Poly anomalous structures

Formation of Anomalous Structures in Poly(vinyl chloride) and Their Influence on the Thermal Stability... 

The low thermal stability of poly(vinyl chloride) (PVC) has been ascribed to the pressure of low amounts of anomalous structures with... 

Copolymers of L-proline and sarcosine have been prepared by Fasman and Blout (1961). These were found to exist in two forms, analogous to poly-L-proline. Form I, which is obtained directly from the copolymerization mixture showed anomalous optical rotatory dispersion and relatively low viscosity. On dissolving form I in 2-chloroethanol, form II is obtained which exhibits normal optical rotatory dispersion and relatively high viscosity. Fasman and Blout have suggested that the transition, form I —> form II, involves a conversion of the structure from ds- amide bonds to fmns-amide bonds. 

Several other experimental findings support the existence of a microceliular structure in oligomeric foams. Thus, Oween and Denis ) observed an anomalous pattern (in the expression of the authors) for certain types of silicone surfactants the liquid foam system consists of gas bubbles the sizes of which differ by several orders of magnitude. The possibility of formation of very small gas bubbles after a marked reduction of the surface tension coefficient in poly-lurethane formulations has been reported by Dubyaga and Tarakanov ). 

Quemer C, Schmidt T, Arndt K-F (2004) Oiaracterization of structural changes of poly(vinyl methyl ether) y-irradiated in diluted aqueous solutions. Langmuir 20 2883-2889 Ren SZ, Shi WF, Zhang WB, Sorensen CM (1992) Anomalous diffusion in aqueous solutions of gelatin. Phys Rev A 45 2416-2422... 

There is evidence that poly(ADP-ribosyl)ation, in response to DNA damage (review [1]), permits changes in chromatin structure [2] which may facilitate the activity of repair enzymes [3] and become a major factor in the control of cell-cycle traverse [4], This paper explores the role of chromatin structure and poly(ADP-ribosyl)ation (using the inhibitor, 3-aminobenzamide 3AB [5]) in the responses of human cells to either a DNA specific ligand (Hoechst dye 33341 Ho33342) or X-radiation. Cells derived from an ataxia telangiectasia (A-T) patient have been included in the study to provide a h) ersensitive control (reviews [6, 7]) in which anomalous cell survival and cell-cycle responses [8-10] to radiation may reflect a primary defect in chromatin structure [11,12]. 

Cao, H., Lin, G., and Jones, A.A. (2004) Anomalous penetrant diffusion as a probe of the local structure in a blend of poly (ethylene oxide) and poly (methylmethacrylate)./. Polym. Sci. Part B Polym. Phys., 42, 1053-1067. 

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