Calculation of transition metal compounds using an extension of the CNDO formalism. II. Metal to metal bonding in binuclear transition metal compounds

A recently developed extension of the CNDO-method (Freund and Hohlneicher, 1979) is used to study the electronic structure of a no. of binuclear transition metal carbonyls and carboxylates with 4-fold or quasi-4-fold symmetry. The results are compared to those available from nonempirical calcns. Special attention is paid to the nature of the metal-metal bond. Connections with qual. MO-considerations allow a fairly general discussion of metal-metal bonding in binuclear transition metal complexes with basic 4-fold symmetry. A few, up to now unknown, but possibly existing, complexes are considered

The T1 state of p-nitroaniline and related molecules: a CNDO/S study

The nature of the lowest energy triplet state (T1) of p-nitroaniline (PNA), N,N-dimethyl-p-nitroaniline (DMPNA) and nitrobenzene (NB) is reexamd. using the semiempirical CNDO/S-CI method with selected parameter options. In the case of the unperturbed mols. the short-axis polarized p* A- singlet excitation. Computations suggest, however, that polar solvents strongly stabilize the PNA and DMPNA p* <- p charge-transfer triplet relative to other excitations, whereas specific solvent hydrogen-bonded interactions stabilize the p* <- n(s) triplet of NB below those of p* <- p character. These assignments allow a rationalization of phosphorescence lifetime data, Tn <- T1 absorption measurements and relative photochem. behavior

Spinocerebellar Ataxia Type 2

1. Introduction: The autosomal dominant cerebellar ataxias (ADCA) are a clinically, pathologically and genetically heterogeneous group of neurodegenerative disorders caused by degeneration of cerebellum and its afferent and efferent connections. The degenerative process may additionally involves the ponto- medullar systems, pyramidal tracts, basal ganglia, cerebral cortex, peripheral nerves (ADCA I) and the retina (ADCA II), or can be limited to the cerebellum (ADCA III) (Harding et al., 1993). The most common of these dominantly inherited autosomal ataxias, ADCA I, includes many Spinocerebellar Ataxias (SCA) subtypes, some of which are caused by pathological CAG trinucleotide repeat expansion in the coding region on the mutated gene. Such is the case for SCA1, SCA2, SCA3/MJD, SCA6, SCA7, SCA17 and Dentatorubral-pallidoluysian atrophy (DRPLA) (Matilla et al., 2006). Among the almost 30 SCAs, the variant SCA2 is the second most prevalent subtype worldwide, only surpassed by SCA3 (Schöls et al., 2004; Matilla et al., 2006; Auburger, 2011)..

Effect of lattice-gas atoms on the adsorption behaviour of thioether molecules

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Using STM topographic imaging and spectroscopy, we have investigated the adsorption of two thioether molecules, 1,2-bis(phenylthio)benzene and (bis(3-phenylthio)-phenyl)sulfane, on noble and transition metal surfaces. The two substrates show nearly antipodal behaviour. Whereas complexes with one or two protruding centres are observed on Au(111), only flat and uniform ad-structures are found on NiAl(110). The difference is ascribed to the possibility of the thioethers to form metal–organic complexes by coordinating lattice-gas atoms on the Au(111), while only the pristine molecules adsorb on the alloy surface. The metal coordination in the first case is driven by the formation of strong Au–S bonds and enables the formation of characteristic monomer, dimer and chain-like structures of the thioethers, using the Au atoms as linkers. A similar mechanism is not available on the NiAl, because no lattice gas develops at this surface at room temperature. Our work demonstrates how surface properties, i.e. the availability of mobile ad-species, determine the interaction of organic molecules with metallic substrates.DFG, EXC 314, Unifying Concepts in Catalysi

Analysis of the interaction of influenza virus polymerase complex with human cell factors

12 pages, 4 figures.-- PMID: 18491320 [PubMed].-- Supplementary information (Suppl. figure S1, 2 pages) available at: http://www.wiley-vch.de/contents/jc_2120/2008/pro200700508_s.pdfThe influenza virus polymerase is formed by the PB1, PB2 and PA subunits and is required for virus transcription and replication in the nucleus of infected cells. Here we present the characterisation of the complexes formed intracellularly by the influenza polymerase in human cells. The virus polymerase was expressed by cotransfection of the polymerase subunits cDNAs, one of which fused to the tandem-affinity purification (TAP) tag. The intracellular complexes were purified by the TAP approach, which involves IgG-Sepharose and calmodulin-agarose chromatography, under very mild conditions. The purified complexes contained the heterotrimeric polymerase and a series of associated proteins that were not apparent in purifications of untagged polymerase used as a control. Several influenza polymerase-associated proteins were identified by MALDI-MS and their presence in purified polymerase-containing complexes were verified by Western blot. Their relevance for influenza infection was established by colocalisation with virus ribonucleoproteins in human infected cells. Most of the associated human factors were nuclear proteins involved in cellular RNA synthesis, modification and nucleo-cytoplasmic export, but some were cytosolic proteins involved in translation and transport. The interactions recognised in this proteomic approach suggest that the influenza polymerase might be involved in steps of the infection cycle other than RNA replication and transcription.N. J. was a fellow from Ministerio de Educación y Ciencia. E. T. was a fellow from Instituto de Salud Carlos III. P. G. was a fellow from Gobierno Vasco. This work was supported by the Spanish Ministry of Education and Science (Ministerio de Educación y Ciencia) (grant BFU2004-491), the VIRHOST Program financed by Comunidad de Madrid, European Vigilance Network for the Management of Antiviral Drug Resistance (VIRGIL) and the FLUPOL strep project (SP5B-CT-2007-044263).Peer reviewe

Prefrontal involvement in imitation learning of hand actions : effects of practice and expertise.

In this event-related fMRI study, we demonstrate the effects of a single session of practising configural hand actions (guitar chords) on cortical activations during observation, motor preparation, and imitative execution. During the observation of non-practised actions, the mirror neuron system (MNS), consisting of inferior parietal and ventral premotor areas, was more strongly activated than for the practised actions. This finding indicates a strong role of the MNS in the early stages of imitation learning. In addition, the dorsolateral prefrontal cortex (DLPFC) was selectively involved during observation and motor preparation of the non-practised chords. This finding confirms Buccino et al.’s (2004a) model of imitation learning: for actions that are not yet part of the observer’s motor repertoire, DLPFC engages in operations of selection and combination of existing, elementary representations in the MNS. The pattern of prefrontal activations further supports Shallice’s (2004) proposal of a dominant role of the left DLPFC in modulating lower-level systems, and of a dominant role of the right DLPFC in monitoring operations

WALTER ROTHKEGEL (1874 – 1959) Begründer der Reichsbodenschätzung

Das Bodenschätzungsgesetz von 1934 geht im Wesentlichen auf die Initiativen von ROTHKEGEL und HERZOG zurück. Es ist ein Verdienst von W. ROTHKEGEL, dass er erstmalig und bisher einmalig eine einheitliche Bodenbonitierung und zugleich auch großmaßstäbige Boden-kartierung für Deutschland durchgesetzt und flächendeckend realisiert hat. W. ROTHKEGEL hat als Wegbereiter der Bodenschätzung auch deren Ausrichtung für die nichtsteuerliche Auswertung und Anwendung und damit die bodenkund-liche Zielstellung gesetzlich verankert. Die einheitliche Datenfülle der Boden-schätzung ist für die Umsetzung der Bodenschutzgesetze eine wesentliche Voraussetzung

Variation of bending rigidity with material density: bilayer silica with nanoscale holes

Two dimensional (2D) materials are a young class of materials that is foreseen to play an important role as building blocks in a range of applications, e.g. flexible electronics. For such applications, mechanical properties such as the bending rigidity κ are important. Only a few published measurements of the bending rigidity are available for 2D materials. Nearly unexplored is the question of how the 2D material density influences the bending rigidity. Here, we present helium atom scattering measurements on a “holey” bilayer silica with a density of 1.4 mg m−2, corresponding to 1.7 monolayers coverage. We find a bending rigidity of 6.6 ± 0.3 meV, which is lower than previously published measurements for a complete 2D film, where a value of 8.8 ± 0.5 meV was obtained. The decrease of bending rigidity with lower density is in agreement with theoretical predictions.publishedVersio

Combined UHV and ambient pressure studies of 1,3-butadiene adsorption and reaction on Pd(1 1 1) by GC, IRAS and XPS

Abstract The hydrogenation of 1,3-butadiene on Pd(1 1 1) at 300 K was studied at atmospheric pressure by infrared reflection absorption spectroscopy (IRAS) and gas chromatography (GC). Kinetic measurements showed 1-butene, trans-2-butene and cis-2-butene as primary products. Once 1,3-butadiene had been completely consumed, 1-butene was re-adsorbed on the surface producing trans-/cis-2-butene through isomerization and n-butane through hydrogenation. These results were corroborated by in situ IRAS spectroscopy. Post-reaction analysis by X-ray photoelectron spectroscopy (XPS) in the C1s region revealed a band at 284.2 eV, corresponding to adsorbed butadiene and/or carbonaceous deposits. Quantification of this peak revealed a total carbon coverage of 0.3 ML. Nevertheless, deactivation due to carbon deposition was a minor effect under our reaction conditions, as indicated by the kinetics of the subsequent butene hydrogenation reaction. Temperature-dependent XPS experiments after butadiene adsorption at 100 K indicated a high stability of the diene molecule with hardly any desorption and/or decomposition up to 500 K. Above this temperature, butadiene decomposed to carbon species that eventually dissolved in the Pd bulk above 700 K

Правове регулювання внутрішнього ринку Європейського Союзу

Навчально-методичний посібник підготовлено відповідно до курсу "Правове регулювання внутрішнього ринку ЄС". Він містить програму курсу теми даного курсу, плани семінарських занять, завдання для самостійної роботи студентів, варіанти контрольних робіт, запитання до іспиту, термінологічний словник, а також список рекомендованої літератури та джерела законодавства для більш ретельного вивчення даної дисципліни. Посібник буде корисним як для студентів, так і для викладачів