. Scientific Frontline: Chemistry
Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Wednesday, April 19, 2023

Chemists Have Developed a Guide to Oxygen Electrode Design Strategies

Structure of perovskite materials for solid oxide electrochemical devices.
Illustration Credit: Et al., Sustainable Energy Technologies and Assessments

The group of scientists created a guide to oxygen electrode design strategies for solid oxide electrochemical devices. The researchers formulated key directions for the chemical and structural design of oxygen electrodes for solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC). The scientists published their work on current strategies for improving the electrochemical performance of oxygen electrodes at reduced operating temperatures in the journal Sustainable Energy Technologies and Assessments.

According to the authors of the study, the guide will be useful to scientists whose work is related to the development and design of air electrodes for electrochemical cells.

"Many of the processes in hydrogen energy technology are implemented using fuel cells and electrolysis, in which SOFCs and SOECs are involved. These electrochemical devices are very promising due to their high energy conversion efficiency and wide range of operating characteristics," explains Dmitry Medvedev, Head of the Scientific Laboratory of Hydrogen Energy at UrFU.

Tuesday, April 18, 2023

Revealed: Molecular “superpower” of antibiotic-resistant bacteria

Scanning electron micrograph of en:Clostridioides difficile bacteria from a stool sample
Photo Credit: Public Health Image Library

A species of ordinary gut bacteria that we all carry flourishes when the intestinal flora is knocked out by a course of antibiotics. Since the bacteria is naturally resistant to many antibiotics, it causes problems, particularly in healthcare settings. A study led from Lund University in Sweden now shows how two molecular mechanisms can work together make the bacterium extra resistant. “Using this knowledge, we hope to be able to design even better medicines,” says Vasili Hauryliuk, senior lecturer at Lund University, who led the study.

The threat from antibiotic resistant bacteria is as well-known as it is grave. Last year, The Lancet reported that an estimated 1.27 million people died in 2019 as a result of bacterial infection that could not be treated with existing medicines. To tackle this threat is it is essential to understand the underpinning molecular mechanisms.

Monday, April 17, 2023

Leaps in artificial blood research aim to improve product safety, efficacy

Artificial blood has been used in a variety of clinical trials, but no safe alternative has yet made it to market.
Image Credit: Narupon Promvichai

Researchers have made huge strides in ensuring that red blood cell substitutes – or artificial blood – are able to work safely and effectively when transfused into the bloodstream.  

The key is to make the artificial blood molecules big enough so they don’t leak from blood vessels into tissue and cause dangerous cardiovascular side effects, notes a new study led by researchers from The Ohio State University. 

Although blood loss is typically treated by transfusing units of donated blood, in cases where transfusions aren’t readily available or time is too limited to screen for patient blood type compatibility (such as in certain rural areas or on the battlefield), artificial blood products offer medical professionals more flexibility for treatment. In clinical trials, previous generations of these blood substitutes often resulted in several poor health outcomes, as individuals experienced symptoms ranging from narrowing of blood vessels and high blood pressure to tissue injury.   

In this study, researchers found that a certain sized fraction of red blood cell substitute can provide a range of health benefits, and can decrease the risk of cardiovascular side effects – if its components are the right size. 

Methane from megafires: more spew than we knew

Sky filled with wildfire pollution in 2020.
Photo Credit: Frausto-Vicencio/UCR

Using a new detection method, UC Riverside scientists found a massive amount of methane, a super-potent greenhouse gas, coming from wildfires — a source not currently being accounted for by state air quality managers. 

Methane warms the planet 86 times more powerfully than carbon dioxide over the course of 20 years, and it will be difficult for the state to reach its required cleaner air and climate goals without accounting for this source, the researchers said. 

Wildfires emitting methane is not new. But the amount of methane from the top 20 fires in 2020 was more than seven times the average from wildfires in the previous 19 years, according to the new UCR study. 

“Fires are getting bigger and more intense, and correspondingly, more emissions are coming from them,” said UCR environmental sciences professor and study co-author Francesca Hopkins. “The fires in 2020 emitted what would have been 14 percent of the state’s methane budget if it was being tracked.” 

The state does not track natural sources of methane, like those that come from wildfires. But for 2020, wildfires would have been the third biggest source of methane in the state. 

Friday, April 14, 2023

Drug form of traditional Chinese medicine compound improved survival of mice with brain tumors

Indirubin is a natural product present in indigo plants and the active ingredient of the traditional Chinese medicine Dang Gui Long Hui Wan, which is used to treat chronic diseases.
Photo Credit: Courtesy of Brown University

A new study shows how a drug made from a natural compound used in traditional Chinese medicine works against malignant brain tumors in mice, creating a promising avenue of research for glioblastoma treatment.

In the study, published in Cell Reports Medicine, researchers showed how a formulation of the compound, called indirubin, improved the survival of mice with malignant brain tumors. They also tested a new formulation that was easier to administer, taking the potential pharmaceutical approach one step closer to clinical trials with human participants.  

“The interesting thing about this drug is that it targets a number of important hallmarks of the disease,” said Sean Lawler, lead author, associate professor of pathology and laboratory medicine, and researcher at the Legorreta Cancer Center of Brown University. “That's appealing because this type of cancer keeps finding ways around individual mechanisms of attack. So, if we use multiple mechanisms of attack at once, perhaps that will be more successful.”

Wednesday, April 12, 2023

Nanotubes as an optical stopwatch for the detection of messenger substances

Bochum research team: Linda Sistemich and Sebastian Kruß
Photo Credit: © RUB, Kramer

Carbon nanotubes not only lighten in the presence of dopamine, but also longer. The lighting duration can serve as a new measurement for the detection of messenger substances.

An interdisciplinary research team from Bochum and Duisburg has found a new way to detect the important messenger substance dopamine in the brain. The researchers used carbon nanotubes for this. In previous studies, the team led by Prof. Dr. Sebastian Kruß has already shown that the tubes light up in the presence of dopamine. Now the interdisciplinary group showed that the duration of the lighting also changes. "It is the first time that an important messenger like dopamine has been detected in this way," says Sebastian Kruß. “We are convinced that this will open up a new platform that will also enable better detection of other human messenger substances such as serotonin. "The work was a cooperation between Kruß’ two working groups in physical chemistry at the Ruhr University Bochum and the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS).

The results are described by a team led by Linda Sistemich and Sebastian Kruß from the Ruhr University Bochum together with colleagues from the IMS and the University of Duisburg-Essen in the journal Angewandte Chemie - International Edition, published online on 9. March 2023.

Researchers devise new system for turning seawater into hydrogen fuel

Researchers collect seawater in Half Moon Bay, California, in January 2023 for an experiment that turned the liquid into hydrogen fuel. From left: Joseph Perryman, a SLAC and Stanford postdoctoral researcher; Daniela Marin, a Stanford graduate student in chemical engineering and co-author; Adam Nielander, an associate staff scientist with the SUNCAT, a SLAC-Stanford joint institute; and Charline Rémy, a visiting scholar at SUNCAT.
Photo Credit: Adam Nielander/SLAC National Accelerator Laboratory

The SLAC-Stanford team pulled hydrogen directly from ocean waters. Their work could help efforts to generate low-carbon fuel for electric grids, cars, boats and other infrastructure.

Seawater’s mix of hydrogen, oxygen, sodium and other elements makes it vital to life on Earth. But that same complex chemistry has made it difficult to extract hydrogen gas for clean energy uses. 

Now, researchers at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University with collaborators at the University of Oregon and Manchester Metropolitan University have found a way to tease hydrogen out of the ocean by funneling seawater through a double-membrane system and electricity. Their innovative design proved successful in generating hydrogen gas without producing large amounts of harmful byproducts. The results of their study, published in Joule, could help advance efforts to produce low-carbon fuels.

“Many water-to-hydrogen systems today try to use a monolayer or single-layer membrane. Our study brought two layers together,” said Adam Nielander, an associate staff scientist with the SUNCAT Center for Interface Science and Catalysis, a SLAC-Stanford joint institute. “These membrane architectures allowed us to control the way ions in seawater moved in our experiment.” 

Tuesday, April 11, 2023

Scientists uncover a key chemical structure in pigment molecule

Photo Credit: NCI

After nearly a century of scientific inquiry, scientists have at last been able to characterize a key component in the substance responsible for giving countless living organisms their color. 

In the study, published online today in the journal Nature Chemistry, an international team of researchers isolated a key molecule involved in the synthesis of melanin, a substance in the human body that produces pigmentation in the hair and skin and protects the cells from being damaged by ultraviolet radiation from the sun. The molecule they studied has many of the physical properties of eumelanin, a type of melanin that typically produces only black and brown pigments. 

Despite what researchers know about melanin, its chemical structure has remained elusive, said Bern Kohler, an Ohio Eminent Scholar and professor of chemistry and biochemistry at The Ohio State University, one of three senior authors on the study.  

“Melanin is literally as plain as the nose on our face and we still don't know exactly what it's made of and how it works,” said Kohler. “It's thought to be a material made of large numbers of interacting components, and so what my collaborators and I are trying to get at is, what are melanin’s underlying chemical units and what are the interactions that give rise to its properties?”

From greenhouse gas to value-added product

Dogukan Apaydin, Dominik Eder, Hannah Rabl, electrochemical cell (from left)
Photo Credit: Dogukan Apaydin / TU Wien

If one converts CO2 into synthesis gas, a valuable starting material for the chemical industry can be obtained. Researchers at TU Wien show how this works even at room temperature and atmospheric pressure.

Thinking of CO2, terms like climate-damaging or waste product probably quickly come to mind. While CO2 has been that for a long time – a pure waste product – more and more processes are being developed with which the greenhouse gas can be converted into valuable raw materials. Researchers then speak of "value-added chemicals". A new material with which this is possible was developed at TU Wien and recently presented in the journal Communications Chemistry.

Researchers at Dominik Eder's group developed a new material that facilitates the conversion of CO2. These are MOCHAs – organometallic chalcogenolate compounds that serve as catalysts. The result of the electrochemical conversion is synthesis gas, or syngas for short, which is an important raw material for the chemical industry.

Friday, March 31, 2023

Fast light pulse triggers the charge transfer into the water

The study was only made possible by the new laser laboratories in the ZEMOS research building, in which all external interference signals are minimized.
Photo Credit: © RUB, Marquard

With new technology, researchers were able to observe live what happens in the first picosecond when a proton detaches from a dye after light.

In certain molecules, the so-called photoc acids, a proton can be released locally by excitation with light. The solution suddenly changes the pH - a kind of fast switch that is important for many chemical and biological processes. So far, however, it is still unclear what actually happened at the moment of proton release. This is exactly what researchers in the Ruhr Explores Solvation Cluster of Excellence could do RESOLV the Ruhr University Bochum is now experimentally observing using new technology. They saw a tiny quake that only lasted three to five picoseconds before the proton came loose. They report on this in the journal Chemical Sciences.

Scientists Get Closer to Curing Alzheimer's and Parkinson's Diseases

In Russia, the incidence of dementia, Parkinson's disease and Alzheimer's disease will reach the epidemiological threshold of 5%
Image Credit: Gerd Altmann

Prospective compounds for the treatment of neurodegenerative diseases have been synthesized by Russian scientists. The compounds are of great interest for medicinal chemistry, especially for the development of treatments for Alzheimer's and Parkinson's diseases.

According to Timofey Moseev, a member of the group and an employee of the UrFU Chemical Pharmaceutical Center, the researchers managed to test the toxicity of the compounds in vitro on the kidney cells of a healthy human embryo. The researchers used the strategy of nucleophilic hydrogen substitution (a substitution reaction in which the substrate is attacked by a nucleophile, a reagent that carries a pair of unshared electrons). The process does not require metal catalysis, which is particularly important in the production of biologically active compounds, where any metal impurity can significantly distort toxicity and activity data.

To assess the ability of the synthesized molecules to bind to biotargets (proteins that play an important role in a particular disease), the researchers conducted experiments using docking - a molecular modeling technique. Docking allows predicting with a certain probability how a molecule interacts with targeted proteins.

Thursday, March 30, 2023

AI predicts enzyme function better than leading tools

An Illinois research team created an AI tool to predict an enzyme’s function from its sequence using the campus network and resource group servers. Pictured, from left: Tianhao You, Haiyang (Ocean) Cui, Huimin Zhao and Guangde Jiang.   
Photo Credit: Fred Zwicky

A new artificial intelligence tool can predict the functions of enzymes based on their amino acid sequences, even when the enzymes are unstudied or poorly understood. The researchers said the AI tool, dubbed CLEAN, outperforms the leading state-of-the-art tools in accuracy, reliability and sensitivity. Better understanding of enzymes and their functions would be a boon for research in genomics, chemistry, industrial materials, medicine, pharmaceuticals and more.

“Just like ChatGPT uses data from written language to create predictive text, we are leveraging the language of proteins to predict their activity,” said study leader Huimin Zhao, a University of Illinois Urbana-Champaign professor of chemical and biomolecular engineering. “Almost every researcher, when working with a new protein sequence, wants to know right away what the protein does. In addition, when making chemicals for any application – biology, medicine, industry – this tool will help researchers quickly identify the proper enzymes needed for the synthesis of chemicals and materials.”

The researchers will publish their findings in the journal Science and make CLEAN accessible online March 31.

Wednesday, March 29, 2023

Mimicking biological enzymes may be key to hydrogen fuel production

Nickel-iron hydrogenase, described by researchers as “one of nature’s most complicated and beautiful enzymes,” may be crucial in the world’s push toward a renewable energy economy. 
Illustration Credit: Courtesy Mirica group

An ancient biological enzyme known as nickel-iron hydrogenase may play a key role in producing hydrogen for a renewables-based energy economy. Careful study of the enzyme has led chemists from the University of Illinois Urbana-Champaign to design a synthetic molecule that mimics the hydrogen gas-producing chemical reaction performed by the enzyme.

The researchers reported their findings in the journal Nature Communications

Currently, industrial hydrogen is usually produced by separating hydrogen gas molecules from oxygen atoms in water using a process called electrolysis. To boost this chemical reaction in the industrial setting, platinum metal is used as a catalyst in the cathodes that direct the reaction. However, many studies have shown that the expense and rarity of platinum make it unattractive as the world pushes toward more environmentally sound energy sources.

ORNL-led team designs molecule to disrupt SARS-CoV-2 infection

Oak Ridge National Laboratory led a team of scientists to design a molecule that disrupts the infection mechanism of the SARS-CoV-2 coronavirus and could be used to develop new treatments for COVID-19 and future virus outbreaks.
Video Credit: Michelle Lehman/ORNL, U.S. Dept. of Energy

A team of scientists led by the Department of Energy’s Oak Ridge National Laboratory designed a molecule that disrupts the infection mechanism of the SARS-CoV-2 coronavirus and could be used to develop new treatments for COVID-19 and other viral diseases.

The molecule targets a lesser-studied enzyme in COVID-19 research, PLpro, that helps the coronavirus multiply and hampers the host body’s immune response. The molecule, called a covalent inhibitor, is effective as an antiviral treatment because it forms a strong chemical bond with its intended protein target.

“We’re attacking the virus from a different front, which is a good strategy in infectious disease research,” said Jerry Parks, who led the project and leads the Molecular Biophysics group at ORNL.

The research, detailed in Nature Communications, turned a previously identified noncovalent inhibitor of PLpro into a covalent one with higher potency, Parks said. Using mammalian cells, the team showed that the inhibitor molecule limits replication of the original SARS-CoV-2 virus strain as well as the Delta and Omicron variants.

Tuesday, March 28, 2023

Electricity from Air

Graphic illustration of titanium-air battery properties, in the style of the periodic table of elements
Illustration Credit: Courtesy of Technion – Israel Institute of Technology

Scientists at Forschungszentrum Jülich have developed and successfully lab-tested a novel titanium-air battery in cooperation with researchers at the Technion – Israel Institute of Technology in Haifa. This is the first time that experimental results of such a battery have been published, in which titanium is used as an active material. The metal is of interest as an electricity storage material because each atom can donate up to four electrons for charge transfer, while at the same time being relatively light and extremely resistant.

Scientific Results

Titanium is known as a passive, stable material. The researchers succeeded in utilizing its electrochemical potential for the storage of electrical energy by applying an ionic liquid called EMIm(HF)2.3F. Ionic liquids consist of salts with an atypical, very low melting point, which are used in a variety of applications due to their special electrical and material properties.

Eco-efficient cement could pave the way to a greener future

Wei Meng (left) and Bing Deng are co-authors on the study. Deng holds a sample of cement made with coal fly ash purified through a flash Joule heating-based process.
Photo Credit: Gustavo Raskosky/Rice University

The road to a net-zero future must be paved with greener concrete, and Rice University scientists know how to make it.

The production of cement, an ingredient in concrete, accounts for roughly 8% of the world’s annual carbon dioxide emissions, making it a significant target of greenhouse gas emissions reduction goals. Toward those efforts, the Rice lab of chemist James Tour used flash Joule heating to remove toxic heavy metals from fly ash, a powdery byproduct of coal-based electric power plants that is used frequently in concrete mixtures. Using purified coal fly ash reduces the amount of cement needed and improves the concrete’s quality.

In the lab’s study, replacing 30% of the cement used to make a batch of concrete with purified coal fly ash improved the concrete’s strength and elasticity by 51% and 28%, respectively, while reducing greenhouse gas and heavy metal emissions by 30% and 41%, respectively, according to the paper published in the Nature journal Communications Engineering.

Monday, March 27, 2023

How football-shaped molecules occur in the universe

Graphic Credit: Shane Goettl/Ralf I. Kaiser

For a long time, it has been suspected that fullerene and its derivatives could form naturally in the universe. These are large carbon molecules shaped like a football, salad bowl or nanotube. An international team of researchers using the Swiss SLS synchrotron light source at PSI has shown how this reaction works. The results have just been published in the journal Nature Communications.

“We are stardust, we are golden. We are billion-year-old carbon.” In the song they performed at Woodstock, the US group Crosby, Stills, Nash & Young summarized what humans are essentially made of: star dust. Anyone with a little knowledge of astronomy can confirm the words of the cult American band – both the planets and we humans are actually made up of dust from burnt-out supernovae and carbon compounds billions of years old. The universe is a giant reactor and understanding these reactions means understanding the origins and development of the universe – and where humans come from.

In the past, the formation of fullerenes and their derivatives in the universe has been a puzzle. These carbon molecules, in the shape of a football, bowl or small tube, were first created in the laboratory in the 1980s. In 2010 the infrared space telescope Spitzer discovered the C60 molecules with the characteristic shape of a soccer ball, known as buckyballs, in the planetary nebula Tc 1. They are therefore the biggest molecules to have been discovered to date known to exist in the universe beyond our solar system.

Researchers develop electrolyte enabling high efficiency of safe, sustainable zinc batteries

Photo Credit: Courtesy of Oregon State University

Scientists led by an Oregon State University researcher have developed a new electrolyte that raises the efficiency of the zinc metal anode in zinc batteries to nearly 100%, a breakthrough on the way to an alternative to lithium-ion batteries for large-scale energy storage.

The research is part of an ongoing global quest for new battery chemistries able to store renewable solar and wind energy on the electric grid for use when the sun isn’t shining and the wind isn’t blowing.

Xiulei “David” Ji of the OSU College of Science and a collaboration that included HP Inc. and GROTTHUSS INC., an Oregon State spinout company, reported their findings in Nature Sustainability.

“The breakthrough represents a significant advancement toward making zinc metal batteries more accessible to consumers,” Ji said. “These batteries are essential for the installation of additional solar and wind farms. In addition, they offer a secure and efficient solution for home energy storage, as well as energy storage modules for communities that are vulnerable to natural disasters.”

A battery stores electricity in the form of chemical energy and through reactions converts it to electrical energy. There are many different types of batteries, but most of them work the same basic way and contain the same basic components.

Thursday, March 23, 2023

New wood-based technology removes 80 percent of dye pollutants in wastewater

Researchers at Chalmers have developed a new biobased material, a form of powder based on cellulose nanocrystals to purify water from pollutants, including textile dyes. When the polluted water passes through the filter with cellulose powder, the pollutants are absorbed, and the sunlight entering the treatment system causes them to break down quickly and efficiently. Laboratory tests have shown that at least 80 percent of the dye pollutants are removed with the new method and material, and the researchers see good opportunities to further increase the degree of purification.
Illustration Credit: David Ljungberg | Chalmers University of Technology

Clean water is a prerequisite for our health and living environment, but far from a given for everyone. According to the WHO, there are currently over two billion people living with limited or no access to clean water.

This global challenge is at the center of a research group at Chalmers University of Technology, which has developed a method to easily remove pollutants from water. The group, led by Gunnar Westman, Associate Professor of Organic Chemistry, focuses on new uses for cellulose and wood-based products and is part of the Wallenberg Wood Science Center.

The researchers have built up solid knowledge about cellulose nanocrystals* – and this is where the key to water purification lies. These tiny nanoparticles have an outstanding adsorption capacity, which the researchers have now found a way to utilize.

“We have taken a unique holistic approach to these cellulose nanocrystals, examining their properties and potential applications. We have now created a biobased material, a form of cellulose powder with excellent purification properties that we can adapt and modify depending on the types of pollutants to be removed,” says Gunnar Westman.

Chemists Synthesize Material with Unusual Properties

Micrographs of ceramics based on barium stannate doped with yttrium. The percentage indicates the amount of yttrium in the tin sublattice. It can be used for electrolytes, electrodes and converters with varying amounts of additives
Photo Credit: Courtesy of the authors of the article

Researchers of the Institute of Hydrogen Energy of the Ural Federal University and the Institute of High Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences have created a promising material for hydrogen energy devices. The new material has high proton conductivity and unusual properties (depending on the degree of doping). It can be used as an electrolyte (at high doping levels) and as an electrode (at low doping levels) in solid oxide fuel cells and electrolyzers. A description of the new material and the results of the study are presented in the Journal of Power Sources.

"We synthesized an electrolyte material with a perovskite structure based on barium stannate. By modifying barium stannate with different amounts of yttrium, we obtained materials with curious properties. At high degrees of substitution of tin for yttrium, the materials are ionic (protonic) conductors, which makes them promising electrolytes. At the same time, the introduction of a small amount of yttrium in the composition leads to a pronounced electron transport. This allows these materials to be used as electrodes for the same electrochemical devices, both solid oxide fuel cells (SOFC) and electrolyzers. This opens up wide possibilities for applications in electrochemical converters, in particular for oxygen-, hydrogen- and water-permeable membranes," explains Georgy Starostin, co-author and Research Engineer at the Hydrogen Energy Laboratory of UrFU.

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