Tech

New York, NY--June 25, 2020--Water security is becoming an urgent global challenge. Hundreds of millions of people already live in water-scarce regions, and the UN projects that by 2030 about half the world's population will be living in highly water-stressed areas. This will be a crisis even for developed countries like the U.S., where water managers in 40 states expect freshwater shortages within the next 10 years. As the global population and GDP grow, so will the demand for freshwater. And, with the continuing rise of global temperatures, water shortages will only get worse.

Desalination processes are increasingly being relied upon to augment water supplies. In fact, global desalination capacity is projected to double between 2016 and 2030. But these processes are expensive and can be harmful to the environment. The ultrahigh salinity brines that are the byproduct of desalination can be several times that of seawater salinity and its management options are especially challenging for inland desalination facilities such as those in Arizona, California, Florida, and Texas.

Over the past year, Columbia Engineering researchers have been refining their unconventional desalination approach for hypersaline brines--temperature swing solvent extraction (TSSE)--that shows great promise for widespread use. TSSE is radically different from conventional methods because it is a solvent-extraction-based technique that does not use membranes and is not based on evaporative phase-change: it is effective, efficient, scalable, and sustainably powered. In a new paper, published online June 23 in Environmental Science & Technology, the team reports that their method has enabled them to attain energy-efficient zero-liquid discharge (ZLD) of ultrahigh salinity brines--the first demonstration of TSSE for ZLD desalination of hypersaline brines.

"Zero-liquid discharge is the last frontier of desalination," says Ngai Yin Yip, an assistant professor of earth and environmental engineering who led the study. "Evaporating and condensing the water is the current practice for ZLD but it's very energy intensive and prohibitively costly. We were able to achieve ZLD without boiling the water off--this is a major advance for desalinating the ultrahigh salinity brines that demonstrates how our TSSE technique can be a transformative technology for the global water industry."

Yip's TSSE process begins with mixing a low-polarity solvent with the high salinity brine. At low temperatures (the team used 5 °C), the TSSE solvent extracts water from the brine but not salts (which are present in the brine as ions). By controlling the ratio of solvent to brine, the team can extract all the water from the brine into the solvent to induce the precipitation of salts--after all the water is "sucked" into the solvent, the salts form solid crystals and fall to the bottom, which can then be easily sieved out.

After the researchers separate out the precipitated salts, they warm up the water-laden solvent to a moderate temperature of around 70 °C. At this higher temperature, the solvent's solubility for water decreases and water is squeezed out from the solvent, like a sponge. The separated water forms a layer below the solvent and has much less salt than the initial brine. It can be readily siphoned off and the regenerated solvent can then be reused for the next TSSE cycle.

"We were not expecting TSSE to work as well as it did," Yip says. "In fact, when we were discussing its potential for ZLD, we thought just the opposite, that the process would likely give out at some point when there is just too much salt for it to keep working. So it was a happy surprise when I convinced lead researcher Chanhee Boo to give it a try, for the heck of it, on a Friday afternoon and we got such great results."

With a simulated (lab-prepared) brine feed of 292,500 part-per-million total dissolved solids, Yip's group was able to precipitate more than 90% of the salt in the original solution. In addition, the researchers estimated that the process used only about a quarter of the energy required for evaporation of water--a 75% energy savings compared to thermally evaporating the brine. They reused the solvent for several cycles with no noticeable loss in performance, demonstrating that the solvent was conserved and not expended during the process.

Then, to demonstrate the practical applicability of the technology, the team took a field sample of high-salinity brine, the concentrate of irrigation drainage water in California's Central Valley, where irrigation drainage water is difficult and costly to treat, and achieved ZLD with TSSE.

Conventional distillation methods require high-grade steam and are frequently supplemented with electricity to power vacuum pumps. Because TSSE requires only moderate temperature inputs, the low-grade thermal energy necessary can come from more sustainable sources, such as industrial waste heat, shallow-well geothermal, and low-concentration solar collectors.

"With the right solvent and right temperature conditions, we can provide cost-effective and environmentally sustainable concentrate management options for inland desalination facilities, utilizing brackish groundwater to alleviate the current and pending water stresses," Yip notes.

In addition to managing inland desalination concentrates, TSSE can also be used for other high salinity brines including flowback and produced water from oil and gas extraction, waste streams from steam-driven electric power stations, discharges from coal-to-chemical facilities, and landfill leachate. Yip's group is continuing to investigate the fundamental working mechanisms of TSSE, to engineer further improvements in its performance. This work includes further testing with real samples from the field, as well as optimization of the overall process.

A new machine learning algorithm allows researchers to explore possible designs for the microstructure of fuel cells and lithium-ion batteries, before running 3D simulations that help researchers make changes to improve performance.

Improvements could include making smartphones charge faster, increasing the time between charges for electric vehicles, and increasing the power of hydrogen fuel cells running data centres.

The paper is published today in npj Computational Materials.

Fuel cells use clean hydrogen fuel, which can be generated by wind and solar energy, to produce heat and electricity, and lithium-ion batteries, like those found in smartphones, laptops, and electric cars, are a popular type of energy storage. The performance of both is closely related to their microstructure: how the pores (holes) inside their electrodes are shaped and arranged can affect how much power fuel cells can generate, and how quickly batteries charge and discharge.

However, because the micrometre-scale pores are so small, their specific shapes and sizes can be difficult to study at a high enough resolution to relate them to overall cell performance.

Now, Imperial researchers have applied machine learning techniques to help them explore these pores virtually and run 3D simulations to predict cell performance based on their microstructure.

The researchers used a novel machine learning technique called "deep convolutional generative adversarial networks" (DC-GANs). These algorithms can learn to generate 3D image data of the microstructure based on training data obtained from nano-scale imaging performed synchrotrons (a kind of particle accelerator the size of a football stadium).

Lead author Andrea Gayon-Lombardo, of Imperial's Department of Earth Science and Engineering, said: "Our technique is helping us zoom right in on batteries and cells to see which properties affect overall performance. Developing image-based machine learning techniques like this could unlock new ways of analysing images at this scale."

When running 3D simulations to predict cell performance, researchers need a large enough volume of data to be considered statistically representative of the whole cell. It is currently difficult to obtain large volumes of microstructural image data at the required resolution.

However, the authors found they could train their code to generate either much larger datasets that have all the same properties, or deliberately generate structures that models suggest would result in better performing batteries.

Project supervisor Dr Sam Cooper, of Imperial's Dyson School of Design Engineering, said: "Our team's findings will help researchers from the energy community to design and manufacture optimised electrodes for improved cell performance. It's an exciting time for both the energy storage and machine learning communities, so we're delighted to be exploring the interface of these two disciplines."

By constraining their algorithm to only produce results that are currently feasible to manufacture, the researchers hope to apply their technique to manufacturing to designing optimised electrodes for next generation cells.

Under changing, increasingly dynamic climatic conditions, temperate soils are forecast to experience a high degree of variability in moisture conditions due to periods of drought and/or flood. These periodic shifts between well-drained and waterlogged conditions have the potential to enhance carbon cycling by microbes and influence soil quality and land-derived greenhouse gas emissions.

In a recently published study in Vadose Zone Journal, researchers subjected a soil column to controlled periods of waterlogging versus drainage. The team showed that dynamic water saturation led to pronounced pulses of carbon dioxide emissions and higher depletion of soil organic carbon at the depth exposed to fluctuating water saturation. The research was carried out in a novel experimental setup, in which the water saturation conditions experienced by the soil column were manipulated while monitoring oxygen content, redox potential and porewater composition.

Remarkably, the depth region of the soil columns exposed to dynamic waterlogging developed lower microbial biomass relative to static conditions, but these remaining microbes exhibited a higher activity. In contrast to expected results, dynamic waterlogging conditions did not result in a higher diversity of the microbial community.

The ability to understand the factors controlling the cycling of nutrients and carbon under dynamic environmental conditions can be achieved by applying novel experimental techniques such as these. The findings suggest that the enhanced carbon cycling under dynamic waterlogging is driven by a more active, and not a more abundant or compositionally more diverse, microbial community. Ultimately, these effects of dynamic waterlogging can be incorporated into global scale predictive models to improve our predictive capabilities of the biosphere's response to environmental change.

An international team of researchers, affiliated with UNIST has unveiled a novel material that could enable major leaps in the miniaturization of electronic devices. Published in the prestigious journal Nature, this study represent a significant achievement for future electronics.

This breakthrough comes from a research, conducted by Professor Hyeon Suk Shin (School of Natual Sciences, UNIST) and Principal Researcher Dr. Hyeon-Jin Shin from Samsung Advanced Institute of Technology (SAIT), in collaboration with Graphene Flagship researchers from University of Cambridge (UK) and Catalan Institute of Nanoscience and Nanotechnology (ICN2, Spain).

In this study, the team successfully demonstrated the synthesis of thin film of amorphous boron nitride (a-BN) with extremely low dielectric constant as well as high breakdown voltage and superior metal barrier properties. The research team noted that this newly fabricated material has great potential as interconnect insulators in the next-generation of electronic circuits.

In the ongoing process of miniaturization of logic and memory devices in electronic circuits, minimizing the dimensions of interconencts - metal wires that link the different device components on the chip - is crucial to guarantee improved performance and faster response of the device. Extensive research efforts have been devoted to decreasing the resistance of scaled interconnects because integration of dielectrics using complementary metal oxide semiconductor (CMOS) compatible processes has proven to be exceptionally challenging. According to the research team, the required interconnect isolation materials should not only possess low relative dielectric constants (referred to as k-values), but should also be thermally, chemically, and mechanically stable.

There has been an ongoing quest to obtain materials with ultra-low-k (relative permittivity around or below 2) avoiding the artificial addition of pores in the thin film in the semiconductor industry for at least the past 20 years. Several attempts had been made to develop materials with desired characteristics, yet those materials have failed to be successfully integrated in interconnects due to poor mechanical properties or poor chemical stability upon integration, causing reliability failures.

In this study, the joint research has succeeded in demonstrating a Back-End-ofthe-Line (BEOL) compatible approach to grow amorphous boron nitride (a-BN) with extremely low-k dielectrics. In particular, they synthesized approximately 3 nm thin a-BN on a Si substrate, using low temperature remote inductively coupled plasma-chemical vapour deposition (ICP-CVD). The resulting material showed an extremely low dielectric constant in the range of 1.78, which is 30% lower than the dielectric constant of currently available insulators.

In this study, the joint research has succeeded in demonstrating a Back-End-ofthe-Line (BEOL) compatible approach to grow amorphous boron nitride (a-BN) with extremely low-k dielectrics. In particular, they synthesized approximately 3 nm thin a-BN on a Si substrate, using low temperature remote inductively coupled plasma-chemical vapour deposition (ICP-CVD). The resulting material showed an extremely low dielectric constant in the range of 1.78, which is 30% lower than the dielectric constant of currently available insulators.

"We found that temperature was the most important parameter with ideal a-BN film deposition occurring at 400° C," says Seokmo Hong in the Doctoral program of Natural Sciences, the first author of the study. "This material with ultra-low-k also manifests a high breakdown voltage and likely superior metal barrier properties, making the film very attractive for practical electronic applications."

Angle-dependent near-edge X-ray absorption fine structure (NEXAFS) measured in partial electron-yield (PEY) mode at Pohang Light Source-II 4D beam line was also used to investigate the chemical and electronic structures of a-BN. Their findings indicated that the irregular, random atomic arrangement causes the dielectric constant value to drop.

The new material also manifests excellent mechanical properties of high strength. Moreover, when researchers tested the diffusion barrier properties of a-BN in very harsh conditions, they found it can prevent metal atom migration from the interconnects into the insulator. This result will help resolves a long-standing issue of interconnects in CMOS integrated circuit fabrication, enabling further miniaturaization of electronic devices.

"Development of electrically, mechanically and thermally robust low-k materials (k

"Our results demonstrate that the amorphous counterpart of two-dimensional hexagonal BN possesses the ideal low-k dielectric characteristics for high-performance electronics," says Professor Shin. "If they are commercialized, it will be a great help in overcoming the crisis looming over the semiconductor industry."

Xiang-Dong Fu, PhD, has never been more excited about something in his entire career. He has long studied the basic biology of RNA, a genetic cousin of DNA, and the proteins that bind it. But a single discovery has launched Fu into a completely new field: neuroscience.

For decades, Fu and his team at University of California San Diego School of Medicine studied a protein called PTB, which is well known for binding RNA and influencing which genes are turned "on" or "off" in a cell. To study the role of a protein like PTB, scientists often manipulate cells to reduce the amount of that protein, and then watch to see what happens.

Several years ago, a postdoctoral researcher working in Fu's lab was taking that approach, using a technique called siRNA to silence the PTB gene in connective tissue cells known as fibroblasts. But it's a tedious process that needs to be performed over and over. He got tired of it and convinced Fu they should use a different technique to create a stable cell line that's permanently lacking PTB. At first, the postdoc complained about that too, because it made the cells grow so slowly.

But then he noticed something odd after a couple of weeks -- there were very few fibroblasts left. Almost the whole dish was instead filled with neurons.

In this serendipitous way, the team discovered that inhibiting or deleting just a single gene, the gene that encodes PTB, transforms several types of mouse cells directly into neurons.

More recently, Fu and Hao Qian, PhD, another postdoctoral researcher in his lab, took the finding a big step forward, applying it in what could one day be a new therapeutic approach for Parkinson's disease and other neurodegenerative diseases. Just a single treatment to inhibit PTB in mice converted native astrocytes, star-shaped support cells of the brain, into neurons that produce the neurotransmitter dopamine. As a result, the mice's Parkinson's disease symptoms disappeared.

The study is published June 24, 2020 in Nature.

"Researchers around the world have tried many ways to generate neurons in the lab, using stem cells and other means, so we can study them better, as well as to use them to replace lost neurons in neurodegenerative diseases," said Fu, who is a Distinguished Professor in the Department of Cellular and Molecular Medicine at UC San Diego School of Medicine. "The fact that we could produce so many neurons in such a relatively easy way came as a big surprise."

There are several different ways to mimic Parkinson's disease in mice. In this case, the researchers applied a dopamine look-a-like molecule to poison neurons that produce dopamine. As a result, the mice lose dopamine-producing neurons and develop symptoms similar to Parkinson's disease, such as movement deficiencies.

The treatment works like this: The researchers developed a noninfectious virus that carries an antisense oligonucleotide sequence -- an artificial piece of DNA designed to specifically bind the RNA coding for PTB, thus degrading it, preventing it from being translated into a functional protein and stimulating neuron development.

Antisense oligonucleotides, also known as designer DNA drugs, are a proven approach for neurodegenerative and neuromuscular diseases -- study co-author, Don Cleveland, PhD, pioneered the technology, and it now forms the basis for a Food and Drug Administration (FDA)-approved therapy for spinal muscular atrophy and several other therapies currently in clinical trials. Cleveland is chair of the Department of Cellular and Molecular Medicine at UC San Diego School of Medicine and member of the Ludwig Institute for Cancer Research, San Diego.

The researchers administered the PTB antisense oligonucleotide treatment directly to the mouse's midbrain, which is responsible for regulating motor control and reward behaviors, and the part of the brain that typically loses dopamine-producing neurons in Parkinson's disease. A control group of mice received mock treatment with an empty virus or an irrelevant antisense sequence.

In the treated mice, a small subset of astrocytes converted to neurons, increasing the number of neurons by approximately 30 percent. Dopamine levels were restored to a level comparable to that in normal mice. What's more, the neurons grew and sent their processes into other parts of brain. There was no change in the control mice.

By two different measures of limb movement and response, the treated mice returned to normal within three months after a single treatment, and remained completely free from symptoms of Parkinson's disease for the rest of their lives. In contrast, the control mice showed no improvement.

"I was stunned at what I saw," said study co-author William Mobley, MD, PhD, Distinguished Professor of Neurosciences at UC San Diego School of Medicine. "This whole new strategy for treating neurodegeneration gives hope that it may be possible to help even those with advanced disease."

What is it about PTB that makes this work? "This protein is present in a lot of cells," Fu said. "But as neurons begin to develop from their precursors, it naturally disappears. What we've found is that forcing PTB to go away is the only signal a cell needs to turn on the genes needed to produce a neuron."

Of course, mice aren't people, he cautioned. The model the team used doesn't perfectly recapitulate all essential features of Parkinson's disease. But the study provides a proof of concept, Fu said.

Next, the team plans to optimize their methods and test the approach in mouse models that mimic Parkinson's disease through genetic changes. They have also patented the PTB antisense oligonucleotide treatment in order to move forward toward testing in humans.

"It's my dream to see this through to clinical trials, to test this approach as a treatment for Parkinson's disease, but also many other diseases where neurons are lost, such as Alzheimer's and Huntington's diseases and stroke," Fu said. "And dreaming even bigger -- what if we could target PTB to correct defects in other parts of the brain, to treat things like inherited brain defects?

"I intend to spend the rest of my career answering these questions."

UC researchers have found a potential new combination therapy for breast cancer that would integrate use of the body's immune system with targeted treatment for a particular protein that advances cancer.

The study, published in the journal Cancer Research, a journal of the American Association for Cancer Research, provides data that could eventually lead to a new breast cancer therapy, says co-lead author Syn Kok Yeo, PhD, research instructor in the department of cancer biology and a member in the lab of Jun-Lin Guan, the Francis Brunning Professor and Cancer Biology Department Chair.

Guan is a corresponding author on the paper.

Both researchers are members of the UC Cancer Center.

"Cancer immunotherapy uses a patient's immune system against tumor cells," Yeo says. "It has emerged as a crucial treatment strategy, resulting in stable outcomes for cancer patients. However, most breast cancers are not responsive to immunotherapy, and this remains a colossal hurdle."

In this study, researchers found that targeting a protein called FIP200 could "overwrite" the nonresponsive nature of breast cancers to certain immunotherapies, called immune checkpoint inhibitors.

"Disruption of the protein's functions in tumor cells could essentially turn 'cold', or nonresponsive, tumors into 'hot', or responsive, tumors, susceptible to immunotherapy," Yeo says. "Tumors that didn't have this protein contained more T-cells, which is indicative of an immunologically 'hot' tumor. When coupled with immune checkpoint inhibitors in animal models with breast cancer, improved outcomes were observed when the protein wasn't present.

"These findings indicate that targeting FIP200 could create a 'hot spot' for immunotherapy within these tumors."

These findings expand upon previous studies by Guan's lab that identified a tumor-promoting role of the protein in breast cancer.

"While the function of this protein in a cell-recycling process was previously identified as a culprit in breast cancer growth and progression, targeting this function did not make the tumors susceptible to immunotherapy," Yeo adds. "This would imply that the protein has many roles in the development of breast cancer and targeting all of them simultaneously could improve treatment outcomes.

"Future studies are needed to develop therapeutic agents against this protein, to be used in combination with immunotherapy. These findings form a foundation for future clinical trials involving drugs that target the protein in breast cancers."

What The Viewpoint Says: The use of online platforms to guide effective consumption of information, facilitate social support and continue mental health care delivery during the COVID-19 pandemic is discussed in this Viewpoint.

Authors: Yuval Neria, Ph.D., of the Columbia University Irving Medical Center in New York, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamapsychiatry.2020.1730)

Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

Scientists from the German Cancer Research Center and the Universities of Cambridge and Edinburgh have been studying the evolution of tumors following chemical damage. They discovered that the DNA lesions caused by the chemical are not eliminated immediately, but are passed on unrepaired over several rounds of cell division. Both DNA strands with their independent sets of lesions are separated during cell division, resulting in two daughter cells with different patterns of DNA changes - their mutation profiles. During further rounds of replication, the lesions repeatedly generated new combinations of mutations, providing many chances to find the best combination for tumor growth. This "lesion segregation" can drive unexpectedly complex patterns of mutations in the tumor genome, as the scientists have now published in the journal Nature.

Tobacco smoke, many chemicals or the UV radiation of sunlight: Numerous environmental and lifestyle factors damage the genetic material of our cells and can thus trigger cancer. These factors modify individual DNA building blocks, called nucleotides, in such a way that they are no longer correctly recognized when the DNA is duplicated. The consequence: False "counterparts" are incorporated into the newly synthesized DNA strand.

Cells have a variety of repair systems that can remove and replace such defective nucleotides. But which defects are repaired and which escape repair and can lead to cancer-promoting mutations? What effect does this have on the mutation pattern of tumor cells? And how do these mutations spread during the clonal expansion of individual cells during tumorigenesis?

Answering these questions was the goal of a collaboration among the laboratories of Duncan Odom at the German Cancer Research Center (DKFZ) and the University of Cambridge's Cancer Research UK - Cambridge Institute, Martin Taylor and Colin Semple at the University of Edinburgh's MRC Human Genetics Unit, as well as Paul Flicek at EMBL EBI and Professor Nuria Lopez-Bigas at IRB Barcelona. These researchers used the DNA-damaging chemical diethylnitrosamine to induce hundreds of liver tumors in mice and analyzed the genomes of these cancers. On average, this chemical mutagen caused about 60,000 point mutations in the genome of each cancer cell.

To their surprise, the scientists discovered during the analysis of the mutation signatures that the lesions caused by the chemical remains largely unrepaired over several cell generations. The two DNA strands, which were damaged independently of each other, are separated during cell division. The two resulting daughter cells then develop two different mutation profiles. The researchers refer to this as "lesion segregation".

During further replication rounds, the lesions repeatedly lead to new, different mutations, since four different DNA nucleotides can be incorporated at the defective site. Cancer cells are usually exposed to several mutagenic events, so that this cycle of DNA damage and lesion segregation repeats over time, ultimately resulting in extremely complex patterns of mutations in cancers.

The mutations affect important genes known as cancer drivers. In their study, the scientists found defects in genes of the cancer-promoting BRAF, RAS and RAF signaling pathways. "In the end, those cancer cells that carry the most favorable pattern of mutations will prevail. They can grow the fastest, escape the immune system and possibly survive therapies better," says lead author Sarah Aitken, a Cambridge-based clinician-scientist.

"Persistent DNA lesions induced by chemotherapeutic agents also segregate and produce several generations of further mutations. We need to be aware of this therapeutically, and in future drug development," said Martin Taylor from University of Edinburgh's MRC Human Genetics Unit.

"Thanks to the concept of lesion segregation, we now understand better how the surprising complexity of mutations in cancer cells can arise," summarizes Duncan Odom. "This may help explain how cancer cells can react so flexibly to survival challenges, which in turn helps them to quickly develop resistance to drugs or adapt to foreign tissue environments."

"If in doubt, always follow your nose," said Gandalf in The Lord of the Rings.

Despite Gandalf's advice, humans tend to regard themselves as "microsmatic" - having a poor sense of smell. Human navigation is thought to rely primarily on vision and audition. Specifically, subtle differences between the inputs to the paired eyes and ears are exploited by the brain to construct three-dimensional experiences that guide navigation.

Although humans also have two separate nasal passages that simultaneously sample from nonoverlapping regions in space, it is widely held that inter-nostril differences in odor concentration do not provide directional information in humans unless that odor also stimulates the trigeminal nerve (i.e., elicits hot, cold, spicy, tingling, or electric feelings), in which case it is really the trigeminal system that generates a directional cue.

However, a new study conducted by graduate student WU Yuli and his colleagues at the Institute of Psychology of the Chinese Academy of Sciences (CAS) argues otherwise.

WU and his colleagues introduced various levels of binaral concentration disparity to a heading judgment paradigm based on optic flow - a unique type of visual stimulus that captures the pattern of apparent motion of surface elements in a visual scene and induces the illusory feeling of self-movement in stationary observers.

The odorants they used were phenylethyl alcohol and vanillin, which smell like rose and vanilla, respectively, and are known to activate only the olfactory nerve.

Results from stringent psychophysical testing in four experiments involving a total of 180 participants consistently showed that a moderate binaral disparity biases recipients' perceived direction of self-motion toward the higher-concentration side in manners reminiscent of stereo vision (i.e., binocular stereopsis), despite not being able to verbalize which nostril smells a stronger odor.

In addition, the effect depends on the inter-nostril ratio of odor concentrations as opposed to the numeric difference in concentration between the two nostrils.

"Our work presents clear behavioral evidence that humans have a stereo sense of smell that subconsciously guides navigation," said Dr. ZHOU Wen, senior author of the study. "The findings underscore the multisensory nature of heading perception and could provide guidance for the design and development of olfactory virtual-reality systems for humans."

"Neuromorphic" refers to mimicking the behavior of brain neural cells. When one speaks of neuromorphic computers, they are talking about making computers think and process more like human brains-operating at high-speed with low energy consumption.

Despite a growing interest in polymer-based neuromorphic devices, researchers have yet to establish an effective method for controlling the response speed of devices. Researchers from Tohoku University and the University of Cambridge, however, have overcome this obstacle through mixing the polymers PSS-Na and PEDOT:PSS, discovering that adding an ion conducting polymer enhances neuromorphic device response time.

Polymers are materials composed of long molecular chains and play a fundamental aspect in modern life from the rubber in tires, to water bottles, to polystyrene. Mixing polymers together results in the creation of new materials with their own distinct physical properties.

Most studies on neuromorphic devices based on polymer focus exclusively on the application of PEDOT: PSS, a mixed conductor that transports both electrons and ions. PSS-Na, on the other hand, transports ions only. By blending these two polymers, the researchers could enhance the ion diffusivity in the active layer of the device. Their measurements confirmed an increase in device response time, achieving a 5-time shorting at maximum. The results also proved how closely related response time is to the diffusivity of ions in the active layer.

"Our study paves the way for a deeper understanding behind the science of conducting polymers." explains co-author Shunsuke Yamamoto from the Department of Biomolecular Engineering at Tohoku University's Graduate School of Engineering. "Moving forward, it may be possible to create artificial neural networks composed of multiple neuromorphic devices," he adds.

Many pharmaceuticals work by targeting what are known as "G-protein-coupled receptors". In a new study, scientists from Uppsala University describe how they have been able to predict how special molecules that can be used in new immunotherapy against cancer bind to these receptors. The researchers' calculation methods, presented in the journal Angewandte Chemie are a vital contribution to future structure-based drug design.

G-protein-coupled receptors (GPCRs) are among the protein target groups of the greatest importance for drug development. These receptors react to, for example, light, flavours, smells, adrenaline, histamine, dopamine and a long list of other molecules by transmitting further biochemical signals inside cells. The researchers who carried out the survey of GPCRs were rewarded with the Nobel Prize in Chemistry in 2012.

Today, roughly 30 per cent of all drugs on the market have GPCRs as their target proteins. Some drug molecules, such as morphine, activate the receptors (agonists) while others, such as beta blockers, inactivate them (antagonists).

One important GPCR is the adenosine A2A receptor. Its antagonists can be used in new immunotherapy against cancer. Jointly with the biopharmaceutical company Sosei-Heptares, the researchers Willem Jespers, Johan Åqvist and Hugo Gutierrez-de-Terán of Uppsala University have succeeded in showing how a series of A2A antagonists bind to the receptor and inactivate it.

With molecular dynamic simulations and calculation of binding energies, it became possible to predict how molecules from the pharmaceutical company would bind to the receptors and how strongly they do so. Thereafter, new antagonists were designed, and synthesized by chemists from Santiago de Compostela University, Spain. Three-dimensional structures of the complexes that form between these molecules and the receptor were then determined experimentally with X-ray crystallography. Computer calculations proved capable of predicting both the structure and the binding strength in the complexes with high precision.

"This is a solid step forward, and we managed to predict with great precision how this family of molecules bind the A2A receptor. Our calculation methods are now having a major breakthrough in structure-based drug design," says Hugo Gutierrez-de-Terán, who headed the Uppsala group's project.

Forensic scientists at the University of Portsmouth have discovered a new way of presenting fragile evidence, by reconstructing a 'jigsaw' of human bone fragments using 3D printing.

In the first known study of its kind, researchers took fragmented burnt human bones and tested the ability to make 3D models suitable to be shown to a jury in court.

Forensic investigation of crime scenes and other incidents requires the analysis of many different items as evidence, including human remains, some of which may be damaged or fragmented. To determine whether these pieces of evidence were originally one whole, they have to undergo a process called 'physical fit analysis'.

One of the scientists involved in the research, Dr Katherine Brown, Senior Lecturer, Institute of Criminal Justice Studies, University of Portsmouth, says: "A positive physical fit indicates that two or more fragments having originated from the same object. Confirming physical fit at a crime scene is essential to draw links between locations, place suspects at the scene, and allow for object reconstruction."

However, physical fit analysis relies on the manual handling and then placing back together of the human remains and is often challenging to conduct with bone fragments particularly when fragile, sharp, or embedded in other materials.

Dr Brown says: "We wanted to find a way to circumvent the need to manually handle the delicate bones, so we looked to 3D technology. Whilst the use of 3D technology has become increasingly widespread within the field of forensics to our knowledge, this approach has not yet been applied explicitly to physical fit analysis."

The scientists compared two different 3D imaging techniques, micro computed tomography and structured light scanning. By generating virtual 3D models and prints of burned human bone fragments, they tested the suitability of these imaging techniques and subsequent 3D printing for physical fit analysis. The researchers ultimately found that 3D imaging and printing allowed for effective physical fit analysis without excessively handling the original fragments.

Limiting the handling of fragile forensic evidence minimises damage and contamination. Additionally, the use of 3D prints opens up the possibility for physical fit demonstration, and the opportunity for a jury to explore the evidence replicas. Interaction with 3D virtual models and animations also provides 360 degree visualisation in an engaging, understandable and potentially impactful way, improving a jury's understanding.

Dr Brown says: "The application of 3D imaging and printing for physical fit analysis has many advantages compared with traditional methods. Overall, the techniques demonstrated by the study add value in forensic investigation and evidence presentation within the courtroom."

Scientists at Tokyo Institute of Technology (Tokyo Tech) elucidate the underlying cause behind the different critical transition temperatures reported for ultrathin iron selenide (FeSe) superconductors. Their results clarify why the interface between the first FeSe layer and its substrate play an essential role in superconductivity, giving new insights into a long-standing puzzle in this field.

Superconductors are materials that, below a certain temperature, have fascinating electromagnetic properties. They exhibit zero resistance, which means that they conduct electricity without losing energy in the form of heat, and can also completely repel external magnetic fields. Because of such feats, superconductors are very attractive for fundamental physics studies and electronics applications.

Although it's been fourteen years since iron-based superconductors were discovered, scientists are still at a loss regarding the underlying mechanisms of superconductivity in ultrathin layers of iron selenide (FeSe). While the critical transition temperature (Tc) below which bulk FeSe behaves as a superconductor is 8 K, significantly different values have been reported for monolayers of FeSe crystals grown uniformly on a strontium titanate (STO) substrate; these values range from 40 K to as high as 109 K.

In a recent study published in Physical Review Letters, Prof. Satoru Ichinokura and colleagues from Tokyo Tech shed some light on this problem. Ichinokura describes the problem at hand: "Even though several studies indicate that the interface between FeSe and STO, or the area where FeSe and STO come in contact, plays an essential role in the enhancement of Tc, there is room for further work to accurately explain the microscopic origin of this behavior." Moreover, there is also an ongoing debate concerning the depth at which superconductivity occurs with respect to the thickness of the FeSe film.

To tackle these questions, the researchers prepared samples by stacking FeSe at thicknesses ranging from one to five unit-cell layers onto an insulating STO substrate. Through four-point probe measurements in vacuum, they deduced the resistivity (the inverse of conductivity) of the samples at various temperatures and different depths. First, they found definite evidence that their electrical measurements correspond to conduction along the FeSe films, without influence from the underlying STO substrate. More importantly, they consistently observed a marked resistivity drop at 40 K (indicating the onset of superconductivity; see Figure ) regardless of the thickness of the FeSe layer. Ichinokura remarks: "These results unambiguously suggest that high-temperature superconductivity is essentially located at the interface between FeSe and STO or at the bottommost FeSe monolayer without spreading to the upper ones."

Now, why did other studies report different Tc values? After carefully reviewing previous works, Ichinokura and his colleagues conclude that differences in the number of dopants in the STO substrate or oxygen vacancies in the STO subsurface layers are responsible for the variability in Tc values. In some previous studies, the fabrication procedure employed is likely to have induced oxygen vacancies at the surface of the otherwise uniform STO layer. In others, STO doped with niobium impurities was used. These differences in the substrate allow more charge carriers (electrons) to reach the STO/FeSe interface, which results in sustained superconductivity even at higher temperatures (in other words, increased Tc).

Excited by these results, Ichinokura concludes: "Our results strongly indicate the interfacial nature of the two-dimensional superconductivity observed in FeSe/STO and reconfirm the importance of charge accumulation from the substrate into the interface. We have been able to obtain new insights into the long-standing puzzle of finding low Tc of about 40 K when using insulating STO substrates instead of conductive ones." This study puts us one step closer to elucidating the mysteries concerning the enhanced superconductivity.

When batteries are charged and used, a complex SEI (solid electrolyte interphase) layer is formed. Its structure resembles a mosaic consisting of organic and inorganic parts assembled from several blocks.

Researchers have noticed that if an artificial layer is applied to the electrode surface of a battery, the batteries can be recharged and used longer. The actual electrode material is saved when the separately added layer reacts and forms a protective SEI layer. The surface of an artificially produced SEI is also more even and of a higher quality than that of a naturally developed layer.

Inorganic materials, i.e. materials that do not contain carbon, have been used in the atomic layer deposition. Now, Aalto University's researchers have been the first in the world to produce a coating using carbon dioxide in molecular layer deposition.

'We will make a coating that imitates a completely natural SEI layer and which we hope will protect the actual electrode material', says doctoral candidate Juho Heiska.

In addition to increasing battery durability, the artificial SEI can also enable the use of new, more efficient electrode materials. The battery is always composed of two electrodes, each with its own characteristics that affect the performance of the battery.

'It would be a jackpot, if batteries could use metallic lithium. If clean lithium metal could be used safely, it would significantly increase the capacity of batteries. With the help of an artificial SEI, this might be possible', says Juho Heiska. Metal lithium can ignite the battery if it comes into contact with water or air. It is, therefore, challenging to use it in batteries.

The use of batteries is increasing rapidly in society, as, for example, electric vehicles become more common. Therefore, improving sustainability and efficiency are important for the environment.

'Metal extraction is too cheap at the moment, which is why companies do not have the incentive to produce products with a longer life span. And consumers are not interested in paying more for batteries', says Juho Heiska.

The study succeeded in building an organic part of SEI. Next, the researchers will test how the artificial coating now developed protects the battery.

Can obesity define health? It is a question for much debate. Still, obesity is generally classified into metabolically healthy obesity (MHO) and an unhealthy version of obesity. As we grow older, we tend to put on excess fat more around the waist than the hips and legs with aging, becoming more "apple-shaped" than "pear-shaped" and also at a greater risk of metabolic syndrome. As fat accumulates around our abdominal organs, instead of under the skin where most of our body fat usually sits, this visceral fat releases fatty acids and inflammatory substances directly into the liver, causing toxicity and insulin resistance. People with MHO, meanwhile are characterized by favorable health parameters, including high insulin sensitivity, no signs of hypertension, and less inflammation, and a healthier immune system.

It is undeniable that where body fat sits matters for health, but little has been known about what mechanism determines whether we have the pear shape or the apple shape. Led by Dr. KOH Gou Young at the Center for Vascular Research, within the Institute for Basic Science (IBS), South Korea, scientists have reported Angiopoietin-2 (Angpt2) - a hormone secreted from fat tissue, previously known as a protein coding peptide involved in embryonic vascular development - as a key driver that inhibits the accumulation of potbellies by enabling the proper transport of fatty acid into general circulation in blood vessels, thus preventing insulin resistance. Their findings have been published online in the journal Nature Communications (12 June 2020).

"Previous approaches blocked the expression of Angpt2 in the whole circulatory system with pharmacological interventions to inhibit displaced fat accumulation that leads to metabolic disorders. Though the vascular endothelial cell is the anatomic and metabolic gatekeeper of fat shuttling into tissues, it has still remained uncertain whether the displaced accumulation of excess fat in fat tissues is a cause or an indicator of metabolic syndrome. We specifically focused on the fatty acid shuttling in the specific fat tissues under the skin. Angpt2 is found to play a key role in packing on fat on proper locations where they should be to contain wider waistline," says BAE Hosung, the first author of this study.

Noting that the blood vessels under the skin are home to certain fatty acid transport proteins, the researchers compared samples from MHO and metabolically unhealthy obese individuals. Angpt2 turned out to be the single potential candidate for sustaining metabolic health via regulation of body fat distribution. Through various tissue-specific knock out mouse models and mechanistic studies in primary cultured cells, they revealed Angpt2 produced from fat cells interacts with its receptor integrin α5β1 to drive fatty acid transporters and ensure normal distribution of circulating fat. "Intriguingly, Angpt2-integrin α5β1 signaling took just few minutes. This near-instant processing makes sense since this biological mechanism should cope with the surge of fat levels in the blood after a meal," explains Bae.

The inhibition of this process triggered fat accumulation in other fat depots and abdominal organs, leading to systemic glucose intolerance, which is reminiscent of the pattern in metabolically unhealthy obese patients.

Can Angpt2 treatment be a therapeutic strategy to normalize fat distribution and treat obesity-induced metabolic disorders? As shown in previous efforts, systemic modulation of Angpt2 through pharmacological blockade is limited as Angpt2 is individual, and it depends on heterogeneity of different fat depots. Alternatively, activating integrin receptors or fatty acid transporters may be a more feasible approach for its relatively restricted expression in fat cells under the skin. "It requires further investigation to test these possibilities genetically or pharmaceutically to open new therapeutic paths for transformation of metabolically unhealthy obesity to healthy obesity," adds Bae.