556 research outputs found

    Design and fabrication of a low cost implantable bladder pressure monitor

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    In the frame of the Flemish Community funded project Bioflex we developed and fabricated an implant for short term (< 7 days) bladder pressure monitoring, and diagnosis of incontinence. This implant is soft and flexible to prevent damaging the bladder's inner wall. It contains a standard flexible electronic circuit connected to a battery, which are embedded in surface treated silicone to enhance the biocompatibility and prevent salt deposition. This article describes the fabrication of the pill and the results of preliminary cytotoxicity tests. The electronic design and its tests, implantation and the result of the in-vivo experimentation will be presented in other articles

    Resonant tunneling diodes as sources for millimeter and submillimeter wavelengths

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    High-quality Resonant Tunneling Diodes have been fabricated and tested as sources for millimeter and submillimeter wavelengths. The devices have shown excellent I-V characteristics with peak-to-valley current ratios as high as 6:1 and current densities in the range of 50-150 kA/cm(exp 2) at 300 K. Used as local oscillators, the diodes are capable of state of the art output power delivered by AlGaAs-based tunneling devices. As harmonic multipliers, a frequency of 320 GHz has been achieved by quintupling the fundamental oscillation of a klystron source

    Evolution of the electronic structure with size in II-VI semiconductor nanocrystals

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    In order to provide a quantitatively accurate description of the band gap variation with sizes in various II-VI semiconductor nanocrystals, we make use of the recently reported tight-binding parametrization of the corresponding bulk systems. Using the same tight-binding scheme and parameters, we calculate the electronic structure of II-VI nanocrystals in real space with sizes ranging between 5 and 80 {\AA} in diameter. A comparison with available experimental results from the literature shows an excellent agreement over the entire range of sizes.Comment: 17 pages, 4 figures, accepted in Phys. Rev.

    Electronic structure and optical properties of ZnS/CdS nanoheterostructures

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    The electronic and optical properties of spherical nanoheterostructures are studied within the semi-empirical sp3s∗sp^{3}s^{*} tight-binding model including the spin-orbit interaction. We use a symmetry-based approach previously applied to CdSe and CdTe quantum dots. The complete one-particle spectrum is obtained by using group-theoretical methods. The excitonic eigenstates are then deduced in the configuration-interaction approach by fully taking into account the Coulomb direct and exchange interactions. Here we focus on ZnS/CdS, ZnS/CdS/ZnS and CdS/ZnS nanocrystals with particular emphasis on recently reported experimental data. The degree of carrier localization in the CdS well layer is analyzed as a function of its thickness. We compute the excitonic fine structure, i.e., the relative intensities of low-energy optical transitions. The calculated values of the absorption gap show a good agreement with the experimental ones. Enhanced resonant photoluminescence Stokes shifts are predicted.Comment: 6 pages, 4 Figures, revtex

    The war on street 'terror': why tackle anti-social behaviour?

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    This article examines the rationales of Dutch politicians for tackling the perceived pressing problem of 'anti-social behaviour' (ASB) and the question did they copy the British approach? The first part will describe in short the concept of policy transfer and the recent British fight against ASB. The focus will be on the introduction of the Anti-social Behaviour Order. The second part is an empirical study into the Dutch retreat from 'condoning' ASB, consisting of interviews with Dutch politicians focusing on their ideas for tackling ASB. Those are compared with the British's rationales. This kind of comparative elite ethnography is not common in criminology, but this article aims at providing evidence of its benefits. By answering the research question an insight into the origins of policy in the sphere of criminal justice can be obtained

    Single cell analysis of kynurenine and System L amino acid transport in T cells

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    Acknowledgements We thank Cantrell group members for their critical discussion of the data, the Biological Resources unit, Sarah Thomson (for rLM work) and the Flow Cytometry facility (A. Whigham and R. Clarke) at the University of Dundee. This work was supported by the Wellcome Trust (Principal Research Fellowship to D.A.C. 097418/Z/11/Z and 205023/Z/16/Z, and Wellcome Trust Equipment Award 202950/Z/16/Z).Peer reviewedPublisher PD
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