Computer meets cell - effzett (3/2014) by Forschungszentrum Jülich

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eﬀzett FORSCHUNGSZENTRUM JÜLICH’S MAGAZINE

Computer meets cell Researchers eavesdrop on the dialogue between neurons

CLEAN

ELEMENTARY

UNCANNY

How the atmosphere cleans itself

New additions to the particle zoo

When fear makes us ill

AS WE SEE IT

A thousand droplets of green Colour is on the agenda: green fuel for aeroplanes is what will be harvested from the microalgae growing here. Plant researchers at J端lich are testing different facilities for algae production. In this facility, a nutrient solution with algae drips through several layers of nets. During this process, the algae absorb light and carbon dioxide and multiply. The aqueous algae solution eventually drips into tanks installed in the floor. Christina Schreiber uses a water squeegee to help collect the valuable mixture. From the tanks, the solution is pumped back up and sprayed onto the nets again. One single alga makes this journey up to six times in an hour. If enough algae have grown in one cycle, they are harvested and their oil is processed to kerosene.

TO PI C S

Washing with an “OH” eﬀect

FOCUS

Topical issues on how the atmosphere cleans itself – a look inside the washing drum.

NEWS IN BRIEF

Building bridges between two worlds Bioelectronics technicians want to decode communication between nerve cells. For this, they are growing neurons on microchips.

The chemistry of fear

New information on protein

8 Alarm in the nervous system: chemical changes in the brain trigger panic attacks.

RESEARCH

A licence to lubricate

24 From ﬂash freezing to bombarding: Jülich researchers decipher the structure of three proteins.

SECTIONS

18 Editorial 4

It’s all in the eyes

Publication details

Gossipers are rewarded – in the brain. Eye contact plays an important role in this.

What’s your research all about? 19

New species in the particle zoo

Beyond the campus 26

Thumbs up 27 Prof. Martin Müser radically reduces friction between parts: with water, oil, and molecular brushes.

Research in a tweet Further proof for physicists’ conception of the world: quarks also come in six-packs.

E D ITO R I A L

Whetting your appetite Do you fish? We don’t. That’s why we were a bit uneasy this year in autumn. Since spring, we have been working on relaunching our magazine Research in Jülich. Livelier and fresher than before – that was our brief. In summer, the first drafts of the new layout were finalized; in autumn, the texts followed. Only the name remained: tried and tested, but no longer very snappy. We thought about it long and hard: should we stick with it? We came up with a wealth of suggestions, collected and rejected ideas, and finally decided to go for something completely new. Research in Jülich became effzett – named Want to read effzett on your tablet? Either scan the QR code with your tablet or visit our website: www.fz-juelich.de/effzett

for the two most important letters in the word “Forschungszentrum”: F and Z. But just as the decision was made, we discovered that the name had a catch – better said a ﬁshy catch! Decades ago, an artiﬁcial bait known as the Effzett spoon was launched on the market as bait for preda-

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tory ﬁsh. But no need to panic, said our legal department: the ﬂashy namesake is at home in very different waters; media products are not affected. Which means that we can use it to whet your appetite as

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readers. Fingers crossed, you’ll take the bait! We hope you enjoy reading the very ﬁrst edition of effzett – which is also available as usual online and as an app for tablets. Your effzett editorial team

Publication details effzett Forschungszentrum Jülich’s magazine ISSN 1433-7371 Published by: Forschungszentrum Jülich GmbH, 52425 Jülich, Germany Conception and editorial work: Annette Stettien, Dr. Barbara Schunk, Christian Hohlfeld, Dr. Anne Rother (responsible under German Press Law) Authors: Marcel Bülow, Dr. Frank Frick, Christian Hohlfeld, Katja Lüers, Christoph Mann, Tobias Schlößer, Dr. Barbara Schunk, Annette Stettien, Ilse Trautwein, Angela Wenzik, Erhard Zeiss, Peter Zekert

Translation: Language Services, Forschungszentrum Jülich Graphics and layout: SeitenPlan GmbH, Corporate Publishing Dortmund Images: Forschungszentrum Jülich (2, 3 left, 6 top left, 10, 12, 13 right, 14-15, 19, 21 [screen], 23 top, 24 bottom, 25 small top image, 27 left, 28), Forschungszentrum Jülich/SeitenPlan (3 bottom centre, 23 bottom), © Ed Bock/CORBIS (20), Cranach/Shutterstock.com (3 top right, 24), IAGOS (7 bottom left), Liashko/Shutterstock.com (21 screen), NorGal/Shutterstock.com

(6 bottom left), paintings/Shutterstock.com (3 top centre, 18), Eka Panova/shutterstock (22), pockygallery/Shutterstock.com (27 right), RWTH Aachen/A. Vogel and R. Knauf (5), Sailorr/Shutterstock.com (7 top right), W. Schürmann/TUM (26), SeitenPlan illustrations (1, 8-13, 16-17), Wasserwirtschaftsamt Ansbach (7 left), Lisa F. Young/Shutterstock.com (6 right) Contact: Corporate Communications, Tel: +49 2461 61-4661, Fax: +49 2461 61-4666, Email: info@fz-juelich.de

NEWS IN BRIEF

B I O S C IE N C E

Wild genes withstand stress Scientists have uncovered new evidence as to why the wild tomato species Solanum pennellii is extremely stress tolerant. An international team of researchers has decoded the plant’s entire genome – and thus parts of the genome that are responsible for things like stress tolerance. The ﬁndings provide important information for future breeding of cultivated tomatoes. Breeders often use this species to hybridize tomatoes due to its properties. An advantage of the wild tomato: it can deal with drought much better. – INSTITUTE OF BIO - AND GEOSCIENCES –

Wild tomato Solanum pennellii

M AT E R I A L S R E S E A R C H

Keeping a distance Scientists from Graz and Jülich have discovered that an organic semiconductor has an extraordinary property. Perylenetetracarboxylic acid dianhydride, PTCDA for short, keeps its distance when it binds more closely. To be more precise, the semiconductor molecules move away from a metal surface when they are mixed with copper phthalocyanine (CuPc), another semiconductor material. At the same time, however, they strengthen their own chemical bond to the surface. Atoms and molecules usually seek close contact when a bond is strengthened. The reason for the apparently paradoxical situation: the PTCDA molecule is stronger in the compound and takes up electrons from the weaker CuPc molecule. In addition to being extremely important for basic research, these new findings will also be incorporated into the development of organic LEDs and solar cells. – PETER GRÜNBERG INSTITUTE –

NEWS IN BRIEF

61,000 hours of operating time …

… is a new world record. A stack of planar solid oxide fuel cells (SOFCs) has been operating non-stop since 2007 at Forschungszentrum Jülich (photo: single SOFC). This veriﬁes that the materials used are stable over a long period of time and that the system is capable of continuously producing electric current. The stack is made of the same components that a future commercial product would also have. – I N S T I T U T E O F E N E R GY A N D C L I M AT E R E S E A R C H –

B I O C H E M I S T RY

Potential drug for Alzheimer’s N A N O E LE C T R O N I C S

More ﬂexible than expected Jülich and US scientists have observed for the ﬁrst time exactly how structures inside certain pioneering switching devices are formed. Images taken using a transmission electron microscope reveal how metal nanoclusters move in a resistive memory cell when the cell is switched from one state to another. Similar mobility was previously only associated with liquids. – PETER GRÜNBERG INSTITUTE –

Scientists at Jülich are currently testing a new candidate drug for Alzheimer’s disease. The potential drug is derived from a D-peptide by the name of D3 and was developed by a research group headed by Jülich biochemist Prof. Dieter Willbold. It intervenes on a molecular level in the process responsible for Alzheimer’s, namely the formation of small clumps of the beta amyloid protein in the brain. These “oligomers” destroy nerve cells. The scientists are now testing the safety of the substance – an essential step towards developing a drug. For its work, the research group has been granted € 2 million in funding from the Helmholtz Validation Fund. – INSTITUTE OF COMPLE X SYSTEMS –

E N V IR O N M E N TA L R E S E A R C H

Adieu, algae The end could be in sight for the algae problem in the Altmühlsee lake in North Bavaria (photo). A Jülich study has determined from precisely what sources and in what quantities the phosphate, which is responsible for the excessive algae production, is seeping into the lake. The main culprits are agriculture and nearby sewage treatment plants. The sewage treatment plants will now be optimized and the farmers concerned will be advised on how they can minimize phosphate pollution from manure and mineral fertilizers in the long term. The artiﬁcial Altmühlsee lake is often referred to as “Franconia’s Adriatic”. Due to the algae problem, swimming in the lake had to be forbidden time and again.

Frequent ﬂyer

– INSTITUTE OF BIO - AND GEOSCIENCES –

Every line represents a flight route: since 2011, commercial airliners have made some 4,700 flights with measuring instruments on board. The instruments analyse greenhouse substances during the flights. They are operated by the European research infrastructure IAGOS, which is headed by Forschungszentrum Jülich.

STILL IN THE TOP TE N

MORE LIGHT IN THE CE LL

BIOCATALYST MADE TO ORDE R

JUQUEEN is once again among the world's top ten fastest computers. In the TOP 500 list published in mid-November, Jülich’s supercomputer was ranked eighth. This sees it hold its own as Germany’s fastest computer. With 458,752 processor cores, JUQUEEN has a peak performance of 5.9 petaﬂop/s (5.9 quadrillion calculations per second).

Researchers at Jülich have developed a new etching method for silicon thin-film solar cells that specifically improves light trapping. This increases the efficiency. The new method combines the conventional fabrication technique, which uses hydrochloric or hydrofluoric acid, with an electrochemical etching technique.

(S)-benzoin, a special building block in organic chemistry, can be produced more efficiently and sustainably in future. A new process developed at Jülich with a tailor-made biocatalyst will make this possible. It works with fewer reaction steps, milder reaction conditions, and better selectivity than previous synthesis pathways.

FOCUS

Building bridges between two worlds In the brain, some 100 billion nerve cells “communicate” permanently with each other. But how and via what? To eavesdrop on the conversation and decode the communication, Jülich bioelectronics technicians are growing neurons on microchips.

FOCUS

T The cell envelops a mushroom-shaped nanoelectrode – the optimum shape for establishing contact with living cells.

he future begins behind glass: golden light, glistening steel, countless pipes, cables, and bright displays dominate the picture. People walk around the ultramodern laboratories in protective suits and overshoes. One or two take a quick look outside through the glass. We can’t tell whether or not they say hi to each other; all of them are wearing surgical masks. If you want to enter the area behind the glass, you need an access code and you must pass through the airlock ﬁrst, where air jets blow off the last remaining dust particles. On the other side of the airlock, probably the cleanest place on Forschungszentrum Jülich’s campus awaits: the Helmholtz Nanoelectronic Facility (HNF) – a cleanroom laboratory that is millions of times cleaner than our normal environment. For Prof. Andreas Offenhäusser, this futuristic looking atmosphere is no more than his everyday world. In the cleanroom laboratory, those highly sensitive microchips are created that provide the basis for work at the Peter Grünberg Institute/Institute of Complex Systems in the ﬁeld of bioelectronics. A network of physicists, chemists, biologists, and electronics engineers hope to discern how individual nerve cells,

Science ﬁction atmosphere: in Jülich’s cleanroom laboratory, researchers fabricate microchips on which nerve cells subsequently grow.

called neurons, and neuron clusters communicate with each other. For this, the researchers grow neurons on electronic components and connect biology to electronics – on a scale of micrometres to nanometres. In other words, the team of researchers headed by Offenhäusser builds bridges between two worlds. And the team does so successfully, because biological systems and electronic circuits both use electrical impulses to process information.

“LISTENING TO NEURONS” The electrodes on the chip convert the electrical or biochemical signals from the cells – depending on the test set-up – into electric current or voltage. The signals that they pick up provide the scientists with clues as to how the neurons in the brain “talk” to each other and how they pass information on. To make it possible for the nerve cells to grow on the chip surface, the researchers use a micrometre-ﬁne stamp to apply proteins as a growth stimulus to the electrodes. If the scientists were to successfully create a permanent good connection to the nerve cells, decode the “conversation” from neuron to neuron, and trace the propagation of information, then this would be a quantum leap for medicine.

L I F E A S A C Y B O R G (1)

The first cyborg Neil Harbisson’s story made the news worldwide in 2013: born unable to perceive colours, a device known as the “Eyeborg” now allows him to “hear” colours. After weeks of campaigning, the British authorities ﬁnally recognized the camera as part of his body. The electronic eye is now pictured on his passport. Harbisson refers to himself as the ﬁrst-ever cyborg to be officially recognized by a government.

Bioelectronic implants for the ears or eyes could be optimized, deaf people would be able to hear again, and blind people would be able to see. Artiﬁcial limbs could be controlled by nerve impulses, and paraplegic patients would be able to walk again. The ﬁrst steps towards cyborgs would have been taken. This idea of a hybrid being – part-human and part-machine – was predicted by William Gibson back in 1984 in his novel Neuromancer. There’s still a long way to go until we reach this stage. The some 100 billion neurons in the brain which constantly communicate via electrical and biochemical connections present scientists with huge challenges. Our brain is more powerful than any supercomputer. Offenhäusser, who has been working at the electronics/biology interface for more than 20 years, compares his work to a giant jigsaw puzzle made up of an ever-growing number of pieces. Depending on the intended application, Jülich researchers grow the neurons on various types of chips: from robust microelectrode arrays to the much more sensitive silicon nanowire transistors as well as graphene transistors. Heralded as a miraculous material, graphene has recently attracted a lot of attention. The honeycomb-like structure of carbon atoms, arranged a bit like a chain-link fence, is harder than diamonds, stronger than steel, and extremely light. The two-dimensional network also has outstanding electronic properties, is chemically stable, and is biologically compatible. “For us, graphene

is particularly interesting as a material for neuro-implants,” says Offenhäusser. While rigid silicon implants can easily damage tissue or be rejected by the body, the ultrathin graphene layers are ﬂexible and could prove to be invaluable as retinal, hearing, or brain implants. Today, neuroprostheses still fail because the electronics are difficult to connect to the nerve cells. “The resolution over a long period of time is still not good enough. That’s why we need new materials,” says Offenhäusser.

OPTIMUM CONTACT Over the years, researchers at Jülich have developed a platform technology, which they are continuously expanding and making more sensitive to ensure the availability of tools for particular problems. Sometimes the researchers stimulate neurons; sometimes, they “listen” to the answers. They use electrical, electrochemical, and optogenetic methods for this. The latter involves using light to control genetically modified cells. All systems are based on optimum contact between nerve cells and electrodes. “This is one of our research priorities: can we create artificial synapses?” says the physicist succinctly. A synapse is the closest connection between two nerve cells. The distance between a cell and an electrode influences how many signals, if any,

FOCUS

L I F E A S A C Y B O R G (2)

Account in your upper arm A radio chip the size of a grain of rice – the VeriChip – was originally developed in the USA as an implantable form of emergency ID storing all relevant personal information. In Barcelona, nightclub customers had the chip implanted under their skin, allowing them to gain entry without showing personal identiﬁcation and to order drinks without paying cash. Today, the chip is suspected of causing cancer.

the scientists can measure. “A distance as tiny as ten-thousandths of a millimetre means that we can measure hardly anything at all,” says Offenhäusser. Recently, the researchers attracted international attention when they showed that in addition to this distance, the design of nanoelectrodes is also decisive for good signal transduction. To ensure that the nerve cell is as close as possible to the electrode, the researchers use a trick. Most cells envelop foreign bodies and engulf them – experts speak of phagocytosis. Offenhäusser’s team attached tiny spheres on a gold stem as a nanoelectrode to the chip surface. The nerve cells attempt to envelop this nanomushroom and in so doing move closer to the electrode than before. “What happens when communication in the brain breaks down?” Dr. Bernhard Wolfrum and his team are looking for answers.

In a second step, the researchers make the cell believe it is not sitting on a hard electrode but rather on a soft cell with which it then forms a synapse. “These are the topics spearheading our research at the moment,” says Offenhäusser. The platform technology also aims to become even more sensitive when recording signals and stimulating. “For this, we need new microelectronic components that are more sensitive – that’s one of the main parts of our work,” says Offenhäusser. The third strand of the platform technology concentrates on designing and controlling networks

of nerve cells. The bioelectronics technicians are already positioning individual neurons on chips and determining their growth. The next step will involve connecting one of these neurons with another neuron. In this way, the researchers hope to create their own network of neurons, which they will control completely. “But we’re not quite at this stage yet!” interjects Offenhäusser. What does already work is the following: The scientists can create a population of 20–30 neurons, and although they can’t control the transmission of signals within this network itself, they can create a speciﬁc neuronal connection with a second population. “We can follow the communication between two nerve cell populations, a bit like what separate regions in the brain do,” says Offenhäusser.

COMPLETING THE JIGSAW PUZZLE Even though the researchers are mainly interested in basic research, their work often has tangible relevance. Dr. Bernhard Wolfrum, who heads the working group Nanotechnology Tools for Cell-Chip Communication, currently focuses on the electrochemical detection of neurotransmitters, such as dopamine. In Parkinson’s disease, the neurons in the brain that produce dopamine die first. Wolfrum and his team are investigating the release of dopamine in the artificial nerve networks. The institute aims to create a “lab-on-a-chip” platform for Parkinson’s, which researchers will be able to use to reproduce the network paths on a single microchip exactly as they occur in the brain. This would allow them to observe chemical communication and to influence the “conversation”. “By adding proteins, for example, that have been identified

Technology for the senses as playing a role in the neurological disease, we would be able to measure how the cell reacts and then draw conclusions on the causes of the disease,” explains the physicist. Potential drugs for Parkinson’s will also be tested using the electrochemical system. One thing is certain, at the Institute of Complex Systems – Bioelectronics, there are several approaches and ways of improving our understanding of the conversation between neurons. And most importantly, there are scientists who are listening very closely, and will soon be able to move one or more pieces of the complex neuron jigsaw puzzle into the correct place. K ATJ A L Ü E R S

Prof. Andreas Offenhäusser has been conducting research at the biology/microelectronics interface for more than 20 years. The physicist is director at the Peter Grünberg Institute/Institute of Complex Systems – Bioelectronics. For him, the human being is a phenomenal all-rounder against whom cyborgs have almost no chance. The cyborg: a hybrid being, part-human and partmachine. Do you think it’s a fairy-tale or soon to become reality? There will undoubtedly be areas in future where technology will strengthen and improve human sensory systems. But the human being as an all-rounder is phenomenally good. For example, I ﬁnd it difficult to imagine that there could ever be a retinal implant that will be better than the human eye.

Implants in our heads; magnets in our ﬁngers: the mechanization of humans is no longer avoidable. What motivates and drives you? I see it as our responsibility to develop and provide technologies that we can fall back on when sensory systems fail. We are interested in overcoming deﬁcits, not in optimizing humans. L I F E A S A C Y B O R G (3)

Cyborg club

You have been working on this topic for decades. What do you expect the future to bring?

“Hello, I’m a cyborg”: East Frisian Enno Park set up the ﬁrst German cyborg club in Berlin. The members believe in a future where technology will optimize humans. Park himself is deaf. Several months ago, a cochlear implant made it possible for him to hear.

Technical progress is rapid. When I started studying, scientists had only just begun to talk about retinal implants. Research has come a very long way since then. The cochlear ear implant is a huge success today. Consequently, I am convinced that in the not too distant future, the blind will see and the deaf will hear. THE INTERVIEW WAS CONDUCTED BY KATJA LÜERS.

RESEARCH

A licence to lubricate Prof. Martin Müser’s latest publication stems from an idea that came to him during his research on friction. The idea is simple but it could start a lubricant revolution – and considerably increase the lifetime of devices and machines. Nature was used as a model.

Mixtures lubricate better: Prof. Martin Müser has developed a water-oil emulsion that could reduce friction between parts by a factor of 100.

Knee joints and elbows, hard drives, hand mixers and CD players, turbines, pumps, and ball bearings – all of these things have one thing in common: friction. Bones, moving parts, or surfaces rub against each other. A lubricant prevents them from wearing each other away. While technology utilizes oil for this, nature uses an aqueous solution. Nature has made the wiser choice, and Prof. Martin Müser, head of the research group Computational Materials Physics at the Jülich Supercomputing Centre (JSC), explains why. “Oil produces greater friction than water. And as friction causes abrasion, wear and tear is higher.” Scientists have long wanted to lubricate devices with water, but in the past this proved tricky. The problem is that water is displaced when pressure increases. As soon as two surfaces near each other, the water escapes, and the surfaces touch. Oil, in contrast, hardens somewhat and stays where it is. Nature employs a trick, which allows aqueous solutions to function as lubricants – in knee joints, for example. “Polymer brushes grow on the cartilage in knees. These brushes are made of chains of linked sugar molecules, which are charged in such a way that they attract water. The water tries to escape when under pressure, but it can’t,” explains Müser.

Although engineers could emulate this trick and attach polymer brushes to parts, this creates a new problem: “The brushes touch, become entangled, and eventually wear out. In the knee, they re-grow; but in devices, instead of the parts wearing out, the brushes would be abraded. The maintenance costs would simply move from A to B,” says the physicist.

MIXED BRUSHES The overarching topic of Müser’s research is friction. “We understand far less about friction than is generally thought. Although we are aware of many of the microscopic mechanisms behind it, we know too little about how they interact.” While working on such fundamental questions, Müser was struck by an idea of how the problem could indeed be solved using polymer brushes. “Scientiﬁcally, there’s not a lot involved,” he tells us. “You’ll laugh at how easy it is. All you have to do is use two different types of polymer brushes: the ﬁrst is hydrophilic, which attracts water, and the second is hydrophobic, which repels water and attracts oil. If we make a salad dressing of sorts – by mixing oil and water – and use this as a lubricant, a layer is formed that prevents the brushes from touching each other. That’s all there is to it!”

The computer simulation shows that thanks to the lubricant, the two surfaces with polymer brushes do not touch.

FRICTION RADICALLY REDUCED In order to demonstrate that the idea actually works, Müser and his colleague Sissi de Beer simulated the polymer brushes in action on supercomputers. The virtual surfaces that they investigated measured no more than 100 nanometres. That sounds small, but for a detailed atomic simulation, it’s actually quite big. Even more calculations were required to simulate the touching of surfaces at realistic time intervals. “Physically, friction is a relatively slow process that takes around 100 nanoseconds. For every nanosecond in the simulation, a thousand time steps must be calculated – which meant that the computers had a lot to do.” Müser and de Beer repeated the simulation, varying parameters such as temperature, material, and speed, and a year and a half later, they can conclude that friction can be reduced by a factor of one hundred compared to conventional lubrication with oil. To verify the results, De Beer performed the virtual experiments with real materials in a laboratory at the Dutch University of Twente. The result was the same: if parts are equipped with different types of polymer brushes and a water-oil mixture is used as a lubricant, friction can be reduced by a factor of a hundred. For all devices and machines that ﬁll both factories and households, this promises longer lifetimes. CHRISTOPH MANN

RESEARCH

Washing with an “OH” eﬀect Every day is washing day in the sky. The most diligent player in this process is the “hydroxyl radical” or OH radical for short. This molecule is a sort-of “detergent”, allowing the atmosphere to cleanse itself of pollutants. Until recently, this process was thought to be well understood. But over the last few years, this has changed. Measurements by climate researchers at Jülich are the reason: in wooded regions, there are up to ten times more OH radicals in the atmosphere than classical models predict.

THE NEW QUESTIONS • Where does the additional detergent come from? • What unknown processes occur during the washing cycle? • How good is the atmosphere’s ability to cleanse itself in reality? • What happens when air pollution increases?

Carbon monoxide

Methane

THE NE W FIND IN G S • Unexpected formation of OH from degradation products of isoprene. Isoprene is one of the most important atmospheric hydrocarbons emitted by forests. • Source of OH ruled out that was previously considered certain: nitrous acid (HONO). HONO is formed mainly over conurbations from nitrogen oxides.

Nitrogen monoxide

Hydrocarbons

Sulfur dioxide Greenhouse gases Greenhouse substances

Forest and savanna ﬁres Industry and combustion

Biogenic sources

Deforestation

T H E S O U R C E O F E N E R GY 17

The sun supplies the energy for the entire washing process

T H E D E T E R G E NT

THE MEASUREMENT PL AT F O R M S

• is formed mainly from ozone, water vapour, and sunlight • is only available in tiny concentrations: the average annual ratio of OH to air is 1:25 trillion • reacts with almost all trace gases in the air • is recycled to a large extent when trace gases are degraded

of the Institute of Energy and Climate Research Zeppelin NT: can take measurements and ﬂy in the decisive atmospheric layer (up to 1000 m) Saphir: a 300 m3 atmospheric simulation chamber for verifying chemical models

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Saphir Plus: a plant chamber connected to Saphir that accounts for the inﬂuence of plant emissions

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Details on the chemistry of the washing process can be found in the tablet edition of effzett.

Ozone

Nitric acid

Steam

Carbon dioxide

Particles, e.g. ﬁne dust

Sulfuric acid

THE WAS HIN G PR O C E S S … Hydrogen peroxide

OH converts trace gases into water-soluble substances. These can then be removed from the atmosphere by precipitation.

Oxidized organic compounds, e.g. formaldehyde

… AND E X E M PL ARY WAS HIN G PR O G R A MME S Trace gas

Degradation by OH radicals (%)

Atmospheric lifetime

Long-distance transport over lifetime

NO2

50 %

1 – 2 days

approx. 1,000 km

90 %

2 – 3 months

hemisphere

CH4

90 %

8 years

entire globe

Washing by precipitation

Dry deposition

≈ 1,000 m

THE OBJECTIVE

Deciding on the right measures to improve air quality and climate

OH is directly or indirectly involved in hundreds of chemical processes, which occur simultaneously and are linked to each other. Only when researchers understand these correlations will they be able to predict the consequences of measures. Not everything that improves air quality is good for the climate. One example is ﬁne dust. Reducing ﬁne dust improves the air quality, but simultaneously causes increased global warming because sunlight is not shielded as effectively.

RESEARCH

Three unique insights have been gained by Jülich researchers.

#1 E RR ATIC

New information on protein Without it, nothing in our body would function. Not even our body itself would exist. Proteins are involved in everything. They structure our organism and ensure the smooth running of our metabolism, immune system, and signal transduction, to name but a few processes: proteins. Each and every protein is tailor-made for its specific task from a long chain of amino acids, which wind themselves systematically into a clearly defined coil. Here, there are niches and cavities, as well as flexible and rigid areas that allow movements like those in small motors. The tiniest defect in the architecture of molecules can cause illnesses and diseases, such as Parkinson’s or Alzheimer’s. This is why researchers are working intensively on clarifying the structure of the giant molecules and understanding their function. The big challenge: developing methods to unveil the three-dimensional structure atom by atom and show how this structure changes when the proteins work as molecular machines.

> 100,000 different proteins can be found in the human body

34,350 amino acids form the largest human protein titin

13 percent protein is all a hen’s egg contains; three-quarters of an egg is water

A very short-lived structure that occurs at any given point in time in only every tenth molecule on average was observed by Jülich researchers collaborating with colleagues from Grenoble. They were using a newly developed method to investigate the protein ubiquitin. It is contained in almost all organisms and plays a role, for example, in degrading defective proteins. In the past, it was thought that ubiquitin existed in two slightly different structures: sometimes in the one and sometimes in the other. In fact, both structures exist in parallel: parts of the protein can ﬂip, and the molecule can jump back and forth between two structures.

#2 BOMBARDING AND C OMPUTING Bombarding proteins with tiny atomic particles – neutrons – is another method of getting to the bottom of their structure and movements. The deflection of the neutrons when they hit the protein provides information on its structure. By cleverly combining the results of such measurements with possible structural models on the computer, the Jülich researchers clarified the dynamics of a protein from the brain of vertebrates, the myelin basic protein (MBP). It is very flexible in aqueous environments. However, the new findings show that the molecule has a compact core and is only flexible at the ends.

#3 FL ASH FROZE N Researchers flash-froze a protein with the long name of cytochrome c peroxidase (CCP). The iron-containing protein plays a central role in the detoxification of cells: it degrades harmful hydrogen peroxide, which can form in cells during metabolism. This degradation occurs in several steps during which the protein continuously changes its structure. A team of researchers from the UK, Munich, and Jülich succeeded in observing the first step: at -173 °C, they shock-froze CCP in action, and then bombarded it with neutrons. In this way, they discovered how the protein’s iron atom binds the oxygen from the peroxide, thus solving the decades of guesswork surrounding this state. Their findings also apply to similar enzymes, such as those that metabolize drugs.

What’s your research all about, Mr Tsai? Dr. Chih-Long Tsai, research scientist at the Institute of Energy and Climate Research – Materials Synthesis and Processing

“At the moment, I’m working here at Jülich on a new type of lithium ion batteries. In this battery, the ions migrate through a thin ceramic layer. Such a solid-state battery is very safe because it doesn’t need flammable liquids. And it ages very slowly. This makes it ideal for use in electric cars and other forms of power storage. At present, we’re working on increasing the energy density using new mixtures of materials and improved manufacturing processes.”

Other cultures; other customs In Western cultures, direct eye contact is usually considered a sign of trustworthiness. Looking away is interpreted as a sign of disinterest or uncertainty. In other cultures, other customs prevail. For example, looking intensively into the eyes of an Asian is considered impolite.

It’s all in the eyes “What a cute dog!” – one small remark, and all of a sudden, you’re deep in conversation with your new neighbour. We humans like to talk to each other. Whether it’s just small talk, while jogging together, or while playing cards. Why? Gossipers are rewarded – in the brain. What sounds simple is difficult to demonstrate. But Jülich researchers Prof. Kai Vogeley from the Institute of Neuroscience and Medicine (INM-3) and his colleague Dr. Ulrich Pfeiffer succeeded. In a comprehensive study, the two Jülich scientists looked at what happens in the brain during social contact. “The crux when researching social activities is that people usually speak, gesticulate,

and move at the same time,” says Vogeley. “But we can only measure what’s happening in the brain with magnetic resonance imaging (MRI) if the test person quite literally stays still.” Together with Ulrich Pfeiffer, he came up with the idea of measuring brain activity during social exchanges using people’s gazes. After all, eye contact plays a key role when we talk to each other or do things together. “Our eyes continuously seek contact when we meet other people, regardless of whether we’re playing football, meeting up with friends, or simply chit-chatting with the saleswoman when paying,” says Pfeiffer. Looking intensively into somebody’s eyes, rolling our eyes, or looking away can sometimes say more than words. Measuring brain activity via eye movements is possible

RESEARCH

“First, look into the avatar’s eyes for a few seconds, and then focus on a blue square beside his face.”

using gaze-contingent eye tracking in an MRI scanner. This allows scientists to use eye contact to simulate and measure how people experience social contacts.

MAN OR MACHINE? The researchers were actively supported by Paul. The young man is an avatar, a made-up ﬁgure, who only exists on screen in the experimental setup at the Institute of Neuroscience and Medicine. From here, he looks at the person opposite him – ready to make eye contact with the test persons and communicate, or not, as the case may be. Mary* is a test person who looks into Paul’s intensive green eyes. She is lying on her back in the narrow MRI scanner. On her head, she is wearing a helmet of sorts packed with technology; on her ears, she has headphones that dampen the loud noise of the MRI scanner. Mary sees Paul in a mirror through an opening in the helmet. The mirror is mounted above her face. A screen directly in the scanner would interfere with the measurements. “Look into the avatar’s eyes for a few seconds and then shift your gaze to the left and right of his face and focus on a blue square,” were the scientists’ instructions. No sooner said than done. Sometimes, the avatar followed Mary’s gaze; sometimes he didn’t. Brain activity was measured in parallel. After ﬁve runs came the question: “Was the animated face controlled by a human or a computer?” – “Hmmm, I think it was a human,” surmised the 23-year-old. “The more often the avatar followed the gaze of the test persons in the test runs, the more cooperative and thus more human he was assessed

to be,” says Ulrich Pfeiffer, summarizing the ﬁndings of the study. At the same time, the MRI scan showed considerably higher brain activity in the test persons’ “social brain” and in the reward system – the medial orbitofrontal cortex and the ventral striatum. Scientiﬁcally, this causes more of the neurotransmitter dopamine to be released, which in turn triggers a feeling of well-being. When the test persons assumed that the test run was controlled by a computer, these areas of the brain were calmer in comparison.

CONSISTENTLY IMPORTANT Talking to each other or doing things together is known to do us humans good. Kai Vogeley jumps back in the history of human development. For him, the activity in the reward system during eye contact can also be explained by evolution. “Even back in the Stone Age, it was important not to go hunting alone but to go together and warn each other of dangerous animals or other hazards.” This behaviour sets the Homo sapiens apart from other close genetic relations, such as the chimpanzee. Evolution may even have optimized humans physically in this respect. “We are the only species with a white retina, offering a clear contrast to the pupil and so allowing us to recognize eye movements from quite a large distance. Chimpanzees in contrast have a dark retina. Instead of nonverbal communication, camouﬂage is probably more of a priority for this species of monkey.”

Training for autists People with an autism spectrum disorder have difﬁculty reading social and emotional signals. Their reactions are therefore often regarded as inappropriate. They frequently avoid eye contact with the person opposite them or they simply just stare. The gaze-contingent eye-tracking paradigm may offer patients a new form of treatment, which scientists at Jülich are also researching. Eye contact with other people and brain activity in the reward system can be trained.

I L S E T R AU T W E I N

* name changed

RESEARCH

New species in the particle zoo An experiment at the Jülich particle accelerator COSY recently showed that quarks also come in six-packs. This provides physicists with another piece of the jigsaw puzzle depicting the creation of the world. Previously, researchers had only observed quarks in threes in a particle or as a quark-antiquark combination.

What’s so special about this discovery? In a comprehensive theory known as the Standard Model, physicists describe all elements of matter and the forces at work between them. According to the Standard Model, quarks have an electric charge. In addition, the Standard Model attributes quarks with a colour charge to explain the forces – jargon: interactions – between them. There are three types of colour charge: red, green, and blue. Up to now, physicists had only observed particles whose colour charges combined in line with conventional colour theory to create white. One example of this are “baryons”, which also include protons and neutrons: they are made up of three quarks each, whose colour charges of red, green, and blue combine to become white or colourless. Quarks don’t just bind to form a trio; they also form mesons, which are made up of quark-antiquark pairs. An antiquark has

the same mass as its counterpart, the quark, but it possesses an opposite charge. Mesons are also colourless: antiquarks appear in antired, antigreen, and antiblue. When combined with the corresponding quarks, white is the result. Theoretically, other colourless particles with more than three quarks or more than a quark-antiquark pair are also conceivable. But for decades, no such particles were found. Now, a team of more than 120 scientists from eight countries – known as the WASA-at-COSY collaboration – have proven at the Jülich particle accelerator that a bound state of six quarks also exists. The group had ﬁrst observed this state in 2011 during another experiment. However, the state only exists for a mere hundred-sextillionth of a second (0.000 000 000 000 000 000 000 01 seconds). This time span is so short that light only travels in this state a distance equivalent to the diameter of a tiny atomic nucleus.

What does this detection mean? “At least one of the exotic particles predicted by the Standard Model actually exists,” says Jülich nuclear physicist Volker Hejny who is involved in the WASA-at-COSY collaboration. In other words, the scientists have conﬁrmed another part of the picture they have painted of the world, of matter, and of the creation of both. The quark six-pack was produced artiﬁcially in the particle accelerator. It is highly likely that it also occurs naturally in the universe, for example when stars are born, and that it plays a role in cosmic events.

What are quarks anyway?

What is a particle accelerator?

All matter in our world is made of chemical elements, which are composed of atoms. Atoms have a nucleus made of protons and neutrons, which is surrounded by a cloud of electrons. Protons and neutrons, in turn, are each composed of three quarks. Unbound or free quarks have never been observed. According to present knowledge, quarks cannot be broken down any further and are thus elementary particles. Different types of quarks and other elementary particles are collectively referred to by researchers as the “particle zoo”.

Physicists use accelerators to make protons and other particles collide at almost the speed of light. The quark six-pack can only be detected via its decay products – in other words via what’s left of it after a hundred-sextillionth of a second. These secondary products are detected by the scientists using precision measurements and enormously complex instruments, the detectors. For the experiments, the WASA-at-COSY collaboration uses the WASA detector (pictured). It was originally in Uppsala, Sweden, but has been in operation for eight years at Jülich’s particle accelerator COSY. FRANK FRICK

Lifetime: From >1030 years to <10 -10 seconds

FAMILIAR STATES

Quark bound states

Lifetime: <10 -8 seconds

NEW ADDITIONS FROM JÜLICH

Lifetime: <10 -23 seconds

RECENTLY DISCOVERED

Lifetime: <10 -23 seconds

Quarks

Antiquarks

Type of interaction unclear

RESEARCH

The chemistry of fear Fear saves lives. Excessive fear can make you sick. Researchers at Jülich are tracking down the biological causes of this mental disorder. Their attention is focused on receptors, which play an important role in transmitting signals in the brain.

Prof. Andreas Bauer (52) investigates neurochemical processes in the brain. These include the emergence of fear as well as diseases such as Alzheimer’s.

Your hands are sweaty. Your head is pounding. Your heart is racing. Your breathing is raspy. Your knees are weak. When we’re afraid, it’s not just emotions that overwhelm us. Yet fear is not actually a bad thing in itself. It’s an important survival mechanism, which warns us of danger, a bit like pain. But some people experience it differently. They manifest fear and its physical symptoms more intensively than healthy people. Things that most other people wouldn’t be afraid of in the slightest, they perceive as life-threatening. Such panic attacks can be caused by narrow spaces, dirt, or even the fear of being afraid. “Anxiety disorders have a considerable impact on everyday life,” says Prof. Andreas Bauer from Jülich’s Institute of Neuroscience and Medicine. In Germany, it is estimated that 1.5 million people suffer from such disorders. This makes anxiety disorders the most common mental disorders alongside depression.

UNCLEAR CAUSES However what causes anxiety disorders is still unclear. “The disorders are most likely caused by a combination of different factors,” says the Jülich

expert. These can include physical illnesses, traumatic experiences, and life stresses both at home and at work. Another important factor is the human nervous system. When we’re afraid, the autonomous nervous system – the system that controls our heart, breathing, and internal organs – is in a state of excitation. Neuroscientists assume that chemical changes in the brain cause the nervous system to over-react and trigger panic attacks. What actually happens in the brain is being investigated by research groups all over the world. Andreas Bauer’s team is concerned with “adenosine receptors”. These molecules play an important role in transmitting signals between nerve cells. What makes them particularly interesting is that in healthy individuals, a panic attack can be caused by artificially blocking the receptors. “Certain genetic variants in adenosine receptors are also a risk factor for neurological and psychiatric disorders, which include anxiety disorders. These gene modifications influence the concentration and function of the receptors,” says Andreas Bauer.

Unexpected density Researchers from Jülich, Münster, and Würzburg discovered high concentrations of the adenosine A1 receptor in the brain of healthy individuals with a genetic predisposition to anxiety disorders. The concentrations were highest in the red regions and lowest in the blue. Certain genetic variants of adenosine receptors are known to be a genetic risk factor for anxiety disorders.

PROTECTIVE MECHANISM? The Jülich neuroscientists are investigating how the genetic modiﬁcations actually impact on the concentration of adenosine receptors in cooperation with researchers at the universities of Münster and Würzburg. As part of this work, they used positron emission tomography to image the brains of around 30 test persons. This group included individuals with and without a genetic predisposition to anxiety disorders. None of the test persons had actually manifested an anxiety disorder prior to the study. The result: the researchers found a clear difference in the brains of both groups. The risk gene carriers had large quantities of a certain adenosine receptor in all brain areas investigated – the adenosine A1 receptor. The concentrations were considerably higher than in individuals who were not carrying a risk gene. “We presume that the increased concentration is a compensation or protection mechanism that prevents the outbreak of anxiety disorders,” says Bauer. Up to now, research was unable to

explain exactly why not all risk gene carriers had manifested an anxiety disorder. “Why anxiety disorders only tend to manifest in individuals older than around 30 would then also make sense. The production of adenosine receptors decreases namely as we grow older and – according to our assumption – so too does the protection mechanism,” says Bauer. To test their theory, the researchers now want to examine risk gene carriers who already suffer from an anxiety disorder. In these individuals, they should – if their theory is correct – only ﬁnd small concentrations of the protective receptor. If the assumptions are proven true, the adenosine A1 receptor could in future function as an indicator for an impending anxiety disorder. And that’s not all: if the concentration of this receptor can be artiﬁcially controlled, new research approaches would make it possible to develop drugs to treat these disorders. CHRISTIAN HOHLFELD

69,100,000 people suffer from anxiety disorders in Europe

22,700,000 of them suffer from speciﬁc phobias, such as a fear of small spaces, ﬂying, or the dentist

RESEARCH

Jülich researchers at the source The Bavarian city of Garching is an “El Dorado” for materials research. Scientists from the Jülich Centre of Neutron Science have played no small role in creating it.

Jülich

480 km Garching Jülich’s campus measures 2.2 km2. But Jülich scientists are active beyond the campus. This section features brief reports on where they conduct research. This time around, south Germany is in the limelight.

Jülich researchers Dr. Olaf Holderer and Dr. Oxana Ivanova at the neutron spin-echo spectrometer, one of the eleven Jülich instruments in Garching

2.2

Dirnismaning and Hochbrück: these are instruments available at the joint facility plus but two examples of the compelling names run by TU Munich and the Helmholtz of parts of the city in Upper Bavaria. But in centres in Jülich and Geesthacht. Scientists the city of Garching with a population of 17,000, use them to uncover the secrets of materials with these aren’t the only districts. There is also an special properties. Once they have uncovered area with the matter-of-fact name of “University these secrets, they will be able to develop new and Research Centre”. It’s actually an “El Dorado” and more efficient functional materials. The for researchers from all over the world, who come team from the Jülich Centre of Neutron Science here to unearth scientific treasures for a few days (JCNS) operates and maintains eleven of the at least. Around 70 men and women working instruments – some alone and some in cooperfor Forschungszentrum Jülich are permanently ation with partners. “A few of these originally based in Garching. With state-of-the-art instrucame from the neutron source FRJ-2 in Jülich ments and decades of experience, they provide (also known as DIDO), which was shut down in many of these scientists with a helping hand. 2006 and have since been further developed at Garching. Others we built from scratch. Two new Materials researchers go on expeditions to instruments are currently being constructed,” Garching because Germany’s most powerful says Dr. Alexander Ioffe, head of the JCNS lab at neutron source can be found there. Neutrons are Garching. electrically neutral nuclear particles and they are ideal probes for exploring atoms and their move- NOT JUST FOR THEIR OWN USE Two-thirds of the measuring time on the instruments in matter. Heinz Maier-Leibnitz Zentrum, ments is used by external researchers. They must a research centre named for the physicist under first convince a group of independent experts whose leadership the nuclear reactor known as that their research projects are of a high scientific the “atomic egg” was built in the 1950s, ensures quality. The other one-third of time is reserved that the users can make optimal use of the source. Currently, there are 25 highly specialized for the Jülich scientists, who mainly investigate magnetic nanomaterials and soft matter like plastics and proteins. Conducting their own research is incentive enough for the Jülich researchers to continuously improve the quality of the instruments. Optimal instruments, in turn, attract further expeditions to the Bavarian region, which has already provided scientists with many enriching insights. And this is not a legend like that of El Dorado, but is indeed reality. FRANK FRICK

Thumbs up PE N G UIN WATC H

Volunteer researchers wanted! Penguins have something magical, as most visitors to the zoo will be able to confirm. In order to learn more about their lives in their natural habitats, an international team of researchers flew to the Antarctic and photographed the nesting sites of the flightless seabirds. They took so many photos, that the scientists need help analysing them. On the website “Penguin Watch”, anyone who is interested can take a look at the pictures and mark the birds and their eggs. The researchers hope to use these data to learn what nesting sites penguins prefer and how the sizes of colonies change. Up to now, more than 7,000 hobby researchers have lent the project a helping hand and classified more than 550,000 images. – W W W. P E N G U I N WAT C H . O R G –

J U B R ÄU

Jülich team wins brewing contest “Mojito” is the name of the exotic creation that won the Jülich biotechnologists the ﬁfth international brewing contest run by Hamburg University of Technology (TUHH). The “JuBräu” team of undergraduates and PhD students held their own against 17 competitors and displayed great skill in one of the oldest biotechnological processes. The winning beer captivated the jury with its typical sweet-and-sour mojito taste, which was very similar to the Cuban cocktail. The team produced the taste using special malts, a selection of hops, and a unique way of controlling the fermentation process in the beer. The refreshing kick was provided by boiled mojito mint leaves. – W W W. F Z - J U E L I C H . D E/J U B R A E U –

PA R T I C L - O - M AT I C

Which particle suits who best? Just like us humans, physical particles have certain properties. Among them, there are lightweights, those who like to be the centre of attention, and motor mouths. But which particle resembles your own personality? The “Particl-o-matic” provides answers. By asking ten questions, the program can ascertain whether we are more like a proton or whether the character of a Higgs particle suits us better. The “Particlo-matic” is part of the Particle Zoo exhibition – a joint project being pursued by the DESY research centre and Universum® Bremen. Videos and particle proﬁles explain the different properties of physical particles. – T E I L C H E N Z O O . D E S Y. D E/ PA R T I C L O M AT I C –

Research in a tweet With a minute of computing time, we want to look 15 minutes into the future. This could help us to save lives. #Basigo Dr. Armel Ulrich Kemloh Wagoum works on optimizing the controlled evacuation of large crowds. He develops models for this, which use data from real ﬁlm footage to calculate what routes pedestrians will take and where bottlenecks are likely to emerge. The data for his models come from experiments with up to 1,000 volunteers, such as the large-scale project “Basigo”. www.basigo.de