Dr. Sergey Korchak, Dr. Stefan Glöggler, and Dr. Anil Jagtap (from left) with their home-made portable MRI unit. Frederik Köpper. Max Planck Institute for Biophysical Chemistry

Magnetic resonance imaging (MRI) is indispensable in medical diagnostics. However, MRI units are large and expensive to acquire and operate. With smaller and cost-efficient systems, MRI would be more flexible and more people could benefit from the technique. Such mini MRI units generate a much weaker signal that is difficult to analyze, though. Researchers at the Max Planck Institute (MPI) for Biophysical Chemistry and the Center for Biostructural Imaging of Neurodegeneration have now developed a method amplifying the signal so much that they could monitor a metabolic reaction in real time with a miniature MRI. This is an important contribution to making flexible small MRI devices usable.

Photons in a cavity can be equipped with particular properties to control the resulting light-matter hybrid states and could be specifically designed to break specific symmetries. Umberto de Giovannini / Hannes Hübener, MPSD

Crystal symmetry is one of the decisive physical attributes that determines the properties of a material. In particular, the behaviour of an electron is largely affected by the symmetry of the crystal which in turn governs the fundamental behaviour of the material, such as its conductive or optical properties. With recent developments of experimental techniques and advances in ultrafast laser experiments, another symmetry besides the crystal has turned out to influence the electrons: the symmetry of light.

Fig. 1: (a) Rotational excitation of H2 in the pump pulse: starting the "internal clock". (b) The two possible mechanisms of molecular cleavage (ATD and EI) in the probe pulse and detection of the fragments. MPIK

Using a new method, physicists at the Heidelberg Max Planck Institute for Nuclear Physics have investigated the ultrafast fragmentation of hydrogen molecules in intense laser fields in detail. They used the rotation of the molecule triggered by a laser pulse as an "internal clock" to measure the timing of the reaction that takes place in a second laser pulse in two steps. Such a “rotational clock” is a general concept applicable to sequential fragmentation processes in other molecules. [Physical Review Letters, Oct 23rd 2020]

Cryo-EM visualizes individual atoms in a protein for the first time. The cartoon shows a part of the apoferritin protein (yellow) with a tyrosine side chain highlighted in grey. Atoms are individually recognizable (red grid structures). © Holger Stark / Max Planck Institute for Biophysical Chemistry

A crucial resolution barrier in cryo-electron microscopy has been broken. Holger Stark and his team at the Max Planck Institute (MPI) for Biophysical Chemistry have observed single atoms in a protein structure for the first time and taken the sharpest images ever with this method. Such unprecedented details are essential to understand how proteins perform their work in the living cell or cause diseases. The technique can in future also be used to develop active compounds for new drugs.