SELMA MATHEUS LOUREIRO GUEDES
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Artigo IPEN-doc 28415 Manufacture of non-thrombogenic polymer surfaces by gamma irradiation to induce simultaneous grafting and heparinization of thin PVC films2021 - PANZARINI, LUZ C.G.A.; MORANDIM-GIANNETTI, ANDREIA de A.; GUEDES, SELMA M.L.Investigations regarding alternative methods for producing polymeric materials with hydrophilic properties have increased considerably. In this context, polymeric biomaterials with hemocompatible surface properties have been successfully obtained by grafting hydrophilic monomers onto commercial polymer films by simultaneous irradiation processes. In this study, simultaneous irradiation and grafting were used to produce a copolymer PVC-co-DMAEMA-co-heparin with hemocompatible surface properties. Characterization by FTIR of the graft copolymer indicates that the increase in monomer grafting levels inhibits the bonding sites to heparin. FTIR-PAS analyses of the graft copolymers showed that the highest graft levels were obtained for the irradiated samples containing 45% of monomer. Heparin, however, could only be detected in the irradiated samples containing 30% of DMAEMA. The analysis of the micrographs, on the other hand, showed that increasing the monomer concentration enhances surface roughness of the graft copolymers. Roughness however decreased with heparin addition. It was possible to verify that an excess of surface roughness of the graft copolymers inhibits anticoagulant properties of heparin, triggering thrombus formation. Platelet adhesion, on its turn, was not significantly affected by the presence of heparin when PVC-co-DMAEMA and PVC-co-DMAEMA-co-heparin, obtained from the systems containing 45% of monomer, are compared. The addition of heparin in the systems containing 30% of DMAEMA resulted in fewer thrombogenic surfaces.Artigo IPEN-doc 22588 Gamma irradiation effects on poly(hydroxybutyrate)2006 - OLIVEIRA, LETICIA M.; ARAUJO, ELMO S.; GUEDES, SELMA M.L.Artigo IPEN-doc 18875 Boron thin films and CR-39 detectors in BNCT: A method to measure the sup(10)B(n, 'alfa')sup(7)Li reaction rate2013 - SMILGYS, B.; GUEDES, S.; MORALES, M.; ALVAREZ, F.; HADLER, J.C.; COELHO, P.R.P.; SIQUEIRA, P.T.D.; ALENCAR, I.; SOARES, C.J.; CURVO, E.A.C.Artigo IPEN-doc 13000 Determination of the sup(238)U spontaneous fission decay constant without neutron irradiation2002 - GUEDES, S.; HADLER, J.C.; IUNES, P.J.; BURKE, A.K.; KAKAZU, M.H.; SARKIS, J.E.S.; PAULO, S.R.; TELLO, C.A.Artigo IPEN-doc 09591 Spontaneous-fission decay constant of sup(238)U measured by nuclear track techniques without neutron irradiation2003 - GUEDES, S.; HADLER NETO, J.C.; SARKIS, J.E.S.; OLIVEIRA, K.M.G.; KAKAZU, M.H.; IUNES, P.J.; SAIKI, M.; TELLO SAENZ, C.A.; PAULO, S.R.Artigo IPEN-doc 02935 Efeito da radiacao gama em polimeros usados como imobilizadores de resinas de troca ionica. Parte I: Propriedades do PEBD1996 - HUNG, L.C.; GUEDES, S.M.L.; RIELLA, H.G.Artigo IPEN-doc 02536 Reactivity of H sup(.) formed in the radiolysis of benzyl alcohol containing tetracycline hydrochloride at 77K1986 - GUEDES, S.M.L.; VASCONCELLOS, M.B.A.Artigo IPEN-doc 02679 The reactivity of the electron formed in the radiolysis of aerated alkaline aqueous solutions containing tetracycline hydrochloride, at 77Ksup(+)1986 - GUEDES, S.M.L.; VASCONCELLOS, M.B.A.Artigo IPEN-doc 03129 Kinetic decay of H. in the radiolysis of tetracycline hydrochloride in powder form at 77 K+1988 - GUEDES, S.M.L.; VASCONCELLOS, M.B.A.Artigo IPEN-doc 04622 Determinacao da distribuicao do peso molecular do perfluoropolieter atraves da destilacao fracionada em alto vacuo1992 - MARTELLINI, F.; GUEDES, S.M.L.