TY - JOUR A1 - Trimpin, Sarah A1 - Yenchick, Frank S. A1 - Lee, Chuping A1 - Hoang, Khoa A1 - Pophristic, Milan A1 - Karki, Santosh A1 - Marshall, Darrell D. A1 - Lu, I-Chung A1 - Lutomski, Corinne A. A1 - El-Baba, Tarick J. A1 - Wang, Beixi A1 - Pagnotti, Vincent S. A1 - Meher, Anil K. A1 - Chakrabarty, Shubhashis A1 - Imperial, Lorelei F. A1 - Madarshahian, Sara A1 - Richards, Alicia L. A1 - Lietz, Christopher B. A1 - Moreno-Pedraza, Abigail A1 - Leach, Samantha M. A1 - Gibson, Stephen C. A1 - Elia, Efstathios A. A1 - Thawoos, Shameemah M. A1 - Woodall, Daniel W. A1 - Jarois, Dean R. A1 - Davis, Eric T.J. A1 - Liao, Guochao A1 - Muthunayake, Nisansala S. A1 - Redding, McKenna J. A1 - Reynolds, Christian A. A1 - Anthony, Thilani M. A1 - Vithanarachchi, Sashiprabha M. A1 - DeMent, Paul A1 - Adewale, Adeleye O. A1 - Yan, Lu A1 - Wager-Miller, James A1 - Ahn, Young-Hoon A1 - Sanderson, Thomas H. A1 - Przyklenk, Karin A1 - Greenberg, Miriam L. A1 - Suits, Arthur G. A1 - Allen, Matthew J. A1 - Narayan, Srinivas B. A1 - Caruso, Joseph A. A1 - Stemmer, Paul M. A1 - Nguyen, Hien M. A1 - Weidner, Steffen A1 - Rackers, Kevin J. A1 - Djuric, Ana A1 - Shulaev, Vladimir A1 - Hendrickson, Tamara L. A1 - Chow, Christine S. A1 - Pflum, Mary Kay H. A1 - Grayson, Scott M. A1 - Lobodin, Vladislav V. A1 - Guo, Zhongwu A1 - Ni, Chi-Kung A1 - Walker, J. Michael A1 - Mackie, Ken A1 - Inutan, Ellen D. A1 - McEwen, Charles N. T1 - New Processes for Ionizing Nonvolatile Compounds in Mass Spectrometry: The Road of Discovery to Current State-of-the-Art N2 - This Perspective covers discovery and mechanistic aspects aswell as initial applications of novel ionization processes for use in massspectrometry that guided us in a series of subsequent discoveries, instrumentdevelopments, and commercialization. Vacuum matrix-assisted ionization onan intermediate pressure matrix-assisted laser desorption/ionization sourcewithout the use of a laser, high voltages, or any other added energy wassimply unbelievable, at first. Individually and as a whole, the variousdiscoveries and inventions started to paint, inter alia, an exciting new pictureand outlook in mass spectrometry from which key developments grew thatwere at the time unimaginable, and continue to surprise us in its simplisticpreeminence. We, and others, have demonstrated exceptional analyticalutility. Our current research is focused on how best to understand, improve, and use these novel ionization processes throughdedicated platforms and source developments. These ionization processes convert volatile and nonvolatile compounds from solid orliquid matrixes into gas-phase ions for analysis by mass spectrometry using, e.g., mass-selected fragmentation and ion mobilityspectrometry to provide accurate, and sometimes improved, mass and drift time resolution. The combination of research anddiscoveries demonstrated multiple advantages of the new ionization processes and established the basis of the successes that lead tothe Biemann Medal and this Perspective. How the new ionization processes relate to traditional ionization is also presented, as wellas how these technologies can be utilized in tandem through instrument modification and implementation to increase coverage ofcomplex materials through complementary strengths. KW - Mass spectrometry PY - 2024 DO - https://doi.org/10.1021/jasms.3c00122 SN - 1879-1123 VL - 35 IS - 12 SP - 2753 EP - 2784 PB - American Chemical Society (ACS) AN - OPUS4-61417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nelson, G. A1 - Boehm, U. A1 - Bagley, S. A1 - Bajcsy, P. A1 - Bischof, J. A1 - Brown, C. M. A1 - Dauphin, A. A1 - Dobbie, I. M. A1 - Eriksson, J. E. A1 - Faklaris, O. A1 - Fernandez-Rodriguez, J. A1 - Ferrand, A. A1 - Gelman, L, A1 - Gheisari, A. A1 - Hartmann, H. A1 - Kukat, C. A1 - Laude, A. A1 - Mitkovski, M. A1 - Munck, S. A1 - North, A. J. A1 - Rasse, T. A1 - Resch-Genger, Ute A1 - Schuetz, L. C. A1 - Seitz, A. A1 - Strambio-De-Castillia, C. A1 - Swedlow, J. R. A1 - Alexopoulos, I. A1 - Aumayr, K. A1 - Avilov, S. A1 - Bakker, G.-J. A1 - Bammann, R. R. A1 - Bassi, A. A1 - Beckert, H. A1 - Beer, S. A1 - Belyaev, Y. A1 - Bierwagen, J. A1 - Birngruber, K. A. A1 - Bosch, M. A1 - Breitlow, J. A1 - Cameron, L. A. A1 - Chalfoun, J. A1 - Chambers, J. J. A1 - Chen, C.-L. A1 - Conde-Sousa, E. A1 - Corbett, A. D. A1 - Cordelieres, F. P. A1 - Del Nery, E. A1 - Dietzel, R. A1 - Eismann, F. A1 - Fazeli, E. A1 - Felscher, A. A1 - Fried, H. A1 - Gaudreault, N. A1 - Goh, W. I. A1 - Guilbert, T. A1 - Hadleigh, R. A1 - Hemmerich, P. A1 - Holst, G. A. A1 - Itano, M. S. A1 - Jaffe, C. B. A1 - Jambor, H. K. A1 - Jarvis, S. C. A1 - Keppler, A. A1 - Kirchenbuechler, D. A1 - Kirchner, M. A1 - Kobayashi, N. A1 - Krens, G. A1 - Kunis, S. A1 - Lacoste, J. A1 - Marcello, M. A1 - Martins, G. G. A1 - Metcalf, D. J. A1 - Mitchell, C. A. A1 - Moore, J. A1 - Mueller, T. A1 - Nelson, M. S. A1 - Ogg, S. A1 - Onami, S. A1 - Palmer, A. L. A1 - Paul-Gilloteaux, P. A1 - Pimentel, J. A. A1 - Plantard, L. A1 - Podder, S. A1 - Rexhepaj, E. A1 - Royon, A. A1 - Saari, M. A. A1 - Schapman, D. A1 - Schoonderwoert, V. A1 - Schroth-Diez, B. A1 - Schwartz, S. A1 - Shaw, M. A1 - Spitaler, M. A1 - Stoeckl, M. T. A1 - Sudar, D. A1 - Teillon, J. A1 - Terjung, S. A1 - Thuenauer, R. A1 - Wilms, C. D. A1 - Wright, G. D. A1 - Nitschke, R. T1 - QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy N2 - A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated, quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist’s experiments, while more than half have even failed to reproduce their own experiments1. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique2,3. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g., DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE4), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common Standards and guidelines for quality assessment and reproducibility5. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative6 was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models7,8, and tools9,10, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper 1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; 2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of Stakeholders including, researchers, imaging scientists11, bioimage analysts, bioimage informatics developers, corporate partners, Funding agencies, standards organizations, scientific publishers, and observers of such; 3) outlines the current actions of the QUAREPLiMi initiative, and 4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics. KW - Fluorescence KW - Microscopy KW - Quality assurance KW - Comparability KW - Imaging KW - Standards KW - Reference materials KW - Reliability KW - Data KW - Reference data KW - Biology KW - Medicine KW - Life science PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530629 DO - https://doi.org/10.1111/jmi.13041 SN - 1365-2818 VL - 284 IS - 1 SP - 56 EP - 73 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-53062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mozetic, M. A1 - Ostrikov, K. A1 - Ruzic, D.N. A1 - Curreli, D. A1 - Cvelbar, U. A1 - Vesel, A. A1 - Primc, G. A1 - Leisch, M. A1 - Jousten, K. A1 - Malyshev, O.B. A1 - Hendricks, J.H. A1 - Kövér, L. A1 - Tagliaferro, A. A1 - Conde, O. A1 - Silvestre, A.J. A1 - Giapintzakis, J. A1 - Buljan, M. A1 - Radic, N. A1 - Drazic, G. A1 - Bernstorff, S. A1 - Biedermann, H. A1 - Kylián, O. A1 - Hanus, J. A1 - Milosevic, S. A1 - Galtayries, A. A1 - Dietrich, Paul A1 - Unger, Wolfgang A1 - Lehocky, M. A1 - Sedlarik, V. A1 - Stana-Kleinschek, K. A1 - Drmota-Petric, A. A1 - Pireaux, J.J. A1 - Rogers, J.W. A1 - Anderle, M. T1 - Recent advances in vacuum sciences and applications N2 - Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure measurements with temporal resolution of 2 ms. Vacuum issues in the construction of huge ultra-high vacuum devices worldwide are reviewed. Recent advances in surface science and thin films include new phenomena observed in electron transport near solid surfaces as well as novel results on the properties of carbon nanomaterials. Precise techniques for surface and thin-film characterization have been applied in the conservation technology of cultural heritage objects and recent advances in the characterization of biointerfaces are presented. The combination of various vacuum and atmospheric-pressure techniques enables an insight into the complex phenomena of protein and other biomolecule conformations on solid surfaces. Studying these phenomena at solid–liquid interfaces is regarded as the main issue in the development of alternative techniques for drug delivery, tissue engineering and thus the development of innovative techniques for curing cancer and cardiovascular diseases. A review on recent advances in plasma medicine is presented as well as novel hypotheses on cell apoptosis upon treatment with gaseous plasma. Finally, recent advances in plasma nanoscience are illustrated with several examples and a roadmap for future activities is presented. KW - Vacuum KW - Surface KW - Plasma KW - Interface KW - Nanoscience PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-304884 DO - https://doi.org/10.1088/0022-3727/47/15/153001 SN - 0022-3727 SN - 1361-6463 VL - 47 IS - 15 SP - 153001-1 EP - 153001-23 PB - IOP Publ. CY - Bristol AN - OPUS4-30488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westwood, S. A1 - Josephs, R. A1 - Daireaux, A. A1 - Wielgosz, R. A1 - Davies, S. A1 - Wang, H. A1 - Rodrigues, J. A1 - Wollinger, W. A1 - Windust, A. A1 - Kang, M. A1 - Fuhai, S. A1 - Philipp, Rosemarie A1 - Kuhlich, Paul A1 - Wong, S.-K. A1 - Shimizu, Y. A1 - Pérez, M. A1 - Avila, M. A1 - Fernandes-Whaley, M. A1 - Prevoo, D. A1 - de Vos, J. A1 - Visser, R. A1 - Archer, M. A1 - LeGoff, T. A1 - Wood, S. A1 - Bearden, D. A1 - Bedner, M. A1 - Boroujerdi, A. A1 - Duewer, D. A1 - Hancock, D. A1 - Lang, B. A1 - Porter, B. A1 - Schantz, M. A1 - Sieber, J. A1 - White, E. A1 - Wise, S. A. T1 - Final report on key comparison CCQM-K55.a (estradiol): an international comparison of mass fraction purity assignment of estradiol N2 - Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM K55.a, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2009/2010. Eleven national measurement institutes and the BIPM participated. Participants were required to assign the mass fraction of estradiol present as the main component in the comparison sample (CCQM-K55.a) which consisted of a bulk estradiol hemihydrate material obtained from a commercial supplier that had been extensively but not exhaustively dried prior to sub-division into the units supplied for the comparison. Estradiol was selected to be representative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molar mass range 300–500 Da] and low polarity (pKOW < -2) for which related structure impurities can be quantified by capillary gas phase chromatography (GC) or by high performance liquid chromatography (LC). The majority of participants used a mass balance approach to determine the estradiol content. The key comparison reference value (KCRV) for estradiol in CCQM-K55.a was assigned by combination of KCRVs assigned by consensus from participant results for each orthogonal impurity class. This allowed participants to demonstrate the efficacy (or otherwise) of their implementation of the mass balance approach and to demonstrate that their assigned value for the main component agreed with the KCRV through use of internally consistent contributing methods. The KCRV for the estradiol content of the material was 984.3 mg/g with a combined standard uncertainty of 0.42 mg/g. The individual participant results showed that a relative expanded uncertainty for the purity assignment of 0.2% is a reasonable estimate of the best achievable result by an individual laboratory for a material of this complexity available in this amount at this level of purity. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 0.2% to 0.8%. The review of results that were biased from the KCRV showed that two major analytical challenges are posed by the material: the measurement of its water content and controlling for related substance artefact formation during the analysis process. The results displaying a positive bias relative to the KCRV (overestimation of estradiol content) were due to underestimation of the water content of the material, while those with a negative bias (underestimation of estradiol) overestimated the total related substance impurities through a failure to detect and control for artefact formation arising from in situ oxidative dimerization of estradiol in neutral solution prior to analysis. There was however good agreement between all participants in the identification and the quantification of the individual related structure impurities actually present in the sample. The comparison also demonstrated the utility of high-field 1H NMR for both quantitative and qualitative analysis of high purity compounds. It is noted that all the participants who used qNMR as a major or contributing technique and included it as part of, combined it or confirmed it with a conventional 'mass balance' data estimate, obtained results consistent with the KCRV. PY - 2012 DO - https://doi.org/10.1088/0026-1394/49/1A/08009 SN - 0026-1394 SN - 1681-7575 VL - 49 IS - 1A Tech. Suppl. / 08009 SP - 1 EP - 33 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-26411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ankli, P.P. A1 - Ali, A. A1 - Hodzic, S. A1 - Logachov, A. A1 - Maciejczuk, K. A1 - Milochiv, A. A1 - Hardy, S. A1 - Hardy, B. A1 - Novak, S. A1 - Kranjc, E. A1 - Kononenko, V. A1 - Saje, S. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Akmal, Loay A1 - Mrkwitschka, Paul A1 - Pellegrino, F. A1 - Rossi, A. A1 - Alladio, E. A1 - Sordello, F. A1 - Gulumian, M. A1 - Valsami-Jones, E. A1 - Andraos, C. A1 - Wepener, V. A1 - Jurkschat, K. A1 - Jones, E. A1 - Singh, D. A1 - Ibrahim, B. A1 - van der Zande, M. A1 - Fernandez-Poulussen, D. A1 - Queipo, P. A1 - Drobne, D. T1 - Data management for image-based characterisation of 2D nano-materials N2 - The ACCORDs project, funded through Horizon Europe, is pioneering a novel approach to investigate Graphene Family Materials (GFMs) through image analysis. Our aim is to unveil how these materials might influence health and the environment. To achieve this, we are developing a platform designed for the easy retrieval, access, sharing, and utilisation of GFM data and the coordination between biological and physico-chemical data formats. Integral to this platform is an OMERO-based library for image storage, alongside data collection forms and image analysis tools. Efforts are underway to streamline the process for researchers to upload and disseminate their findings, manage information within a database and navigate the data with ease. Adhering to REMBI guidelines, which set the standard for annotating biological images with metadata, we ensure our data collection is comprehensive and adheres to established best practices. Initially, we are employing thresholding and basic machine learning techniques for image segmentation, laying the groundwork for advanced analysis through deep learning to gain more profound insights. Upon completion, the project will deliver a comprehensive platform facilitating efficient data and image management concerning GFMs. This platform will enable the straightforward discovery and use of protocols and results, all organised in accordance with the FAIR principles – Findable, Accessible, Interoperable, and Reusable. This initiative is poised to significantly impact materials science, enhancing our comprehension of the safety and environmental implications of 2D materials. KW - Graphene KW - Image analysis KW - Data management PY - 2024 DO - https://doi.org/10.1016/j.toxlet.2024.07.655 VL - 399 SP - S271 PB - Elsevier B.V. AN - OPUS4-61011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Belsey, N. A. A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Araujo, J. R. A1 - Bock, B. A1 - Brüner, P. A1 - Castner, D. G. A1 - Ceccone, G. A1 - Counsell, J. D. P. A1 - Dietrich, Paul M. A1 - Engelhardt, M. H. A1 - Fearn, S. A1 - Galhardo, C. E. A1 - Kalbe, H. A1 - Kim, J. W. A1 - Lartundo-Rojas, L. A1 - Luftman, H. S. A1 - Nunney, T. S. A1 - Pseiner, J. A1 - Smith, E. F. A1 - Spampinato, V. A1 - Sturm, J. M. A1 - Thomas, A. G. A1 - Treacy, J. P. W. A1 - Veith, L. A1 - Wagstaffe, M. A1 - Wang, H. A1 - Wang, M. A1 - Wang, Y.-C. A1 - Werner, W. A1 - Yang, L. A1 - Shard, A. G. T1 - Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS N2 - We report the results of a Versailles Project on Advanced Materials and Standards (VAMAS) interlaboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage, or sample preparation resulted in a variability in thickness of 53%. The calculation method chosen by XPS participants contributed a variability of 67%. However, variability of 12% was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors since this contributed a variability of 33%. The results from the LEIS participants were more consistent, with variability of less than 10% in thickness, and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films, and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results. KW - VAMAS KW - Interlaboratory Study KW - Nanoparticle coating KW - XPS KW - LEIS KW - shell thicknss and chemistry PY - 2016 UR - http://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.6b06713 DO - https://doi.org/10.1021/acs.jpcc.6b06713 IS - 120 SP - 24070 EP - 24079 PB - ACS Publications AN - OPUS4-38428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Graf, Nora A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Schüpbach, B. A1 - Bashir, A. A1 - Wöll, Ch. A1 - Terfort, A. A1 - Unger, Wolfgang T1 - Self-assembled monolayers of aromatic omega-aminothiols on gold: surface chemistry and reactivity N2 - Amino-terminated self-assembled monolayers on gold substrates were studied by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS) measurements, and atomic force microscopy (AFM). Two different ω-amino-4,4'-terphenyl substituted alkanethiols of the general structure H2N-(C6H4)3-(CH2)n-SH (ATPn) were used: 2-(4''-amino-1,1':4',1''-terphenyl-4-yl)ethane-1-thiol (n = 2, ATP2) and 3-(4''-amino-1,1':4',1''-terphenyl-4-yl)propane-1-thiol (n = 3, ATP3). Moreover, the addressability of amino groups within the films was investigated by chemical derivatization of ATPn SAMs with 3,5-bis(trifluoromethyl)phenyl isothiocyanate (ITC) forming fluorinated thiourea ATPn-F films. Evaluation of high-resolution C 1s and N 1s XPS data revealed successful derivatization of at least 50% of surface amino species. Furthermore, it could be demonstrated by angle-resolved NEXAFS spectroscopy that chemical derivatization with ITC has no noticeable influence on the preferential upright orientation of the molecules in the SAMs. KW - Gold KW - Self-assembled monolayer KW - Thiols KW - Amino surfaces KW - XPS KW - NEXAFS PY - 2010 DO - https://doi.org/10.1021/la903293b SN - 0743-7463 SN - 1520-5827 VL - 26 IS - 6 SP - 3949 EP - 3954 PB - American Chemical Society CY - Washington, DC AN - OPUS4-20990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Nefedov, A. A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Illgen, René A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Wöll, Ch. A1 - Unger, Wolfgang T1 - Interperetation of experimental N K NEXAFS of azide, 1,2,3-triazole and terpyridyl groups by DFT spectrum simulations N2 - Experimental N K-edge NEXAFS data of surface immobilized azide, 1,2,3-triazole and terpyridyl groups are interpreted with the help of DFT spectrum simulations. Assignments of π* resonances in experimental N K-edge NEXAFS spectra to nitrogen atoms within these functional groups have been made. The azide was immobilized on gold as the head group of a thiol SAM, 1,2,3-triazole was formed on this SAM by click reaction and terpyridyl groups were introduced as substituents of the acetylene used for the click reaction. For azide-terminated molecules, DFT spectrum simulations are found to be useful to find measurement conditions delivering experimental N K-edge NEXAFS data with negligible X-ray damage. The 1,2,3-triazole group is found to be rather stable under X-ray irradiation. KW - N K-edge NEXAFS KW - XANES KW - Surface click chemistry KW - Density functional theory KW - Azide KW - 1,2,3-Triazole PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.09.008 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 12 SP - 621 EP - 624 PB - Elsevier CY - Amsterdam AN - OPUS4-27774 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 - Fischer, Tobias A1 - Dietrich, Paul A1 - Streeck, C. A1 - Ray, S. A1 - Nutsch, A. A1 - Shard, A. A1 - Beckhoff, B. A1 - Unger, Wolfgang A1 - Rurack, Knut T1 - Quantification of variable functional-group densities of mixed-silane monolayers on surfaces via a dual-mode fluorescence and XPS label N2 - The preparation of aminated monolayers with a controlled density of functional groups on silica surfaces through a simple vapor deposition process employing different ratios of two suitable monoalkoxysilanes, (3-aminopropyl)diisopropylethoxysilane (APDIPES) and (3-cyanopropyl)dimethylmethoxysilane (CPDMMS), and advances in the reliable quantification of such tailored surfaces are presented here. The one-step codeposition process was carried out with binary silane mixtures, rendering possible the control over a wide range of densities in a single step. In particular, APDIPES constitutes the functional silane and CPDMMS the inert component. The procedure requires only small amounts of silanes, several ratios can be produced in a single batch, the deposition can be carried out within a few hours and a dry atmosphere can easily be employed, limiting self-condensation of the silanes. Characterization of the ratio of silanes actually bound to the surface can then be performed in a facile manner through contact angle measurements using the Cassie equation. The reliable estimation of the number of surface functional groups was approached with a dual-mode BODIPY-type fluorescence label, which allows quantification by fluorescence and XPS on one and the same sample. We found that fluorescence and XPS signals correlate over at least 1 order of magnitude, allowing for a direct linking of quantitative fluorescence analysis to XPS quantification. Employment of synchrotron-based methods (XPS; reference-free total reflection X-ray fluorescence, TXRF) made the traceable quantification of surface functional groups possible, providing an absolute reference for quantitative fluorescence measurements through a traceable measurement chain. KW - Oberflächenanalytik KW - Fluoreszenz KW - XPS KW - TXRF KW - Funktionelle Gruppen PY - 2015 DO - https://doi.org/10.1021/ac503850f SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 5 SP - 2685 EP - 2692 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chan, George C.-Y. A1 - Hieftje, Gary M. A1 - Omenetto, Nicoló A1 - Axner, Ove A1 - Bengtson, Arne A1 - Bings, Nicolas H. A1 - Blades, Michael W. A1 - Bogaerts, Annemie A1 - Bolshov, Mikhail A. A1 - Broekaert, José A.C. A1 - Chan, WingTat A1 - Costa-Fernández, José M. A1 - Crouch, Stanley R. A1 - De Giacomo, Alessandro A1 - D’Ulivo, Alessandro A1 - Engelhard, Carsten A1 - Falk, Heinz A1 - Farnsworth, Paul B. A1 - Florek, Stefan A1 - Gamez, Gerardo A1 - Gornushkin, Igor B. A1 - Günther, Detlef A1 - Hahn, David W. A1 - Hang, Wei A1 - Hoffmann, Volker A1 - Jakubowski, Norbert A1 - Karanassios, Vassili A1 - Koppenaal, David W. A1 - Kenneth Marcus, R. A1 - Noll, Reinhard A1 - Olesik, John W. A1 - Palleschi, Vincenzo A1 - Panne, Ulrich A1 - Pisonero, Jorge A1 - Ray, Steven J. A1 - Resano, Martín A1 - Russo, Richard E. A1 - Scheeline, Alexander A1 - Smith, Benjamin W. A1 - Sturgeon, Ralph E. A1 - Todolí, José-Luis A1 - Tognoni, Elisabetta A1 - Vanhaecke, Frank A1 - Webb, Michael R. A1 - Winefordner, James D. A1 - Yang, Lu A1 - Yu, Jin A1 - Zhang, Zhanxia T1 - Landmark Publications in Analytical Atomic Spectrometry: Fundamentals and Instrumentation Development N2 - The almost-two-centuries history of spectrochemical analysis has generated a body of literature so vast that it has become nearly intractable for experts, much less for those wishing to enter the field. Authoritative, focused reviews help to address this problem but become so granular that the overall directions of the field are lost. This broader perspective can be provided partially by general overviews but then the thinking, experimental details, theoretical underpinnings and instrumental innovations of the original work must be sacrificed. In the present compilation, this dilemma is overcome by assembling the most impactful publications in the area of analytical atomic spectrometry. Each entry was proposed by at least one current expert in the field and supported by a narrative that justifies its inclusion. The entries were then assembled into a coherent sequence and returned to contributors for a round-robin review. KW - Analytical atomic spectrometry KW - Spectroscopy KW - Instrumental analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621588 DO - https://doi.org/10.1177/00037028241263567 SN - 1943-3530 VL - 78 SP - 1 EP - 456 PB - Sage CY - London AN - OPUS4-62158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bender, R. A1 - Féron, D. A1 - Mills, D. A1 - Ritter, S. A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - de Graeve, I. A1 - Dugstad, A. A1 - Grassini, S. A1 - Hack, T. A1 - Halama, M. A1 - Han, E.-H. A1 - Harder, T. A1 - Hinds, G. A1 - Kittel, J. A1 - Krieg, R. A1 - Leygraf, C. A1 - Martinelli, L. A1 - Mol, A. A1 - Neff, D. A1 - Nilsson, J.-O. A1 - Odnevall, I. A1 - Paterson, S. A1 - Paul, S. A1 - Prošek, T. A1 - Raupach, M. A1 - Revilla, R. I. A1 - Ropital, F. A1 - Schweigart, H. A1 - Szala, E. A1 - Terryn, H. A1 - Tidblad, J. A1 - Virtanen, S. A1 - Volovitch, P. A1 - Watkinson, D. A1 - Wilms, M. A1 - Winning, G. A1 - Zheludkevich, M. T1 - Corrosion challenges towards a sustainable society N2 - A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate‐resilient energy systems and infrastructures brings with it a long‐term direction, so as a result the long‐term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind “Corrosion Challenges Towards a Sustainable Society” presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics. KW - Corrosion KW - Corrosion costs KW - Corrosion protection KW - Preventive strategies PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554801 DO - https://doi.org/10.1002/maco.202213140 SN - 1521-4176 VL - 73 IS - 11 SP - 1730 EP - 1751 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Esakkiraja, N. A1 - Vishwakarma, A. A1 - Makineni, S. K. A1 - Jayaram, V. A1 - Hickel, Tilmann A1 - Divinski, S. V. A1 - Paul, A. T1 - Diffusion-controlled growth and microstructural evolution between Pt and Pd containing B2-NiAl bondcoats and Ni-based single crystal superalloy N2 - Pt-modified NiAl bond coats are used to extend the lifetime of blades in gas turbine engine applications. However, they suffer from the growth of deleterious precipitates within the interdiffusion zone. Partial substitution of Pt by Pd is advantageous in reducing the interdiffusion zone thickness between the bond coat and the superalloy, providing comparable oxidation properties, and critically reducing the propensity to form brittle (Pt,Ni)Al2 precipitates. In this study, we utilize the pseudo-binary diffusion couple method to estimate the interdiffusion coefficients of Ni and Al in Pd, Pd-Pt and Pt-modified nickel aluminides. Additionally, the main and cross-interdiffusion coefficients are estimated in the ternary diffusion couples. The estimated diffusion coefficients in the 𝛽-NiAl phase reflect on the thickness of the 𝛽 phase in the superalloy bond coat interdiffusion zone. Pd reduces the pseudo-binary interdiffusion coefficients of Ni–Al and also decreases the main and cross-ternary interdiffusion coefficients. This correlates with the reduction of the interdiffusion zone thickness by Pd. The diffusion process is strongly assisted by point defects in this phase. Ab initio-informed defect calculations are done to explain diffusion retardation in the presence of Pd (compared to Pt) with decreased defect concentrations. Furthermore, through in-depth microstructure characterization performed by electron probe micro analyser, transmission electron microscopy, and atom probe tomography, the presence of 𝜎, 𝑅 and 𝜇 phases as TCP precipitates in the interdiffusion zone are identified. The results give insights into the coatings’ diffusional properties that influence the service life of the product. KW - Interdiffusion KW - Bondcoat KW - Topologically close pack (TCP) phase KW - Transmission electron microscopy KW - Atom probe tomography PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618091 DO - https://doi.org/10.1016/j.actamat.2024.119687 SN - 1359-6454 VL - 266 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-61809 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El-Khatib, A. H. A1 - Radbruch, H. A1 - Trog, S. A1 - Neumann, B. A1 - Paul, F. A1 - Koch, A. A1 - Linscheid, M. W. A1 - Jakubowski, Norbert A1 - Schellenberger, E. T1 - Gadolinium in human brain sections and colocalization with other elements N2 - Recent recommendations by the Food and Drug Administration1 and the European Medicines Agency2 are to limit the clinical use of linear gadolinium-based contrast agents (GBCAs) due to convincing evidence of deposition in tissues. Macrocyclic GBCA continued to be considered safe, provided that patients have normal renal function. To date, given the low sensitivity of conventional MRI, there has been a debate about the signal increase following the injections of a macrocyclic GBCA. KW - Gadolinium PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471309 DO - https://doi.org/10.1212/NXI.0000000000000515 SN - 2332-7812 VL - 6 IS - 1 SP - e515, 1 EP - 3 PB - American Academy of Neurology AN - OPUS4-47130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steglich, Patrick A1 - Paul, Martin A1 - Mai, C. A1 - Böhme, A. A1 - Bondarenko, S. A1 - Weller, Michael G. A1 - Mai, A. T1 - A monolithically integrated microfluidic channel in a silicon-based photonic-integrated-circuit technology for biochemical sensing N2 - In this work, a cost-effective optofluidic system is proposed and preliminary experimental results are presented. A microfluidic channel monolithically integrated into a photonic integrated circuit technology is used in conjunction with a cyclic olefin copolymer (COC) substrate to provide fluidic in- and output ports. We report on initial experimental results as well as on the simple and cost-effective fabrication of this optofluidic system by means of micro-milling. KW - Biosensors KW - Biophotonics KW - Optical sensors KW - Photonic sensors KW - Ring resonators KW - Silicon photonics KW - Lab-on-a-chip KW - Microfluidics KW - Chip KW - Biochip PY - 2021 DO - https://doi.org/10.1117/12.2588791 VL - 11772 SP - 1 EP - 5 PB - SPIE AN - OPUS4-53559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tscheuschner, Georg A1 - Ponader, Marco A1 - Raab, Christopher A1 - Weider, Prisca S. A1 - Hartfiel, Reni A1 - Kaufmann, Jan Ole A1 - Völzke, Jule L. A1 - Bosc-Bierne, Gaby A1 - Prinz, Carsten A1 - Schwaar, T. A1 - Andrle, Paul A1 - Bäßler, Henriette A1 - Nguyen, Khoa A1 - Zhu, Y. A1 - Mey, A. S. J. S. A1 - Mostafa, A. A1 - Bald, I. A1 - Weller, Michael G. T1 - Efficient Purification of Cowpea Chlorotic Mottle Virus by a Novel Peptide Aptamer N2 - The cowpea chlorotic mottle virus (CCMV) is a plant virus explored as a nanotechnological platform. The robust self-assembly mechanism of its capsid protein allows for drug encapsulation and targeted delivery. Additionally, the capsid nanoparticle can be used as a programmable platform to display different molecular moieties. In view of future applications, efficient production and purification of plant viruses are key steps. In established protocols, the need for ultracentrifugation is a significant limitation due to cost, difficult scalability, and safety issues. In addition, the purity of the final virus isolate often remains unclear. Here, an advanced protocol for the purification of the CCMV from infected plant tissue was developed, focusing on efficiency, economy, and final purity. The protocol involves precipitation with PEG 8000, followed by affinity extraction using a novel peptide aptamer. The efficiency of the protocol was validated using size exclusion chromatography, MALDI-TOF mass spectrometry, reversed-phase HPLC, and sandwich immunoassay. Furthermore, it was demonstrated that the final eluate of the affinity column is of exceptional purity (98.4%) determined by HPLC and detection at 220 nm. The scale-up of our proposed method seems to be straightforward, which opens the way to the large-scale production of such nanomaterials. This highly improved protocol may facilitate the use and implementation of plant viruses as nanotechnological platforms for in vitro and in vivo applications. N2 - Das Cowpea Chlorotic Mottle Virus (CCMV) ist ein Pflanzenvirus, das als nanotechnologische Plattform erforscht wird. Der robuste Selbstorganisationsmechanismus seines Kapsidproteins ermöglicht die Verkapselung und gezielte Abgabe von Medikamenten. Darüber hinaus kann das Kapsid-Nanopartikel als programmierbare Plattform für die Präsentation verschiedener molekularer Komponenten verwendet werden. Im Hinblick auf künftige Anwendungen ist eine effiziente Produktion und Reinigung von Pflanzenviren von entscheidender Bedeutung. In etablierten Protokollen stellt die notwendige Ultrazentrifugation aufgrund von Kosten, schwieriger Skalierbarkeit und Sicherheitsaspekten eine erhebliche Einschränkung dar. Darüber hinaus bleibt die Reinheit des endgültigen Virusisolats oft unklar. Hier wurde ein fortschrittliches Protokoll für die Reinigung von CCMV aus infiziertem Pflanzengewebe entwickelt, wobei der Schwerpunkt auf Effizienz, Wirtschaftlichkeit und Reinheit lag. Das Protokoll beinhaltet eine Fällung mit Polyethylenglycol (PEG 8000), gefolgt von einer Affinitätsextraktion mit einem neuartigen Peptid-Aptamer. Die Effizienz des Protokolls wurde mithilfe von Größenausschluss-Chromatographie (SEC), MALDI-TOF-Massenspektrometrie, Umkehrphasen-HPLC und Sandwich-Immunoassay validiert. Darüber hinaus wurde nachgewiesen, dass das endgültige Eluat der Affinitätssäule eine außergewöhnliche Reinheit (98,4 %) aufweist, die durch HPLC und Detektion bei 220 nm bestimmt wurde. Die Skalierung der von uns vorgeschlagenen Methode scheint einfach zu sein, was den Weg für eine größer angelegte Produktion solcher Nanomaterialien ebnet. Dieses stark verbesserte Protokoll könnte die Verwendung und Umsetzung von Pflanzenviren als nanotechnologische Plattformen für In-vitro- und In-vivo-Anwendungen erleichtern. KW - Affinity chromatography KW - Nanoparticles KW - Nanoscience KW - Carrier protein KW - Encapsulation KW - Combinatorial peptide library KW - Peptide binder KW - Vigna unguiculata KW - Augenbohne KW - Schlangenbohne KW - Pflanzenvirus KW - Plant virus KW - Upscaling KW - Commercialization KW - Reference material KW - Nanocarrier PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572645 DO - https://doi.org/10.3390/v15030697 VL - 15 IS - 3 SP - 1 EP - 24 PB - MDPI CY - Basel, Schweiz AN - OPUS4-57264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eckel, S. A1 - Zscherpel, Uwe A1 - Huthwaite, P. A1 - Paul, N. A1 - Schumm, A. T1 - Radiographic film system classification and noise characterisation by a camera-based digitisation procedure N2 - Extracting statistical characteristics from radiographic films is vital for film system classification and contrast sensitivity evaluation and serves as a basis for film noise simulation. A new method for digitising radiographic films in order to extract these characteristics is presented. The method consists of a camera-based setup and image processing procedure to digitise films. Correct optical density values and granularity can be extracted from the digitised images, which are equal to results obtained by standardised measurement procedures. Specific statistical characteristics of film noise are theoretically derived and subsequently verified by the obtained data, including characteristics such as Gaussianity and spatial spectral characteristics of the optical density fluctuations. It is shown that the presented method correctly measures the granularity of film noise and can therefore replace time-consuming microdensitometer measurements traditionally required for film system classifications. Additionally, the inherent unsharpness of film systems was investigated and compared with literature data. This comparison serves as another validation approach of the presented method. KW - Radiography KW - Image processing KW - Film noise KW - Film system classification KW - Digitisation PY - 2020 DO - https://doi.org/10.1016/j.ndteint.2020.102241 SN - 0963-8695 VL - 111 IS - 4 SP - 102241 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-50517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eckel, S. A1 - Huthwaite, P. A1 - Zscherpel, Uwe A1 - Schumm, A. A1 - Paul, N. T1 - Realistic film noise generation based on experimental noise spectra N2 - Generating 2D noise with local, space-varying spectral characteristics is vital where random noise fields with spatially heterogeneous statistical properties are observed and need to be simulated. A realistic, non-stationary noise generator relying on experimental data is presented. That generator is desired in areas such as photography and radiography. For example, before performing actual X-ray imaging in practice, output images are simulated to assess and improve setups. For that purpose, realistic film noise modelling is crucial because noise downgrades the detectability of visual signals. The presented film noise synthesiser improves the realism and value of radiographic simulations significantly, allowing more realistic assessments of radiographic test setups. The method respects space-varying spectral characteristics and probability distributions, locally simulating noise with realistic granularity and contrast. The benefits of this approach are to respect the correlation between noise and image as well as internal correlation, the fast generation of any number of unique noise samples, the exploitation of real experimental data, and its statistical non-stationarity. The combination of these benefits is not available in existing work. Validation of the new technique was undertaken in the field of industrial radiography. While applied to that field here, the technique is general and can also be utilised in any other field where the generation of 2D noise with local, space-varying statistical properties is necessary. KW - Nondestructive testing KW - Image quality KW - Noise simulation KW - Radiography PY - 2020 DO - https://doi.org/10.1109/TIP.2019.2955284 SN - 1057-7149 VL - 29 SP - 2987 EP - 2998 PB - IEEE Xplore CY - Washington, D.C. AN - OPUS4-50518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Goedecke, Caroline A1 - Wiesner, Yosri A1 - Jekel, M A1 - Ruhl, A S A1 - Braun, Ulrike T1 - Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine N2 - The adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation. KW - Aktivkohle KW - TED-GC/MS KW - Adsorption KW - Thermoanalytik PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506946 DO - https://doi.org/10.1038/s41598-020-63481-y VL - 10 IS - 1 SP - 6695 PB - Nature Publishing Group AN - OPUS4-50694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Streeck, C. A1 - Glamsch, Stephan A1 - Ehlert, Christopher A1 - Lippitz, Andreas A1 - Nutsch, A. A1 - Kulak, N. A1 - Beckhoff, B. A1 - Unger, Wolfgang T1 - Quantification of silane molecules on oxidized silicon: Are there options for a traceable and absolute determination? N2 - Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXRF) and X-ray photoelectron spectroscopy (XPS). An areic density of 2−4 silane molecules per nm2 was calculated from the layer’s nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/ARXPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)−inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceable values for the areic density of silanes containing nitrogen as intrinsic marker are obtained by calibration of the XPS methods with reference-free TXRF. Furthermore, ER/AR-XPS is shown to facilitate the determination of areic densities in (mono)layers made from silanes having no heteroatomic marker other than silicon. After calibration with reference-free TXRF, these areic densities of silane molecules can be determined when using the XPS component intensity of the silane’s silicon atom. PY - 2015 DO - https://doi.org/10.1021/acs.analchem.5b02846 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 19 SP - 10117 EP - 10124 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Girard-Lauriault, P.-L. A1 - Unger, Wolfgang A1 - Dietrich, Paul A1 - Holländer, A. T1 - Innovative and established strategies for the surface analysis of nitrogen and oxygen-rich plasma polymer films by XPS: an introductory guide N2 - Nitrogen- and oxygen-based plasma polymer films are materials with a complex and partially elusive surface chemistry. We present an overview of innovative and established X-ray photoelectron spectroscopy (XPS)-based analysis strategies developed to elucidate the surface chemistry of such films. We focus on both experimental methods and data analysis strategies and include the following topics: high-resolution spectra curve fitting, aging, chemical derivatization, and depth profiling by angle- and energy-resolved XPS. KW - Chemical derivatization KW - Functional groups KW - Plasma polymerization KW - X-ray photoelectron spectroscopy PY - 2015 DO - https://doi.org/10.1002/ppap.201500115 SN - 1612-8850 SN - 1612-8869 VL - 12 IS - 9 SP - 953 EP - 967 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pech May, Nelson Wilbur A1 - Paul, A. A1 - Ziegler, Mathias T1 - Pulse-compression laser thermography using a modified Barker code: Enhanced detection of subsurface defects N2 - Pulse-compression thermography is an emerging technique that has shown versatility by combination of pulsed and lock-in thermography. Accordingly, several aspects of this technique are still unexplored, and some others not fully developed yet. Barker codes were widely used in radar applications due to their simplicity and their optimum autocorrelation function. Nevertheless, applications were limited by the amplitude of the sidelobes present in the autocorrelation function and therefore, several filters have been developed which aim to reduce the sidelobes. However, the filters usually depend on empirical parameters which must be determined for each application. A better alternative would improve the applicability of the Barker codes. In this work, we further develop the pulse-compression thermography technique by introducing a 13-bit modified Barker code (mBC): This allows to drastically reduce the sidelobes characteristic of the 13-bit Barker code (BC). Consequently, the thermographic impulse response, obtained by cross-correlation, is almost free of such sidelobes. Deeper defects become easier to detect in comparison with using a 13-bit Barker code. Numerical simulations using the finite element method are used for comparison and experimental measurements are performed in a sample of steel grade St 37 with machined notches of three different depths: 2 mm, 4 mm and 6 mm. T2 - SPIE Defense + Commercial Sensing 2021 CY - Online meeting DA - 13.04.2021 KW - Pulse-compression laser thermography KW - Barker codes KW - Non-destructive testing PY - 2021 DO - https://doi.org/10.1117/12.2586078 SN - 0277-786X VL - 11743 SP - 1 EP - 11 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-53247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Singh, S. A1 - Palani, I. A. A1 - Paul, C. P. A1 - Funk, Alexander A1 - Gokuldoss, P. K. T1 - Wire Arc Additive Manufacturing of NiTi 4D Structures: Influence of Interlayer Delay N2 - Shape memory alloy structures for actuator and vibration damper applications may be manufactured using wire arc additive manufacturing (W AAM), which is one of the additive manufacturing technologies. Multilayer deposition causes heat accumulation during W AAM, which rises the preheat temperature of the previously created layer. This leads to process instabilities, which result in deviations from the desired dimensions and mechanical properties changes. During W AAM deposition of the wall structure, a systematic research is carried out by adjusting the interlayer delay from 10 to 30 s. When the delay period is increased from 10 to 30 s, the breadth decreases by 45% and the height increases by 33%. Grain refinement occurs when the interlayer delay duration is increased, resulting in better hardness, phase transformation temperature, compressive strength, and shape recovery behavior. This study shows how the interlayer delay affects the behavior of W AAM-built nickel-titanium alloy (NiTi) structures in a variety of applications. KW - Wire are additive manufacturing KW - Shape memory alloy KW - Nitinol KW - Interlayer delay PY - 2022 DO - https://doi.org/10.1089/3dp.2021.0296 SN - 2329-7662 SP - 1 EP - 11 PB - Liebert CY - New Rochelle, NY AN - OPUS4-55795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Kerndorff, A. A1 - Ricking, M. A1 - Bednarz, M. A1 - Obermaier, N. A1 - Lukas, M. A1 - Asenova, M. A1 - Bordós, G. A1 - Eisentraut, Paul A1 - Hohenblum, P. A1 - Hudcova, H. A1 - Humer, F. A1 - István, T. G. A1 - Kirchner, M. A1 - Marushevska, O. A1 - Nemejcová, D. A1 - Oswald, P. A1 - Paunovic, M. A1 - Sengl, M. A1 - Slobodnik, J. A1 - Spanowsky, K. A1 - Tudorache, M. A1 - Wagensonner, H. A1 - Liska, I. A1 - Braun, U. A1 - Bannick, C. G. T1 - Microplastics in the Danube River Basin: A First Comprehensive Screening with a Harmonized Analytical Approach N2 - In this study, carried out within the Joint Danube Survey 4, a comprehensive microplastic screening in the water column within a large European river basin from its source to estuary, including major tributaries, was realized. The objective was to develop principles of a systematic and practicable microplastic monitoring strategy using sedimentation boxes for collection of suspended particulate matter followed by its subsequent analysis using thermal extraction desorption-gas chromatography/mass spectrometry. In total, 18 sampling sites in the Danube River Basin were investigated. The obtained suspended particulate matter samples were subdivided into the fractions of >100 μm and <100 μm and subsequently analyzed for microplastic mass contents. The results showed that microplastics were detected in all samples, with polyethylene being the predominant polymer with maximum contents of 22.24 μg/mg, 3.23 μg/mg for polystyrene, 1.03 μg/mg for styrene-butadiene-rubber, and 0.45 μg/mg for polypropylene. Further, polymers such as different sorts of polyester, polyacrylates, polylactide, and natural rubber were not detected or below the detection limit. Additional investigations on possible interference of polyethylene signals by algae-derived fatty acids were assessed. In the context of targeted monitoring, repeated measurements provide more certainty in the interpretation of the results for the individual sites. Nevertheless, it can be stated that the chosen approach using an integrative sampling and determination of total plastic content proved to be successful. KW - Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS), monitoring KW - Microplastics KW - River KW - Suspended particulate matter (SPM) KW - Sedimentation box (SB) PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551444 DO - https://doi.org/10.1021/acsestwater.1c00439 VL - 2 IS - 7 SP - 1174 EP - 1181 PB - ACS Publications AN - OPUS4-55144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Godard, A. A1 - Kalot, G. A1 - Privat, M. A1 - Bendellaa, M. A1 - Busser, B. A1 - Wegner, Karl David A1 - Denat, F. A1 - Le Guevel, X. A1 - Coll, J.-L. A1 - Paul, C. A1 - Bodio, E. A1 - Goze, C. A1 - Sancey, L. T1 - NIR-II Aza-BODIPY Dyes Bioconjugated to Monoclonal Antibody Trastuzumab for Selective Imaging of HER2-Positive Ovarian Cancer N2 - Using fluorescence-guided surgery (FGS) to cytoreductive surgery helps achieving complete resection of microscopic ovarian tumors. The use of visible and NIR-I fluorophores has led to beneficial results in clinical trials; however, involving NIR-II dyes seems to outperform those benefits due to the deeper tissue imaging and higher signal/noise ratio attained within the NIR-II optical window. In this context, we developed NIR-II emitting dyes targeting human epidermal growth factor receptor 2 (HER2)-positive ovarian tumors by coupling water-soluble NIR-II aza-BODIPY dyes to the FDA-approved anti-HER2 antibody, namely, trastuzumab. These bioconjugated NIR-II-emitting dyes displayed a prolonged stability in serum and a maintained affinity toward HER2 in vitro. We obtained selective targeting of HER2 positive tumors (SKOV-3) in vivo, with a favorable tumor accumulation. We demonstrated the fluorescence properties and the specific HER2 binding of the bioconjugated dyes in vivo and thus their potential for NIR-II FGS in the cancer setting. KW - NIR-II KW - Fluorescent dye KW - In vivo imaging KW - Ovarian cancer KW - Antibody conjuagtes KW - Bioimaging PY - 2023 DO - https://doi.org/10.1021/acs.jmedchem.3c00100 SN - 0022-2623 VL - 66 IS - 7 SP - 5185 EP - 5195 PB - ACS Publications AN - OPUS4-57293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chazeau, E. A1 - Fabre, C. A1 - Privat, M. A1 - Godard, A. A1 - Racoeur, C. A1 - Bodio, E. A1 - Busser, B. A1 - Wegner, Karl David A1 - Sancey, L. A1 - Paul, C. A1 - Goze, C. T1 - Comparison of the In Vitro and In Vivo Behavior of a Series of NIR-II-Emitting Aza-BODIPYs Containing Different Water-Solubilizing Groups and Their Trastuzumab Antibody Conjugates N2 - The development of new fluorescent organic probes effective in the NIR-II region is currently a fast-growing field and represents a challenge in the domain of medical imaging. In this study, we have designed and synthesized an innovative series of aza-boron dipyrromethenes emitting in the NIR-II region. We have investigated the effect of different water-solubilizing groups not only on the photophysical properties of the compounds but also on their in vitro and in vivo performance after bioconjugation to the antibody trastuzumab. Remarkably, we discovered that the most lipophilic compound unexpectedly displayed the most favorable in vivo properties after bioconjugation. This underlines the profound influence that the fluorophore functionalization approach can have on the efficiency of the resulting imaging agent. KW - NIR-II KW - In vivo imaging KW - Fluorescence KW - Spectroscopy KW - Antibody conjugates PY - 2024 DO - https://doi.org/10.1021/acs.jmedchem.3c02139 SN - 1520-4804 VL - 67 IS - 5 SP - 3679 EP - 3691 PB - ACS Publications CY - Washington, DC AN - OPUS4-59607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Davison, Nathan A1 - Hemingway, Jack M. A1 - Wills, Corinne A1 - Stolar, Tomislav A1 - Waddell, Paul G. A1 - Dixon, Casey M. A1 - Barron, Luke A1 - Dawson, James A. A1 - Lu, Erli T1 - Mechanochemical Synthesis of a Sodium Anion Complex [Na+(2,2,2-cryptand)Na] and Studies of Its Reactivity: Two-Electron and One-Electron Reductions N2 - Group 1 metal molecular chemistry is dominated by a +1 oxidation state, while a 0 oxidation state is widespread in the metals. A more exotic, yet still available, oxidation state of group 1 metal is −1, i.e., alkalide. Reported as early as the 1970s, the alkalides appear in every modern inorganic chemistry textbook as an iconic chemical curiosity, yet their reactivity remains unexplored. This is due to their synthetic hurdles. In this work, we report the first facile synthesis of the archetypical alkalide complex, [Na+(2,2,2-cryptand)Na–], which allows us to unveil a versatile reactivity profile of this once exotic species. KW - Mechanochemistry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608632 DO - https://doi.org/10.1021/acs.inorgchem.4c02914 VL - 63 IS - 32 SP - 15247 EP - 15258 PB - American Chemical Society (ACS) AN - OPUS4-60863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosemann, Paul A1 - Müller, Christina A1 - Meyer, A. A1 - Halle, T. T1 - Influence of nitrogen on the corrosion resistance of martensitic stainless steels N2 - The corrosion resistance of martensitic stainless steels (MSS) depends strongly on the chemical composition and the applied heat treatment. Both determines the distribution of the alloying elements in the microstructure and the resulting material properties. The addition of nitrogen is known to be beneficial for the pitting corrosion resistance of stainless steels. In case of MSS this effect is not only connected to nitrogen itself because nitrogen can be used to substitute carbon which also influences the result of the heat treatment process. This paper shows the effect of nitrogen on the corrosion resistance in relation to the hardening process of MSS. Therefore the effects of austenitization duration, austenitization temperature and cooling rate on microstructure, hardness and corrosion resistance were studied on the MSS X30CrMoN15 1 and X50CrMoV15. The effect of different cooling rates was studied in the range of > 100 K/s down to 1 K/s using the jominy end quench test. The changes in corrosion resistance were detected with electrochemical potentiodynamic reactivation (EPR) and by the determination of critical pitting potentials. Besides this experimental approach thermodynamic calculations with the software thermocalc will be presented and used for the interpretation of the effect of nitrogen on the corrosion resistance of MSS. T2 - 18th Chemnitz Seminar on Materials Engineering – 18. Werkstofftechnisches Kolloquium CY - Chemnitz, Germany KW - Martensitic stainless steels KW - Corrosion resistance KW - Heat treatment PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366956 DO - https://doi.org/10.1088/1757-899X/118/1/011002 VL - 118 IS - 1 SP - 19 EP - 19 PB - IOP Publishing AN - OPUS4-36695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heyn, A. A1 - Rosemann, Paul A1 - Babutzka, Martin A1 - Bender, S. T1 - Electrochemical noise of unalloyed steel in mixtures of water-based binders and pigments N2 - The development of organic coatings for corrosion protection is an elaborate process with a multitude of often interminable investigations and tests of protection properties. Electrochemical methods support the processes of development to a great extent and help to understand mechanisms of action and failure. They are usually carried out on applied coating systems with a completed formulation. An examination possibility is presented in this publication that enables the characterization of waterbased coatings with different formulation variations in the liquid (aqueous) state with the aid of electrochemical noise technique. Thus, selection of binders, pigments, and other additives is supported essentially and made more efficient in a very early Phase of formulation development. The paper shows that a unique insight into the dynamic processes of a metal in contact with an aqueous coating dispersion is possible using the example of the development of zinc-free corrosion-inhibiting pigments for waterbased coatings. In addition, it is presented in which way the results correlate with the performance of applied coatings. KW - Organic coatings KW - Electrochemical noise KW - Corrosion KW - Corrosion protection KW - Corrosion protection pigments PY - 2017 DO - https://doi.org/10.1002/maco.201709671 SN - 0947-5117 SN - 1521-4176 VL - 68 IS - 12 SP - 1295 EP - 1301 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-43319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eisentraut, Paul A1 - Dümichen, Erik A1 - Ruhl, A. A1 - Jekel, M. A1 - Albrecht, M. A1 - Gehde, M. A1 - Braun, Ulrike T1 - Two Birds with One Stone-Fast and Simultaneous Analysis of Microplastics: Microparticles Derived from Thermoplastics and Tire Wear N2 - Analysis of microplastic particles (MP) in environmental samples needs sophisticated techniques and is time intensive due to sample preparation and detection. An alternative to the most common (micro ) spectroscopic techniques, FTIR or Raman spectroscopy, are the thermoanalytical methods, where specific decomposition products can be analyzed as marker compounds for different kind of plastics types and mass contents. Thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) allows the fast identification and quantification of MP in environmental samples without sample preparation. Whereas up to now only the analysis of thermoplastic polymers was realized, this is the first time that even the analysis of tire wear (TW) content in environmental samples is possible. Various marker compounds for TW were identified. They include characteristic decomposition products of elastomers, antioxidants and vulcanization agents. Advantages and drawbacks of these marker substances were evaluated. Environmental samples from street run off were exemplarily investigated and presented. KW - TED-GC-MS KW - Microplastic KW - Tire wear PY - 2018 DO - https://doi.org/10.1021/acs.estlett.8b00446 VL - 5 IS - 10 SP - 608 EP - 613 PB - American Chemical Society AN - OPUS4-46460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grötzsch, D. A1 - Streeck, C. A1 - Nietzold, Carolin A1 - Malzer, W. A1 - Mantouvalou, I. A1 - Nutsch, A. A1 - Dietrich, Paul A1 - Unger, Wolfgang A1 - Beckhoff, B. A1 - Kanngießer, B. T1 - A sealable ultrathin window sample cell for the study of liquids by means of soft X-ray spectroscopy N2 - A new sample cell concept for the analysis of liquids or solid-liquid interfaces using soft X-ray spectroscopy is presented, which enables the complete sealing of the cell as well as the Transport into vacuum via, for example, a load-lock system. The cell uses pressure monitoring and active as well as passive pressure regulation systems, thereby facilitating the full control over the pressure during filling, sealing, evacuation, and measurement. The cell design and sample preparation as well as the crucial sealing procedure are explained in detail. As a first proof-of-principle experiment, successful nitrogen K-edge fluorescence yield near-edge X-ray absorption fine structure experiments of a biomolecular solution are presented. For this purpose, it is shown that the careful evaluation of all involved parameters, such as window type or photon flux, is desirable for optimizing the experimental result. KW - X-ray spectroscopy KW - Analysis of liquids KW - Wet cell KW - Concanavalin A KW - NEXAFS PY - 2017 DO - https://doi.org/10.1063/1.5006122 SN - 0034-6748 SN - 1089-7623 VL - 88 IS - 12 SP - 123112-1 EP - 123112-7 PB - American Institute of Physics AN - OPUS4-43611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koegler, M. A1 - Paul, Andrea A1 - Anane, E. A1 - Birkholz, M. A1 - Bunker, A. A1 - Viitala, T. A1 - Maiwald, Michael A1 - Junne, S. A1 - Neubauer, P. T1 - Comparison of time-gated surface-enhanced Raman spectroscopy (TG-SERS) and classical SERS based monitoring of Escherichia coli cultivation samples N2 - The application of Raman spectroscopy as a monitoring technique for bioprocesses is severely limited by a large background signal originating from fluorescing compounds in the culture media. Here, we compare time-gated Raman (TG-Raman)-, continuous wave NIRprocess Raman (NIR-Raman), and continuous wave micro-Raman (micro-Raman) approaches in combination with surface enhanced Raman spectroscopy (SERS) for their potential to overcome this limit. For that purpose, we monitored metabolite concentrations of Escherichia coli bioreactor cultivations in cell-free supernatant samples. We investigated concentration transients of glucose, acetate, AMP, and cAMP at alternating substrate availability, from deficiency to excess. Raman and SERS signals were compared to off-line metabolite analysis of carbohydrates, carboxylic acids, and nucleotides. Results demonstrate that SERS, in almost all cases, led to a higher number of identifiable signals and better resolved spectra. Spectra derived from the TG-Raman were comparable to those of micro-Raman resulting in well-discernable Raman peaks, which allowed for the identification of a higher number of compounds. In contrast, NIR-Raman provided a superior performance for the quantitative evaluation of analytes, both with and without SERS nanoparticles when using multivariate data analysis. KW - Time-gated Raman (TG-Raman) KW - Surface-enhanced Raman spectroscopy (SERS) KW - Multivariate data analysis KW - Metabolite quantification KW - Escherichia coli PY - 2018 DO - https://doi.org/10.1002/btpr.2665 SN - 1520-6033 SN - 8756-7938 VL - 34 IS - 6 SP - 1533 EP - 1542 PB - Wiley AN - OPUS4-45831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Babutzka, Martin A1 - Heyn, A. A1 - Rosemann, Paul T1 - Influence of austenitizing and tempering on the corrosion behavior and sensitization of martensitic stainless steel X50CrMoV15 N2 - Electrochemical tests, hardness measurements, and microstructure analysis are performed to study the influence of austenitizing, quenching, and tempering parameters on the corrosion resistance of the martensitic stainless steel grade X50CrMoV15 (1.4116). Different heat treatment states were studied using an adapted EPR-Test to evaluate the chromium distribution and depletion caused by the formation and dissolution of chromium rich carbides. The EPR results were correlated with pitting corrosion behavior, demonstrating the strong effect of heat treatment parameters on the susceptibility of martensitic stainless steels to corrosion phenomena. KW - Martensitic stainless steel KW - Electrochemical potentiokinetic reactivation KW - Heat treatment KW - Pitting corrosion PY - 2018 DO - https://doi.org/10.1002/maco.201810170 SN - 0947-5117 SN - 1521-4176 VL - 69 IS - 10 SP - 1338 EP - 1349 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-46138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Graf, Nora A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Krakert, S. A1 - Schüpbach, B. A1 - Terfort, A. A1 - Unger, Wolfgang T1 - Amine species on self-assembled monolayers of omega-aminothiolates on gold as identified by XPS and NEXAFS spectroscopy N2 - Functionalised surfaces are of interest in many fields, e.g. in biomedicine, materials science and molecular electronics. In this study a series of self-assembled aliphatic and aromatic monolayers on gold substrates with terminal amino groups was investigated. Four different thiol molecules were used: aliphatic 11-aminoundecane-1-thiol (AUDT), aromatic 4-aminobenzenethiol (ABT) and aromatic ω-amino thiols with an alkyl spacer as 4-aminophenylbutane-1-thiol (APBT) and 3-(4''-amino-1,1':4',1''-terphenyl-4-yl)propane-1-thiol (ATPT). Evaluation of N 1s XPS data revealed that on the aromatic self-assembled monolayers (SAMs) amino groups exist preferentially as primary amines, whereas on the aliphatic SAM protonated and/or hydrogen-bonded amines are the major species. This result is crosschecked by N K edge near edge X-ray absorption fine structure (NEXAFS) spectroscopy and can be rationalised by the different basicity of aliphatic and aromatic amines. KW - Self-assembled monolayer KW - Amines KW - XPS KW - NEXAFS KW - Surface analysis PY - 2010 DO - https://doi.org/10.1002/sia.3224 SN - 0142-2421 SN - 1096-9918 VL - 42 SP - 1184 EP - 1187 PB - Wiley CY - Chichester AN - OPUS4-21498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dietrich, Paul A1 - Horlacher, T. A1 - Gross, Thomas A1 - Wirth, Thomas A1 - Castelli, R. A1 - Shard, A.G. A1 - Alexander, M. A1 - Seeberger, P. H. A1 - Unger, Wolfgang T1 - Surface analytical characterization of carbohydrate microarrays N2 - Microarrays are a versatile platform for diagnostics and high-throughput analysis. Carbohydrate microarrays are valuable tools to investigate interactions with other molecules since many glycans are involved in fundamental biological processes. A combined X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) surface analysis was used to investigate the basic steps in the production of carbohydrate microarrays. The preparation included coupling of a thiol-terminated mannoside to maleimide-functionalized glass surfaces derived from γ-aminopropyl silane (GAPS) slides. XPS results clearly demonstrate successful chemical modification in each fabrication step, and ToF-SIMS imaging revealed immobilized carbohydrates in the spotted regions of the final microarray. KW - Carbohydrates KW - Microarrays KW - XPS KW - ToF-SIMS KW - Nona-mannoside KW - Maleimide surfaces KW - Surface analysis PY - 2010 DO - https://doi.org/10.1002/sia.3255 SN - 0142-2421 SN - 1096-9918 VL - 42 SP - 1188 EP - 1192 PB - Wiley CY - Chichester AN - OPUS4-21500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jiang, J. A1 - Bauer, I. A1 - Paul, Andrea A1 - Kappler, A. T1 - Arsenic redox changes by microbially and chemically formed semiquinone radicals and hydroquinones in a humic substance model quinone N2 - Arsenic is a redox-active metalloid whose toxicity and mobility strongly depends on its oxidation state, with arsenite (As(III)) being more toxic and mobile than arsenate (As(V)). Humic substances (HS) are also redox-active and can potentially react with arsenic and change its redox state. In this study we show that semiquinone radicals produced during microbial or chemical reduction of a HS model quinone (AQDS, 9,10-anthraquinone-2,6-disulfonic acid) are strong oxidants. They oxidize arsenite to arsenate, thus decreasing As toxicity and mobility. This reaction depends strongly on pH with more arsenite (up to 67.3%) being oxidized at pH 11 compared to pH 7 (12.6% oxidation) and pH 3 (0.5% oxidation). In addition to As(III) oxidation by semiquinone radicals, hydroquinones that were also produced during quinone reduction reduced As(V) to As(III) at neutral and acidic pH values (less than 12%) but not at alkaline pH. In order to understand redox reactions between arsenite/arsenate and reduced/oxidized HS, we quantified the radical content in reduced quinone solutions and constructed Eh-pH diagrams that explain the observed redox reactions. The results from this study can be used to better predict the fate of arsenic in the environment and potentially explain the occurrence of oxidized As(V) in anoxic environments. KW - Natural organic-matter KW - Electron-acceptors KW - Reducing bacteria KW - Ferric iron KW - Reduction KW - Acid KW - Groundwater KW - Release KW - Kinetics KW - pH PY - 2009 DO - https://doi.org/10.1021/es803112a SN - 0013-936X SN - 1520-5851 VL - 43 IS - 10 SP - 3639 EP - 3645 PB - ACS Publ. CY - Washington, DC AN - OPUS4-19982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roden, E. A1 - Kappler, A. A1 - Bauer, I. A1 - Jiang, J. A1 - Paul, Andrea A1 - Stoesser, R. A1 - Konishi, H. A1 - Xu, H. T1 - Extracellular electron transfer through microbial reduction of solid-phase humic substances KW - Natural organic-matter KW - Electron-acceptors KW - Reducing bacteria KW - Ferric iron KW - Reduction KW - Acid KW - Groundwater KW - Release KW - Kinetics KW - PH PY - 2010 DO - https://doi.org/10.1038/NGEO870 SN - 1752-0894 SN - 1752-0908 VL - 3 SP - 417 EP - 421 PB - Nature Publishing Group CY - London AN - OPUS4-22345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chazeau, E. A1 - Pipier, A. A1 - Wegner, Karl David A1 - Ghiringhelli, F. A1 - Sancey, L. A1 - Paul, C. A1 - Goze, C. T1 - NIR-II aza-BODIPY Platform for the Development of a Fluorescent Antibody Drug Conjugate N2 - Real-time imaging of antibody-drug conjugates (ADCs) offers valuable insights for assessing tumor targeting specificity, monitoring therapeutic efficacy, and detecting off-target accumulation that may cause adverse effects. To enable precise tracking, we developed a versatile fluorescent platform based on an NIR-II emitting aza-BODIPY dye, which can be site-specifically grafted onto an IgG1 antibody to generate well-defined fluorescent ADCs. As a proof of concept, we synthesized an HER2-targeting trastuzumab immunoconjugate bearing a NIR-II aza-BODIPY fluorophore. The cytotoxic monomethyl auristatin E (MMAE) payload was introduced in the final step, resulting in a trackable and homogeneous ADC suitable for both in vitro and in vivo investigations. The resulting Trastu-azaNIRII-MMAE selectively accumulated in HER2-positive subcutaneous tumors, significantly reducing the tumor growth. Using NIR-II optical imaging, a single injection of the NIR-II-ADC allowed for the detection of the conjugate over a period of more than one month, highlighting its potential for long-term tracking and therapeutic applications. KW - NIR-II KW - Fluorescence KW - Quality assurance KW - Antibody drug conjugate KW - In vivo imaging PY - 2025 DO - https://doi.org/10.1021/acs.jmedchem.4c02777 VL - 68 IS - 7 SP - 7232 EP - 7242 PB - ACS Publications AN - OPUS4-63025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nietzold, Carolin A1 - Dietrich, Paul A1 - Holzweber, M. A1 - Lippitz, Andreas A1 - Kamalakumar, A. A1 - Blanchard, V. A1 - Ivanov-Pankov, S. A1 - Weigel, W. A1 - Panne, Ulrich A1 - Unger, Wolfgang T1 - Surface chemical characterization of model glycan surfaces and shelf life studies of glycan microarrays using XPS, NEXAFS spectroscopy, ToF-SIMS and fluorescence scanning N2 - Biomedical applications, including functional biomaterials, carbohydrate-arrays, and glycan-based biosensors. The chemistry of glycan immobilization plays an essential role in the bioavailability and function of surface bound carbohydrate moieties. For biomedical applications the stability over time (shelf life) of glycan arrays is a crucial factor. Herein we report on approaches for surface and interface characterization relevant to the needs of production of glycan microarrays which were tested using model carbohydrate surfaces. For detailed characterization of glycan model surfaces we used a combination of X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and ToF SIMS which are complementary techniques of surface chemical analysis. Links to fluorescence spectroscopy often used for characterization in the microarray community were established as well. In detail, amine-reactive silicon oxide and glass surfaces were used for anchoring oligosaccharides with an amino linker. The amount of surface bound carbohydrates was estimated by X-ray photoelectron spectroscopy (XPS). Glycan immobilization was investigated using lectins, which are glycan-binding molecules. A shelf life study of model glycan microarrays on epoxy-coated glass surfaces was done over a period of 160 days under different storage conditions utilizing fluorescence, ToF-SIMS and XPS analysis. It was shown that glycan activity of the models used can be maintained at least for half a year of storage at 4 °C. KW - Glycan microarray KW - XPS KW - NEXAFS KW - ToF-SIMS KW - Fluorescence PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0169433218320300?via%3Dihub DO - https://doi.org/10.1016/j.apsusc.2018.07.133 SN - 0169-4332 SN - 1873-5584 VL - 459 SP - 860 EP - 873 PB - Elsevier B.V. AN - OPUS4-46212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wander, Lukas A1 - Vianello, A. A1 - Vollertsen, J. A1 - Westad, F. A1 - Braun, Ulrike A1 - Paul, Andrea T1 - Exploratory analysis of hyperspectral FTIR data obtained from environmental microplastics samples N2 - Hyperspectral imaging of environmental samples with infrared microscopes is one of the preferred methods to find and characterize microplastics. Particles can be quantified in terms of number, size and size distribution. Their shape can be studied and the substances can be identified. Interpretation of the collected spectra is a typical problem encountered during the analysis. The image datasets are large and contain spectra of countless particles of natural and synthetic origin. To supplement existing Analysis pipelines, exploratory multivariate data analysis was tested on two independent datasets. Dimensionality reduction with principal component analysis (PCA) and uniform manifold approximation and projection (UMAP) was used as a core concept. It allowed for improved visual accessibility of the data and created a chemical two-dimensional image of the sample. Spectra belonging to particles could be separated from blank spectra, reducing the amount of data significantly. Selected spectra were further studied, also applying PCA and UMAP. Groups of similar spectra were identified by cluster analysis using k-means, density based, and interactive manual clustering. Most clusters could be assigned to chemical species based on reference spectra. While the results support findings obtained with a ‘targeted analysis’ based on automated library search, exploratory analysis points the attention towards the group of unidientified spectra that remained and are otherwise easily overlooked. KW - Microplastics KW - FTIR KW - Exploratory analysis PY - 2020 DO - https://doi.org/10.1039/c9ay02483b VL - 12 IS - 6 SP - 781 EP - 791 PB - Royal Society of Chemistry AN - OPUS4-50396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, S.C. A1 - Pirskawetz, Stephan A1 - Van Zijl, G.P.A.G. A1 - Schmidt, Wolfram T1 - Acoustic emission for characterising the crack propagation in strain-hardening cement-based composites (SHCC) N2 - This paper presents the analysis of crack propagation in strain-hardening cement-based composite (SHCC) under tensile and flexural load by using acoustic emission (AE). AE is a non-destructive technique to monitor the development of structural damage due to external forces. The main objective of this research was to characterise the cracking behaviour in SHCC in direct tensile and flexural tests by using AE. A better understanding of the development of microcracks in SHCC will lead to a better understanding of pseudo strain-hardening behaviour of SHCC and its general performance. ARAMIS optical deformation analysis was also used in direct tensile tests to observe crack propagation in SHCC materials. For the direct tensile tests, SHCC specimens were prepared with polyvinyl alcohol (PVA) fibre with three different volume percentages (1%, 1.85% and 2.5%). For the flexural test beam specimens, only a fibre dosage of 1.85% was applied. It was found that the application of AE in SHCC can be a good option to analyse the crack growth in the specimens under increasing load, the location of the cracks and most importantly the identification of matrix cracking and fibre rupture or slippage. KW - Acoustic emission KW - Crack Detection (B) KW - Microcracking (B) KW - Fibre Reinforcement (E) KW - Tensile Properties (C) PY - 2015 DO - https://doi.org/10.1016/j.cemconres.2014.12.003 SN - 0008-8846 SN - 1873-3948 VL - 69 SP - 19 EP - 24 PB - Pergamon Press CY - New York, NY AN - OPUS4-33579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kauss, Norman A1 - Heyn, A. A1 - Halle, T. A1 - Rosemann, Paul T1 - Detection of sensitisation on aged lean duplex stainless steel with different electrochemical methods N2 - Ageing at 600 °C (from 0.1 h up to 20 h) leads to the formation of precipitations at the ferrite-ferrite (α/α) and ferrite-austenite (α/γ) grain boundaries of the lean duplex stainless steel (LDSS) X2CrNiN22-2. This leads to sensitisation due to chromium depletion and decreased pitting corrosion resistance proven by the results of various electrochemical methods (DL-EPR and determination of CPT, Epit). These results were compared with the KorroPad method, which uses an agar-based gel-electrolyte for the detection of stainless steel surfaces prone to pitting corrosion. However, the standard configuration of the KorroPad showed no differentiation for the various ageing conditions. Therefore, modified versions of the KorroPad with two, five and ten times higher NaCl and potassium ferrocyanide III (K3[Fe(CN)6]) concentrations were successfully used to visualise the behaviour detected by DL-EPR, Epit and CPT. Therefore, the KorroPad method can also detect a microstructure related reduction of pitting corrosion resistance, which can drastically reduce the experimental effort to generate sensitisation diagrams for stainless steels. KW - Lean duplex KW - Stainless steel KW - Sensitisation KW - Polarisation KW - Critical pitting temperature KW - Pitting corrosion KW - KorroPad KW - Ageing treatment PY - 2019 DO - https://doi.org/10.1016/j.electacta.2019.05.081 SN - 0013-4686 SN - 1873-3859 VL - 317 SP - 17 EP - 24 PB - Elsevier AN - OPUS4-48374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Maaßdorf, A. A1 - Rooch, Heidemarie A1 - Österle, Werner A1 - Malcher, M. A1 - Schmidt, M. A1 - Kollmer, F. A1 - Paul, D. A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Unger, Wolfgang T1 - Lateral resolution of nanoscaled images delivered by surface-analytical instruments: application of the BAM-L200 certified reference material and related ISO standards N2 - The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1–xAs and InxGa1–xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface-analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013. KW - AES KW - BAM-L200 KW - CRM KW - EDX KW - Imaging KW - Lateral resolution KW - Sharpness KW - Standardisation KW - STXM KW - ToF-SIMS KW - XPEEM KW - XPS KW - Certified reference material KW - Imaging surface analysis PY - 2015 DO - https://doi.org/10.1007/s00216-014-8135-7 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3211 EP - 3217 PB - Springer CY - Berlin AN - OPUS4-33033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klöckner, P. A1 - Reemtsma, T. A1 - Eisentraut, Paul A1 - Braun, Ulrike A1 - Ruhl, A. S. A1 - Wagner, S. T1 - Tire and road wear particles in road environment e Quantification and assessment of particle dynamics by Zn determination after density separation N2 - In this study, a method for the determination of tire and road wear particle (TRWP) contents in particulate samples from road Environment was developed. Zn was identified as the most suitable elemental marker for TRWP, due to its high concentration in tire tread and the possibility of separation from other Zn sources. The mean concentration of 21 tire samples was 8.7 ± 2.0 mg Zn/g. Before quantification in samples from road environment, TRWP were separated from the particulate matrix by density separation. Method development was conducted using shredded tread particles (TP) as a surrogate for TRWP. Recovery of TP from spiked sediment was 95 ± 17% in a concentration range of 2 - 200 mg TP/g. TP determination was not affected by other Zn containing solids or spiked Zn-salts. By adjusting the density of the separation solution to 1.9 g/cm3, more than 90% of total TRWP were separated from the sample matrix. TRWP concentrations in particulate matter collected in two road runoff treatment Systems ranged from 0.38 to 150 mg TRWP/g. Differences in quantified TRWP contents of the two Systems indicate changes in particle dynamics due to ageing and aggregation processes. The developed method allows TRWP determination in road runoff and in environments that are influenced by road traffic. The validated separation procedure can also be applied for TRWP characterization in future studies. KW - Zinc analysis KW - Microplastics KW - Tire particles PY - 2019 VL - 222 SP - 714 EP - 721 PB - Elsevier AN - OPUS4-47433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kern, Simon A1 - Wander, Lukas A1 - Meyer, Klas A1 - Guhl, Svetlana A1 - Gottu Mukkula, A. R. A1 - Holtkamp, M. A1 - Salge, M. A1 - Fleischer, C. A1 - Weber, N. A1 - Engell, S. A1 - Paul, Andrea A1 - Pereira Remelhe, M. A1 - Maiwald, Michael T1 - Flexible automation with compact NMR spectroscopy for continuous production of pharmaceuticals N2 - Modular plants using intensified continuous processes represent an appealing concept for the production of pharmaceuticals. It can improve quality, safety, sustainability, and profitability compared to batch processes; besides, it enables plug-and-produce reconfiguration for fast product changes. To facilitate this flexibility by real-time quality control, we developed a solution that can be adapted quickly to new processes and is based on a compact nuclear magnetic resonance (NMR) spectrometer. The NMR sensor is a benchtop device enhanced to the requirements of automated chemical production including robust evaluation of sensor data. Beyond monitoring the product quality, online NMR data was used in a new iterative optimization approach to maximize the plant profit and served as a reliable reference for the calibration of a near-infrared (NIR) spectrometer. The overall approach was demonstrated on a commercial-scale pilot plant using a metal-organic reaction with pharmaceutical relevance. KW - NMR Spectroscopy KW - NIR Spectroscopy KW - Real-time process monitoring KW - Real-time quality control KW - Continuous processes KW - CONSENS KW - Data Fusion PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-480623 DO - https://doi.org/10.1007/s00216-019-01752-y SN - 1618-2642 SN - 1618-2650 VL - 411 IS - 14 SP - 3037 EP - 3046 PB - Springer Nature CY - Heidelberg AN - OPUS4-48062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Thomas A1 - Traulsen, Christoph Hans-Henning A1 - Darlatt, Erik A1 - Richter, S. A1 - Poppenberg, J. A1 - Traulsen, N.L. A1 - Linder, I. A1 - Lippitz, Andreas A1 - Dietrich, Paul A1 - Dib, B. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - The versatility of 'Click' reactions at surfaces: Molecular recognition at interfaces N2 - In order to investigate molecular recognition on surfaces, an azide-functionalized monolayer was deposited on gold. The monolayer was characterized by X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) experiments and the decomposition of the azide upon irradiation with X-ray beams was investigated. Subsequently, various alkyne-functionalized host and guest molecules were attached to the azide by 1,3-dipolar cycloaddition. These modified surfaces and their host–guest chemistry were analysed by XPS and angle-resolved NEXAFS. The reversibility of guest binding was shown for one example as a proof of principle. KW - 'Click' reaction KW - Azide-terminated surfaces KW - SAMs KW - Host guest molecules KW - Molecular recognition at interfaces PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-306463 DO - https://doi.org/10.1039/C4RA01730G SN - 2046-2069 VL - 4 IS - 34 SP - 17694 EP - 17702 PB - RSC Publishing CY - London AN - OPUS4-30646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Varadarajan, A. A1 - Allan, R. A1 - Valentin, J. A1 - Castañeda Ocampo, O. A1 - Somerville, V. A1 - Buhmann, M. A1 - West, J. A1 - Skipp, Paul A1 - van der Mei, H. A1 - Ren, Q. A1 - Schreiber, Frank A1 - Webb, J. A1 - Pietsch, Franziska A1 - Ahrens, C. T1 - An integrated model system to gain mechanistic insights into biofilm-associated antimicrobial resistance in Pseudomonas aeruginosa MPAO1 N2 - Pseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and biofilm-associated antibiotic resistance. Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and genes missed within existing assemblies by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq data sets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth and a screen with the Tn-mutant library in microtiter plates. The screen identified hitherto unknown genes involved in biofilm growth and antibiotic resistance. Experiments conducted with the flow chamber across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated the function of both known genes and genes identified in the Tn-mutant screens. Differential Protein abundance data from planktonic cells versus biofilm confirmed the upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type VI secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance, and resistance evolution in biofilms. KW - Biofilms PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515108 DO - https://doi.org/10.1038/s41522-020-00154-8 VL - 6 IS - 1 SP - Article number: 46 PB - Springer Nature CY - Singapore AN - OPUS4-51510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraehnert, R. A1 - Ortel, Erik A1 - Paul, B. A1 - Eckhardt, B. A1 - Kanis, M. A1 - Liu, R. A1 - Antoniou, A. T1 - Electrochemically dealloyed platinum with hierarchical pore structure as highly active catalytic coating N2 - Micro structured reactors are attractive candidates for further process intensification in heterogeneous catalysis. However, they require catalytic coatings with significantly improved space-time yields compared to traditional supported catalysts. We report the facile synthesis of homogeneous nanocrystalline Pt coatings with hierarchical pore structure by electrochemical dealloying of amorphous sputter-deposited platinum silicide layers. Thickness, porosity and surface composition of the catalysts can be controlled by the dealloying procedure. XPS analysis indicates that the catalyst surface is primarily composed of metallic Pt. Catalytic tests in gas-phase hydrogenation of butadiene reveal the typical activity, selectivity and activation energy of nanocrystalline platinum. However, space time yields are about 13 to 200 times higher than values reported for Pt-based catalysts in literature. The highly open metallic pore structure prevents heat and mass transport limitations allowing for very fast reactions and reasonable stability at elevated temperatures. KW - Pt catalysts KW - Pt–Si layers KW - Scanning Electron Microscopy (SEM) KW - Transmission Electron Microscopy (TEM) KW - pore structure KW - electrochemical dealloying PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351393 DO - https://doi.org/10.1039/C4CY00851K SN - 2044-4753 SN - 2044-4761 VL - 5 IS - 1 SP - 206 EP - 216 PB - RSC Publ. CY - Cambridge AN - OPUS4-35139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steglich, P. A1 - Rabus, D. G. A1 - Sada, C. A1 - Paul, Martin A1 - Weller, Michael G. A1 - Mai, C. A1 - Mai, A. T1 - Silicon Photonic Micro-Ring Resonators for Chemical and Biological Sensing: A Tutorial N2 - Silicon photonic micro-ring resonators (MRR) developed on the silicon-on-insulator (SOI) platform, owing to their high sensitivity and small footprint, show great potential for many chemical and biological sensing applications such as label-free detection in environmental monitoring, biomedical engineering, and food analysis. In this tutorial,we provide the theoretical background and give design guidelines for SOI-based MRR as well as examples of surface functionalization procedures for label-free detection of molecules. After introducing the advantages and perspectives of MRR, fundamentals of MRR are described in detail, followed by an introduction to the fabrication methods, which are based on a complementary metal-oxide semiconductor (CMOS) technology. Optimization of MRR for chemical and biological sensing is provided, with special emphasis on the optimization of waveguide geometry. At this point, the difference between chemical bulk sensing and label-free surface sensing is explained, and definitions like waveguide sensitivity, ring sensitivity, overall sensitivity as well as the limit of detection (LoD) of MRR are introduced. Further, we show and explain chemical bulk sensing of sodium chloride (NaCl) in water and provide a recipe for label-free surface sensing. KW - Biosensors KW - Biophotonics KW - Chemosensor KW - Biosensor KW - Microresonator KW - Nanophotonics KW - Optical sensors KW - Photonic sensors KW - Optoelectronic KW - Ring resonator KW - Silicon photonics KW - Miniaturization KW - Lab-on-a-chip KW - Lab-on-chip KW - Waveguide KW - Surface chemistry KW - Silanization KW - Glutaraldehyde KW - Affinity immobilization KW - Antibody KW - Oriented immobilization KW - Real-time measurement PY - 2022 DO - https://doi.org/10.1109/JSEN.2021.3119547 SN - 1530-437X VL - 22 IS - 11 SP - 10089 EP - 10105 PB - IEEE AN - OPUS4-55147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steglich, P. A1 - Bondarenko, S. A1 - Mai, C. A1 - Paul, Martin A1 - Weller, Michael G. A1 - Mai, A. T1 - CMOS-Compatible Silicon Photonic Sensor for Refractive Index Sensing Using Local Back-Side Release N2 - Silicon photonic sensors are promising candidates for lab-on-a-chip solutions with versatile applications and scalable production prospects using complementary metal-oxide semiconductor (CMOS) fabrication methods. However, the widespread use has been hindered because the sensing area adjoins optical and electrical components making packaging and sensor handling challenging. In this work, a local back-side release of the photonic sensor is employed, enabling a separation of the sensing area from the rest of the chip. This approach allows preserving the compatibility of photonic integrated circuits in the front-end of line and metal interconnects in the back-end of line. The sensor is based on a micro-ring resonator and is fabricated on wafer-level using a CMOS technology. We revealed a ring resonator sensitivity for homogeneous sensing of 106 nm/RIU. KW - Photonic biosensor KW - Lab-on-a-chip KW - Ring resonator KW - Resonance wavelength shift KW - PIC technology KW - Back-side integration PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517139 DO - https://doi.org/10.1109/LPT.2020.3019114 VL - 32 IS - 19 SP - 1241 EP - 1244 PB - IEEE AN - OPUS4-51713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Bannick, C.G. A1 - Szewzyk, R. A1 - Ricking, M. A1 - Schniegler, S. A1 - Obermaier, N. A1 - Barthel, A. K. A1 - Altmann, Korinna A1 - Eisentraut, Paul T1 - Development and testing of a fractionated filtration for sampling of microplastics in water N2 - A harmonization of sampling, sample preparation and detection is pivotal in order to obtain comparable data on microplastics (MP) in the environment. This paper develops and proposes a suitable sampling concept for waterbodies that considers different plastic specific properties and influencing factors in the environment. Both artificial water including defined MP fractions and the discharge of a wastewater treatment plant were used to verify the derived sampling procedure, sample preparation and the subsequent analysis of MP using thermal extraction-desorption gas chromatography - mass spectrometry (TED-GC-MS). A major finding of this paper is that an application of various particle size classes greatly improves the practical handling of the sampling equipment. Size classes also enable the TED-GC-MS to provide any data on the MP size distribution, a substantial sampling property affecting both the necessary sampling volume and the optimal sampling depth. In the artificial water with defined MP fractions, the recovery rates ranged from 80 to 110%, depending on the different MP types and MP size classes. In the treated wastewater, we found both Polyethylene and polystyrene in different size classes and quantities. KW - Microplastics KW - Sampling KW - Sampling techniques KW - Water PY - 2019 DO - https://doi.org/10.1016/j.watres.2018.10.045 SN - 0043-1354 VL - 149 SP - 650 EP - 658 PB - Elsevier AN - OPUS4-47200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ortel, Erik A1 - Polte, J. A1 - Bernsmeier, D. A1 - Eckhardt, B. A1 - Paul, B. A1 - Bergmann, A. A1 - Strasser, P. A1 - Emmerling, Franziska A1 - Kraehnert, R. T1 - Pd/TiO2 coatings with template-controlled mesopore structure as highly active hydrogenation catalyst N2 - Micro-structured reactors offer excellent mass and heat transport capabilities and can therefore sustain very high reaction rates and space–time-yields also for highly exothermic catalytic reactions. However, such high rates cannot be reached when the reactors are coated or filled with conventional catalysts powders. We present a strategy for the direct synthesis of highly active wall-coated supported catalysts via co-deposition of a pore template (here micelles formed from PEO-b-PPO-b-PEO) and a precursors for the metal oxide (TiCl4) along with a compatible precursor for the active metal (PdCl2). The obtained catalytic coatings possess a template-controlled open pore structure and excellent mechanical stability. Moreover, the active metal is highly dispersed and well-distributed across the coating also at high Pd loadings. The corresponding high activity along with rapid mass transfer enabled by the open pore system results in the best space–time-yields in the gas-phase hydrogenation of butadiene reported so far in literature for a supported catalyst. KW - Titanium oxide films KW - Palladium nanoparticle KW - Wall-coated supported catalysts KW - Template-controlled mesoporous materials KW - Hydrogenation of 1,3-butadiene PY - 2015 DO - https://doi.org/10.1016/j.apcata.2014.12.044 SN - 0926-860X SN - 1873-3875 VL - 493 SP - 25 EP - 32 PB - Elsevier CY - Amsterdam AN - OPUS4-32465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eitzen, L. A1 - Paul, S. A1 - Braun, Ulrike A1 - Altmann, Korinna A1 - Jekel, M. A1 - Ruhl, A. T1 - The challenge in preparing particle suspensions for aquatic microplastic research N2 - The occurrence of small particles consisting of organic polymers, so-called microplastic (MP), in aquatic Environments attracts increasing interest in both public and science. Recent sampling campaigns in surface Waters revealed substantial numbers of particles in the size range from a few micrometers to a few millimeters. In order to validate sample preparation, identification and quantification and to investigate the behavior of MP particles and potential toxic effects on organisms, defined MP model particles are needed. Many studies use spherical compounds that probably behave differently compared to irregularly shaped MP found in environmental samples. However, preparation and handling of MP particles are challenging tasks and have been systematically investigated in the present study. Polystyrene (PS) as a commonly found polymer with a density slightly above that of water was selected as polymer type for milling and fractionation studies. A cryogenic ball mill proved to be practical and effective to produce particles in the size range from 1 to 200 μm. The yield of small particles increased with increasing pre-cooling and milling durations. Depending on the concentration and the size, PS particles do not completely disperse in water and particles partly creep vertically up along glass walls. Stabilized MP suspensions without use of surfactants that might harm organisms are needed for toxicological studies. The stabilization of PS particle suspensions with ozone treatment reduced the wall effect and increased the number of dispersed PS particles but increased the dissolved organic carbon concentration and changed the size Distribution of the particles. KW - Reference material KW - Microplastic PY - 2018 DO - https://doi.org/10.1016/j.envres.2018.09.008 SN - 0013-9351 SN - 1096-0953 VL - 168 SP - 490 EP - 495 PB - Elsevier AN - OPUS4-46462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wuithschick, M. A1 - Paul, B. A1 - Bienert, Ralf A1 - Sarfraz, A. A1 - Vainio, U. A1 - Sztucki, M. A1 - Kraehnert, R. A1 - Strasser, P. A1 - Rademann, K. A1 - Emmerling, Franziska A1 - Polte, J. T1 - Size-controlled synthesis of colloidal silver nanoparticles based on mechanistic understanding N2 - Metal nanoparticles have attracted much attention due to their unique properties. Size control provides an effective key to an accurate adjustment of colloidal properties. The common approach to size control is testing different sets of parameters via trial and error. The actual particle growth mechanisms, and in particular the influences of synthesis parameters on the growth process, remain a black box. As a result, precise size control is rarely achieved for most metal nanoparticles. This contribution presents an approach to size control that is based on mechanistic knowledge. It is exemplified for a common silver nanoparticle synthesis, namely, the reduction of AgClO4 with NaBH4. Conducting this approach allowed a well-directed modification of this synthesis that enables, for the first time, the size-controlled production of silver nanoparticles 4–8 nm in radius without addition of any stabilization agent. KW - Silver nanoparticles KW - Growth mechanism KW - SAXS KW - Size control KW - Sodium borohydride PY - 2013 DO - https://doi.org/10.1021/cm401851g SN - 0897-4756 SN - 1520-5002 VL - 25 IS - 23 SP - 4679 EP - 4689 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -