Mechanical properties and thermal shock in thin ZrO2–Y2O3–Al2O3 films obtained by the sol-gel method

Thin multilayer coatings of ZrO₂–Y₂O₃–Al₂O₃ were prepared using the sol-gel method and dip-coating technique in order to advance in the study of what influence the incorporation of Al₂O₃ has on films of Y₂O₃-doped ZrO₂, investigating its role in the synthesis of the solutions and in the characteristics and properties of the coatings. After the characterization of the solutions used in the process, the microstructure of the films was studied and their mechanical behaviour and resistance to thermal shock were determined so as to optimize the characteristics and functionality of these coatings. With increased alumina content, 3YSZ-Al₂O₃ (20 mol%), the cubic phase of the zirconia disappeared completely at the sintering temperature used (700 °C), resulting in the tetragonal phase with Al in solution. There was also a decrease in the coatings' hardness and Young's modulus, and an increase in toughness and resistance to thermal shock. These results allow guidelines to be established for the design of multilayer structures that are, tougher, more resistant, and have improved surface properties.     

Comparative Genomics Reveals 13 Different Isoforms of Mytimycins (A-M) in Mytilus galloprovincialis

Mytimycins are cysteine-rich antimicrobial peptides that show antifungal properties. These peptides are part of the immune network that constitutes the defense system of the Mediterranean mussel (Mytilus galloprovincialis). The immune system of mussels has been increasingly studied in the last decade due to its great efficiency, since these molluscs, particularly resistant to adverse conditions and pathogens, are present all over the world, being considered as an invasive species. The recent sequencing of the mussel genome has greatly simplified the genetic study of some of its immune genes. In the present work, we describe a total of 106 different mytimycin variants in 16 individual mussel genomes. The 13 highly supported mytimycin clusters (A–M) identified with phylogenetic inference were found to be subject to the presence/absence variation, a widespread phenomenon in mussels. We also identified a block of conserved residues evolving under purifying selection, which may indicate the “functional core” of the mature peptide, and a conserved set of 10 invariable plus 6 accessory cysteines which constitute a plastic disulfide array. Finally, we extended the taxonomic range of distribution of mytimycins among Mytilida, identifying novel sequences in M. coruscus, M. californianus, P. viridis, L. fortunei, M. philippinarum, M. modiolus, and P. purpuratus.     

A novel ceramic matrix composite based on YNbO4–TiO2 for microwave applications

This work presents the dielectric properties of YNbO₄ (YNO)–TiO₂ composites in the microwave range. X-ray diffraction analysis demonstrates that the addition of TiO₂ to YNO results in the formation of a Y(Nb_0.5Ti_0.5)₂O₆ phase. In the microwave range, the values of permittivity and dielectric loss did not present major changes with the increment of TiO₂. Moreover, the addition of TiO₂ results in an improvement in the thermal stability of YNO, with YNO63 demonstrating a resonant frequency of ?8.96 ppm.°C^?1. We utilised numerical simulations to evaluate the behaviour of these materials as dielectric resonator antennae and it is found that they exhibit a reflection coefficient below ?10 dB at the resonant frequency, with a realised gain of 4.94 – 5.76 dBi, a bandwidth of 665–1050 MHz and a radiation efficiency above 84%. Our results indicate that YNO–TiO₂ composites are interesting candidates for microwave operating devices.     

Portrait of Cancer Stem Cells on Colorectal Cancer: Molecular Biomarkers,Signaling Pathways and miRNAome

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.     

Thermal and dynamic mechanical behavior of epoxy composites reinforced with post-consumed yerba mate

Yerba mate (YM) is widely consumed in Latin American countries, and its residues can be used as bio-resources such as reinforced in epoxy composites. The present work aims to produce epoxy resin composites and evaluate the influence of post-consumed YM as reinforcement. The concentrations of YM used were 5, 10, and 20% (wt/wt). Chemical, thermal, morphological, and dynamic mechanical behaviors were explored. The YM incorporation did not influence chemically on the epoxy structure and a pull-out phenomenon was observed as YM content increased. The YM at lower concentrations (5 and 10%) led to higher values of activation energies calculated from model-free isoconversional methods. On the other hand, the composite e/YM 20 wt% improved all dynamic-mechanical properties. YM proved to be a suitable and cheap reinforcement for epoxy resin.     

Rheological and viscoelastic properties of colloidal solutions based on gelatins and chitosan as affected by pH

The objective of this study was to evaluate the influence of pH on rheological and viscoelastic properties of solutions based on blends of type A (GeA) or type B (GeB) gelatin and chitosan (CH). Solutions of GeA, GeB, CH, GeA:CH, and GeB:CH were prepared in several pH (3.5–6.0) and analyzed for determination of zeta-potential. Rheological analyses (stationary and dynamic essays) were carried out with blends allowing to study the effect of pH on shear stress, apparent viscosity, loss (G”) and storage (G’) moduli, and angle phase (Tanδ). Zeta potential of all biopolymers decreased linearly as a function of pH. CH presented higher values, and GeB, the lowest one, being the only having negative values at pH > 5. Overall, the pH influenced the rheological and viscoelastic properties of the colloidal solutions: shear stress and apparent viscosity increased as a function of pH. Other assays were carried out at 3% and 5% strain, for GeA:CH and GeB:CH, respectively. In the sol domain, G’ and G” (1 Hz) increased linearly for GeA:CH. But for GeB:CH, they increased in two linear different regions: one function between pH 3.5 and 5.0 and another one between 5.0 and 6.0, being a more important effect was visible in this last domain probably due to the negative net charge of gelatin, above it pI. An effect in two domains was also visible for Tanδ, explained in the same manner as previously. The GeB:CH blends behaved like diluted solutions, and transition temperatures increased as a function of pH.     

Semantic web technologies applied to software accessibility evaluation: a systematic literature review

Universal Access in the Information Society - Software accessibility is a current field of interest. Governments and organizations boost initiatives and legislations to assure universal access. On...     

Gluten-free cakes with walnut flour: a technological,sensory, and microstructural approach

Walnut flour (WF), a by-product of walnut oil production, is characterised by high polyunsaturated fatty acids, proteins, and fibre contents and presents suitability for bakery products. However, when using non-traditional ingredients, it is essential to evaluate the effect on the quality properties of the final product. So, this work aimed to assess the impact of WF on the technological, physicochemical, and sensory properties of gluten-free (GF) cakes. WF was added at a flour blend (cassava (CS) and maize (MS) starches and rice flour) at 0, 10%, 15%, and 20%. The results showed that WF modified starch gelatinisation, increased amylose–lipid complex (ALC) content, and made crumbs easier to chew. Besides, the total dietary fibre (TDF) and protein content significantly increased. Cakes with 15% WF presented the highest specific volume (SV) and no differences in overall acceptability with respect to control. Hence, WF is a suitable ingredient for gluten-free bakery products.     

Foliar Spraying of Silicon Associated with Salicylic Acid Increases Silicon Absorption and Peanut Growth

Silicon - Silicon (Si) combined with foliar spraying of salicylic acid (SA) can affect the absorption of this beneficial element. A study with Si non-accumulators plants (soybean and bean) observed...