Semiconductor-metal core-shell nanostructures by colloidal heterocoagulation in aqueous medium

In contrast to complex syntheses for the preparation of colloidal nanocomposites in a core-shell structure proposed in the literature, we present herein a facile colloidal route based on a heterocoagulation process promoted by the electrostatic interaction among ceramic NiO nanoplatelets and metallic Ni nanoparticles (NPs). Before the heterocoagulation process, NiO and Ni were synthetized separately in presence of ultrasound, by chemical precipitation and chemical reduction of the same nickel precursor, respectively. After that, NiO-Ni core-shell nanostructures were prepared forcing the electrostatic interaction among surfaces in aqueous medium. The surface charge balances of both types of particles were tuned effectively by adjusting the pH in a free-additives suspension. For the surface modification of NiO by Ni, the ceramic suspensions maintain a positive zeta potential at pH 9, while the surface of metallic particles is negatively charged. Then the uniform coating of NiO platelets, by the electrostatically induced coagulation with Ni NPs, was favors. The degree of coverage and the formation of NiO-Ni core-shell nanostructures were followed referring the evolution of zeta potential with the geometric calculation in terms of size and morphology of both nanoparticles, and then corroborated by field emission scanning electron microscopy (FESEM).The authors acknowledge the support of the projects S2013/MIT-2862 and MAT2012–38650-02–01, MAT2012–38650-C02–02. M. de Dios acknowledges MINECO through the grant FPI-2013 and Dr. Z González acknowledges to MINECO through the grant PTQ-13–05985

Heat exchange between two interacting nanoparticles beyond the fluctuation-dissipation regime

We show that the observed non-monotonic behavior of the thermal conductance between two nanoparticles when they are brought into contact is originated by an intricate phase space dynamics. Here it is assumed that this dynamics results from the thermally activated jumping through a rough energy landscape. A hierarchy of relaxation times plays the key role in the description of this complex phase space behaviour. Our theory enables us to analyze the heat transfer just before and at the moment of contact.Comment: 4 pages, 1 figure, approved for publication in Physical Review Letter

Physical States in Canonically Quantized Supergravity

We discuss the canonical quantization of $N=1$ supergravity in the functional Schrodinger representation. Although the form of the supersymmetry constraints suggests that there are solutions of definite order $n$ in the fermion fields, we show that there are no such states for any finite $n$. For $n=0$, a simple scaling argument definitively excludes the purely bosonic states discussed by D'Eath. For $n>0$, the argument is based on a mode expansion of the gravitino field on the quantization 3-surface. It is thus suggested that physical states in supergravity have infinite Grassmann number. This is confirmed for the free spin-3/2 field, for which we find that states satisfying the gauge constraints contain an infinite product of fermion mode operators.Comment: 36 pages (uses jnl.tex), CTP #227

La-images: A Software For Elemental Distribution Bioimaging Using La-icp-ms Data

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The spatial distribution of chemical elements in different types of samples is an important field in several research areas such as biology, paleontology or biomedicine, among others. Elemental distribution imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an effective technique for qualitative and quantitative imaging due to its high spatial resolution and sensitivity. By applying this technique, vast amounts of raw data are generated to obtain high-quality images, essentially making the use of specific LA-ICP-MS imaging software that can process such data absolutely mandatory. Since existing solutions are usually commercial or hard-to-use for average users, this work introduces LA-iMageS, an open-source, free-to-use multiplatform application for fast and automatic generation of high-quality elemental distribution bioimages from LA-ICP-MS data in the PerkinElmer Elan XL format, whose results can be directly exported to external applications for further analysis. A key strength of LA-iMageS is its substantial added value for users, with particular regard to the customization of the elemental distribution bioimages, which allows, among other features, the ability to change color maps, increase image resolution or toggle between 2D and 3D visualizations.8Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo, Brazil)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brasilia, Brazil)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brasilia, Brazil)Provincial Council of Ourense [INOU-16-05]national funds from FCT/MEC [UID/QUI/50006/2013, UID/Multi/04378/2013]ERDF under the PT2020 Partnership Agreement [POCI-01-0145-FEDER-007265, POCI-01-0145-FEDER-007728]Unidade de Ciencias Biomoleculares Aplicadas-UCIBIOXunta de GaliciaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Novel colloidal approach for the microstructural improvement in Ti(C,N)/FeNi cermets

In this work, the combination of colloidal and powder metallurgy techniques was proposed as an alternative route to produce Ti(C,N)-based cermets with a 15-20 vol% of Fe/Ni alloy (85/15 wt%) as metal matrix. The novelty of this processing route is based in the mixture of fine powders (1;-3 µm) in suspension which promotes the uniformity of the phase distribution and consequently its reactivity, leading to 99.9% dense cermets with 1300 Vickers Hardness (HV30). The preparation of colloidal and chemically stable slurries of non-oxide and metal powders in aqueous media is a key step of the process. Highly concentrated aqueous slurries of Ti(C,N), Fe, Ni and C powders were prepared and mixed. Then bulk pieces were shaped by Slip casting (SC), Slip Casting + Cold Isostatic Pressing (SC-CIP) and Spray-Dry + Uniaxial Pressing of the obtained spherical granules (SDP). The composite formulation and the thermal treatment were optimized to prevent Ni sublimation during sintering as well as to improve liquid phase sintering in terms of wetting and reactivity among well packed particles. The effective dispersion of the slurry and the synergistic effect of combined techniques yielded the preparation of reliable materials by the SDP process with 15 wt% of FeNi with the addition of 0.5 wt% of C. The optimization of the composite formulation and the processing parameters improves both density and hardness of a finer microstructure of the composite after a short sintering treatment (120 min) at 1450 °C in vacuum.The authors acknowledge the financial support from the Spanish Government through the projects MAT2015-70780-C4-1-P and MAT2015-70780-C4-2-P, and the Regional Government of Madrid through the program MULTIMAT CHALLENGE, ref. S2013/MIT-2862. M. Dios acknowledges MINECO through the grant BES-2013-06576

L’atenció primerenca a les Illes Balears

El treball descriu el programa d’atenció primerenca que es desenvolupa a les Illes Balears, la seva evolució, els professionals i les seves funcions en cada un dels àmbits implicats. Per altra part, també s’ofereixen dades sobre la població atesa. Els autors són professionals dels tres àmbits responsables del Pla integral d’atenció primerenca de les Illes Balears (educatiu, sanitari i social), els quals destaquen la importància de la coordinació interdisciplinària i la necessitat de disposar d’una xarxa de serveis que doni resposta a les necessitats dels infants i les seves famílies.El trabajo describe el programa de atención primaria que se desarrolla en las Islas Baleares, su evolución, los profesionales y sus funciones en cada uno de los ámbitos implicados. Por otra parte, también se ofrecen datos sobre la población atendida. Los autores son profesionales de los tres ámbitos responsables del Plan integral de atención primaria de las Islas Baleares (educativo, sanitario y social), los cuales destacan la importancia de la coordinación interdisciplinar y la necesidad de disponer de una red de servicios que den respuesta a las necesidades de los niños y sus familias

Mechanical characterization of Ti(C,N)-based cermets fabricated through different colloidal processing routes

In this work the influence of different colloidal processing routes on the mechanical behavior of several Ti(C,N)-based cermets has been studied. The materials were designed with a Ti(C, N) content ranging between 80 and 85 vol %, in a Fe-Ni alloy matrix (with and without carbon addition). Three processing techniques were investigated: (i) Slip Casting (SC), (ii) Slip Casting + Cold Isostatic Pressing (SC+CIP), and (iii) Spray-Dry + Uniaxial Pressing (SDP). Biaxial strength distributions were determined in all samples using the ball-on-three-balls (B3B) method on disc-shaped specimens. Results were interpreted in the framework of Weibull theory. The characteristic strength ranged between 1090 MPa and 1870 MPa. A fractographic analysis performed on selected specimens showed different critical flaws, depending on the processing route, related to the composition and porosity level in each case. Single Edge V-Notched Beam (SEVNB) specimens fabricated with SDP were tested under 4-point-bending, in order to identify the effect of Fe-Ni content and carbon addition on their fracture resistance. Detailed fractographic analyses revealed slightly different mechanisms of fracture associated with the Fe-Ni and carbon content. Fracture toughness values ranging between similar to 12 and similar to 14 MPa m(1/2) were measured. Based upon these findings the SDP route is proposed to improve both the strength and toughness of Ti(C, N) cermets, which can be enhanced by the addition of carbon during the colloidal processing.The authors acknowledge the financial support from the Spanish Government through the projects MAT2015-70780-C4-1-P and MAT2015-70780-C4-2-P, and the Regional Government of Madrid through the program MULTIMAT-CHALLENGE, ref. S2013/MIT-2862. M.Dios acknowledges MINECO through the grant BES-2013-065760

Robust Light Driven Enzymatic Oxyfunctionalization via Immobilization of Unspecific Peroxygenase

Unspecific peroxygenases have attracted interest in synthetic chemistry, especially for the oxidative activation of C−H bonds, as they only require hydrogen peroxide (H2O2) instead of a cofactor. Due to their instability in even small amounts of H2O2, different strategies like enzyme immobilization or in situ H2O2 production have been developed to improve the stability of these enzymes. While most strategies have been studied separately, a combination of photocatalysis with immobilized enzymes was only recently reported. To show the advantages and limiting factors of immobilized enzyme in a photobiocatalytic reaction, a comparison is made between free and immobilized enzymes. Adjustment of critical parameters such as (i) enzyme and substrate concentration, (ii) illumination wavelength and (iii) light intensity results in significantly increased enzyme stabilities of the immobilized variant. Moreover, under optimized conditions a turnover number of 334,500 was reached

Variation in assignment of the COPD patients into a GOLD group according to symptoms severity

Introduction: The Global Organization of Lung Disease (GOLD) classifies patients with chronic obstructive pulmonary disease (COPD) taking into account the symptoms. The modified Medical Research Council’s dyspnea scale (mMRC) and the COPD assessment test (CAT) are used to assess these symptoms. In this study, we analyze the concordance of GOLD classification using mMRC and CAT. Patients and Methods: This is an observational study of a cohort of 169 patients with COPD, who were classified following the GOLD 2017 recommendations, using both mMRC and CAT. A concordance analysis was applied, and a ROC curve was generated to identify the CAT score that best concorded with the mMRC scale. Results: The concordance for the GOLD groups classified by CAT and mMRC was moderate (kappa 0.492). For mMRC score of 1 and 2, a CAT score of =9 and =16 showed the maximum value of the Youden index, respectively. By reclassifying the patients with the new cut-off points obtained, the best concordance was obtained between the cut-off point for CAT of 16 and for mMRC of 2, followed by CAT of 9 and mMRC of 1. Conclusion: Because of the deficient concordance between CAT and mMRC, we propose the use of new cut-off points in future updates of the GOLD strategy

Logic-based schedulability analysis for compositional hard real-time embedded systems

This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in SIGBED Review, VOL.12, ISS.1, http://doi.acm.org/10.1145/2752801.2752808Over the past decades several approaches for schedu- lability analysis have been proposed for both uniprocessor and multi-processor real-time systems. Although different techniques are employed, very little has been put forward in using formal specifications, with the consequent possibility for misinterpretations or ambiguities in the problem statement. Using a logic based approach to schedulability analysis in the design of hard real-time systems eases the synthesis of correct-by- construction procedures for both static and dynamic verification processes. In this paper we propose a novel approach to schedulability analysis based on a timed temporal logic with time durations. Our approach subsumes classical methods for uniprocessor scheduling analysis over compositional resource models by providing the developer with counter-examples, and by ruling out schedules that cause unsafe violations on the system. We also provide an example showing the effectiveness of our proposal.This work was partially supported by National Funds through FCT (Portuguese Foundation for Science and Technology) and by ERDF (European Regional Development Fund) through COMPETE (Operational Programme ’Thematic Fac- tors of Competitiveness’), within projects Ref. FCOMP-01- 0124-FEDER-022701 (CISTER), FCOMP-01-0124-FEDER- 015006 (VIPCORE) and FCOMP-01-0124-FEDER-020486 (AVIACC)