@article{PornsawadSapsakulBoeckmann2019,
  author    = {Pornsawad, Pornsarp and Sapsakul, Nantawan and B{\"o}ckmann, Christine},
  title     = {A modified asymptotical regularization of nonlinear ill-posed problems},
  series = {Mathematics},
  volume    = {7},
  journal   = {Mathematics},
  edition   = {5},
  publisher = {MDPI},
  address   = {Basel, Schweiz},
  issn      = {2227-7390},
  doi       = {10.3390/math7050419},
  pages     = {19},
  year      = {2019},
  abstract  = {In this paper, we investigate the continuous version of modified iterative Runge-Kutta-type methods for nonlinear inverse ill-posed problems proposed in a previous work. The convergence analysis is proved under the tangential cone condition, a modified discrepancy principle, i.e., the stopping time T is a solution of ∥𝐹(𝑥𝛿(𝑇))-𝑦𝛿∥=𝜏𝛿+ for some 𝛿+>𝛿, and an appropriate source condition. We yield the optimal rate of convergence.},
  language  = {en}
}
@misc{RancanVolkmannGiulbudagianetal.2019,
  author    = {Rancan, Fiorenza and Volkmann, Hildburg and Giulbudagian, Michael and Schumacher, Fabian and Stanko, Jessica Isolde and Kleuser, Burkhard and Blume-Peytavi, Ulrike and Calder{\´o}n, Marcelo and Vogt, Annika},
  title     = {Dermal Delivery of the High-Molecular-Weight Drug Tacrolimus by Means of Polyglycerol-Based Nanogels},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1339},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-47327},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-473270},
  pages     = {14},
  year      = {2019},
  abstract  = {Polyglycerol-based thermoresponsive nanogels (tNGs) have been shown to have excellent skin hydration properties and to be valuable delivery systems for sustained release of drugs into skin. In this study, we compared the skin penetration of tacrolimus formulated in tNGs with a commercial 0.1\% tacrolimus ointment. The penetration of the drug was investigated in ex vivo abdominal and breast skin, while different methods for skin barrier disruption were investigated to improve skin permeability or simulate inflammatory conditions with compromised skin barrier. The amount of penetrated tacrolimus was measured in skin extracts by liquid chromatography tandem-mass spectrometry (LC-MS/MS), whereas the inflammatory markers IL-6 and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). Higher amounts of tacrolimus penetrated in breast as compared to abdominal skin or in barrier-disrupted as compared to intact skin, confirming that the stratum corneum is the main barrier for tacrolimus skin penetration. The anti-proliferative effect of the penetrated drug was measured in skin tissue/Jurkat cells co-cultures. Interestingly, tNGs exhibited similar anti-proliferative effects as the 0.1\% tacrolimus ointment. We conclude that polyglycerol-based nanogels represent an interesting alternative to paraffin-based formulations for the treatment of inflammatory skin conditions.},
  language  = {en}
}
@article{RancanVolkmannGiulbudagianetal.2019,
  author    = {Rancan, Fiorenza and Volkmann, Hildburg and Giulbudagian, Michael and Schumacher, Fabian and Stanko, Jessica Isolde and Kleuser, Burkhard and Blume-Peytavi, Ulrike and Calderon, Marcelo and Vogt, Annika},
  title     = {Dermal Delivery of the High-Molecular-Weight Drug Tacrolimus by Means of Polyglycerol-Based Nanogels},
  series = {Pharmaceutics : Molecular Diversity Preservation International},
  volume    = {11},
  journal   = {Pharmaceutics : Molecular Diversity Preservation International},
  number    = {8},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1999-4923},
  doi       = {10.3390/pharmaceutics11080394},
  pages     = {14},
  year      = {2019},
  abstract  = {Polyglycerol-based thermoresponsive nanogels (tNGs) have been shown to have excellent skin hydration properties and to be valuable delivery systems for sustained release of drugs into skin. In this study, we compared the skin penetration of tacrolimus formulated in tNGs with a commercial 0.1\% tacrolimus ointment. The penetration of the drug was investigated in ex vivo abdominal and breast skin, while different methods for skin barrier disruption were investigated to improve skin permeability or simulate inflammatory conditions with compromised skin barrier. The amount of penetrated tacrolimus was measured in skin extracts by liquid chromatography tandem-mass spectrometry (LC-MS/MS), whereas the inflammatory markers IL-6 and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). Higher amounts of tacrolimus penetrated in breast as compared to abdominal skin or in barrier-disrupted as compared to intact skin, confirming that the stratum corneum is the main barrier for tacrolimus skin penetration. The anti-proliferative effect of the penetrated drug was measured in skin tissue/Jurkat cells co-cultures. Interestingly, tNGs exhibited similar anti-proliferative effects as the 0.1\% tacrolimus ointment. We conclude that polyglycerol-based nanogels represent an interesting alternative to paraffin-based formulations for the treatment of inflammatory skin conditions.},
  language  = {en}
}
@misc{OPUS4-41639,
  title     = {Dicion{\´a}rio de l{\´i}ngua geral amaz{\^o}nica},
  editor    = {Muller, Jean-Claude and Dietrich, Wolf and Monserrat, Ruth and Barros, C{\^a}ndida and Arenz, Karl-Heinz and Prudente, Gabriel},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  organization    = {Museu Paraense Emilio Goeldi},
  isbn      = {978-85-61377-99-1},
  doi       = {10.25932/publishup-41639},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416390},
  pages     = {384},
  year      = {2019},
  abstract  = {Permettez {\`a} l'inventeur du manuscrit dont vous avez l'{\´e}dition diplomatique sous les yeux d'exposer en exergue les principales {\´e}tapes qui ont conduit en 2012 {\`a} la d{\´e}termination de la langue et {\`a} l'identification de l'auteur. {\´E}tant inscrit {\`a} la conf{\´e}rence de linguistique missionnaire {\`a} l'universit{\´e} de Br{\`e}me en mars 2012 et conscient que maintes biblioth{\`e}ques et archives renferment des tr{\´e}sors non identifi{\´e}s ou mal catalogu{\´e}s, je suivis le conseil d'un coll{\`e}gue de la biblioth{\`e}que de l'universit{\´e} de Tr{\`e}ves, Hans-Ulrich Seiffert, d'inspecter le manuscrit 1136 / 2048 4° de la biblioth{\`e}que municipale de Tr{\`e}ves. Cette biblioth{\`e}que est riche de plus de 2.500 manuscrits et incunables provenant pour la plupart des saisies r{\´e}volutionnaires fran{\c{c}}aises dans les biblioth{\`e}ques des ci-devant couvents tr{\´e}virois. Parmi ces tr{\´e}sors un manuscrit portugais des missions qui {\´e}tait rentr{\´e} dans les fonds de la biblioth{\`e}que de Tr{\`e}ves d{\`e}s 1799 et avait {\´e}t{\´e} expos{\´e} en 1991 dans le cadre d'une {\´e}vocation des activit{\´e}s missionnaires globales des J{\´e}suites. Michael Embach, alors directeur de la biblioth{\`e}que du s{\´e}minaire {\´e}piscopal de Tr{\`e}ves, l'avait bri{\`e}vement d{\´e}crit dans une notice qui pr{\´e}tendait qu'il {\´e}tait r{\´e}dig{\´e} en espagnol et en portugais et avait peut-{\^e}tre {\´e}t{\´e} compos{\´e} par un auteur « Meirin » dans le cadre de ses pr{\´e}parations pour partir dans les missions… Dans ma copie du catalogue de 1991 se trouve inscrit « la langue reste {\`a} d{\´e}terminer ». J'allais r{\´e}soudre le myst{\`e}re en cette m{\´e}morable journ{\´e}e du jeudi 23 f{\´e}vrier 2012 quand je me r{\´e}solus {\`a} l'autopsier dans la salle d{\´e}sormais historique de la Biblioth{\`e}que municipale de Tr{\`e}ves, dirig{\´e}e depuis peu par le coll{\`e}gue Embach. Il parut {\`a} l'{\´e}vidence que le manuscrit ne contenait aucun mot d'espagnol mais que dans la premi{\`e}re partie, les entr{\´e}es en portugais, strictement num{\´e}rot{\´e}es et arrang{\´e}es dans l'ordre alphab{\´e}tique, {\´e}taient suivies par leurs {\´e}quivalences dans une langue inconnue qui, cependant, avait pour un linguiste une forte odeur de l'Am{\´e}rique amazonienne. La partie post{\´e}rieure du manuscrit pr{\´e}sentait l'arrangement inverse. Les entr{\´e}es dans la langue inconnue {\´e}taient suivies de leurs {\´e}quivalences portugaises. Ce n'est que plus tard que nous avons compris le myst{\´e}rieux ordre des lemmata dans cette partie, bas{\´e}e qu'elle est sur la rime finale des mots. Deux facteurs ont grandement facilit{\´e} l'identification de la langue inconnue : 1. la permission du directeur Embach de pouvoir prendre des photos de travail de tous les folios du manuscrit et 2. l'entr{\´e}e dans le premier catalogue de la Biblioth{\`e}que de Tr{\`e}ves de 1802 : "Codex maxime memorabiblis est, cum nondum grammatica praeter Lusitani Anchieta nota sit, et nullum vocabularium huius linguae existet. Sine dubio scriptum est a quodam Missionario Jesuita". Rentrant de Tr{\`e}ves chez moi, je fis une br{\`e}ve halte dans mon bureau d'alors pour consulter Internet. L'entr{\´e}e "Anchieta" dans l'encyclop{\´e}die {\´e}lectronique Wikipedia m'informait que ce j{\´e}suite portugais avait compos{\´e} une grammaire du Vieux Tupi, publi{\´e}e en 1595. Sous le vocable "Old Tupi" ensuite, j'appris que l'auto-d{\´e}signation pour cette langue est {\~n}eengat{\´u} (la bonne langue, le parler correct). De l{\`a} {\`a} retrouver au folio 25 de mes photos la traduction du portugais linguagem par nhe{\´e}nga ne prit que quelques minutes. D{\`e}s ce premier soir donc, le myst{\`e}re de la langue inconnue {\´e}tait r{\´e}solu! Un projet de recherche international, voire transcontinental allait se mettre peu {\`a} peu en place apr{\`e}s. {\`A} la conf{\´e}rence de Br{\`e}me, d{\´e}but mars 2012, je fis la connaissance du linguiste et romaniste, le professeur Wolf Dietrich de l'universit{\´e} de M{\"u}nster en Westphalie, un des meilleurs connaisseurs des parlers amazoniens. Il rentrait avec une copie de mes photos de travail et confirma bient{\^o}t l'importance du manuscrit de Tr{\`e}ves pour la connaissance de la Lingua Geral, le parler qui s'{\´e}tait d{\´e}velopp{\´e} {\`a} partir du Vieux Tupi moribond. Je communiquai {\´e}galement ma d{\´e}couverte au fr{\`e}re Karl-Heinz Arenz de la congr{\´e}gation des p{\`e}res de Steyl, originaire de l'Eifel allemande et enseignant d'histoire aux universit{\´e}s br{\´e}siliennes de Bel{\´e}m et de Santar{\´e}m dans l'{\´E}tat du Par{\´a}. Arenz est l'auteur d'une {\´e}tude sur le j{\´e}suite luxembourgeois Jean-Philippe Bettendorf, actif au Maranh{\~a}o dans la seconde moiti{\´e} du XVIIe si{\`e}cle. Nous avions collabor{\´e} en 2007 {\`a} une exposition didactique consacr{\´e}e {\`a} ce personnage. Arenz ne tarda pas {\`a} passer l'information sur le manuscrit de Tr{\`e}ves aux deux linguistes br{\´e}siliennes C{\^a}ndida Barros et Ruth Monserrat, qui {\`a} leur tour pr{\´e}sentaient un projet de recherche qui fut accept{\´e} par les autorit{\´e}s br{\´e}siliennes. Les reals de ce subside furent bien investis en effet : l'{\´e}tudiant doctoral Gabriel Prudente r{\´e}alisa une transcription int{\´e}grale du manuscrit de Tr{\`e}ves qui fit appara{\^i}tre des couches dialectales et sociolectales dans le texte, et m{\^e}me quelques mots allemands. La biblioth{\`e}que municipale de Tr{\`e}ves, quant {\`a} elle, contribua « en nature » les images digitales qui sont consultables sur les pages de gauche de cette {\´e}dition {\´e}lectronique. D{\´e}but avril 2014, nous f{\^i}mes tous connaissance personnellement dans le cadre d'un colloque {\`a} l'universit{\´e} de Bel{\´e}m o{\`u} fut d{\´e}cid{\´e}e la pr{\´e}sente {\´e}dition digitale et o{\`u} furent prononc{\´e}es la plupart des contributions scientifiques que vous pouvez lire en guise d'introduction. Restait {\`a} percer l'{\´e}nigme du v{\´e}ritable auteur du manuscrit. C{\^a}ndida Barros avait assez t{\^o}t propos{\´e} les noms de trois J{\´e}suites allemands, actifs dans les ann{\´e}es 1750 dans la r{\´e}gion du fleuve Xingu et chass{\´e}s par les mesures anti-j{\´e}suites du pouvoir portugais en 1756. L'{\´e}tude pal{\´e}ographique des Quattuor vota des trois candidats, aux archives centrales des J{\´e}suites {\`a} Rome, me permit d{\´e}but septembre 2015 d'{\´e}liminer les p{\`e}res Eckart et Kaulen et de ne retenir que Antonius Meisterburg, originaire de Bernkastel sur la Moselle, comme le scribe du manuscrit de Tr{\`e}ves. Qu'il me soit permis d'exprimer ma GRATITUDE {\`a} toutes celles et {\`a} tous ceux qui ont contribu{\´e} {\`a} cette belle aventure de d{\´e}couverte intellectuelle et scientifique et {\`a} rendre au Br{\´e}sil une petite pierre de son histoire.},
  language  = {pt}
}
@techreport{MuellerWrohlich2019,
  type      = {Working Paper},
  author    = {M{\"u}ller, Kai-Uwe and Wrohlich, Katharina},
  title     = {Does subsidized care for toddlers increase maternal labor supply?},
  series = {CEPA Discussion Papers},
  journal   = {CEPA Discussion Papers},
  number    = {9},
  issn      = {2628-653X},
  doi       = {10.25932/publishup-42772},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427727},
  pages     = {50},
  year      = {2019},
  abstract  = {Expanding public or publicly subsidized childcare has been a top social policy priority in many industrialized countries. It is supposed to increase fertility, promote children's development and enhance mothers' labor market attachment. In this paper, we analyze the causal effect of one of the largest expansions of subsidized childcare for children up to three years among industrialized countries on the employment of mothers in Germany. Identification is based on spatial and temporal variation in the expansion of publicly subsidized childcare triggered by two comprehensive childcare policy reforms. The empirical analysis is based on the German Microcensus that is matched to county level data on childcare availability. Based on our preferred specification which includes time and county fixed effects we find that an increase in childcare slots by one percentage point increases mothers' labor market participation rate by 0.2 percentage points. The overall increase in employment is explained by the rise in part-time employment with relatively long hours (20-35 hours per week). We do not find a change in full-time employment or lower part-time employment that is causally related to the childcare expansion. The effect is almost entirely driven by mothers with medium-level qualifications. Mothers with low education levels do not profit from this reform calling for a stronger policy focus on particularly disadvantaged groups in coming years.},
  language  = {en}
}
@phdthesis{Yishai2019,
  author    = {Yishai, Oren},
  title     = {Engineering the reductive glycine pathway in Escherichia coli},
  school      = {Universit{\"a}t Potsdam},
  pages     = {86},
  year      = {2019},
  language  = {en}
}
@phdthesis{Beamish2019,
  author    = {Beamish, Alison Leslie},
  title     = {Hyperspectral remote sensing of the spatial and temporal heterogeneity of low Arctic vegetation},
  doi       = {10.25932/publishup-42592},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-425922},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 102},
  year      = {2019},
  abstract  = {Arctic tundra ecosystems are experiencing warming twice the global average and Arctic vegetation is responding in complex and heterogeneous ways. Shifting productivity, growth, species composition, and phenology at local and regional scales have implications for ecosystem functioning as well as the global carbon and energy balance. Optical remote sensing is an effective tool for monitoring ecosystem functioning in this remote biome. However, limited field-based spectral characterization of the spatial and temporal heterogeneity limits the accuracy of quantitative optical remote sensing at landscape scales. To address this research gap and support current and future satellite missions, three central research questions were posed: • Does canopy-level spectral variability differ between dominant low Arctic vegetation communities and does this variability change between major phenological phases? • How does canopy-level vegetation colour images recorded with high and low spectral resolution devices relate to phenological changes in leaf-level photosynthetic pigment concentrations? • How does spatial aggregation of high spectral resolution data from the ground to satellite scale influence low Arctic tundra vegetation signatures and thereby what is the potential of upcoming hyperspectral spaceborne systems for low Arctic vegetation characterization? To answer these questions a unique and detailed database was assembled. Field-based canopy-level spectral reflectance measurements, nadir digital photographs, and photosynthetic pigment concentrations of dominant low Arctic vegetation communities were acquired at three major phenological phases representing early, peak and late season. Data were collected in 2015 and 2016 in the Toolik Lake Research Natural Area located in north central Alaska on the North Slope of the Brooks Range. In addition to field data an aerial AISA hyperspectral image was acquired in the late season of 2016. Simulations of broadband Sentinel-2 and hyperspectral Environmental and Mapping Analysis Program (EnMAP) satellite reflectance spectra from ground-based reflectance spectra as well as simulations of EnMAP imagery from aerial hyperspectral imagery were also obtained. Results showed that canopy-level spectral variability within and between vegetation communities differed by phenological phase. The late season was identified as the most discriminative for identifying many dominant vegetation communities using both ground-based and simulated hyperspectral reflectance spectra. This was due to an overall reduction in spectral variability and comparable or greater differences in spectral reflectance between vegetation communities in the visible near infrared spectrum. Red, green, and blue (RGB) indices extracted from nadir digital photographs and pigment-driven vegetation indices extracted from ground-based spectral measurements showed strong significant relationships. RGB indices also showed moderate relationships with chlorophyll and carotenoid pigment concentrations. The observed relationships with the broadband RGB channels of the digital camera indicate that vegetation colour strongly influences the response of pigment-driven spectral indices and digital cameras can track the seasonal development and degradation of photosynthetic pigments. Spatial aggregation of hyperspectral data from the ground to airborne, to simulated satel-lite scale was influenced by non-photosynthetic components as demonstrated by the distinct shift of the red edge to shorter wavelengths. Correspondence between spectral reflectance at the three scales was highest in the red spectrum and lowest in the near infra-red. By artificially mixing litter spectra at different proportions to ground-based spectra, correspondence with aerial and satellite spectra increased. Greater proportions of litter were required to achieve correspondence at the satellite scale. Overall this thesis found that integrating multiple temporal, spectral, and spatial data is necessary to monitor the complexity and heterogeneity of Arctic tundra ecosystems. The identification of spectrally similar vegetation communities can be optimized using non-peak season hyperspectral data leading to more detailed identification of vegetation communities. The results also highlight the power of vegetation colour to link ground-based and satellite data. Finally, a detailed characterization non-photosynthetic ecosystem components is crucial for accurate interpretation of vegetation signals at landscape scales.},
  language  = {en}
}
@phdthesis{RuizRodriguez2019,
  author    = {Ruiz Rodriguez, Janete Lorena},
  title     = {Osmotic pressure effects on collagen mimetic peptides},
  school      = {Universit{\"a}t Potsdam},
  pages     = {139},
  year      = {2019},
  abstract  = {Collagen is the most abundant protein in mammals. In many tissues, collagen molecules assemble to form a hierarchical structure. In the smallest supramolecular unit, named fibril, each molecule is displaced in the axial direction with respect to its neighbors. This staggering creates a periodic gap and overlap regions, where the gap regions exhibit 20\% less density. These fibril-forming collagens play an essential role in the strength of connective tissues. Despite much effort, directed at understanding collagen function and regulation, the influence of the chemical environment on the local structural and mechanical properties remains poorly understood. Recent studies, aimed at elucidating the effect of osmotic pressure, showed that collagen contracts upon water removal. This observation highlights the importance of water for the stabilization and mechanics of the collagen molecule. Using collagen mimetic peptides (CMPs), which fold into triple helical structures reminiscent of natural collagen, the primary goal of this work was to investigate the effect of the osmotic pressure on specific collagen-mimetic sequences. CMPs were used as the model system as they provide sequence control, which is essential for discriminating local from global structural changes and for relating the observed effects to existing knowledge about the full-length collagen molecule. Of specific interest was the structure of individual collagen triple helices as well as their organization into self-assembled higher order structures. These key structural features were monitored with infrared spectroscopy (IR) and synchrotron X-ray scattering, while varying the osmotic pressure. For controlling the osmotic pressure, CMP powder samples were incubated in air of defined relative humidity, ranging from dry conditions to highly "humid". In addition, to obtain more biologically relevant conditions, the CMPs were measured in ultrapure water and in solutions containing small molecule osmolytes. Using the sequences (Pro-Pro-Gly)10, (Pro-Hyp-Gly)10 and (Hyp-Hyp-Gly)10, it was shown that CMPs with different degrees of proline hydroxylation (Hyp = hydroxyproline) exhibit a sequence-specific response to osmotic pressure. IR spectroscopy revealed that osmotic pressure changes affect the strength of the triple helix stabilizing, interchain hydrogen bond and that the extent of this change depends on the degree of hydroxylation. X-ray scattering experiments further showed that changes in osmotic pressure affect both the molecular length as well as the higher order organization of CMPs. Starting from a pseudo-hexagonal packing in the dry state, all three CMPs showed isotropic swelling when increasing the water content to approximately 1.2 water molecules per amino acid, again to different extents depending on the degree of hydroxylation. When increasing the water content further, this pseudo-hexagonal arrangement breaks down. In the fully hydrated state, each CMP is characterized by its own specific and more complex packing geometry. While these changes in the lateral packing arrangement suggest swelling upon hydration, an overall decrease of the molecular length (i.e. contraction) was observed in the axial direction. Also for this structural feature, a strong dependency on the specific amino acid sequence was found. Interestingly, the observed contraction is the opposite of what has been reported for natural collagen. As (Pro-Pro-Gly)n, (Pro-Hyp-Gly)n and (Hyp-Hyp-Gly)n repeat units are found in collagen with a relatively high abundance, this suggests that other collagen sequence fragments need to respond to hydration in the opposite way to obtain a net elongation of the full-length collagen molecule. To test this hypothesis, sequences predicted to be sensitive to osmotic pressure were considered. One such sequence, consisting of two repeat units (Ala-Arg-Gly-Ser-Asp-Gly), was inserted as a guest into a (Pro-Pro-Gly) host. When compared to the canonical CMP sequences investigated earlier, the lateral helix packing follows a similar trend with increasing hydration; however, the host-guest CMP axially elongates with increasing water content. This behavior is more similar to what has been found for natural collagen and suggests that different sequences do determine the molecular length of collagen sequences differently. Interestingly, the canonical sequences are more abundant in the overlap region while the guest sequence is found in the gap region. This allows to speculate that sequences in the gap and overlap regions possess a specifically fine-tuned local response to osmotic pressure changes. Clearly, more experiments with additional sequences are needed to confirm this. In conclusion, the results obtained in this work indicate a highly sequence specific interaction between collagen and water. Osmotic pressure-induced conformational changes mostly originate from local geometries and bonding patterns and affect both the structure of individual triple helices as well as higher order assemblies. One key remaining question is how these conformational changes affect the local mechanical properties of the collagen molecule. As a first step, the stiffness (persistence length) of full-length collagen was determined using atomic force microscopy. In the future, experimental strategies need to be developed that allow for investigating the mechanical properties of specific collagen sequences, e.g. performing single-molecule force spectroscopy of CMPs.},
  language  = {en}
}
@misc{KotthoffLisecSchwerdtleetal.2019,
  author    = {Kotthoff, Lisa and Lisec, Jan and Schwerdtle, Tanja and Koch, Matthias},
  title     = {Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1340},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-47326},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-473262},
  pages     = {12},
  year      = {2019},
  abstract  = {The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid+ chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation},
  language  = {en}
}
@article{KotthoffLisecSchwerdtleetal.2019,
  author    = {Kotthoff, Lisa and Lisec, Jan and Schwerdtle, Tanja and Koch, Matthias},
  title     = {Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis},
  series = {Molecules},
  volume    = {24},
  journal   = {Molecules},
  number    = {15},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules24152732},
  pages     = {12},
  year      = {2019},
  abstract  = {The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation.},
  language  = {en}
}