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        검색결과 168

        81.
        2013.10 구독 인증기관·개인회원 무료
        The centipede Scolopendra subspinipes mutilans has been a medically important arthropod species by using it as a traditional medicine for the treatment of various diseases. In this study, we derived a novel lactoferricin B like peptide (LBLP) from the whole bodies of adult centipedes, S. s. mutilans, and investigated the antifungal effect of LBLP. LBLP exerted an antifungal and fungicidal activity without hemolysis. To investigate the antifungal mechanism of LBLP, a membrane study with propidium iodide was first conducted against Candida albicans. The result showed that LBLP caused fungal membrane permeabilization. The assays of the three dimensional flow cytometric contour plot and membrane potential further showed cell shrinkage and membrane depolarization by the membrane damage. Finally, we confirmed the membrane-active mechanism of LBLP by synthesizing model membranes, calcein and FITC-dextran loaded large unilamellar vesicles. These results showed that the antifungal effect of LBLP on membrane was due to the formation of pores with radii between 0.74 nm and 1.4 nm. In conclusion, this study suggests that LBLP exerts a potent antifungal activity by pore formation in the membrane, eventually leading to fungal cell death.
        82.
        2013.10 구독 인증기관·개인회원 무료
        We carried out DNA barcoding of five Korean Lymantria species to establish identification references library for quarantine inspection. Total of 118 samples including 34 samples obtained through quarantine inspection, two from USDA, and one collected from Philiphine were used for this study. And 30 sequences of 10 species from GenBank of NCBI were used as reference sequences. In a result of DNA barcoding of the Korean Lymantria species, sequence divergence of 148 DNA barcodes ranged from null to 17.0%, intraspecific divergence from null to 1.0%, and interspecific divergence from 5.1 to 17.0%. In NJ tree, L. dispar contained three clusters, which were identified as L. dispar asiatica, L. albescens, and L. xylina, respectively. L. xylina was collected through quarantine inspection on a foreign merchant ship in Yeosu port, and L. albescens was obtained by pheromone trap on L. dispar installed in Busan port. And L. monacha known as single species in Korea was revealed as species complex with three species, L. monacha, L. minomonis, and L. sugii. In subspecies level, L. dispar dispar (EGM) built single cluster, but L. d. asiatica (AGM) and L. d. japonica showed as multiple cluster. Therefore, DNA barcoding lead to rapid and accurate identification in species level, but in subspecies level, only a taxon showing geographically far distance was discriminated from the others. And the results could provide a taxonomic outline of the Korean Lymantria fauna and might be used as identification reference for Lymantria species in quarantine inspection.
        83.
        2013.10 구독 인증기관·개인회원 무료
        A taxonomic review on the Korean Lymantria Hübner, 1819 was conducted. In a result, a total of nine species under four subgenera including two new recorded species were detected as followings: L. dispar asiatica Vnukovskij, 1926, L. xylina Swinhoe, 1903, L. monacha (Linnaeus, 1758), L. minomonis Matsumura, 1933, L. sugii Kishida, 1986, L. lucescens (Butler, 1881), L. mathura Moore, 1865, L. fumida Butler, 1877, and L. bantaizana Matsumura, 1933. Of the two unrecorded species, L. minomonis was found only in Is. Bogildo of Jeollanam-do, the southern part of Korea, and the other one, L. sugii was collected in the middle part of Korea. On the two species, L. xylina and L. fumida, the Korean specimens could not be examined through this study. Therefore, we considered that the two species might be excluded from the Korean Lymantria fauna. Each species was identified on the basis of wing pattern and genitalia of male/female adult. We provided diagnosis, male/female adult habitus photos, male genitalia photos, and female ovipositor photos.
        84.
        2013.04 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover), is one of the most serious pests in various vegetable crops. In Korea, some field populations of A. gossypii especially in greenhouse showed high resistance against neonicotinoids. The imidaclopridresistant strain (IR) selected from one of the greenhouse strains was found to be about 3,800 folds more resistant to imidacloprid, compared to the susceptible strain (S), as judged by LC50 values. To identify differentially expressed genes in IR, an isogenic strain, reverse susceptible strain (IRS) was generated from IR and comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from both IR and IRS. Also we confirmed protein expression patterns by 2DE and detoxification enzyme over-expression by synergist test. However there was no significant variation among IR, IRS and S. Comparison of the nucleotide sequence of seven nicotinic acetylcholine receptor (nAChR) subunit (alpha 1-5,7 and beta 1) genes from S and IR strain revealed a point mutation causing an arginine to threonine substitution (R81T) in the loop D region of the nAChR beta 1 subunit of the IR. These mechanisms were also reported in M. persicae and this amino acid change confers a vertebrate-like character to the insect nAChR and results in reduced sensitivity to neonicotinoids. Moreover an extra point mutation, L80S (leucine to serine substitution) was also detected nearby R81T mutation in nAChR beta 1 subunit variant. These mutations can be an additive factor in imidacloprid resistance in A. gossypii. This is the first report of imidacloprid resistance mechanism in A.gossypii. Further, this would be helpful in managing A. gossypii resistant populations in field.
        86.
        2012.05 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in seed potato and various vegetable cultivation. The imidacloprid-resistant strain (IR) was over 300-fold more resistant to imidacloprid compared to a susceptible strain (S) as judged by LC50 values. A highly imidacloprid-resistant local field population (L) was collected from cucumber at Gangwha island in 4th August 2011. Even though neonicotinoid insecticides especially imidacloprid were sprayed six times during June and July, aphid density was too high to be counted. To identify differentially expressed genes in IR or L, comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from IR, L and S strains. Futhermore, to search the resistance associated proteins in IR or L, comparative proteome analyses based on 2DE were conducted using total proteins extracted from IR, L and S strains. Few common candidate genes detected among IR and L such as ABC genes. Comparison of the nucleotide sequence of six nicotinic acetylcholine receptor (nAChR) subunit (alpha 1-5, beta 1) genes from IR, L and S strain revealed a point mutation in the loop D region of the nAChR beta 1 subunit of the IR, causing an arginine to threonine substitution (R81T). These mechanisms also reported in Myzus persicae and this amino acid change confers a vertebrate-like character to the insect nAChR and results in reduced sensitivity to neonicotinoids.
        88.
        2011.10 구독 인증기관·개인회원 무료
        Testes‐derived unipotent male germ‐line stem (GS) cells can acquire multipotency under appropriate culture conditions to become mGS cells which can contribute to all three germ‐layers. This study was designed to investigate the epigenetic characteristics of mGS cells derived from adult mouse testes (maGS cells). The GS cells were isolated from 4 6 week DBA mouse and were cultured in Dulbecco’s modified Eagle Medium supplemented with 15% (v/v) fetal bovine serum, 1,000 U/ml LIF, 4 ng/ml GDNF at 37℃ in an humidified atmosphere of 5% CO2 in air to derive the maGS cells. The multipotency of maGS cells were verified by morphological and gene expression analyses, teratoma formation upon transplantation into nude mouse and in vitro differentiation ability. Bisulfite genomic sequencing revealed that GS cells had androgenetic DNA methylation pattern at the Igf2‐H19, Gnas‐Nespas , and Dlk1‐Dio3 imprinted gene clusters which changed to hemi‐zygotic embryonic stem (ES)‐cell like pattern in the maGS cells. Western blot analysis, using modification‐ and residue‐specific antibodies, revealed that both maGS and ES cells had similar level of histone di‐methylation at 4th and 27th lysine residue of histone 3 (H3K4me2 and H3K27me2) which represent “bivalent domain” for regulating self‐renewal and differentiation of mouse ES cells. Both maGS and ES cells also shared similar hisone modification for H3K9me2, H3K79me2, H3K9ac and H3K18ac. However, maGS cells had higher level of H3K- 36me2 and H3S10p. These data suggest that maGS and ES cells share several epigenetic characteristics but they also have their own unique epigenetic marks that may be useful as a molecular marker for their identification.
        89.
        2011.10 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover), is one of the most serious pest in the cultivation of various vegetables. A highly imidacloprid-resistant field population (CA-L) was collected from cucumber at Gangwha island in 4th August 2011. Even though neonicotinoid insecticides especially imidacloprid were sprayed six times during June and July, aphid density was too high to be counted. IEF and 2DE analyses revealed that general esterase isozyme (pI. 5) in CA-L were dramatically overexpressed and more isozyme spots identified in CA-L compared to susceptible (CA-S) strain. To identify differentially expressed genes in CA-L, comparative transcriptome analyses based on GS-FLX were conducted with total RNA extracted from CA-L, which generated ca. 143 Mb reads. Previously reported, comparative transcriptome analyses performed in imidacloprid resistant (CA-IR) and CA-S. The comparative transcriptome analyses re-investigated after all data sets were combined together. As previously reported, seven ATP-binding cassette (ABC) transporter genes were newly identified in A. gossypii, among which only ABCC9 gene was highly expressed in CA-IR and L. These results suggested that ABCC subfamily associated with imidacloprid resistance in A. gossypii.
        90.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 저온처리기간, 온도 및 광의 유무가 초롱꽃 4 종의 생장과 개화에 미치는 영향을 조사하였다. 모주로 사용된 고성종인 자주초롱꽃, 왜성종인 애기초롱꽃 2 품종과 이들의 교잡 육성된 ‘직녀’, ‘견우’ F1 2 품종의 조직배양묘를 식물재료로 사용하였다. 조직배양묘는 광 도가 약 75 μmol·m2·s−1이고 온도가 25oC인 기내에서 5주 동안 발근시켰다. 광의 유무는 알루미늄 호일로 포장한 암처리와 명처리(약 10 μmol·m2·s−1 PPFD)를 사 용하였고, 저온처리기간은 3, 6, 또는 9주로 하여 4와 25oC 온도에서 저장하였다. 저온처리 후 식물을 10 cm 화분에 상토를 채워 이식하여 생장조절챔버에서 순화시 켜 온실로 옮겨 재배하였다. 4종 중 자주초롱꽃에서 생존 율이 가장 높았다. 생존율은 암처리보다 명처리에서 더 높았다. 기내에서 6주 이상 저장된 처리구는 생존율이 감소하였다. 4종을 실험한 결과 개화를 한 품종은 ‘직 녀’로 저장기간 3주, 명처리, 25oC에서 62.8%의 높은 개화율을 보였다. 개화는 온도, 저장기간, 그리고 광의 유무에 따라 영향이 있었다. 저장기간 3주, 암조건, 4oC 에서 저장한 처리에서 현저하게 개화소요일수가 단축되 고 개화특성도 좋았다. 이 결과는 개화를 위해 저온을 요구하는 것은 질적인 것보다 양적임을 암시한다. 이 실험은 조직배양묘를 사용하여 저온처리를 하고 순화 하는 과정에서 많이 고사하였으므로, 식물의 개체수를 더 늘려서 이 결론을 확인할 필요가 있다.
        4,000원
        92.
        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
        93.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        커피나무를 실내분화로 개발할 목적으로 광도에 따 른 생육반응과 겨울철 온도관리에 대한 실험을 수행한 결과는 다음과 같다. 50% 차광망으로 0~3겹까지 차광 하여 생육을 조사한 결과, 1겹과 2겹에서 생육이 가장 양호하고 엽색도 진한 녹색이며 잎에 광택이 있어 관 상가치도 가장 높은 것으로 나타났다. 3겹 차광에서는 엽색은 진하나, 생육이 지나치게 억제된 결과를 보였으 며, 무차광에서는 엽색이 탈색되고 생육도 현저하게 저 하되었다. 겨울철에 최저 온도를 5, 10, 15, 20oC로 설정하고 커피나무를 관리한 결과, 15oC 이상에서 정 상적인 생육이 가능했으며, 엽색도 진한 녹색으로 관상 가치가 높게 나타났다. 그러나 10oC에서는 생육이 현 저하게 저하되었고, 5oC에서는 생육저하뿐 아니라 일 부 개체는 저온피해로 고사되었다. 따라서 커피나무를 분화로 재배하고자 할 때는 50% 차광망으로 2겹이 가장 좋으며, 겨울철 야간 최저 온도는 15oC이라고 판단되었다.
        4,000원
        94.
        2006.03 구독 인증기관 무료, 개인회원 유료
        Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.
        3,000원
        100.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        Roasting has revealed coffee’s potentials as a good source of bioactive compounds. This study was done to investigate the quantitative presence and activity of bioactive compounds including caffeine, chlorogenic acid (CGA), amino acids, and antioxidant capacity on Coffea arabica L. (Guatemala finca San Sebastian) and C. robusta L. (India Azad Hind). Analysis was performed on Green Bean (GB) Medium-Light (ML), Medium (ME) and Medium-Dark (MD) samples of both varieties. From the results, caffeine content was highest in ME samples of both varieties. GB samples of both varieties had high CGA content which decreased after increasing roasting time and temperature. Most amino acids in GB samples was highest, however, glutamic acid, valine, tyrosine, isoleucine, leucine and phenylalanine had highest quantitative increase in ME samples for both varieties. IC50 of DPPH and ABTS radical scavenging activity was highest in ML samples of both varieties. IC50 of reducing power and total phenolic content was highest in GB sample of both varieties but decreased after increasing roasting conditions. Generally Robusta had the highest quantity of bioactive compounds and antioxidant activity. From this study, the optimal roasting condition for coffee is ME above which there is a significant reduction of bioactive compounds and antioxidant activity.
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