This work reports on combining current-voltage characteristics, electroluminescence (EL) measurements, and modeling to identify the selectivity of the electrodes in bulk-heterojunction organic solar cells. Devices with the same photoactive layer but different contact materials are compared and the impact of surface recombination at the contacts on their performance is determined. The open-circuit voltage, V OC , depends strongly on the selectivity of the electrodes and it is observed that the EL signal of cells with lower V OC is dramatically reduced. This is ascribed to an enhanced rate of surface recombination, which is a non-radiative recombination pathway and does therefore not contribute to the EL yield. In addition, these cells have a lower current in forward direction despite the fact that the surface recombination occurs in addition to the recombination in the bulk. A theoretical model was set up and in the corresponding numerical simulations all three fi ndings (lower V OC , strongly reduced EL signal and lower forward current) could be clearly reproduced by varying just one single parameter which determines the selectivity of the electrode.

To determine the prevalence of bacteremia caused by Bartonella henselae in domestic cats in the region of Freiburg, Germany, we investigated cultures of blood from 100 cats from 89 different households over a 12-month period. B. henselae could be isolated from 13% (13 of 100) of these cats. In eight households with two cats each and in one household with three cats, B. henselae bacteremia was found either in all of the animals or in none of the animals. Positive cultures were more likely to be found for female, young (24 months of age or younger) cats than for male or older cats. Identification of the Bartonella isolates was made by colony morphology, by Gram staining, biochemically by RapID ANA II or Rapid ID 32 A systems, and by whole-cell fatty acid analysis. Differentiation between B. henselae and Bartonella quintana was only possible by 16S rRNA sequencing, enterobacterial repetitive intergenic consensus (ERIC)-PCR, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Genomic fingerprinting of the B. henselae isolates by ERIC-PCR yielded two different patterns based on three distinct bands.

The synthesis of ionically functionalized branched polythiophenes with either carboxylic acid (anionic, P3T-COOH) or methylimidazolium (cationic, P3T-MIM) end groups is presented. Due to the large number of end groups present in the polymer, the functionalization has a major impact on the solubility of the polymers. In the case of P3T-COOH, the polymer shows a fully reversible phase transfer between organic solvents and water, depending on the pH. Remarkably, the ionic-liquid-modified polymer P3T-MIM is soluble in a room-temperature ionic liquid. The absorption properties are unaffected by the functional end groups.

Bartonella quintana was grown from a lysis-centrifugation blood culture of an HIV-positive man who presented with lesions of bacillary angiomatosis in skin and bones. The isolate was identified by sodium dodecylsulfate-polyacrylamide gel electrophoresis, 16S rRNA gene sequencing, and amplification of the enterobacterial repetitive intergenic consensus sequences.