Monthly Archives: May 2020
Tiny fibrils extracted from plants have been getting a lot of attention for their strength. These nanomaterials have shown great promise in outperforming plastics, and even replacing them. A team led by Aalto University (Finland) has now shown another remarkable property of nanocelluloses: their strong binding properties to form new materials with any particle.
Cohesion, the ability to keep things together, from the scale of nanoparticles to building sites is inherent to these nanofibrils, which can act as mortar to a nearly infinite type of particles as described in the study. The ability of nanocelluloses to bring together particles into cohesive materials is at the root of the study that links decades of research into nanoscience towards manufacturing.
In a paper just published in Science Advances, the authors demonstrate how nanocellulose can organize itself in a multitude of different ways by assembling around particles to form highly robust materials.
Nanocellulose can also form structures known from pulp technology with the particles
‘This means that nanocelluloses induce high cohesion in particulate materials in a constant and controlled manner for all particles types. Because of such strong binding properties, such materials can now be built with predictable properties and therefore easily engineered’, explained the main author, Dr Bruno Mattos, The moment anytime a material is created from particles, one has to first come up with a way to generate cohesion, which has been very particle dependent, ‘Using nanocellulose, we can overcome any particle dependency’, Mattos adds.
The universal potential of using nanocellulose as a binding component rises from their ability to form networks at the nanoscale, that adapt according to the given particles. Nanocelluloses bind micrometric particles, forming sheet-like structures, much like the paper-mâché as done in schools. Nanocellulose can also form tiny fishnets to entrap smaller particles, such as nanoparticles. Using nanocellulose, materials built from particles can be formed into any shape using an extremely easy and spontaneous process that only needs water. Importantly, the study describes how these nanofibers form network following precise scaling laws that facilitates their implementation. This development is especially timely in the era of the nanotechnologies, where combining nanoparticles in larger structures is essential. As Dr Blaise Tardy points out, ‘New property limits and new functionalities are regularly showcased at the nanoscale, but implementation in the real world is rare. Unraveling the physics associated with the scaling of the cohesion of nanofibers is therefore a very exciting first step towards connecting laboratory findings with current manufacturing practices’. For any success, strong binding among the particles is needed, an opportunity herein offered by nanocellulose.
Tiny droplets of saliva that are sprayed into the air when people speak may be sufficient to spread coronavirus, according to US government scientists who say the finding could help control the outbreak. Researchers at the US National Institutes of Health (NIH) in Maryland found that talking released thousands of fine droplets into the air that could pose a risk to others if the speaker were infected with the virus.
The scientists used laser imaging and high-speed videography to show how thousands of droplets that are too small to see with the naked eye are emitted in normal speech, even in short phrases such as “stay healthy”. The work is preliminary and has not been peer-reviewed or published, but in a report the scientists claim the findings may have “vital implications” for containing the pandemic.
“If speaking and oral fluid viral load proves to be a major mechanism of Sars-CoV-2 [the official name of the virus] transmission, wearing any kind of cloth mouth cover in public by every person, as well as strict adherence to social distancing and handwashing, could significantly decrease the transmission rate and thereby contain the pandemic until a vaccine becomes available,” the researchers write.
The results will fuel the ongoing debate over whether or not healthy people should wear face masks in public. Recent advice from the US Centers for Disease Control and Prevention called for members of the public to wear cloth face covers when they visit places where it is hard to maintain physical distancing, such as pharmacies and grocery stores.
But the US advice contrasts with that from the World Health Organization, which reviewed its stance on face masks last week. In updated guidance published on Monday it restated that there was no evidence wearing a mask in public prevented people from picking up respiratory infections such as Covid-19.
Abbott Laboratories’ antibody test for the new coronavirus is highly likely to correctly determine whether people have ever been infected with the fast-spreading virus, the company said, citing a U.S. study.
Researchers at the University of Washington School of Medicine report in the Journal of Clinical Microbiology that Abbott‘s test had a specificity of 99.9% and a sensitivity of 100%, suggesting very few false positives and no false negatives.
Antibody tests can tell whether a person has ever been infected and are considered crucial in efforts to get Americans back to work safely as the presence of antibodies to the virus indicates possible immunity to future infection.
Abbott’s test was launched last month under the U.S. Food and Drug Administration’s relaxed rules for some coronavirus tests, allowing their distribution before regulatory clearance. It has since received emergency use authorization from the FDA.
Abbott has already shipped more than 10 million antibody tests to hospitals and labs.
Swedish telecom equipment maker Ericsson said on Monday it will lift its forecast for 5G subscriptions globally to around 2.8 billion by 2025 from 2.6 billion seen previously as a consequence of the novel coronavirus pandemic. The telecoms sector has been among few industries to experience a surge in demand despite the economic uncertainty linked to the pandemic, a result of more people work remotely from home to avoid contagion and adhere to lockdown rules.
Patrik Cerwall, head of strategic marketing at Ericsson, said that the 2020 forecast would also be raised, but gave no further detail.
“Long-term we look at 2025, 2.8 billion 5G subscriptions”, he told a web seminar held by the company. Ericsson is competing against Nokia and China’s Huawei Technologies to sign up telecoms customers looking to upgrade their networks to 5G.
The firm, due to publish its biannual Mobility Report next month, said in November 5G uptake was expected to be significantly faster than that of LTE, and that 5G subscriptions would account for 29 percent of all mobile subscriptions in 2025.
The new generation of mobile phone technology will bring faster data speeds and better accommodate a greater variety of connected devices.
The Food and Drug Administration (FDA) has authorized a COVID-19 test that uses the gene-editing technology CRISPR and returns results in around one hour.
Though the test was only authorized for emergency use, this marks the first time the FDA has allowed a CRISPR-based tool to be used in patients. CRISPR technology can quickly find and link onto any genetic sequence in a specimen. The new test, created by the biotech company Sherlock Biosciences, uses one molecule to search for the virus gene in a patient sample. Then, if the molecule finds the gene, it releases a signal that the system can detect.
The standard method for COVID-19 testing, called PCR, also looks for tiny bits of the virus gene. However, that method is slow and takes specialized equipment to run. The recently approved Abbott test gives results in minutes but can only run on that company’s platform. CRISPR-based techniques, on the other hand, are relatively fast and only need basic equipment found in most labs.
Experts say that the United States needs to run hundreds of thousands more tests each day to control the pandemic. Rapid, simple tests could help reach that scale.
Antibodies from Winter, a 4-year-old llama with great eyelashes, have neutralized coronavirus and other infections in lab experiments.
Winter is a 4-year-old chocolate-colored llama with spindly legs, ever-so-slightly askew ears and envy-inducing eyelashes. Some scientists hope she might be an important figure in the fight against the novel coronavirus.
She is not a superpowered camelid. Winter was simply the lucky llama chosen by researchers in Belgium, where she lives, to participate in a series of virus studies involving both SARS and MERS. Finding that her antibodies staved off those infections, the scientists posited that those same antibodies could also neutralize the new virus that causes Covid-19. They were right, and published their results in the journal Cell.
Scientists have long turned to llamas for antibody research. In the last decade, for example, scientists have used llamas’ antibodies in H.I.V. and influenza research, finding promising therapies for both viruses.
Humans produce only one kind of antibody, made of two types of protein chains — heavy and light — that together form a Y shape. Heavy-chain proteins span the entire Y, while light-chain proteins touch only the Y’s arms. Llamas, on the other hand, produce two types of antibodies. One of those antibodies is similar in size and constitution to human antibodies. But the other is much smaller; it’s only about 25 percent the size of human antibodies. The llama’s antibody still forms a Y, but its arms are much shorter because it doesn’t have any light-chain proteins. This more diminutive antibody can access tinier pockets and crevices on spike proteins — the proteins that allow viruses like the novel coronavirus to break into host cells and infect us — that human antibodies cannot. That can make it more effective in neutralizing viruses. Llamas’ antibodies are also easily manipulated, said Dr. Xavier Saelens, a molecular virologist at Ghent University in Belgium and an author of the new study. They can be linked or fused with other antibodies, including human antibodies, and remain stable despite those manipulations.
Researchers at the Sainte-Anne Psychiatric Hospital in Paris have noticed a possible protective effect from a drug used to treat bipolarity. A first clinical trial in humans is expected to start soon. The first antipsychotic treatment in history could play a key role in the fight against the proliferation of the coronavirus. This is what researchers at Sainte-Anne Hospital are trying to discover thanks to the reCoVery project, the first global study on this subject.
The scientists noted a low prevalence of severe symptomatic forms of Covid-19 in patients with mental disorders. In the Paris hospital, around 19% of the medical staff contracted the virus, while only 3% of the patients tested positive. Other psychiatric units in China, Italy, Spain and elsewhere in France have noticed the same trend.
The team then turned their attention to chlorpromazine, the first antipsychotic drug used to treat disorders such as bipolarity or schizophrenia. To find out more, they launched the reCoVery project in collaboration with the Institut Pasteur. Previous in vitro studies on chlorpromazine conducted in 2014 and 2018 had demonstrated an inhibitory action on the entry of the virus into the cells. This effect is thought to occur in the early and late stages of infection.
Tests with the Institut Pasteur confirm the antiviral effect of chlorpromazine on the coronavirus. A second part of the study, based on serologies, will take place within the GHU Paris. And a first clinical trial in patients hospitalized in the Covid + unit will be the third step to verify these results.
The Pasteur Institute announces at the same time that it has joined an international initiative bringing together researchers from the California University of San Francisco (UCSF), the Gladstone Institutes, and the Icahn School of Medicine at Mount Sinai. Their goal: to study promising compounds for clinical trials in order to fight against Covid-19.
The first results are encouraging. After creating a catalog of more than 300 human proteins that the virus needs to infect cells and reproduce, the team looked at existing molecules that could be targeted to these proteins. Some antipsychotic drugs are among the antivirals considered to be promising.
“The results obtained not only allow researchers to identify the best drug candidates to launch new clinical trials, but also shed light on the cellular processes involved in SARS-CoV-2 infection,” says the Pastor Institute. This research would also allow the discovery of treatments applicable to different viruses and non-viral diseases.
Rice University researchers have created an efficient, low-cost device that splits water to produce hydrogen fuel. The platform developed by the Brown School of Engineering lab of Rice materials scientist Jun Lou integrates catalytic electrodes and perovskite solar cells that, when triggered by sunlight, produce electricity. The current flows to the catalysts that turn water into hydrogen and oxygen, with a sunlight-to-hydrogen efficiency as high as 6.7%. This sort of catalysis isn’t new, but the lab packaged a perovskite layer and the electrodes into a single module that, when dropped into water and placed in sunlight, produces hydrogen with no further input. The platform introduced by Lou, lead author and Rice postdoctoral fellow Jia Liang and their colleagues in the American Chemical Society journal ACS Nano is a self-sustaining producer of fuel that, they say, should be simple to produce in bulk.
A schematic and electron microscope cross-section show the structure of an integrated, solar-powered catalyst to split water into hydrogen fuel and oxygen. The module developed at Rice University can be immersed into water directly to produce fuel when exposed to sunlight
“The concept is broadly similar to an artificial leaf,” Lou said. “What we have is an integrated module that turns sunlight into electricity that drives an electrochemical reaction. It utilizes water and sunlight to get chemical fuels.”
Perovskites are crystals with cubelike lattices that are known to harvest light. The most efficient perovskite solar cells produced so far achieve an efficiency above 25%, but the materials are expensive and tend to be stressed by light, humidity and heat. “Jia has replaced the more expensive components, like platinum, in perovskite solar cells with alternatives like carbon,” Lou commented. “That lowers the entry barrier for commercial adoption. Integrated devices like this are promising because they create a system that is sustainable. This does not require any external power to keep the module running.”
Liang said the key component may not be the perovskite but the polymer that encapsulates it, protecting the module and allowing to be immersed for long periods. “Others have developed catalytic systems that connect the solar cell outside the water to immersed electrodes with a wire,” he explained. “We simplify the system by encapsulating the perovskite layer with a Surlyn (polymer) film.”
The patterned film allows sunlight to reach the solar cell while protecting it and serves as an insulator between the cells and the electrodes, Liang said. “With a clever system design, you can potentially make a self-sustaining loop,” Lou added. “Even when there’s no sunlight, you can use stored energy in the form of chemical fuel. You can put the hydrogen and oxygen products in separate tanks and incorporate another module like a fuel cell to turn those fuels back into electricity.”
People who are affected by Alzheimer’s disease have a specific type of plaque, made of self-assembled molecules called β-amyloid (Aβ) peptides, that build up in the brain over time. This buildup is thought to contribute to loss of neural connectivity and cell death. Researchers are studying ways to prevent the peptides from forming these dangerous plaques in order to halt development of Alzheimer’s disease in the brain.
In a multidisciplinary study, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, along with collaborators from the Korean Institute of Science and Technology (KIST) and the Korea Advanced Institute of Science and Technology (KAIST), have developed an approach to prevent plaque formation by engineering a nano-sized device that captures the dangerous peptides before they can self-assemble.
Transmission Electron Microscopy (TEM) images of Aβ peptide samples in the presence of the Aβ nanodevices (scale bar: 200 nm). The lack of grains in the image indicates the effectiveness of the nanodevice in trapping the peptides
We’ve taken building blocks from nanotechnology and biology to engineer a high-capacity cage’ that traps the peptides and clears them from the brain.” — Elena Rozhkova, scientist, Center for Nanoscale Materials
The β-amyloid peptides arise from the breakdown of an amyloid precursor protein, a normal component of brain cells,” said Rosemarie Wilton, a molecular biologist in Argonne’s Biosciences division.In a healthy brain, these discarded peptides are eliminated.”
In brains prone to the development of Alzheimer’s, however, the brain does not eliminate the peptides, leaving them to conglomerate into the destructive plaques.
The idea is that, eventually, a slurry of our nanodevices could collect the peptides as they fall away from the cells — before they get a chance to aggregate,” added Elena Rozhkova, a scientist at Argonne’s Center for Nanoscale Materials (CNM), a DOE Office of Science User Facility.
In an effort to curb the spread of the coronavirus outbreak, many countries imposed lockdown restrictions on public life, prompting the closure of schools, restaurants and businesses deemed non essential. But Sweden did something different. Instead of imposing strict social-distancing policies like most of the world, Sweden aimed at keeping public life as open as possible, allowing for some exposure to the virus to build immunity among its population. Sweden rolled out voluntary measures, advising older people and others particularly vulnerable to the virus to avoid social contact. It also recommended people work from home, wash their hands regularly and avoid nonessential travel. But the country’s borders stayed open, along with some schools and many businesses.
“Herd immunity could be reached in Stockholm in the coming weeks. In major parts of Sweden, around Stockholm, we have reached a plateau [in new cases] and we’re already seeing the effect of herd immunity, and in a few weeks’ time we’ll see even more of the effects of that. And in the rest of the country, the situation is stable,” says Dr. Anders Tegnell, chief epidemiologist at Sweden’s Public Health Agency. Herd immunity is when a high proportion of the population is immune to an infection, and usually occurs with a vaccine. There’s currently no vaccine for the coronavirus that causes COVID-19, and scientists are investigating whether exposure and recovery from the coronavirus leads to long-term immunity.
Tegnell said data indicate 20 percent of Stockholm’s population is already immune to the virus, and that “in a few weeks’ time we might reach her immunity and we believe that is why we’re seeing a slow decline in cases, in spite of sampling [testing for the coronavirus] more and more.” “Unfortunately the mortality rate is high due to the introduction in elderly care homes and we are investigating the cause of that,” Tegnell explained. The country, with a population of roughly 10 million, has more than 16,000 confirmed cases, most in Stockholm and surrounding areas. The number of cases in Sweden is nearly double that of Denmark and Finland, which have put lockdown measures in place. Both Denmark and Finland have populations about half of Sweden’s. Sweden has recorded more than 1,900 deaths.
Sweden’s strategy has stirred some controversy, as some health experts have criticized the approach. Some even liken it to playing Russian roulette with public health, CNBC reports. More than 20 high-profile scientists last week wrote in a Swedish newspaper that public-health authorities had failed, and urged politicians to step in with stricter measures, according to Nature. “Closing borders, in my opinion, is ridiculous,” Tegnell told Nature. “Because COVID-19 is in every European country now. We have more concerns about movements inside Sweden. As a society, we are more into nudging: continuously reminding people to use measures, improving measures where we see day by day that they need to be adjusted. We do not need to close down everything completely because it would be counterproductive.”