or instability such as vortex-induced vibration and displacement amplification due to earthquake and critical flutter velocity, and it is thus important to make determination of damping ratio and frequency accurate. As bridges are getting longer, small scale model test considering similitude law must be conducted to evaluate damping ratio and frequency. Analysis conditions modified by similitude law are applied to experimental test considering different scale ratios. Generally, Nyquist frequency condition based on natural frequency modified by similitude law has been used to determine sampling rate for different scale ratios, and total time length has been determined by users arbitrarily or by considering similitude law with respect to time for different scale ratios. However, Nyquist frequency condition is not suitable for multimode system with noisy signals. In addition, there is no specified criteria for determination of total time length. Those analysis conditions severely affect accuracy of damping ratio. The focus of this study is made on the determination of minimum analysis conditions for different scale ratios. Influence of signal to noise ratio is studied according to the level of noise level. Free initial value problem is proposed to resolve the condition that is difficult to know original initial value for free vibration. Ambient and free vibration tests were used to analyze the dynamic properties of a system using data collected from tests with a two degree-of-freedom section model and performed on full bridge 3D models of cable stayed bridges. The free decay is estimated with the stochastic subspace identification method that uses displacement data to measure damping ratios under noisy conditions, and the iterative least squares method that adopts low pass filtering and fourth order central differencing. Reasonable results were yielded in numerical and experimental tests.

• 지구물리와물리탐사
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• 제16권4호
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• pp.203-210
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• 2013

화천 시추공 지진관측소의 부지특성을 살펴보기 위해 지표와 시추공 자료에 기록된 배경잡음과 지진신호의 특성을 분석하였다. 배경잡음을 분석한 결과, 비교적 잡음유입이 적은 밤 시간대에 비하여 낮 시간대에서 지표/시추공 잡음에너지 비가 약 15배 높게 나타났으며, 저주파에서 고주파로 갈수록 지표/시추공 스펙트럼 비가 크게 나타났다. 지진신호에 대해서는 P파와 SH파의 우세주파수 양상을 비교하였는데, 진앙거리가 가깝고, 규모가 작은 국내지진은 지표자료에서 8 Hz와 46 Hz에서 우세주파수를 보이며 시추공 자료와 다른 값을 나타내었다. 이는 수평/수직 스펙트럼 비 분석으로 구한 퇴적층의 공명주파수(7.4 Hz, 46 Hz)와 일치하며 상부 퇴적층에 영향을 받아 증폭현상이 나타나고 있음을 시사한다. 이번 연구를 통해 지표 관측소에 비하여 시추공 관측소에서는 배경잡음이 최대 20,000배 이상 감소되고, 상부퇴적층에 의한 증폭현상이 나타나지 않아 양질의 자료를 획득하여 지진관측능력이 향상될 수 있음을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1783-1789
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• 2014

Background: The EMSY gene encodes a BRCA2-binding partner protein that represses the DNA repair function of BRCA2 in non-hereditary breast cancer. Although amplification of EMSY gene has been proposed to have prognostic value in breast cancer, no data have been available concerning EMSY tissue expression patterns and its associations with clinicopathological features. Materials and Methods: In the current study, we examined the expression and localization pattern of EMSY protein by immunohistochemistry and assessed its prognostic value in a well-characterized series of 116 unselected breast carcinomas with a mean follow up of 47 months using tissue microarray technique. Results: Immunohistochemical expression of EMSY protein was detected in 76% of primary breast tumors, localized in nuclear (18%), cytoplasmic (35%) or both cytoplasmic and nuclear sites (23%). Univariate analysis revealed a significant positive association between EMSY expression and lymph node metastasis (p value=0.045) and larger tumor size (p value=0.027), as well as a non-significant relation with increased risk of recurrence (p value=0.088), whereas no association with patients' survival (log rank test, p value=0.482), tumor grade or type was observed. Conclusions: Herein, we demonstrated for the first time the immunostaining pattern of EMSY protein in breast tumors. Our data imply that EMSY protein may have impact on clinicipathological parameters and could be considered as a potential target for breast cancer treatment.

• Journal of Plant Biotechnology
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• 제43권3호
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• pp.367-375
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• 2016

국내에서 육성된 옥수수 90 품종 및 자식 계통에 대하여 microsatellite 마커를 활용하여 DNA 프로파일 데이터베이스를 구축한 다음 공시품종에 따른 유전적 유사도 분석 및 품종식별력 검정에 대한 연구를 수행하였다. 옥수수 90품종을 100개의 microsatellite 마커로 검정하고 대립유전자의 패턴이 우수하고 다형성 정도가 높은 13개를 선정하여 분석하였을 때 대립유전자의 수는 5 ~ 24개까지 다양하게 분포하였고 평균 대립유전자의 수는 13.69개로 높았다. PIC 값의 경우도 0.716 ~ 0.942 범위에 속하였고 평균값은 0.865로 아주 높았다. 옥수수 90품종 및 계통에 대하여 UPGMA 분석에 의한 계통도를 작성하였을 때, 옥수수의 품종 유형 및 품종 육성 계보에 따라 5개의 대그룹으로 나누어졌다. 본 연구에서 구축됨 옥수수 자식계통 및 품종별 microsatellite DNA 프로파일 데이터베이스는 신품종과 기 육성된 품종과 유전적 유사도 분석이 가능하기 때문에 품종보호출원시 대조품종 선정 및 품종진위성과 관련된 종자분쟁에 매우 유용하게 활용될 수 있을 것이다.

• Genomics & Informatics
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• 제13권3호
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• pp.81-85
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• 2015

Molecular characterization technology in genetically modified organisms, in addition to how transgenic biotechnologies are developed now require full transparency to assess the risk to living modified and non-modified organisms. Next generation sequencing (NGS) methodology is suggested as an effective means in genome characterization and detection of transgenic insertion locations. In the present study, we applied NGS to insert transgenic loci, specifically the epidermal growth factor (EGF) in genetically modified rice cells. A total of 29.3 Gb (${\sim}72{\times}coverage$) was sequenced with a $2{\times}150bp$ paired end method by Illumina HiSeq2500, which was consecutively mapped to the rice genome and T-vector sequence. The compatible pairs of reads were successfully mapped to 10 loci on the rice chromosome and vector sequences were validated to the insertion location by polymerase chain reaction (PCR) amplification. The EGF transgenic site was confirmed only on chromosome 4 by PCR. Results of this study demonstrated the success of NGS data to characterize the rice genome. Bioinformatics analyses must be developed in association with NGS data to identify highly accurate transgenic sites.

• Journal of Korean Neurosurgical Society
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• 제30권2호
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• pp.137-143
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• 2001

Objective : Telomerase, a ribonucleoprotein adds telomere repeats to the ends of telomeres to compensate for the progressive loss. A favorable prognosis associated with low or no telomerase activity in some tumors, and cells transfected with antisense human telomerase lost telomeric repeats and die. We studied about the relationship between telomerase activity and apoptosis in the human brain tumors. Material and Methods : Between July 1998 and December 1999, 62 patients with brain tumors underwent surgery and their surgical specimens were obtained. Telomerase activity was investigated by telomeric repeats amplification protocol(TRAP) assay. Apoptosis was also evaluated by DNA fragmentation analysis. Differences and correlation in data were analyzed using Mann-Whitney test and Wilcoxon-signed rank test. Results : Expression rate of telomerase activity and apoptosis were 80% and 30% in malignant gliomas, 33% and 0% in low grade gliomas, 63% and 38% in meningiomas, 67% and 33% in pituitary adenomas, 33% and 33% in metastatic tumors, 67% and 17% in acoustic neurinomas, 100% and 100% in pineoblastomas, 100% and 0% in the hemangioblastoma, respectively. There was no significant difference of telomerase activity and apoptosis between histological types. But a significant difference was noted in the expression of telomerase activity between malignant gliomas and low grade gliomas(p = 0.022). Brain tumors with telomerase activity expressed the lower rate of apoptosis. A significant correlation was also found between telomerase activity and absence of apoptosis in the human brain tumors(p = 0.005). Conclusions : Our data suggests that telomerase may protect from apoptosis of the human brain tumors and also may play an important role in the biological malignancy of the gliomas.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.681-687
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• 2020

Giardia lamblia is a common enteric pathogen associated with diarrheal diseases. There are some reports of G. lamblia infection among different breeds of cattle in recent years worldwide. However, it is yet to know whether cattle in Jiangxi province, southeastern China is infected with G. lamblia. The objectives of the present study were to investigate the prevalence and examine the multilocus genotypes of G. lamblia in cattle in Jiangxi province. A total of 556 fecal samples were collected from 3 cattle breeds (dairy cattle, beef cattle, and buffalo) in Jiangxi province, and the prevalence and genotypes of G. lamblia were determined by the nested PCR amplification of the beta-giardin (bg) gene. A total of 52 samples (9.2%) were positive for G. lamblia. The highest prevalence of G. lamblia was detected in dairy cattle (20.0%), followed by that in beef cattle (6.4%), and meat buffalo (0.9%). Multilocus sequence typing of G. lamblia was performed based on sequences of the bg, triose phosphate isomerase and glutamate dehydrogenase loci, and 22, 42, and 52 samples were amplifiable, respectively, forming 15 MLGs. Moreover, one mixed G. lamblia infection (assemblages A and E) was found in the present study. Altogether, 6 novel assemblage E subtypes (E41*-E46*) were identified for the first time. These results not only provided baseline data for the control of G. lamblia infection in cattle in this southeastern province of China, but also enriched the molecular epidemiological data and genetic diversity of G. lamblia in cattle.

• 농업과학연구
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• 제48권2호
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• pp.283-297
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• 2021

Investigation of genetic diversity and molecular characterization in high yielding rice varieties is important for their identification. The experiment was conducted during 2016 - 2017 to analyse the genetic diversity of fifteen high yielding rice varieties in Bangladesh by using random amplification of polymorphic DNA (RAPD) markers. Polymorphism was revealed in 12 RAPD primers out of 30, whereas no other reaction was detected on the remaining 18 primers. The 40 out of 45 bands (88.89%) polymorphics were produced by the primers and ranged from 50 to 100%. The maximum number of polymorphic bands was produced by the primer OPB-18 whereas the lowest number of polymorphic bands belonged to OPC-12. The genetic similarity coefficients were determined with the RAPD data, which ranged from 0.47 to 0.94. The unweighted paired group of arithmetic means (UPGMA) dendrogram presented the studied rice varieties into two major clusters. Moreover, the value of Nei's genetic diversity is 0.26 and the Shanon information index is 0.41. The study produced distinct positions, suggesting that the genotypes were different from each other. The results indicated that these markers could be efficient for comparing the genetic relationships, patterns of variation, and measurement of genetic distance among rice varieties. Considering all of these results, RAPD analysis is found to be an effective tool for estimating the genetic diversity of different rice varieties. The outcomes of this research may contribute to the germplasm data of rice accessions and a future breeding program of rice genotypes.