TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Zwaka, H. A1 - Menzel, R. A1 - Johnen, D. A1 - Fischer-Tenhagen, C. A1 - Rolff, J. A1 - Nehls, Irene T1 - In vitro cultured lung cancer cells are not suitable for animal-based breath biomarker detection N2 - In vitro cultured lung cancer cell lines were investigated regarding the possible identification of volatile organic compounds as potential biomarkers. Gas samples from the headspace of pure culture medium and from the cultures of human lung adenocarcinoma cell lines A549 and Lu7466 were exposed to polypropylene fleece in order to absorb odour components. Sniffer dogs were trained with loaded fleeces of both cell lines, and honey bees were trained with fleeces exposed to A549. Afterwards, their ability to distinguish between cell-free culture medium odour and lung cancer cell odour was tested. Neither bees nor dogs were able to discriminate between odours from the cancer cell cultures and the pure culture medium. Solid phase micro extraction followed by gas chromatography with mass selective detection produced profiles of volatiles from the headspace offered to the animals. The profiles from the cell lines were largely similar; distinct differences were based on the decrease of volatile culture medium components due to the cells' metabolic activity. In summary, cultured lung cancer cell lines do not produce any biomarkers recognizable by animals or gas chromatographic analysis. KW - A549 KW - Honey bees KW - Odour discrimination task KW - Sniffer dogs KW - Solid phase microextraction KW - Volatile organic compounds KW - Volatilome PY - 2015 DO - https://doi.org/10.1088/1752-7155/9/2/027103 SN - 1752-7155 SN - 1752-7163 VL - 9 IS - 2 SP - 027103-1 EP - 027103-10 PB - IOP CY - Bristol AN - OPUS4-34161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rohde, H. A1 - Menzel, Michael A1 - Renz, F. A1 - Filippou, A.C. T1 - Investigation of Mo- and W-stannylidyne complexes by Mössbauer spectroscopy N2 - Systematic 119mSn-Mössbauer spectroscopy studies of three different types of five and six coordinated molybdenum and tungsten stannylidyne complexes are presented. The measured isomer shifts (IS) range from 2.38 to 2.50 mm/s and the quadrupole splittings (QS) from 1.8 to 2.8 mm/s. The values are dependent on the metal centre, the ligand sphere and the charge of the complexes. The influence of the neighbouring metal atoms (Mo, W) and their coordination sphere on the electron density at the tin atom is observed and will be discussed. KW - Molybdenum KW - Tungsten KW - Stannylidyne complexes KW - Phosphane complexes KW - 119mSn-Mössbauer spectroscopy PY - 2008 DO - https://doi.org/10.1007/s10751-008-9821-7 SN - 0304-3843 SN - 1572-9540 VL - 185 IS - 1-3 SP - 129 EP - 132 PB - Kluwer CY - Dordrecht AN - OPUS4-18623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lawaczeck, R. A1 - Menzel, Michael A1 - Pietsch, H. T1 - Superparamagnetic iron oxide particles: contrast media for magnetic resonance imaging N2 - The mainstream magnetic iron oxide particles used as contrast media for magnetic resonance (MR) imaging are composed of a magnetic iron oxide core surrounded by a dextran or carboxydextran coat. The core size ranges from 2 nm to less than 10 nm, and the hydrodynamic diameter ranges from 20 nm to about 120 nm. The coat prevents aggregation and sedimentation of the particles in aqueous solutions, achieves high biological tolerance, and prevents toxic side effects. Two kinds of particles are considered: (i) large particles (>30 nm), called superparamagnetic iron oxide particles (SPIOs) for liver imaging; (ii) smaller particles (<30 nm hydrodynamic diameter), called ultrasmall SPIOs (USPIOs), e.g. for MR angiography. To characterize the particles, Mössbauer spectra are presented for the two particle ensembles. These spectra allow insight into the magnetic coupling, the valency of the iron ions and a rough estimate of the core size to be deduced. On the basis of the concentration dependence of the MR signal intensities, two applications are discussed together with two representative clinical examples. KW - Superparamagnetic KW - Iron oxide particles KW - MR imaging KW - Contrast media PY - 2004 DO - https://doi.org/10.1002/aoc.753 SN - 0268-2605 SN - 1099-0739 VL - 18 SP - 506 EP - 513 PB - Longman CY - Harlow AN - OPUS4-4580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Berndt, H. A1 - Claus, P. T1 - Mössbauer studies of platinum and rhodium catalysts promoted by tin T2 - International Conference on Applications of the Mössbauer Effect (ICAME '97) ; in memoriam of Professor Jacques CY - Rio de Janeiro, Brazil DA - 1997-09-14 PY - 1998 SN - 0304-3843 SN - 1572-9540 VL - 113 IS - 1-4 SP - 92 EP - 95 PB - Kluwer CY - Dordrecht AN - OPUS4-6932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reuther, H. A1 - Menzel, Michael A1 - Vinnichenko, M. A1 - Kolitsch, A. ED - Garcia, M. T1 - Investigation of the Sn4+ Charge Density Variation in In2O3 using Mössbauer Spectroscopy T2 - International Symposium on the Industrial Application of the Mössbauer Effect CY - Madrid, Spain DA - 2004-10-04 PY - 2005 SN - 0-7354-0250-7 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 765 SP - 132 EP - 136 PB - American Inst. of Physics CY - Melville AN - OPUS4-12150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cieslak, J. A1 - Dubiel, S.M. A1 - Eichhorn, F. A1 - Menzel, Michael A1 - Reuther, H. T1 - Investigation of single-crystals of chromium implanted with 119Sn-ions of various energies N2 - Single-crystals of chromium doped with 10 16 119Sn ions per cm2 and energies ranging between 45 and 190 keV were investigated with conversion electron Mössbauer spectroscopy (CEMS), Auger electron spectroscopy (AES), grazing angle X-ray diffraction (GAXRD), and scanning electron microscopy (SEM). The Mössbauer spectra were found to be significantly different than those of the bulk. Both the maximum and the average hf. field values were higher by a factor of ˜3 than the corresponding quantities for the bulk. The overall shape of the spectra is also different. GAXRD study has revealed that the near-surface zone of the investigated samples has a nanocrystalline structure with the average size of grains ranging between ˜20 and ˜40 nm. The latter seems to be the main reason for the observed enhancement of the spin-density and its distortion. KW - Magnetically ordered materials KW - Crystal growth KW - Hyperfine interactions KW - Mössbauer spectroscopy PY - 2007 DO - https://doi.org/10.1016/j.jallcom.2006.07.143 SN - 0925-8388 SN - 1873-4669 VL - 442 IS - 1-2 SP - 235 EP - 238 PB - Elsevier Sequoia CY - Lausanne AN - OPUS4-15730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Berndt, H. A1 - Mönnich, I. A1 - Lücke, B. T1 - Tin promoted palladium catalysts for nitrate removal from drinking water N2 - Hydrogenation of nitrate to nitrogen using Pd/Al2O3 catalysts promoted by a second metal offers a promising process for nitrate removal in drinking water treatment. This study was aimed to elucidate the nature and function of promoting tin species in PdSn/Al2O3 catalysts obtained in different preparation routes. On one hand, a parent Pd/Al2O3 catalyst was doped via impregnation with aqueous solutions of SnCl2 of different concentrations. On the other hand, the palladium surface of the same parent Pd/Al2O3 catalyst was modified via controlled surface reaction (CSR) with hexane solutions of Sn(C4H9)4. The structure of the different PdSn/Al2O3 catalysts was investigated by 119Sn-Mössbauer spectroscopy and by means of various chemisorption techniques (static and pulse chemisorption of H2 or CO, measurement of the differential heat of CO chemisorption, FTIR spectroscopy of CO chemisorption). Catalytic properties were studied in batch experiments under atmospheric pressure. Promoting of the Pd/Al2O3 catalyst by CSR resulted in catalysts with a significantly higher activity compared to PdSn/Al2O3 catalysts obtained via incipient wetness method. Obviously, Sn(II)-species being present in the latter in high portion inhibit the nitrate reduction on bimetallic PdSn ensembles. CO chemisorption reflected a ‘palladium site blocking’ by tin species in both kinds of catalysts and indirectly indicated the generation of palladium–tin ensembles. In case of the CSR preparation the palladium is alloyed by metallic tin. The palladium surface is diluted by tin atoms, i.e. bimetallic PdSnx ensembles are generated which are able to adsorb and activate nitrate ions. There is an optimum of tin loading, i.e. the activity decreases and the undesired ammonium production in a site reaction increases when the surface becomes too tin rich. Sn(II) species, being preferentially present in catalysts obtained by SnCl2 impregnation also strongly modify the chemisorption properties of the palladium surface, but obviously these species inhibit the nitrate reduction on the bimetallic PdSn ensembles, which are also present in these catalysts. KW - Nitrate hydrogenation KW - Drinking water treatment KW - Bimetallic catalysts KW - Characterization KW - Palladium-tin interactions PY - 2001 DO - https://doi.org/10.1016/S0926-3373(00)00225-3 SN - 0926-3373 SN - 1873-3883 VL - 30 IS - 1-2 SP - 111 EP - 122 PB - Elsevier CY - Amsterdam AN - OPUS4-1021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Mehner, Hartmut A1 - Mönnich, I. A1 - Berndt, H. T1 - Investigation of PdSn-catalysts for nitrate removal in drinking water processing N2 - PdSn catalysts prepared by various methods and used for nitrate reduction were investigated by means of in situ 119mSn Mössbauer spectroscopy. Characterization by 119mSn Mössbauer spectroscopy revealed significant differences concerning the modification of the palladium particles supported on alumina. The controlled surface reaction preparation method (CSR) leads to formation of PdSn alloys with different tin contents besides small amounts of Sn(II) species and unalloyed metallic Sn. On the other hand the impregnation method leads to a small amount of PdSn alloys and higher contents of Sn(II) species. Sn(IV) species were found in both kinds of catalysts. The CSR prepared PdSn catalysts showed an improved activity and selectivity compared to the catalysts obtained by the impregnation method. PY - 2000 DO - https://doi.org/10.1023/A:1012688627310 SN - 0304-3843 SN - 1572-9540 VL - 126 IS - 126 SP - 89 EP - 93 PB - Kluwer CY - Dordrecht AN - OPUS4-986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keller, Julia A1 - Borzekowski, Antje A1 - Haase, H. A1 - Menzel, R. A1 - Rueß, L. A1 - Koch, Matthias T1 - Toxicity assay for citrinin, zearalenone and zearalenone-14-sulfate using the nematode Caenorhabditis elegans as model organism N2 - To keep pace with the rising number of detected mycotoxins, there is a growing need for fast and reliable toxicity tests to assess the potential threat to food safety. Toxicity tests with the bacterial-feeding nematode Caenorhabditis elegans as model organism are well established. In this study the C. elegans wildtype strain N2 (var. Bristol) was used to investigate the toxic effects of the food-relevant mycotoxins citrinin (CIT) and zearalenone-14-sulfate (ZEA-14-S) and zearalenone (ZEA) on different life cycle parameters including reproduction, thermal and oxidative stress resistance and lifespan. The metabolization of the mycotoxins by the nematodes in vivo was investigated using HPLC-MS/MS. ZEA was metabolized in vivo to the reduced isomers α-zearalenol (α-ZEL) and β-ZEL. ZEA 14-S was reduced to α-/β-ZEL 14-sulfate and CIT was metabolized to mono-hydroxylated CIT. All mycotoxins tested led to a significant decrease in the number of nematode offspring produced. ZEA and CIT displayed negative effects on stress tolerance levels and for CIT an additional shortening of the mean lifespan was observed. In the case of ZEA-14-S, however, the mean lifespan was prolonged. The presented study shows the applicability of C. elegans for toxicity testing of emerging food mycotoxins for the purpose of assigning potential health threats. KW - Mycotoxins KW - Metabolization KW - Toxicity testing KW - Biotests PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-455772 DO - https://doi.org/10.3390/toxins10070284 VL - 10 IS - 7 SP - 284, 1 EP - 12 PB - MDPI AN - OPUS4-45577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adam, Christian A1 - Reuther, H. A1 - Vogel, Christian A1 - Adamczyk, Burkart A1 - Menzel, Michael A1 - Emmerling, Franziska A1 - Simon, Franz-Georg T1 - First identification of the tridymite form of AlPO4 in municipal sewage sludge ash N2 - Sewage sludge and sewage sludge ashes (SSA) are produced in huge amounts at municipal waste water treatment plants (WWTP) all around the world and have become an issue for many urbanized areas. To deal with this unceasing mass flow in an ecologically and economically responsible way a comprehensive chemical and structural characterization of all types of SSA is needed. X-ray powder diffraction (XRD) is one of the most promising analytical methods for this task. Although, there has been ample chemical evidence showing that many SSA contain aluminium phosphate as a major component up to now no aluminium phosphate or aluminium-rich mixed phosphate phase has been reported to be identified by XRD in a SSA produced at a mono-incineration facility. The outcome of the present com-bined XRD and Mossbauer spectroscopy investigation provides comprehensive evidence closing this gap for the first time. KW - Aluminium phosphate KW - AlPO4 KW - Tridymite KW - Sewage sludge ash KW - Incinerator KW - Ash PY - 2011 DO - https://doi.org/10.1524/zkpr.2011.0067 SN - 0044-2968 VL - 1 SP - 443 EP - 448 PB - Oldenbourg CY - München AN - OPUS4-24297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -