Proton Microprobe Analysis in Biology

This paper is intended as an introduction to the field of proton microprobe analysis with special emphasis on applications in biological sciences. It is mainly intended for users of electron microscopes equipped with microprobes or other analytical equipment. The basic principles of Particle Induced X-ray Emission analysis are discussed as well as the instrumental requirements for the proton microprobe. The analytical characteristics including quantification procedures are compared with those of the electron microprobe and a review is given of various analytical applications of the proton microprobe within biology and medicine

Enhancing the optical excitation efficiency of a single self-assembled quantum dot with a plasmonic nanoantenna

We demonstrate how the controlled positioning of a plasmonic nanoparticle modifies the photoluminescence of a single epitaxial GaAs quantum dot. The antenna particle leads to an increase of the luminescence intensity by about a factor of eight. Spectrally and temporally resolved photoluminescence measurements prove an increase of the quantum dot's excitation rate. The combination of stable epitaxial quantum emitters and plasmonic nanostructures promises to be highly beneficial for nanoscience and quantum optics.Comment: 5 pages, 4 figure

Identification of functional p53-binding motifs in the mouse wig-1 promoter

AbstractWe previously identified wig-1 as a p53-induced mouse gene that encodes a nuclear zinc finger protein with unknown function. To investigate whether wig-1 is a direct target of p53-dependent transactivation, a DNA fragment corresponding to the promoter region was cloned and sequenced. Three regions containing consensus p53-binding sites were identified. Two p53-binding motifs formed DNA–protein complexes with p53 and were able to drive p53-dependent transcription in a luciferase reporter assay. Our results demonstrate that wig-1 is a direct target of p53-mediated transcriptional transactivation

NO formation during co-combustion of coal with two thermally treated biomasses

The combustion behavior of biomass as a fuel varies dependent on source of the raw material, but also on the type of pre-treatment. In this work steam exploded and torrefied woody biomass were studied with respect to NOx formation in co-firing experiments. Most of the reported data is based on small scale experiments and simulations. In this work, however, have three different cases been investigated experimentally in a 1.5MW(th) combustor supported by reaction simulations. One case corresponds to firing 100% Utah bituminous coal and two cases where 15% of the coal (on a mass basis) has been replaced with either torrefied or steam exploded biomass. Two of the cases was also studied in a utility scale 1.3 GW(th) industrial boiler. In both units did the case with pure coal result in the highest amount of NO formed, which was expected due to the higher amount of fuel-bound nitrogen in the coal, as compared to the biomass fuels. The fuel analyses indicate that the nitrogen content is the same in the two investigated biofuels. However, the amount of NO formed differed. Gas composition measurements reveal that the partitioning of volatile nitrogen species (HCN and NH3) varies between the biomass co-firing cases. This was investigated further using detailed reaction simulations and is suggested as the main reason for the observed difference in NO formation

Anomalous AMS radiocarbon ages for foraminifera from high-deposition-rate ocean sediments

Radiocarbon ages on handpicked foraminifera from deep-sea cores are revealing that areas of rapid sediment accumulation are in some cases subject to hiatuses, reworking and perhaps secondary calcite deposition. We present here an extreme example of the impacts of such disturbances. The message is that if precise chronologies or meaningful benthic planktic age differences are to be obtained, then it is essential to document the reliability of radiocarbon ages by making both comparisons between coexisting species of planktomc foraminifera and detailed down-core sequences of measurements

The p53 target protein Wig-1 binds hnRNP A2/B1 and RNA Helicase A via RNA

AbstractThe p53-induced Wig-1 gene encodes a double stranded RNA-binding zinc finger protein. We generated Saos-2 osteosarcoma cells expressing tetracycline-inducible Flag-tagged human Wig-1. Induction of Wig-1 expression by doxycycline inhibited cell growth in a long-term assay but did not cause any changes in cell cycle distribution nor increased fraction of apoptotic cells. Using co-immunoprecipitation and mass spectrometry, we identified two Wig-1-binding proteins, hnRNP A2/B1 and RNA Helicase A, both of which are involved in RNA processing. The binding was dependent on the presence of RNA. Our results establish a link between the p53 tumor suppressor and RNA processing via hnRNPA2/B1 and RNA Helicase A.Structured summaryMINT-6542926, MINT-6542899:WIG1 (uniprotkb:Q9HA38) physically interacts (MI:0218) with hnRNP A2/B1 (uniprotkb:P22626) by anti bait coimmunoprecipitation (MI:0006)MINT-6542945:RHA (uniprotkb:Q08211) physically interacts (MI:0218) with hnRNP A2/B1 (uniprotkb:P22626) by anti bait coimmunoprecipitation (MI:0006)MINT-6542918, MINT-6542891:WIG1 (uniprotkb:Q9HA38) physically interacts (MI:0218) with RHA (uniprotkb:Q08211) by anti bait coimmunoprecipitation (MI:0006)MINT-6542867:WIG1 (uniprotkb:Q9HA38) physically interacts (MI:0218) with RHA (uniprotkb:Q08211) by anti tag coimmunoprecipitation (MI:0007)MINT-6542879:WIG1 (uniprotkb:Q9HA38) physically interacts (MI:0218) with hnRNP A2/B1(uniprotkb:P22626) by anti tag coimmunoprecipitation (MI:0007