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

Tuesday, March 21, 2023

Uracil found in Ryugu samples

A conceptual image for sampling materials on the asteroid Ryugu containing uracil and niacin by the Hayabusa2 spacecraft
Image Credit: NASA Goddard/JAXA/Dan Gallagher

Samples from the asteroid Ryugu collected by the Hayabusa2 mission contain nitrogenous organic compounds, including the nucleobase uracil, which is a part of RNA.

Researchers have analyzed samples of asteroid Ryugu collected by the Japanese Space Agency’s Hayabusa2 spacecraft and found uracil—one of the informational units that make up RNA, the molecules that contain the instructions for how to build and operate living organisms. Nicotinic acid, also known as Vitamin B3 or niacin, which is an important cofactor for metabolism in living organisms, was also detected in the same samples. 

This discovery by an international team, led by Associate Professor Yasuhiro Oba at Hokkaido University, adds to the evidence that important building blocks for life are created in space and could have been delivered to Earth by meteorites. The findings were published in the journal Nature Communications.

“Scientists have previously found nucleobases and vitamins in certain carbon-rich meteorites, but there was always the question of contamination by exposure to the Earth’s environment,” Oba explained. “Since the Hayabusa2 spacecraft collected two samples directly from asteroid Ryugu and delivered them to Earth in sealed capsules, contamination can be ruled out.”

Purifying water with the power of the sun

A Notre Dame researcher’s invention could improve access to clean water for some of the world’s most vulnerable people.

 “Today, the big challenges are information technology and energy,” says László Forró, the Aurora and Thomas Marquez Professor of Physics of Complex Quantum Matter in the University of Notre Dame's Department of Physics and Astronomy. “But tomorrow, the big challenge will be water.”

The World Health Organization reports that today nearly 2 billion people regularly consume contaminated water. It estimates that by 2025 half of the world’s population could be facing water scarcity. Many of those affected are in rural areas that lack the infrastructure required to run modern water purifiers, while many others are in areas affected by war, natural disasters or pollution. There is a greater need than ever for innovative ways to extend water access to those living without power, sanitation and transportation networks.

Recently, Forró's lab developed just such a solution. They created a water purifier, described in the Nature partner journal Clean Water, that is powered by a resource nearly all of the world’s most vulnerable people have access to: the sun.

New method to identify and explore functional proteoforms and their associations with drug response in childhood acute lymphoblastic leukemia

Rozbeh Jafari, senior researcher at the Department of Oncology-Pathology.
Photo Credit: Courtesy of Rozbeh Jafari

Researchers at the Department of Oncology-Pathology have together with researchers from The European Molecular Biology Laboratory published a paper in Nature Chemical Biology where they developed a method that can identify important differences between proteins in an unbiased way.

The paper examines melting behavior of proteins to define cases where portions of the protein melt differently. In these cases, the method can identify that the protein is likely to exist in multiple physical forms, called proteoforms. Therefore, a new perspective on variations between proteins can be interpreted. The method is applied in the context of childhood acute lymphoblastic leukemia cell lines, and is used to identify specific proteoforms associated with disease biology and drug response. This disease was selected as a proof of principle due to the need for improved precision therapies for patients.

Monday, March 20, 2023

Can synthetic polymers replace the body’s natural proteins?

Biological fluids are made up of hundreds or thousands of different proteins (represented by space filling models above) that evolved to work together efficiently but flexibly. UC Berkeley polymer scientists are trying to create artificial fluids composed of random heteropolymers (threads inside spheres) with much less complexity, but which mimic many of the properties of the natural proteins (right), such as stabilizing fragile molecular markers.
Illustration Credit: Zhiyuan Ruan, Ting Xu lab

Most life on Earth is based on polymers of 20 amino acids that have evolved into hundreds of thousands of different, highly specialized proteins. They catalyze reactions, form backbone and muscle and even generate movement.

But is all that variety necessary? Could biology work just as well with fewer building blocks and simpler polymers?

Ting Xu, a University of California, Berkeley, polymer scientist, thinks so. She has developed a way to mimic specific functions of natural proteins using only two, four or six different building blocks — ones currently used in plastics — and found that these alternative polymers work as well as the real protein and are a lot easier to synthesize than trying to replicate nature’s design.

As proof of concept, she used her design method, which is based on machine learning or artificial intelligence, to synthesize polymers that mimic blood plasma. The artificial biological fluid kept natural protein biomarkers intact without refrigeration and even made the natural proteins more resistant to high temperatures — an improvement over real blood plasma.

Researchers Separate Cotton from Polyester in Blended Fabric

A cotton knit fabric dyed blue and washed 10 times to simulate worn garments is enzymatically degraded to a slurry of fine fibers and "blue glucose" syrup that are separated by filtration - both of these separated fractions have potential recycle value.
Photo Credit: Sonja Salmon.

In a new study, North Carolina State University researchers found they could separate blended cotton and polyester fabric using enzymes – nature’s tools for speeding chemical reactions. Ultimately, they hope their findings will lead to a more efficient way to recycle the fabric’s component materials, thereby reducing textile waste.

However, they also found the process needs more steps if the blended fabric was dyed or treated with chemicals that increase wrinkle resistance.

“We can separate all of the cotton out of a cotton-polyester blend, meaning now we have clean polyester that can be recycled,” said the study’s corresponding author Sonja Salmon, associate professor of textile engineering, chemistry and science at NC State. “In a landfill, the polyester is not going to degrade, and the cotton might take several months or more to break down. Using our method, we can separate the cotton from polyester in less than 48 hours.”

Discovering the Unexplored: Synthesis and Analysis of a New Orthorhombic Sn3O4 Polymorph

Tuning the reaction conditions such as degree of filling and gas composition can have a major impact on the products obtained by hydrothermal synthesis obtained. This was clearly represented in the new Tokyo Tech study where they synthesized an unreported orthorhombic polymorph of Sn3O4 instead of conventional monoclinic phase by optimizing the conditions inside the hydrothermal reactor. The orthorhombic Sn3O4 has a narrower bandgap than the conventional one, thus making it useful as a visible-light active photocatalyst.

Oxides of tin (SnxOy) are found in many of modern technologies due to their versatile nature. The multivalent oxidation states of tin—Sn2+ and Sn4+—impart tin oxides with electroconductivity, photocatalysis, and various functional properties. For the photocatalysis application of tin oxides, a narrow bandgap for visible-light absorption is indispensable to utilize a wide range of solar energy. Hence, the discovery of new SnxOy could help improve the efficiency of many environmentally significant photocatalytic reactions like water splitting and CO2 reduction. While there are many theoretical and computational predictions of the new stable SnxOy, there still remains a need for experimental studies that can turn the predictions into reality.

Thursday, March 16, 2023

Ural Scientists Design Plastics That Resist Radiation from Technology

Aleksey Korotkov tests the material for electrodynamic properties in an anechoic chamber.
Photo Credit: Rodion Narudinov

The team of scientists from the Institute of Technical Chemistry of the Ural Branch of the Russian Academy of Sciences (branch of the Perm Federal Research Centre of UB RAS) and the Ural Federal University created a composite polymer material. The new composite is made from recycled materials and has unique properties. It reflects electromagnetic waves. It is suitable for wireless systems, including radar and satellite communications systems. Such a composite (actually a plastic) can be used to make housing for devices such as smartphones. It will allow them to reduce their electromagnetic radiation. The description of the new material is published in the journal Diamond and Related Materials.

"It is extremely important that we have been able to create a new composite material from virtually recycled raw materials. The basis of the material is chopped carbon fibers, which we extracted from carbon plastics. In addition, the composition of the composite includes magnetite (it is the magnetic nanoparticles) synthesized in our laboratory. Our work can increase the attractiveness of carbon plastics processing due to the use of secondary extracted carbon fibers in the expensive technologies," says Svetlana Astafieva, the co-author of the development, the Head of the Laboratory of Structural-Chemical Modification of Polymers of the Institute of Technical Chemistry of UB RAS.

Sunday, March 12, 2023

Researchers find access to new fluorescent materials

Cover picture of Chemical Science. The glow of the glow-worm, which represents the class of phospholes, grows more intense as a result of modification.
Illustration Credit: Dr Christoph Selg.

Fluorescence is a fascinating natural phenomenon. It is based on the fact that certain materials can absorb light of a certain wavelength and then emit light of a different wavelength. Fluorescent materials play an important role in our everyday lives, for example in modern screens. Due to the high demand for applications, science is constantly striving to produce new and easily accessible molecules with high fluorescence efficiency. Chemist Professor Evamarie Hey-Hawkins from Leipzig University and her colleagues have specialized in a particular class of fluorescent materials – phospholes. These consist of hydrocarbon frameworks with a central phosphorus atom. In experiments with this substance, Nils König from Hey-Hawkins’ working group has found access to new fluorescent materials. He has now published his findings in the journal Chemical Science.

“Phospholes can be modified by certain chemical reactions, which has a major impact on the color and efficiency of the fluorescence of the molecule. Another special feature of these substances is their propeller-like structure,” explains König. When these molecules are dissolved in a solvent and exposed to UV light, they do not fluoresce. The absorbed energy is released in the form of rotational motion, causing the molecules to spin like a propeller in the solvent. In a crystalline state, however, the ability to rotate is severely limited, which makes the substances fluoresce strongly under UV light. This behavior is known as aggregation-induced emission (AIE).

Wednesday, March 8, 2023

New Tool for Understanding Disease

Lina Pradham (left), a post-doctoral researcher in the Kloxin Group points out dormant breast cancer cells in 3D cultures imaged using confocal microscopy to UD engineer April Kloxin, Thomas and Kipp Gutshall Development Professor of Chemical and Biomolecular Engineering. In the image, the dormant cells (shown in green) are viable, not proliferating, and remain capable of proliferating upon stimulation.
Photo Credit: Evan Krape / University of Delaware

UD model illuminates environmental cues that may contribute to breast cancer recurrence

Nearly 270,000 people in the United States are diagnosed with breast cancer each year. 

According to the Susan G. Komen Foundation, about 70-80% of these individuals experience estrogen receptor-positive (ER+) breast cancer, where cancer cells need estrogen to grow. In terms of treatment, this presence of hormone receptors provides a nice handle for targeting tumors, say with therapies that knock out the tumor cell’s ability to bind to estrogen and prevent remaining breast cancer cells from growing.

However, even if treated successfully, on average, one in five individuals with ER+ breast cancer experiences a late recurrence when dormant tumor cells in distant parts of the body, such as the bone marrow, reactivate anywhere from 5 to over 20 years after initial treatment.

Tuesday, March 7, 2023

New Fluorescent Sensors Make it Possible to Detect the Concentration of Mercury in Water

New fluorophores selectively and with high sensitivity recognize mercury ions.
Photo Credit: Anna Marinovich

Scientists from the UrFU, together with Italian and Bulgarian colleagues, synthesized new heterocyclic fluorophores - four types of carboxamides of 2-aryl-1,2,3-triazoles. Their photophysical properties have been investigated under different conditions - solvents and their binary mixtures with water. Sensors based on the fluorophores obtained were sensitive to mercury, so they can be used to detect mercury concentrations in water. Further research will focus on determining the possibility of using these fluorophores to target medicines to affected organs. The authors have published an article on their research and results in the journal Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy.

"A disadvantage of organic fluorophores is their poor solubility in water and aqueous environments. At the same time, when water is added to organic solvents, most dyes and fluorophores have fluorescence quenching. However, in 2001, Professor Ben Zhong Tan of the Chinese University of Hong Kong found that some fluorophores observed not quenching, but rather an increase the fluorescence intensity. This is due to the formation of much larger particles, or nano-aggregates, from the molecules of fluorophores. Tan's discovery was of great significance. Much scientific effort has been devoted to studying the mechanism of his discovery, as well as to the design and synthesis of new fluorophores with the effect of increasing the emission. The fluorophores we obtained have also demonstrated in a mixture of organic solvent and water the effect described by Tang, and with a particular intensity. This opens the way to the practical application of the obtained fluorophores in various fields, especially in the aquatic environment," says Natalya Belskaya, Full Professor of the UrFU Department of Technology of Organic Synthesis and leader of the research team.

Study finds silicon, gold and copper among new weapons against COVID-19

New Curtin research has found the spike proteins of SARS-CoV-2, a strain of coronaviruses that caused the COVID-19 pandemic, become trapped when they come into contact with silicon, gold and copper, and that electric fields can be used to destroy the spike proteins, likely killing the virus.

Lead researcher Dr Nadim Darwish, from the School of Molecular and Life Sciences at Curtin University said the study found the spike proteins of coronaviruses attached and became stuck to certain types of surfaces.

“Coronaviruses have spike proteins on their periphery that allow them to penetrate host cells and cause infection and we have found these proteins becomes stuck to the surface of silicon, gold and copper through a reaction that forms a strong chemical bond,” Dr Darwish said.

“We believe these materials can be used to capture coronaviruses by being used in air filters, as a coating for benches, tables and walls or in the fabric of wipe cloths and face masks.

Wednesday, March 1, 2023

Chemical imaging could help predict efficacy of radiation therapy for an individual cancer patient

Concept illustration of body chemistry.
Image Credit: Nicole Smith, made with Midjourney. Courtesy of University of Michigan

Decisions on cancer treatment could become better tailored to individual patients with the adoption of a new imaging method being developed by University of Michigan researchers that maps the chemical makeup of a patient’s tumor.

Today, treatment methods for cancer—whether surgery, radiation therapy or immunotherapy—are recommended based mainly on the tumor’s location, size and aggressiveness. This information is usually obtained by anatomical imaging—MRI or CT scans or ultrasound and by biological assays performed in tissues obtained by tumor biopsies.

Yet, the chemical environment of a tumor has a significant effect on how effective a particular treatment may be. For example, a low oxygen level in tumor tissue impairs the effectiveness of radiation therapy.

Now, a team of scientists from the University of Michigan and two universities in Italy has demonstrated that an imaging system that uses special nanoparticles can provide a real-time, high-resolution chemical map that shows the distribution of chemicals of interest in a tumor.

It could lead to a way to help clinicians make better recommendations on cancer therapy tailored to a particular patient—precision medicine.

Monday, February 27, 2023

Chaos on the Nanometer Scale

Nanochaos on an asymmetric Rhodium nanocrystal
Illustration Credit: Vienna University of Technology

Sometimes, chemical reactions do not solely run stationary in one direction, but they show spatio-temporal oscillations. At TU Wien, a transition to chaotic behavior on the nanometer scale has now been observed.

Chaotic behavior is typically known from large systems: for example, from weather, from asteroids in space that are simultaneously attracted by several large celestial bodies, or from swinging pendulums that are coupled together. On the atomic scale, however, one does normally not encounter chaos – other effects predominate. Now, for the first time, scientists at TU Wien have been able to detect clear indications of chaos on the nanometer scale – in chemical reactions on tiny rhodium crystals. The results have been published in the journal Nature Communications.

Researchers Uncover How Photosynthetic Organisms Regulate and Synthesize ATP

The redox regulation mechanism responsible for efficient production of ATP under varying light conditions in photosynthetic organisms has now been unveiled by Tokyo Tech researchers. They investigated the enzyme responsible for this mechanism and uncovered how the amino acid sequences present in the enzyme regulate ATP production. Their findings provide valuable insights into the process of photosynthesis and the ability to adapt to changing metabolic conditions.

ATP, the compound essential for the functioning of photosynthetic organisms such as plants and algae, is produced by an enzyme called "chloroplast ATP synthase" (CFoCF1). To control ATP production under varying light conditions, the enzyme uses a redox regulatory mechanism that modifies the ATP synthesis activity in response to changes in the redox state of cysteine (Cys) residues, which exist as dithiols under reducing (light) conditions, but forms a disulfide bond under oxidizing (dark) conditions. However, this mechanism has not been fully understood so far.

Now, in a study published in the Proceedings of the National Academy of Sciences, a team of researchers from Japan, led by Prof. Toru Hisabori from Tokyo Institute of Technology (Tokyo Tech), has uncovered the role of the amino acid sequences present in CFoCF1, revealing how the enzyme regulates ATP production in photosynthetic organisms.

Wednesday, February 22, 2023

New zirconia-based catalyst can make plastics upcycling more sustainable

A representation of the zirconia catalyst. The teal shows the mesoporous silica plates, the red represents the zirconia nanoparticles between the two sheets. The polymer chains enter the pores, contact the zirconia nanoparticles, and are cut into shorter chains.
Illustration Credit: Courtesy of Ames National Laboratory

A new type of catalyst breaks down polyolefin plastics into new, useful products. This project is part of a new strategy to reduce the amount of plastic waste and its impact on our environment, as well as recover value that is lost when plastics are thrown away. The catalyst was developed by a team from the Institute for Cooperative Upcycling of Plastic (iCOUP), a U.S. Department of Energy, Energy Frontier Research Center. The effort was led by Aaron Sadow, the director of iCOUP, scientist at Ames National Laboratory, and professor at Iowa State University; Andreas Heyden, professor at the University of South Carolina; and Wenyu Huang, scientist at Ames Lab and professor at Iowa State. The new catalyst is made only of earth-abundant materials, which they demonstrated can break carbon-carbon (CC) bonds in aliphatic hydrocarbons.

Aliphatic hydrocarbons are organic compounds made up of only hydrogen and carbon. Polyolefin plastics are aliphatic hydrocarbon materials composed of long chains of carbon atoms linked together to form strong materials. These materials are a big part of the plastic waste crisis. Wenyu Huang said, “More than half of produced plastics so far are polyolefin based.”

UrFU Chemists Found a Non-toxic Way to Obtain Piperine from Black Pepper

A new method of obtaining piperine from black pepper is more environmentally friendly than the traditional one.
Photo Credit: Anas Alhajj

An international research team of chemists from Russia (UrFU), the Republic of Congo, and India came up with an alternative to the traditional method of obtaining piperine from black pepper. The scientists used a natural solvent for extraction, which has no toxic properties because it consists of a composition from organic salts and acids that are well soluble in water. Moreover, the extract obtained using this technology has better antioxidant activity. The results of the study are published in the journal Sustainable Chemistry.

"Piperine is a bioactive substance that is found in black pepper. It has many useful properties. First of all, it causes that particular pungent taste. Piperine is used in food to increase the absorption of micro and macronutrients in the human body. For example, piperine may be added to yogurt and cheese. There are numerous studies about piperine, but the novelty of our work is the development of a new technology for extracting this substance from black pepper using natural, "green" solvents," - says Full Professor Elena Kovaleva from the UrFU Department of Organic Synthesis Technology.

Thursday, February 16, 2023

Tsunami in a water glass

Fabio Novelli, Martina Havenith and Claudius Hoberg (from left) were able to observe the birth of an electron dissolved in water in RESOLV.
Photo Credit: © RUB, Marquard

With a new experiment, the effects of an electron in solution on the surrounding liquid have been observed.

So-called hydrated electrons play a major role in many physical, chemical and biological processes. They are not bound to an atom or molecule and are freely in the solution. Since they are only ever produced as an intermediate product, they are extremely short-lived. The team of the Ruhr Explores Solvation Cluster of Excellence RESOLV at the Ruhr University Bochum, a new experiment was the first time to observe how the hydrated electron acts on the solution over its life. The researchers around Prof. Dr. Martina Havenith-Newen report in the journal Proceedings of the National Academy of Science PNAS from 15. February 2023.

The simplest anion

"A single electron in water is the simplest conceivable anion, which, however, plays a major role in a large number of chemical processes," Martina Havenith describes the importance of the object of investigation. “For example, it plays an important role in energy transmission during photochemical and electrochemical phenomena, in atmospheric chemistry, in the radiation damage to biological substances and in medical therapy." For several decades, this has given the hydrated electron the constant attention of experimental and theoretical groups.

New Horizons for Organoboron and Organosilicon Chemistry with Triple Elementalization

A technique for easily modifying quinolines with carbon, boron, and silicon groups simultaneously has been unveiled by scientists at Tokyo Tech. With organoboron and organosilicon compounds becoming more and more important in pharmaceuticals, the novel technique could facilitate the development of new drugs. Moreover, modified quinolines can be readily used as convenient scaffolds for synthesizing organic chemicals.

In recent years, organic chemicals containing boron (B) and silicon (Si) have found applications in various fields, including optoelectronics and pharmaceuticals. Moreover, they can also serve as building blocks for complex organic chemicals. As a result, scientists are actively looking for new ways to leverage these versatile chemical tools as well as produce more kinds of organosilicon and organoboron compounds.

One limitation of the synthesis methods currently available for these chemicals is that we cannot introduce multiple B- and Si-containing groups in aromatic nitrogen heterocycles, i.e., carbon rings in which one of the carbon atoms is replaced by a nitrogen atom. If we could produce and freely transform such molecules, it would unlock the synthesis of several compounds relevant in medicinal chemistry.

Wednesday, February 15, 2023

New compound that withstands extreme heat and electricity could lead to next-generation energy storage devices

A new type of polysulfate compound can be used to make polymer film capacitors that store and discharge high density of electrical energy while tolerating heat and electric fields beyond the limits of existing polymer film capacitors.
Illustration Credit: Yi Liu and He (Henry) Li/Berkeley Lab

Society’s growing demand for high-voltage electrical technologies – including pulsed power systems, cars and electrified aircraft, and renewable energy applications – requires a new generation of capacitors that store and deliver large amounts of energy under intense thermal and electrical conditions. Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Scripps Research have now developed a new polymer-based device that efficiently handles record amounts of energy while withstanding extreme temperatures and electric fields. The device is composed of materials synthesized via a next-generation version of the chemical reaction for which three scientists won the 2022 Nobel Prize in Chemistry.

Polymer film capacitors are electrical components that store and release energy within an electric field using a thin plastic layer as the insulating layer. They make up 50% of the global high voltage capacitor market and offer advantages including light weight, low cost, mechanical flexibility, and robust cyclability. But state-of-the-art polymer film capacitors decrease dramatically in performance with increasing temperature and voltages. Developing new materials with improved tolerance for heat and electric fields is paramount; and creating polymers with near-perfect chemistry offers a way to do so.

Pesticides in Capsules Are Less Toxic and More Effective at Killing Pests

Pesticides are taken up by the roots of plants when they germinate, and move up the food chain into the human body.
Photo Credit: Elizaveta Veretennikova

Pesticides in capsules are less toxic and more effective in killing pests. This was discovered by a group of chemists from China and Russia, including scientists from the Ural Federal University. The researchers proposed the use of β-cyclodextrins as capsule shells, which weaken the toxic effect of pesticides. Reducing toxicity in the long term will reduce the amount of pesticides not only in plants, but also in the human body. Humans can absorb them by eating plant foods and animal flesh. An article with the results of the research has been published in the journal Advanced Agrochem.

"Pesticides are used to kill pests and plant pathogens. They are also used to control various parasites, weeds, pests of grain and grain products, and wood. They are among the most toxic pollutants. They are very difficult to remove from the soil and are slow to decompose. As a result, they are absorbed into the roots of plants during germination and move up the food chain to enter the human body. Pesticides also tend to accumulate, especially in fatty tissues, which poses a serious threat to humans. In addition, in hot weather they can become gaseous and pollute the air," says Elena Kovaleva, Professor of the Department of Technology of Organic Synthesis at the Ural Fereral University.

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