• 제목/요약/키워드: Sa

검색결과 6,514건 처리시간 0.039초

Construction of Bifunctional Fusion Enzyme between Maltooligosyltrehalose Synthase and Maltooligosyltrehalose Trehalohydrolase of Sulfolobus acidocaldarius and Overexpression in E. coli

  • Kim, Chung Ho
    • Journal of Applied Biological Chemistry
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    • 제43권4호
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    • pp.240-245
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    • 2000
  • Two genes encoding maltooligosyltrehalose synthase (SaMTS) and maltooligosyltrehalose trehalohydrolase (SaMTH) were isolated from a hyperthermophilic microorganism, Sulfolobus acidocaldarius (ATCC 49462). ORFs of the SaMTS and SaMTH genes are 2,163 and 1,671 bp long and encode 720 and 556 amino acid residues, respectively. A bifunctional fusion enzyme (SaMTSH) was constructed through the gene fusion of SaMTS and SaMTH. Recombinant SaMTS, SaMTH, and SaMTSH fusion enzyme were overexpressed in E. coli BL21. SaMTS and SaMTH produced trehalose and maltotriose from maltopentaose in a sequential reaction. SaMTSH fusion enzyme catalyzed the sequential reaction in which the formation of maltotriosyltrehalose was followed by hydrolysis leading to the synthesis of trehalose and maltotriose. The SaMTSH fusion enzyme showed the highest activity at pH 5.0-5.5 and $70-75^{\circ}C$. SaMTS, SaMTH, and SaMTSH fusion enzyme were active in soluble starch, which resulted in the production of trehalose.

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Salicylic acid가 닭의장풀의 광합성에 미치는 영향 (The Effect of Salicylic Acid (SA) on the Photosynthetic Activity in Commelina communis L.)

  • 이준상
    • 환경생물
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    • 제17권3호
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    • pp.359-364
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    • 1999
  • 살리실릭산(SA)이 닭의장풀의 잎의 생장, 엽록소 함량, 광합성능, 기공전도도에 미치는 영향을 조사하였다. Hoagland 용액에 SA를 처리한 후 3주 동안 배양한 닭의장풀은 잎의 길이, 너비, 면적이 크게 감소하였다. 1 mM SA를 1, 2주 처리 시에 엽면적 생장이 약 10%억제되었으며, 3주 째에는 22%억제하였다. SA는 또한 2주 째는 47%그리고 3주 째는 53%엽록소 함량을 감소시켰다. SA를 처리한 샘플의 엽록소 a/b는 3주 째에 약 3으로 크게 증가하였다. SA를 분리 엽록체에 직접 처리하여 전자전달활성을 직접 측정하였다. PSII+PSI, PSII 그리고 PSI활성에 SA가 영향을 주지 않았다. 이는 SA가 직접 광합성 기작에는 영향을 주지 않는 다는 것을 나타낸다. 그러나, SA를 오랜 기간 처리하면 광합성의 감소는 매우 뚜렷하게 관찰되었다. Hoagland 용액에 SA를 처리한 후 3주 동안 배양한 닭의장풀에 다양한 빛 광도(100~1000$\mu$mo1 m­$^2$$^1$)를 조사하면 약 23~65%의 광합성능의 저하가 나타났다. 기공전도도가 유사한 반응을 보여주었다. SA처리구의 기공은 거의 닫혔다. 여러 광조건에서 기공전도도가 같다는 것은 SA가 기공의 조절 기능을 상실하게 한 것으로 보여진다. 이들 결과들로부터 광합성능에 대한 SA의 효과는 SA자체에 의한 것이 아니라 간접적인 대사 경로를 통해 매개되는 것으로 추측된다.

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잇사매와 함사매의 名稱

  • 김진구
    • 복식문화연구
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    • 제7권2호
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    • pp.220-224
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    • 1999
  • This study is concerned with the names of is sa mai(잇사매) and ham sa mai(함사매). Origins and meanings of these terms were traced and examined. Some significant findings can be summarized as follows : Korean word is sa mai(잇사매) was a compound word. Korean character is (잇) is derived from Chinese character i, and sa mai(사매) in Korean means sleeves 神 in Chinese character. The character ham in Ham sa mai(함사매) is its origin in Chinese : Korean character ham was Korean pronounciation of the Chinese character, han. ham sa mai is a compound word of ham(함) (Korean), (han ) (Chinese) and sa mai(사매) sleeves(Korean). Thus, first characters of is(잇) in is sa mai(잇사매) and ham(함) in ham sa mai(함사매) are originated from Chinese, where as the word sa mai in the end of is sa mai and ham sa mai is pure Korean. Both character i and ham(han, Chinese) in Chinese means a jaw. Thus, both is sa mai(잇사매) and ham sa mai(함사매) means “jawed sleeves”. That is long and wide round sleeves with narraw wrists.

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카드뮴에 의해 유도된 담배 식물의 생장, 엽록소와 rubisco/rubisco activase에 대한 salicylic acid의 전환 효과 (The Reverse Effect of Salicylic Acid on Cd-induced Growth, Chlorophyll, and Rubisco/Rubisco Activase in Tobacco)

  • 왕옥산;노광수
    • 생명과학회지
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    • 제22권6호
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    • pp.778-787
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    • 2012
  • 카드뮴에 의해 유도되는 담배의 생장, 엽록소 함량, rubisco와 rubisco activase에 미치는 SA의 영향과, 이에 대한 변성제의 효과를 연구하였다. 담배 기내생장에 대한 SA의 최적농도를 찾기 위해, $10^{-6}$ mM - $10^2$ mM SA를 처리하여 9주간 생장시킨 결과, $10^{-4}$ mM SA에서 가장 높은 생장을 보였다. SA와 카드뮴을 4개의 실험구(대조구, SA, 카드뮴, 카드뮴 + SA)로 하여 생장, 엽록소 함량 및 rubisco와 rubisco activase의 함량과 활성을 측정한 결과, 카드뮴 > 카드뮴 + SA < 대조구 카드뮴 + SA < 대조구 ${\beta}$-mercaptoethanol은 활성을 촉진시켰으며, urea, thiourea, guanidium-HCl은 억제시켰다. 이는 L-cysteine과 ${\beta}$-mercaptoethanol은 변성에 관여하지 않으며, urea, thiourea, guanidium-HCl은 변성에 관여하였음을 의미한다. Rubisco activase의 활성에 대한 변성제들의 영향을 조사한 결과, 5종 모두는 비처리구와 비교하여 현저한 영향은 나타내지 않았다.

조선 말기 사ㆍ라에 관한 연구 (A Study on Sa(紗) and Ra(羅) at the End of the Joseon Period)

  • 이은진;조효숙
    • 복식
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    • 제53권8호
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    • pp.121-135
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    • 2003
  • The purpose of this study is to suggest a theoretical basis to name Sa(紗) and Ra(羅) remains properly by comparing and analyzing the name, usage, value, length and width of Sa(紗) and Ra(羅) recorded on documents made at the end period of Joseon. The features of Sa(紗) and Ra(羅) at the end of the Joseon Period are as follows. 1. The kinds of Sa(紗) are about 80, those of Ra(羅) are about 12, and those of Sa(紗) are significantly more than those of Ra(羅). In regard to the aspect of patterns, there were about 20 types of patterns in the case of Sa(紗), but no specific pattern for Ra(羅). 2. Some newly revealed patterns in the case of Sa (紗) are as follows. Baek -bok-mun(백복문) was a pattern full of ‘bats(박쥐[복])’, and Baek-jeop-mun(백접문) was a pattern full of ‘butterflies(나비[蝶])’ Jeop-mun(접문) was classified into ‘butterfly patterns(나비문[접문])’ and ‘traditional window flame patterns(창살문[접문])‘. 3. When considering the usages of Sa(紗) and Ra(羅), Sa(紗) was used for various detailed purposes according to their kinds and patterns, but Ra(羅) was mostly used for underwear. The most commonly used Sa(紗) was the Gab-sa type(甲紗類). On the contrary, the Go-sa type(庫紗類) was significantly less used than the Gab-sa type(甲紗類). However, it must have been of relatively high quality Sa(紗), shown by the fact that it was used for outer garments. In addition, the Gung-sa type(宮紗類) was the best quality Sa(紗), shown by the fact that it was used for court dress and official uniforms in the royal court. 4. Sa(紗) and Ra(羅) whose features have been examined we Gapsa(甲紗), Sun-in (純仁), Gosa(庫紗), Gwansa(官紗), Jusa(走紗), Eunjosa(은조사), Gwangsa(廣紗), Waesa(倭紗), Dorisa(도리사), Gong-yangsa(공양사), Rasa(羅紗), Danghangra(唐亢羅), Yanghangra(洋亢羅), Yunjura(윤주라), Eunra(銀羅), Jeohangra(저항라), Chura(秋羅). 5. Regarding the values of Sa(紗) and Ra(羅), they were high quality textures and its length and width of 1 Pil(疋), a roll of cloth, were not subdivided in detail such as in the case of plain weaved silks(平絹).

The Expression Patterns of AtBSMT1 and AtSAGT1 Encoding a Salicylic Acid (SA) Methyltransferase and a SA Glucosyltransferase, Respectively, in Arabidopsis Plants with Altered Defense Responses

  • Song, Jong Tae;Koo, Yeon Jong;Park, Jong-Beum;Seo, Yean Joo;Cho, Yeon-Jeong;Seo, Hak Soo;Choi, Yang Do
    • Molecules and Cells
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    • 제28권2호
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    • pp.105-109
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    • 2009
  • We reported previously that overexpression of a salicylic acid (SA) methyltransferase1 gene from rice (OsBSMT1) or a SA glucosyltransferase1 gene from Arabidopsis thaliana (AtSAGT1) leads to increased susceptibility to Pseudomonas syringae due to reduced SA levels. To further examine their roles in the defense responses, we assayed the transcript levels of AtBSMT1 or AtSAGT1 in plants with altered levels of SA and/or other defense components. These data showed that AtSAGT1 expression is regulated partially by SA, or nonexpressor of pathogenesis related protein1, whereas AtBSMT1 expression was induced in SA-deficient mutant plants. In addition, we produced the transgenic Arabidopsis plants with RNAi-mediated inhibition of AtSAGT1 and isolated a null mutant of AtBSMT1, and then analyzed their phenotypes. A T-DNA insertion mutation in the AtBSMT1 resulted in reduced methyl salicylate (MeSA) levels upon P. syringae infection. However, accumulation of SA and glucosyl SA was similar in both the atbsmt1 and wild-type plants, indicating the presence of another SA methyltransferase or an alternative pathway for MeSA production. The AtSAGT1-RNAi line exhibited no altered phenotypes upon pathogen infection, compared to wild-type plants, suggesting that (an)other SA glucosyltransferase(s) in Arabidopsis plants may be important for the pathogenesis of P. syringae.

A Predictive Model of Situation Awareness with ACT-R

  • Kim, Junghwan;Myung, Rohae
    • 대한인간공학회지
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    • 제35권4호
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    • pp.225-235
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    • 2016
  • Objective: The aim of this study is to model all levels of situation awareness (SA), which would be able to predict situation awareness quantitatively. Background: When measuring situation awareness, directly measuring SA methods such as SAGAT and SART have been utilized. Several approaches (cognitive modeling approaches) were introduced to model SA but level 3 SA was not completed. For real-life situation, however, it is necessary to detect the problematic level of SA rather than overall SA. Therefore, we proposed a new model of all levels of SA in this study. Method: In order to model all levels of SA, this study chose factors in ACT-R architecture through literature review. ATC (Air Traffic Control)-related simulation task was video-taped to analyze human behaviors in order to model all levels of SA including level 3. Results: As a result, regression analyses show that cognitive activities (neural activations) represented for all levels of SA were highly correlated with SAGAT. Conclusion: In conclusion, neural activations in ACT-R could be proved to be effective to model all levels of SA. Application: Our SA model could be used to predict all levels of SA quantitatively without directly measuring the SA of operators.

SA-SUPPLEMENT SUBMODULES

  • Durgun, Yilmaz
    • 대한수학회보
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    • 제58권1호
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    • pp.147-161
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    • 2021
  • In this paper, we introduced and studied sa-supplement submodules. A submodule U of a module V is called an sa-supplement submodule in V if there exists a submodule T of V such that V = T + U and U ∩ T is semiartinian. The class of sa-supplement sequences ������ is a proper class which is generated by socle-free modules injectively. We studied modules that have an sa-supplement in every extension, modules whose all submodules are sa-supplement and modules whose all sa-supplement submodules are direct summand. We provided new characterizations of right semiartinian rings and right SSI rings.

Sequence-Pair 기반의 플로어플랜을 위한 개선된 Simulated-Annealing 기법 (Improved Simulated-Annealing Technique for Sequence-Pair based Floorplan)

  • 성영태;허성우
    • 대한전자공학회논문지SD
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    • 제46권4호
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    • pp.28-36
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    • 2009
  • Sequence-Pair(SP) 모델은 모듈간의 위상 관계를 표현하는 방법으로써, 일반적으로 SP 모델에 기반한 플로어플래너(floorplanner)는 Simulated-Annealing(SA) 알고리즘을 통해 해를 탐색한다. 다양한 논문에서 SP와 SA 기반 배치 알고리즘의 성능 향상을 위해 SP의 평가 함수의 개선, SA의 스케줄링 기법 향상과 변형 함수의 개선 등을 모색하였다. 제안 기법은 기존의 SA 프레임웍을 수정한 2단계 SA 알고리즘으로써, 전 단계에선 SP로부터 구한 플로어플랜에 압축기법을 적용하여 모듈 사이에 존재하는 빈 공간을 가능한 최소화시켰다. 압축기법이 적용된 플로어플랜으로터 SP를 얻고, 이를 변환함으로써 해 공간을 탐색해 간다. 해가 기준 값에 수렴되었다고 판단되면 전 단계의 SA 기반 검색을 중단하고 압축기법을 사용하지 않은 기존의 SA 프레임웍을 이용하여 최적 해를 계속 탐색해 간다. MCNC 벤치마크 회로를 이용한 실험을 통해 제안 기법이 SA의 해 탐색 과정에 끼치는 효과를 보이며, 제안 기법을 통해 얻은 결과가 기존의 SA 기반 알고리즘으로 구한 결과보다 우수함을 보인다.

Biochemistry of Salicylic Acid and its Role in Disease Resistance

  • Lee, Hyung-Il;Raskin, Ilya
    • 식물조직배양학회지
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    • 제24권4호
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    • pp.233-238
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    • 1997
  • Salicylic acid (SA) is involved in the establishment of systemic acquired resistance (SAR) in many plant including tobacco. Considering the important role of SA in disease resistance, biosynthetic and metabolic pathways of SA in tobacco have been studied extensively: The initial step for biosynthetic pathway of SA is conversion of phenylalanine to trans-cinnamic acid, followed by decarboxylation of trans-cinnamic acid to benzoic acid and ie subsequent ring hydroxylation at the C-2 position to form SA. In TMV inoculated tobacco, most of the newly synthesized SA is glucosylated or methylated. Methyl salicylate has been identified as a biologically active, volatile signal. In contrast, the two glucosylated forms accumulate in the vicinity of lesions and consist of SA glucoside, a major metabolite, and SA glucose ester, a relatively minor from. Two enzymes involved in SA biosynthesis and metabolism have been purified and characterized : benzoic acid 2-hydroxylase which catalyzes conversion of benzoic acid to SA; UDP-Glucose: SA 1-O-D glucosyltransferase which converts SA to SA glucose ester. Further studies of the biosynthetic and metabolic pathways of SA will help to elucidate the SAR signal transduction pathway and provide potential tools for the manipulation of disease resistance.

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