• Korean Journal of Ichthyology
• /
• v.30 no.4
• /
• pp.185-193
• /
• 2018

From 2017 to 2018, the disease has been monitored at four culturing eel farms in Incheon and Gyeonggi region in Korea. As a result, diseases with gill congestion frequently occurred. This disease occurred regardless of size of eel, but the frequency and cumulative mortality were high in eels within 3 months after stocking. The infected fish showed pathological histopathological features such as intense congestion and dilation in the central venous sinus (CVS) of gill filaments and hemorrhages in liver and kidney. Hexagonal viral particles measuring about 70 nm in diameter was observed in nuclei and cytoplasm of gill vascular endothelial cells. Molecular biologic diagnosis by both PCR and genetic analysis has been revealed that the causative agent of this disease is Japanese eel endothelial cells-infecting virus (JEECV), the cause of viral endothelial cell necrosis of eel (VECNE), which is mainly reported in Japan. This study is the first report on the characteristics of JEECV and VECNE infection in domestic eel farms.

• Particle and aerosol research
• /
• v.18 no.1
• /
• pp.1-8
• /
• 2022

Since 2019, the corona virus has been continuously affect human life. In particular, in the indoor space where people live, infection by airborne transmission of viruses is a problem. Among them, the spread in the subway, which is the main mode of transport for humans, can be serious. To solve this problem, our research team developed an ionic wind collector to collect and remove corona virus using an ionic wind collector and ozone. In order to apply the ionic wind collector to the subway, it must operate in two modes. Because large amounts of ozone are harmful to the human body. There is a mode that collects bio-aerosol from the air using ionic wind and a mode that inactivates viruses floating in the air by generating a large amount of ozone. As the applied voltage increased, the cleaning ability of the ionic wind collector increased, and the farther the distance between the discharge electrode and the ground plate, the higher the cleaning ability even at low current. In addition, clean air delivery rate (CADR) of an ionic wind collector was up to 5.5 m³/min. As a result of measuring the amount of ozone generated, it was confirmed that 50 ppb to 250 ppb was generated, and it was confirmed that ozone generation was controllable in the ionic wind dust collector.

• Korean Journal of Veterinary Service
• /
• v.22 no.1
• /
• pp.43-52
• /
• 1999

Presently, viral isolation in the diarrheal feces can be reached by many tools such as fluorescent antibody test(FA), negative contrast electron microscopy(NCEM), virus neutralization test, cell culture, and so on. The purpose of the study was to aimed at the establishment of simplified NCEM technique which can be efficiently applied for diarrheal feces and also the understanding on prevalence of viral-induced diarrhea in calves. One hundred fourty-seven korean indigenous calves with diarrhea were examined to their feces by the modified NCEM. Among them, 98(66.7%) were confirmed to have one or more viruses in feces. The viruses detected were identified as rotavirus(33.3%), coronavirus(16.3% ), togavirus(10.2%) and herpesvirus(0.7%). Ten cases of combined viral infection were consisted of 8 with rotavirus+coronavirus, one with rotavirus+togavlrus and one with rotavirus+herpesvirus. Dirrheal types could classified by yello-wish watery(44.9a ), blood-tinged(19.7% ), white watery(17.7% ) , brownish watery(14.3%), greenish watery(3.4%) diarrhea, respectively. Yellowish watery diarrhea(66cases) was frequently included rotavirus(31.8%), coronavirus(15.2%), and togavirus(13.6%), respectively. Consequently, these results suggest that the modified NCEM is reliable and efficient diagnostic tool for detection of viruses in the diarrheal feces and many calves rearing in Chonnam province have been exposed to some enteric viral agents mainly including rotavirus and coronavirus.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2011.11a
• /
• pp.43-43
• /
• 2011

현대인들은 생활환경에서 발생하는 각종 미세먼지 등의 입자상 오염물질 뿐만 아니라 각종 VOCs 등의 가스상 오염물질과 곰팡이, 박테리아, 바이러스 등 생물학적 오염물질까지 생활공간 내의 공기환경은 점점 악화 되고 있으며 공기 정화 등의 필요성이 증대 되고 있다. 이에 본 연구에서는 닥 펄프와 활성탄이 주성분인 Sheet를 Corrugation 장치를 통해 편파형(골판지)으로 제작하고, 다시 다층 구조로 적층된 골판지 sheet을 제작한 후 이를 두께 방향으로 일정 폭(20mm이하)으로 절단하여 필터부품의 소자로 이용하는 활성탄 필터의 제조 및 그 특성을 확인하고자 하였다. 닥펄프/펄프와 무기물의 혼합비, 해리시간 등의 변화를 주어 샘플을 만들었고, 강도, 평활성, 생산성 향상을 위해 첨가보조제 선정을 하였다. 이렇게 제조된 필터의 물리적 특성을 알아보고자 인장시험을 실시하였고, 주사전자현미경을 통하여 필터의 평활성과 표면을 관찰하였고 흡착성능 및 기능성을 VOCs 방출량, 탈취율, 항균도, 곰팡이 저항성 등의 실험을 통하여 알아보았다.

• Research in Plant Disease
• /
• v.20 no.4
• /
• pp.307-313
• /
• 2014

In May 2013, an angel's trumpet leaves showing mosaic and malformation symptoms were collected from Suwon city, Gyeonggi-do. An analysis of the collected sample by transmission electron microscopy observation showed filamentous rod particles of 720-800 nm in length. On the basis of the these observations, we performed PCR against three reported Potyviruses (Brugmansia mosaic virus, Colombian datura virus and Brugmansia suaveolens mottle virus), and the sample was positive for BruMV. Pathogenicity and host range test of BruMV was determined by mechanical inoculation. Solanaceae (tobacco, tomato and eggplant) and Amaranthaceae (ground cherry) appeared typical virus symptoms. To determine coat protein of this virus, we designed specific primer pairs, and performed PCR amplification, cloning, and sequencing. Phylogenetic analysis showed that BruMV-SW was most closely related to BruMV isolate SK. Comparison of the BruMV-SW coat protein nucleotide sequences showed 92% to 99% identities to the other BruMV isolates.

• Reproductive and Developmental Biology
• /
• v.30 no.3
• /
• pp.181-187
• /
• 2006

In recent years the number of patients waiting for organ transplantation has greatly outpaced the supply of human organs available, which leads to a renewed interest in pig-to-human xenotransplantation as an alternative. However, one of the biggest barriers in the xenotransplantation is presence of porcine endogenous retroviruses(PERV) that can infect human cells. In this study, to present a possible solution for this problem we tried to inhibit expression of PERVs using shRNAs(short hairpin RNA) at the level of RNA synthesis and virus release. The shRNA targeting the sequence of PERV A, B type was cloned into pSIREN-RetroQ vector under the control of polymerase-III U6-RNA gene promoter. Quantitative real-time PCR was performed to detect my alterations in mRNA production of PERV A, B targeted by the shRNA in each done. Depending on the target sequence of the shRNA, the transcription of PERV was decreased to as much as 4% and the number of progeny viruses was reduced to less than 1/200,000. Transgenic pigs producing such shRNAs may result in a highly reduced PERV expression in cells and organs, which is a prerequisite for safe xenotransplantations.

• Applied Chemistry for Engineering
• /
• v.33 no.1
• /
• pp.83-89
• /
• 2022

Since the pandemic of COVID-19, active investigation to develop immunity to infectious disease by delivering nucleic acids has been proceeded. Particularly, many studies have been conducted on non-viral vector as several vital side-effects which were found on nucleic acid delivery system using viral vectors. In this study, we have developed plasmid DNA (pDNA) loaded-hyaluronic acid derivative (HA) coated-polyethyleneimine (PEI) based polyplex for enhanced nucleic acid delivery efficiency. We have optimized the ratio of pDNA : PEI : HA by measuring size and protein transcription efficiency. The final product, polyplex-HA, was characterized through measuring size, zeta-potential and TEM image. Intracellular uptake and protein transcription efficiency were compared to commercially available transfection reagent, lipofectamine, through fluorescence image and flow cytometry. In conclusion, polyplex-HA presents a novel gene delivery system for efficient and stable protein transcription since it is available for delivering various genetic materials and has less immunoreactivity.

• Particle and aerosol research
• /
• v.18 no.1
• /
• pp.9-21
• /
• 2022

In this study, a novel antiviral coating method for the air filtration system of subway station was investigated. Using dry aerosol coating process, we developed a high-performance antiviral air filter with spark discharger and carbon brush type ionizer. Silver nanoparticles were produced by a spark discharge generation system with ion injection system and were used as antiviral agents coated onto a medium grade air filter. The pressure drop, filtration efficiency, and antiviral ability of the filter against aerosolized MS2 virus particles as a surrogate of SARS-CoV-2 virus were tested with dust contamination. Dust contamination caused the increase of the filtration efficiency and pressure drop, while the antiviral agents (in this study, silver nanoparticles) coating did not have any significant effect on the filtration efficiency and pressure drop. Using these properties, we suggested a novel method to maximize the antiviral performance of the antiviral air filter that was contaminated by dust particles. Moreover theoretical analysis of antiviral ability with dust contamination and re-coated antiviral agents was carried out using a mathematical model to calculate the time-dependent antiviral effect of the filter under actual conditions of subway station. Our model can be used to apply on antiviral air filtration system of subway station for prevention of pandemic diffusion, and predict the life cycle of an antiviral filter.

• Particle and aerosol research
• /
• v.18 no.3
• /
• pp.51-59
• /
• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.

• Journal of Korean Society on Water Environment
• /
• v.26 no.6
• /
• pp.1028-1033
• /
• 2010

Wastewater reuse for agricultural irrigation needs treatment and control of pathogens to minimize risks to human health and the environment. In order to evaluate the water quality of UV-treated reclaimed water, this study focused on the relationship between micro-pathogens and particulate matters. MS2 was selected as an index organism because it has similar characteristics to human enteric virus and strong resistance to UV disinfection. The turbidity and suspended solid (SS) were selected for test parameters. In this study, it was performed with different UV doses (30 and $60mJ/cm^2$) for estimation of the MS2 inactivation rate using collimated beam batch experiments in the laboratory. The experiment results by turbidity or SS concentration presented that the increased concentration of them lowered MS2 inactivation. At the turbidity (below 4.27 NTU) and SS (below 1.47 mg/L) of the low level range, the inactivation of 60 UV dose is higher than 30 UV dose. However, at the turbidity and SS of the high level, the increasing UV dose did not show apparent increasing the MS2 inactivation. In quantitative microbial risk assessment (QMRA), it can confirm the trend that $P_D$ and turbidity concentrations have positive correlationship at the low concentration, which was also observed in SS. The QMRA can be helpful in communication with public for safe wastewater reuse and be recommended.