| 1. |
- BERTOLOTTO, L, et al.
(författare)
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RESULTS FROM (P)OVER-BAR-P-]PHI-PHI
- 1994
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Ingår i: NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA A-NUCLEI PARTICLES AND FIELDS. - : EDITRICE COMPOSITORI BOLOGNA. ; , s. 2329-2337
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Konferensbidrag (refereegranskat)abstract
- The reaction ($) over bar pp --> phi phi is investigated in the JETSET (PS202) experiment using an internal target in LEAR. Data have been analysed at a variety of beam momenta from 1.2 GeV/c to 2.0 GeV/c, corresponding to centre-of-mass energies between
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| 2. |
- Holmberg, K, et al.
(författare)
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Effects on protein adsorption, bacterial adhesion and contact angle of grafting PEG chains to polystyrene
- 1993
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Ingår i: Journal of Adhesion Science and Technology. - 0169-4243 .- 1568-5616. ; 7, s. 503-517
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Tidskriftsartikel (refereegranskat)abstract
- Poly(ethylene glycol) (PEG) has been grafted to polystyrene using branched poly(ethylene imine) (PEI) as an anchoring polymer. A dense grafting of PEG chains is obtained if a PEG-PEI adduct is first prepared by treatment of PEI with PEG epoxide and the adduct subsequently adsorbed on an oxidized polystyrene surface. Prepared in this way the PEG-PEI adduct is irreversibly attached to the surface with the PEG chains oriented towards the aqueous phase, as shown by ESCA and ellipsometry. This dense PEG coating is highly effective in preventing adsorption of fibrinogen and IgG, as well as adhesion of the oral bacterium Streptococcus mutans. Somewhat surprisingly, the degree of PEG branching, as well as the PEG molecular weight, did not markedly influence protein rejecting properties. The water contact angle on polystyrene decreased in the order: untreated polystyrene > oxidized > PEI treated > PEG-PEI treated. Block copolymers of poly(ethylene glycol)/poly(propylene glycol) type attached to polystyrene showed temperature dependent protein rejecting properties. At temperatures well below the cloud point of the polymer in water the surface is protein repellant whereas around and above the cloud point protein adsorption occurs to a considerable extent. The block copolymer layer expands and contracts with temperature variations, as can be monitored by ellipsometry.
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| 3. |
- Van Alstine, JM, et al.
(författare)
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Electrokinetic characterization of hydrophilic polymer coatings of biotechnical significance
- 1993
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Ingår i: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 77, s. 149-158
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Tidskriftsartikel (refereegranskat)abstract
- Analytical microparticle electrophoresis was used to characterize various polymer coatings known to control protein adsorption and related phenomena of biotechnical significance. The electrophoretic mobility of polystyrene latex microspheres and the electroosmosis associated with quartz capillaries were characterized over the pH range 2 to 11. Such characterization provides information related to surface modification. Aminopropylsilane and mercaptopropylsilane were shown to be effective sublayers for covalent attachment of hydrophilic polymers to quartz glass surfaces. Polyethyleneimine was similarly verified as an effective sublayer for polystyrene latex. Polymer coatings based on poly(ethylene glycol) and three polysaccharides, dextran, ethyl(hydroxyethyl)cellulose, and hydroxypropylcellulose, were found to significantly reduce capillary electroosmosis and microsphere electrophoretic mobility over a broad pH range. This reduction corresponds with the ability of these coatings to reduce protein adsorption and control surface wetting by aqueous polymer two-phase systems.
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