16 4 / 2022 // LEOPOLDINA / NEWS
Leopoldina fellowships for postdocs
Jonathan Daume and Johanna Schröder are researchers at prestigious universities in California
The postdoctoral fellowship enables young researchers like Jonathan Daume and Johanna Schröder to pursue their studies on an international level .
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The Leopoldina supports postdocs with a two-year fellowship . A chemical engineer and a brain researcher are using this opportunity to further their studies at prestigious universities in California .
The COVID-19 pandemic also had an impact on the international exchange between researchers . This is what brain researcher Jonathan Daume discovered when he started his Leopoldina-funded position at Cedars Sinai Medical Center in Los Angeles / USA in spring 2020 . “ I was only in the office for two days before I was sent home ,” recalls Daume .
Short-term and long-term memory
In the lockdown Daume only got to know his new colleagues virtually . However , this did not affect his research too badly : The Medical Center had already collected a large amount of data from patients that Daume wanted to work with . He therefore spent most of the first year of his fellowship on his home computer analysing this data .
Jonathan Daume is researching the interaction between the short-term and long-term memory in the brain . How do we consolidate the sensory impressions that we have every day and turn them into lasting memories ?
At the Cedars Sinai Medical Center , epilepsy patients are studied by using electrodes inserted deep into their brain for several weeks . Daume uses this to stimulate their memory in seizure-free phases with test games on a laptop and to observe what happens in the relevant brain regions – especially the hippocampus and amygdala .
The electrodes can partially identify individual neurons that are involved in these memory processes . This would be impossible with other methods such as an EEG . In the meantime , Daume has been able to work with patients himself , and will continue his studies in Los Angeles after his Leopoldina postdoctoral fellowship expires .
Hydrogen as an energy carrier
Almost 600 kilometres further north , Johanna Schröder is researching the technical foundations for the energy industry of the future . She took up her post at the University of Stanford in April . Her work is about the production and consumption of hydrogen as an alternative energy carrier . The principle is : to use
renewable energies such as wind power and solar energy to split water into hydrogen and oxygen . The hydrogen can be stored and in fuel cells it later reacts with oxygen from the air back to water , thereby releasing the stored energy . Fuel cells can power large trucks for example .
Replacing rare elements
These two chemical processes are understood in principle , but the devil is in the detail : The reaction of oxygen is very slow , but metallic catalysts can speed up the process . At the moment , rare metals such as platinum and iridium are used for this . Schröder is working on replacing these elements with more common ones such as copper and nickel . The metals are used as nanoparticles to obtain the largest possible surface area .
The focus of this research is sustainability – there are simply not enough rare elements for the hydrogen economy of the future . There is also a problem of not becoming dependent on the few countries where these metals are mined .
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