TY - JOUR A1 - Golusda, L. A1 - Kühl, A. A. A1 - Lehmann, M. A1 - Dahlke, K. A1 - Mueller, S. A1 - Boehm-Sturm, P. A1 - Saatz, Jessica A1 - Traub, Heike A1 - Schnorr, J. A1 - Freise, C. A1 - Taupitz, M. A1 - Biskup, K. A1 - Blanchard, V. A1 - Klein, O. A1 - Sack, I. A1 - Siegmund, B. A1 - Paclik, D. T1 - Visualization of inflammation in experimental colitis by magnetic resonance imaging using very small superparamagnetic iron oxide particles JF - Frontiers in physiology N2 - Inflammatory bowel diseases (IBD) comprise mainly ulcerative colitis (UC) and Crohn´s disease (CD). Both forms present with a chronic inflammation of the (gastro) intestinal tract, which induces excessive changes in the composition of the associated extracellular matrix (ECM). In UC, the inflammation is limited to the colon, whereas it can occur throughout the entire gastrointestinal tract in CD. Tools for early diagnosis of IBD are still very limited and highly invasive and measures for standardized evaluation of structural changes are scarce. To investigate an efficient non-invasive way of diagnosing intestinal inflammation and early changes of the ECM, very small superparamagnetic iron oxide nanoparticles (VSOPs) in magnetic resonance imaging (MRI) were applied in two mouse models of experimental colitis: the dextran sulfate sodium (DSS)-induced colitis and the transfer model of colitis. For further validation of ECM changes and inflammation, tissue sections were analyzed by immunohistochemistry. For in depth ex-vivo investigation of VSOPs localization within the tissue, Europium-doped VSOPs served to visualize the contrast agent by imaging mass cytometry (IMC). VSOPs accumulation in the inflamed colon wall of DSS-induced colitis mice was visualized in T2* weighted MRI scans. Components of the ECM, especially the hyaluronic acid content, were found to influence VSOPs binding. Using IMC, colocalization of VSOPs with macrophages and endothelial cells in colon tissue was shown. In contrast to the DSS model, colonic inflammation could not be visualized with VSOP-enhanced MRI in transfer colitis. VSOPs present a potential contrast agent for contrast-enhanced MRI to detect intestinal inflammation in mice at an early stage and in a less invasive manner depending on hyaluronic acid content. KW - Inflammation KW - Imaging KW - Immunohistochemistry KW - MRI KW - Nanoparticle KW - Extracellular matrix KW - Laser ablation KW - ICP-MS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555395 DO - https://doi.org/10.3389/fphys.2022.862212 SN - 1664-042X VL - 13 IS - July 2022 SP - 1 EP - 15 PB - Frontiers Research Foundation CY - Lausanne AN - OPUS4-55539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wintzheimer, S. A1 - Szczerba, Wojciech A1 - de Oliveira Guilherme Buzanich, Ana A1 - Kashiwaya, S. A1 - Klein, A. A1 - Jaegermann, W. A1 - Toupance, T. A1 - Shmeliov, A. A1 - Nicolosi, V. A1 - Heuzé, K. A1 - Mandel, K. A1 - Dembski, S. T1 - Discovering the determining parameters for the photocatalytic activity of TiO2 colloids based on an anomalous dependence on the specific surface area JF - Particle & Particle Systems Characterization N2 - The photocatalytic (PC) performance of titanium dioxide (TiO2) nanoparticles strongly depends on their specific surface, the presence of crystal defects, their crystal phase, and the exposed crystal facets. In order to understand which of these factors contributes most significantly to the PC activity of TiO2 colloids, all of them have to be individually analyzed. This study entails the synthesis of five anatase nanocrystal samples. By maintaining the same reactant ratios as well as hydrothermal sol–gel synthesis route and only varying the autoclaving time or temperature, different crystallite sizes are obtained under comparable experimental conditions. A decrease in PC performance with increase in specific surface area is found. Such an unexpected counterintuitive result establishes the basis for a better understanding of the crucial factors that ultimately determine the PC activity. These are investigated by studying nanocrystals bulk and surface structure and morphology using a selection of complementary analysis methods (X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS), X-ray diffraction (XRD)…). It is found that a change in the nanocrystal morphology from an equilibrium state truncated tetragonal bipyramid to a more elongated rod-like structure accompanied by an increase in oxygen vacancies is responsible for an augmented PC activity of the TiO2 nanocrystals. KW - Ti-based colloids KW - Photocatalysis KW - Spectroscopy KW - XAFS PY - 2018 DO - https://doi.org/10.1002/ppsc.201800216 SN - 0934-0866 SN - 1521-4117 VL - 35 IS - 9 SP - 1800216, 1 EP - 10 PB - Wiley Online Library AN - OPUS4-46068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kelm, Jürgen A1 - Kühn, H. A1 - Klein, M. A1 - Wiesmath, A. A1 - Demco, D.E. A1 - Blümich, B. A1 - Gold, P.W. T1 - The NMR-MOUSE: quality control of elastomers JF - Journal of magnetic resonance KW - NMR-MOUSE KW - Double-quantum NMR KW - Quality control KW - Elastomers PY - 2001 SN - 1090-7807 SN - 0022-2364 VL - 19 SP - 497 EP - 499 PB - Elsevier CY - San Diego, Calif. AN - OPUS4-1034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ressel, P. A1 - Österle, Werner A1 - Urban, Ingrid A1 - Dörfel, Ilona A1 - Klein, A. A1 - Vogel, K. A1 - Kräutle, H. T1 - Transmission electron microscopy study of rapid thermally annealed Pd/Ge contacts on IN0.53Ga0.47As JF - Journal of applied physics PY - 1996 SN - 0021-8979 SN - 1089-7550 VL - 88 SP - 3910 EP - 3914 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-2514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klein, A. A1 - Urban, Ingrid A1 - Ressel, P. A1 - Nebauer, E. A1 - Merkel, U. A1 - Österle, Werner T1 - Preparation, transmission electron microscopy, and microanalytical investigations of metal-III-V semiconductor interfaces JF - Materials characterization PY - 1996 SN - 1044-5803 SN - 1873-4189 VL - 37 SP - 143 EP - 151 PB - Elsevier CY - New York, NY AN - OPUS4-2528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Nebauer, E. A1 - Hilsenbeck, J. A1 - Würfl, J. A1 - Klein, A. T1 - XTEM and TFXRD investigations of ohmic Ti/Al/Ti/Au/WSiN contacts on AlGaN/GaN HFET layer systems JF - Semiconductor science and technology N2 - The microstructural features of the high-temperature-stable ohmic contact system Ti/Al/Ti/Au/WSiN on AlGaN/GaN were investigated using analytical transmission electron microscopy and thin film x-ray diffraction. For two typical rapid thermal annealing steps at 750 °C (non-ohmic behaviour) and 850 °C (ohmic behaviour) the intermetallic phases at the metal-semiconductor interface are presented. Increased annealing leads to the transformation of an Al2Au-AlAuTi phase mixture to a mixture of Al2Au-Al3Au8 phases and the formation of Ti-Al-nitride layers at the interfaces. In light of these results the electrical contact properties are discussed. PY - 2002 DO - https://doi.org/10.1088/0268-1242/17/3/312 SN - 0268-1242 SN - 1361-6641 VL - 17 IS - 3 SP - 249 EP - 254 PB - IOP Publ. CY - Bristol AN - OPUS4-1380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Klein, A. A1 - Rechenberg, I. A1 - Krüger, D. T1 - AES Depth Profiling of Semiconducting Epitaxial Layers with Thicknesses in the Nanometre Range Using an Ion Beam Bevelling Technique JF - Surface and interface analysis KW - AES KW - Depth profiling KW - Ion beam bevelling PY - 1997 SN - 0142-2421 SN - 1096-9918 VL - 25 SP - 458 EP - 463 PB - Wiley CY - Chichester AN - OPUS4-7098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Klein, H.-H. A1 - Schade, A. A1 - Pruckner, F. A1 - Michel, S. T1 - Kathodischer Korrosionsschutz von Stahl in Beton - Instandsetzung des Parkhauses "Am Gericht" in Frankfurt am Main JF - Beton- und Stahlbetonbau N2 - Die Instandsetzung von Stahlbetonbauteilen bzw.-werken, welche durch chloridinduzierte Korrosion der Bewehrung gefährdet oder bereits geschädigt sind, hat in den letzten Jahrzehnten weltweit an Bedeutung gewonnen. Der kathodische Korrosionsschutz, als elektrochemisches Instandsetzungsverfahren, bildet in diesem Fall eine zuverlässige und oftmals kostengünstige Methode zur Instandsetzung. Am Beispiel des Parkhauses Am Gericht in Frankfurt am Main werden die Durchführung solch einer Maßnahme sowie die Besonderheiten des Verfahrens beschrieben. Es werden die theoretischen Hintergründe erläutert und die praktische Umsetzung sowie zu klärende Detailfragen beschrieben. Die Daten der ersten Depolarisationsmessungen zeigen den aktuellen Zustand der Anlage sowie des Schutzobjektes. KW - Stahlbeton KW - Kathodischer Korrosionsschutz KW - Korrosion KW - Lochkorrosion KW - Instandsetzung KW - Elektrochemische Verfahren PY - 2007 SN - 0005-9900 SN - 1437-1006 VL - 102 IS - 5 SP - 310 EP - 320 PB - Ernst CY - Berlin AN - OPUS4-14769 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klein, H.-H. A1 - Schade, A. A1 - Eichler, Thorsten A1 - Pruckner, F. T1 - Parkhaus "Am Gericht" in Frankfurt am Main - Eine Sanierung mit kathodischem Korrosionsschutz JF - Bautechnik N2 - Parkhäuser haben nach mehreren Jahrzehnten der Nutzung häufig Sanierungsbedarf in Bezug auf die tragende Stahlbetonkonstruktion, die durch eingedrungene Chloride aus eingeschlepptem Tausalz und die hierdurch hervorgerufene Korrosion der Bewehrung in der Tragfähigkeit erheblich beeinträchtigt sein kann. Das Verfahren des kathodischen Korrosionsschutzes kann hier als elektrochemisches Instandsetzungsverfahren eine wirtschaftliche und zuverlässige Alternative zu herkömmlichen Sanierungsverfahren bieten. Voraussetzungen sind intensive Voruntersuchungen, die Kenntnis der sinnvollen Anwendungsgrenzen des Systems, eine qualitativ hochwertige bauliche Umsetzung des Systems und die Nutzung der Möglichkeiten der Überwachung des Instandsetzungserfolges durch Monitoring, was am Beispiel des Parkhauses Am Gericht in Frankfurt am Main erläutert wird. Parking garage Am Gericht in Frankfurt am Main - a refurbishment with cathodic corrosion protection. After several decades in use a refurbishment is often necessary for the bearing structure of reinforced concrete parking garages due to chlorides, which have been brought into concrete by road salt, and the resulting corrosion of the reinforcement, which may lead to a serious decrease of the bearing capacity. With the system of the cathodic protection of the reinforcement exists a cost-effective and reliable technique as an alternative to common solutions. An intensive investigation of the structure, the knowledge of the reasonable limits of the system, excellent design and execution of the construction work and the monitoring of the working system are nevertheless required, which is illustrated by the example of the parking garage Am Gericht in Frankfurt am Main. KW - Stahlbeton KW - Kathodischer Korrosionsschutz KW - Korrosion KW - Lochkorrosion KW - Instandsetzung KW - Elektrochemische Verfahren PY - 2007 DO - https://doi.org/10.1002/bate.200710040 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 SN - 0932-8351 VL - 84 IS - 7 SP - 465 EP - 476 PB - Ernst & Sohn CY - Berlin AN - OPUS4-17871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Renz, F. A1 - Zaba, C. A1 - Roßberg, L. A1 - Jung, S. A1 - Klein, M. A1 - Klingelhöfer, G. A1 - Wünsche, A. A1 - Reinhardt, S. A1 - Menzel, Michael T1 - Spin transition in heptanuclear star-shaped iron(III)-antimony(V) NCS- and CN-bridged compounds JF - Polyhedron N2 - The precursor [FeIII(L)Cl] (LH2 = N,N'-bis(2'-hydroxy-benzyliden)-1,6-diamino-3-azahexane) has been prepared and Mössbauer spectroscopy assigned a high-spin (S = 5/2) state at room temperature. The precursor is combined with the bridging units [SbV(X)6]- (X = CN-, NCS-) to yield star-shaped heptanuclear clusters [(LFeIII-X)6SbV]Cl5. The star-shaped compounds are in general high-spin systems at room temperature. On cooling to 20 K some of the iron(III) centers switch to the low-spin state as indicated by Mössbauer spectroscopy, i.e. multiple electronic transitions. While the cyano-bridged complex performs a multiple spin transition the thiocyanate-compound shows no significant population at both temperatures. KW - Heptanuclear KW - High-spin molecule KW - SbV KW - Multistability KW - Multiple spin transition PY - 2009 DO - https://doi.org/10.1016/j.poly.2008.12.027 SN - 0277-5387 VL - 28 IS - 9-10 SP - 2036 EP - 2038 PB - Elsevier CY - Amsterdam [u.a.] ; Jena AN - OPUS4-19659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -