• Research in Plant Disease
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• v.21 no.4
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• pp.321-325
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• 2015

A rapid and simple RT-PCR diagnosis method for detection of Rice stripe virus (RSV), one of major virus infecting rice, was developed using porous ceramic cubes in this study. The porous ceramic cube can rapidly absorb biological molecules such as small-sized proteins and nucleic acid fragments into its pores. We examined whether this ability of porous ceramic cubes could be applied for isolating viral nucleic acids or particles from the RSV- infected plant tissues. In this study, we found that the porous ceramic cube was capable of absorbing a detection level of viruses from the rice tissues infected with RSV and established RT-PCR-based RNA diagnosis method using porous ceramic cubes.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.335-339
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• 2001

Grapevine leafroll-associated 3 closterovirus (GLRaV-3) is phloem limited virus, and one of the most severe viral diseases found in Korea. However, nonhomogenous distribution and low concentration and seasonal variations of GLRaV-3 in grapevines remain as main problems which prevent the introduction and molecular biology or serology experiments. Virus-infected plantlet in vitro was obtained from node tissue cuttings, which was GLRaV-3 infected 'kyoho' vines. The amount of purified virus was highest in vitro plantlet. Moreover, viruses seem to be relatively homogeneously distributed in all organs including leaf, stem and callus derived from in vitro plantlets. RT-PCR detection using in vitro plantlet tissue as template was most effective. When comparing ELISA to RT-PCR, RT-PCR detection was 1,000 times as effective as ELISA. These results can be explained by improved quality such as tenderness or less tannins in plantlet in vitro. In conclusion, until infected herbaceous host will be available, tissue culture can be usefully adopted as a technique for a good source of GLRaV-3 closterovirus for further studies.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.115-123
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• 1992

A total of453 wilci hats inhabiting in Korea were captured ancl .he IgG antibodies againstJapanese Encephalitis Virus(J1IV) were detected by the heniagglut:nation inhibition te5t. 35501' the 453 blood sera showecl positive reaction to JEV with titers of I0 up to 40. Positiverates of male and kniale hats were 70.0'%1 anel 78.1'k. rcspectivclv. Positive ratci accordingto area were 74.7%) in Chungnan~. 72.h'\ulcorner6 in Kangwon and 74.3'"; in C'hungbuk. the resultbof which indicated no dil'krencc in areii. Whereas positive ratus according to hats specie5were 87.5(% f i ~ rC i..cpc~rtilios upernns. fi~llowedb y 83 3'%, k)r Mpoii.\ i ~ ~ : t r u ~ i tci.i~lis~. ~75l.0. '\4 1 forRhitrolol~h.\ '||'&'||',rurn~uic,r~unal ncl 59.6'!41 for Minioprc,ru.s schrc~ibersii.I t was Ibund by incli rrctini~nunofluorosce~icae nd clectron microscope techniques that the virus particles 01. JEVcould infect the brain of a Korean wilcl bats and proliferatn ill the brain cells.he brain cells.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.845-851
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• 2014

Dielectrophoresis (DEP) is defined as the motion of suspended particles in solvent resulting from polarization forces induced by an inhomogeneous electric field. DEP has been utilized for various biological applications such as trapping, sorting, separation of cells, viruses, nanoparticles. However, the analysis of DEP trapping has mostly employed the period-averaged ponderomotive forces while the dynamic features of DEP trapping have not been attracted because the target object is relatively large. Such approach is not appropriate for the nanoscale analysis in which the size of object is considerably small. In this study, we thoroughly investigate the dynamic response of trapping to various system parameters and its influence on the trapping stability. The effects of particle conductivity on its motion are also focused.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.131-136
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• 1985

The calculation of the resulting fluid motion is an important problem of ship hydrodynamics. For a partially immersed body the condition of constant pressure at the free surface can be linearized. The resulting linear boundary-value problem for the velocity potential is the Neumann-Kelvin problem. The two-dimensional Neumann-Kelvin problem is studied for the half-immersed circular cylinder by Ursell. Maruo introduced a slender body approach to simplify the Neumann-Kelvin problem in such a way that the integral equation which determines the singularity distribution over the hull surface can be solved by a marching procedure of step by step integration starting at bow. In the present pater for the two-dimensional Neumann-Kelvin problem, it has been suggested that any solution of the problem must have singularities in the corners between the body surface and free surface. There can be infinitely many solutions depending on the singularities in the coroners.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.203-213
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• 1985

The in situ posture of anterior body of Metagonimus yokogawai was observed in experimental metagonimiasis of dog. The metacercariae were collected from naturally infected sweetfish by peptic digestion; a total of 8 dogs was orally infected with 10,000 metacercariae respectively. Two dogs were killed on 3 days, 9 days, 4 weeks and 10 weeks after the infection. The postures of worms in histological section of small intestine and of whole worms collected from the fixed intestinal mucosa were examined by light and scanning electron microscope. The results were summarized as follows: 1. The recovery rates of worms were 42.6% on 3 days, 55.0% on 9 days, 33.2% on 4 weeks and 9. 8% on 10 weeks after the infection respectively. 2. In histological sections of small intestine, most of worms were found at intervillous spaces as ovoid sections of posterior body. However, many worms, especially in 3 day-old worms, revealed protruded anterior body in glandular lumens of crypt. Some sections of anterior body were bifurcated or sacculated. 3. The worms collected from fixed intestinal mucosa under dissecting microscope exhibited a variety of postures. Many worms showed flat shapes with a concavity or curvatures. However, in many worms, the anterior body made a single or multiple protrusions. 4. By SEM observation of protruded anterior body, a longitudinal groove was found. 5. The frequency of worms with protruded anterior body decreased in 9 days, 4 weeks and 10 weeks than in 3 day-old worms. The above findings indicated that the anterior body of juvenile and adult M. yokogawai protruded to lumens of glandular crypt by folding their lateral portions to make a reversible tubelike structure. Frequent multiple protrusions were considered to be made to adapt the microniche of glandular crypts of dog intestine.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.225-231
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• 2004

An endoparasitoid wasp, Cotesia plutellae, has been used for a biological control agent against the diamondback moth, Plutellae xylostella. It has a symbiotic polydnavirus in their reproductive tract, which is required for its successful parasitization. Here, we measured a specific replication time of the polydnavirus during female development of C. plutellae. We, also, analyzed the reproductive potentials of female C. plutellae under mating or different host conditions. At $25^{\circ}C$, pupal C. plutellae began to develop adult tissues such as compound eyes and wings since day 2. At day 5, all adult tissues including antennae were developed and were ready to emerge. With polyclonal antibody raised against C. plutellae polydnavirus, an immunobloting could confirm virus replication at day 4 during pupal stage. Virus particles could be visualized by transmission electron microscope in the oviduct lumen of day 5 pupae. After adult eclosion, venom gland and ovarian calyx increased in size, though ovarioles did not. Mated females layed large number of eggs (over $60\%$) at first 4 days during their mean longevity of ca. 8 days at $25^{\circ}C$. Unmated females showed less active ovipositional behavior, where all the eggs developed into males. C. Plutellae parasitized both P. xylostella and fall webworm, Hyphantria cunea. However, C. Plutellae developed faster and showed higher successful paarasitization in P. xylostella than in H. cunea.

• Journal of Sericultural and Entomological Science
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• v.33 no.1
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• pp.21-26
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• 1991

Bombyx mori nuclear polyhedrosis virus (BmNPV) was successfully multiplied in the nuclear of BmN4 cells cultured with insect Grace's medium. By electron microscopic observation, the virons had a single nucleocapsid in an envelope. Polyhedral protein synthesis of BmNPV in BmN4 cells was detected at 18 hr p.i. and polyhedral protein was a singlepolypeptide with a M.W of 30 kd. At 48 hr p.i. polyhedra formation was observed by inverted mociroscope and electron microscope. Genome analysis of BmNPV by restriction endonucleases was not revealed the difference between virus produced in vivo and that in vitro.

• Applied Microscopy
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• v.31 no.3
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• pp.215-222
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• 2001

Pathogenicities of the five BBWV isolates were differentiated by the reactions on the 29 host plants including Chenopodium amaranticolor. Three specific ultrastructures were observed in cells infected with BBWV The first ultrastructure was the tube made of $1\sim2$ layers of virus particles. The second one was the comb structure consists of round and angled structures. The last one was the membrane proliferation in the cytosol.

• Korean journal of applied entomology
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• v.16 no.2 s.31
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• pp.121-125
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• 1977

This is the first report on. rice black-streaked dwarf virus in Korea. The occurrence of this virus in Korea was confirmed by symptoms On rice Plants, Vector transmission and microscopic Observation in 1975. The smaller brown planthopper, Laodelphax striatellus FALLEN, transmits this virus which is spherical with a diameter of about 60 nm. Higher infection was observed in earlier transplanted rice with higher levels of fertilizer than in normal and standard cultivation fields.