Special amplifying agents can make MRI scanners and NMR techniques hundreds of times more sensitive. Leiden physicists have now found a method to test their efficiency. More sensitive MRI scans could for example improve our understanding of cystic fibrosis or More info
MRI scanners are a useful tool for medical doctors to look inside the human body. It allows them for example to easily check for torn ankle ligaments or study lungs by having patients breath in xenon gas, while xenon is clearly visible on the scan. Sometimes however, the defect is so well hidden that the MRI scanner is not sensitive enough.
Leiden physicists research amplifying agents, which increase the sensitivity of MRI scans and NMR, with a method called dynamic nuclear polarization (DNP). Those agents collaborate with the substance that is actually scanned—like xenon—but how this happens exactly is still very unclear. Dr. Martina Huber and her research group have now developed a method to explore this mysterious collaboration. ‘Nowadays scientists look for new DNP agents through trial-and-error,’ says Huber. ‘With our new method we can start to understand how agents work, and then we can eventually make much better predictions on which substances would be good agents.’
To research DNP agents at the molecular level, Huber studies them with extreme high-field Electron Paramagnetic Resonance (EPR). With MRI itself they are of course invisible; otherwise they would cause noise instead of being a utility. To test their method, the researchers characterized the agent AMUPol, and published the results together with Prof. Marc Baldus’ group (Utrecht University) in the journal PCCP.
MRI scans with a hundred times more sensitivity could for example detect rare proteins in the human body, enabling scientists to better understand why they stop functioning in patients with cystic fibrosis, Parkinson’s, amyloidosis or Alzheimer’s. The DNP method already proved to be highly successful by exposing many details in solid state physics NMR research.
At the new year’s reception, Scientific Director of Casimir Tjerk Oosterkamp handed out the 2016 Hendrik Casimir Prize to physics students Andrea Peña (Leiden) and Jorrit Hortensius (Delft). The Casimir Research School yearly awards the Hendrik Casimir Prize to the More info
best MSc students in (Applied) Physics of Leiden University and TU Delft. The prize consists of a certificate and a sum of €750.
The prize is based on the revenues from a donation by the late Josina Casimir-Jonker, wife of the famous Hendrik Casimir. Peña and Hortensius were nominated by a committee formed by Jos Thijssen (director of Master Education Delft), Martin van Exter (Director of Education Leiden), Hara Papathanassiou (study advisor Leiden) and Christophe Danelon (coordinator of the Casmir pre-PhD Master program in Delft). They wrote the following about the two MSc students.
"Andrea is a talented student who has performed very well in her first year. Andrea has first joined the Physics program as an Erasmus exchange student from Spain. She adapted remarkably well and even followed a MSc course and carried out a successful research project in her BSc. She has a low key approach and proceeds carefully, delivering high performance while never overstating her capacity or achievements. Moreover, she is a very friendly person, always ready to help and share her experience with others. In the current semester she has been carrying out a project at ARCNL (local supervisor D. Bouwmeester) on investigating potential correlation of the amplitude of THz pulses from a two-color laser with the excited modes of an air-plasma mix."
"Jorrit completed a double bachelor programme in Applied Physics and Applied Mathematics with both diplomas awarded ‘cum laude’ (with distinction). His performance in the master programme is equally stellar. Jorrit usually does his coursework with a group of about five very good students in the master Applied physics and these students all have an exemplary working attitude which, together with their talent for physics and math, has a stimulating effect on a wide fraction of their cohort. Jorrit emanates enthusiasm for physics and for the courses he takes. He participates in activities of the student physics society VvTP."
Header image, left to right: Prof. Tjerk Oosterkamp, Andrea Peña, Jorrit Hortensius
For many years, scientists have observed a correlation between Alzheimer’s disease and a surplus of iron in the brain. However, a causal link between the two has not been proven yet. We lack knowledge concerning the specific form of iron More info
We eat daily between ten and twenty milligrams of iron. After being absorbed by the gut, this metal participates in a wide variety of essential metabolic processes, including oxygen transportation, DNA replication and electron transport. However, if it’s not properly regulated, iron can cause damage to cells.
In the brains of patients with neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, iron is upregulated: it can increase to up to three times greater than the normal level. Scientists can use MRI scans to indirectly image iron in post-mortem brain tissue, but the data interpretation remains much debated. Such measurements are indirect, affected by several sources of artifacts, and poorly quantitative.
Magnetism and biology
A multidisciplinary team of Leiden physicists (LION) and radiologists from the Leiden University Medical Centre (LUMC), led by postdoc Lucia Bossoni, has developed a method based on the combination of Electron Paramagnetic Resonance Spectroscopy (EPR) and SQUID magnetometry to detect and quantify complementary species of iron in post-mortem brain tissue. In combination with MRI, this approach will allow scientists to better understand the role played by iron in Alzheimer’s disease.
Physics Outreach Officer, Leiden University
arends [at] physics.leidenuniv.nl
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X-band EPR spectra of brain tissue. The graphs show a comparison between Alzheimer’s disease tissue (left) and healthy control tissue (right). The potentially toxic iron appears as a band at a magnetic field of about 1.5 kG.
In the latest episode of DWDD University on 'Light', Prof. Robbert Dijkgraaf used a number of experiments from the Leiden Physics Practicum Lab. He showed why the sky is blue, that light is a wave phenomenon, how magnetism and electricity More info
are connected and that white light consists of all colors of the rainbow.