In comparison with the well-described ionic eutectic mixtures, hydrophobic eutectic solvents (HESs) composed of two non-ionic compounds represent a relatively new class of eutectics. In this work, a ...number of non-ionic HESs liquid at room temperature were identified from a large initial screening of potential mixtures. Three new HESs based on thymol + TOPO (trioctylphosphine oxide), TOPO + capric acid and hydrocinnamic acid + capric acid were investigated as extracting media for the recovery and separation of platinum group and transition metals in HCl media. Full phase diagrams and physical properties including viscosities, densities, chemical stability and the influence of water were characterised, with these HESs presenting low viscosities and high hydrophobicity suitable for application as solvents for liquid-liquid extraction. By simple variation of the eutectic component the selectivity of the system for a given metal could be tuned, with the TOPO-based system displaying good to excellent selectivity towards Pt
4+
, Pd
2+
and Fe
3+
under a range of conditions. The extraction mechanism was found to vary due to a complex interplay between the HES composition, acid concentration and the predominant metal complex present. The observed extraction behaviour in HESs composed of two metal complexing ligands such as TOPO + capric acid, in which each respective component is responsible for metal extraction under given conditions, opens the possibility to design hydrophobic eutectic mixtures presenting synergistic effects. Finally, the HES phase following palladium extraction was used as the template for the formation of palladium nanoparticles. The results presented highlight the great potential of HESs as environmentally benign and tuneable media for the solvent extraction of metal ions.
The potential of HESs as environmentally benign and tunable media for the solvent extraction of metal ions is presented.
One of the main goals in flux-cored arc welding processes is the optimization of bead geometry, in which multiple geometric characteristics of the welding bead are important; therefore, ...multiobjective optimization programming is often applied. However, several optimization problems that use stochastic programming do not consider the impact of the correlation between the output variables on their probabilistic constraints. In this context, this paper aims to present a multiobjective optimization method based on multivariate stochastic programming. To demonstrate the applicability of the proposal, we conducted a design of experiments to optimize a flux-cored arc welding process for stainless-steel claddings. The weighting-sums method was applied to formulate the multiobjective optimization problem. It was possible to formulate a multivariate probability distribution for the penetration and dilution. In addition, a 95% probability to meet the predefined specification limits of the geometric characteristics was achieved.
In this paper, we present data from measurements made in the textured fibers bobbins in two different conditions, presenting critical quality characteristics such as diameter, mass and density. In ...order to obtain a significant amount of information, in each of the two conditions, 270 measurements were obtained for each of the quality characteristics. Three different equipments (Automatic Package Analyzer - APA) were used in ten different parts, replicated three times for each of them. Considering the two measurement data collection, an amount of 540 bobbins measurements were obtained. Almeida et al., (2019) applied these measurement data in his study. Taking into account the multicorrelated nature of the information, we also have the representation of the principal components' scores for these measurements, besides the eigenvalues and eigenvectors of the data.
Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people ...worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼ 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a hyperinflammatory state and lymphocytopenia, a hallmark that appears as both signature and ...prognosis of disease severity outcome. Although cytokine storm and a sustained inflammatory state are commonly associated with immune cell depletion, it is still unclear whether direct SARS-CoV-2 infection of immune cells could also play a role in this scenario by harboring viral replication. We found that monocytes, as well as both B and T lymphocytes, were susceptible to SARS-CoV-2 infection in vitro, accumulating double-stranded RNA consistent with viral RNA replication and ultimately leading to expressive T cell apoptosis. In addition, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from coronavirus disease 2019 (COVID-19) patients. The rates of SARS-CoV-2-infected monocytes in peripheral blood mononuclear cells from COVID-19 patients increased over time from symptom onset, with SARS-CoV-2-positive monocytes, B cells, and CD4+ T lymphocytes also detected in postmortem lung tissue. These results indicated that SARS-CoV-2 infection of blood-circulating leukocytes in COVID-19 patients might have important implications for disease pathogenesis and progression, immune dysfunction, and virus spread within the host.
Ethanol extracts of powdered genipap (Genipa americana L.), umbu (Spondia tuberosa A.) and siriguela (Spondia purpurea L.) prepared from separate pulp, seeds and peel were investigated for their (i) ...antioxidant capacity, which was evaluated by various known methods; (ii) acetylcholinesterase (AChE) inhibitory activity; and (iii) cytotoxic effect on corneal epithelial cells of sheep. The highest values of total phenolic content were obtained with peel and seed extracts. Siriguela and umbu (seeds and peel) extracts displayed the highest antioxidant activities. Lipid peroxidation assays using mimetic biomembranes and mouse liver homogenates indicated that genipap pulp is a promising antioxidant. The investigation of phenols and organic acid contents revealed the presence of quercetin, citric and quinic acids, chlorogenic acid derivatives, among others, in several extracts, with the highest amount found in siriguela seeds. Genipap pulp and siriguela seed ethanol extracts presented an AChE inhibition zone similar to that of the positive control, carbachol. AChE inhibition assay with chlorogenic acid, one of the main constituents of siriguela seeds, revealed that this acid showed activity similar to that of the control physostigmine. These data suggest that these extracts are potentially important antioxidant supplements for the everyday human diet, pharmaceutical and cosmetic industries.
•Pulsed light reduced acerola climacteric respiration and delayed ethylene peak.•Pulsed light-treated acerola was firmer and lost less weight.•Pulsed light enhanced polyamines by stimulating ...synthesis and inhibiting degradation.•Pulsed light increased vitamin C by reducing degradation and improving recycling.
This study investigated how pulsed light (PL) postharvest treatment influences acerola ripening physiology and quality, thus physiologically mature acerola ‘Okinawa’ were treated with PL (0.6 J.cm−2) and stored for 16 days at 10 °C. Compared to untreated, PL-treated acerola showed a 5% reduction in climacteric respiration with 78.65 mol CO2 kg−1 h−1 and a one-day delay in ethylene peak of 2.65 µL C2H4 kg−1 h−1. PL-treated acerola also showed 13% lower weight loss and was 12% firmer probably due to the enhanced antioxidant enzymes that reduced hydrogen peroxide content with lower membrane lipid peroxidation, in addition to inhibition of cell wall hydrolysis. The higher polyamine levels induced by PL may be explained by the greater synthesis, inhibition of degradation, and enhancement of back-conversion reactions. PL treatment would have increased the total vitamin C by 33% as a result of lower degradation and more efficient recycling reactions, while polyphenols would have increased 10% by reducing oxidation and enhancing synthesis. Although the storage period exerted the main influence on ‘Okinawa’ acerola, results indicate that PL delayed ripening and promoted quality as an elicitor of antioxidant metabolism thus representing a hormetic phenomenon.
Proposed mode of action of pulsed light (0.6 J.cm−2) on the physiology of ‘Okinawa’ acerola. Display omitted
Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes ...conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come.
Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using ...LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
Editor’s summary
Indigenous societies have lived in the Amazon for at least 12,000 years. Finding evidence of these societies, however, has been greatly hampered by the density of the forest in Amazonia. Peripato
et al
. used LIDAR (light detection and ranging) surveys to identify more than 20 previously unidentified developments and then modeled the occurrence of others across the Amazon. The authors predict that between 10,000 and 24,000 ancient earthworks are waiting to be discovered. Sampling of some of the LIDAR transects revealed a consistent set of domesticated tree species associated with the developments, suggesting active forestry practices among these societies. —Sacha Vignieri
Amazon-wide LIDAR surveys and predictive models suggest thousands of undocumented archaeological sites across the basin.
One of the least understood aspects in atmospheric chemistry is how urban emissions influence the formation of natural organic aerosols, which affect Earth's energy budget. The Amazon rainforest, ...during its wet season, is one of the few remaining places on Earth where atmospheric chemistry transitions between preindustrial and urban-influenced conditions. Here, we integrate insights from several laboratory measurements and simulate the formation of secondary organic aerosols (SOA) in the Amazon using a high-resolution chemical transport model. Simulations show that emissions of nitrogen-oxides from Manaus, a city of ~2 million people, greatly enhance production of biogenic SOA by 60-200% on average with peak enhancements of 400%, through the increased oxidation of gas-phase organic carbon emitted by the forests. Simulated enhancements agree with aircraft measurements, and are much larger than those reported over other locations. The implication is that increasing anthropogenic emissions in the future might substantially enhance biogenic SOA in pristine locations like the Amazon.
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