73 research outputs found

    Modality, Potentiality and Contradiction in Quantum Mechanics

    Get PDF
    In [11], Newton da Costa together with the author of this paper argued in favor of the possibility to consider quantum superpositions in terms of a paraconsistent approach. We claimed that, even though most interpretations of quantum mechanics (QM) attempt to escape contradictions, there are many hints that indicate it could be worth while to engage in a research of this kind. Recently, Arenhart and Krause [1, 2, 3] have raised several arguments against this approach and claimed that, taking into account the square of opposition, quantum superpositions are better understood in terms of contrariety propositions rather than contradictory propositions. In [17] we defended the Paraconsistent Approach to Quantum Superpositions (PAQS) and provided arguments in favor of its development. In the present paper we attempt to analyze the meanings of modality, potentiality and contradiction in QM, and provide further arguments of why the PAQS is better suited, than the Contrariety Approach to Quantum Superpositions (CAQS) proposed by Arenhart and Krause, to face the interpretational questions that quantum technology is forcing us to consider.Comment: Published in: New Directions in Paraconsistent Logic, J-Y B\'eziau M. Chakraborty & S. Dutta (Eds.), Springer, in press. arXiv admin note: text overlap with arXiv:1404.518

    Mesenchymal stem cells promote macrophage polarization toward M2b-like cells

    Get PDF
    Mesenchymal stem or stromal cells (MSCs) act on different components of the immune response including macrophages (MPhis). Therefore this study has been committed to explore how MSCs may modify the effect of MPhi polarization upon an inductive environment using mouse bone marrow (BM)-derived "naive", unpolarized MPhis. Phagocytosis of various MPhi subtypes was different since M1 and M2b showed poorer, while M2a higher rate of phagocytosis. MSCs significantly promoted yeast ingestion by M1 and M2b and diminished it by M2a cells. Under polarizing conditions, MSCs profoundly affected the TNFalpha production of MPhi subtypes since M1 and M2b MPhis produced less and M2a produced higher amount of TNFalpha while the amount of IL-10 was not affected. The most striking effect of MSCs was registered on M2b cells since the inflammatory TNFalpha dominance remarkably shifted to the immunosuppressive IL-10. Prepolarized M1 cells readily converted to M2a and M2b states when polarizing conditions changed from M1 to M2a or M2b induction, respectively. Repolarizing from M1 to M2a resulted in the decline of IL-10 and TNFalpha and defined elevation of Ym1 similar to levels characteristic to M2a primarily polarized from naive BM-MPhis. Similarly, polarization of M1 to M2b MPhis was successful showing increase in IL-10 and reduction in TNFalpha levels characteristic to M2b cells. However, when co-culturing with MSCs, M1-M2a or M1-M2b transition was not affected. Crosstalk between MPhis and MSCs depended on PGE-2 since COX-2 inhibition reduced the effect of MSCs to establish an IL-10-dominant cytokine production by MPhis

    Acetylated bacterial cellulose coated with urinary bladder matrix as a substrate for retinal pigment epithelium

    Get PDF
    This work evaluated the effect of acetylated bacterial cellulose (ABC) substrates coated with urinary bladder matrix (UBM) on the behavior of Retinal Pigment Epithelium (RPE), as assessed by cell adhesion, proliferation and development of cell polarity exhibiting transepithelial resistance and polygonal shaped-cells with microvilli. Acetylation of bacterial cellulose (BC) generated a moderate hydrophobic surface (around 65°) while the adsorption of UBM onto these acetylated substrates did not affect significantly the surface hydrophobicity. The ABS substrates coated with UBM enabled the development of a cell phenotype closer to that of native RPE cells. These cells were able to express proteins essential for their cytoskeletal organization and metabolic function (ZO-1 and RPE65), while showing a polygonal shaped morphology with microvilli and a monolayer configuration. The coated ABC substrates were also characterized, exhibiting low swelling effect (between 1.52.0 swelling/mm3), high mechanical strength (2048 MPa) and non-pyrogenicity (2.12 EU/L). Therefore, the ABC substrates coated with UBM exhibit interesting features as potential cell carriers in RPE transplantation that ought to be further explored.The authors would also like to acknowledge José Ramalho for kindly supplying the RPE65 primary antibody. The authors acknowledge the Portuguese Foundation for Science and Technology (FCT, Portugal) for the financial support provided through the doctoral and posdoctoral grants SFRH/BD/63578/2009, SFRH/BD/64901/2009, SFRH/BPD/64958/2009 and SFRH/BPD/63148/2009 for Sara Gonc¸ alves, Jorge Padrão, João Pedro Silva, and Vitor Sencadas, respectively. The authors also acknowledge the projects PEst-OE/EQB/LA0004/2013, PEst-OE/EQB/LA0023/2013, PEST-C/FIS/UI607/2014, PTDC/BBB-BQB/2450/2012 and PTDC/SAU-ORG/118694/2010, co-funded by QREN, FEDER. Finally, the authors thank the FCT strategic project UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124- FEDER-027462) and the project “BioInd—Biotechnology and Bioengineering for improved Industrial and Agro-Food processes”, REF. NORTE-07-0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER
    corecore