Dextrin and conducting polymer containing biocomposites: properties and behavior as cellular matrix

Both α-cyclodextrin and linear dextrin are used to prepare biocomposites with poly(3,4- ethylenedioxythiophene). Materials are prepared electrochemically in aqueous solution. Comparison with the pure polymer indicates that the electroactivity and electrostability decrease with the incorporation of the dextrins while the electrical conductivity is retained. The different properties of the two biocomposites suggest that the linear dextrin is mainly located at the surface, whereas the cyclodextrin is homogeneously distributed in the polymeric matrix. Cell adhesion and proliferation assays indicate that the cellular activity is significantly higher in the dextrin-containing biocomposites.Acknowledgements: Financial support from the MICINN and FEDER (MAT2009-09138) and Generalitat de Catalunya (research group 2009 SGR 925 and XRQTC) is gratefully acknowledged. B.T.-D. acknowledges support from the MICINN through an FPI grant and financial support for his stay at the 3B’s Research Group (Portugal). The support from project PTDC/FIS/115048/2009 (FCTPortugal) is also acknowledged. Authors are indebted to Dr. Elaine Armelin for helpful suggestions and to David Aradilla for assistance in electrical measures and SEM micrographs. Support for the research of C.A. was received through the prize ‘‘ICREA Academia’’ for excellence in research funded by the Generalitat de Catalunya

Total factor productivity growth in East Asia: A critical survey

This article surveys the recent empirical literature on total factor productivity (TFP) growth in East Asia, and the debate about the sources of growth in the region. It is concluded that: (i) the main merit of this literature is that it has helped focus the attention of scholars on the growth process of East Asia; (ii) the theoretical problems underlying the notion of TFP are so significant that the whole concept should be seriously questioned; (Hi) the TFP growth estimates for the region vary significantly, even for the same country and time period; and (iv) research on growth in East Asia based on the estimation of TFP growth is an activity subject to decreasing returns. If we are to advance in understanding how East Asia grew during the last 30 years we need new avenues of research.