TY  - JOUR
A1  - Baumann, Franz Erich
A1  - Burschka, Christian
A1  - Schenk, Wolfdieter A.
T1  - Ligandensubstitution an cis-Mo(CO)\(_2\)(PPh\(_3\)h(MeCN)(\(\eta^2\)-S0\(_2\)), Kristall- und Molekülstruktur von cis-Mo(CO)\(_2\)(PMe\(_3\))\(_3\)(\(\eta^2\)-S0\(_2\)) [1]
T1  - Ligand Substitution at cis-Mo(CO)\(_2\)(PPh\(_3\)h(MeCN)(\(\eta^2\)-S0\(_2\)), crystal and molecular structure of cis-Mo(CO)\(_2\)(PMe\(_3\))\(_3\)(\(\eta^2\)-S0\(_2\)) [1]
N2  - No abstract available
KW  - Chemie
KW  - Molybdenum-Sulfur Dioxide Complexes
KW  - Ligand Displacement
KW  - Structure
KW  - Stereochemistry . Linkage Isomerism
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47143
ER  - 
TY  - JOUR
A1  - Horn, Michael
A1  - Baumann, Reto
A1  - Pereira, Jorge A.
A1  - Sidiropoulos, Páris N. M.
A1  - Somandin, Christian
A1  - Welzl, Hans
A1  - Stendel, Claudia
A1  - Lühmann, Tessa
A1  - Wessig, Carsten
A1  - Toyka, Klaus V.
A1  - Relvas, João B.
A1  - Senderek, Jan
A1  - Suter, Ueli
T1  - Myelin is dependent on the Charcot–Marie–Tooth Type 4H disease culprit protein FRABIN/FGD4 in Schwann cells
JF  - Brain
N2  - Studying the function and malfunction of genes and proteins associated with inherited forms of peripheral neuropathies has provided multiple clues to our understanding of myelinated nerves in health and disease. Here, we have generated a mouse model for the peripheral neuropathy Charcot–Marie–Tooth disease type 4H by constitutively disrupting the mouse orthologue of the suspected culprit gene FGD4 that encodes the small RhoGTPase Cdc42-guanine nucleotide exchange factor Frabin. Lack of Frabin/Fgd4 causes dysmyelination in mice in early peripheral nerve development, followed by profound myelin abnormalities and demyelination at later stages. At the age of 60 weeks, this was accompanied by electrophysiological deficits. By crossing mice carrying alleles of Frabin/Fgd4 flanked by loxP sequences with animals expressing Cre recombinase in a cell type-specific manner, we show that Schwann cell-autonomous Frabin/Fgd4 function is essential for proper myelination without detectable primary contributions from neurons. Deletion of Frabin/Fgd4 in Schwann cells of fully myelinated nerve fibres revealed that this protein is not only required for correct nerve development but also for accurate myelin maintenance. Moreover, we established that correct activation of Cdc42 is dependent on Frabin/Fgd4 function in healthy peripheral nerves. Genetic disruption of Cdc42 in Schwann cells of adult myelinated nerves resulted in myelin alterations similar to those observed in Frabin/Fgd4-deficient mice, indicating that Cdc42 and the Frabin/Fgd4–Cdc42 axis are critical for myelin homeostasis. In line with known regulatory roles of Cdc42, we found that Frabin/Fgd4 regulates Schwann cell endocytosis, a process that is increasingly recognized as a relevant mechanism in peripheral nerve pathophysiology. Taken together, our results indicate that regulation of Cdc42 by Frabin/Fgd4 in Schwann cells is critical for the structure and function of the peripheral nervous system. In particular, this regulatory link is continuously required in adult fully myelinated nerve fibres. Thus, mechanisms regulated by Frabin/Fgd4–Cdc42 are promising targets that can help to identify additional regulators of myelin development and homeostasis, which may crucially contribute also to malfunctions in different types of peripheral neuropathies.
KW  - Frabin/Fgd4
KW  - myelination
KW  - hereditary motor and sensory neuropathy
KW  - Charcot–Marie–Tooth disease
KW  - Rho-GTPase Cdc42
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125390
VL  - 135
ER  - 
TY  - JOUR
A1  - Baumann, A.
A1  - Tvingstedt, K.
A1  - Heiber, M. C.
A1  - Väth, S.
A1  - Momblona, C.
A1  - Bolink, H. J.
A1  - Dyakonov, V.
T1  - Persistent photovoltage in methylammonium lead iodide perovskite solar cells
JF  - APL Materials
N2  - We herein perform open circuit voltage decay (OCVD) measurements on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer–fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70BM blends. We observe two very different time domains of the voltage transient in the perovskite solar cell with a first drop on a short time scale that is similar to the decay in the studied organic solar cells. However, 65%–70% of the maximum photovoltage persists on much longer timescales in the perovskite solar cell than in the organic devices. In addition, we find that the recombination dynamics in all time regimes are dependent on the starting illumination intensity, which is also not observed in the organic devices. We then discuss the potential origins of these unique behaviors.
KW  - solar cells
KW  - illumination
KW  - dielectric oxides
KW  - carrier density
KW  - bioelectrochemistry
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119397
VL  - 2
IS  - 8
ER  - 
TY  - JOUR
A1  - Burschka, Christian
A1  - Baumann, F.-E.
A1  - Schenk, W. A.
T1  - Schwefel(IV)-Verbindungen als Liganden. II. Die Kristall- und Molekülstruktur von Pentacarbonyl-(schwefeldioxid)chrom
T1  - Sulfur(IV) Compounds as Ligands. II. The Crystal and Molecular Structure of Pentacarbonyl-(sulfur dioxide)chromium
N2  - Die Struktur von Pentacarbonyl(schwefeldioxid)chrom (1) wurde röntgenographisch aus Einkristalldaten bestimmt. Die Verbindung kristallisiert mit acht Formeleinheiten in der rhombischen Elementarzelle (Raumgruppe Pbn2\(_1\)) folgender Dimensionen: a = 657,8(2) pm, b = 1245,2(4) pm, c = 2177,4(5) pm (bei 180 K). Das Schwefeldioxid ist \(\eta^1\)-koplanar koordiniert, der Cr-S-Abstand ist mit 219 pm der kürzeste bisher gefundene Abstand zwischen Chrom(O) und Schwefel. Die Cr-C(ax)-Bindung ist mit 189 pm fast genau so lang wie die Cr-C(eq).Bindungen (190 pm), ein Beleg für das hohe \(\pi\)-Akzeptorvermögen des S0\(_2\).
N2  - The structure of pentacarbonyl(sulfurdioxide)chromium (1) has been determined from single crystal X-ray data. The compound crystallizes with eight formula units in the rhombic unit cell (space group Pbn2\(_1\) ) of the dimensions a = 657.8(2) pm, b = 1245.2(4) pm, c = 2177.4(5) pm (at 180 K). The sulfur dioxide ia \(\eta^1\)-coplanar coordinated, the Cr-S distance is 219 pm, the shortest. bond reported so far between chromium(O) and sulfur. The Cr-C(ax) bond (189 pm) was found only marginally shorter than the Cr-C(eq) bonds (190 pm) providing proof of the high \(\pi\)·acceptor capacity of S0\(_2\)
KW  - Chemie
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31388
ER  -