20 research outputs found

    Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films

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    We show that thin films of C60 with a thickness ranging from 10 to 100 nm can promote adhesion between a Au thin film deposited on mica and a solution-deposited layer of the elastomer polymethyldisolaxane (PDMS). This molecular adhesion facilitates the removal of the gold film from the mica support by peeling and provides a new approach to template stripping which avoids the use of conventional adhesive layers. The fullerene adhesion layers may also be used to remove organic monolayers and thin films as well as two-dimensional polymers which are pre-formed on the gold surface and have monolayer thickness. Following the removal from the mica support the monolayers may be isolated and transferred to a dielectric surface by etching of the gold thin film, mechanical transfer and removal of the fullerene layer by annealing/dissolution. The use of this molecular adhesive layer provides a new route to transfer polymeric films from metal substrates to other surfaces as we demonstrate for an assembly of covalently-coupled porphyrins

    Who Controls the Looking Glass? Towards a Conversational Understanding of Organizational Theatre

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    This paper presents a longitudinal study of interactive organizational theatre. Managers of a large home care organization used 30 instances of organizational theatre over a one year period to effect organizational change. We found that neither management, who had hoped that employees would accept and internalize the messages accompanying the play, nor employees, who used the liminal spaces to express their own take on the organization’s issues, achieved their aims directly. Yet a year later, organizational performance and satisfaction were significantly improved—much of this was attributed to the play. To explain this, we develop a conversational theory of change, one where ‘conversation pieces’ are central. We also speculate on the properties that conversation pieces and conversational systems like organizational theatre must have if they are to effect change.N/

    Influence of molecular design on radical spin multiplicity: characterisation of BODIPY dyad and triad radical anions

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    This journal is © the Owner Societies. A strategy to create organic molecules with high degrees of radical spin multiplicity is reported in which molecular design is correlated with the behaviour of radical anions in a series of BODIPY dyads. Upon reduction of each BODIPY moiety radical anions are formed which are shown to have different spin multiplicities by electron paramagnetic resonance (EPR) spectroscopy and distinct profiles in their cyclic voltammograms and UV-visible spectra. The relationship between structure and multiplicity is demonstrated showing that the balance between singlet, biradical or triplet states in the dyads depends on relative orientation and connectivity of the BODIPY groups. The strategy is applied to the synthesis of a BODIPY triad which adopts an unusual quartet state upon reduction to its radical trianion

    The practice of 'doing' evaluation: Lessons learned from nine complex intervention trials in action

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    Background: There is increasing recognition among trialists of the challenges in understanding how particular 'real-life' contexts influence the delivery and receipt of complex health interventions. Evaluations of interventions to change health worker and/or patient behaviours in health service settings exemplify these challenges. When interpreting evaluation data, deviation from intended intervention implementation is accounted for through process evaluations of fidelity, reach, and intensity. However, no such systematic approach has been proposed to account for the way evaluation activities may deviate in practice from assumptions made when data are interpreted.Methods: A collective case study was conducted to explore experiences of undertaking evaluation activities in the real-life contexts of nine complex intervention trials seeking to improve appropriate diagnosis and treatment of malaria in varied health service settings. Multiple sources of data were used, including in-depth interviews with investigators, participant-observation of studies, and rounds of discussion and reflection.Results and discussion: From our experiences of the realities of conducting these evaluations, we identified six key 'lessons learned' about ways to become aware of and manage aspects of the fabric of trials involving the interface of researchers, fieldworkers, participants and data collection tools that may affect the intended production of data and interpretation of findings. These lessons included: foster a shared understanding across the study team of how individual practices contribute to the study goals; promote and facilitate within-team communications for ongoing reflection on the progress of the evaluation; establish processes for ongoing collaboration and dialogue between sub-study teams; the importance of a field research coordinator bridging everyday project management with scientific oversight; collect and review reflective field notes on the progress of the evaluation to aid interpretation of outcomes; and these approaches should help the identification of and reflection on possible overlaps between the evaluation and intervention.Conclusion: The lessons we have drawn point to the principle of reflexivity that, we argue, needs to become part of standard practice in the conduct of evaluations of complex interventions to promote more meaningful interpretations of the effects of an intervention and to better inform future implementation and decision-making. © 2014 Reynolds et al.; licensee BioMed Central Ltd

    Synthesis and analysis of fluorescent dye molecules

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    The nature of non-covalent bonding interactions was investigated through the deposition and subsequent scanning tunnelling microscopy (STM) imaging of tetra-substituted porphyrins. Porphyrins bearing iodo, bromo, nitro, pyridyl and carboxylic acid groups were synthesised and deposited on either Au(110) or Au(l11). STM imaging and analysis showed a variety of different orientations and packing for the different functional groups. The unusual tip induced growth of honeycomb packing orientations was seen for tetra-pyridyl substituted porphyrin. Tetra-bromo substituted porphyrin was observed to adopt different ordered orientations of the saddle shape conformation on Au(111). The synthesis of novel porphyrin dimers bearing carboxylic acid groups was investigated, with a variety of different pathways being identified and explored. Furthermore, upon cooling unusual spectroscopic behaviour was observed for a hexa-phenyl substituted meso-linked porphyrin dim er. The synthesis of novel BODIPY dimers and trimers was investigated. A number of fluoro and catecholate substituted BODIPY compounds were synthesised, bearing a variety of different linkers. Linkers investigated included phenyl, biphenyl, terphenyl, durene and terphenylene. Electrochemical and spectroscopic investigations demonstrated a variety of differences between meta- and para-substitution positions. The extension of the linker length from phenyl through to terphenyl displayed a reduction in communication of BODIPY moieties. The durene linked dimer added steric bulk to the centre of the BODIPY dimer, resulting in increased fluorescence lifetimes and quantum yields. 1EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Influence of molecular design on radical spin multiplicity: characterisation of BODIPY dyad and triad radical anions

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    A strategy to create organic molecules with high degrees of radical spin multiplicity is reported in which molecular design is correlated with the behaviour of radical anions in a series of BODIPY dyads. Upon reduction of each BODIPY moiety radical anions are formed which are shown to have different spin multiplicities by electron paramagnetic resonance (EPR) spectroscopy and distinct profiles in their cyclic voltammograms and UV-visible spectra. The relationship between structure and multiplicity is demonstrated showing that the balance between singlet, biradical or triplet states in the dyads depends on relative orientation and connectivity of the BODIPY groups. The strategy is applied to the synthesis of a BODIPY triad which adopts an unusual quartet state upon reduction to its radical trianion
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