Tech

Children with Inflammatory Bowel Disease (IBD) run a greater risk of psychiatric disorders, according to a new study from Karolinska Institutet in Sweden published in JAMA Pediatrics. The researchers claim that more psychological support and longer follow-up is needed for the children affected and their parents.

It is already known that adults with IBD (Ulcerative Colitis or Crohn's Disease) run an increased risk of psychiatric disorders. Now a new study shows that children with IBD also run a higher risk of mental health problems.

More than 6,400 children with IBD, born between 1973 and 2013, were included in the study. Using population registers, the researchers compared the risk of psychiatric disorders later on in life with both healthy children from the general population and with the patients' own siblings. By comparing the patients with their siblings, it was possible to take a large number of so-called confounders, such as socioeconomics, lifestyle and heredity into account, factors that are known to affect the risk of psychiatric disorders in children.

During an average follow-up period of 9 years, approximately 17 per cent of the children with IBD were given a psychiatric diagnosis compared with just under 12 per cent of the healthy children and about 10 per cent of the siblings. This means that the risk of psychiatric disorders was 1.6 times higher in children with IBD compared to Swedish children from general population. Likewise, the risk for the children with IBD was greater than for their siblings.

The higher risk applied to a number of psychiatric diagnoses such as depression, anxiety, eating disorders, personality disorders, ADHD and autism spectrum disorder. There was also a higher risk of suicide attempt after reaching adulthood.

"The study shows that children with IBD and their parents are in need of psychological support and longer follow-up," says Agnieszka Butwicka, researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. "Special help could be offered to children who become ill at a young age and to children of parents with mental health problems.

The risk of mental health problems was greatest during the first year with IBD. The risk was particularly high for children who were diagnosed with IBD before the age of 6 years and for children of parents with psychiatric disorders.

The study is an observation study that cannot identify causality with certainty. However, according to the researchers, the results do indicate that IBD contributes to mental health problems.

"Because the risk for these children is higher compared with their own siblings, it is likely that it is IBD affecting their mental health rather than other factors such as socioeconomics, lifestyle or heredity in the family," says Jonas F. Ludvigsson, professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

Scientists at Johns Hopkins have successfully created personalized digital replicas of the upper chambers of the heart and used them to guide the precise treatment of patients suffering from persistent irregular heartbeats. These simulations accurately identified where clinicians need to destroy tissue to restore the heart's normal rhythm.

The proof-of-concept study, published in Nature Biomedical Engineering on August 19, is a promising step towards simulation-driven treatments and sets the stage for the team's FDA-approved clinical trial slated to begin this fall.

"The personalized digital replicas allowed us to accurately simulate and analyze heart electrical activity in 10 patients and determine where tissue needs to be destroyed," says Natalia Trayanova, the Murray B. Sachs Professor in the Department of Biomedical Engineering at The Johns Hopkins University Schools of Engineering and Medicine.

"The beauty of working with such replicas is that we could test for and predict where irregular heartbeats persist in ways we never could in the clinic We ran a mock of the clinical procedure over and over again, until we were sure irregular beats will not re-emerge."

This approach has the potential to eliminate the process of trial-and-error in treating such heart rhythm disorders and to prevent repeat procedures, says Trayanova.

Atrial fibrillation, or abnormal electrical signals stemming from the heart's two upper chambers, the atria, is the most common cause of irregular heartbeats and affects 1-2% of people worldwide. If left untreated, atrial fibrillation can cause fatal strokes.

The typical treatment for the disorder, called catheter ablation, is to thread a catheter emitting radio frequency into the heart to destroy tissue that sends off erratic electrical signals. Specifically, cardiologists will destroy tissue around the atria's four pulmonary veins, which is where researchers believe the misfiring signals usually begin.

However, a subset of patients with a persistent form of atrial fibrillation and scarring in the atria (fibrosis) don't benefit from receiving standard lesions around the pulmonary veins and often have to undergo multiple procedures because abnormal signals keep emerging from new areas of their atria. With each procedure, new scar tissue forms, which changes the atria's electrical activity and makes targeting of the misfiring areas that much harder.

The team's personalized simulation-driven guidance of the ablation procedure, called Optimal Target Identification via Modelling of Arrhythmogenesis (OPTIMA), used contrast-enhanced MRI scans from 10 patients at the Johns Hopkins Hospital to create personalized digital replicas of the diseased atria.

For each personalized model, the team ran initial simulations to predict erratic electrical signals and where tissue should be destroyed. Because each ablation reconfigures the atrial electrical activity and can create new arrhythmias, the researchers performed virtual ablations until no new arrhythmias emerged.

The researchers then took the final 'map' of tissue target areas and imported it in the clinical system for catheter navigation. Physicians then steered the catheter towards not only the tissue that currently causes errant electrical firing, but also towards the tissue that will cause misfiring in the future, as predicted by the simulations. The entire process, from obtaining an MRI to displaying the final map in the operating room took less than a week. In the future, Trayanova and the team hope the entire process can be shortened to a day.

While this was a proof-of-concept study meant to demonstrate feasibility and not a clinical trial meant to measure patient outcomes, atrial fibrillation did not recur in any of the patients over the more than 300-day observation period. Out of the 10 patients, only one returned for another ablation, and it was for a simpler atrial arrhythmia.

"I'm very optimistic that this personalized simulation-driven approach will prove to be the missing link needed to markedly improve catheter ablation outcomes in patients with more advanced forms of atrial fibrillation. This new approach may transform current approach to catheter ablation of atrial fibrillation," adds Hugh Calkins, a professor of medicine at Johns Hopkins Medicine and an author on the study.

This study and its success is just one project out of the Johns Hopkins University Alliance for Cardiovascular Diagnostic and Treatment Innovation (ADVANCE), a center that aims to bring cardiovascular engineering approaches to the clinic, co-directed by Trayanova and Calkins.

"This success is an exciting example of how engineering technology can be used in the clinic to help make treatment more accurate and spare patients from multiple, costly and sometimes risky procedures," adds Trayanova

Researchers believe that stuttering - a potentially lifelong and debilitating speech disorder - stems from problems with the circuits in the brain that control speech, but precisely how and where these problems occur is unknown. Using a mouse model of stuttering, scientists report that a loss of cells in the brain called astrocytes are associated with stuttering. The mice had been engineered with a human gene mutation previously linked to stuttering. The study, which appeared online in the Proceedings of the National Academy of Sciences, offers insights into the neurological deficits associated with stuttering.

The loss of astrocytes, a supporting cell in the brain, was most prominent in the corpus callosum, a part of the brain that bridges the two hemispheres. Previous imaging studies have identified differences in the brains of people who stutter compared to those who do not. Furthermore, some of these studies in people have revealed structural and functional problems in the same brain region as the new mouse study.

The study was led by Dennis Drayna, Ph.D., of the Section on Genetics of Communication Disorders, at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health. Researchers at the Washington University School of Medicine in St. Louis and from NIH's National Institute of Biomedical Imaging and Bioengineering, and National Institute of Mental Health collaborated on the research.

"The identification of genetic, molecular, and cellular changes that underlie stuttering has led us to understand persistent stuttering as a brain disorder," said Andrew Griffith, M.D., Ph.D., NIDCD scientific director. "Perhaps even more importantly, pinpointing the brain region and cells that are involved opens opportunities for novel interventions for stuttering - and possibly other speech disorders."

Stuttering is characterized by pauses and repeated or prolonged sounds, syllables or words, which disrupt the normal flow of speech. People who stutter know what they want to say, but they have trouble saying it. The condition is most commonly seen in young children who typically outgrow the problem. However, for 1 in 4 children who experience early stuttering, the condition persists as a lifelong communication problem. It is estimated that as many as 1% of adults in the United States are affected by stuttering.

"The brain imaging studies of people who stutter are important, but those results can only take us so far," said Drayna. One challenge, he said, is that the imaging studies cannot decipher if the differences contribute to stuttering or are an effect of stuttering.

"By taking a genetic approach, we have been able to begin deciphering the neuropathology of stuttering, first at the molecular level by identifying genetic mutations, and now at the cellular level," added Drayna.

Earlier research by Drayna and colleagues has identified several genes associated with stuttering. In this study, the researchers set out to identify changes in the brain brought on by the mutations in a gene called GNPTAB, one of the genes previously linked to stuttering. The scientists engineered this human stuttering mutation into the mice to create a mouse model. The mice with the GNPTAB mutation had long pauses in their stream of vocalizations, similar to those found in people with the same mutation. Like people who stutter, the mice were normal in all other ways, reinforcing earlier research that suggests that the mice can serve as a valid animal model for important features of this disorder.

The investigators next examined brain tissue from the mice and found a decrease in astrocytes, but not other cell types, in the animals with the genetic mutation compared to the mice without the mutation. Astrocytes play a critical role in supporting nerve cells by carrying out a wide range of functions, such as supplying nerve cells with oxygen and nutrients and providing structural support.

The loss of astrocytes was more pronounced in the corpus callosum of the mutant mice. In addition, using advanced magnetic resonance imaging (MRI) methods, the researchers detected reduced local volume of the corpus callosum in the mutant mice despite normal diffusion tensor MRI values, providing further support for a defect in this brain region.

Containing as many as 200 million nerve fibers, the corpus callosum enables communication between the brain's left and right hemispheres, helping to integrate signals for processes that involve both hemispheres, such as physical coordination and use of language.

Follow-up experiments in which the GNPTAB human stuttering mutation was introduced into individual brain cell types--rather than the entire mouse--confirmed that the vocalization defect is specific to astrocytes. The mice did not have the stuttering-like vocalizations when the mutation was engineered into other types of brain cells.

All of the stuttering genes that have been identified over the past decade are involved in intracellular trafficking, the process that cells use to move proteins and other components to their correct locations within the cell. Defects in cellular trafficking have been linked to other neurological disorders, such as amyotrophic lateral sclerosis (ALS), Parkinson's disease, and Alzheimer's disease, suggesting that certain nerve cell pathways are particularly sensitive to impairment of this process. The research does not indicate, however, that persistent stuttering is an early indicator of these other disorders.

If future research confirms that stuttering in people with GNPTAB mutations derives from a loss of astrocytes in the brain, these findings could open the door to new therapeutic strategies for some people with persistent developmental stuttering by targeting associated molecular pathways and cells.

Swine fever, rabies, bird flu - outbreaks of diseases in wildlife populations often also affect farm animals and humans. However, their causes and the dynamics of their spread are often complex and not well understood. A team of scientists led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) has now carried out an analysis of long-term data of an outbreak of classical swine fever in wild boars in the German federal state of Mecklenburg-Vorpommern that occurred between 1993 and 2000. The results suggest that non-infected regions have a higher risk of infection due to changes in movement patterns, particularly during the mast and rutting seasons (autumn and winter), and thus highlighting the importance for focusing intervention efforts on specific individuals, seasons and areas in the event of future outbreaks. The findings are published in the Journal of Animal Ecology.

The study was conducted by a team of scientists from the Helmholtz Centre for Environmental Research (UFZ), the Friedrich Loeffler Institute (FLI) and the University of Potsdam under the direction of Leibniz-IZW. "Studies such as these help us to uncover the temporal and spatial dynamics of diseases such as classical swine fever and to use these findings to derive possible causes for long-lasting epidemics as well as measures to prevent new infections and outbreaks," explains first author Cédric Scherer (Leibniz-IZW). The seasonal patterns of disease spread varied dramatically. "Interestingly, at the county level, infection was more likely to occur in autumn and winter, while individual wild boars, especially the young, are most likely to become infected in spring during birth season," reports Stephanie Kramer-Schadt, who heads the Leibniz-IZW project. "We assume that this is due to the increased movement activity in autumn and winter. In particular, the search for mating partners and the shortage of food lead to more frequent changes of location and thus likely enable the spread of the disease beyond district boundaries," Kramer-Schadt continues. Contrary to common interpretations, the density of wild boar in a municipality was not decisive. "This finding is understandable, as almost all districts have more wild boar than necessary for the spread of infectious diseases," explains epidemiologist Hans-Herrmann Thulke (UFZ), who co-initiated the study.

The detailed long-term data collected by the authorities in Mecklenburg-Vorpommern during the outbreak made it possible to investigate the temporal and spatial differences in the spread of the disease. The authors analysed the data for different phases of disease spread on the one hand and for individual animals and entire municipalities on the other.

Classical swine fever (or European swine fever) is a viral infection affecting wild and domestic pigs. Despite similar symptoms, the pathogens of classical swine fever and African swine fever are not related in the course of the disease. Long-lasting outbreaks of classical swine fever among wild boars often lead to the spread of the infection to agricultural pig farms. This can cause considerable economic damage if millions of domestic pigs are emergency slaughtered and export bans are imposed on pork products.

In order to limit the spread of classical swine fever in a wildlife population, vaccination baits could be used and/or the density of wild boar could be reduced by hunting. Although lowering the density to a theoretical minimum was often discussed as a measure, this study shows that in later times of an outbreak it was not the density but the contact rates, which likely increased due to changes in movement behaviour and made it possible for the disease to persist for several years. In order to prevent such persistence or future outbreaks, the focus should therefore be on reducing the contact rates between wild boar groups.

New Rochelle, NY, August 19, 2019--A new case study demonstrates the steps being taken by the U.S. National Aeronautics and Space Agency (NASA) to make it easier for small businesses and entrepreneurs to understand its needs and do business with it. The detailed case study, which provides insights on the design, results, and lessons learned from these efforts, is published in New Space: The Journal of Space Entrepreneurship and Innovation, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. Click here to read the full-text article free on the New Space website through September 19, 2019.

Jennifer Gustetic, NASA Headquarters (Washington, DC) and colleagues from NASA Ames Research Center (Mountain View, CA), REI Systems (Sterling, VA), and the Department of Energy (Washington, DC) coauthored the article entitled "Making NASA More Business Friendly: A Small Business Innovation Research and Small Business Technology Transfer Case Study." They describe the three core initiatives of the effort to make NASA more open to collaboration with small businesses. These included developing an annual Request for Information (RFI), which offered an opportunity for businesses to provide input and submit ideas. A second initiative was the establishment of Industry Day, an annual small business-NASA event that provided a forum in which small business customers and NASA subject matter experts could convene, to increase the likelihood for commercialization of innovations and successful uptake of new technologies by NASA. Lastly, NASA prioritized the modernization of its Electronic Handbook, an IT system used to manage the solicitation of proposals and awards process. The authors discuss the results of these efforts, draw conclusions, and suggest future steps that can be taken to further improve collaboration between NASA and the small business community.

"NASA has been one of the most proactive U.S. government actors for the promotion of innovation, and developing small business capabilities, to help meet the agency's mission goals," says New Space Editor-in-Chief of Ken Davidian, who has worked in the commercial space transportation industry for over 30 years.

PROVIDENCE, R.I. [Brown University] -- A new study reveals why the magma chambers that feed recurrent and often explosive volcanic eruptions tend to reside in a very narrow depth range within the Earth's crust. The findings, published in Nature Geoscience, could help scientists to better understand volcanic processes the world over.

The research makes use of computer models that capture the physics of how magma chambers, reservoirs in the crust that contain partially molten rock, evolve over time. The models showed that two factors -- the ability of water vapor to bubble out of the magma, and the ability of the crust to expand to accommodate chamber growth -- are the key factors constraining the depth of magma chambers, which are generally found between six and 10 kilometers deep.

"We know from observations that there seems to be a sweet spot in terms of depth for magma chambers that erupt repeatedly," said Christian Huber, a geologist at Brown University and the study's lead author. "Why that sweet spot exists has been an open question for a long time, and this is the first study that explains the processes that control it."

Depths of six to 10 kilometers generally correspond to pressures of about 1.5 kilobars on the shallow side and 2.5 kilobars on deep side. The models showed that at pressures less than 1.5 kilobars, water trapped within the magma forms bubbles readily, leading to violent volcanic explosions that blast more magma out of a chamber than can be replaced. These chambers quickly cease to exist. At pressures more than 2.5 kilobars, warm temperatures deep inside the Earth make the rocks surrounding the magma chamber soft and pliable, which enables the chamber to grow comfortably without erupting to the surface. These systems cool and solidify over time without ever erupting.

"Between 1.5 and 2.5, the systems are happy," Huber said. "They can erupt, recharge and keep going."

The key to the models, Huber said, is that they capture the dynamics of both the host crust and of the magma in the chamber itself. The ability of deep magma chamber to grow without erupting was fairly well understood, but the limit that water vapor exerts on shallow magma chambers hadn't been appreciated.

"There hadn't been a good explanation for why this habitable zone should end at 1.5 kilobars," Huber said. "We show that the behavior of the gas is really important. It simply causes more mass to erupt out than can be recharged."

Huber says the findings will be helpful in understanding the global magma budget.

"The ratio of magma that stays in the crust versus how much is erupted to the surface is a huge question," Huber said. "Magma supplies CO2 and other gases to the atmosphere, which influences the climate. So having a guide to understand what comes out and what stays in is important."

A new, four-minute video explains "5 Cool Technologies Your Tax Dollars are Funding." The science education resource features a selection of recent advances developed to help people stay healthy, get treatment sooner, or have a better quality of life.

The five highlighted technologies are:

1. a painless, non-invasive blood glucose monitoring device to replace testing by a finger-prick,

2. a skin patch that monitors blood pressure continuously using ultrasound, without a cuff,

3. a painless laser scan for breast cancer screening, instead of a mammogram,

4. a fingernail scan to count white cells for patients having chemotherapy, as an early indicator for risk of infection, and

5. a prosthetic hand that provides a sense of touch for the user.

To view the video, which is free to share, go to https://www.youtube.com/watch?v=kRP4i-WZGSU&t=15s

The National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health, assembled the resource, the latest in a series of brief videos in recent years that shine a spotlight on exciting technologies developed at labs around the country funded by the institute.

The valve train is the "respiratory organ" of combustion engines: it manages the aspiration of fresh air and the discharge of exhaust gases, which is referred to as "gas exchange". Today, only mechanically driven camshafts are used in series production for this purpose, often equipped with an additional mechanism, some of which are quite complex. This allows to modify a valve movement pattern given by the camshaft, which is not possible without an increase in friction. At the same time, flexibility is not given to the desired extent. What is in demand - among other things for adaptation to changing fuel properties - are fast valve movements even at low speeds, stroke adaptations and cylinder-selective widely variable valve timing.

Optimized gas exchange and less friction save fuel

Patrik Soltic and his team at Empa's Automotive Powertrain Technologies laboratory, together with hydraulics specialist Wolfgang Schneider, invented and developed an electrohydraulic valve train that is significantly more flexible than today's series production technology. The valves are actuated hydraulically and controlled electrically via a solenoid coil. As soon as a control current flows, a specially designed hydraulic valve opens, allowing hydraulic fluid to open the gas exchange valve to the desired extent in milliseconds counter to a spring. When the current is switched off, the gas exchange valve is closed again by the spring force and feeds a large part of the hydraulic energy required for opening back into the hydraulic system. The system achieves a significantly lower energy requirement over a wide operating range compared to camshaft-driven systems. Together with an optimized gas exchange, the fuel consumption of the test spark-ignition engine is about 20 percent lower than with conventional valve control using a throttle in combination with camshafts in the low load range typical for passenger cars.

Adaptable to renewable fuels

By selecting the operating parameters, the opening and closing times as well as the valve lift for each cylinder can be chosen completely unrestricted. This means that each engine operating condition can be varied from cycle to cycle, for example by intelligent load control, by selecting the residual gas quantity remaining in the cylinder (exhaust gas recirculation), or by deactivating unneeded cylinders without the driver noticing. This makes the engine highly adaptable to new renewable fuels: Oxygen-containing fuels such as methanol or ethanol, for example, allow more residual gas to remain in the cylinder. Natural gas, biogas and syngas generated from wind and solar power offer increased anti-knock properties, and the valve train can react flexibly to this as well. In addition, alternative combustion concepts can also be implemented comparatively easily, for example homogeneous self-ignition: a fuel-air mixture is ignited at the right moment without ignition sparks by setting the correct conditions towards the end of compression. The mixture is combusted almost without pollution.

Cylinder head without oil

Another speciality of the system set up at Empa is the choice of hydraulic fluid: instead of using oil as usual, a water-glycol mixture, i.e. engine cooling water, can be used. Due to its physical properties, this medium is very suitable for fast-switching hydraulic systems, as it is very stiff and therefore creates fewer hydraulic losses. This makes the cylinder head completely oil-free, which can allow a cheaper engine oil with extended change intervals to be used for the rest of the engine.

Several months of testing operation

As part of the "FlexWork" project funded by the SFOE, the new valve train was put into operation in a passenger car engine powered by natural gas and derived from a VW 1.4l TSI engine. The required components were manufactured by Empa's own workshop. The control system for the test engine was developed by the Empa researchers themselves. The valve train has been running on an Empa engine test bench since October 2018 and has already survived many millions of cycles in fired engine operation flawlessly.

The FlexWork valve control needs only low-cost components. No expensive, very fast switching valves and no complex sensors are required. The valve train system was presented to technical experts in the magazine MTZ Worldwide on August 16. Empa is in discussions with engine manufacturers for the transfer of this technology, which is suitable not only for combustion engines but also for compressors.

A tiny lab the size of a postage stamp could be the next big thing in the search for safer anti-clotting drugs to prevent heart attacks and strokes.

The effectiveness of current anti-clotting medication can be limited due to the risk of complications, driving a need for alternatives that can both prevent the formation of blood clots and reduce the risk of excessive and life-threatening bleeding.

The new biocompatible lab-on-a-chip, detailed in a paper published recently in the journal Analytical Chemistry, could help accelerate the discovery and development of new anti-clotting therapies.

The technology has been developed by a team of biochemists and engineers led by RMIT University and the Haematology Micro-platforms group at the Australian Centre for Blood Diseases (ACBD) in Melbourne, Australia.

It effectively shrinks a medical pathology laboratory onto a small chip, with automated processes that can achieve in a few minutes what could take days in a full-sized lab.

The new device is designed specifically to work with the complex and sensitive biology of blood, featuring a unique system of micropumps and analysis tools for testing the effect of chemical compounds on how the blood clots.

Lead investigator Dr Warwick Nesbitt, RMIT and Monash University, is working with collaborators at the ACBD to use the pioneering device to better understand clotting mechanisms and develop new anti-clotting drugs.

Nesbitt said very few microdevices developed to date were suitable for clinical or research use, because they had not been driven by insight into how blood actually behaves.

"Blood is extremely sensitive to artificial surfaces and clots very easily, so blood-handling technologies must be equally sensitive," Nesbitt, a Vice-Chancellor's Senior Research Fellow at RMIT and group leader at ACBD, said.

"We've combined a deep understanding of the biology of blood with precision microfabrication engineering and design, to deliver a device that can work with whole blood and produce reliable results.

"We hope this powerful new tool will give researchers an edge in delivering better and safer anti-clotting treatments, to improve the health and wellbeing of millions around the world."

Co-lead author Dr Crispin Szydzik said the device could mimic conditions within blood vessels.

"It's a key step towards the development of quick and efficient microsystems for pre-clinical and clinical haematology screening and diagnostics."

Honey I shrunk the lab: how it works

The microlab can screen hundreds of drug compounds in just a few hours, revealing their effect on blood and quickly identifying those that have the most potential for clinical use.

The device is based on microfluidic chip technology developed at RMIT's Micro Nano Research Facility (MNRF) and within the Vascular Biology Laboratory (ACBD - Monash University).

A microfluidic chip contains an array of miniature channels, valves, processors and pumps that can precisely and flexibly manipulate fluids.

The chips combine speed, portability and capacity, handling vast quantities of tiny processing elements. Importantly, they are also scaleable and cheap to produce.

The microfluidic technology was combined with a sensitive assay for testing how platelets - the component of blood that forms clots - respond to different chemical combinations.

In a proof-of-concept application, the microlab was used to investigate how dosing blood with select small molecule inhibitors affects platelet thrombus dynamics, that is, how the platelets clump together.

The promising results demonstrated that the automated lab-on-chip could accurately control blood flow, deliver and mix drug compounds with blood in seconds and send the dosed blood to a downstream thrombus assay system.

MNRF Director, Distinguished Professor Arnan Mitchell, said existing technologies for testing chemical compounds in blood are highly labour intensive and time consuming, limiting how many can be screened at any time.

"Our device enables researchers to send hundreds of potential combinations through the system, mixing them with blood extremely rapidly and delivering results in just a few minutes," Mitchell said.

"Small, targeted, automated and precise - it's the future of drug development technology."

Transition metal dichalcogenides (TMDCs) formed by group 10 metals (e.g. PtSe2, PtTe2) have emerged as important materials with intriguing properties discovered both in bulk single crystals and atomically thin films. While bulk PtSe2 and PtTe2 are type-II Dirac semimetals, monolayer (ML) PtSe2 film is a semiconductor with helical spin texture induced by local Rashba effect. However, the properties of atomically thin PtTe2 films and the evolution with film thickness remain unexplored. Recently, Shuyun Zhou's group from Tsinghua University reported a systematic study on the electronic structure of high quality PtTe2 thin films with thickness from 2 ML to 6 ML grown by molecular beam epitaxy (MBE). This work provides direct experimental evidence for a crossover from 2D metal (2ML film, distinguished from the semiconducting PtSe2 film) to 3D Dirac semimetal in PtTe2 films with spin texture induced by local Rashba effect.

In bulk PtTe2 crystal, massless Dirac fermions are found to emerge at the topologically protected touching points of electron and hole pockets. The strongly tilted Dirac cone along the out-of-plane momentum direction breaks the Lorentz invariance and therefore the low energy excitations are Dirac fermions that do not have counterpart in high-energy physics. Their previous work shows that the isostructural material PtSe2 is also a type-II Dirac semimetal, and there is a 3D Dirac semimetal-semiconductor transition with decreasing thickness. In addition, monolayer PtSe2 shows interesting helical spin texture induced by local Rashba effect (R-2) despite the fact that the monolayer film itself is centrosymmetric. Such hidden spin texture induced by local Rashba effect has been expected to provide an important platform for realizing novel topological superconductivity with odd parity if superconductivity with s-wave pairing can be induced. However, considering that monolayer PtSe2 is a semiconductor with a large gap size of 1.2 eV, it is difficult to tune the Fermi energy in such a large range to make it a superconductor. It is therefore critical to find a similar centrosymmetric film with local Rashba effect yet with metallic property, which can provide a better opportunity for realizing topological superconductivity.

In this work, by using ARPES, Shuyun Zhou's group directly detects the electronic structure of PtTe2 thin films with different thickness, and observed metallic band dispersion of PtTe2 thin films even down to 2 ML. A crossover from 2D metal (2ML, distinguished from the 2 ML semiconducting PtSe2 film) to 3D Dirac semimetal is also revealed. The electronic dispersion exhibits strong thickness dependent: with increasing film thickness, the V-shaped pockets at the Fermi level in 2 ML and 3 ML films move down in energy and eventually touch the hole-like pocket at higher binding energy, leading to the formation of a three-dimensional type-II Dirac fermions in 4-6 ML films, which show similar dispersion to bulk crystal and thus are effectively a topological semimetal. Further spin-ARPES measurements on PtTe2 bulk crystal reveal a helical spin texture induced by local Rashba effect. Since the Rashba effect is determined by the crystal symmetry and bulk and thin film PtTe2 share the same symmetry, similar spin texture by local Rashba effect is also expected in PtTe2 thin films.

This systematic investigation on PtTe2 thin films with controlled thickness offers a unique platform to study the metallic thin films with local Rashba effect, and opens up opportunities for further investigating the intriguing properties, e.g. doping induced superconductivity or topological superconductivity.

Researchers have designed a flexible pressure sensor that is expected to have a much wider applicability. A KAIST research team fabricated a piezoresistive pressure sensor of high uniformity with low hysteresis by chemically grafting a conductive polymer onto a porous elastomer template.

The team discovered that the uniformity of pore size and shape is directly related to the uniformity of the sensor. The team noted that by increasing pore size and shape variability, the variability of the sensor characteristics also increases.

Researchers led by Professor Steve Park from the Department of Materials Science and Engineering confirmed that compared to other sensors composed of randomly sized and shaped pores, which had a coefficient of variation in relative resistance change of 69.65%, their newly developed sensor exhibited much higher uniformity with a coefficient of variation of 2.43%. This study was reported in Small as the cover article on August 16.

Flexible pressure sensors have been actively researched and widely applied in electronic equipment such as touch screens, robots, wearable healthcare devices, electronic skin, and human-machine interfaces. In particular, piezoresistive pressure sensors based on elastomer?conductive material composites hold significant potential due to their many advantages including a simple and low-cost fabrication process.

Various research results have been reported for ways to improve the performance of piezoresistive pressure sensors, most of which have been focused on increasing the sensitivity. Despite its significance, maximizing the sensitivity of composite-based piezoresistive pressure sensors is not necessary for many applications. On the other hand, sensor-to-sensor uniformity and hysteresis are two properties that are of critical importance to realize any application.

The importance of sensor-to-sensor uniformity is obvious. If the sensors manufactured under the same conditions have different properties, measurement reliability is compromised, and therefore the sensor cannot be used in a practical setting.

In addition, low hysteresis is also essential for improved measurement reliability. Hysteresis is a phenomenon in which the electrical readings differ depending on how fast or slow the sensor is being pressed, whether pressure is being released or applied, and how long and to what degree the sensor has been pressed. When a sensor has high hysteresis, the electrical readings will differ even under the same pressure, making the measurements unreliable.

Researchers said they observed a negligible hysteresis degree which was only 2%. This was attributed to the strong chemical bonding between the conductive polymer and the elastomer template, which prevents their relative sliding and displacement, and the porosity of the elastomer that enhances elastic behavior.

"This technology brings forth insight into how to address the two critical issues in pressure sensors: uniformity and hysteresis. We expect our technology to play an important role in increasing practical applications and the commercialization of pressure sensors in the near future," said Professor Park.

Physicists from the Hong Kong University of Science and Technology (HKUST) and Peking University (PKU) have successfully created the world's first 3D simulation of topological matter consisting of ultracold atoms. Previous attempts at topological matter simulations were limited to lower dimensions, due to challenges on how to characterize 3D band topology in atomic systems. This breakthrough paves an opening to further examining new topological matter that cannot be well realized in solids. Such never-before-done engineering artificial material with ultracold atoms may allow physicist to model unusual phases of matter.

Prof. Gyu-Boong JO, Associate Professor from the Department of Physics at HKUST collaborated with Prof. Xiong-Jun LIU, Professor from the School of Physics at PKU and devised an artificial crystal lattice structure, previously proposed by the PKU group, to model ultracold atoms prepared at 30 billionths of a degree above absolute zero. This new synthetic quantum matter is a 3D spin-orbit coupled nodal-line topological semimetal, and exhibits an emergent magnetic group symmetry. The researchers correlated the atom spin with the direction of atomic motion, which made the overall atom behavior topological. With such symmetry the researchers proved that the 3D band topology can be resolved by only imaging 2D spin patterns on the symmetric planes, and further successfully observed the 3D topological semimetal in experiment. The detection techniques used here can be generally applied to exploring all 3D topological states of similar symmetries when those become available.

The research was recently published online in Nature Physics on July 29, 2019 [DOI:10.1038/s41567-019-0564-y].

Complex topological matter has become the focus of both industrial and academic research because it is seen as a way to pave the way to making quantum computing more noise free and robust. Today's physical quantum computers are still noisy, and quantum error correction is a growing field of research. The goal of fault tolerant quantum computing has driven investment into complex topological matter.

Topological matter is classified by the geometric properties of the quantum state in material. The topological nature of the material means that it tends to withstand imperfections within an operating system and also holds the potential for other yet unknown exotic properties.

"Our work opens up many possibilities for developing new topological materials that do not occur naturally," said Prof. Jo. "This development demonstrates there is a new possibility to explore complex topological material in 3D, and will provide a useful platform for quantum simulation."

"This is a breakthrough progress for quantum simulation with ultracold atoms," said Prof. Liu. "It enables the experimental investigation and observation of nontrivial phases of all physical dimensions, including various insulating, semimetal, and superfluid phases with nontrivial topology in ultracold atoms".

Many companies are working on materials that would be as light and resistant as plastic but at the same time fully biodegradable. What if they could be made from ..... rubbish? A modern, ecological (waste-free - the conversion of raw material to product reaches 100%) and economical (does not require high temperatures or expensive catalysts) method of obtaining organic monomers is coming into being at the IPC PAS.

It's hard to imagine our modern world without plastics, but the plastic we know today also poses a great threat. It litters practically all corners of the earth - it can be found in the depths of the Mariana Trench as well as on Mount Everest. Each one of us, in one way or another, consumes 5 grams of plastic every week - that's enough for a credit card - and these are not compounds that are neutral to our health.

But what if we managed to replace plastic with a material that is equally light, equally resistant and at the same time fully biodegradable? This is the idea that a team of scientists from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS), led by Professor Juan Colmenares, is working on. They have taken a common product - hydroxymethylfurfural (HMF) - which on an industrial scale is obtained by the acid hydrolysis of sugars obtained, among others, from cellulose, lignin or inulin. They have turned it into aldehyde, 2,5-diformylfurfural (DFF), a compound that finds an application in so many fields of industry that it would take several lines of print to list them all. It can be used to produce medicines, cosmetics, fragrances, chemical agents, fuels, but above all - environmentally friendly plastic. "We want it to be possible to replace PETs with something that decomposes in a few months or at most a few years," explains Professor Colmenares. "Today's plastics, made from petroleum, contain phthalates and other plasticizers - a sort of "soup" of organic and even inorganic compounds - and no bacteria or fungus on their own can break them down. That's why they remain for so long in the forests and seas. Materials produced based on DFF contain furans - sugars, and what comes from nature is better received by nature," explains the professor. "There have already been tests of such polymers. They break down into monomers resembling sugars. And sugars are a tasty treat for many microorganisms. Even if a bottle of this sort of plastic is thrown away into the forest, it will decompose much faster than conventional polymers, after a few years at the latest."

It is not the product itself (DFF) which is new here, but the method of obtaining it, described in a paper published in Applied Cat. B. Until now, high temperatures (in the order of 100-150 degrees C) and complicated technology have been needed, which meant that though being ecological, it could not compete with petroleum products. Professor Colmenares' team only need a box they themselves produce - a photoreactor, a light (at present this is an LED lamp emitting near UV - 375 nm, but ultimately the energy is to be provided simply by the sun) and a catalyst - manganese dioxide nanowires. "These are long and very, very thin, and their structure increases the absorption of light. Due to the unique thermo-photo-catalytic properties of manganese dioxide, the nanorods have a much larger contact surface with the particles of the starting material and are better at activating it. So, virtually all the HMF changes into DFF. 100%!" enthuses the professor. "It's a waste-free method, without the addition of oxygen or additional compounds (e.g. hydrogen peroxide H2O2). The oxygen in the air suffices to obtain the pure monomer needed for the production of linear polymers and ... for example, bottles like this. Even the nanorods can be re-used many times as photocatalysts, because the DFF does not destroy them, it does not release manganese 2+ and 4+ ions so in addition it does not need to be purified. The conditions needed are room temperature and atmospheric pressure. At the same time, it is a very cheap and common material is used (manganese oxide is not platinum, gold or silver), and the production method is simple. They simply precipitate and all you need is to select the right conditions for the process to be efficient," says Professor Colmenares, describing the invention. "At present we are restricted by the capacity of the reactor, but when we change it to a flow reactor, we will be able to increase production greatly. And, of course, obtain a patent," he adds.

But won't such rapidly decomposing plastic break down too quickly? Before, for example, we manage to drink the juice poured into it? "No," laughs the professor, "In practice it takes a few years to decompose, but even if the reaction occurred faster, the user would at most drink a little "good" plastic. One that is harmless to the body. Generally speaking it would simply be degraded by our intestinal bacteria and their enzymes."

In addition, the method developed by the team lead by Professor Colmenares uses ... rubbish. Something that would otherwise end up in rivers, polluting the water, or would require a high level of purification, as is now the case with the paper industry's waste. "Currently, such waste can be transformed or converted, for example, into bioethanol, or it can be burned to provide energy for production, but if it could be better used, this would be amazing. Anyway, there's enough rubbish for everything. And were it to be shown that there's money in it, a lot of people would immediately be found to clean it up," says the professor.

Poland is, for example, a large producer of apples and juice, but do we know what happens to all that apple peel and all the waste products? Not much, although we "produce" hundreds of tons every year. "It's poured into the waste disposal, it pollutes the water, takes up oxygen, and then it's the end of all water life," worries the professor. "Meanwhile, it contains all the sugar, pectin and levulinic compounds that even medicines can be made from," he explains. You can make very desirable compounds from something that is made of neither oil nor coal, but from waste. This is "how to make something out of nothing".

A new QUT-led study has developed a statistical toolbox to help avoid seagrass loss which provides shelter, food and oxygen to fish and at-risk species like dugongs and green turtles.

The research has been published in Methods in Ecology and Evolution run by the British Ecological Society.

The paper describes key monitoring and management designs to maximise seagrass resilience to human activities, to better inform seagrass dredging operations and development of coastal areas.

Seagrasses are a critical habitat that have been declining rapidly globally[i].

Led by statistical data researcher and lecturer Dr Paul Wu, from QUT's School of Mathematical Sciences, the study identified and analysed factors that drove variations in a global seagrass dredging case study.

"Real world ecosystems like seagrasses are dynamic and ever changing," Dr Wu said.

"Successful implementation of any seagrass management plan requires effective, efficient and timely monitoring and adaptation to changing circumstances."

Through statistical modelling, researchers can mimic what is happening in real time and predict what is going to happen on the sea bed.

Dr Wu said the objectives of the study included:

identifying the set of most influential variables to monitor eg. genus, light, growth and seed

finding similar sites and environmental and/or dredging scenarios

understanding how often to monitor and the time lag between action and effect.

The toolbox of methods included new applications of functional Principal Components Analysis (fPCA) and boosted trees to discover patterns over time relevant to environmental monitoring and management.

In 2017, Dr Wu led a study into predicting when coastal dredging was least likely to stress seagrass by pinpointing 'ecological windows' for timing of dredging operations in ports.

It predicted ahead of time how much repeated stress was too much, to allow for better planning of dredge operations.

Dr Wu's latest research builds on the previous study by providing the mathematical analysis to extract details from complex data and models about how to best implement an environmental management plan for seagrass.

He said the key monitoring and management design could also be applied to any ecosystem model and management scenario, such as coral under climate change.

"Managers of ports and coastal development areas can use the tools we've developed, to take something very complex and distil from it answers to key questions like 'what variables should I keep an eye on and how often'?"

The study included analysis of 3024 scenarios with 75 influential variables on seagrass survival including genus, location type, light, growth and seed.

The research team's work is being expanded, joining French scientists on an EU project called Marine Habitats to progress seagrass modelling research.

The problem of access to safe drinking water in most parts of Bangladesh is a persistent challenge. Now, a team of scientists from Uppsala University, Sweden, and Dhaka University, Bangladesh, shows that a locally growing and previously unexploited green macroalgae species could be used to extract cellulose nanofibers, which can then be formed into paper sheets with tailored pore size that are utilized for point-of-use water treatment.

The paper filter has demonstrated excellent virus and bacteria removal capacity both in the lab and in real-life tests. The scientists believe that with further development, the paper filter produced from Pithophora algae (or "Shewla"), could be an affordable and efficient remedy to prevent numerous potentially deadly water-borne infections.

"Pithophora algae have been largely overlooked in the past as a valuable raw material. It is with great satisfaction that we can now document excellent pathogen removal clearance for both water-borne bacteria and viruses with efficiency above 99.999 percent. It can purify even the smallest virus particles of 27-28 nanometers", says Albert Mihranyan, Professor of Nanotechnology at Uppsala University, who heads the study.

Bangladesh is a country with a population of over 168 million people, which is larger than that of Russia (144.5 million). By 2050, the projected growth rates suggest that the population of Bangladesh may reach the mark of 200-225 million people. In parts of the biggest cities in Bangladesh, such as Dhaka or Chittagong, the density of population is as high as 205,000 inhabitants/km2, which is almost 58 times more than that in Stockholm and nearly 20 times more than that in New York city.

In 2018, about 15 million people lived below the extreme poverty line of USD 1.90 (18 SEK) per day. Hyper-high density of population, poor hygiene, and lack of clean water increase the risk of spreading water-borne infections. The cities of Dhaka and Chittagong are the only cities with extensive piped water and sewage system, but even there the water is available at most a few hours per day and may still be contaminated with infectious pathogens due to leakage in pipelines. With Dhaka population growing over 300,000 persons/year, access to clean water is critical for sustainable life.

To prevent the spread of water-borne infections, affordable point-of-use water treatment strategies that can be effective against all kinds of water-borne pathogens are needed. Boiling, sunlight pasteurization, or chemical disinfection are some of the methods that are currently used for point-of-use water treatment. An excellent way of treating water to physically remove all kinds of pathogens is filtration. Thus, new types of affordable point-of-use filters that can remove all kinds of pathogenic bacteria, spores, and viruses are highly in demand. Now, thanks to the joint efforts by the Swedish and Bangladeshi teams a new source of locally growing raw material has been discovered that can be used for manufacturing paper filter for water treatment applications.

"Access to clean water will contribute strongly to improved health thus reducing poverty. We are optimistic that through future development of devices the filter paper produced from the locally growing algae will be useful to prevent potentially deadly water-borne diseases and improve the quality of life for millions of people" says Khondkar Siddique-e-Rabbani, Honorary Professor at University of Dhaka and project coordinator in Bangladesh.