94 research outputs found
Degradation studies of hydrophilic, partially degradable and bioactive cements (HDBCs) incorporating chemically modified starch
The degradation rate in Hydrophilic, Degradable and Bioactive Cements (HDBCs) containing starch/cellulose acetate blends (SCA) is still low. In order to increase degradation, higher amounts of starch are required to exceed the percolation threshold. In this work, gelatinization, acetylation and methacrylation of corn starch were performed and assessed as candidates to replace SCA in HDBCs. Formulations containing methacrylated starch were prepared with different molar ratios of 2-hydroxyethyl methacrylate and methyl methacrylate in the liquid component and the amount of residual monomer released into water was evaluated. The concentration of reducing sugars, percentage of weight loss and morphologic analyses after degradation all confirmed increased degradation of HDBC with alpha-amylase, with the appearance of pores and voids from enzymatic action. Methacrylated starch therefore is a better alternative to be used as the solid component of HDBC then SCA, since it leads to the formation of cements with a lower release of toxic monomers and more prone to hydrolytic degradation while keeping the other advantages of HDBCs.The authors acknowledge to Foundation for Science and Technology (FCT), who supported this study through funds from project Concept2Cement (POCTI/CTM/60735/2004)
Local anaesthetic infiltration for peri-operative pain control in total hip and knee replacement: systematic review and meta-analyses of short- and long-term effectiveness
Correlation of microbial response in model food systems with physico-chemical and mobility (NMR molecular and structural) descriptors of the media
1H, 2H and 17O NMR water mobility in heterogeneous food model systems as related to microbial response
Correlation of microbial response in model food systems with physico-chemical and mobility (NMR molecular and structural) descriptors of the media
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