• Current Optics and Photonics
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• v.4 no.6
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• pp.566-570
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• 2020

The present paper computes the refractive indices of different corona viruses (H5N1, H5N2, H9N2, H4N6, FAdV and IBV) through reflectance analysis of a virus solution. The computational analysis indicates that the refractive indices of all viruses are negative at the signal of 412 nm. Further the numerical output shows that the infectious bronchitis viruses (family of novel corona viruses, COVID-19) have higher negative refractive indices as compared to other corona viruses. Finally refractive indices of the family of COVID-19 are investigated with respect to the EID (Electronic infusion Device) concentration of the viruses, showing that the refractive index which ranges from "-0.96725 to -0.999998" corresponds to '0.01 to 10000' EID virus concentration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5615-5622
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• 2012

Seasonal distributions of the viral abundance and physicochemical parameters were analyzed at three different regions in Gwangyang Bay. Morphological structure of marine virus was observed using transmission electron microscopy. Most of marine virus had bacteriophage-like structure, but some were similar with eukaryotic microalgal virus, Ectocarpus siliculosus virus (EsV). Viral abundance at Group 1 (closed eutrophic region) was higher than viral abundances at Group 2 (closed oligotrophic region) and Group 3 (open oligotrophic region). Seasonal abundances of marine virus at Group 1 were dynamically changed. The viral density was variably changed from maximum $7.33{\times}10^8ml^{-1}$ in August to minimum $0.3{\times}10^8ml^{-1}$ in December and maintained middle value in spring and autumn. The concentration of nitrogen and phosphate sources was correlated with viral abundance. Particularly, seasonal change of dissolved oxygen concentration was opposite to the variation of viral abundance. These results showed that viral abundances were closely related with fluctuation of marine physicochemical environment in Gwangyang bay.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.1
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• pp.11-17
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• 1989

Inhibition of tobacco mosaic virus (TMV) infection by 4 surfactants, sodium salts of alpha olefin (AOS), linear alkylbenzene (LAS), dioctyl sulfosuccinate (OSS), and dodecyl benzene sulfonic acid (SAS), was examined on tobacco cv. Xanthi-nc and NC 82. Infection of virions or TMV RNA was inhibited over 98% by the surfactants (2500 rpm). However, symptom development and viral concentration in tobacco plants treated with the surfactants into the rhizosphere soil 3 days before inoculation with TMV on leaves were not different from those in untreated tobacco plants. This indicates no significant systemic effects of the surfactants on the inhibition of TMV infection. The surfactants, except LAS, had no effect on the inhibition of viral infection when purified virions mixed with each surfactant and ultracentrifuged were inoculated on the tobacco plants. The virus was almost inactivated by LAS, showing that the viral infection was reduced more than 96%. The virus particles treated with the surfactants were not distinguishable in size and dimension from untreated normal particles, suggesting that the inhibitory action of the surfactants to TMV infection may not involve disintergration or uncoating of the virus at the early stage of infection.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.117-124
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• 2016

In this study, the virucidal efficacy of a fumigant containing 20% ortho-phenylphenol against classical swine fever virus (CSFV) and porcine reproductive and respiratory syndrome virus (PRRSV) was examined. After each carrier deposited with CSFV and PRRSV suspensions was exposed to the fumigant in a $25-m^3$ test room for 15 h, all carriers were neutralized and diluted, and each diluted suspension was inoculated into each proper cell line. After incubation, CSFV and PRRSV viability in each cell line was examined and 50% tissue culture infectious dose $(TCID_{50})/mL$ was calculated. In the results, the concentration of viable virus in all of pathogen control-carriers was more than $2{\times}10^5TCID_{50}/mL$, and there were no cytotoxicity in all of toxicity control-carriers. In addition, the fumigant inactivated ${\geq}4.8{\log}_{10}(TCID_{50}/mL)$ of both CSFV and PRRSV. These findings will be useful for preventing the spread of CSFV and PRRSV infection.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.219-226
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• 1991

A cytoplasmic polyhedrosis virus isolated from the oriental tobacco budworm, Heliothis assulta (HaCPV), was studied on morphology of the polyhedron and virus particles, analysis of viral protein and nucleic acid, and bioassay of the HaCPV to determine the feasibility of application as a microbial control agent. The shape of polyhedron was hexagonal ranging 0.5-3.7 ${\mu}m$ and the virus particles were icosahedral outline measured 55 nm in diameter. Polyhedral protein was composed of a major polypetide of 24.3 Kd and 5 minor components and virus particle had seven polypeptides ranging in 28.0 Kd-133. 6 Kd by the SDS-P AGE. The genome of virus was segmented with 10 double stranded RNA in the total mol. wt. of 18.08 Md ranging in 0.65 Md -2.79 Md. The $LC_{50}$ values of the HaCPV to the 3rd instar of H. assulta larvae were calculated to $2.895{\times}10^5PIBs/ml$. The $LT_{50}$ values in the concentration of $5.0{\times}10^{6}PIBs/ml$ was 16.4 days.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.137-143
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• 2008

Production of Indian citrus ringspot virus (ICRSV)-free plants from an infected plant of kinnow mandarin (Citrus nobilis Lour ${\times}$ C. deliciosa Tenora) is reported. The shoot apices of different sizes (0.2-1.0 mm) excised from the ICRSV-infected plant were micrografted onto decapitated rootstock seedlings of rough lemon (C. jambhiri). Micrograft survival depended on the size of shoot apex and the sucrose concentration of the culture medium. Increase in scion size from 0.2 to 0.7 mm resulted in an increase in micrografting success rate from 30.55 to 51.88%. Further, micrograft survival obtained with 0.2 mm was improved from 30.55 to 38.88% by increasing sucrose concentration in the culture media from 5 to 7.5%. The micrografted plants were tested for ICRSV using ELISA and RT-PCR. All plants raised from 0.2-mm scion were found negative with both ELISA and RT-PCR whereas only 20% of the ELISA negative plants raised from 0.3-mm scion were found negative for ICRSV with RT-PCR. The outcome of this research is the successful establishment, acclimatization and virus testing of micrografted plants.

• Journal of fish pathology
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• v.13 no.1
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• pp.61-66
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• 2000

A method was developed for concentrating fish pathogenic virus from sea water using membrane ultrafiltration system and centricon. The method consists of passing large volumes (Ca. 20 liter) of sea water through ultrafiltration (PAN) filter followed by cross-flow filtration method and centrifugation use the centricon (Plus-20). This procedure permitted the processing of 20 liter of sea water which resulted in a 20,000-fold reduction in the volume of water and greater than 90% recovery of the seeded MABV.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.632-640
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• 2021

Cucumber mosaic virus (CMV) and Pepper mild mottle virus (PMMoV) causes severe economic loss in crop productivity of both agriculture and horticulture crops in Korea. The previous surveys showed that naturally available biopolymer material - chitosan (CS), which is from shrimp cells, reduced CMV accumulation on pepper. To improve the antiviral activity of CS, it was synthesized to form phosphate cross-linked chitosan (PCS) and compared with the original CS. Initially, the activity of CS and PCS (0.01%, 0.05%, and 0.1% concentration) compound against PMMoV infection and replication was tested using a half-leaf assay on Nicotiana glutinosa leaves. The total number of local lesions represented on a leaf of N. glutinosa were counted and analyzed with phosphate buffer treated leaves as a negative control. The leaves treated with a 0.1% concentration of CS or PCS compounds exhibited an inhibition effect by 40-75% compared with the control leaves. The same treatment significantly reduced about 40% CMV accumulation measured by double antibody sandwich enzyme-linked immunosorbent assay and increased the relative expression levels of the NPR1, PR-1, cysteine protease inhibitor gene, LOX, PAL, SRC2, CRF3 and ERF4 genes analyzed by quantitative reverse transcriptase-polymerase chain reaction, in chili pepper plants.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.125-130
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• 1993

The araC prodrugs (1~5) carrying a special acyl group at 5'-Ο-or $N^4$-position were evaluated for in vitro antiviral activity against various human viruses. When tested against HSV-1 and HSV-2 cultured in the verso cells, the prodrugs exhibited slightly higher $ED_{50}$ values compared with one of the parent araC but showed more increased $CC_{50}$ values in all cases. Consequently the overall selectivity indexes of prodrugs were higher than that of arab. The prodrugs, except compound 5, exhibited very potent activity similar to that of araC ($ED_{50}$ about $0.12{\mu}g/mι$) when evaluated against another human DNA virus, cytomegarovirus. However, theses araC prodrugs were completely inactive against RNA viruses i.e. poliovirus and coxackie B3 virus at the concentration of 4250{\mu}g/mι.$

• YAKHAK HOEJI
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• v.43 no.4
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• pp.469-473
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• 1999

EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers). Karst. Anti-influenza A virus (anti-Flu A) activity of EA was examined of Vero cells by plaque reduction assay in vitro. And the combined antiviral effects fo EA with interferon (IFN) alpha and gamma were examined on the multiplication of Flu A with 50% effective concentration ($EC_50$) of 1.50 mg/ml. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. The combination of EA with IFN alpha on Flu A showed more potent synergism with CI values of 0.50~0.52 of 50%, 70%, 90% effective levels than that with IFN gamma with CI values of 0.82~0.99.