• 제목/요약/키워드: elucidation

검색결과 516건 처리시간 0.026초

Utilization of fish gut analysis to elucidation of microcrustacean species composition (cladoceran and copepoda) in a shallow and vegetated lake (Jangcheok Lake, South Korea)

  • Choi, Jong-Yun;Jeong, Kwang-Seuk;Lee, Eunkyu;Choi, Kee-Ryong;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • 제37권3호
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    • pp.147-153
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    • 2014
  • Structural heterogeneity results in different spatial distributions of microcrustaceans. Thus, in ecosystems with excessive macrophyte development, it may be difficult to determine the microcrustacean species composition. Given the importance of microcrustaceans in the food web, the elucidation of microcrustacean diversity is essential. In vegetated habitats, bluegill sunfish can prey on microcrustaceans, and therefore have a potential role as microcrustacean monitoring agents. In the present study, we compared microcrustacean species compositions in the field with those in the guts of bluegill, in Jangcheok Lake, South Korea. Our results showed that the number of microcrustacean species was higher in bluegill guts than in the field. Further, microcrustacean species, such as Daphnia galeata, Graptoleveris testudinaria, Leydigia leydigii, Rhynchotalona sp., and Simocephalus exponisus, were found only in bluegill guts. Our findings verify the validity of the fish gut analysis to monitor microcrustacean species compositions and to clarify spatial distributions of microcrustacean species in structurally heterogeneous ecosystems with excessive macrophyte development.

연안유속분포 형상에 미치는 제인자 (Factors Affecting Longshore Current Profile)

  • 김경호;윤영호;조재희
    • 한국해안해양공학회지
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    • 제3권2호
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    • pp.108-115
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    • 1991
  • 쇄파후 발생하는 에너지 손실과 밀접한 관계를 가지며 또한 쇄파대내에 국한되어 분포하고 있는 연안류 분포형상과 그 형상에 영향을 미치는 제인자에 대해서 고찰하였다. 연안류는 연안역의 물질확산에 관계하며 연안표사와 밀접한 관계가 있어 이에 대한 구명은 공학상으로 커다란 의미를 갖는다. 계산결과로부터 수평확산계수, 마찰계수, 파향각, 파형경사 및 해저경사 등의 연안류의 유속 분포형상에 미치는 영향을 검토하고, 계산의 타당성을 검토하기 위해 기왕의 연구결과와 본 연구에서의 계산결과를 비교 검토한다.

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식물 병원균 Bipolaris cynodontis로부터 분리한 새로운 Cochlioquinol 유도체의 구조 분석 (Structure Elucidation of New Cochlioquinol Derivatives from Pathogenic Fungus Bipolaris cynodontis)

  • 임치환
    • 분석과학
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    • 제9권1호
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    • pp.112-117
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    • 1996
  • 이탈리안 라이그라스(Lolium multiflorum Lam.) 및 버뮤다그라스와 같은 벼과 잡초에 병해를 일으키는 Bipolaris cynodontis의 배양 추출물로부터 이탈리안 라이그라스 뿌리의 생육저해를 나타내는 3종류의 활성물질을 분리 정제하고 $^1H$, $^{13}C$ 및 2차원 NMR을 포함한 각종 기기분석방법을 통하여 이들 화함물들의 구조를 결정하였다. 이들 화합물들은 저자에 의하여 보고된 바 있는 cochlioquinol이라 명명된 화합물의 유도체들로서 지금까지 보고된 바 없는 새로운 물질이며 숙주식물 중의 하나인 이탈리안 라이그라스에 대하여 활성(20~70%)을 나타내는 것으로 보아 병원균의 병징 발현에 관여하는 것으로 보여진다.

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Structure elucidation of a newly isolated saponin from Clerodendrum serratum (L) Moon

  • Bhujbal, Santosh S.;K.Nanda, Rabindra;S.Deoda, Ramesh;Kumar, Dinesh;Kewatkar, Shailesh M.;S.More, Laxmikant;J.Patil, Manohar
    • Advances in Traditional Medicine
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    • 제10권4호
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    • pp.319-321
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    • 2010
  • Plant saponins are widely distributed amongst plants and have a wide range of biological properties. Icosahydropicenic acid, $C_{51}H_{80}O_{19}$ ((4S,6bS)-8a-((4,5-dihydroxy-6-methyl-3-((3R)-3,4,5-trihydroxy-6-methyl-tetrahydro-2H-pyran-2-yloxy)-tetrahydro-2H-pyran-2-yloxy)carbonyl)-2-hydroxy-4, 6a, 6b, 11, 14b-pentamethyl-11-(2-methylprop-1-enyl)-3-(3,4,5-trihydroxy-6-(hydroxymethyl) - tetrahydro-2Hpyran-2-yloxy)-1, 2, 3, 4, 4a, 5, 6, 6a, 6b, 7, 8, 8a, 9, 10, 11, 12, 12a, 14, 14a, 14b-icosahydropicene-4-carboxylic acid), a new saponin was first time isolated from the roots of Clerodendrum Serratum (L) Moon (Verbenaceae). The structure elucidation of the compound was carried out by $^1H$ NMR and DART-MS studies.

The peduncle-specific expression during floral transition by high-throughput transcriptome analysis in wheat

  • Lee, Cheol Won;Seo, Yong Weo
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.87-87
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    • 2017
  • Flowering time of either early or late is one of the crucial parameters that determine the crop productivity. Therefore, elucidation of regulatory mechanisms of flowering time should contribute to breeding for yield enhancement. However, comprehensive explanation on molecular mechanism of flowering has not yet been reported in hexaploidy common wheat (Triticum asetivum L.). The mechanism of flowering in wheat has been studied mostly using flag leaf or floral meristem. The exposed peduncle, which is a shoot part between bottom of the spike and flag leaf, could be an important tissue that is responsible for flowering through various molecules expressing. To clarify for transcriptomic dynamics in the wheat peduncle that was uncovered by leaf sheath of flag leaf, RNA sequencing and transcriptomic analysis were conducted. With this, we also analyzed other transcriptomic results deposited in the public DB to identify genes specially expressed in peduncle tissue at transition from vegetative to reproductive phase. The obtained results will provide valuable information to understand the role of peduncle for flowing regulation in wheat aimming for elucidation of the regulatory mechanism of wheat flowering.

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Meroparamycin Production by Newly Isolated Streptomyces sp. Strain MAR01: Taxonomy, Fermentation, Purification and Structural Elucidation

  • El-Naggar Moustafa Y.;El-Assar Samy A.;Abdul-Gawad Sahar M.
    • Journal of Microbiology
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    • 제44권4호
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    • pp.432-438
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    • 2006
  • Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified. the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, $^1H$ NMR, $^{13}C$ NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of $C_{19}H_{29}NO_2$ and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.

섬유제품 함유 PCP 분석 및 근원 규명 (Analysis of PCP in Textile Products and Elucidation of its Source in Textile-Producing Chains)

  • 최은경;박경수;조영달;정진갑
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 봄 학술발표회 논문집
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    • pp.283-286
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    • 2003
  • PCP(pentachlorophenol)는 독일 법규 혹은 에코라벨 부여기준 시 고려되는 항목으로서, 인체에 유해한 물질로 규정되어 섬유제품 내에 0.5 ppm 이상 존재해서는 안 되며 특히, 유아복은 0.05 ppm 이하로 검출되어야 한다. 유럽 수출시 PCP의 검출로 인해 수출 장벽이 되었던 한 원단제품의 경우를 보면, 외국 시험기관에서 positive 혹은 negative의 판정만을 알려주므로, 원단을 생산한 염색공장이나 원단을 구매하여 수출한 바이어 모두 해결책을 찾기에 애로사항이 있는 경우가 적지 않게 발생하고 있다. (중략)

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