Sights Set on Safety - Research in Jülich (2/2014)

::SightSSetonSafety Jülich Researchers Work on Solutions for Nuclear Waste Management

:: In Close Contact: How Cells Take Up Nanoparticles

:: Exhibition in Ghent: Art from a Supercomputer

02|2014The Magazine of Forschungszentrum Jülich

RESEARCH in Jülich

:: IN THE PICTURE

“It never gets boring around here!” Glassware maker Patrick Pistel and his colleagues at Jülich’s Central Institute of Engineering, Electronics and Analytics fabricate customized glassware – from flasks to kerosene reformers. The only thing the intricate objects have in common is that there is nothing quite like them on the market. Otherwise they are all one-of-a-kind – designed, developed, and fabricated for the specific questions addressed by Jülich researchers. The result: “visionary solutions”, as the glassware makers themselves dub their custom-made products.

ContentS

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32 | 2014 Research in Jülich

:: NEWS IN BRIEF 4

:: COVER STORY 6

6 SafetyforFutureGenerations Research on the final disposal of radioactive waste

9 TheEffectsofWater Understanding the processes in a final repository

:: RESEARCH AT THE CENTRE 12

12 InspirationfromtheSupermarketNeuroscience uses statistical method from retailing market research

14 UpCloseandPersonalontheNanoscaleHow cells let nanoparticles in

16 Nanomedicine:SomewhereBetweenHypeandHopeInterview with Munich professor Wolfgang M. Heckl

17 SomethingintheAiroverSpaTown?Climate researchers measure air quality in Bad Homburg

18 GlowofSatisfactionasDreamComesTrueExcellent business model: sorting facility for bacteria

20 GoldMineintheCowshedManure as a raw material for customized fertilizers

:: LAST BUT NOT LEAST 22

22 ArtfromaSupercomputerUnusual computing task for JUROPA

23 PublicationDetails

Research in Jülich 2 | 20144

Even though nobody wants it, it’s there, and we cannot simply leave it to take care of itself: high-level radioac-tive waste from our nuclear power plants, which will con-tinue to emit radiation for

thousands of years to come. We need to find a solution for its final disposal in order to pro-tect future generations in the best possible way.

Forschungszentrum Jülich, with its exper-tise in waste management research, consid-ers it a special duty to make a contribution to these efforts. Jülich experts analyse the be-haviour of radioactive waste under different final disposal conditions right down to the level of atoms and molecules, thus helping to find the safest solution. You will also discover what brain researchers have to do with super-markets and why cells love to be in close con-tact.

I hope that this issue makes for interesting reading!

Yours sincerely,Prof.AchimBachemChairman of the Board of Directorsof Forschungszentrum Jülich

:: EDITORIAL

Sharp Images of Thicker Samples

Peter grünberg institute | 3D cryo- electron microscopy provides research-ers with important insights into the cell structure of biological samples. As in computer tomography, the method cre-ates a three-dimensional image from a large number of two-dimensional pic-tures. Scientists from the Ernst Ruska- Centre – a cooperation between For- schungszentrum Jülich and RWTH Aachen University – and from the Weiz-

mann Institute of Science in Israel have applied scanning transmission electron microscopy, a well-established method in materials research, to biological samples. Compared with conventional phase-contrast methods, this proce-dure makes it possible to record high-resolution images of thicker sam-ples, such as bacteria. It thus widens the range of options for 3D cryo-elec-tron microscopy. ::

Jülich Supercomputing Centre | Male birds-of-paradise im-press females with the iridescence of their feathers. Research-ers from Jülich and Groningen in the Netherlands have now suc-ceeded in simulating the complex optical properties of their plumage on a computer. The computer model developed for this purpose could also help to produce nanostructured materials with special optical properties. ::

3D image of Agrobacterium tumefaciens soil bacteria

Just Like Paradise


NEWS IN BRIEF

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instituteofenergyandClimateResearch|A hundred nanometres is quite sufficient a size for an aerosol particle in the air to have an impact on climate – for example by acting as a condensation nucleus for cloud formation or by reflecting incident sunlight back into the atmosphere. Scien-tists have long puzzled over the exact processes in which these suspended par-ticles form. An international team of re-searchers headed by Thomas Mentel from Jülich have now reported in the scien tific journal Nature that certain va-pours in the atmosphere cause aerosol particles to grow. Supported by numer-ous experiments, the scientists have been able to clarify how these vapours form almost immediately when trees and other plants release certain substances into the atmosphere. ::

Vapours Cause Growth Spurt

Crowding in Blood Vessels Simulated

Certain vapours in the atmosphere make aerosols grow so large that they have an impact on climate.

Speed Matters

Petergrünberg institute| Spin elec-tronics is considered a promising ba-sis for faster and more energy-effi-cient future data processing. Re-searchers from Jülich, Strasbourg, and Shanghai have discovered an effect that produces spin waves with defined frequencies with much greater ease than was previously thought possible. Their computer simulations demon-strate that such waves form when a magnetic field pulse passes alongside a magnetic material at sufficient veloc-ity. The scientists were even able to control the frequency of the spin waves by influencing the speed at which the field pulse moves. Targeted control is important for spin waves to be utilized for technical purposes. The researchers have named the new phe-nomenon the “Spin-Cherenkov effect” based on the Cherenkov effect, which occurs when charged particles pass through water faster than the phase velocity of light. ::

institute of Complex Systems/institute for advanced Simulation |White blood cells serve as the police force of the body’s immune system. They drift through arteries and veins with the blood. If nec-essary, they penetrate the walls of arteria to fight intruders such as viruses. Since they do not move actively in the blood stream, it was until recently unclear how they reach the walls of the blood vessels. Jülich researchers have now been the first to examine the process in detail using three-dimensional computer simulations. An average number of red blood cells and a low flow velocity will push a white blood cell towards the wall of the blood vessel (a). It can then pass through the vessel wall. However, if the number of red blood cells is low and the flow velocity high, the white blood cell will continue to go with the particle flow and cannot reach the vessel wall (b). The simulation could also be helpful in developing new techniques for diagnosing illnesses. ::

a)Pushedtotheedgeor… b)…rightinthemiddleof theparticlestream

Whatspursmeonisthatidon’tjustworkwithmodelsubstances,butwiththeverymaterialthatwilleventuallybesenttoafinalrepository.Dr. Hildegard Curtius

»Research in Jülich 2 | 20146

Safetyforfuturegenerations“It’s an issue we don’t want our children to have to deal with,” is how Prof. Dirk Bosbach sums up his mission in the field of nuclear waste management research. The Jülich scientist and his team are working on the fundamentals of safely storing radioactive waste.


CoVeRStoRy|WasteManagementResearch

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By the end of 2011, German nuclear power plants had already left a leg-acy of 7,790 tonnes of spent nucle-

ar fuel rods. It will take hundreds of thousands of years until their radioactive decay is more or less complete. The Ger-man Office for Radiation Protection esti-mates that another 2,760 tonnes will be added before the last German nuclear power plant stops producing electricity in 2022. Together with storage contain-ers and the high-level radioactive waste that Germany has to take back from the reprocessing plants in France and the United Kingdom, the spent nuclear fuel rods will have a total volume of around 28,100 m3. This corresponds roughly to the volume of ten Olympic-size swim-ming pools. The long-term radioactivity is emitted by substances that make up less than 1 % of the spent fuel elements.

But how can high-level radioactive waste be disposed of safely? Almost all experts agree that it would be best to store the radioactive waste several hun-dred metres below the surface of the Earth in suitable rock formations – an option that was first proposed as early as the 1960s. The rock naturally pre-vents radioactivity from being released into the biosphere. In addition, contain-ers, filling materials, and other technical barriers will also protect the material.

The search for the best site and con-cept for such a final repository, and the associated risk analyses, raise questions regarding geology, engineering, nuclear chemistry, and physics that can only be answered by means of research. In Ger-many, the related research tasks have

been assigned to different public institu-tions. For example, the Federal Institute for Geosciences and Natural Resources is responsible for geological research. The Helmholtz Association, of which Forschungszentrum Jülich is a member, investigates the behaviour of different types of radioactive atoms – or radionu-clides, as the experts say – under differ-ent conditions.

50yeaRSofReSeaRChAs a former nuclear research centre, Jülich has been pursuing nuclear waste management research for the last 50 years. However, the framework condi-tions have changed substantially during this time: In the early years, buoyed by great enthusiasm for the new technolo-gy, researchers worked on the use of nu-clear energy with a closed fuel cycle, in-cluding a reprocessing step. “Today, in contrast, after the federal government decided to phase out nuclear power in Germany and Jülich’s DIDO research re-actor was decommissioned in 2006, our research helps us to meet long-term re-sponsibilities for the disposal of nuclear fuels, for example from the reactors that used to be operated at Jülich,” says Prof. Dirk Bosbach, who heads Nuclear Waste Management at the Institute of Energy and Climate Research.

What he means by long-term respon-sibilities: “The behaviour of the radioac-tive waste in a final repository must be projected hundreds of thousands of years into the future,” says Bosbach. In order to look this far ahead, scientists usually employ the scenario method: ex-

perts devise a range of scenarios – pos-sible future developments – that is so comprehensive that it includes the actu-al future development. “For each individ-ual scenario, it must then be demon-strated that the final repository is safe,” says Bosbach’s colleague Dr. Guido Deissmann. For a final repository in a rock formation deep underground, one scenario is that radioactive waste comes into contact with water. “We use ex-periments, simulation results, and ther-modynamic calculations to determine the processes that would occur in a final repository in such a case,” says Bos-bach.

Prof. Dirk Bosbach is a director at the Institute of Energy and Climate Research and lectures at RWTH Aachen University.

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They work particularly closely with elec-tron microscopy experts at the Ernst Ruska-Centre, theoretical physicists at the Peter Grünberg Institute, and with the Jülich Supercomputing Centre. “Co-operation helps us to understand the be-haviour of radioactive waste under the conditions in a final repository right down to the level of atoms and mole-cules – which is a prerequisite for mak-ing reliable forecasts regarding long-term safety,” says Bosbach.

Such forecasts will play a decisive role in the selection of a site for a per-manent nuclear repository in Germany. The law stipulates that this process should be completed by 2031. “The waste management concept requires the interim storage of the high-level radioac-

WinDoWS50CMthiCKJülich has a comprehensive infrastruc-ture for collecting experimental data. For example, so-called “hot cells” were introduced at Forschungszentrum Jülich in the 1970s. These are laboratory areas with radiation protection windows 50 cm thick and shielded with special walls. Here, highly radioactive material – the material that will eventually be stored in a final repository – can be examined us-ing telemanipulators. The only other hot cells in Germany are located at Karlsru-he. The Jülich hot cell facility is also used by fusion researchers and for reactor dismantling. In addition, the researchers headed by Bosbach also benefit from the know-how and devices used by other disciplines at Forschungszentrum Jülich.


tive waste for a period of 30 to 40 years,” says Bosbach. Numerous radio-nuclides in the waste become stable nu-clides after a relatively short period of time. Radioactivity and the associated heat generation in the nuclear waste thus drop particularly quickly during the first few decades, so that after this peri-od, it becomes easier to build a final re-pository that meets the requirements for heat removal and the safe confinement of the waste. ::

Frank Frick

finalrepositorywithamulti-barriersystem

naturalbarriers

1 Environment

2 Geosphere

3 Host rock

geotechnicalbarriers

4 Seals

5 Backfill material

technicalbarriers

6 Container

7 Waste form

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1

3

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This concept envisages that the radioactive waste will be stored at a depth of several hun-dred metres. Various barriers shield the waste from the envi-ronment completely. All of these (geo)technical barriers are intended to compensate for the weaknesses of the natural barriers. The aim is to prevent the radioactive waste from coming into direct contact with the biosphere.



theeffectsofWater

A woman’s voice is giving instruc-tions, such as “move closer” or “check position of hands”. Dr.

Hildegard Curtius is familiar with the pro-cedure. She calmly follows the instruc-tions and positions herself correctly in a space the size of a shower cubicle: the tip of her nose almost touching the metal wall, her hands raised to her left and right, and her feet standing on wire grat-ing. While the voice counts down from ten to zero, Curtius’ body is scanned to detect any ionizing radiation. Then the sliding glass door opens and Curtius can leave the cubicle. The measure-ments are prescribed by law and are routinely performed every time someone leaves the “hot cells”. These are specially shielded labo-ratories in which experiments can be carried out on highly radioac-tive substances using gripper arms referred to as manipulators. Only in these laboratories can Jülich re-searchers handle real waste from nuclear reactors – a prerequisite for examining the behaviour of these substances in a final reposi-tory.

Hildegard Curtius has been working at Forschungszentrum Jülich for 18 years. She studies the behaviour of spent nuclear fuels. “What spurs me on is that I don’t just work with model substances, but with the very material that will eventually be sent to a final repos-itory,” she says. She studies one of the greatest risks associated with a final repository, namely what would happen if the spent fuel came into contact with water.

For example, Curtius discov-ered that water corrodes spent fu-el elements from research reac-tors much faster than those from reactors for power generation.

The composition of research reactor fuel elements is different because they are intended to emit as many neutrons – electrically neutral nuclear particles – as pos-

sible during operation. After only a few years of contact with water, these fuel elements lose their shape and form a mud-like residue. At first sight, this doesn’t bode well for safety because it means that the radionuclides – radioac-tive atoms – could reach the water par-ticularly quickly. However: “Almost all corrosion products in the mud-like resi-due bind to, or absorb, the radioactive atoms that are initially released, so that they cannot spread any further,” summa-rizes Curtius. The next task is to under-stand these processes in detail in order

to reliably assess long-term safety in the scenario of contact with water.

An entirely different phenomenon al-so involving water in direct contact with radioactive waste is being investigated by Dr. Felix Brandt and PhD student Juli-ane Weber from the Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety (IEK-6). After about 100,000 years, spent fuel elements form relatively large amounts of radium as a result of the ra-dioactive decay of uranium-238. In prin-ciple, radium dissolves well in water

thematerialswestudyhereserveascatalystsinchemistry–it’sfascinatingtometolookatanothersideofthesematerials.Yulia Arinicheva

»

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and doesn’t bind strongly to the miner-als that may be used as a barrier in a final repository. So far, this process has not played a major role in safety con-siderations, because it will only become significant in the distant future. Never-theless, for the actual construction of a final repository, such processes need to be taken into account. This is one of the reasons why Svensk Kärnbränsle-hantering (SKB), the company that is planning to build a final repository in

Sweden, is providing funding for We-ber’s PhD thesis.

ReSPonSiBLeReSeaRChWeber is examining a process in a final repository that may reduce the amount of radium that could end up in the water and thus be transported out of the re-pository: the reaction of radium with barium, which also arises from the radio-active waste, and with sulfate, which oc-curs naturally. These three components

together form solid mixed crystals. Based on Weber’s experiments com-bined with atomistic simulations and thermodynamic calculations, the re-searchers headed by Brandt have demonstrated the extent to which mixed crystals are formed. SKB needs these figures for the safety analyses the company is required to submit to the authorities. Weber comments: “For me, it’s important to work on a topic that is of relevance for society.”

it’sincrediblyexcitingtoanalysematerialswithavarietyofmethodsandtocooperatewithscientistsfromdiversebackgroundsanddisciplines.Sarah Finkeldei


2 | 2014 Research in Jülich 11

Using supercomputers, Dr. Piotr Kowalski is solving the riddle of the structure of radioactive materials.

fact that they are so complicated,” says Kowalski.

It is not surprising that, as a theoreti-cian, he doesn’t work in the hot cells. However, neither do Juliane Weber, Yulia Arinicheva, and Sarah Finkeldei perform their experiments in hot cells behind 50 cm of lead glass. They work in a radia-tion protection area similar to those found in radiological laboratories in hos-pitals. The main reason for this is that in their experiments, the researchers use the tiniest amounts of these substances, so that at most they are only slightly ra-dioactive. However, this is sufficient to gain fundamental findings on the techni-cal aspects of final disposal. ::

Frank Frick

natURaLRaDiationPRoteCtionPhD student Yulia Arinicheva, in con-trast, is motivated primarily by scientific curiosity. She and her colleague Sarah Finkeldei are studying the possibility of integrating long-lived radionuclides from nuclear waste into ceramic materials. Disposing of the waste in this form could reduce the probability of radioactivity from the final repository being released into the biosphere. Such ceramics are chemically very stable under the influ-ence of water, high temperatures, and ionizing radiation. This is demonstrated by the natural relatives of these ceram-ics: monazites, phosphate minerals that contain up to 30 % radioactive thorium and uranium. They do not exhibit any ra-diation damage, although some of them have been around for billions of years. Arinicheva and Finkeldei therefore pro-duce ceramics in the laboratory in order to study their properties in detail.

“In Germany, the law stipulates that high-level radioactive waste should be disposed of directly, without integrating it into ceramics,” says Prof. Dirk Bos-bach, director at IEK-6. “However, as sci-entists, we want to see what’s possible and explore options that may be particu-larly safe and advantageous.”

Arinicheva wrote her master’s disser-tation on “green chemistry”, namely the conversion of biomass using catalysts. “The materials we study here serve as catalysts in those processes – it’s fasci-nating to me to look at another side of these materials now,” says Arinicheva. She also knows how to share this fasci-nation with others: with a short and en-tertaining presentation on her work, she won the science slam at the end of March at Kulturbahnhof Jülich – a com-petition where scientists present their own work to a diverse audience.

Her colleague Sarah Finkeldei par-ticularly likes the varied, interdiscipli-nary, and international environment at Nuclear Waste Management: “It’s in-credibly exciting to analyse materials with a variety of state-of-the-art meth-ods and to cooperate with scientists from diverse backgrounds and disci-plines in order to find out how the re-sults, all of which constitute pieces of a large puzzle, fit together and contribute to a fundamental understanding.”

SUPeRCaLCULationSTwo researchers who have been particu-larly helpful to Finkeldei are Dr. Piotr Kowalski, head of the Jülich young inves-tigators group “Atomistic Modeling” at IEK-6, and PhD student George Beridze. They use supercomputers to calculate the structural arrangement of radionu-clides – mostly actinoids – in Finkeldei’s pyrochlore ceramics and in other materi-als based on their quantum chemical properties. “Jülich enjoys international renown not only for its expertise in ma-terials research, but also its supercom-puters and the associated know-how – and we benefit from both,” says Kowalski. His colleague George Beridze is motivated by the fact that Jülich is a leading institution and the knowledge that his theoretical model calculations are important for experimenters and al-so for practical considerations.

The two scientists’ calculations are extremely sophisticated. All of the acti-noids have a particularly large number of electrons that have a strong impact on each other, and all of these interactions need to be taken into account in their calculations. “We’re proud that our cal-culations are very reliable despite the

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inspirationfromtheSupermarket

Have you ever wanted to know how long a glance lasts in scientific terms? And what happens in the

process? Take a quick look at this photo:

The eye doesn’t take long to identify the mosquito. Your gaze scans the con-tours, rests on a point near the end of the wing – scientists call this “fixation” – and then abruptly moves to another point, such as the eye. Scientists refer to this movement as a saccade. The eye re-quires a total of 250 milliseconds, or a quarter of a second, to register the visual information, process it, and pre-pare for another eye movement to a new point of fixation. That’s how long a glance lasts.

For the brain, this rapid perception of an object is a trivial task. It performs this action thousands of times a day, leaving us free to concentrate on other thoughts. For brain researchers, howev-er, it is a mystery. How do we perceive things? How do our neurons process sig-nals from the eye? Which cells communi-cate with each other, and in what way? And how do they decide in a matter of milliseconds where our gaze should go?

It is questions like these that interest Prof. Sonja Grün from the Institute of Neuroscience and Medicine (INM-6). She investigates what happens in the brain during a glance – and has shown that neurons form teams in order to co-

ordinate the processes that occur, such as fixation or saccades. The professor set out to discover which neurons are active simultaneously, and at which times. When evaluating the data, she made use of a helpful algorithm that is also applied in retailing market research.

The analogy with retailing market re-search struck Sonja Grün for the first time during a spring school held by the Interdisciplinary College at the Möhne Reservoir. She was listening to a pres-entation by a computer scientist on in-telligent data mining in retailing market research. Retailing market researchers want to find out how products should be placed in supermarkets so as to in-crease sales. If someone buys charcoal and sausages, for instance – wouldn’t they be more likely to pick up a bottle of barbecue sauce, too, if it was right be-side the charcoal? To identify product groups like the “barbecue group”, the researchers analyse the contents of shopping trolleys. In doing so, however, they are confronted with a statistical problem: while charcoal, sausages, and sauce obviously belong together, the presence of mustard and chocolate in one trolley is more likely to be a random occurrence. But how can you tell the dif-ference?

RanDoMoRSySteMatiC?At this point, Sonja Grün pricked up her ears. She had a similar question, even though it concerned an entirely different field – brain research. She wanted to identify and analyse the activity patterns of neurons. Which concurrencies are random, and which point to a group of neurons that fire in unison, thereby trig-gering another process – such as an eye movement, perhaps?

Retailing market researchers, ex-plained the computer scientist, solve such problems by means of frequent itemset mining (FIM). This method de-tects groups of objects in large data vol-umes quickly and efficiently, counts their frequencies, and sorts them ac-cording to various criteria, such as the probability of a pattern – for example, products often purchased together. FIM helps large online retailers to generate product suggestions that can be aston-ishingly accurate.

Sonja Grün realized that this tech-nique could also be used to identify functional groups of neurons. The pro-fessor promptly approached the comput-er scientist, and from a lengthy, animat-ed conversation grew a successful exchange between two very different disciplines.

“In the course of several years’ work, we supplemented the statistical meth-ods of retailing market research, trans-ferred them to brain research, and have

Neuroscientist Sonja Grün uses methods from retailing market research to understand how neurons cooperate.

Physicist Prof. Sonja Grün uses statistical methods to explain how neurons organize themselves in the brain.


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ReSeaRChattheCentRe|BrainResearch

now applied them to existing data,” ex-plains Sonja Grün. Experiments had pro-vided detailed measurements of the ac-tivity of up to 100 individual neurons while an animal gazed at objects for sev-eral moments. “Normally, a small num-ber of neurons are always active at any given millisecond. However, during cer-tain actions, such as fixating on an ob-ject, a much larger number of neurons suddenly become active at the same time. To distinguish behaviour-depend-ent activity patterns from random pat-terns, we supplemented the FIM method with a statistical method. Using the modified FIM, we were able to establish which of the simultaneously active neu-

rons form a functional group, for in-stance while the gaze is directed at a given object,” explains Sonja Grün. The professor has thus come closer than any other researcher to understanding gaze in the brain.

MySteRyStiLLUnSoLVeDAs yet, however, the mystery remains

unsolved. Why do the neuron groups form, and how are they disbanded? Do they interact with other teams? And could a thought be a group of signals travelling through the brain?

Satisfactory answers to these ques-tions have not yet been found. “In neuroscience, we’re in a similar situa-

tion to that faced in physics before the discovery of quantum theory: despite having increasing amounts of increas-ingly accurate data, we lack an all-en-compassing theory for interpreting those data,” says Sonja Grün. In her search for such a theory, the professor will continue to look beyond the bound-aries of her discipline. ::

Christoph Mann

1 2Time

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Random combinations

Random simultaneous activity

Same combination, thus a high probability that it is not random

Same group of neurons active simultaneously

ShoppingbehaviourandneuronactivityThe statistical method known as “frequent itemset mining” (FIM) finds groups of objects in large volumes of data quickly and effi-ciently and counts their frequencies. In retailing market re-search, this is used, for example, to identify products that are often purchased together. In brain research, a modified version of the FIM method helps to distinguish behaviour-dependent ac-tivity patterns from random patterns. This enabled Jülich scien-tists to establish which of the simultaneously active neurons form a functional group, for instance while the eye focuses on a given object.

Neu

rons

Time in seconds


The more physical contact, the better: by means of computer sim-ulations, Jülich researchers have

demonstrated that the shape of a parti-cle docking on to a cell influences its up-take by that cell. Using an innovative computing model, they tested whether and how cubic, spherical, or cylindrical particles are absorbed. The findings will help to selectively develop nanopharma-ceuticals that are implanted into certain

cells, where they release active sub-stances to fight diseases such as cancer, diabetes, or Crohn’s disease.

Cells love close contact. Physically, therefore, the particle and the cell mem-brane want to achieve as large a contact area as possible. Because only when there is sufficient mechanical binding between the membrane and the particle – known as adhesion strength – can the elasticity of the cell membrane be over-come and the particle can penetrate into the interior of the cell.

ReLationWithCoRneRSanDeDgeS“Our computerized model calculations show that the membrane can wrap around the particles either continuously or in stages,” says Prof. Gerhard Gomp-per, director at the Institute of Complex Systems of Forschungszentrum Jülich. The sides of a cube, for instance, adhere to the cell membrane easily, as this re-quires hardly any membrane deforma-tion. In the next stage, however, the membrane must position itself over the cube’s edges at a 90-degree angle. The high level of membrane deformation costs the cell a great deal of energy. In the case of a spherical particle, in con-trast, the membrane wraps itself around the particle continuously, always requir-ing the same amount of energy per unit area, as the particle has the same curva-ture at every point. To do so, the force of attraction must simply be greater than the stiffness of the membrane.

For cubes, cuboids, and ellipsoids, the Jülich researchers systematically in-vestigated the influence of edge curva-

UpCloseandPersonalonthenanoscaleCells are charming. They cosy up to large molecules or tiny nanoparticles that attach themselves to their outer wall. When letting them into their interior, cells have certain preferences, as Jülich researchers recently discovered.

Outlook for the future: tiny particles of active substanc-es penetrate the cell mem-brane and fight diseases such as cancer or Crohn’s disease directly at their place of origin.

10,000timessmallerthan

ahumanhair

nanoparticleshaveadiameteraround


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ReSeaRChattheCentRe|nanoscience


tures and side lengths. They analysed the conditions under which membranes wrap around nanoparticles either com-pletely or only partially. They also looked at the conditions under which this does not occur at all or particles get stuck in the boundary layer. To do so, they devel-oped a mathematical relation that ena-bled them to make predictions. “The in-tensity of the relationship between the cell and the nanoparticle depends on the ratio of the particle’s length to its width as well as on the curvature of the tiny particle’s edges,” says Gompper.

KnoWLeDgefoRnanoMeDiCineThe knowledge thus gained on the per-fect “passer-by” is a further step to-wards future nanopharmaceuticals. Some background information: many processes in the human body take place on a tiny level – the nanolevel. For exam-ple, a cell takes up nutrients and dis-cards toxins again by cutting off tiny bubbles that enter or leave the cell. To illustrate how inconceivably small nano-particles are, we can compare them with the diameter of a human hair; nanoparti-cles are around 10,000 times smaller.

Nanoscientists are eager to make use of the insights obtained into the pro-cesses in the human organism. Their vi-sion is to use minute implanted particles of active substances to fight diseases directly at their place of origin. Special

coatings on the nanopharmaceuticals ensure that the tiny particles will only be taken up by a certain type of cell. Jülich’s latest investigations will help to design particles from suitable materials in fu-ture so that they will either only adhere to the membrane in the form of sensor

molecules – for example in the field of drug-loaded nanoparticles in oncology research – or else be completely ab-sorbed in the form of active pharmaceu-tical substances. ::

Ilse Trautwein

Many oncology patients suffer from severe side effects associated with modern forms of treatment such as chemotherapy. They hope for new treatments with few side effects as soon as possible. Nanotechnology is one option: active substances will be “fired” – like nanomissiles – di-rectly into tumour cells, where they will selectively destroy diseased tis-sue.

For example, a promising treat-ment method currently in the test phase makes use of the magnetic properties of nanoparticles made from iron oxide. These are injected directly into the tumour. A magnetic field is then generated around the tissue. The nanoparticles absorb the energy from the magnetic field and convert it to heat, which in turn de-

stroys the tumour tissue. European authorization has already been re-ceived for this treatment. However, it will take several years for the in-novative cancer treatment to over-come all of the subsequent hurdles of clinical trials and win widespread acceptance in hospitals.

nanomedicinetocombatcancer

In chemotherapy, additional treat-ment methods are often required to relieve side effects.

Sabyasachi Dasgupta, Prof. Gerhard Gompper, and Dr. Thorsten Auth (left to right) investigated the influence of edges, side lengths, and curvatures on the implantation of nanoparticles in cells.

16 Research in Jülich 2 | 2014

Prof. Wolfgang M. Heckl, nanotechnology advisor to the German federal government and the European Commission

nanomedicine:SomewhereBetweenhypeandhope

Great hopes are pinned on nano-technology. It is believed that in future, it will enable diseases

such as cancer or diabetes to be identi-fied in good time and treated successful-ly. Prospects range from nanomaterials that promote the growth of new skin or bone in the body to nanopharmaceuti-cals that restore optic nerves in blind people. Prof. Dr. rer. nat. Wolfgang M. Heckl, professor at Technische Universi-tät München and Director General of Deutsches Museum, shares his thoughts on the subject. For years, he has been an advisor to the German federal gov-ernment and the European Commission in the field of nanotechnology.

Prof.heckl,agreatdealisexpectedofnanomedicine.howrealisticare theseexpectations?

Many of the ideas circulating in the me-dia are fantasies and still a long way from current research and clinical appli-cation. The fact is that in many areas, nanomedicine is unfortunately still in its infancy.

Whatisthereasonforthis?

This is primarily because to this very day, we still do not understand the mo-lecular principles behind many of the processes in the human body. We need this foundation, however, in order to use nanotechnology to improve the diagno-sis and treatment of diseases. That is why research projects focusing on the interaction between cells and nanoparti-cles – such as those by Prof. Gompper’s team at Jülich – are so important.

arethereanynanoproductsalreadyonthemarkettoday?

Of course. Just think of plasters with sil-ver particles that kill bacteria, or nano

toothpaste containing minute particles that fill tiny cavities in your teeth. How-ever, it all depends on how you define “nano” – in this sense, the figures vary somewhat. In scientific terms, the defini-tion of nanotechnology only applies to applications with nanoparticles smaller than 100 nanometres, whose effects are based on their nanoscale nature.

howbigisthenanomedicinemarket?

According to a study on nanomedicine released by Bionest Partners last year, there are 230 products on the market or in clinical trials, and this figure is on the rise. Recent analyses suggest that by 2016, the international nanomedicine market will have doubled in size within the space of five years. The estimated market value will then be $ 97–129 mil-lion.

in which field of medicine are nano-technological developments at an ad-vancedstage?

Most potential applications are in the field of oncology. Nanoparticles can be used to both diagnose and treat cancer. But – to use a popular metaphor – there is still a long way to go before we can send tiny nano-submarines on missions into the body to perform medical opera-tions.

This interview was conducted by Ilse Trautwein.

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Bad Homburg’s traditional advertis-ing slogan – “air of champagne” – emphasizes the exhilarating ef-

fects of its air. But town officials are worried: measurements by the German National Meteorological Service (DWD) show that nitrogen oxide values exceed the limit – 18 µg/m3 of air – and that the town’s certification as a top-class spa town is at risk. Bad Homburg has there-fore commissioned scientists from Jülich’s Institute of Energy and Climate Research – Troposphere (IEK-8) to inves-tigate the level of pollutants in the air. The measurement campaign, which con-centrates on nitrogen oxide and particu-late matter, was launched in February and will last until July. Initial interim re-sults indicate that the principle cause of Bad Homburg’s problems is road traffic. The scientists aim to present their final report by the end of the year.

“Our task is to collect data, inform the town of the cause of the air pollu-tion, and provide it with the necessary information to take countermeasures,” says Prof. Andreas Wahner, director at IEK-8. Since February, his colleagues Dr.

Dieter Klemp and Dr. Christian Ehlers have been hard at work: they are in charge of Jülich’s measurement labora-tory, which has been set up at the edge of the spa gardens. This is where they record meteorological data such as tem-perature, wind direction and speed, and the radiation intensity of the sun. They also measure the concentrations of hy-drocarbons, nitrogen oxides, carbon monoxide, formaldehyde, and ozone, as well as particulate matter pollution and the proportion of diesel soot it contains. With a mobile laboratory called “Mobi-lab”, the atmospheric researchers con-duct measurements outside of Bad Homburg to find out which pollutants are being brought into the town. To this end, Klemp and Ehlers use Mobilab to determine the level of nitrogen oxides and particulate matter in the air at vari-ous locations in the surrounding area.

In April, the town presented the measurement campaign at a press con-ference. At the time, Andreas Wahner provided an initial assessment: “Meas-urements taken so far indicate that the principal cause of air pollution in Bad

Homburg is road traffic.” The measure-ments showed particularly high levels of nitrogen oxides and particulate matter during rush hour. The scientist estimated that the percentage of soot particles in the particulate matter – 20–30 % – was caused by domestic heating, i.e. radia-tors and open fireplaces, and by road traffic.

The measurement results will be in-corporated into simulations of pollutant levels. These will show the expected air quality in seven and in twenty years if the current situation remains the same. However, they will also help to illustrate the potential impacts of individual pro-jects such as traffic management meas-ures or the conversion of heating sys-tems in Bad Homburg. ::

Erhard Zeiss

SomethingintheairoverSpatown?

Bad Homburg is concerned about its clean air. Why? Because of nitrogen oxide and particulate matter. At the request of the town’s authorities, Jülich climate re-searchers are searching for the causes of the pollution.

Prof. Andreas Wahner (left) explained the measurements conducted with “Mobi-lab”, Jülich’s mobile measurement lab-oratory, to Lord Mayor of Bad Homburg Michael Korwisi.

ReSeaRChattheCentRe|ClimateResearch


Initial funding of € 2.6 million: biotechnologists Stephan Binder and Georg Schendzielorz have won the GO-Bio competition for business spin-offs. Their sensor system for a targeted search for highly productive microorganisms could help to produce promising anticancer substances that are as yet almost impossible to synthesize chemically.

Though they could have jumped for joy, at first they weren’t allowed to tell anyone when, at the end of

March, Stephan Binder and Georg Schendzielorz from the Institute of Bio- and Geosciences (IBG-1) found out that they were to receive € 2.6 million for their business spin-off. The two Jülich bio technologists had been select-ed from 106 applications as winners of the GO-Bio competition for business spin-offs instituted by the Federal Ministry of Education and Research (BMBF). The scientists, who recently completed their PhDs, were awarded the prize money as initial funding to bring their special sensor system for a fast and targeted search for highly pro-ductive microorganisms to the market and found a company. They had to keep their victory a secret for a few days, as the winners had not yet been officially announced. “It was almost surreal,” recalls Schendzielorz.

PRoDUCtionMethoDSinDeManDIt became obvious that their method – which makes highly productive cells glow, thus making them stand out from millions of others – was on the right track in summer 2013, when they received the Innovation Award of the German BioRegions. Funding from the Helmholtz Enterprise initiative followed in December. With these funds, the postdocs laid careful preparations for their spin-off company, developed a viable business model, met with poten-tial customers, created a business plan, and submitted their application to GO-Bio – and met with success. “It’s been a dream come true for us,” they both say.

Binder and Schendzielorz jointly de-veloped the technology, which is known as High-Throughput Screening & Recom-bineering (HTSR), during their PhDs. The basic idea is as follows: In industrial or “white” biotechnology, microorganisms produce active ingredients for drugs, foodstuffs, and chemical substances. The more of the desired substance they produce, the more effective the entire industrial process. There is a growing demand for such organisms due to the increasing number of bio-based produc-

glowofSatis-factionasDreamComestrue

In a matter of seconds, the FACS (fluorescence-activated cell sorter) sorts the individual bacterial cells into culture tubes or microtitre plates. On the “flower plates” (large image), the bacteria can be cultivated and analysed.


ReSeaRChattheCentRe|Biotechnology

tion methods. But how do you distin-guish the few extremely productive cells from the millions of others? Convention-al methods require weeks or even months to isolate and cultivate the bac-teria. “With HTSR, we can do it in a few days,” says Binder. To track down the most hardworking cells, the scientists implant a circular DNA molecule into the cell. Ultimately, this genetic extra causes all those cells producing the desired substance to glow – the principle being that the more productive the cell, the more fluorescent it is. A device usually used to analyse blood continuously flushes individual microorganisms – at a rate of 50,000 bacteria per second – past a laser beam, which individually sorts the brightest cells in a microtitre plate. There, each selected bacterium multiplies and is then examined further. The scientists have already demonstrat-ed the method’s efficacy for the devel-opment of bacterial strains for amino acid production. “We want to consoli-date our technology and transfer it to other production organisms, for example for the manufacture of industrial prod-ucts such as polymer precursors,” ex-

plains Binder. The resulting biopolymers could replace oil-based products such as plastic bags.

MyxoBaCteRiatofightCanCeRAnother of the Jülich colleagues’ major goals is to extend the technology to pharmaceutical products. They have set their sights on anticancer substances, known as cytostatics, which are pro-duced by microorganisms. A strain of soil bacteria looks very promising in this regard. These myxobacteria produce ex-tremely small quantities of various sub-stances that can kill living cells or stop them from growing. One example is epothilone B, an active ingredient that has already been in use for several years to treat breast cancer. “Although there are other promising developments with myxobacteria, they cannot be continued, as the active ingredient could not be produced in sufficient quantities for clin-ical studies,” says Binder. He and Schendzielorz are putting their faith in HTSR to make the most productive myxo bacteria glow and thus pave the way for the development of more effec-tive bacterial strains.

The two biotechnologists have big ambitions. In addition to their innovative ideas and passion for research, they are motivated to explore new avenues by the positive response they have received from industry. “We have spoken with companies like Bayer, Evonik, and BASF – all of whom expressed strong inter-est,” says Schendzielorz. In autumn, they and four employees will be moving to new facilities at Forschungszentrum Jülich. From there, the research group will make the microorganisms glow for as long as it takes to ready their proto-type for the market.

Katja Lüers

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Two scientists, one business idea: Stephan Binder and Georg Schendzielorz (right) from the Institute of Bio- and Geosciences are among the winners of the GO-Bio competition for business spin-offs.


goldMineintheCowshed

Agricultural historians estimate that both human and animal waste has been used to improve

harvests for over 8,000 years. However, there is no comparison between the practices of the small farmers of the past and the mass dimensions of mod-ern factory farms. Today, over one billion tonnes of manure are produced each year in the European Union alone. And not all of it can be spread on the fields as fertilizer. The desire to make use of this valuable raw material while prevent-ing environmental pollution is the force driving the scientists in the “Manure-EcoMine” project. Their goal is to use

manure, a natural product, in a more environmentally friendly and specific way. The European Union has allocated € 3.8 million to the project for the next three years.

USingUPLeftoVeRSAt the moment, a significant proportion of the manure produced is sent to bio-gas facilities and provides energy in the form of biogas. However, a product known as digestate is left over, which ei-ther can also be used as fertilizer or else must be disposed of at considerable ex-pense. “Whatever feed goes in at one end comes out the other end,” says Dr.

A team of scientists and engineers from eleven European institutions are on a hunt for treasure. Their destination: the slurry pit. The goal: customized, sustainable, and environmentally friendly fertilizer. Jülich plant researchers are part of the search team.

Dr. Nicolai David Jablonowski is testing the effectiveness of the new fertilizer in promoting plant growth.

Obtaining valuable specialized fertilizers from manure instead of disposing of it laboriously – such is the goal of an inter-national research group.


ReSeaRChattheCentRe|Bioeconomy

Nicolai David Jablonowski from Jülich’s Institute of Bio- and Geosciences – Plant Sciences (IBG-2). Depending on the type of feedstuff, therefore, the chemical composition of both the manure and the digestate varies considerably. Diges-tates with a high phosphate and nitrate content, for example, result from a mix-ture of fermented cereal grains and poultry manure. Smaller proportions of these two plant nutrients are produced by a biogas facility supplied with silage maize and cattle manure.

For this reason, it is not yet possible to create a specific fertilizer for particu-lar crop types either with manure or with digestates. Either too many or too few important plant nutrients such as nitrogen, phosphate, or potassium end up on the fields. European farmers therefore spend around € 15.5 billion on synthetic fertilizers each year in order to maintain stable harvests. The research-ers in the ManureEcoMine project are confident that replacing a large propor-tion of the synthetic fertilizers with nu-trients from manure would be both cost-effective and environmentally friendly. This involves first separating the valuable substances from the manure and then, in a second stage, recombining them depending on the intended purpose.

CoMPoSingfeRtiLizeRThis is to be achieved with the aid of bio-logical, physical, and chemical process-es. The scientists use the well-known methods of fermentation, centrifugation, and precipitation as a basis. “We believe it’s important to establish a sustainable process chain,” stresses Nicolai David Jablonowski. “Ideally, the energy the farmer obtains from his biogas facility would be used to separate the nutrients from the manure, and the result would be a bag of specialized fertilizer.”

Pilot facilities in the Netherlands and Spain are currently testing potential methods of separating the desired con-stituents from the manure. At a later stage, Peltracom, a Belgian company specializing in potting soils, will take the individual materials and compose differ-ent substrate blends – which will be mixed with different quantities of nutri-ents from the manure as required. These will then be tested at Jülich on crops and

ornamental plants, such as maize, toma-toes, or petunias. At the same time, the new fertilizer must compete with un-treated manure and synthetic fertilizers. The effect of the different fertilizers on plant growth above and below ground will be investigated in detail in the inter-

nationally unique rhizotron facility at Jülich. With cameras, plant growth will be recorded continually and evaluated objectively.

USingnatURaLReSoURCeSThe project is coordinated by Ghent Uni-versity in Belgium. Prof. Dr. Siegfried Vlaeminck from the university’s Labora-tory of Microbial Ecology and Technolo-gy (LanMET) says: “Throughout the en-tire project, we will focus particular attention on economic efficiency as well as on environmental compatibility and life cycle assessment.” It goes without saying that the end product will also be free of any harmful substances such as heavy metals or pharmaceutical or hor-mone residues. ::

Brigitte Stahl-Busse

Today in the European Union, 1.27 billion tonnes of manure are produced each year. To protect the environment, the EU Nitrates Directive restricts the nitrogen input to 170 kg per hectare and year. Up to the end of 2013, German farmers, under certain conditions, could apply up to 230 kg of nitro-gen per hectare from fertilizers of animal origin on intensively farmed grass-land. This has now been brought to an end. The EU is urging the national legislator to revise the German regulation on fertilizers (Düngeverordnung). Rising nitrate levels in the groundwater in regions with intensive farming prove that urgent action is required. In a recent statement, the German Fed-eral Environment Agency announced that groundwater in Germany’s rural areas contains too much nitrate. Consumers are currently footing the bill, as uncontaminated water has to be added at the waterworks in the affected regions.

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22 Research in Jülich 2 | 2014

froma

SupercomputerartThe photograms currently on display at the Museum of Contemporary Art (S.M.A.K.) in Ghent, Belgium, are the result of a most unusual collaboration. Artist Thomas Ruff teamed up with researchers from the Jülich Supercomputing Centre (JSC) to produce them.

23

LAST BUT NOT LEAST


PUBLiCationDetaiLS

ResearchinJülich Magazine of Forschungszentrum Jülich, ISSN 1433-7371 Publishedby: Forschungszentrum Jülich GmbH | 52425 Jülich | Germa-ny Conceptionandeditorialwork: Annette Stettien, Dr. Barbara Schunk, Dr. Anne Rother (responsible according to German press law) authors: Dr. Frank Frick, Christian Hohlfeld, Katja Lüers, Christoph Mann, Tobias Schlößer, Dr. Barbara Schunk, Brigitte Stahl-Busse, Ilse Trautwein, Angela Wenzik, Erhard Zeiss translation: Lan-guage Services | Forschungs-zentrum Jülich graphicsandlayout: SeitenPlan GmbH, Cor-porate Publishing, Dortmund | Germany images: Deutsches Museum (16); Forschungs-zentrum Jülich (2, 3 centre and right, 4 top left, 5 top, 12 left and right, 14, 15 top, 18 left and right, 19 right, 20 bottom, 23 bottom); Forschungszen-trum Jülich/Sascha Kreklau (cover page, 3 left, 6, 7, 9–11); Justin Marshall (4 top right); Na-ture Methods/Sharon Grayer Wolf, Lothar Houben & Michael Elbaum (4 bottom); SeitenPlan GmbH (8, 13); Town of Bad Homburg (17 bottom); VG Bild Kunst Bonn, 2014 (22, 23 top left and top right); Jo Cham-bers (17 top), fotoscool (24), hjschneider (21), Image Point Fr (15 bottom), Lumir Jurka Lumis (5 bottom), Symbiot (20 top), all from Shutterstock.com Con-tact: Corporate Communica-tions | Tel: +49 2461 61-4661 | Fax: +49 2461 61-4666 | Email: [email protected]

The idea originated nearly a year ago. The internationally acclaimed artist Thomas Ruff was working on a new series – pho-

tograms. Strictly speaking, these are black-and-white photographic images created with-out a camera in a darkroom. To do so, objects are arranged on light-sensitive paper and ex-posed to light. The shadows produce fascinat-ing patterns. Ruff introduced photograms to the digital age: his images were created in a kind of virtual darkroom on a computer.

“Unlike in the analogue world, this makes it possible to produce colour photograms. Ob-jects and light sources can also be modified much more quickly and easily, and the images aren’t restricted to the size of the photographic paper,” explains the 56-year-old. His photo-grams can reach sizes of 2.20 m x 1.64 m – which corresponds to at least nine gigabytes of data per image. This pushes ordinary comput-ers to their limits. “At some point I simply want-

ed to compute one of my images on a super-computer,” says Ruff. The goal was to produce photograms with even better resolution and the highest possible quality. He therefore got in touch with JSC. “From our point of view, the high demands for data storage, data rates, and local processing power provided us with an ide-al opportunity to determine important charac-teristics for the design of the computer to suc-ceed the JUROPA system,” says Prof. Thomas Lippert, head of JSC. “It was also a good occa-sion to get people other than our usual clien-tele interested in high-performance comput-ing.”

For some three months, Thomas Ruff and JSC worked together in close cooperation. The artist is thrilled with the results of the 20 pho-tograms, saying: “The improvement in the con-trasts and intricate structures alone is extraor-dinary.” The fact that the higher resolution led to data sizes of at least 18 terabytes per image was no problem for JUROPA: the supercomput-er required a maximum of 15 hours to compute one image. It would have taken Ruff’s comput-er over a year.

Christian Hohlfeld

exhiBitionThe photograms by Thomas Ruff that were computed at Jülich are being exhibited at S.M.A.K. until 24 August. In September they will go on display in Düsseldorf.

The artist and his work: Thomas Ruff’s photograms were created entirely on a computer.

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