Culture

In the journal Nature Communications, an interdisciplinary team from the Max Planck Institute of Colloids and Interfaces presents for the first time a laser-driven technology that enables them to create nanoparticles such as copper, cobalt and nickel oxides. At the usual printing speed, photoelectrodes are produced in this way, for example, for a wide range of applications such as the generation of green hydrogen.

Previous methods produce such nanomaterials only with high energy input in classical reaction vessels and in many hours. With the laser-driven technology developed at the institute, the scientists can deposit small amounts of material on a surface and simultaneously perform chemical synthesis in a very short time using high temperatures from the laser. 'When I discovered the nanocrystals under the electron microscope, I knew I was onto something big,' says Junfang Zhang, first author of the study and doctoral researcher. The discovery turned into a new and environmentally friendly method for synthesizing materials that can, among other things, efficiently convert solar energy into electricity.

Without detours with sunlight to hydrogen: 'Nowadays most of green hydrogen is produced from water using electricity generated by solar panels and stored in batteries. By employing photoelectrodes we can use solar light directly,' says Dr. Aleksandr Savateev.

The newly developed principle works with so-called transition metal oxides, mainly copper, cobalt and nickel oxides, all of which are good catalysts. The special feature of these oxides is the variety of their crystal forms (nanocrystals such as nanorods or nanostars), which affect their surface energy. Each structure can have a different effect on catalytic reactions. Therefore, it is important that these nanostructures can be made targeted - or even untargeted, but repeatable. The developed technology could also be used to find quickly and efficiently new catalysts. 'Laser dot by laser dot, we can create different catalysts side by side by simply varying the composition and conditions, and then also test them in parallel right away,' says Dr. Felix Löffler adding, 'But now we need to work on making the catalyst systems more persistent in all applications'.

The method

Similar to the principle of a typewriter, material is transferred from a donor to an acceptor carrier. On the former is the 'ink', a solid polymer, which is mixed with metal salts, the latter consists of a thin carbon nitride film on a conductive electrode. Targeted laser irradiation transfers the salts to the acceptor along with the molten polymer. The brief high temperatures cause the salts to react within milliseconds and they transform into metal oxide nanoparticles with desired morphology.

SAN ANTONIO (June 2, 2021) -- Scientists from The University of Texas Health Science Center at San Antonio have discovered a mechanism by which SARS-CoV-2 exploits changes in metal ion concentrations to disguise itself in the body. Varying concentrations of metal ions -- positively charged atoms such as magnesium, manganese and calcium -- are observed in hospitalized COVID-19 patients.

"This is a newly described metal-dependent mechanism by which these ions help the virus to evade immune surveillance," said Yogesh Gupta, PhD, senior author of the research published June 2 in the journal Nature Communications. Dr. Gupta is assistant professor of biochemistry and structural biology at the UT Health Science Center San Antonio and investigator with its Greehey Children's Cancer Research Institute.

Dr. Gupta and colleagues captured atomic-level snapshots during various stages of camouflaging activity of the coronavirus. It turns out metal ions have an architectural purpose -- they form a bridge between viral messenger RNA (which are instructions for encoding the virus) and a protein complex consisting of viral proteins nsp16 and nsp10. The activity is sort of like a scaffold swaying in the wind and workers laying hands on it to steady it.

With the scaffold stabilized, the virus then uses nsp16 to modify its messenger RNA cap into a Trojan horse unrecognizable to the immune system. This tricks the defenses, protects the RNA code from being degraded and enhances viral growth in the body. This activity is required each time the virus multiplies.

The nsp16/nsp10 protein complex stretches itself when the RNA cap is modified, which is a second finding the scientists reported. The stretching is facilitated by metal ion binding.

The understandings gleaned in this research can eventually aid treatment of all coronaviruses.

"The next step is to use this structural knowledge to develop novel therapies to treat COVID-19 and emerging coronavirus infections," Dr. Gupta said. "We are already studying how imbalances in metal concentrations regulate the host immune response to these infections."

In collaborative international effort, laser physicists at LMU have built the first hybrid plasma accelerator.

Particle accelerators have made crucial contributions to some of the most spectacular scientific discoveries of modern times, and greatly augmented our knowledge of the structure of matter. Now a team of laser physicists led by Prof. Stefan Karsch at the Ludwig-Maximilian University (LMU) in Munich and the Max Planck Institute for Quantum Optics, in cooperation with scientists based at the Helmholtz Centre in Dresden-Rossendorf (HZDR), the Laboratoire d'Optique Appliquée in Paris (LOA), Strathclyde University in Glasgow and the DESY Electron Synchrotron in Hamburg, have now achieved a significant breakthrough in accelerator miniaturization. They have built the first compact two-stage plasma-based accelerator in which particles in a plasma wave initiated by a powerful laser are used to accelerate a beam of electrons.

Particle accelerators have become an indispensable tool for studies of the structure of matter at sub-atomic scales, and have important applications in biology and medicine. Most of these systems make use of powerful radio-frequency waves to bring particles up to the desired energy. One drawback of this approach, which has been the standard methodology in the field for decades, lies in the risk of electrical breakdown when very high levels of electrical power at radio frequencies are coupled into the accelerator. This potential risk effectively limits the field strengths attainable, and is one of the reasons why these accelerator systems are typically many kilometers long. Physicists have therefore been exploring ways of reducing their size by exploiting the fact that a plasma can sustain much higher acceleration fields. In this case, the electric field generated by a powerful laser or a particle beam is used to strip electrons from the atoms in a gas and to create a wake similar to the one produced by a speedboat on water, Electrons surfing on that wake can get accelerated to nearly the speed of light within a distance of only a few millimeters.

Studies on plasma-based acceleration with the aid of lasers, i.e. Laser Wakefield Acceleration (LWFA), are now in progress in many research institutions around the world. In contrast, work with accelerators based on particle beams - a field which is known as Plasma Wakefield Acceleration (PWFA) - has so far been possible only in large-scale accelerator facilities (e.g. CERN, DESY and SLAC), although it offers a number of advantages over LWFA. For example, particle beams do not heat the plasma as much as laser beams and allow to use a longer accelerating distance. This in turn promises to improve the quality of the beam and increase its energy, parameters that are a very important in terms of the technique's potential range of applications.

In their experiments, the authors of the new study were able, for the first time, to build and successfully test a practical and compact particle-based plasma accelerator. The essential breakthrough lies in the fact that the PWFA, which accelerates the final electron beam, is driven by a particle beam from an LWFA. The latter is itself highly compact, so that the hybrid plasma accelerator is only a few centimeters long. Moreover, simulations indicate that the acceleration fields are more than three orders of magnitude higher than that attainable in conventional accelerators. Another promising result of the study is that the data obtained at LMU are confirmed by complementary tests performed with the DRACO laser at the HZDR.

Dr. Andreas Döpp, a member of the Munich group led by Prof. Stefan Karsch, points out that "only a few years ago, the practical realization of such a combination would have been unthinkable. The hybrid accelerator was made possible by subsequent developments in the design of laser-based accelerators, which have led to tremendous improvements in the stability of the beam and in other vital parameters." Much of this progress has been made at LMU, following the installation in the Centre for Advanced Laser Applications (CALA) of the ATLAS laser, which is one of the most powerful of its kind in Germany.

The successful demonstration of the hybrid plasma accelerator represents the latest advance ahead. "We had already shown that our compact plasma accelerator behaves very similarly to its conventional and far larger conventional cousins. So we are confident that we will be able to generate extremely bright electron beams with this set-up in the near future," says Stefan Karsch.

Before the technology can be applied on a wider scale, a number of outstanding challenges must be overcome, but the team are already considering a variety of possible contexts in which such instruments would highly advantageous. "For instance, research groups that have not had easy access to a particle accelerator could utilize the technique and develop it further. Secondly, our hybrid accelerator could serve as the basis for what is called a free-electron laser (FEL)," says Dr. Arie Irman, who coordinated the experiments at the HZDR.

FELs are highly prized radiation sources, which can be used for extremely precise characterizations of nanomaterials, biomolecules and geological samples. Competition for access to these sources, such as the European XFEL in Hamburg, has been correspondingly intense. If such large-scale X-ray lasers could be complemented by the new plasma-based technology in future, such more compact sources could potentially be made available for a broader user base, therefore boosting research with brilliant X-rays as a whole.

Smoking in early puberty in boys may have negative consequences for their future generations of offspring, a study from the University of Bergen (UiB) shows.

By continued analysis of data gathered in the large international RHINESSA, RHINE and ECRHS studies, researchers have found that the health of future generations depends on actions and decisions made by young people today. This is particularly relevant for boys in early puberty and mothers/grandmothers both pre-pregnancy and during pregnancy, the study shows.

The paper "Prenatal and prepubertal exposures to tobacco smoke in men may cause lower lung function in future offspring: a three-generation study using a causal modelling approach" was recently published in the European
Respiratory Journal. The study highlights the importance of putting greater focus on smoking in young people (defined as before 15 years of age) to prevent potential damage on lung function in future generations. It also suggests including the use of moist oral tobacco (snus) and e-cigarette use.

According to the World Health Organization (WHO), roughly 6 million people die from tobacco-related ailments every day. The number is projected to rise over 8 million by 2030. The UiB-study underlines that the smokers not only jeopardize their own health, but also the health of their children and possibly their grandchildren.

Changes in the male germ cells

The study finds that both the pre-natal period and the pre-puberty period are times of high importance for the growing of cells, in particular germ cells. The researchers suggest that lifestyle and environmental factors impact respiratory health by epigenetic changes transmitted through male germ cells. Further, the study finds that lifestyle-related exposures during these periods influence the health of future generations.

In addition to reduced lung-function, the RHINESSA study finds that prepubertal smoking in boys can lead to obesity in their sons. However, interventions that aim to prevent smoking (nicotine use) in the most vulnerable time-windows, might have potential benefits for several generations.

Humans can observe what and where something happens around them with their hearing, as long as sound frequencies lie between 20 Hz and 20 000 Hz. Researchers at Aalto University have now developed a new audio technique that enables people to also hear ultrasonic sources that generate sound at frequencies above 20,000 Hz with simultaneous perception of their direction. The results have been published in Scientific Reports on 2 June 2021.

'In our study, we used bats in their natural habitat as sources of ultrasonic sound. With our new technique, we can now hear the directions-of-arrival of bat sounds, which means we can track bats in flight and hear where they are - we're essentially giving ourselves super hearing,' says Professor Ville Pulkki from Aalto University.

Small devices have been used before to listen to bats but previous versions haven't allowed listeners to locate the bats, just hear them. With their device the researchers record ultrasound using an array of microphones flush mounted and uniformly distributed on the surface of a small sphere. After the signal has been pitch-shifted to audible frequencies, the sound is played back on the headphones immediately. Currently, the pitch-shifting is performed on a computer, but, in the future, it could be done with electronics attached to the headphones.

'A sound-field analysis is performed on the microphone signals, and as a result we obtain the most prominent direction of the ultrasonic sound field and a parameter that suggests that the sound comes only from a single source. After this, a single microphone signal is brought to the audible frequency range of human hearing and its single-source signal is played back on the headphones so that the listener can perceive the source from the direction the sound was analysed to arrive,' Pulkki says.

On top of its popular appeal, the technique has tangible real-world applications.

'In science and art, people have always been interested in how they could improve their senses. Finding sources of ultrasonic sound is also useful in many practical situations, such as finding leaks in pressurised gas pipes. Minor pipe leaks often produce strong ultrasound emissions not detected by normal hearing. The device allows us to spot the sound source quickly,' Pulkki explains.

'Sometimes, damaged electrical equipment also emit ultrasound, and the device could be used for locating faulty equipment faster in places such as data centres,' he continues.

What drives the feasibility of climate scenarios commonly reviewed by organizations like the Intergovernmental Panel on Climate Change (IPCC)? And can they actually be achieved in practice? A new systematic framework can help understand what to improve in the next generation of scenarios and explore how to make ambitious emission reductions possible by strengthening enabling conditions.

While the IPCC is in the midst of the drafting cycle of the Sixth Assessment Report, whose publication will start in the second half of 2021, there is an ongoing debate on how to assess the feasibility of ambitious climate mitigation scenarios developed through integrated assessment models and to what extent they are actually achievable in the real world. In their new study published in Environmental Research Letters, researchers from IIASA and the RFF-CMCC European Institute on Economics and the Environment (EIEE) developed a systematic framework that allows identifying the type, timing, and location of feasibility concerns raised by climate mitigation scenarios.

"Feasibility - in other words, how plausible it is that a scenario materializes in the real world - is a complex concept that is currently getting significant academic attention. In our research, we built on past advancements in theoretical discussions and propose to operationalize feasibility in terms of the timing, disruptiveness, and scale of transformation across geophysical, technological, economic, institutional, and sociocultural feasibility dimensions," explains the paper's first author, Elina Brutschin, researcher in the IIASA Transformative Institutional and Social Solutions Research Group.

"Another major insight concerns the necessity to improve the assessment of socio-cultural feasibility concerns by including more indicators and incorporating insights on attitudes and behavioral changes from the social sciences," says Silvia Pianta, a postdoctoral researcher at EIEE and PhD fellow at Bocconi University.

"We found that the current generation of scenarios does not explore demand-side mitigation to its full potential and that more research is necessary in this area," adds coauthor Bas van Ruijven, IIASA Sustainable Service Systems Research Group leader.

To address these issues, the researchers developed a feasibility evaluation of indicators in each decade, with a flexible aggregation procedure that allows assessing feasibility concerns across dimensions and time. This flexible approach enabled them to look at the "big picture" to, for instance, assess which dimension raises major feasibility concerns, but also to analyze more detailed questions such as trade-offs over time, both within and across different dimensions. The resulting systematic framework is extremely useful, not only to understand what to improve in the next generation of scenarios, but also to analyze more systematically what type of enabling factors might bring us closer to more ambitious mitigation paths in the future.

The authors specifically applied the framework to the publicly available scenario set from the IPCC Special Report on Global Warming of 1.5°C and found that many scenarios currently assume a relatively fast overall decarbonization rate in regions that have a relatively low mitigation capacity. According to Brutschin, this suggests that many feasibility concerns are related to institutional constraints such as government effectiveness. While improving the quality of governance in many regions might be complicated, targeted capacity building and investments can significantly contribute to overcoming this challenge.

The authors highlight that the framework allows tracing important trade-offs over time, noting that while past studies focused on mitigation costs, the new research clearly shows that delayed climate action might generally be much more risky than an early disruptive transformation as delayed action requires an overall larger system to be transformed much faster and by relying on new technologies. In this regard, a better understanding of inter-temporal and inter-dimensional trade-offs incorporating insights from experts and policymakers is essential to take the overall understanding of the feasibility concepts to the next level.

"The new versatile framework that emerged from this collaborative project can be applied to any set of scenarios and can be constantly improved by incorporating new insights from the empirical literature on what is feasible in the real world. Although it was originally developed to evaluate global scenarios, it can be adjusted to have a more systematic evaluation of regional or national feasibility concerns in the future," notes IIASA Energy, Climate, and Environment Program Director, Keywan Riahi, who is also a coordinating lead author in Working Group III of the IPCC Sixth Assessment Report.

In addition to the new framework, the researchers also developed an interactive visual tool with key contributions by Giacomo Marangoni, a researcher at EIEE and Assistant Professor at Politecnico di Milano.

"A new data visualization method is extremely valuable when looking at multidimensional concepts such as feasibility. The tool we developed allows us to visualize our feasibility evaluations for different scenarios and to assess the sensitivity of our results to the definition of different feasibility concern thresholds," he says.

The data visualization tool can be accessed here: https://data.ece.iiasa.ac.at/climate-action-feasibility-dashboard/

Reference
Brutschin, E., Pianta, S., Tavoni, M., Riahi, K., Bosetti, V., Marangoni, G., & van Ruijven, B. (2021) A multidimensional feasibility evaluation of low-carbon scenarios. Environmental Research Letters DOI: 10.1088/1748-9326/abf0ce

Contacts:
Researcher contact
Elina Brutschin
Research Scholar
Transformative Institutional and Social Solutions Research Group
Energy, Climate, and Environment Program
Tel: +43 2236 807 350
brutschin@iiasa.ac.at

Press Officer
Ansa Heyl
IIASA Press Office
Tel: +43 2236 807 574
Mob: +43 676 83 807 574
heyl@iiasa.ac.at

About IIASA:
The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe.

About: RFF-CMCC European Institute on Economics and the Environment (EIEE)
RFF-CMCC European Institute on Economics and the Environment leverages two leading international centers for economic and environmental research: RFF - Resources for the Future and CMCC - Euro-Mediterranean Center on Climate Change. EIEE's research aims to improve environmental, energy, and natural resource decisions through impartial economic research and policy engagement to facilitate the transition to a sustainable, inclusive society. The focus is on issues surrounding but not limited to climate change, including a wide range of environmental, energy, natural resource, and societal issues.

One-quarter of people who take the drug methotrexate for common immune system disorders -- from rheumatoid arthritis to multiple sclerosis -- mount a weaker immune response to a COVID-19 vaccine, a new study shows.

Published (online May 25) recently in Annals of the Rheumatic Diseases, the study addressed disorders that result when the immune system, meant to fight disease and drive healing, is triggered abnormally. This in turn causes inflammation, the pain and swelling that come as immune cells rush into damaged or infected tissue, but often in the wrong amount or context. Called immune-mediated inflammatory disorders, they are typically treated with drugs that reduce inflammation, including methotrexate.

Led by researchers at NYU Grossman School of Medicine, the new study looked specifically at patients' responses to the Pfizer-BioNTech mRNA COVID-19 vaccine, which they measured by looking at the antibodies produced in each patient by the vaccine. Once injected into the body, vaccine ingredients are meant to trigger the production of antibodies, immune proteins that specifically glom onto this viral target protein, disabling it and tagging it for removal from the body.

The lower antibody response in patients who take methotrexate does not necessarily mean that these patients are not protected against COVID-19, cautions co-first study author Rebecca Haberman, MD, clinical instructor in the Department of Medicine at NYU Langone Health.

"It is most important to state that patients should not be concerned about our study findings as the majority of patients with immune system disorders are responding well to the mRNA vaccines," Dr. Haberman says. "It is also possible that methotrexate is delaying, rather than preventing, an adequate immune response against COVID-19."

Researchers have known that rheumatoid arthritis patients who take methotrexate have a reduced response to seasonal flu vaccines. Because mRNA vaccines use a new mechanism of action that patients with these common immune disorders have not seen before, the researchers wanted to determine how well these patients are protected.

The research was conducted at NYU Langone and at Friedrich-Alexander University Erlangen Nuremberg in Germany and enrolled healthy people and patients treated for common immune-mediated disorders, including rheumatoid arthritis, psoriatic arthritis and psoriasis. Study participants received two doses of Pfizer-BioNTech mRNA COVID-19 vaccine. The researchers analyzed blood samples to determine the amount of antibodies patients produced after receiving the vaccine and measured the activation of key immune system cells, including CD8 killer T cells, which are generated as part of the body's immune response.

The researchers found that over 90 percent of healthy subjects and patients taking drugs other than methotrexate to control inflammation in both the New York and German study groups mounted strong antibody responses. Patients with immune-mediated inflammatory disorders who were taking methotrexate achieved an adequate response in only 62 percent of cases. Similarly, while healthy patients and those with common immune disorders who were taking anti-inflammatory drugs other than methotrexate produced CD8 T cells, patients taking methotrexate did not show an increase in CD8 T cell activation after vaccination.

"More research is needed to understand why such a significant proportion of people with common immune disorders who take methotrexate have deficiencies in mounting an antibody and cellular response," says study co-senior author Jose U. Scher, MD, an associate professor in the Department of Medicine at NYU Langone. "This may not necessarily mean that the vaccine is not efficacious, but that alternate vaccine strategies need to be investigated."

These alternate vaccine strategies include potentially discontinuing methotrexate during the time these patients receive the vaccine, changing the dosage of methotrexate or possibly administering a booster shot to the vaccine, says Dr. Scher, who is also director of the Psoriatic Arthritis Center at NYU Langone. The research team is currently leading studies to determine the best course of action for these patients.

Zebrafish exposed to the leading cannabinoids found in cannabis in the earliest stages of development suffer a significant drop in neural activity later in life, according to a University of Alberta study that has implications for prenatal development in humans.

Richard Kanyo, the lead author on the study and post-doctoral fellow in the Faculty of Medicine & Dentistry, said despite the popular narrative that the health benefits of cannabis are many, it turns out there is a surprisingly large knowledge gap.

"Once the legalization happened, people got really excited about it and there's a lot of bias in the media about positive effects, so we began wondering about the negative implications," said Kanyo.

Kanyo teamed up with Declan Ali, a biological sciences researcher in the Faculty of Science, whose lab had an ongoing interest in how certain chemicals and compounds alter development in young animals "when their neurons are contacting each other and trying to communicate."

For the study, developing zebrafish embryos were left to incubate for 10 hours in a solution containing one of the two main active cannabinoids found in cannabis--tetrahydrocannabinol (THC) or cannabidiol (CBD)--or a combination of these two compounds, immediately after fertilization.

Ali explained that 10 hours represents a period in animal development that includes a stage of development known as gastrulation, when the multiplying cells start to form multiple tissue layers. In zebrafish it happens between five and 10 hours after the egg has been fertilized; in humans it lasts about a week and occurs roughly three weeks after egg fertilization.

The amount of drug used would be equivalent to someone consuming cannabis or the active compounds every day for two to three weeks at the very start of a pregnancy.

On the fourth day of development, Kanyo looked at brain activity using cutting-edge fluorescing calcium sensors that measure calcium, which is increased in active neurons.

He found that neural activity decreased by 60 to 70 per cent in the group bathed in THC and by more than 70 per cent in the group immersed in CBD. The decrease was even more pronounced in zebrafish that developed in a solution containing both compounds.

"The interesting part is when combined, like how it is found in a cannabis edible or cigarette, we needed much less to get the same reduction in neural activity," said Kanyo.

Ali said the concentrations used in the experiment are a little bit on the high side for just a single cigarette, to make up for the fact that the compounds have to work their way through an outer egg casing to get to the embryo.

"By the time that happens, we don't know what the exact concentrations are, but they're definitely going to be much lower than what we put in the baths themselves."

Compared with one of the control compounds, MS222, a local anesthetic that blocks activity along nerves, the drop in neural activity on the high end of the concentrations tested was the equivalent to the drop in animals that have been anesthetized, Kanyo noted.

At five days after fertilization, when the larvae slowly begin to swim, the reduction in activity compared with normally developed zebrafish was about 20 per cent for CBD and THC individually, but 80 per cent or higher when in combination.

"This reduction in locomotion is consistent with earlier studies as well," said Ali.

Ali said the research follows earlier studies showing that exposure of young organisms to THC and CBD, either alone or in combination, could have a detrimental impact on overall brain and neural activity that could be manifested in different ways.

And though more work is needed to better understand the mechanism behind the effects on neural activity, Ali said people who are thinking of having children would certainly want to limit exposure to any of these compounds in the same way they would limit exposure to nicotine and alcohol.

"We're not saying that these compounds are bad for you," he said. "I think in some contexts--pain relief or reducing seizures--there's a great potential there.

"However, what we're seeing is cannabis is not all good for everyone all the time and probably should not be taken during pregnancy."

By Karina Toledo  |  Agência FAPESP – The novel coronavirus is transmitted mainly via inhalation of saliva droplets or respiratory secretions suspended in air, so that face covering and social distancing are the most effective ways to prevent COVID-19 until enough vaccines are available for all. In Brazil, fabric masks are among the most widely used because they are cheap, reusable and available in several colors or designs. However, this type of face covering’s capacity to filter aerosol particles of a size equivalent to the novel coronavirus can vary between 15% and 70%, according to a study conducted in Brazil by the University of São Paulo (USP).

The study was supported by FAPESP, and the principal investigator was Paulo Artaxo, a professor in the university’s Physics Institute (IF-USP). It was part of an initiative called (respire! to assure access to safe masks for the university community. The results are reported in an article in the journal Aerosol Science and Technology.

“We appraised the filtration efficacy of 227 models sold by drugstores and other common types of store in Brazil to see how much genuine protection they afford the general public,” Artaxo told Agência FAPESP.

The scientists conducted a test using a device that contained a sodium chloride solution and emitted aerosol particles of 100 nanometers. SARS-CoV-2 is about 120 nanometers in diameter. A burst of aerosols was triggered, and particle concentration was measured before and after the mask.

As expected, surgical masks were most effective in the test, as were the FFP2 or N95 models certified for professional use, filtering 90%-98% of the particles. Next came masks made of non-woven fabric (TNT) or polypropylene and sold in many kinds of store, with an efficiency of 80%-90%, followed by those made of ordinary cotton, spandex or microfiber, which filtered 40% on average (15%-70%). 

Several factors were critical in enhancing or reducing the degree of protection. “Generally speaking, masks with a central seam protect less because the sewing machine makes holes that increase the passage of air. A tightly fitting top edge improves filtration significantly. Some masks made of fabric include fibers of nickel, copper or other metals that inactivate the virus and hence protect the wearer more effectively. There are even electrically charged models that retain more particles. In all cases, however, efficacy drops when the mask is washed because of wear and tear,” said Fernando Morais, first author of the article. Morais is a PhD candidate at IF-USP and a researcher at the Nuclear and Energy Research Institute (IPEN), an agency of the São Paulo State Government. 

Breathability

According to Artaxo, dual-layer cotton masks filtered considerably better than single-layer models, but efficacy was hardly altered by a third layer, which reduced breathability.

“The study innovated in several ways. One was its evaluation of breathability or resistance to air passage,” Artaxo said. “TNT and cotton masks were best in this regard. The FFP2 and N95 models were not as comfortable, but paper masks were the worst. This is important because if a person can’t bear wearing a mask even for five minutes, it’s useless.”

The authors of the article note that although mask efficacy varies, all types help reduce transmission of the virus, and mask-wearing in conjunction with social distancing is fundamental to control the pandemic. They advocate mass production of FFP2/N95 masks for distribution free of charge to the general public. This “should be considered in future pandemics”, according to Vanderley John, penultimate author and coordinator of (respire!, which is organized by USP’s Innovation Agency.

“Transmission of the virus is demonstrably airborne and wearing a mask all the time is one of the best prevention strategies, as well as leaving doors and windows open to ventilate rooms as much as possible,” Artaxo said.

Researchers from Sinai Health have published a study providing an ultra-detailed look at the organization of a living human cell, providing a new tool that can help scientists around the world better understand what happens during disease.

The new study, out today in the journal Nature, was conducted in the laboratory of Dr. Anne-Claude Gingras, a senior investigator at the Lunenfeld-Tanenbaum Research Institute (LTRI) and professor in the Department of Molecular Genetics at the University of Toronto.

Co-first authors Christopher Go and Dr. James Knight surveyed the human cell landscape using 192 markers for proteins known to reside in specific organelles that can "tag" neighbouring proteins in the same compartment.

"The Human Cell Map was able to predict the localization of 4,000 proteins across all compartments in living human cells," said Go. "We sampled all the major organelles of the human cell and used innovative analysis to create the highest resolution map to date, with high accuracy in predicting novel localizations for many unmapped proteins."

The human body is composed of trillions of cells that are each further separated into different compartments with dedicated functions, much like a house has different rooms for sleeping or preparing food. These compartments, called organelles, each contain different proteins that perform specific activities associated with the compartment. The mitochondria, the so-called powerhouse of the cell, is one example of an organelle.

The scientists said knowing which proteins are residing in which organelles is an important first step towards understanding the role of each cellular protein. Earlier approaches often used methods that first kill the cells before trying to separate the organelles from one another.

"Previously, it was like taking the house apart to isolate each of the individual rooms," said Go. "These approaches tend to provide only crude views of the organization of a cell."

The Gingras lab develops tools to detect proteins using instruments known as mass spectrometers. In the new research, they purified the proteins that are "tagged" by organelle markers and identified each of them by mass spectrometry. The team then used Computational tools to reconstruct the human cell.

"Through our research, we have shown that we can precisely localize thousands of proteins at a time with relatively little effort," said Dr. Knight, a bioinformatician in the Gingras Lab at the LTRI. "Previous methods for localizing a protein required each protein to be investigated individually, or required a limited focus."

Given the expansive nature of the Human Cell Map, the team also created an analysis portal to allow researchers around the world to delve deeper into the data. Users can scan each of the 192 markers in detail and compare their own data on protein localization to predictions made in the Human Cell Map.

Knight said while this work provides a greater understanding of the organization within the human cell, it also can be leveraged to better understand what happens during disease.

"Human diseases are typically characterized at the molecular level by proteins with aberrant behaviour that cause the cell to behave in pathological ways. In these situations, proteins will often change where they reside in the cell," said Dr. Knight. "Our research is a first step in addressing this challenge in normal cells and we can use it for comparisons against altered cell states, such as disease conditions, to identify proteins with unexpected localizations that may help us understand a diseased cell better."

The team said the map will now be used in a variety of projects to help shed additional light on protein localization in human cells. Future efforts will include using chemical, viral and disease conditions to better characterize how cells adapt structurally to these stressors. This can inform future research efforts towards a mechanistic understanding of diseased states and the development of future therapeutics.

When the COVID-19 pandemic arrived in North America in March 2020, health care facilities stopped providing all but "essential" care, to reduce infection risks and preserve protective gear known as PPE.

That included changes at many centers that provide ECT (electroconvulsive therapy) for severe depression and other conditions, a new survey shows.

Because ECT involves anesthesia, so that patients are unconscious when carefully controlled pulses of electricity are delivered to key areas of the brain, it is considered an 'aerosol generating' procedure. That means it poses special risks when a respiratory virus such as the novel coronavirus is in widespread circulation.

In a new commentary in the American Journal of Psychiatry, a team led by Daniel Maixner, M.D., of the University of Michigan Department of Psychiatry and U-M Eisenberg Family Depression Center, describes the experiences of ECT centers during spring of 2020. Maixner leads the ECT program at Michigan Medicine, U-M's academic medical center.

Some centers temporarily stopped accepting new patients for ECT, or prioritized ECT care for only the most severely ill and hospitalized patients. Many changed the schedule for the repeated treatments that a course of ECT entails. All followed newly developed protocols to reduce staff exposure to aerosols using patient screening, used advanced personal protective equipment, also called PPE, and collaborated extensively with anesthesia teams to safely administer treatments.

In all, 16 of the centers reduced their capacity to less than half of their usual patient volume between March and June, including 5 that treated less than a quarter of their usual number of patients. For new patients, and those who had completed their initial course of treatment but needed maintenance, 18 of the 20 centers reduced the frequency of treatments.

The changes came with a price. One center lost a patient to suicide. Three other centers had patients who made serious suicide attempts. Seventy percent of sites had patients return to inpatient psychiatric care after living in the community because they weren't able to receive ECT on the planned schedule, and 80% of the centers had patients who had to restart ECT care from the beginning to get back on track.

Because of this, the authors call for ECT to be seen as "essential" in future waves of COVID-19 activity, and in other crises and pandemics, so that care can continue.

With improved availability of COVID testing and PPE, and treatment protocols, most of the academic ECT programs were able to react promptly and return to caring for most patients again by mid-summer 2020, despite many challenges.

However, Maixner said, "risks are high for our patients during the time of COVID-19 and any other pandemic if access to ECT is curtailed. It is important for psychiatrists and patients to advocate for ECT to remain an essential treatment and not just be considered elective."

The survey was conducted by the ECT Task Group of the National Network of Depression Centers. In addition to the new commentary, Maixner presented additional data on the effects of the pandemic on ECT practice at a recent meeting of the International Society for ECT and Neurostimulation, which has also issued a position statement on the essential role of ECT.

Maixner and colleagues have also studied the efficacy and cost-effectiveness of ECT as a key option for patients who have not responded to other forms of treatment for depression and other mental health conditions.

SMU Office of Research & Tech Transfer - Whether they are in the technology or oil sector, selling shoes or healthcare products, for many companies, green is the new black. While maximising profit might have been the sole priority for most businesses a decade ago, these days it is common for mission-oriented companies to pursue the 'triple bottom line' of people, planet and profit, particularly through corporate social responsibility (CSR) efforts.

While such efforts are commendable, some investors remain primarily concerned about whether firms can do well by doing good; in other words, whether CSR actually can increase a company's value. For instance, CSR activities could enhance brand image and improve customer loyalty, or even make it easier to attract and retain talent, leading to higher future stock returns. However, the wide-ranging and vague quality of these CSR efforts - which can encompass everything from donations to charities to promoting volunteerism among company staff - have typically presented a problem for academics trying to quantify their impact.

To determine the effect of sustainability-related activities on firm value, academics from SMU and INSEAD have embarked on a research project that effectively narrows the scope of CSR efforts to concrete and measurable environmental and social (E&S) activities; for example, redesigning factory processes to reuse water. By zooming in on observable improvements in future operating performance and stock returns, the researchers were able to quantify how E&S activities led to benefits for some - but not all - firms. Interestingly, the impact of E&S activities on future operating performance was largely dependent on company-specific factors such as the nature of assets owned by the business, SMU Assistant Professor of Accounting Grace Fan shared at the SMU/NUS/NTU Accounting Research Conference on April 17, 2021.

A tale of two firms

Crunching the data for more than 4,000 US public companies from 1995 to 2016 including corporate heavyweights such as Apple and Chevron, Professor Fan and team focused on E&S scores in five main categories: environment, community, diversity, employee relations and human rights. They found that in general, E&S activities are related to future improvements in operating performance, but only for firms in tangible asset-intensive industries such as manufacturing, utilities, energy and chemicals. For companies in sectors that are more intangible asset-intensive, which rely more heavily on assets such as intellectual property to derive profits, there was no such beneficial effect.

"For the tangible asset-intensive companies, they have a lot of fixed and heavy assets and processes. We imagine they would derive more benefits from improving their process efficiency and making their workers happier as a result of E&S activities," Professor Fan shared, citing case studies of such process improvements in China, India, the Czech Republic and more.

For instance, US-based conglomerate Honeywell redesigned its chemical cleaning process in a Czech Republic-based plant, which helped reduce its production of chemical waste and consumption of natural gas. Not only did worker safety improve due to reduced handling of toxic chemicals, production time was shortened and the plant saved the company an additional $15,000 a year. Similarly in India, workers at a Honeywell plant implemented an energy conservation programme that allowed it to save an extra 5,000 kilowatt-hours of energy a month, and almost $900,000 a year, Professor Fan explained.

Tracing correlation to causation

Further tracking the impact of E&S activities on stock returns, Professor Fan and team found that E&S activities did in fact correlate with positive stock returns. However, this relationship again occurred mainly in tangible asset-intensive industries. The significant boost in stock returns also disappeared once the researchers controlled for improvements in operating performance, suggesting the positive stock returns were likely due to better internal processes and increased operational efficiencies in these tangible asset-heavy firms.

"It's possible that the stock market does not value the E&S ratings of firms in intangibles-intensive industries such as technology and consumer nondurables as much," Professor Fan said. "Or, the stock market has already incorporated the E&S activities of these firms when determining their value, since their E&S activities may be more easily observable through consumer branding and advertisements compared with tangibles-intensive firms who may embark more on internal process innovations which are more difficult to observe."

Wrapping the virtual session up, Professor Fan delved into the limitations of the study, including the difficulty of claiming causality between E&S ratings and firm value instead of mere correlation. To further investigate this issue, the team will work on collecting more specific data on firm operations, such as the level of carbon emissions and waste production, in addition to E&S ratings.

A new study published in the journal Stem Cell Reports by University of Alberta researchers is shedding light on why many COVID-19 patients, even those not in hospital, are suffering from hypoxia--a potentially dangerous condition in which there is decreased oxygenation in the body's tissues. The study also shows why the anti-inflammatory drug dexamethasone has been an effective treatment for those with the virus.

"Low blood-oxygen levels have been a significant problem in COVID-19 patients," said study lead Shokrollah Elahi, associate professor in the Faculty of Medicine & Dentistry. "Because of that, we thought one potential mechanism might be that COVID-19 impacts red blood cell production."

In the study, Elahi and his team examined the blood of 128 patients with COVID-19. The patients included those who were critically ill and admitted to the ICU, those who had moderate symptoms and were admitted to hospital, and those who had a mild version of the disease and only spent a few hours in hospital. The researchers found that, as the disease became more severe, more immature red blood cells flooded into blood circulation, sometimes making up as much as 60 per cent of the total cells in the blood. By comparison, immature red blood cells make up less than one per cent, or none at all, in a healthy individual's blood.

"Immature red blood cells reside in the bone marrow and we do not normally see them in blood circulation," Elahi explained. "This indicates that the virus is impacting the source of these cells. As a result, and to compensate for the depletion of healthy immature red blood cells, the body is producing significantly more of them in order to provide enough oxygen for the body."

The problem is that immature red blood cells do not transport oxygen--only mature red blood cells do. The second issue is that immature red blood cells are highly susceptible to COVID-19 infection. As immature red blood cells are attacked and destroyed by the virus, the body is unable to replace mature red blood cells--which only live for about 120 days--and the ability to transport oxygen in the bloodstream is diminished.

The question was how the virus infects the immature red blood cells. Elahi, known for his prior work demonstrating that immature red blood cells made certain cells more susceptible to HIV, began by investigating whether the immature red blood cells have receptors for SARS-CoV-2. After a series of studies, Elahi's team was the first in the world to demonstrate that immature red blood cells expressed the receptor ACE2 and a co-receptor, TMPRSS2, which allowed SARS-CoV-2 to infect them.

Working in conjunction with the the lab of virologist Lorne Tyrrell at the U of A's Li Ka Shing Institute of Virology, the team performed investigative infection testing with immature red blood cells from COVID-19 patients and proved these cells got infected with the SARS-CoV-2 virus.

"These findings are exciting but also show two significant consequences," Elahi said. "First, immature red blood cells are the cells being infected by the virus, and when the virus kills them, it forces the body to try to meet the oxygen supply requirements by pumping more immature red blood cells out of the bone marrow. But that just creates more targets for the virus.

"Second, immature red blood cells are actually potent immunosuppressive cells; they suppress antibody production and they suppress T-cell immunity against the virus, making the entire situation worse. So in this study, we have demonstrated that more immature red blood cells means a weaker immune response against the virus."

Following the discovery that immature red blood cells have receptors that allow them to become infected by the coronavirus, Elahi's team then began testing various drugs to see whether they could reduce immature red blood cells' susceptibility to the virus.

"We tried the anti-inflammatory drug dexamethasone, which we knew helped to reduce mortality and the duration of the disease in COVID-19 patients, and we found a significant reduction in the infection of immature red blood cells," said Elahi.

When the team began exploring why dexamethasone had such an effect, they found two potential mechanisms. First, dexamethasone suppresses the response of the ACE2 and TMPRSS2 receptors to SARS-CoV-2 in immature red blood cells, reducing the opportunities for infection. Second, dexamethasone increases the rate at which the immature red blood cells mature, helping the cells shed their nuclei faster. Without the nuclei, the virus has nowhere to replicate.

Luckily, putting Elahi's findings into practice doesn't require significant changes in the way COVID-19 patients are being treated now.

"For the past year, dexamethasone has been widely used in COVID-19 treatment, but there wasn't a good understanding as to why or how it worked," Elahi said. "So we are not repurposing or introducing a new medication; we are providing a mechanism that explains why patients benefit from the drug."

Elahi noted that Wendy Sligl and Mohammed Osman had a crucial role in recruiting COVID-19 patients for the study. The research was supported by Fast Grants, the Canadian Institutes of Health Research and a grant from the Li Ka Shing Institute of Virology.

BROOKLYN, New York, Wednesday, June 2, 2021 - Perovskite solar cells have progressed in recent years with rapid increases in power conversion efficiency (from 3% in 2006 to 25.5% today), making them more competitive with silicon-based photovoltaic cells. However, a number of challenges remain before they can become a competitive commercial technology.

Now a team at the NYU Tandon School of Engineering has developed a process to solve one of them, a bottleneck in a critical step involving p-type doping of organic hole-transporting materials within the photovoltaic cells. The research, "CO2 doping of organic interlayers for perovskite solar cells," appears in Nature.

Currently, the p-doping process, achieved by the ingress and diffusion of oxygen into the hole transporting layer, is time intensive (several hours to a day), making commercial mass production of perovskite solar cells impractical.

The Tandon team, led by André D. Taylor, an associate professor, and Jaemin Kong, a post-doctoral associate, along with Miguel Modestino, assistant professor -- all in the Department of Chemical and Biomolecular Engineering -- discovered a method of vastly increasing the speed of this key step through the use of carbon dioxide (CO2) instead of oxygen.

In perovskite solar cells, doped organic semiconductors are normally required as charge-extraction interlayers situated between the photoactive perovskite layer and the electrodes. The conventional means of doping these interlayers involves the addition of lithium bis(trifluoromethane)sulfonimide (LiTFSI), a lithium salt, to spiro-OMeTAD, a π-conjugated organic semiconductor widely used for a hole-transporting material in perovskite solar cells. The doping process is then initiated by exposing spiro-OMeTAD:LiTFSI blend films to air and light.

Not only is this method time consuming, it largely depends on ambient conditions. By contrast, Taylor and his team reported a fast and reproducible doping method that involves bubbling a spiro-OMeTAD:LiTFSI solution with CO2 under ultraviolet light. They found that their process rapidly enhanced electrical conductivity of the interlayer by 100 times compared to that of a pristine blend film, which is also approximately 10 times higher than that obtained from an oxygen bubbling process. The CO2 treated film also resulted in stable, high-efficiency perovskite solar cells without any post-treatments.

"Besides shortening the device fabrication and processing time, application of the pre-doped spiro-OMeTAD in perovskite solar cells makes the cells much more stable," explained Kong, the lead author. "That's partly because most of the detrimental lithium ions in the spiro-OMeTAD:LiTFSI solution were stabilized as lithium carbonates during the CO2 bubbling process."

He added that the lithium carbonates end up being filtered out when the investigators spincast the pre-doped solution onto the perovskite layer. "Thus, we can obtain fairly pure doped organic materials for efficient hole transporting layers."

The team, which included researchers from Samsung, Yale University, Korea Research Institute of Chemical Technology, The Graduate Center of the City University, Wonkwang University, and the Gwangju Institute of Science and Technology also found that the CO2 doping method can be used for p-type doping of other π-conjugated polymers, such as PTAA, MEH-PPV, P3HT, and PBDB-T. According to Taylor the researchers are looking to push the boundary beyond typical organic semiconductors used for solar cells.

"We believe that wide applicability of CO2 doping to various π-conjugated organic molecules stimulates research ranging from organic solar cells to organic light emitting diodes (OLEDs) and organic field effect transistors (OFETs) even to thermoelectric devices that all require controlled doping of organic semiconductors," Taylor explained, adding that since this process consumes quite a large amount of CO2 gas, it can be also considered for CO2 capture and sequestration studies in the future.

"At a time when governments and companies alike are now looking to reduce CO2 emissions if not de-carbonize, this research offers an avenue for reacting large amounts of CO2 in lithium carbonate to improve next generation solar cells, while removing this greenhouse gas from the atmosphere," he explained, adding that the idea for this novel approach was a counterintuitive insight from the team's battery research.

"From our long history of working with lithium oxygen/air batteries we know that lithium carbonate formation from exposure of oxygen electrodes to air is a big challenge because it depletes the battery of lithium ions, which destroys battery capacity. In this Spiro doping reaction, however, we are actually exploiting lithium carbonate formation, which binds lithium and prevents it from becoming mobile ions detrimental to the long term stability of the Perovskite solar cell. We are hoping that this CO2 doping technique could be a stepping stone for overcoming existing challenges in organic electronics and beyond."

The organization of the human genome relies on physics of different states of matter - such as liquid and solid - a team of scientists has discovered. The findings, which reveal how the physical nature of the genome changes as cells transform to serve specific functions, point to new ways to potentially better understand disease and to create improved therapies for cancer and genetic disorders.

The genome is the library of genetic information essential for life. Each cell contains the entire library, yet it uses only part of this information. Special types of cells, such as a white blood cell or a neuron, have only certain "books" open - those containing information relevant for their function. Researchers have long sought to determine how the genome manages these enormous libraries and allows access to the "books" that are needed, while storing away the ones not in use.

In the newly published study, which appears in the journal Physical Review Letters, the researchers revealed how this happens within a cell.

"We found that the parts of the genome that are being used are liquid, while the unused parts form solid-like islands," explains Alexandra Zidovska, an assistant professor in New York University's Department of Physics and the senior author of the study. "These solid-like islands serve as library bookshelves storing the books with genes not currently in use, while the liquid genome part acts like an 'open book,' which is readily accessible and used for a cell's life and function."

The genome's genetic information is encoded in the DNA molecule. Proper reading and processing of this information is critical for human health and aging. In a human cell, the genome, which contains the genetic code, is housed in the cell nucleus. Barely 10 micrometers in size - or about 10 times smaller than the width of a strand of human hair - it stores about two meters of DNA.

Storing this vast amount of genetic information in such a small space requires packing in such a way so that each piece of DNA, and thus of genetic code, is easily accessible when needed.

What had been less understood is how this information was stored and what was the role of physics in it.

To explore this phenomenon, the researchers, who also included Iraj Eshghi and Jonah Eaton, NYU doctoral candidates, compared cells before and after they become specialized.

Specifically, the scientists mapped motions of the genome in nuclei of mouse stem cells - those that do not yet have a specialized function, but are poised to become any cell type, such as a neuron or a white blood cell - and then let these cells undergo a differentiation into neuronal cells before mapping the genomic motions again. In doing so, they generated the first-ever maps of a genome's motions before and after cell differentiation.

Here they found that stem cells keep their genome "open" - making it as accessible as an open book, with "genetic pages" being easily reachable.

However, the mapping also showed that once a stem cell becomes a specialized cell, e.g. a neuron, this specialized cell keeps readily accessible only parts of the genome that are needed for its specific function. It puts away the unused parts of the genome on "bookshelves." This leaves more space for information that is being actively read out and processed.

"These motions tell us exactly how accessible the genome is in a given place in the cell nucleus," explains Zidovska. "Moreover, these motions reveal the physical state of different parts of the genome, with liquid parts corresponding to loosely packed DNA, and solid-like parts corresponding to tightly packed DNA gels. The genome packing in these different states of matter directly impacts the genome's accessibility; the liquid parts are accessible, in contrast to the solid-like parts. The amazing thing is that this organization relies on physics of different states of matter, liquid and solid."

"Measuring motions of distinct parts of the genome allowed us to show these different physical properties of different parts of the genome, and thus understand the genome organization--the cell's 'library system,' " she adds.

A proper cellular filing system is vital for human health, the researchers note.

"Considering the vast number of cell types in the human body, if a book is missing or misplaced in this cellular library, it may lead to missing or unnecessary information, possibly leading to developmental and inherited disorders as well as afflictions such as cancer," explains Zidovska. "Therefore, revealing how the genome is organized inside the cell nucleus is critical to our understanding of these conditions and diseases. Moreover, such knowledge may help us in designing future therapies and diagnostics of such disorders."