Tech

Ishikawa, Japan - Protons--subatomic particles with a positive electric charge--are one of the first particles to have formed after the universe began and are a constituent of every atom today out there. The movement of protons plays a key role in energy conversion processes, such as photosynthesis and respiration, in biological systems. In addition, proton conduction is an important factor for hydrogen fuel cells, which are often touted as the ideal clean energy source for the next generation.

High proton conduction observed in biomaterials such as sugar and protein derivatives is attributed to the presence of proton-donating functional groups (substituents in a molecule that governs its characteristic chemical reactions). However, the exact mechanism of proton transport in these materials is not clearly understood (for instance, whether the protons prefer to flow along the biomaterial surface i.e. interfacial transport, or through the bulk). Moreover, it is not clear how the concentration of the functional group might affect proton transport pathway.

Against this backdrop, in a new study recently published in the journal Electrochemistry, a team of researchers from Japan, led by Assoc.Prof. Yuki Nagao from Japan Advanced Institute of Science and Technology (JAIST) and Athchaya Suwansoontorn, a PhD student at JAIST, as well as Assoc.Prof. Katsuhiro Yamamoto from Nagoya Institute of Technology, Prof. Shusaku Nagano from Rikkyo University and Prof. Jun Matsui from Yamagata University, set out to explore how proton conduction was affected in styrene-based polymers with the change in the concentration of carboxylic acid, a proton-donating organic acid found commonly in biomaterials. Suwansoontorn lays out the motivation for their research: "The study of proton transport pathways is fundamentally important to elucidate the functioning of many biological systems."

The research team systematically synthesized polymers with different concentrations of carboxylic acid and prepared them as thin films with high surface-to-bulk ratio to enable investigation of interfacial transport properties. Following this, they characterized the polymer structures using a variety of standard characterization techniques.

The research team observed the presence of two kinds of carboxylic acid groups (COOH) in the polymers: free COOH groups, which were more abundant at higher concentrations, and cyclic dimer COOH groups, which were prevalent at low concentrations. To correlate this with proton transport, the researchers examined in-plane proton conduction using impedance spectroscopy and calculated the interfacial resistance to gauge the possibility of interfacial transport.

They found that a high COOH concentration was more conducive to internal proton transport while lower concentrations favored interfacial transport. They attributed this to the presence of free COOH groups at high concentrations that generated more hydrogen bonding networks, facilitating proton conduction. Furthermore, they verified this idea by showing that a higher number of free COOH groups on the interface led to higher interfacial conduction.

"Our research may contribute to developing bio-conductive materials for biological devices involved with proton conduction and eco-friendly fuel cells," says Suwansoontorn, contemplating the practical ramifications of the findings. "From a broader perspective, it can facilitate people's lives by supporting biological technologies and green energy application development."

To combat climate change, greener energy is the need of the hour. In that context, the findings of this study promise some exciting consequences to look forward to, for sure!

In a paper published in NANO, the author reviewed many kinds of nanofibrous filters including the component, preparation process, and application performances to provide directional guidance for improvement of the air purification field.

Poor air quality is worldwide recognized as one of five health risks for causing adverse impacts on human health. Nanofibrous membrane is competitive to capture unclean nanoparticles since its lightweight, small diameter, high specific surface area, and easy to combine with functional additives. However, the trade-off between high filtration efficiency and low pressure drop posts challenge.

The removal mechanisms of fibrous filters to nanoparticles follow two main principles, that is mechanical adsorption and electrostatic adsorption. In this review, various nanofibrous membranes were listed according to the two principles to provide the train of thought of seeking optimal results between their filtration efficiency and pressure drop.

Besides, to articulate the filter classification in this review, compare summary table was listed into six parts, which were net/nanofiber, nonwoven substrate/nanofiber, nanofiber/microsphere, multilayer structure, electric filters, and conductive filters.

How to construct the dual emission nitrogen-doped carbon dots (CDs) by a simple method? Professor Lili Ren with her collaborators proposed a new strategy to prepare such materials which were used to the detection of dopamine.

The traditional ratiometric fluorescence (FL) probe usually needs to combine different nanomaterials by chemical or physical methods and the manufacturing process is more complicated. While the dual-emission carbon dots (DECDs) can simplify the detection process. Therefore, it is of great significance to design a simple ratiometric fluorescence probe based on the DECDs for the accurate determination of DA concentration. Here, a new kind of dual-emission N-doped carbon dots (N-CDs) was prepared by one-pot hydrothermal method with p-phenylenediamineas as carbon source and triethylamine as nitrogen dopant. The synthesized N-CDs show FL emission at 435 nm and 595 nm under 360 nm excitation wavelength. The N-CDs can be used as a ratiometric fluorescence probe for highly selective detection of DA. This is the first time to report the dual-emission fluorescence carbon dots to detect DA.

This work not only develops a new method for preparing dual emission nitrogen-doped carbon dots, but also exploits an economic, environmentally friendly, sensitive and specific DA detection method.

This work was supported by A Project Subsidized the Priority Academic Program Development of Jiangsu Higher Education Institutions (1107047002).

The paper https://www.worldscientific.com/doi/10.1142/S1793292021500302 can be found in NANO https://www.worldscientific.com/worldscinet/nano journal.

Multiple scientific studies show switching completely to vaping with high-quality products has reduced health risks
compared to smoking, contrary to many consumer beliefs

Study data indicates that vaping products can provide an alternative for smokers who would not otherwise quit

Review supports the important role for vaping products in Tobacco Harm Reduction

Reinforces the importance of BAT's unique consumer-centric model and how we are reducing the health impact of our business and building A Better Tomorrow™ through our multicategory approach

To mark World Vape Day, BAT has today published a comprehensive review of the scientific evidence for vaping products (e-cigarettes), their potential health effects and their role in Tobacco Harm Reduction.

This review shows that, over the past decade, the number of people who incorrectly believe vaping is as harmful or more harmful than smoking conventional cigarettes has risen in the UK, Europe, and the U.S. This is despite several scientific reviews , , published in the same period showing that vaping products manufactured in accordance with quality standards present less risk to health than cigarettes.*

According to population modelling studies cited in the review, a significant reduction in premature deaths could be achieved if current smokers switched exclusively to vaping rather than continuing to smoke. These modelling studies use population data and simulations to project the health-related outcomes associated with the long-term risks of smoking versus vapour use over time.

Dr. David O'Reilly, Director of Scientific Research at BAT, commented: "This paper is a comprehensive summary of more than 300 peer-reviewed scientific papers and other evidence published by an estimated 50 institutions over the past decade.

"The scientific evidence is clear - but consumer misperceptions remain. In England and the United States, only one in three adults is aware that there is scientific evidence available, including from leading public health authorities, that supports the conclusion that vaping is less harmful than smoking.

"The reality is that many leading public health authorities have reported that vaping is less harmful than smoking, and that this harm reduction potential can be maximised if those smokers who would otherwise continue to smoke switch exclusively to using vapour products.

"We hope this paper will be used as a resource by public health authorities, and support adult smokers seeking to understand the breadth of scientific evidence that exists to inform their choices."

"Reducing the health impact of our business is at the heart of our purpose - to create A Better Tomorrow by offering the widest range of reduced-risk alternatives to cigarettes*," David O'Reilly continued. "This is why we aim to have 50 million consumers of our New Category products, which include our vapour product range, Vuse, by 2030."

This review highlights that vaping products can effectively compete with combustible cigarettes by providing nicotine and the sensorial enjoyment sought by smokers. Therefore, access to high-quality, extensively tested and well-regulated vapour products is crucial. However, vaping will only be considered a compelling alternative to smoking if public health institutions unambiguously and accurately inform smokers that switching completely to vaping can reduce their health risks.

The paper also reviews current vapour product regulations, and notes that these regulations largely relate only to labelling, ingredients and taxation - but not manufacturing standards. This has resulted in highly variable product quality standards globally.

The review stresses the need for consistent product manufacturing regulations and the universal adoption of robust product stewardship standards by manufacturers with the aim of increasing public confidence in vaping.

A research group from Aarhus University has developed a special biocompatible electrode for electrical muscle stimulation that the group has integrated and 3D-printed onto medical support stockings.

In the winter 2020/2021, the stockings were tested on hospitalised Covid patients. The studies were completed in March, but apart from a case study (Danish Medical Journal) data have not yet been published. However, the project group reveal that the results are very promising.

The stockings were tested on 16 Covid-19 patients who agreed to try the support stocking during their hospitalisation. The participants were hospitalised for five to seven days and were given a support stocking on each leg, but only one of them had the printed electrodes. The leg without electrodes on the support stocking functioned as a control.

Via the electrodes, participants' thigh muscles were electrically stimulated for 30 minutes, twice a day, with an individually adapted intensity.

"The study demonstrated that these patients lost approximately 10 percent of their muscle mass after just five to six days of hospitalisation. However, with this new technology we've been able to counteract the loss," says Charlotte Suetta, Chief Physician and professor at the University of Copenhagen and head of the clinical trials in the project.

Muscle loss is a serious problem for hospitalised patients, especially patients that need intensive care and are on ventilators for long periods. Recovering from muscle loss after several weeks of total inactivity may take months or years, and some patients will even never recover fully.

There is nothing new about electrical stimulation of muscles, but there are several disadvantages with existing solutions. For example, difficulties in getting electrodes on and off, and skin irritation in the stimulated areas.

"Our invention is much easier to use because the electrodes are an integral part of the textile," says Shweta Agarwala, who is an expert in printed electronics, and who has been responsible for the electronics part of the setup, which was developed after breakthroughs within printed electronics technology.

The electrodes have three ultra-thin, flexible layers, and these can be printed directly onto different types of material, making it possible to stimulate the muscles through the stocking with minimal irritation.

"And since the electrodes are an integral part of the stockings, they can also tolerate hospitals' cleaning processes," continues the assistant professor.

So far, Aarhus University has printed almost 600 support stockings for medical use, and it is likely that the stockings can be used for a far larger group than just Covid patients, including bedridden patients in general, as well as in rehabilitation and for wheelchair users.

The countries around the Baltic Sea do not respect their binding international agreement to reduce agricultural pollution of the marine environment. Despite farming activities being the single most important source of nutrient pollution to the Baltic Sea.

An international research team presents evidence on these circumstances in a recent scientific article in the journal Ambio, published by the Royal Swedish Academy of Sciences.

The countries made a commitment 20 years ago to implement 10 specific reduction measures in their national legislation on agricultural pollution - e.g. featuring minimum storage capacity for manure and regulations on animal densities.

Now the researchers' study of legislations and regulations in place at national level, to address nutrients, finds that none of the nine signatories to the Convention is respecting fully the legally binding agreement. Hence, nutrients are leaching to the marine environment in excess of the Baltic Sea's tolerance limits, causing excess algae growth and eutrophication even in the open sea (see photo).

The larger countries, Poland, Germany and Russia, have the weakest record of implementing the reduction measures in their national legislation. Performance is especially poor in Russia and Poland, but also Germany, despite a ruling by the European Court, lags behind. The best performing countries are Sweden and Estonia. Nevertheless, in all nine countries the study identifies shortcomings in compliance with important reduction measures of the Convention.

"Although the Convention specifies ceilings on the amounts of nutrients that farmers may apply to their crops, ceilings are not implemented fully by any country. Either nutrient ceilings are too generous, apply to part of the territory only or are entirely absent. Notably the ceiling of 25 kg phosphorus per hectare is absent in most places, even if the reduction needs are now most pressing with regard to phosphorus" says Mikael Skou Andersen, professor of environmental science at Aarhus University. He is part of the research authors' team.

The reduction measures were adopted under the Convention in anticipation of financial transfers from the EU to farmers in Poland and the Baltic countries. Yet, the researchers find that the eastern countries only to a very limited extent have put to use the economic support available as part of the Common Agricultural Policy, to provide support for reducing nutrient pollution of the marine environment.
The Baltic Sea Action Plan is up for revision every seven years. During the current German Presidency of HELCOM an update and revision is expected to be concluded at the Ministerial meeting October 20.th in Lübeck.

The study was conducted by a research team with participants from Denmark, Finland, Latvia and Sweden, with financial support from the BONUS research program and the Swedish research council FORMAS.

As the cleanest renewable energy, hydrogen energy has attracted special attention in the research. Yet the commercialization of traditional proton exchange membrane fuel cells (PEMFCs), which consume hydrogen and produce electricity, is seriously restricted due to the chemical reaction of PEMFCs cathode largely relies on expensive platinum-based catalysts.

A solution is to change the acidic electrolyte of PEMFCs to alkaline. Such fuel cells are called anion exchange membrane fuel cells (AEMFCs), and they allow for the use of cheaper metal elements like Co, Ni or Mn to design electrocatalysts.

The research team led by Prof. GAO Minrui from University of Science and Technology of China (USTC) followed this solution and developed a practical and scalable way to manufacture a novel Ni-W-Cu alloy, Ni5.2WCu2.2, as the cathode for AEMFCs. The result was published on Nature Communications.

The team first grew Cu(OH)2 nanowires from a three-dimensional foam copper skeleton by anodic oxidation. The obtained nanowires were then immersed in a solution containing Ni and W elements. After hydrothermal synthesis and annealing, the Ni-W-Cu alloy is produced.

The ternary Ni5.2WCu2.2 alloy can catalyze the oxidation of hydrogen in alkaline medium 4.31 times more efficient than the benchmark platinum/carbon anode.

It has an oxidation potential as high as 0.3V in comparison with the reversible hydrogen electrode and can maintain high activity for up to 20h under such overpotential, proceeding anodes based on non-platinum-group metals.

The alloy catalyst also showed excellent resistance to CO poisoning, and maintained high activity in 20000 ppm CO/H2 mixed atmosphere.

Analysis showed that the projected density of states of Ni5.2WCu2.2 alloy lies in the lowest at Fermi level, which indicates that the alloy has the optimal hydrogen binding energy. The multiple-element alloying effect renders the Ni-based alloy a high activity catalyst and offers oxidation resistance.

This work sheds light on further exploration of multiple-element alloys composed of cheap metals, thereby aiding the development of more efficient hydrogen oxidation catalysts for AEMFC anodes.

During the era of commercial whaling, fin whales were hunted so intensively that only a small percentage of the population in the Southern Hemisphere survived, and even today, marine biologists know little about the life of the world's second-largest whale. That makes the findings of researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and the Johann Heinrich von Thünen Institute for Sea Fisheries, which show that a large number of the baleen whales regularly frequent the krill-rich waters surrounding Elephant Island, all the more welcome. Evidence for this is provided by underwater sound recordings from the region, where in the peak month of May, so many fin whale vocalizations can be heard that the individual calls merge into a veritable chorous of sound, as the research team now reports in the journal Royal Society Open Science. In view of this, the marine biologists call for protective measures for this important habitat so as not to jeopardise the apparent recovery of the fin whale population.

Fin whales are still rare and, according to the textbooks, normally appear in groups of three to a maximum of seven. As such, AWI marine biologist Elke Burkhardt was all the more surprised when in the late southern summer of 2012, while on an expedition in the Scotia Sea on board the German research icebreaker Polarstern, she counted more than 100 hundred fin whales in the waters north of Elephant Island. Was this a chance find, or did it mean that such large numbers of the world's second-largest baleen whale gathered here regularly? And if so, why?

To answer this question, in January 2013 Burkhardt and her team installed a mooring with two underwater acoustic recorders and a device used to determine the food supply in the coastal area northwest of the island. Over a period of three years, from January 2013 to February 2016, the instruments recorded the soundscape of the underwater world and gathered data on the food supply in the upper water column. By doing so, they helped identify one of the southern fin whale's most important habitats.

"Our observations from Polarstern were no fluke. As our results show, from December to August the whales regularly inhabit the waters surrounding Elephant Island. Here they not only hunt Antarctic krill, but also search for mates. Our recorders registered the most fin whale calls precisely in the season when the breeding period begins for the Southern Hemisphere population," Burkhardt reports.

Fin whales can be identified by the low-frequency calls that are typical of the species: "Humans would probably only perceive them as vibrations in the pit of the stomach, since their central frequency is roughly 20 hertz, making them exceptionally deep," explains Burkhardt. Male Fin whales that are ready to mate and want to attract females emit these bass sounds in rapid, regular intervals. "Their courtship behaviour may also explain why, in the month of May, our instruments recorded so many of these calls that they merged and were barely discernable as individual sounds," says the AWI marine biologist.

New arguments in favour of a marine protected area around Elephant Island

She was thrilled to discover the numerous fin whales around Elephant Island: "If this aggregation really is an indication that the fin whale population is growing, it would represent a notable achievement for the international whaling moratorium, which entered into effect 35 years ago," she explains.

At the same time, the new findings are a cause for concern. "On the one hand, Antarctic krill are extensively fished in the Scotia Sea; on the other, the region, which is extremely important for fin whales, is frequently visited by cruise ships. That makes it all the more important to comprehensively protect the waters around Elephant Island, and to regulate both krill fishing and tourism in order to avoid harming the fin whale stocks," Burkhardt says. Accordingly, the soundscape should be recorded at regular intervals to document any changes in the population.

Where do the fin whales from Elephant Island spend the winter?

While analysing the underwater recordings, the research team discovered another interesting detail: the 20-Hz pulse also contains an accompanying sound with a frequency of 86 Hz. This in turn resembles the fin whale calls that Chilean marine biologists had previously recorded off the coast of central Chile - particularly at the time of year when the instruments at Elephant Island rarely recorded the sounds of the baleen whales. Was it possible that the same whale population produced the sounds in both regions, and that it moved back and forth between the South Shetland Islands, which Elephant Island belongs to, and the Pacific coast of Chile?

"It is believed that fin whales produce population-specific accompanying higher frequency sounds, which can be used to distinguish between different populations. If this is the case, we can likely conclude that those fin whales that inhabit the waters surrounding Elephant Island in the southern summer may give birth to their calves in the warmer waters off Chile's Pacific coast later in the year, and that these whales regularly travel between the two regions," says Burkhardt.

However, to verify this, further studies are required. To this end, the Bremerhaven-based research team has installed additional underwater recording devices, which will tentatively be retrieved in 2022, in the vicinity of the island. The marine biologists are currently analysing their underwater recordings from the period since 2016. And the first excerpts are promising: in the summers after 2016, Elephant Island continued to be a favourite gathering place for fin whales.

By putting a piece of soft, strain-sensing sheet on the skin may be able to detect skin disorders non-invasively and in real-time very soon. A research team co-led by a scientist from City University of Hong Kong (CityU) has designed a simple electromechanical device that can be used for deep tissue pathology diagnosis, such as psoriasis, in an automated and non-invasive fashion. The findings will lay a foundation for future applications in the clinical evaluation of skin cancers and or dermatology diseases.

The research is co-led by Dr Yu Xinge, Assistant Professor from CityU’s Department of Biomedical Engineering, and scientists from and Northwestern University in the US. Their findings have been published in the science journal Nature Biomedical Engineering, titled “Miniaturized electromechanical devices for the characterization of the biomechanics of deep tissue”.

Electromechanical systems that enable precise, rapid measurements of the stiffness of soft tissues of the human body can provide useful clinical information for monitoring, diagnosing and treating various pathologies, particularly those of the skin. However, existing diagnostic evaluations, for example, magnetic resonance elastography, usually involve huge instruments at hospitals and trained practitioners. And the latest tissue stiffness-measuring technology based on sensing can only measure to superficial depths of upper skin, up to micrometre scale.

New device for real-time evaluations of deep tissue stiffness

To address the issue, the research team designed a simple, miniature electromechanical device for high-precision, real-time evaluations of deep tissue stiffness. The team used a miniature electromagnetic system that integrates a vibratory actuator and a soft strain-sensing sheet to monitor in real-time the Young’s modulus, ie the tensile stiffness, of skin and other soft biological tissues at depths of approximately 1 to 8 mm, depending on the sensor designs.

The team evaluated the device’s performance with a range of synthetic and biological materials, such as hydrogels, pigskin and on various parts of human skin. “The lesions exhibited higher stiffness than those of the nearby skin, primarily due to differences in skin elasticity and hydration. These simple measurements have potential clinical significance in rapidly identifying and targeting skin lesions, with capabilities that complement those of recently reported methods for sensing mechanical properties at tissue surface (typically micrometre-scale),” explained Dr Yu. He pointed out that cancer tissue is typically stiffer or softer than normal tissue, and such difference can be used as diagnostic biomarker for a range of skin conditions, like skin cancer or tumours under the skin.

A simple structure of the electromechanical device

The electromechanical device’s thickness is only about 2.5 mm, and the contacting area is about 2 cm². It operated well on both hair-bearing and hairless areas of the skin. Its working mechanism is adapted from the basis of a skin-integrated haptic interface for virtual/augmented reality developed by Dr Yu and the collaborators from Northwestern University before.

The device works like this: after applying an alternating current through the copper coil, the magnet vibrates and creates pressures onto the bottom surface of the sensor. This would direct deformations that extend to millimetre-scale depths of tissue, which leads to periodic variations in electrical resistance. Analyses of these responses by simultaneously measuring the voltage allows quantitative determination of the stiffness of the tissues. Each measurement could be done within one minute.

The team then conducted clinical studies on patients with skin disorders with their newly invented electromechanical device. The results indicated a potential for accurate targeting of lesions associated with psoriasis, showing the practical medical utility of the device. “The data produced can assist in diagnosis, treatment tracking and disease monitoring particularly for skin associated disorders such as skin cancer, as well as in aspects of aesthetic dermatology and of the recovery from surface wounds,” said Dr Yu.

Dr Yu also pointed out that their device has the potential to be used for the evaluation of skin physical properties under various conditions such as ageing, hydration loss or associated dermatological disorders. “In the near future, we believe this technology will allow people to monitor their skin health status anytime with a simple wearable device,” said Dr Yu.

Dr Yu, together with Professor John A. Rogers, Professor Huang Yonggang and Dr Chang Jan-Kai from Northwestern University are the corresponding authors of the paper. Dr Song Enming, Senior Research Fellow in Dr Yu’s group, and Professor Xie Zhaoqian, a former Senior Research Fellow in Dr Yu’s group and now a Professor at the Dalian University of Technology, Professor Bai Wubin from University of North Carolina at Chapel Hill, and Dr Luan Haiwen from Northwestern University, are the first authors. Li Dengfeng, Yao Kuanming and Zhou Jingkun from CityU also participated in this research. Other researchers are from Northwestern Polytechnical University, The Pennsylvania State University, the University of Illinois at Urbana-Champaign, Sungkyunkwan University, Fudan University, and the Dalian University of Technology.

The research received funding support from including CityU, the National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, Ministry of Science and ICT of Korea, and National Science Foundation.

DOI number: 10.1038/s41551-021-00723-y

Journal

Nature Biomedical Engineering

DOI

10.1038/s41551-021-00723-y

New Haven, Conn. -- When San Francisco voters overwhelmingly approved a ballot measure banning the sale of flavored tobacco products in 2018, public health advocates celebrated. After all, tobacco use poses a significant threat to public health and health equity, and flavors are particularly attractive to youth.

But according to a new study from the Yale School of Public Health (YSPH), that law may have had the opposite effect. Analyses found that, after the ban's implementation, high school students' odds of smoking conventional cigarettes doubled in San Francisco's school district relative to trends in districts without the ban, even when adjusting for individual demographics and other tobacco policies.

The study, published in JAMA Pediatrics on May 24, is believed to be the first to assess how complete flavor bans affect youth smoking habits.

"These findings suggest a need for caution," said Abigail Friedman, the study's author and an assistant professor of health policy at YSPH. "While neither smoking cigarettes nor vaping nicotine are safe per se, the bulk of current evidence indicates substantially greater harms from smoking, which is responsible for nearly one in five adult deaths annually. Even if it is well-intentioned, a law that increases youth smoking could pose a threat to public health."

Friedman used data on high school students under 18 years of age from the Youth Risk Behavior Surveillance System's 2011-2019 school district surveys. Prior to the ban's implementation, past-30-day smoking rates in San Francisco and the comparison school districts were similar and declining. Yet once the flavor ban was fully implemented in 2019, San Francisco's smoking rates diverged from trends observed elsewhere, increasing as the comparison districts' rates continued to fall.

To explain these results, Friedman noted that electronic nicotine delivery systems have been the most popular tobacco product among U.S. youth since at least 2014, with flavored options largely preferred.

"Think about youth preferences: some kids who vape choose e-cigarettes over combustible tobacco products because of the flavors," she said. "For these individuals as well as would-be vapers with similar preferences, banning flavors may remove their primary motivation for choosing vaping over smoking, pushing some of them back toward conventional cigarettes."

These findings have implications for Connecticut, where the state legislature is currently considering two flavor bills: House Bill 6450 would ban sales of flavored electronic nicotine delivery systems, while Senate Bill 326 would ban sales of any flavored tobacco product. As the U.S. Food and Drug Administration recently announced that it will ban flavors in all combustible tobacco products within the next year, both bills could result in a Connecticut policy that is similar to the complete ban enacted in San Francisco.

The San Francisco study does have limitations. Because there has been only a short time since the ban was implemented, the trend may differ in coming years. San Francisco is also just one of several localities and states that have implemented restrictions on flavored tobacco sales, with extensive differences between these laws. Thus, effects may differ in other places, Friedman wrote.

Still, as similar restrictions continue to appear across the country, the findings suggest that policymakers should be careful not to indirectly push minors toward cigarettes in their quest to reduce vaping, she said.

What does she suggest as an alternative? "If Connecticut is determined to make a change before the FDA's flavor ban for combustible products goes into effect, a good candidate might be restricting all tobacco product sales to adult-only -- that is 21-plus -- retailers," she said. "This would substantively reduce children's incidental exposure to tobacco products at convenience stores and gas stations, and adolescents' access to them, without increasing incentives to choose more lethal combustible products over non-combustible options like e-cigarettes."

This new 3D effect can be the foundation for topological quantum phenomena, which are believed to be particularly robust and therefore promising candidates for extremely powerful quantum technologies. These results have just been published in the scientific journal Nature Communications.

Dr. Tobias Meng and Dr. Johannes Gooth are early career researchers in the Würzburg-Dresdner Cluster of Excellence ct.qmat that researches topological quantum materials since 2019. They could hardly believe the findings of a recent publication in "Nature" claiming that electrons in the topological metal zirconium pentatelluride (ZrTe5) move only in two-dimensional planes, despite the fact that the material is three-dimensional. Meng and Gooth therefore started their own research and experiments on the material ZrTe5. Meng from the Technische Universität Dresden (TUD) developed the theoretical model, Gooth from the Max Planck Institute for Chemical Physics of Solids designed the experiments. Seven measurements with different techniques always lead to the same conclusion.

Electrons waiting for their turn

The research by Meng and Gooth paints a new picture of how the Hall effect works in three-dimensional materials. The scientists believe that electrons move through the metal along three-dimensional paths, but their electric transport can still appear as two-dimensional. In the topological metal zirconium pentatelluride, this is possible because a fraction of the electrons is still waiting to be activated by an external magnetic field.

„The way electrons move is consistent in all of our measurements, and similar to what is otherwise known from the two-dimensional quantum Hall effects. But our electrons move upwards in spirals, rather than being confined to a circular motion in planes. This is an exciting difference to the quantum Hall effect and to the proposed scenarios for what happens in the material ZrTe5", comments Meng on the genesis of their new scientific model. „This only works because not all electrons move at all times. Some remain still, as if they were queuing up. Only when an external magnetic field is applied do they become active."

Experiments confirm the model

For their experiments, the scientists cooled the topological quantum material down to -271 degree Celsius and applied an external magnetic field. Then, they performed electric and thermoelectric measurements by sending currents through the sample, studied its thermodynamics by analysing the magnetic properties of the material, and applied ultrasound. They even used X-ray, Raman and electronic spectroscopy to look into the inner workings of the material. "But none of our seven measurements hinted at the electrons moving only two-dimensionally", explains Meng, head of the Emmy Noether group for Quantum Design at TUD and leading theorist in the present project. "Our model is in fact surprisingly simple, and still explains all the experimental data perfectly."

Outlook for topological quantum materials in 3D

The Nobel-prize-winning quantum Hall effect was discovered in 1980 and describes the stepwise conduction of current in a metal. It is a cornerstone of topological physics, a field that has experienced a surge since 2005 due to its promises for the functional materials of the 21st century. To date, however, the quantum Hall effect has only been observed in two-dimensional metals. The scientific results of the present publication enlarge the understanding of how three-dimensional materials behave in magnetic fields. The cluster members Meng and Gooth intend to further persue this new research direction: "We definitely want to investigate the queueing behavior of electrons in 3D metals in more detail", says Meng.

The group of experts includes Professor and Academician of Tallinn University of Technology Jarek Kurnitski, who said that improving ventilation can be regarded more broadly as a paradigm shift equal in scale to the transformation in the standards of drinking water supplies and food hygiene. "There has long been no doubt that you can get infection when you drink water or eat food that has been contaminated. Now we must work towards providing clean air so we can breathe safely," Kurnitski said.

He added, "Researchers see updating of ventilation standards, ventilation requirements based on the probability of infection and more efficient and flexible ventilation systems as a solution. High air change rates are required only in the event of an epidemic, at any other time it is important to ensure good energy efficiency of ventilation, because energy and climate goals cannot be compromised."

In their address to the WHO (the World Health Organisation) and the general public worldwide, the researchers recommend including pathogen control requirements in air quality standards to combat the spread of airborne pathogens. Ventilation systems should also be demand-controlled to adjust for different room occupancies, and differing activities and breathing rates, such as exercising in a gym versus sitting in a movie theatre.

That risk of people becoming cross-infected inside a building can be reduced through ventilation coupled with air disinfection and air filtration systems. This means more efficient and flexible ventilation systems than today. In addition, the researchers recommend use of monitors displaying the parameters characterizing indoor air quality, which would provide information also to the general public.

According to the researchers, previous response efforts to combat airborne viruses have been too weak because airborne infections are harder to trace and current ventilation standards only control for perceived air quality, i.e. odour, CO2 levels, temperature and humidity in the room. The only exception is specialised health care and research facilities.

Today, the global monthly harm from COVID-19 had been estimated as $1 trillion. The new standards would likely result in less than a 1% increase in the designing and construction cost of new buildings. The benefits are better health and savings in the healthcare system. Improved indoor air quality increases labour productivity and reduces the 'sick building syndrome' and allergic reactions.

Your immune system is always busy fighting incoming threats. It consists of a system of cells, and when there is a shortage of cells, it affects the performance of the immune system.

This is seen in e.g. cancer patients following chemotherapy. This is because chemotherapy targets all the cells in your body, including the stem cells in your bone marrow, which were meant to develop into new immune cells. This means that the immune system then lacks cells to fight new infections.

There are drugs that can harvest stem cells from the bone marrow, so that they can be returned to the patients after treatment. They then develop into new immune cells, enabling the body to once again fight incoming threats. But previously, we lacked detailed knowledge of how these drugs worked.

Now, a study conducted in mice by researchers at the University of Copenhagen demonstrates how the medicine works at the cell level - and, surprisingly, how one of the two applied and tested drugs is more effective than the other, despite the fact that the other drug, on paper, appears to be the most effective of the two. This discovery may not just help improve stem cell transplantation; it may also lead to improved drugs in the future.

"We have tested two drugs for stem cell transplantation which appear to have the same effect. What they do is block a receptor, causing the bone marrow to release stem cells into the blood. What the new study shows, though, is that they do not just block the receptor; one of the two drugs also affects other signalling pathways in the cell. And in short, that makes it more effective than the other of the two drugs," says PhD Student Astrid Sissel Jørgensen from the Department of Biomedical Sciences at the University of Copenhagen.

"We used to believe that all we had to do was block the receptor, and that the two drugs had the same effect. It now appears that there is more to it," she says.

The drugs tested by the researchers mobilize stem cells by acting as CXCR4 receptor antagonists. This means that they inhibit or reduce activity of the receptor. Several drugs target this receptor, including drugs inhibiting HIV replication.

"The drugs not only block the receptor's normal signalling. One of the two drugs we have tested also affect some of the other cell pathways and even make the receptor withdraw into the cell and disappear from the surface," explains Professor Mette Rosenkilde, who is the corresponding author of the study. The study results reveal that one of the two drugs makes the bone marrow release more stem cells into the blood.

This knowledge about how drugs affect cell pathways differently is also known as biased signalling. And it is things like these that make one of the drugs more effective in practice than on paper.

According to the researchers, the new knowledge on biased signalling challenges our current view of these drugs.

"The results of our study directly influence our view of drugs used for stem cell transplantation. In the long term, though, it may also affect our view of future drugs, and how new drugs should be designed to have the best possible effect, both in connection with stem cell mobilisation, but also for treating HIV infections, where this particular receptor also plays a main role," says Mette Rosenkilde.

The findings have been published in "Science", the renowned journal.

The world market for electroceramics is in the region of 25 billion euros a year. These very small components are often not even perceived in daily life. A smartphone alone contains 600 capacitors, 3 trillion - that's 3000 billion - of which are manufactured every year. The way many electroceramics function is not based on current flow through the material, but on small charge dislocations, called polarisation, over fractions of an atomic diameter. About a quarter of the electroceramics produced in the world link this polarisation to an extension of the material, which in turn can be adjusted to the accuracy of an atomic diameter. Only then can ever-smaller computer components and microrobots be structured.

Replacing atomic series in the atom

The properties of the electroceramics can be improved by using chemical interventions to replace individual atoms in the regularly shaped crystal lattice with others (endowing) - a little like sitting a single Borussia Dortmund fan in a black-and-yellow jersey in a cinema full of FC Bayern Munich fans in red tops. However, where there are special requirements, such as a higher temperature or electric voltage, the endowed atom would lose its place (the fan would be pushed around), much to the detriment of the function of the ceramic.

The installation of individual atoms in a ceramic crystal lattice is not stable enough for complex requirements, but the installation of entire atomic series (displacement) is robust. In the football example, this would correspond to having a row of Borussia fans in among the Bayern fans. Material scientists from three working groups of the TU Darmstadt are cooperating with research groups from Switzerland, the Netherlands and the USA in the research on these displacements.

New atoms, new properties

"Chemical methods are no longer sufficient for planned displacements," explains Professor Jürgen Rödel, Head of the research group of Non-Metallic Inorganic Materials at the TU Darmstadt. Instead, the researchers succeeded in achieving the displacement mechanically. They used a process in which the ceramics are mechanically deformed under controlled pressure and temperature conditions so the displacement can be imprinted in the ceramic. An approach such as this is trivial with metals, but until now it was largely deemed impossible with ceramics because of their tremendous hardness. Plus the surface of ceramic is extremely brittle and can easily break. In order to overcome these obstacles, the scientists carried out a mechanical imprint at 1150 degrees Celsius in a single crystal of the previously calculated optimised orientation.

This method now allows a well-ordered field of newly occupied atomic rows. These series control the local polarisation, the load dislocation, in the material. As the imprinted series clearly limit polarisation, it cannot lose structure even under very high operating conditions. In the operation of electroceramics, the material areas now delimited by the series (displacements) take up certain charge shifts; continuing with the football analogy, it is as if the Bayern fans were to lean forward or to the side in sections. As these material areas do not change under high conditions, no energy is converted by internal friction and the material behaviour remains stable.

These materials now make it possible to ensure consistent properties even at raised temperatures and with increased energy use. At the same time, the researchers are addressing the cost reduction necessary in order to provide the displacements by means of several options of mechanical imprinting.

UNIVERSITY PARK, Pa. -- Developing new ultrathin metal electrodes has allowed researchers to create semitransparent perovskite solar cells that are highly efficient and can be coupled with traditional silicon cells to greatly boost the performance of both devices, said an international team of scientists. The research represents a step toward developing completely transparent solar cells.

"Transparent solar cells could someday find a place on windows in homes and office buildings, generating electricity from sunlight that would otherwise be wasted," said Kai Wang, assistant research professor of materials science and engineering at Penn State and co-author on the study. "This is a big step -- we finally succeeded in making efficient, semitransparent solar cells."

Traditional solar cells are made from silicon, but scientists believe they are approaching the limits of the technology in the march to create ever more efficient solar cells. Perovskite cells offer a promising alternative and stacking them on top of the traditional cells can create more efficient tandem devices, the scientists said.

"We've shown we can make electrodes from a very thin, almost few atomic layers of gold," said Shashank Priya, associate vice president for research and professor of materials science and engineering at Penn State. "The thin gold layer has high electrical conductivity and at the same time it doesn't interfere with the cell's ability to absorb sunlight."

The perovskite solar cell that the team developed achieved 19.8% efficiency, a record for a semitransparent cell. And when combined with a traditional silicon solar cell, the tandem device achieved 28.3% efficiency, up from 23.3% from the silicon cell alone. The scientists reported their findings in the journal Nano Energy.

"A 5% improvement in efficiency is giant," Priya said. "This basically means you are converting about 50 watts more sunlight for every square meter of solar cell material. Solar farms can consist of thousands of modules, so that adds up to a lot of electricity, and that's a big breakthrough."

In previous research, ultrathin gold film showed promise as a transparent electrode in perovskite solar cells, but issues in creating a uniform layer resulted in poor conductivity, the scientists said.

The team found that chromium used as a seed layer allowed the gold to form on top in a continuous ultrathin layer with good conductive properties.

"Normally, if you grow a thin layer of something like gold, the nanoparticles will couple together and gather like small islands," said Dong Yang, assistant research professor of materials science and engineering at Penn State. "Chromium has a large surface energy that provides a good place for the gold to grow on top of, and it actually allows the gold to form a continuous thin film."

Perovskite solar cells are composed of five layers and other materials tested as transparent electrodes damaged or degraded layers of the cells. The scientists said solar cells made with the gold electrodes are stable and maintain high efficiencies over time in laboratory tests.

"This breakthrough in the design of tandem cell architecture based on a transparent electrode offers an efficient route toward the transition to perovskite and tandem solar cells," said Yang.