Tech

Plants need nitrogen in the form of ammonium if they are to grow. In the case of a great many cultivated plants, farmers are obliged to spread this ammonium on their fields as fertiliser. Manufacturing ammonium is an energy-intensive and costly process - and today's production methods also release large amounts of CO2.

However, a handful of crops replenish their own supply of ammonium. The roots of beans, peas, clover and other legumes harbour bacteria (rhizobia) that can convert nitrogen from the air into ammonium. This symbiosis benefits both the plants and the rhizobia in an interaction that scientists had until now seen as relatively straightforward: the bacteria supply the plant with ammonium; in return, the plant provides them with carbonaceous carboxylic acid molecules.

A surprisingly complex interaction

Under the leadership of Beat Christen, Professor of Experimental Systems Biology, and Matthias Christen, a scientist at the Institute for Molecular Systems Biology, ETH researchers have now succeeded in demonstrating that the plant-bacteria interaction is in fact surprisingly complex. Along with carbon, the plant gives the bacteria the nitrogen-rich amino acid arginine.

"Although nitrogen fixation in rhizobia has been studied for many years, there were still gaps in our knowledge," Beat Christen says. "Our new findings will make it possible to reduce farmers' dependence on ammonium fertiliser, thereby making agriculture more sustainable."

Using systems biology methods, the researchers investigated and unravelled the metabolic pathways of rhizobia that cohabit with clover and soya. Joining forces with ETH Professor Uwe Sauer, they verified the results in growth experiments with plants and the bacteria in the lab. The scientists suspect that their new findings will apply not just to clover and soya, and that the metabolic pathways of other legumes are regulated in similar fashion.

A battle royal, not a voluntary symbiosis

The findings shed new light on the coexistence of plants and rhizobia. "This symbiosis is often misrepresented as a voluntary give and take. In fact, the two partners do their utmost to exploit each other," Matthias Christen says.

As the scientists were able to demonstrate, soya and clover do not exactly roll out the red carpet for their rhizobia, but rather regard them as pathogens. The plants try to cut off the bacteria's oxygen supply and expose them to acidic conditions. Meanwhile, the bacteria toil ceaselessly to survive in this hostile environment. They use the arginine present in the plants because it enables them to switch to a metabolism that does not require much oxygen.

To neutralise the acidic environment, the microbes transfer acidifying protons to nitrogen molecules taken from the air. This produces ammonium, which they get rid of by conducting it out of the bacterial cell and passing it on to the plant. "The ammonium that is so crucial for the plant is thus merely a waste product in the bacteria's struggle for survival," Beat Christen says.

Converting molecular nitrogen into ammonium is an energy-intensive process not only for industry but also for rhizobia. The newly characterised mechanism explains why the bacteria expend so much energy on the process: it ensures their survival.

Biotechnology: paving the way to sustainable agriculture

Agriculture and biotechnology will be able to use this new insight to transfer the process of bacterial nitrogen fixation to non-leguminous crops, such as wheat, maize or rice. Scientists have made many attempts to achieve this transfer, but have always met with limited success because an important piece of the metabolic puzzle was missing. "Now that we've mapped the mechanism down to the last detail, this is likely to improve our chances of achieving a favourable result," Beat Christen says.

One possible approach is to use biotechnological methods to insert all genes necessary for the metabolic pathway directly into the crops. Another line of action would be to transfer these genes into bacteria interacting with the roots of wheat or maize. These bacteria do not currently convert nitrogen in the air to ammonium, but biotechnology has the means to make it happen - and the ETH researchers will now pursue this approach.

Superhydrophobic surfaces repel water like nothing else. This makes them extremely useful for antimicrobial coatings - as bacteria, viruses and other pathogens cannot cling to their surfaces. However, superhydrophobic surfaces have one major flaw - they are extremely susceptible to cuts, scratches or dents. If a superhydrophobic surface gets damaged, the damaged area can trap liquids and the benefits of the coating are lost. Now, however, a collaboration between researchers in China and Finland has developed an armour-plated superhydrophobic surface which can take repeated battering from sharp and blunt objects, and still repel liquids with world-record effectiveness.

The research - which is the cover feature of this week's issue of Nature - has designed superhydrophobic surfaces that can be made out of metal, glass, or ceramic. The superhydrophobic properties of the surface come from nano-sized structures spread all over it. The trick is to pattern the surface of the material with a honeycomb-like structure of tiny inverted pyramids. The fragile water-repellent chemical is then coated on the inside the honeycomb. This prevents any liquid from sticking to the surface, and the fragile chemical coating is protected from damage by the pyramid's walls.

"The armour can be made from almost any material, it's the interconnection of the surface frame that makes it strong and rigid," says Professor Robin Ras, a physicist at Aalto University whose research group was part of the project. "We made the armour with honeycombs of different sizes, shapes and materials. The beauty of this result is that it is a generic concept that fits for many different materials, giving us the flexibility to design a wide range of durable waterproof surfaces."

As well as their useful antimicrobial properties for biomedical technology, superhydrophobic surfaces can also be used more generally in any application requiring a liquid-repellent surface. One example is photovoltaics, where the build-up of moisture and dirt over time blocks the amount of light they can absorb, which reduces electricity production. Making a solar panel out of a superhydrophobic glass surface would maintain their efficiencies over long periods of time. Furthermore, as solar cells are often on roof tops and other difficult to reach locations, the repellent coatings would cut down the amount of cleaning that is needed.

"By using the decoupled design, we introduce a new approach for designing a robust superhydrophobic surface. Our future work would be to push this method further, and to transfer robust superhydrophobic surfaces to different materials and its commercialization" said Professor Xu Deng, the leader of the group at the University of Electronic Science and Technology of China in Chengdu who took part in this research.

Other desirable applications for superhydrophobic surfaces include in machines and on vehicles, where conditions can be very tough for brittle materials for long periods of time. To simulate these working environments, the researchers subjected their new surfaces to extreme conditions, including baking them at 100 °C nonstop for weeks, immersing them in highly corrosive liquids for hours, blasting them with high-pressure water jets, and subjecting them to physical exertion in extreme humidity. The surfaces were still able to repel liquid as effectively as before.

Now that the strengths of this new material design have been demonstrated, future research will explore its broad potential in real-world applications.

Researchers at UC Santa Cruz have developed a theoretical foundation and new computational tools for predicting a material's spin dynamics, a key property for building solid-state quantum computing platforms and other applications of spintronics.

Spin is a fundamental property of electrons and other particles, and the rapidly growing field of spintronics uses spin states in a manner analogous to the use of electrical charge in electronics. Spin can be used as the basis for qubits (quantum bits) and single-photon emitters in applications of quantum information science, including quantum computation, communication, and sensing.

Qubits can be made from any quantum system that has two states, but the challenge is to maintain quantum coherence (a relationship between quantum states) long enough to allow manipulation of the qubits. Decoherence means a loss of information from the system, and spin qubits can lose coherence by interacting with their environment through, for example, lattice vibrations within the material.

"The key property for quantum information science is the lifetime of the spin states, known as the spin relaxation and decoherence time," said Yuan Ping, assistant professor of chemistry at UC Santa Cruz. "For quantum information applications, we need materials with long spin relaxation times."

In a paper published June 3 in Nature Communications, Ping and her coauthors at UCSC and Rensselaer Polytechnic Institute present a new theoretical framework and computational tools for accurately predicting the spin relaxation time of any material, which was not previously possible.

"These days, people just make a material and try it to see whether it works. Now we have the predictive capability from quantum mechanics that will allow us to design materials with the properties we want for applications in quantum information science," she said. "And if you have a promising material, this can tell you how to change it to make it better."

The researchers established methods for determining spin dynamics from first principles, meaning that no empirical parameters from experimental measurements are needed to do the calculations. They also showed that their approach is generalizable to different types of materials with vastly different crystal symmetries and electronic structures.

For example, they predicted accurately the spin relaxation time of centrosymmetric materials such as silicon, ferromagnetic iron, and graphene, as well as non-centrosymmetric materials such as molybdenum disulfide and gallium nitride, highlighting the predictive power of their method for a broad range of quantum materials.

By enabling the rational design of materials, instead of searching blindly and testing a wide range of materials experimentally, these new methods could enable rapid advances in the field of quantum information technologies.

University of New Mexico (UNM) Professor of Earth and Planetary Sciences, Dr. Tobias Fischer and Syracuse University research fellow (now University of Auckland Lecturer), Dr. James Muirhead led an international team of interdisciplinary researchers to investigate the role of carbon in the break-up of continents.

This work, much of which has been funded by grants from the National Science Foundation, is a culmination of research efforts that started with former students from UNM and other US, French, Tanzanian and Kenyan universities.

The collaboration, which also included scientists from New Mexico Tech, the University of Oregon, University of Dar Es Salaam, Seoul National University, University of Tokyo, University of Alberta, Macquarie University, Goethe University and Université de Montpellier II, led to new insights into the storage and dynamic transfer of carbon below thick and very old continental crust currently published in the journal Nature titled, Displacement of cratonic mantle and lithospheric channeling concentrates deep carbon during continental rifting.

It was first recognized by former UNM student, now assistant professor at Seoul National University, Dr. Hyunwoo Lee, that the East African Rift and continental rifts in general are significant sources of carbon degassed from the Earth's mantle to the atmosphere. While later work by other groups showed that CO2 emissions from the East African Rift are variable along its 3,000 km extent, the question remained "where does all this carbon come from and how is it so efficiently released?"

Subsequent work by Fischer and collaborator Professor Stephen Foley from Macquarie University, Australia, proposed a model in which the degassing CO2 is ultimately sourced from carbon that has accumulated over billions of years at the base of the thick old cratonic lithosphere located in the center and edge of the East African Rift.

"The model suggests that this accumulated carbon originates from subducting oceanic plates and deep mantle plumes," said Fischer. "These processes could deliver sufficient carbon to the bottom of very thick and billion year old continental lithosphere to explain the high CO2 fluxes observed in the actively deforming part of the rift."

However, the model proposed by Fischer and Foley could not explain how this deep CO2 managed to leak out from the actively extending part of the rift, which is exactly where the current work connects the dots.

Muirhead and Fischer together with Master's student Amani Laizer from University of Dar Es Salaam in Tanzania and geophysics Ph.D. student Sarah Jaye Oliva from Tulane University returned to Tanzania in 2018 and collected data and samples in locations where active rifting,

i.e. where the plates move apart, intersect the old thick craton that lies above a mantle plume. Gas samples were collected from hot springs in this region that have never been sampled before.

The analyses of these samples within the context of already existing data from the earlier work showed a striking difference in chemical composition of the gases that are released from the active rift and the craton. Craton gases are entirely crustal with no sign of any mantle gases, including CO2. Nitrogen and crustal helium dominate these craton gases. Rift gases on the other hand are stuffed with mantle CO2 and have a strong mantle helium isotope signature. Measured mantle CO2 fluxes are close to zero on the craton but surge in the adjacent actively extending rift.

"Right at the boundary between the craton and the deforming rift sits the world's only currently erupting carbonatite volcano, Oldoinyo Lengai," said Fischer. "This volcano erupts lavas that are so liquid they move like motor oil. The reason for this is that they are devoid of the silica that makes up most igneous rocks but contain about 30 percent carbon, a staggeringly high amount that gives the rock its name carbonatite. Looking back in geologic time, it turns out that there are many carbonatite volcanoes right at the edge of the Tanzania craton, but they are just not currently active."

This distribution of carbonatites led the team to propose a mechanism that causes the lateral migration of the deep cratonic lithosphere where all that stored solid carbon is located, into the mantle at the edges of the craton.

Geophysical data acquired and analyzed by Tulane University and Université de Montpellier II image a steep step in plate thickness at the craton edge. The geophysicists led by Professor Cindy Ebinger, Drs. Sarah Oliva and Professor Christel Tiberi proposed that this step enhances formation of melt and explains the concentration of magma that carries the excess CO2, as well as the spatial distribution of sometimes damaging earthquakes that open cracks for the CO2 to rise to the surface. This would explain the striking difference in CO2 release and source as documented by the surface measurements.

This conceptual model also fits into quantitative physical models developed by Dr. Jolante van Wjik, professor at New Mexico Tech and Dr. Claire Currie, professor at University of Alberta, which shows that unusually thick and low density mantle rocks beneath a craton will be swept laterally by mantle flow, moving toward the thinner plate beneath the continental rift.

This material transfer may enhance melt production. Therefore, the research team concluded, lateral migration of deep cratonic lithosphere soaked with ancient accumulated carbon is ultimately responsible for carbonatite volcanism and the on-going continental break-up in this region of East Africa.

A review of 56 randomized clinical trials finds that psychological and behavioral therapies may be effective non-drug treatments for reducing disease-causing inflammation in the body.

The results of the analysis, published in JAMA Psychiatry, found that cognitive behavior therapy, or CBT, was superior to other psychotherapies at boosting the immune system.

The senior author of the new study is Dr. George Slavich, director of the UCLA Laboratory for Stress Assessment and Research. Along with two of his colleagues at UC Davis and San Diego State University, the team looked at whether interventions typically used for treating mental health problems, such as anxiety and depression, might also boost biological processes involved in physical health. They further analyzed the duration and types of psychotherapy received, including group versus non-group therapy. Finally, they examined how the treatments affected different markers of inflammation and other immune system processes in the body.

"People automatically go to medication first to reduce chronic inflammation, but medications can be expensive and sometimes have adverse side effects," Slavich said. "In this review, we wanted to know whether psychotherapies can also affect the immune system and, if so, which ones have the most beneficial effects over the long term."

The researchers analyzed randomized clinical trials that investigated the effects of several different types of interventions, including CBT, CBT plus medication, grief and bereavement support, a combination of two or more psychotherapies, and psychoeducation, among others.

"This seems to be a case of mind over matter," Slavich said. "Psychotherapies like CBT can change how we think about ourselves and the world, and changing these perceptions can in turn affect our biology. The results of this study take this idea one step further and suggest that psychotherapy may be an effective and relatively affordable strategy for reducing individuals' risk for chronic diseases that involve inflammation."

Through their analyses, the researchers sought to better understand how the body reacts to non-drug treatments for chronic inflammation, which increases the risk of developing several deadly diseases and can lead to premature death.

They looked at several different immune outcomes. Of those outcomes, pro-inflammatory cytokines were most strongly affected by psychotherapy in general and CBT in particular. Pro-inflammatory cytokines are notable because they help the immune system heal physical wounds and battle infections. If these proteins remain persistently elevated, though, they can lead to chronic inflammation, which increases the risk of physical illnesses, such as heart disease, cancer and Alzheimer's disease, as well as mental health problems, including anxiety disorders, depression, PTSD, schizophrenia, self-harm and suicide.

"There are many people who would prefer to use non-drug interventions for improving their immune system function," Slavich said. "In some cases, they can't take certain medications because of medical reasons, and in other instances the medications they need are too expensive. And then there are people who simply prefer a more holistic approach to improving their health."

Slavich said that these findings provide strong evidence that psychotherapy may be helpful in this regard.

"Out of all of the interventions we examined, CBT was the most effective for reducing inflammation, followed by multiple or combined interventions," Slavich said. "Moreover, we found that the benefits of CBT on the immune system last for at least six months following treatment. Therefore, if you're looking for a well-tested, non-drug intervention for improving immune-related health, CBT is probably your best choice."

Researchers suggest that modulation of local CO2 concentration improves the selectivity, conversion rate, and electrode stability, and shed a new light on the electrochemical CO2 reduction technology for controlling emissions at a low cost.

A KAIST research team presented three novel approaches for modulating local carbon dioxide (CO2) concentration in gas-diffusion electrode (GDE)-based flow electrolyzers. Their study also empirically demonstrated that providing a moderate local CO2 concentration is effective in promoting Carbon-Carbon (C-C) coupling reactions toward the production of multi-carbon molecules. This work, featured in the May 20th issue of Joule, serves as a rational guide to tune CO2 mass transport for the optimal production of valuable multi-carbon products.

Amid global efforts to reduce and recycle anthropogenic CO2 emissions, CO2 electrolysis holds great promise for converting CO2 into useful chemicals that were traditionally derived from fossil fuels. Many researches have been attempting to improve the selectivity of CO2 for commercially and industrially high-value multi-carbon products such as ethylene, ethanol, and 1-propanol, due to their high energy density and large market size.

In order to achieve the highly-selective conversion of CO2 into valuable multi-carbon products, past studies have focused on the design of catalysts and the tuning of local environment related to pH, cations, and molecular additives.

Conventional CO2 electrolytic systems relied heavily on an alkaline electrolyte that is often consumed in large quantities when reacting with CO2, and thus led to an increase in the operational costs. Moreover, the life span of a catalyst electrode was short, due to its inherent chemical reactivity.

In their recent study, a group of KAIST researchers led by Professor Jihun Oh from the Department of Materials Science and Engineering reported that the local CO2 concentration has been an overlooked factor that largely affects the selectivity toward multi-carbon products.

Professor Oh and his researchers Dr. Ying Chuan Tan, Hakhyeon Song, and Kelvin Berm Lee proposed that there is an intimate relation between local CO2 and multi-carbon product selectivity during electrochemical CO2 reduction reactions. The team employed the mass-transport modeling of a GDE-based flow electrolyzer that utilizes copper oxide (Cu2O) nanoparticles as model catalysts. They then identified and applied three approaches to modulate the local CO2 concentration within a GDE-based electrolytic system, including 1) controlling the catalyst layer structure, 2) CO2 feed concentration, and 3) feed flow rate.

Contrary to common intuition, the study showed that providing a maximum CO2 transport leads to suboptimal multi-carbon product faradaic efficiency. Instead, by restricting and providing a moderate local CO2 concentration, C-C coupling can be significantly enhanced.

The researchers demonstrated experimentally that the selectivity rate increased from 25.4% to 61.9%, and from 5.9% to 22.6% for the CO2 conversion rate. When a cheap milder near-neutral electrolyte was used, the stability of the CO2 electrolytic system improved to a great extent, allowing over 10 hours of steady selective production of multi-carbon products.

Dr. Tan, the lead author of the paper, said, "Our research clearly revealed that the optimization of the local CO2 concentration is the key to maximizing the efficiency of converting CO2 into high-value multi-carbon products."

Professor Oh added, "This finding is expected to deliver new insights to the research community that variables affecting local CO2 concentration are also influential factors in the electrochemical CO2 reduction reaction performance. My colleagues and I hope that our study becomes a cornerstone for related technologies and their industrial applications."

Osaka, Japan - Many common household items and devices have a coating that improves performance. For example, the thin Teflon coating on cookware helps prevent food from sticking to the surface. However, it's difficult to prepare—at room temperature—the strongly adhering, high-performance ceramic coatings that are commonly used in many applications, such as electronics. Now, researchers from Japan have solved this problem.

In a study published in ACS Applied Electronic Materials, researchers from Osaka University have shown how to coat glass and plastic—and presumably many other surfaces—with a thin, porous ceramic. The fabrication process is straightforward, the materials are cheap, and the ceramic's gas sensing performance is considerably improved compared with current devices.

The researchers' ceramic coating, porous titanium dioxide, is an exciting material.

"Titanium dioxide is cheap and abundant, and has many applications such as in gas sensing," explains Tohru Sugahara, senior author. "Porous films have a high surface area to volume ratio, and can detect gas analytes at lower concentrations than corresponding nonporous films."

The researchers first used spin coating to deposit a thin film—approximately 1 micrometer thick—of porous titanium dioxide onto a glass or plastic surface, in only one step. They then tested two approaches to strongly adhere their films onto the surface: high-temperature sintering for the glass, and high-intensity light for the plastic. Both approaches retain the nanometer-scale pores and strongly adhere the ceramic film.

The thin ceramic films prepared by high-temperature sintering performed remarkably compared with nonporous titanium-based gas sensors. "For example, gas detection is fast," says Sugahara. "The response time—the time required for the sensor to attain an optimum response—is approximately 1 s, whereas other sensors require a few minutes."

The researchers envision many applications of their porous ceramic coatings. For example, viruses can be entrapped in the pores. Once caught, the viruses can be destroyed by irradiating the films with UV or visible light, without damaging the films. Another application is whitening agents; the porous films diffuse a great deal of UV and visible light. Many useful applications are possible with the researchers' economical, straightforward approach to strongly adherent ceramic coatings.

The past 60 years have not seen any fundamental change to the design of bridge decks for suspensions bridges - best known in Denmark from the Great Belt Link. To accommodate the request for ever longer bridges, the Technical University of Denmark (DTU) and COWI, studied how to optimise structures to reduce the weight of the bridge deck, in particular increasing the span. Recently published in the recognised scientific magazine Nature Communications, the results of that research project indicate vast potential.

"We applied different methods for examining how to better utilise materials, which primarily consist of steel and concrete. Initially, we sought to optimise their use in traditional structures by using transverse diaphragms in the bridge deck, thereby achieving a theoretical weight reduction of up to 14 per cent," says Mads Jacob Baandrup, who carried out the analyses in connection with his PhD project and today works as an engineer in COWI's bridges department.

New curved design makes the difference

With a view to achieving additional savings, the researchers looked at the possibility of altering the structural design. That was done by using topology optimization, a method known in car and aircraft industries, that had not previously been used for large-scale building structures.

"In popular terms, it's about 'emptying' a bridge girder of its existing elements, providing complete freedom for choosing a new design. The inner volume of the bridge girder is then divided into a structure of very small voxels (3D pixels), like small dice. The topology optimisation method is then used for determining whether each individual voxel should consist of air or steel material. The result is a bridge girder design that uses the least possible steel without impairing the strength of the structure," says Associate Professor Niels Aage, DTU Mechanical Engineering, who is one of the world's leading scientists in large-scale optimization and was responsible for the project analyses.

Specifically, a bridge element measuring 30 x 5 x 75 metres was analysed, divided into two billion voxels, each no bigger than a few centimetres. The result was an incredibly extensive calculation performed by a supercomputer, which would have taken an ordinary computer 155 years to do and is the largest structural optimisation ever carried out.

Carbon saving and economically interesting solution

The computer calculation presented input for how to best structure the design space of the bridge deck. Among other things, that meant curving part of the currently straight transverse diaphragms, making it possible to shave off 28 per cent of the material that is used for bridge decks and thereby achieve a corresponding reduction of the CO2 emissions generated by the production and transport of concrete and steel.

"We interpreted and adjusted calculations so the result became a suggested bridge girder structure with the optimum design that can be carried out without too costly production methods. The economic aspect is important in order for the design to be a realistic option for future bridge projects," says Mads Jacob Baandrup.

Valuable knowledge for tomorrow's suspension bridges

Naturally, additional analyses will be required before the new design can be used for building bridges, but COWI is confident that the results of the research project add valuable knowledge to tomorrow's suspension bridges.

"The new bridge girder design can be converted into a weight and CO2 reduction of up to 20 per cent for the entire bridge, which of course benefits the climate. COWI is also involved in a wide range of the world's largest bridge projects, so a potential new design will also benefit our customers and society," says Technical Director Henrik Polk, COWI, who participated in the research.

DTU is also very excited about the results.

"We believe there are huge perspectives to using topology optimisation for ensuring the sustainable design of other large building structures, such as high-rises, stadiums or highway bridges. We want to explore that field, and since the construction industry accounts for 39 per cent of global CO2 emissions, almost any reduction can be of interest," says Professor Ole Sigmund, DTU Mechanical Engineering.

The calculations for the topology optimisation were carried out on a PRACE (Partnership for Advanced Computing in Europe) supercomputer.

Anyone who is injured hopes for a speedy recovery. But wounds that heal too quickly can heal badly: if the concentration of certain growth factors becomes too high and the healing process overshoots the mark, then bulging (in technical jargon: hypertrophic) scars form and even the surrounding skin loses some of its elasticity. This is the conclusion that Sabine Werner, at the Institute for Molecular Health Sciences, and Edoardo Mazza, at the Institute for Mechanical Systems, and their two research groups have reached following joint investigations.

Complex interactions

As the researchers just reported in the journal Nature Communications, they have deconstructed the complex mechanisms that control the process of tissue repair (and scar formation) in more detail. Their current work, which was made possible by University Medicine Zurich's flagship project Skintegrity (see box), focuses on a signal molecule: activin. This molecule plays an important role both in healing wounds and in cancer. "We've shown how profoundly a single signal molecule affects the complex interaction between cells and their surroundings," Werner says.

The greater the quantity of activin in the wound, the more connective tissue cells are generated. Higher activin concentrations also change the composition of what is known as the extracellular matrix, the scaffold surrounding the cells of the wound. In this scaffold, which is produced and remodelled by the cells, higher activin concentrations translate into greater accumulation of collagen, and the collagen fibres are also more strongly cross-?linked with each other. While this promotes the speed of wound healing, it also causes the injured tissue to stiffen and harden.

Influencing the healing process

During their interdisciplinary collaboration, the researchers learned a lot from each other, emphasise the two lead authors, molecular biologist Mateusz Wietecha and mechanical engineer Marco Pensalfini. While biochemical and bioinformatic analyses of the molecular processes in the wound gave the engineers a chance to expand their understanding of tissue mechanobiology, developing the new wound measurement technologies was new ground for the biologists. The result is a method for measuring the biomechanical properties of healing tissue in vivo for the first time.

This new method will permit early diagnosis and tracking of the tissue repair process over time - and the knowledge gained might even allow doctors to influence it, Werner says; how to influence healing will depend on the type and location of the injury. If a wound threatens to become chronic, it might be possible to perform an intervention to accelerate the healing process, for example by enriching the concentration of activin or of matrix proteins influenced by activin, she adds. When it comes to facial injuries, it would be prudent to slow down the healing process and thereby reduce scarring, for example by blocking activin signals. As things stand, however, applications like this are still a long way off. "Our interdisciplinary approach improves our understanding of healing processes and thus lays the foundation for future clinical applications" Mazza says.

Flagship project Skintegrity

The skin protects our body and serves as an important barrier. Serious and common problems include large acute wounds, but also chronic ulcers. In 2016, University Medicine Zurich launched a flagship project, Skintegrity, which brings together the expertise of 30 research groups from across ETH, the University of Zurich and the University Hospitals of Zurich. The aim of the project is to gain a detailed understanding of the molecular, cellular and biomechanical mechanisms underlying normal and impaired tissue repair and various skin diseases. Doctors, biologists, material scientists and engineers are all collaborating closely to develop new methods and approaches - with the aim of improving the diagnosis and therapy of major skin diseases and acute and chronic wounds.

The tremendous increase in the use of mobile technology, wearable electronics, and a wide range of portable devices in general over the past few decades, has driven scientists worldwide to seek out the next breakthrough in rechargeable batteries. Lithium-sulfur batteries (LSBs)--composed of a sulfur-based cathode and lithium anode submerged in a liquid electrolyte--are promising candidates to replace the ubiquitous lithium-ion battery because of their low cost and the non-toxicity and abundance of sulfur.

However, using sulfur in batteries is tricky for two reasons. First, during the "discharge" cycle, soluble lithium polysulfides (LiPS) form at the cathode, diffuse into the electrolyte, and easily reach the anode, where they progressively degrade the capacity of the battery. Second, sulfur is non-conducting. Thus, a conductive and porous host material is required to accommodate sulfur and simultaneously trap LiPS at the cathode. In the recent past, carbon-based host structures have been explored because of their conductivity. However, carbon-based hosts cannot trap LiPS.

In a recent study published in Advanced Energy Materials, scientists from the Daegu Gyeongbuk Institute of Science and Technology proposed a novel host structure called "platelet ordered mesoporous silica (pOMS)." What is unusual about their choice is that silica, a low-cost metal oxide, is actually non-conducting. However, silica is highly polar and attracts other polar molecules such as LiPS.

Upon application of a conductive carbon-based agent to the pOMS structure, the initial solid sulfur in the pores of the structure dissolves into the electrolyte, from where it then diffuses towards the conductive carbon-based agent to be reduced to generate LiPS. In this manner, the sulfur effectively participates in the necessary electrochemical reactions despite the silica's non-conductivity. Meanwhile, the polar nature of the pOMS ensures that the LiPS remains close to the cathode and away from the anode.

The scientists also constructed an analogous non-polar, highly conductive conventional porous-carbon host structure to run comparative experiments with the pOMS structure. Prof Jong-Sung Yu, who led the study, remarks: "The battery with the carbon host exhibits high initial capacity that soon drops due to the weak interaction between non-polar carbon and LiPS. The silica structure clearly retains much more sulfur during continuous cycles; this results in much greater capacity retention and stability over as many as 2000 cycles."

Yet, all this considered, perhaps the most important insight to derive from this study is that host structures for LSBs need not be as conductive as was previously thought. Prof Yu comments: "Our results are surprising, as no one might have ever thought that non-conductive silica could be a highly efficient sulfur host and even outperform state-of-the-art carbon hosts." This study broadens the selection of host materials for LSBs and could lead to a paradigm shift in realizing next-generation sulfur batteries.

Animal experiments are typically conducted under highly standardized laboratory conditions. While standardization is meant to improve reproducibility of scientific results, in reality reproducibility is surprisingly low. To produce more robust results, experts from different fields of research now recommend introducing biological variation into the design of animal experiments.

"The ability to reproduce scientific findings through an independent replication study is the acid test by which scientists distinguish facts from mere anecdotes," says lead author Bernhard Voelkl, who hosted the workshop together with Hanno Wuerbel, professor of animal welfare at the University of Bern. Wuerbel adds: "Poor reproducibility produces economic costs and scientific uncertainty - and also raises ethical concerns, if it hampers medical progress and animals are used for inconclusive studies."

Last year, Voelkl, Wuerbel and other experts in animal biology, experimental design, and biostatistics convened to discuss strategies to address this challenge. They concluded that a paradigm shift in experimental design is needed and present their considerations in the journal Nature Reviews Neuroscience.

More biological variation needed

Strict standardization of both the animals' characteristics and their environment is the norm when studying the effects of an experimental intervention, such as being given a candidate drug. Eliminating all sources of variation other than the experimental intervention is meant to increase the precision of the results, while at the same time reducing the number of animals per experiment. However, this rigorous standardization narrows down the range of animals and conditions to which the findings can reliably be generalized.

"Many animal experiments are conducted under such a narrow range of conditions that there is a significant risk of obtaining results that are unlikely to be reproducible," says Wuerbel. The team therefore advocates "heterogenization", the deliberate inclusion of biological variation into the design of animal experiments to improve the range of conditions to which findings can be generalized and thus improve reproducibility.

Maximizing knowledge gain per animal and experiment

"With this design we can balance the need to compare interventions under similar conditions with the ability to introduce heterogeneity, which allows us to determine whether effects are robust over a range of conditions," says Naomi Altman, professor emeritus of statistics at Penn State. Researchers can introduce biological variation to study populations in many ways, for example, by including different strains of animals, age groups, or animals housed under different housing conditions. Alternatively, they may split experiments into several independent batches of animals or conduct multi-laboratory studies.

"There is no single best solution for every experiment," says Voelkl. "Therefore, we recommend heterogenization of animals and environmental conditions in general terms. Researchers should justify their choices with respect to the range of animals and conditions to which their findings should generalize." Potential strategies should be explored in future studies to provide researchers better guidance in their choices.

The experts are convinced that by introducing biological variation into study desigsn, fewer studies, and thus fewer animals, will be needed to produce robust results. Therefore, although in some cases the number of animals used in a single study may increase, the overall number of animals used in research will be reduced, the authors emphasize. "We propose a paradigm shift to increase the benefit of the research and reduce the number of animals used in research," says Wuerbel. "Instead of minimizing the number of animals per experiment, we should maximize the amount of knowledge we gain per animal and experiment."

Reconsideration by funders and regulators

To promote this paradigm shift, the team recommends that funders, regulators and scientific journal editors consider heterogenization as the default option and ask researchers to justify study designs in terms of the range of conditions to which their findings should apply.

Black women have the highest prevalence of low birthweight babies compared to other racial and ethnic groups, but black immigrants typically have much better outcomes than their U.S.-born counterparts. Yet, little has been known about whether this "healthy immigrant" effect persists across generations.

According to a new study published by Princeton University researchers, the substantial "birthweight advantage" experienced by the foreign-born black population is lost within a single generation. In contrast, a modest advantage among foreign-born Hispanics persists across generations.

The authors suspect discrimination and inequality in the U.S. may be a contributing factor to this decline. Experiences of interpersonal discrimination, both before and during pregnancy, are likely to trigger physiological stress responses that negatively affect birth outcomes, they said.

The study, published in Epidemiology, has important public health implications given that low birthweight is a significant predictor of a broad range of health and socioeconomic outcomes throughout one's life. The findings also underscore the potential role of discrimination in producing racial and intergenerational disparities in birth outcomes.

The research was conducted by Noreen Goldman, the Hughes-Rogers Professor of Demography and Public Affairs in the Woodrow Wilson School of Public and International Affairs, and first author Theresa Andrasfay, who received her Ph.D. from Princeton's Program in Population Studies.

Motivated by an earlier study of a small number of black immigrants in Illinois in the 1950-1970s, the researchers felt that conclusions regarding intergenerational changes in birthweight warranted a larger sample based on recent data in a popular immigrant destination state.

The authors analyzed administrative records from 1971 to 2015 in Florida, which receives a large number of black immigrants from the Caribbean. They linked several hundred thousand birth records of daughters to those of their mothers. This allowed them to compare birthweights of daughters born to foreign-born and U.S.-born mothers with the birthweights of their granddaughters. The study provides estimates of these intergenerational changes in birthweight for white, Hispanic, and black women.

The results point to what the researchers call a large foreign-born advantage among blacks: 7.8% of daughters born to foreign-born black women are low birthweight (under 2,500 grams or 5.5 pounds) compared to 11.8% among U.S.-born black women. But, whereas foreign-born Hispanic women maintain a birthweight advantage in the next generation, black women see this advantage essentially eliminated with the birth of their granddaughters. These granddaughters are more than 50% more likely than their mothers to be low birthweight. In contrast, the increase in low birthweight prevalence between daughters and granddaughters of U.S.-born black women is only about 10%, which is more in line with national increases in low birthweight over the same time period.

Andrasfay and Goldman were surprised by the rapidity with which the foreign-born advantage among black women was lost. After only one generation spent in the U.S., the prevalence of low birthweight is almost as high among the granddaughters of foreign-born black women as among the granddaughters of U.S.-born black women (12.2% vs. 13.1%) and is considerably higher for both groups of black infants than for white and Hispanic babies.

The authors identified an equally striking finding with regard to differences in low birthweight by level of schooling. Contrary to the pattern found among all other racial and ethnic groups, foreign-born black women are about as likely to have a low birthweight daughter if they have low or high levels of schooling. However, in the next generation, the prevalence of low birthweight declines as maternal education increases. This likely reflects a difference in the context in which mothers received their education. "In the U.S., mothers with less than high school education are disadvantaged in multiple ways," said Andrasfay, "but women who obtained this same level of schooling before immigrating to the U.S. were likely relatively advantaged in their origin countries."

The authors controlled for socioeconomic and health-related risk factors, including characteristics of women's neighborhoods that varied among racial, ethnic, and nativity groups, but these factors did not account for their findings. They concluded that the high frequency of low birthweight babies among blacks, and the increase from daughters to granddaughters among black immigrants, were likely both due to exposure to discrimination and inequality. "Unfortunately," said Goldman, "high quality measures of discrimination are notoriously difficult to obtain."

The researchers note several limitations of the study. The study is based on birth records from only one state, Florida, and in order to observe multiple generations within the same family, the study was restricted to families in which both daughters and granddaughters were born in Florida. Though the main analysis used only female births, there is evidence that the findings extend to male births. Nevertheless, their study has important implications.

"Though black immigrants currently make up a small share of the population, their numbers are growing," said Andrasfay. "This growth emphasizes the importance of understanding how their health evolves with time in the U.S. to better understand future disparities."

"Foreign-born blacks may experience less prejudice than their U.S.-born peers because they have spent part of their lives in majority black countries where discrimination may be less severe than in the U.S.," said Goldman. "In contrast, their children spend their entire lives in a more racialized social environment than found in the Caribbean, which could explain the worsening of birth outcomes between generations."

"This study also underscores the need for more research," said Goldman, "both to develop better measures of interpersonal discrimination and to identify epigenetic mechanisms that link social stressors to birth outcomes among black women."

Acute myeloid leukemia (AML) is one of the most common forms of blood cancer among adults and is associated with a low survival rate, and leads to the inhibition of normal blood formation. Now, a research team at Lund University in Sweden has identified one of the genes that is the basis for leukemia stem cells' survival and multiplication. The study is published in Cell Reports.

AML is the result of acquired genetic changes in the blood-forming stem cells and among other things affects genes that control the cells' maturation and growth. Although the disease occurs at all ages from childhood onwards, it is more common among the elderly.

"It is the leukemia stem cells in the bone marrow that drive the disease forwards and that is why we want to investigate which genes control these stem cells. By employing special gene scissors, CRISPR, we have been able, using an animal model, to study around 100 genes at the same time. It is the first time we have conducted such a large-scale study", says Marcus Järås, research team manager at Lund University.

The new method using gene scissors means that the researchers can effectively control which gene is turned off, making it possible to study the gene's function and thus better understand how diseases arise. The Lund researchers found that the gene CXCR4 is essential for the leukemia stem cells' survival. When they cut off this gene, the leukemia stem cells could not survive, as they are totally dependent on the protein that the gene produces.

"When we turned off CXCR4 this created oxidative stress and the leukemia stem cells matured into cells with a limited lifetime. Oxidative stress arises due to the waste products formed when oxygen is converted into energy. It is a process that is well regulated in the cell, but when there is an increase in waste products this results in toxicity which leads to the death of the cell", says Ramprasad Ramakrishnan, first author of the study.

In normal blood formation, the interaction between the proteins CXCL12 and CXCR4 is important for the blood stem cells. In contrast, the research team discovered that CXCL12 is not necessary for the leukemia stem cells, which shows a fundamental difference in how leukemia stem cells and normal blood stem cells are regulated.

"It was surprising that CXCL12 is not significant for the leukemia stem cells. This is somthing that in the long term can be utilised in the design of new drugs against AML", concludes Ramprasad Ramakrishnan.

Vienna, Austria, June 3, 2020 - AFFiRiS, a clinical-stage biotechnology company developing novel disease-modifying specific active immunotherapies (SAITs), today announced that detailed preclinical results with its monoclonal antibody mAB C6-17 to treat Huntington's Disease (HD) were published in the peer-reviewed journal Neurobiology of Disease.

Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by changes in personality, impairments in cognition and loss of motor function, leading to death over a period of 10 to 30 years. The disease is caused by a highly polymorphic CAG trinucleotide expansion in the gene encoding for the huntingtin protein (HTT). The resulting mutant huntingtin protein (mutHTT) is ubiquitously expressed but also exhibits the ability to propagate from cell-to-cell to disseminate pathology; a property, which may serve as a new therapeutic focus and suggest that immunotherapy may provide a viable approach to neutralize mutHTT in the extracellular space.

Accordingly, AFFiRiS set out to develop a monoclonal antibody (mAB) targeting a particularly exposed region of the HTT protein. The results published in Neurobiology of Disease show that this monoclonal antibody, designated C6-17 effectively binds mutHTT and is able to deplete the protein from cell culture supernatants. Using cell-based assays, AFFiRiS demonstrated that extracellular secretion of mutHTT into cell culture media and its subsequent uptake in recipient HeLa cells can be almost entirely blocked by mAB C6-17. Immunohistochemical stainings of post-mortem HD brain tissue confirmed the specificity of mAB C6-17 to human mutHTT aggregates.

Günther Staffler, PhD, Chief Technology Officer of AFFiRiS AG, comments: "New therapies for Huntington's disease are urgently needed to address the root cause of this debilitating disease. Our findings demonstrate that mAB C6-17 not only successfully engages with its target, mutHTT, but also inhibits cell uptake. This suggests that the antibody could interfere with the pathological processes of mutHTT spreading in vivo. These results validate our HTT/mutHTT targeting
monoclonal antibody that could ultimately be used as passive immunotherapy to treat features of Huntington's disease."

The majority of current preclinical and clinical mutHTT lowering strategies are based on gene silencing such as micro ribonucleic acids (miRNA) and anti-sense oligonucleotides (ASOs). These strategies are geared towards targeting mutHTT expression in the brain to interfere with the abnormal protein directly within neurons. However, mutHTT is ubiquitously expressed and antibodies would allow targeting of extracellular mutHTT throughout the body (brain and peripheral organs, tissues and plasma). This would be one of the most attractive features of this therapeutic approach.

"Previous reports indicate that the ability of peripheral antibodies to enter the brain is limited. However, considering that the peripheral nervous system can impact the central nervous system, our antibody may have the capacity to exert some beneficial effect on the brain as well, by influencing mutHTT levels in the periphery", says Noel Barrett, PhD, CEO of AFFiRiS AG. "Additionally, combining our antibodies with intracellularly acting ASO or miRNA could provide us with a two-pronged therapy that can simultaneously tackle both intra and extracellular mutHTT. Antibody-based interventions have been demonstrated to be safe and straightforward in application and handling. As such we foresee that antibodies, such as our lead antibody C6-17, could pioneer a new therapeutic strategy for reducing extracellular mutHTT, giving hope to patients suffering from this extremely serious and difficult to treat disease."

Scientists from IFJ PAN in cooperation with researchers from the Nara Women's University (Japan) and the Jagiellonian University (Poland) took another important step towards building a functional quantum computer. Using material containing terbium ions and dedicated experimental tools, they performed a detailed analysis of dynamic magnetic properties in individual molecular magnets concerning their orientation in a magnetic field. Discovered strong anisotropy of these properties is vital in the construction of molecular electronics components.

One of the biggest challenges faced by modern science is to build an affordable and highly efficient quantum computer that will revolutionize the IT industry. Today, various solutions are sought that could lead to the construction of such a device. These include superconducting systems, quantum dots and photons in the resonance cavity. Intensive research is also carried out on the use of molecular magnets made of single molecules of 1 nm in size (SMM - Single Molecular Magnets). For this purpose, however, scientists not only need to find materials with the right characteristics but also thoroughly understand the behavior of magnetic molecules. One of the key research directions in this area focuses on the dynamics of magnetic properties. These so-called magnetic relaxations tell us how the magnetic properties of a given substance change over time. In the quantum world, such dynamics is an abundant and complicated phenomenon, which is why researchers carefully examine its various aspects.

So far, extensive studies have revealed the possibility of using molecular magnets to create memory cells or a spin transistor. Scientists are also able to place individual molecules on a suitable substrate and use them to build simple electronic systems. Measurements confirm that magnetic relaxations play a vital role in the operation of molecular systems. On the other hand, it is known that the dynamics of magnetic properties depend on the anisotropy of static magnetic properties. However, in most previous studies, either the influence of the orientation of the examined molecule on its dynamic magnetic properties has not been tested, or it has been done only to a limited extent.

Accordingly, a team of scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences led by Dr. Eng. Piotr Konieczny decided to investigate how the dynamic magnetic properties of individual molecular magnets change depending on the orientation of the molecules. Most of research work on magnetic relaxation deals with materials in the form of powder, i.e. chaotically oriented crystallites, or polycrystals, which makes it impossible to analyze how these properties change with the molecule orientation. The Polish group, therefore, decided to study a single crystal - a monocrystalline - in which all molecules were oriented in the same way. This starting point enabled scientists to look at the effects taking place in a single molecule. To do this, it was also necessary to build an appropriate experimental system that would allow studying magnetic relaxation depending on the orientation of the tested substance.

"We were looking for a material that meets the expected requirements, and in particular is characterized by strong magnetic anisotropy and can be synthesized as high-quality crystal. At the same time, we developed laboratory equipment for testing the angle dependence of magnetic dynamics using ac magnetic susceptibility," explains Dr. Eng. Konieczny. "The specific crystal was found in Japan, in the laboratory of Prof. Takashi Kajiwara from the Nara Women's University. In the meantime, we tested various polymers that we intended to apply in the measurement system construction. We used plastic materials revealing the weakest magnetic signal and well tolerating low temperatures (2.0 K) to build a fully functional prototype of the device. The measurements confirmed our hypothesis: magnetic relaxation depends on the orientation of the molecule, and therefore shows anisotropy. We were surprised that this relationship was so strong. However, the theoretical analysis provides us with a quantitative explanation of the observed effect."

The studies were carried out using a commercial SQUID magnetometer. To analyze magnetic dynamics in the range of 0.1-1000 Hz, it was necessary to use the ac magnetic susceptibility method. This technique is commonly adopted to study magnetic relaxation. The innovation was the use of the developed setup which enabled to analyze anisotropy of dynamic magnetic properties (i.e. magnetic relaxation). This dedicated system was built in IFJ PAN for the described investigations. It allows the crystal to rotate inside the magnetometer at very low temperatures (2 K), high magnetic fields (7 T) and in a wide frequency range of the electromagnetic field (from 0.1 Hz to 1500 Hz). The device was designed and constructed to eliminate the unwanted background signal. Hence, it is possible to study the magnetic dynamics of small crystals.

The examined material - a terbium ion molecular magnet - was synthesized and structurally tested by Prof. Kajiwara's group, while most of theoretical and experimental analyses were carried out at IFJ PAN. The studies have confirmed that magnetic molecules show anisotropy of dynamic magnetic properties. In the investigated molecule, which looks like a ship's propeller, magnetic relaxation rate is four times greater when rotated 80 degrees.

The described research work allows scientists to learn how magnetic relaxation in individual molecules can change depending on their orientation. This knowledge will be applied for designing molecular systems used in spintronic applications and quantum computers. Now it is known that the orientation of molecules has a significant impact on the operation of such systems. Scientists also managed to build an experimental device that would allow more detailed studies of the magnetic dynamics of materials.

"Our work helps us to better understand the behavior of individual magnetic molecules," says Dr. Eng. Konieczny. "Now we know that the orientation of molecules plays an important role in molecular electronics, for example, a molecular transistor. The random orientation of the molecules will cause chaotic operation of electronic or spintronic systems. The identical arrangement of the particles, however, will ensure their smooth interaction and better control."

The results obtained by scientists from IFJ PAN are particularly important for engineers designing and building new generation electronic systems with magnetic molecules. "Our further research will continue to focus on the dynamic magnetic properties of molecular magnets," concludes Dr. Eng. Konieczny. "We believe that a profound knowledge of the phenomena occurring in these materials will bring us closer to creating a fully functional molecular quantum computer."