• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.213-221
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• 2015

The aim of this study was to set up the optimal exposure condition according to detector type considering image quality (IQ) with radiation dose in chest digital radiography. We used three detector type such as flat-panel detector (FP) and computed radiography (CR), and charge-coupled device (CCD). Entrance surface dose (ESD) was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image informations. Standard exposure condition using each institution was 117 kVp-AEC at FP and 117 kVp-8 mAs at CR, and 117 kVp-8 mAs at CCD. Statistical analysis was performed by One way ANOVA (Dunnett T3 test) using SPSS ver. 19.0. In FP, IQ scores were not significant difference between 102 kVp-4 mAs and 117 kVp-AEC (28.4 vs. 31.1, p=1.000), even though ESD was decreased up to 50% ($62.3{\mu}Gy$ vs. $125.1{\mu}Gy$). In CR, ESD was greatly decreased from 117 kVp-8 mAs to 90 kVp-8 mAs without significant difference of IQ score (p=1.000, 24.6 vs. 19.5). In CCD, IQ score of 117 kVp-8 mAs was similar with 109 kVp-8 mAs (29.6 vs. 29.0), with decreasing from $320.8{\mu}Gy$ to $284.7{\mu}Gy$ (about 11%). We conclude that optimal x-ray exposure condition for chest digital radiography is 102 kVp-4 mAs in FP and 90 kVp-8 mAs in CR, and 109 kVp-8 mAs in CCD.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.449-456
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• 2003

The VP2 gene of aquatic birnavirus, Korean isolate (GC-1) was cloned and expressed using the baculovirus expression system. The VP2 gene and VP2 partial gene, which contained a neutralizing epitope, were constructed for recombinant transfer vectors, for baculovirus expression. The expressed recombinant proteins were confirmed by indirect immuno fluorescence antibody (IFA), SDS-PAGE and Western blot. The level of expression was checked at regular time using IFA and Western blot. To measure the neutralizing activity of recombinant proteins against GC-1 strain, the antisera against recombinant proteins were produced by using guinea pigs. The result showed that the antisera neutralized the GC-1 strain. However, the neutralizing titer was higher in antisera against the VP2 gene expressed recombinant protein than that of VP2 partial gene recombinant protein.

• BMB Reports
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• v.32 no.5
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• pp.456-460
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• 1999

The promoter of the HSV-1 VP16 gene contains binding sites for the cellular transcription factors such as USF, CTF, and Sp1, each of which affects basal level expression of the VP16 gene. Transcription of the VP16 gene was induced by viral immediate-early proteins, ICP0 and ICP4, in a synergistic manner but repressed by ICP22. To gain further insight into the role of ICP0 in the expression of the VP16 gene during virus infection, several mutants with deletions in each of their transcriptional regulatory elements were generated. According to transient gene expression assays of these mutants using the CAT gene as a reporter, the USF and CTF binding sites were necessary for efficient induction of the promoter in the presence of transfected ICP0 or during virus infection, whereas the Sp1 binding site had little effect on ICP0-mediated VP16 expression. These results indicate that the immediate early proteins of HSV-1 regulate expression of the VP16 gene during virus infection by modulating the activities of cellular transcription factors such as USF and CTF.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.176-179
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• 2013

본 논문에서는 JCT-VC 에서 2013 년 1 월에 표준화가 완료된 High Efficiency Video Coding (HEVC)과 구글에서 2013 년 6 월에 개발 완료 예정인 VP9 의 압축 효율 비교를 수행한다. HEVC 는 UHD 등 고화질 방송 등에 대응하도록 디자인 되었으며, VP9 은 유튜브 (YouTube) 등과 같은 인터넷 비디오 스트리밍에 적합하도록 디자인되었다. VP9 의 경우 HEVC 와는 달리 로열티 프리 (royalty-free)를 지향하며 오픈소스 (open source) 방식으로 개발이 진행되고 있다. 본 논문에서는 HEVC 와 VP9 의 디자인 차별점을 소개하고, 랜덤 액세스 환경(Random Access, RA)과 저지연 환경 (Low Delay, LD)에서 HEVC 와 VP9 의 압축 효율을 비교한다. 실험 결과에 따르면, 방송 및 패키지 미디어 등에서 많이 사용될 랜덤 액세스 환경에서는 VP9 이 HEVC 대비 32.7% 열세를 보인다. 비디오 컨퍼런스등과 같은 저지연 환경에서는 VP9 이 HEVC 대비 26.7% 열세를 보인다. VP9 의 경우 개발이 완료된 것이 아니므로, 향후 압축 효율의 향상이 있을 것으로 기대된다.

• Polymer(Korea)
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• v.24 no.2
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• pp.252-258
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• 2000

Various crosslinked poly(4-vinylpyridines) (CHP4VP) having different degrees of crosslinking were synthesized by radical copolymerization of 4-vinylpyridine with if N,N' -1, 6-hexamethylenebisacrylamide, and CHP4VP- Cu(II) complexes were prepared by the method of adsorption equilibrium. The catalytic activity of the complexes for the oxidation of ascorbic acid (AA) was investigated. The oxidation of AA by these complexes showed a kinetic behavior of the Michaelis-Menten type. The catalytic activity of CHP4VP-Cu(I ) catalytic system was increased with increasing the degree of crosslinking of CHP4VP, and its activity was scarcely decreased even after repeated use. However, the tendency of the catalytic activity of CHP4VP-Cu(II) complexes was decreased for the oxidation of AA when compared with that of the previously reported catalytic system containing crosslinked poly(4-vinylpyridine) prepared using N,N'-methylenebisacrylamide as a crosslinker. These results indicate that the degree of crosslinking of CHP4VP and the hydrophobicity of the crosslinker play an important role in the catalytic system of the oxidation of AA.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.463-469
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• 2002

Rotaviruses are the world-wide leading causative agents of severe dehydrating gastroenteritis in young children and animals. The outer capsid glycoprotein VP7 and inner capsid glycoprotein VP6 of rotaviruses are highly antigenic and immunogenic. An SFV-based expression system has recently emerged as a useful tool for heterologous protein production in mammalian cells, exhibiting a much more efficient performance compared to other gene expression systems. Accordingly, the current study adopted an SFV-based expression system to express the VP7 of a group A human rotavirus from a Korean isolate, and the VP6 of a group B bovine rotavirus from a Korean isolate, in mammalian cells. The genes of the VP6 and VP7 were inserted into the SFV expression vector pSFV-1. The RNA was transcribed in vitro from pSFV-VP6 and pSFV-VP7 using SP6 polymerase. Each RNA was then electroporated into BHK-21 cells along with pSFV-helper RNA containing the structural protein gene without the packaging signal. The expression of VP6 and VP7 in the cytoplasm was then detected by immunocytochemistry. The recombinant virus was harvested by ultracentrifugation and examined under electron microscopy. After infecting BHK-21 cells with the defective viruses, the expressed proteins were separated by SDS-PAGE and analyzed by a Western blot. The results indicate that an SFV-based expression system fur the VP6 and VP7 of rotaviruses is an efficient tool for developing a diagnostic kit and/or preventive vaccine.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.7-12
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• 2006

We have studied pharmacokinetics of a new anti-human immunodeficiency virus (HIV) agent VP-0501 and its amino acid prodrug VP-0501AL which is designed to improve oral bioavailability. After oral administration at 100 mg/kg dose in rats (n = 4), VP-0501 was not detectable in plasma (<50 ng/ml), while after the administration of VP-0501AL, VP-0501 was quantitatively detected, at least for 8 hrs, with Cmax of ca. $2.5{\mu}g/ml$ and AUC of $8hr^{\ast}{\mu}g/ml$. When VP-0501 was intravenously administered at 50mg/kg, this compound appeared at a marginal level in plasma with AUC of $2hr^{\ast}{\mu}g/ml$, $t_{1/2}$ of 2 hr, $C_0$ of $0.7{\mu}g/ml$, and MRT of 3 hr. On the other hand, with intravenous VP-0501AL at the same dose, both the prodrug VP-0501AL and its metabolite VP-0501 appeared comparatively at higher level in the plasma: pharmacokinetic parameters of VP-0501AL including $Vd_{\beta}$, AUC, $t_{1/2,{\beta}}$, $C_0$, $CL_{tot}$, and MRT were ca. 2 L/kg, $70hr^{\ast}{\mu}g/ml$, 2 hr, $180{\mu}g/ml$, 0.7 L/hr/kg, and 1 hr, respectively. These results demonstrate that attachment of amino acid alanine to VP-0501 is an effective approach for improvement of its oral bioavailability. Therefore, VP-0501AL is expected to become a new highly bioavailable and potent anti-AIDS drug candidate/lead compound.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.261-267
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• 2017

The study has attempted to evaluate and compare the image evaluation and exposure dose by respectively applying filter back projection (FBP), the existing test method, and adaptive statistical iterative reconstruction (ASIR) with different values of tube voltage during the low dose computed tomography (LDCT). With the image reconstruction method as basis, chest phantom was utilized with the FBP and ASIR set at 10%, 20% respectively, and the change of tube voltage (100 kVp, 120 kVp). For image evaluation, back ground noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were measured, and, for dose assessment, CTDIvol and DLP were measured respectively. In terms of image evaluation, there was significant difference in ascending aorta (AA) SNR and inpraspinatus muscle (IM) SNR with the different amount of tube voltage (p < 0.05). In terms of CTDIvol, the measured values with the same tube voltage of 120 kVp were 2.6 mGy with no-ASIR and 2.17 mGy with 20%-ASIR respectively, decreased by 0.43 mGy, and the values with 100 kVp were 1.61 mGy with no-ASIR and 1.34 mGy with 20%-ASIR, decreased by 0.27 mGy. In terms of DLP, the measured values with 120 kVp were $103.21mGy{\cdot}cm$ with no-ASIR and $85.94mGy{\cdot}cm$ with 20%-ASIR, decreased by $17.27mGy{\cdot}cm$ (about 16.7%), and the values with 100 kVp were $63.84mGy{\cdot}cm$ with no-ASIR and $53.25mGy{\cdot}cm$ with 20%-ASIR, a decrease by $10.62mGy{\cdot}cm$ (about 16.7%). At lower tube voltage, the rate of dose significantly decreased, but the negative effects on image evaluation was shown due to the increase of noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2C
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• pp.131-142
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• 2002

It is Proposed thatthe Algorithm for Self healing to restoration the backup VP Occurrence Error in ATM Network. This study focuses on self-healing algorithm to restore failed VP. and backup-VP algorithm, one of the popular self-healing algorithm, is applied in this study. The problem with the existing algorithm is that when backup-VP is failed, there is no solution. This study proposes backup-VP algorithm to guarantee QoS in accordance with class. This study evaluates the effect of failure and proposes two algorithms. One is a disjointed path group to node pair class, and the other is one that applied different backup-VP case by case. Through simulation network restoring ability is compared, analyzed and synthesized.

• Korean Journal of Veterinary Research
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• v.61 no.2
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• pp.19.1-19.7
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• 2021

Feline panleukopenia virus (FPV) causes leukopenia and severe hemorrhagic diarrhea, killing 50% of naturally infected cats. Although intact FPV can serve as an antigen in the hemagglutination inhibition (HI) test, an accidental laboratory-mediated infection is concern. A non-infectious diagnostic reagent is required for the HI test. Here, we expressed the viral protein 2 (VP2) gene of the FPV strain currently prevalent in South Korea in a baculovirus expression system; VP2 protein was identified by an indirect immunofluorescence assay, electron microscopy (EM), Western blotting (WB), and a hemagglutination assay (HA). EM showed that the recombinant VP2 protein self-assembled to form virus-like particles. WB revealed that the recombinant VP2 was 65 kDa in size. The HA activity of the recombinant VP2 protein was very high at 1:2¹⁵. A total of 143 cat serum samples were tested using FPV (HI-FPV test) and the recombinant VP2 protein (HI-VP2 test) as HI antigens. The sensitivity, specificity, and accuracy of the HI-VP2 test were 99.3%, 88.9%, and 99.3%, respectively, compared to the HI-FPV test. The HI-VP2 and HI-FPV results correlated significantly (r = 0.978). Thus, recombinant VP2 can substitute for intact FPV as the serological diagnostic reagent of the HI test for FPV.