• Title/Summary/Keyword: 합성 작용

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Insect Juvenile Hormone Antagonists as Eco-friendly Insecticides (친환경 살충제로서의 곤충 유충호르몬 길항제)

  • Choi, Jae Young;Je, Yeon Ho
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.101-108
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    • 2022
  • Because of their specificity to target insects and relatively low toxicity to non-target organisms, insect growth regulators (IGRs) have been regarded as attractive alternatives to chemical insecticides. Commercially available IGRs are classified into juvenile hormone agonists (JHAs), ecdysone agonists (EAs), and chitin synthesis inhibitors (CSIs) according to their mode of action. Recently, JH-mediated interaction of methoprene-tolerant (Met), which is JH receptor, and its binding partners have been replicated in vitro using yeast cells transformed with the Met and FISC/CYC genes of A. aegypti. Using this in vitro yeast two-hybrid β-galactosidase assay, juvenile hormone antagonists (JHANs) have been identified from various sources including chemical libraries, plants, and microorganisms. As juvenile hormone (JH) is an insect specific hormone and regulates development, reproduction, diapause and other physiological processes, JHANs fatally disrupt the endocrine signals, which result in abnormal development and larval death. These results suggested that JHANs could be efficiently applied as IGR insecticides with a broad insecticidal spectrum. This review discuses JH signaling pathway mediated by Met and future prospects of JHANs as environmentally benign IGR insecticides.

Molecular Structure of PCP Pincer Complexes: Poisoning Catalyst on the Dehydrogenation of Alkanes (알칸의 탈수소화반응에서의 촉매독 화합물의 분자구조)

  • Lee Ji Hyun;Chun Sang Jin;Kwon Ki Hyeok;Lee Do Weon
    • Korean Journal of Crystallography
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    • v.16 no.1
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    • pp.43-53
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    • 2005
  • The dihydrido P-C-P pincer complex, $IrH_2{C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (1), was successfully prepared from the reaction of the hydrochloride complex, $IrClH (C_6H_3-2,6-(CH_2PBu_2^t)_2}$, and super acid $(LiBEt_3H)$ under 1 atm of hydrogen in pentane solution at room temperature and followed by Heating at $130^{\circ}C$ in vacuo. Jensen recently found that the dihydrido P-C-P pincer complex 1 is a highly active homogeneous catalyst for the transfer dehydrogenation of alkanes with unusual longterm stability at temperatures as high as $200^{\circ}C$. The treatment of dihydrido complex 1 with nitrogen, water, carbon dioxide, and carbon monoxide in presence of tert-butylethylene (the) at room temperature in an appropriate solution gave the dinitrogen complex, $[Ir{C-6H_3-2,6-(CH_2PBu_2^t)_2}]_2({\mu}-N_2)$ (2), the hydrido hydroxyl complex, $IrH(OH){C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (3), the carbon dioxide complex, $Ir({\eta}^2-CO_2) {C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (including the bicarbonate complex, $IrH({\kappa}^2-O_2COH){C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(4))$, and the carbonyl complex, $Ir(CO) {C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(5)$ (including the carboxyl complex, $IrH(C(O)OH) {C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(6))$, in good yield, respectively. These P-C-P iridium complexes were isolated and characterized by $^1H,\;^{13}C,\;^{31}P\; NMR$, and IR spectroscopy. In addition, the complexes (1-6) were characterized by a single crystal X-ray crystallography. These complexes account for these small molecules' inhibition of dehydrogenation of alkanes catalyzed by the dihydrido complex 1.

The Study on Local Composite Behavior of Connection Member between Steel Pipe Pile and Concrete Footing (강관 말뚝 기초 두부 연결부의 합성거동에 대한 연구)

  • You, Sung-Kun;Park, Jong-Myen;Park, Dae-Yong;Kim, Young-Ho;Kang, Won-Ho
    • Journal of the Korea Concrete Institute
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    • v.15 no.2
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    • pp.288-296
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    • 2003
  • Generally, application of steel pipe pile as deep foundation member needs special requirement for the connection method between steel pipe pile and concrete footing. Even though two types of connection method are suggested in the related specification, type B-method is provident. To investigate real structural behavior of type B connection, several load tests are done with carefully designed experimental system. The purpose of this experiment is mainly focused on the understanding of actual behavior which can be predicted by design theory. At this research stage, vertical and lateral loading test are done for three types of specimen to review stress concentration, formation and behavior of imaginary RC column in the footing and effect of non-slip device installed in the steel pipe pile. The load resistance mechanism in these specific connection method is predicted based on both experimental results. The three-dimensional finite element modeling is also done for the purpose of comparison between numerical and experimental result. With all the results gained from experiment the structural behavior of imaginary RC column in the design concept is confirmed. The role of non-slip device is very important and it affects the resistance capacity with help of composite action of concrete and steel pipe pile.

Study on Biological Activities of Extracts for Cosmeceutical Development from Lagerstroemia indica L. Branch (화장품 개발을 위한 배롱나무(Lagerstroemia indica Linnaeus) 가지 추출물의 생리활성에 관한 연구)

  • Lee, Byung-Guen;Kim, Jong-Hyeop;Ham, Sang-Gyeong;Lee, Chang-Eeon
    • Korean Journal of Plant Resources
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    • v.27 no.1
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    • pp.29-34
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    • 2014
  • The aim of the study was to examine the cosmetic and biological activity of Lagerstroemia indica L. and it is possible that can be used as a cosmetic ingredient for application of cosmetic industries. Lagerstroemia indica L. branch was extracted with 70% acetone in water. In the result of DPPH (1,1-diphenyl-2-picryl-hydrazyl) scavenging radical activity, acetone extract of Lagerstroemia indica L. branch were higher than 73% at the 50 ppm concentration. ABTS radical cation decolorization activity by acetone extract were higher than 78% at the 50 ppm. Both examine of DPPH and ABTS showed high antioxidative activities at the 50 ppm. In the result of nitrite scavenging ability, acetone extract were higher than 63% at the 50 ppm. Collagenase inhibition activity by extract were higher than 85% at the 50 ppm. Extract is showed high collagenase inhibition more than comparison group EGCG at all concentration. These results suggest that Lagerstroemia indica L. has a great potential as a cosmeceutical raw material as well as anti-oxidant and anti-inflammatory and collagenase inhibition activity.

A Vision Transformer Based Recommender System Using Side Information (부가 정보를 활용한 비전 트랜스포머 기반의 추천시스템)

  • Kwon, Yujin;Choi, Minseok;Cho, Yoonho
    • Journal of Intelligence and Information Systems
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    • v.28 no.3
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    • pp.119-137
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    • 2022
  • Recent recommendation system studies apply various deep learning models to represent user and item interactions better. One of the noteworthy studies is ONCF(Outer product-based Neural Collaborative Filtering) which builds a two-dimensional interaction map via outer product and employs CNN (Convolutional Neural Networks) to learn high-order correlations from the map. However, ONCF has limitations in recommendation performance due to the problems with CNN and the absence of side information. ONCF using CNN has an inductive bias problem that causes poor performances for data with a distribution that does not appear in the training data. This paper proposes to employ a Vision Transformer (ViT) instead of the vanilla CNN used in ONCF. The reason is that ViT showed better results than state-of-the-art CNN in many image classification cases. In addition, we propose a new architecture to reflect side information that ONCF did not consider. Unlike previous studies that reflect side information in a neural network using simple input combination methods, this study uses an independent auxiliary classifier to reflect side information more effectively in the recommender system. ONCF used a single latent vector for user and item, but in this study, a channel is constructed using multiple vectors to enable the model to learn more diverse expressions and to obtain an ensemble effect. The experiments showed our deep learning model improved performance in recommendation compared to ONCF.

Miscibility and Specific Intermolecular Interaction Strength of PBI/PI Blends Depending on Polyimide Structure(II) - Blend Systems with PIs Synthesized by DSDA - (폴리이미드 구조변화에 의한 방향족 PBI/PI 블렌드의 상용성 및 상호작용의 세기(II) - DSDA로 합성한 PI들과의 블랜드들 -)

  • Ahn, Tae-Kwang
    • Applied Chemistry for Engineering
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    • v.9 no.2
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    • pp.207-213
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    • 1998
  • On the basis of the previous study[1], miscibility were investigated and intermolecular interaction strength for the miscibility were relatively compared for the blends poly{2,2-(m-phenylene)-5,5'-bibenzimidazole}(PBI) with two aromatic polyimides (PIs) synthesized by another dianhydride. Aromatic PAAs were prepared by the reaction of condensation of two diamines, 4,4'-methylene dianiline(4,4'-MDA) and 4,4'-oxydianiline(4,4'-ODA) with 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride(DSDA) using DMAc, and then converted into PIs after curing. PBI/PAA blends were prepared by solution blending. Cast films or precipitated powders of the PBI/PAA blends were cared at a high temperature to transform into PBI/PIs blends. Miscibility and specific intermolecular interaction for miscibility in the blends were investigated, and compared with previous polyimide structures of PBI/PIs blends [1]. Two blends, PBI/DSDA+4,4'-MDA(Blend-V) and PBI/DSDA+4,4'-ODA(Blend-VI), were found miscible : the evidences were optically clear films, synergistic single composition dependent $T_g{\prime}s$, and frequency shifts of N-H stretching band as much as $39{\sim}40cm^{-1}$, and of C=O stretching band near 1730 and $1780cm^{-1}$, 5~6 and $3{\sim}4cm^{-1}$, respectively. The specific intermolecular interactions existing between PBI and PIs were relatively analyzed with the area(A) formed between the $T_g{\prime}s$ of the measured and that of the calculated by the Fox equation at all compositions, the ${\kappa}$ values in Gordon-Taylor equation obtained from the measured $T_g{\prime}s$, and differences of the frequency shifts in the functional N-H and carbonyl stretching band. From the results, the area(A) and the ${\kappa}$ values for Blend-V and VI were smaller than those for Blend-III and IV used in previous study[1]. Differences of the frequency shifts in the functional groups(N-H and C=O) also showed similar tendency. Thus, specific intermolecular interaction strength in terms of hydrogen bonding of PBI/PI blends is dependent upon chemical structures of PIs, that is, PIs it seems that $SO_2$ group in dianhydride(DSDA) has weaker hydrogen bond strength than those of C=O in BTDA. In other words, it implies that the former occupied bulk space than the latter due to the sterric effect.

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Emotional System Applied to Android Robot for Human-friendly Interaction (인간 친화적 상호작용을 위한 안드로이드 로봇의 감성 시스템)

  • Lee, Tae-Geun;Lee, Dong-Uk;So, Byeong-Rok;Lee, Ho-Gil
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.04a
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    • pp.95-98
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    • 2007
  • 본 논문은 한국생산기술연구원에서 개발된 안드로이드 로봇(EveR Series) 플랫폼에 적용된 감성 시스템에 관한 내용을 제시한다. EveR 플랫폼은 얼굴 표정, 제스처, 음성합성을 수행 할 수 있는 플랫폼으로써 감성 시스템을 적용하여 인간 친화적인 상호작용을 원활하게 한다. 감성 시스템은 로봇에 동기를 부여하는 동기 모듈(Motivation Module), 다양한 감정들을 가지고 있는 감정 모듈(Emotion Module), 감정들, 제스처, 음성에 영향을 미치는 성격 모듈(Personality Module), 입력 받은 자극들과 상황들에 가중치를 결정하는 기억 모듈(Memory Module)로 구성되어 있다. 감성 시스템은 입력으로 음성, 텍스트, 비전, 촉각 및 상황 정보가 들어오고 감정의 선택과 가중치, 행동, 제스처를 출력하여 인간과의 대화에 있어서 자연스러움을 유도한다.

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Bioenvironmental Interaction of Toxic Peptide Hornet Venom with Phospholipid (Hornet 독액의 독성 Peptide와 Phospholipid 간의 생체환경적 상호작용)

  • 김광호;이봉헌
    • Journal of Environmental Science International
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    • v.6 no.2
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    • pp.189-194
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    • 1997
  • Toxic peptides from hornet venom, mastoparan and mastoparan-B were synthesized us- ing the solid phase peptide synthesis method and investigated the interaction of them with phospholipid bilayer, antibacterial activity, and hemolytic activity. Both toxic peptides could induce dye release at a low concentration in neutral liposome. The binding affinity of mastoparan-B for neutral liposome was smaller than that for acidic one. Mastoparan and mastoparan-B had strong antibacterial activity for gram-positive bacteria, but weak or potent activity for gram-negative ones, respectively. Mastoparan and mastoparan-B lysed erythrocyte very little up to 5 $\mu$M.

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Screening of PAF Antagonists from Medicinal Plants (수종의 생약으로부터 혈소판활성화인자 (PAF) 길항제 검색)

  • 손건호;김소희;정근영;장현욱
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.249-249
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    • 1994
  • PAF (Platelet-activating factor: 혈소판 활성화인자)는 1972년 Benveniste등에 의해 토끼의 호중구 배양 상청액중에서 발견되어 1979년 그 구조가 1-alkyl-2-acethyl-sn glycero-3-phosphocholine의 구조를 갖는 에테르형 인 지질임이 밝혀졌다. 그후 혈소판 이외 과립구, 단구나 macrophage, 혈관내피세포등 조직의 염증담당세포가 다양한 자극에 응하여 PAF를 생성됨이 보고되었다. PAF가 나타내는 대표적 활성으로는 혈소판, 호중구, 단구들의 활성화, 호중구의 유주 활성, 혈관투과성 항진, 혈압강하작용. 기관지 수축 등이 알려졌으며. 또한 염증, 알러지, 천식 endotoxin shock 등 여러질병에 직·간접적으로 관여함이 알려졌다. 이와같은 여러 생리 현상은 PAF의 특이적수용체를 개재하여 일어난다는 것이 밝혀졌다. 따라서 PAF의 다양한 질병의 관여가 밝혀짐으로서, PAF길항제의 개발이 활발히 진행되어왔다. 지금까지 PAF길항제의 개발은 PAF 구조 유사체. benzodiazepam유도체, thiazole유도체 등과 같은 합성품과 ginkolide, kadsurenone과 같은 천연물 유리의 것이 알려져 in vivo model에서도 그 효능이 확인되었다. 본 연구는 이와 같은 배경에서 20여 종의 생약에서 PAF 길항제를 검색하던 중 5종류의 생약에서 PAF 길항작용을 갖는 분획을 찾았기에 이에 보고한다.

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An Equivalent Fatigue Load Model for Prestressed Concrete Bridges Girders (프리스트레스트 콘크리트 교량거더의 등가피로하중모델)

  • 김지상
    • Magazine of the Korea Concrete Institute
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    • v.6 no.2
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    • pp.148-158
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    • 1994
  • The goal of this study is to develop an equivalent fatigue load model for prestressed concrete composite girder bridges in Korea. To meet this goal, the probabilistic characteristics of traffics which cause fatigue damage in bridges are properly modeled. An equivalent fatigue load inodel for prestressed concrete composite girder bridges with constant. amplitude and frequency is established. The model proposed in this paper is very simple to use and gives fairly good results.