Monday, January 11, 2021

Core design strategy for fire-resistant batteries

Development of a strategy for reducing 'electrolyte-electrode interface resistance,' which limits the commercialization of all-solid-state batteries; new material design strategy to increase performance by improving the cathode material

NATIONAL RESEARCH COUNCIL OF SCIENCE & TECHNOLOGY

Research News

IMAGE: SCHEME OF EXPOSED CRYSTAL FACETS OF CUBIC STRUCTURES WITH (100), (110), AND (111) ORIENTATIONS. view more
CREDIT: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY(KIST)

All-solid-state batteries are the next-generation batteries that can simultaneously improve the stability and capacity of existing lithium batteries. The use of non-flammable solid cathodes and electrolytes in such batteries considerably reduces the risk of exploding or catching fire under high temperatures or external impact and facilitates high energy density, which is twice that of lithium batteries. All-solid-state batteries are expected to become a game changer in the electric vehicle and energy storage device markets. Despite these advantages, the low ionic conductivity of solid electrolytes combined with their high interfacial resistance and rapid deterioration reduce battery performance and life, thus limiting their commercialization.

The Korea Institute of Science and Technology (KIST) is proud to announce that the research team of Dr. Sang-baek Park at the Center for Energy Materials Research, in collaboration with the research team of Professor Hyun-jung Shin of Sungkyunkwan University, has developed a breakthrough material design strategy that can overcome the problem of high interfacial resistance between the solid electrolyte and the cathode, which is an obstacle to the commercialization of all-solid-state batteries.

Unique physical phenomena occur at the interface where two different substances meet. Unlike the atoms inside the bulk of a substance, which hold hands with other atoms around themselves and form stable bonds, the atoms at the interface, having no neighboring atom of the same substance on one side, are likely to form a different atomic arrangement.

In all-solid-state batteries having a solid electrode-solid electrolyte interface, a phenomenon occurs that disturbs the atomic arrangement and limits charge transfer, thereby increasing resistance and accelerating deterioration. Methods of coating an appropriate material on the surface of the cathode and the electrolyte or inserting an intermediate layer are currently being studied to solve the above-mentioned problem. However, this further increases the costs and lowers the overall activity and energy density of the batteries.

In order to solve these problems, the KIST-Sungkyunkwan University joint research team first systematically identified the crystal structure of the material that directly affects the solid interface. Using epitaxial film technology (a semiconductor manufacturing technology) to grow a thin film along the direction in which the crystals of the substrate were formed, cathode films having different exposed crystal planes were obtained under varying conditions. The effect of the exposed crystal plane on the interface between the solid electrolyte and the cathode material was analyzed in detail, disregarding other factors such as particle size and contact area that could affect the result.

The results indicated that the leakage of the transition metal from the cathode material into the electrolyte was suppressed by the closely-packed structure of the exposed crystal plane, which improved the stability of the all-solid-state battery. In addition, when the interface of the crystals was arranged in parallel with the direction of movement of the electrons, the movement of ions and electrons along the crystals was not hindered, resulting in reduced resistance and improved output.

"This means that improving the cathode material itself by increasing the density of the crystal plane and adjusting the direction of the interface between the crystals can ensure high performance and stability," said Dr. Sang-baek Park, KIST. "We plan to accelerate the development of all-solid-state battery materials by overcoming the instability of the solid electrolyte and solid cathode interface and imparting improved ion-charge exchange characteristics through this study, which has investigated the mechanism of all-solid-state battery degradation."

CAPTION

Photo and scheme of an ASSLB configuration for an LNMO thin film cathode.

CREDIT

Korea Institute of Science and Technology(KIST)

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This research was carried out as a major project of KIST with the support of the Ministry of Science and ICT (MSIT). The results of this study were published in the latest issue of "Nano Energy" (IF: 16.602, the highest rating of 4.299% by JCR), an international journal in the field of nanotechnology.

Acta Pharmaceutica Sinica B volume 10, issue 12 publishes

COMPUSCRIPT LTD

Research News

IMAGE: ACTA PHARMACEUTICA SINICA B VOLUME 10, ISSUE 12 PUBLISHES view more
CREDIT: ACTA PHARMACEUTICA SINICA B

The Journal of the Institute of Materia Medica, the Chinese Academy of Medical Sciences and the Chinese Pharmaceutical Association, Acta Pharmaceutica Sinica B (APSB) is a monthly journal, in English, which publishes significant original research articles, rapid communications and high quality reviews of recent advances in all areas of pharmaceutical sciences -- including pharmacology, pharmaceutics, medicinal chemistry, natural products, pharmacognosy, pharmaceutical analysis and pharmacokinetics.

Chloroplasts on the move

How different plants can share their genetic material with each other

MAX-PLANCK-GESELLSCHAFT

Research News

IMAGE: A NATURAL STEM GRAFT BETWEEN A BEECH (FRONT) AND A MAPLE (BACK) IN A FOREST NEAR MONROE, NEW JERSEY (LEFT PICTURE), AND AN SIMILAR STEM GRAFT BETWEEN TWO TOBACCO PLANTS... view more
CREDIT: MPI-MP, NATURE 511

The genetic material of plants, animals and humans is well protected in the nucleus of each cell and stores all the information that forms an organism. For example, information about the size or color of flowers, hair or fur is predefined here. In addition, cells contain small organelles that contain their own genetic material. These include chloroplasts in plants, which play a key role in photosynthesis, and mitochondria, which are found in all living organisms and represent the power plants of every cell. But is the genetic material actually permanently stored within one cell? No! As so far known, the genetic material can migrate from cell to cell and thus even be exchanged between different organisms. Researchers at the Max Planck Institute of Molecular Plant Physiology (MPI-MP) in Potsdam have now been able to use new experimental approaches to show for the first time how the genetic material travels. They published their results in the journal Science Advances.

After a short time, the two partners grow together at the graft junction, resulting in a physiological connection between the two plants. "We were able to observe that genome transfer from cell to cell occurs in both directions with high frequency at this site", explains Dr. Alexander Hertle, first author of the study.

Using a new experimental setup, the researchers were able to observe structural changes in the cell walls in the wound tissue of the graft site. "The cell walls formed protrusions, creating junctions between the two partners. The size of those created pores allows the migration of an entire plastid. Therefore, the genome does not migrate freely, but encapsulated from cell to cell," Hertle continues. However, to actually make this possible, the plastids have to shrink and become mobile. These rod-shaped plastids are equal to an amoeba and grow back to normal size after transfer into the target tissue.

The researchers have thus uncovered a new pathway for intercellular exchange of very large cell structures, which may also be used by parasitic plants, such as mistletoe, to carry out gene exchange with their host. In addition, it now needs to be clarified whether mitochondria and the nuclear genome also use similar transfer mechanisms.

The transfer of genetic material occurs quite frequently in plants. This can either result in a new combination of the genetic material, or alternatively the recipient cell can establish both genetic variants in parallel. This union of two different genomes, called allopolyploidization, is very interesting in evolutionary terms, as it leads to the formation of new plant species and is widespread in many plant groups. Many important crops, such as bread and durum wheat, oats, cotton, canola, coffee, and tobacco have such combined genomes from at least two crossed species.

In order to understand the mechanisms of genome transfer from cell to cell, the researchers led by Ralph Bock at MPI-MP conducted experiments with tobacco plants using grafting, which is commonly used in agriculture. Here, two different tobacco plants were grafted onto each other and the cells of the junction were observed microscopically in real time. To differentiate between the genome of nucleus and plastids, fluorescent reporter proteins were integrated and expressed from both genomes and the researchers used a trick using a specialization of the chloroplasts. In the plastids, a gene is integrated by transformation that encodes a chloroplast-specific fluorescence protein, which is produced exclusively in plastids and cannot leave them. This creates an absolutely specific and stable label for the plastids.

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Original publication

Alexander P. Hertle, Benedikt Haberl, Ralph Bock
Horizontal genome transfer by cell-to-cell travel of whole organelles
Science Advances
01 Jan 2021: Vol. 7, no. 1, eabd8215

Breakthrough on diarrhea virus opens up for new vaccines

UMEA UNIVERSITY

Research News

IMAGE: ILLUSTRATION FROM CRYO-ELECTRON MICROSCOPE IMAGE OF THE ENTERIC ADENOVIRUS HADV-F41. view more
CREDIT: IMAGE: KARIM RAFIE

"The findings provide an increased understanding of how the virus gets through the stomach and intestinal system. Continued research can provide answers to whether this property can also be used to create vaccines that ride 'free rides' and thus be given in edible form instead of as syringes," says Lars-Anders Carlson, researcher at Umeå University.

The virus that the researchers have studied is a so-called enteric adenovirus. It has recently been clarified that enteric adenoviruses are one of the most important factors behind diarrhea among infants, and they are estimated to kill more than 50,000 children under the age of five each year, mainly in developing countries.

Most adenoviruses are respiratory, that is, they cause respiratory disease, while the lesser-known enteric variants of adenovirus instead cause gastrointestinal disease. The enteric adenoviruses therefore need to be equipped to pass through the acidic environment of the stomach without being broken down, so that they can then infect the intestines.

With the help of the advanced cryo-electron microscope available in Umeå, the researchers have now managed to take such detailed images of an enteric adenovirus that it has been possible to put a three-dimensional puzzle that shows what the virus looks like right down to the atomic level. The virus is one of the most complex biological structures studied at this level. The shell that protects the virus' genome when it is spread between humans consists of two thousand protein molecules with a total of six million atoms.

The researchers were able to see that the enteric adenovirus manages to keep its structure basically unchanged at the low pH value found in the stomach. They could also see other differences compared to respiratory adenoviruses in how a particular protein is altered in the shell of the virus as well as new clues to how the virus packs its genome inside the shell. All in all, it provides an increased understanding of how the virus manages to move on to create disease and death.

"The hope is that you will be able to turn the ability that this unpleasant virus has to get to something that can instead be used as a tool to fight disease, perhaps even COVID-19. This is a step in the right direction, but it is still a long way off," says Lars-Anders Carlson.

Several of the new vaccines being tested against COVID-19 are based on genetically modified adenovirus. Today, these adenovirus-based vaccines must be injected to work in the body. If a vaccine could instead be based on enteric adenovirus, the vaccine might be given in edible form. This would, of course, facilitate large-scale vaccination.

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The virus that the researchers have studied is called HAdV-F41. The study is published in the scientific journal Science Advances. It is a collaboration between Lars-Anders Carlson's and Niklas Arnberg's research groups at Umeå University.

Bacterium produces pharmaceutical all-purpose weapon

Study should significantly facilitate research into the promising substance

UNIVERSITY OF BONN

Research News

IMAGE: FROM LEFT: DR. RENÉ RICHARZ WITH AN AGAR PLATE CONTAINING THE BACTERIUM, CORNELIA HERMES WITH AN EXTRACT OBTAINED FROM THE BACTERIUM, AND WORKING GROUP LEADER DR. MAX CRÜSEMANN. A CORALBERRY... view more
CREDIT: © AG CRÜSEMANN / UNIVERSITY OF BONN

For some years, an active substance from the leaves of an ornamental plant has been regarded as a possible forerunner of a new group of potent drugs. So far, however, it has been very laborious to manufacture it in large quantities. That could now change: Researchers at the University of Bonn (Germany) have identified a bacterium that produces the substance and can also be easily cultivated in the laboratory. The results are published in the journal Nature Communications.

The coralberry currently once again adorns many living rooms: In winter it bears bright red fruits, which make it a popular ornamental plant at this time of year. For pharmacists, however, it is interesting for a different reason: It contains an active substance that has emerged in recent years as a beacon of hope against asthma and certain types of cancer.

Unfortunately, obtaining the substance with the cryptic name FR900359 (abbreviated: FR) in larger quantities is rather laborious. Cultivating the plants in greenhouses takes many weeks; moreover, the yield can vary enormously depending on the specimen. Incidentally, they do not produce the active ingredient themselves, but have bacteria in their leaves that do it for them. "However, these only grow in the coralberry and cannot be cultivated in the laboratory," explains Dr. Max Crüsemann of the Institute of Pharmaceutical Biology at the University of Bonn.

Complex assembly line

Manufacturing FR is a complex undertaking. The bacteria have a special assembly line for this purpose, in which a number of enzymes work hand in hand. The bacterial genetic makeup specifies how this assembly line must be set up. "We have now searched huge databases for other microorganisms that also have these genes for FR synthesis," Crüsemann explains. "In the process, we came across another bacterium. Unlike its coralberry relative, it does not grow in plants, but in soil and is easily propagated in culture media."

This finding should greatly facilitate the production of FR in the future. However, it also allows more detailed insights into how the active substance works. "We have known for several years that FR inhibits an important group of signaling molecules in cells, the Gq proteins," explains Cornelia Hermes of the Institute of Pharmaceutical Biology. "That makes FR extremely effective: To date, no other compound is known to inhibit Gq proteins with similar potency."

Hermes is pursuing her doctoral studies in the group of Max Crüsemann and Prof. Gabriele König and, together with her colleague Dr. René Richarz, was responsible for a large part of the study now published. One of the questions the researchers explored was, why FR is such a good inhibitor. The molecule consists of two parts, the actual core and a side chain that is attached to it like an arm. Both are produced separately and then linked together. "The side chain is essential for the function of FR," Crüsemann explains. "When it is absent or even slightly modified, the inhibitory effect on Gq proteins decreases significantly."

Central control station in the cell

The function of Gq proteins in the cell is similar to that of the emergency call center of a city: They are the place where various signals from outside the cell converge. This activates them and then in turn certain metabolic processes are switched on or off. Instead of inhibiting numerous signaling pathways, it is therefore sufficient to inhibit the Gq protein in order to achieve a therapeutic effect. This means that FR is extremely effective, but also, if it were administered to the whole body, very toxic. "The goal is therefore to administer FR only to cells with pathologically altered behavior," Crüsemann explains. Bacterial genes can be easily and specifically modified nowadays. "In this way, we can in principle generate FR variants with specific properties, such as those that are transported precisely to certain cells in the body and only do their work there," says the pharmaceutical biologist.

The history of the FR molecule is therefore likely to be extended by another chapter as a result of the study: The active substance was discovered more than 30 years ago by Japanese researchers. In 2015, its biological mode of action was described by the research groups led by Professors Gabriele M. König and Evi Kostenis at the Institute of Pharmaceutical Biology. This work now forms the basis for a research group of the German Research Foundation (DFG). Today, more and more research groups around the world are exploring the potential of the molecule. With the newly discovered bacterium, they now have a new tool at hand.

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Publication: Cornelia Hermes, René Richarz, Daniel A. Wirtz, Julian Patt, Wiebke Hanke, Stefan Kehraus, Jan Hendrik Voß, Jim Küppers, Tsubasa Ohbayashi, Vigneshwaran Namasivayam, Judith Alenfelder, Asuka Inoue, Peter Mergaert, Michael Gütschow, Christa E. Müller, Evi Kostenis, Gabriele M. König & Max Crüsemann:
Thioesterase-mediated side chain transesteri ?cation generates potent Gq signaling inhibitor FR900359; Nature Communications; DOI: 10.1038/s41467-020-20418-3

Unravelling the mystery that makes viruses infectious

UNIVERSITY OF YORK

Research News

IMAGE: VISUALISATION OF AN ENTEROVIRUS-E VIRION ASSEMBLING view more
CREDIT: UNIVERSITY OF LEEDS

Researchers have for the first time identified the way viruses like the poliovirus and the common cold virus 'package up' their genetic code, allowing them to infect cells.

The findings, published in the journal PLOS Pathogens by a team from the Universities of York and Leeds, open up the possibility that drugs or anti-viral agents can be developed that would stop such infections.

Once a cell is infected, a virus needs to spread its genetic material to other cells. This is a complex process involving the creation of what are known as virions - newly -formed infectious copies of the virus. Each virion is a protein shell containing a complete copy of the virus's genetic code. The virions can then infect other cells and cause disease.

What has been a mystery until now is a detailed understanding of the way the virus assembles these daughter virions.

Professor Reidun Twarock, from the University of York's Department of Mathematics, said: "Understanding in detail how this process works, and the fact that it appears conserved in an entire family of viral pathogens, will enable the pharmaceutical industry to develop anti-viral agents that can block these key interactions and prevent disease."

The study focuses on a harmless bovine virus that is non-infectious in people, Enterovirus-E, which is the universally adopted surrogate for the poliovirus. The poliovirus is a dangerous virus that infects people, causing polio and is the target of a virus eradication initiative by the World Health Organization.

The enterovirus group also includes the human rhinovirus, which causes the common cold.

Professor Peter Stockley, former Director of the Astbury Centre for Structural Molecular Biology at Leeds, said: "This study is extremely important because of the way it shifts our thinking about how we can control some viral diseases. If we can disrupt the mechanism of virion formation, then there is the potential to stop an infection in its tracks.

"Our analysis suggests that the molecular features that control the process of virion formation are genetically conserved, meaning they do not mutate easily - reducing the risk that the virus could change and make any new drugs ineffective."

The study details the role of what are called RNA packaging signals, short regions of the RNA molecule which together with proteins from the virus's casing ensure accurate and efficient formation of an infectious virion.

Using a combination of molecular and mathematical biology, the researchers were able to identify possible sites on the RNA molecule that could act as packaging signals. Using advanced electron microscopes, scientists were able to directly visualise this process - the first time that has been possible with any virus of this type.

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The work was funded by the Wellcome Trust, the Engineering and Physical Sciences Research Council (EPSRC) and the British Medical Foundation for Medical Researc

TU Graz identifies bacterium that protects rice plants against diseases

Bacterium inside the seed can lead to complete resistance to a particular pathogen and is naturally transmitted from one plant generation to another

GRAZ UNIVERSITY OF TECHNOLOGY

Research News

IMAGE: RISING GLOBAL WARMING IS PROBLEMATIC FOR THE WATER-INTENSIVE CULTIVATION OF RICE, THE STAPLE FOOD FOR ABOUT HALF THE WORLD'S POPULATION. view more
CREDIT: MENGCEN WANG

Rice is the staple food of about half the world's population. The cultivation of the rice plant is very water-intensive and, according to the German aid organization Welthungerhilfe, around 15 per cent of rice is grown in areas with a high risk of drought. Global warming is therefore becoming increasingly problematic for rice cultivation, leading more and more often to small harvests and hunger crises. Crop failures caused by plant pathogens further aggravate the situation. Here, conventional agriculture is trying to counteract this with pesticides, which are mostly used as a precautionary measure in rice cultivation. The breeding of resistant plants is the only alternative to these environmentally harmful agents - and currently only moderately successful. If the plants are resistant to one pathogen thanks to their breeding, they are usually more susceptible to other pathogens or are less robust under adverse environmental conditions.

Bacterium confers pathogen resistance

For this reason, an international research group which includes the Institute of Environmental Biotechnology at Graz University of Technology has been studying the microbiome of rice plant seeds for some time now in order to establish correlations between plant health and the occurrence of certain microorganisms. The group has now achieved a major breakthrough. They identified a bacterium inside the seed that can lead to complete resistance to a particular pathogen and is naturally transmitted from one plant generation to another. The findings published in the scientific journal Nature Plants provide a completely new basis for designing biological plant protection products and additionally reducing harmful biotoxins produced by plant pathogens.

The microbiome of rice

In conventional rice cultivation in the Chinese province of Zhejiang, it was observed that one genotype of rice plants (cultivar Zhongzao 39) sometimes develops resistance to the plant pathogen Burkholderia plantarii. This pathogen leads to crop failures and also produces a biotoxin that can cause organ damage and tumours in persistently exposed humans and animals. "Up to now, the sporadic resistance of rice plants to this pathogen could not be explained," says Tomislav Cernava from the Institute of Environmental Biotechnology at Graz University of Technology. Together with the luminary of microbiome research and Institute head, Gabriele Berg, and his institute colleague Peter Kusstatscher, Cernava has been investigating the microbiome of rice seeds from different cultivation regions in detail in the context of a collaboration with Zhejiang University (Hangzhou) and Nanjing Agricultural University in China as well as with the Japanese Hokkaido University in Sapporo.

Bacterial composition as a decisive factor

The scientists found that the resistant plants have a different bacterial composition inside the seeds than the disease-susceptible plants. The bacterial genus Sphingomonas in particular was found significantly more often in resistant seeds. The researchers therefore isolated bacteria of this genus from the seeds and identified the bacterium Sphingomonas melonis as the responsible agent for disease resistance. This bacterium produces an organic acid (anthranilic acid), which inhibits the pathogen and thereby renders it harmless. "This also works when the isolated Sphingomonas melonis is applied to non-resistant rice plants. This automatically makes them resistant to the plant pathogen Burkholderia plantarii," explains Tomislav Cernava. In addition, the bacterium establishes itself in certain rice genotypes and is then passed on naturally from one plant generation to the next. "The potential of this finding is enormous. In the future, we will be able to use this strategy to reduce pesticides in agriculture and at the same time achieve good crop yields," emphasizes Cernava.

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This research is anchored in the Field of Expertise "Human & Biotechnology", one of five strategic foci of Graz University of Technology.

Details of the original publication:

Bacterial seed endophyte shapes disease resistance in rice.
Haruna Matsumoto, Xiaoyan Fan, Yue Wang, Peter Kusstatscher, Jie Duan, Sanling Wu, Sunlu Chen, Kun Qiao, Yiling Wang, Bin Ma, Guonian Zhu, Yasuyuki Hashidoko, Gabriele Berg, Tomislav Cernava, Mengcen Wang. Nature Plants, January 2021. DOI: 10.1038/s41477-020-00826-5
https://www.nature.com/articles/s41477-020-00826-5

Articles on previous results of the Institute's microbiome research:

Minimizing post-harvest food losses
https://www.tugraz.at/en/tu-graz/services/news-stories/tu-graz-news/singleview/article/lebensmittelverluste-nach-der-ernte-minimieren0/

The microbiome: Our planet's tiny engine
https://www.tugraz.at/en/tu-graz/services/news-stories/planet-research/singleview/article/mikrobiom-der-winzige-motor-unseres-planeten0/

Germ-free hatching eggs: An alternative to the usual formaldehyde
https://www.tugraz.at/en/tu-graz/services/news-stories/tu-graz-news/singleview/article/germ-free-hatching-eggs-an-alternative-to-formaldehyde-application/

Excessive hygiene promotes resistance to antibiotics
https://www.tugraz.at/en/tu-graz/services/news-stories/planet-research/singleview/article/uebertriebene-hygiene-foerdert-antibiotikaresistenz0/

The origin of pandemics in the microbiome
https://www.tugraz.at/en/tu-graz/services/news-stories/tu-graz-news/singleview/article/den-ursprung-von-pandemien-im-mikrobiom0/

Laypeople have difficulty estimating severity of blood loss

LINKÖPING UNIVERSITY

Research News

When an accident occurs, the reactions of bystanders are important. Researchers have studied whether laypeople realise the severity of the situation when someone in their proximity begins to bleed, and whether they can estimate how much the person is bleeding. The results show a discrepancy related to the victim's gender: for a woman losing blood, both blood loss and life-threatening injuries were underestimated. The study has been published in the scientific journal PLoS One.

Researchers from Linköping University and Old Dominion University in the United States wanted to study the ability of laypeople to visually assess blood loss, and what influences them when judging the severity of an injury.

"Laypeople's knowledge of haemorrhage is very important because many deaths occur outside the hospital. Our study showed, among other things, that haemorrhage in women is perceived as less serious, which can have profound consequences", says Erik Prytz at Linköping University and the Centre for Teaching & Research in Disaster Medicine and Traumatology.

Previous research has shown that people have difficulty estimating how much an injured person is bleeding. Those with medical training often overestimate small volumes of blood, and underestimate larger volumes. Also, previous studies point to differences in how laypeople treat victims, depending on the victim's gender. For this reason, the researchers wanted to investigate the role of victim gender in the laypeople's ability to estimate blood loss - a factor that has never been studied.

The researchers had 125 study participants view 78 video clips of female or male actors who appear to be bleeding from the inside of the thigh. The participants got to see the simulated injuries from various angles, and the victims bled at different rates and with different volumes. Based on this, the participants were to assess whether the blood loss was not dangerous, dangerous or life-threatening. Bleeding is normally considered life-threatening when 1.5 litres of blood is lost.

The result supported previous research; laypeople also overestimated small volumes of blood and underestimated larger volumes of blood. However the study, unlike previous studies, also showed at which volumes the test participants made incorrect estimates. Blood losses of up to 2 decilitres were perceived as larger than they actually were, while volumes of more than 4 decilitres were underestimated. Blood volumes of 3 decilitres, however, were estimated correctly.

The study also showed that the participants underestimated blood loss among female victims more than for male victims, regardless of volume. And for female victims, the loss was classified as less life-threatening.

In Sweden, and especially in the United States, laypeople are trained to intervene in the event of an accident. In the United States, this training has become more common as a response to the many school shootings; more people must know how to stop a haemorrhage. What the researchers learn from the study, they will incorporate in the design of this training.

"If gender affects how a layperson perceives an injury, we must include this in the calculation when planning the training" says Erik Prytz.

Erik Prytz stresses that further study is required into how gender affects the response given to haemorrhaging victims.

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The other authors of the study are Marc Friberg, Mattias Lantz Cronqvist and Carl-Oscar Jonson from Linköping University, and Rachel Phillips from Old Dominion University in the United States.

The study received funding from the Swedish Civil Contingencies Agency

Inspired by kombucha tea, engineers create "living materials"

A symbiotic culture of specialized yeast and bacteria can generate tough materials able to perform a variety of functions.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

CAMBRIDGE, MA -- Engineers at MIT and Imperial College London have developed a new way to generate tough, functional materials using a mixture of bacteria and yeast similar to the "kombucha mother" used to ferment tea.

Using this mixture, also called a SCOBY (symbiotic culture of bacteria and yeast), the researchers were able to produce cellulose embedded with enzymes that can perform a variety of functions, such as sensing environmental pollutants. They also showed that they could incorporate yeast directly into the material, creating "living materials" that could be used to purify water or to make "smart" packaging materials that can detect damage.

"We foresee a future where diverse materials could be grown at home or in local production facilities, using biology rather than resource-intensive centralized manufacturing," says Timothy Lu, an MIT associate professor of electrical engineering and computer science and of biological engineering.

Lu and Tom Ellis, a professor of bioengineering at Imperial College London, are the senior authors of the paper, which appears today in Nature Materials. The paper's lead authors are MIT graduate student Tzu-Chieh Tang and Cambridge University postdoc Charlie Gilbert.

Division of labor

Several years ago, Lu's lab developed a way to use E. coli to generate biofilms embedded with materials such as gold nanowires. However, those films are very small and thin, making them difficult to use in most large-scale applications. In the new study, the researchers set out to find a way to use microbes to generate larger quantities of more substantial materials.

They thought of creating a microbe population similar to a kombucha mother, which is a mixture of certain types of bacteria and yeast. These fermentation factories, which usually contain one species of bacteria and one or more yeast species, produce ethanol, cellulose, and acetic acid, which gives kombucha tea its distinctive flavor.

Most of the wild yeast strains used for fermentation are difficult to genetically modify, so the researchers replaced them with a strain of laboratory yeast called Saccharomyces cerevisiae. They combined the yeast with a type of bacteria called Komagataeibacter rhaeticus, which their collaborators at Imperial College London had previously isolated from a kombucha mother. This species can produce large quantities of cellulose.

Because the researchers used a laboratory strain of yeast, they could engineer the cells to do any of the things that lab yeast can do -- for example, producing enzymes that glow in the dark, or sensing pollutants in the environment. The yeast can also be programmed so that they can break down pollutants after detecting them.

Meanwhile, the bacteria in the culture produce large-scale quantities of tough cellulose to serve as a scaffold. The researchers designed their system so that they can control whether the yeast themselves, or just the enzymes that they produce, are incorporated into the cellulose structure. It takes only a few days to grow the material, and if left long enough, it can thicken to occupy a space as large as a bathtub.

"We think this is a good system that is very cheap and very easy to make in very large quantities," Tang says. "It's at least a thousand times more material than the E.coli system."

Just add tea

To demonstrate the potential of their microbe culture, which they call "Syn-SCOBY," the researchers created a material incorporating yeast that senses estradiol, which is sometimes found as an environmental pollutant. In another version, they used a strain of yeast that produces a glowing protein called luciferase when exposed to blue light. These yeasts could be swapped out for other strains that detect other pollutants, metals, or pathogens.

The culture can be grown in normal yeast culture medium, which the researchers used for most of their studies, but they have also shown that it can grow in tea with sugar. The researchers envision that the cultures could be customized for people to use at home for growing water filters or other useful materials.

"Pretty much everyone can do this in their kitchen or at home," Tang says. "You don't have to be an expert. You just need sugar, you need tea to provide the nutrients, and you need a piece of Syn-SCOBY mother."

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The research was funded, in part, by the U.S. Army Research Office, the MIT Institute for Soldier Nanotechnologies, and the MIT-MISTI MIT-Imperial College London Seed Fund. Tang was supported by the MIT J-WAFS Fellowship.

LA REVUE GAUCHE - Left Comment

Monday, January 11, 2021

Core design strategy for fire-resistant batteries

CAPTION

CREDIT

Acta Pharmaceutica Sinica B volume 10, issue 12 publishes

Chloroplasts on the move

Breakthrough on diarrhea virus opens up for new vaccines

Inspired by kombucha tea, engineers create "living materials"

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