Research
Our research aims to unravel the structure and dynamics of biological systems using various experimental and theoretical approaches. Here we present the researchers of the network and the research in progress.
Carl Caleman
Carl Caleman is a professor at the Division of X-ray Photon Science and also employed at the Center for Free-electron Laser Science in Hamburg. His research group focuses on three main directions
- Radiation damage on biological samples, induced by the intense X-ray pulses from Free Electron Laser, using both experiments and simulations (Molecular Dynamics, Non-thermal Equilibrium and Density Functional Theory) to understand what happens to matter as it is exposed to the extreme ionization caused by FEL pulse in coherent imaging experiments.
- Interaction of electric fields on gas phase proteins: In order to improve Single Particle Imaging using FEL pulses, exploring the possibilities to use external electric fields to orient and manipulate gas phase proteins. This is mainly done using Molecular Dynamics simulations, and collaborators are developing devices to test these ideas experimentally at the European XFEL in Hamburg.
- Ions and organic molecules at the water interfaces. Many chemical processes in the atmosphere are related to the surface concentration of ions and organic molecules on small water droplets. Using Molecular Dynamics as well as X-ray Photoelectron Spectroscopy, we try to understand how temperature, pH, and chemical composition affects the surface activity of ions and organic molecules.
Tomas Ekeberg
Tomas Ekeberg is a researcher in Molecular Biophysics and his goal is to use the remarkable X-ray free electron laser facilities to study the constituents of life in new ways. Proteins are, in most cases, highly dynamic particles that exert their function by transitioning between many semi-stable conformations. In many cases these transitions are much faster than a millisecond and are very hard to study with current methods.
One of our goals is to utilize the ultra-fast pulse-length of free-electron lasers together with new algorithms to pick out diffraction from these short-lived states among a much larger set of data. In this pursuit we perform experiments at free-electron laser facilities across the world and study and develop the analysis algorithms that are required to filter and combine the large datasets required. The result is an interdisciplinary group that combines biology and physics, theory and experiment to develop the imaging methods of the future.
Filipe Maia
Filipe Maia is a Professor in Molecular Biophysics with specialization in coherent imaging with X-ray lasers. He develops lensless imaging methods, making use of X-ray free-electron lasers, to explore the wonderfully complex world of biological structural dynamics at the nanoscale. His projects span X-ray single particle diffractive imaging, fluctuation X-ray scattering and X-ray ptychography.
Erik Marklund
Erik Marklund is a researcher in Biochemistry and his research aims to unravel the dynamics and interactions of proteins and protein complexes. To this end, he works from a foundation of advanced computations that are matched with experiments, where mass-spectrometric techniques such as ion-mobility spectrometry currently are of particular interest. The latter also motivates to investigate the fundamentals of gas-phase proteins and how to keep them native-like in the absence of solvent. The research span from the technically oriented, where we explore new means to interrogate macromolecules, to application to specific biological systems.
Nicusor Timneanu
Nicusor Timneanu is an Associate Professor at the Division of X-ray Photon Science and a guest researcher in the Laboratory of Molecular Biophysics, with a keen interest in studying light-matter interaction and X-ray lasers. With their intense and short coherent pulses, X-ray lasers can be used to study the structure of biological systems, complex materials and even create and probe extreme states of matter. He uses both experiments and theoretical simulations to investigate the ultrafast electron and atomic dynamics of biological samples.
X-ray lasers are creating new capabilities in understanding the structure of biological systems, complex materials and matter under extreme conditions. Extremely intense coherent X-ray pulses can be exploited to create and probe extreme states of matter, and also hold promise for structural determination of single macromolecules. Nicusor uses the extremely short X-ray pulses to flash-image living cells, viruses, protein nanocrystals, and will ultimately investigate single protein macromolecules. All the samples exposed to these brilliant sources turn rapidly into plasma, offering us tantalizing possibilities to study fundamental physics problems in the high-energy density regime.
Malin Wohlert
Malin Wohlert is an Associate Professor at the Division of Applied Mechanics, Department of Materials Science and Engineering under the Department of Materials Science and Engineering. Her main research interest is modeling and understanding of biomaterials such as wood in both native and processed state.
The purpose of the modeling efforts vary from developing new biobased materials, refining existing processes in pulp and paper industry or to engineer new materials through biomimetics. By modeling constituents of wood - cellulose, lignin and hemicelluloses - at the atomistic scale with Molecular Dynamics simulations and combine the theoretical work with experiments important insights in the material's structure and physical properties are obtained. Since wood is a material with structure at several length scales, the results at molecular scale are also transferred to larger scale models in order to study properties such as mass transport within the kraft process.