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Free Monomers (free + monomer)
Selected AbstractsNeutrophil elastase in pressure ulcer fluid degrades fibronectin in the exudatesGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2004Shingo Ai Background: Pressure ulcers are classified as chronic wounds, which do not heal in a timely fashion. Fibronectin is condensed in granulation tissue, and essential glycoprotein of wound healing. It has been proposed that fibronectin degradation may be involved in delaying wound healing. We have investigated whether pressure ulcer fluid (PUF) contains degraded fibronectin. In addition, we tried to identify the proteinase which contributes to fibronectin degradation in PUF. Methods: Fibronectin degradation and the presence of neutrophil elastase (NE) in PUF were determined by immunoblot analysis. Fibronectin degradation activity in PUF was determined in the presence of various proteinase inhibitors. NE activity was assessed using NE specific substrate. Results: Immunoblot analysis revealed that degraded fibronectin was observed in PUF samples but not in acute wound fluid (AWF). The PUF contained a proteinase capable of degrading freshly added fibronectin and its activity in PUF was blocked by a broad-spectrum serine proteinase inhibitor or sivelestat, a specific neutrophil elastase inhibitor, but not by metalloproteinase and cysteine proteinase inhibitors. Immunoblot analysis of PUF using an antineutrophil elastase antibody revealed that neutrophil elastase was detected as three bands at molecular weights of ,30 kDa, ,38 kDa, and ,54 kDa, indicating that neutrophil elastase in the exudates existed not only as free monomers, but also in polymers or complexes with other molecules. Conclusion: These results suggest that PUF contains a high level of neutrophil elastase which may be involved in the delay of the healing of pressure ulcer through the fibronectin degradation. [source] Copolymerization of Fluorinated Monomers with Hydrophilic Monomers in Aqueous Solution in Presence of CyclodextrinMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 11 2006Oliver Kretschmann Abstract Summary: New fluorinated copolymers were synthesized by copolymerization of 1H,1H,2H,2H- perfluorodecyl methacrylate (1) with hydrophilic comonomers methacrylic acid (3), 2-acrylamido-2-methylpropane sulfonic acid (6), 3-trimethylammonium propyl methacrylamide chloride (7) and N,N -dimethylmethacrylamidopropyl- N -3-sulfopropylammoniumbetaine (8). The reaction was carried out in water using randomly methylated , -cyclodextrin (RAMEB) for solubilization of the fluorinated monomer by forming a host-guest complex (1a). Polymerization kinetics were investigated and copolymerization parameters were determined. Additionally, a RAMEB complex of tert -butyl methacrylate (2a) was copolymerized with 1a in water. For comparison, copolymerization of the uncomplexed monomers 1 and 2 were carried out in organic solvents. Evaluation of copolymerization kinetics and parameters showed significant differences in the relative reactivities of the free monomers and the monomer-RAMEB complexes. [source] Hyperbranched macromolecules through donor-acceptor type copolymerization of allyl,vinylene bifunctional monomers,POLYMER INTERNATIONAL, Issue 10 2002O Rzaev, Zakir M Abstract Present review is an attempt to generalize and systematize the results accumulated in synthesis of cyclolinear and hyperbranched reactive macromolecules via radical alternating copolymerization of various bifunctional monomers containing donor and acceptor type double bonds. Synthesis of hyperbranched reactive macromolecules was carried out using complex-radical cyclocopolymerization of donor-acceptor type bifunctional monomers such as monoallyl ester of maleic acid (MAM), allyl acrylate (AA), allyl methacrylate (AM), allyl trans -cinnamate (AC), methylallylmaleate (MeAM), methylallylfumarate (MAF) and allyl-,-(N-maleimido)acetate (AMI), and maleic anhydride (MA) and styrene (St) as typical acceptor and donor comonomers, respectively. The kinetic parameters of these reactions, constants of cyclization, complex-formation and copolymerization, as well as the ratios of chain growth rates for the participation of monomeric charge transfer complexes and free monomers, were all determined. It was demonstrated that in the studied systems, copolymerizations predominantly proceed according to alternating mechanism with formation of macromolecules having cyclolinear structure in the steady-state and hyperbranched structure in the high conversion conditions. It was shown that formation of linear and hyperbranched macromolecules containing allyl or vinylene groups in the side chain occurs selectively carry out and depends on the nature of used comonomer. General schemes and proposed mechanism of hyperbranching and crosslinking reactions were also described. Some useful properties of synthesized reactive copolymers were discussed. © 2002 Society of Chemical Industry. [source] Photoinitiated alternating copolymerization of vinyl ethers with chlorotrifluoroethylenePOLYMER INTERNATIONAL, Issue 7 2002Manuel Gaboyard Abstract The photoinitiated copolymerization of chlorotrifluoroethylene (CTFE) with several vinyl ethers [ethyl vinyl ether (EVE), 2-chloroethyl vinyl ether (CEVE), cyclohexyl vinyl ether (CHVE), 4-hydroxybutyl vinyl ether (HBVE)] was studied. CTFE is an acceptor monomer (e,,,1.5) whereas vinyl ethers are donor monomers (e,,,,1.5), and therefore their copolymerization led to alternating copolymers, as indicated by elementary analysis. The equilibrium constant (KF) of the charge-transfer complex formation (CTC) was determined by 19F NMR spectroscopy. Under our experimental conditions, KF was low for CHVE/CTFE and HBVE/CTFE systems, 0.058 and 0.013,l mol,1 respectively. It can be assumed that the copolymerization involves the free monomers rather than propagation via the donor,acceptor complex. The alternating structure arises from the great difference in polarity between the two types of monomers. Several functional copolymers were prepared in good yield and with molecular weight close to 15,000,g,mol,1. © 2002 Society of Chemical Industry [source] | ||||||||||