Unidirectional transport of superparamagnetic beads and biological cells along oval magnetic elements

Prion diseases are a group of fatal transmissible neurological conditions caused by the change in conformation of the normal intrinsic cellular prion protein (PrPC) in to the highly ordered insoluble amyloid state conformer (PrPSC). We present a rapid assay using Aptamers and Resistive Pulse Sensing, RPS, to extract and quantify proteins from complex sample matrices, demonstrate with the quantification of PrPc. We functionalise the surface of superparamagnetic beads, SPBs, with a DNA aptamer. First SPB’s termed P-Beads, are used to pre-concentrate the analyte from a large sample volume. The PrPc protein is then eluted from the P-Beads before aptamer modified sensing beads, S-Beads, are added. The velocity of the S-Beads through the nanopore reveals the concentration of the PrPc protein. The process is done in under an hour and allows the detection of picomol’s of protein. The technique could be easily adopted to the mutated version of the protein and integrated into clinical workflows for the screening of blood donations and transfusions.

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Faculty Opinions recommendation of Macroscopic dynamics of biological cells interacting via chemotaxis and direct contact.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1161686.623269 ◽

2009 ◽

Author(s):

Philip Maini ◽

Alexander Fletcher

Keyword(s):

Direct Contact ◽

Biological Cells

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An Algorithm for the Removal of Cosmic Ray Artifacts in Spectral Data Sets

Applied Spectroscopy ◽

10.1177/0003702819839098 ◽

2019 ◽

Vol 73 (8) ◽

pp. 893-901

Author(s):

Sinead J. Barton ◽

Bryan M. Hennelly

Keyword(s):

Cosmic Ray ◽

Data Sets ◽

Biological Cells ◽

Statistical Classification ◽

Signal To Noise ◽

Multivariate Statistical ◽

Data Set ◽

Artefact Removal ◽

Single Capture ◽

Acquisition Method

Cosmic ray artifacts may be present in all photo-electric readout systems. In spectroscopy, they present as random unidirectional sharp spikes that distort spectra and may have an affect on post-processing, possibly affecting the results of multivariate statistical classification. A number of methods have previously been proposed to remove cosmic ray artifacts from spectra but the goal of removing the artifacts while making no other change to the underlying spectrum is challenging. One of the most successful and commonly applied methods for the removal of comic ray artifacts involves the capture of two sequential spectra that are compared in order to identify spikes. The disadvantage of this approach is that at least two recordings are necessary, which may be problematic for dynamically changing spectra, and which can reduce the signal-to-noise (S/N) ratio when compared with a single recording of equivalent duration due to the inclusion of two instances of read noise. In this paper, a cosmic ray artefact removal algorithm is proposed that works in a similar way to the double acquisition method but requires only a single capture, so long as a data set of similar spectra is available. The method employs normalized covariance in order to identify a similar spectrum in the data set, from which a direct comparison reveals the presence of cosmic ray artifacts, which are then replaced with the corresponding values from the matching spectrum. The advantage of the proposed method over the double acquisition method is investigated in the context of the S/N ratio and is applied to various data sets of Raman spectra recorded from biological cells.

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