Non-Intercepting Ion Phase Measuring Equipment of the Isochronous Cyclotrons at Karlsruhe and Julich

A non-intercepting ion phase measuring equipment is in use at the Karlsruhe cyclotron. Five phase signals, steadily and simultaneously displayed are presenting a good survey of phase width and phase distribution versus radius. High noise immunity is obtained by the use of differential electrostatic pickup probes. Concerning the Jülich cyclotron a similar device with twelve double electrostatic probes is in construction.     

Contribution of effluents from hospitals and private households to the total loads of diclofenac and carbamazepine in municipal sewage effluents--modeling versus measurements

The anti-epileptic drug carbamazepine and the non-steroidal anti-inflammatory drug diclofenac are frequently found as residues in the aquatic environment and also in samples of ground and drinking water. For both compounds, their loads occurring in the effluents from a military hospital and in the combined (household and hospital) sewage of a sewage pumping station (SPS) and a large municipal sewage treatment plant (STP) were predicted and measured within a field trial by collecting and analyzing defined composite samples over a time period of 1 week. The use of pharmacokinetic data and precise information on the administration of the individual medicinal formulation was found to be essential for the validity of the predicted data. The measured data confirmed the validity of the predicted loads with recoveries between 63 and 102% for carbamazepine and around 35% for diclofenac in the hospital wastewater. A comparison of the weekly loads predicted and measured in the influents and effluents of a STP in Berlin (Germany) yielded a very low removal rate for diclofenac (less than 15%) and a removal rate of up to 40% for carbamazepine. In total, 2.0 kg of carbamazepine per week (105 kg/a) and 4.4 kg of diclofenac per week (226 kg/a) were discharged into Berlin's surface water by the municipal STP, which treats both household sewage from approximately one million inhabitants and large amounts of hospital effluents (approximately 12,060 hospital beds).     

Gold nanoparticles quench fluorescence by phase induced radiative rate suppression

The fluorescence quantum yield of Cy5 molecules attached to gold nanoparticles via ssDNA spacers is measured for Cy5-nanoparticle distances between 2 and 16 nm. Different numbers of ssDNA per nanoparticle allow to fine-tune the distance. The change of the radiative and nonradiative molecular decay rates with distance is determined using time-resolved photoluminescence spectroscopy. Remarkably, the distance dependent quantum efficiency is almost exclusively governed by the radiative rate.     

Direct solution hybridization of guanidine thiocyanate-solubilized cells for quantitation of mRNAs in hepatocytes

The sensitivity of direct solution hybridization of hepatocytes solubilized in guanidium thiocyanate (GuSCN) for detecting alpha 1-acid glycoprotein and albumin mRNAs was studied. The sensitivity of detection was inversely correlated with the DNA concentration. Raising the hybridization temperature from 20 to 37 or 50 degrees C (with formamide) increased the hybridization efficiency three- to fourfold in cell lysates with a high DNA concentration (1 microgram/microliter), whereas the hybridization efficiency was already maximal at 20 degrees C in diluted samples. It was most important to normalize all hybridization reactions with an internal standard, such as sense mRNA, because of the great variation in hybridization efficiency from one cell preparation to another depending on the DNA concentration. Direct hybridization of GuSCN cell lysates labeled in vivo with [6-14C]orotic acid was more efficient than hybridizing equivalent amounts of purified [6-14C]-labeled RNA, perhaps because of greater mRNA integrity and/or better recoveries of mRNA in GuSCN cell lysates. Therefore, direct solution hybridization of GuSCN-solubilized hepatocytes, which avoids the problem of RNA purification, appears to be a rapid, sensitive, and reliable method for quantifying mRNA in hepatocytes.     

Interfacial Strain‐Induced Oxygen Disorder as the Cause of Enhanced Critical Current Density in Superconducting Thin Films

To understand the origin of the increase in critical current density of rare earth barium cuprate superconductor thin films with decreasing thickness, a series of sub‐300‐nm EuBa₂Cu₃O_7?δ thin films deposited on SrTiO₃ substrates are studied by X‐ray diffraction and electrical transport measurements. The out‐of‐plane crystallographic mosaic tilt and the out‐of‐plane microstrain both increase with decreasing film thickness. The calculated density of c‐axis threading dislocations matches the extent of the observed low‐field enhancement in critical current density for fields applied parallel to c. The in‐plane mosaic twist and in‐plane microstrain are both around twice the magnitude of the out‐of‐plane values, and both increase with decreasing film thickness. The results are consistent with the observed stronger field enhancement in critical current density for fields applied parallel to ab. The lattice parameter variation with thickness is not as expected from consideration of the biaxial strain with the substrate, indicative of in‐plane microstrain accommodation by oxygen disorder. Collectively, the results point to an enhancement of critical current by interfacial strain induced oxygen disorder which is greatest closest to the film‐substrate interface. The findings of this study have important implications for other thin functional oxide perovskite films and nanostructures where surface and interfacial strains dominate the properties.     

Charge Transfer Excitons in Polymer/Fullerene Blends: The Role of Morphology and Polymer Chain Conformation

Here, it is shown how carrier recombination through charge transfer excitons between conjugated polymers and fullerene molecules is mainly controlled by the intrachain conformation of the polymer, and to a limited extent by the mesoscopic morphology of the blend. This experimental result is obtained by combining near‐infrared photoluminescence spectroscopy and transmission electron microscopy, which are sensitive to charge transfer exciton emission and morphology, respectively. The photoluminescence intensity of the charge transfer exciton is correlated to the degree of intrachain order of the polymer, highlighting an important aspect for understanding and limiting carrier recombination in organic photovoltaics.