47 research outputs found

    Critical agency and development: applying Freire and Sen to ICT4D in Zambia and Brazil

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    This paper draws upon critical theories and the capability approach. It argues for a conceptualization of development as a process designed to enable people to free themselves from structural disadvantage. Amartya Sen has argued that people’s “critical-agency” to question and reject unjust social norms is “pivotal” to human development and important for tackling inequalities of any kind. Freire’s critical pedagogy, and critical feminism, go further by providing disadvantaged people with the practical means to do this; to identify the structural root causes of unjust social norms and the critical-agency to challenge and change them. Two empirical case studies of ICT4D are presented, from Zambia and Brazil, which draw upon these critical approaches but use them in different ways. The paper argues that ICT4D must go beyond addressing people’s immediate practical needs for access to ICT tools and skills, to also address their strategic interest in identifying and tackling the root causes of disadvantage

    Dexamethasone and zinc loaded polymeric nanoparticles reinforce and remineralize coronal dentin. A morpho-histological and dynamic-biomechanical study.

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    Objective: To investigate the effect of novel polymeric nanoparticles (NPs) doped with dexamethasone (Dex) on viscoelasticity, crystallinity and ultra-nanostructure of the formed hydroxyapatite after NPs dentin infiltration. Methods: Undoped-NPs, Dex-doped NPs (Dex-NPs) and zinc-doped-Dex-NPs (Zn-Dex-NPs) were tested at dentin, after 24 h and 21 d. A control group without NPs was included. Coronal dentin surfaces were studied by nano-dynamic mechanical analysis measurements, atomic force microscopy, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). Results: At 21 d of storage time, both groups doped with Dex exhibited the highest complex, storage and loss moduli among groups. Zn-Dex-NPs and Dex-NPs promoted the highest and lowest tan delta values, respectively. Dex-NPs contributed to increase the fibril diameters of dentin collagen over time. Dentin surfaces treated with Zn-Dex-NPs attained the lowest nano-roughness values, provoked the highest crystallinity, and produced the longest and shortest crystallite and grain size. These new crystals organized with randomly oriented lattices. Dex-NPs induced the highest microstrain. Crystalline and amorphous matter was present in the mineral precipitates of all groups, but Zn and Dex loaded NPs helped to increase crystallinity. Significance: Dentin treated with Zn-Dex-NPs improved crystallographic and atomic order, providing structural stability, high mechanical performance and tissue maturation. Amorphous content was also present, so high hydroxyapatite solubility, bioactivity and remineralizing activity due to the high ion-rich environment took place in the infiltrated dentin.This work was funded by Grant PID2020-114694RB-I00 funded by MCIN/AEI 10.13039/501100011033
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