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Synthesis of 2-Substituted 4H-Thieno[2,3-b][1]benzothiopyran-4-ones as Potential Chemotherapeutic Agents

  • El-Subbagh, H.I.;Yousif, M.Y.;El-Eman, A.A.;El-Kerdawy, M.M.
    • Archives of Pharmacal Research
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    • v.12 no.2
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    • pp.135-137
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    • 1989
  • A convenient route is reported for the synthesis of certain series of 4H-thieno[2,3-b][1]benzothiopyran-4-ones, carrying various substituents at position 2 such as arylazomethines (7,8), thiazolidin-4-ones (9-13), ${\alpha},\;{\beta}-unsaturated$ ketones (16,17), 2-pyridones (19-23), tetrahydrothiophen-4-ones (24,28), and nitroalkenes (29,30), as potential schistosomicidal or antihistaminic agents.

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Fabrication and Characteristics of Electroluminescent Lamp (전계발광램프의 제작 및 특성)

  • 박욱동;최규만;최병진;김기완
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.5
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    • pp.101-105
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    • 1994
  • The EL lamp have been fabricated by screen printing method. the thickness of BaTiO$_3$ dielectric layer and ZnS:Cu phosphor layer was 20 $\mu$m and 40 $\mu$m, respectively. The threshold voltage of green El lamp was 50 $V_{p-p}$ and the maximum brightness was 13.5 $\mu$ W/cm$^2$ at frequency of 700 Hz and the input voltage of 250 $V_{p-p}$. Also when the Rodamin G6 of 0.02 g was doped, the threshold voltage of white EL lamp was 70 $V_{p-p}$ and the maximum brightness was 34 $\mu$W/cm$^2$.

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La Frontera que Se Formó Durante la Guerra de Castas de Yucatán (까스따 전쟁 사이에 이루어진 국경 : 꾸르스옵이 국경형성에 미친 영향)

  • Chung, Hea-Joo
    • Iberoamérica
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    • v.13 no.1
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    • pp.255-286
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    • 2011
  • Las fronteras de México. Guatemala y Belize se formaron cuando se indepedizaron desde España. Generalmente se adaptaron la división establecida durante la época colonial. Sin embargo, se han sucedido varios incidentes para alterarla. Uno de los incidentes más importantes fue 'la Guerra de Castas de Yucatán'. Los mayas aprovecharon esa oportunidad para expresar sus resentimientos que se formaron bajo el sistema colonial. Las rebeliones mayas ocuparon la parte oriente de la península y se formaron un país independiente que se duró más de 50 años. Para apacificar esta gran rebelión de los mayas indígenas, el gobierno mexicano dejó de perder el territorio de Belize que mantenía su soberania durante pasados tres siglos. Finalmente se formaron la frontera con Belize.

Characteristics of LB Layer for White Light Organic Electroluminescent Device (백색 유기 EL 소자의 발광층용 LB막 특성)

  • Kim, Ju-Seung;Gu, Hal-Bon;Lee, Kyung-Sup;Song, Min-Jong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05b
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    • pp.90-93
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    • 2002
  • In the surface pressure-area isotherms of mixed monolayers, mixtures containing as much as 30 mol% of AA form stable condensed monolayer while the monolayer without AA is in the expanded state because PVK take on 3D collapsed. All of the mixed monolayers with 0, 10, 20 and 30 mol% of AA could be readily transferred onto ITO substrate at 16, 17, 24 and 26 mN/m, respectively. The monolayer containing 30 mol% of AA, however, showed a roughness value of 28A and became homogeneous decreasing with the phase separation. We fabricated organic EL device of ITO/CuPc/MEL/BBOT/iLiF/Al using mixed monolayer of 13, 19 and 25 layer deposited by LB method as a emitting layer. In the voltage-current characteristics of EL device, current density was much smaller than that of the spin-coated devices. It may due to the large contact resistance existed at the interface of LB layer/organic layer inhibit carrier injection to the emitting layer. EL spectra of device showed peaks at 450. 470, 505, 555 and 650 nm and the white light emission indicate the CIE coordinate x=0.306, y=0.353.

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Structure and Characteristics of Biodegradable Polyester from Actinobacillus sp. EL-9 (Actinobacillus sp. EL-9로부터 생산된 생분해성 폴리에스터의 구조 및 특성)

  • Son, Hong-Ju;Lee, Gun;Kim, Geun-Ki;Kim, Han-Soo;Kim, Yong-Kyun;Lee, Sang-Jun
    • Journal of Life Science
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    • v.8 no.5
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    • pp.526-531
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    • 1998
  • In this study, the composition and characteristics of poly-$\beta$-hydroxybutyrate (PHB) biosynthesized by Actinobacillus sp. EL-9 are investigated. PHB produced by Actinobacillus sp. EL-9 was identified as the homopolymer of 3-hydroxy-butyric acid (PHB) by infrared spectroscopy and nuclear magnetic resonance spectroscopy analysis. The melting tem-perature (T$_{m}$), and crystallization temperature(T$_{c}$) of PHB was 169.7$^{\circ}C$ and 69.13$^{\circ}C$, respectively. The viscosity on he basis of Brookfield viscometer was 6.01 ㎗/g. The viscosity-average molecular weight estimated by Mark-Ho-wink-Sakurada equation was 1.08$\times$10$^{6}$ ($\pm$3,000).00).

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On The Chemical, Botanical, and Chemotaxonomical Evaluation of The Genus Citrus -Part I : Polymethoxyflavones of The Leaf of Citrus deliciosa Ten.-

  • El-Domiaty, Maher M.;Abdel-Aal, Mahmoud M.;El-Shafae, Azza M.
    • Natural Product Sciences
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    • v.2 no.2
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    • pp.106-114
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    • 1996
  • Four polymethoxyfavones were isolated from the leaves of Citrus deliciosa, three of which (nobiletin, 5-O-demethylnobiletin, and tangeritin) are bioactive. The fourth (7,4'-dihydroxy-5,6,8,3'-tetramethoxyflavone) is reported for the first time in the genus Citrus and is a potential chemotaxonomic marker. The structures of these flavones were confirmed by analysing their spectral data and comparison with similar compounds. The previously reported $^{13}C$ NMR assignment of 5-O-demethylnobiletin has been revised on the basis of 2D NMR experiments (HETCOR, COSY, and COLOC). The chemotaxonomic value of the present finding is verified.

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Synthesis and Luminescent Properties of Blue Light Emitting Polymers Containing a 4,4' or 3,3'-Linked Biphenyl Unit

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.6
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    • pp.317-321
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    • 2012
  • Poly[4,4'(3,3')-biphenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene], 4,4'(3,3')-PBPMEH-PPV, and poly[4,4'(3,3')-biphenylenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene], 4,4'(3,3')-PBPCAR-PPV, of varying effective conjugation lengths, were synthesized by the well-known Wittig condensation polymerization between the appropriate biphenyl diphosphonium salts and dialdehyde monomers such as carbazole or dialkoxyphenyl dialdehyde. The conjugation lengths of the polymers were controlled by biphenyl linkages (4,4' or 3,3'). The resulting polymers were highly soluble in common organic solvents and exhibited good thermal stability up to $300^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 314-400 nm and 430-507 nm, respectively. Carbazole and 3,3'-biphenyl containing 3,3'-PBPCAR-PPV showed a blue PL peak at 430 nm. A single-layer light-emitting diode was fabricated in a configuration of ITO/polymer/Al. Electroluminescence (EL) emission of 3,3'-PBPCAR-PPV was shown at 455 nm.

Synthesis of Certain Mercapto and Aminopyrimidine Derivatives as Potential Antimicrobial Agents

  • El-Kerdawy, M.M.;Eisa, H.M.;El-Emam, A.A.;Massoud, M.A.;Nasr, M.N.
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.142-146
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    • 1990
  • Reaction of ethyl 4-chloro-2-phenylpyrimidine-4-carboxylate (4) with 5-chloro-2-methylthiophenol or 3-aryl-4-phenyl-1, 2, 4-triazole-5 thiol yielded the corresponding thioethers (5) and (8a, b), respectively. Careful alkaline hydrolysis of (5) yielded the corresponding carboxylic acid (6). Reaction of (4) with p-aminoacetophenone yielded compound (10) which was reacted with certain aromatic aldehyde to afford the$\alpha,\beta$-unsaturated ketones (11a-d). Condensation of (11a-d) with malononitrile or phenylhydrazine yielded the 2-amino-3-cyanopyridines (12a-f) or the 2-pyrazolines (13a, b) respectively. Seven representative compounds were tested for their in vitro antimicrobial activity against some pathogenic micro-organisms, some of them were proved to be active.

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Synthesis of Blue Emission Hydrazone Derivatives for Organic Electroluminescence (유기 EL용 청색 발광 히드라존 유도체의 합성)

  • Chung, Pyung-Jin;Lim, Hoi-Deuk
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.514-518
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    • 2003
  • As a fundamental study on organic electroluminescence(EL), blue emitting materials were synthesized and characterized. Individual blue colored hydrazone derivatives were synthesized from the reaction of aldehydes (phthalaldehyde, isophthalaldehyde) with the corresponding amnios (1-methyl -1-phenylhydrazine, 1,1-diphenylhydrazine hydrochloride). Recrystallization of hydrazones from chloroform revealed the melting temperature within $142∼156^{\circ}C$. Photoluminescence(PL) analysis on each hydrazone showed that emission range were blue(458∼478 nm). The structure of obtained hydrazones were elucidated by FT-IR, $^1$H-NMR and C, H, N elemental analyzer.