Interface Diffusion and Compatibility of (Ba,La)FeO Perovskite Electrodes in Contact with Barium Zirconate and Ceria.

BaLaFeO perovskites (BLF) capable of conducting electrons, protons, and oxygen ions are promising oxygen electrodes for efficient solid oxide cells (fuel cells or electrolyzers), an integral part of prospected large-scale power-to-gas energy storage systems. We investigated the compatibility of BLF with lanthanum content between 5 and 50%, in contact with oxide-ion-conducting CeGdO and proton-conducting BaZrYO electrolytes, annealing the electrode-electrolyte bilayers at high temperature to simulate thermal stresses of fabrication and prolonged operation. By employing both bulk X-ray diffraction and synchrotron X-ray microspectroscopy, we present a space-resolved picture of the interaction between electrode and electrolyte as what concerns cation interdiffusion, exsolution, and phase stability.

Ion transport mechanism in anhydrous lithium thiocyanate LiSCN part III: charge carrier interactions in the premelting regime.

In lithium thiocyanate Li(SCN), the temperature regime below the melting point (274 °C) is characterized by excess conductivities over the usual Arrhenius behavior (premelting regime). Here, the Schottky defect pair concentration is high, and the point defect chemistry can no longer be considered as dilute. Coulomb interactions of Schottky pairs are expected to occur lowering the formation energy of new carriers and hence leading avalanche-like to a transition into a fully defective superionic state.

Ion transport mechanism in anhydrous lithium thiocyanate LiSCN Part I: ionic conductivity and defect chemistry.

This work reports on the ion transport properties and defect chemistry in anhydrous lithium thiocyanate Li(SCN), which is a -halide Li cation conductor. An extensive doping study was conducted, employing magnesium, zinc and cobalt thiocyanate as donor dopants to systematically vary the conductivity and derive a defect model. The investigations are based on impedance measurements and supported by other analytical techniques such as X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, and density functional theory (DFT) calculations.

Ion transport mechanism in anhydrous lithium thiocyanate LiSCN part II: frequency dependence and slow jump relaxation.

Specific aspects of the Li cation conductivity of anhydrous Li(SCN) are investigated, in particular the high migration enthalpy of lithium vacancies. Close inspection of impedance spectra and conductivity data reveals two bulk relaxation processes, with comparatively fast ion transport at high frequencies and slow ion migration at low frequencies. The impedance results are supported by solid state nuclear magnetic resonance (ssNMR), and pair distribution function (PDF) analysis.

Synthesis, characterization and thermal behaviour of solid phases in the quasi-ternary system Mg(SCN)-HO-THF.

Mg(SCN)2·4H2O can be converted into previously unknown compounds Mg(SCN)2·(4 - x) H2O·xTHF with x = 0, 2 and 4 by multiple recrystallization in tetrahydrofuran (THF). The phases were characterized by infrared spectroscopy (IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and their crystal structures were solved from X-ray powder diffraction (XRPD) data. In the crystal structures isolated Mg(NCS)2(H2O)4-x(THF)x units form layered motifs.

Probing Charge Accumulation at SrMnO/SrTiO Heterointerfaces via Advanced Electron Microscopy and Spectroscopy.

The last three decades have seen a growing trend toward studying the interfacial phenomena in complex oxide heterostructures. Of particular concern is the charge distribution at interfaces, which is a crucial factor in controlling the interface transport behavior. However, the study of the charge distribution is very challenging due to its small length scale and the intricate structure and chemistry at interfaces.

Humidity-Controlled Water Uptake and Conductivities in Ion and Electron Mixed Conducting Polythiophene Films.

Mixed conducting polymer films are of great interest in applications where an interface between electronic and ionic charge transport is needed, e.g., in bioelectronics, electrochemical energy applications, and photovoltaic device interfaces.

The oxidation kinetics of thin nickel films between 250 and 500 °C.

The oxidation kinetics of thin polycrystalline Ni films is of fundamental interest as well as being relevant for potential applications. It was investigated between 250 and 500 °C for 10-150 nm thick films. Even for the thinnest films, oxidation was found to be diffusion controlled.

TTCA: an R package for the identification of differentially expressed genes in time course microarray data.

Background: The analysis of microarray time series promises a deeper insight into the dynamics of the cellular response following stimulation. A common observation in this type of data is that some genes respond with quick, transient dynamics, while other genes change their expression slowly over time. The existing methods for detecting significant expression dynamics often fail when the expression dynamics show a large heterogeneity.

Identification of Cell Type-Specific Differences in Erythropoietin Receptor Signaling in Primary Erythroid and Lung Cancer Cells.

Lung cancer, with its most prevalent form non-small-cell lung carcinoma (NSCLC), is one of the leading causes of cancer-related deaths worldwide, and is commonly treated with chemotherapeutic drugs such as cisplatin. Lung cancer patients frequently suffer from chemotherapy-induced anemia, which can be treated with erythropoietin (EPO). However, studies have indicated that EPO not only promotes erythropoiesis in hematopoietic cells, but may also enhance survival of NSCLC cells.

Distinguishing Between Legally and Illegally Produced Gold in South Africa.

The identification of gold-bearing material is essential for combating the theft of gold in South Africa. Material seized in police operations is generally a mixture of gold from different mines, and as such cannot be traced back to a single location. ICP-OES analysis of material dissolved by acid dissolution provided a database of gold compositions comprising gold from South African mines, illegal gold stolen from the mines, and commercial gold alloys and jewelery.

Downregulation of the TGFβ Pseudoreceptor BAMBI in Non-Small Cell Lung Cancer Enhances TGFβ Signaling and Invasion.

Non-small cell lung cancer (NSCLC) is characterized by early metastasis and has the highest mortality rate among all solid tumors, with the majority of patients diagnosed at an advanced stage where curative therapeutic options are lacking. In this study, we identify a targetable mechanism involving TGFβ elevation that orchestrates tumor progression in this disease. Substantial activation of this pathway was detected in human lung cancer tissues with concomitant downregulation of BAMBI, a negative regulator of the TGFβ signaling pathway.

Proton uptake in the H(+)-SOFC cathode material Ba(0.5)Sr(0.5)Fe(0.8)Zn(0.2)O(3-δ): transition from hydration to hydrogenation with increasing oxygen partial pressure.

Thermogravimetric investigations on the perovskite Ba(0.5)Sr(0.5)Fe(0.

Erythropoietin improves the accumulation and therapeutic effects of carboplatin by enhancing tumor vascularization and perfusion.

Recombinant human erythropoietin (rhuEpo) is currently under debate for the treatment of chemotherapy-induced anemia due to clinical trials showing adverse effects in Epo-treated patients and the discovery of the erythropoietin-receptor (EpoR) in tumor and endothelial cells. Here, using Epo-Cy5.5 as theranostic near-infrared fluorescent probe we analyzed the effects of rhuEpo as co-medication to carboplatin in non-small-cell-lung-cancer (NSCLC)-xenografts with different tumor cell EpoR-expression (H838 ~8-fold higher than A549).

Proton conductivity in mixed-conducting BSFZ perovskite from thermogravimetric relaxation.

The proton conductivity of mixed hole-, oxygen ion- and proton-conducting Ba0.5Sr0.5Fe0.

Enhanced ionic conductivity in polycrystalline TiO2 by "one-dimensional doping".

The influence of line defects (dislocations) on the electrical properties of polycrystalline TiO2 was investigated. Line defects were created in TiO2 during spark plasma sintering at 1000 °C and 400 MPa. TEM characterisation indicates dislocations to be preferably oriented on {110} and {101} planes.

Electron and ion transport in Li2O2.

Bulk Li2O2 is shown to exhibit ionic conductivity via lithium vacancies and electronic conductivity via electron holes (localized as superoxide ions). This is the first systematic study on the charge carrier chemistry of peroxides with high relevance for the performance kinetics of Li-oxygen batteries.

Combined theoretical and experimental analysis of processes determining cathode performance in solid oxide fuel cells.

Solid oxide fuel cells (SOFC) are under intensive investigation since the 1980's as these devices open the way for ecologically clean direct conversion of the chemical energy into electricity, avoiding the efficiency limitation by Carnot's cycle for thermochemical conversion. However, the practical development of SOFC faces a number of unresolved fundamental problems, in particular concerning the kinetics of the electrode reactions, especially oxygen reduction reaction. We review recent experimental and theoretical achievements in the current understanding of the cathode performance by exploring and comparing mostly three materials: (La,Sr)MnO3 (LSM), (La,Sr)(Co,Fe)O3 (LSCF) and (Ba,Sr)(Co,Fe)O3 (BSCF).

Formation and migration of oxygen vacancies in La(1-x)Sr(x)Co(1-y)Fe(y)O(3-δ) perovskites: insight from ab initio calculations and comparison with Ba(1-x)Sr(x)Co(1-y)Fe(y)O(3-δ).

The formation and migration of oxygen vacancies in the series of (La,Sr)(Co,Fe)O(3-δ) perovskites, which can be used as mixed conducting SOFC cathode materials and oxygen permeation membranes, are explored in detail by means of first principles density functional calculations. Structure distortions, charge redistributions and transition state energies during the oxygen ion migration are obtained and analyzed. Both the overall chemical composition and vacancy formation energy are found to have only a small impact on the migration barrier; it is rather the local cation configuration which affects the barrier.

Measuring electrical properties of thin film fuel cell electrodes by in situ infrared spectroscopy.

The electrical conductivities of cathode films on a solid oxide fuel cell electrolyte can be determined quantitatively by in situ infrared spectroscopy over a wide range of temperatures and partial oxygen pressures. This method allows measurement of the electrical conductivity of an electrode film on the electrolyte excluding leakage current effects through the substrate.

Coordination polymers based on [Cp*Fe(η5-P5)]: solid-state structure and MAS NMR studies.

Slow diffusion reactions of the pentaphosphaferrocene [Cp*Fe(η(5)-P(5))] (Cp*=η(5)-C(5)Me(5) (1)) with CuX (X=Cl, Br, I) in different stoichiometric ratios and solvent mixtures result in the formation of one- and two-dimensional polymeric compounds 2-6 with molecular formula [{Cu(μ-X)}{Cp*Fe(μ(3),η(5):η(1):η(1)-P(5))}](n) (X=Cl (2a), I (2'c)), [{Cu(μ-I)}{Cp*Fe(μ(3),η(5):η(1):η(1)-P(5))}](n) (3), [{CuX}{Cp*Fe(μ(4),η(5):η(1):η(1):η(1)-P(5))}](n) (X=Cl (4a), Br (4b), I (4c), Br (4'b), I (4'c)), [{Cu(3)(μ-I)(2)(μ(3)-I)}{Cp*Fe(μ(5),η(5):η(1):η(1):η(1):η(1)-P(5))}](n) (5) and [{Cu(4)(μ-X)(4)(CH(3)CN)}{Cp*Fe(μ(7),η(5):η(2):η(1):η(1):η(1):η(1):η(1)-P(5))}](n) (X=Cl (6a), Br (6b)), respectively. The polymeric compounds have been characterised by single-crystal X-ray diffraction analyses and, for selected examples, by magic angle spinning (MAS) NMR spectroscopy. The solid-state structures demonstrate the versatile coordination modes of the cyclo-P(5) ligand of 1, extending from two to five coordinating phosphorus atoms in either σ or σ-and-π fashion.

Nonlinear electrical grain boundary properties in proton conducting Y-BaZrO3 supporting the space charge depletion model.

The overall proton conductivity of polycrystalline acceptor-doped BaZrO(3) is limited by the high resistivity of its grain boundaries. To investigate the nature of the electrical response of the grain boundaries as a function of the DC bias, Y-doped BaZrO(3) ceramics with a very large grain size (up to 200 μm) have been prepared in an infrared image furnace. The grains are so large that even individual grain boundaries can be addressed by microelectrodes.

Fast oxygen exchange kinetics of pore-free Bi(1-x)Sr(x)FeO(3-δ) thin films.

The oxygen incorporation/extraction kinetics of the potential solid oxide fuel cell (SOFC) cathode material Bi(1-x)Sr(x)FeO(3-δ) with x = 0.5 and 0.8 was studied by electrochemical impedance spectroscopy on geometrically well-defined pore-free thin film electrodes.

An alternate approach to improving healthcare worker influenza vaccination rates.

Optimizing employee influenza vaccination rates has become a healthcare focus. We detail an approach involving a strong requirement for unvaccinated workers to wear a face mask and a superconvenient vaccination process. Our major teaching hospital achieved 95% compliance in 2009, and our health system reached 90% and 92% compliance for 2 years.