56,971 research outputs found

    Metallkomplexe mit biologisch wichtigen Liganden, LXV

    Get PDF
    Cp*Co(CO)I2 (Cp* = 5-C5Me5), [(6-arene)RuCl2]2 (arene = p-cymene, hexamethylbenzene), and [Cp*MCl2]2 (M = Rh, Ir) react with -amino amides and various peptide esters to give the N,O-chelate complexes [Cp*(I)Co - NH2C(H)(R1)C(NHR2)-O]+ (1), [(6-arene)(Cl)Ru - NH2C(H)(R1)C(NHR2)O]+ (2), and [CP*(Cl)M - NH2CH2C(NHR)O]+ (M = Rh, Ir) (5, in solution), respectively. In the solid state the ligands are 1N-bonded in 5. By deprotonation of the peptide bond in 2 and 5 the neutral N, N-chelate complexes (6-arene)(Cl)Ru - NH2C(H)(R1)C(O)-2 (6) and Cp*(Cl)M - NH2C(H)(R1)C(O)NR2 (M = Rh, Ir) (7) have been obtained. Glycinenitrile is 1-bonded in (6-p-cymene)(Cl)2Ru(NH2CH2CN) (3) and Cp*(Cl)2Rh(NH2CH2CN) (4). Double deprotonated triglycine methyl ester is a N,N,N-tridentate ligand in (6-C6Me6)Ru(NH2CH2C(O)NCH2C(O)-NCH2CO2Me) (8). The anions of L-asparagine and of aspartame (L-aspartyl-L-phenylalanine methyl ester) give the complexes 9-12 with tridentate O,N,O- or O,N,N-chelate ligands. The crystal structures of 1d (L = glyglyOEt), 5a (L = glycinamide), 6e (L = glyglyOEt), and 7k (L = glyglyglyOEt) have been determined by X-ray structural analysis

    Crystal structure of [butane-2,3-dione bis(4-methylthiosemicarbazonato](pyridine)zinc(II)

    Get PDF
    In the structure of the title complex, [Zn(C8H14N6S2)(C5H5N)], the ZnII ion has a pseudo-square-pyramidal coordination environment and is displaced by 0.490 Å from the plane of best fit defined by the bis­(thio­semicarbazonate) N2S2 donor atoms. Chains sustained by intermolecular N-H...N and N-H...S hydrogen-bonding interactions extend parallel to [10-1]

    Koordinationschemie -gebundener Cyclopentadienyl-Chalkogeno-Ether

    Get PDF
    Coordination Chemistry of rr-Bonded Cyclopentadienyl Chalcogeno Ethers, I. - Chelate Complexes of Pentakis(methylthio)cymantrene with Metal Carbonyls [C5(SMe)5]Mn(CO)3 (1) reacts with W(CO)5(THF), Mo(CO)4(C7H8), Cr(CO)3(NCMe)3, and Re(CO)4(-C3H5)/HBF4 to yield the monochelate complexes [[C5(SMe)5]Mn(C0)3][M(CO)4] (M = W: 2; M = Mo: 3) and the dichelate complexes [[C5(SMe)5]Mn(CO)3][M(C0)4]2 (M = W: 4; M = Cr: 5; M = Re BFF4 : 6). The reaction with Mo(CO)3(p-xylene) in THF leads via unstable intermediates, which contain coordinated THF, to a mixture of 3 and [[C5(SMe)5]Mn(CO)3][Mo(CO)4]2 (7). The structures of 3 and 4 in the crystal have been determined by X-ray diffraction methods

    Developing Scenarios for Product Longevity and Sufficiency

    Get PDF
    This paper explores the narrative of peoples’ relationships with products as a window on understanding the types of innovation that may inform a culture of sufficiency. The work forms part of the 'Business as Unusual: Designing Products with Consumers in the Loop' [BaU] project, funded as part of the UK EPSRC-ESRC RECODE network (RECODE, 2016) that aims to explore the potential of re-distributed manufacturing (RdM) in a context of sustainability. This element of the project employed interviews, mapping and workshops as methods to investigate the relationship between people and products across the product lifecycle. A focus on product longevity and specifically the people-product interactions is captured in conversations around product maintenance and repair. In exploring ideas of ‘broken’ we found different characteristics of, and motivations for, repair. Mapping these and other product-people interactions across the product lifecycle indicated where current activity is, who owns such activity (i.e. organisation or individual) and where gaps in interactions occur. These issues were explored further in a workshop which grouped participants to look at products from the perspective of one of four scenarios; each scenario represented either short or long product lifespans and different types of people engagement in the design process. The findings help give shape to new scenarios for designing sufficiency-based social models of material flows

    A novel magnetic resonance imaging postprocessing technique for the assessment of intervertebral disc degeneration-Correlation with histological grading in a rabbit disc degeneration model.

    Get PDF
    Introduction:Estimation of intervertebral disc degeneration on magnetic resonance imaging (MRI) is challenging. Qualitative schemes used in clinical practice correlate poorly with pain and quantitative techniques have not entered widespread clinical use. Methods:As part of a prior study, 25 New Zealand white rabbits underwent annular puncture to induce disc degeneration in 50 noncontiguous lumbar discs. At 16 weeks, the animals underwent multi-echo T2 MRI scanning and were euthanized. The discs were stained and examined histologically. Quantitative T2 relaxation maps were prepared using the nonlinear least squares method. Decay Variance maps were created using a novel technique of aggregating the deviation in the intensity of each echo signal from the expected intensity based on the previous rate of decay. Results:Decay Variance maps showed a clear and well demarcated nucleus pulposus with a consistent rate of decay (low Decay Variance) in healthy discs that showed progressively more variable decay (higher Decay Variance) with increasing degeneration. Decay Variance maps required significantly less time to generate (1.0 ± 0.0 second) compared with traditional T2 relaxometry maps (5 (±0.9) to 1788.9 (±116) seconds). Histology scores correlated strongly with Decay Variance scores (r = 0.82, P < .01) and weakly with T2 signal intensity (r = 0.32, P < .01) and quantitative T2 relaxometry (r = 0.39, P < .01). Decay Variance had superior sensitivity and specificity for the detection of degenerate discs when compared to T2 signal intensity or Quantitative T2 mapping. Conclusion:Our results show that using a multi-echo T2 MRI sequence, Decay Variance can quantitatively assess disc degeneration more accurately and with less image-processing time than quantitative T2 relaxometry in a rabbit disc puncture model. The technique is a viable candidate for quantitative assessment of disc degeneration on MRI scans. Further validation on human subjects is needed

    2,6-Diacetylpyridine-resorcinol (1/1)

    Get PDF
    The title co-crystal, C9H9NO2·C6H6O2, is composed of one 2,6-diacetylpyridine molecule and one resorcinol molecule as the asymmetric unit. In the 2,6-diacetylpyridine molecule, the two carbonyl groups are antiperiplanar to the pyridine N atom. In the crystal, the 2,6-diacetylpyridine and resorcinol molecules are connected by two O-H...O hydrogen bonds, forming planar chains of alternating components running along [120]

    Tetragonal to Orthorhombic Transition of GdFeAsO Studied by Single-Crystal Synchrotron X-Ray Diffraction

    Full text link
    A study of the tetragonal to orthorhombic phase transition of GdFeAsO is presented. Planes of the reciprocal space were reconstructed form single-crystal synchrotron X-ray diffraction data. By cooling below the structural transition temperature splitting of the Bragg reflections was observed corresponding to four different twin domain orientations. A model was developed to quantify the distortion of the lattice from the position of the splitted reflections relative to each other. Constrained 2D-Cauchy fits of several splitted reflections provided positions of the reflections. The influence of the structural distortion was detectable already above the structural transition temperature hinting at fluctuations in the tetragonal phase.Comment: 6 pages, 6 figure

    Crystal structure of sodium (1S )-D-lyxit-1-ylsulfonate

    Get PDF
    The title compound, Na+·C5H11O8S- [systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate], is formed by reaction of D-lyxose with sodium bis­ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hy­droxy­methyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexa­coordination of sodium ions by O atoms, three of which are provided by a single D-lyxose-sulfonate unit and the other three by two sulfonate groups and one hy­droxy­methyl group, each from separate units of the adduct. Extensive inter­molecular O-H...O hydrogen bonding supplements this bonding network

    Crystal structure of potassium (1S)-D-lyxit-1-ylsulfonate monohydrate

    Get PDF
    The title compound, K+·C5H11O8S-·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate monohydrate], formed by reaction of D-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy­droxy­methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter­molecular O-H...O hydrogen bonding

    A landscape of repair

    Get PDF
    This paper reports on EPSRC-funded research that explores the role of repair in creating new models of sustainable business. In the lifecycle stage of repair we explore what 'broken' means and uncover the nature of local and dispersed repair activities. This in turn allows us to better understand how the relationship between products and people can help shape new modes of consumption. Therefore, narratives of repair are collected to identify diverse people-product interactions and illustrate the different characteristics of, and motivations for, repair. The paper proposes that mapping the different product-people interactions across the product lifecycle, particularly at the stage of fragile-functionality (performance or function failure, emotional disengagement, superseded technology) is important in understanding the potential for enduring products and their repair. Building a landscape of repair creates new opportunities for manufacture and for slowing resource loops across product lifetimes, which together provide a framework for a sufficiency-based model of production and consumption
    corecore