• Journal of Microbiology and Biotechnology
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• 제27권6호
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• pp.1098-1105
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• 2017

Vesicular stomatitis virus G glycoprotein (VSV-G) has been widely used for pseudotyping retroviral, lentiviral, and artificial viral vectors. The objective of this study was to establish a potential approach for large-scale production of VSV-G. To this end, VSV-G was cloned with an N-terminal His-tag into Pichia pastoris expression vector pPIC3.5K. Three clones ($Mut^s$) containing the VSV-G expression cassette were identified by PCR. All clones proliferated normally in expansion medium, whereas the proliferation was reduced significantly under induction conditions. VSV-G protein was detected in cell lysates by western blot analysis, and the highest expression level was observed at 96 h post induction. VSV-G could also be obtained from the condition medium of yeast protoplasts. Furthermore, VSV-G could be incorporated into Ad293 cells and was able to induce cell fusion, leading to the transfer of cytoplasmic protein. Finally, VSV-G-mediated DNA transfection was assayed by flow cytometry and luciferase measurement. Incubation of VSV-G lysate with the pGL3-control DNA complex increased the luciferase activity in Ad293 and HeLa cells by about 3-fold. Likewise, incubation of VSV-G lysate with the pCMV-DsRed DNA complex improved the transfection efficiency into Ad293 by 10% and into HeLa cells by about 1-fold. In conclusion, these results demonstrate that VSV-G could be produced from P. pastoris with biofunctionalities, demonstrating that large-scale production of the viral glycoprotein is feasible.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.354-361
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• 2005

Physical parameters such as porosity and effective porosity are important physical parameters that determine the transfer and movement of water and solutes in porous media. Various methods of determining these parameters have been developed, with varying degrees of accuracy and applicability. Most of the existing methods produce static results. They do not produce instantaneous and real time of porosity and effective porosity in a porous media. In this study, a new permittivity method called Frequency Domain Reflectometry with Vector analyzer (FDR-V) is proposed to determine the porosity and effective porosity of some sand samples in the laboratory. The advantage of the FDR-V method is that it instantaneously determines the temporal variation of dielectric constants of porous media. Then, the porosity and the effective porosity of porous media are computed using well established empirical equations. Results obtained from the FDR-V method compared favorably with results from other permittivity methods such as gravimetric, injection and replacement tests. The ratio of effective porosity to porosity was $85{\sim}92%$, when FDR-V was used. This value compared favourably with 90%, which has been usually quoted in previous studies. Considering the convenience and its applicability, the measurement system of FDR-V permittivity holds a great potential in porous media and contaminant transport studies.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.349-356
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• 2011

The existence of symbiotic relationships between Acanthamoeba and a variety of bacteria is well-documented. However, the ability of Acanthamoeba interacting with host bacterial pathogens has gained particular attention. Here, to understand the interactions of Escherichia coli K1 and E. coli K5 strains with Acanthamoeba castellanii trophozoites and cysts, association assay, invasion assay, survival assay, and the measurement of bacterial numbers from cysts were performed, and nonpathogenic E. coli K12 was also applied. The association ratio of E. coli K1 with A. castellanii was 4.3 cfu per amoeba for 1 hr but E. coli K5 with A. castellanii was 1 cfu per amoeba for 1 hr. By invasion and survival assays, E. coli K5 was recovered less than E. coli K1 but still alive inside A. castellanii. E. coli K1 and K5 survived and multiplied intracellularly in A. castellanii. The survival assay was performed under a favourable condition for 22 hr and 43 hr with the encystment of A. castellanii. Under the favourable condition for the transformation of trophozoites into cysts, E. coli K5 multiplied significantly. Moreover, the pathogenic potential of E. coli K1 from A. castellanii cysts exhibited no changes as compared with E. coli K1 from A. castellanii trophozoites. E. coli K5 was multiplied in A. castellanii trophozoites and survived in A. castellanii cysts. Therefore, this study suggests that E. coli K5 can use A. castellanii as a reservoir host or a vector for the bacterial transmission.

• The Plant Pathology Journal
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• 제25권2호
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• pp.151-156
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• 2009

Tomato spotted wilt virus (TSWV) has occurred on fields annually disease occurrence rates were 73.3% in 2005, 53.3% in 2006 and 41.6% in 2007 at Anyang area in Gyeonggi Province. Seasonal occurrence pattern of TSWV showed a dramatic increase from 8.7% in late May to 30.1 % in early June in 2007 at Anyang area, coincided with the high population of a thrip, Frank-liniella occidentalis at that time. The rate of viruliferous thrips with TSWV on lettuce and red pepper was 20.2% and 52.1%, respectively, in greenhouses. Dazomat, soil fumigation pesticide, reduced TSWV disease incidence drastically on table tomato as treatment the chemical into the soil with humidity in early spring in 2006 and 2007. Spraying insecticide periodically after treatment with Dazomat was more effective to control TSWV than spraying if on plants or applying into the soil of the insecticide during growing season. Control efficiency through treatments both of the soil fumigation and of spraying insecticide was significantly high with 85.3% in 2006 and 87.8% in 2007. Removing the potential vector from the soil of TSWV infested area can be an effective strategy for reducing TSWV disease.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1349-1353
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• 2012

Increasing evidence has revealed that thy-1 was a potential stem cell marker of liver cancer, but no data have been shown on how thy-1 regulates the pathophysiology of liver cancer, such as proliferation, apoptosis, invasion and migration. We previously demonstrated that thy-1 was expressed in about 1% of hepg2 cells, thy-1+hepg2 cells, but not thy-1-, demonstrating high tumorigenesis on inoculation $0.5{\times}10^5$ cells per BACA/LA mouse after 2 months. In the present study, our results showed that higher expression of thy-1 occurs in 72% (36/50 cases) of neoplastic hepatic tissues as compared to 40% (20/50 cases) of control tissues, and the expression of thy-1 is higher in poorly differentiated liver tumors than in the well-differentiated ones. In addition, thy-1 expression was detected in 85% of blood samples from liver cancer patients, but none in normal subjects or patients with cirrhosis or hepatitis. There was a significant negative correlation between thy-1expression and E-cadherin expression (a marker of invasion and migraton), but not between thy-1 expression and AFP expression in all the liver cancer and blood samples. We further investigated the relationship between thy-1 and E-cadherin in liver cancer hepg2 cell line which was transfected with pReceiver-M29/thy-1 eukaryotic expression vector followed by aspirin treatment. Lower expression of E-cadherin but higher expressions of thy-1 were detected in hepg2 cells transfected with pReceiver-M29/thy-1. Taken together, our study suggested that thy-1 probably regulates liver cancer invasion and migration.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1531-1537
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• 2014

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

• 한국자기학회지
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• 제25권2호
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• pp.58-65
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• 2015

본 논문은 양측식 슬롯리스 고정자 할박 배열 영구자석 선형 발전기의 발전특성해석을 하였다. 자기 벡터자위와 맥스웰 방정식 이용하여 지배방정식을 도출하고, 특히 영구자석 자화와 고정자 권선의 전류밀도 분포는 무한 푸리에 급수을 이용하여 모델링 하였다. 도출된 지배방정식으로부터, 영구자석 및 고정자 권선에 의한 자계 특성식과 역기전력, 저항, 인덕턴스와 같은 회로정수를 도출 하였다. 발전 특성 해석 결과는 유한요소 해석법과 비교하여 매우 잘 부합함을 확인함으로 그 타당성이 검증되었다.

• 한국응용곤충학회지
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• 제35권1호
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• pp.66-73
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• 1996

Bacillus thuringiensis subsp. morrisoni PG-14의 cryIVD 유전자를 포함하고 있는 발현벡터 pCYASK5-1을 제작하여 Synechocystis PCCC6803에 형질전환시킨 후, 학질모기(Anopheles sinensis)유충에 대한 독성을 검정하였다. Kanamycin이 포함된 BG-11배지에서 선발된 형질전환체의 cryIVD 유전자 발현은 SDS-PAGE와 West-ern blot분석으로 확인하였다. 형질전환체는 A. sinensis 유충에 대해 높은 독성을 나타내었으며, 성장은 야생주인 Synechocystis Pccc6803과 유사하였다. 또 수심에 따른 형질전환체의 분포도 조사에서 전체적으로 살충농도의 세포수로 분포함을 확인하였다. 이러한 결과들은 B. thuringiensis subsp. morrisoni PG-14의 cryIVD 유전자로 형질전환된 Synechocystis PCCC6803이 모기유충 방제에 효율적으로 이용될 수 있음을 나타내었다.

• 비파괴검사학회지
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• 제21권5호
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• pp.485-492
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• 2001

본 논문에서는 누설자속탐상에 대한 전자기 수치해석을 수행하였다. 수치해석방법으로 2차원 유한요소법을 이용하였다. 자기벡터포텐셜을 미지수호 사용하였으며, 자기비선형(磁氣非線型)을 고려한 자장해석을 수행하여 자기포화에 의한 영향을 고려하였다. 수치해석 결과를 검증하기 위하여 실험장치를 자체 제작하여 실험을 수행하였다 시료로는 SM 45C 탄소강을 사용하였으며, 표면에 몇 가지 결함을 생성하였다. 시편과 실험장치를 이용하여 결함을 검출하는 비파괴검사를 수행하였다. 결함의 깊이 변화 및 결함의 형상변화에 대하여 결과를 비교 검토하였다. 수치해석 및 실험에서 유사한 결과를 얻었으며, 수치해석을 통하여 누설자속탐상의 시뮬레이션이 가능함을 보였다.

• Parasites, Hosts and Diseases
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• 제48권4호
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• pp.351-353
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• 2010

To investigate the population densities of potential malaria vectors, Anopheles species were collected by light traps in malaria endemic areas, Paju and Gimpo, Gyeonggi-do of Korea. Five Anopheles Hyrcanus sibling species (An. sinensis, An. pullus, An. lesteri, An. kleini, and An. belenrae) were identified by PCR. The predominant species, An. pullus was collected during the late spring and mid-summer, while higher population consists of An. sinensis were collected from late summer to early autumn. These 2 species accounted for 92.1 % of all Anopheles mosquitoes collected, while the other 3 species accounted for 7.9%. Taking into account of these population densities, late seasonal prevalence, and long-term incubation period (9-13 months) of the Korean Plasmodium vivax strain, An. sinensis s.s is thought to play an important role in the transmission of vivax malaria in the study areas.