Press releases

 

Jul 24 2018
13:55

Range of applications for silicones on the increase thanks to modular, combinable building blocks

Made-to-measure silicon building blocks

FRANKFURT. Silicones are synthetic materials used in a broad range of applications. Thanks to the stability of the silicon-oxygen bond, they are resistant to chemicals and environmental influences and also harmless from a physiological point of view. As a result, silicones contribute to making everyday life easier in almost all areas. In the Journal of the American Chemical Society, chemists at Goethe University Frankfurt have now described a new way to produce long-awaited silicon building blocks in a simple and efficient way.

The broad spectrum of applications for silicones ranges from medical implants and cosmetics to hydraulic oils and sealants to corrosion protection – an important topic in view of global corrosion damage to the tune of about US$ 3.3 trillion per year. To optimize silicon-based synthetic materials for specific applications, made-to-measure chlorosilane building blocks are required in order to produce and crosslink the long-chain polymers. This influences, for example, the material’s viscosity and flow properties. Completely new challenges are emerging in the area of 3D printing, with the aid of which products such as individualized running shoes can be manufactured.

Since 1940, the Müller-Rochow Direct Process has formed the backbone of the silicone industry. In this process, elementary silicon is converted with methyl chloride into methylchlorosilanes at high temperatures and pressures in the presence of a copper catalyst. The working group led by Professor Matthias Wagner at the Institute of Inorganic and Analytical Chemistry of Goethe University Frankfurt has now developed a complementary process that has several advantages over the Direct Process: It uses hexachlorodisilane and chlorinated hydrocarbons as starting materials. “Hexachlorodisilane is already mass-produced for the semiconductor industry and the perchlorethylene (PER) we use particularly frequently is a non-flammable liquid which is so inexpensive that it’s used worldwide as a solvent for dry cleaning,” says Matthias Wagner. In addition, the process runs at room temperature and under normal pressure. To activate it, just a small concentration of chloride ions is needed in place of a catalyst.

“Our process produces highly functionalized organochlorosilanes that are ideal crosslinkers. In addition, their special structure offers excellent possibilities to adjust the mechanical flexibility of the silicon chains as desired,” explains co-inventor Isabelle Georg, whose doctoral dissertation is being sponsored by the Evonik Foundation. Julian Teichmann was also involved in the project. He confirms that above all the close collaboration between Goethe University and Evonik had a tremendous influence on his training: “Regular discussion of our results with Evonik’s industrial chemists opened my eyes from the beginning to economic constraints and ecological requirements. It was fascinating to follow the path from our discoveries in the lab via the patenting procedures to realization on a technical scale in practice.”

The chemists in Frankfurt believe that their monomers’ special potential lies in the fact that they contain not only silicon-chlorine bonds but also carbon-carbon multiple bonds. The purpose of the former is to construct the inorganic silicon-oxygen chains; the latter can be linked to form organic polymers. This unique combination permits new routes to inorganic-organic hybrid materials.

Publication: I. Georg et al: Exhaustively Trichlorosilylated C1 and C2 Building Blocks: Beyond the Müller-Rochow Direct Process, in: J. Am. Chem. Soc. 2018, DOI: 10.1021/jacs.8b05950

Further information: Professor Matthias Wagner, Institute of Inorganic and Analytical Chemistry, Riedberg Campus, Tel.: ++49(0)69-798-29156, Matthias.Wagner@chemie.uni-frankfurt.de

 

Jul 10 2018
17:46

National and regional governments pledge total of around € 97 million for LOEWE Centre “Frankfurt Cancer Institute”

Goethe University awarded funds for new cancer research institute including new building

FRANKFURT. Goethe University has a new LOEWE Centre under its belt – together with its own research building that is planned for completion by 2023. As announced on 29 June, a good € 73.4 million are being made available for this purpose; the decision followed a recommendation by the German Council of Science and Humanities in April 2018. Hessen’s State Ministry for Higher Education, Research and the Arts had officially announced just the day before that the Frankfurt Cancer Institute would be integrated as a LOEWE Centre in the state’s scientific support programme. Around € 23.6 million in regional funding are available for operating costs in the first phase from 2019 to 2022.

LOEWE Centre “Frankfurt Cancer Institute”

Nowadays, it is possible to completely decode cancer genes within just a few days. However, to be able to forecast how well a patient will respond to treatment, genetic data are only useful to a limited degree because for this it is necessary to know the effect of mutations within the tumour cell and in turn what impact this will have on the surrounding tissue and the immune system. Exploring this complex process is the task of the LOEWE Centre “Frankfurt Cancer Institute” (LOEWE FCI), where basic researchers and clinicians will work closely together in interdisciplinary teams. Partners from the pharmaceutical industry are also involved. Particularly gratifying is the news that the Frankfurt Cancer Institute will receive a new building on Niederrad Campus paid for by the national government: € 73.4 million have now been approved. According to a press release by Hessen’s State Ministry for Higher Education, Research and the Arts, the national and regional governments are each contributing 50 % towards € 52.1 million of this sum; German Cancer Aid will donate € 20 million towards building costs and additional funds will come from other partners.

“The two grants mean tremendous progress for university medicine in Frankfurt, especially for oncology. Translational cancer research at Goethe University has seen a very positive development in the last ten years. These efforts are now being rewarded by Hessen’s state government and German Cancer Aid in the shape of the new LOEWE Centre and the new research building, for which we’re very grateful. It raises our work to a new level,” says Professor Florian Greten, Director of the Georg Speyer Haus and professor for tumour biology at the Faculty of Medicine of Goethe University. 

Apart from Goethe University, also participating in the project are the Georg Speyer Haus (GSH), the German Cancer Consortium (DKTK), the Paul-Ehrlich-Institut (PEI) and the Max Planck Institute for Heart and Lung Research in Bad Nauheim. 

“Congratulations to our researchers on Niederrad Campus, who following the approval of the LOEWE jurors have now also been given the green light for their new building by the Joint Science Conference of the state ministry responsible here in Hessen and the federal government in Berlin,” says Professor Birgitta Wolff, President of Goethe University. She is very pleased about the double success. “The Frankfurt Cancer Institute will perform a task that is very important for the future. It will contribute not only to our scientific understanding of cancer but also to its more targeted treatment. This requires staying power and an opportunity to bring together the corresponding disciplines on a long-term basis. We’re very grateful to the national and regional governments for enabling us to establish the necessary framework. The funds for our own new research building are an important milestone that will give cancer research here in Frankfurt a tremendous boost. I’m very happy that Hessen’s state government initiated the LOEWE programme: It’s an indispensable instrument for developing large-scale research programmes at our region’s universities and keeping them running over a long period.”

Funding applications with good prospects

Thanks to the positive evaluation of their preliminary proposals, a further three projects were invited to submit full proposals in the 12th round of funding:

  • In the planned LOEWE Focus Group “Warm Periods of the Past as a Natural Analogy to our ‘High CO2’ Climate Future (VeWa)”, geologists, biologists, geographers and climate modellers want to study what we can expect if the carbon dioxide content in the atmosphere virtually doubles compared to pre-industrial levels.
  • The LOEWE Focus Group “Digitalised Education Processes” (DBP) aims to investigate mechanisms relevant for digital education processes and provide an insight into how these processes can be optimised. Psychologists and educational scientists will deal with the changes that accompany digital education processes.
  • Last but not least, the LOEWE Focus Group “Minority Studies: Language and Identity” deals from an interdisciplinary perspective with the question of the role played by identity-dependent factors in the context of migration by minorities. The researchers are particularly interested in minorities which already had a minority status in their country of origin.

Further information on the LOEWE Centre “Frankfurt Cancer Institute”: Professor Florian Greten, Director of the Georg Speyer Haus, Faculty of Medicine, Goethe University, Tel.: +49(0)69-63395-183, Greten@gsh.uni-frankfurt.de.

 

Jun 26 2018
12:15

Comparison of billions of theoretical models with gravitational waves results in the answer to an old riddle

Frankfurt physicists set limits on size of neutron stars

FRANKFURT. How large is a neutron star? Previous estimates varied from eight to sixteen kilometres. Astrophysicists at the Goethe University Frankfurt and the FIAS have now succeeded in determining the size of neutron stars to within 1.5 kilometres by using an elaborate statistical approach supported by data from the measurement of gravitational waves. The researchers’ report appears in the current issue of Physical Review Letters.

Neutron stars are the densest objects in our universe, with a mass larger than that of our sun compacted into a relatively small sphere whose diameter is comparable to that of the city of Frankfurt. This is actually just a rough estimate, however. For more than 40 years, the determination of the size of neutron stars has been a holy grail in nuclear physics whose solution would provide important information on the fundamental behaviour of matter at nuclear densities.

The data from the detection of gravitational waves from merging neutron stars (GW170817) make an important contribution toward solving this puzzle. At the end of 2017, Professor Luciano Rezzolla, Institute for Theoretical Physics at the Goethe University Frankfurt and FIAS, together with his students Elias Most and Lukas Weih already exploited this data to answer a long-standing question about the maximum mass that neutron stars can support before collapsing to a black hole - a result that was also confirmed by various other groups around the world. Following this first important result, the same team, with the help of Professor Juergen Schaffner-Bielich, has worked to set tighter constraints on the size of neutron stars.

The crux of the matter is that the equation of state which describes the matter inside neutron stars is not known. The physicists therefore decided to pursue another path: they selected statistical methods to determine the size of neutron stars within narrow limits. In order to set the new limits, they computed more than two billion theoretical models of neutron stars by solving the Einstein equations describing the equilibrium of these relativistic stars and combined this large dataset with the constraints coming from the GW170817 gravitational wave detection.

“An approach of this type is not unusual in theoretical physics," remarks Rezzolla, adding: "By exploring the results for all possible values of the parameters, we can effectively reduce our uncertainties." As a result, the researchers were able to determine the radius of a typical neutron star within a range of only 1.5 km: it lies between 12 and 13.5 kilometres, a result that can be further refined by future gravitational wave detections.

"However, there is a twist to all this, as neutron stars can have twin solutions," comments Schaffner-Bielich. It is in fact possible that at ultra-high densities, matter drastically changes its properties and undergoes a so-called "phase transition." This is similar to what happens to water when it freezes and transitions from a liquid to a solid state. In the case of neutron stars, this transition is speculated to turn ordinary matter into "quark matter," producing stars that will have the exact same mass as their neutron star "twin," but that will be much smaller and consequently more compact.

While there is no definite proof for their existence, they are plausible solutions and the researchers from Frankfurt have taken this possibility into account, despite the additional complications that twin stars imply. This effort ultimately paid off as their calculations have revealed an unexpected result: twin stars are statistically rare and cannot be deformed very much during the merger of two such stars. This is an important finding as it now allows scientists to potentially rule out the existence of these very compact objects. Future gravitational-wave observations will therefore reveal whether or not neutron stars have exotic twins.

Publication: Elias R. Most, Lukas R. Weih, Luciano Rezzolla, Jürgen Schaffner-Bielich: New constraints on radii and tidal deformabilities of neutron stars from GW170817,  Phys. Rev. Lett. 120, 261103. https://doi.org/10.1103/PhysRevLett.120.261103

Picture material can be downloaded under: www.muk.uni-frankfurt.de/72776172?

Figure caption: "Range of the size for a typical neutron star compared to the city of Frankfurt (satellite image: GeoBasis-DE/BKG (2009) Google)".

Further information: Professor Luciano Rezzolla, Frankfurt Institute for Theoretical Physics, Faculty of Physics, and Frankfurt Institute for Advanced Studies, Riedberg Campus, Tel. +49 (0) 69 798-47871, rezzolla@fias.uni-frankfurt.de.

 

Jun 11 2018
11:42

Economists at Goethe University Frankfurt show that inflation in Europe is more burdensome for low income groups

Does inflation put poorer households at a disadvantage?

FRANKFURT. It is quite obvious that inflation may affect individuals differently. However, the extent to which the rate of inflation in the EU’s Member States disadvantages poorer individuals has now been shown by economists Eren Gürer and Professor Alfons Weichenrieder in a recent study.

Essential expenditure, for example for food, rent and electricity, make up a greater percentage of the budget of less well-off families than for more affluent ones. If the prices for such items rise more sharply than for luxury goods, this leads to low-income households having to put up with a higher rate of inflation in their individual shopping baskets. This means that the inflation rate can differ from the general rate of inflation depending on individual consumer habits. Is there a systematic distortion of the individual rate of inflation in the EU to the detriment of lower income brackets? This is a question that economists Eren Gürer and Professor Alfons Weichenrieder of Goethe University Frankfurt have now explored.

The analysis of data from 25 EU Member States from 2001 to 2015 shows that in most countries inflation tends to disadvantage poorer households: The annual inflation rate during this period for the poorest ten percent in a country was on average about 0.7 percent higher than for the richest ten percent. At an average inflation rate of 2.7 percent, this equates to a difference of slightly more than a quarter of the general rate of inflation.

Costs for electricity, rent, private means of transport and food, which have increased at an above-average rate, are above all responsible for this development. These items make up a far greater share in the shopping baskets of lower income groups. However, the effects are not equally pronounced in all countries: Whilst households in Italy and Portugal escaped this “discriminating inflation”, the EU’s Eastern European countries as well as the United Kingdom and Finland were particularly affected.

In Germany, the effect is comparatively moderate. Indeed, the gap here between nominal disposable incomes has by all means widened, as is known from other studies. The influence of inflation on income distribution - a topic neglected in previous studies – is, however, quite modest: It accounts for about one tenth of the increase in inequality already measured in the years under consideration.

This should not, however, blind us to the fact that in the representative German sample the shopping baskets of the lower ten percent became about 4.5 percent more expensive than the shopping baskets of the upper ten percent.

Publication: Eren Gürer and Alfons Weichenrieder, Pro-Rich Inflation in Europe: Implications for the Measurement of Inequality, Goethe University, SAFE Working Paper No. 209, May 2018. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3183723

Further information: Professor Alfons Weichenrieder, Chair of Economics and Public Finance, Theodor-W.-Adorno-Platz 4, Westend Campus, Tel.: +49(0)69-798-34788; email aw@em.uni-frankfurt.de

 

Jun 8 2018
09:01

Repeated stimulation enlarges dendritic spines

Thorny life of new-born neurons

FRANKFURT. Even in adult brains, new neurons are generated throughout a lifetime. In a publication in the scientific journal PNAS, a research group led by Goethe University describes plastic changes of adult-born neurons in the hippocampus, a critical region for learning: frequent nerve signals enlarge the spines on neuronal dendrites, which in turn enables contact with the existing neural network.

Practise makes perfect, and constant repetition promotes the ability to remember. Researchers have been aware for some time that repeated electrical stimulation strengthens neuron connections (synapses) in the brain. It is similar to the way a frequently used trail gradually widens into a path. Conversely, if rarely used, synapses can also be removed – for example, when the vocabulary of a foreign language is forgotten after leaving school because it is no longer practised. Researchers designate the ability to change interconnections permanently and as needed as the plasticity of the brain.

Plasticity is especially important in the hippocampus, a primary region associated with long-term memory, in which new neurons are formed throughout life. The research groups led by Dr Stephan Schwarzacher (Goethe University), Professor Peter Jedlicka (Goethe University and Justus Liebig University in Gießen) and Dr Hermann Cuntz (FIAS, Frankfurt) therefore studied the long-term plasticity of synapses in new-born hippocampal granule cells. Synaptic interconnections between neurons are predominantly anchored on small thorny protrusions on the dendrites called spines. The dendrites of most neurons are covered with these spines, similar to the thorns on a rose stem.

In their recently published work, the scientists were able to demonstrate for the first time that synaptic plasticity in new-born neurons is connected to long-term structural changes in the dendritic spines: repeated electrical stimulation strengthens the synapses by enlarging their spines. A particularly surprising observation was that the overall size and number of spines did not change: when the stimulation strengthened a group of synapses, and their dendritic spines enlarged, a different group of synapses that were not being stimulated simultaneously became weaker and their dendritic spines shrank.

“This observation was only technically possible because our students Tassilo Jungenitz and Marcel Beining succeeded for the first time in examining plastic changes in stimulated and non-stimulated dendritic spines within individual new-born cells using 2-photon microscopy and viral labelling,” says Stephan Schwarzacher from the Institute for Anatomy at the University Hospital Frankfurt. Peter Jedlicka adds: “The enlargement of stimulated synapses and the shrinking of non-stimulated synapses was at equilibrium. Our computer models predict that this is important for maintaining neuron activity and ensuring their survival.”

The scientists now want to study the impenetrable, spiny forest of new-born neuron dendrites in detail. They hope to better understand how the equilibrated changes in dendritic spines and their synapses contribute the efficient storing of information and consequently to learning processes in the hippocampus.

Publication: Structural homo- and heterosynaptic plasticity in mature and adult new-born rat hippocampal granule cells. DOI: 10.1073/pnas.1801889115 (Jungenitz et al. PNAS, 115:E4670 2018)

Picture material can be downloaded at: www.uni-frankfurt.de/72306770

Caption: The dendrites of newborn neurons (green) are covered with spines, similar to the thorns on a rose stem (Credit: Tassilo Jungenitz).

Further information: Dr Stephan Schwarzacher, Institute for Anatomy I, Faculty of Medicine, Niederrad Campus, Tel.: +49 (0)69 6301-6914, schwarzacher@em.uni-frankfurt.de