TY - JOUR A1 - Gregório, Bruno J.R. A1 - Ramos, Inês I. A1 - Marques, Sara S. A1 - Barreiros, Luísa A1 - Magalhães, Luís M. A1 - Schneider, Rudolf A1 - Segundo, Marcela A. T1 - Microcarrier-based fluorescent yeast estrogen screen assay for fast determination of endocrine disrupting compounds N2 - The presence of endocrine-disrupting compounds (EDCs) in water poses a significant threat to human and animal health, as recognized by regulatory agencies throughout the world. The Yeast Estrogen Screen (YES) assay is an excellent method to evaluate the presence of these compounds in water due to its simplicity and capacity to assess the bioaccessible forms/fractions of these compounds. In the presence of a compound with estrogenic activity, Saccharomyces cerevisiae cells, containing a lacZ reporter gene encoding the enzyme β-galactosidase, are induced, the enzyme is synthesised, and released to the extracellular medium. In this work, a YES-based approach encompassing the use of a lacZ reporter gene modified strain of S. cerevisiae, microcarriers as solid support, and a fluorescent substrate, fluorescein di-β-D-galactopyranoside, is proposed, allowing for the assessment of EDCs’ presence after only 2 h of incubation. The proposed method provided an EC50 of 0.17 ± 0.03 nM and an LLOQ of 0.03 nM, expressed as 17β-estradiol. The assessment of different EDCs provided EC50 values between 0.16 and 1.2 × 103 nM. After application to wastewaters, similar results were obtained for EDCs screening, much faster, compared to the conventional 45 h spectrophotometric procedure using a commercial kit, showing potential for onsite high-throughput screening of environmental contamination. KW - Biosensoren KW - YES assay KW - Endokrine Disruptoren PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602315 DO - https://doi.org/10.1016/j.talanta.2024.125665 VL - 271 SP - 1 EP - 7 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-60231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pereira, P.M.R. A1 - Korsak, B. A1 - Sarmento, B. A1 - Schneider, Rudolf A1 - Fernandes, R. A1 - Tomé, J.P.C. T1 - Antibodies armed with photosensitizers: from chemical synthesis to photobiological applications N2 - Targeting photosensitizers to cancer cells by conjugating them with specific antibodies, able to recognize and bind to tumor-associated antigens, is today one of the most attractive strategies in photodynamic therapy (PDT). This comprehensive review updates on chemical routes available for the preparation of photo-immunoconjugates (PICs), which show dual chemical and biological functionalities: photo-properties of the photosensitizer and the immunoreactivity of the antibody. Moreover, photobiological results obtained with such photo-immunoconjugates using in vitro and in vivo cancer models are also discussed. KW - Therapeutische Antikörper KW - Krebstherapie KW - Photodynamische Therapie KW - Konjugate KW - Porphyrine KW - Phthalocyanine KW - Chlorine KW - Kopplungsmethoden PY - 2015 DO - https://doi.org/10.1039/c4ob02334j SN - 1477-0520 SN - 1477-0539 VL - 13 IS - 9 SP - 2518 EP - 2529 PB - RSC CY - Cambridge AN - OPUS4-32734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhne, Maren A1 - Dippong, Martin A1 - Flemig, Sabine A1 - Hoffmann, Katrin A1 - Petsch, K. A1 - Schenk, J.A. A1 - Kunte, Hans-Jörg A1 - Schneider, Rudolf T1 - Comparative characterization of mAb producing hapten-specific hybridoma cells by flow cytometric analysis and ELISA N2 - A novel method that optimizes the screening for antibody-secreting hapten-specific hybridoma cells by using flow cytometry is described. Cell clones specific for five different haptens were analyzed. We selectively double stained and analyzed fixed hybridoma cells with fluorophore-labeled haptens to demonstrate the target-selectivity, and with a fluorophore-labeled anti-mouse IgG antibody to characterize the level of surface expression of membrane-bound IgGs. ELISA measurements with the supernatants of the individual hybridoma clones revealed that antibodies from those cells, which showed the highest fluorescence intensities in the flow cytometric analysis, also displayed the highest affinities for the target antigens. The fluorescence intensity of antibody-producing cells corresponded well with the produced antibodies' affinities toward their respective antigens. Immunohistochemical staining verified the successful double labeling of the cells. Our method makes it possible to perform a high-throughput screening for hybridoma cells, which have both an adequate IgG production rate and a high target affinity. KW - Immunization KW - Hapten KW - Monoclonal antibodies KW - Hybridoma KW - Flow cytometry KW - ELISA KW - Estradiol KW - Estrone KW - Digoxigenin KW - Zearalenone KW - Aflatoxin KW - CLSM PY - 2014 DO - https://doi.org/10.1016/j.jim.2014.07.004 SN - 0022-1759 SN - 1872-7905 VL - 413 SP - 45 EP - 56 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-32322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kopineck, H.-J. A1 - Mundry, Eberhard A1 - Schneider, H. T1 - Zerstörungsfreie Materialprüfung in Gegenwart und Zukunft - 50 Jahre Deutsche Gesellschaft für Zerstörungsfreie Prüfung N2 - Die Darstellung der Arbeiten und Aufgaben der DGZfP und ihrer Mitglieder zeigt, daß sie sich auf die Förderung der in die Zukunft gerichteten Forschungs- und Entwicklungsschwerpunkte und auf Arbeiten für wirtschaftlich erfolgreiche Anwendungen konzentriert; intensiv ein Programm der Ausbildung und Qualifizierung von Prüfpersonal durchführt, das den Bedürfnissen aller Partner der Wirtschaft gerecht wird und das hoffentlich in den wichtigsten Teilen international gültig werden kann. Die DGZfP ist sich in ihren Bemühungen in Deutschland der Unterstützung durch alle wichtigen Behörden und Dienststellen sicher und setzt zudem Vertrauen in die ausländischen ZfP-Partner und in die Bereitschaft zur internationalen Zusammenarbeit. Unter Berücksichtigung dessen und des Bewußtseins der eigenen Möglichkeiten glaubt sie, daß sie den gesetzten Verpflichtungen gerecht werden kann, nämlich die zerstörungsfreien Prüfungen und Verfahren, richtig anzuwenden, Aussagen und Folgerungen durch Forschung, Entwicklung, Anwendung und Ausbildung zu intensivieren und zu unterstützen. Die zerstörungsfreie Materialprüfung der Gegenwart und Zukunft wird von zwei menschlichen Eckpfeilern bestimmt: Einmal von den Menschen, die auf der Basis solider Fachkenntnisse die Materialprüfung erfolgreich durchführen, und zum anderen von den Menschen, die als Forscher, Ingenieure und Techniker sich den Anforderungen für Forschung und praxisbezogene Anwendung stellen, die ideenreich Geräte, Anlagen und Verfahren konzipieren und realisieren, mit denen Prüfanforderungen vielfältiger Art erfüllt werden können. Beide Gruppen müssen die gegenseitigen nationalen und internationalen Kontakte pflegen und intensivieren. PY - 1983 SN - 0025-5300 VL - 25 IS - 4 SP - 101 EP - 104 PB - Hanser CY - München AN - OPUS4-40454 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witke, Klaus A1 - Klaffke, Dieter A1 - Schneider, Thomas A1 - Schreckenbach, J.P. T1 - Laser-damaging as a useful tool for materials characterization by Raman microscopy KW - Raman-Mikroskopie KW - Raman-Laser KW - Laserstrahlbearbeitung PY - 1999 SN - 0169-4332 SN - 1873-5584 VL - 151 IS - 1-2 SP - 33 EP - 39 PB - North-Holland CY - Amsterdam AN - OPUS4-709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ralf A1 - Weigert, Florian A1 - Lesnyak, V. A1 - Leubner, S. A1 - Lorenz, T. A1 - Behnke, Thomas A1 - Dubavik, A. A1 - Joswig, J.-O. A1 - Resch-Genger, Ute A1 - Gaponik, N. A1 - Eychmüller, A. ED - Resch-Genger, Ute ED - Schneider, Ralf T1 - pH and concentration dependence of the optical properties of thiol-capped CdTe nanocrystals in water and D2O N2 - The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which – together with alloyed CdₓHg₁₋ₓTe – are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell. Aiming at a better understanding of the role of stabilizing ligands for the control of the application-relevant fluorescence features of SC NCs, we assessed the influence of two of the most commonly used monodentate thiol ligands, thioglycolic acid (TGA) and mercaptopropionic acid (MPA), on the colloidal stability, photoluminescence (PL) quantum yield (QY), and PL decay behavior of a set of CdTe NC colloids. As an indirect measure for the strength of the coordinative bond of the ligands to SC NC surface atoms, the influence of the pH (pD) and the concentration on the PL properties of these colloids was examined in water and D₂O and compared to the results from previous dilution studies with a set of thiol-capped Cd₁₋ₓHgₓTe SC NCs in D₂O. As a prerequisite for these studies, the number of surface ligands was determined photometrically at different steps of purification after SC NC synthesis with Ellman’s test. Our results demonstrate ligand control of the pH-dependent PL of these SC NCs, with MPA-stabilized CdTe NCs being less prone to luminescence quenching than TGA-capped ones. For both types of CdTe colloids, ligand desorption is more pronounced in H₂O compared to D₂O, underlining also the role of hydrogen bonding and solvent molecules. KW - Quantum dots KW - Fluorescence KW - Ligand analysis KW - Nano particles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371253 DO - https://doi.org/10.1039/c6cp03123d VL - 18 IS - 28 SP - 19083 EP - 19092 PB - RSC CY - Cambridge AN - OPUS4-37125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duwe, M. A1 - Quast, J.-H. A1 - Schneider, S. A1 - Fischer, Daniel A1 - Beck, Uwe T1 - Thin-film metrology of tilted and curved surfaces by imaging Mueller-matrix ellipsometry N2 - For the vast majority of ellipsometric measurements, the application of planar substrates is mandatory and requires a proper sample alignment prior to the measurement. Here, the authors present a generalized approach of how to extract the isotropic ellipsometric sample parameters from an imaging Mueller-matrix measurement even if the sample is significantly misaligned. They validate the method by layer-thickness calculations based on imaging Mueller-matrix measurements of flat crystalline silicon samples that were misaligned on purpose. Furthermore, they also exploit this method’s capabilities to perform spatially resolved layer-thickness measurements of a single-layer indium-tin-oxide coating on a fused-silica microlens without the need of realignment or repositioning of the sample during the measurement. T2 - 8th International conference on spectroscopic ellipsometry (ICSE-8) CY - Barcelona, Spain DA - 26.05.2019 KW - Metrology KW - Thin films KW - Polarization spectroscopy KW - Spectroskopic Imaging KW - Mueller-Matrix imaging ellipsometry PY - 2019 DO - https://doi.org/10.1116/1.5122757 SN - 2166-2746 SN - 2327-9877 VL - 37 IS - 6 SP - 062908 PB - AIP CY - New York, NY AN - OPUS4-50209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Daniel A1 - Griepentrog, Michael A1 - Beck, Uwe A1 - Duwe, M. A1 - Quast, J.-H. A1 - Schneider, S. T1 - Effect of curvature of spherical microscopic indentations on the ellipsometric readout N2 - The authors describe and interpret curvature-related changes to the ellipsometric readout. As model system for a concave curvature, a set of three spherical microscopic indents in silicon (100) of different sizes was prepared by instrumented indentation testing using a spherical indenter. For reference, these samples were characterized by AFM to reveal the topography of each structure. The concavelike indents were analyzed by Mueller-Matrix imaging ellipsometry to extract lateral intensity images of 12 elements of the Mueller-Matrix. As a result of the detailed analysis of the image elements m22, m23, and m14, it was possible to correlate intensity changes and symmetry properties to depolarization and cross polarization induced by the edge threshold and the curved surface of the indent. KW - Spectroskopic Imaging KW - Mueller-Matrix imaging ellipsometry KW - Structural anomalies KW - Structural inhomogenities PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498105 DO - https://doi.org/10.1116/1.5122252 VL - 37 IS - 6 SP - 062906-1 EP - 062906-5 PB - American Vacuum Society AN - OPUS4-49810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Carvalho, José Joao A1 - Walter, Astrid A1 - Baermann, Yvonne A1 - Weller, Michael G. A1 - Panne, Ulrich A1 - Schenk, J.A. A1 - Schneider, Rudolf T1 - Non-invasive monitoring of immunization progress in mice via IgG from feces N2 - A non-invasive method to monitor the humoral immune response in mice after immunization is described. From fecal pellets of an individual mouse, a sufficient amount of active immunoglobulins or their fragments can be extracted to perform a regular examination of the status of the immune response by immunoassay. Hapten-specific antibodies from the feces of mice from three immunization trials showed very similar characteristics to those obtained from serum at a given date. Therefore, it can be suspected that some serum IgG enters the intestinal lumen and ends up in the feces, where they appear to be considerably stable. Hapten-specific IgAs were not found in the feces. Being able to analyze antibody titers in feces could be an interesting animal welfare refinement to standard practice that does not entail repeated blood sampling. KW - Immunization monitoring KW - IgG KW - Coproantibodies KW - Feces KW - Animal welfare KW - 3R concept PY - 2012 UR - http://iv.iiarjournals.org/content/26/1/63.full.pdf+html SN - 0258-851x VL - 26 IS - 1 SP - 63 EP - 70 PB - In vivo CY - Athens AN - OPUS4-25283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -