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  • Artikel  (37)
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  • Wiley-Blackwell  (37)
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  • Artikel  (37)
  • Forschungsdaten
  • 1
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 1633-1640 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The Friedel-Crafts acylation of various crosslinked polystyrenes, both microporous and macroporous, by ω-halogenoacyl chlorides, a reaction used by others to functionalise polystyrenes, was carefully investigated. As judged by elemental analyses, the desired reaction to give ω-halogenoacyl residues is always accompanied by side reactions. Infrared spectroscopy indicates that these include crosslinking and the introduction of carboxylic acid groups. The side reactions are less pronounced with the ω-chloro compounds and with the 2% crosslinked microporous polymer. For many applications these side reactions will not be important, but in some cases an awareness of their occurrence could be crucial.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 267-274 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Carboxylgruppen Können in vernetztes Polystyrol über einen Zweistufenprozeß durch 2-Chlorbenzoylierung und Aufspaltung des Reaktionsproduktes mit einer Mischung von Kalium-tert-butoxid und Wasser eingeführt werden. Den Umsatz kann man durch die Gewichtsänderung des Harzes und durch Chloranalyse leicht abschätzen. Carboxylgruppen können auch durch Benzoylierung eingeführt werden. Das bereits beschriebene Verfahren, um Carboxylgruppen einzuführen, indem man vernetztes Polystyrol chlormethyliert, das erhaltene Produkt zu einem Formylharz oxidiert und dieses Produkt zu einem Carboxylharz weiteroxidiert, kann durch die Verwendung von Peressigsäure in Methansulfonsäure als Oxidationsmittel im letzten Schritt verbessert werden.
    Notizen: Carboxyl groups can be introduced into crosslinked polystyrene by a two step process involving 2-chlorobenzoylation and cleavage of the product using a mixture of potassium tert-butoxide and water. The reaction yields can be estimated easily by the change in weight of the resin and by chlorine analysis. Carboxyl groups can also be introduced via benzoylation. The previously described method of introducing carboxyl groups, in which crosslinked polystyrene is chloromethylated and the product oxidized to a formyl resin, which is then oxidized to a carboxyl resin, can be improved by using peracetic acid in methanesulphonic acid as the oxidant in the last step.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 489-497 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Several reactions involving crosslinked polymers, a solid, and a liquid phase were investigated. Witting reactions between crosslinked polymers (1 and 5) contaning phosphonium salt residues, solid potassium carbonate, and aldehydes in tetrahydrofuran were found to proceed satisfactorily, even in the absence of a phase transfer catalyst. The Oxidation of 2-phenyl-1,2-propanediol in methylene chloride by solid sodium periodate (but not postassium periodate) is catalysed by the periodate form (9a) of an anion exchange resin. The reaction of 1-bromooctane in benzene, tetrahydrofuran, or acetonitrile with potassium cyanide or sodium cyanide and of benzyl bromide in tetrahydrofuran or acetonitrile with potassium acetate or sodium acetate are catalysed only slightly, if at all, by the cyanide or acetate forms (9e and 9f) of an anion exchange resin. Crosslinked polymers containing crown ether residues catalyse the reaction of 1-bromooctane in toluene with sodium iodide. It is not clear how the crosslinked polymers and solid reagents manage to react with each other, but possible mechanisms are discussed. The importance of carrying out control reactions in such studies is stressed.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 64 (1939), S. 375-399 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 66 (1940), S. 581-603 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 9 (1894), S. 449-463 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 72 (1943), S. 87-123 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 6 (1894), S. 268-272 
    ISSN: 0863-1778
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 4 (1984), S. 231-239 
    ISSN: 0886-1544
    Schlagwort(e): pseudostereoscopy ; particle speed distribution ; velocity distribution ; fast axonal transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: We describe a simple method for direct visualization of the velocity distribution of particles moving against an immobile background. The technique involves pseudostereoscopic viewing of image pairs separated by an appropriate time interval in a sequential recording of the subject. Under these conditions, the positive or negative parallax arising from particle motion results in the binocular image of a particle being perceived as raised or lowered relative to an immobile background plane depending on its direction of movement, and with the degree of perceived elevation being proportional to its speed. In effect, the binocular optic axis becomes a velocity (speed) axis under these conditions. The technique is illustrated with examples of image pair sequences showing fast axonal transport in lobster and squid axons using video-enhanced differential interference contrast microscopy. However, the pseudostereoscopic method is quite generally applicable to both microscopic and macroscopic time-dependent phenomena. Particle speeds can be quantitated using standard procedures for measuring frame-to-frame particle displacements, or alternatively, by determination of parallax using stereogrammatic methods. It should be also readily adaptable for on-line monitoring of particle velocity distribution, particularly in video systems where frame buffers can be utilized to extract and present serial image pairs having any desired time separation from video-taped sequences.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    ISSN: 0899-0042
    Schlagwort(e): Chiral stereospecificity ; esterase ; metabolism ; human tissue ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Famciclovir is the oral form of the potent antiherpesvirus agent, penciclovir. Hydrolysis of one of the acetyl ester groups of famciclovir creates a chiral centre leading to the possible formation of (R)- and (S)-enantiomers. During its conversion to penciclovir, famciclovir forms two chiral metabolites, namely monoacetyl-6-deoxy-penciclovir and monoacetyl-penciclovir. The absolute configuration and stereospecificity of the monoacetyl metabolites of famciclovir, produced in human intestinal wall extract, were determined using isotopically chiral famciclovir and 13C NMR spectroscopy of the isolated metabolites. 13C NMR showed that the esterase(s), in human intestinal wall extract, hydrolysed the acetyl group preferentially from the pro-(S)-acetoxymethyl group of famciclovir. The specificity of esterase action in forming monoacetyl-6-deoxy-penciclovir and monoacetyl-penciclovir was about 77 and 72%, respectively. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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