478 research outputs found

    \u3cem\u3ecis\u3c/em\u3e-(Diethyldithiocarbamato)diiodo(phenyl)tellurium(IV), PhTe(S\u3csub\u3e2\u3c/sub\u3eCNEt\u3csub\u3e2\u3c/sub\u3e)I\u3csub\u3e2\u3c/sub\u3e, and its Methoxy-Substituted Mixed Br/1 Analogue \u3cem\u3ecis\u3c/em\u3e-Bis(0.4-bromo/0.6-iodo)-(diethyldithiocarbamato)(4-methoxyphenyl) tellurium(IV), \u3cem\u3ep\u3c/em\u3e-MeOC\u3csub\u3e6\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3eTe(S\u3csub\u3e2\u3c/sub\u3e CNEt\u3csub\u3e2\u3c/sub\u3e)(Br\u3csub\u3e0.4\u3c/sub\u3eI\u3csub\u3e0.6\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e

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    The TeIV complexes PhTe(S2CNEt2)I2, (1), and p-MeOC6H4Te(S2CNEt2)Br0.4/I0.6) 2, (2), have been synthesized by reacting PhTeI3 with NaS2CNEt2, and p-MeOC6H4Te(S2CNEt2)2I with Br2, respectively. In (2), both I atoms are partially replaced by Br atoms in a 3:2 ratio. The structures display distorted octahedral Te coordination with two symmetrically coordinated S atoms [Te—S 2.550 (2)—2.569 (2) Å in three independent molecules of (1) and 2.523 (1) Å in (2)] and with two cis-disposed halogen atoms [Te—I 2.941 (1)—2.986 (1) Å in (1) and 3.003 (4) and 3.049 (3) Å in (2); Te—Br 2.962(8) and 2.967 (8) Å in (2)] in equatorial positions. The aryl group is axial in both complexes [Te—C 2.137(6)—2.146(6) and 2.123(5) Å in (1) and (2) respectively] and the second axial position is occupied by a halogen atom of a neighbouring molecule [Te⋅⋅⋅I 3.898(1)—4233(1) Å in (1); Te⋅ ⋅ ⋅I3872(3) Å and Te⋅ ⋅ ⋅Br 3.676(6) Å in (2); trans angles C---Te⋅ ⋅ ⋅ (Br) 153.4(2)—177.7(2)°] so that the molecules are joined into (quasi)centrosymmetric pairs by these secondary interactions

    1989 Charleston Conference

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    A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugÀnglich.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.A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.BMBF, 01RC0901F, Dream Reactions - Stoffliche CO2-VerwertungDFG, EXC 314, Unifying Concepts in Catalysi

    Digital literacy of teachers of adult education. On the possibility of its integration into models of generic education competences: the example of GRETA

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    FĂŒr die kompetente DurchfĂŒhrung von Bildungsangeboten sind (erwachsenen-)pĂ€dagogische, fachliche und (fach-)didaktische sowie technologische und medienpĂ€dagogische Kompetenzen nötig. Letztere, hier zusammengefasst unter dem Begriff der digitalen Kompetenzen, werden nicht zuletzt auch vor dem Hintergrund der Covid-19-Pandemie immer wichtiger. In welcher Relation aber sollen digitale und pĂ€dagogische Kompetenzen zueinanderstehen und wie kann ein entsprechendes Kompetenzmodell aussehen? Der vorliegende Beitrag setzt sich mit der Relation pĂ€dagogischer und digitaler Kompetenzen auseinander und stellt am Beispiel des GRETA-Kompetenzmodells die Möglichkeit einer integrierten Darstellung in einem Kompetenzmodell fĂŒr Lehrende in der Erwachsenen- und Weiterbildung vor. Am Ende der konzeptionellen und empirischen Arbeiten soll das GRETA-Kompetenzmodell 2.0 stehen, welches fĂŒr alle Lehrenden in der Erwachsenenbildung tragfĂ€hig ist. (DIPF/Orig.)Competent implementation of educational programs requires (adult) education, professional and didactic competences as well as technological and media education competences. Summarized here as digital competences, the last two are increasingly important against the backdrop of the COVID-19 pandemic. Yet how are digital and educational competences interrelated and what would such a competence model look like? This article deals with the relation between educational and digital competences and presents the possibility for integrated representation in a competence model for teachers of adult education and continuing education as exemplified by the GRETA competence model. The conceptual and empirical work should yield the GRETA competence model 2.0, which is viable for all adult education teachers. (DIPF/Orig.

    Strong Antiferromagnetism in Isolated Anionic Dicopper(II) Methanoato Paddle-wheel Complex

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    A new ionic compound (C5H6NO)2[Cu2(ÎŒ-O2CH)4(O2CH)2], 1 formed of 4-hydroxy-pyridinium cations and a complex anion was synthesized. The anion is a paddle-wheel dicopper carboxy-late complex with four syn,syn-bridging and two axial anionic methanoato ligands. The XRD structure de-termination of 1 reveals that the molecular structure is stabilized by two H-bonds between the cations and the axial paddle-wheel anions (N–H···O 2.755(3), O–H···O 2.489(2) Å). The compound exhibits a very strong (2J = 500 cm–1) intra-binuclear antiferromagnetic interaction noticed already at room temperature attributed to the methanoato intra-binuclear bridges. The typical EPR S = 1 spin system signals of the dicopper paddle-wheel complexes at 90 and 450–700 mT are found in the room temperature spectrum, but they are poorly seen in the 110 K spectrum. These signals are of very low intensity and are accompanied by a dominant signal at 320 mT, all closely related to a very strong antiferromagnetic interaction present in 1

    1000 Genomes-based meta-analysis identifies 10 novel loci for kidney function

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    HapMap imputed genome-wide association studies (GWAS) have revealed > 50 loci at which common variants with minor allele frequency > 5% are associated with kidney function. GWAS using more complete reference sets for imputation, such as those from The 1000 Genomes project, promise to identify novel loci that have been missed by previous efforts. To investigate the value of such a more complete variant catalog, we conducted a GWAS meta-analysis of kidney function based on the estimated glomerular filtration rate (eGFR) in 110,517 European ancestry participants using 1000 Genomes imputed data. We identified 10 novel loci with p-value < 5 x 10(-8) previously missed by HapMap-based GWAS. Six of these loci (HOXD8, ARL15, PIK3R1, EYA4, ASTN2, and EPB41L3) are tagged by common SNPs unique to the 1000 Genomes reference panel. Using pathway analysis, we identified 39 significant (FDR < 0.05) genes and 127 significantly (FDR < 0.05) enriched gene sets, which were missed by our previous analyses. Among those, the 10 identified novel genes are part of pathways of kidney development, carbohydrate metabolism, cardiac septum development and glucose metabolism. These results highlight the utility of re-imputing from denser reference panels, until wholegenome sequencing becomes feasible in large samples

    Tetrahalidocuprates(II)-structure and EPR spectroscopy. Part 1: Tetrabromidocuprates(II)

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugĂ€nglich.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.Tetrahalidocuprates(II) show a high degree of structural flexibility. We present the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of four new tetrabromidocuprate(II) compounds and compare the results with previously reported data. The cations in the new compounds are the sterically demanding benzyltriphenylphosphonium, methyltriphenylphosphonium, tetraphenylphosphonium, and hexadecyltrimethylammonium ions; they were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. X-Ray crystallography shows that in all four complexes the [CuBr4]2− units have a distorted tetrahedral coordination geometry which is in agreement with DFT calculations. The EPR hyperfine structure was not resolved. This is due to the exchange broadening resulting from still incomplete separation of the paramagnetic Cu(II) centres. Nevertheless, the principal values of the electron Zeemann tensor (gand g⊄) of the complexes could be determined. A correlation of structural (X-ray) parameters with the spin density at the copper centres (DFT) is well reflected in the EPR spectra of the bromidocuprates. This enables the correlation of X-ray and EPR parameters to predict the structure of tetrabromidocuprates in physical states other than the crystalline state. As a result, we provide a method to structurally characterize [CuBr4]2− in, for example, ionic liquids or in solution, which has important implications for e.g. catalysis or materials science

    Changes of Gene Expression in Euglena gracilis Obtained During the 29th DLR Parabolic Flight Campaign

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    Parabolic flight maneuvers of Novespace’s Airbus A310 ZERO-G produce subsequent phases of hypergravity (about 20 s), microgravity (about 22 s) and another 20 s hypergravity on experiments located in the experiment area of the aircraft. The 29th DLR parabolic flight campaign consisted of four consecutive flight days with thirty-one parabolas each day. Euglena gracilis cells were fixed with TRIzol during different acceleration conditions at the first and the last parabola of each flight. Samples were collected and analyzed with microarrays for one-color gene expression analysis. The data indicate significant changes in gene expression in E. gracilis within short time. Hierarchical clustering shows that changes induced by the different accelerations yield reproducible effects at independent flight days. Transcription differed between the first and last parabolas indicating adaptation effects in the course of the flight. Different gene groups were found to be affected in different phases of the parabolic flight, among others, genes involved in signal transduction, calcium signaling, transport mechanisms, metabolic pathways, and stress-response as well as membrane and cytoskeletal proteins. In addition, transcripts of other areas, e.g., DNA and protein modification, were altered. The study contributes to the understanding of short-term effects of microgravity and different accelerations on cells at a molecular level

    Using Colistin as a Trojan Horse: Inactivation of Gram-Negative Bacteria with Chlorophyllin

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    Colistin (polymyxin E) is a membrane-destabilizing antibiotic used against Gram-negative bacteria. We have recently reported that the outer membrane prevents the uptake of antibacterial chlorophyllin into Gram-negative cells. In this study, we used sub-toxic concentrations of colistin to weaken this barrier for a combination treatment of Escherichia coli and Salmonella enterica serovar Typhimurium with chlorophyllin. In the presence of 0.25 ”g/mL colistin, chlorophyllin was able to inactivate both bacteria strains at concentrations of 5–10 mg/L for E. coli and 0.5–1 mg/L for S. Typhimurium, which showed a higher overall susceptibility to chlorophyllin treatment. In accordance with a previous study, chlorophyllin has proven antibacterial activity both as a photosensitizer, illuminated with 12 mW/cm2, and in darkness. Our data clearly confirmed the relevance of the outer membrane in protection against xenobiotics. Combination treatment with colistin broadens chlorophyllin’s application spectrum against Gram-negatives and gives rise to the assumption that chlorophyllin together with cell membrane-destabilizing substances may become a promising approach in bacteria control. Furthermore, we demonstrated that colistin acts as a door opener even for the photodynamic inactivation of colistin-resistant (mcr-1-positive) E. coli cells by chlorophyllin, which could help us to overcome this antimicrobial resistance
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