TY - JOUR A1 - Weise, Frank A1 - von Werder, Julia A1 - Manninger, Tanja A1 - Maier, Bärbel A1 - Fladt, Matthias A1 - Simon, Sebastian A1 - Gardei, Andre A1 - Höhnel, Desirée A1 - Pirskawetz, Stephan A1 - Meng, Birgit T1 - A multiscale and multimethod approach to assess and mitigate concrete damage due to alkali-silica reaction N2 - Alkali-silica reaction (ASR) is a chemical reaction within concrete which can lead over time to cracking and spalling. Due to the complexity of the problem, it still causes damage to concrete constructions worldwide. The publication aims to illustrate the interdisciplinary research of the German Federal Institute for Materials Research and Testing (BAM) within the last 20 years, considering all aspects of ASR topics from the macro to the micro level. First, methods for characterization and assessment of ASR risks and reaction products used at BAM are explained and classified in the international context. Subsequently the added value of the research approach by combining different, preferably nondestructive, methods across all scales is explained using specific examples from a variety of research projects. Aspects covered range from the development of new test-setups to assess aggregate reactivity, to analysis of microstructure and reaction products using microscopical, spectroscopical and X-ray methods, to the development of a testing methodology for existing concrete pavements including in-depth analysis of the visual damage indicator and the de-icing salt input using innovative testing techniques. Finally, research regarding a novel avoidance strategy that makes use of internal hydrophobization of the concrete mix is presented. KW - Mitigation strategies KW - Concrete KW - Damage analysis KW - Alkali silica reaction KW - Road pavement KW - Accelerated testing KW - Non-destructive testing KW - Microstructure PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:101:1-2022052515100075090235 DO - https://doi.org/10.1002/adem.202101346 SN - 1527-2648 VL - 24 IS - 6 SP - 1 EP - 36 PB - Wiley-VCH CY - Weinheim AN - OPUS4-54951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bayram, Rabia T1 - Rekombinante Herstellung einer Amin-Oxidase aus Aspergillus niger und deren Einsatz in der Biosensorik N2 - Das Ziel der vorliegenden Arbeit war die rekombinante Herstellung der AnFAO in E. coli, welche ursprünglich von A. niger produziert wird, und deren anschließende Anwendung in der Entwick-lung eines Fumonisin- Biosensors für die Lebensmittelanalytik. In Bezug auf die aktuell steigen-den Lebensmittel- und Rohstoffpreise ist die Entwicklung eines Schnelltestsystems zur Detektion von Kontaminationen mit Mykotoxinen besonders gefragt, da zusätzliche Verluste und Kosten verhindert werden können. Für die Herstellung der AnFAO als MBP-Fusionsprotein und Biotin-Fusionsprotein mit zusätzlichem 6x His-Tag wurden die pET-MBP-AnFAO und pRSET-BH6-An-FAO Expressionsvektoren erfolgreich konstruiert. Die lösliche Expression im Cytoplasma wurde von MBP-AnFAO erreicht, wobei die Expression von BH6-AnFAO in inclusion bodies erfolgte und keine Aktivität des Enzyms nachgewiesen wurde. Die Enzymaktivität von MBP-AnFAO wurde im optischen Assay und amperometrisch durch die Detektion von H2O2 ermittelt. Im optischen Assay wurde die maximale spezifische Aktivität von 2,45 U/mg bei 45 °C, einer Enzymkonzentration von 3 μM und 50 μM FB1 erreicht. Generell wurden mit FB1 als Enzymsubstrat höhere Fluoreszenzsig-nale und dementsprechend höhere Enzymaktivitäten als für FB2 beobachtet. Es wurde ein linearer Zusammenhang der Enzymaktivitäten mit der Substratkonzentration beobachtet. Außerdem wurde ein Anstieg der H2O2-Konzentration mit zunehmender Inkubationszeit (bis zu 60 Minuten) erkannt. Des Weiteren wurde der Einfluss des MBP-Fusionsproteins auf die Enzymaktivität des AnFAO untersucht. Dabei wurde anhand von wesentlich geringeren Aktivitäten für AnFAO allein ein eventueller Einfluss des MBP auf dessen Aktivität festgestellt. Ein elektrochemischer Aufbau wurde zur Entwicklung eines Fumonisin- Sensors genutzt. Dazu wurde nachgewiesen, dass FB1 von rekombinant hergestelltem MBP-AnFAO unter Bildung von NH3 und H2O2 zu weniger toxi-schem FB1, dem FPy1, oxidiert werden kann. An der PB/Kohlenstoff-Elektrode, welche sensitiver gegenüber H2O2 und stabiler als die CoPC/Kohlenstoff Elektrode war, wurde die Reduktion des enzymatisch gebildeten H2O2 gemessen. Die Erstellung einer FB1- Kalibriergerade mit FB1- Lösun-gen verschiedener Konzentrationen zeigte, dass das Enzym auch in immobilisierter Form in der Lage ist unterschiedliche Konzentrationen an FB1 zu desaminieren. Dazu gehört auch der Kon-zentrationsbereich unterhalb des festgelegten Grenzwertes von 2,7 μmol/kg für Fumonisin. Die amperometrischen Kurven hierfür wurden an der PB/Kohlenstoff-Elektrode erfolgreich aufge-nommen. Störungen des H2O2- Redoxstroms durch das Enzym, der Enzymsubstrate und der Ne-benprodukte während der amperometrischen Messung wurden ausgeschlossen. Sowohl im opti-schen als auch im amperometrischen Assay wurde ausschließlich das enzymatisch gebildete H2O2 bestimmt. KW - Fumonisin KW - Mykotoxin KW - rekombinante Protein Expression KW - Amperometrie PY - 2022 SP - 1 EP - 104 PB - Berliner Hochschule für Technik CY - Berlin AN - OPUS4-57724 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yao, J. A1 - Jiang, T. A1 - Ji, Y. A1 - An-Stepec, Biwen Annie A1 - Koerdt, Andrea A1 - Cai, Z. A1 - Dong, C. A1 - Ge, Y. A1 - Qi, Z. T1 - Water-Fueled Autocatalytic Bactericidal Pathway based on e-Fenton-Like Reactions Triggered by Galvanic Corrosion and Extracellular Electron Transfer N2 - Water is generally considered to be an undesirable substance in fuel system, which may lead to microbial contamination. The antibacterial strategies that can turn water into things of value with high disinfection efficacy have been urgently needed for fuel system. Here, we reveal a water-fueled autocatalytic bactericidal pathway comprised by bi-metal micro-electrode system, which can spontaneously produce reactive oxygen species (mainly H2O2 and O2•–) by the electron Fenton-like reaction in water medium without external energy., The respiratory chain component of bacteria and the galvanic corrosion on the coated metals were two electron sources in the system. The specific model of Ag-Ru water-fueled autocatalytic (WFA) microelectrode particles presents extremely high disinfection efficiency (>99.9999%) in less than one hour for three aerobic bacteria (Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis) in LB media and high disinfection efficiency for the anaerobic bacteria (Desulfovibrio alaskensis) in Postgate E media without natural light irradiation. Overall, the novel WFA Ag-Ru antibacterial material explored in this study has a high potential for sterilizing applications in fuel system and this work provides the potential for the development of non-chemical and water-based antibacterial materials, such as WFA Ag-Ru antibacterial coating on stainless steel. KW - Fenton-like reaction KW - Reactive oxygen species KW - Disinfection Fuel KW - Silver KW - Ruthenium KW - MIC PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555186 DO - https://doi.org/10.1016/j.jhazmat.2022.129730 SN - 0304-3894 VL - 440 SP - 1 EP - 11 PB - Elsevier CY - Amsterdam AN - OPUS4-55518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaufmann, Jan Ole A1 - Brangsch, J. A1 - Kader, A. A1 - Saatz, Jessica A1 - Mangarova, D. B. A1 - Zacharias, M. A1 - Kempf, W. E. A1 - Schwaar, T. A1 - Ponader, Marco A1 - Adams, L. C. A1 - Möckel, J. A1 - Botnar, R. M. A1 - Taupitz, M. A1 - Mägdefessel, L. A1 - Traub, Heike A1 - Hamm, B. A1 - Weller, Michael G. A1 - Makowski, M. R. T1 - ADAMTS4-specific MR-probe to assess aortic aneurysms in vivo using synthetic peptide libraries N2 - The incidence of abdominal aortic aneurysms (AAAs) has substantially increased during the last 20 years and their rupture remains the third most common cause of sudden death in the cardiovascular field after myocardial infarction and stroke. The only established clinical parameter to assess AAAs is based on the aneurysm size. Novel biomarkers are needed to improve the assessment of the risk of rupture. ADAMTS4 (A Disintegrin And Metalloproteinase with ThromboSpondin motifs 4) is a strongly upregulated proteoglycan cleaving enzyme in the unstable course of AAAs. In the screening of a one-bead-one-compound library against ADAMTS4, a low-molecular-weight cyclic peptide is discovered with favorable properties for in vivo molecular magnetic resonance imaging applications. After identification and characterization, it’s potential is evaluated in an AAA mouse model. The ADAMTS4-specific probe enables the in vivo imaging-based prediction of aneurysm expansion and rupture. KW - Peptide KW - Peptide library KW - OBOC library KW - Combinatorial chemistry KW - Peptide aptamers KW - Binding molecule KW - Affinity KW - Synthetic peptides KW - Contrast agent KW - Magnetic resonance imaging KW - One-bead-one-compound library KW - On-chip screening KW - Lab-on-a-chip KW - MALDI-TOF MS KW - SPR KW - Surface plasmon resonance KW - Alanine scan KW - Fluorescence label KW - MST KW - Docking KW - Chelate PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560930 DO - https://doi.org/10.1038/s41467-022-30464-8 N1 - Geburtsname von Ponader, Marco: Wilke, M. - Birth name of Ponader, Marco: Wilke, M. VL - 13 IS - 1 SP - 1 EP - 18 PB - Springer Nature Limited CY - Heidelberg AN - OPUS4-56093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Hampel, S. A1 - Fittschen, UEA A1 - Streli, C. A1 - Radtke, Martin T1 - Reconstruction for coded aperture full-field x-ray fluorescence imaging N2 - X-ray fluorescence imaging is a well-established tool in materials characterization. In this work, we present the adaption of coded aperture imaging to full-field X-ray fluorescence imaging at the synchrotron. Coded aperture imaging has its origins in astrophysics, and has several advantages: Coded apertures are relatively easy to fabricate, achromatic, allow a high photon throughput, and high angular acceptance. Coded aperture imaging is a two-step-process, consisting of the measurement process and a reconstruction step. Different programs have been written, for the raytracing/forward projection and the reconstruction. Experiments with coded aperture in combination with a Color X-ray Camera and an energy-dispersive area detector, have been conducted at the BAMline. Measured samples were successfully reconstructed, and gave a 9.1-fold increase in count rate compared to a polycapillary optic. KW - Synchrotron KW - BAMline KW - Coded Aperture PY - 2022 SN - 1097-0002 VL - 65 SP - 57 EP - 70 PB - Cambridge University Press CY - Cambridge AN - OPUS4-56350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Häusler, I. A1 - Knigge, Xenia A1 - Hodoroaba, Vasile-Dan A1 - Emmerling, Franziska A1 - Reiss, P. A1 - Resch-Genger, Ute T1 - One-Pot Heat-Up Synthesis of ZnSe Magic-Sized Clusters Using Thiol Ligands N2 - The synthesis of two new families of ZnSe magic-sized clusters (MSCs) is achieved using the thiol ligand 1-dodecanethiol in a simple one-pot heat-up approach. The sizes of the MSCs are controlled with the thiol ligand concentration and reaction temperature. KW - ZnSe KW - Magic-sized cluster KW - Dodecanethiol KW - Semiconductor nanocrystals KW - One-pot synthesis PY - 2022 DO - https://doi.org/10.1021/acs.inorgchem.2c00041 VL - 61 IS - 19 SP - 7207 EP - 7211 PB - ACS Publications CY - Washington, DC (USA) AN - OPUS4-54880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shimada, Y. A1 - Ikeda, Yuki A1 - Yoshida, K. A1 - Sato, M. A1 - Chen, J. A1 - Du, Y. A1 - Inoue, K. A1 - Maaß, Robert A1 - Nagai, Y. A1 - Konno, T. T1 - In situ thermal annealing transmission electron microscopy of irradiation induced Fe nanoparticle precipitation in Fe–Si alloy N2 - The typical experimental conditions inside a transmission electron microscope (TEM), such as ultra-high vacuum, high-energy electron irradiation, and surface effects of ultrathin TEM specimens, can be the origin of unexpected microstructural changes compared with that of bulk material during in situ thermal-annealing experiments. In this paper, we report on the microstructural changes of a Fe–15%Si alloy during in situ TEM annealing, where, in its bulk form, it exhibits an ordering transformation from D03 to B2 at 650 °C. Using a heating-pot type double tilt holder with a proportional–integral–differential control system, we observed the precipitation of α-Fe both at the sample surface and inside the sample. Surface precipitates formed via surface diffusion are markedly large, several tens of nm, whereas precipitates inside the specimen, which are surrounded by Fe-poor regions, reach a maximum size of 20 nm. This unexpected microstructural evolution could be attributed to vacancies on Si sites, which are induced due to high-energy electron irradiation before heating, as well as enhanced thermal diffusion of Fe atoms. KW - In situ thermal-annealing experiment KW - Microstructural changes of a Fe Si alloy KW - Microstructural evolution PY - 2022 DO - https://doi.org/10.1063/5.0070471 SN - 0021-8979 VL - 131 IS - 16 SP - 1 EP - 8 PB - AIP Publishing AN - OPUS4-54728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Anderhalten, L. A1 - Silva, R. V. A1 - Morr, A. A1 - Wang, S. A1 - Smorodchenko, A. A1 - Saatz, Jessica A1 - Traub, Heike A1 - Mueller, S. A1 - Boehm-Sturm, P. A1 - Rodriguez-Sillke, Y. A1 - Kunkel, D. A1 - Hahndorf, J. A1 - Paul, F. A1 - Taupitz, M. A1 - Sack, I. A1 - Infante-Duarte, C. T1 - Different Impact of Gadopentetate and Gadobutrol on Inflammation-Promoted Retention and Toxicity of Gadolinium Within the Mouse Brain N2 - Objectives: Using a murine model of multiple sclerosis, we previously showed that repeated administration of gadopentetate dimeglumine led to retention of gadolinium (Gd) within cerebellar structures and that this process was enhanced with inflammation. This study aimed to compare the kinetics and retention profiles of Gd in inflamed and healthy brains after application of the macrocyclic Gd-based contrast agent (GBCA) gadobutrol or the linear GBCA gadopentetate. Moreover, potential Gd-induced neurotoxicity was investigated in living hippocampal slices ex vivo. Materials and Methods: Mice at peak of experimental autoimmune encephalomyelitis (EAE; n = 29) and healthy control mice (HC; n = 24) were exposed to a cumulative dose of 20 mmol/kg bodyweight of either gadopentetate dimeglumine or gadobutrol (8 injections of 2.5 mmol/kg over 10 days). Magnetic resonance imaging (7 T) was performed at baseline as well as at day 1, 10, and 40 post final injection (pfi) of GBCAs. Mice were sacrificed after magnetic resonance imaging and brain and blood Gd content was assessed by laser ablation-inductively coupled plasma (ICP)-mass spectrometry (MS) and ICP-MS, respectively. In addition, using chronic organotypic hippocampal slice cultures, Gd-induced neurotoxicity was addressed in living brain tissue ex vivo, both under control or inflammatory (tumor necrosis factor α [TNF-α] at 50 ng/μL) conditions. Results: Neuroinflammation promoted a significant decrease in T1 relaxation times after multiple injections of both GBCAs as shown by quantitative T1 mapping of EAE brains compared with HC. This corresponded to higher Gd retention within the EAE brains at 1, 10, and 40 days pfi as determined by laser ablation-ICP-MS. In inflamed cerebellum, in particular in the deep cerebellar nuclei (CN), elevated Gd retention was observed until day 40 after last gadopentetate application (CN: EAE vs HC, 55.06 ± 0.16 μM vs 30.44 ± 4.43 μM). In contrast, gadobutrol application led to a rather diffuse Gd content in the inflamed brains, which strongly diminished until day 40 (CN: EAE vs HC, 0.38 ± 0.08 μM vs 0.17 ± 0.03 μM). The analysis of cytotoxic effects of both GBCAs using living brain tissue revealed an elevated cell death rate after incubation with gadopentetate but not gadobutrol at 50 mM. The cytotoxic effect due to gadopentetate increased in the presence of the inflammatory mediator TNF-α (with vs without TNF-α, 3.15% ± 1.18% vs 2.17% ± 1.14%; P = 0.0345). Conclusions: In the EAE model, neuroinflammation promoted increased Gd retention in the brain for both GBCAs. Whereas in the inflamed brains, efficient clearance of macrocyclic gadobutrol during the investigated time period was observed, the Gd retention after application of linear gadopentetate persisted over the entire observational period. Gadopentetate but not gadubutrol appeared to be neurotoxic in an ex vivo paradigm of neuronal inflammation. KW - Imaging KW - ICP-MS KW - Gadolinium KW - Contrast agent KW - Laser ablation KW - Brain KW - Multiple sclerosis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546910 DO - https://doi.org/10.1097/RLI.0000000000000884 SN - 0020-9996/22/0000–0000 VL - 57 IS - 10 SP - 677 EP - 688 PB - Wolters Kluwer N.V. CY - Alphen aan den Rijn, The Netherlands AN - OPUS4-54691 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kolmangadi, Mohamed Aejaz A1 - Smales, Glen Jacob A1 - ZhuoQing, Li A1 - Yildirim, Arda A1 - Wuckert, E. A1 - Eutionnat, S. A1 - Demel, F. A1 - Huber, P A1 - Lasachat, S. A1 - Schönhals, Andreas T1 - Side Chain Length-Dependent Dynamics and Conductivity in Self-Assembled Ion N2 - We study the molecular mobility and electrical conductivity of a homologous series of linear shaped columnar ionic liquid crystals ILCn, (n = 8, 10, 12, 14, 16) using broadband dielectric spectroscopy (BDS), specific heat spectroscopy (SHS), and X-ray scattering. We aim to understand how the alkyl chain length influences the dynamics and electric conductivity in this system. Two dielectrically active relaxation modes are observed, the γ and the αcore process, that correspond to the localized fluctuations of the alkyl chains and cooperative motions of the aromatic core in the columns, respectively. Both the γ relaxation and the αcore process slow down with increasing alkyl chain length. SHS reveals one relaxation process, the αalkyl process that has a similar temperature dependence as that of the αcore process for ILC12, 14, and 16 but shifts to higher temperature for ILC8 and 10. For ILC12, 14, and 16, the absolute values of DC conductivity increase by 4 orders of magnitude at the transition from the plastic crystalline to hexagonal columnar phase. For ILC8 and 10, the DC conductivity behavior is similar to ionic liquids, where the conductivity is coupled with structural relaxation. Small-angle X-ray investigations reveal that both the intercolumnar distance and the disorder coherence length increase with alkyl chain length; conversely, the DC conductivity decreases monotonically. KW - Ionic Liquid Crystals PY - 2022 DO - https://doi.org/10.1021/acs.jpcc.2c03023 SN - 1932-7447 VL - 126 IS - 27 SP - 10995 EP - 11006 PB - ACS AN - OPUS4-55194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Boyraz, B. A1 - Saatz, Jessica A1 - Pompös, I.-M. A1 - Gad, Michel A1 - Dernedde, J. A1 - Maier, A.-M. B. A1 - Moscovitz, O. A1 - Seeberger, P. H. A1 - Traub, Heike A1 - Tauber, R. T1 - Imaging Keratan Sulfate in Ocular Tissue Sections by Immunofluorescence Microscopy and LA-ICP-MS N2 - Carbohydrate-specific antibodies can serve as valuable tools to monitor alterations in the extracellular matrix resulting from pathologies. Here, the keratan sulfate-specific monoclonal antibody MZ15 was characterized in more detail by immunofluorescence microscopy as well as laser ablation ICP-MS using tissue cryosections and paraffin-embedded samples. Pretreatment with keratanase II prevented staining of samples and therefore demonstrated efficient enzymatic keratan sulfate degradation. Random fluorescent labeling and site-directed introduction of a metal cage into MZ15 were successful and allowed for a highly sensitive detection of the keratan sulfate landscape in the corneal stroma from rats and human tissue. KW - Laser ablation KW - Imaging KW - Glycosaminoglycan KW - ICP-MS KW - Immunohistochemistry KW - Immunofluorescence KW - Tissue PY - 2022 DO - https://doi.org/10.1021/acsabm.1c01240 VL - 5 IS - 2 SP - 853 EP - 861 PB - American Chemical Society CY - Washington AN - OPUS4-54341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -