• Korean journal of applied entomology
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• v.32 no.4
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• pp.407-413
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• 1993

Twelve recombinant viruses with wider host range were plaque purified after coinfectian of Autographa cahjornica and Bombyx mOT! NPVs into Sf9 ar BmN-4 cells. Restriction endonucleases analysis of the recombinant's DNAs showed that the recombinatIOn between AcNPV and BmNPV genomes had occurred more than once. When the recombinam RecB-8, derived from BrnN-4 cells, was observed by electron rntcroscopy, the shape of the polyhedron was a regular tetrahedron, and few virions were occluded into a polyhedron.

• Korean journal of applied entomology
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• v.28 no.2
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• pp.82-87
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• 1989

Mass production of Spodoptera litura nuclear polyhedrosis virus (SINPV) was carried out on massively reared host insects. The yield of SINPV was maximal with $6.7{\;}\times{\;}10^9$ PIBs per larva on the 8th day post inoculation, when 5th instar larvae were inoculated with $1.1{\;}{\times}{\;}10^7$ PIBs per ml, and 2 g of artificial diet was sufficient for food consumption of a larva. The moribund larvae were more suitable for handling and mass production of virus than the completely dead larvae. The larvae, when treated with methoprene ($Manta^{\circledR}$), prolonged their larval period and consequently became bigger to result in higher yield(about 15%) of virus.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.451-454
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• 2020

Sericulture is a main insect industry in Sangju (Kyungpook, Korea). This study reports an occurrence of a viral disease in the sericulture farms in 2020. More than 20% silkworm larvae (Bombyx mori) suffered diarrhea and melted tissues with pathogenic lethality at 4th or 5th instars. PCR diagnosis showed a positive response against B. mori nucleopolyhedrosis virus (BmNPV) infection. Tissue extract of the infected larvae was applied to healthy larvae by a leaf-dipping method and exhibited the same viral symptoms. The viral extract was used to be overlaid on Sf9 cells. The infected Sf9 cells showed polyhedra in the cytoplasm. These results indicate that the silkworm larvae reared in the sericulture farms in Sangju were infected with BmNPV.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.449-460
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• 2022

The morphology and whole genome sequence of Spodoptera exigua nucleopolyhedrovirus K1 (SeNPV-K1) isolated in Korea were analyzed for the use as an eco-friendly control source against S. exigua. The polyhedra of SeNPV-K1 was amorphous with a size of 0.6-1.8 ㎛, and there was no external difference with the previously reported SeNPV. As a result of analyzing the nucleotide sequence of the whole genome, it was composed of 135,756 bp, which is 145 bp more than that of the previously reported SeNPV. The G+CG+C content was 44% and there were 6 homologous repeated sequences, so there was no significant difference from the previous report. As a result of ORF analysis, SeNPV-K1 had 137, two fewer than those previously reported, and 4 ORFs present only in SeNPV-K1 were confirmed. These 4 ORFs are non-essential genes and were not considered to have a significant influence on the characteristics of the SeNPV. The genome vista analysis showed that the overall sequence similarity between SeNPV-K1 and the previously reported SeNPV was very high. The whole genome of SeNPV-K1 analyzed for the first time in Korea was found to be similar to the previously reported SeNPV, but it was confirmed that it was a novel resource in Korea with different isolate.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2000.10a
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• pp.67-67
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• 2000

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.20-27
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• 1985

This study was carried out to investigate the histological changes after the infection of nuclear and cytoplasmic polyhedrosis viruses(NPV, CPV) and the resistance to the viruses in various varieties of the silkworm fed on artificial diet. The results obtained were as follows; Among four varieties of silkworm tested, Jam 107$\times$Jam 108 was more resistant than the other varieties tested and Jam 119$\times$Jam 120 was the most resistant to CPV. In case of peroral infection with NPV, Jam 107$\times$Jam 108 showed lower mortality than the remained varieties in low concentration (104/ml). However, all varieties showed high mortality as the concentration of viruses was increased. With infection of CPV, the varieties showed high mortality at the concentration of 107 and 108/ml, while Jam 119$\times$Jam 120 showed the lowest mortality at virus concentration of 104/ml. The fat bodies, epidermal cells and tracheal epithelial cells showed high susceptibility to NPV to break the cells completely and liberate the debris to the body cavity. The CPV infected only the cylindrical cells of mid-gut and formed polyhedrons. In some cells, CPV was liberated to gastral cavity. In the electrophoretic pattern of hemolymph protein of silkworm larvae infected with NPV, bands were dimmed and disappeared as symptom aggravated after infection. Electrophoretic pattern of homolymph proteins of silkworm larvae infected with CPV showed no numerical difference at the later stage of infection, and one or two bands was observed along with lowering the concentrations.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.513-519
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• 1993

The alkaline protease in the polyhedra preparation of Spodoptera litura nuclear polyhedrosis virus was successfully inactivated by heating at 100C for 20 minutes. SDS-PAGE analysis indicated that heat inactivated polyhedra is composed of major proteins of 31kDa and presumptive its polymer protein of 62kDa. However, this polyhedra was converted into several smaller molecular weight proteins when treated with midgut juice, but not by treatment with heat-inactivated midgut juice.

• KOREAN POULTRY JOURNAL
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• v.39 no.1 s.447
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• pp.146-149
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• 2007

국내 수의과 대학의 조류질병과는 조류에서 발생하는 질병연구를 목적으로 다양한 방법을 이용하여 질병의 원인체 혹은 병원체, 역학 등을 규명하고 효과적인 질병 방역대책에 대하여 연구를 하고 있다. 나아가 병원체의 여러 가지 성상에 중점을 두어 방역대책에 기초자료를 제공하며, 최근에는 분자생물학적 기법을 이용한 병원체의 특성을 규명함으로서 질병에 대해 좀더 근본적이고 다각적인 연구를 수행하고 있다. 본고는 새해를 맞이하여 국내에 있은 수의과대학을 찾아 릴레이 형식으로 가금질병 교수와의 인터뷰를 통해 가금질병에 입문하게 된 계기, 가금질병 이야기, 질병감정의뢰 절차 등의 이야기를 들어보고자 한다. 이달은 서울대학교 수의과대학교 김선중 교수를 찾아 인터뷰를 한 내 용을 정리하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.6
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• pp.571-579
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• 1987

The integral equations used in electromagnetic fields theory can be used for scattering problems. We can obtain various characteristics of scatterer. Ie, power pattern, scattered field, by finding current distribution on the scatterer. In this paper, current distribution on polygonal cylinder is obtained using integral equations in 2 dimension. For numerical aualysis, the moment method is used with pulse function as a basis function and integral equation is used with extrapolation method, which saves cpu time.

• Journal of Sericultural and Entomological Science
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• v.32 no.1
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• pp.49-57
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• 1990

To investigate the pathway of Nuclear Polyhedrosis Virus(NPV) of Bombyx mori in early stage infection of 2nd instar larva, the larval tissues were observed under electron microscope at interval of 6, 12, 24, and 48 hours after virus inoculation. The results are as follows. 1. The intact and enveloped nucleocapsids released from the polyhedra protein in the gut lumen apparently entered with the microvilli. 2. Virus progenies were observed in columnar cell nuclei 24 hours after inoculation, but polyhedra was not seen. The enveloped virus was observed in some of the intercellular spaces between mid-gut cells. 3. Many enveloped virus particles appeared in the basement membrane. These enveloped virus particles passed the basement membrane and gathered at blood cells in heomocoeal. 4. The NPV muliplicates in nuclei of the blood cells and the tracheal cells normally.