Percorrer por autor "Cruz, C."
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- Addressing critical fungal pathogens under a One Health perspective: key insights from the Portuguese Association of Medical MycologyPublication . Sabino, Raquel; Antunes, F.; Araujo, Ricardo; Bezerra, Ana Rita; Brandão, João; Carneiro, C.; Carvalho, Agostinho; Carvalho, D.; Conceição, I. C.; Medeiros, F. Cota; Cruz, C.; Duarte, E.; Holum, Stephanie; Matos, O.; Maltez, Fernando; Mendonça, Alexandre; Moura, Gabriela; Pereira, A.; Rodrigues, Célia Fortuna; Teixeira, P.; Valdoleiros, S. R.; Veríssimo, C.; Viegas, CarlaFungal infections have emerged as a significant public health concern, especially with the increasing incidence of severe mycoses caused by pathogens such as Aspergillus fumigatus, Candida auris, Candida albicans, and Cryptococcus neoformans. These fungi, listed as critical priorities by the World Health Organization, pose a heightened risk due to the rising prevalence of antifungal resistance and their severe impact on immunocompromised individuals. This article, coordinated by the Portuguese Association of Medical Mycology, emphasizes the importance of adopting a One Health approach to comprehensively address fungal threats. Drawing on interdisciplinary collaboration, the association aims to foster greater awareness, improve diagnostic capabilities, and stimulate research and public health policies in Portugal, but also at the global level. The paper outlines key strategies for surveillance, prevention, and innovation in fungal diagnostics and therapeutics. Moreover, it emphasizes the urgent need for national coordination and international cooperation in managing fungal infections, advocating for integrative approaches that link human, animal, and environmental health. By presenting a consolidated overview of current challenges and future priorities, this work seeks to enhance preparedness and response mechanisms in the face of escalating fungal threats.
- How foam-like is the shear-induced lamellar phase of an ionic liquid crystal?Publication . Cruz, C.; Godinho, M. H.; Ferreira, A. J.; Kulkarni, P. S.; Afonso, C. A. M.; Teixeira, PauloIn a recent article [ M. H. Godinho et al., Liq. Cryst. 35, 103 ( 2008)] we reported that sheared films of two n-alkylimidazolium salts exhibit liquid crystalline behaviour below their bulk equilibrium freezing temperature. The resulting morphologies are strongly reminiscent of two-dimensional liquid foams: the materials partition into dark domains ( cells) separated by brighter ( birefringent) walls, which are approximately arcs of circle and meet at vertices ("Plateau borders") with three or more sides. Here we investigate whether they satisfy known quantitative results for foams [see, e. g. D. Weaire and S. Hutzler, The Physics of Foams ( Oxford University Press, Oxford, 1999)]. We find that: (i) where three walls meet, they do so at approximately 120 degrees angles, for all times studied; (ii) Lewis's law of linear relation between cell area and number of sides is approximately satisfied at late times; (iii) the morphological patterns coarsen in time, both T1 and T2 processes are observed and, at late times, evolution is consistent with von Neumann's law; and (iv) relatively large numbers of 5-sided cells survive up to fairly late times. Results ( i) and ( iii) suggest that surface tension may play a key role in determining the physics of this system, as it does in low-viscosity liquid foams.
- Shear-induced lamellar ionic liquid-crystal foamPublication . Ferreira, A. J.; Cruz, C.; Godinho, M. H.; Kulkarni, P. S.; Afonso, C. A. M.; Teixeira, Paulon a recent paper we reported an experimental study of two N-alkylimidazolium salts. These ionic compounds exhibit liquid crystalline behaviour with melting points above 50 degrees C in bulk. However, if they are sheared, a (possibly non-equilibrium) lamellar phase forms at room temperature. Upon shearing a thin film of the material between microscope slides, textures were observed that are strikingly similar to liquid (wet) foams. The images obtained from polarising optical microscopy (POM) were found to share many of the known quantitative properties of a two-dimensional foam coarsening process. Here we report an experimental study of this foam using a shearing system coupled with POM. The structure and evolution of the foam are investigated through the image analysis of time sequences of micrographs obtained for well-controlled sets of physical parameters (sample thickness, shear rate and temperature). In particular, we find that there is a threshold shear rate below which no foam can form. Above this threshold, a steady-state foam pattern is obtained where the mean cell area generally decreases with increasing shear rate. Furthermore, the steady-state internal cell angles and distribution of the cell number of sides deviate from their equilibrium (i.e. zero-shear) values.
- Shear-induced lamellar phase of an ionic liquid crystal at room temperaturePublication . Godinho, M. H.; Cruz, C.; Teixeira, Paulo; Ferreira, A. J.; Costa, Carla; Kulkarni, P. S.; Afonso, C. A. M.The phase behaviour of a number of N-alkylimidazolium salts was studied using polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction. Two of these compounds exhibit lamellar mesophases at temperatures above 50 degrees C. In these systems, the liquid crystalline behaviour may be induced at room temperature by shear. Sheared films of these materials, observed between crossed polarisers, have a morphology that is typical of (wet) liquid foams: they partition into dark domains separated by brighter (birefringent) walls, which are approximately arcs of circle and meet at "Plateau borders" with three or more sides. Where walls meet three at a time, they do so at approximately 120 degrees angles. These patterns coarsen with time and both T1 and T2 processes have been observed, as in foams. The time evolution of domains is also consistent with von Neumann's law. We conjecture that the bright walls are regions of high concentration of defects produced by shear, and that the system is dominated by the interfacial tension between these walls and the uniform domains. The control of self-organised monodomains, as observed in these systems, is expected to play an important role in potential applications.