Publications by authors named "Mark Platt"

Article Synopsis
  • Superconducting qubits can get messed up by tiny energy sources that break apart the pairs of particles needed for superconductivity, making a problem known as "quasiparticle poisoning."
  • Researchers found that a silicon crystal glued to its holder has way more low-energy sound events (called phonons) compared to a similar crystal that wasn't glued, which could affect how well these systems work.
  • The extra phonon events in the glued crystal get less frequent over time, suggesting that the stress from the glue is causing these disturbances and may be impacting other scientific devices too.
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Down syndrome (DS) is characterized by skeletal and brain structural malformations, cognitive impairment, altered hippocampal metabolite concentration and gene expression imbalance. These alterations were usually investigated separately, and the potential rescuing effects of green tea extracts enriched in epigallocatechin-3-gallate (GTE-EGCG) provided disparate results due to different experimental conditions. We overcame these limitations by conducting the first longitudinal controlled experiment evaluating genotype and GTE-EGCG prenatal chronic treatment effects before and after treatment discontinuation.

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Mutations of the human TRAFFICKING PROTEIN PARTICLE COMPLEX SUBUNIT 9 (TRAPPC9) cause a neurodevelopmental disorder characterised by microcephaly and intellectual disability. Trappc9 constitutes a subunit specific to the intracellular membrane-associated TrappII complex. The TrappII complex interacts with Rab11 and Rab18, the latter being specifically associated with lipid droplets (LDs).

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The immunomodulatory properties of MSCs can be recreated using their extracellular vesicles (EVs). Yet, the true capabilities of the MSC EVs cannot be distinguished from contaminating bovine EVs and protein derived from supplemental foetal bovine serum (FBS). FBS EV depletion protocols can minimise this, but vary in terms of depletion efficiency, which can negatively impact the cell phenotype.

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Age-related macular degeneration (AMD) is a leading cause of blindness. Vision loss is caused by the retinal pigment epithelium (RPE) and photoreceptors atrophy and/or retinal and choroidal angiogenesis. Here we use AMD patient-specific RPE cells with the Complement Factor H Y402H high-risk polymorphism to perform a comprehensive analysis of extracellular vesicles (EVs), their cargo and role in disease pathology.

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Changes in glioblastoma (GBM) metabolism was investigated in response to JAS239, a choline kinase inhibitor, using MRS. In addition to the inhibition of phosphocholine synthesis, we investigated changes in other key metabolic pathways associated with GBM progression and treatment response. Three syngeneic rodent models of GBM were used: F98 (N = 12) and 9L (N = 8) models in rats and GL261 (N = 10) in mice.

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Resistive pulse sensors have been used to characterise everything from whole cells to small molecules. Their integration into microfluidic devices has simplified sample handling whilst increasing throughput. Typically, these devices measure a limited size range, making them prone to blockages in complex sample matrixes.

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A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing (RPS) for the rapid (≤20 min) and label free detection of small molecules. The surface of a magnetic nanocarrier was first modified with a ssDNA (anchor) which is designed to be partially complimentary in sequence to the ssDNA aptamer. The aptamer and anchor form a stable dsDNA complex on the nanocarriers surface.

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DNAzymes are DNA oligonucleotides that can undergo a specific chemical reaction in the presence of a cofactor. Ribonucleases are a specific form of DNAzymes where a tertiary structure undergoes cleavage at a single ribonuclease site. The cleavage is highly specificity to co-factors, which makes them excellent sensor recognition elements.

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Single-cell gene expression is inherently variable, but how this variability is controlled in response to stimulation remains unclear. Here, we use single-cell RNA-seq and single-molecule mRNA counting (smFISH) to study inducible gene expression in the immune toll-like receptor system. We show that mRNA counts of tumor necrosis factor α conform to a standard stochastic switch model, while transcription of interleukin-1β involves an additional regulatory step resulting in increased heterogeneity.

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Technologies that can detect and characterize particulates in liquids have applications in health, food, and environmental monitoring. Simply counting the numbers of cells or particles is not sufficient for most applications; other physical properties must also be measured. Typically, it is necessary to compromise between the speed of a sensor and its chemical and biological specificity.

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The interface between two immiscible liquids represent an ideal substrate for the assembly of nanomaterials. The defect free surface provides a reproducible support for creating densely packed ordered materials. Here a droplet flow reactor is presented for the synthesis and/or assembly of nanomaterials at the interface of the emulsion.

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Prion diseases are a group of fatal transmissible neurological conditions caused by the change in conformation of intrinsic cellular prion protein (PrP). We present a rapid assay using aptamers and resistive pulse sensing, RPS, to extract and quantify PrP from complex sample matrices. We functionalise the surface of superparamagnetic beads, SPBs, with a DNA aptamer.

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The use of nanocarriers within resistive pulse sensing facilitates the detection and quantification of analytes. To date the field has been dominated by polyionic carriers or nanomaterials. Together they combine the recognition elements of a ligand with a stable support, facilitating the sample handling, analysis times, and multiplex detection.

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Article Synopsis
  • Raman spectroscopy was used to analyze urinary extracellular vesicles (UEVs) and endothelium-derived extracellular vesicles (EVs), revealing distinct differences in the fingerprints of UEVs, particularly in diabetic samples.
  • Cluster analysis showed that UEVs can differentiate between diabetic patients and control groups, while endothelium-derived EVs displayed similar patterns between long and short hyperglycemia.
  • This study highlights Raman spectroscopy's potential as a noninvasive method for identifying molecular signatures in urine, aiding in the discovery of new diabetes-related biomarkers and assessing renal complications.
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Resistive pulse sensors (RPSs) provide detailed characterization of materials from the nanoparticle up to large biological cells on a particle-to-particle basis. During the RPS experiment, particles pass through a channel or pore that conducts ions, and the change in the ionic current versus time is monitored. The change in current during each translocation, also known as a "pulse", is dependent on the ratio of the particle and channel dimensions.

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Extracellular vesicles (EVs) have prevalent roles in cancer biology and regenerative medicine. Conventional techniques for characterising EVs including electron microscopy (EM), nanoparticle tracking analysis (NTA) and tuneable resistive pulse sensing (TRPS), have been reported to produce high variability in particle count (EM) and poor sensitivity in detecting EVs below 50 nm in size (NTA and TRPS), making accurate and unbiased EV analysis technically challenging. This study introduces direct stochastic optical reconstruction microscopy (d-STORM) as an efficient and reliable characterisation approach for stem cell-derived EVs.

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Mammalian sperm undergo a series of biochemical and physiological changes collectively known as capacitation in order to acquire the ability to fertilize. Although the increase in phosphorylation associated with mouse sperm capacitation is well established, the identity of the proteins involved in this signaling cascade remains largely unknown. Tandem mass spectrometry (MS/MS) has been used to identify the exact sites of phosphorylation and to compare the relative extent of phosphorylation at these sites.

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Aptamer-modified nanomaterials provide a simple, yet powerful sensing platform when combined with resistive pulse sensing technologies. Aptamers adopt a more stable tertiary structure in the presence of a target analyte, which results in a change in charge density and velocity of the carrier particle. In practice the tertiary structure is specific for each aptamer and target, and the strength of the signal varies with different applications and experimental conditions.

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Article Synopsis
  • Many diseases are linked to specific patterns of DNA methylation that affect gene expression.
  • A new rapid assay using resistive pulse sensing enables detailed analysis of DNA methylation sites without needing precise DNA sequencing.
  • This method allows for quick, low-cost detection of methylation patterns and even quantifies the amount of methylated DNA in under 60 minutes.
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Article Synopsis
  • - A new method has been developed to quickly synthesize single crystal gold particles (both spherical and nonspherical) using various liquid phases and the reducing agent decamethylferrocene (DmFc) at room temperature.
  • - The process takes advantage of a microfluidic chip to create emulsion droplets, allowing control over droplet number, size, and reactant concentration, which determines the size and shape of the resulting gold nanoparticles (AuNP).
  • - By adjusting reaction conditions and adding other nanoparticles, this technique enables the production of core@shell particles, suggesting its potential for large-scale manufacturing of complex nanoparticle structures.
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The aim of this study was to check the relationship between the density of urinary EVs, their size distribution, and the progress of early renal damage in type 2 diabetic patients (DMt2). Patients were enrolled to this study, and glycated hemoglobin (HbA1c) below 7% was a threshold for properly controlled diabetic patients (CD) and poorly controlled diabetic patients (UD). Patients were further divided into two groups: diabetic patients without renal failure (NRF) and with renal failure (RF) according to the Glomerular Filtration Rate.

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Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and nanoparticles. Tunable resistive pulse sensing (TRPS) is a relatively recent adaptation to RPS that incorporates a tunable pore that can be altered in real time. Here, we use TRPS to monitor the translocation times of DNA-modified nanoparticles as they traverse the tunable pore membrane as a function of DNA concentration and structure (i.

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