• Title/Summary/Keyword: Inclusion-complex

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Studies on Dissolution Rate of Flurbiprofen from Solvent Deposition Systems (Flurbiprofen 용매침착물(溶媒沈着物)의 용출특성(溶出特性)에 관(關)한 연구(硏究))

  • Choi, Bo-Kyung;Yong, Jae-Ick
    • Journal of Pharmaceutical Investigation
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    • v.15 no.3
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    • pp.100-112
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    • 1985
  • Dissolution characteristics of flurbiprofen solvent deposited on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, lactose and corn starch were studied to evaluate the pharmaceutical aspects of solvent deposition method where drug was solvent deposited on the surface of excipients. In a solvent deposition system, the drug to excipient ratio and kind of excipient affect much on dissolution rates of flurbiprofen. The solvent deposition system formation was confirmed by scanning electron microscope. By increasing the amounts of matrix, it was possible to enhance the dissolution rate of flurbiprofen solvent deposition system. The amount of flurbiprofen dissolved from ${\beta}-cyclodextrin$ deposition system (1:10) at 60 minutes was enhanced 6.5 times in water and 28 times in simulated gastric juice compared with flurbiprofen alone. Flurbiprofen solvent deposited system (1:10) enhanced dissolution rate greater than inclusion complex and dispersion system.

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Concentration distributions during flow of confined flowing polymer solutions at finite concentration: slit and grooved channel

  • Hernandez-Ortiz, Juan P.;Ma, Hong-Bo;de Pablo, Juan J.;Graham, Michael D.
    • Korea-Australia Rheology Journal
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    • v.20 no.3
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    • pp.143-152
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    • 2008
  • Simulations of solutions of flexible polymer molecules during flow in simple or complex confined geometries are performed. Concentrations from ultradilute up to near the overlap concentration are considered. As concentration increases, the hydrodynamic migration effects observed in dilute solution unidirectional flows (Couette flow, Poiseuille flow) become less prominent, virtually vanishing as the overlap concentration is approached. In a grooved channel geometry, the groove is almost completely depleted of polymer chains at high Weissenberg number in the dilute limit, but at finite concentration this depletion effect is dramatically reduced. Only upon inclusion of hydrodynamic interactions can these phenomena be properly captured.

Immobilization of MTBE using cyclodextrins

  • Baek, Ki-Tae;Yang, Ji-Won
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.120-123
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    • 2003
  • Immobilization behavior of methyl tert-butyl ether (MTBE) by various cyclodextrins(CDs) was studied to investigate the feasibility of MTBE removal using cyclodexrins. Even though MTBE has relatively low hydrophobicity and higher polarity compared to other organics, it was effectively immobilized by CDs. The immobilization isotherms was shown as a type of Freundlich isotherms, and the immobilization capacity of -CDs was the largest among natural COs. The initial apparent association constant for MTBE-CD complex follows the order : gamma = beta > methyl-beta > hydroxypropyl beta > alpha. These differences of the constants are related to the size of MTBE and CDs. The size of beta-CD and gamma-CD is large to encapsulate MTBE molecule into the cavity, which that of alpha-CB is too small to encapsulate MTBE.

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On the Fibonacci Almost Convergent Sequence Space and Fibonacci Core

  • DEMIRIZ, SERKAN;KARA, EMRAH EVREN;BASARIR, METIN
    • Kyungpook Mathematical Journal
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    • v.55 no.2
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    • pp.355-372
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    • 2015
  • In the present paper, by using the Fibonacci difference matrix, we introduce the almost convergent sequence space $\hat{c}^f$. Also, we show that the spaces $\hat{c}^f$and $\hat{c}$ are linearly isomorphic. Further, we determine the ${\beta}$-dual of the space $\hat{c}^f$ and characterize some matrix classses on this space. Finally, Fibonacci core of a complex-valued sequence has been introduced, and we prove some inclusion theorems related to this new type of core.

The interaction of zipeprol with $\beta$-cyclodextrin

  • Kim, Chong-Kook;Choi, Han-Gon
    • Archives of Pharmacal Research
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    • v.10 no.2
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    • pp.69-74
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    • 1987
  • The characteristics of zipeprol-$\beta$-cyclodextrin system were studied by circular dichroism, competitive UV method and dialysis method. In this experiment, binding constants by competitive UV method, circular dichroism and dialysis method were 155 M$^{-1}$ 187 M$\^{-1}$/($\pm$ 5%) and 315 $^{-1}$, repectively. It shows that zipeprol forms 1:1 compelx with $\beta$-cyclodextrin by circular dichroism and 1:2 by dialysis method. pH profile shows that binding force seems to be a hydrophobic interaction. It is suggested that benzene ring be accomodated in the cavity of $\beta$-cyclodextrin.

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Supramolecular aminocatalysis via inclusion complex: Amino-doped β-cyclodextrin as an efficient supramolecular catalyst for the synthesis of chromeno pyrimido[1,2-b]indazol in water

  • Shinde, Vijay Vilas;Jeong, Daham;Jung, Seunho
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.6-13
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    • 2018
  • Well-modified amino-appended ${\beta}$-cyclodextrin ($AA-{\beta}-CD$) with an amino group at the primary face of the ${\beta}-CD$ was synthesized and used in the catalytic synthesis of chromeno pyrimido[1,2-b]indazol as supramolecular catalysts in water for the first time. $AA-{\beta}-CD$ was characterized by FT-IR, NMR, MALDI-TOF mass spectrometry, and SEM analysis. A possible reaction mechanism featuring molecular complexation was suggested based on 2D NMR (ROESY) spectroscopy, FE-SEM, DSC, and FT-IR. Advantages such as operational simplicity, recyclability of the catalysts, and accessibility in aqueous medium render this protocol eco-friendly.

Sharp-line Electronic Spectroscopy and Ligand Field Analysis of Cr(III) Complexes with Amino Acid Ligands

  • 박성진;최영근;한승석;이규왕
    • Bulletin of the Korean Chemical Society
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    • v.20 no.12
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    • pp.1475-1478
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    • 1999
  • Ligand field calculations have been performed based on the data from the absorption and low temperature sharp-line excitation spectra of fac-Cr(gly)₃, fac-Cr(L-serine)₃ · 2H₂O and fac-Cr(L-leucine)₃·2H₂O. The optimized ligand field parameters for all complexes show that the carboxylate and the amino groups are moderate σ-donor. The values of $e_{{\pi}O}$ are typical of other complexes with carboxylate ligands. However, the π-interaction of carboxylic oxygen to the chromium in serinato complex is much weaker than that of other complexes. The inclusion of π-anisotropy is necessary to adequately explain the large doublet splittings.

Studies on the interaction of thiamines and cyclodextrins

  • Im, In-Seon;Lee, Wang-Kyu;Park, Man-Ki;Kim, Bak-Kwang
    • Archives of Pharmacal Research
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    • v.6 no.1
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    • pp.35-44
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    • 1983
  • Interactions between thiamine.HCl and its disulfide derivatives TTFD. TPD and .alpha., .betha. cyclodextrins were investigated. By measuring the H-NMR, C-NMR chemical shifts, the assumption that cyclodextrin may from a inclusion complex with thiamines was supported qualitatively. To calculated the stability constants of them, anion exchange chromatography was applied. The simple, rapid HPLC method was proved to be pertinent thiamine/cyclodextrin system which was chemically unstable and less soluble.

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The Mental Health of Ethnic Minority Youths in South Korea and Its Related Environmental Factors: A Literature Review

  • Lee, Yeeun;Lee, Minji;Park, Subin
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.30 no.3
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    • pp.88-99
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    • 2019
  • Objectives: With increasing concerns for the rapidly growing minority population in South Korea, this literature review addressed a range of mental health risks among multiethnic youths (MY) in South Korea by 1) comparing mental health outcomes with those of native-born youths and 2) identifying multiple layers of relevant environmental factors, from family and school relationships to culture. Methods: We reviewed 54 studies that fulfilled specific inclusion criteria. Results: Multiple common risk/protective factors, including family separation, family relationship quality, parental socioeconomic and mental health status, social relationships at school, and cultural acceptance, were noted. Conclusion: In general, empirical evidence indicates that minority youths have relatively heightened risks for emotional and behavioral problems. Future studies must elucidate the complex interplay between multiple risk and protective factors and the long-term adaptation and mental health service utilization of MY.

Theoretical Foundations of Management of the Education System: Optimization of the Complex of Organizational and Pedagogical Conditions for Effective Management

  • Yuryk, Olha;Sitsinskiy, Nazariy;Zaika, Liudmyla;Рshenychna, Lіubov;Boiko, Svitlana;Filipovych, Myroslava
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.168-174
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    • 2022
  • The article defines the organizational conditions for effective management, the actions of the team to implement the concept of marketing management using the tools of pedagogical and strategic management. Due to this, results are achieved - indicators, since in our study they will be indicators of managerial efficiency: improving the "organization" function through the construction of new organizational structures; improving the functions of "analytical activity and planning" through enriching managerial work with economic and gnostic methods, analytical activities with the mandatory inclusion of financial activities, introspection of all participants, widespread use of licensed automated systems; synthesis of educational, economic, social results.