Cork is a renewable, non-wood high valued forest product, with relevant ecological and economic impact in the Mediterranean-type ecosystems. Currently, cork is ranked according to its commercial quality. The most valuable planks are chosen for cork stoppers production. Cork planks with adequate thickness and porosity are classified as stoppable quality cork (SQC). The chemical composition of cork is known, but the regulation of metabolic pathways responsible of cork production and composition, hence of cork quality, is largely unknown. Here, we tested the hypothesis that post-genomic events may be responsible for the development of SQC and N-SQC (non-stoppable quality cork). Here, we show that combined proteomics and targeted metabolomics (namely soluble and cell wall bound phenolics) analyzed on recently formed phellem allows discriminate cork planks of different quality. Phellem cells of SQC and N-SQC displayed different reducing capacity, with consequential impact on both enzymatic pathways (e.g., glycolysis) and other cellular functions, including cell wall assembly and suberization. Glycolysis and respiration related proteins were abundant in both cork quality groups, whereas the level of several proteins associated to mitochondrial metabolism was higher in N-SQC. The soluble and cell wall-bound phenolics in recently formed phellem clearly discriminated SQC from N-SCQ. In our study, SQC was characterized by a high incorporation of aromatic components of the phenylpropanoid pathway in the cell wall, together with a lower content of hydrolysable tannins. Here, we propose that the level of hydrolysable tannins may represent a valuable diagnostic tool for screening recently formed phellem, and used as a proxy for the quality grade of cork plank produced by each tree.

This paper investigates the effect of recycled coarse aggregate incorporation on the relationship between 150 mm cubic and Փ 150 mm cylindrical compressive strength (the reference strength of standards) by comparing data from recycled and natural aggregate concrete compositions in which both cubes and cylinders were tested. A conversion factor from cubic to cylindrical strength is proposed in two versions: A deterministic and a probabilistic one. Such factor has not been studied before and researchers have been converting cubic data as if natural aggregate concrete were tested. The probabilistic factor is intended for reliability analyses on the structural behaviour of recycled aggregate concrete using data from laboratory cube tests. It was found that the incorporation of recycled coarse aggregates sourced from concrete waste significantly decreases the expected value of the factor but the factor’s scatter is relatively unaffected.

The durability of adhesively bonded fiber-reinforced polymers (FRP) and concrete substrates has been the subject of recent studies. The degradation of bonded interfaces conjugated with other factors that affect the interface strength may compromise the potentialities of using FRP in externally bonded reinforced (EBR) concrete structures. However, the estimation of the effects of degradation on these bonded interfaces and the analytical methodologies to quantify them are not fully understood. The present work focuses on a local bond-slip model characterized by two parameters for which the values are obtained experimentally. Then, the determination of the local bond-slip relationship of a glass (G) FRP-to-concrete interface can be estimated. The assessment of the degradation of the bonded interface when subjected to cycles of (1) salt fog; (2) wet-dry environments with salt water; (3) temperatures between −10°C and +30°C; and (4) temperatures between +7.5°C and +47.5°C is presented. The results obtained using the proposed bond-slip model led to the conclusion that after 10,000 h of exposure to temperature cycles between −10°C and +30°C, there was a small change in the GFRP-to-concrete interface performance, whereas the effects on the bonded interface for the specimens subjected to temperature cycles between +7.5°C and +47.5°C were far more most severe.

The durability of adhesively bonded fiber-reinforced polymers (FRP) and concrete substrates has been the subject of recent studies. The degradation of bonded interfaces conjugated with other factors that affect the interface strength may compromise the potentialities of using FRP in externally bonded reinforced (EBR) concrete structures. However, the estimation of the effects of degradation on these bonded interfaces and the analytical methodologies to quantify them are not fully understood. The present work focuses on a local bond-slip model characterized by two parameters for which the values are obtained experimentally. Then, the determination of the local bond-slip relationship of a glass (G) FRP-to-concrete interface can be estimated. The assessment of the degradation of the bonded interface when subjected to cycles of (1) salt fog; (2) wet-dry environments with salt water; (3) temperatures between -10°C and +30°C; and (4) temperatures between +7.5°C and +47.5°C is presented. The results obtained using the proposed bond-slip model led to the conclusion that after 10,000 h of exposure to temperature cycles between -10°C and +30°C, there was a small change in the GFRP-to-concrete interface performance, whereas the effects on the bonded interface for the specimens subjected to temperature cycles between +7.5°C and +47.5°C were far more most severe. © 2019 American Society of Civil Engineers.

It is supposed that the adhesively bonded structures would perform well during their lifetime, but the action of high temperatures may affect the initial integrity of the joints, as recognized by some researchers. Still, there are few studies proposing a model to locally predict the interfacial bond behaviour of Carbon Fibre Reinforced Polymers (CFRP) bonded to a steel substrate when subjected to temperature changes. The influence of temperature on CFRP-to-steel bonded joints is, therefore, not very well understood yet and more studies are needed to better understand how these joints behave under such circumstances. The present work aims to contribute to the mitigation of the existing lack of knowledge on the performance of CFRP-to-steel bonded joints under high temperatures. Therefore, an experimental program was considered and specimens were tested at different temperatures: 20 °C, 35 °C, 50 °C, 65 °C, 80 °C, and 95 °C. To help the interpretation of the results, an analytical model is proposed to predict the load capacity of the CFRP-to-steel joints. The local bond-slip behaviour of the tested specimens is also analyzed and, based on a literature review, a temperature-dependent bond-slip model with a bi-linear shape is proposed and implemented into a commercial software based on the Finite Element Method (FEM). © 2019 Elsevier Ltd

ZnSnO3 semiconductor nanostructures have several applications as photocatalysis, gas sensors, and energy harvesting. However, due to its multicomponent nature, the synthesis is far more complex than its binary counter parts. The complexity increases even more when aiming for low-cost and low-temperature processes as in hydrothermal methods. Knowing in detail the influence of all the parameters involved in these processes is imperative, in order to properly control the synthesis to achieve the desired final product. Thus, this paper presents a study of the influence of the physical parameters involved in the hydrothermal synthesis of ZnSnO3 nanowires, namely volume, reaction time, and process temperature. Based on this study a growth mechanism for the complex Zn:Sn:O system is proposed. Two zinc precursors, zinc chloride and zinc acetate, were studied, showing that although the growth mechanism is inherent to the material itself, the chemical reactions for different conditions need to be considered.

Physics Letters B, 795 (2019) 682–688. 10.1016/j.physletb.2019.06.069

Phys. Rev. A 97, 032517 (2018). doi:10.1103/PhysRevA.97.032517

The durability performance of stainless steel makes it an interesting alternative for the structural strengthening of reinforced concrete. Like external steel plates or fibre reinforced polymers, stainless steel can be applied using externally bonded reinforcement (EBR) or the near surface mounted (NSM) bonding techniques. In the present work, a set of single-lap shear tests were carried out using the EBR and NSM bonding techniques. The evaluation of the performance of the bonding interfaces was done with the help of the digital image correlation (DIC) technique. The tests showed that the measurements gathered with DIC should be used with caution, since there is noise in the distribution of the slips and only the slips greater than one-tenth of a millimetre were fairly well predicted. For this reason, the slips had to be smoothed out to make it easier to determine the strains in the stainless steel and the bond stress transfer between materials, which helps to determine the bond–slip relationship of the interface. Moreover, the DIC technique allowed to identify all the states developed within the interface through the load–slip responses which were also closely predicted with other monitoring devices. Considering the NSM and the EBR samples with the same bonded lengths, it can be stated that the NSM system has the best performance due to their higher strength, being observed the rupture of the stainless steel in the samples with bond lengths of 200 and 300 mm. Associated with this higher strength, the NSM specimens had an effective bond length of 168 mm which is 71.5% of that obtained for the EBR specimens (235 mm). A trapezoidal and a power functions are the proposed shapes to describe the interfacial bond–slip relationships of the NSM and EBR systems, respectively, where the maximum bond stress in the former system is 1.8 times the maximum bond stress of the latter one.

Main conclusion: The phenylpropanoid pathway impacts the cork quality development. In cork of bad quality, the flavonoid route is favored, whereas in good quality, cork lignin and suberin production prevails. Cork oaks develop a thick cork tissue as a protective shield that results of the continuous activity of a secondary meristem, the cork cambium, or phellogen. Most studies applied to developmental processes do not consider the cell types from which the samples were extracted. Here, laser microdissection (LM) coupled with transcript profiling using RNA sequencing (454 pyrosequencing) was applied to phellogen cells of trees producing low- and good quality cork. Functional annotation and functional enrichment analyses showed that stress-related genes are enriched in samples extracted from trees producing good quality cork (GQC). This process is under tight transcriptional (transcription factors, kinases) regulation and also hormonal control involving ABA, ethylene, and auxins. The phellogen cells collected from trees producing bad quality cork (BQC) show a consistent up-regulation of genes belonging to the flavonoid pathway as a response to stress. They also display a different modulation of cell wall genes resulting into a thinner cork layer, i.e., less meristematic activity. Based on the analysis of the phenylpropanoid pathway regulating genes, in GQC, the synthesis of lignin and suberin is promoted, whereas in BQC, the same pathway favors the biosynthesis of free phenolic compounds. This study provided new insights of how cell-specific gene expression can determine tissue and organ morphology and physiology and identified robust candidate genes that can be used in breeding programs aiming at improving cork quality.

The high global burden of over one million annual lethal fungal infections reflects a lack of protective vaccines, late diagnosis and inadequate chemotherapy. Here, we have generated a unique set of fully human anti-Candida monoclonal antibodies (mAbs) with diagnostic and therapeutic potential by expressing recombinant antibodies from genes cloned from the B cells of patients suffering from candidiasis. Single class switched memory B cells isolated from donors serum-positive for anti-Candida IgG were differentiated in vitro and screened against recombinant Candida albicans Hyr1 cell wall protein and whole fungal cell wall preparations. Antibody genes from Candida-reactive B cell cultures were cloned and expressed in Expi293F human embryonic kidney cells to generate a panel of human recombinant anti-Candida mAbs that demonstrate morphology-specific, high avidity binding to the cell wall. The species-specific and pan-Candida mAbs generated through this technology display favourable properties for diagnostics, strong opsono-phagocytic activity of macrophages in vitro, and protection in a murine model of disseminated candidiasis.

Semiconductor nanowires are mostly processed by complex, expensive and high temperature methods. In this work, with the intent of developing zinc tin oxide nanowires (ZTO NWs) by low-cost and low-complexity processes, we show a detailed study on the influence of chemical parameters in the hydrothermal synthesis of ZTO nanostructures at temperatures of only 200 °C. Two different zinc precursors, the ratio between zinc and tin precursors, the concentration of the surfactant agent and of the mineralizer were studied. The type and the crystallinity of the nanostructures was found to be highly dependent on the used precursors and on the concentration of each reagent. Conditions for obtaining different ZTO nanostructures were achieved, namely Zn2SnO4 nanoparticles and ZnSnO3 nanowires with length ≈ 600 nm, with the latter being reported for the first time ever by hydrothermal methods without the use of seed layers. Optical and electrical properties were analyzed, being obtained band gaps of 3.60 and 3.46 eV, fo...