Publications by authors named "J C Prangsma"

The Timepix (TPX) is a position- and time-sensitive pixelated charge detector that can be coupled with time-of-flight mass spectrometry (TOF MS) in combination with microchannel plates (MCPs) for the spatially and temporally resolved detection of biomolecules. Earlier generation TPX detectors used in previous studies were limited by a moderate time resolution (at best 10 ns) and single-stop detection for each pixel that hampered the detection of ions with high mass-to-charge (/) values at high pixel occupancies. In this study, we have coupled an MCP-phosphor screen-TPX3CAM detection assembly that contains a silicon-coated TPX3 chip to a matrix-assisted laser desorption/ionization (MALDI)-axial TOF MS.

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Worldwide, farmers use insecticides to prevent crop damage caused by insect pests, while they also rely on insect pollinators to enhance crop yield and other insect as natural enemies of pests. In order to target pesticides to pests only, farmers must know exactly where and when pests and beneficial insects are present in the field. A promising solution to this problem could be optical sensors combined with machine learning.

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Article Synopsis
  • The study investigates the fluorescence quantum yields of four red fluorescent proteins (mCherry, mKate2, mRuby2, and mScarlet) by measuring excited state lifetimes near a gold mirror to control the local density of optical states.
  • The analysis reveals the bright state quantum yield of these proteins is significantly higher than previous reports, emphasizing that mCherry, mKate2, and mRuby2 have up to 45% dark chromophores.
  • In contrast, mScarlet shows a much lower dark fraction (14%) and a high bright state quantum yield of 81%, suggesting that reducing dark chromophores is crucial for optimizing red fluorescent proteins in various applications.
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We present a dual-wavelength polarimetric measurement method to distinguish species and sexes of disease transmitting mosquitoes in flight. By measuring co- and de-polarized backscattered light at 808 and 1550 nm, the degree of linear polarization, wingbeat frequency, reflectance, spectral ratio and glossiness of mosquitoes can be retrieved. Body and wing contributions to these signals can be separated.

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We report oriented immobilization of proteins using the standard hexahistidine (His)-Ni:NTA (nitrilotriacetic acid) methodology, which we systematically tuned to give control of surface coverage. Fluorescence microscopy and surface plasmon resonance measurements of self-assembled monolayers (SAMs) of red fluorescent proteins (TagRFP) showed that binding strength increased by 1 order of magnitude for each additional His-tag on the TagRFP proteins. All TagRFP variants with His-tags located on only one side of the barrel-shaped protein yielded a 1.

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