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        검색결과 829

        422.
        2008.10 구독 인증기관·개인회원 무료
        To determine the characteristics of the Korean porcine reproductive and respiratory syndrome virus (PRRSV), CA, which was isolated from the serum of an infected pig in 2006, we investigated the nucleotide sequence and expression of the structural ORFs (ORFs 2 to 7) using the bApGOZA system. We found that the structural ORFs 2 to 7 of CA consisted of 3188 nucleotides that were the same as those formed from VR-2332. Comparison of the CA with the other strains revealed nucleotide sequence identity ranging from 89.8 to 99.5%. To better understand the genetic relationships between other strains, phylogenetic analyses were performed. The CA strain was closely related to the other North American genotype strains but formed a distinct branch with high bootstrap support. Additionally, expression levels of the PRRSV proteins in Sf21 cells were strong or partially weak. The results of this study have implications for both the taxonomy of PRRSV and vaccine development.
        423.
        2008.10 구독 인증기관·개인회원 무료
        The porcine reproductive and respiratory syndrome virus (PRRSV) has six structural proteins which encoded by ORFs 2 to 7 are designated as GP2, 3, 4, 5, M and N, repectively. In this study, we determined the expression of each protein using novel transfer vector, pBmKSK4 which has the polyhedrin promoter of BmNPV and 6xHis tag. The recombinant transfer vector was co-transfected into Bm5 cells along with bBpGOZA DNA. Recombinant virus was purified by plaque assay and amplified in Bm5 cells. Expression of each protein was identified by SDS-PAGE and Western blot analysis using anti-6xHis monoclonal antibody. The expression levels of the structural proteins in Bm5 cells were stronger than the expression system using pBacPAK9 transfer vector in Sf21 cells. As expected, GP5 was expressed at low levels from its structural properties and its toxicity for cells. In addition, each recombinant protein was purified using Ni-NTA spin columns. The ability to produce each protein in the baculovirus system indicates that these could be major candidates for the development of a vaccine against PRRSV.
        424.
        2008.10 구독 인증기관·개인회원 무료
        Pine wilt is the most important disease of pine trees in Korea, Japan and China. The pathogen causing this disease, the pinewood nematode (Bursaphelenchus xylophylus), is transmitted vectored by adults of some cerambycid beetle species and the Japanese pine sawyer, Monochamus alternatus, is the major vector species in Korea. Although chemical insecticides have been used to kill vector insect and thus prevent transmission of the pathogen, the efficacy is not good. In Japan, to control this insect, an entomopathogenic fungus was studied and developed as an insecticide. This is thought to be the convenient and effective method to control M. alternatus. Recently, there are several reports about the pinewood nematode is vectored by also the pine sawyer, M. saltuarius, in Korea. The objective of this study, therefore, was to isolate and identify entomopathogenic fungi from M. saltuarius cadaver to control it. We collected the cadaver of M. saltuarius and then screened several fungi colonies. The pathogenicity of each fungus was tested using oak longicorn beetle, Moechotypa diphysis, as substitutive insect. M. diphysis is also serious pest to various trees in forest. As the result, only one of them showed high pathogenicity against M. diphysis. Selected fungus was identified by microscopic examination and DNA analysis. Pathogenicity was also evaluated to M. saltuarius.
        425.
        2008.10 구독 인증기관·개인회원 무료
        Propylea japonica is small ladybug(approximately 4-5mm) and is met with everywhere in Korea. When there was no aphid, the survival rate of P. japonica was 0% among another instar bugs and 26.7~32.8% among same instar bugs after 48 hours. When there were sufficient aphids, the cannibalism of P. japonica was low, so the survival rate of P. japonica was 78.6~95.8% among another instar bugs and 80.6~100% among same instar bugs after 48 hours. In the comparison of the number of eggs at different oviposition site, P. japonica preferred the corrugated cardboard. In experiment using T-tube, the rate of decoy was 81% at cotton aphid compared with pepper leaf and 62% at cotton aphid compared with artificial diet. In the artificial diet using shrimp and chicken liver, the developmental period from egg to adult was 17days and the survival rate from egg to adult was 66.7% but the vitality was not good. These data suggest that P. japonica can be used effective natural enemy for control of aphids and is needed to research about artificial diet, mass rearing system and control effect in field.
        426.
        2008.09 구독 인증기관 무료, 개인회원 유료
        수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드 스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동 방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색 특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율 면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위 칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.
        4,000원
        427.
        2008.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        As a continuation of a previous work by Park et al. (2006), we have developed a two-element radio interferometer that can measure both the phase and amplitude of a visibility function. Two small radio telescopes with diameters of 2.3 m are used as before, but this time an external reference oscillator is shared by the two telescopes so that the local oscillator frequencies are identical. We do not use a hardware correlator; instead we record signals from the two telescopes onto a PC and then perform software correlation. Complex visibilities are obtained toward the sun at λ=21cm for 24 baselines with the use of the earth rotation and positional changes of one element, where the maximum baseline length projected onto UV plane is ~90λ As expected, the visibility amplitude decreases with the baseline length, while the phase is almost constant. The image obtained by the Fourier transformation of the visibility function nicely delineates the sun, which is barely resolved due to the limited baseline length. The experiment demonstrates that this system can be used as a "toy" interferometer at least for the education of (under)graduate students.
        4,000원
        432.
        2007.12 구독 인증기관 무료, 개인회원 유료
        Physicochemical qualities and consumer acceptability of chocolate layer cake were studied with varied levels of rosemary powder at 0, 0.2, 0.4 and 0.6%. The ash content of the cake increased from 2.30 to 3.10%, as the amount of rosemary powder increased from 0 to 0.6%, and the carbohydrate content of the cake decreased as the addition of rosemary powder increased. There were no significant differences in moisture contents and pH values among the samples and the pH values of all samples were within the typical pH range of 7.5-8.0 for chocolate, layer cakes. Water loss from the control cake was greater than that from the cakes with rosemary powder supporting the suggestion that the addition of rosemary powder to the chocolate layer cake could increase moisture retention of the cake. Consumer acceptability of all the samples showed higher prefierences of more than 7 points. Rosemary aroma, mint flavor and after taste were highly positively corrεlated with the fat content. Fat and ash content of the cake, which tended to increase in proportion to the rosemary powder content, were negatively correlated with acceptance of herb flavor, sweet taste, moistness, softness and intensity of softness but positivεly correlated with intensity of herb flavor. With the results above, trials on chocolate layer cake using rosemary powder were successfully performed within the ranges tested.
        4,000원
        437.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 온시디움에 있어서 particle bombardment 및 아그로박테리움 매개 형질전환 최적 조건을 구명하 고자 실시하였다. 실험재료는 ‘Sharry Baby’의 PLBs를 사용하였으며, 유전자는 pCAMBIA3301 vector에 삽입 되어 있는 bar와 intron-gus를 사용하였다. Particle bombardment 법에 있어서는 직경이 0.6 μm인 금 입자 에 유전자를 혼합하여 9 cm의 거리에서 1,100 psi 헬륨 가스 압으로 발사하는 것이 유전자 도입에 효과적이었 다. 아그로박테리움 매개법에 있어서는 미성숙 PLBs를 O.D 0.6 정도인 균주에 접종 후 5일간 광조건 없이 공동 배양하는 것이 유전자 도입에 효과적이었다.
        4,000원