• Title/Summary/Keyword: Bioinspired

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Tailoring Porosity of Colloidal Boehmite Sol by Controlling Crystallite Size

  • Park, Myung-Chul;Lee, Sung-Reol;Kim, Hark;Park, In;Choy, Jin-Ho
    • Bulletin of the Korean Chemical Society
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    • v.33 no.6
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    • pp.1962-1966
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    • 2012
  • Boehmite sols have been prepared by crystallization of amorphous aluminum hydroxide gel obtained by hydrolysis and peptization of aluminum using acetic acid. The size of the boehmite crystallites could be controlled by Al molar concentration in amorphous gel by means of controlling grain growth at nucleation stage. The size of boehmite increases as a function of Al molar concentration. With increasing boehmite crystallite size, the $d_{(020)}$ spacing and the specific surface area decreases, whereas the pore volume increases along with pore size. Especially, the pore size of the boehmite sol particles is comparable to the crystallite size along the b axis, suggesting that the fibril thickness along the b axis among the crystallite dimensions of the boehmite contributes to the pore size. Therefore, the physical properties of boehmite sols can be determined by the crystallite size controlled as a function of initial Al concentration.

New 7-Hydroxycoumarin-Based Fluorescent Chemosensors for Zn(II) and Cd(II)

  • Swamy, K.M.K.;Kim, Min-Jung;Jeon, Hye-Ryeong;Jung, Ji-Young;Yoon, Ju-Young
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3611-3616
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    • 2010
  • Five new 4- or 8-substituted-7-hydroxycoumarin derivatives (1-5) were synthesized as fluorescent sensors for metal ions. Fluorescent changes and selectivity for metal ions were compared based on the introduction of different ligands and/or testing with different substitution positions of 7-hydroxycoumarin in aqueous solution. Especially, probes 2, 3 and 5 displayed large fluorescence enhancements with $Zn^{2+}$ and $Cd^{2+}$. Probes 2 and 3 showed moderate selectivity for $Zn^{2+}$ over $Cd^{2+}$. On the other hand, probe 4 showed large fluorescence quenching effects upon the addition of $Ag^+$ and $Hg^{2+}$.

Synthesis and Binding Affinity of Homologated Adenosine Analogues as A3 Adenosine Receptor Ligands

  • Lee, Hyuk-Woo;Choi, Won-Jun;Jacobson, Kenneth A.;Jeong, Lak-Shin
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1620-1624
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    • 2011
  • Homologated analogues 3a and 3b of potent and selective A3 adenosine receptor ligands, IB-MECA and dimethyl-IB-MECA were synthesized from commercially available 1-O-acetyl-2,3,5-tri-O-benzoyl-${\beta}$-D-ribofuranose (4) via $Co_2(CO)_8$-catalyzed siloxymethylation as a key step. Unfortunately, homologated analogues 3a and 3b did not show significant binding affinities at three subtypes of adenosine receptors, indicating that free rotation, resulting from homologation, induced unfavorable interactions in the binding site of the receptor maybe due to the presence of many conformations.

A Straightforward Synthesis of K-7174, a GATA-Specific Inhibitor

  • Majik, Mahesh S.;Yu, Jin-Ha;Jeong, Lak-Shin
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.2903-2906
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    • 2012
  • K-7174, a GATA-specific inhibitor, is a putative anti-inflammatory agent that attenuates effects of inflammatory cytokines in certain cell types. An expeditious four-step synthesis of K-7174 is described in this paper. The route employs Wittig olefination and bis-alkylation of homopiperazine as the key reactions. The iodine-catalyzed isomerization of the Z-isomer results in complete conversion to the E-isomer is the highlight of our synthetic endeavors.

Fluidity and strength characteristics according to BSC(Bioinspired Self-Healing Capsule) incorporation rate (BSC(Bioinspired Self-Healing Capsule) 혼입율에 따른 모르타르의 유동성 및 강도 특성)

  • Lee, Jae-In;Kim, Chae-Young;Na, Bum-Su;Song, Won-Il;Kim, Sung-Hoon;Choi, Se-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.253-254
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    • 2022
  • In this study, as part of a study to improve the self-healing performance of concrete, the fluidity and strength characteristics of mortar mixed into cement composites were compared and analyzed by controlling the mixing rate of BSC(Bioinspired Self-Healing capsule)

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Fluidity and engineering properties of mortar mixed with bioinspired polymer according to mixing ratio of mixed slag fine aggregate. (혼합슬래그 잔골재 혼입율에 따른 생체모방 폴리머 혼입 모르타르의 유동성 및 공학적 특성)

  • Bae, Sung-Ho;Park, Sa-Min;Kim, Dae-Sung;Lee, Jae-In;Ko, Haye-Min;Choi, Se-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.259-260
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    • 2022
  • In this study, as part of a study to solve the problem of aggregate supply and demand, blast furnace slag fine aggregate and ferronickel slag fine aggregate were used as substitutes for natural fine aggregate, and a bioinspired polymer, a catechol-functionalized chitosan, was used instead of the mixing water.

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