Multi-component alloys containing 5 and 6 platinum group metals have been prepared by thermal decomposition of single-source precursors. It is the first successful example of high-entropy alloy preparation not requiring direct melting at high temperature or mechanical alloying, and can be further extended to other multicomponent metallic systems. Our single-source precursor strategy for the preparation of multicomponent alloys can be considered as a new approach in the design and optimization of refractory high-entropy alloys for a broad range of applications. Thermal decomposition occurs at low temperatures (below 800°C in H2 flow). The resulting hexagonal Ir0.19Os0.22Re0.21Rh0.20Ru0.19 alloy is the first example of a single-phase hexagonal high-entropy alloy. Heat treatment does not result in any phase changes up to 1500 K, which is a record temperature stability for a single-phase high-entropy alloy. Room temperature hydrostatic compression up to 45 GPa also highlights the system's stability as a single phase, with a bulk modulus smaller then individual platinum group metals (except Rh). The prepared alloys show pronounced electrocatalytic activity in methanol oxidation, which opens a route for the use of highentropy alloys as materials for sustainable energy conversion.

By means of empirical fits to the differential cross section data on pp andpp elastic scattering, above 10 GeV (center-of-mass energy), we determine the eikonal in the momentum -transfer space (q 2 -space). We make use of a numerical method and a novel semi-analytical method, through which the uncertainties from the fit parameters can be propagated up to the eikonal in the q 2 -space. A systematic study of the effect of the experimental information at large values of the momentum transfer is developed and discussed in detail. We present statistical evidence that the imaginary part of the eikonal changes sign in the q 2 -space and that the position of the zero decreases as the energy increases; after the position of the zero, the eikonal presents a minimum and then goes to zero through negative values. We discuss the applicability of our results in the phenomenological context, outlining some connections with nonperturbative QCD. A short review and a critical discussion on the main results concerning "model-independent" analyses are also presented.PACS. 13.85.Dz Elastic scattering -13.85.-t Hadron-induced high-energy interactions

Nontuberculous mycobacteria (NTM) are emergent pathogens whose importance in human health has been gaining relevance after being recognized as etiological agents of opportunist infections in HIV patients. Currently, NTM are recognized as etiological agents of several respiratory and extra-respiratory infections of immune-competent individuals. The environmental nature of NTM together with the ability to assemble biofilms on different surfaces plays a key role on their pathogenesis. In the present work the ability of three fast-growing NTM (Mycobacterium smegmatis, Mycobacterium fortuitum and Mycobacterium chelonae) to persist within a model of human alveolar macrophages was evaluated. Most often human infections with NTM occur by contact with the environment. Biofilms can work as environmental reservoirs. For this reason, it was decided to evaluate the ability of NTM to assemble biofilms on different surfaces. Scanning electron microscopy was used to elucidate the biofilm structure. The ability to assemble biofilms was connected with the ability to spread on solid media known as sliding. Biofilm assembly and intracellular persistence seems to be ruled by different mechanisms.

We present the results of fitting elastic $pp$ differential cross section data at 23.5 $\leq \sqrt{s} \leq$ 62.5 GeV with a novel analytic parametrization for the scattering amplitude. Making use of a fitting method, the errors from the free parameters are propagated to the imaginary part of the eikonal in the momentum transfer space. A novel systematic study of the effects coming from data at large momentum transfer is also performed. We find statistical evidence for the existence of eikonal zeros in the interval of momentum transfer 5-9 $GeV^{2}$.Comment: Text with 9 pages in Revtex (preprint form), 8 figures in PostScript. Replaced with small changes. Final version to be published in Physical Review

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technology is everywhere. Currently, it is the Von Neumann's architecture that is applied to the electronic computing systems in which the different elements (memory, processor, and controller) are separated. [1] Nearly all the circuits within the memory and the processor are composed of complementary metal-oxidesemiconductor (CMOS) devices, which can be a problem once this technology cannot be further miniaturized without compromising its performance. [2] A practical example could be that in order to increase the operating frequency and the device density, which is necessary when downscaling, the power supply and the operation temperature would also increase, which would obviously degrade the system performance. Moreover, the Von Neumann system is not suited to solve real world problems where inputs and outputs are sometimes not specified [3] or to execute adaptive learning algorithms as it would be necessary in tasks, such as classification of unstructured data or pattern recognition. [4] To overcome the Von Neumann's bottleneck, the development of artificial intelligence technologies and new computer architecture designs are necessary. One of such novel approaches is neuromorphic computation, which operates with extremely low power consumption. It also maintains the massive parallelism found in the human brain [5] where neurons communicate information by electrical or chemical input signals passing through synapses. Synapses present a very important behavior called plasticity which consists in changing their strength (synaptic weight), either facilitating or inhibiting the connection between two neurons, through potentiation and depression, respectively. [6] One of the solutions to emulate biological synapses is the resistive switching (RS) device, or memristor. A memristor is basically a nonlinear two-terminal device whose conductance can be altered by external inputs and depends on the history of current that has flowed through the device. Application of both weight programming and weight processing signals are through its input terminals thus mimicking a synapse. In fact, the memristor can simulate the synapses' plasticity by continuously adapting its resistance into excitatory and inhibitory weights upon application of electrical Amorphous indium-gallium-zinc-oxide (a-IGZO) based memristive devices with molybdenum contacts as both top and bottom electrodes are presented aiming to be used in neuromorphic applications. Devices down to 4 µm 2 are fabricated using conventional photolithography processes, with an extraordinary yield of 100%. X-ray photoelectron spectroscopy and transmission electron microscopy performed on the developed structures confirm the presence of a thin intermixed oxide layer (4-5 nm) containing Mo 6+ oxidation state at the interface with the bottom contact. This results in Schottky diodelike characteristics at the pristine state with a rectification ratio of 3 orders of magnitude. The devices have electroforming-free and area-dependent analog resistive switching properties. Temperature...

The plasmonic properties of gold nanoparticles (AuNPs) are a promising tool to develop sensing alternatives to traditional, enzyme-catalyzed reactions. The need for sensing alternatives, especially in underdeveloped areas of the world, has given rise to the application of nonenzymatic sensing approaches paired with cellulosic substrates to biochemical analysis. Herein, we present three individual, low-step, wet-chemistry, colorimetric assays for three target biomarkers, namely, glucose, uric acid, and free cholesterol, relevant in diabetes control and their translation into paper-based assays and microfluidic platforms for multiplexed analysis. For glucose determination, an in situ AuNPs synthesis approach was applied into the developed μPAD, giving semiquantitative measures in the physiologically relevant range. For uric acid and cholesterol determination, modified AuNPs were used to functionalize paper with a gold-on-paper approach with the optical properties changing based on different aggregation degrees and hydrophobic properties of particles dependent on analyte concentration. These paper-based assays show sensitivity ranges and limits of detection compatible for target analyte level determination and detection limits comparable to those of similar enzymatic, colorimetric systems, relying only on plasmonic transduction without the need for enzymatic activity or other chromogenic substrates. The resulting paper-based assays were integrated into a single 3D, multiplex paper-based device using paper microfluidics, showing the capability for performing different colorimetric assays with distinct requirements in terms of sample flow and sample uptake in test zones using a combination of both horizontal and vertical flows inside the same device. The presented device allows for multiparametric, colorimetric measures of different metabolite levels from a single complex sample matrix drop using digital color analysis, showing the potential for development of low-cost, low-complexity tools for diagnostics toward the point-of-care.

In this work we present a significant advancement in cubic silicon carbide (3C-SiC) growth in terms of crystal quality and domain size, and indicate its potential use in photovoltaics. To date, the use of 3C-SiC for photovoltaics has not been considered due to the band gap of 2.3 eV being too large for conventional solar cells. Doping of 3C-SiC with boron introduces an energy level of 0.7 eV above the valence band. Such energy level may form an intermediate band (IB) in the band gap. This IB concept has been presented in the literature to act as an energy ladder that allows absorption of sub-bandgap photons to generate extra electron-hole pairs and increase the efficiency of a solar cell. The main challenge with this concept is to find a materials system that could realize such efficient photovoltaic behavior. The 3C-SiC bandgap and boron energy level fits nicely into the concept, but has not been explored for an IB behavior.For a long time crystalline 3C-SiC has been challenging to grow due to its metastable nature. The material mainly consists of a large number of small domains if the 3C polytype is maintained. In our work a crystal growth process was realized by a new approach that is a combination of initial nucleation and step-flow growth. In the process, the domains that form initially extend laterally to make larger 3C-SiC domains, thus leading to a pronounced improvement in crystalline quality of 3C-SiC. In order to explore the feasibility of IB in 3C-SiC using boron, we have explored two routes of introducing boron impurities; ion implantation on un-doped samples and epitaxial growth on un-doped samples using pre-doped source material. The results show that 3C-SiC doped with boron is an optically active material, and thus is interesting to be further studied for IB behavior.For the ion implanted samples the crystal quality was maintained even after high implantation doses and subsequent annealing. The same was true for the samples grown with pre-doped source material, even with a high concentration of boron impurities.We present optical emission and absorption properties of as-grown and boron implanted 3C-SiC. The low-temperature photoluminescence spectra indicate the formation of optically active deep boron centers, which may be utilized for achieving an IB behavior at sufficiently high dopant concentrations. We also discuss the potential of boron doped 3C-SiC base material in a broader range of applications, such as in photovoltaics, biomarkers and hydrogen generation by splitting water.