Tech

In a new publication from Opto-Electronic Advances; DOI 10.29026/oea.2021.200030 , Researchers led by Professor Liu Yan from Xidian University, China and Professor Gan Xuetao from Northwestern Polytechnical University, China consider generation and application of the high-Q resonance in all-dielectric metasurfaces.

Metamaterials are artificial composite electromagnetic structures consisting of subwavelength units, which can realize efficient and flexible control of the electromagnetic waves. Metamaterials are an emerging research area for optoelectronics, physics, chemistry and materials, due to their novel physical properties and potential applications.

With the development in the fabrication of nanostructures, all-dielectric metasurfaces have attracted much research attention because of their high efficiency and low loss. However, metasurfaces based on traditional optical materials (such as silicon) can only support relatively low Q resonances, limiting their applications in lasing action, sensing, and nonlinear optics. A recently emerged concept of bound states in the continuum (BICs) provides a new solution to overcome this problem. The concept of BICs was first introduced in quantum mechanics. It represents a wave phenomenon of modes, which have the energy lying in the delocalized states inside the continuum. The BIC-supporting metasurfaces can achieve controllable high-Q resonance, which can extend their applicability to the devices requiring sharp spectral features.

The authors of this article propose a Si metasurface based on symmetry-broken blocks, which can achieve the high-Q resonance. Nanoparticles made of conventional materials can only support a relatively low quality factor. The concept of BIC provides a new solution to overcome this problem. This concept firstly appears in quantum mechanics, where a true BIC is a mathematical abstraction with infinite Q factor. In this work, symmetry breaking is introduced into the symmetric periodic structure and the ideal BICs turn into the leaky mode with a high Q factor. At the same time, the Q factor of the resonance can be controlled by varying the size of the introduced defects. In addition, by changing the design proposal, the relationship between the Q factor and defect size can also be adjusted. A high-Q resonance can be easily realized in this way and the nonlinear optical effect of the structure can be obviously enhanced at the resonance.

The research reported in this article paves a way to manipulate BICs and realize high-Q dynamic resonances, which constitutes a significant step towards the development of high-Q resonant photonic applications. innovative and advanced optical technologies.

The Alum Shale of Northern Europe not only has an eventful history of formation, connected with the microcontinent Baltica, it also holds great potential as an object of investigation for future research questions. Geologists use the rock to reconstruct processes of oil and gas formation, and even possible traces of past life on Mars can be identified with its help. Researchers at the German Research Centre for Geosciences Potsdam GFZ, together with colleagues from Canada, China, Switzerland and Denmark, have summarised the state of knowledge about the multi-layered rock. Their article was published in July in the journal Earth-Science Reviews.

The Microcontinent Baltica

"This rock tells a story," says Hans-Martin Schulz when he talks about the Northern European Alum Shale. It is the chequered history of a microcontinent called "Baltica", which was located in the southern hemisphere about 500 million years ago. "The microcontinent is surrounded by a calm, shallow marginal sea," says the scientist in the GFZ's Organic Geochemistry Section, describing the situation in the period from the Middle Cambrian to the Lower Ordovician. Higher land plants do not yet exist, and the surface of Baltica is exposed to wind and weather. "Rocks weather, and debris and dust are carried into the sea. Together with components of algae and other microorganisms, they trickle through the layers of the calm marginal sea and settle layer by layer in the oxygen-free bottom water," Schulz continues. These organic-mineral deposits fossilize and form the dark claystone that makes up today's Alum Shale. Over millions of years, Baltica migrated northwards and is now integrated into northern Europe. "Almost half a billion years later, the Baltic Sea forms on Baltica," Schulz concludes the first part of the story.

Oil and gas formation in phases

For three years, Schulz's group and international colleagues have been combing through their own data and that of other research groups. In their comprehensive synopsis, they also describe the different phases of oil and gas formation during Baltica's development. Parts of the microcontinent sink to depths of several thousand metres during migration. Oil forms under the influence of geothermal heat. "The oil that was generated at that time is now produced on the Swedish island of Gotland and in the Baltic Sea off the Polish coast," Schulz explains.

Other parts of the microcontinent occur more near the surface, for example in what is now southern Sweden. There, about 300 million years ago, increased expansion of the earth's crust takes place. Magma escapes, the heat of which causes further crude oil to form in the Alum Shale. "These rather regional deposits are enclosed in the rock," the geologist describes. At the end of the last ice age, about ten thousand years ago, sweet meltwater penetrates the shale here. "It meets tiny inclusions of ancient seawater. They contain bacteria that have survived for millions of years," Schulz describes. The fresh water awakens them to new activity, and further bacteria are possibly contained in the meltwater. The microbes decompose components of the oil and form methane gas.

Influence of Uranium

And that's not the end of the story: although there is still plenty of organic material, the oil-forming potential of the Alum Shale is declining. This is because it contains uranium, whose radiation alters the enclosed carbon compounds over long periods of time - "with fatal consequences for oil formation", as Schulz says. "The long chains are split off," he explains. "What remains are ring-shaped hydrocarbons, predominantly benzene rings, which are linked together." These changes prevent the further formation of petroleum from the organic remnants of Cambrian and Ordovician life. The uranium probably originated in the rocks that were eroded on Baltica and settled in the sea. "And seawater also contains dissolved uranium, so some of the radioactive metal could have been absorbed by the sediments from it," Schulz adds.

Alum Shale has many talents

The GFZ researcher and his team are investigating the significance of the very high uranium concentrations in places in the Alum Shale: "Can organic material altered by uranium still feed a deep biosphere?" they are asking themselves in ongoing studies, for example. Or does the radioactive fission of hydrocarbons prevent microbes from surviving at great depths? And it is not only the influence of uranium on microbial life that interests him. "The Alum Shale is a rock with many talents," Schulz says. "We can study numerous processes on it at different depths, at different degrees of maturity of the organic material, different uranium concentrations and sometimes extreme conditions."

The Alum Shale may even have answers to the question of past life at a distance of 70 million kilometres from Earth: organic components have been found on Mars that have structural similarities to those found in the Alum Shale. And similar to the uranium-containing terrestrial mudstone, these molecules were exposed to the equally radioactive cosmic over long periods of time. "So these hydrocarbon compounds could be the altered remains of organisms similar to our earlier bacteria," Schulz explains. "The Alum Shale serves as a Mars analogue for us to interpret the possible traces of past life on our neighbouring planet."

Insights into final disposal of nuclear waste?

For us on Earth, another aspect of his research is topical: besides salts and granites, mudstone is a candidate for the final disposal of nuclear waste. "We also have ideas for future projects on this," Schulz reveals. "At the core of this is the question of microbial life over long periods of time in the low-porosity, uranium-rich Alum Shale - but that story is on another page."

(Text: Dr. Ulrike Schneeweiß)

The touchscreen technology used in billions of smartphones and tablets could also be used as a powerful sensor, without the need for any modifications.

Researchers from the University of Cambridge have demonstrated how a typical touchscreen could be used to identify common ionic contaminants in soil or drinking water by dropping liquid samples on the screen, the first time this has been achieved. The sensitivity of the touchscreen sensor is comparable to typical lab-based equipment, which would make it useful in low-resource settings.

The researchers say their proof of concept could one day be expanded for a wide range of sensing applications, including for biosensing or medical diagnostics, right from the phone in your pocket. The results are reported in the journal Sensors and Actuators B.

Touchscreen technology is ubiquitous in our everyday lives: the screen on a typical smartphone is covered in a grid of electrodes, and when a finger disrupts the local electric field of these electrodes, the phone interprets the signal.

Other teams have used the computational power of a smartphone for sensing applications, but these have relied on the camera or peripheral devices, or have required significant changes to be made to the screen.

"We wanted to know if we could interact with the technology in a different way, without having to fundamentally change the screen," said Dr Ronan Daly from Cambridge's Institute of Manufacturing, who co-led the research. "Instead of interpreting a signal from your finger, what if we could get a touchscreen to read electrolytes, since these ions also interact with the electric fields?"

The researchers started with computer simulations, and then validated their simulations using a stripped down, standalone touchscreen, provided by two UK manufacturers, similar to those used in phones and tablets.

The researchers pipetted different liquids onto the screen to measure a change in capacitance and recorded the measurements from each droplet using the standard touchscreen testing software. Ions in the fluids all interact with the screen's electric fields differently depending on the concentration of ions and their charge.

"Our simulations showed where the electric field interacts with the fluid droplet. In our experiments, we then found a linear trend for a range of electrolytes measured on the touchscreen," said first author Sebastian Horstmann, a PhD candidate at IfM. "The sensor saturates at an anion concentration of around 500 micromolar, which can be correlated to the conductivity measured alongside. This detection window is ideal to sense ionic contamination in drinking water."

One early application for the technology could be to detect arsenic contamination in drinking water. Arsenic is another common contaminant found in groundwater in many parts of the world, but most municipal water systems screen for it and filter it out before it reaches a household tap. However, in parts of the world without water treatment plants, arsenic contamination is a serious problem.

"In theory, you could add a drop of water to your phone before you drink it, in order to check that it's safe," said Daly.

At the moment, the sensitivity of phone and tablet screens is tuned for fingers, but the researchers say the sensitivity could be changed in a certain part of the screen by modifying the electrode design in order to be optimised for sensing.

"The phone's software would need to communicate with that part of the screen to deliver the optimum electric field and be more sensitive for the target ion, but this is achievable," said Professor Lisa Hall from Cambridge's Department of Chemical Engineering and Biotechnology, who co-led the research. "We're keen to do much more on this - it's just the first step."

While it's now possible to detect ions using a touchscreen, the researchers hope to further develop the technology so that it can detect a wide range of molecules. This could open up a huge range of potential health applications.

"For example, if we could get the sensitivity to a point where the touchscreen could detect heavy metals, it could be used to test for things like lead in drinking water. We also hope in the future to deliver sensors for home health monitoring," said Daly.

"This is a starting point for broader exploration of the use of touchscreen sensing in mobile technologies and the creation of tools that are accessible to everyone, allowing rapid measurements and communication of data," said Hall.

Plastics offer many benefits to society and are widely used in our daily life: they are lightweight, cheap and adaptable. However, the production, processing and disposal of plastics are simply not sustainable, and pose a major global threat to the environment and human health. Eco-friendly processing of reusable and recyclable plastics derived from plant-based raw materials would be an ideal solution. So far, the technological challenges have proved too great. However, researchers at the University of Göttingen have now found a sustainable method - "hydrosetting", which uses water at normal conditions - to process and reshape a new type of hydroplastic polymer called cellulose cinnamate (CCi). The research was published in Nature Sustainability.

Plastics are polymers, meaning that their molecular structure is built up from a large number of similar units bonded together. Currently, most plastics are manufactured using petrochemicals as raw materials, which is damaging to our environment to both extract and dispose of. In contrast, cellulose, which is the main constituent of plant cell walls, is the most abundant natural polymer on earth, constituting an almost inexhaustible source of raw material. By slightly modifying a very small portion of the chemistry of cellulose by introducing a "cinnamoyl" group, the researchers succeeded in making a specific CCi that is suitable for the formation of a new type of bioplastic with hydroplastic (ie soft and mouldable on contact with water) polymers.

This means that it can be moulded using little more than water at everyday temperature and pressure. This unique method - known as hydrosetting - enabled the researchers to produce a variety of shapes simply by immersing the bioplastic in water and leaving it to dry in the air. The moulded shapes kept their stability in the long-term and could be reshaped over and over again into a variety of 2D and 3D shapes. Although the plastic should not be used for direct contact with water - because it will lose its shape - it can hold water and be used in humid conditions. The CCi bioplastics showed high quality mechanical properties when compared with plastics that are currently widely used.

"Our research provides a feasible method to design other eco-friendly hydroplastics from renewable resources," explains Professor Kai Zhang from the University of Göttingen. "This should open up new avenues of research, stimulating further exploration of other sustainable bioplastics with superior mechanical properties and new features."

The hydrosetting process avoids expensive and complex machinery and harsh processing conditions. This eco-friendly method highly simplifies plastics manufacture, making their processing and recycling more economical and sustainable. "This research offers tremendous potential for bioplastics like this to be applied in many different situations, such as biology, electronics and medicine," says Zhang before adding: "In particular, the detrimental effects of plastics on the environment, which is damaging to all forms of life on earth, would be minimized by reusing hydroplastics with their unique features."

Nuclear fusion offers the potential for a safe, clean and abundant energy source.

This process, which also occurs in the sun, involves plasmas, fluids composed of charged particles, being heated to extremely high temperatures so that the atoms fuse together, releasing abundant energy.

One challenge to performing this reaction on Earth is the dynamic nature of plasmas, which must be controlled to reach the required temperatures that allow fusion to happen. Now researchers at the University of Washington have developed a method that harnesses advances in the computer gaming industry: It uses a gaming graphics card, or GPU, to run the control system for their prototype fusion reactor.

The team published these results May 11 in Review of Scientific Instruments.

"You need this level of speed and precision with plasmas because they have such complex dynamics that evolve at very high speeds. If you cannot keep up with them, or if you mispredict how plasmas will react, they have a nasty habit of going in the totally wrong direction very quickly," said co-author Chris Hansen, a UW senior research scientist in the aeronautics and astronautics department.

"Most applications try to operate in an area where the system is pretty static. At most all you have to do is 'nudge' things back in place," Hansen said. "In our lab, we are working to develop methods to actively keep the plasma where we want it in more dynamic systems."

The UW team's experimental reactor self-generates magnetic fields entirely within the plasma, making it potentially smaller and cheaper than other reactors that use external magnetic fields.

"By adding magnetic fields to plasmas, you can move and control them without having to 'touch' the plasma," Hansen said. "For example, the northern lights occur when plasma traveling from the sun runs into the Earth's magnetic field, which captures it and causes it to stream down toward the poles. As it hits the atmosphere, the charged particles emit light."

The UW team's prototype reactor heats plasma to about 1 million degrees Celsius (1.8 million degrees Fahrenheit). This is far short of the 150 million degrees Celsius necessary for fusion, but hot enough to study the concept.

Here, the plasma forms in three injectors on the device and then these combine and naturally organize into a doughnut-shaped object, like a smoke ring. These plasmas last only a few thousandths of a second, which is why the team needed to have a high-speed method for controlling what's happening.

Previously, researchers have used slower or less user-friendly technology to program their control systems. So the team turned to an NVIDIA Tesla GPU, which is designed for machine learning applications.

"The GPU gives us access to a huge amount of computing power," said lead author Kyle Morgan, a UW research scientist in the aeronautics and astronautics department. "This level of performance was driven by the computer gaming industry and, more recently, machine learning, but this graphics card provides a really great platform for controlling plasmas as well."

Using the graphics card, the team could fine-tune how plasmas entered the reactor, giving the researchers a more precise view of what's happening as the plasmas form -- and eventually potentially allowing the team to create longer-living plasmas that operate closer to the conditions required for controlled fusion power.

"The biggest difference is for the future," Hansen said. "This new system lets us try newer, more advanced algorithms that could enable significantly better control, which can open a world of new applications for plasma and fusion technology."

A new study, led by University of Minnesota Twin Cities engineering researchers, shows that the stiffness of protein fibers in tissues, like collagen, are a key component in controlling the movement of cells. The groundbreaking discovery provides the first proof of a theory from the early 1980s and could have a major impact on fields that study cell movement from regenerative medicine to cancer research.

The research is published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), a peer-reviewed, multidisciplinary, high-impact scientific journal.

Directed cell movement, or what scientists call "cell contact guidance," refers to a phenomenon when the orientation of cells is influenced by the alignment of fibers within soft tissues. Cells have protrusions, almost like multiple little arms, that move them within the tissue. Cells obviously don't have eyes to sense where they are going, so understanding the mechanisms for how they align their movement with the fibers is considered by researchers to be a final frontier in controlling cell migration.

"It's kind of like if someone dropped you in a swimming pool filled with water and thousands of skinny ropes aligned along the length of the pool and told you to swim laps--and then turned off the lights," said Robert Tranquillo, the senior researcher on the study and a University of Minnesota professor in the Department of Biomedical Engineering and the Department of Chemical Engineering and Materials Science. "You'd reach out your arms and legs to try to move through the water and figure out the right direction using the ropes."

Cells need to move for many reasons. They must move to the right places in a developing embryo to become the right cell types. In wound healing, skin cells need to enter into blood clots efficiently to convert the wound into a scar. And research shows that when cancer cells migrate away from solid tumors to spread throughout the body, they're following tracks of a line of fibers. In more recent years, researchers have found that contact guidance is the underlying cellular mechanism by which they can make engineered tissues for regenerative medicine to regrow, repair, or replace damaged or diseased cells, organs, or tissues.

"Even though we use cell contact guidance for many processes in my lab to engineer tissues to mimic heart valves and blood vessels, the signal that induces the cell movement in an aligned fiber network has been unclear to us all of these years," said Tranquillo, a Distinguished McKnight University Professor.

In this new study aimed at understanding contact guidance and improving tissue engineering, Tranquillo's team partnered with researchers at the University of California, Irvine and University of California, Los Angeles to test the mechanical resistance (the stiffness of the fibers) in two different directions in gels of aligned fibers to see if that was a major factor in cell movement instead of the porosity of the fibers or the adhesion (stickiness) of the fibers.

"Using a special set of tools previously unavailable to us, we were able to test skin cells that we consider a 'work horse' for developing engineered tissues," Tranquillo said. "What we found is that when we cross-linked the fibers (connecting them at intersections) and increased the difference in the stiffness in the two directions, but kept all the other factors the same, the cells aligned better. This is evidence that a directional difference in mechanical resistance of the fiber network influences cell orientation and movement."

This is the first time anyone has been able to prove one major aspect of the contact guidance theory first proposed by Graham Dunn at King's College in London back in 1982, Tranquillo said.

The next steps are to study the porosity and adhesion of the fibers to see if they have an impact on cell movement, as well as to study other cell types.

"This is just the first step to truly understand how cells move," Tranquillo added. "If we can learn more about how cells move, it could be a game-changer in many scientific fields."

Lithium-ion batteries (LIBs), which are a renewable source of energy for electrical devices or electric vehicles, have attracted much attention as the next-generation energy solution. However, the anodes of LIBs in use today have multiple inadequacies, ranging from low ionic electronic conductivity and structural changes during the charge/discharge cycle to low specific capacity, which limits the battery's performance.

In search of a better anode material, Dr. Jun Kang of Korea Maritime and Ocean University, along with his colleagues from Pusan National University, Republic of Korea, has designed an anode that, owing to its unique structural features, overcomes many of the existing barriers of anodic efficiency. Dr. Kang explains, "We focused on manganese selenide (MnSe), an affordable transition metal compound known for its high electrical conductivity and applicability in developing semiconductors and supercapacitors- as a possible candidate for the advanced LIB anode." However, MnSe undergoes a drastic volume change (by almost 160%) during the charging-discharging cycles, which not only reduces the performance of the electrode but also raises safety issues.

In an effort to prevent this volume change, the aforementioned researchers developed a simple and low-cost process: they uniformly infused the MnSe nanoparticles into a three-dimensional porous carbon nanosheet matrix (or 3DCNM). In the newly developed anode material (which they termed "MnSe ? 3DCNM"), the carbon nanosheet scaffold endowed the anchored MnSe nanoparticles with numerous advantages, such as a high number of active sites and an enhanced contact area with the electrolyte and protected them from drastic volume expansion.

The researchers were able to synthesize a variety of MnSe ? 3DCNM materials. Among these, they found MnSe ? 3DCNM-1.92 to exhibit the best cycle stability and rate capabilities. When combined with lithium manganese (III,IV) oxide (LiMn2O4, a commonly used cathode material) in a full cell, the team observed that MnSe ? 3DCNM-1.92 remarkably continued to demonstrate superior electrochemical properties, including superior lithium ion and electron transport kinetics!

The team is excited about the potential implications of their accomplishment. As Dr. Kang explains, "Using a conducive filler scaffold, we have developed an anode that boosts the battery performance while simultaneously allowing reversible energy storage. This strategy can serve as a guide for other transition metal selenides with high surface areas and stable nanostructures, with applications in storage systems, electrocatalysis, and semiconductors."

Along with this new development in the field of LIBs, the possibility of realizing a greener future becomes brighter!

- Data show dose-responsive, non-saturated increases in gastrointestinal consumption of Phe in humans by SYNB1618 -

- SYNB1618 Phase 2 study in patients with PKU ongoing with proof-of-concept readout anticipated in 2H 2021 -

- Phase 1 study of SYNB1934, an evolved strain of SYNB1618 in the PKU portfolio, initiated -

CAMBRIDGE, Mass., July 22, 2021 /PRNewswire/ -- Synlogic, Inc. (Nasdaq: SYBX), a clinical stage company bringing the transformative potential of synthetic biology to medicine, announced today the publication of two papers in the journals Nature Metabolism and Communications Biology. The publications detail findings from a first-in-human study of investigational Synthetic Biotic™ medicine SYNB1618 and the development of a mechanistic model to predict the function of an engineered bacterial therapeutic in healthy volunteers and Phenylketonuria (PKU) patients. These data add to the growing body of scientific research demonstrating the therapeutic potential of Synthetic Biotic™ medicines for the treatment of PKU.

"Our orally administered Synthetic Biotic medicines are intended to address the needs of PKU patients of all ages and disease types through the consumption of phenylalanine (Phe) in the gastrointestinal tract. With two Phe-consuming strains now in the clinic, and a proof-of-concept readout in SYNB1618 anticipated in the second half of 2021, we look forward to advancing our PKU pipeline and developing a meaningful treatment for those living with PKU," said Aoife Brennan, M.B. Ch.B., Synlogic's President and Chief Executive Officer.

Key findings from the Nature Metabolism paper entitled, "Safety and pharmacodynamics of an engineered E. coli Nissle for the treatment of phenylketonuria: a first-in-human Phase 1/2a study":

In this first-in-human study of a frozen liquid formulation of SYNB1618 in healthy volunteers and patients with PKU, SYNB1618 was safe and well tolerated, with no systemic toxicity and no evidence of colonization. SYNB1618 was cleared within four days of the last dose.

Dose-responsive increases in strain-specific Phe metabolites in plasma and urine were observed, demonstrating SYNB1618 is able to consume Phe and convert it to non-toxic metabolites in the GI tract of both healthy volunteers and patients with PKU.

These data demonstrate the potential to use engineered bacteria in the treatment of rare metabolic disorders through the consumption of toxic substances in the GI tract.

Concurrently, the development of a mechanistic model predicting the potential for Phe-lowering efficacy in PKU patients was published today in Communications Biology. The paper, entitled, "Development of a Mechanistic Model to Predict Synthetic Biotic Activity in Healthy Volunteers and Patients with Phenylketonuria," used findings from the Phase 1/2a study to inform a mechanistic model of strain activity in PKU patients.

Key findings include:

Construction of a mechanistic model that predicts SYNB1618 function in non-human primates and healthy subjects is feasible by combining in vitro simulations and prior knowledge of human physiology.

The model can be extended using plasma Phe kinetics to PKU patients, informing clinical development of potential treatments for PKU.

Increases in Phe removal from the GI tract are predicted to correlate strongly with reduction of Phe in the blood.

The results of this dose-response model suggest Phe-consuming Synthetic Biotic medicines such as SYNB1618 may have potential to achieve clinically meaningful reduction of blood phenylalanine levels in patients with PKU.

Data on the solid oral formulation of SYNB1618 was presented at the American College of Medical Genetics meeting in April 2021. Data on the development of SYNB1934, an evolved strain of SYNB1618, was presented at the Synthetic Biology: Engineering, Evolution & Design (SEED) conference in June 2021.

SYNB1618 continues to advance in a proof-of-concept Phase 2 clinical trial in adults with PKU, SynPheny-1 study (NCT04534842), with data expected in the second half of 2021. Learn more by visiting https://pkuresearchstudy.com. Information about Synlogic's programs and pipeline can be found at https://www.synlogictx.com.

The body's so-called good cholesterol may be even better than we realize. New research from Washington University School of Medicine in St. Louis suggests that one type of high-density lipoprotein (HDL) has a previously unknown role in protecting the liver from injury. This HDL protects the liver by blocking inflammatory signals produced by common gut bacteria.

The study is published July 23 in the journal Science.

HDL is mostly known for mopping up cholesterol in the body and delivering it to the liver for disposal. But in the new study, the researchers identified a special type of HDL called HDL3 that, when produced by the intestine, blocks gut bacterial signals that cause liver inflammation. If not blocked, these bacterial signals travel from the intestine to the liver, where they activate immune cells that trigger an inflammatory state, which leads to liver damage.

"Even though HDL has been considered 'good cholesterol,' drugs that increase overall HDL levels have fallen out of favor in recent years because of clinical trials that showed no benefit in cardiovascular disease," said senior author Gwendalyn J. Randolph, PhD, the Emil R. Unanue Distinguished Professor of Immunology. "But our study suggests that raising levels of this specific type of HDL, and specifically raising it in the intestine, may hold promise for protecting against liver disease, which, like heart disease, also is a major chronic health problem." In the study, the researchers showed that HDL3 from the intestine protects the liver from inflammation in mice.

Any sort of intestinal damage can impact how a group of microbes called Gram-negative bacteria can affect the body. Such microbes produce an inflammatory molecule called lipopolysaccharide that can travel to the liver via the portal vein. The portal vein is the major vessel that supplies blood to the liver, and it carries most nutrients to the liver after food is absorbed in the intestine. Substances from gut microbes may travel along with nutrients from food to activate immune cells that trigger inflammation. In this way, elements of the gut microbiome may drive liver disease, including fatty liver disease and liver fibrosis, in which the liver develops scar tissue.

Randolph became interested in this topic through a collaboration with two Washington University surgeons, Emily J. Onufer, MD, a surgical resident, and Brad W. Warner, MD, the Jessie L. Ternberg PhD, MD, Distinguished Professor of Pediatric Surgery and chief surgeon at St. Louis Children's Hospital, both co-authors on the study. Some premature infants develop a life-threatening condition called necrotizing enterocolitis, an inflammation of the intestine that can require a portion of the intestine to be surgically removed. Even after a successful bowel surgery, such babies often develop liver disease, and Onufer and Warner wanted to understand why.

"They were studying this problem in a mouse model of the condition: They remove a portion of the small intestine in mice and study the liver fibrosis that results," Randolph said. "There were hints in the literature that HDL might interfere with lipopolysaccharide's detection by immune cells and that the receptor for lipopolysaccharide might be linked to liver disease following the bowel surgery.

"However, no one thought that HDL would directly move from the intestine to the liver, which requires that it enter the portal vein," she said. "In other tissues, HDL travels out through a different type of vessel called a lymphatic vessel that, in the intestine, does not link up to the liver. We have a very nice tool in our lab that lets us shine light on different organs and track the HDL from that organ. So, we wanted to shine light on the intestine and see how the HDL leaves and where it goes from there. That's how we showed that HDL3 leaves only through the portal vein to go directly to the liver."

As the HDL3 makes this short journey down the portal vein, it binds to a protein called LBP -- lipopolysaccharide binding protein -- which binds to the harmful lipopolysaccharide. When the harmful lipopolysaccharide is bound to this complex, it is blocked from activating immune cells called Kupffer cells. These are macrophages that reside in the liver and, when activated by lipopolysaccharide, can drive liver inflammation.

As a complex of proteins and fats, HDL3 uses its partnership with LBP to bind to lipopolysaccharide. When LBP is part of the HDL3 complex, it prevents the harmful bacterial molecule from activating the liver Kupffer cells and inducing inflammation, according to experiments conducted by first author Yong-Hyun Han, PhD, when he was a postdoctoral researcher in Randolph's lab. Han is now on the faculty of Kangwon National University in South Korea.

"We think that LBP, only when bound to HDL3, is physically standing in the way, so lipopolysaccharide can't activate the inflammatory immune cells," Han said. "HDL3 is essentially hiding the harmful molecule. However, if LBP is binding to lipopolysaccharide and HDL3 is not present, LBP is not able to stand in the way. Without HDL3, LBP is going to trigger stronger inflammation."

The researchers showed that liver injury is worse when HDL3 from the intestine is reduced, such as from surgical removal of a portion of the intestine.

"The surgery seems to cause two problems," Randolph said. "A shorter intestine means it's making less HDL3, and the surgery itself leads to an injurious state in the gut, which allows more lipopolysaccharide to spill over into the portal blood. When you remove the part of the intestine that makes the most HDL3, you get the worst liver outcome. When you have a mouse that cannot genetically make HDL3, liver inflammation is also worse. We also wanted to see if this dynamic was present in other forms of intestinal injury, so we looked at mouse models of a high-fat diet and alcoholic liver disease."

In all of these models of intestinal injury, the researchers found that HDL3 was protective, binding to the additional lipopolysaccharide released from the injured intestine and blocking its downstream inflammatory effects in the liver.

The researchers further showed that the same protective molecular complexes were present in human blood samples, suggesting a similar mechanism is present in people. They also used a drug compound to increase HDL3 in the intestines of mice and found it to be protective against different types of liver injury. While the drug is only available for animal research, the study reveals new possibilities for treating or preventing liver disease, whether it stems from damage to the intestine caused by high-fat diets, alcohol overuse or physical injury, such as from surgery.

"We are hopeful that HDL3 can serve as a target in future therapies for liver disease," Randolph said. "We are continuing our research to better understand the details of this unique process."

By analyzing peoples' visitation patterns to essential establishments like pharmacies, religious centers and grocery stores during Hurricane Harvey, researchers at Texas A&M University have developed a framework to assess the recovery of communities after natural disasters in near real time. They said the information gleaned from their analysis would help federal agencies allocate resources equitably among communities ailing from a disaster.

"Neighboring communities can be impacted very differently after a natural catastrophic event," said Dr. Ali Mostafavi, associate professor in the Zachry Department of Civil and Environmental Engineering and director of the Urban Resilience.AI Lab. "And so, we need to identify which areas can recover faster than others and which areas are impacted more than others so that we can allocate more resources to areas that need them more."

The researchers have reported their findings in Interface, a publication of The Royal Society, a scientific academy.

The metric that is conventionally used to quantify how communities bounce back from nature-caused setbacks is called resilience and is defined as the ability of a community to return to its pre-disaster state. And so, to measure resilience, factors like the accessibility and distribution of resources, connection between residents within a community and the level of community preparedness for an unforeseen disaster are critical.

The standard way of obtaining data needed to estimate resilience is through surveys. The questions considered, among many others, are how and to what extent businesses or households were affected by the natural disaster and the stage of recovery. However, Mostafavi said these survey-based methods, although extremely useful, take a long time to conduct, with the results of the survey becoming available many months after the disaster.

"For federal agencies allocating funds, recovery information is actually needed in a faster and more near real-time fashion for communities that are trailing in the recovery process," said Mostafavi. "The solution, we thought, was to look for emerging sources of data other than surveys that could provide more granular insights into community recovery at a scale not previously investigated."

Mostafavi and his collaborators turned to community-level big data, particularly the information collected by companies that keep track of visits to locations within a perimeter from anonymized cell phone data. In particular, the researchers partnered with a company called SafeGraph to obtain location data for the people in Harris County, Texas, around the time of Hurricane Harvey. As a first step, they determined "points of interest" corresponding to the locations of establishments, like hospitals, gas stations and stores, that might experience a change in visitor traffic due to the hurricane.

Next, the researchers mined the big data and obtained the number of visits to each point of interest before and during the hurricane. For different communities in Harris County, they calculated the time taken for the visits to return to the pre-disaster level and the general resilience, that is, the combined resilience of each point of interest based on the percent change in the number of visits due to the hurricane.

Their analysis revealed that communities that had low resilience also experienced more flooding. However, their results also showed that the level of impact did not necessarily correlate with recovery.

"It's intuitive to assume, for example, that businesses impacted more will have slower recovery, which actually wasn't the case," said Mostafavi. "There were places where visits dropped significantly, but they recovered fast. But then others that were impacted less but took longer to recover, which indicated the importance of both time and general resilience in evaluating a community's recovery."

The researchers also noted that another important finding was that the areas that are in close proximity to those that had flooding are also impacted, suggesting that the spatial reach of flooding goes beyond flooded areas.

"Although we focused on Hurricane Harvey for this study, our framework is applicable for any other natural disaster as well," said Mostafavi. "But as a next step, we'd like to create an intelligent dashboard that would display the rate of recovery and impacts in different areas in near real time and also predict the likelihood of future access disruption and recovery patterns after a heavy downpour."

DURHAM, N.C. - Scientists at Duke University have developed a suite of four new tests that can be used to detect coal ash contamination in soil with unprecedented sensitivity.

The tests are specifically designed to analyze soil for the presence of fly ash particles so small other tests might miss them.

Fly ash is part of coal combustion residuals (CCRs) that are generated when a power plant burns pulverized coal. The tiny fly ash particles, which are often microscopic in size, contain high concentrations of arsenic, selenium and other toxic elements, many of which have been enriched through the combustion process.

While the majority of fly ash is captured by traps in the power plant and disposed to coal ash impoundments and landfills, some escapes and is emitted into the environment. Over time, these particles can accumulate in soil downwind from the plant, potentially posing risks to environment and human health.

"Because of the size of these particles, it's been challenging to detect them and measure how much fly ash has accumulated," said Avner Vengosh, Distinguished Professor of Environmental Quality at Duke's Nicholas School of the Environment. "Our new methods give us the ability to do that - with high level of certainty."

Coal combustion residuals are the largest industrial solid wastes produced in the United States. When soil contaminated with fly ash is disturbed or dug up, dust containing the ash can be transported through the air into nearby homes and other indoor environments. Inhaling dust that contains fly ash particles with high levels of toxic metals has been linked to lung and heart disease, cancer, nervous system disorders and other ill effects.

"Being able to trace the contamination back to its source location is essential for protecting public health and identifying where remediation efforts should be focused," said Zhen Wang, a doctoral student in Vengosh's lab at Duke, who led the study. "These new methods complement tests we've already developed for tracing coal ash in the environment and expand our range of investigation."

The new tests are designed to be used together to provide independent corroborations of whether fly ash particles are present in a soil sample and if so, at what proportion to the total soil.

"First, we measure the abundance of certain metals, such as arsenic, selenium and antimony, that we know are more enriched in coal ash than in normal soil," Wang said. "If these metals are present at higher-than-normal levels, we test the sample using two other geochemical indicators, radium nuclides and lead stable isotopes, which are more sensitive than trace metals and can be used to detect low occurrence of fly ash in soils. We also examine the soil under a microscope to test if we can physically identify fly ash particles and estimate what proportion of the soil they comprise."

Each method has its own strengths and weaknesses, and if used solely could lead to overestimates or underestimates the occurrence of fly in soil, Vengosh said. "By using all four together, we are able to verify the forensic investigation of fly ash presence in soils."

To assess the reliability of the new tests, the researchers analyzed surface soil from 21 sites downwind of the Tennessee Valley Authority's Bull Run Fossil Plant in Claxton, Tenn., and 20 sites downwind of Duke Energy's Marshall Steam Station on Lake Norman, N.C. The North Carolina samples came from Mooresville, a town located across the lake from the Marshall plant. Control samples were also collected at sites upwind of each plant.

The tests consistently showed that most of the samples collected downwind of both plants contained fly ash contamination, but because the proportion of the fly ash was low, the concentrations of toxic elements did not exceed human health guidelines for metals occurrence in soil.

The tests also showed that soil samples near Bull Run Fossil Plant in Tennessee generally contained significantly higher levels of fly ash than those from North Carolina, and that the highest concentration was in soil from the Claxton Community Park, a playground and recreational site located outside the Bull Run plant.

What does this all tell us?

"First, it confirms that our new tools perform consistently and, when used together, provide a reliable method for detecting contamination that other tests might miss," Vengosh said.

"Second, it underscores the need to regularly monitor sites in close downwind proximity to a coal-fired power plant, even if levels of contamination are below current safety thresholds. Fly ash accumulates over time, and risks can grow with repeat exposures to playground dust or home dust," Vengosh said.

"Low concentrations of toxic metals in soil does not equal to no risk," Vengosh said. "We need to understand how the presence of fly ash in soils near coal plants could affect the health of people who live there. Even if coal plants in the United States are shutting down or replaced by natural gas, the environmental legacy of coal ash in these areas will remain for decades to come."

The peer-reviewed study was published in July 20 in Environmental Science & Technology.

According to the United Nations' telecommunications agency, 93% of the global population has access to a mobile-broadband network of some kind. With data becoming more readily available to consumers, there is also an appetite for more of it, and at faster speeds.

Ramy Rady, doctoral student in the Department of Electrical and Computer Engineering at Texas A&M University, is working with Dr. Kamran Entesari, his faculty advisor and professor, and Dr. Christi Madsen, professor, to design a chip that can revolutionize the current data rate for processors and technologies such as smartphones, laptops, etc. Dr. Sam Palermo, professor, is also involved with the project.

Photons are very fast - moving at the speed of light. By contrast, electrons move much slower at about 2,200 kilometers per second, which is less than 1% of the speed of light. By integrating photonic structures onto a silicon substrate by way of optics, Rady is taking advantage of the speed that photons provide while utilizing the features of existing electronic CMOS (Complementary Metal Oxide Semiconductor) technology to make silicon photonic integrated circuits.

Silicon photonic integrated circuits consume less power and generate less heat than conventional electronic circuits, which allows for an increase in data transmission. Previous work in this area was only conducted using optical processing. Rady and his team are moving toward the use of microwave photonics, which is a branch of optics that focuses on improving the quality of microwave signals using photonic structures. The advantage to Rady's project over all previous solutions is its small size and high-speed operation, i.e. frequency and data rates.

"My prototype chip operates from 25 to 40 gigahertz, creating four channels each of a 5 gigahertz bandwidth," Rady said. "This chip operates at a higher speed with a higher data rate than the previous generation of chips which relied on optical processing. The new chip is capable of reaching nearly five times the bandwidth compared to a contemporary cell phone."

Rady explained that the motion of electrons is limited, and subsequently, the quality of energy that is sent and stored to your phone, for example, is also limited. This is where the integration of photons comes into play.

Scientists have completed the largest and most diverse genetic study of type 1 diabetes ever undertaken, identifying new drug targets to treat a condition that affects 1.3 million American adults.

Several potential drugs are already in the pipeline. Drugs targeting 12 genes identified in the diabetes study have been tested or are being tested in clinical trials for autoimmune diseases. That could accelerate the drugs' repurposing for treating or preventing type 1 diabetes, the researchers say.

"This work represents the largest, most ancesty-diverse study of type 1 diabetes that identifies the most likely causal genetic variants associated with risk, their target genes and those genes that are implicated in other autoimmune diseases with known drug targets," said researcher Stephen S. Rich, PhD, of the University of Virginia School of Medicine and its Center for Public Health Genomics. "Using these results, we hope that the number of plausible genetic variants will be reduced, their function and gene targets clarified, and existing drugs used in other diseases can be tested for their impact on delaying onset of type 1 diabetes, or improved treatment outcomes."

About Type 1 Diabetes

Formerly known as juvenile diabetes, type 1 diabetes can affect both children and adults. In type 1 diabetes, the body's own immune system attacks the insulin-producing beta-cells in the pancreas, such that the body doesn't make enough insulin, a hormone that helps the body burn sugar as fuel. Treatment is insulin replacement, but it is not a cure.

Type 1 diabetes increases the risk for heart problems, stroke, nerve damage and vision loss, and can even cause pregnancy complications and miscarriages. It also reduces blood flow to the feet, meaning that small injuries left untreated can become serious problems, possibly requiring amputation.

The new type 1 diabetes study examined 61,427 participants, which is twice the size of the previous largest study. Most prior research has focused on type 1 diabetes risk in people of European ancestry, while the new findings provide important insights about the type 1 diabetes "genetic landscape" in people of African, Asian and other backgrounds as well, the researchers report in a new scientific paper.

"Increasing diversity in all aspects of research is ethically important but, in addition, diverse populations potentially provide unique genetic insights that can reduce the number of putatively causal variants on risk, as well as interactions with novel non-genetic risk factors," said Rich, of UVA's Department of Public Health Sciences. "For example, in African-ancestry populations, there is evidence in some genomic regions the type 1 diabetes risk variants have narrowed the list of causal variants, while in other regions, the risk variants are distinct from those in European-ancestry populations. These data are critical for implementing genetic risk scores for identifying those children at high genetic risk for future screening and entry into immune-intervention trials."

New Diabetes Findings

In total, the scientists identified 78 regions on our chromosomes where genes are located that influence our risk for type 1 diabetes. Of those, 36 regions were previously unknown.

In addition, the researchers identified specific, naturally occurring gene variations that influence risk, and determined how those variations act on particular types of cells. They were then able to use their findings to identify and prioritize potential drug targets.

Among the potential targets are a dozen examined in current or completed clinical trials for autoimmune diseases. For example, the gene IL23A has been successfully targeted in the treatment of inflammatory bowel disease and psoriasis. Targeting this gene may also prove useful in the battle against type 1 diabetes, the researchers believe.

While more study is needed, the scientists' work has broadened our understanding of type 1 diabetes in different groups and produced many promising leads that could ultimately benefit patients.

"Based upon this work, we are now approaching knowledge of almost 90% of the genetic risk for type 1 diabetes, which is about one-half of the total risk for the disease," Rich said. "This work moves us closer to the goal of precision medicine in type 1 diabetes, when we can use genetics to help identify those at risk for autoantibody screening and early detection, with genetic insights to therapies that would enhance the search for a cure."

Scientists have developed a 'nanobody' - a small fragment of a llama antibody - that is capable of chasing out human cytomegalovirus (HCMV) as it hides away from the immune system. This then enables immune cells to seek out and destroy this potentially deadly virus.

Around four out of five people in the UK are thought to be infected with HCMV, and in developing countries this can be as high as 95%. For the majority of people, the virus remains dormant, hidden away inside white blood cells, where it can remain undisturbed and undetected for decades. If the virus reactivates in a healthy individual, it does not usually cause symptoms. However, for people who are immunocompromised - for example, transplant recipients who need to take immunosuppressant drugs to prevent organ rejection - HCMV reactivation can be devastating.

At present, there is no effective vaccine against HCMV, and anti-viral drugs often prove ineffective or have very serious side-effects.

Now, in a study published in Nature Communications, researchers at Vrije Universiteit Amsterdam in the Netherlands and at the University of Cambridge have found a way to chase the virus from its hiding place using a special type of antibody known as a nanobody.

Nanobodies were first identified in camels and exist in all camelids - a family of animals that also includes dromedary, llamas and alpacas. Human antibodies consist of two heavy and two light chains of molecules, which together recognise and bind to markers on the surface of a cell or virus known as antigens. For this special class of camelid antibodies, however, only a single fragment of the antibody - often referred to as single domain antibody or nanobody - is sufficient to properly recognize antigens.

Dr Timo De Groof from Vrije Universiteit Amsterdam, the study's joint first author, said: "As the name suggests, nanobodies are much smaller than regular antibodies, which make them perfectly suited for particular types of antigens and relatively easy to manufacture and adjust. That's why they're being hailed as having the potential to revolutionise antibody therapies."

The first nanobody has been approved and introduced onto the market by biopharmaceutical company Ablynx, while other nanobodies are already in clinical trials for diseases like rheumatoid arthritis and certain cancers. Now, the team in The Netherlands and the UK have developed nanobodies that target a specific virus protein (US28), one of the few elements detectable on the surface of a HCMV latently infected cell and a main driver of this latent state.

Dr Ian Groves from the Department of Medicine at the University of Cambridge said: "Our team has shown that nanobodies derived from llamas have the potential to outwit human cytomegalovirus. This could be very important as the virus can cause life threating complications in people whose immune systems are not functioning properly."

In laboratory experiments using blood infected with the virus, the team showed that the nanobody binds to the US28 protein and interrupts the signals established through the protein that help keep the virus in its dormant state. Once this control is broken, the local immune cells are able to 'see' that the cell is infected, enabling the host's immune cells to hunt down and kill the virus, purging the latent reservoir and clearing the blood of the virus.

Dr Elizabeth Elder, joint first author, who carried out her work while at the University of Cambridge, said: "The beauty of this approach is that it reactivates the virus just enough to make it visible to the immune system, but not enough for it to do what a virus normally does - replicating and spreading. The virus is forced to put its head above the parapet where it can then be killed by the immune system."

Professor Martine Smit, also from from the Vrije Universiteit Amsterdam, added: "We believe our approach could lead to a much-needed new type of treatment for reducing - and potentially even preventing - CMV infectious in patients eligible for organ and stem cell transplants."

The research team of Prof. Xiaobo Ji and associate Prof. Guoqiang Zou has proposed an ingenious oxygen vacancy (OV)-engineering strategy to realize high content anionic doping in TiO2 and offered valuable insights into devise electrode materials with fast charge transfer kinetics in the bulk phase. The article titled "High content anion (S/Se/P) doping assisted by defect engineering with fast charge transfer kinetics for high-performance sodium ion capacitors" is published in Science Bulletin. Xinglan Deng is listed as first author and Prof. Guoqiang Zou as corresponding author.

The rate-determining process for sodium storage in TiO2 is greatly depending on charge transfer happening in the electrode materials owing to its inferior diffusion coefficient and electronic conductivity. Apart from reducing the diffusion distance of ion/electron, the increasement of ionic/electronic mobility in crystal lattice is very important for charge transport. Here, an OV engineering assisted in high content anion (S/Se/P) doping strategy to enhance its charge transfer kinetics for ultrafast sodium-storage performance is proposed. The theoretical calculations have predicted that OV-engineering evokes the spontaneous S doping into TiO2 phase and achieves high anionic dopant concentration to bring about impurity state electron donor and electronic delocalization over S occupied sites, which can largely reduce the migration barrier of Na+. Accordingly, experimental measurements validate the realization of high content anion (S/Se/P) doping and the significantly enhanced Na ion diffusivity and conductivity in prepared electrode materials.

The optimized A-TiO2-x-S/C anode (with S content of 9.82 at%) exhibits extraordinarily high-rate capability with 209.6 mAh g-1 at 5000 mA g-1. When applied as anode materials, the assembled SIC delivers an ultrahigh energy density of 150.1 Wh kg-1 at a power density of 150 W kg-1. This work provides a new strategy to realize the high content doping of anion, and enhance the charge transfer kinetics for TiO2, which sheds a light on the design of electrode materials with fast kinetic.