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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 47 (1993), S. 2083-2091 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Water-borne enzymatic coating-based dry chemistries have been used for more than 20 years, especially by diabetics, for self-monitoring of blood glucose. Until now, it has been believed that enzymes work only in water and not in organic solvents. Synthesis of a hydroxylated acrylic polymer and the novel concept of dispersing enzymes have enabled us to design nonaqueous diagnostic coatings. These coating films gave excellent dose response and dynamic range. Additionally, these coatings can easily be ranged by a wide variety of antioxidants. In contrast, water-borne coatings are extremely difficult to range. Furthermore, nonaqueous coating films produce color signals that are independent of the reaction time with excellent thermal stability. Molecular forces and thermodynamical considerations have been used to explain the performance of the new dry chemistries. An organic reaction mechanism of ranging has also been proposed for the nonaqueous system. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell biology and toxicology 12 (1996), S. 1-9 
    ISSN: 1573-6822
    Keywords: Amoeba proteus ; cytotoxicity ; polyamine ; polyamine oxidase ; spermine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract It has been shown that oxidation of polyamines by polyamine oxidases can produce toxic compounds (H2O2, aldehydes, ammonia) and that the polyamine oxidase-polyamine system is implicated, in vitro, in the death of several parasites. Using Amoeba proteus as an in vitro model, we studied the cytotoxicity to these cells of spermine, spermidine, their acetyl derivatives, and their hypothetical precursors. Spermine and N 1-acetylspermine were more toxic than emetine, an amoebicidal reference drug. Spermine presented a short-term toxicity, but a 48-h contact time was necessary for the high toxicity of spermidine. The uptake by Amoeba cells of the different polyamines tested was demonstrated. On the other hand, a high polyamine oxidase activity was identified in Amoeba proteus crude extract. Spermine (theoretical 100%) and N 1-acetylspermine (64%) were the best substrates at pH 9.5, while spermidine, its acetyl derivatives, and putrescine were very poorly oxidized by this enzyme (3–20%). Spermine oxidase activity was inhibited by phenylhydrazine (nil) and isoniazid (≈ 50%). Mepacrine did not inhibit the enzyme activity at pH 8. Neither monoamine nor diamine oxidase activity (≈ 10%) was found. It must be emphasized that spermine, the best enzyme substrate, is the most toxic polyamine. This finding suggests that knowledge of polyamine oxidase specificity can be used to modulate the cytotoxicity of polyamine derivatives. Amoeba proteus was revealed as a simple model for investigation of the connection between cytotoxicity and enzyme activity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell biology and toxicology 14 (1998), S. 419-428 
    ISSN: 1573-6822
    Keywords: bisbenzylpolyamine analogs ; cytotoxicity ; DFMO ; MDL 72,527 ; polyamine content ; polyamine oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The effects of a series of bisbenzyldiamine analogs have been tested on P388D1 cell line in vitro. Their effects on cell growth, polyamine oxidase (PAO) activity and intracellular polyamine content were determined. The cytotoxicity tests were performed in culture medium supplemented with 100 μmol/L aminoguanidine (I), 100 μmol/L aminoguanidine and 100 μmol/L N,N′-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72,527) (II), and finally 100 μmol/L aminoguanidine and 200 μmol/L D,L-difluoromethylornithine (DFMO) (III). The IC50 values under conditions I and III were similar, suggesting that inhibition of ornithine decarboxylase by DFMO did not affect the biological effect of our derivatives. Spermine and spermidine remained nontoxic in conditions I and III. However in the condition II, the toxicity of all tested compounds (excepted spermidine) was increased, suggesting that the inhibition of cellular PAO increased their toxicity. The enzymatic test of PAO showed that at high doses inhibition of this enzyme by putrescine analogs occurred, while the N-methylated propanediamine derivative increased the enzyme activity; however, these results do not correlate with cytotoxicity tests. When these derivatives were incubated for 48 h with the cells, all of them increased the cell content in putrescine (∼160%) and spermine (∼145%) and decreased the spermidine content (∼75%) without any modification of the total amount of polyamine. The correlation between the cytotoxic results and the intracellular polyamine determination shows that the increase in spermine content along with the inhibition of retroconverting PAO enzyme increases the toxic effect of tested compounds (including spermine), suggesting that spermine toxicity is more important in the absence of intracellular oxidation processes.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 72 (1978), S. 45-55 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Polymerization of acetoxy-2 styrene, parachloro acetoxy-2 styrene, paramethyl acetoxy-2 styrene and paranitro acetoxy-2 styrene was carried out by means of free radical initiators or by thermic reaction. The polymers therefrom showed molecular weights of about 200 000. Studies on the thermal behaviour reveal that these polymers do not undergo any change of phase, either vitreous or crystalline. Dielectric experiments show losses of about 10-3 radian; the losses are practically constant within a large scale of temperature and frequency. Over 320°K one notices a relaxation process of small magnitude and the presence of water brings about a marked change in the way the polymer reacts to dielectric treatment.
    Notes: La polymérisation de I'acttoxy-2 styrène, du parachloro acétoxy-2 styrène, du paramb thyl acétoxy-2 styrène et du paranitro acetoxy-2 styrène a été obtenue avec des amorceurs radicalaires ou par voie thermique. Les polymtres obtenus possedent des masses moyennes en nombre atteignant 200000. L'étude du comportement thermique permet d'établir que ces polymtres ne presentent pas de transition de phase, vitreuse ou cristalline. L'étude diklectrique de ces polymtres a été effectue: on releve des pertes de I'ordre de 10-3 radian, pratiquement constantes dans un large domaine de temphture et de fréquence. Au-delà de 320°K on décèle un mkanisme de relaxation de faible amplitude et la presence d'eau modilie sensiblement son comportement diélectrique.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 2005-2013 
    ISSN: 0887-6266
    Keywords: sphere doublets ; light scattering ; suspension ; flow ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polarized or depolarized light scattering by well-defined monodispersed sphere doublets is investigated. Two configurations of doublets are studied. In the first (at rest) the doublets are randomly oriented in a plane, in the second the doublets are oriented in a preferred direction. This is achieved by submitting a suspension of doublets to a shear flow. The scattering patterns are compared to two theoretical predictions based on simplified geometries. In the first approach, the doublet is approximated by two interpenetrating spheres scattering independently, whereas in the second, an ellipsoid geometry is used. A good qualitative comparison is obtained. However, the HV and VH patterns of a randomly dispersed suspension are not similar. The observation of the flow of a doublet suspension in shear shows that the doublets are spiraling around the vorticity axis. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2005-2013, 1998
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 48 (1997), S. 47-87 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 38 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 22 (1984), S. 149-152 
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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