Research Field Matter
The Helmholtz research field Matter explores the constituent parts of matter and the forces acting between them over completely different orders of magnitude, from the smallest units, elementary particles, to the largest structures in the universe.
Insights into Research Field Matter
Here, we present projects currently being carried out by scientists at the Helmholtz Centres.
A promising approach in the flight against hospital terms
Antibiotic-resistant bacteria are a growing problem, especially in hospitals. Conventional antibiotics are often ineffective against so-called methicillin-resistant Staphylococcus aureus bacteria (MRSA). Resistance is increasing due to the use of antibiotics in industrial livestock farming and other factors.
Together with colleagues in Brazil and China, researchers in Hamburg working with the DESY’s X-ray light sources have developed a promising method of outsmarting hospital germs that are resistant to antibiotics. Instead of attacking the MRSA bacteria directly, the scientists intervene in a metabolic pathway that is vital to the survival of the germs.
“Conventional drugs block a particular function of the bacterium,” explains Christian Betzel from the University of Hamburg, who is conducting research at the Laboratory for Structural Biology of Infection and Inflammation on the DESY campus. “However, bacteria can then find a way round this blockade, thereby becoming resistant to the drug in question.” To overcome this problem, the researchers working with Betzel and Carsten Wrenger from the University of Sao Paulo are skilfully intervening in the vitamin B1 pathway of the staphylococci without actually blocking it.
In order to achieve this, they have determined the precise atomic structure of one of the enzymes involved. The scientists “feed” this enzyme with a custom-made, apparently useful substance. However, this so-called substrate is slightly modified so that it differs from its natural version. As a result, the vitamin B1 produced is actually useless to the bacteria. “It’s a way of tricking the organism,” explains Betzel. “We give it something that it believes it needs in a slightly modified form so that it is ultimately unable to use it.” Vitamin B1 is particularly suited to this approach for two reasons. “The vitamin B1 pathway is essential. There are no alternatives,” say Markus Perbandt, co-author of the study. “Moreover, the human body does not have any similar enzymes, which is extremely important for the avoidance of cross reactions.”
Using knowledge of the precise atomic structure of a biomolecule to custom-design an active substance is not only relevant to the fight against hospital germs, but may also prove an effective means of combating other pathogens.
BESSY II electron highway gets a second lane
Helmholtz-Zentrum Berlin für Materialien und Energie (HZB)
The BESSY II electron storage ring at the HZB can now be operated with not just one but two simultaneous electron paths. By precisely tuning the magnetic components involved, physicists can create an additional stable path along which packets of electrons orbit, emitting light pulses at the device’s experiment stations. This could provide future users with the option of selecting light pulses from either path for their experiments. This development represents a further milestone in the HZB’s pioneering BESSY-VSR project.
New atomic nuclei discovered
GSI Helmholtz Centre for Heavy Ion Research
An international research team has managed to produce four new heavy atomic nuclei: one isotope of berkelium, one of neptunium and two isotopes of americium. These nuclei decay after a few milliseconds or seconds depending on the isotope. The products of this decay can be separated and analysed using special filters composed of electrical and magnetic fields generated at the GSI research facility. By detecting all the decay products, researchers were able to identify the new isotopes.
Steering spin waves with domain walls
Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
In future, spin waves could provide the basis for faster and more energy-efficient information processing. These information carriers are based on the intrinsic angular momentum, or spin, of electrons. Until now, controlling them at the nanolevel has required a great deal of energy. Researchers at the HZDR have managed to steer spin waves in a targeted fashion for the first time with the help of so-called domain walls. Using small magnetic fields, they have succeeded in manipulating these boundary areas between differently magnetised domains and hence the spin wave propagation – a key step towards the creation of nanocircuits based on spin waves.
New technique for detecting cosmic radiation
Karlsruhe Institute of Technology (KIT)
When high-energy cosmic rays hit the Earth’s atmosphere, they generate “air showers” made up of secondary particles and electromagnetic radiation. Measuring these cascades of particles provides scientists with information about the properties of the primary particles involved. With the help of radio antennas at the LOFAR (Low Frequency Array) radio telescope and the Pierre Auger Observatory, researchers have demonstrated that the energy and elemental composition of the primary particles can be determined with a high degree of precision using the CoREAS simulation code developed at KIT. This represents a highly promising step towards determining the origins of such particles.
Setting a new standard for 3D images of the nanoworld
Scientists at the Ernst Ruska-Centre, which is jointly operated by Forschungszentrum Jülich and RWTH Aachen, used a transmission electron microscope to record about 3,500 images in 3.5 seconds. The series of images served as the basis for a 3D tomographic reconstruction. The recording of such image sequences has “hitherto” taken between 10 and 60 minutes and required 10 times the electron dose.
This gentler recording method is particularly suitable for the examination of cells, bacteria and viruses. In addition, it allows chemical reactions and electrical switching phenomena to be visualised in real time and in three dimensions.
Improving tools by analysing the film growth of thin coatings in-situ
Helmholtz-Zentrum Geesthacht Centre for Materials and Coastal Research (HZG)
The thin coatings applied to high-performance milling, turning and drilling tools make these products particularly durable. Scientists at the HZG, working with Swedish colleagues, have now developed a special chamber for the in situ examination of the growth of these hard layers. Using the HEMS beamline at PETRA III, they conducted experiments with high-energy X-rays during the coating process. The studies are providing valuable information on the dynamics of film growth and on ways to optimise the parameters for the production of coatings.