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Castaldo, V. (author), Withagen, J. (author), Hagen, C. (author), Kruit, P. (author), Van Veldhoven, E. (author)In recent years, novel ion sources have been designed and developed that have enabled focused ion beam machines to go beyond their use as nano-fabrication tools. Secondary electrons are usually taken to form images, for their yield is high and strongly dependent on the surface characteristics, in terms of chemical composition and topography. In...journal article 2011
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Bol, E. (author), Broers, N.J. (author), Hagen, W.R. (author)Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a homotetrameric protein with one tungstodipterin and one [4Fe–4S] cubane per 69-kDa subunit. The enzyme kinetics have been studied under steady-state conditions at 80 °C and pre-steady state conditions at 50 °C, in the latter case via monitoring of the relatively weak (? ? 2 mM...journal article 2007
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Sevcenco, A.M. (author), Bevers, L.E. (author), Pinkse, M.W.H. (author), Krijger, G.C. (author), Wolterbeek, H.T. (author), Verhaert, P.D.E.M. (author), Hagen, W.R. (author), Hagedoorn, P.L. (author)The hyperthermophilic archaeon Pyrococcus furiosus expresses five aldehyde oxidoreductase (AOR) enzymes, all containing a tungsto-bispterin cofactor. The growth of this organism is fully dependent on the presence of tungsten in the growth medium. Previous studies have suggested that molybdenum is not incorporated in the active site of these...journal article 2010
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Cook, B.J. (author), Verduin, T. (author), Hagen, C.W. (author), Kruit, P. (author)Emission theory predicts that high brightness cold field emitters can enhance imaging in the electron microscope. This (neglecting chromatic aberration) is because of the large (coherent) probe current available from a high brightness source and is based on theoretically determined values of reduced brightnesses up to 1014?A/(m2?sr?V). However,...journal article 2010
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- Van Dorp, W.F. (author), Crozier, P.A. (author), Hagen, C.W. (author), Kruit, P. (author) journal article 2005
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Overeijnder, M.L. (author), Hagen, W.R. (author), Hagedoorn, P.L. (author)Pyrococcus furiosus hybrid cluster protein (HCP) was expressed in Escherichia coli, purified, and characterized. This is the first archaeal and thermostable HCP to be isolated. Compared with the protein sequences of previously characterized HCPs from mesophiles, the protein sequence of P. furiosus HCP exhibits a deletion of approximately 13 kDa...journal article 2009
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Hagen, C.W. (author), Fokkema, E. (author), Kruit, P. (author)The virtual source size of a liquid metal ion source is an order of magnitude larger than the size of the region from which the ions are emitted at the source. This source size has a direct effect on the reduced brightness and, hence, on the performance of these sources. The variation of the virtual source size of a gallium liquid metal ion...journal article 2008
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- Pagonabarraga, I. (author), Hagen, M.H.J. (author), Lowe, C.P. (author), Frenkel, D. (author) journal article 1999
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Ebrahimi, K.H. (author), Hagedoorn, P.L. (author), Jongejan, J.A. (author), Hagen, W.R. (author)The hollow sphere-shaped 24-meric ferritin can store large amounts of iron as a ferrihydrite-like mineral core. In all subunits of homomeric ferritins and in catalytically active subunits of heteromeric ferritins a diiron binding site is found that is commonly addressed as the ferroxidase center (FC). The FC is involved in the catalytic Fe(II)...journal article 2009
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Sevcenco, A.M. (author), Paravidino, M. (author), Vrouwenvelder, J.S. (author), Wolterbeek, H.T. (author), Van Loosdrecht, M.C.M. (author), Hagen, W.R. (author)Oxo-anion binding properties of the thermostable enzyme ferritin from Pyrococcus furiosus were characterized with radiography. Radioisotopes 32P and 76As present as oxoanions were used to measure the extent and the rate of their absorption by the ferritin. Thermostable ferritin proved to be an excellent system for rapid phosphate and arsenate...journal article 2015
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Bevers, L.E. (author), Hagen, W.R. (author)Reversible binding of the tetrahedral oxoanions MoO4 2- and WO4 2- to two carboxylato ligands of the soluble scavenger protein WtpA from the hyperthermophilic archaeon Pyrococcus furiosus enforces a quasi-octahedral MO6 coordination in which the +VI oxidation state is destabilized.journal article 2009
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Botman, A. (author), Mulders, J.J.L. (author), Hagen, C.W. (author)The creation of functional nanostructures by electron-beam-induced deposition (EBID) is becoming more widespread. The benefits of the technology include fast ‘point-and-shoot’ creation of three-dimensional nanostructures at predefined locations directly within a scanning electron microscope. One significant drawback to date has been the low...journal article 2009
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Bevers, L.E. (author), Schwarz, G. (author), Hagen, W.R. (author)The essential trace compounds tungstate and molybdate are taken up by cells via ABC transporters. Despite their similar ionic radii and chemical properties, the WtpA protein selectively binds tungstate in the presence of molybdate. Using site-directed mutagenesis of conserved binding pocket residues, we established a molecular basis for...journal article 2011
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Castaldo, V. (author), Hagen, C.W. (author), Kruit, P. (author), Van Veldhoven, E. (author), Maas, D. (author)The determination of the quality of an imaging system is not an easy task for, in general, at least three parameters, strictly interdependent, concur in defining it: resolution, contrast, and signal-to-noise ratio. The definition of resolution itself in scanning microscopy is elusive and the case of scanning ion microscopy is complicated by the...journal article 2009
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Hari, S. (author), Hagen, C.W. (author), Verduin, T. (author), Kruit, P. (author)In a first study to analyze the feasibility of electron beam-induced deposition (EBID) for creating certain patterns in advanced lithography, line patterns were fabricated on silicon wafers using EBID. The growth conditions were such that the growth rate is fully determined by the electron flux (the current limited growth regime). It is...journal article 2014
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Sevcenco, A.M. (author), Krijger, G. (author), Pinkse, M. (author), Verhaert, P.D.E.M. (author), Hagen, W.R. (author), Hagedoorn, P.L. (author)A combination of techniques to separate and quantify the native proteins associated with a particular transition metal ion from a cellular system has been developed. The procedure involves four steps: (1) labeling of the target proteins with a suitable short-lived radioisotope (suitable isotopes are Cu-64, Cu-67, W-187, Mo-99, Zn-69, Mn-56, Ni...journal article 2009
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Hagen, C.W. (author), Kruit, P. (author)The authors have analyzed how much current can be obtained in the probe of an optimized two-lens focused ion beam (FIB) system. This becomes relevant, as systems become available that have the potential to image and/or fabricate structures smaller than 10 nm. The probe current versus probe size curves were calculated for a commercial gallium-FIB...journal article 2009
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Rosenberg, S.G. (author), Landheer, K. (author), Hagen, C.W. (author), Fairbrother, D.H. (author)Using three different precursors [MeCpPtMe3, Pt(PF3)4, and W(CO)6], an ultra-high vacuum surface science approach has been used to identify and rationalize the effects of substrate temperature and electron fluence on the chemical composition and bonding in films created by electron beam induced deposition (EBID). X-ray photoelectron spectroscopy...journal article 2012
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Zonnevylle, A.C. (author), Hagen, C.W. (author), Kruit, P. (author), Valenti, M. (author), Schmidt-Ott, A. (author)Positioning of charged nanoparticles with the help of charge patterns in an insulator substrate is a known method. However, the creation of charge patterns with a scanning electron microscope for this is relatively new. Here a scanning electron microscope is used for the creation of localized charge patterns in an insulator, while a glowing wire...journal article 2009
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Hagen, W.R. (author)EPR spectroscopy employs a resonator operating at a single microwave frequency and phase-sensitive detection using modulation of the magnetic field. The X-band spectrometer is the general standard with a frequency in the 9–10 GHz range. Most (bio)molecular EPR spectra are determined by a combination of the frequency-dependent electronic Zeeman...journal article 2013