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  • 1980-1984  (11)
  • 1970-1974  (5)
  • 1965-1969  (3)
  • 1950-1954  (1)
  • 1925-1929  (3)
  • 1915-1919  (1)
  • 1890-1899  (4)
  • Chemistry  (27)
  • polyvinylpyrrolidone
Material
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 2 (1974), S. 511-524 
    ISSN: 1573-8744
    Keywords: absorption ; reserpine ; bioavailability ; coprecipitates ; polyvinylpyrrolidone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The effect of varying the composition of drug- polyvinylpyrrolidone coprecipitates on the oral absorption characteristics of reserpine was assessed in the rat by urinary excretion studies. Both the rate and extent of absorption of reserpine from either a 1∶2,1∶5,or 1∶10 (w/w)ratio reserpinepolyvinylpyrrolidone coprecipitate were increased two- to threefold. This finding indicates that at coprecipitate ratios of 0.5or less, the enhanced absorption of reserpine is apparently independent of polyvinylpyrrolidone content. The in vitrodissolution rates of these test systems at 37°Ccorrelated very well with the in vivoabsorption data, suggesting dissolution rate- limited absorption, The results of physicochemical studies suggest that on coprecipitation of reserpine with polyvinylpyrrolidone a highly energetic form of the drug, most probably amorphous in nature, is formed. The solubility characteristics of this high- energy crystal form, as compared to those of the most thermodynamically stable form of the drug, appear to be responsible for the marked enhancement noted in both the dissolution and the absorption of reserpine from polyvinylpyrrolidone coprecipitates.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 4 (1966), S. 1053-1053 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbiological Transformations of Nonsteroidal Structures, V. Microbiological Reactions of Substituted 1-Ethyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acids1-Ethyl-7-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (1) is transformed to the methyl ester by Streptomyces surinam. Penicillium adametzi hydroxylates the substrate at the 7-methyl substituent, whereas 1 -ethyl-8-methoxy-5-methyl-4-oxo- 1,4-dihydroquinoline-3-carboxylic acid (4) is hydrolyzed to the free phenol by the same fungi. l-Ethyl-4-oxo-1,4,6,7,8,9-hexahydrobenzo[g]quinolinc-3-carboxylic acid (6) is hydroxylated in 7 - and 8-position by Penicillium adametzi, in 6- and 7- (or 8-) position by Streptomyces achromogenes and in 6-position by Sporotrichum sulfurescens. 5-Ethyl-8-oxo-2,3,5,8-tetrahydrofuro[2,3-g]quinoline-7-carboxylic acid (10) undergoes only a hydrolytic cleavage of the dihydrofuranering.
    Notes: 1-Äthyl-7-methyl-4-oxo-1,4-dihydrochinolin-3-carbonsäure (1) wird durch Streptomyces surinam in den Methylester umgewandelt. Penicillium adametzi hydroxyliert das Substrat am 7-Methylsubstituenten, während bei der 1 -Äthyl-8-methoxy-5-methyl-4-oxo- 1, 4-dihydrochinolin-3-carbonsäure (4) mit dem gleichen Pilz nur eine Phenolätherspaltung eintritt. 1-Äthyl-4-oxo-l,4,6,7,8,9-hexahydrobenzo[g]chinolin-3-carbonsäure (6) wird von Penicillium adametzi in 7- und 8-, von Streptomyces achromogenes in 7-(oder 8-) und 6- sowie von Spororrichum sulfurescens in 6-Stellung hydroxyliert. 5-Äthyl-8-oxo-2,3,5,8-tetrahydrofuro[2,3-g]-chinolin-7-carbonsäure (10) zeigt nur eine hydrolytische Spaltung des Dihydrofuranringes.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 11 (1928), S. 731-750 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: L'étude de la conductibilité des silicates aux températures élevées peut servir à déceler et à suivre des réactions dont ces silicates peuvent être le siège.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbiological Transformations of Nonsteroidal Structures, III. Hydroxylation of 5-Alkyl-2-(benzenesulfonylamino)pyrimidines and Structurally Related Antidiabetics5-Alkyl-2-(arylsulfonylamino)pyrimidines (1-5 and 11-16) have been hydroxylated microbiologically Propyl, butyl, and isobutyl groups were hydroxylated at C-2, ethyl groups at C-1, isopropyl groups at C-1 and C-2, and neopentyl groups at C-3, respectively, by Streptomyces griseolus. The sulfonylurea part of the antidiabetics glibenclamid (25) and glisoxepid (29) was degradated to sulfonamide; in addition, hydroxyl groups were introduced into the 2- and 4-positions of the cyclohexane ring of 25.
    Notes: 5-Alkyl-2-(arylsulfonylamino)pyrimidine (1-5 und 11-16) wurden mikrobiologisch hydroxyliert. Mit Streptomyces griseolus wurden Propyl-, Butyl- und lsobutylgruppen an C-2, äthylgruppen an C-1, Isopropylgruppen an C-1 und C-2, sowie Neopentylgruppen an C-3 hydroxyliert. Die Antidiabetika Glibenclamid (25) und Glisoxepid (29) mit Sulfonylharnstoff-Struktur wurden zu Sulfonamiden abgebaut, ferner wurden in 2- und 4-Stellung des Cyclohexanrings von 25 Hydroxylgruppen eingeführt.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 177 (1929), S. 137-144 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 182 (1929), S. 74-92 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Während die Brom-Austreibung in Gegenwart von Sulfaten in allen Konzentrationen des betreffenden Salzes, je nach dem an- gewandten Sulfat, entweder beschleunigt oder verzögert wird, wirken alle Chloride niederer Konzentration ausschließlich verzögernd. Überall hat man ein Maximum der Verzögerung im Gebiet von etwa n/1-Endkonzentration. Es ergibt sich folgende Reihe ab- nehmender Verzögerung: \documentclass{article}\pagestyle{empty}\begin{document}$$ Me^I Cl 〉 Me^{II} Cl_2 \ge Me^{III} Cl_3. $$\end{document}Eine spezifische Kationenwirkung ist nicht feststellbar. HCl ver- hält sich genau wie ein neutrales Chlorid. Das H-Ion liegt in seiner Wirkung zwischen den ein- und mehrwertigen Kationen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1725-1735 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Emulsan, the extracellular bioemulsifier of Acinetobacter RAG-1, bound up to 0.9 μm of uranium per 1 mg emulsan. The dissociation constant for the emulsan-uranium complex, KappI was 1.2 × 10-4M. Much larger amounts of uranium were bound to emulsan when the biopolymer occurred on hexadecane-water interfaces. Under these conditions, more than 3.5 µm uranium were bound per 1 mg emulsan and the dissociation constant KappII was 5.1 × 10-5M. At pH 2, more than 90% of the uranium bound to emulsan on the hexadecane-water interface was desorbed, while less than 10% bioemulsifier was released from the interface. The different binding parameters of emulsan when free in solution and while adsorbed onto the hexadecane water interface are discussed in view of potential applications and as a model system for studying the properties of an extracellular amphipathic polymer bound to a hydrophobic surface.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 24 (1982), S. 281-292 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Emulsan is a polymeric extracellular emulsifying agent produced by Acinetobacter RAG-1. Hydrocarbon-in-water emulsions (Vf of hydrocarbon of 0.01-0.10) were stabilized by small quantities of emulsan (0.02-0.2 mg/mL). Although both aliphatic and aromatic hydrocarbon emulsions were stabilized by emulsan, mixtures containing both aliphatics and aromatics were better substrates for emulsan than the individual hydrocarbon by themselves. The emulsan remained tightly bound to the hydrocarbon even after centrifugation as determined by (a) residual emulsan in the aqueous phase and (b) the fact that the resulting “cream” readily dispersed in water to reform stable emulsions. With hexadecane-to-emulsan weight ratio of 39 and 155, the noncoalescing oil droplets had average droplet diameters of 2.0 and 4.0 μm, respectively. Dialysis studies showed that the water-soluble dye Rhodamine B adsorbed tightly to the interface of hexadecane-emulsan droplets although the dye did not bind to either hexadecane or emulsan alone. At saturating concentrations of dye, 2.2 μmol of dye were bound per mg emulsan.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 28 (1982), S. 765-772 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A generalized mathematical model is developed to describe the process of multicomponent adsorption on activated carbon in fixed beds. Numerical, finite difference, solutions for the adsorption of binary, and ternary organic mixtures are shown to satisfactorily match previously published experimental data.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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