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To date, the four-gluon vertex is the least explored component of the QCD Lagrangian, mainly due to the vast proliferation of Lorentz and color structures required for its description. In this work we present a nonperturbative study of this vertex, based on the one-loop dressed Schwinger–Dyson equation obtained from the 4PI effective action. A vast simplification is brought about by resorting to “collinear” kinematics, where all momenta are parallel to each other, and by appealing to the charge conjugation symmetry in order to eliminate certain color structures. Out of the fifteen form factors that comprise the transversely-projected version of this vertex, two are singled out and studied in detail; the one associated with the classical tensorial structure is moderately suppressed in the infrared regime, while the other diverges logarithmically at the origin. Quite interestingly, both form factors display the property known as “planar degeneracy” at a rather high level of accuracy. With these results we construct an effective charge that quantifies the strength of the four-gluon interaction, and compare it with other vertex-derived charges from the gauge sector of QCD. [ABSTRACT FROM AUTHOR]

The pseudo-ilmenite structure ABO3 have been increasingly highlighted in the optoelectronic area. Nanoparticles of undoped lithium niobates (LiNbO3) and codoped with rare earths (LiNbO3: Dy3+/Tb3+) were synthesized by the solid-state reaction method and calcined in a controlled way. The properties and structural changes of niobates were evaluated from data obtained in XRD and Rietveld refinement. The SEM-FEG micrographs showed different morphologies obtained (cubes, plates, tetrahedrons and polyhedra) according to the variation of the doping and co-doping process. Optical properties were measured and studied based on the results obtained from the UV-Vis spectrophotometer and photoluminescence assays. The photoluminescence presented by LiNbO3 was associated with the existence of superficial defects in the particles, i.e., centers of recombination of photogenerated charges favorable to the property. The effect of concentration of dopants was investigated in properties photoluminescence. Photometric measurements (CRI, purity, CCT, LER) were analyzed and a modulation of the emitted color as a function of the concentration of the dopants. According to the obtained results, LiNbO3: Dy3+/Tb3+ presents itself as a material with great potential in optical device applications. [ABSTRACT FROM AUTHOR]

Selecting orbits for a satellite to observe the Earth is a very important task in aerospace engineering. There are several constraints to be followed, like regions of the Earth to be observed, interval between observations, the necessity or not of having sunlight to make the observations, etc. In this study, we search for orbits that can be used to collect data from platforms located around the Earth and send them to particular ground stations. Since we are considering that these missions will be performed in the extra life of old satellites, it is necessary to add the constraint of having sunlight during the communications, because the old batteries will no longer be able to keep charge. So, we need to find the best orbits for a mission of this type, such that we can consider this possibility as one more parameter to design the orbits of satellites to be launched, and/or to choose the most adequate satellites that are already in space to accomplish this task. To carry out this study, we considered different latitudes for the platforms and ground stations. The satellites are assumed to be in Low Earth Orbit (LEO) with different inclinations. [ABSTRACT FROM AUTHOR]

We report the synthesis of nanostructured Co 3 O 4 using the hydrothermal method, without the need for any additives, such as surfactants or reducing agents. The hydrothermal synthesis was conducted at a temperature of 180 ∘ C over a 5-h period. The obtained results confirmed the presence of both β -Co(OH) 2 and Co 3 O 4 phases in the as-synthesized material, referred to here as the precursor. Upon thermal analysis, it was observed that β -Co(OH) 2 underwent complete decomposition into Co 3 O 4 at temperatures above 300 ∘ C. After subjecting the precursor to a heat treatment at 500 ∘ C for 3 h, we successfully obtained pure-phase Co 3 O 4 exhibiting a cubic spinel-like structure. The optical behavior of Co 3 O 4 was characterized by the presence of electronic transitions, specifically O 2 - → Co 3 + and O 2 - → Co 2 + , which occurred at wavelengths of 388 and 689 nm, respectively. Additionally, the results suggest that manipulating the synthesis duration and the concentration of Co 2 + in the chemical solution can lead to the formation of various Co 3 O 4 morphologies, including nanospheres, microspheres, or a mixture of nanoparticles with both spherical and octahedral shapes. All Co 3 O 4 samples were effectively employed as catalysts for the hydrogen evolution reaction in an alkaline environment. These catalysts demonstrated remarkable stability, sustaining continuous gas evolution for over 5 h at a current density of - 10 mA · cm - 2 , indicating their promising potential for large-scale H 2 generation. Notably, the samples featuring octahedral-shaped nanoparticles exhibited superior electrocatalytic activity for H 2 production, attributable to the exposure of (111) crystallographic planes on their surfaces. These samples initiated gas evolution at a low potential of 84 mV and reached the desired current density of - 10 mA · cm - 2 at 320 mV. Finally, the mechanism for H 2 formation followed the Volmer–Heyrovsky reaction pathway. [ABSTRACT FROM AUTHOR]

The implementation of the Schwinger mechanism endows gluons with a nonperturbative mass through the formation of special massless poles in the fundamental QCD vertices; due to their longitudinal character, these poles do not cause divergences in on-shell amplitudes, but induce detectable effects in the Green’s functions of the theory. Particularly important in this theoretical setup is the three-gluon vertex, whose pole content extends beyond the minimal structure required for the generation of a gluon mass. In the present work we analyze these additional pole patterns by means of two distinct, but ultimately equivalent, methods: the Slavnov–Taylor identity satisfied by the three-gluon vertex, and the nonlinear Schwinger–Dyson equation that governs the dynamical evolution of this vertex. Our analysis reveals that the Slavnov–Taylor identity imposes strict model-independent constraints on the associated residues, preventing them from vanishing. Approximate versions of these constraints are subsequently recovered from the Schwinger–Dyson equation, once the elements responsible for the activation of the Schwinger mechanism have been duly incorporated. The excellent coincidence between the two approaches exposes a profound connection between symmetry and dynamics, and serves as a nontrivial self-consistency test of this particular mass generating scenario. [ABSTRACT FROM AUTHOR]

In theory, the application of fertilizers is a relationship between the requirement of the crop and the content already present in the soil. However, in acidic soils, it is estimated that only 10–15% of the total phosphorus (P) applied is available to plants, requiring higher doses. As the importance of P in plants is notorious and unquestionable, being involved in the regulation of photosynthesis and plant development, there are several alternatives to increase its application efficiency. However, there is a lack of research that seeks to understand how different genotypes of the same species respond to different availability of P. The aim of this study was to evaluate the development of maize varieties under different conditions of P availability, thus bringing a new perspective for future studies that seek to increase the availability of P to plants. A randomized block experiment was carried out in a factorial scheme with five maize hybrids and five P availability, with four replications. The plants were evaluated for gas exchange, chlorophyll a fluorescence, chloroplast pigment content, shoot length and biomass accumulation. In low availability, there is a negative feedback control of photoassimilates export, which results in reduced photosynthesis, growth and biomass accumulation. This reduction in growth may also be associated with the hormonal control of plants. Despite the well-established relationship between photosynthesis and biomass accumulation, it is not always possible to establish a parallel between the two processes, depending on the genetic composition. [ABSTRACT FROM AUTHOR]

We obtain new exact solutions for the gravitational field equations in the context of f(R, T) gravity, thereby obtaining different classes of black holes surrounded by fluids, taking into account some specific values of the parameter of the equations of state, w. In order to obtain these solutions in the context of f(R, T) gravity, we consider viable particular choices of the f(R, T). Considering an anisotropic energy-momentum tensor, we write the field equations with the required symmetries for this type of solution. Then, we analyze the conditions of energy in a general way and also for particular values of the parameter w of the equation of state. In addition, thermodynamic quantities, such as Hawking temperature and mass associated to the horizons of solutions, are taken into account in our analysis. [ABSTRACT FROM AUTHOR]

We present a detailed exploration of certain outstanding features of the transversely-projected three-gluon vertex, using the corresponding Schwinger–Dyson equation in conjunction with key results obtained from quenched lattice simulations. The main goal of this study is the scrutiny of the approximate property denominated "planar degeneracy", unveiled when the Bose symmetry of the vertex is properly exploited. The planar degeneracy leads to a particularly simple parametrization of the vertex, reducing its kinematic dependence to essentially a single variable. Our analysis, carried out in the absence of dynamical quarks, reveals that the planar degeneracy is particularly accurate for the description of the form factor associated with the classical tensor, for a wide array of arbitrary kinematic configurations. Instead, the remaining three form factors display considerable violations of this property. In addition, and in close connection with the previous point, we demonstrate the numerical dominance of the classical form factor over all others, except in the vicinity of the soft-gluon kinematics. The final upshot of these considerations is the emergence of a very compact description for the three-gluon vertex in general kinematics, which may simplify significantly nonperturbative applications involving this vertex. [ABSTRACT FROM AUTHOR]

The circumcentered-reflection method (CRM) has been applied for solving convex feasibility problems. CRM iterates by computing a circumcenter upon a composition of reflections with respect to convex sets. Since reflections are based on exact projections, their computation might be costly. In this regard, we introduce the circumcentered approximate-reflection method (CARM), whose reflections rely on outer-approximate projections. The appeal of CARM is that, in rather general situations, the approximate projections we employ are available under low computational cost. We derive convergence of CARM and linear convergence under an error bound condition. We also present successful theoretical and numerical comparisons of CARM to the original CRM, to the classical method of alternating projections (MAP), and to a correspondent outer-approximate version of MAP, referred to as MAAP. Along with our results and numerical experiments, we present a couple of illustrative examples. [ABSTRACT FROM AUTHOR]

Conventional pesticides are biosynthetic chemicals that are effectively used for the control of weeds, diseases, and pests worldwide. Among them, glyphosate, one of the most commonly used broad-spectrum herbicides, might cause a series of environmental problems and pose a toxicological risk to aquatic organisms; even though many developed countries currently prohibit its use, it is still commercialized and used in some countries. Alternatively, melamine resins have been used as adsorbents for many substances due to their chemical and physical properties. Hence, this study focuses on determining the capacity of melamine resin derivatives to serve as adsorbents of glyphosate. Melamine resin was synthesized using a condensation reaction between melamine and glyoxal. The reaction product was fully characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, thermogravimetry analysis and molecular dynamics simulations. The ability to remove glyphosate from water was tested, and the adsorption efficiency was evaluated. Furthermore, the kinetics and equilibrium of the adsorption process on the resin were studied with Langmuir isotherms. The maximum adsorption of glyphosate by the synthesized resin was 62.1 mg g−1, which is comparable to that by activated carbon. [ABSTRACT FROM AUTHOR]

Both forest stratification and habitat characteristics interact dynamically, affecting arthropod distribution in tropical forests. Ants are highly diverse and abundant organisms that occupy several microhabitats in tropical forests. Here, we evaluated how habitat structure (vertical forest stratification, tree and shrub height, tree and shrub density, canopy cover, density of terrestrial Bromeliads) affects ant assemblages in forest patches of the Brazilian Pantanal, one of the largest flooded areas in the world. We captured 57 ant species on the ground and 30 in the canopy of ten forest patches using 160 pitfall traps baited with tuna for each vertical stratum, 320 in total. We found that the ant species composition was different between vertical strata and the ground assemblage was more homogenous than the canopy assemblage. Only forest vertical stratification and tree density were determinants in shaping ant species composition among all habitat structure characteristics based on an RDA analysis. Also, the sympatric congeneric species, belonging to Pseudomyrmex, Camponotus, and Crematogaster, use the vertical strata differently from each other, being species-related. We found higher homogeneity in ant assemblages inhabiting the ground stratum, which can be related to the higher dispersal ability of ground-dwelling than arboreal-dwelling across forest patches. Also, tree density raises as an essential factor shaping ant species composition, probably related to increased resource availability and habitat heterogeneity on forest patches provided by trees. Our findings revealed that trees are critical elements structuring ant communities in forest islands surrounded by a matrix of fields subject to flooding. In this sense, the maintenance of trees supports a comprehensive ant community in forest patches. [ABSTRACT FROM AUTHOR]

In this paper, we present necessary and sufficient optimality conditions for multiobjective problems with equality and inequality constraints defined in Banach spaces. We focus on the nonregular case when the linear independence qualification or Mangasarian-Fromovitz constraint qualification are not satisfied at the solution of the multiobjective problem. For this case, we present new generalized p-order necessary optimality conditions of Karush–Kuhn–Tucker type. The conditions subsume the classical conditions and give new and nontrivial conditions for the nonregular case. Our results were obtained from the theory of p-regularity, introduced by Brezhneva and Tret’yakov (SIAM J Control Optim 42:729-745, 2003). Some examples are presented to illustrate the results. [ABSTRACT FROM AUTHOR]

In the present work, a series of supports with varying compositions (ranging from pure CeO2 to pure PrO2-y) was designed to investigate their ability to release oxygen (with the concomitant formation of oxygen vacancies) under diverse reducing atmospheres: hydrogen (H2), helium (He), and in the presence of a carbonaceous substance that mimics eventual carbon deposits formed under practical reaction conditions (DRM). Oxygen vacancies were generated effectively in all three atmospheres (following the order He < H2 < carbon material). With regard to the influence of the composition, the capability to generate oxygen vacancies clearly increased with the Pr content, for whatever the conditions tested. Notably, the non-stoichiometry obtained with the support of pure praseodymia in both inert and reducing atmospheres is very remarkable, as it approaches the maximum non-stoichiometry value of the well-established theoretical Bevan cluster. This leads to consider this formulation as a very promising support for applications in catalysis and other fields where oxygen vacancies play a crucial role. Dry Reforming of Methane requires catalytic supports that possess highly mobile oxygen, enabling it to actively participate in the reactions step involved or potentially gasify undesirable carbon deposits generated during parallel reactions. Consequently, designing and elucidating the behavior of ceria-praseodymium-based supports with high reducibility and generation of oxygen vacancies (oxygen storage and release capacity) holds particular relevance in this context. Actually, the very preliminary results comparing two counterpart formulations (5%Ni/PrO2-y versus 5%Ni/Al2O3) already confirm the suitability of the choice of pure praseodymia in terms of activity, stability and very high selectivity towards H2 and CO, reaching a very close value to the ideal H2/CO ratio of 1. [ABSTRACT FROM AUTHOR]

Stall flutter is turning into a more likely condition to be encountered as the demand for increasingly more flexible wings grows for HALE-like aircraft. Due to the various nonlinearities involved that can lead to complex motion, the characterization of the dynamical behavior in the post-flutter condition becomes important. The dynamics of a pitch–plunge idealized HALE typical section with aerodynamic, structural and kinematic nonlinearities in the stall flutter regime was investigated using an aeroelastic state-space formulation which includes a modified Beddoes-Leishman dynamic stall model. The results reveal that period-doubling was possible without stall, but chaos arose at discontinuity-induced bifurcations due to dynamic stall. A parametric study has been conducted to assess the influence of key parameters in the development of bifurcations and chaos. [ABSTRACT FROM AUTHOR]

We present a new algorithm for large-scale unconstrained minimization that, at each iteration, minimizes, approximately, a quadratic model of the objective function plus a regularization term, not necessarily based on a norm. We prove convergence assuming only gradient continuity and complexity results assuming Lipschitz conditions. For solving the subproblems in the case of regularizations based on the 3-norm, we introduce a new method that quickly obtains the approximate solutions required by the theory. We present numerical experiments. [ABSTRACT FROM AUTHOR]

Nanoparticles of cobalt, nickel, and zinc spinel ferrites were successfully synthesized by a low-cost method named as proteic sol-gel method, and a comparative study was performed. Commercial metal nitrates and gelatin from bovine skin were used as precursors. Thermogravimetric analysis and differential scanning calorimetry were performed to investigate the thermal behavior of the precursor powders as well as to select the appropriate calcination temperature for oxide formation. Structural, morphological, optical, and magnetic properties were studied by X-ray diffraction, Mössbauer spectroscopy, transmission electron microscopy, vibrating sample magnetometry, Raman spectroscopy, and UV/VIS diffuse reflectance spectroscopy. Spherical nanoparticles with a single cubic spinel structure were obtained. The results indicate that the average particle sizes are less than 10 nm. CoFe 2 O 4 and NiFe 2 O 4 exhibited ferrimagnetic and superparamagnetic behavior simultaneously, whereas ZnFe 2 O 4 was found to be paramagnetic. The optical band gaps obtained were 1.40, 1.75, and 2.12 eV for CoFe 2 O 4 , NiFe 2 O 4 , and ZnFe 2 O 4 samples, respectively. [ABSTRACT FROM AUTHOR]

The interest in bioactive compounds from microalgae is increasing since they have medicinal and nutritional areas. The present work aims to evaluate the potential pharmaceutical interest of extracts from three eustigmatophyte strains from the Coimbra Collection of Algae (ACOI): Chlorobotrys gloeothece, Chlorobotrys regularis and Characiopsis aquilonaris. Antioxidant and antiproliferative activities were determined as well as chlorophyll a, carotenoid and phenolic total contents. In addition, major pigments and sterols were identified and quantified. The three strains were grown until the stationary phase and then the biomass was extracted. Antioxidant activity was measured by TEAC, DPPH and FRAP assays and antiproliferative effect was assessed by the MTT method on MCF-7, PC-3 and NHDF cells. The pigment and phenolic total contents were determined by spectrophotometry. Of these strains, C. aquilonaris showed the highest antioxidant activity measured by TEAC and FRAP assays (23.98 ± 0.01 μmol TE eq g−1 DW and 42.57 ± 0.04 μmol TE eq g−1 DW, respectively), a selective effect in reduting MCF-7 cells proliferation and a larger amount of chlorophyll a, carotenoids and phenolic content (18.40 ± 0.00 μg chlorophyll a mg−1 DW, 2.27 ± 0.00 mg carotenoids g−1 DW and 6.23 ± 0.01 mg GAE g−1 DW, respectively). A positive correlation between chlorophyll a and TEAC assay was observed, as well as between carotenoids and TEAC and FRAP assays, suggesting these compounds as important contributors to significant antioxidant activity. Violaxanthin, cholesterol and stigmasterol were present in larger amount in C. aquilonaris while C. regularis showed a higher amount of β-carotene. These results suggest that these three ACOI eustigmatophytes are promising for applications in the improvement of human health, particularly in cancer prevention and treatment. [ABSTRACT FROM AUTHOR]

This study aimed to address the Ophiothela species distribution worldwide, report invasive populations, and investigate their association with benthic organisms through an extensive review of the scientific literature. All six Ophiothela species occur between latitudes 33º S and 38º N and, together, are dispersed across 75% of the marine realms. Spread throughout more than 6700 km of the Western Atlantic Ocean coastline, O. mirabilis is the only species recorded as invasive. Higher plasticity in substrate use was detected in invaded areas than in native ones, which indicates that substrate availability does not limit the invasive potential of O. mirabilis. The colonization affinity of Ophiothela species is high for Cnidaria species, irrespective of population origin. High densities (e.g., up to 2.8 brittle stars cm−2 per gorgonian surface) and opportunistic habitat colonization pattern found for O. mirabilis invasive populations suggest fast dispersion rates along the Atlantic coast. Therefore, the expansion of this species to nearby systems is likely, and the potential to damage native host species is high. [ABSTRACT FROM AUTHOR]

The economic recession that recently affected most European countries has led to a worsening of the mental health situation in the general population and an associated rise in outpatient psychiatric care. The aim of this study was to analyse the socio-demographic, clinical and assistential features of the demand for specialist mental health attention. A descriptive and analytical study was conducted in the period 2011–2015 (N = 1252). The principal relations among variables were analysed by an χ2 test, followed by a Z test with Bonferroni's correction. For a global perspective a Multiple Correspondence Analysis was performed. 2 The most frequent disorders were adjustment, anxiety and mood disorders, and in addition there were a large number of patients without diagnosis. The percentage of unemployed or inactive patients was high, as it was for those with a low academic level. The younger patients were more prone to have adjustment disorders, especially among the unemployed ones, while anxiety disorders were more frequent in the patients with jobs. A close association seems to exist between unemployment, low academic level and mental health problems. The high demand for mental health attention reveals a clear need to optimize the utilization of specialized care in mental health. [ABSTRACT FROM AUTHOR]

Background: The use of layer jamming materials has promising applications in soft robotics and vibration control, where there is a need to have materials that can change their properties in situ. However, there is limited research on analytically modeling the plastic deformation response of layer jamming materials attributed to the level of cohesion between layers that controls the shear resistance to achieve variable mechanical properties in shear and bending deformation modes. Objective: In this paper, we present and validate a model for engineering layer jamming materials with programmable elastic-plastic properties. Methods: The model is validated using Digital Image Correlation (DIC) displacement measurements to track layer decohesion for the following test scenarios: (i) variable vacuum pressure, (ii) variable layered material, and (iii) variable transverse symmetry. To illustrate the utility of the model, we conducted a sensitivity study on a multi-material layer jamming specimen to identify the critical regions of a beam where greater interfacial adhesion can enhance the resistance of the beam to plastic deformation. Results: The layer decohesion measurements are consistent with existing knowledge that for laminated materials, layer decohesion will initiate towards the free edge. However, it contradicts a previous assertion that in layer jamming materials, decohesion would initiate at the fixed end. Conclusions: With this model, we have a better understanding of how to design layer jamming materials to improve the performance of structures through variable compliance, load bearing capacity, and energy absorption. [ABSTRACT FROM AUTHOR]

A priority of the industrial applications of microalgae is the reduction of production costs while maximizing algae biomass productivity. The purpose of this study was to carry out a comprehensive evaluation of the effects of pH control on the production of Nannochloropsis gaditana in tubular photobioreactors under external conditions while considering the environmental, biological, and operational parameters of the process. Experiments were carried out in 3.0 m3 tubular photobioreactors under outdoor conditions. The pH values evaluated were 6.0, 7.0, 8.0, 9.0, and 10.0, which were controlled by injecting pure CO2 on-demand. The results have shown that the ideal pH for microalgal growth was 8.0, with higher values of biomass productivity (Pb) (0.16 g L−1 d−1), and CO2 use efficiency ( E CO 2 ) (74.6% w w−1); R CO 2 /biomass value obtained at this pH (2.42 g CO 2 gbiomass−1) was close to the theoretical value, indicating an adequate CO2 supply. At this pH, the system was more stable and required a lower number of CO2 injections than the other treatments. At pH 6.0, there was a decrease in the Pb and E CO 2 ; cultures at pH 10.0 exhibited a lower Pb and photosynthetic efficiency as well. These results imply that controlling the pH at an optimum value allows higher CO2 conversions in biomass to be achieved and contributes to the reduction in costs of the microalgae production process. [ABSTRACT FROM AUTHOR]

In the present work a method was proposed for the direct determination of Ca, Fe, K, and Mg and qualitative analysis of anthropized and cabruca soil samples from different depths (0–20 and 20–40 cm) by laser-induced breakdown spectroscopy (LIBS). The LIBS instrumental parameters were evaluated using a central composite design with a central point. The variables evaluated were as follows: delay time in five levels (0.5, 0.7, 1.2, 1.7, and 1.9 μs) and fluence at five levels (1448, 1811, 2659, 3514, and 3820 J·cm–2). The best results obtained were with a delay time of 1.2 μs and fluence of 2659 J × cm–2. The proposed calibration model for Ca, Fe, K, and Mg obtained using LIBS data presented a good correlation with the reference values obtained by inductively coupled plasma atomic emission spectrometry (ICP OES). In addition, multivariate data analysis from LIBS spectra in the region of 186–1042 nm was performed using principal component analysis (PCA). From the LIBS spectra it was possible to discriminate the different analyzed samples, showing that the combination of LIBS with PCA is an excellent option for the discrimination of soils. [ABSTRACT FROM AUTHOR]

Tendon and ligament shows extremely limited endogenous regenerative capacity. Current treatments are based on the replacement and or augmentation of the injured tissue but the repaired tissue rarely achieve functionality equal to that of the preinjured tissue. To address this challenge, tissue engineering has emerged as a promising strategy. This study develops a regenerative and resorbable hybrid construct for tendon and ligament engineering. The construct is made up by a hollow poly-lactic acid braid with embedded microspheres carrying cells and an anti-adherent coating, with all the parts being made of biodegradable materials. This assembly intends to regenerate the tissue starting from the interior of the construct towards outside while it degrades. Fibroblasts cultured on poly lactic acid and hyaluronic acid microspheres for 6 h were injected into the hollow braid and the construct was cultured for 14 days. The cells thus transported into the lumen of the construct were able to migrate and adhere to the braid fibers naturally, leading to a homogeneous proliferation inside the braid. Moreover, no cells were found on the outer surface of the coating. Altogether, this study demonstrated that PLA/HA hybrid construct could be a promising material for tendon and ligament repair. [ABSTRACT FROM AUTHOR]

Dynamic strain aging at different temperatures and its effects on the strain hardening behavior, dislocation substructure and fracture morphology in a stainless steel grade 430 was investigated. Sheet type specimens were subjected to tensile tests performed at a temperature range of 298 K to 873 K. Subsequently, the strain hardening behavior of the material was depicted via modified Crussard–Jaoul analysis, strain hardening rate, and instantaneous strain hardening exponent curves. Changes in the dislocation substructure during the tests were characterized by means of X-ray diffraction and transmission electron microscopy. Scanning electron microscopy was used to investigate the fracture morphology of the specimens. The results indicated the occurrence of dynamic strain aging from 523 K to 773 K by the presence of the Portevin–Le Chatelier effect. These results were reinforced by the strain hardening analysis that revealed a three staged behavior at most of the studied temperatures, except during the dynamic strain aging regime, which presented an extra stage. Different substructures were observed as a function of the test temperatures: cellular dislocation substructure in the samples deformed at 298 K and 673 K, an array of straight and parallel dislocations in conjunction with a cellular substructure at 673 K, and finally a subgrained substructure with fine precipitates was formed at 873 K. A ductile surface fracture presenting a network of dimples and voids was present at all investigated temperatures, with a dimple size refinement being observed during the dynamic strain aging regime. [ABSTRACT FROM AUTHOR]

This work reports the effect of different processing parameters on the structural and morphological characteristics of MoSe2 layers grown by chemical vapour deposition (CVD), using MoO3 and Se powders as solid precursors. It shows the strong dependence of the size, shape and thickness of the MoSe2 layers on the processing parameters. The morphology of the samples was investigated by field emission scanning electron microscopy (FESEM) and the thickness of the deposited layers was determined by atomic force microscopy (AFM). Raman and photoluminescence (PL) spectroscopies were used to confirm the high quality of the MoSe2 layers. Surface composition was examined by photoelectron spectroscopy (XPS). Moreover, the MoSe2/SiOx/Si heterojunctions exhibit diode behaviour, with a rectification ratio of 10, measured at ±2.0 V, which is due to the p-i-n heterojunctions formed at the p-Si/SiOx/MoSe2 interface. A photovoltaic effect was observed with a short circuit current density (Jsc), open circuit voltage (VOC) and efficiency of −0.80 mA/cm2, 1.55 V and 0.5%, respectively. These results provide a guide for the preparation of p-i-n heterojunctions based on few-layer MoSe2 with improved photovoltaic response. [ABSTRACT FROM AUTHOR]

The wear resistance of boron-modified supermartensitic stainless steel coatings produced by high-velocity oxygen fuel (HVOF) was investigated through pin-on-disk measurements. It was shown that addition of boron leads to the formation of an interconnected and rigid boride network delimiting the grain boundaries of the martensitic matrix. A very refined structure was formed as result of the high cooling rates imposed to the molten alloy during the HVOF process. The specific wear rates of the HVOF coatings were about tenfold lower than the boron-free supermartensitic stainless steel, lying in the order of 10−5 mm3/N m. The refined boride skeleton along the HVOF coating was found to be effective to reduce the materials' removal from the exposed softer martensitic matrix. While the supermartensitic stainless steel master alloy and the mild steel substrate displayed severe adhesive wear, the HVOF coatings exhibited mild delamination wear at low sliding velocities (10 and 20 cm/s) and abrasive wear at the highest tested velocity (40 cm/s). The studied boron-modified supermartensitic HVOF coatings are an interesting approach to protect the surface of inexpensive steel substrates against wear. [ABSTRACT FROM AUTHOR]

The wild pig (Sus scrofa) is an invasive species that negatively impacts new areas into which it is introduced. In this study, we evaluated the effects of wild pig presence on the estimated occupancy and detection probabilities of native mammals in the Brazilian Atlantic Forest. We used camera traps at 100 different points for 8 days (800 trap-days) to collect data and two-species conditional occupancy models to estimate the probability of occupancy (ψ) and the probability of detection (p) of mammal species. We detected a total of 23 native mammal species and two non-native mammal species [wild pig and European hare (Lepus europaeus)] and generated 21 models to evaluate the effects of wild pig occupancy on the European hare and the following 13 native mammals: Cerdocyon thous, Pseudalopex gymnocercus, Hydrochoerus hydrochaeris, Mazama americana, Mazama gouazoubira, Mazama nana, Dasyprocta aguti, Dasypus novemcinctus, Leopardus wiedii, Puma yagouaroundi, Didelphis albiventris, Conepatus chinga, and Procyon cancrivorus. Overall, the presence of wild pig had a range of negative effects on the occupancy and detection of the other mammals, which were less likely to occupy areas that were occupied by wild pig. In addition, we observed lower occurrence and richness of native mammal species in sampling points where wild pig were present compared with locations where wild pig were not present. These results highlight the importance of wild pig management and control for the conservation of native mammals in the Atlantic Forest, a region that is already threatened by a high degree of fragmentation. [ABSTRACT FROM AUTHOR]

The mass was located along the removed lead's intracardiac route; one end of the mass was attached to the right ventricular wall and the other end was located below the tricuspid valve and had a very mobile tip. After transvenous right ventricular lead extraction (LE), transthoracic echocardiography revealed a hyperechogenic, filiform, anomalous mass of 8 × 5 mm (Fig. Video online The online version of this article contains two videos. [Extracted from the article]

We analyze the electrostatic self-energy of a point like electrically charged particle induced by a cosmic string in the context of gravity's rainbow, as well the electrostatic self-force on this particle. The possibility of the solution associated with a charged particle to be altered by modifications in dispersion relations of the space-time is discussed. We show that the self-energy depends on the rainbow functions and that this quantity can either increase or decrease depending on the rainbow function chosen, as compared with analogous result in the framework of general relativity. With respect to the self-force, its dependence with the rainbow functions is also pointed out. [ABSTRACT FROM AUTHOR]

The aim of this work was to assess the occupational dose received by an interventional radiologist (IR) during computed tomography fluoroscopy (CTF)-guided procedures; to identify the most exposed areas of the body including the hands and fingers; to suggest recommendations for individual monitoring; and to improve radiation safety of the practice. A total of 53 CTF-guided procedures were studied. Twelve whole-body dosimeters were worn by the IR in each procedure for the assessment of the personal dose equivalent, Hp(10), on the chest, waist, and back, both over and under the lead apron, as well as the personal dose equivalent, Hp(0.07), on both arms, knees, and feet. Special gloves with casings to fit extremity dosimeters were prepared to assess Hp(0.07) to the fingers. The measured chest dose values were higher than those on the waist and back; the dominant hand or the left side was the most exposed. In general, the ring, middle, and index fingers of the dominant hand were the most exposed (maximum in the 36–39 mSv range), while wrist dose was negligible compared to finger doses. Based on the results obtained the following recommendations are suggested: protective devices (lead aprons, thyroid shield, and goggles) should be worn; Hp(10) should be assessed at the chest level both above and below the lead apron; finger doses can be measured on the basis of each middle finger; the arm closer to the beam should be monitored; and finally, a wrist dosimeter will not provide useful information. [ABSTRACT FROM AUTHOR]

Low sugarcane productivity in Brazil is due to insufficient rainfall and would benefit from irrigation. Thus, the application of treated wastewater, such as treated domestic sewage (TDS), becomes an alternative water and nutrient source for sugarcane cultivation. The objective of this research was to evaluate the productivity, soil fertility, fertilizer savings and nutritional balance during 2 years of sugarcane crops using TDS applied through subsurface drip irrigation. The experiment was conducted in the field under a randomized block design with five treatments, with two dripline depths and two water qualities (domestic sewage and surface reservoir) and finally non-irrigated plots. Productivity, nutritional balance, and soil fertility were measured during two harvest cycles. The irrigated treatments presented greater productivity in both ratoons (28.5% and 42.8%) and, consequently, higher nutrient extraction compared to the input, which provided a reduction of average soil fertility during the cycles evaluated. The dripline depths and the water qualities applied influenced concentrations of sodium in the soil profile, with highest levels in TDS treatments. Treatments with TDS also showed, in both cycles, significant savings of up to 100% on the application of nitrogen and phosphorus. Therefore, TDS applied by subsurface drip can be used as an irrigation alternative in sugarcane cultivation. [ABSTRACT FROM AUTHOR]

Scrambling in interacting quantum systems out of equilibrium is particularly effective in the chaotic regime. Under time evolution, initially localized information is said to be scrambled as it spreads throughout the entire system. This spreading can be analyzed with the spectral form factor, which is defined in terms of the analytic continuation of the partition function. The latter is equivalent to the survival probability of a thermofield double state under unitary dynamics. Using random matrices from the Gaussian unitary ensemble (GUE) as Hamiltonians for the time evolution, we obtain exact analytical expressions at finite N for the survival probability. Numerical simulations of the survival probability with matrices taken from the Gaussian orthogonal ensemble (GOE) are also provided. The GOE is more suitable for our comparison with numerical results obtained with a disordered spin chain with local interactions. Common features between the random matrix and the realistic disordered model in the chaotic regime are identified. The differences that emerge as the spin model approaches a many-body localized phase are also discussed. [ABSTRACT FROM AUTHOR]

There is increasing evidence suggesting that one of the most relevant pathophysiological features of Alzheimer’s disease (AD) is neuroinflammation, which plays an important role in the production and regulation of AD-related proteins (amyloid beta (Aβ) and Tau) and exacerbates AD pathology. Neuroinflammation can also be induced by systemic influences (factors from outside the central nervous system). However, the role of systemic inflammation in AD pathophysiology is much less understood. Thus, our main objective in this study was to verify whether the presence of serum cytokines (IL-1β, IL-6, IL-10, IL-12, and TNF-α) affects different AD biomarkers: Aβ1-42 and Tau protein levels, hippocampal volumes (HV), and default mode network functional connectivity (DMN FC) in healthy elderly controls, amnestic mild cognitive impairment (aMCI) patients due to AD, and mild AD patients. To accomplish this, we acquired 3-T MRI, blood, and cerebrospinal fluid (CSF) samples from 42 healthy controls, 55 aMCI patients due to AD, and 33 mild AD patients. Comparing the groups, we found that the mild AD patients presented smaller HV, disrupted DMN FC, and proportionally less IL-1β than the controls. The aMCI patients only differed from the controls in DMN FC. In intra-group comparison, aMCI and mild AD with detectable levels of cytokines (TNF-α, IL-1β, IL-10, and IL-12) had decreased DMN FC. On the other hand, patients with detectable levels of IL-10 and IL-12 presented a more favorable AD biomarkers profile (larger HV, more CSF Aβ1-42, and less p-Tau), indicating a possible protective role of these ILs. Our findings indicate a possible relationship between systemic inflammation with DMN FC disruption, hippocampal atrophy, and CSF protein levels in the subjects with mild AD and aMCI. [ABSTRACT FROM AUTHOR]

Chlorogenic acids, the main polyphenolic group present in coffee, which include the caffeoylquinic acids, are recognized as antioxidants with growing interest in pharmacological, cosmetic, and food applications. However, they can be easily oxidized and they are also very unstable when exposed to high temperatures. Therefore, they can suffer transesterification reactions during storage or food processing, limiting their applications. Nevertheless, this situation can be overcome or minimized by microencapsulation. The purpose of the present study was to prepare by a spray-drying process sodium alginate and modified chitosan microparticles with chlorogenic acid (3-CQA), characterize them (morphological analysis), and evaluate the release profile of 3-CQA from the microparticles in in vitro studies. Furthermore, their antioxidant activity and moisture content were determined. The results address the success of chlorogenic acid microencapsulation, resulting in stable microparticles with controlled release properties and good antioxidant activity, suggesting increasing applications in food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Background: Resistance training (RT) has selective effects on body composition that may counteract the deleterious effects of aging. Changes in phase angle (PhA) may serve to monitor the influence of RT in older people.Objectives: To describe the effect of RT in training, detraining and retraining on body composition, including PhA in older women.Subjects/methods: Thirty-three older women (⩾60 years old) participated. The RT program was carried out over 12 weeks for each stage (training, detraining and retraining). Whole-body fat-free mass and fat mass (FM) and appendicular lean soft tissue (ALST) measurements were carried out using a dual energy X-ray absorptiometry. Bioimpedance spectroscopy was used to estimate total body water (TBW), intra (ICF) and extracellular (ECF) fluids, whole-body resistance (R) and reactance (Xc) and PhA. Upper and lower body muscle strength were also assessed.Results: From baseline to after training muscle strength, ALST and PhA significantly (P<0.05) increased. In detraining, significant (P<0.05) reductions in muscle strength, TBW, ECF, ICF and PhA along with significant (P<0.05) increases in R were observed, with the greatest magnitude observed for PhA (Δ=-7.6%). From detraining to retraining a significant reduction in FM along with increases in Xc, PhA and muscle strength were observed. Although an increase was observed from detraining to retraining in PhA, the values were still lower than baseline PhA.Conclusions: In untrained older women, a RT is associated with increases in PhA, whereas detraining results in a marked decrease in PhA, and more time may be required in retraining to counteract the negative influence of absence of exercise stimulus. [ABSTRACT FROM AUTHOR]

We will show examples in which the primal sequence generated by the Newton-Lagrange method converges to a strict local minimizer of a constrained optimization problem but the gradient of the Lagrangian does not tend to zero, independently of the choice of the dual sequence. [ABSTRACT FROM AUTHOR]

Despite the great scientific advances that have been made in cancer treatment, there is still much to do, particularly with regard to urinary bladder cancer. Some of the drugs used in urinary bladder cancer treatment have been in use for more than 30 years and show reduced effectiveness and high recurrence rates. There have been several attempts to find new and more effective drugs, to be used alone or in combination with the drugs already in use, in order to overcome this situation. The biologically important mammalian target of rapamycin (mTOR) pathway is altered in cancer and mTOR inhibitors have raised many expectations as potentially important anticancer drugs. In this article, the authors will review the mTOR pathway and present their experiences of the use of some mTOR inhibitors, sirolimus, everolimus and temsirolimus, in isolation and in conjunction with non-mTOR inhibitors cisplatin and gemcitabine, on urinary bladder tumour cell lines. The non-muscle-invasive cell line, 5637, is the only one that exhibits a small alteration in the mTOR and AKT phosphorylation after rapalogs exposure. Also, there was a small inhibition of cell proliferation. With gemcitabine plus everolimus or temsirolimus, the results were encouraging as a more effective response was noticed with both combinations, especially in the 5637 and T24 cell lines. Cisplatin associated with everolimus or temsirolimus also gave promising results, as an antiproliferative effect was observed when the drugs were associated, in particular on the 5637 and HT1376 cell lines. Everolimus or temsirolimus in conjunction with gemcitabine or cisplatin could have an important role to play in urinary bladder cancer treatment, depending on the tumour grading. [ABSTRACT FROM AUTHOR]

We present a study of the electrical properties of electrochemically doped conjugated polymers using polymeric light-emitting electrochemical cells (PLECs) and interpreting the results according to a phenomenological model (PM) which assumes that, above the device turn-on voltage, the bulk transport properties of the doped organic semiconductor are responsible for the main contribution to the whole device conductivity. To confirm the predictions of this model, the dependence of the conductivity of PLECs with different parameters is evaluated and compared with the behavior expected for a doped semiconducting polymeric material. The organic semiconductor doping level, the blend concentration of organic semiconducting molecules, the device thickness, the charge carrier mobility, and the temperature are the parameters varied to perform this analysis. We observed that the device conductivity is independent of the active layer thickness, weakly dependent on the temperature, but strongly dependent on the semiconductor doping level, on the semiconductor fraction in the blend, and on the intrinsic charge carrier mobility. These results were well described by the variable range hopping (VRH) model, which has been widely employed to describe the charge transport in doped semiconducting polymeric materials, confirming the prediction of the phenomenological model. The current analysis demonstrates that PLECs are a suitable system for studying, in situ, the electrochemical doping of semiconducting polymers, permitting the evaluation of material properties as, for instance, the density of electronic charge carriers (and, consequently, the ionic charge carrier concentration) necessary to achieve the maximum electrochemical doping level of the organic semiconductor. [ABSTRACT FROM AUTHOR]

Hepatic encephalopathy (HE) is a late complication of liver cirrhosis and is clearly associated with poor outcomes. Chronic liver insufficiency leads to progressive muscle wasting, impairing ammonia metabolism and thus increasing the risk for HE. Given the association between lean mass and adductor pollicis muscle thickness (APMT), it has been used to predict outcome and complications in many conditions, but not yet in cirrhotic patients. Therefore, this article aimed to study the association between HE manifestations and measures related to muscle mass and strength. This cross-sectional study included 54 cirrhotic outpatients with HE varying from subclinical to grade II according to the West-Haven criteria, who were submitted to neuropsychometric tests, electroencephalogram, brain Single Photon Emission Computed Tomography (SPECT), anthropometric measurements, handgrip strength (HGS) and dual energy X-ray absorptiometry exam (DXA). Multiple logistic regression analysis was performed to investigate the association between body composition measures and HE grade. Analysis of the area under the receiver operator characteristic (AUROC) curve revealed the values related to neurological manifestations (HE grades I and II). Reductions in APMT and HGS were associated with higher HE grades, suggesting a big impact caused by the loss of muscle mass and function on HE severity. The link between HE manifestations and anthropometric measures, namely APMT and HGS, point to a significant relation concerning skeletal muscles and the neurological impairment in this population. [ABSTRACT FROM AUTHOR]

This study aimed to contribute to the enhancement of the knowledge of levels, trends and behaviour of eight siloxanes (four linear and four cyclic) in the environment. Adding to the prioritised scrutiny of the incidence in the atmosphere through passive samplers (sorbent-impregnated polyurethane foam disks-SIPs), the sampling of pine needles and soil was also performed, thus closing the circle of atmospheric exposure in the areas of study. Two sampling campaigns (one in summer and one in winter) were done in a total of eight sampling points in the Portuguese territory, which covered a wide range of human presence and land uses (urban, industrial, remote and beach areas). By adopting a 'green' approach in terms of analytical methods, namely reducing the clean-up steps for the passive air samples and using the quick, easy, cheap, effective, rugged and safe (QuEChERS) technology for soils and pine needles, the results showed total concentration of siloxanes between 5 and 70 ng g (dry weight) for soils and from 2 to 118 ng g (dry weight (dw)) for pine needles, with no clear seasonal trend. For SIPs, the levels varied from 0.6 to 7.8 ng m and were higher in summer than in winter in all sites. Overall, the cyclic siloxanes were found in much higher concentrations, with D5 and D6 being the most predominant in a great majority of cases. Also, the urban and industrial areas had the highest incidence, suggesting a strong anthropogenic fingerprint, in line with their main uses. [ABSTRACT FROM AUTHOR]

We study the dynamics of the rotational motion of a gyrostat satellite moving in the central Newtonian force field along a circular orbit. We propose a method for determining the equilibrium attitudes (equilibrium orientations) of a gyrostat satellite in the orbital coordinate system for given values of the gyrostatic moment vector and principal central moments of inertia, and obtain their existence conditions. For each equilibrium orientation, sufficient conditions for stability are obtained using a generalized energy integral such as a Lyapunov function. We conduct a detailed numerical analysis of domains where the stability conditions for equilibrium attitudes are satisfied depending on four dimensionless parameters of the problem. It is shown that the number of equilibrium attitudes of a gyrostat satellite for which the sufficient conditions of stability are satisfied in the general case varies from four to two with an increase in the magnitude of a gyrostatic moment. The results obtained in this paper can be used for constructing gravitational systems of control over the orientation of the Earth's artificial satellites. [ABSTRACT FROM AUTHOR]