Behavior of different soot combustion catalysts under NOx/O2. Importance of the catalyst–soot contact

Four different catalysts (Pt/Al2O3, Ce0.8Zr0.2O2, PrO2−x and SrTiCuO3) have been investigated on a laboratory scale to evaluate their potential as diesel soot combustion catalysts under different experimental conditions, which simulate the situation found in a continuous regeneration technology trap (dual-bed configuration of catalyst and soot) or a catalyst-coated filter system (single-bed configuration, both catalyst and soot particles mixed under loose-contact mode). Under dual-bed configuration, the behavior of the catalysts towards soot combustion are very similar, despite the differences observed in the NO2 production profiles. However, under single-bed configuration, there are important differences in the soot combustion activities and in the NO2 slip profiles. The configurations chosen have an enormous impact on CO/(CO + CO2) ratios of combustion products as well. The most active catalyst under NOx + O2 is PrO2−x combining a high contribution of active oxygen-assisted soot combustion as well as high NO2 production activity along the catalytic bed.Financial support of Generalitat Valenciana (Prometeo/2009/047 project) and the Spanish Ministry of Science and Innovation (project CTQ2012-30703, which is co-funded by FEDER resources). N. G. H. wishes to thank Generalitat Valenciana her Ph.D. grant within VAL i+d Program

miR-7 Modulates hESC Differentiation into Insulin-Producing Beta-like Cells and Contributes to Cell Maturation

Human pluripotent stem cells retain the extraordinary capacity to differentiate into pancreatic beta cells. For this particular lineage, more effort is still required to stress the importance of developing an efficient, reproducible, easy, and cost-effective differentiation protocol to obtain more mature, homogeneous, and functional insulin-secreting cells. In addition, microRNAs (miRNAs) have emerged as a class of small non-coding RNAs that regulate many cellular processes, including pancreatic differentiation. Some miRNAs are known to be preferentially expressed in islets. Of note, miR-375 and miR-7 are two of the most abundant pancreatic miRNAs, and they are necessary for proper pancreatic islet development. Here we provide new insight into specific miRNAs involved in pancreatic differentiation. We found that miR-7 is differentially expressed during the differentiation of human embryonic stem cells (hESCs) into a beta cell-like phenotype and that its modulation plays an important role in generating mature pancreatic beta cells. This strategy may be exploited to optimize the potential for in vitro differentiation of hESCs into insulin-producing beta-like cells for use in preclinical studies and future clinical applications as well as the prospective uses of miRNAs to improve this process.Spanish Ministry of Economy and Competitiveness BFU2016-74932-C2 BFU2013-45564-C2FEDER Funds PI-0272-2017Andalusian Regional Ministry of Health PI-0272-2017European Cooperation in Science and Technology BM1305Spanish Ministry of Economy, Industry and Competitiveness CD16/00118Spanish Institute of Health Carlos III PI16/00259 PI17/02104 RD16/0011/0034 CD16/0011

Oscillatons formed by non linear gravity

Oscillatons are solutions of the coupled Einstein-Klein-Gordon (EKG) equations that are globally regular and asymptotically flat. By means of a Legendre transformation we are able to visualize the behaviour of the corresponding objects in non-linear gravity where the scalar field has been absorbed by means of the conformal mapping.Comment: Revtex file, 6 pages, 3 eps figure; matches version published in PR

Fourth virial coefficients of asymmetric nonadditive hard-disc mixtures

The fourth virial coefficient of asymmetric nonadditive binary mixtures of hard disks is computed with a standard Monte Carlo method. Wide ranges of size ratio ($0.05\leq q\leq 0.95$) and nonadditivity ($-0.5\leq \Delta\leq 0.5$) are covered. A comparison is made between the numerical results and those that follow from some theoretical developments. The possible use of these data in the derivation of new equations of state for these mixtures is illustrated by considering a rescaled virial expansion truncated to fourth order. The numerical results obtained using this equation of state are compared with Monte Carlo simulation data in the case of a size ratio $q=0.7$ and two nonadditivities $\Delta=\pm 0.2$.Comment: 9 pages, 7 figures; v2: section on equation of state added; tables moved to supplementary material (http://jcp.aip.org/resource/1/jcpsa6/v136/i18/p184505_s1#artObjSF

Virial coefficients, equation of state, and demixing of binary asymmetric nonadditive hard-disk mixtures

Values of the fifth virial coefficient, compressibility factors, and fluid-fluid coexistence curves of binary asymmetric nonadditive mixtures of hard disks are reported. The former correspond to a wide range of size ratios and positive nonadditivities and have been obtained through a standard Monte Carlo method for the computation of the corresponding cluster integrals. The compressibility factors as functions of density, derived from canonical Monte Carlo simulations, have been obtained for two values of the size ratio ($q=0.4$ and $q=0.5$), a value of the nonadditivity parameter $\Delta=0.3$), and five values of the mole fraction of the species with the biggest diameter ($x_1=0.1$, $0.3$, $0.5$, $0.7$, and $0.9$). Some points of the coexistence line relative to the fluid-fluid phase transition for the same values of the size ratios and nonadditivity parameter have been obtained from Gibbs Ensemble Monte Carlo simulations. A comparison is made between the numerical results and those that follow from some theoretical equations of state.Comment: 11(+4) pages, 11 figures; Supplemental Material include

Etablierung verschiedener Bead-basierter Multiplexmethoden mit einem Suspensions Array-System für molekulardiagnostische Zwecke

Die simultane Bestimmung mehrerer Analyten und die Erstellung komplexer Parameterprofi e erlangt immer größere Bedeutung in der heutigen Labordiagnostik. Die Bead-basierte Multiplexanalytik bietet hier eine flexible, schnelle und einfache Methode zur Erstellung individueller Analysen. Aufgrund der Vielzahl von Anwendungsmöglichkeiten, die diese moderne Nachweismethode im Bereich molekularbiologischer Fragestellungen bietet, ist die Etablierung der Beadbasierten Multiplexanalytik im Labor für Molekularbiologie und funktionelle Genomik der Technischen Hochschule Wildau von großem Nutzen. Zur Einarbeitung in das Testsystem wurden die Konzentrationen der Zytokine IL-2, IL-4, IFN-γ und TNF-α in Zellkulturüberständen mit kommerziellen Fertigsystemen gemessen und mit mRNA-Expressionsraten der gleichen Proben verglichen. Des Weiteren wurde ein Testsystem zum Nachweis von humanen Antikörpern der Klassen IgG und IgM sowie deren antigen-spezifischer Anteil in Zellkulturüberständen entwickelt. Außerdem konnte durch die erfolgreiche Detektion von DNA-gekoppelten Beads mittels markierter Oligonukleotidsequenz die Kopplung und die Anwendbarkeit der Methode auf Bindungsexperimente mit Nukleotidsequenzen gezeigt werdenThe simultaneous determination of multiple analytes and the generation of complex parameter profi les gains increasing importance in today’s laboratory diagnostics. The bead-based multiplex assay is offering a flexible, rapid and easy to handle method for the creation of individual analyses. Because of the multitude of applications this modern detection system offers, the establishment of the bead-based multiplex technique is of great benefit for the Laboratory for Molecular Biology and Functional Genomics of the Technical University of Applied Sciences Wildau. To familiarize with the testing system the concentrations of the cytokines IL-2, IL-4, IFN-γ and TNF-α in cell culture supernatant were analysed with commercially available assays and compared with mRNA expression ratios of the same samples. Furthermore a custom testing system was developed for the detection of human IgG and IgM antibodies and also antigen specific antibodies in cell culture supernatants. The assignability of the method to binding experiments with nucleotide sequences could be shown by the successful detection of DNA-modified beads by conjugated oligonucleotide

Erratum: Virial coefficients and demixing in the Asakura-Oosawa model (vol 142, 014902, 2015)

© 2015 AIP Publishing LLCDepto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEpu

Pt–Sn/C catalysts prepared by sodium borohydride reduction for alcohol oxidation in fuel cells: Effect of the precursor addition order

A series of Pt–Sn/C catalysts used as anodes during ethanol oxidation are synthesized by a deposition process using NaBH4 as the reducing agent. The order in which the precursors are added affects the electrocatalytic activity and physical-chemical characteristics of the bimetallic catalysts, where the Pt–Sn catalyst prepared by co-precipitation of both metals functions best below a potential of 0.5 V and the catalyst prepared by sequential deposition of Sn and Pt (drying after Sn addition) is most active above a potential of 0.5 V. The electrochemical behavior of catalysts during ethanol oxidation in an acidic medium are characterized and monitored in a half-cell test at room temperature by cyclic voltammetry, chronoamperometry and anode potentiostatic polarization. Catalyst structure and chemical composition are investigated by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). This behavior presented for best Pt–Sn catalyst can be attributed to the so-called bifunctional mechanism and to the electronic interaction between Pt and Sn.The authors thank the Brazilian National Council of Technological and Scientific Development-CNPq (grants: 303630/2012-4, 402243/2012-9 and 310282/2013-6) for the scholarships and financial support for this work