Research and people

Carl Caleman

Professor Carl Caleman is employed at the division of X-ray Photon Science, Department of Physics and Astronomy and at the Centre for Free-Electron Laser Science in Hamburg. He is coordinator for the Biophysics network and his research focuses on X-ray matter interaction and bio imaging.

• Radiation damage on biological samples, induced by the intense X-ray pulses from free-electron lasers, 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 intense photon pulses, and how the damage can be used for improving single protein imaging.
• Interaction of electric fields with gas-phase proteins. In order to improve Single Particle Imaging using FEL pulses, the group explores the possibilities of using external electric fields to orient and manipulate gas-phase proteins. This is mainly done using Molecular Dynamics simulations, while collaborators develop devices to test these ideas experimentally at the European XFEL in Hamburg.
• Ions and organic molecules at 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, the group aims to understand how temperature, pH and chemical composition affect the surface activity of ions and organic molecules.

Erik Marklund

Researcher Erik Marklund from Biochemistry, Department of Chemistry - BMC is the deputy coordinator for the network.

• 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 are of particular interest. This also motivates investigations of the fundamentals of gas-phase proteins and how to keep them native-like in the absence of solvent. The research spans from technically oriented work, exploring new means to interrogate macromolecules, to applications in specific biological systems.

Olle Björneholm

Professor Olle Björneholm from the division of X-ray Photon Science, Department of Physics and Astronomy, is a director of the Centre for Photon Science and has a keen interest in phenomena and processes connected to the electronic and geometric structure of liquids and clusters/nanoparticles, including x-ray-induced dynamics

Filipe Maia

Professor Filipe Maia from Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology

• He develops lensless imaging methods, making use of X-ray free-electron lasers, to explore the 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.

Kenta Okamoto

Dr. Kenta Okamoto from Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, aims to unveil new functional structural features of problematic viruses using cryo-EM single particle analysis.

Nicusor Timneanu

Nicusor Timneanu is a professor at the X-ray Photon Science, Department of Physics and Astronomy and a guest researcher in the Laboratory of Molecular Biophysics, with a keen interest in studying light-matter interaction and X-ray lasers.

• His research interest is 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 and complex materials, and to 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 for 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 extremely short X-ray pulses to flash-image living cells, viruses and protein nanocrystals, with the ultimate goal of investigating single protein macromolecules. Samples exposed to these brilliant sources rapidly turn into plasma, offering possibilities to study fundamental physics problems in the high-energy-density regime.

Malin Wohlert

Associate Professor Malin Wohlert from Applied Mechanics, Department of Materials Science and Engineering, main research interest is modeling and understanding of biomaterials such as wood in both native and processed state.

• The purpose of the modelling efforts varies from developing new biobased materials and refining existing processes in the pulp and paper industry to engineering new materials through biomimetics. By modelling constituents of wood — cellulose, lignin and hemicelluloses — at the atomistic scale with Molecular Dynamics simulations and combining the theoretical work with experiments, important insights into the material's structure and physical properties are obtained. Since wood has structure at several length scales, results at the molecular scale are also transferred to larger-scale models to study properties such as mass transport within the kraft process.

Ralph Scheicher

Dr. Ralph Scheicher from the Division of Materials Theory, Department of Physics and Astronomy, studies systems from the area of nanobiotechnology using atomistic computational materials science methods, such as molecular dynamics simulations. His research focuses on exploring nanopore-based approaches to sequence individual DNA and protein molecules.

• When it comes to biophysics, his research interest is focused on how to utilize nano-materials to electrically sense individual bio-molecules. In particular, the goal is to achieve sequencing of single proteins as they are translocated through a nanopore in aqueous solution with ions present. To reach this goal, a better understanding is required of the complex interplay of proteins and the various types of nanopores. For that reason, Dr. Scheicher is conducting research that utilizes atomistic computational modelling, such as molecular dynamics simulations, to study advanced nano-architectures interacting with proteins. - More information is available on his research group homepage.

Alumni

Tomas Ekeberg

Dr. Tomas Ekeberg was a researcher in Molecular Biophysics. His research focused on using X-ray free-electron laser facilities to study biological structures and on developing methods for extracting information about short-lived protein conformations from large diffraction datasets.

• His work combined experiments at free-electron laser facilities with the development of analysis algorithms required to filter and combine large datasets. This interdisciplinary research brought together biology and physics, theory and experiment, to develop new X-ray imaging methods.