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Nanobiotechnology, IEE Proceedings -

Issue 1 • Date 5 Feb. 2004

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Displaying Results 1 - 4 of 4
  • Adaptive, integrated sensor processing to compensate for drift and uncertainty: a stochastic 'neural' approach

    Publication Year: 2004 , Page(s): 28 - 34
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1101 KB)  

    An adaptive stochastic classifier based on a simple, novel neural architecture - the Continuous Restricted Boltzmann Machine (CRBM) is demonstrated. Together with sensors and signal conditioning circuits, the classifier is capable of measuring and classifying (with high accuracy) the H+ ion concentration, in the presence of both random noise and sensor drift. Training on-line, the stochastic classifier is able to overcome significant drift of real incomplete sensor data dynamically. As analogue hardware, this signal-level sensor fusion scheme is therefore suitable for real-time analysis in a miniaturised multisensor microsystem such as a Lab-in-a-Pill (LIAP). View full abstract»

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  • Analysis of cellular structure by light scattering measurements in a new cytometer design based on a liquid-core waveguide

    Publication Year: 2004 , Page(s): 10 - 16
    Cited by:  Papers (1)  |  Patents (30)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (377 KB)  

    The results of applying a novel microfluidic optical cytometer to generate and observe the light scattered from biological cells over a wide range of angles are presented. This cytometer incorporates a waveguide that increases the intensity of the scattered light to the extent that an inexpensive digital camera can be used to detect the light over a large solid angle. This device was applied to yeast cells and latex beads and experimental data were compared with the results of a finite difference time-domain (FDTD) method of simulation. The simulated scattering patterns were calculated from reported values of optical parameters and are in good qualitative agreement with experiment. It is demonstrated that this system could be used to acquire information on the microstructure and potentially the nanostructure of cells. View full abstract»

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  • Kv channel S6 helix as a molecular switch: simulation studies

    Publication Year: 2004 , Page(s): 17 - 27
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (747 KB)  

    Ion channels form pores of nanoscopic dimensions in biological membranes and play a key role in the physiology of cells. The majority of ion channels are gated, i.e. they contain a molecular switch that allows a transition between a closed (functionally 'off') and open (functionally 'on') state. Comparison of crystal structures of potassium channels suggest that the gating mechanism of voltage-gated potassium (Kv) channels involves a key role for the pore-lining S6 helix. There is a conserved PVP sequence motif in the S6 helix. Molecular dynamics simulations are used here to explore the conformational dynamics of the S6 helix hinge in models of fragments of a Kv channel, namely an S5-P-S6 monomer and an (S5-P-S6)4 tetramer. The latter is a model of the complete pore-forming domain of a Kv channel. All models were simulated embedded in an octane slab (a simple membrane mimetic). The results of these simulations indicate that the PVP motif may form a molecular hinge, even when the S6 helix forms part of a more complex model. The conformational dynamics of S6 are modulated by the remainder of protein, but it remains flexible. These simulation results are compatible with a channel gating model in which S6 bends in the vicinity of the PVP motif in addition to the region around the conserved glycine (G466) that is N-terminal to the PVP motif. This model is supported by comparison of the Kv S6 models with the S6 helix of the bacterial KvAP channel crystal structure. Thus, K channel gating may depend on a complex nanoswitch with three rigid helical sections linked by two molecular hinges. View full abstract»

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  • The future of computing - new architectures and new technologies

    Publication Year: 2004 , Page(s): 1 - 9
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (305 KB)  

    All modern computers are designed using the 'von Neumann' architecture and built using silicon transistor technology. Both architecture and technology have been remarkably successful. Yet there are a range of problems for which this conventional architecture is not particularly well adapted, and new architectures are being proposed to solve these problems, in particular based on insight from nature. Transistor technology has enjoyed 50 years of continuing progress. However, the laws of physics dictate that within a relatively short time period this progress will come to an end. New technologies, based on molecular and biological sciences as well as quantum physics, are vying to replace silicon, or at least coexist with it and extend its capability. The paper describes these novel architectures and technologies, places them in the context of the kinds of problems they might help to solve, and predicts their possible manner and time of adoption. Finally it describes some key questions and research problems associated with their use. View full abstract»

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