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

Tuesday, January 17, 2023

New method for designing tiny 3D materials could make fuel cells more efficient

Authors of the study Professor Richard Tilley and Dr Lucy Gloag.
Photo Credit: UNSW Sydney / Courtesy of the researchers 

Researchers have developed an innovative technique for creating nanoscale materials with unique chemical and physical properties.

Scientists from UNSW Sydney have demonstrated a novel technique for creating tiny 3D materials that could eventually make fuel cells like hydrogen batteries cheaper and more sustainable.

In the study published in Science Advances, researchers from the School of Chemistry at UNSW Science show it’s possible to sequentially ‘grow’ interconnected hierarchical structures in 3D at the nanoscale which have unique chemical and physical properties to support energy conversion reactions.

In chemistry, hierarchical structures are configurations of units like molecules within an organization of other units that themselves may be ordered. Similar phenomena can be seen in the natural world, like in flower petals and tree branches. But where these structures have extraordinary potential is at a level beyond the visibility of the human eye – at the nanoscale.

Chemists Created a Substance with Potential Antitumor Activity

The new antitumor substance was synthesized at Ural Federal University's Scientific-educational and Innovation Center of Chemical and Pharmaceutical Technologies.
Photo Credit: Rodion Narudinov

New compound could be the basis of a drug for tumor cells

Chemists from the Ural Federal University and Volgograd State Medical University have created a compound that suppresses cancer cells. The powerful new substance could become the basis for antitumor drugs because it affects the pathology that leads to the development of malignant tumors, such as cancer of the breast, lung, prostate, and lymph nodes. The substance and the results of the experiments were published in the journal Molecules.

"Type 2 casein kinase (CK2) is known to suppress apoptosis in cells, but increased levels of type 2 casein kinase are observed in tumor cells, indicating that these cells are resistant to apoptosis compared to normal cells. If you block this protein, you can achieve tumor cell death. So, our team managed to develop a universal approach to the synthesis of new azolopyrimidines and obtain a library of corresponding heterocycles as potential inhibitors of casein kinase type 2," explains Grigory Urakov, an Engineer of the Scientific Laboratory of Medical Chemistry and Advanced Organic Materials at UrFU.

Monday, January 16, 2023

Speeding up sugar's conversion into fuel

The research has accelerated the production rate and yield of isobutanol from sugar.
Photo Credit: Bishnu Sarangi

University of Queensland researchers have found a way to more efficiently convert sugarcane into a building block of aviation fuel and other products.

By zeroing in on a specific enzyme, a UQ team working in collaboration with the Technical University of Munich (TUM) has sped up the slowest step in processing sugar into a chemical called isobutanol.

Professor Gary Schenk from UQ’s School of Chemistry and Molecular Biosciences said isobutanol from a renewable resource could be used to make fuels, plastics, rubbers and food additives.

“Our research into this particular enzyme means we can accelerate the production rate and yield of isobutanol from sugarcane, ultimately enabling biomanufacturers to make diverse products at scale sustainably and efficiently,” Professor Schenk said.

“Usually during a biomanufacturing process, cells such as yeasts are used as a production platform, but in our research only a small number of a sugar acid-specific dehydratase enzyme was used.

Friday, January 6, 2023

Lithium-sulfur batteries are one step closer to powering the future

Image shows microstructure and elemental mapping (silicon, oxygen and sulfur) of porous sulfur-containing interlayer after 500 charge-discharge cycles in lithium-sulfur cell.
Image Credit: Guiliang Xu/Argonne National Laboratory.

Batteries are everywhere in daily life, from cell phones and smart watches to the increasing number of electric vehicles. Most of these devices use well-known lithium-ion battery technology. And while lithium-ion batteries have come a long way since they were first introduced, they have some familiar drawbacks as well, such as short lifetimes, overheating and supply chain challenges for certain raw materials.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are researching solutions to these issues by testing new materials in battery construction. One such material is sulfur. Sulfur is extremely abundant and cost effective and can hold more energy than traditional ion-based batteries.

In a new study, researchers advanced sulfur-based battery research by creating a layer within the battery that adds energy storage capacity while nearly eliminating a traditional problem with sulfur batteries that caused corrosion.

UCR scientists develop method to turn plastic waste into potentially valuable soil additive

Recent rain storms washed plastic waste into a creek bed in Riverside's Fairmount Park.
Photo Credit: David Danelski/UCR

University of California, Riverside, scientists have moved a step closer to finding a use for the hundreds of millions of tons of plastic waste produced every year that often winds up clogging streams and rivers and polluting our oceans.

In a recent study, Kandis Leslie Abdul-Aziz, a UCR assistant professor of chemical and environmental engineering, and her colleagues detailed a method to convert plastic waste into a highly porous form of charcoal or char that has a whopping surface area of about 400 square meters per gram of mass.

Such charcoal captures carbon and could potentially be added to soil to improve soil water retention and aeration of farmlands. It could also fertilize the soil as it naturally breaks down. Abdul-Aziz, however, cautioned that more work needs to be done to substantiate the utility of such char in agriculture.

The plastic-to-char process was developed at UC Riverside’s Marlan and Rosemary Bourns College of Engineering. It involved mixing one of two common types of plastic with corn waste — the leftover stalks, leaves, husks, and cobs — collectively known as corn stover. The mix was then cooked with highly compressed hot water, a process known as hydrothermal carbonization.

Monday, December 19, 2022

Daylong wastewater samples yield surprises

Rice University engineers compared wastewater “grabs” to daylong composite samples and found the grab samples were more likely to result in bias in testing for the presence of antibiotic-resistant genes.
 Illustration Credit: Stadler Research Group/Rice University

Testing the contents of a simple sample of wastewater can reveal a lot about what it carries, but fails to tell the whole story, according to Rice University engineers.

Their new study shows that composite samples taken over 24 hours at an urban wastewater plant give a much more accurate representation of the level of antibiotic-resistant genes (ARGs) in the water. According to the Centers for Disease Control and Prevention (CDC), antibiotic resistance is a global health threat responsible for millions of deaths worldwide.

In the process, the researchers discovered that while secondary wastewater treatment significantly reduces the amount of target ARG, chlorine disinfectants often used in later stages of treatment can, in some situations, have a negative impact on water released back into the environment.

The lab of Lauren Stadler at Rice’s George R. Brown School of Engineering reported seeing levels of antibiotic-resistant RNA concentrations 10 times higher in composite samples than what they see in “grabs,” snapshots collected when flow through a wastewater plant is at a minimum.

Scientists from NUS and NUHS identify predictive blood biomarker for cognitive impairment and dementia

Prof Barry Halliwell (left) and Dr Irwin Cheah (right), together with their collaborators from the National University Health System, have discovered that low levels of ergothioneine in blood plasma may predict an increased risk of cognitive impairment and dementia.
Photo Credit: National University of Singapore

Identification of elderly persons at risk of developing cognitive impairment and dementia could be made possible by examining ergothioneine levels in the blood

A recent study by a team comprising researchers from the National University of Singapore (NUS) and the National University Health System (NUHS) revealed that low levels of ergothioneine (ET) in blood plasma may predict an increased risk of cognitive impairment and dementia, suggesting possible therapeutic or early screening measures for cognitive impairment and dementia in the elderly.

The research teams were led by Professor Barry Halliwell from the Department of Biochemistry under the NUS Yong Loo Lin School of Medicine and Associate Professor Christopher Chen and Dr Mitchell Lai from the Memory, Ageing and Cognition Centre under NUHS. The results of their most recent study were published in the scientific journal Antioxidants.

Saturday, December 17, 2022

UCLA-developed soft brain probe could be a boon for depression research

 Illustration of the soft probe with aptamer biosensors implanted in the brain.
Illustration Credit: Zhao, et al., 2022

Anyone familiar with antidepressants like Prozac or Wellbutrin knows that these drugs boost levels of neurotransmitters in the brain like serotonin and dopamine, which are known to play an important role in mood and behavior.

It might come as a surprise, then, that scientists still have very little data about the specific relationship between neurotransmitters — chemicals that relay messages from one brain cell to others — and our psychological states. Simply put, monitoring fluctuations of these neurochemicals in living brains has proved a persistent challenge.

Now, for the first time, UCLA scientists have attached nanoscale biochemical sensors, which are tuned to identify specific neurotransmitters, to a soft, implantable brain probe in order to continuously monitor these chemicals in real time. The new brain probe, described in a paper published in ACS Sensors, would allow scientists to track neurotransmitters in laboratory animals — and, ultimately, humans — during their day-to-day activities.

Friday, December 16, 2022

A poison helps to understand hydrogen-producing biocatalysts

Thomas Happe researches biocatalysts that can produce hydrogen in an environmentally friendly way.
 Photo Credit: RUB, Marquard

The toxic cyanide molecule attacks the enzymes, but also enables new insights into catalysis.

In nature, certain enzymes, so-called hydrogenases, are able to produce molecular hydrogen (H2) to produce. Special types of these biocatalysts, so-called [FeFe] hydrogenases, are extremely efficient and therefore of interest for bio-based hydrogen production. Although science already knows a lot about how these enzymes work, some details have not yet been fully clarified. The photobiotechnology working group at the Ruhr University Bochum around Dr. Jifu Duan and Prof. Dr. Close Thomas Happe. The researchers showed that external cyanide binds to the [FeFe] hydrogenases and inhibits hydrogen formation. They were able to demonstrate a structural change in the proton transport path that helps to understand the coupling of electron and proton transport. They report in the journal Angewandte Chemie.

Thursday, December 15, 2022

Biodegradable medical gowns may add to greenhouse gas

Photo Credit: National Cancer Institute

The use of disposable plasticized medical gowns – both conventional and biodegradable – has surged since the onset of the COVID-19 pandemic. Landfills now brim with them.

Because the biodegradable version decomposes faster than conventional gowns, popular wisdom held that it offers a greener option by less space use and chronic emissions in landfills.

That wisdom may be wrong.

Biodegradable medical gowns actually introduce harsh greenhouse gas discharge problems, according to new research published Dec. 20 in the Journal of Cleaner Production.

“There’s no magic bullet to this problem,” said Fengqi You, the Roxanne E. and Michael J. Zak Professor in Energy Systems Engineering, in the Smith School of Chemical and Biomolecular Engineering.

“Plasticized conventional medical gowns take many years to break down and the biodegradable gowns degrade much faster, but they produce gas emissions faster like added methane and carbon dioxide than regular ones in a landfill,” said You, who is a senior faculty fellow in the Cornell Atkinson Center for Sustainability. “Maybe the conventional gowns is not so bad.”

Scientists Have Figured Out How to Use Silicone to Protect against Radiation

Scientists plan to investigate a broader set of materials that can attenuate radiation.
Photo Credit: Anastasia Farafontova

An international team of scientists has developed a material that can be used in the future as radiation protection against gamma radiation, in particular, it can be used to create radiation protection for Nuclear Power Station workers. The new material is based on silicone using zinc oxide nano powder additions. The results of research on the new material and its properties have been published in the journal Optical Materials. Physicists from Russia (Ural Federal University), Jordan, and Turkey took part in the work.

"Gamma radiation is widespread in the health care, food and aerospace industries. Excessive exposure can be harmful to human health. Gamma radiation is now attenuated or absorbed using lead, concrete, lead-oxide, tungsten, or tin-based materials. These protective materials are not always convenient to use as protection against gamma rays. In addition, they are expensive, too heavy and highly toxic to humans and the environment. This is why it is important to find new materials and optimize their composition for radiation protection, which will ensure human and environmental safety," says Oleg Tashlykov, Associate Professor at the Department of Nuclear Power Plants and Renewable Energy Sources at UrFU.

Wednesday, December 14, 2022

New Study Sheds Light on Boric Acid Transport and Excretion in Marine Fish

Seawater is known to contain a significant concentration of boric acid, which can be toxic and deadly to living systems. As such, fish living in marine habitats need to be able to excrete boric acid in order to maintain a healthy boron balance. Tokyo Tech researchers have now identified the gene and mechanism of boric acid transport in seawater fish and contrasted it to freshwater species.

Marine fishes live in highly saline environments with ionic concentrations that are vastly different from their blood plasma. Seawater contains a variety of toxic ion species that can build up in the body if the fish does not excrete them. One example of this is boric acid, which—in small amounts—is a vital micronutrient for animals but can prove toxic in excess. Hence, marine fish must develop physiologic means to excrete boric acid. However, how they do this is, as yet, unknown. Now, an international team led by researchers from Tokyo Institute of Technology (Tokyo Tech) has unveiled and demonstrated the molecular mechanisms underlying boric acid secretion in marine pufferfish.

Associate Professor Akira Kato of Tokyo Tech is the principal author of the study, which was published in the Journal of Biological Chemistry. He tells us more about it. "We compared euryhaline pufferfish (which are pufferfish that can survive in varying levels of salinity) accustomed to saltwater, brackish water, and freshwater. On comparing fish from these three habitats, we found that the urine of a seawater pufferfish (Takifugu pufferfish) contained 300 times more boric acid than pufferfish blood, and 60 times more boric acid than seawater." The urine of freshwater fish contained almost 1000 times less boric acid than that of seawater pufferfish. These findings established that Takifugu pufferfish living in seawater excrete boric acid in their urine. Just like in humans, the process of excretion via urine in pufferfish is mediated by the kidneys.

Tuesday, December 13, 2022

UH lab produces building blocks to DNA and RNA in deep space

Conceptualization of the role of methanediamine in the galactic cosmic ray mediated synthesis of DNA and RNA bases in deep space.
Illustration Credit: University of Hawaiʻi

The synthetic production of a critical building block called methanediamine for the first time by researchers in University of Hawaiʻi at Mānoa’s Department of Chemistry could lead to key insights into the origins of life. The researchers have discovered a method to produce it in a lab under conditions that mimic icy interstellar nanoparticles in cold molecular clouds in space.

Nitrogen is the most abundant element in Earth’s atmosphere. It is also incorporated into nearly one-third of some 300 molecules identified in the interstellar medium, which is the material that exists in the space between the stars in a galaxy.

Most nitrogen-containing molecules in deep space carry exclusively the nitrile moiety (organic compound that has a carbon, nitrogen functional group), while amines (a member of a family of nitrogen-containing organic compounds that is derived from ammonia) and imines (compounds containing a carbon-nitrogen double bond) are relatively rare. According to experts, an understanding of the origin of these less common molecule parts in deep space is central to the hypothesis for the origin of life because all nucleobases (nitrogen-containing compounds) found in contemporary RNA and DNA contain amines and imines.

Monday, December 12, 2022

Princeton chemists create quantum dots at room temp using lab-designed protein

Nature uses 20 canonical amino acids as building blocks to make proteins, combining their sequences to create complex molecules that perform biological functions.

But what happens with the sequences not selected by nature? And what possibilities lie in constructing entirely new sequences to make novel, or de novo, proteins bearing little resemblance to anything in nature?

That’s the terrain where Michael Hecht, professor of chemistry, works with his research group. And recently, their curiosity for designing their own sequences paid off.

They discovered the first known de novo (newly created) protein that catalyzes, or drives, the synthesis of quantum dots. Quantum dots are fluorescent nanocrystals used in electronic applications from LED screens to solar panels.

Their work opens the door to making nanomaterials in a more sustainable way by demonstrating that protein sequences not derived from nature can be used to synthesize functional materials — with pronounced benefits to the environment.

Scientists Have Created New Substance to Treat Neurological Disorders

Scientists used a set of 1,2,3-triazole derivatives and modeled the structure of the putative inhibitor.
 Photo Credit: Andrey Fomin

The international team of scientists, including chemists from the Ural Federal University, has developed a substance that may become the basis for drugs that suppress or alleviate a number of neurological disorders. These include, for example, psychosis, schizophrenia, Parkinson's and Huntington's diseases, etc. The scientists reported the development and first results of the study in the Journal of Biomolecular Structure and Dynamics. The study was supported by a grant from the Ministry of Science and Higher Education of the Russian Federation (Project No. 075-15-2020-777).

"We found that the enzyme Phosphodiesterase 10A, which is produced in the body, is directly linked to neurological disorders. If you inhibit this enzyme, you can significantly slow down or even suppress the disease. For this purpose, we used a set of derivatives of 1,2,3-triazole, a pharmacophore whose fragments are contained in many drugs, and modeled the structure of the putative TP-10 inhibitor. We hypothesize that it would have a positive effect on conditions associated with brain dysfunction by reducing the activity of the Phosphodiesterase 10A enzyme. Other inhibitors developed by foreign companies still have no reliable antipsychotic efficacy so far," notes Dhananjay Bhattacherjee, senior researcher at the Department of Organic and Biomolecular Chemistry at UrFU.

Thursday, December 8, 2022

Intricate ‘snowflakes’ created in liquid metal

A snowflake-like zinc crystal synthesized in liquid gallium by researchers at UNSW Sydney.
Image Credit: Dr Jianbo Tang

Researchers, including those from UNSW Sydney, have synthesized complex symmetrical zinc crystals in liquid gallium which can potentially be used in a range of catalysis applications.

It’s beginning to look a lot like Christmas at UNSW Sydney’s School of Chemical Engineering where researchers have grown crystals made of zinc that look like snowflakes - inside a liquid metal.

The team predominantly used zinc metal dissolved in liquid gallium as the solvent, creating distinctive structures that often resembled those of six-branched snowflake crystals.

Apart from their structural beauty, these liquid metal-grown crystals can enable future processes for making catalytic materials for producing hydrogen from organic fuels. The metallic crystals can also be specially formulated, during their synthesis and extraction, to make semiconductors for electronic and optical devices of computers, mobile phones and solar cells of the future.

Tuesday, December 6, 2022

Why synonymous mutations are not always silent

New modeling shows how synonymous mutations that change the DNA sequence of a gene, but not the sequence of the encoded protein can impact protein production and function by changing the rate of protein synthesis. Top: illustration of a new class of protein misfolding called a non-covalent lasso entanglement that can result from changes to the rate of protein synthesis caused by synonymous mutations. Bottom: structure of a protein showing its native state and misfolded state with non-covalent lasso entanglement.
Illustration Credit: Yang Jiang | Pennsylvania State University

New modeling shows how synonymous mutations — those that change the DNA sequence of a gene but not the sequence of the encoded protein — can still impact protein production and function. A team of researchers led by Penn State chemists modeled how genetic changes that alter the speed of protein synthesis, but not the sequence of amino acids that comprise the protein, can lead to misfolding that changes the protein’s activity level, and then corroborated their models experimentally. The results demonstrate the importance of kinetics — the rate of protein synthesis — in addition to sequence for determining protein structure and function and could have implications in fields such as biopharmaceutics for fine tuning the activity of synthesized proteins.

Proteins are composed of long strings of amino acids that then fold up into three-dimensional functional structures. Each amino acid is encoded by a triplet of letters in the DNA alphabet of A, T, C and G called a codon, but there is redundancy built in to the system such that more than one codon can correspond to the same amino acid. Therefore, a mutation that changes the DNA sequence of a gene won’t necessarily change the sequence of the encoded protein if the mutation results in a "synonymous codon." To make a protein, DNA in the nucleus of a cell is first transcribed into a messenger RNA (mRNA). The mRNA is then transported out of the nucleus where it is translated into a nascent protein by a cellular organelle called a ribosome. After translation the protein is folded into its final functional form.

Monday, December 5, 2022

Scientists invent pioneering technique to construct rare molecules

Bahamaolide A is a polyketide natural product with potent antifungal activity, which was isolated from bacteria cultured from a sediment sample collected at North Cat Cay in the Bahamas and has now been synthesized in the chemical laboratory for the first time.
Image Credit: University of Bristol and Wikimedia Commons

Scientists have created a much faster way to make certain complex molecules, which are widely used by pharmaceuticals for antibiotics and anti-fungal medicines.

The first-of-its-kind discovery by chemists at the University of Bristol has the potential to speed up the production of such drugs, making them cheaper and more accessible.

The breakthrough, published in Nature Chemistry, marks the culmination of a five-year research project which has finally cracked how to reconstruct in a laboratory a particularly complex molecule, from the family of molecules known as polyketides.

Lead author Sheenagh Aiken, a PhD student at the university’s School of Chemistry when the work was completed, said: “It’s an exciting discovery, which could bring important benefits for the pharmaceutical industry and public health.

Ural Chemists Improved Material for Fuel Cells

Scientists were able to identify the optimal amount of iron administered.
Photo Credit: Ilya Safarov

Chemists at Ural Federal University and the Institute of High-Temperature Electrochemistry, Ural Branch of the Russian Academy of Sciences have improved a material for high-performance electrochemical devices. Such materials are used as electrodes in solid oxide fuel cells (SOFC) or proton-ceramic fuel cells (PCFC). Scientists proposed the infiltration method as a simple and affordable way to improve electrochemical performance. Their method increased the conductivity of this material, consequently improving the performance (increased power) of fuel cells. The change now makes the reaction go faster. The material and method are described in the journal Catalysts.

In the course of their research, chemists introduced iron into the basic barium cerate-zirconate, which means that they added iron ions to the complex oxide perovskites. In this way they were able to obtain a high level of mixed ion-electron conductivity, which is necessary for good electrodes. Similar materials exist today, but scientists around the world are trying to optimize them-improving their properties to increase efficiency.

Wednesday, November 30, 2022

Automated chemical reaction prediction: now in stereo

The AFIR method traces back the reaction of endiandric acid C methyl ester, a 52-atom natural product, to its starting materials using only quantum chemical calculations.
Illustration Credit: Tsuyoshi Mita et al. JACS. November 30, 2022

Automated reaction path search method predicts accurate stereochemistry of pericyclic reactions using only target molecule structure.

Researchers at the Institute for Chemical Reaction Design and Discovery (WPI-ICReDD) have demonstrated the expanded use of a computational method called the Artificial Force Induced Reaction (AFIR) method, predicting pericyclic reactions with accurate stereoselectivity based only on information about the target product molecule. The accurate prediction of a molecule’s stereochemistry—i.e., the 3D arrangement of its constituent atoms—is unprecedented for such an automated reaction path search method. This study serves as proof of concept that the AFIR method has the potential to discover novel reactions with specific stereochemistry.

In this study, AFIR is used to calculate retrosynthetic, or reverse, reactions going from product molecules to starting materials. Previously, AFIR has been used to predict small, simple reactions, but accurate stereochemistry predictions were out of reach, limiting the technique’s applicability. In this study, researchers overcome this hurdle by using the AFIR method on a major class of chemical reactions called pericyclic reactions, which are commonly found in biological processes, including the synthesis of Vitamin D.

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