TY - GEN A1 - Herrmann, Stefan T1 - Charakterisierung zweier monoklonaler Antikörper zur Detektion von Sprengstoffen N2 - In 2019 over 30 000 people were killed or injured by explosions caused by explosives like TNT, PETN, HMX and RDX. Therefore, highly sensitive assays for the detection of TNT are needed. In this study we compared two commercially available TNT antibodies: A1.1.1 and EW75C with a highly optimized indirect competitive ELISA based on a BSA-TNA conjugate. As a result, a precision profile for both antibodies was determined with a LOD of 170 pmol L-1 for the clone A1.1.1 and a LOD of 3,2 nmol L-1 for the clone EW75C. The measurements showed that the clone A1.1.1 is a highly sensitive antibody for the detection of TNT while the clone EW75C does show medium performance at most. In the cross-reactivity characterization of both antibodies many substances, closely related to the structure of TNT were tested. Both antibodies showed strong cross reactivity with trinitroaniline and trinitrobenzene. For the clone A1.1.1, which is known to originate from immunization of mice with an TNP-glycine-KLH conjugate, this has to be expected. Interestingly the clone EW75C, which was not characterized yet, showed similar behavior. This suggests a TNA-conjugate as immunogen for the EW75C antibody as well. None of both antibodies showed cross-reactions to the high explosives PETN, HMX and RDX. Also, the cross-reactions of nitro musks with the antibodies were investigated. Despite their prohibition, nitro musks are still used in Asia especially and are particularly popular in India. The overall superior clone A1.1.1 showed a significant cross-reactivity to musk ambrette. For practical reasons the influence of musk ambrette on this assay when used in natural environment should be investigated. In further experiments, the highly sensitive TNT antibody A1.1.1 was digested with papain to obtain monovalent Fab-fragments. Due to its high stability against the digestion, a custom protocol for the IgG1 subclass of mice, to which the clone A1.1.1 belongs, was developed, resulting in a quantitative digestion of the intact antibody to Fab fragments. The success of the digestion was determined with MALDI-TOF-MS and SDS-PAGE. It was shown that this protocol worked for many different antibodies of IgG1 subclass as well. KW - TNT KW - Trinitrotoluol KW - Nitroaromaten KW - Nitromoschus KW - Duftstoffe KW - ELISA KW - Immunoassay KW - Antibody KW - Explosives KW - Klon A1.1.1 KW - Klon EW75C KW - Fab Fragment KW - Kreuzreaktion KW - Crossreactivity KW - Precision Profile KW - Präzisionsprofil KW - Affinity KW - Affinitätskonstante KW - IC50 PY - 2020 SP - 1 EP - 113 PB - Hochschule für Technik und Wirtschaft Berlin - htw CY - Berlin AN - OPUS4-54556 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Denkler, Tilman T1 - Comparison of the Operation of Accreditation Bodies in Europe - Final Report 2nd Round N2 - In 2019 the Bundesanstalt für Materialforschung und –prüfung (BAM) conducted a benchmarking to compare the operations of European accreditation bodies and to identify best practices, with the aim of improving key processes in accreditation. Ten European accreditation bodies attended the comparison, four of which had already taken part in the pilot phase of the benchmarking project, which was conducted in 2017 by the German accreditation body Deutsche Akkreditierungsstelle GmbH (DAkkS) and BAM. The study, designed to examine and compare the operation of accreditation bodies in Europe, used a management tool called Process Maturity Benchmarking Tool, which was especially elaborated and validated for this purpose in the pilot phase, in order to determine the values of indicators, thus enabling a comparison of the accreditation bodies despite different operational processes and organizational forms. The management tool is based on the analysis of selected processes with high relevance for the operation of accreditation bodies. The processes are derived from a process map designed for accreditation bodies in a universally applicable way. The indicators used to characterize the processes come from two sources: The first source relates to data already available from internal databases, reports, financial audits, and others. The second source is derived from the self-evaluation of process maturity performed by the accreditation bodies. The criteria for evaluating process maturities were designed by applying the criteria of the EFQM excellence model 2013 of the European Foundation for Quality Management (EFQM) to the processes identified in the process map. The results of the analysis were presented to and discussed with representatives of the ten accreditation bodies at a Results-Workshop that took place at BAM on 21/22 January 2020. KW - Akkreditierung KW - Accreditation KW - Benchmarking KW - EFQM Excellence Modell KW - Quality Infrastructure KW - Total Quality Management PY - 2020 SP - 1 EP - 70 AN - OPUS4-54712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steger, Simon A1 - Stege, H. A1 - Bretz, S. A1 - Hahn, Oliver ED - Tomasin, P. T1 - Disclosing glittering and sparkling effects in 20th-century reverse glass paintings: a study of metallic pigments and metal foils by means of in situ XRF and DRIFTS analysis N2 - This work presents a spectroscopic study of metallic pigments and metal foils used in reverse glass paintings that were created between 1912 and 1954. Metallic pigments induce a notable sparkling effect by means of the lateral incidence of light, whereas metal foils enhance the gloss and create a glittering effect when the painting is viewed in reflected light. Both effects were desired features especially in modern reverse paintings on glass and applied by artists in manifold creative manner. The paper gives an overview on the composition of the metalfoils and metal pigments in 14 works as determined in situ by X-ray spectrometry. Metal foils made of tin, brass, aluminium and silver were found in nine paintings. Gold imitating Cu-Zn pigments in different hues and with various Cu/Zn net intensity ratios were recorded for six paintings. Silvery pigments were identified mainly as Al pigments, but also as Cu-Zn-Ni alloy in one case. Other uncommon metallic pigments were detected in Arlequin vindicatif (c. 1925) by Floris Jespers, who used not only Cu-Zn and Al pigments, but also brownish Cu and Cu-Zn-Sn pigments. Non-invasive diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) was used to classify the binding media of the metallic pigments. Drying oil and natural resin probably mixed with oil were the most common binding media. A polysaccharide-based binder was found in the silvery Cu-Zn-Ni pigment of Ohne Titel (1954) by Marianne Uhlenhuth. KW - Archaeometry KW - Non-invasive analysis KW - Reverse paintings on glass PY - 2020 U6 - https://doi.org/10.1016/j.culher.2020.11.008 SN - 1296-2074 VL - 48 SP - 196 EP - 204 PB - Elsevier Masson SAS CY - Amsterdam AN - OPUS4-54428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zancajo, V. M. R. A1 - Lindtner, T. A1 - Eisele, M. A1 - Huber, A. J. A1 - Elbaum, R. A1 - Kneipp, Janina T1 - FTIR Nanospectroscopy Shows Molecular Structures of Plant Biominerals and Cell Walls N2 - Plant tissues are complex composite structures of organic and inorganic components whose function relies on molecular heterogeneity at the nanometer scale. Scattering-type near-field optical microscopy (s-SNOM) in the mid-infrared (IR) region is used here to collect IR nanospectra from both fixed and native plant samples. We compared structures of chemically extracted silica bodies (phytoliths) to silicified and nonsilicified cell walls prepared as a flat block of epoxy-embedded awns of wheat (Triticum turgidum), thin sections of native epidermis cells from sorghum (Sorghum bicolor) comprising silica phytoliths, and isolated cells from awns of oats (Avena sterilis). The correlation of the scanning-probe IR images and the mechanical phase image enables a combined probing of mechanical material properties together with the chemical composition and structure of both the cell walls and the phytolith structures. The data reveal a structural heterogeneity of the different silica bodies in situ, as well as different compositions and crystallinities of cell wall components. In conclusion, IR nanospectroscopy is suggested as an ideal tool for studies of native plant materials of varied origins and preparations and could be applied to other inorganic–organic hybrid materials. KW - Cells KW - Plants KW - Organic polymers KW - Silica KW - Infrared light PY - 2020 U6 - https://doi.org/10.1021/acs.analchem.0c00271 SN - 0003-2700 VL - 92 IS - 20 SP - 13694 EP - 13701 PB - ACS Publications AN - OPUS4-54445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha T1 - ANNforPAT - Artificial Neural Networks for Process Analytical Technology N2 - This code accompanies the paper "Artificial neural networks for quantitative online NMR spectroscopy" published in Analytical and Bioanalytical Chemistry (2020). KW - Artificial neural networks KW - Automation KW - Online NMR spectroscopy KW - Process industry KW - Real-time process monitoring PY - 2020 UR - https://github.com/BAMresearch/ANNforPAT PB - GitHub CY - San Francisco AN - OPUS4-54481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adams, L. C. A1 - Brangsch, J. A1 - Reimann, C. A1 - Kaufmann, Jan Ole A1 - Nowak, K. A1 - Buchholz, R. A1 - Karst, U. A1 - Botnar, R. M. A1 - Hamm, B. A1 - Makowski, M. R. T1 - Noninvasive imaging of vascular permeability to predict the risk of rupture in abdominal aortic aneurysms using an albumin binding probe N2 - Abdominal aortic aneurysm (AAA) remains a fatal disease. Its development encompasses a complex interplay between hemodynamic stimuli on and changes in the arterial wall. Currently available biomarkers fail to predict the risk of AAA rupture independent of aneurysm size. Therefore, novel biomarkers for AAA characterization are needed. In this study, we used a mouse model of AAA to investigate the potential of magnetic resonance imaging (MRI) with an albumin-binding probe to assess changes in vascular permeability at different stages of aneurysm growth. Two imaging studies were performed: a longitudinal study with follow-up and death as endpoint to predict rupture risk and a week-by-week study to characterize AAA development. AAAs, which eventually ruptured, demonstrated a significantly higher in vivo MR signal enhancement from the albumin-binding probe (p = 0.047) and a smaller non-enhancing thrombus area compared to intact AAAs (p = 0.001). The ratio of albumin-binding-probe enhancement of the aneurysm wall to size of non-enhancing-thrombus-area predicted AAA rupture with high sensitivity/specificity (100%/86%). More advanced aneurysms with higher vascular permeability demonstrated an increased uptake of the albumin-binding-probe. These results indicate that MRI with an albumin-binding probe may enable noninvasive assessment of vascular permeability in murine AAAs and prediction of rupture risk. KW - Magnetic resonance imaging KW - Imaging KW - Tomography KW - Gadolinium KW - Contrast agent KW - Atherosclerosis KW - ICP-MS KW - Gadofosveset KW - Angiography KW - LA-ICP-MS PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-525541 VL - 10 SP - Article number: 3231 PB - Springer Nature Limited CY - London, New York, Berlin, Shanghai and Tokyo AN - OPUS4-52554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gordon, N. A1 - Bonnerot, Olivier A1 - Rabin, Ira ED - Friedrich, M. ED - Quenzer, J. T1 - Inks Used to Write the Divine Name in a Thirteenth-Century Ashkenazic Torah Scroll: Erfurt 7 (Staatsbibliothek zu Berlin, Ms. or. fol. 1216) N2 - The scribe of ‘Erfurt 7’, a thirteenth-century Torah scroll now kept in Berlin, initially left blank spaces for the divine appellations Elohim ( אלהים ) and YHWH Elohim ( ,(יהוה אלהים which were filled in during a second stage of writing. The appearance of the ink employed to write the appellations was significantly darker than that of the surrounding ink. X-ray fluorescence analysis (XRF) has shown that the light and dark brown inks had similar elemental compositions, but contained different ratios of iron to potassium, which could be explained by the use of different batches of ink. According to some medieval sources, the divine appellations were sometimes filled in during a second stage of writing in the presence of ten men from the Jewish community. In Erfurt 7, the two-stage procedure was only performed in the first 1.5 columns of the original sheets, suggesting it may have been part of a public ceremony inaugurating the writing of the divine names in the scroll. Erfurt 7 emerges from this study not only as a ritual object used for liturgy, but as a rallying point for the Jews of Erfurt to come together as a community to express their reverence for the written form of God’s name. The divine name YHWH ( יהוה ) was written in a smaller script than the surrounding text on three replacement sheets using the same two-stage procedure. The ink used on the replacement sheets contained zinc, which is characteristic of other Erfurt manuscripts as well. This suggests that Erfurt was the place where the scroll was used, cherished and eventually repaired. KW - Torah KW - Ink KW - Erfurt KW - 13th century PY - 2020 SN - 1867–9617 VL - 15 SP - 163 EP - 184 AN - OPUS4-52965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bulling, Jannis T1 - Numerical methods (part II) Finite element method (FEM), Spectral element method (SEM) and Scaled Boundary FEM (SBFEM) N2 - A general presentation on numerical methods. In particular, the Finite Element Method, the Spectral Element Method, and the Scaled Boundary Finite Element Method. T2 - ITN-Trainingsevent CY - Online meeting DA - 22.11.2020 KW - FEM KW - SBFEM KW - SEM PY - 2020 AN - OPUS4-52271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tiebe, Carlo A1 - Melzer, Michael T1 - Seminar about the expression of uncertainty in measurement N2 - The evaluation of measurement uncertainty is essential for testing and calibration laboratories. This paper provides a general process description for the determination of the measurement uncertainty of quantitative data and its application to the conformity assessment with examples, and how to deal with the uncertainty of qualitative (Boolean) results, e. g. when "Alarm" or "No alarm" occours in an instrument display. T2 - GW4SHM - 1st Training Event CY - Online meeting DA - 23.11.2020 KW - Uncertainty KW - Conformity assessment KW - Boolean results PY - 2020 AN - OPUS4-52040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abram, Sarah-Luise A1 - Mrkwitschka, Paul A1 - Prinz, Carsten A1 - Rühle, Bastian A1 - Kuchenbecker, Petra A1 - Hodoroaba, Vasile-Dan A1 - Resch-Genger, Ute T1 - Monodisperse iron oxide nanoparticles as reference material candidate for particle size measurements N2 - In order to utilize and rationally design materials at the nanoscale the reliable characterization of their physico-chemical properties is highly important, especially with respect to the assessment of their environmental or biological impact. Furthermore, the European Commission’s REACH Regulations require the registration of nanomaterials traded in quantities of at least 1 ton. Powders or dispersions where 50% (number distribution) of the constituent particles have sizes ≤ 100 nm in at least one dimension are defined as nanomaterials. This creates a need for industrial manufacturers and research or analytical service facilities to reliably characterize potential nanomaterials. Currently, BAM is developing reference nanoparticles, which shall expand the scarce list of worldwide available nano reference materials certified for particle size distribution and will also target other key parameters like shape, structure, porosity or functional properties. In this respect, materials like iron oxide or titanium dioxide are considered as candidates to complement the already available silica, Au, Ag, and polystyrene reference nanoparticles. The thermal decomposition of iron oleate precursors in high boiling organic solvents can provide large quantities of iron oxide nanoparticles that can be varied in size and shape.[1, 2] The presence of oleic acid or other hydrophobic ligands as capping agents ensures stable dispersion in nonpolar solvents. Such monodisperse, spherical particles were synthesized at BAM and pre-characterized by electron microscopy (TEM, SEM including the transmission mode STEM-in-SEM) and dynamic light scattering comparing cumulants analysis and frequency power spectrum. 1. REACH regulations and nanosafety concerns create a strong need for nano reference materials with diverse properties. 2. Iron oxide nanoparticles are under development as new candidate reference material at BAM. 3. Narrow particle size distribution confirmed by light scattering and electron microscopy. T2 - Nanosafety 2020 CY - Online meeting DA - 05.10.2020 KW - Iron oxide nanoparticles KW - Reference material KW - Particle size KW - Electron microscopy KW - Nanoplattform PY - 2020 AN - OPUS4-52774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -