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1.
Erich Metzger Roland Aeschimann Martin Egli Gaby Suter Ren Dohner Daniel Ammann Max Dobler Wilhelm Simon 《Helvetica chimica acta》1986,69(8):1821-1828
Lipophilic neutral carriers were synthesized which show Li+/Na+ selectivities of up to ca. 80 in highly lipophilic liquid membranes. The sensor membranes exhibit improved response times and increased lifetimes as compared to systems described earlier. They allow reliable measurements of Li+ in blood serum within the clinical concentration range. A 1:1 Li+/ionophore complex of one representative (N,N,N′,N′-tetracyclohexyl-5,5-dimethyl-3,7-dioxaazelaamide) has been prepared, and its structure was elucidated by X-ray analysis. 相似文献
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Mohamed S. A. El‐Gaby Ahmed M. Sh El‐Sharief Ahmed A. Atalla Abu‐Bakr A. A. M. El‐Adasy 《中国化学会会志》2004,51(2):327-333
The novel cyanothioformamides 2a‐d were prepared by treatment of isothiocyanatosulfonamides 1a‐d with potassium cyanide at room temperature. Cyclocondensation of compounds 2b,c with phenyl isocyanate as electrophile furnished the corresponding imidazolidines 3a,b . The reactivity of compound 3a towards some nitrogen nucleophiles was investigated. Thus, the thiosemicarbazone 4 and imidazo[4,5‐b]quinoxaline 6 were synthesized by condensation of compound 3a with thiosemicarbazide and o‐phenylenediamine, respectively. Treatment of 3a with hydrochloric acid afforded compound 7 . Our investigation was extended to include the reactivity of cyanothioformamide 2 towards o‐aminophenol, anthranilic acid, and o‐phenylenediamine and yielded the corresponding heterocycles 9 , 11 and 13 derivatives, respectively. Structures of the synthesized compounds were established by their elemental analysis and spectral data. 相似文献
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Dendrimers are macromolecules characterized by high controlled size, shape and architecture, presence of inner cavities able to accommodate small molecules and many peripheral functional groups to bind target entities. They are of eminent interest for biomedical applications, including gene transfection, tissue engineering, imaging, and drug delivery. The well-known pharmacological activities of ursolic and oleanolic acids are limited by their small water solubility, non-specific cell distribution, low bioavailability, poor pharmacokinetics, and their direct administration could result in the release of thrombi. To overcome such problems, in this paper we described their physical incorporation inside amino acids-modified polyester-based dendrimers which made them highly water-soluble. IR, NMR, zeta potential, mean size of particles, buffer capacity and drug release profiles of prepared materials were reported. The achieved water-soluble complexes harmonize a polycationic character and a buffer capacity which presuppose efficient cell penetration and increased residence time with a biodegradable cell respectful scaffold, thus appearing as a promising team of not toxic prodrugs for safe administration of ursolic and oleanolic acids. 相似文献
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M. M. Ghorab N. E. Amin M. S. A. El Gaby N. M. H. Taha M. A. Shehab I. M. I. Faker 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2918-2928
The key intermediate diisothiocyanate 2 was allowed to react with 5-amino-3-methyl-pyrazole-4-carbonitrile 3, ethyl 5-amino-1-phenyl-pyrazole-4-carboxylate 6, 2-amino-tetrahydrobenzo[b]thiophene-3-car-bonitrile 9, ethyl-2-amino-tetra-hydrobenzo[b]thiophene-3-carboxylate 12, and/or 1,2,4-triazole 15 to give the corresponding biscompounds 4, 5, 7, 8, 10, 11, 13, 14, and 16, respectively. The structure of the synthesized compounds was elucidated by elemental analyses and spectral data. Some of the prepared compounds were tested for their antimicrobial and antitumor activities. 相似文献
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Aromatic-solvent-induced 11B NMR shifts (11B ASIS effects), observed for closo-2, 4-C2B5H7 and its 5-chloro and 5, 6-dichloro derivatives, are correlated to ab initio STO-3G derived atom charge densities. A near linear relationship is found upon incorporating nearestneighbor charge density contributions. 相似文献
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Pell Gaby S. Landeryou Mark A. Cottenden Alan M. Ordidge Roger J. 《Colloid and polymer science》2003,281(12):1127-1135
The use of nuclear magnetic resonance to make quantitative measurements of the absorption processes occurring in the constituent materials of disposable incontinence pads was investigated. Modern incontinence pads often have a layered structure with the absorbent layer principally consisting of superabsorbent polymer (SAP) grains distributed in fluffed wood pulp. T 2-weighted and magnetisation transfer contrast (MTC) measurements were made using samples of SAP, fluffed wood pulp, and a mixture of 50% SAP and 50% fluffed wood pulp following the addition of water and NaCl solutions. The T 2-weighted signal always decreased on mixing the liquid and material samples, with SAP showing the smallest magnitude of signal decline. The MTC change was minimal for SAP, but increased for the other samples. The small changes in the T 2-weighted signals and the MTC observed when adding water to SAP indicate that water is not principally being tightly bound by the polymer. The absorption time-course was further evaluated by acquiring proton-density-weighted 1D profiles after the addition of water to the samples. In SAP, the fitted time constant was comparable to the activation energy measured by other methods. The relaxation times both declined on mixing the liquids with samples of SAP and fluffed wood pulp. The reduction in spin–spin relaxation is sufficient to account for the T 2-weighted signal changes. 相似文献
7.
Y. A. Ammar A. M. Sh. El‐Sharief A. G. Al‐Sehemi Y. A. Mohamed M. A. Senussi M. S. A. El‐Gaby 《中国化学会会志》2005,52(3):553-558
Ketene dithioacetal 3 , aminopyrazole 5 , tetrazine 7 , benzoazole 9 and pyridone 11 , 12 , 13 and 16 derivatives were prepared from cyanoacetanilide 1 as a starting material. 相似文献
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A. M. Sh. El‐Sharief Y. A. Ammar Y. A. Mohamed M. S. A. El‐Gaby 《Heteroatom Chemistry》2002,13(4):291-298
Reactions of cyanothioformamides ( I ) with o‐phenylenediamines, o‐aminophenol, and anthranilic acids furnished benzimidazole ( II,III ), benzoxazole ( VII ), and quinazoline ( IX ) derivatives, respectively. Oxazolidine (thiones or iminothiones) ( IV ) were reacted with the same binucleophiles to produce quinoxaline ( V ), benzimidazole ( VI ), and quinazoline ( XI ) derivatives. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:291–298, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10031 相似文献