Research highlights
To study the biological function of a protein, knowing the sequence of the hundreds of amino acids it contains is essential. Mass spectrometry is widely used to identify this sequence. The protein of interest is first dissociated into small peptides. Thousands of peptides can be introduced to the mass spectrometer. Powerful algorithms can match the data from possible peptide sequences in databases.
30 November 2018
Optically pumped lasers can create intense, coherent beams of light using two different mechanisms: inversion based and inversionless. Time-resolved spectroscopy reveals that the system rapidly alternates between the two lasing mechanisms. Theoretical modelling shows that this behaviour arises from the ultrafast evolution of electron populations among all three energy levels. The change in the contribution to the total laser output from a particular mechanism occurs within just a few picoseconds. This research might stimulate searches for similar simultaneous lasing mechanisms in other media.
22 October 2018
FELIX researchers Anouk Rijs en Sjors van Bakel investigated, in collaboration with Florian Hirsch, Philipp Constantinidis and Ingo Fisher(University of Würzburg), the chemistry of reactive intermediates that are of relevance in combustion processes and in atmospheric chemistry.
10 July 2018
Together with researchers at the Radboud university medical centre, our colleagues Jonathan Martens, Giel Berden and Jos Oomens pointed out that infrared ion spectroscopy has the potential to play a pivotal role in the identification of challenging biomarkers.
10 July 2018
Glycosyl cations, including the elusive oxocarbenium ion, have been experimentally formed and structurally characterized for the first time by combining tandem mass spectrometry and IR ion spectroscopy using the free electron laser FELIX and quantum chemical calculations.
20 April 2018
The combined research team of the High Field Magnet Laboratory and the FELIX laboratory has observed magnetoquantum oscillations at THz frequencies in a doped semiconductor. Those results have been obtained by measuring the transmission of free electron laser radiation through a InSb sample in magnetic fields up to 33 T. Most remarkably, at frequencies above 0.9 THz, when the radiation period is shorter than the electronic scattering time, an anomalously high transmission is observed that can be interpreted as carrier localization at high frequencies. These findings have been reported in Physical Review Letters on October 6th, 2017.
10 October 2017
A prerequisite for a catalyst that can chemically transform methane in larger hydrocarbons is that it weakens or breaks one C-H bond, but leaves other bonds intact. A team of researchers from the universities of Ulm (Germany), Georgia Tech (US) and Nijmegen used FELIX to find that gold clusters selectively break one CH bond in methane. Their work recently appeared in Angewandte Chemie.
27 September 2017
A team of researchers from the FELIX Laboratory (the Netherlands), the National Physical Laboratory (UK), University College London (UK), Heriot Watt University (UK), and ETH Zurich, EPF Lausanne and Paul Scherrer Institut (Switzerland) have demonstrated THz laser pulse control of Si:P orbitals using multiple orbital state admixtures, observing beat patterns produced by Zeeman splitting. This study is recently published in Nature Communications.
13 September 2017
Researchers at the FELIX laboratory have identified systematic shifts the frequencies of three hydrogen bond vibrational modes, representing the inter- and intramolecular hydrogen bond strength. These hydrogen bond (H-bond) deforming modes are measured via the infrared spectra of isolated clusters of saligenin with water molecules, which exhibit intra- and intermolecular hydrogen bonds. In cooperation with groups at the University of Wisconsin-Madison (USA) and the Université d'Evry val d'Esonne (France), advanced, anharmonic calculations were applied to identify the three dimensional structures of the clusters, and the spectral signatures of the hydrogen bonds.
14 August 2017
A team of researchers from the FELIX Laboratory in Nijmegen and the universities of Cologne (D) and Sheffield (UK) have now uncovered a particularly clear example of room-temperature tunneling of a hydrogen atom in an isolated system. This study is recently published in the Journal of American Chemical Society.
18 April 2017