Addition compounds of alkali metal hydrides—XIX: Rapid reaction of trialkylboranes with lithium aluminum hydride in the presence of triethylene-diamine. A facile and quantitative synthesis of lithium trialkylborohydrides,including derivatives with exceptionally large steric requirements

Trialkylboranes react rapidly with lithium alumimum hydride (LAH) in diethyl ether in the presence of triethylenediamine (TED) at 0° to form the corresponding lithium triakylborohydrides and aluminum hydride. The aluminum hydride precipitates out of solution as its triethylenediamine adduct. The reaction is applied to a wide variety of triakylboranes. Consequently, the present reaction provides a general, convenient synthesis of lithium trialkylborohydrides including those with exceptionally large steric requirements.     

Fundamental relationships between deformation-induced surface roughness,critical strain localisation and failure in AA5754-O

This research employs two approaches to characterise the apparent structure observed in localised strain maps constructed from surface topography data acquired from AA5754-O sheet stock that was deformed in three in-plane stretching modes. The first uses a conventional two-point autocorrelation function (ACF), while the second uses the combination of the eigenvalue spectrum associated with each map and information theory. The results from the ACF analysis are inconclusive, implying that this technique lacks the sensitivity necessary to quantify the relationships between multi-point clustering and strain localisation. The information theory-based approach reveals that the relative spectral entropy increases monotonically, attains a maximum and then decreases sharply to the failure strain. This behaviour occurs in all three strain modes and results from two competing processes: one where the formation of structure is favourable and one where it is not. The crossover point is a clear indicator of the onset of critical strain localisation and, therefore, can be regarded as a precursor to failure because once the dominant process shifts, additional strain results in the precipitate formation of a critical strain localisation event.     

Lessons for fragment library design: analysis of output from multiple screening campaigns

Over the past 8 years, we have developed, refined and applied a fragment based discovery approach to a range of protein targets. Here we report computational analyses of various aspects of our fragment library and the results obtained for fragment screening. We reinforce the finding of others that the experimentally observed hit rate for screening fragments can be related to a computationally defined druggability index for the target. In general, the physicochemical properties of the fragment hits display the same profile as the library, as is expected for a truly diverse library which probes the relevant chemical space. An analysis of the fragment hits against various protein classes has shown that the physicochemical properties of the fragments are complementary to the properties of the target binding site. The effectiveness of some fragments appears to be achieved by an appropriate mix of pharmacophore features and enhanced aromaticity, with hydrophobic interactions playing an important role. The analysis emphasizes that it is possible to identify small fragments that are specific for different binding sites. To conclude, we discuss how the results could inform further development and improvement of our fragment library. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Linking supply chain processes’ performance to a company’s financial strategic objectives

The main aim of this paper is to develop a performance measurement method which links supply chain (SC) processes’ performance to a company’s financial strategy through demonstrating and utilising the relationship between SC processes’ performance and a company’s financial performance.     

Angle independent ultrasonic blood flow detection by frame-to-frame correlation of B-mode images

We have previously reported initial clinical results of a novel blood velocity imaging technique utilizing a two-dimensional correlation search applied to consecutively acquired echoes. In this paper, we describe both the physical principles underlying this technique and test tank experiments which define its performance under a variety of conditions. The results indicate that, unlike Doppler flow imaging systems, this technique defines the flow velocity vector in two dimensions and is not subject to aliasing.     

Syntheses of metal carbonyls: XVII. Formation of a heteronuclear organometallic cluster containing ruthenium and rhodium; crystal and molecular structure of {[Rh(η-C5Me5)]3Ru(CO)3](μ3-CO)2}

Ru(C₆Me₆)(C₂H₄)₂ reacts with Rh(C₅Me₅)(CO)₂ to give the known dinuclear complex [Rh(C₅Me₅)(CO)]₂ and the new heteronuclear cluster complex {[Rh(C₅Me₅)]₃[Ru(CO)₃](μ₃-CO)₂} which has been fully characterized by a single crystal X-ray diffraction study.     

Mobility fluctuations and electrophoretic light scattering from macromolecular solutions

We discuss the origins and the effects of mobility fluctuations of rigid, globular macromolecules on a solution's electrophoretic light scattering spectrum. Assuming a dilute solution, a modified van Hove self-correlation function is calculated via van Kampen's time-ordered cumulant method and the results are compared with less rigorous approaches. The consequences of generalizing to dynamic external fields are briefly considered.