• 한국동물위생학회지
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• 제36권3호
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• pp.209-216
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• 2013

A total of 301 samples of bovine liver, spleen and omasum were collected from butchers and restaurants in Gwangju, Korea during 2012 and all samples were subjected to bacteriological examination and antibiotic residues. Also, this study was performed to survey the consciousness for hygiene of livestock workers who are handling bovine by-products in Gwangju. The detection rate of aerobic plate count (APC) was higher in summer than in other seasons in all by-products (P=0.000). The detection rate of E. coli count was lower in the liver than the spleen and omasum (P=0.000). Twenty four of the samples (8.0%) were contaminated with S. aureus while one spleen sample (0.3%) was contaminated with L. monocytogenes and finally 10 (3.3%) of the liver and omasum samples were contaminated with Cl. perfringens. Five of the twenty-four S. aureus isolates harbored enterotoxin gene. However, the cpe gene of Cl. perfingens was not detected among any of the 10 isolates. Antibiotic residues were not detected in the liver samples. The consciousness survey's results showed that most of them (58.8%) were safe.

• 한국어병학회지
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• 제13권1호
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• pp.61-66
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• 2000

해수중에 소수로 분포하는 어류 병원 바이러스의 검출을 목적으로 해산어류 병원바이러스의 일종인 marine birnavirus (MABV)를 대상으로하여 한외 여과막과 centricon을 이용한 농축효과를 바이러스의 주화세포내 감염에 의해 형성되어지는 CPE (cytopathic effect) 출현에 근거한 바이러스 감염가 측정법인 $TCID_{50}$ 계수법 및 주화세포상의 바이러스 감염에 의해 형성되어지는 plaque 계수법을 통해 검토하였다. 바이러스 희석액 시료 20 L를 1차 중공사한외여과막으로 3 시간 가동하면 200배로 농축되어지고, centricon으로 2차 농축하여 최초 시료 대비 20,000배 (최종량: 1 ml)로 농축가능하였다. 바이러스 회수율은 농축 전 바이러스 감염가와 비교하여 $TCID_{50}$치로서는 94.4%, plaque 계수법으로는 88.7%를 나타내었다. 중공사 한외여과막과 centricon을 이용한 본 농축법은 해수내 바이러스의 검출을 위한 효과적인 농축방법으로 수계 바이러스 연구에 이용되어질 수 있을 것으로 판단되어졌다.

• The Plant Pathology Journal
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• 제16권3호
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• pp.142-146
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• 2000

Ordered differential display using RT-PCR (ODD-PCR) was conducted to have a profile of the differently expressed genes between a hypovirulent strain of Cryphonectria parasitica (UEP1) and its isogenic wild type strain (EP155/2). ODD-PCR has advantages of high sensitivity, reproducibility, proportional representation, and limited number of primer combinations comparing with other differential display methods. RNAs were prepared from 1 and 5 day liquid culture of both hypovirulent and wild type strains, and were further evaluated with the marker genes of C. parasitica such as cryparin and mating factor MF2-1, which were already proven to be specifically down-regulated by the presence of mycovirus CHV1-713. ODD-PCR was conducted using those RNAs and expressed genes were categorized to five groups according to their temporal and quantitative expression patterns. Those fives groups are CPC, CPE, CPL, CPD, and CPU which represent constitutively-expressed, early-expressed, late-expressed, down-regulated, and up-regulated, respectively. Ninety two primer combinations out of a total of 192 have been tested so far. Among the twenty to fifty distinct bands per each reaction, an average of four to ten genes was identified as viral-regulated fungal genes. Those viral-specifc genes were further analyzed by DNA sequencing followed by homology search. Characterization of 30 clones including all five groups were conducted as a preliminary data and more are under investigation.

• 한국동물위생학회지
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• 제39권2호
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• pp.87-92
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• 2016

Porcine edema disease (ED) is a communicable disease of pigs caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) which expresses F18 fimbriae and/or Stx type 2e (Stx2e). While STEC causes a severe illness including hemorrhagic colitis and hemolytic-uremic syndrome in humans, it induces damage to the vascular endothelium, which results in edema, hemorrhage, and microthrombosis, leading in high mortality in pigs. In the present study, we cultured Stx2e-producing E. coli field isolates from conventional pig farms that experienced sudden deaths previously with symptoms similar to porcine edema disease, which were further investigated with Shiga toxin profiles. A total of 43 strains were identified from the collected samples by F18 or Stx2e specific PCR. Based on the PCR, 42 isolates out of 43 isolates were proved to carry one of F18 or Stx2e genes and 14 isolates to carry both F18 and Stx2e genes. All of the 30 isolates that harbored Stx2e gene induced the cytopathic effect (CPE) in vero cells and especially, the isolate 150229 produced the highest level of Shiga toxin. Therefore, we identified the virulence genes (F18 and Stx2e) and demonstrated Shiga toxin-producing abilities from porcine edema disease causing E. coli filed isolates. These results suggested that one of the isolates could be a vaccine antigen candidate against STEC through further investigating to elicit an immune response.

• 한국표면공학회지
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• 제45권6호
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• pp.219-225
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• 2012

The aim of the present study was to investigate the corrosion resistance and characteristics of passive layer between naturally passivated and chemically passivated duplex stainless steel, UNS S31803 (EN 1.4462) using CPT, XPS, and EIS. The treatment of $HNO_3$(II) and $HNO_3$(III) in ASTM A 967 was applied. In case of chemically passivated specimen, CPT of $HNO_3$(II) and $HNO_3$(III) were higher than that of naturally passivated specimen. In addition, from XPS results, the protectiveness index (Cr/(Fe+Cr)) of chemically passivated specimens was also higher than that of naturally passivated specimen. The reason for this result is considered due to post-cleaning treatment in chemical passivation process, that is, immersion in $Na_2Cr_3O_7$ solution. The fact that $HNO_3$(II) passivation treatment showed the highest film resistance and 'n', which is exponent related with constant phase element (CPE) of passivation film, was in good agreement with results of CPS and XPS. The chemical passivation treatment was an effective method to improve corrosion resistance of duplex stainless steel.

• 산업융합연구
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• 제18권2호
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• pp.69-75
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• 2020

산업용 IoT는 비용 효율적이고 넓은 커버리지를 제공하는 무선 메쉬 네트워크에 관심이 많았다. 하지만, 무선 메쉬 네트워크는 멀티홉 환경의 심각한 성능 절하를 겪는다. 이를 극복하기 위해 메쉬 라우터에 캐시를 장착하는 연구가 많았으나 캐시 파워 소모 모델 연구는 적었다. 최근 캐시 파워 효율 기반 모델은 캐시까지 콘텐츠 전달 파워를 모두 측정했기 때문에 무선 메쉬 네트워크에서 쓰기에 부적절합니다. 본 논문은 CPU의 동작속도가 캐시 크기에 비례한다는 사실을 이용하여 캐시 적중률 기반 파워 소모 모델을 제안하고, 기존 캐시 파워 효율 기반 소모 모델과 비교하여 정확하게 측정되었다. 제안된 캐시 적중률 기반 파워 소모 모델은 산업용 IoT에서 무선 메쉬 네트워크를 구성할 시 에너지 효율적인 캐시 운용을 위한 참조 모델로 활용되길 기대합니다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.41-41
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• 2016

Influenza viruses are RNA viruses that belong to the Orthomyxoviridae family, and those can be divided into three types; A, B, and C, which based on the differences of the inner nucleoproteins and genomic structures. All three genera differ in their genomic structure and nucleoprotein content, they are further classified into various serotypes based on the two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). These glycoproteins play crucial roles in viral infection and replication. Hemagglutinin mediates binding of virions to sialic acid receptors on the surfaces of target cells at the initial stage of infection. Neuraminidase cleaves the glycosidic bonds of sialic acids from the viral and cell surfaces to release the mature virions from infected cells, after viral replication. Because NA plays an important role in the viral life cycle, it is considered an attractive therapeutic target for the treatment of influenza. The methanolic extracts of Phellinus baumii and Phellinus igniarius exhibited significant activity in the neuraminidase inhibition assay. Polyphenolic compounds were isolated from the methanolic extracts. The structures of these compounds were determined to be hispidin, hypholomine B, inoscavin A, davallialactone, phelligridin D, phelligridin E, and phelligridin G by spectroscopic methods. Compounds inhibited the H1N1 neuraminidase activity in a dose-dependent manner with $IC_{50}$ values of 50.9, 22.9, 20.0, 14.2, 8.8, 8.1 and $8.0{\mu}M$, respectively. Moreover, these compounds showed anti-influenza activity in the viral cytopathic effect (CPE) reduction assay using MDCK cells. These results suggests that the polyphenols from P. baumii and P. igniarius are promising candidates for prevention and therapeutic strategies against viral infection.

• 생명과학회지
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• 제13권2호
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• pp.197-205
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• 2003

미국 EPA (Environment Protection Agency)와 환경부에서 규정하고 있는 표준검출법인 총세포배양법 (Total Culturable Virus Assay : TCVA)을 이용하여 부산시 상수원수 및 정수장을 대상으로 2001년 7월에서 2002년 11월까지 바이러스 검사를 실시하였다. 검사결과 21개의 상수원수 시료 중 13개 시료에서 CPE (cytopathic effect)가 확인되어 61.9%의 양성률을 보였으며, 정수 및 수도꼭지수에서는 모두 검출되지 않았다. 또한, 검출된 바이러스를 계절별로 보면 주로 여름철과 초겨울에 분포하는 특성을 보였다. 검출된 바이러스는 TCVA-MPN 방법에 의해 1.92-9.70 MPN/100 L의 범위로 전량 되었으며, 면역형광법 (Immunofluorescent assay)에 의해 human poliovirus type 1과 enterovirus종으로 동정되었다.

• 한국동물위생학회지
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• 제27권4호
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• pp.345-354
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• 2004

Two cases of classical swine fever (CSF) disease have broken out in Cheolwon (7 April, 2002). The suspected pig herds were huddled together because of high fever (over $40^{\circ}C$) and showed remarkable decrease of the leukocytes. The staggering gait related to posterior weakness, constipation and lethargy, hyperemia, hemorrhagic lesions (on the skin, muzzle, ears, limbs, tail and inner part of legs) and conjunctivitis with dirty streaks below the eyes were observed. The inflammation in the lung, infarction in the spleen, swelling and hemorrhage in lymph nodes, kidney, intestine, heart and cheese like purulent inflammation of the tonsil were observed. The ulcers of the colon were also detected. Several clinical and laboratory techniques including blood test, histo-pathological examinations, indirect fluorescent antibody (IFA) test and RT-PCR test were applied to diagnose the disease. Inoculation test on PK-15 cell was also performed. The necrosis of the lymphatic cells and infiltration of the vessel circumferential cells in the brain and lymph organs were commonly viewed. The proliferation of the glia cell (gliosis) in the lymph was particular. Cytopathogenic effect (CPE) and specific fluorescent-bright-green areas (with IFA) appeared in PK-15 cells inoculated with suspected blood plasma. The IFA test on the epithelial and mucous membrane cells of tonsil was positive. RT-PCR technique required more working hours and labor than other techniques in this examination but it was useful because of the sensitivity to the CSF viral gene.

• Journal of Electrochemical Science and Technology
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• 제13권3호
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• pp.362-368
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• 2022

The application of polymer composite electrolyte in all-solid-state lithium-sulfur battery (ASSLSBs) can guarantee high energy density and improve the interface contact between electrolyte and electrode, which has a broader application prospect. However, the inherent insulation of the sulfur-cathode leads to a low electron/ion transfer rate. Carbon materials with high electronic conductivity and electrolyte materials with high ionic conductivity are usually selected to improve the electron/ion conduction of the composite cathode. In this work, PEO-LiTFSI-LLZO composite polymer electrolyte (CPE) with high ionic conductivity was prepared. The ionic conductivity was 1.16×10^-4 and 7.26×10^-4 S cm^-1 at 20 and 60℃, respectively. Meanwhile, the composite sulfur cathode was prepared with Sulfur, reduced graphene oxide and composite polymer electrolyte slurry (S-rGO-CPEs). In addition to improving the ion conductivity in the cathode, CPEs also replaces the role of binder. The influence of different contents of CPEs in the cathode material on the performance of the constructed battery was investigated. The results show that the electrochemical performance of the all-solid-state lithium-sulfur battery is the best when the content of the composite electrolyte in the cathode is 40%. Under the condition of 0.2C and 45℃, the charging and discharging capacity of the first cycle is 923 mAh g^-1, and the retention capacity is 653 mAh g^-1 after 50 cycles.