Tech

Many foods produced on an industrial scale include raw ingredients mixed together in enormous stainless steel machines that can be difficult to clean. With repeated use, equipment surfaces get minute scratches and grooves, providing bacteria and biofilms the perfect place to hide. While surface scratches may appear small to the naked eye, they are like a canyon to bacteria, which are only a few micrometers in size. Surface-trapped food residue and bacteria then increase the risk of contamination from microorganisms such as Salmonella, Listeria and E. coli.

Professor Ben Hatton of the University of Toronto's Department of Materials Science & Engineering, Dr. Dalal Asker and Dr. Tarek Awad research cheaper, safer and more effective ways to prevent bacteria thriving inside these machines. This minimizes the risk of cross contamination, which can lead to food-borne disease. Their team have proposed a simple new solution: trapping a thin layer of cooking oil at the metal surface to fill in microscopic scrapes, cracks and fissures and create a barrier to bacterial attachment.

They found that this solution resulted in a 1,000x reduction in bacterial levels inside the industrial machines tested. Their work is recently published in the journal ACS Applied Materials & Interfaces.

"Coating a stainless steel surface with an everyday cooking oil has proven remarkably effective in repelling bacteria," says Hatton who collaborated on the project with AGRI-NEO, an Ontario seed processing company looking for a solution to a common problem in its industry. "The oil fills in the cracks, creates a hydrophobic layer and acts as a barrier to contaminants on the surface."

This simple and cost-effective alternative builds on the Slippery Liquid-Infused Porous Surfaces (SLIPS) principle, initially developed at Harvard to trap lubricant layers into a surface microstructure and create slippery, non-wetting and non-adhesive properties. Cooking oils such as olive, corn or canola also provide a safer option for cleaning food-processing equipment than the harsh chemicals and disinfectants that are typically used. The sheer size of the machines makes it harder for cleaning materials to do a thorough job, and leftover bacteria can build up resistance to the cleaning agents. Hatton's method of filling the scratches with oil prevents bacteria from settling and essentially cleans the surface without leaving chemical residues on the stainless steel surface.

"Contamination in food preparation equipment can impact individual health, cause costly product recalls and can still result after chemical-based cleaning occurs," says Hatton. "The research showed that using a surface treatment and a cooking oil barrier provides greater coverage and results in 1,000 less bacteria roaming around."

The Hatton research group continues to test new combinations of oils, foods and biofilm types to increase the efficiency of the bacteria barriers. They will also explore options of using this method in developing countries to minimize bacterial infection and improve mortality rates.

The Eastern Pacific Ocean's Tropical Depression 8E formed on July 26 and strengthened into a tropical storm by 5 a.m. EDT on July 27. At that time the storm was renamed Gilma. NASA's Terra satellite provided forecasters with an early look at the eighth depression as it was developing.

On July 26 at 2:25 p.m. EDT (1825 UTC) when Tropical Depression 8E was strengthening, NASA's Terra satellite passed overhead and the MODIS instrument or Moderate Resolution Imaging Spectroradiometer captured a visible light image. The image showed strongest storms around the center and in fragmented bands extending to the north and south.

On July 27, the National Hurricane Center noted that the northwesterly wind shear disrupted the already poorly organized cloud pattern associated with Gilma. The center is now exposed and located on the northwestern edge of the convection.

By 11 a.m. EDT (1500 UTC) the center of Tropical Storm Gilma was located near latitude 14.9 degrees North and longitude 128.4 degrees West. Gilma is 1,325 miles (2,135 km) west-southwest of the southern tip of Baja California, Mexico. The National Hurricane Center said that Gilma is moving toward the west-northwest near 17 mph (28 km/h), and this motion is forecast to continue for the next 2 to 3 days. The estimated minimum central pressure is 1006 millibars.

Maximum sustained winds are near 40 mph (65 kph) with higher gusts.

NHC noted "Wind shear and cooler waters will induce weakening, and Gilma is expected to become a remnant low in 3 days or earlier. Dissipation is expected thereafter."

The Global Precipitation Measurement mission or GPM core satellite provided a rainfall and cloud analysis on powerful Typhoon Jongdari as it moves toward Japan. Jongdari follows another powerful typhoon that made landfall in Japan earlier this year.

A tropical cyclone called Prapiroon formed in late June and impacted Japan and South Korea as a typhoon in early July. Record breaking rainfall that began with Prapiroon caused flooding, landslides and many deaths. Today, another called Typhoon Jongdari is located in the northern Pacific Ocean to the southeast of Japan. It is also expected to hit southern Japan and possibly affect South Korea as it is steered toward the northwest from its current position.

Intensifying Typhoon Jongdari had maximum sustained winds estimated at 90 knots (104 mph) when the GPM core observatory satellite passed over it on July 27, 2018 at 0358 UTC (July 26 at 11:58 p.m. EDT). GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency JAXA.

From GPM imagery, it was evident that Jongdari was a large typhoon with extensive areas of heavy precipitation located near the eye and in intense feeder bands. GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) data were used in this analysis of JongdarI's precipitation. GPM's data indicated that precipitation was falling at a rate of over 267 mm (10.5 inches) per hour in a band of rain well to the northwest of the typhoon's center.

Extreme rain rates were also revealed in storms around Jongdari's eye. The most extreme rainfall rates were measured by DPR in a large feeder band on the eastern side of the typhoon. GPM's radar indicated that rain in those storms was falling at a rate of over 277 mm (10.9 inches) per hour.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, a 3-D view of Typhoon Jongdari was created using GPM's radar data (DPR Ku Band). The simulated 3-D cross-section portion of this image showed the structure and heights of precipitation within Jongdari. GPM saw that the tallest storms around Typhoon Jongdari were located in the large feeder band on the eastern side of the tropical cyclone. Heights of the tallest storms there were found to reach altitudes above 15.5 km (9.6 miles).

At 11 a.m. EDT (1500 UTC) on July 27, Typhoon Jongdari had maximum sustained winds near 90 knots. It was located near 26.5 degrees north latitude and 143.9 degrees east longitude, about 565 nautical miles south-southeast of Yokosuka, Japan. Jongdari was moving to the northeast at 20 knots (23.02 mph/37 kph) and had maximum sustained winds near 90 knots (103.6 mph/166.7 kph).

The Joint Typhoon Warning Center expects Jongdari will move northeast, later turning north and northwest and intensifying to 105 knots (120.8 mph/194.5 kph) over the next 24 hours, before gradually weakening. The typhoon will move west and pass along the southern coast of Honshu, over Kyushu and westward.

Scientists at the University of Illinois at Urbana-Champaign have developed an algorithm that could provide meaningful answers to condensed matter physicists in their searches for novel and emergent properties in materials. The algorithm, invented by physics professor Bryan Clark and his graduate student Eli Chertkov, inverts the typical mathematical process condensed matter physicists use to search for interesting physics. Their new method starts with the answer--what kinds of physical properties would be interesting to find--and works backward to the question--what class of materials would host such properties.

Inverse problem solving isn't a new technique in classical physics, but this algorithm represents one of the first successful examples of an inverse problem solving method with quantum materials. And it could make searching for interesting physics a more streamlined and deliberate process for many scientists. More physicists are working in condensed matter than any other subfield of physics--the rich diversity of condensed matter systems and phenomena provide ample unsolved problems to explore, from superconductivity and superfluidity to magnetism and topology. Experimentalists probe the macro-and microscopic properties of materials to observe the behavior and interactions of particles in materials under a strict set of controls. Theoretical condensed matter physicists, on the other hand, work to develop mathematical models that predict or explain the fundamental laws that govern these behaviors and interactions.

The field of theoretical condensed matter physics has the well-earned reputation for being esoteric and difficult for the lay person to decipher, with its focus on understanding the quantum mechanics of materials. The process of writing and solving condensed matter equations is extremely intricate and meticulous. That process generally starts with a Hamiltonian--a mathematical model that sums up the energies of all the particles in the system.

Clark explains, "For a typical condensed matter problem, you start with a model, which comes out as a Hamiltonian, then you solve it, and you end up with a wave function--and you can see the properties of that wave function and see whether there is anything interesting. This algorithm inverts that process. Now, if you know the desired type of physics you would like to study, you can represent that in a wave function, and the algorithm will generate all of the Hamiltonians--or the specific models--for which we would get that set of properties. To be more exact, the algorithm gives us Hamiltonians with that wave function as an energy eigenstate."

Clark says the algorithm gives a new way to study physical phenomena such as superconductivity.

"Typically, you would guess Hamiltonians that are likely to be superconducting and then try to solve them. What this algorithm - in theory - will allow us to do is to write down a wave function that we know superconducts and then automatically generate all of the Hamiltonians or the specific models that give that wave function as their solution. Once you have the Hamiltonians, in some sense, that gives you all the other properties of the system--the excitation spectrum, all the finite temperature properties.

That requires some more steps once you have the Hamiltonian, so we didn't improve that part of the research process. But what we did, we found a way to find interesting models, interesting Hamiltonians."

Chertkov adds, "There are lots of wave functions people have written down for which there are no known Hamiltonians--maybe 50 years worth. Now we can take any of these wave functions and ask if any Hamiltonians give those as eigenstates and you may end up with one model, no models, or many. For example, we are interested in spin-liquid wave functions, highly entangled quantum states with interesting topological properties.

Theorists have constructed many spin-liquid wave functions, but don't know which Hamiltonians give them.

In the future, our algorithm should let us find these Hamiltonians."

Clark and Chertkov tested the algorithm on wave functions related to frustrated magnetism, a topic that presents interesting physics with many open questions. Frustrated magnetism occurs in a class of materials that is insulating, so the electrons don't move around, but their spins interact. Clark explains one such wave function they tested, "The electron spins in a frustrated magnet want to be anti-aligned, like the north and south on a magnet, but can't because they live on triangles. So we make a wave function out of a linear-superposition of all of these frustrated states and we turn the crank of this algorithm, and ask, given this wavefunction, which is an interesting quantum state on a frustrated magnet, are there

Hamiltonians that would give it. And we found some."

Chertkov says the results of the algorithm could point experimentalists in the right direction to find interesting new physics: "That would hopefully be one way it would be used. You pick a wave function that has some kind of physics that you care about and you see what sort of interactions can give you that sort of physics, and hopefully then the models you find through this method can be looked for in experiments. And it turns out you find many models with our method."

Clark sums up, "This has inverted the part of the process where we were sort of hunting in the dark. Before, you could say, we're going to try lots of models until we find something interesting. Now you can say, this is the interesting thing we want, let's turn the crank on this algorithm and find a model that gives that."

Norovirus is the most common cause of gastroenteritis worldwide; it causes tens hundreds of thousands of deaths each year and is particularly risky for children under 3 years old. If someone gets norovirus in a setting like a hospital, it's critically important to find a way to protect others from getting infected. New research from several universities in Germany, to be published in the Journal of Biological Chemistry, suggests that it may be easier than anticipated to find a compound that could be used as a food supplement to stop the spread of norovirus in children's hospitals.

Norovirus causes disease after entering cells in the gut by binding to a sugar molecule called fucose, which is found on cell surfaces as part of the structure that determines human ABO blood types. Fucose is also found in breast milk and other foods. Norovirus can't tell the difference between fucoses that are part of cells in the gut and those that are simply passing through; for this reason, adding a fucose-based supplement to the diet as a decoy could be a way to capture the virus and keep it from infecting cells.

To develop this strategy, however, researchers needed to understand which features of fucose and virus molecules affected how well they attached to each other. In cells, foods, and milk, fucose is rarely found as a single molecule; rather, it's part of chains or networks of sugars and proteins. Franz-Georg Hanisch, a researcher at the University of Cologne, led a project to disentangle these molecular elements and understand what kind of fucose-based product would best distract noroviruses. He started by screening the many types of fucose-containing human milk oligosaccharides (HMOs).

To Hanisch's surprise, the strength of the binding between the norovirus protein and HMOs did not depend much on the specific structure of the HMO, or the types of fucose molecules it contained. Rather, what mattered was only how many fucoses it contained. Each individual fucose stuck weakly to the virus protein, but the more fucoses there were in the compound, the better the compound and the viral protein stuck together.

"The binding of the virus is not dependent in any way on further structural elements (of HMOs)," Hanisch said. "It's only the terminal fucose which is recognized, and the more fucose at higher densities is presented, the better is the binding."

Hanisch then turned to the industry standard of where to get a lot of fucose fast. Brown algae - the same family of seaweed that includes kelp - produce a compound called fucoidan, which is a complex network of many fucoses. (Fucoidan has independently been explored as a treatment for HIV, CMV, and HSV for unrelated biochemical reasons.)

"There are procedures for isolating the stuff in quite high yields and in high purity," Hanisch said.

The organization of the fucose in fucoidans looks nothing like any fucose-containing molecules found in the human body, but fucoidan nevertheless tightly bound to the virus protein in the team's experiments. This is good news, because it means that fucoidan could be a safe and cheap food additive to block viruses from infecting cells. It also suggests that the sky is the limit for researchers to design an even better fucose-containing compound.

Hanisch and his collaborators are therefore now moving on to experiments with live viruses and live organisms. The hope is to eventually have a fucose-based food supplement that could be given to a group of people, like hospitalized children, at the first sign of a norovirus outbreak, to prevent the circulating viruses from entering their cells and causing disease.

"I hope that in about three years we will have a product which can be used in norovirus defense and to go into clinical studies," Hanisch said.

Water is vital for life.

But as our climate changes, the availability of water is also changing, leaving animals with limited or unreliable supplies of this critical resource.

However, a new Arizona State University study published in the Royal Society journal Proceedings of the Royal Society B: Biological Sciences shows for the first time that animals may be able to use their own muscles to get water when it's not available. Researchers from ASU and the Centre d'Etudes Biologiques de Chizé in France teamed up on the project and the findings were published June 27.

"We know about the importance of fat reserves to fuel the energetic costs of reproduction. But what about water? Our study shows that during reproduction, muscle metabolism is linked to the water requirements of developing offspring. Fat is only about 10 percent water, whereas muscle is closer to 75 percent, so burning muscle will release extra water," said George Brusch IV, lead investigator for the project and doctoral student at Arizona State University. "From an evolutionary perspective, the concept of capital breeding -- or using stored resources to fuel reproduction -- is currently restricted to energetic needs. We propose that this should extend to a broader, multi-resource strategy that also includes water allocation."

The researchers looked into this concept by studying the effects of water deprivation on the reproductive efforts of female Children's pythons, a medium-sized snake that reproduces during the dry-season in Australia, where natural water sources are extremely limited. They found that muscles play an important role in providing water to the body when none is available.

"Female Children's pythons can change how they use internal resources based on limitations in the environment," said Brusch. "Understanding exactly how animals cope with resource restrictions will help scientists predict whether the animals might be impacted by future climate change, where, in many regions, rain is expected to be less reliable," said Brusch, a doctoral candidate in the School of Life Sciences biology PhD program.

During the study, the researchers paired pregnant Children's pythons with similarly sized non-reproductive females. During a three-week period when the snakes were pregnant, only half of the pairs had access to water. Reproductive females, both in the lab and the wild, don't eat during pregnancy and rely on internal reserves such as fat and muscle for their energy needs.

The scientists then measured the by-products of burning fat and muscle such as ketones and uric acid, as well as muscle size and impact on the snakes' eggs and clutch sizes. The animals without water burned more muscle than fat to meet their water requirements. In addition, the animals without water laid a similar number of eggs per clutch, but their eggs weighed less and the shells were thinner.

Brittany Kaminsky, an ASU student researcher on the team, just graduated from the School of Life Sciences with a Bachelor of Science degree in neurobiology, physiology and behavior. Kaminsky, who will attend U.C. Davis School of Veterinary Medicine in the fall, coordinated much of the project.

"I think what was most interesting about our results is that dehydration can play complex roles in reproduction, such that it affects other body systems. I feel, at the organism level, a single ailment can manifest in a variety of ways, and I think this is valuable information that I will carry with me into my veterinary career," said Kaminsky.

During the project, Kaminsky helped pair the females into the reproductive and non-reproductive groups by mass and snout-vent length. She also monitored the reproductive progress of the females by ultrasound and learned how to collect blood samples, process and store them.

"Few of my peers have had the opportunity to train a team of other undergraduates or learn some of the technical skills I developed throughout the course of the study, such as cardiocentesis and ultrasound," said Kaminsky. "Dr. Dale DeNardo and George were both there when I needed guidance, but they also gave me a lot of space to learn on my own and grow as a scientist. I couldn't have asked for better mentors."

Most animals need steady access to water in order to survive, especially during reproduction, and the authors suggest that using muscle as a water store may be a widespread phenomenon. "Our enhanced knowledge regarding the relationship between hydration and reproductive investment will also enable us to better understand global responses to water limitations and change the way scientists approach reproductive investment in ecological contexts, which, in the past, frequently ignore water and focus solely on energetic resources," said Brusch.

DURHAM, N.C. -- Engineers at Duke University have developed a way to manipulate, split and mix droplets of biological fluids by having them surf on acoustic waves in oil. The technology could form the basis of a small-scale, programmable, rewritable biomedical chip that is completely reusable for disparate purposes from on-site diagnostics to laboratory-based research.

The study appears on July 26 in the journal Nature Communications.

Automated fluid handling has driven the development of many scientific fields. Robotic pipetting systems have, for example, revolutionized the preparation of sequencing libraries, clinical diagnostics and large-scale compound screening. While ubiquitous in the modern biomedical research and pharmaceutical industries, these systems are bulky, expensive and do not handle small volumes of liquids well.

Lab-on-a-chip systems have been able to fill this space to some extent, but most are hindered by one major drawback -- surface absorption. Because these devices rely on solid surfaces, the samples being transported inevitably leave traces of themselves that can lead to contamination.

"There are a lot of protein-laden fluids and certain reagents that tend to stick to the chips that are handling them," said Tony Jun Huang, the William Bevan Professor of Mechanical Engineering and Materials Science at Duke. "This is especially true of biological samples like undiluted blood, sputum and fecal samples. Our technology is well-suited for processing these difficult samples."

The new lab-on-a-chip platform uses a thin layer of inert, immiscible oil to stop droplets from leaving behind any trace of themselves. Just below the oil, a series of piezoelectric transducers vibrate when electricity is passed through them. Just like the surface of a subwoofer, these vibrations create sound waves in the thin layer of oil above them.

By carefully controlling the sound waves, the researchers create vertical vortexes that form small dimples in the oil to either side of the active transducer. These dimples can hold droplets with volumes ranging from one nanoliter to 100 microliters and pass them along the surface of the oil as the sound waves are modulated and different transducers are activated.

The droplets are effectively surfing on tiny soundwaves.

"Our contactless liquid-handling mechanism inherently eliminates cross-contamination associated with surface adsorption and the need for surface modification," Huang said. "It enables reusable paths for the droplets to be dynamically processed on arbitrary routes without cross-talk between each other, exponentially increasing the allowable number of combinations of reagent inputs on the same device."

Huang next wants to take this proof-of-concept demonstration and create a fully automated lab-on-a-chip platform that can handle complex operations with dozens of droplets simultaneously. He's planning to collaborate with peers at Duke for various applications in biology and medicine.

Detectors that are presently used for mammograms and for dose measurements in radiotherapy are often rigid, causing errors in screening, or dose delivery to surrounding healthy tissue. This has raised concerns of additional tissue damage or the growth of secondary tumours. While flexible x-ray films such as those used in dentistry or chest x-rays bypass this issue, they are not able to achieve real-time imaging. Similarly, high-speed monitoring of people and vehicles over large geographical areas, which is important in border security, is impeded with the current technology.

In a study published in Nature Communications, researchers from the University of Surrey's Advanced Technology Institute (ATI) detail how they have developed an x-ray detector by embedding oxide nanoparticles in a bulk organic structure that allows for large area detectors to be produced inexpensively. The detectors created by ATI researchers are able to achieve high sensitivity levels that strongly compete with current technologies, while still operating at low voltages, as well as over the whole x-ray energy range spectrum .

The team also proved that it is possible to create a device that conforms to the subject - something that is not possible with current x-ray detectors. This means that it could be possible for breast cancer screenings to be carried out by adapting the x-ray detector arrays to the specification of different patients. A new start-up company to further develop this technology and bring it to market - looking specifically at the health, food monitoring and pharmaceuticals sectors -- has been formed.

Hashini Thirimanne, lead author of the study and PhD student at the University of Surrey, said: "Our new technology has the potential to transform many industries that rely on x-ray detectors. We believe that this innovation could help save lives, and keep our borders more secure, and make sure that the food we eat is as safe as it could possibily be."

Dr Imalka Jayawardena, co-author of the study at the University of Surrey, said: "We are excited to pursue this technology further and bring it to market. I would like to thank the University of Surrey for their support over the years and I look forward to continuing this relationship ."

Professor Ravi Silva, Director of ATI at the University of Surrey, and corresponding author said: "We are incredibly proud of the young researchers at ATI who have progressed this project and have produced technology that could very well save lives and make the world safer. We look forward to helping the team bring this technology to market. We are grateful to the Leverhulme Trust who funded the work via a major research programme."

CHAMPAIGN, Ill. -- Many city drinking water systems add softening agents to keep plumbing free of pipe-clogging mineral buildup. According to new research, these additives may amplify the risk of pathogen release into drinking water by weakening the grip that bacteria - like those responsible for Legionnaires' disease - have on pipe interiors.

Biofilms, which are similar to the films that grow on the glass of fish tanks, are present in almost all plumbing systems and anchor themselves to mineral scale buildups in pipes. They are teeming with harmless microbial life and incidents of waterborne illness are rare.

"The groundwater that supplies many cities may be high in magnesium and calcium," said Helen Nguyen, a professor of civil engineering and co-author of the study. "When combined with other elements, they can form thick deposits of mineral scale that clog up engineered water systems. Because of this, water treatment plants add chemicals called polyphosphates to dissolve the minerals to keep the scale buildup under control."

A recent study by co-author and civil and environmental engineering professor Wen-Tso Liu has shown that even with the addition of antimicrobial agents by water companies, the bacteria that grow on the mineral scale can reproduce to harmful levels in supplies that stagnate within indoor plumbing.

In a new study published in the journal Biofilms and Microbiomes, a team of University of Illinois engineers shows that the addition of anti-scalant chemicals cause the biofilms to grow thicker and become softer.

The team measured the thickness and stiffness of lab-grown biofilms using magnetomotive optical coherence elastography - a tool used to measure the strength of cancer tissues. The analytical method, developed by Stephen Boppart, a professor of electrical and computer engineering and study co-author, allowed the team to quantify the effect that polyphosphate has on the strength of biofilms.

To reproduce what happens in engineered plumbing systems, the team used PVC pipe and groundwater from the Champaign-Urbana area source to grow biofilms. They set up multiple scenarios with and without added polyphosphates. All scenarios produced biofilms, but the system that used polyphosphates grew a much thicker and softer biofilms than the others, the researchers said.

"Increased biofilm thickness means more bacteria, and the softening increases the chance that pieces will detach and foul the water supply under normal flow pressure," Nguyen said. "Tap water is regulated by the Environmental Protection Agency up to the property line, not the tap. So, in buildings where water has been stagnating for a while, this could become a public health issue."

A problem, according to researchers, is that some sort of anti-scalant chemical is required to maintain adequate water flow through pipes. "Of course, one solution could be to replace pipes once they become clogged with mineral buildup," Nguyen said. "But that would be a very expensive endeavor for public utilities and property owners in a country as large as the United States."

Nguyen believes that the most affordable and realistic solution will come through a better understanding of water chemistry, not by trying to kill all microbes, ripping out pipes or changing regulations.

"Before this work, we did not have a good understanding of the relationship between the water chemistry and microbiome that exists in plumbing. This work has given us initial insight and tools to help determine what chemicals will work best and at what concentration," Nguyen said.

The team is moving ahead with related studies that look at ways to help physically remove biofilms while pipes remain in place and others that look at the effects of anti-corrosive chemicals on biofilms and water quality.

"We will not be able to control how long a drinking water user will allow water to stagnate, but we can work to understand how the chemicals we add to our water interact with biofilms."

An international team of materials scientists from France, Russia and Kazakhstan found a way to boost the efficiency of organic solar cells several times. The new study, published in the Journal of Materials Chemistry A, has shown that ordered structures based on organic molecules can be used to produce solar power.

Solar panels, or batteries, are one of the most promising ways to generate electrical power. As of 2017, the combined power of solar panels installed worldwide amounted to 400 gigawatts. The solar power industry is experiencing a rapid growth, which depends on cheaper and more efficient batteries.

One way of improving solar power systems is by introducing new materials. The basic elements of a solar panel converting light into electricity are photovoltaic cells, or solar cells. They are mostly made of polysilicon -- a highly pure polycrystalline form of silicon. But scientists are busy looking for alternative materials. Organic polymers with photovoltaic properties are one of the prime candidates to replace polysilicon.

A team of researchers from France (the University of Strasbourg, University of Lyon, Institut de Sciences des Matériaux de Mulhouse, Synchrotron SOLEIL), Russia (Moscow Institute of Physics and Technology, Moscow State University), and Kazakhstan (Nazarbayev University) has described a way of boosting the efficiency of organic solar cells by incorporating fluorine atoms in the polymer. This process, known as fluorination, was previously shown to enhance polymer photovoltaic properties, but the mechanism was poorly understood. The new study clarifies the effect of fluorination on cell efficiency.

By experimenting with various polymer modifications, the team increased cell efficiency from 3.7 to 10.2 percent. While this still falls short of the commercial silicon photovoltaics, the massive gain in efficiency suggests that polymer-based cells are a technology to be reckoned with. Perhaps with further tweaks organic solar cells could outperform their polysilicon-based counterparts.

The generic polymer used in the experiment has a rather complex molecular structure. It consists of a chain of repeating units shown in the left part of figure 1. Each of them includes sulfur heterocycles -- rings made of one sulfur and four carbon atoms -- and hydrocarbon side chains with a branched structure.

The researchers produced a number of modifications of this polymer to find which one has better photovoltaic properties. They changed the structure by adding fluorine atoms (figure 1, right) and varying the length of the side chains. One polymer configuration proved to result in vastly superior properties. Namely, the cell efficiency and current output were several times higher.

The team then investigated the microscopic structure of the best-performing compound. X-ray analysis revealed polymer stacking to be more ordered. Also, the molecules were characterized by higher charge carrier mobility, which means the material conducts electricity better. For a solar cell, this is clearly an advantage.

Co-author of the study Professor Dimitri Ivanov pointed out the technological advantages of the organic solar cells. He said they can be manufactured in fewer stages, compared with conventional silicon photovoltaics. The light-absorbing polymers can also function as a thin film, which means the solar panels need not be flat.

"For example, you could deposit organic solar batteries on roof tiles," adds Ivanov, who heads the Laboratory of Functional Organic and Hybrid Materials at MIPT and is director of research at the French National Center for Scientific Research.

According to Ivanov, what made the study challenging was the "need to optimize solar cell efficiency by picking the right molecular energy levels of the donor and the acceptor, while also creating the appropriate supramolecular structure that would facilitate charge transport to the electrodes."

(Vienna, July 25, 2018) In order to move, a body needs a strong scaffold. This is not only true on a macroscopic level, where animals rely on skeletons to support their muscles. It is also true on a cellular level: the cytoskeleton composed of actin filaments is crucial for every active movement of a cell. By rearranging these filaments, cells can stretch and wander in every direction, squeeze into the smallest gaps or wrap themselves around an object. Those processes are particularly important for the cells of the immune system, which are the most motile cells of the human body in order to fight against infectious agents. Defects of the cytoskeleton thus can have detrimental effects on the immune response and thereby on the ability of the organism to control infections.

In their most recent study, scientists from the Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD) and the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences in cooperation with the University of Toulouse III, and INSERM, found that a rare genetic defect, characterized by a malfunctioning of the immune system, affects the ability of lymphocytes - the most important cells of the adaptive immunity - to rearrange their actin cytoskeleton. The study, published in the Journal of Allergy and Clinical Immunology (DOI: 10.1016/j.jaci.2018.04.023) was conducted in collaboration with clinicians from Izmir and Ankara and specialists of lymphocyte biology from the University of Vienna and the University of Rotterdam.

The gene defect was found in six patients who presented with severe infections of the lung, skin and oral mucosa. Genetic analyses of their genomes revealed mutations in a gene for a protein called WDR1, an important factor for the turn-over of actin filaments and thereby the dynamic remodeling of the cytoskeleton. It was recently shown that the innate arm of the immune system is affected by WDR1 mutations - the impact on cells of the adaptive immunity, however, was hitherto unknown. Through a series of extensive analyses, the researchers found that WDR1 deficiency leads to aberrant T-cell activation and B-cell development.

"We were able to show that T lymphocytes, although they appeared to develop normally in the patients, accumulated atypical actin structures. However, even more severe were the observed abnormalities in B lymphocytes" says Laurène Pfajfer, PhD student at LBI-RUD and shared first author of the study.

"Only few B cells were observed in the blood, and their progenitors in the bone marrow were also rare", Visiting Key Researcher at LBI-RUD and shared senior author Loïc Dupré, specifies. "And the few B cells we found showed a whole range of abnormalities, including reduced clonal diversity, abnormal spreading and increased apoptosis upon B-cell receptor stimulation".

"Our report expands the phenotypic spectrum of WDR1 deficiency, which comprises marked defects of both innate and adaptive immunity and illustrates the tight connection between immune system and uncontrolled inflammation which results in disease," summarizes Kaan Boztug, Director of LBI-RUD and shared senior author. "The results allowed us to gain new insights into the key role of actin cytoskeletal dynamics in supporting immune cell function. This study is another example for the value of research on rare diseases - not only for the few affected patients, but for a more global and fundamental understanding of human biology. Furthermore the elucidation of the fine mechanisms leading to such diseases provides unique insights for the development of precision medicine.

Alexandria, Va., USA - At the 96th General Session of the International Association for Dental Research (IADR), held in conjunction with the IADR Pan European Regional (PER) Congress, Caroline Shiboski, University of California, San Francisco, USA gave an oral presentation titled "Increased Caries Risk Among Perinatally HIV-infected Youth on Integrase Inhibitors." The IADR/PER General Session & Exhibition is in London, England at the ExCeL London Convention Center from July 25-28, 2018.

Combination antiretroviral therapy (cART) has been successful at preserving immune function and controlling opportunistic infections, including oral mucosal diseases, among individuals infected with HIV. Shiboski and co-authors explored the association between cART and dental and periodontal outcomes among HIV-infected youth.

Through a cross-sectional study of oral health among perinatally HIV-infected (PHIV) youth participating in the Oral Health substudy of the Pediatric HIV/AIDS Cohort, dentists at 11 sites were trained to perform standardized dental/periodontal examinations. They used the decayed-missing-filled-surfaces/teeth index (DMFS/T) to determine the number of decayed surfaces/teeth and the full-mouth periodontal evaluation to derive the number of teeth with bleeding on probing. The zero-inflated negative binomial model was used to assess the association between cART type and dental or periodontal outcomes.

Among the PHIV youth, 89% were on cART at time of enrollment. For the PHIV youth who were on the same cART for at least one year, the mean decayed tooth score of those receiving an integrase inhibitor was 86% higher than that of those youth without an integrase inhibitor. The median number of teeth with at least two sites with bleeding on probing was significantly higher among youth who started cART at age six years or older compared to youth who started before age two. Initiating protease inhibitors at age six or older was also associated with significantly higher DMFS/T score compared to participants who initiated before age two.

These finding suggests that youth receiving integrase inhibitor should undergo close surveillance of their dental status through preventative visits. Earlier initiation of cART and PI seems to be associated with less gingival inflammation and lower DMFT.

This research was presented as part of the Immunity and Immunotherpay oral session that took place of Thursday, July 26 from 3:15 p.m. - 4:45 p.m. at the ExCeL London Convention Center in London, England.

Alexandria, Va., USA - At the 96th General Session of the International Association for Dental Research (IADR), held in conjunction with the IADR Pan European Regional (PER) Congress, Tian Liang, Texas A&M University, Dallas, USA gave an oral presentation titled "Unfolded Protein Response (UPR) Is Associated With Dentinogenesis Imperfecta (DGI)." The IADR/PER General Session & Exhibition is in London, England at the ExCeL London Convention Center from July 25-28, 2018.

Non-syndromic Dentinogenesis Imperfecta (DGI) is a disorder of tooth development that causes the teeth to be discolored, most often a blue-gray or yellow-brown color and translucent. Teeth are also weaker than normal, making them prone to rapid wear, breakage and loss. DGI is caused by mutations in the dentin sialophosphoprotein (DSPP) gene.

Previously, Liang and co-authors from the Texas A&M University generated a mouse model expressing a mouse equivalent of human mutant DSPP called "Dspp mutant." In this study, they investigated the roles of unfolded protein response (UPR) in mediating the pathogenic effects of mutant DSPP in the Dspp mutant mice.

In situ hybridization, quantitative PCR (qPCR) and immunohistochemistry were used to analyze Dspp expression and the three main branches of UPR, including inositol-requiring enzyme 1a (IRE1a), pancreatic ER eukaryotic translation initiation factor (eIF)-2a kinase. In situ hybridization and qPCR showed that the level of DSPP mRNA was dramatically reduced. Immunohistochemistry revealed that the DSP protein level was increased within the odontoblasts but decreased in the dentin matrix in the Dspp mutant mice. Further analyses demonstrated that all three UPR branches were activated in the Dspp mutant mice. These results suggest that chronic UPR might be associated with DGI caused by mutant DSPP.

This research was presented as part of the Mineralized Tissue 1 oral session that took place on Wednesday, July 25 from 3:15 p.m. - 4:45 p.m. at the ExCeL London Convention Center in London, England.

A catheter based procedure to close a type of 'hole in the heart' followed by antiplatelet drugs (e.g. aspirin) should be recommended for patients under 60 years old, who have also had a stroke, say a panel of experts in The BMJ today.

The procedure involves slowly moving a catheter (a long, thin, flexible tube) into the heart to close the hole. Most guidelines currently advise against the closure procedure and instead recommend taking life long anti-clotting drugs to prevent further strokes.

The panel's recommendation is based on new evidence that closure reduces the risk of future stroke more than drug treatment alone, even though catheter based closure itself carries a risk of complications.

For patients who need or want to avoid the procedure, the panel makes a weak recommendation for anticoagulation over antiplatelet therapy, based on the fact that patients value preventing strokes more than they are concerned about risk of bleeding.

Their advice is part of The BMJ's 'Rapid Recommendations' initiative - to produce rapid and trustworthy guidelines based on new evidence to help doctors make better decisions with their patients.

The recommendation only applies to patients that have a particular type of 'hole in the heart' called patent foramen ovale (PFO) - a hole in the wall that divides the top two chambers of the heart which has not closed naturally after birth.

Up to one in four people have a PFO and for most, it does not cause any problems. This guideline only recommends having the hole closed if the person has had a stroke, and there is no other obvious cause (known as "cryptogenic" stroke).

PFO closure, antiplatelets and anticoagulants are designed to reduce the risk of a second stroke.

The downside of the procedure is that 3.6% of patients will experience an adverse event, but these are usually associated with only short term effects, so may not be as important to patients as cutting their risk of stroke, they suggest.

Three large clinical trials published in 2017 suggested PFO closure might reduce the risk of stroke more than drug treatment alone.

So an international panel made up of doctors, heart and stroke specialists, and people with experience of PFO and cryptogenic stroke, reviewed the latest evidence to see if it might be strong enough to change clinical practice.

Using the GRADE approach (a system used to assess the quality of evidence). They compared three options; PFO closure and antiplatelets to antiplatelets alone; PFO closure compared to anticoagulants; anticoagulants compared to antiplatelets.

However, the panel stresses that doctors should discuss options with the patient, ideally as part of a shared decision making process.

Because PFO closure is associated with higher costs, implementation of this recommendation is likely to have an important cost impact for health funders in the short term, adds the panel. Over the long term, however, they say PFO closure "may reduce costs as a result of reduced stroke rates and reduction in associated costs."

They conclude that further trials are needed to address remaining uncertainties, and that new evidence must be assessed to judge to what extent it may alter the recommendation.

Panel member Bray Patrick-Lake, founding director of the not-for-profit PFO Research Foundation, says: "PFO patients suffering cryptogenic stroke have experienced confusion when navigating the treatment decision making process and reported receiving recommendations based on physician's preference rather than an unbiased assessment of available clinical trial data."

She adds: "The BMJ working group included patient representatives in the critical assessment of PFO research and thoughtfully produced evidence that can help patients understand what their outcomes are likely to be with available therapies so they can work with their physicians to make an informed treatment decision which incorporates their values and preferences."

Patient and carer partner, Joanie Scott, was also included in the working group. "My daughter and I myself both suffered cryptogenic strokes, hers occurred at the age of 18 years," she explains. "A stroke can be life-changing for an individual and their family and so can decisions about possible treatments. The outcome of this guideline should allow patients to discuss all available options with their medical team as well as possible longer term risks."

People living with HIV in rural East African communities that hosted annual community health campaigns initiated antiretroviral therapy (ART) earlier and had higher levels of overall survival and viral suppression than communities receiving standard HIV care, according to study data presented today at a press conference at the 22nd International AIDS Conference (AIDS 2018) in Amsterdam. Communities with annual multi-disease health fairs, which delivered patient-centered, streamlined HIV care, also had fewer cases of tuberculosis (TB), better control of hypertension and approximately 30 percent fewer new HIV cases during the last year of the study compared to the first year. The study, known as Sustainable East Africa Research in Community Health (SEARCH), is supported by the President's Emergency Plan for AIDS Relief (PEPFAR) and the National Institutes of Health (NIH).

SEARCH investigators randomly assigned 32 rural communities in Uganda and Kenya to receive either a multi-faceted intervention that integrated universal HIV testing and treatment into annual health screenings for multiple conditions or standard HIV care at HIV clinics, which consisted of baseline community-wide HIV testing and treatment with ART in accordance with national guidelines. In 2015, while the study was taking place, national guidelines in Uganda and Kenya shifted from a recommendation that individuals begin ART when CD4+ T cell levels--an indicator of immune system health--dipped below a certain threshold to a recommendation that all individuals living with HIV begin ART at the time of diagnosis.

In communities randomized to receive the intervention, the SEARCH team held annual community health campaigns, which began with a census and then engaged community members through two-week health fairs. Participants received health education; screenings for HIV hypertension, diabetes, and TB; and prompt care for any health conditions detected, including providing immediate ART for those who tested positive for HIV.

At the end of the three-year study, rates of deaths from any cause among people living with HIV in the intervention communities were 21 percent lower than in communities receiving standard care. People living with HIV in communities that received the intervention also experienced 59 percent fewer new TB cases compared with the standard care communities. TB, a bacterial infection that affects the lungs, is a leading cause of death among people living with HIV across the globe and is particularly endemic in East Africa.

Prior to the study, investigators found that nearly half of individuals living with HIV in the 32 rural communities in Uganda and Kenya were virally suppressed--consistent use of daily ART had reduced their HIV blood levels to undetectable by standard tests. HIV suppression both benefits the health of those living with HIV and prevents sexual transmission of the virus. At the end of the three-year study, 80 percent of people living with HIV in communities randomized to the intervention were virally suppressed compared to 68 percent in communities that received standard HIV care.

"We know that the ability of antiretroviral therapy to suppress HIV to undetectable levels is not only life-saving for individuals, but also prevents sexual transmission of the virus," said Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases, part of NIH. "Innovative implementation of antiretroviral therapy through community health initiatives may be one way to save lives and change the trajectories of even the most ingrained epidemics."

The SEARCH study outcomes exceeded international HIV testing and treatment goals set by UNAIDS, which call for 90 percent of people living with HIV to be diagnosed, 90 percent of those diagnosed to be on ART, and 90 percent of those in treatment to be virally suppressed by 2020. If met, the 90-90-90 targets would result in 73 percent of people living with HIV being virally suppressed. At the start of the study, the SEARCH team tested about 90 percent of the population in communities set to receive either the intervention or standard care. Through repeated annual testing in intervention communities, more than 95 percent of the population received an HIV test. Those diagnosed through community health campaigns were more likely to start ART, and viral suppression increased dramatically among individuals taking ART in all communities. In intervention communities, population-level viral suppression was 80 percent, surpassing the 90-90-90 target of 73 percent. Standard care communities approached the target with 68 percent of community members living with HIV virally suppressed. The reduction in HIV infections over the course of the study was similar between intervention and standard care communities.

"Our team hypothesized that partnering with communities to deliver patient-centered care for a range of common diseases, including but not exclusively HIV, would reduce new HIV infections and improve community health," said Diane Havlir, M.D., principal investigator of SEARCH, at the University of California, San Francisco.

Investigators found that annual community health campaigns and streamlined care delivery also had a positive impact on the burden of diseases other than HIV. Patient-centered health care in the intervention communities led to better control of hypertension and diabetes. Investigators observed 16 percent fewer cases of uncontrolled hypertension in intervention communities compared with standard care communities, where uncontrolled hypertension was common.

While men and youth have participated at lower rates in HIV testing and treatment programs in Sub-Saharan Africa, the SEARCH model resulted in 74 percent of men living with HIV in intervention communities achieving viral suppression by the end of the study. However, youth between the ages of 15 and 24 living with HIV were nearly 20 percent less likely to be virally suppressed compared with community members over age 24. Investigators also found that about two thirds of all study participants who acquired HIV during the study period were women, but that in Western Uganda, a higher proportion of people who acquired HIV during the study were young, single men of low social and economic status.

These findings comprise the results of the first phase of SEARCH; Dr. Havlir and her colleagues continue to collect data for the second phase of the study, known as SEARCH Phase II, which is applying machine-learning to help develop strategies for implementing pre-exposure prophylaxis, or PrEP , in the same communities. Phase II will investigate whether targeted roll-out of PrEP can reduce new HIV infections.

SEARCH is led by Dr. Havlir and by co-principal investigators Moses Kamya, M.B.Ch.B., Ph.D., at Makerere University in Uganda, and Maya Petersen, M.D., Ph.D., at the University of California, Berkeley. More information about the study Sustainable East Africa Research in Community Health (SEARCH) is available on ClinicalTrials.gov under identifier NCT01864603.

Reference: D Havlir, et al. SEARCH community cluster randomized study of HIV "test and treat" using multi-disease approach and streamlined care in rural Uganda and Kenya. 22nd International AIDS Conference, Amsterdam (2018).

NIAID conducts and supports research--at NIH, throughout the United States, and worldwide--to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

About the U.S. President's Emergency Plan for AIDS Relief (PEPFAR): PEPFAR is the U.S. government's response to the global HIV/AIDS epidemic and represents the largest commitment by any nation to address a single disease in history. Through the compassion and generosity of the American people, PEPFAR has saved and improved millions of lives, accelerating progress toward controlling and ultimately ending the AIDS epidemic as a public health threat. For more information, please visit http://www.pepfar.gov, and follow PEPFAR on Twitter, Facebook, and Instagram.