Projects in RUBION
Adsorption of model surfactants on subsoil samplesHuman Environmental Research - Stumpe, Institute of Geographie, Bergische Universität Wuppertal
Persistent organic pollutants (POPs) are known to have adverse effects on human health and the environment. Thus, an effective risk assessment with concern on POP adsorption potential in the soil compartment is of high interest. The objective of our study was to develop a reliable, rapid and low-cost method which is able to predict the adsorption of two model POPs, 4-n-nonylphenol (NP) and perfluorooctanoic acid (PFOA), in soil samples based on spectral information (MIR) and partial least-square analyses (PLSR). For the model development 96 top- as well as subsoils were used. To characterize the composition of the samples, they were analyzed for particle size distribution, manganese and iron oxide concentration, organic carbon content (SOC), pH and the soil surface area. The KD-values for NP and PFOA were calculated in batch experiments.
Auger-Electron Analysis of Oxide Layers on CopperNano- and Micromechanics, Max-Planck-Institut fuer Eisenforschung GmbH, MPG
Aim of this project is to (i) proof and (ii) quantify the thickness of possible oxide layers on Cu and CuAl systems. The experiments are planned within a large scale micromechanical investigation on dislocation nucleation at coherent twin boundaries, performed at the Max-Planck-Institut für Eisenforschung. So far, using nanoindentation, we have shown that grain boundaries might act as frequent sources of dislocations. However, to ultimately proof this we need to proof the absence of surface oxides.
Bacterial iron acquisitionApplied Microbiology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum
We investigate bacterial iron acquisition, the role of siderophores, and the role of ionophores.
Funded by: Deutsche Forschungsgemeinschaft
Bismuth donor Spins in Silicon for Quantum ComputingQuantronics, CEA Saclay, Université Paris-Saclay
Our research group is expert in Hybrid Quantum Devices where spins in solids are coupled to superconducting quantum circuits. We use these devices for quantum computing applications; in particular we develop spin-based quantum memories for microwave photons. For this application, we need implantation of Bismuth atoms in a silicon substrate. The Bismuth atoms when cooled at low temperature form donors, whose electron spin has a very long coherence time. Therefore, in this project, we will provide silicon substrates (isotopically enriched in the nuclear-spin-free Si28 isotope), and we request implantation of bismuth ions from Rubion.
Cell surface topography and diffusion in the plasma membraneIngela Parmryd, Biomedicine, University of Gothenburg
Cells are neither smooth nor flat and we have demonstrated that ignoring cell surface topography results in an overestimation of anomalous diffusion in the plasma membrane. To complement our simulations and fluorescence correlation spectroscopy studies, we collaborate with the group led by Patrick Happel to obtain high resolution topography maps of live cells using ion conductance microscopy.
Characterisation of Membrane ATPasesMolecular Biochemistry, Faculty of Chemistry and Biochemistry, Rhur University Bochum
ATPases are integral membrane proteins that play a pivotal role in cell homeostasis by pumping substrates as diverse as ions and lipids. Although several members of this group are well-studied, many molecular details involved in their working mechanism and regulation on the molecular level still remain unsolved. In combination with transporter mutants we expect to gain a molecular understanding of how ATP, pH, the ion concentration, and the lipid environment regulate these transporters.
Characterization of funcional coatingsAnalytical Chemistry — Biointerfaces, Faculty for Chemistry and Biochemistry, Ruhr-University Bochum
The chemistry of organic, functional coatings will quantitatively be analyzed. This concerns coatings prepared by grafting from as well as by grafting to approaches. Also polymer coatings with different crosslinking mechanisms will be investigated by element sensitive chemical analysis. The coatings are at a later stage tested in our research group regarding their low-fouling properties and the results from surface analysis will be correlated to protein attachment and biofouling assays.
Composition and density characterization of transition metal nitride filmsMEMS Materials, Institute for Materials, Ruhr University Bochum
The properties of transition metal nitrides (TM-N) strongly depend on their chemical composition (e.g. TM/N ratio) and density. Both, density and composition are affected by synthesis parameters (e.g. temperature, plasma properties). Transition metal nitrides were synthesized by magnetron sputtering using sets of different process parameters. Mechanical properties like Young’s modulus and hardness are determined by nano indentation and residual stress is evaluated by curvature method. The aim of the project is to identify relationships between synthesis parameters, composition and density and mechanical properties. The project is part of the collaborative research center SFB-TR 87.
Development of a Combined Stimulated Emission Depletion and Scanning Ion Conductance MicroscopeNanoscopy, RUBION, Ruhr-Universität Bochum
This project aims a combining a Stimulated Emission Depletion (STED) and a Scanning Ion Conductance Microscope (SICM) to allow simultaneous, correlated recording of the cellular topography and a protein distribution in living cells with diffraction-unlimited resolution.
Funded by: DFG
Development of STED and SICM instrumentsNanoscopy, RUBION, Ruhr-Universität Bochum
This long-term project aims at developing and optimizing our STED and SICM instrument.
Funded by: DFG
Differentiation of microbial activity between bulk soil and rhizosphere hot spots.Marschner, Geographical Institute, RUB
14C-labelled substrates or nutrients and combinations will be added to the moist soil samples after a 10-day pre-incubation period. The incubation will be conducted in a CarbO2Bot® instrument which allows temperature control and records CO2 evolution from the samples through changes in electric conductivity in an alkaline solution. After certain time intervals, the solution is replaced by a fresh one and the evolved 14CO2 is determined in a scintillation counter (Perkin Elmer Tri-Carb 2800 TR). In this way, the substrate-borne CO2 can be differentiated from the SOC-borne CO2 and priming effects are calculated by subtracting the CO2 evolved from an unsupplemented control sample (Hamer and Marschner 2005). Enzyme activities will be determined in soil suspensions to which fluorogenic substrates (MUF, AMC) are added in a 96 well microplate assay as described by Marx et al. (2001).
Diffusion of H bearing species in silicate glasses at low temperatures - development of a new experimental techniqueGroup of Hans-Werner Becker, RUBION, Ruhr-Universität Bochum
The transport of H in glasses at relatively low temperatures (below 200 °C) is relevant for a number of applications such as obisidian dating of archaeological artefacts, palaeoclimate studies, storage of high level nuclear waste and many more. We have developed several new experimental aspects, and in particular (a) the ability to produce H-bearing amorphous thin films to act as a source of H without the presence of free H2O, and (b) the ability to measure low concentrations of H, independent of the speciation, with a high spatial resolution on the nanometer scale. In this project it is intended to use these developments to explore the diffusion of H-bearing species at conditions that have been inaccessible so far. A specific goal is to characterize the compositional dependence of H-diffusion at these conditions and understand the change of diffusion mechanism that leads to a different behaviour from those observed at higher temperatures.
Funded by: DFG, DFG
Diffusion of hyrogen in nominally anhydrous mineralsGroup of Hans-Werner Becker, RUBION, Ruhr-Universität Bochum
The continuous improvement of analytical techniques led to the finding that minerals, which were once thought to be water-free (nominally anhydrous minerals), can indeed incorporate substantial amounts of water in their atomic structure. This observation changed fundamental aspects of our geodynamic models. The detection of water in minerals that are part of mantle xenoliths is one example. This information is interpreted to be evidence for a "wet mantle". To better understand the entity of the geologic water cycle in our earth it is necessary to quantify the transport rates of hydrogen in various phases in dependence of intensive variable (e.g. temperature). In this project we study the diffusion of hydrogen in minerals specifically at low temperatures using hydrogen implantation and NRRA.
Diffusion of Nitrogen in diamondNukleare Festkörperphysik, Felix-Boch Institut für Festkörperphysik, Universität Leipzig
The generation of NV centers in diamond is an essential task of quantum technology. NV centers can be used as qubits in quantum computers. For this task it is necessary to address single NVs and to generate them deterministically. The latter is not yet possible and should be the subject of this investigation. It should be clarified whether near-surface nitrogen diffuses. For this purpose, high-purity diamonds are irradiated with 15N, annealed at high temperature and investigated at the University of Munich with ERDA. A complimentary investigation with protons 15N(p,gamma) in Bochum would also be very helpful.
Effects of nutrient inputs on the carbon turnover of urban and remote forest soilsMarschner, Geographical Institute, RUB
14C-labelled substrates or nutrients and combinations will be added to the moist soil samples after a 7-day pre-incubation period. The incubation will be conducted in a CarbO2Bot® instrument which allows temperature control and records CO2 evolution from the samples through changes in electric conductivity in an alkaline solution. After certain time intervals, the solution is replaced by a fresh one and the evolved 14CO2 is determined in a scintillation counter (Perkin Elmer Tri-Carb 2800 TR). In this way, the substrate-borne CO2 can be differentiated from the SOC-borne CO2 and priming effects are calculated by subtracting the CO2 evolved from an unsupplemented control sample (Hamer and Marschner 2005). Enzyme activities will be determined in soil suspensions to which fluorogenic substrates (MUF, AMC) are added in a 96 well microplate assay as described by Marx et al.(2001).
Experimental Simulation of Solar Wind Implantation in Silicate MineralsElectron Microscopy Unit, Electron Microscopy Unit, Hamburg University of Technology
The surface of asteroids and planets, with no atmosphere and a strong magnetic field, in the Solar System (e.g. Moon, Mercury) is impacted by energetic (~1 keV/nucleon) solar wind ions. The solar wind consists of 95% protons, 2-4% He++, and the rest heavy ions. The interaction of ions with minerals, present on the surface of planets and asteroids, changes the structure and chemical composition of the upper few nanometers of the mineral surface and this leads to changes in the optical properties (UV, VNIR) of the material. Since optical spectroscopy is generally used to characterize the surface composition of solar system bodies, it is important to understand the mechanism and products of interaction between ions and minerals. Here, I propose to experimentally implant 40-60 keV Ar++ ions (Fluence: 1e16-1e18 ions/cm2) into thin slices of minerals (e.g. olivine, pyroxene) crystals and pressed powder pellets. After irradiation the samples will be studied using FIB and TEM.
Functional metal oxides for sensor applications (FunALD)Inorganic Materials Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum
Fabricating metal oxide based nanostructures for their application in gas phase sensors. The project covers precursor development and its evaluation for thin film deposition via thermal and plasma assisted atomic layer deposition
High energy implantation of group IV elements into diamondAG Becher, Natural science and technical departement, Saarland University
In order to produce group IV elements based colour centres in diamond, samples are prepared using high implantation energies. The aim is to have these centres situated deeply (>50nm) in the diamond to minimize the impact of charge fluctuations at the surface. The characterization afterwards is performed optically by looking at the homogeneity of different emitters emission wavelength and coherence properties.
High-energy-ion-implantationIon implantation for research and industry, RUBION / rubitec GmbH, Ruhr-Universität Bochum
In the department RUBION ion-beams, in the area of the industrial implantation, ion irradiations in the MeV range are carried out on behalf of customers in cooperation with our partner, the rubitec GmbH. There is a wide range of different ions available. The available energy and dose range depends on the respective species and the wafer size of our customers. The possibilities are determined by us depending on the application for each customer on request. In this field we are certified according to DIN EN ISO 9001: 2015 !
Hydrogen Dynamics in Elementary Reactions on Molybdenum sulfide and carbidePhysical Chemistry, FB 8, Westphalian University of Applied Sciences
Molybdenum Compunds, MoS2 and Mo(2)C are promising new catalysts for electrochemical applications, e.g. water electrolysers. It is planned to study several aspects of hydrogen dynamics in these materials using neutron scattering (ILL Grenoble), electrochemical spectroscopy (WH Recklinghausen) and nuclear reaction analysis (present proposal): hydrogen sorption, fast hydrogen diffusion under reaction conditions, hydrogen modes and substrate phonons as well as ortho-para-conversion of hydrogen on cold catalyst surfaces. Model systems of bulk materials, pure powder samples and electrochemical electrodes will be used. The expected results of these studies are diffusion parameters (binding sites, pathways, activation energies), and key parameters of structure and dynamics of the active surface. Since hydrogen sorption and the motion of several hydrogen species are involved, hydrogen concentrations profiles are required for the full interpretation of the neutron scattering results.
Funded by: Institut Laue-Langevin, Doktorandenstipendium
Hydrogen quantification in ALD-ZnO grown by deuterated precursorsPhotovoltaics, Research School of Engineering, Australian National University (ANU)
ZnO thin films grown by atomic layer deposition (ALD) are intrinsically highly conductive although no intentional dopants are added. ALD-ZnO is an In-free transparent conductive oxides (TCO) and can be used in optoelectronic devices. It was also recently proposed as carrier-selective passivating contact for silicon solar cells. For bulk ZnO crystals both intrinsic point defects and hydrogen were proposed to explain the conductivity. However, ALD-ZnO is orders of magnitude more conductive and the reason for which is not yet fully understood. Previously, we quantified the total amount of hydrogen in the highly conductive ALD-ZnO thin films via nuclear reaction analysis (NRA) at RUBION to be ~1 at% [J. Appl. Phys. 122, 025306 (2017)]. Since both of the ALD-precursors that are used to deposit ZnO (diethylzinc and water) contain hydrogen, it is unknown which of them provides the majority of the incorporated hydrogen that is likely to cause the high conductivity. Therefore, we use light water (H2O) and heavy water
Implantation of hydrogen in olivine (Yale University, Group Shun-ichiro Karato)Group of Hans-Werner Becker, RUBION, Ruhr-Universität Bochum
Space weathering involves solar wind implantation of elements, such as hydrogen, in planetary materials. Thus, it is crucial to study this process in order to evaluate its impact on the hydrogen budget of planetary bodies. We implant different amounts of hydrogen (fluences) in olivine at different energies to study at which fluence hydrogen saturation in this mineral is attained. This project is a collaboration with Shun-ichiro Karato, Jiang Zhenting, and Qinting Jiang of the Yale University.
Implantation of Ni ions in diamond to create novel defect centersUltrafast Quantum Optics and Optical Metrology, Clarendon Laboratory, University of Oxford
In this project we would like to implant Ni into ultrapure as well as p-doped synthetic diamonds to create a class of inversion-symmetric Ni defects, the nickel vacancy center (NiV), which so far hasn't been studied in great detail. Theoretical investigations and preliminary experiments suggest that the NiV could offer electronic properties excelling those of the known color centers such as NV and SiV and the defects might therefore be of great interest for quantum technologies. We will use the samples fabricated at RUBION to perform optical spectrocopy experiments at high-resolution to validate the theoretically predicted electronic structure of the defect on an ensemble and single-defect level.
In-depth practical »Superresolution microscopy« for bachelor students of BiochemistryNanoscopy, RUBION, Ruhr-Universität Bochum
Every winter term
Interactions between microbial activities and hierarchical aggregation in soil carbon and nutrient retention.Marschner, Geographical Institute, RUB
Interactions between microbial activities and hierarchical aggregation in soil carbon and nutrient retention: analysis of organic fertilization practices for sustainable production of vegetable crops in West-Africa I intend to carry out a 18-week incubation experiment with 220 bulk/aggregate soil samples using a temperature controlled respirometer which automatically records carbondioxide evolution from the samples through changes in electrical conductivity in an alkaline solution.
Investigating the composition of perovskite layers applied into electroluminescent devices such as lasers, and LEDsRiedl Group, Chair of Electronic Devices, University of Wuppertal
The work includes material development and structural Layering of perovskite for electroluminescence and laser applications. Different layer formation procedures such as pure liquid phase processes, pure vacuum deposition, as well as hybrid deposition processes are demonstrated. The work aims to study and optimize luminescence quantum efficiency and optical amplification and to understand the relationship between composition / structure and optical amplification. And then, selected materials are integrated into electroluminescent devices.
Measurement of alpha-induced reaction cross section on Ru-isotopesZilges, Institute for Nuclear Physics, University of Cologne
One major nuclear-physics uncertainty for the prediction of branching points in the γ-process reaction network is the α+nucleus optical model potential at sub-Coulomb energies. To improve the scarce experimental database of α-induced reaction cross sections, our group is interested in measuring the (α,γ) cross sections on ruthenium isotopes via the 4π-summing method at RUBION. We plan to measure the cross section at alpha energies from 12 MeV down to ca. 7 MeV.
MnSb Nano clusters on GaAsSurface Science, Experimental Physics IV, Ruhr-University Bochum
MnSb is a promising candidate for efficient spin injection into GaAs structures, which has a high Curie temperature and is compatible with the III-V lattice structure. The influence of different growth parameters on the formation of nanoclusters and their properties such as size, shape, density and magnetic behavior will be investigated. The aim of the project is to use RBS to investigate the influence of growth parameters on the chemical composition of nanostructures.
NRRA analysis of hydrogen in natural garnet samples as a calibration for FTIR spectroscopy (University Bern, Group Jörg Hermann)Group of Hans-Werner Becker, RUBION, Ruhr-Universität Bochum
Fourier Transform Infrared (FTIR) Spectroscopy is a frequently used technique for measuring water species in geological materials. However, the method has to be calibrated for each type of mineral or glass. We use the "standard-free" NRRA technique to analyse hydrogen depth profiles, which can then be used to calibrate methods such as FTIR or SIMS. This project is a collaboration with Prof. Jörg Hermann and Julien Reynes of the Geological Department of the University Bern.
Ouabain binding study on cell cultures from the central nervous systemElectrobiochemistry of Neural Cells, Department of Biochemistry II, Ruhr-Universität Bochum
In the course of this project cell cultures will be obtained from postnatal rats. These cultures primarily composed of neurons and astrocytes will be treated with growth factors or other proteins and factors that are capable of modulating neuronal excitability. Our aim is to test the hypothesis that an increased excitability in neurons also leads to an upregulated expression of Na+/K+-ATPase. We use Tritium-labeled ouabain which selectively binds to the Na+/K+-ATPase to determine the density of this enzyme in the cell membrane.
Partially fluorinated metal oxide filmsProf. Stephan Schulz, Inorganic Chemistry, University of Duisburg-Essen
We are currently investigating the deposition of metal oxide thin films by chemical vapor deposition processes (CVD) using partially fluorinated metal acetylacetonate complexes. We are particularly interested in the relationship between the degree of fluorination of the precursor complex and the degree of F-doping of the resulting metal oxide filmt (CoO and Co3O4). A correlation was already confirmed by TOF-SIMS but couldn't be quantifized. For quantification of the F-doping as well as the metal-to-oxygen relation and to further investigate the degree of N-doping from the precursor awe are intersted in RBS and DNRA measurements.
Practical course on radioligand binding assayRadioligand-Assay, Deptartment of Animal Physiology, Ruhr-Universität Bochum
As a part of the advanced module "Gene, Cell, Organism" students practice the characterization of intracellular steroid hormone receptors in tissue samples of vertebrates.
Prekursor incorporation experimentsApplied Microbiology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum
Using radiolabeled precursors in incorporation experiments, we analyze the antibacterial mechanism of action.
Funded by: BMBF, NIH
Producing Ti-bearing quartz by ion-implantation for use as secondary standard in electron microprobe analysisDiffusion in Minerals and Melts, Institut fuer Geologie, Mineralogie und Geophysik, Ruhr Universitaet Bochum
The amount of Ti incorporated in quartz (SiO2) is dependent on the temperature of formation. Therefore, Ti in quartz from natural rocks can be used as a geothermometer. Electron microprobe analysis can be used to quantify the amount of Ti in quartz, but as a low accuracy of such measurements would result in erroneous temperature estimates, secondary quartz standards with known Ti contents are needed. Such standards do not yet exist. This project is aimed at producing six standards with defined Ti content (10 μg g-1, 50 μg g-1, 100 μg g-1, 250 μg g-1, 500 μg g-1, and 1000 μg g-1) by means of ion implantation. Rutherford Backscattering Spectrometry should be used for chemical depth profiling before homogenizing the newly produced materials by heating. Finally, these secondary standard materials will be used for data verification during microprobe measurements of high-temperature metamorphic rocks.
Proteomic response of bacteriaApplied Microbiology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum
We use pulse-labeling to investigate the proteins newly synthesized in response to stress, e.g. antibiotic treatment.
Funded by: BMBF, Deutsche Forschungsgemeinschaft, National Institutes of Health, EFRE, Investing in your future, NRW, DAAD
Qualitative and quantitative analysis of major and trace elements by PIXEParticle Induced X-ray Emission (PIXE), RUBION, Ruhr University Bochum
PIXE technique is applied for the qualitative and quantitative analysis of major and trace elements in various kinds of samples, such as in minerals, glasses, alloys etc. The concentrations of elements from Si up to U can be determined in samples of different structures, i.e. in homogeneous thin or thick samples, as well as in layered ones. The sensitivity of PIXE can reach levels of the order of a few parts per million (ppm).
Quantification of Oxygen, Vanadium and Dopants (M) in V-M-O thin film librariesMEMS Materials, Institute for Materials, Ruhr University Bochum
VO2 is of interest due to its Semiconductor-to-Metal phase transition. Elmental addition can modulate the transition properties of VO2. To systematically study the effect of elemental doping, V-M-O thin film libraries with continuous composition spread are fabricated by magnetron reactive co-sputtering. The concentration of dopant (M) will be determined by Rutherford backscattering spectrometry (RBS). In addition, it has been reported that the stoichiometry of VOx, e.g., the ratio of oxygen to the metals, can also influence the transition properties. To estimate the amount of oxygen, Nuclear reaction analysis (NRA) will be performed on the libraries.
Rare-earth-based single photon sources for quantum telecommunicationRare Earths, 3rd Institute of Physics, University of Stuttgart
The project aims at the realization of single photon sources in the telecom wavelength regime, based on single rare-earth ions (like erbium or ytterbium) precisely doped into optical crystals by means of ion implantation (up to 200nm below the surface). The main advantage of the proposed single photon sources are their true single photon emission, their fourier-limited linewidth and the ability to store emitted photons directly in a medium based on rare-earth ions (straight forward interfacing). The typically low fluorescent signal of single erbium/ytterbium ions can be boosted by orders of magnitude through coupling them to optical resonators (fabricated from thin film lithium niobate) with high Q factors. The single photon source behaviour will be assessed by the indistinguishability of the emitted photons in a Hong-Ou-Mandel experiment.
Funded by: European Commission
RBS measurements to identify the composition and thickness of targets for accelerator experimentsZilges, Institute for Nuclear Physics, University of Cologne
At the Tandem Accelerator Laboratory of the University of Cologne experiments ar performed in the fields of Nuclear Structure and Nuclear Astrophysics. For the data analysis it is mandatory to know the exact composition and thickness of the targets. From previous measurements we know that the RBS setup ab RUBION is ideally suited for such studies.
Surface chemical characterization of ALD and CVD deposited thin filmsInorganic Materials Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum
This project supports the other ongoing RUBION-projects of RUB's IMC group. Complementary to the RBS/NRA project, selected thin films are subjected to XPS and AES analysis to gain insights into their surface chemical composition.
Thermography for the detection of soil propertiesHuman Environmental Research - Stumpe, Institute of Geographie, Bergische Universität Wuppertal
Spatio-temporal analyses of soil properties are important for more profound insights into soil processes. Up to now, non-invasive approaches analyzing physical and biological soil properties and dynamics at the microscale are not available due to methodological, instrumental, and analytical challenges. In this study, we evaluate the use of active and passive infrared thermography (IRT), a non-invasive and non-contact technique, for the detection of surface temperature-based parameters on soil surfaces. The potential and possibilities of IRT were analyzed with a focus on the detection and calibration of soil moisture using active IRT and the determination of microbial activity using passive IRT. A pool of 51 soil samples was used to cover a wide range of chemical, physical, and biological soil properties. The samples were rewetted to 16 different moisture contents, filled into vessels, and placed in an air-proof glove box with an adjusted relative humidity of about 92% to reduce soil drying. Immediately after
Thin-film refractory metamaterials for ThermophotovoltaikThin-film technology, Institute of Materials Research, Helmholtz-Zentrum Geesthacht
Thin film refractory metamaterials for high-temperature application are prepared by magnetron sputtering and characterized by non-ambient x-ray diffraction. An interesting candidate is a multilayered structure of metallic tungsten and dielectric hafnia. During annealing we observed structural changes of the obtained phases which require a confirmation with further methods. It is planned to carry out RBS and XPS measurements of three different sub-units (3-layer-stacks: as prepared and after two different annealing temperatures).
Transport and insertion mechanisms of plastid-encoded thylakoid membrane proteinsMolecular biology of plant organelles, Faculty of Biology and Biotechnology, Ruhr-University Bochum
The biogenesis of photosynthetic protein complexes of the chloroplast thylakoid membrane requires highly specific protein sorting, integration and assembly mechanisms of nucleus as well as plastid encoded subunits. Central steps in the biogenesis of photosystem II (PS II) are the cotranslational insertion of the plastid encoded D1 protein into the thylakoid membrane and its subsequent assembly into functional PS II. We recently established a technique to partially reconstitute the cotranslational insertion of [35S]-D1 using a homologous in vitro translation system derived from pea chloroplasts. The aims of this proposal are (I) to identify novel components involved in cotranslational protein insertion in thylakoid membranes, (II) to dissect the protein contacts of the nascent D1 chain during translation and insertion and (III) to get insight into the mechanisms underlying targeting and attachment of ribosome-nascent chain complexes to the thylakoid membrane.
Funded by: Deutsche Forschungsgemeinschaft
Uptake, efflux and conversion of radiolabelled substrates by cells and plant organsMolecular Genetics and Physiology of Plants, Molecular Genetics and Physiology of Plants, Ruhr University Bochum
We will quantify uptake rates of radioisotopes of various mineral nutrients and/or their toxic analogues into roots of Arabidopsis or into plant gene-expressing cells. We will measure the incorporation of radiolabelled organic and inorganic substrates into endogenous metabolites and/or macromolecules of plant cells, organs and/or cells of heterologous expression systems. We will localize various elements of interest in sections of plant tissues by imaging using Particle Induced X-Ray Emission (PIXE) combined with Rutherford Backscattering Spectrometry (RBS) comparatively between wild type and mutant/transgenic plants. We will conduct live cell imaging of plant cells expressing suitably marker proteins using the Olympus IX 81 live cell imaging microscope with the goal of determining protein localization and its dynamics. It is possible that it might be necessary to apply STED super-resolution fluorescence imaging to answer our research questions.
Using infrastructure of the Bandow labApplied Microbiology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum
This "project" covers a conglomerate of activities that entail the use of infrastructure of the Bandow lab that is located at RUBION, but does not entail work with unstable isotopes.
ZnSe-based II-VI crystals implanted with Transition Metals (TM)Preparation of mixed/doped crystals of AII-BVI, INSTITUTE OF PHYSICS, Nicolaus Copernicus University in Torun
II-VI compound forms predominantly cubic crystallographic structures. Ternary compound with a different atomic ration of magnesium, manganese and beryllium gives us the opportunity to change compound bandgap and lattice constant. Sets of (Zn,Mg)Se (Mg at.% ~5%) and (Zn,Mn,Be)Se (Mn at.% ~5%, Be at.% ~5%) crystals grown by modified Bridgman-Stockbarger method can be implanted with transition metals (TM) elements to check the influence of the crystal field of host material to energy levels of d-electrons. Additionally, optical constants (refractive index, extinction coefficient) can be modified selectively when implanted with TM due to split in spectroscopic terms. Chemical composition of obtained samples can be checked with XPS and PIXE methods. Host damage caused by ions implantation and electrical properties of implanted II-VI crystals are also important concerns.