@misc{deVeraAlawiBackhausetal.2019, author = {de Vera, Jean-Pierre Paul and Alawi, Mashal and Backhaus, Theresa and Baque, Mickael and Billi, Daniela and Boettger, Ute and Berger, Thomas and Bohmeier, Maria and Cockell, Charles and Demets, Rene and de la Torre Noetzel, Rosa and Edwards, Howell and Elsaesser, Andreas and Fagliarone, Claudia and Fiedler, Annelie and Foing, Bernard and Foucher, Frederic and Fritz, J{\"o}rg and Hanke, Franziska and Herzog, Thomas and Horneck, Gerda and H{\"u}bers, Heinz-Wilhelm and Huwe, Bj{\"o}rn and Joshi, Jasmin Radha and Kozyrovska, Natalia and Kruchten, Martha and Lasch, Peter and Lee, Natuschka and Leuko, Stefan and Leya, Thomas and Lorek, Andreas and Martinez-Frias, Jesus and Meessen, Joachim and Moritz, Sophie and Moeller, Ralf and Olsson-Francis, Karen and Onofri, Silvano and Ott, Sieglinde and Pacelli, Claudia and Podolich, Olga and Rabbow, Elke and Reitz, G{\"u}nther and Rettberg, Petra and Reva, Oleg and Rothschild, Lynn and Garcia Sancho, Leo and Schulze-Makuch, Dirk and Selbmann, Laura and Serrano, Paloma and Szewzyk, Ulrich and Verseux, Cyprien and Wadsworth, Jennifer and Wagner, Dirk and Westall, Frances and Wolter, David and Zucconi, Laura}, title = {Limits of life and the habitability of Mars}, series = {Astrobiology}, volume = {19}, journal = {Astrobiology}, number = {2}, publisher = {Liebert}, address = {New Rochelle}, issn = {1531-1074}, doi = {10.1089/ast.2018.1897}, pages = {145 -- 157}, year = {2019}, abstract = {BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.}, language = {en} } @article{MoazzenOberhaensliHajialioghlietal.2009, author = {Moazzen, Mohssen and Oberh{\"a}nsli, Roland and Hajialioghli, Robab and Moeller, Andreas and Bousquet, Romain and Droop, Giles and Jahangiri, Ahmad}, title = {Peak and post-peak P-T conditions and fluid composition for scapolite-clinopyroxene-garnet calc-silicate rocks from the Takab area, NW Iran}, issn = {0935-1221}, doi = {10.1127/0935-1221/2009/0021-1887}, year = {2009}, abstract = {The Takab calcareous rocks of northwest Iran crop out in association with a variety of metamorphic rocks including mafic granulites, amphibolites, granitic gneisses, pelitic schists and meta-ultramafic rocks. They can be divided into marbles and calc-silicate rocks on the basis of the dominance of calcite/dolomite and silicate minerals. Dominant peak metamorphic granulite facies assemblage of calc-silicate rocks is Scp + Grt(I) + Cpx + Cal + Qtz +/- Hbl(I). The decrease of temperature and pressure during exhumation produced post-peak metamorphic assemblages. Coronal garnet (Grt II) in the calc-silicate rocks was produced by retrograde reactions consuming plagioclase and clinopyroxene, while peak metamorphic garnet (Grt I) occurs as preserved xenoblastic grains in calcite and/or plagioclase (Pl II). Regional metamorphism took place at 740 degrees C and X-CO2 similar to 0.9. Garnet-clinopyroxene-plagioclase-quartz (GADS) barometry yields a pressure of 8-9 kbar, corresponding to a depth of ca. 24-27 km. This was followed by decompression and hydration during exhumation of the crustal rocks up to the surface. Secondary phases such as garnet (II) hornblende (II), plagioclase (II), zoisite and titanite (II) constrain the temperature and pressure of post-peak metamorphism as similar to 600 degrees C and similar to 6 kbar respectively and a fluid with XCO2 as low as 0.4. Halogens were near-absent during the peak metamorphic stage. The scapolite and hornblende crystallized underpeak metamorphic conditions contain very low fluorine and chlorine, whereas relatively high fluorine (similar to 0.8 wt\%) in the titanite (II) and hornblende (II) suggests a possible infiltration of F-rich fluids into the calc-silicate rocks during retrogression. It is interpreted to be related to external fluids released during crystallisation of granitoid magmas and/or leucosome patches in the adjacent migmatites.}, language = {en} } @article{SchmitzMoellerWilkeetal.2009, author = {Schmitz, Sylvia and Moeller, Andreas and Wilke, Max and Malzer, Wolfgang and Kanngiesser, Birgit and Bousquet, Romain and Berger, Alfons and Schefer, Senecio}, title = {Chemical U-Th-Pb dating of monazite by 3D-Micro X-ray fluorescence analysis with synchrotron radiation}, issn = {0935-1221}, doi = {10.1127/0935-1221/2009/0021-1964}, year = {2009}, abstract = {A confocal set-up for three-dimensional (3D) micro X-ray fluorescence (micro-XRF) was used at the mySpot beamline at BESSY II, which allows compositional depth profiling for various applications. We present results obtained with a confocal 3D micro-XRF set-up for chemical age dating using the U, Th and Pb concentrations of monazite within rock thin sections. The probing volume was determined to be approximately 21 x 21 x 24 mu m(3) for W-L alpha using an excitation energy of 19 keV. The relative detection limits particularly for Pb are below 10 ppm (for Counting times}, language = {en} } @article{SchildknechtPapeMeiseretal.2015, author = {Schildknecht, Stefan and Pape, Regina and Meiser, Johannes and Karreman, Christiaan and Strittmatter, Tobias and Odermatt, Meike and Cirri, Erica and Friemel, Anke and Ringwald, Markus and Pasquarelli, Noemi and Ferger, Boris and Brunner, Thomas and Marx, Andreas and Moeller, Heiko M. and Hiller, Karsten and Leist, Marcel}, title = {Preferential Extracellular Generation of the Active Parkinsonian Toxin MPP+ by Transporter-Independent Export of the Intermediate MPDP+}, series = {Antioxidants \& redox signaling}, volume = {23}, journal = {Antioxidants \& redox signaling}, number = {13}, publisher = {Liebert}, address = {New Rochelle}, issn = {1523-0864}, doi = {10.1089/ars.2015.6297}, pages = {1001 -- 1016}, year = {2015}, abstract = {Aims: 1-Methyl-4-phenyl-tetrahydropyridine (MPTP) is among the most widely used neurotoxins for inducing experimental parkinsonism. MPTP causes parkinsonian symptoms in mice, primates, and humans by killing a subpopulation of dopaminergic neurons. Extrapolations of data obtained using MPTP-based parkinsonism models to human disease are common; however, the precise mechanism by which MPTP is converted into its active neurotoxic metabolite, 1-methyl-4-phenyl-pyridinium (MPP+), has not been fully elucidated. In this study, we aimed to address two unanswered questions related to MPTP toxicology: (1) Why are MPTP-converting astrocytes largely spared from toxicity? (2) How does MPP+ reach the extracellular space? Results: In MPTP-treated astrocytes, we discovered that the membrane-impermeable MPP+, which is generally assumed to be formed inside astrocytes, is almost exclusively detected outside of these cells. Instead of a transporter-mediated export, we found that the intermediate, 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+), and/or its uncharged conjugate base passively diffused across cell membranes and that MPP+ was formed predominately by the extracellular oxidation of MPDP+ into MPP+. This nonenzymatic extracellular conversion of MPDP+ was promoted by O-2, a more alkaline pH, and dopamine autoxidation products. Innovation and Conclusion: Our data indicate that MPTP metabolism is compartmentalized between intracellular and extracellular environments, explain the absence of toxicity in MPTP-converting astrocytes, and provide a rationale for the preferential formation of MPP+ in the extracellular space. The mechanism of transporter-independent extracellular MPP+ formation described here indicates that extracellular genesis of MPP+ from MPDP is a necessary prerequisite for the selective uptake of this toxin by catecholaminergic neurons.}, language = {en} } @article{GoebelHesemannWeberetal.2009, author = {Goebel, Ronald and Hesemann, Peter and Weber, Jens and Moeller, El{\´e}onore and Friedrich, Alwin and Beuermann, Sabine and Taubert, Andreas}, title = {Surprisingly high, bulk liquid-like mobility of silica-confined ionic liquids}, issn = {1463-9076}, doi = {10.1039/B821833a}, year = {2009}, abstract = {Mesoporous silica monoliths were prepared by the sol - gel technique and. lled with 1-ethyl-3-methyl imidazolium [Emim]-X (X = dicyanamide [N(CN)(2)], ethyl sulfate [EtSO4], thiocyanate [SCN], and triflate [TfO]) ionic liquids (ILs) using a methanol-IL exchange technique. The structure and behavior of the ILs inside the silica monoliths were studied using X-ray scattering, nitrogen sorption, IR spectroscopy, solid-state NMR, and thermal analysis. DSC finds shifts in both the glass transition temperature and melting points (where applicable) of the ILs. Glass transition and melting occur well below room temperature. There is thus no conflict with the NMR and IR data, which show that the ILs are as mobile at room temperature as the bulk (not confined) ILs. The very narrow line widths of the NMR spectra suggest that the ILs in our materials have the highest mobility reported for confined ILs so far. As a result, our data suggest that it is possible to generate IL/silica hybrid materials (ionogels) with bulk-like properties of the IL. This could be interesting for applications in, e.g., the solar cell or membrane fields.}, language = {en} }