Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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31742 Publications
[18F]Fluoracetat: Vom Gift zum PET-Tracer [18F]Fluoroacetate: From toxin to PET-tracer
Bergmann, R.; Richter, S.; Pietzsch, J.; Wüst, F.;
kein Abstract verfügbar
  • Contribution to HZDR-Annual report
    Wissenschaftlich-Technische Berichte / Forschungszentrum Dresden-Rossendorf; FZD-469 April 2007, 36-38

Downloads:

Publ.-Id: 10128 - Permalink


Radioaktive Metalle für die Tumortherapie
Pietzsch, H.-J.; Stephan, H.; Steinbach, J.;
kein Abstract verfügbar
  • Contribution to HZDR-Annual report
    Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-451 März 2006, 19-22

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Publ.-Id: 10127 - Permalink


PET-Bilder – scharf gemacht
Bühler, P.; Just, U.; Möckel, D.; Langner, J.; van den Hoff, J.;
kein Abstract verfügbar
  • Contribution to HZDR-Annual report
    Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-421 März 2005, 20-21

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Publ.-Id: 10126 - Permalink


Strain profile of (001) silicon implanted with nitrogen by plasma immersion
Diaz, B.; Abramof, E.; Castro, R. M.; Ueda, M.; Reuther, H.;
In this work, we investigate the strain and defect state of silicon implanted with nitrogen by plasma immersion ion implantation, with doses between 4.5 1016 and 8.7 1016 cm 2. For this purpose, we have used Auger electron spectroscopy, x-ray reflectivity, and high-resolution x-ray diffraction. Auger spectra showed that nitrogen concentration profiles broaden and shift deeper into the substrate as the dose increases. High oxygen concentration in the first 20 nm suggested the presence of an amorphous oxide layer at the sample surface, which was confirmed by x-ray reflectivity measurements. Reciprocal space maps revealed a tensile strain perpendicular to the surface, while no in-plane strain was detected. Since no significant diffuse scattering was found, randomly distributed point defects must be predominant in the strained region compared to large displacement field defects such as clusters and dislocations. 2 scans around (004) Bragg reflection were fitted using dynamical theory of x-ray diffraction. The strain profiles obtained from the best fits correlated well with nitrogen concentration depth profiles, signaling interstitial nitrogen as the main source of strain.
  • Journal of Applied Physics 101(2007), 103523

Publ.-Id: 10125 - Permalink


Vom Radioiod zum molekularen Imaging: Potential und Grenzen der Radiopharmazie
Steinbach, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Fachforum der Hanns-Seidel-Stiftung, 27.-29.10.2006, Kolster Banz, Germany

Publ.-Id: 10124 - Permalink


Radiopharmaceutical research at Saxony - an overview
Steinbach, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    General Electric Meeting, 30.09.2006, Dresden, Germany

Publ.-Id: 10123 - Permalink


A short overview to radiopharmaceutical research at Saxony (Germany)
Steinbach, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Fa. Esteve (Laboratorios del Dr. Esteve, S.A.), 09.06.2006, Barcelona, Spain

Publ.-Id: 10122 - Permalink


Potential, limitations and application of organic PET- radiochemistry
Steinbach, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Fa. Esteve (Laboratorios del Dr. Esteve, S.A.), 09.06.2006, Barcelona, Spain

Publ.-Id: 10121 - Permalink


Wissenschaftliche und organisatorische Perspektiven des Instituts für Bioanorganische und Radiopharmazeutische Chemie beim Übergang zum Institut für Radiopharmazie
Steinbach, J.;
kein Abstract verfügbar
  • Lecture (others)
    Alumni-Treff des Instituts für Bioanorganische und Radiopharmazeutische Chemie, 02.-03.12.2005, Gohrisch, Germand

Publ.-Id: 10120 - Permalink


Entwicklung hochtemperaturstabiler Kontakte auf SiC
Weishart, H.; Heera, V.;
  • Lecture (others)
    3. NanoHoch-Projekttreffen in Dresden, 25.05.2007, Dresden, Germany

Publ.-Id: 10119 - Permalink


Magnetic patterning by means of ion irradiation and implantation
Fassbender, J.ORC; McCord, J.
A pure magnetic patterning by means of ion irradiation which relies on a local modification of the magnetic anisotropy of a magnetic multilayer structure has been first demonstrated in 1998. Since then also other magnetic properties like the interlayer exchange coupling, the exchange bias effect, the magnetic damping behavior and the saturation magnetization to name a few have also been demonstrated to be affected by ion irradiation or ion implantation. Consequently, all these effects can be used if combined with a masking technique or employing direct focused ion beam writing for a magnetic patterning and thus an imprinting of an artificial magnetic domain structure, which subsequently modifies the integral magnetization reversal behavior or the magnetization dynamics of the film investigated. The present review will summarize how ion irradiation and implantation can affect the magnetic properties by means of structural modifications. The main part will cover the present status with respect to the pure magnetic patterning of micro- and nanostructures.
Keywords: magnetism, patterning, ion irradiation, ion implantation

Publ.-Id: 10118 - Permalink


Properties of unflattened photon beams shaped by a multi leaf collimator
Pönisch, F.;
  • Poster
    AAPM Konferenz, 01.06.2006, Orlando, USA

Publ.-Id: 10116 - Permalink


Entwicklung eines Verfahrens zur Korrektur der Atembewegung in der Positronen-Emissions-Tomographie (PET)
Möckel, D.;
  • Lecture (others)
    Seminarvortrag Martin-Luther-Universität, 01.10.2004, Halle-Wittenberg, Dtl.

Publ.-Id: 10115 - Permalink


Design Criteria for an In-beam PET
Enghardt, W.;
  • Invited lecture (Conferences)
    Scientific Workshop for In-beam PET, 09.-10.05.2006, Dresden, Deutschland

Publ.-Id: 10114 - Permalink


Mikro-spill extraction
Crespo, P.;
  • Invited lecture (Conferences)
    Scientific Workshop for In-beam PET, 09.-10.05.2006, Dresden, Dtl.

Publ.-Id: 10113 - Permalink


Study of graded Ni-Ti Shape Memory Alloy film growth on Si(100) substrate
Martins, R. M. S.; Mücklich, A.; Reuther, H.; Beckers, M.; Schell, N.; Silva, R. J. C.; Pereira, L.; Braz Fernandes, F. M.;
In-situ x-ray diffraction (XRD) was employed to study the effect of the deliberate change of the ratio Ti/Ni during the deposition of Ni-Ti films. Thus, graded films were deposited exhibiting distinctive composition and crystalline structure along the growth direction. The as-sputtered films were ex-situ characterized by Auger Electron Spectroscopy (AES), Cross-sectional Transmission Electron Microscopy (XTEM), and Electrical Resistivity (ER) measurements (during thermal cycling). In this paper results are presented concerning a film with a Ti-rich composition in the central part and near-equiatomic composition in the extremities, following 4 distinct deposition periods (different Ti target powers). During the initial deposition step (near-equiatomic composition) the Ni-Ti B2 phase starts by stacking onto (h00) planes on the naturally oxidized Si(100) substrate due to the presence of the native Si oxide (2-3 nm). The increase of the power of the Ti target in the second and third steps induced the precipitation of Ti2Ni. When stopping the Ti co-sputtering, Ti2Ni “dissolves” and, thus, plays the role of a reservoir for the formation of B2 phase now preferentially stacking onto (110) with the system approaching again the equiatomic composition. The ex-situ study of the interface’s morphology has shown the presence of NiSi2 silicides (A-NiSi2 and B-NiSi2), Ti4Ni4Si7, Ti2Ni and a non-identified phase constituted by Ni, Ti and Si, most likely amorphous. During thermal cycling, electrical resistivity measurements revealed phase transitions associated with the B2, R-phase and B19’ phases. This type of studies allow the identification of intermediate states during deposition and annealing, and the correlation with the final structure of the film, being useful for the optimisation of the deposition parameters in order to fabricate films with a two-way reversible actuation.
Keywords: Ni-Ti thin films; Co-sputtering deposition; In-situ x-ray diffraction; Texture development; Interfacial diffusion
  • Applied Physics A 91(2008)2, 291-299

Publ.-Id: 10112 - Permalink


COVERS WP4 Benchmark 1 Fracture mechanical analysis of a thermal shock scenario for a VVER-440 RPV
Abendroth, M.; Altstadt, E.;
This paper describes the analytical work done by modelling and evaluating a thermal shock in a WWER-440 reactor pressure vessel due to an emergency case. An axial oriented semielliptical underclad/surface crack is assumed to be located in the core weld line. Threedimensional finite element models are used to compute the global transient temperature and stress-strain fields. By using a three-dimensional submodel, which includes the crack, the local crack stress-strain field is obtained. With a subsequent postprocessing using the j-integral technique the stress intensity factors KI along the crack front are obtained. The results for the underclad and surface crack are provided and compared, together with a critical discussion of the VERLIFE code.
Keywords: thermal shock, crack intensity factor, j-integral, fracture toughness, VVER-440
  • Open Access LogoWissenschaftlich-Technische Berichte / Forschungszentrum Dresden-Rossendorf; FZD-474 2007

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Publ.-Id: 10111 - Permalink


Jahresbericht 2006 / Annual Report 2006
Forschungszentrum Dresden - Rossendorf, Vorstand;
  • Open Access LogoWissenschaftlich-Technische Berichte / Forschungszentrum Dresden-Rossendorf; FZD-469 2007

Downloads:

Publ.-Id: 10110 - Permalink


Annual Report 2006 - Institute of Ion Beam Physics and Materials Research
von Borany, J.; Heera, V.; Helm, M.; Möller, W.; (Editors)
  • Open Access LogoWissenschaftlich-Technische Berichte / Forschungszentrum Dresden-Rossendorf; FZD-466 2007

Downloads:

Publ.-Id: 10108 - Permalink


4-[18F]Fluorobenzaldehyde-O-(2-{2-[2-(pyrol-2,5-dion-1-yl)ethoxy] ethoxy}ethyl)oxim ([18F]FBOM): A novel prosthetic group for mild labelling of SH-group bearing biomacromolecules
Vogler, L.; Berndt, M.; Pietzsch, J.; Hultsch, C.; Wüst, F.;
The synthesis and application of 4-[18F]fluorobenzaldehyde-O-(2-{2-[2-(pyrol-2,5-dion-1-yl)ethoxy]ethoxy}ethyl)oxim ([18F]FBOM) as a novel prosthetic group for 18F labelling of SH-group bearing biomacromolecules is described.
The aminooxy-functionalised labelling precursor for the radiosynthesis of [18F]FBOM was synthesised in a four-step synthesis sequence with a total yield of 14%. [18F]FBOM could be obtained in a condensation reaction between the labelling precursor and [18F]fluorobenzaldehyde through formation of an oxim. The radiochemical yield ranged between 14 and 19% (decay-corrected). In a typical experiment, starting from 6.5 GBq of [18F]fluoride 730MBq of [18F]FBOM could be obtained within 80 minutes (including HPLC purification). The specific activity was determined to be 51 GBq/µmol. The lipophilicity of [18F]FBOM was determined to be logP = 0.84. The use of [18F]FBOM as SH-reactive group prosthetic group was demonstrated by the reaction with glutathion, low densitiy lipoproteins (LDL) and modified neurotensin derivatives. [18F]FBOM can easily be synthesised, and [18F]FBOM represents an interesting novel prosthetic group for the labelling of SH-group containing biomacromolecules with 18F under mild conditions.
  • Lecture (others)
    14. Arbeitsgruppentagung Radiochemie/Radiopharmazie, 04.-05.10.2006, Marburg, Germany

Publ.-Id: 10107 - Permalink


Formation and morphology control of nanostructures produced by PIII
Shevchenko, N.; Weber, J.; Reuther, H.; Kolitsch, A.;
Development of novel materials and structures for drug delivery systems is currently a very active field of research. Recently the drug-eluting stents were designed to deliver a drug locally from a surface layer to reduce restenosis. Noble gas ion implantation into metals can be used to form nanoscale cavities or sponge like structures. These nanostructures have unique characteristics which offer potential for medical applications such as metal-based drug-eluting stents.
Investigations of the influence of implantation parameters on the surface morphology and cavity characteristics (e.g. size, distribution, and degree of interconnection) have to date been rather limited.
In the present work we have studied the formation of nanostructures on stainless steel surfaces by plasma immersion ion implantation (PIII) using different gases (helium or argon), ion energies (between 5 – 35 keV) and ion fluences (> 1e18 at/cm2). The surface topography and structure of the modified materials have been analyzed by scanning electron microscopy and atomic force microscopy. The phase and element compositions have been examined by grazing incidence X-ray diffraction analysis (GIXRD), X-ray photoelectron spectroscopy, and elastic recoil detection analysis.
Varying the ion energy, fluences, and substrate temperature has been found to produce either void or sponge like structures on the nano- (~10 nm) to micro-scale (~1 µm). Apart from the austenite iron peaks, the GIXRD patterns of the implanted samples display weak peaks of ferrite (bcc iron) as well as oxide phases.
Keywords: Spongy structures, nanostructures, ion implantation, noble gas, stainless steel, drug-eluting stents
  • Poster
    PBII&D 07 - 9th International Workshop on Plasma Based Ion Implantation and Deposition, 02.-6.09.2007, Leipzig, Germany

Publ.-Id: 10106 - Permalink


Structural properties of thin HfSiO films
Teichert, S.; Muehle, U.; Fachmann, J.; Steinhoff, J.; Kudelka, S.; Wilde, L.; von Borany, J.; Eichhorn, F.;
Kein Abstract vorhanden.
  • Lecture (Conference)
    11th International Conference on the Formation of Semiconductor Interfaces (ICFSI), 19.-24.08.2007, Manaus-Amazonas, Brazil

Publ.-Id: 10105 - Permalink


Polymorphism in ferroic functional elements - Bridging length and time scales
Gemming, S.; Luschtinetz, R.; Chaplygin, I.; Seifert, G.; Loppacher, C.; Eng, L. M.; Kunze, T.; Olbrich, C.;
The present study describes an approach for the scale-bridging modeling of ferroic materials as functional elements in micro- and nanoelectronic devices. Ferroic materials are characterized by temperature-dependent complex ordering phenomena of the internal magnetic, electronic, and structural degrees of freedom with several involved length and time scales. Hence, the modelling of such compounds is not straightforward, but relies on a combination of electronic-structure-based methods like ab-initio and density-functional schemes with classical particle-based approaches given by Monte-Carlo simulations with Ising, lattice-gas, or Heisenberg Hamiltonians, which incorporate material-specific parameters both from theory and experiment. The interplay of those methods is demonstrated for device concepts based on electroceramic materials like ferroelectrics and multiferroics, whose functionality is closely related with their propensity towards structural and magnetic polymorphism.

In the present case, such scale-bridging techniques are employed to aid the development of an organic field effect transistor on a ferroelectric substrate generated by the self-assembly of field-sensitive molecules on the surfaces of ferroic oxides. Electronic-structure-based methods yield the microscopic properties of the oxide, the surface, the molecules, and the respective interactions. They are combined with classical particle-based methods on a scale-hopping basis. This combination allows to study the morphology evolution during the self-assembly of larger adsorbate arrays on the (defective) oxide surface and to investigate the interplay of low-temperature magnetic ordering phenomena with the ferroelectric functionality at higher temperatures in multiferroic oxides like the hexagonal manganites. The combination of density-functional data with classical continuum modelling also yielded a model Hamiltonian for the quick determination of the properties of a gate structure based on bio-functionalized carbon nanotubes.
Keywords: multiferroic, density-functional, tight-binding, Ising, Monte-Carlo, simulation, OFET

Publ.-Id: 10104 - Permalink


Neue Möglichkeiten der Modellierung und Beeinflussung der Strömungsverhältnisse in Gießprozessen
Eckert, S.; Boden, S.; Galindo, V.; Gerbeth, G.; Stefani, F.; Willers, B.;
Metallschmelzen in industriellen Prozessen unterliegen in der Regel verschiedenen Arten von Strömungen. Diese Strömungen haben einen entscheidenden Einfluss auf den Wärme- und Stofftransport, und damit zumeist auch auf die Effizienz des Prozesses oder die Qualität des Endproduktes. Zukünftige Anstrengungen im Hinblick auf eine Optimierung derartiger Anlagen oder Technologien müssen aus diesem Grund eine wirksame Strömungskontrolle berücksichtigen.
Elektromagnetische Felder eröffnen aufgrund des kontaktlosen Zugangs und der einfachen Regelbarkeit eine attraktive Möglichkeit zur Strömungskontrolle. Eine gezielte Einflussnahme setzt aber ein umfangreiches Wissen über das Strömungsfeld und die Wechselwirkung mit den elektromagnetischen Kraftfeldern voraus. Neben numerischen Simulationen sind Modellexperimente mit sogenannten „kalten“ Schmelzen, d.h. mit Flüssigmetallen mit einem Schmelzpunkt < 300°C, ein unverzichtbares Mittel, um die Strömungsvorgänge besser zu verstehen und geeignete Maßnahmen zur Strömungskontrolle zu ergreifen.
Im Vortrag werden an ausgewählten Beispielen mit Bezügen zu industriellen Anwendungen die Möglichkeiten einer elektromagnetischen Strömungskontrolle erläutert. In diesem Zusammenhang wird auf die wechselseitige Abhängigkeit von numerischen Berechnungen und Modellexperimenten mit „kalten“ Modellschmelzen hingewiesen. Es werden neue Entwicklungen auf dem Gebiet Messtechnik für Flüssigmetalle vorgestellt, die einen wirkungsvollen Einsatz der Modellexperimente erst ermöglichen.
Keywords: liquid metal flow, electromagnetic flow control, cold models, measuring techniques, casting, solidification
  • Invited lecture (Conferences)
    VDG-Seminar "Technologie des Feingießens - Innovation durch fundiertes Wissen", 23.-24.05.2007, Bad Dürkheim, Deutschland

Publ.-Id: 10103 - Permalink


Nanostructured metal surfaces by plasma immersion ion implantation
Shevchenko, N.; Weber, J.; Kolitsch, A.;
For bare metal stents the in-stent restenosis was a serious problem for about 25 - 35% of the patients and this spurred the medical device companies to come up with a solution. Drug-eluting stents are designed to deliver a drug locally from a polymeric coating to reduce tissue in growth and reduce restenosis to less then 8% of the treated patients. Development of novel materials and structures for drug delivery systems is still very actual topic.
In the present work plasma immersion ion implantation (PIII) using helium or argon plasmas has been employed for the nanostructures formation on metal surfaces with a view to their applications for metal-based drug-eluting stents. A multi-layer pore system on stent surfaces in the range from nanoscale to microscale sizes is desired for drug loading and controlling the rate of elution of therapeutic agents.
Recently we have investigate the formation of nanostructures on stainless steel surfaces by PIII at different gases (He, Ar), ion energies (between 5 – 35 keV) and ion fluences (> 1e18 at/cm2). The surface topography and structure of the implanted materials were analysed by scanning electron microscopy and atomic force microscopy. The phase and element compositions were examined by grazing incidence X-ray diffraction analysis, auger electron spectroscopy, and elastic recoil detection analysis.
Variety of nanostructures as well as their characteristics (e.g. size, distribution, degree of interconnection) can be controlled by varying the implantation parameters. The results of these studies have demonstrated that PIII is a promising technique for the surface topography modification of stainless steel for cardiovascular application.
Keywords: nanostructures, metal surfaces, ion implantation, PIII, stents, drug delivery systems
  • Poster
    EuroNanoForum 2007, 19.-21.06.2007, Düsseldorf, Germany

Publ.-Id: 10102 - Permalink


Tetrahydroquinoline and tetrahydroisoquinoline mixed ligand rhenium complexes with the SNS/S donor atom set
Zablotskaya, A.; Segal, I.; Lukevics, E.; Belyakov, S.; Spies, H.;
New oxorhenium complexes with 3-methylazapentane-1,5-dithiolate (SNMeS) and thiol functionalized monodentate tetrahydroquinolyl and tetrahydroisoquinolyl derivatives have been synthesized by simultaneous reaction of [PPh3]2[Re(O)Cl3] with tridentate HSNMeSH and the corresponding N-heterocycle containing thiol. The characterization of complexes involved elemental analysis, IR, 1H and 13C NMR spectroscopy and X-ray crystallographic analysis. The nature of the heterocycle in monodentate ligand, even situated at the distance of two methylene group length, has been found to have a significant influence on the molecular conformation. Metal complexes were found to be active in psychotropic in vivo and cytotoxicity in vitro screening.
Keywords: rhenium • mixed-ligand oxorhenium complexes • tetrahydroquinoline • tetrahydroisoquinoline • molecular structure • psychotropic activity • cytotoxicity • metal-based drugs

Publ.-Id: 10101 - Permalink


Synthese von 18F-markierten Biphenylen über Suzuki-Kupplung mit 4-[18F]Fluoriod-benzol
Steiniger, B.; Wüst, F.;
Als neuartige Markierungsmethode in der 18F-Chemie wurde die Suzuki-Kupplung von 4-[18F]Fluoriodbenzol mit verschiedenen Organoborverbindungen entwickelt. Anhand der Modellreaktion von p-Tolylboronsäure mit 4-[18F]Fluoriodbenzol wurde der Einfluss verschiedener Palladiumkomplexe, Basen und Lösungsmittel auf die Reaktion untersucht. Mittels der so optimierten Reaktionsbedingungen wurden verschiedene funktionelle Gruppen tragende 18F-markierte Biphenyle synthetisiert. Die Reaktion zeigte eine hohe Kompatibilität gegenüber vielen funktionellen Gruppen. Die radiochemischen Ausbeuten erreichten bis zu 95% (bezogen auf 4-[18F]Fluoriodbenzol) innerhalb von 5 Minuten.
  • Lecture (others)
    14. Arbeitsgruppentagung Radiochemie/Radiopharmazie, 04.-05.10.2006, Marburg, Germany

Publ.-Id: 10100 - Permalink


Effect of radiation on local control correlates with pre-treatment [18F]FDG uptake in FaDu tumours in nude mice
Schütze, C.; Bergmann, R.; Yaromina, A.; Hessel, F.; Kotzerke, J.; Steinbach, J.; Baumann, M.; Beuthien-Baumann, B.;
kein Abstract verfügbar
  • Poster
    10th International Wolfsberg Meeting 2007, 12.-14.05.2007, Ermatingen, Switzerland
  • Abstract in refereed journal
    Molecular Radiation Biology/Oncology 7(2007), 94

Publ.-Id: 10099 - Permalink


3-O-Methyl-6-18F-Fluoro-L-DOPA (OMFD) Uptake via L- Amino Acid Transporter in Tumor Cells and Inflammatory Cells
Haase, C.; Oswald, J.; Bergmann, R.; Füchtner, F.; Hoepping, A.; Pietzsch, J.;
System L amino acid transport is increased in various types of cancer. The new positron emission tomography (PET) tracer 3-O-methyl-6-18F-fluoro-L-DOPA (OMFD) is mainly accumulated via the system L and could serve to image cancer in vivo. However the differentiation between tumor and inflammatory reaction in tissues is often complicated. Therefore, we studied in vitro the accumulation mechanisms of OMFD in model systems of human tumors and inflammation, respectively. It is suggested that the high uptake of amino acid tracers is primarily caused by the higher transporter expression in tumors when compared to other tissues, e.g., inflammatory cells.
As previously shown, the subtype L-type amino acid transporter 1 (LAT1) is playing a key role of L amino acid transport in tumor cells. The functional LAT1 is a heterodimeric complex comprising a single membrane-spanning catalytic light chain protein (hLAT1) and the heavy chain of 4F2 antigen (h4F2hc), which are covalently linked via a disulfide bond.
For molecular characterization of L-type amino acid transporters focusing on the hLAT1-h4F2hc subtype quantitative RT-PCR was performed using the two different human tumor cell lines FaDu (squamous cell carcinoma) and HT-29 (colorectal adenocarcinoma). In comparison, phorbol ester stimulated THP-1 cells (a human monocyte/macrophage cell line) representing inflammatory cells were used. In vitro uptake assays were performed with HT-29, FaDu and THP-1 cells with OMFD under physiological amino acid concentrations.
OMFD demonstrated a saturable and sodium- and energy-independent accumulation in vitro in the different tumor cell lines, suggesting its uptake to be mediated mainly by sodium-independent LAT1. However, OMFD showed a significantly higher uptake in tumor cells when compared to inflammatory cells.
Our data demonstrate that OMFD could be a promising PET tracer for imaging of specific amino acid transport via LAT1 in tumors and, furthermore, for possible differentiation of tumorigenic from inflammatory processes. In conclusion, the identification and characterization of tumor specific amino acid transporters like LAT1 will be a helpful tool for diagnosis and therapy monitoring.
  • Poster
    Proteogenomics for Diagnosis, Imaging and Therapy of Cancer, 27.02.-01.03.2006, San Diego, California, USA

Publ.-Id: 10098 - Permalink


In vivo measurement of spin-spin relaxation time for localized PRESS magnetic resonance spectroscopy (MRS) of lipids
Strobel, K.; van den Hoff, J.; Pietzsch, J.;
Accumulation of excess abdominal visceral fat has been shown to play a crucial role in the development of cardiovascular disease and obesity-related disorders like diabetes mellitus, hyperlipidemia, and hypertension.
In the last years, rodent models have gained an important role in the investigation of adipose tissue (AT) biology and disorder. In this line, non-invasive differentiation and characterization of various AT deposits in the living animal is a current challenge. MRS at high magnetic field strength is a potential tool to learn more about the pathophysiological role of lipids in vivo.

The aim of the present study was to derive the spin-spin relaxation times T2 of 9 different proton resonances occurring in lipid spectra in vivo. With these values the correction factors M0/MTE (with the magnetization MTE = M0 x exp(-TE/T2), TE = echo time) for the peak integrals of the 9 different peaks can be calculated for specific TE. These correction factors can then be used to correct in vivo PRESS spectra to derive the true values for saturation and unsaturation of the triacylglycerols in lipids.

Localized MR spectra were generated in male Wistar rats with a 7 Tesla small animal scanner with a 30 cm bore (BioSpec 70/30, Bruker BioSpin MRI GmbH, Ettlingen, Germany) equipped with a mini imaging gradient coil system (gradient strength 400 mT/m) and a 1H transmit-receive quatrature coil with 72 mm inner diameter.

We used a localized PRESS sequence with a repetition time of 1.8 s and a series of different TE (TE = 12 – 50 ms) to calculate T2. We determined T2 for 9 different peaks (in the range from 0.9 – 5.35 ppm) by fitting the monoexponential model function MTE to the measured signal intensities at the different TE.

As results we got values for the spin-spin relaxation times T2 in the range from 24.7 ms to 57.4 ms. These values result in correction factors M0/MTE in the range from 2.25 to 1.42 for the 9 different peak integrals arising in lipid spectra derived with localized PRESS spectroscopy with TE = 20 ms.

We have measured 9 different T2-relaxation times of the protons of lipids in rats in vivo. These values have been used to correct localized PRESS spectra measured in vivo to obtain the true values for saturation and unsaturation of the fatty acids of AT deposits in experimental animal models. Prospectively, this method is also applicable in human studies using clinical MRS.
  • Poster
    EUROMAR 2007, 01.-06.07.2007, Tarragona, Spain

Publ.-Id: 10097 - Permalink


Expression of Neurotensin Receptors in Human Adeno- and Squamous Cell Carcinoma
Haase, C.; Bergmann, R.; Pietzsch, J.;
There is increasing interest in targeting peptide receptors and their ligands for tumor diagnostics and therapy since there is evidence that some of these receptors are overexpressed in tumors compared to normal tissues. Among these receptors playing a key role in tumor progression is the neurotensin receptor (NTR) family. The present study investigated both mRNA and protein expression of NTR in human adeno- (HT-29) and squamous (FaDu) cell carcinoma cell lines and in corresponding mouse xenograft models. mRNA analysis revealed a higher expression of NTR3 compared to NTR1 and NTR2. Protein analysis revealed enhanced signals for NTR1 followed by NTR2 both in tumor cells and xenografts. In contrast, no NTR3 protein expression was detected. Autoradiography with [3H]neurotensin showed higher receptor binding activity on HT-29 compared to FaDu.
  • Poster
    4th International Conference on Tumor Microenvironment: Progression, Therapy & Prevention, 06.-10.03.2007, Florence, Italy
  • Contribution to proceedings
    4th International Conference on Tumor Microenvironment: Progression, Therapy and Prevention, 06.-10.03.2007, Florence, Italy
    Current Contents

Publ.-Id: 10096 - Permalink


Einfluss verschiedener Y-86-DOTA-Chelate auf die Bioverteilung von Y-86-markierten DOTA L RNA Oligonukleotiden in Ratten
Schlesinger, J.;
Ziel/Aim:
Spiegelbildliche Oligonukleotide sind chemisch synthetisierte Desoxyribonukleinsäuren bzw. Ribonukleinsäuren, mit einer nicht natürlich vorkommenden L-Konfiguration der Ribose. Diese Modifizierung der Nukleinsäurestruktur führt zu einer besonders hohen Stabilität gegenüber dem enzymatischen Abbau in biologischen Medien (1). Zur Markierung von L Oligonukleotiden mit dem Positronen emittierenden Radiometall Y-86-Yttrium (t1/2 = 14,7 h) muss das Molekül mit einem Chelator funktionalisiert sein. Der Einfluss unterschiedlicher Y-86-Chelatstrukturen auf die pharmakologischen Eigenschaften von Y-86-Chelat-L Nukleinsäuren wurde am Beispiel eines L RNA 12mers 1 (Sequenz: 5’ Aminohexyl UGA CUG ACU GAC-3’, MW 3975) untersucht. Dazu wurde die L RNA 1 über zwei verschiedene Chelatoren mit 86Y(III) radiomarkiert und die Bioverteilung in Ratten untersucht.

Methodik/Methods:
Die Modifizierung des L RNA 12mers 1 mit DOTA erfolgte zum einen über einen reaktiven N Succinimidylester 2 – zu DOTA L RNA 3, zum anderen über ein Isothiocyanatderivat 4 zu DOTA bz L RNA 5. Die über eine Amidbindung 3 und eine Thioharnstoffbindung 5 DOTA-modifizierten L RNAs wurden anschließend mit Y-86 in radiochemischen Ausbeuten von 76 % bzw. 85 % radiomarkiert (2). Die Identität der Verbindungen 3a und 5a wurde mit geträgerten Y-86/Y-Markierungen und Massenspektrometrie nachgewiesen (3a m/z: 4447,0 [M+H]+; 5a m/z: 4611,3 [M+H]+). Die Bioverteilungsstudien wurden für jede Verbindung mit acht männlichen Wistar Ratten durchgeführt (3a: 240 ± 15 g Gewicht; 5a: 150 ± 7.5 g Gewicht).

Ergebnisse/Results:
Die Untersuchung der Bioverteilung der beiden Y-86-markierten L RNAs 3a und 5a zeigte für beide Substanzen eine hohe renale Ausscheidung, wobei aber eine unterschiedliche Retention der radiomarkierten Verbindungen in Nieren und Nebennieren beobachtet wurde. Der Standardized uptake value (SUV) ereichte für 3a in den Nieren einen Wert von 10 ± 2,0 nach 5 min und 6,1 ± 0,53 nach 60 min. Für die Verbindung 5a stieg der SUV in den Nieren von 13 ± 1,6 nach 5 min auf 14 ± 1,1 nach 60 min. Bemerkenswert hohe SUVs (3,5 ± 0,48 und 3,2 ± 0,33) wurden in den Nebennieren nach 60 min für beide Verbindungen beobachtet. Der SUV anderer Organe lag in dieser Untersuchung für 3a und 5a nach 60 min unter 1,0. Nach 12 h Inkubation in Rattenblut bei 37 °C konnte keine Zersetzung von 5a über HPLC-Analyse beobachtet werden.

Schlussfolgerungen/Conclusions:
Die unterschiedliche chemische Anbindung der Y-86-DOTA Chelate an die L-RNA 1 deutet neben den strukturellen Unterschieden der Y-86-Komplexe in 3a und 5a auf eine starke Beeinflussung der Bioverteilung des L Oligonukleotides hin. Die hohe metabolische Stabilität der L RNA verdeutlicht das Potential von L Oligonukleotiden als molekulare Sonden für die PET.

Literatur/References:
(1) Nat Biotechnol 14 (1996), 1112-5
(2) LDDD 3(5) (2006), 330-5
  • Poster
    45. Jahrestagung der Deutschen Gesellschaft für Nuklearmedizin, 25.-28.04.2007, Hannover, Deutschland
  • Abstract in refereed journal
    Nuklearmedizin 46(2007)2, A104

Publ.-Id: 10095 - Permalink


Combined 18Fluoro-L-DOPA-PET/CT as a tool for localization diagnostic in patients with congenital hyperinsulinism (CHI)
Blankenstein, O.; Mohnike, W.; Füchtner, F.; Mohnike, K.;
kein Abstract verfügbar
  • Lecture (Conference)
    ESPE / LWPES 7th Joint Meeting Paediatric Endocrinology, 21.-24.09.2005, Lyon, France

Publ.-Id: 10094 - Permalink


Effect of Moderate Hypercapnic Hypoxia on Cerebral Dopaminergic Activity and Brain O2 Uptake in Intrauterine Growth–Restricted Newborn Piglets
Bauer, R.; Walter, B.; Vorwieger, G.; Fritz, A.; Füchtner, F.; Zwiener, U.; Brust, P.;
There is evidence that intrauterine growth restriction (IUGR) is associated with altered dopaminergic function in the immature brain. Compelling evidence exists that in the newborn brain, specific structures are especially vulnerable to O2 deprivation. The dopaminergic system is shown to be sensitive to O2 deprivation in the immature brain. However, the respective enzyme activities have not been measured in the living neonatal brain after IUGR under hypercapnic hypoxia (H/H). Therefore, 18F-labeled 6-fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) together with positron emission tomography was used to estimate the aromatic amino acid decarboxylase activity of the brain of seven normal weight (body weight 2078 +/- 434g) and seven IUGR newborn piglets (body weight 893 +/- 109 g). Two positron emission tomography scans were performed in each piglet. All animals underwent a period of normoxia and moderate H/H. Simultaneously, cerebral blood flow was measured with colored microspheres and cerebral metabolic rate of O2 was determined. In newborn normal-weight piglets, the rate constant for FDOPA decarboxylation was markedly increased in mesostriatal regions during H/H, whereas brain oxidative metabolism remained unaltered. In contrast, moderate H/H induced in IUGR piglets a marked reduction of clearance rates for FDOPA metabolites (p < 0.05), which was accompanied by a tendency of lowering the rate constant for FDOPA conversion. Furthermore, IUGR piglets maintained cerebral O2 uptake in the early period of H/H, but during the late period of H/H, a significantly reduced cerebral metabolic rate of O2 occurred (p < 0.05). Thus, IUGR is accompanied by a missing activation of dopaminergic activity and attenuated brain oxidative metabolism during moderate H/H. This may indicate endogenous brain protection against O2 deprivation.

Publ.-Id: 10092 - Permalink


Small-Animal PET of Rat Lung Perfusion in Supine and Prone Position
Bergmann, R.; Richter, T.; Schlesinger, J.; Schiller, E.; Ragaller, M.; Strobel, K.; Pietzsch, J.;
Emerging experimental data indicate that the pulmonary blood flow remained directed toward the dorsal regions after turning animals from a supine to a prone position. This finding supported the hypothesis that the distribution of perfusion throughout the lung was not primarily dictated by the gravity but by the fractal behavior of the pulmonary vasculature. However there are only limited data about the spatial distribution of lung perfusion in rats in prone and supine position. The purpose of the study was to quantify the relative perfusion (Q) distribution in rat lungs in both positions using [68Ga]Ga-DOTA-microspheres with small-animal PET, -CT, and -MRI to obtain reference data for further investigations on injured rat lungs.

Methods:
Regional pulmonary perfusion was investigated after injection of [68Ga]Ga-DOTA-microsphers (20 micrometer diameter) of albumin in both prone and supine positions in normal breathing rats, anesthetized with desflurane. The heart rate was continuously recorded. The right femoral artery and vein were cannulated, arterial blood pressure, blood gases, and pH were measured. The microspheres were intravenously applied. Emission data were collected for 30 min. Before and after the PET measurement the animals were studied with CT to investigate the lungs and to calculate their volumes. Randomly selected animals were studied also with smallanimal MRI. The [68Ga]-activity 3D distributions were analyzed from the coregistered volume data reconstructed with 3D OSEM MAP algorithm (resolution in the center of field of view 1.8 mm).

Results:
There were no significant differences of mean Q in the ventral and dorsal elements of normal rat lungs.

Conclusion:
The body position (prone and supine) of normal breathing rats does not influence the mean Q btained with small-animal PET and the lung volumes measured with small-animal CT. The histogram of the regional blood flow in supine position reflects a more heterogeneous blood flow distribution.
Keywords: small-animal PET ; rat lung perfusion ; [68Ga]Ga-DOTA-microspheres ; supine and prone position
  • Poster
    Joint Molecular Imaging Conference 2007, 08.-11.09.2007, Providence, Rhode Island, USA

Publ.-Id: 10091 - Permalink


[18F]Fluoroacetate and [11C]Acetate Small-Animal PET Studies in Rats and Tumor Xenografts in Mice
Bergmann, R.; Richter, S.; Wüst, F.; Beuthien-Baumann, B.; Pietzsch, J.;
[18F]Fluoroacetate ([18F]FAC) is discussed as an addition to the well-established PET radiotracer [11C]acetate ([11C]ACE) for the diagnosis and treatment monitoring of low [18F]FDG accumulating cancer entities. The purpose of this study was to establish a reproducible method of [18F]FAC synthesis, and to assess the biodistribution and kinetics in rats and tumor bearing mice to evaluate the potential of [18F]FAC for tumor imaging, and to gain information about the [18F]FAC accumulation mechanism in human squamous cell carcinoma (FaDu) and adenocarcinoma (HT-29) xenografts.

Results and Discussion:
The optimized radiosynthesis of n.c.a. sodium [18F]FAC was performed in two steps: (1) Incorporation of fluorine into (methanesulfonyloxy)-acetic acid tert.-butyl ester as the superior labeling precursor in acetonitrile followed by (2) acidic hydrolysis of the resulting [18F]fluoroacetic acid tert.-butyl ester to afford [18F]FAC. Several consecutive purification gave sodium [18F]FAC in very reproducible radiochemical yields in high radiochemical purity (>95%) within 50 min. Arterial blood samples were analyzed and no metabolites of [18F]FAC were observed up to 60 min p.i. [18F]FAC was readily accumulated in FaDu and HT-29 tumors (tumor/muscle 1.8+/-0.2 mean+/-SEM, n=6) as shown in small-animal PET studies. [18F]FAC and [11C]ACE could clearly delineate the tumors and reached a tumor to muscle ratio up to two. Both agents showed a similar biodistribution. The differences were limited to the higher activity accumulation of the [11C]ACE in pancreas, spleen, kidneys, and the slower blood clearance of [18F]FAC. In some animals dehalogenation was observed.

Conclusion:
The remotely-controlled two step/one pot synthesis of [18F]FAC represents a robust and reproducible procedure. The differences of biodistribution between [18F]FAC and [11C]ACE in rats and tumor bearing mice are relatively small. The absence of metabolites in the arterial blood plasma allows using the plasma activity for quantitative kinetic studies without further metabolite analyses.
(Partly supported by the EU project BioCare No. 505785)
Keywords: small-animal PET ; 18F-labeling ; [18F]fluoroacetate ; [11C]acetate ; tumor bearing mice
  • Poster
    Joint Molecular Imaging Conference 2007, 08.-11.09.2007, Providence, Rhode Island, USA

Publ.-Id: 10090 - Permalink


Entwicklungen im Bereich der Nutzung von Listmode am ECAT Exact HR+ des Forschungszentrum Rossendorf
Langner, J.; Pötzsch, C.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Seminar Forschungzentrum Jülich, 23.08.2006, Jülich, Germany

Publ.-Id: 10089 - Permalink


Multimodality Imaging of Tumor Xenografts in Mice with dedicated Small-Animal PET, Small-Animal CT, and Small-Animal MRI: Hardware and Software Solutions
Bergmann, R.; Hauser, J.; Strobel, K.; Pötzsch, C.; Hofheinz, F.; Pietzsch, J.; Beuthien-Baumann, B.;
Dedicated small-animal tomographs are nowadays available for the three major modalities PET, MRI, and CT. Utilization of all three techniques for true multimodality imaging requires the solution of several technical problems including reproducible animal positioning, overcoming file format incompatibilities and coregistration of the different image volumes, preferably without application of markers.
Methods: We developed an isolation chamber and adapter for imaging devices, enabling physiologic animal control, reproducible positioning, pathogen barrier, anesthesia, probe application and the use of catheter systems. Furthermore, we developed the necessary software for file format conversions and coregistration of the image volumes.
The basis is the animal holder system, consisting of the fixing adapters and the animal chamber that could be positioned in our three tomographs (microPET P4, SkyScan 1178, and BioScan 70/30 USR).
The animal holder system is temperature-controled. It allows gas anesthesia of the animals and could be used as a closed system. The bed is air heated.
In the different modalities the data are stored in different formats using different image matrix and pixel sizes. In order to analyze the data they are converted to a common data format (Siemens ECAT7) and the pixel sizes are adjusted. Residual differences in the relative positioning of the animals are corrected via coregistration. We implemented a mutual information algorithm using the conjugate gradient maximization method.
Validation studies showed a good coregistration of the images from PET, CT, and MRI. In longitudinal [18F]FDG studies the coregistration allowed to compare the tumor SUVmax data between different studies.
Conclusion: Multimodality imaging of small animal PET, -CT, and MRI allows the direct comparison and quantification of regional PET, CT, and MRI/MRS parameters enabling the characterization of functional and anatomical changes during tumor development and therapy.
The project was partly supported by the EU project BioCare No. 505785.
Keywords: small-animal PET, CT, MRI ; multimodality imaging ; animal chamber ; coregistration ; mutual information algorithm
  • Poster
    Joint Molecular Imaging Conference 2007, 08.-11.09.2007, Providence, Rhode Island, USA

Publ.-Id: 10088 - Permalink


Cyclam-based dendritic ligands bearing neuropeptides
Röhrich, A.;
kein Abstract verfügbar
  • Lecture (Conference)
    Supraphone meeting 2007, 31.05.-03.06.2007, Lipari, Italy

Publ.-Id: 10087 - Permalink


Neurotensin-Konjugate mit Cyclam-Kern – Synthese und Affinität zu NTR-1
Röhrich, A.; Stephan, H.; Kretzschmann, A.; Noll, S.; Bergmann, R.; Pietzsch, J.; Steinbach, J.;
Dendritische Liganden eröffnen einen neuen Zugang zu Radiometallpharmaka und zwar insbesondere dann, wenn es gelingt, radioaktive Metallnuklide im Kern topologisch so zu verkapseln, dass sie unter physiologischen Bedingungen kinetisch und thermodynamisch stabil fixiert sind. Eine Modifizierung der Dendrimeroberfläche erlaubt dann die Einstellung definierter Löslichkeits- und selektiver Bindungseigenschaften.
Wir berichten über die Synthese von sternförmigen Liganden mit peripheren Peptideinheiten sowie einem metallbindenden Zentrum. Als Peptid wird das biologisch aktive Neurotensinfragment NT-(8-13) eingeführt.[1] Dieses bindet an den Neurotensin-Rezeptor 1 (NTR-1), der insbesondere an duktalen exokrinen Pankreaskarzinomen stark überexprimiert ist.[2] Als Kernbaustein wird Cyclam (1,4,8,11-Tetraazacyclotetradecan) ausgewählt, das zur stabilen Bindung von diagnostisch und therapeutisch relevanten Radiometallnukliden, wie 64/67Cu, 99mTc und 186/188Re, geeignet ist. Derartige radioaktiv markierte Peptidkonjugate können Bedeutung in der Tumordiagnostik und Tumortherapie erlangen.
Es werden Ligand-Rezeptor-Bindungs-studien an NTR-1-überexprimierenden humanen Adenokarzinom(HT-29)-Zellen präsentiert. Erste Ergebnisse weisen auf eine sehr hohe Affinität des Tetramers I sowie des entsprechenden Kupfer(II)-Komplexes zum Neurotensin-Rezeptor 1 im pico-molaren Bereich hin und ist damit vergleichbar zu einem Tetramer anderer Struktur {3]. Es werden sich Untersuchungen zur Markierung mit 64Cu anschließen, um Aussagen zur metabolischen Stabilität dieses Liganden sowie zur Bioverteilung in vivo zu erhalten.

[1] B.M. Tyler-McMahon et al., Regul. Pept. 2000, 93, 125-136
[2] J. C. Reubi, Endocr. Rev. 2003, 24, 389-427.
[3] C. Hultsch et al., Bioorg. Med. Chem. 2006, 14, 5913-5920
  • Poster
    Wissenschaftsforum Chemie 2007, 16.-19.09.2007, Ulm, Deutschland

Publ.-Id: 10086 - Permalink


In vivo Stoffwechseluntersuchungen mit Hilfe der Positronen-Emissions-Tomographie (PET)
Wüst, F.; Pietzsch, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Forschungsinstitut für die Biologie landwirtschaftlicher Nutztiere, 16.01.2006, Dummerstorf, Deutschland

Publ.-Id: 10084 - Permalink


Carbon-11 labelling chemistry
Wüst, F.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Postitron emission tomography (PET): Technology and application, 05.-07.04.2006, London, Great Britain

Publ.-Id: 10083 - Permalink


18F-Markierungen mit kleinen Markierungsbausteinen
Wüst, F.;
  • Invited lecture (Conferences)
    Institutskolloquium, 03.08.2006, München, Germany

Publ.-Id: 10082 - Permalink


Synthesis of 18F-labeled stilbenes from 4-[18F]fluorobenzaldehyde
Wüst, F.; Gester, S.; Pietzsch, J.;
kein Abstract verfügbar
  • Invited lecture (Conferences)
    Positron emission tomography (PET): Technology and application, 28.-30.03.2007, London, Great Britain

Publ.-Id: 10081 - Permalink


Übergangsmetallvermittelte Reaktionen mit den kurzlebigen Positronen-strahlern 11C und 18F: Neue radiochemische Methoden zur C-C und C-N Bindungsknüpfung
Wüst, F.;
kein Abstract verfügbat
  • Lecture (others)
    Jungchemikerforum TU Dresden, 15.11.2004, Dresden, Germany

Publ.-Id: 10080 - Permalink


Characterization of PET radiotracer uptake in human leukemia cell line THP-1, a model for the study of monocyte-macrophage differentiation
Pietzsch, J.; Haase, C.;
kein Abstract verfügbar
  • Poster
    8th World Congress on Inflammation, 16.-21.06.2007, Copenhagen, Denmark
  • Abstract in refereed journal
    Inflammation Research (2007)Suppl. 3, S459

Publ.-Id: 10079 - Permalink


Imaging of metabolic pathways of modified lipoproteins in vivo using small animal positron emission tomography (PET)
Pietzsch, J.; Hoppmann, S.; Haase, C.; Wüst, F.; van den Hoff, J.;
kein Abstract verfügbar
  • Lecture (Conference)
    8th World Congress on Inflammation, 16.-21.06.2007, Copenhagen, Denmark
  • Abstract in refereed journal
    Inflammation Research (2007)Suppl. 3, S394

Publ.-Id: 10078 - Permalink


Lateral variation of target poisoning during reactive magnetron sputtering
Güttler, D.; Grötzschel, R.; Möller, W.;
The reactive gas incorporation into a Ti sputter target has been investigated using laterally resolving ion beam analysis during DC magnetron deposition of TiN in an Ar/N2 atmosphere. At sufficiently low reactive gas flow, the nitrogen incorporation exhibits a pronounced lateral variation, with a lower areal density in the target race track compared to the target centre and edge. The findings are reproduced by model calculations. In the race track, the balance of reactive gas injection and sputter erosion is shifted towards erosion. The injection of nitrogen is dominated by combined molecular adsorption and recoil implantation versus direct ion implantation.
Keywords: Thin Film Deposition, Magnetron Sputtering, Target Poisoning, Modelling
  • Applied Physics Letters 90(2007), 263502

Publ.-Id: 10077 - Permalink


Nanostructures by Ion-Driven Self-Organisation
Möller, W.;
No abstract available
  • Lecture (others)
    Seminar, 20.03.07, Aarhus, Denmark

Publ.-Id: 10076 - Permalink


Nanostructures by Ion-Driven Self-Organisation
Möller, W.;
No abstract available
  • Lecture (others)
    Seminar, 02.02.2007, Caen, France

Publ.-Id: 10075 - Permalink


Oberflächen- und Schichtanalyse mit Hochenergie-Ionen
Möller, W.;
No abstract available
  • Lecture (others)
    Weiterbildungskurs "Surface Engineering und Nanotechnologie (SENT), Charakterisierung dünner Schichten", 08.12.2004, Dresden, Deutschland

Publ.-Id: 10073 - Permalink


Beschichtungsplasmen
Möller, W.;
No abstract available
  • Lecture (others)
    Weiterbildungskurs "Surface Engineering und Nanotechnologie (SENT), Herstellung und Anwendung dünner Schutzschichten", 27.10.2004, Dresden, Deutschland

Publ.-Id: 10072 - Permalink


Ionenstrahltechnologien
Möller, W.;
No abstract available
  • Lecture (others)
    Weiterbildungskurs "Surface Engineering und Nanotechnologie (SENT), Herstellung und Anwendung dünner Schutzschichten", 27.10.2004, Dresden, Deutschland

Publ.-Id: 10071 - Permalink


Plasma Surface Interaction and Ion Bombardment
Möller, W.;
No abstract available
  • Invited lecture (Conferences)
    Tutorial "Fundamentals and Trends in Plasma Processing", Int. Konf. "Plasma Surface Engineering", 11.09.2004, Garmisch-Partenkirchen, Deutschland

Publ.-Id: 10070 - Permalink


Fundamentals of Ion Beam Analysis
Möller, W.;
No abstract available
  • Lecture (Conference)
    Tutorial "Thin Film Diagnostics", EU-RTN "New Fullerene Like Materials", 04.06.2004, Dresden, Deutschland

Publ.-Id: 10069 - Permalink


Experimental hypoxia is a potent stimulus for radiotracer uptake in vitro: Comparison of different tumor cells and primary endothelial cells
Oswald, J.; Treite, F.; Haase, C.; Kampfrath, T.; Mäding, P.; Schwenzer, B.; Bergmann, R.; Pietzsch, J.;
Hypoxia causes upregulation of vascular endothelial growth factor (VEGF) which is a key regulator in tumor angiogenesis and essential for the proliferation of endothelial cells. Endothelial cells have been described to accumulate radiotracers like 18F-FDG. However, the contribution of radiotracer uptake by endothelial cells to uptake measured in tumors by positron emission tomography (PET) is still unclear. In this study 18F-FDG and 18F-FMISO radiotracer uptake in various tumor and primary endothelial cells cultured at hypoxic conditions was investigated. Experimental hypoxia was confirmed by significant upregulation of VEGF mRNA. In comparison to normoxic conditions, cellular uptake of 18F-FDG was significantly increased at hypoxic conditions in two of the tumor and all endothelial cells, whereas 18F-FMISO uptake was only enhanced in tumor cell lines HT-29 and MCF-7. Our data showed a marked influence of experimental hypoxia on the metabolism and gene expression of tumor and endothelial cells in vitro. This indicates an important contribution of endothelial cells to 18F-FDG radiotracer uptake in tumors and for the visualization of tumors by means of PET.
Keywords: Hypoxia; VEGF; Endothelial cells; Radiotracer uptake; 18F-FDG; 18F-FMISO

Publ.-Id: 10068 - Permalink


Receptor for Advanced Glycation Endproducts in Health and Disease
Pietzsch, J.; (Editor)
kein Abstract verfügbar
  • Book (Editorship)
    Trivandrum, Kerala, India: Research Signpost, 2007
    50 Seiten

Publ.-Id: 10067 - Permalink


An algebraic approach to bare nucleon matrix elements
Zschocke, S.;
  • Lecture (others)
    Institut für Theoretische Physik, 10.12.2004, Dresden, Deutschland

Publ.-Id: 10066 - Permalink


Splitting and mixing of the ρ and ω in nuclear matter
Zschocke, S.;
  • Lecture (Conference)
    KFKI-RMKI, 19.11.2004, Budapest, Hungary
  • Invited lecture (Conferences)
    FIAS, 03.12.2004, Frankfurt am Main, Deutschland

Publ.-Id: 10065 - Permalink


Mass-shift of the ρ and ω meson and their mixing in nuclear matter
Zschocke, S.;
Mass-shift of the ρ and ω meson and their mixing in nuclear matter
  • Lecture (others)
    Institut für Theoretische Physik, 06.06.2004, Dresden, Deutschland

Publ.-Id: 10064 - Permalink


ρ − ω splitting and mixing in nuclear matter
Zschocke, S.;
  • Lecture (Conference)
    DPG Frühjahrstagung, 08.-12.03.2004, Köln, Deutschland

Publ.-Id: 10063 - Permalink


Radical Enhanced Atomic Layer Deposition of Tantalum Oxide
Niskanen, A.; Kreissig, U.; Leskelä, M.; Ritala, M.;
Tantalum oxide was deposited by radical enhanced atomic layer deposition using tantalum ethoxide and oxygen radicals. The radicals were produced by dissociating oxygen gas in a remote microwave plasma discharge. Argon was used as the carrier and purge gas. The films were deposited at 150 and 250°C on glass, silicon, and platinum substrates. Growth rate of the films was 0.19 nm per cycle with a 0.6 s pulse length for tantalum ethoxide and 3 s for oxygen radicals. The films were amorphous according to X-ray diffraction. The densities measured by X-ray reflectivity were between 7.1 and 7.6 g/cm3 for films grown both at 150 and 250°C. The dielectric constants were 28 and 36 for films grown on platinum electrodes at 150 and 250 °C, respectively. The leakage current densities at 1 MV/cm electric field were less than 1 x 10-8 A/cm2 for both deposition temperatures. The effect of water as an additional oxidant was studied at 250 °C. The water was supplied as a separate pulse either right before or after the tantalum ethoxide pulse.
  • Chemistry of Materials 19(2007), 2316-2320

Publ.-Id: 10062 - Permalink


Photon scattering from 92Mo, 98Mo and 100Mo up to the neutron-seperation energy
Rusev, G.;
  • Lecture (Conference)
    DPG Frühjahrstagung, 08.-12.03.2004, Köln, Deutschland

Publ.-Id: 10061 - Permalink


The ELBE Microbeam
Pawelke, J.;
  • Lecture (Conference)
    Microbeam-Workshop, 30.-31.03.2004, Darmstadt, Deutschland

Publ.-Id: 10060 - Permalink


Feasibilty of dose quantification with in-beam PET data in radiotherapy with 12C and proton beams
Parodi, K.;
  • Invited lecture (Conferences)
    BROWN BAG - physics seminar, 12.12.2004, Boston, USA

Publ.-Id: 10059 - Permalink


The feasibility of in-beam PET for proton therapy
Parodi, K.;
  • Invited lecture (Conferences)
    BROWN BAG - physics seminar, 02.02.2004, Boston, USA

Publ.-Id: 10058 - Permalink


Testing of X-ray sensitive detectors at ELBE
Naumann, L.;
  • Lecture (Conference)
    CBM Collaboration Meeting, 07.10.2004, Darmstadt, Deutschland

Publ.-Id: 10057 - Permalink


FAIR an international accelerator facility for antiproton and ion beam research in Darmstadt
Naumann, L.;
  • Invited lecture (Conferences)
    INTAS TRD Collaboration Meeting, 01.07.2004, Gatchina, Russia

Publ.-Id: 10056 - Permalink


Structural and tribological properties of cluster-assembled CNx films
Blomqvist, M.; Bongiorno, G.; Podesta, A.; Serin, V.; Abrasonis, G.; Kreissig, U.; Möller, W.; Coronel, E.; Wachtmeister, S.; Csillag, S.; Cassina, V.; Piseri, P.; Milani, P.;
We report the structural and tribological characterization of nanostructured CNx thin films produced by the deposition of a supersonic carbon cluster beam assisted by nitrogen ion bombardment. The influence of the deposition parameters on the chemical composition and structure of the films has been systematically studied by X-ray photoelectron spectroscopy, elastic recoil detection analysis, transmission electron microscopy and atomic force microscopy. Depending on the deposition parameters, the films show a structure ranging from amorphous to disordered graphitic with interlinked planes. Nitrogen content depends on the nitrogen ion kinetic energy. The films have a very low density with a high surface roughness. Friction measurements at the nanoscale show a correlation between nitrogen content and mechanical properties of the system.
  • Applied Physics A 87(2007), 767-772

Publ.-Id: 10055 - Permalink


Bi-annual Report 2005/06 - Rossendorf Beamline at ESRF (ROBL-CRG)
Scheinost, A.; von Borany, J.; (Editors)
  • Open Access LogoWissenschaftlich-Technische Berichte / Forschungszentrum Dresden-Rossendorf; FZD-463 2007

Downloads:

Publ.-Id: 10054 - Permalink


Dileptons and charm as probes of chiral restoration
Kämpfer, B.;
  • Invited lecture (Conferences)
    Int. Conf. High Energy Phys., 16.-22.04.2004, Bejing, China

Publ.-Id: 10053 - Permalink


Quasiparticle model of QCD matter above and below Tc and at large μ
Kämpfer, B.;
  • Lecture (Conference)
    Int. Symp. ”The QCD phase diagramme: from theory to experiment”, 28.05.-03.06.2004, Skopelos, Greece

Publ.-Id: 10052 - Permalink


Phantastische Ausblicke auf unser Universum
Kämpfer, B.;
  • Lecture (others)
    Urania-Seniorenakademie, 05.05.2004, Dresden, Deutschland

Publ.-Id: 10051 - Permalink


QCD equation of state above and below Tc
Kämpfer, B.;
  • Lecture (Conference)
    XLII Int. Winter Meeting on Nucl. Physics, 25.-31.01.2004, Bormio, Italy

Publ.-Id: 10050 - Permalink


Baryon resonances and the production of light vector mesons near thresholds
Kämpfer, B.;
  • Lecture (Conference)
    Internat. Workshop, 11.-17.01.2004, Hirschegg, Österreich

Publ.-Id: 10049 - Permalink


Overview of the present status of the SRF gun design and construction
Michel, P.;
  • Invited lecture (Conferences)
    Workshop on Advanced Free Electron Lasers and Their Applications, 24.-25.06.2004, Taiwan, China

Publ.-Id: 10048 - Permalink


Electron Beam Diagnostics at the ELBE Free Electron Laser
Michel, P.;
  • Invited lecture (Conferences)
    Workshop on Advanced Free Electron Lasers and Their Applications, 24.-25.06.2004, Taiwan, China

Publ.-Id: 10047 - Permalink


Design and Status of the Radiation Source ELBE and its FEL(s)
Michel, P.;
  • Invited lecture (Conferences)
    Workshop on Advanced Free Electron Lasers and Their Applications, 24.-25.06.2004, Taiwan, China

Publ.-Id: 10046 - Permalink


Experiments and simulation on bubbly flow in a complex 3D flow field
Lucas, D.; Prasser, H.-M.; Krepper, E.; Beyer, M.;
A new approach for the modelling of poly-dispersed bubbly flows – the so-called Inhomogeneous Multi Bubble Size Group (MUSIG) model was developed jointly by FZD and ANSYS. It was implemented into the CFX code and is now available starting with code version 10. This model enables the consideration of a number bubble classes in the mass balance as well as in the momentum balance. Usually only few classes are required for the momentum balance to reflect the bubble size dependent de-mixing of small and large bubbles caused by the inversion of the sign of the lift force with increasing bubble diameter. The model was developed and first tested using data for vertical pipe flow. To show the indepen¬dency of the model on geometry and to test it for more complex flow situations, now experiments were conducted with a pronounced three-dimensional character of the flow fields. A diaphragm which blocks about one half of the pipe was placed into the vertical DN200 test sections available at the TOPFLOW facility of FZD. Main feature is the trans¬location of the diaphragm to scan the 3D void field with a stationary wire-mesh sensor. Be¬sides the measurement of time-averaged void fraction fields, a novel data evaluation method was developed to extract estimated liquid velocity profiles from the wire-mesh sensor data. Simulations were done using CFX-10 and applying the Inhomogeneous MUSIG model. In general the complex flow including a recirculation zone behind the obstacle (where bubble coalescence is observed) and a pronounced jet of high liquid velocity at the unobstructed side (were bubble break-up dominates) are reflected well in the simulations. There is a strong interaction between size dependent bubble migration in the complex liquid velocity field (mainly caused by the lift force) and local bubble coalescence and break-up. The data clearly demonstrate the necessity to consider the bubble size dependent bubble migration for an adequate simulation of bubbly flows in complex geometries. Some weaknesses of the simulations are connected with shortcomings in the modelling of bubble coalescence and break-up.
Keywords: bubbly flow, 3D, flow field, CFD
  • Lecture (Conference)
    45th European Two-Phase Flow Group Meeting, 22.-25.05.2007, Toulouse, France

Publ.-Id: 10045 - Permalink


Stability effect of the lateral lift force in bubbly flows
Lucas, D.; Krepper, E.; Prasser, H.-M.; Manera, A.;
The role of the lift force for the stability of bubbly flows is discussed. The main interest is directed towards bubble columns, since instabilities caused by the lift force may be one important reason for the transition from homogeneous to heterogeneous flow regimes. The lift force acts on rising bubbles in lateral direction, when gradients of the liquid velocity are present. Such gradients may result from the main liquid flow or from local disturbances in case of initially homogeneous flows. Depending on the sign of the lift force such local disturbances in a homogeneous flow may be damped or enhanced. The corresponding feedback mechanism was previously analysed by means of a linear stability analyses. In the result criteria for stability were obtained for mono-dispersed flow, for a flow with two bubble size groups and finally with some additional approximations also for the case of N bubble size groups or a given bubble size distribution. Recently two different groups confirmed the stability criteria experimentally. Now the effects were investigated also by means of CFD simulations. In a first step bubble coalescence was excluded, while the second step comprises a numerical study which includes coalescence. In the latter case coalescence leads to a transition from stable to instable flow patterns along the height position in the column. The transitions fit well together with the criteria for stability. Finally the influence of the lift force is discussed also for other flow situations.
Keywords: bubbly flow, stability, bubble column, lift force
  • Contribution to proceedings
    International Conference on Multiphase Flow - ICMF 2007, 09.-13.07.2007, Leipzig, Germany
    paper S1_Mon_C_9
  • Lecture (Conference)
    International Conference on Multiphase Flow - ICMF 2007, 09.-13.07.2007, Leipzig, Germany

Publ.-Id: 10044 - Permalink


Spontaneous symmetry breaking and rotational bands
Frauendorf, S.;
  • Invited lecture (Conferences)
    Fall meeting of the Div. of Nucl. Phys. of the American Physical Society, 02.10.2004, Chicago, USA

Publ.-Id: 10043 - Permalink


Normal persistent currents and gross shell structure at high spin
Frauendorf, S.;
  • Lecture (Conference)
    Workshop on mesoscopic physics, 01.10.2004, Michigan, USA

Publ.-Id: 10042 - Permalink


Probing shape coexistence by dipole excitations
Frauendorf, S.;
  • Lecture (others)
    Forschungszentrum Rossendorf, 01.07.2004, Dresden, Deutschland

Publ.-Id: 10041 - Permalink


Experimental evidence for chirality
Frauendorf, S.;
  • Lecture (others)
    Niels Bohr Institute, University of Copenhagen, 02.06.2004, Copenhagen, Danmark

Publ.-Id: 10040 - Permalink


Symmetries of the cranked mean field
Frauendorf, S.;
  • Invited lecture (Conferences)
    International Nuclear Physics Conference, 07.06.2004, Goeteborg, Sweden
  • Invited lecture (Conferences)
    Niels Bohr Institute, 01.06.2004, Copenhagen, Danmark

Publ.-Id: 10039 - Permalink


Tilted rotation
Frauendorf, S.;
  • Lecture (others)
    Bejing University, 03.04.2004, Bejing, China

Publ.-Id: 10038 - Permalink


Nuclear tidal waves
Frauendorf, S.;
  • Lecture (others)
    Bejing University, 02.04.2004, Bejing, China

Publ.-Id: 10037 - Permalink


Exotic phenomena at high spin
Frauendorf, S.;
  • Lecture (Conference)
    Workshop on AGATA physics, 01.03.2004, Orsay, France

Publ.-Id: 10036 - Permalink


Topology of conformational changes in photoreceptor activation
Fahmy, K.;
  • Lecture (others)
    Universität Frankfurt am Main, 20.12.2004, Frankfurt am Main, Deutschland

Publ.-Id: 10035 - Permalink


Metallisierung von Proteinen: Wege zu neuen Materialien
Fahmy, K.;
  • Lecture (Conference)
    Bruker-Anwendertreffen, 11.11.2004, Ettlingen, Dtl.

Publ.-Id: 10034 - Permalink


Proteinstruktur und Funktion: Ein Infrarot-Blick auf Membranproteine
Fahmy, K.;
  • Lecture (Conference)
    ISAS, 05.05.2004, Berlin, Dtl.

Publ.-Id: 10033 - Permalink


Tomographische Rekonstruktion beim in-beam PET Monitoring der Schwerionentherapie
Enghardt, W.;
  • Invited lecture (Conferences)
    DKFZ, 21.01.2004, Heidelberg, Deutschland

Publ.-Id: 10032 - Permalink


Testing novel time of flight detectors at ELBE: Overview
Dohrmann, F.;
  • Lecture (Conference)
    HADES Collaboration Meeting, 30.10.2004, Darmstadt, Dtl.

Publ.-Id: 10030 - Permalink


Testing novel time of flight detectors at ELBE: Status report
Dohrmann, F.;
  • Lecture (Conference)
    CBM Collaboration Meeting, 07.10.2004, Darmstadt, Dtl.

Publ.-Id: 10029 - Permalink


Electroproduction of 3,4H-λ states on Helium
Dohrmann, F.;
  • Lecture (Conference)
    19th European Conference on FEW-Body Problems in Physics, 23.08.2004, Groningen, Netherlands

Publ.-Id: 10028 - Permalink


Die besondere Rolle der seltsamen Quarks in Kernen und Kernmaterie
Dohrmann, F.;
  • Lecture (others)
    Physikalisches Kolloquium der Technischen Universität Dresden, 22.06.2004, Dresden, Deutschland

Publ.-Id: 10027 - Permalink


Productions of antikaons in p+Au and p+C collisions
Dohrmann, F.;
  • Lecture (Conference)
    DPG Frühjahrstagung, 10.03.2004, Köln, Deutschland

Publ.-Id: 10026 - Permalink


Testing new time of flight detectors at ELBE: Status report
Dohrmann, F.;
  • Lecture (Conference)
    CBM Collaboration Meeting, 13.02.2004, Darmstadt, Deutschland

Publ.-Id: 10025 - Permalink


In-beam PET for hadron therapy using LSO/APD-array detectors
Crespo, P.;
  • Lecture (Conference)
    41th General (Open) Meeting of the Crystal Clear Collaboration, CERN, 29.09.2004, Geneva, Switzerland

Publ.-Id: 10024 - Permalink


In-situ monitoring with PET: Suppression of random coincidences during in-beam PET measurements
Crespo, P.;
  • Lecture (Conference)
    ENLIGHT Workpackage 5, 06.06.2004, Paris, France

Publ.-Id: 10023 - Permalink


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