• Title/Summary/Keyword: reactions

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Cichorium Intybus inhibits mast cell-mediated immediate-type allergic reactions

  • Jippo, Tomoko;Nomura, Shintaro;Kitamura, Yukihiko
    • Advances in Traditional Medicine
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    • v.1 no.1
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    • pp.82-88
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    • 2000
  • We investigated the effect of aqueous extract of Cichorium intybus (CIAE) on mast cell-mediated immediate type allergic reactions. CIAE dose-dependently inhibited systemic anaphylactic reaction induced by compound 48/80 in mice. Especially, CIAE inhibited compound 48/80-induced anaphylactic reaction 100% with the dose of 1000 mg/kg. CIAE 1000 mg/kg also significantly inhibited local anaphylactic reaction activated by anti-dinitrophenyl (DNP) IgE. When mice were pretreated with CIAE at a concentration ranging from 0.1 to 1000 mg/kg, the plasma histamine levels were reduced in a dose-dependent manner. CIAE (1 to 1000 g/ml) dose-dependently inhibited histamine release from the rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. These results indicate that CIAE inhibits mast cell-mediated immediate-type allergic reactions.

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Effects of Ion and Protic Solvent on Nucleophilic Aromatic Substitution (SNAr) Reactions

  • Park, Sung-Woo;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2571-2574
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    • 2010
  • We investigate the mechanism of $S_NAr$ fluorination reactions under the influence of protic solvents and ions. We find that counterion or protic solvent alone retards the $S_NAr$ reactions, but together they may promote the reaction. In this mechanism, the protic solvent acts on the counterion as a Lewis base, and the nucleophile reacts as an ion pair. We also show that an anion (mesylate) may exhibit catalytic effects, suggesting the role of ionic liquids for accelerating the $S_NAr$ reactions.

Mothers' Reactions to Children's Negative Emotions; Relationships to Children's Social Behaviors and Emotionality (아동의 부정적 정서에 대한 어머니의 반응, 아동의 정서성 및 사회적 행동 간의 관계)

  • Kwon, Yeon Hee;Lee, Jong Hee
    • Korean Journal of Child Studies
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    • v.26 no.6
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    • pp.201-216
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    • 2005
  • The social behaviors of 177(84 girls, 93 boys) 5-6 year olds were rated by the SCBE teacher questionnaire. Mothers reported on their reactions to children's negative emotions and on children's emotionality by questionnaires. Results showed that girls' emotionality was related to maternal punitive responses and their withdrawn behaviors. Maternal emotion-focused reponses were associated with boys' social behaviors. Maternal distress reactions were correlated with girls' prosocial behaviors; maternal punitive responses were related to girls' prosocial and withdrawn behaviors. Maternal emotion-focused responses were associated with girls' aggressive behaviors. Partial correlation analysis indicated girls' emotionality was not related to their withdrawn behaviors when maternal punitive responses were taken into account.

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Influence of Solvents on Rates of Reactions of 2,4-Dinitro Substituted Halobenzenes with Substituted Anilines (Ⅱ) (2,4-이니트로할로벤젠과 치환된 아닐린의 반응속도에 대한 용매효과 (제2보))

  • Hai Whang Lee;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.22 no.1
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    • pp.7-11
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    • 1978
  • The reactions of 2,4-dinitroiodobenzene with para subtituted anilines in acetonitrile-methanol binary solvent mixtures have been studied. Rate constants for reactions in methanol rich solvents are greater than for reactions in acetonitrile rich solvents. Kinetic results show that the bond formation step is rate determining in the solvent system studied. The solvent effect can be explained by stabilization of the transition state by formation of hydrogen bond between oxygen atom of methanol and hydrogen atom of aniline.

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Impact of mixer design to reactants mixing characteristics and gas-phase reactions in the mixing region of a hydrocarbon reformer (개질기 혼합영역 형상에 따른 반응물의 혼합도 및 가스상 반응특성에 대한 수치해석적 연구)

  • Kim, Sunyoung;Bae, Joongmyeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.99.1-99.1
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    • 2011
  • Reactant mixing has a critical role in ensuring reformate quality and an important design objective is to achieve sufficiently complete mixture of reactants. For that purpose it is required to understand the coupled transport-kinetics phenomena in the mixing region. Three-dimensional computational fluid dynamics model was developed and validated in previous works. The mixing characteristics in various alternatives of a prototype mixing chamber were compared, and then a reduced reaction kinetics was applied to two extreme designs for investigating the impact of gas-phase reactions. Both designs did not reach threshold ethylene mole fraction of 0.001, but surprisingly more ethylene was generated in the design having better mixing characteristics. The presentation will deliver the development process of coupled transport and kinetics model briefly and the detailed information about the mixing characteristics and gas-phase reactions in two mixer designs.

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ACTIVATION ANALYSIS OF ENVIRONMENTAL SAMPLES USING THE MT-25 MICROTRON OF THE FLNR

  • Maslov, O.D.;Belov, A.G.;Starodub, G.Ya.;Dmitriev, S.N.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.815-820
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    • 1995
  • Instrumental neutron and gamma activation analysis of coal and combustion products, determination of platinum content in natural samples by radiochemical gamma activation analysis and high-sensitive track method of thorium determination has been studied with the use of the MT-25 microtron.The optimal conditions for complete elemental analysis of coal and combustion products, isolation and determination of platinum and thorium are recommended.

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Reactions and Properties of Fullerene ($C_{60}$) (풀러렌의 성질과 반응)

  • Lim, Choong-Sun;Hong, Seong-Kyu;Ko, Weon-Bae
    • Elastomers and Composites
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    • v.45 no.2
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    • pp.74-79
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    • 2010
  • In this review, the properties of buckminsterfullerene and its organic and polymeric reactions were focused. In addition, polymer blending with $C_{60}$ will be briefly introduced. As soon as $C_{60}$ was discovered, chemists put their efforts to explore its reactivity with other compounds. The knowledge of the organic reactions with $C_{60}$ was extended to construct different types of fullerene polymers such as side chain fullerene polymers, main chain fullerene polymers, star shaped fullerene polymers, and dendritic fullerene polymers.

A study of sweating reaction on somato type (체형별 발한 반응에 관한 연구)

  • 심부자
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.72-96
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    • 1997
  • To investigate the difference of sweating reaction on somato types. We measured total sweat rate, locl sweat rate, skin temperature, physiological reactions and psyschological reactions at $25{\pm}1^{\circ}C$ and $25{\pm}1^{\circ}C$ under laboratory conditions. Nine healthy adult females were divided into three somato types (slender(3), normal(3) and obese type(3)). The results were as follows; Total sweat rate was highest in obese type, and then comes normal type and slender type in order. Local sweat rate was highest in infrascapular area, and then breast, the back of the hand, upperarm, ant. leg, and ant. thigh in order in all somato types. Mean skin temperature was highest in slender type, and then normal type and obese type in order. Rectal temperature, blood pressure and pulse rate were highest in boese type. Psychological reactions were appeared 'hot' 'humid' 'sweat' as ambient temperature go up. And somato types make little difference in psychological reactions.

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Regulation of Stereoselectivity and Reactivity in the Inter- and Intramolecular Allylic Transfer Reactions

  • Yu, Chan-Mo;Youn, Jin-soup;Jung, Hee-Keum
    • Bulletin of the Korean Chemical Society
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    • v.27 no.4
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    • pp.463-472
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    • 2006
  • The preparation of enatiomerically enriched homoallylic alcohols through asymmetric addition of chiral allylic transfer reagents and allylating reagents with chiral catalysts to the carbonyl functionalities represents an important chemical transformation. Excellent progress has been made over past decade in the development and application of catalytic asymmetric allylic transfer reactions. In this account, our efforts for the various intermolecular allylic transfer reactions such as allylation, propargylation, allenylation, and dienylation utilizing accelerating strategy and sequential allylic transfer reactions to achieve multiple stereoselection mainly using transition metal catalysts are described.

PULP REACTIONS TO TEMPORARY CEMENTS (임시(臨時) 접착용(接着用) 씨멘트가 치수조직(齒髓組織)에 미치는 영향(影響))

  • Yoon, Doo-Joong
    • The Journal of Korean Academy of Prosthodontics
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    • v.15 no.1
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    • pp.43-47
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    • 1977
  • The purpose of this study was to determine human pulp reactions to temporary cements such as zinc oxide-eugenol cement, modified zinc oxide-eugenol cement (Cavitec) and calcium hydroxide cement (Dycal). Deep class V cavities were prepared in the human teeth with ultrahigh-speed handpiece operating at a free running speed of 300,000 r.p.m., using # 701 bur and water spray coolant. The cavities were flushed with water, dried with cotton pellets and filled with zinc oxide-eugenol cement, modified zinc oxide-eugenol cement and calcium hydroxide cement respectively. The teeth were divided into two groups, which one group was extracted after One day and the other was extracted after seven days. The samples were examined with microscope and the findings were as follows; 1. The pulp reactions to temporary cements were generally mild. Among them the reactions were moderate in zinc oxide-eugenol cement and, slight in calcium hydroxide cement. 2. Calcium hydroxide cement may be used properly as temporary cement for the purpose of pulp protection.

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