Solvent-dependent conformation and hydrogen-bonding capacity of cyclosporin A: Evidence from partition coefficients and molecular dynamics simulations

The partition coefficient of cyclosprin A (CsA) was measured in octanol/water and heptane/water by centrifugal partition chromatography. By comparison with results from model compounds, it was deduced that the hydrogen-bonding capacity of CsA changed dramatically from an apolar solvent (where it is internally H-bonded) to polar solvents (where it exposes its H-bonding groups to the solvent). Molecular dynamics simulations in water and CCl4 support the suggestion that CsA undergoes a solvent-dependent conformational changes and that the interconversion process is slow on the molecular dynamics time scale

Divergent roles of ApoER2 and Vldlr in the migration of cortical neurons

Reelin, its lipoprotein receptors [very low density lipoprotein receptor (Vldlr) and apolipoprotein E receptor 2 (ApoER2; also known as Lrp8)], and the cytoplasmic adaptor protein disabled 1 (Dab1) are important for the correct formation of layers in the cerebral cortex. Reeler mice lacking the reelin protein show altered radial neuronal migration resulting in an inversion of cortical layers. ApoER2 Vldlr double-knockout mutants and Dab1 mutants show a reeler-like phenotype, whereas milder phenotypes are found if only one of the two lipoprotein receptors for reelin is absent. However, the precise role of the individual reelin receptors in neuronal migration remained unclear. In the study reported here, we performed fate mapping of newly generated cortical neurons in single and double receptor mutants using bromodeoxyuridine-labeling and layer-specific markers. We present evidence for divergent roles of the two reelin receptors Vldlr and ApoER2, with Vldlr mediating a stop signal for migrating neurons and ApoER2 being essential for the migration of late generated neocortical neurons

Verbrennung von Mischbrennstoffen (Braunkohle und Klaerschlamm) in einer zirkulierenden Wirbelschichtfeuerung - ein Beitrag zur Abfallentsorgung und zu einer schadstoffarmen Verbrennung Abschlussbericht

Mixed fuels based on dried lignite and sewage sludge were burned in a pilot model with circulated fluidized bed technology. The part of sewage sludge has been varied in the fuel, the different reaction and emission conditions were investigated. In the report were laid emphasis on the primary influence of the waste gas components (CO, NO_x, N_2O). The author started first searchs to the ash composition and to where about of the heavy metals. In the report are recommendation for the industriel effective combustion with low emissions with sewage sludge/lignite mixded fuel. (orig.)In einer Pilotanlage mit zirkulierender Wirbelschichtfeuerung wurden unterschiedliche Brennstoffgemsiche aus Trockenbraunkohle und Klaerschlamm verbrannt. Die Anteile am Klaerschlamm wurden variiert und die sich aendernden Reaktions- und Emissionsverhaeltnisse aufgenommen. Schwerpunkt dieser Arbeit war die primaere Beeinflussung der Gasschadstoffe (CO, NO_x, N_2O). Erste Untersuchungen zur Aschenzusammensetzung und zum Verbleib der Schwermetalle wurden vorgenommen. Empfehlungen fuer die grosstechnische, effektive, schadstoffarme Verbrennung von Klaerschlamm/Braunkohle-Gemischen wurden erarbeitet. (orig.)SIGLEAvailable from TIB Hannover: F97B1535+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

constant restraints

Structure refinement using time-averaged J-couplin

Optical third-harmonic spectroscopy of the magnetic semiconductor EuTe

EuTe possesses the centrosymmetric crystal structure m3m of rocksalt type in which the second-harmonic generation is forbidden in electric dipole approximation but the third-harmonic generation (THG) is allowed. We studied the THG spectra of this material and observed several resonances in the vicinity of the band gap at 2.2-2.5 eV and at higher energies up to 4 eV, which are related to four-photon THG processes. The observed resonances are assigned to specific combinations of electronic transitions between the ground 4f(7) state at the top of the valence band and excited 4f(6)5d(1) states of Eu(2+) ions, which form the lowest energy conduction band. Temperature, magnetic field, and rotational anisotropy studies allowed us to distinguish crystallographic and magnetic-field-induced contributions to the THG. A strong modification of THG intensity for the 2.4 eV band and suppression of the THG for the 3.15 eV band was observed in applied magnetic field. Two main features of the THG spectra were assigned to 5d(t(2g)) and 5d(e(g)) subbands at 2.4 eV and 3.15 eV, respectively. A microscopic quantum-mechanical model of the THG response was developed and its conclusions are in qualitative agreement with the experimental results.DFG - Deutsche Forschungsgemeinschaft[YA65/4-1]RFBR Russian Foundation for Basic ResearchFoNE of the European Science FoundationFAPESPCNPq(DAAD) Deutscher Akademischer Austausch Dienst, GermanyFWF (Vienna, Austria