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Tag: Chemistry

  • Swedish media say winners of Nobel Prize in chemistry may have been announced early

    Swedish media say winners of Nobel Prize in chemistry may have been announced early

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    STOCKHOLM — Three scientists won the Nobel Prize in chemistry for their work on tiny quantum dots.

    Moungi Bawendi, of MIT, Louis Brus, of Columbia University, and Alexei Ekimov, of Nanocrystals Technology Inc., were honored for their work with the tiny particles that are just a few atoms in diameter and whose electrons have constrained movement. This effects how they absorb and release visible light, allowing for very bright colors. They are used in many electronics, like LED displays.

    “These tiny particles have unique properties and now spread their light from television screens and LED lamps. They catalyze chemical reactions and their clear light can illuminate tumor tissue for a surgeon,” according to the Royal Swedish Academy of Sciences, which announced the award in Stockholm.

    In a highly unusual turn of events, Swedish media reported the names of the winners before the prize was announced.

    The academy did not comment on the leaked names before the announcement.

    The Royal Swedish Academy of Sciences, which awards the physics, chemistry and economics prizes, asks for nominations a year in advance from thousands of university professors and other scholars around the world.

    A committee for each prize then discusses candidates in a series of meetings throughout the year. At the end of the process, the committee presents one or more proposals to the full academy for a vote. The deliberations, including the names of nominees other than the winners, are kept confidential for 50 years.

    On Tuesday, the physics prize went to French-Swedish physicist Anne L’Huillier, French scientist Pierre Agostini and Hungarian-born Ferenc Krausz for producing the first split-second glimpse into the superfast world of spinning electrons.

    The tiny part of each atom races around the center and is fundamental to virtually everything: chemistry, physics, our bodies and our gadgets.

    On Monday, Hungarian-American Katalin Karikó and American Drew Weissman won the Nobel Prize in medicine for discoveries that enabled the creation of mRNA vaccines against COVID-19.

    Last year, Americans Carolyn R. Bertozzi and K. Barry Sharpless, and Danish scientist Morten Meldal were jointly awarded the Nobel Prize in chemistry for developing a way of “ snapping molecules together” that can be used to explore cells, map DNA and design drugs that can target diseases such as cancer more precisely.

    The chemistry prize means Nobel season has reached its halfway stage. The prizes in literature, peace and economics follow, with one announcement every weekday until Oct. 9.

    The Nobel Foundation raised the prize money by 10% this year to 11 million kronor (about $1 million). In addition to the money, winners receive an 18-carat gold medal and diploma when they collect their Nobel Prizes at the award ceremonies in December.

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    Corder reported from The Hague, Netherlands.

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    Follow all AP stories about the Nobel Prizes at https://apnews.com/hub/nobel-prizes

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  • Dramatically lower the cost of producing green hydrogen

    Dramatically lower the cost of producing green hydrogen

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    Newswise — According to the International Energy Agency (IEA), global hydrogen demand is expected to reach 530 million tons in 2050, a nearly six-fold increase from 2020. Currently, the primary method of hydrogen production involves the reaction of natural gas and water vapor, resulting in what is known as ‘gray hydrogen’ due to its carbon dioxide emissions, constituting around 80% of total hydrogen production. In contrast, green hydrogen is produced through water electrolysis using electricity, without emitting carbon dioxide. However, a challenge lies in the inevitable use of expensive precious metal catalysts, such as iridium oxide.

    A research team led by Dr. Yoo Sung Jong of the Hydrogen and Fuel Cell Research Center at the Korea Institute of Science and Technology (KIST) have succeeded in significantly reducing the cost of green hydrogen production by implementing an anion exchange membrane water electrolysis device with excellent performance and durability by introducing a carbon support. Carbon supports have been utilized as supports for various electrocatalysts due to their high electrical conductivity and specific surface area, but their usage has been limited because they readily oxidize to carbon dioxide in water electrolysis conditions, specifically at high voltages and in the presence of water.

    The team synthesized a nickel-iron-cobalt layered double hydroxide material, a significantly cheaper alternative to iridium, on a hydrophobic carbon support and used it as an electrocatalyst for the oxygen evolution reaction in anion exchange membrane electrolysis. The catalyst showed excellent durability due to the layered structure facing a hydrophobic carbon support and a nickel-iron-cobalt layered double hydroxide catalyst. In terms of carbon corrosion, it was found that the generation of carbon dioxide during the corrosion process was reduced by more than half, primarily because of decreased interaction with water, a key factor in carbon corrosion. It was found that the carbon dioxide generated during the corrosion process was less than half due to the reduced interaction with water, which causes corrosion of carbon.

    As a result of performance evaluation, it is found that the newly developed supported catalyt achieved a current density of 10.29 A/cm-2 in the 2 V region, exceeding the 9.38 A/cm-2 current density of commercial iridium oxide. demonstrated long-term durability of about 550 hours. We also confirmed a correlation between electrolysis performance and the hydrophobicity of carbon, showing for the first time that the support’s hydrophobicity can significantly affect the water electrolysis device’s performance.

    “The results of this research confirm the applicability of water electrolysis devices on carbon supports, which have previously been limited in use due to corrosion problems, and it is expected that water electrolysis technology can grow to the next level if the research focused on catalyst development is expanded to various supports.” “We will strive to develop various eco-friendly energy technologies, including green hydrogen production,” said Dr. Yoo Sung Jong Yoo in KIST.

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    KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/

    This research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the KIST Major Project and Nano and Material Technology Development Project, and the Korea Energy Technology Assessment Institute(Director Kwon Ki-young) Renewable Energy Core Technology Development Project, and the results were published on August 1 in the international journal Energy & Environmental Science (IF 32.5, top 0.4% in JCR).

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    National Research Council of Science and Technology

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  • Sperm swimming is caused by the same patterns that are believed to dictate zebra stripes

    Sperm swimming is caused by the same patterns that are believed to dictate zebra stripes

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    BYLINE: Laura Thomas

    Newswise — Patterns of chemical interactions are thought to create patterns in nature such as stripes and spots. This new study shows that the mathematical basis of these patterns also governs how sperm tail moves.

    The findings, published today in Nature Communications, reveal that flagella movement of, for example, sperm tails and cilia, follow the same template for pattern formation that was discovered by the famous mathematician Alan Turing. 

    Flagellar undulations make stripe patterns in space-time, generating waves that travel along the tail to drive the sperm and microbes forward.

    Alan Turing is most well-known for helping to break the enigma code during WWII. However he also developed a theory of pattern formation that predicted that chemical patterns may appear spontaneously with only two ingredients: chemicals spreading out (diffusing) and reacting together. Turing first proposed the so-called reaction-diffusion theory for pattern formation.

    Turing helped to pave the way for a whole new type of enquiry using reaction-diffusion mathematics to understand natural patterns. Today, these chemical patterns first envisioned by Turing are called Turing patterns. Although not yet proven by experimental evidence, these patterns are thought to govern many patterns across nature, such as leopard spots, the whorl of seeds in the head of a sunflower, and patterns of sand on the beach. Turing’s theory can be applied to various fields, from biology and robotics to astrophysics. 

    Mathematician Dr Hermes Gadêlha, head of the Polymaths Lab, and his PhD student James Cass conducted this research in the School of Engineering Mathematics and Technology at the University of Bristol. Gadêlha explained: “Live spontaneous motion of flagella and cilia is observed everywhere in nature, but little is known about how they are orchestrated.

    “They are critical in health and disease, reproduction, evolution, and survivorship of almost every aquatic microorganism in earth.”

    The team was inspired by recent observations in low viscosity fluids that the surrounding environment plays a minor role on the flagellum. They used mathematical modelling, simulations, and data fitting to show that flagellar undulations can arise spontaneously without the influence of their fluid environment.

    Mathematically this is equivalent to Turing’s reaction-diffusion system that was first proposed for chemical patterns.

    In the case of sperm swimming, chemical reactions of molecular motors power the flagellum, and bending movement diffuses along the tail in waves. The level of generality between visual patterns and patterns of movement is striking and unexpected, and shows that only two simple ingredients are needed to achieve highly complex motion.

    Dr Gadêlha added: “We show that this mathematical ‘recipe’ is followed by two very distant species – bull sperm and Chlamydomonas (a green algae that is used as a model organism across science), suggesting that nature replicates similar solutions.

    “Travelling waves emerge spontaneously even when the flagellum is uninfluenced by the surrounding fluid. This means that the flagellum has a fool-proof mechanism to enable swimming in low viscosity environments, which would otherwise be impossible for aquatic species.

    “It is the first time that model simulations compare well with experimental data.

    “We are grateful to the researchers that made their data freely available, without which we would not have been able to proceed with this mathematical study.”

    These findings may be used in future to better understand fertility issues associated with abnormal flagellar motion and other ciliopathies; diseases caused by ineffective cilia in human bodies.

    This could also be further explored for robotic applications, artificial muscles, and animated materials, as the team discovered a simple “mathematical recipe” for making patterns of movement.

    Dr Gadêlha is also a member of the SoftLab at Bristol Robotics Laboratory (BRL), where he uses pattern formation mathematics to innovate the next generation of soft-robots.

    “In 1952, Turing unlocked the reaction-diffusion basis of chemical patterns,” said Dr Gadêlha. “We show that the ‘atom’ of motion in the cellular world, the flagellum, uses Turing’s template to shape, instead, patterns of movement driving tail motion that pushes sperm forwards.

    “Although this is a step closer to mathematically decode spontaneous animation in nature, our reaction-diffusion model is far too simple to fully capture all complexity. Other models may exist, in the space of models, with equal, or even better, fits with experiments, that we simply have no knowledge of their existence yet, and thus substantial more research is still needed!”

    The study was completed using funding from the Engineering and Physical Sciences Research Council (EPSRC) and DTP studentship for James Cass PhD.

    The numerical work was carried out using the computational and data storage facilities of the Advanced Computing Research Centre, at the University of Bristol.

     

    Paper:

    ‘The reaction-diffusion basis of animated patterns in eukaryotic flagella’ by James Cass and Dr Hermes Bloomfield-Gadêlha in Nature Communications.

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    University of Bristol

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  • World-class neutron source takes a break for major Proton Power Upgrade

    World-class neutron source takes a break for major Proton Power Upgrade

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    Newswise — The Spallation Neutron Source at Oak Ridge National Laboratory — already the world’s most powerful accelerator-based neutron source — will be on a planned hiatus through June 2024 as crews work to upgrade the facility.

    Much of the work — part of the facility’s Proton Power Upgrade project — will involve building a connector between the accelerator and the planned Second Target Station at SNS. When complete, the PPU project will bring the accelerator up to 2.8 megawatts from its current record-breaking 1.7 megawatts of beam power.

    Workers will add about 3,000 square feet of concrete tunnel, the “stub,” which will integrate with an existing tunnel. Construction tasks include associated structures, roofing, geomembrane liner, tunnel waterproofing, electrical, fire alarm, ventilation systems and controls.

    “The construction crews have performed all of the excavation work and are transitioning to tunnel base and wall construction,” said ORNL’s Mark Champion, PPU project manager.

    The stub is scheduled to be completed within six months, by the end of February, and most of the rest of this outage will involve installing new components and systems to complete the PPU project.

    That work includes:

    • Installing three new cryomodules, adding more radio-frequency stations and upgrading two high-voltage units to support new 3.0 megawatt klystrons.
    • Installing an injection dump imaging system and new magnets and upgrading deionized water systems, power supplies and a beam power limit system.
    • Installing a new liquid hydrogen refill system, mercury overflow tank and target complete with gas injection and recirculation system.
    • Completing controls integration.

    The upgrade will increase the flow of neutrons — known as the neutron flux — to the First Target Station, or FTS, and eventually also power the STS.

    Power to the FTS — which produces thermal neutrons to analyze samples down to the atomic scale — will increase to 2.0 megawatts, enabling new scientific discoveries in such areas as superconductors, energy materials such as those used in batteries, and basic physics. The additional power will be split via the stub, to power the STS, which will have the world’s highest peak brightness of neutrons, tailored for probing soft matter such as polymers and biological materials, and complex engineering materials. This is used in vaccine research, advanced batteries and for decarbonization studies.

    “It’s very gratifying to reach one of the final stages of the project after several years of planning, design and engineering,” said ORNL’s John Galambos, PPU project director. “It’s a huge tribute to the skills and dedication of the entire PPU team and our partner labs that the project has remained on schedule and on budget despite unprecedented challenges, including Covid-19 and subsequent supply chain issues.”

    The Spallation Neutron Source is an Office of Science user facility at ORNL.

    UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

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    Oak Ridge National Laboratory

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  • Enhancing Chemical Identification Challenges

    Enhancing Chemical Identification Challenges

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    Newswise — What chemicals are we exposed to on a daily basis? That is the central question of ‘non-targeted analysis’ or NTA, an emerging field of analytical science that aims to identify all chemicals around us. A daunting task, because how can you be sure to detect everything if you don’t know exactly what you’re looking for? In a paper in Environmental Science and Technology, researchers at the Universities of Amsterdam (UvA, the Netherlands) and Queensland (UQ, Australia) assess this problem. In a meta-analysis of NTA results published over the past six years, they estimate that less than 2% of all chemicals have been identified.

    According to Viktoriia Turkina who performed the research as a PhD student with Dr Saer Samanipour  at the UvA’s Van ‘t Hoff Institute for Molecular Sciences, this limitation underscores the urgent need for a more proactive approach to chemical monitoring and management. “We need to incorporate more data-driven strategies into our studies to be able to effectively protect the human and environmental health”, she says.

    Samanipour explains that current monitoring of chemicals is rather limited since it’s expensive, time consuming, and requires specialized experts. “As an example, in the Netherlands we have one of the most sophisticated monitoring programs for chemicals known to be of concern to human health. Yet we target less than 1000 chemicals. There are far more chemicals out there that we don’t know about.”

    A vast chemical space

    To deal with those chemicals, some 15 to 20 years ago the concept of non-targeted analysis was introduced to look at possible exposure in an unbiased manner. The idea is to take a sample from the environment (air, water, soil, sewer sludge) or the human body (hair, blood, etc ) and analyse it using well-established analytical techniques such as chromatography coupled with high resolution mass spectroscopy. The challenge then is to trace the obtained signal back to the structures of chemicals that may be present in the sample. This will include already known  chemicals, but also chemicals of which the potential presence in the environment is yet unknown.

    In theory, this ‘chemical space’ includes as many as 1060 compounds, an incomprehensible number that exceeds the number of stars in the universe by far. On the other hand, the number of organic and inorganic substances published in the scientific literature and public databases is estimated at around 180 million. To make their research even more manageable, Turkina, Samanipour and co-workers focused on a subset of 60.000 well-described compounds from the NORMAN database. Turkina: “This served as the reference to establish what is covered in NTA studies, and more importantly, to develop an idea about what is being overlooked.”

    The vast ‘exposome’ of chemicals that humans are exposed to on a daily basis is a sign of our times, according to Samanipour. “These days we are soaking in a giant ocean of chemicals. The chemical industry is part of that, but also nature is running all a whole bunch of reactions that result in exposure. And we expose ourselves to chemicals by the stuff we use – think for instance of the problem of microplastics. To solve all this we have to be able to go beyond pointing fingers. With our research, we hope to contribute to finding a solution together. Because we all are in the same boat.”

    Much room for improvement

    The meta analysis, which included 57 NTA papers, revealed that only around 2% of the estimated chemical space was covered. This can indicate that the actual exposure to chemicals is indeed quite low, however, it can also point to shortcomings in the applied analyses. According to Turkina and Samanipour, the latter is indeed the case. They focused on NTA studies applying liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) -one of the most comprehensive methods for the analysis of complex environmental and biological samples.

    It turned out that there was much room for improvement. For instance in sample preparation, they observed a bias towards specific compounds rather than capturing a more diverse set of chemicals. They also observed poor selection and inconsistent reporting of LC-HRMS parameters and data acquisition methods. “In general”, Samanipour says, “the chemical analysis community is to a great extent driven by the available technology that vendors have developed for specific analysis purposes. Thus the instrumental set-up and data processing methods are rather limited when it comes to non-targeted analysis.”

    To Samanipour, the NTA approach is definitely worth pursuing. “But we need to develop it further and push it forward. Together with vendors we can develop new powerful and more versatile analytical technologies, as well as effective data analysis protocols.” He also advocates a data-driven approach were the theoretical chemical space is ‘back calculated’  towards a subset of chemicals that are highly likely to be present in our environment. “Basically we have to better understand what is the true chemical space of exposure. And once those boundaries are defined, then it becomes a lot easier to assess that number of 2% we have determined.”

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    Universiteit van Amsterdam

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  • NSF grant awarded for development of method to recover rare-earth elements from U.S. mines

    NSF grant awarded for development of method to recover rare-earth elements from U.S. mines

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    Newswise — The National Science Foundation (NSF) has awarded a $2 million grant to researchers who are developing new functional materials to separate and recover rare-earth elements and platinum group metals from waste streams of U.S. mines. These critical elements – which are required materials for widely-used products like smartphones and LED lights – are currently largely mined and processed by other countries.

    Chemical & Biomolecular Engineering (ChBE) professor Xiao Su at the University of Illinois Urbana-Champaign leads the project. UIUC professors Diwakar Shukla (ChBE), Alexander Mironenko (ChBE) and Prashant Jain (Chemistry), and Michelle Calabrese (professor in Chemical Engineering & Materials Science at University of Minnesota) are co-Principal Investigators on the project.

    According to the researchers, there is potential for the U.S. to significantly ramp up its production of both rare-earth elements and platinum group metals, as well as secure its supply-chain, through more efficient and sustainable processes for recovery and recycling. Recovery of rare-earth metals and platinum group metals from the waste streams of U.S. mines is currently difficult because they are found as dilute ions in a complex mixture of elements. To address this challenge, the team will develop new polymer-based electrode materials to capture the elements in a way that is highly selective yet reversible, and implement electrically-driven separation processes for sustainable recovery and purification. The researchers combine expertise in machine-learning, molecular dynamics and electronic structure calculations, materials synthesis, characterization, and processing, as well as separation processes.

    “Our aim is to accelerate the discovery of new materials for electrochemical separations through a closed-loop iteration between simulations and experiments,” Su said. “We seek to move beyond a trial-and-error approach for materials design and testing, and establish for the first time a rational framework for creating new redox-polymers tailored for the sustainable electrochemical recovery of critical elements.”

    The grant is administered by NSF’s Designing Materials to Revolutionize and Engineer our Future program. More information about this project, Rational design of redox-responsive materials for critical element separations, is available here. UIUC received $1.6 million in funding, and University of Minnesota received $400,000.

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    University Of Illinois Grainger College Of Engineering

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  • Lithium Sustainability for Decades

    Lithium Sustainability for Decades

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    Newswise — On the way towards climate neutrality, Europe will need large amounts of lithium for battery storage systems. So far, however, its share in the worldwide lithium extraction volume has been one percent only. For this reason, researchers of KIT study ways to extract lithium from geothermal sources. “In theory, geothermal power plants in the Upper Rhine Valley and Northern German Basin might cover between 2 and 12 percent of Germany’s annual lithium demand,” says Valentin Goldberg from KIT’s Institute of Applied Geosciences (AGW). With his team, he calculated this potential based on an extensive data analysis. However, it has not been clear for how long extraction will be possible. Another study of the researchers now offers an optimistic perspective. “According to our findings, lithium extraction will be possible for many years at low environmental cost,” Goldberg says. “The model developed for our study describes lithium extraction in the Upper Rhine Valley. But parameters are chosen such that they can also be transferred to other joint systems.“

    Modeling of Geothermal Lithium Production

    Extraction of lithium from thermal waters is no conventional type of mining. That is why no conventional methods could be applied for analysis. “The lithium dissolved in water exists in a widely branched network of joints and cavities in the rock. However, it can only be accessed at certain points via individual wells,” says Dr. Fabian Nitschke, AGW, who was also involved in this study. “The reservoir dimension, hence, depends on the amount of water that can be accessed hydraulically via wells.” To calculate the lithium production potential, researchers had to consider the potential water extraction volume, its lithium concentration, and lithium extraction per unit time. “We use a dynamic transport model adapted to underground conditions in the Upper Rhine Valley. It couples thermal, hydraulic, and chemical processes. Similar models are known from petroleum and gas industry, but have not yet been applied to lithium,” Nitschke points out.

    When using geothermal energy, the extracted water is pumped back into the ground via a second borehole. Researchers wanted to find out whether lithium concentration of the deep water decreases with time. The results show that lithium concentration in the extraction borehole decreases by 30 to 50 percent in the first third of the investigation period of 30 years, as the deep water is diluted by the returned water. Then, lithium concentration remains constant. “This can be attributed to the open joint system that continuously supplies fresh deep water from other directions,” Nitschke says. Modeling suggests that continuous lithium extraction will be possible for decades: “Actually, extraction of this unconventional resource shows the classical cyclic behavior. Yields of hydrocarbon extraction or ore mining are also highest in the beginning and then start to decrease gradually.”

    Sensible Investment in a Sustainable Future

    Thomas Kohl from AGW, who directs the corresponding research activities as Professor for Geothermal Energy and Reservoir Technology, considers the research results another argument in favor of a wide use of geothermal energy. “We already knew that geothermal sources can supply baseload-capable, renewable energy for decades. Our study now reveals that a single power plant in the Upper Rhine Valley could additionally cover up to 3 percent of the annual German lithium consumption.” Kohl’s group is now working on solutions for practical implementation.. Recently, it published a study in Desalination on the preliminary treatment of thermal water for resource extraction. “The next step now is to transfer this technology to the industrial scale,” Kohl says.

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    Karlsruhe Institute of Technology (KIT)

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  • Observing the Coherent Motion of Electrons with an Attosecond Stopwatch

    Observing the Coherent Motion of Electrons with an Attosecond Stopwatch

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    The Science

    A remarkable consequence of quantum mechanics is that electrons can display interference effects. This interference is similar to waves interacting in the ocean or the electromagnetic waves that carry radio signals. Scientists were able to observe the quantum mechanical motion of electrons in an excited molecule thanks to a device called an “attoclock.” This device measures the motion of electrons with a precision of hundreds of attoseconds (1 billionth of 1 billionth of a second!). This measurement provides insights on how the coherent oscillation of charges inside a molecule displays interference effects at attosecond time scales.

    The Impact

    The motion of electrons happens on such fast time scales that their measurement can only be performed with extremely short flashes of light (typically shorter than one femtosecond). Until now, sub-femtosecond measurements were only possible using extreme ultraviolet sources produced by laser systems. Researchers need a source that extends these short pulses to the X-ray domain in order to enable measurements that can distinguish electron motion between different atoms in a molecule. This new experimental method will enable the study of electron dynamics in complicated molecules. This will advance our understanding of molecular physics and quantum chemistry.

    Summary

    The recent development of attosecond X-ray free-electron lasers has opened new avenues for ultrafast science. In this experiment, researchers used the ultrafast X-ray pulses from the Linac Coherent Light Source, a Department of Energy (DOE) user facility at SLAC National Accelerator Laboratory, to create a coherent superposition of excited states in nitric oxide. These excited states are short-lived and can decay through the Auger-Meitner process, where the excitation energy is released by ejecting a fast electron.

    The researchers measured the Auger-Meitner decay process in the time-domain using an attoclock, a device that is capable of measuring the arrival time of electrons with attosecond precision. The researchers observed that the time-dependence of the decay is not a simple exponential function, but it contains ultrafast oscillations. These oscillations are a signature of coherent electron dynamics, specifically the quantum beat between two coherently excited quantum states. This represents the first atomic site-specific observation of coherent electron motion in a molecule, and the first time-domain experiment with attosecond resolution using an X-ray free-electron laser.

     

    Funding

    This research was supported by the Department of Energy Office of Science, Basic Energy Science and Chemical Sciences, Geosciences, and Biosciences. Other funding sources included the Laboratory Directed Research and Development Program of SLAC National Accelerator Laboratory; the German Research Foundation, the Federal Ministry of Education and Research, and the Max Planck Society, Germany; the Engineering and Physical Sciences Research Council of United Kingdom; the Swiss National Science Foundation and National Center of Competence in Research–Molecular Ultrafast Science and Technology; and the U.S. National Science Foundation. This research used resources of the Linac Coherent Light Source, a DOE Office of Science user facility.


    Journal Link: Science, Jan-2022

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    Department of Energy, Office of Science

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  • Rubber plumbing seals can leak additives into drinking water, study says

    Rubber plumbing seals can leak additives into drinking water, study says

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    Newswise — As drinking water flows through pipes and into a glass, it runs against the rubber seals inside some plumbing devices. These parts contain additives that contribute to their flexibility and durability, but these potentially harmful compounds can leak into drinking water, according to a small-scale study in ACS’ Environmental Science & Technology Letters. The authors report that the released compounds, which are typically linked to tire pollution, also transformed into other unwanted byproducts.

    To enhance rubber’s strength and durability, manufacturers typically mix in additives. Scientists have shown that tire dust can transport these substances, such as 1,3 diphenylguanidine (DPG) and N-(1,3-dimethylbutyl)-N’-phenyl-1,4-benzenediamine (6PPD), into waterways. DPG and 6PPD have also been detected in drinking water samples, though it’s unclear how the compounds got there. In previous research, Shane Snyder and Mauricius Marques dos Santos found that these rubber additives can react with disinfectants in simulated drinking water. Their lab tests generated a variety of chlorinated compounds, some of which could damage DNA. Now, the team wanted to assess whether real-world rubber plumbing fixtures can release DPG and 6PPD and form chlorinated byproducts in drinking water samples.

    In this pilot study, the team collected tap water from 20 buildings and detected polymer additives at parts per trillion levels in every sample. The researchers explain that these compounds are not currently regulated, but the measured levels are potentially concerning, based on their previous study’s results from human cell bioassays. And the samples from faucets with aerators contained the highest total amounts. All of the samples contained DPG and one of its chlorinated byproducts, whereas 6PPD and two other chlorine-containing compounds were each found in fewer than five samples. This is the first report of chlorinated DPG byproducts in drinking water, according to the researchers.

    To see if these compounds could have come from plumbing fixtures, the team tested rubber O-rings and gaskets from seven commercial devices, including faucet aerators and connection seals. In the experiment, the rings sat in water with or without chlorinated disinfectants for up to two weeks. Most of the seals, except for the silicone-based ones, released DPG and 6PPD additives. Additionally, plumbing pieces sitting in disinfectant-treated water generated chlorinated forms of DPG in amounts that were consistent with those observed in the drinking water samples. Because some of the rubber plumbing seals released DPG and 6PPD, the researchers say that drinking water, as well as tire pollution, could be a route of human exposure to these compounds.

    The authors acknowledge funding from the Merlion programme; the French Ministry of Europe and Foreign Affairs; the Nanyang Technological University; the National Research Foundation of Singapore; and the Public Utilities Board, Singapore’s National Water Agency.

    The paper’s abstract will be available on Sept. 6 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.estlett.3c00446

    The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

    To automatically receive news releases from the American Chemical Society, contact [email protected].

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    American Chemical Society (ACS)

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  • Machine learning tool simplifies one of the most widely used reactions in the pharmaceutical industry

    Machine learning tool simplifies one of the most widely used reactions in the pharmaceutical industry

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    BYLINE: Tracy Crane, Department of Chemistry

    Newswise — In the past two decades, the carbon-nitrogen bond forming reaction, known as the Buchwald-Hartwig reaction, has become one of the most widely used tools in organic synthesis, particularly in the pharmaceutical industry given the prevalence of nitrogen in natural products and pharmaceuticals. This powerful reaction has revolutionized the way nitrogen-containing compounds are made in academic and industrial laboratories, but it requires lengthy, time-consuming experimentation to determine the best conditions for a highly effective reaction.

    Now, Illinois researchers in collaboration with chemists at Hoffman La-Roche, a pharmaceutical company in Switzerland, have developed a machine learning tool that predicts in a matter of minutes the best conditions for a high-yielding reaction with no lengthy experimentation.

    In a recently published article in Science (DOI: 10.1126/science.adg2114), Illinois chemistry professor Scott Denmark and Ian Rinehart, a recent PhD graduate in the Denmark lab, describe how they developed, trained, and tested their machine learning model to drastically accelerate the identification of substrate-adaptive conditions for this palladium–catalyzed carbon-nitrogen bond forming reaction.

    Denmark said this reaction is a very general transformation so there is much structural diversity among reactant pairings and a lot of “levers to pull” to make it work.

    “And that’s what we have figured out,” Denmark said.

    User guides and cheat sheets have evolved in the nearly 30 years since this reaction was discovered, and they can provide some direction, Rinehart explained, but experimentation is often necessary. Basically, a trial-and-error process in a lab.

    “It’s a problem that everyone in the pharmaceutical industry recognized was ripe for intervention by informatics methods,” Denmark said. “Lots of people have tried to use the US Patent and Trademark Office or Chemical Abstracts™ or other huge databases to try to model to make predictive tools for this one very important reaction. But they haven’t been able to do very well because the information in the literature is just not very reliable.”

    The design and construction of their machine learning tool required the generation of an experimental dataset that explores a diverse network of reactant pairings across a set of reaction conditions. A large scope of C–N couplings was actively learned by neural network models by using a systematic process to design experiments.

    The challenge for a project like this, Denmark said, was the amount of potential data to collect and the thousands and thousands of experiments required to build a database of information for modeling.

    “One of Ian’s biggest contributions was figuring out the workflow to decide what experiments to do to get a valid predictive model with about 3,500 experiments and still be able to make predictions without an enormous database,” Denmark said.

    They also experimentally validated the predictions from the machine learning tool.

    “We tested them and found with pretty good statistics that the conditions were producing compounds when we expected,” Denmark said.

    The researchers report that their models showed good performance in experimental validation: Ten products were isolated in more than 85 percent yield from a range of couplings with out-of-sample reactants designed to challenge the models.

    Rinehart said they taught machine learning models to have a kind of chemical intuition like what an expert has.

    “So, we have now run or talked about so many of these couplings that we have a good intuition about what’s going to happen, but someone who hadn’t run hundreds or thousands of these might not have a good first guess. We have taught a model at a much more granular level [than user guides] to have an intuition. It’s not perfect. But that’s kind of the point. It doesn’t have to be. It just has to get you to the answer faster,” Rinehart said.

    And the coolest part, Rinehart explained, is that intuition gets honed over time as more people use the machine learning tool. The developed workflow continually improves the prediction capability of the tool as the corpus of data grows.

    “It’s an exciting time as data science merges with chemistry,” Denmark said. “And this is the perfect marriage. A lot of people recognized this, but no one has done it, at least not in a meaningful way that is experimentally validated.”

    The Denmark group is creating a cloud-based version of the workflow to enable scientists around the world to use this tool which will continuously add data to improve the model as more structurally diverse substrates are tested and different catalysts and conditions are added to the database.

    Rinehart said the code is public and on an open-source license, so anyone can download and use it. Also, he is currently working on a more user-friendly interface that will allow someone to draw the two molecules they want to react, copy and paste them into the program, and get predictions in minutes instead of hours, depending on the complexity of the molecules.

    “I think it’s really exciting to do something like that,” Rinehart said. “We don’t often publish a paper and put out a tool in the public domain that people can use in the field. People in academic labs like ours could use this tool and get an answer faster in their own research.”

     

    Funding for this project was provided through the National Science Foundation (NSF) (grant no. CHE 1900617) and the Molecule Maker Lab Institute, an AI Research Institutes program on the University of Illinois Urbana-Champaign campus that is supported by the NSF under grant no. CHE 2019897.

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  • Digging deeper into how vaccines work against parasitic disease

    Digging deeper into how vaccines work against parasitic disease

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    Newswise — COLUMBUS, Ohio – Scientists have established the effectiveness of vaccines they developed to prevent the disfiguring skin disease leishmaniasis in animal studies, and Phase 1 human trial planning is in motion for the most promising candidate. 

    But in new work, the research team has determined how these vaccine candidates, created using mutated disease-causing parasites, prompt molecular-level changes in host cells that have specific roles in helping generate the immune response. 

    Despite using the same CRISPR gene-editing technique to make the vaccines, the two species of Leishmania parasites on which the vaccines are based produced very different effects in the immunized host: One enables the immune response to unfold by inhibiting a host metabolite that suppresses immune activity, and the other drives up activation of a chemical pathway in a way that primes immune cells to fight pathogens. 

    “I think it’s an important finding in the sense that we show that in the big picture, yes, these vaccines are protective, but at the molecular level the mechanisms can be totally distinct,” said Abhay Satoskar, professor of pathology in The Ohio State University College of Medicine and co-leader of the research team. 

    “This is not only conceptually important, but if you can find how these things are modulating the immune response in the right direction, and identify the pathways, then perhaps those pathways could be used for developing new interventions,” said Satoskar, a senior author of two new papers describing the findings. 

    The primary vaccine was made by editing the genome of Leishmania major, which causes cutaneous leishmaniasis in tropical and subtropical regions of the Eastern Hemisphere, and a backup vaccine was made using Leishmania mexicana, a more virulent species found in South, Central and North America. 

    The study findings on the metabolic effects of the L. major and L. mexicana vaccines were published Aug. 29, 2023, in the journal iScience. 

    Leishmaniasis is prevalent in 90 countries affecting about 12 million people globally at any given time, but no licensed human vaccine yet exists and the only drug treatment for the skin lesions requires weeks of daily injections with unpleasant side effects. The more lethal visceral leishmaniasis affects organs and is fatal if left untreated. 

    In developing these live attenuated vaccines, Satoskar and colleagues applied new technology to the century-old Middle Eastern practice of leishmanization – introducing the live parasite to the skin to create a small infection that, once healed, leads to life-long immunity against further disease. 

    The researchers previously reported using CRISPR to delete centrin, the gene for a protein that supports the parasite’s physical structure, from the genomes of both L. major and L. mexicana. Experiments showed vaccinated mice remained clear of skin lesions and the number of parasites at the infection site were held at bay. 

    Digging deeper into the vaccines’ effects in these new studies, researchers inoculated mouse ears with a normal parasite, a mutated parasite vaccine or a placebo, mimicking the bite of a sand fly – in humans and animals, leishmania is transmitted through the bite of infected sand flies. 

    The team used mass spectrometry at the inoculation site to identify the most prominent metabolites – the amino acids, vitamins and other small molecules produced as a result of metabolism, the many chemical reactions that keep the body functioning. 

    Results showed the L. major vaccine promoted a pro-inflammatory metabolic response in mice by using the amino acid tryptophan to block signals from a molecule that helps suppress immunity. The L. mexicana vaccine, on the other hand, enriched a series of metabolic reactions that activated the necessary pro-inflammatory work of front-line immune cells.  

    “We took an unbiased approach to analyze the metabolites detectable at the inoculation site. There is growing interest in understanding the role immune cell metabolism plays in modulating immune function,” said Satoskar, also a professor of microbiology at Ohio State. “We also learned that by removing the centrin gene, we got rid of the parasites’ ability to manipulate metabolic pathways in a way that would impair development of protective immunity and, in fact, promoted vaccine-induced immunity. That’s important to know for a live attenuated vaccine – there is a unique case for each parasite species.” 

    Though this information is not required for regulatory approval of these vaccines, the data could prove useful to supplementing vaccination. 

    “There are only four existing drugs for leishmaniasis,” Satoskar said. “We need to know the mechanism of vaccines so the knowledge can be used to develop newer vaccines or newer drugs that target these pathways. What you learn from immunomodulation can be used for developing other therapeutic agents.”

    This research was funded by the Global Health Innovative Technology Fund and the Center for Biologics Evaluation and Research within the Food and Drug Administration (FDA). The FDA is a co-owner of two U.S. patents associated with the mutated Leishmania species. 

    Co-authors of both papers include Sreenivas Gannavaram and Hira Nakhasi, who co-led the L. major study, and Nazli Azodi and Hannah Markle, all of the FDA; Greta Volpedo of Ohio State; Timur Oljuskin of the USDA Animal Parasitic Diseases Laboratory; Shinjiro Hamano of Nagasaki University; and Greg Matlashewski of McGill University. Thalia Pacheco-Fernandez of Ohio State co-authored the L. mexicana paper and Parna Bhattacharya of FDA co-authored the L. major paper.

     

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  • New antibiotic from ‘dark matter’ targets superbugs

    New antibiotic from ‘dark matter’ targets superbugs

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    Newswise — A new powerful antibiotic, isolated from bacteria that could not be studied before, seems capable to combat harmful bacteria and even multi-resistant ‘superbugs’. Named Clovibactin, the antibiotic appears to kill bacteria in an unusual way, making it more difficult for bacteria to develop any resistance against it. Researchers from Utrecht University, Bonn University (Germany), the German Center for Infection Research (DZIF), Northeastern University of Boston (USA), and the company NovoBiotic Pharmaceuticals (Cambridge, USA) now share the discovery of Clovibactin and its killing mechanism in the scientific journal Cell.

    Urgent need for new antibiotics

    Antimicrobial resistance is a major problem for human health and researchers worldwide are looking for new solutions. “We urgently need new antibiotics to combat bacteria that become increasingly resistant to most clinically used antibiotics,” says Dr. Markus Weingarth, a researcher from the Chemistry Department of Utrecht University.

    However, the discovery of new antibiotics is a challenge: few new antibiotics have been introduced into the clinics over the last decades, and then they often resemble older, already known antibiotics.

    “Clovibactin is different,” says Weingarth. “Since Clovibactin was isolated from bacteria that could not be grown before, pathogenic bacteria have not seen such an antibiotic before and had no time to develop resistance.”

    Antibiotic from bacterial dark matter

    Clovibactin was discovered by NovoBiotic Pharmaceuticals, a small US-based early-stage company, and microbiologist Prof. Kim Lewis from Northeastern University, Boston. Earlier, they developed a device that allows to grow ‘bacterial dark matter’, which are so-called unculturable bacteria. Intriguingly, 99% of all bacteria are ‘unculturable’ and could not be grown in laboratories previously, hence they could not be mined for novel antibiotics. Using the device, called iCHip, the US researchers discovered Clovibactin in a bacterium isolated from a sandy soil from North Carolina: E. terrae ssp. Carolina.

    In the joint Cell publication, NovoBiotic Pharmaceuticals shows that Clovibactin successfully attacks a broad spectrum of bacterial pathogens. It was also successfully used to treated mice infected with the superbug Staphylococcus aureus. 

    A broad target spectrum

    Clovibactin appears to have an unusual killing mechanism. It targets not just one, but three different precursor molecules that are all essential for the construction of the cell wall, an envelope-like structure that surrounds bacteria. This was discovered by the group of Prof. Tanja Schneider from the University of Bonn in Germany, one of the Cell paper’s co-authors.

    Schneider: “The multi-target attack mechanism of Clovibactin blocks bacterial cell wall synthesis simultaneously at different positions. This improves the drug’s activity and substantially increases its robustness to resistance development.”

    A cage-like structure

    How exactly Clovibactin blocks the synthesis of the bacterial cell wall was unraveled by the team of Dr. Markus Weingarth from Utrecht University. They used a special technique called solid-state nuclear magnetic resonance (NMR) that allows to study Clovibactin’s mechanism under similar conditions as in bacteria.

    “Clovibactin wraps around the pyrophosphate like a tightly sitting glove. Like a cage that encloses its target” says Weingarth. This is was gives Clovibactin its name, which is derived from Greek word “Klouvi”, which means cage. The remarkable aspect of Clovibactin’s mechanism is that it only binds to the immutable pyrophosphate that is common to cell wall precursors, but it ignores that variable sugar-peptide part of the targets. “As Clovibactin only binds to the immutable, conserved part of its targets, bacteria will have a much harder time developing any resistance against it. In fact, we did not observe any resistance to Clovibactin in our studies.”

    Fibrils capture the targets

    Clovibactin can do even more. Upon binding the target molecules, it self-assembles into large fibrils on the surface of bacterial membranes. These fibrils are stable for a long time and thereby ensure that the target molecules remain sequestered for as long as necessary to kill bacteria.

    “Since these fibrils only form on bacterial membranes and not on human membranes, they are presumably also the reason why Clovibactin selectively damages bacterial cells but is not toxic to human cells,” says Weingarth. “Clovibactin hence has potential for the design of improved therapeutics that kill bacterial pathogens without resistance development.”.

     

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  • Monell Center Helps Discover Epigenetic Mechanism that Causes Bitter Taste Distortion

    Monell Center Helps Discover Epigenetic Mechanism that Causes Bitter Taste Distortion

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    Newswise — PHILADELPHIA (August 22, 2023) – A bitter taste in the mouth is often a symptom or side effect of illness, which may be the result of how the body reacts to pathogens. A new study published in iScience, by Hong Wang, PhD, an Associate Member at the Monell Chemical Sense Center, and colleagues sheds light on the mechanisms involved in the complex interplay between taste perception and immune function. Their work also highlights the potential of a sequencing tool for investigating epigenetic mechanisms that affect taste-cell gene expression. Epigenetics is the study of how and when genes are expressed rather than alteration of the genetic code itself.

    In addition to being unpleasant, a bitter taste in the mouth or from food can contribute to a loss of appetite, an effect associated with ailments from the common cold to cancer. Bitter taste can also affect patients’ willingness to take certain medications, especially when they are young children. Bitter receptors are encoded by Tas2r genes, which also provide an important defense against bacteria and parasites in the mouth and gut. However, this process is not well understood.

    For this study, the team explored how inducing inflammation would affect gene regulation of these taste receptors. Using lipopolysaccharide (LPS), a compound that induces inflammation similar to that caused by bacterial infections, they found that mice showed a distinct elevated aversion to bitter tastes. The team used nerve-recording experiments to confirm that this aversion originates in the taste buds of mice, rather than in their brains.

    “Our study had very clear data showing this is actually a change at the peripheral level, not deep in the brain,” said Wang, confirming that genes in taste cells govern bitter taste distortion to this type of inflammation.

    This finding has interesting clinical implications for the study of behavioral aspects of illness, such as a loss of appetite. When people are sick they often do not feel like eating. This can affect even humans’ love for sugary treats, as other studies have noted. Mice also have a decreased preference for sweet tastes during illness and forced intake of sugar can make them sicker. These results potentially indicate a protective behavior with a biological or evolutionary basis.

    To investigate the underlying gene expression mechanisms of the bitterness response, the team used several methods of analysis. Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) revealed a significantly increased response across the majority of the Tas2r taste-receptor genes, with peak gene expression ranging from three to five days during the sickness period.

    The researchers also used single-cell sequencing assay for transposase-accessible chromatin (scATAC-seq) to explore the expression of Tas2r genes in response to LPS – the first reported instance of this method to study taste receptor gene expression. LPS markedly increased the accessibility of many Tas2r genes, indicating that the bitter taste distortion in this experiment is caused by an epigenetic mechanism, similar to how disease-causing bacteria can affect those genes.

    Finally, the study showed that LPS-induced inflammation globally affected gene expression in taste stem cells, suggesting a “remodeling” of the cells’ genome. This may leave an epigenetic memory, enabling the cells to respond faster to future infections, but may also contribute to long-lasting effects on taste responses. This finding sheds light on why cancer treatment and certain chronic illnesses can cause a lingering bitter taste in the mouth or alter the taste perception of certain foods.

    This diverse response across taste receptors has potential implications for research on how to make more effective bitter blockers for medications and other edible health and wellness products. “The spectrum of the bitter taste receptor expression is not uniform,” Wang said. “If we want to look at a bitter blocker for an individual taste receptor, we may want to take these factors into consideration, such as whether it’s for after a sickness, during a sickness, or which of the taste receptor genes is most prominently expressed.”

    ###

    The Monell Chemical Senses Center is an independent nonprofit basic research institute based in Philadelphia, Pennsylvania. Founded in 1968, Monell‘s mission is to improve health and well-being by advancing the scientific understanding of taste, smell, and related senses, where our discoveries lead to improving nutritional health, diagnosing and treating disease, addressing smell and taste loss, and digitizing chemosensory data.

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  • Chronicle readers cite pros and cons of medical marijuana | Local News – Medical Marijuana Program Connection

    Chronicle readers cite pros and cons of medical marijuana | Local News – Medical Marijuana Program Connection

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    Yet another medical marijuana dispensary is coming to Citrus County.

    RISE will replace the old Huddle House off State Road 44 in Crystal River and be added to the growing number of such businesses, which now total over 500 in Florida.

    Get more from the Citrus County Chronicle

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    MMP News Author

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  • Health Alert Manhattan: Marijuana smoke is not safe. Doctor Explains | Kansas – Medical Marijuana Program Connection

    Health Alert Manhattan: Marijuana smoke is not safe. Doctor Explains | Kansas – Medical Marijuana Program Connection

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    The Big Picture: Dr. Lindsay Boik-Price says, “We’ve got some misunderstandings that need fixing about daily cannabis smoking!”

    Doctor’s Expert Insights About Lung Health and Cannabis Smoke in Kansas

    Lung Health Alert for Manhattan

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    MMP News Author

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  • Treating back-to-school ear infections without antibiotic resistance (video)

    Treating back-to-school ear infections without antibiotic resistance (video)

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    Newswise — SAN FRANCISCO, Aug. 15, 2023 — “Back-to-school” season means buying pens and paper, figuring out the new bus route, and … earaches. Doctors typically treat these infections with antibiotics, but children don’t always complete the full course, accelerating resistance to these medications. Today, researchers report developing a single-use nanoscale system that’s unlikely to generate resistance. Using a compound similar to bleach in test animals, they show it can kill off one type of bacterium that causes ear infections, and it could someday be easily applied as a gel.

    The researchers will present their results today at the fall meeting of the American Chemical Society (ACS). ACS Fall 2023 is a hybrid meeting being held virtually and in-person Aug. 13–17, and features about 12,000 presentations on a wide range of science topics.

    A video on the research is available at www.acs.org/Earaches.

    “We initially conceived of this idea by looking at the household cleaner bleach. Even though it has been used since the 19th century, bacteria do not appear to have developed any widespread resistance to this cleaner,” says Rong Yang, Ph.D., the project’s principal investigator.

    But Yang quickly warns that people should not treat infections with bleach. The solution sold at stores is highly concentrated and caustic, but when used in a properly controlled manner at extremely low concentrations, the active ingredient in bleach is considered compatible with living tissue. 

    After realizing that the active ingredient in the household cleaner could circumvent antibiotic resistance, the researchers, who are at Cornell University, decided to tackle a nearly universal childhood scourge: acute ear infections. These infections affect more than 95% of children in the U.S., and treatment typically requires taking antibiotics for five to 10 days. However, these regimens can cause problematic side effects, leading some families to discontinue the medication prematurely, particularly if symptoms resolve. But using these medications improperly can speed up the development of antibiotic resistance, which makes infections more difficult, if not impossible, to treat. This issue ranks among the biggest threats to global health, according to the World Health Organization.

    Bacteria have more success fighting against some substances than others. Hypochloric acid from bleach belongs to a family of compounds, known as hypohalous acids, to which bacteria have yet to develop any significant resistance — most likely because of the numerous ways these highly reactive acids damage microbial cells, Yang says. 

    Because these substances break down quickly, Yang and her colleagues sought to generate one of them on an as-needed basis behind the eardrum in the middle ear, where ear infections occur. They found inspiration in an enzyme from giant kelp, which converts hydrogen peroxide (H2O2) to hypobromous acid (HOBr), a chemical relative of bleach.

    A frequent cause of ear infections, the bacterium Streptococcus pneumoniae produces H2O2 to fight off other microbes. To mimic the kelp enzyme, which contains the metal vanadium, Yang and her colleagues designed nanowires made of vanadium pentoxide (V2O5). These produce HOBr only in the presence of the H2O2-producing bacteria, and their rod-like shape helps to keep them in place by reducing their ability to diffuse into body fluids.

    In tests on chinchillas, which contract ear infections from the same pathogens as human children, they succeeded in eliminating most of the S. pneumoniae. Yang and colleagues found that after treatment with the nanowires, the animals’ once-inflamed eardrums returned to normal. Meanwhile, tests in healthy animals found evidence that the treatment did not interfere with hearing.

    For these experiments, the researchers injected the nanowires directly into the middle ear. In more recent work in chinchillas, they developed a less invasive, more practical method for delivering the wires. By decorating the nanowires with peptides known to transport small particles across the eardrum, Yang and her team found they could deliver the treatment topically as a gel deposited into the ear canal. Once the gel was applied, the nanowires within it went through the intact tissue. They are also exploring other approaches for passing the nanowires through the eardrum.

    Because other ear-infection-causing bacteria do not produce H2O2, the researchers are currently examining whether this system is effective in the presence of microbes other than S. pneumoniae, and how they might adapt it to fight the other bugs.

    The researchers have not yet done studies to determine how long the system stays in place, although their evidence suggests the nanowires drain out of the middle ear after the infection clears. However, Yang suspects they could adapt the nanowires’ properties to stay in place for long periods afterward. This latter approach could make it possible to prevent recurrent infections that plague many children.

    “If the bacteria return, the system could restart, so children wouldn’t need antibiotics repeatedly and breed more resistance along the way,” Yang says.

    The researchers acknowledge support and funding from the National Institute on Deafness and Other Communication Disorders.

    A recorded media briefing on this topic will be posted Tuesday, Aug. 15, by 10 a.m. Eastern time at www.acs.org/acsfall2023briefings.

    For health and safety information for ACS Fall 2023, please visit the FAQ webpage.

    The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

    To automatically receive press releases from the American Chemical Society, contact [email protected].

    Note to journalists: Please report that this research was presented at a meeting of the American Chemical Society.

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    Title
    Eradication of ear infection via autonomous synthesis of antimicrobials 

    Abstract
    Otitis media (OM) is the main reason for pediatric antibiotic prescriptions. The current treatment mandates a rigorous regimen of multidose antibiotics over 5–10 days. The systemic antibiotic exposure and often prematurely terminated treatment due to the challenge of drug administration to young patients are believed to breed antibiotic resistance. To address these challenges, we designed a local treatment that converted a metabolic product (H2O2) of an OM pathogen (Streptococcus pneumoniae) into a potent antiseptic (HOBr), a reaction catalyzed by locally administered nanozymes, i.e., vanadium pentoxide nanowires. The therapeutic, HOBr, was only synthesized in the presence of the pathogen, enabling on-demand and targeted generation of therapeutics for OM treatment. Hypohalous acids are broad-spectrum and have a long history in general disinfection applications without breeding substantial drug resistance. A single dose of the nanowire formulation eradicated OM in a standard chinchilla model in 7 days with no observable tissue toxicity or negative impact on hearing sensitivity.

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    American Chemical Society (ACS)

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  • New recycling process could find markets for ‘junk’ plastic waste

    New recycling process could find markets for ‘junk’ plastic waste

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    BYLINE: Jason Daley

    Newswise — Although many Americans dutifully deposit their plastic trash into the appropriate bins each week, many of those materials, including flexible films, multilayer materials and a lot of colored plastics, are not recyclable using conventional mechanical recycling methods. In the end, only about 9 percent of plastic in the United States is ever reused, often in low-value products. With a new technique, however, University of Wisconsin–Madison chemical engineers are turning low-value waste plastic into high-value products.

    The new method, described in the Aug. 11 issue of the journal Science, could increase the economic incentives for plastic recycling and open a door to recycling new types of plastic. The researchers estimate their methods could also reduce greenhouse gas emissions from the conventional production of these industrial chemicals by roughly 60 percent.

    The new technique relies on a couple of existing chemical processing techniques. The first is pyrolysis, in which plastics are heated to high temperatures in an oxygen-free environment. The result is pyrolysis oil, a liquid mix of various compounds. Pyrolysis oil contains large amounts of olefins — a class of simple hydrocarbons that are a central building block of today’s chemicals and polymers, including various types of polyesters, surfactants, alcohols and carboxylic acids.

    In current energy-intensive processes like steam cracking, chemical manufacturers produce olefins by subjecting petroleum to extremely high heat and pressure. In this new process, the UW–Madison team recovers olefins from pyrolysis oil and uses them in a much less energy-intensive chemical process called homogenous hydroformylation catalysis. This process converts olefins into aldehydes, which can then be further reduced into important industrial alcohols.

    “These products can be used to make a wide range of materials that are higher value,” says George Huber, a professor of chemical and biological engineering who led the work alongside postdoctoral researcher Houqian Li and PhD student Jiayang Wu.

    These higher-value materials include ingredients used to make soaps and cleaners, as well as other more useful polymers.

    “We’re really excited about the implications of this technology,” says Huber, who also directs the Department of Energy-funded Center for the Chemical Upcycling of Waste Plastics. “It’s a platform technology to upgrade plastic waste using hydroformylation chemistry.”

    The recycling industry could adopt the process soon; in recent years, at least 10 large chemical companies have built or announced plans for facilities to produce pyrolysis oils from waste plastics. Many of them run the pyrolysis oil through steam crackers to produce low-value compounds. The new chemical recycling technique could provide a more sustainable and lucrative way to use those oils.

    “Currently, these companies don’t have a really good approach to upgrade the pyrolysis oil,” says Li. “In this case, we can get high-value alcohols worth $1,200 to $6,000 per ton from waste plastics, which are only worth about $100 per ton. In addition, this process uses existing technology and techniques. It’s relatively easy to scale up.”

    The study was a collaborative effort across a few different UW–Madison departments, Huber says. Clark Landis, chair of the Department of Chemistry and a world expert on hydroformylation, suggested the possibility of applying the technique to pyrolysis oils. Chemical and biological engineering Professor Manos Mavarikakis used advanced modeling to provide molecular-level insight into the chemical processes. And chemical and biological engineering Professor Victor Zavala provided help analyzing the economics of the technique and the life cycle of the plastic waste.

    The next step for the team is to tune the process and better understand what recycled plastics and catalyst combinations produce which final chemical products.

    “There are so many different products and so many routes we can pursue with this platform technology,” says Huber. “There’s a huge market for the products we’re making. I think it really could change the plastic recycling industry.”

    George Huber is the Richard L. Antoine Professor. Manos Mavrikakis is the Ernest Micek Distinguished Chair, James A. Dumesic Professor and Vilas Distinguished Achievement Professor. Victor Zavala is the Baldovin-DaPra Professor. Other UW–Madison authors include Zhen Jiang and Jiaze Ma.

    The authors acknowledge support from the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office under Award Number DEEE0009285; The National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the DOE, Office of Science, under contract no. DE-AC02-05CH11231 using NERSC award BES-ERCAP0022773; The Center for Nanoscale Materials, a DOE Office of Science User Facility located at Argonne National Laboratory supported by DOE contract DE-AC02-06CH11357; and the UW–Madison Center for High Throughput Computing supported by UW–Madison, the Advanced Computing Initiative, the Wisconsin Alumni Research Foundation, the Wisconsin Institutes for Discovery, and the National Science Foundation.

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  • Mind what you eat and drink. Food and Water Safety stories for media.

    Mind what you eat and drink. Food and Water Safety stories for media.

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    Food and drinking water quality are essential to our health. Below are some of the latest headlines from the Food and Water Safety channel on Newswise. 

    Cleaning water with ‘smart rust’ and magnets (Embargoed until 16-Aug-2023 5:00 AM EDT)

    -American Chemical Society (ACS)

    Current estimates of Lake Erie algae toxicity may miss the mark

    -Ohio State University

    New study identifies disparities in testing and treating well water among low-income, BIPOC households in NC

    -University of North Carolina at Chapel Hill

    Three out of every ten meals ordered from the main food delivery app in Brazil come from dark kitchens

    -Sao Paulo Research Foundation (FAPESP)

    UIC leads field study on home, water safety after Ohio chemical spill

    -University of Illinois Chicago

    NUS scientists develop a new class of artificial water channels for more efficient industrial water purification

    -National University of Singapore (NUS)

    In the wake of aspartame news, should you kick your diet soda habit? FSU experts weigh in

    -Florida State University

    School Meals Would Be Even Healthier if Compliant with U.S. Nutrition Standards, Study Finds

    -Tufts University

    New optimization strategy boosts water quality, decreases diversion costs

    -Chinese Academy of Sciences

    Be wary of low-acidity vinegar options when preserving food at home, Virginia Tech food safety experts say

    -Virginia Tech

    Eliminating public health scourge can also benefit agriculture

    -University of Notre Dame

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  • MSU School of Packaging researchers make a sustainable plastic more compostable

    MSU School of Packaging researchers make a sustainable plastic more compostable

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    BYLINE: Matt Davenport

    Highlights:

    • Researchers led by Rafael Auras in the Michigan State University School of Packaging have shown how to make a bio-based polymer compostable in both home and industrial settings.
    • The team said its research, published in ACS Sustainable Chemistry & Engineering, can help divert plastic packaging that’s been soiled by food, the vast majority of which is not recycled. Another end-of-use option, like composting, can thus help keep plastics out of landfills and the environment.
    • To make the compostable polymer, the team blended bioplastics known as polylactic acid, or PLA, and thermoplastic starch. Both are polymers derived from organic sources — mostly plant carbohydrates — rather than petroleum sources.
    • PLA is already used in packaging and can be composted in industrial settings that use conditions, including higher temperatures, that are more conducive to breaking down polymers when compared to home composting. Even in these settings, though, PLA can be resistant to degrading quickly or completely when compared to organic contents of compost, such as food waste.
    • The inclusion of thermoplastic starch in PLA accelerates industrial composting and opens up the ability to compost in home settings without sacrificing PLA’s attractive material properties. 

    Newswise — EAST LANSING, Mich. – Researchers from Michigan State University’s top-ranked School of Packaging have developed a way to make a promising, sustainable alternative to petroleum-based plastics more biodegradable.

    A team led by Rafael Auras has made a bio-based polymer blend that’s compostable in both home and industrial settings. The work is published in the journal ACS Sustainable Chemistry & Engineering.

    “In the U.S. and globally, there is a large issue with waste and especially plastic waste,” said Auras, MSU professor and the Amcor Endowed Chair in Packaging Sustainability.

    Less than 10% of plastic waste is recycled in the U.S. That means the bulk of plastic waste ends up as trash or litter, creating economic, environmental and even health concerns.

    “By developing biodegradable and compostable products, we can divert some of that waste,” Auras said. “We can reduce the amount that goes into a landfill.”

    Another bonus is that plastics destined for the compost bin wouldn’t need to be cleaned of food contaminants, which is a major obstacle for efficient plastic recycling. Recycling facilities routinely must choose between spending time, water and energy to clean dirty plastic waste or simply throwing it out.

    “Imagine you had a coffee cup or a microwave tray with tomato sauce,” Auras said. “You wouldn’t need to rinse or wash those, you could just compost.”

    PLA and a ‘sweet spot’ for starch 

    The team worked with what’s known as polylactic acid, or PLA, which seems like an obvious choice in many ways. It’s been used in packaging for over a decade, and it’s derived from plant sugars rather than petroleum.

    When managed properly, PLA’s waste byproducts are all natural: water, carbon dioxide and lactic acid.

    Plus, researchers know that PLA can biodegrade in industrial composters. These composters create conditions, such as higher temperatures, that are more conducive to breaking down bioplastics than home composters.

    Yet, the idea of making PLA compostable at home seemed impossible to some people.

    “I remember people laughing at the idea of developing PLA home composting as an option,” said Pooja Mayekar, a doctoral student in Auras’ lab group and the first author of the new report. “That’s because microbes can’t attack and consume PLA normally. It has to be broken down to a point where they can utilize it as food.” 

    Although industrial compost settings can get PLA to that point, that doesn’t mean they do it quickly or entirely. 

    “In fact, many industrial composters still shy away from accepting bioplastics like PLA,” Auras said.

    In its experiments, supported by the U.S. Department of Agriculture and MSU AgBioResearch, the team showed that PLA can sit around for 20 days before microbes start digesting it in industrial composting conditions.

    To get rid of that lag time and enable the possibility of home composting, Auras and his team integrated a carbohydrate-derived material called thermoplastic starch into PLA. Among other benefits, the starch gives composting’s microbes something they can more easily chow down on while the PLA degrades.

    “When we talk about the addition of starch, that doesn’t mean we just keep dumping starch in the PLA matrix,” Mayekar said. “This was about trying to find a sweet spot with starch, so the PLA degrades better without compromising its other properties.”

    Fortunately, postdoctoral researcher Anibal Bher had already been formulating different PLA-thermoplastic starch blends to observe how they preserved the strength, clarity and other desirable features of regular PLA films.

    Working with doctoral student Wanwarang Limsukon, Bher and Mayekar could observe how those different films broke down throughout the composting process when carried out at different conditions.

    “Different materials have different ways of undergoing hydrolysis at the beginning of the process and biodegrading at the end,” Limsukon said. “We’re working on tracking the entire pathway.”

    The team ran these experiments using systems that Auras and lab members, past and present, largely built from scratch during his 19 years with MSU. The equipment the researchers have access to outside their own lab in the School of Packaging also makes a difference.

    “Working with Dr. Auras, the School of Packaging, MSU — it’s great,” Bher said. “Because, at some point, we want to be making actual products. We are using facilities around campus to make materials and test their properties. MSU offers a lot of resources.” 

    “There’s a reason why this is one of the best schools for packaging,” Mayekar said. 

    Read more on MSUToday.

    ### 

    Michigan State University has been advancing the common good with uncommon will for more than 165 years. One of the world’s leading research universities, MSU pushes the boundaries of discovery to make a better, safer, healthier world for all while providing life-changing opportunities to a diverse and inclusive academic community through more than 400 programs of study in 17 degree-granting colleges.

    For MSU news on the Web, go to MSUToday. Follow MSU News on Twitter at twitter.com/MSUnews.

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  • Ecologist Investigates Canopy Soil Abundance and Chemistry in Treetops

    Ecologist Investigates Canopy Soil Abundance and Chemistry in Treetops

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    Newswise — LOGAN, UTAH, USA – When we think of soil, most of us think of dirt on the ground. But a surprising amount of the planet’s soil thrives in the treetops of old-growth forests, high above terra firma.

    This organic matter, composed of decaying leaves and branches, airborne particulates and moisture, is called canopy soil or arboreal soil. Its study is relatively new, says Utah State University ecologist Jessica Murray. She’s among researchers unraveling mysteries of the dense, mossy humus that provides rich habitat for insects, birds, fungi, worms and plants, as well as a generous reservoir for carbon storage.

    Murray and colleagues from Texas A&M University, the University of Toronto Scarborough and Imperial College London published new information about the enigmatic resource in the July 27, 2023, online edition of Geoderma. The team’s research was supported by USU, the U.S. Department of Agriculture National Institute of Food and Agriculture, and the Natural Sciences and Engineering Research Council of Canada.

    “In this study, we sought to understand where canopy soils are found, where they are most abundant, and if their properties – and thus, soil development processes – differ as a function of climate or other small-scale factors,” says Murray, a doctoral student in USU’s Department of Biology and Ecology Center. “This is the first study to look at the distribution patterns of canopy soils across forests and one of very few studies that have sought to examine canopy soil properties.”

    Murray collected much of the data for the study some 80 feet above the ground at six primary forest sites across Costa Rica’s Cordillera de Tilarán and Cordillera Volcánica Central, encompassing both Caribbean and Pacific slope mountain ranges. Her field gear includes climbing gear, ropes, a safety harness and helmet.

    “I climbed about 30 trees to collect data,” she says. “And getting to one of those sites was the hardest hike of my life.”

    Murray is referring to a site designated “Puesto 1070,” located along a contiguous tract of primary forest, which required a steep trek from about 1,970 feet in elevation to 3,608 – in thick mud.

    “It took eight hours to complete the hike just to the study site,” she says. “We were carrying all of our climbing gear, food for eight days, sleeping bags and sampling equipment. Thank heavens we finished that site early, because, with our hard-earned appetites, we also nearly finished our food supply ahead of schedule.”

    Murray says tree canopies in the tropical montane forest systems are especially dense, with thick moss, soil and an abundance of epiphytes – plants that grow on other plants – often referred to as “air plants” – that are not parasitic and have little or no attachment to other obvious nutrient sources.

    “It’s like another world in the air – canopies teeming with plant, insect and animal life,” she says. “I initially conducted surveys to assess canopy soil abundance from the ground with binoculars. But it was really necessary to climb up into the trees to get an accurate picture of what was going on.”

    Murray asserts forest canopies store much more carbon that generally assumed.

    “It’s kind of a back-of-the-envelope calculation on my part, but one I’m ready to defend and eager to investigate further,” she says. “I think canopy soil stores 0.4 to 4 percent of total soil carbon in the forests where it is found, which is not being counted in ecosystem carbon budgets.”

    Mentored by USU Biology Professor John Stark and former USU faculty member Bonnie Waring, the latter now with Imperial College London and an author on the paper, Murray says the team’s results indicate both climate and tree size play an important role in canopy soil abundance, carbon stocks and chemistry.

    “Climate, particularly fog and temperature changes, appear to drive canopy soil abundance across forests, while tree size determines canopy soil abundance within a forest,” she says. “Our findings reveal canopy soil’s vulnerability to climate change, and its decline, could cause a significant decrease in carbon storage resources.”  

    Further, she says, those resources could take longer than expected to restore.

    “When we talk about reforestation, we don’t stop to consider the time needed for forest regrowth plus canopy mat regrowth,” Murray says. “It may take decades longer for recovered forests destroyed by wildfire or development to regenerate robust canopy soil mats.”

    A 2022 recipient of the Ecological Society of America’s Katherine S. McCarter Graduate Student Policy Award, Murray is among a number of Aggies presenting at the ESA’s 2023 Annual Meeting Aug. 6-11, in Portland, Oregon. She presents the talk, “The Persistence of Metabolically Protected vs. Mineral-Associated Soil Organic Carbon in the Presence of Organic Inputs,” Thursday, Aug. 10, at 4:45 p.m., in Room B115 of the Oregon Convention Center.

    “For that meeting, I’ll be presenting on research different from, but related to, the study published in Geoderma, including work about the basic mechanisms of soil carbon sequestration that uses canopy soils from my sites in Costa Rica,” she says.

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