Massive catheter‐related thrombosis of vena cava superior protruding into the right atrium in a hemodialysis patient

A 36‐year‐old man with chronic renal insufficiency secondary to type 1 diabetes mellitus was on hemodialysis via central venous catheter (CVC), newly placed into the right subclavian vein after his arteriovenous fistula became dysfunctional. Seven days after CVC insertion, the patient developed fever and on day 11 echocardiography showed a large nearly occluding thrombus in the superior vena cava (SVC) extending into the right atrium (RA). Emergency surgical thrombectomy was successfully performed and an 11 cm long thrombus extending from the RA cranially into the SVC occupying majority of the vein's lumen was removed. Cultures from the thrombus and CVC were negative, but polymerase chain reaction was positive for Staphylococcus aureus. This particular case was interesting for a marked discrepancy between large SVC occluding thrombosis and a relatively mild clinical presentation with fever, and it highlights the importance of correct timing of echocardiography exam which might prevent potentially fatal consequences such as pulmonary embolism.     

Effect of fungal hyphae on the access of bacteria to phenanthrene in soil

The effect of fungal hyphae on the mobilization of soil-dwelling bacteria and their access to hydrophobic phenanthrene in soil was tested in columns containing air-filled agricultural soil. The experimental design included a spatial separation between zones of bacterial inoculation and contamination. Motile Pseudomonas putida PpG7 (NAH7) and fast-growing, hydrophilic Pythium ultimum were used as the model phenanthrene-degrading and vector organisms, respectively. Efficient translocation of strain PpG7 in the range of centimetres in presence of P. ultimum indicated that the fungal mycelia bridged air-filled pores and thereby provided a continuous network of water-paths that enabled bacteria to spread in the soil. Biodegradation of the soil-associated phenanthrene was found only in the presence of the fungal mycelia, hence proving that the fungal network facilitated the access of the bacteria to the contaminant. Our data suggest that the specific stimulation of indigenous fungi is a promising method to mobilize pollutant degrading bacteria and thereby improve soil bioremediation in-situ.     

Nanoimprint lithography for high-efficiency thin-film silicon solar cells

We demonstrate high-efficiency thin-film silicon solar cells with transparent nanotextured front electrodes fabricated via ultraviolet nanoimprint lithography on glass substrates. By replicating the morphology of state-of-the-art nanotextured zinc oxide front electrodes known for their exceptional light trapping properties, conversion efficiencies of up to 12.0% are achieved for micromorph tandem junction cells. Excellent light incoupling results in a remarkable summed short-circuit current density of 25.9 mA/cm(2) for amorphous top cell and microcrystalline bottom cell thicknesses of only 250 and 1100 nm, respectively. As efforts to maximize light harvesting continue, our study validates nanoimprinting as a versatile tool to investigate nanophotonic effects of a large variety of nanostructures directly on device performance.     

The effect of feed demand on greenhouse gas emissions and farm profitability for organic and conventional dairy farms

The reduction of product-related greenhouse gas (GHG) emissions in milk production appears to be necessary. The reduction of emissions on an individual farm might be highly accepted by farm owners if it were accompanied by an increase in profitability. Using life cycle assessments to determine the product carbon footprints (PCF) and farm-level evaluations to record profitability, we explored opportunities for optimization based on analysis of 81 organic and conventional pasture-based dairy farms in southern Germany. The objective of the present study was to detect common determining factors for low PCF and high management incomes (MI) to achieve GHG reductions at the lowest possible operational cost. In our sample, organic farms, which performed economically better than conventional farms, produced PCF that were significantly higher than those produced by conventional farms [1.61 ± 0.29 vs. 1.45 ± 0.28 kg of CO₂ equivalents (CO₂eq) per kg of milk; means ± SD)]. A multiple linear regression analysis of the sample demonstrated that low feed demand per kilogram of milk, high grassland yield, and low forage area requirements per cow are the main factors that decrease PCF. These factors are also useful for improving a farm's profitability in principle. For organic farms, a reduction of feed demand of 100 g/kg of milk resulted in a PCF reduction of 105 g of CO₂eq/kg of milk and an increase in MI of approximately 2.1 euro cents (c)/kg of milk. For conventional farms, a decrease of feed demand of 100 g/kg of milk corresponded to a reduction in PCF of 117 g of CO₂eq/kg of milk and an increase in MI of approximately 3.1 c/kg of milk. Accordingly, farmers could achieve higher profits while reducing GHG emissions. Improved education and training of farmers and consultants regarding GHG mitigation and farm profitability appear to be the best methods of improving efficiency under traditional and organic farming practices.     

COSMO-CAMPED – Solvent Design for an Extraction Distillation Considering Molecular,Process, Equipment,and Economic Optimization

For an extraction process to be economically feasible, selecting a suitable solvent is imperative. This work extends the computer-aided molecular and process design (CAMPD) framework COSMO-CAMPD for solvent design in an extraction-distillation process by replacing a pinch-based process model with a hybrid, rate-based extraction-distillation process model. The resulting CAMPD framework is able to evaluate solvent candidates by investment costs in addition to operating costs in a fully predictive manner. In a case study for purifying acetone, we show that our framework's guided exploration of a vast design space yields solvents with superior performance compared to a benchmark solvent from the literature.     

Influence of Ni and Cr impurities on the electronic properties of Cu(In,Ga)Se2 thin film solar cells

Deposition of Cu(In,Ga)Se₂ (CIGS) thin film solar cells on metallic substrate is an attractive approach for development of low cost solar modules. However, in such devices, special care has to be taken to avoid diffusion of impurities, such as Fe, Ni, and Cr, from the substrate into the active layers. In this work, the influence of Ni and Cr impurities on the electronic properties of CIGS thin film solar cells is investigated in detail. Impurities were introduced into the CIGS layer by diffusion during the CIGS deposition process from a Ni or Cr precursor layer below the Mo electrical back contact. A high temperature and a low temperature CIGS deposition process were applied in order to correlate the changes in the photovoltaic parameters with the amount of impurities diffused into the absorber layer. Solar cells with Ni and Cr impurities show a reduction in the device performance, whereas the effect was most pronounced in Ni containing devices. The presence of deep defect levels in the absorber layer was identified with admittance spectroscopy and can be related to Ni and Cr impurities, which diffused into the CIGS layer according to secondary ion mass spectroscopy depth profiles and inductively coupled plasma mass spectrometry. Copyright © 2014 John Wiley & Sons, Ltd.     

Molecular Beam Epitaxial Growth and Properties of Bi2Se3 Topological Insulator Layers on Different Substrate Surfaces

Growth of high-quality Bi₂Se₃ films is crucial not only for study of topological insulators but also for manufacture of technologically important materials. We report a study of the heteroepitaxy of single-crystal Bi₂Se₃ thin films grown on GaAs and InP substrates by use of molecular beam epitaxy. Surface topography, crystal structure, and electrical transport properties of these Bi₂Se₃ epitaxial films are indicative of highly c-axis oriented films with atomically sharp interfaces.     

Quaternary ammonium salts ionic liquids for immobilization of chiral Ru-BINAP complexes in asymmetric hydrogenation of β-ketoesters

Chiral catalytic complex (R)—[RuCl(binap)(p-cymene)]Cl was used in asymmetric hydrogenation of methyl acetoacetate to methyl-3-hydroxybutyrate in the mixed methanol-ionic liquid phase. Quaternary ammonium salts ionic liquids, namely n-alkyl-triethylammonium bis(trifluoromethane sulfonyl) imides (N_R222Tf₂N, R = 6, 7, 8, 10, 12, 14), were prepared and employed in this transformation. Enough evidence was provided that only a small amount of this type of IL in a conventional solvent was necessary to accommodate the catalytic complex and that the reaction could be carried out with very high enantioselectivity. Similarly it was proved that under optimized conditions the catalytic complex immobilized in this manner could be used repeatedly. A part of the work was focused on the role of the alkyl chain length in the N_R222Tf₂N ionic liquid which was found as very essential. Role of the reaction impurities with origin in the synthesis of the employed ILs was also investigated.