Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Friday, August 19, 2022

‘Forever chemicals’ destroyed by simple new method

Water samples for PFAS analysis.
Credit: Michigan Department of Environment, Great Lakes and Energy

PFAS, a group of manufactured chemicals commonly used since the 1940s, are called “forever chemicals” for a reason. Bacteria can’t eat them; fire can’t incinerate them; and water can’t dilute them. And, if these toxic chemicals are buried, they leach into surrounding soil, becoming a persistent problem for generations to come.

Now, Northwestern University chemists have done the seemingly impossible. Using low temperatures and inexpensive, common reagents, the research team developed a process that causes two major classes of PFAS compounds to fall apart — leaving behind only benign end products.

The simple technique potentially could be a powerful solution for finally disposing of these harmful chemicals, which are linked to many dangerous health effects in humans, livestock and the environment.

The research is published in the journal Science.

“PFAS has become a major societal problem,” said Northwestern’s William Dichtel, who led the study. “Even just a tiny, tiny amount of PFAS causes negative health effects, and it does not break down. We can’t just wait out this problem. We wanted to use chemistry to address this problem and create a solution that the world can use. It’s exciting because of how simple — yet unrecognized — our solution is.”

University Scientists Found Out How to Efficiently Extract Silver

Yulia Petrova is engaged in the selection of sorbents in the Laboratory of Chemical Design for New Multifunctional Oxide Materials.
Photo credit: Daniil Kovalenko

Chemists at Ural Federal University have identified the best sorbent based on aminopolymers modified with sulfoethyl groups for the extraction of silver ions from multicomponent solutions. The results of the research lead to the production of sorbents for the extraction of metals which concentration in solutions is insignificant. The obtained sorbents are potentially applicable, for example, in the purification of natural drinking water, fish ponds, and in the processing of industrial waste. The research was supported financially by the Russian Science Foundation (grant № 21-73-00052) and is described in a scientific article published in the Russian Journal of Inorganic Chemistry.

"Sorption of metal ions is facilitated by the very nature of the aminopolymer matrix of the sorbents. Adding sulfoethyl groups to it, as our studies show, leads to a significant increase in the selective properties of sorbents, that is the ability to absorb only certain ions from a wide set of different ions. The higher the degree of modification of sorbents by sulfoethyl groups, i.e. the more sulfoethyl groups in their composition, the better their selective properties. This particular work is dedicated to studying the extraction rate of silver ions from multicomponent solutions in the presence of copper, nickel, cobalt, zinc, and several other metals," says Yulia Petrova, Head of the research group and Associate Professor at the Department of Analytical and Environmental Chemistry at UrFU.

Wednesday, August 10, 2022

Eco-glue can replace harmful adhesives in wood construction

Plywood with eco-glue produced in Aalto University.
Photo Credit: Aalto University

A fast and energy-efficient manufacturing process results in a strong, non-toxic and fire-resistant adhesive—and a great opportunity for the Finnish bioeconomy.

Researchers at Aalto University have developed a bio-based adhesive that can replace formaldehyde-containing adhesives in wood construction. The main raw material in the new adhesive is lignin, a structural component of wood and a by-product of the pulp industry that is usually burned after wood is processed. As an alternative to formaldehyde, lignin offers a healthier and more carbon-friendly way to use wood in construction.

The carbon footprint of timber construction is significantly lower than concrete construction, and timber construction has often been viewed as better for the health of human occupants as well. However, wood panels still use adhesives made from fossil raw materials. They contain formaldehyde, which can be harmful to health, especially for those working in the adhesive manufacturing process. People living in or visiting buildings can also be exposed to toxic formaldehyde from wood panels.

Lignin, on the other hand, comes from wood itself. It binds cellulose and hemicellulose together and gives wood its tough, strong structure. Lignin accounts for about a quarter of the weight of wood and is produced in huge quantities in the pulp and bioprocessing industry. Only two to five percent of the lignin produced is used, and the rest is burned in factories for energy.

Tuesday, August 9, 2022

In control of chaos

Assembly line: A different chemical mixture is created in each of the droplets within the "Tubular flow reactor" – under exactly the same boundary conditions.
Image Credit: Empa

Crystals consisting of wildly mixed ingredients - so-called high-entropy materials - are currently attracting growing scientific interest. Their advantage is that they are particularly stable at extremely high temperatures and could be used, for example, for energy storage and chemical production processes. An Empa team is producing and researching these mysterious ceramic materials, which have only been known since 2015.

Nature strives for chaos. That's a nice, comforting phrase when yet another coffee cup has toppled over the computer keyboard and you imagine you could wish the sugary, milky brew back into the coffee cup - where it had been just seconds before. But wishing won't work. Because, as mentioned, nature strives for chaos.

Scientists have coined the term entropy for this effect - a measure of disorder. In most cases, if the disorder increases, processes run spontaneously and the way back to the previously prevailing order is blocked. See the spilled coffee cup. Even thermal power plants, which generate a huge cloud of steam above their cooling tower from a neat pile of wood or a heap of hard coal, operate driven by entropy. Disorder increases dramatically in many combustion processes - and humans take advantage of this, tapping a bit of energy in the form of electricity from the ongoing process for their own purposes.

Monday, August 8, 2022

Funding for catalyst research

The teams of Stefan Huber (left) and Dirk Tischler receive funding from the Mercator Research Center Ruhr.
Credit: RUB, Marquard

With a total of around 240,000 euros, the Mercator Research Center Ruhr supports two RUB cooperation projects with its partners of the Ruhr University Alliance.

In order to develop new tools for catalysis, the Mercator Research Center Ruhr (MERCUR) is funding two projects with Bochum participation with a total of around 240,000 euros. The team around Prof. Dr. Dirk Tischler from the Microbial Biotechnology Working Group at the Ruhr University Bochum (RUB) is developing new bio-building blocks in cooperation with a team from the Technical University (TU) Dortmund, which can be reliably and easily assembled into bio-catalysts. Prof. Dr. Stefan Huber and his working group at the Chair of Organic Chemistry I at RUB are developing new methods for catalysis using halogen bridges together with the University of Duisburg-Essen (UDE).

Biocatalysts from the tool case

These catalysts are complex proteins; Genes contain the building instructions for this. Different gene sections contain the building instructions for different protein components. In synthetic biology, researchers produce gene building blocks that can be used for different biocatalysts. These so-called biobricks form a kind of kit from which a catalyst can be put together for a specific purpose. The appropriate gene building blocks are put together and introduced into an organism such as the bacterium E. coli. This translates the gene into proteins with catalytic function.

Optical Fibers with Unusual Properties Created in Russia

Monocrystal.
Credit: Vladimir Petrov

Researchers of the Science Lab of Fiber Technology and Photonics at Ural Federal University have developed and produced infrared optical fibers with unique properties. The fibers are nontoxic and, as studies have shown, retain their outstanding properties when treated with ionizing beta radiation by doses up to 1 MGy. The team of scientists published an article describing the research, properties and areas of application of the obtained fibers in the scientific journal Optical Materials.

"This opens up the prospect of application of light guides made of the obtained fibers in conditions of intense ionizing radiation. That is, not only in the traditional field of optoelectronics, but also in laser surgery, endoscopic and diagnostic medicine, in determining the composition of hazardous waste from the nuclear industry, and in space," lists Liya Zhukova, Chief Scientist of the Laboratory, Professor of the Department of Physical Chemistry and Chemistry of Colloids at UrFU.

Because the fibers are capable of receiving and transmitting radiation from space objects, they can be embedded in infrared space telescopes, replacing massive mirrors and lenses. The lifespan of the fibers will be longer than the life cycle of the telescopes themselves, the developers claim.

Fibers are also highly productive in the non-hazardous for humans terahertz radiation region (between the region of mid- and far-infrared radiation, on the one hand, and microwave radiation, on the other hand). This means that fiber optic cables are suitable for creating equipment that could become a safe substitute for magnetic resonance imaging and x-rays - in medicine or in the process of pre-boarding scanning of passengers and their luggage. It would not require the use of cumbersome and expensive metal detectors, and passengers would not even feel that they are being screened.

Monday, August 1, 2022

New Method to Promote Biofilm Formation and Increase Efficiency of Biocatalysis

 The researchers screened synthetic polymers for their ability to induce biofilm formation in a strain of E. coli (MC4100), which is known to be poor at forming biofilms. They also monitored the biomass and biocatalytic activity of both MC4100 and PHL644 (a good biofilm former), incubated the presence of these polymers, and found that MC4100 matched and even outperformed PHL644.
Credit: EzumeImages

Birmingham scientists have revealed a new method to increase efficiency in biocatalysis, in a paper published today in Materials Horizons.

Biocatalysis uses enzymes, cells or microbes to catalyze chemical reactions, and is used in settings such as the food and chemical industries to make products that are not accessible by chemical synthesis. It can produce pharmaceuticals, fine chemicals, or food ingredients on an industrial scale.

However, a major challenge in biocatalysis is that the most commonly used microbes, such as probiotics and non-pathogenic strains of Escherichia coli, are not necessarily good at forming biofilms, the growth promoting ecosystems that form a protective micro-environment around communities of microbes and increase their resilience and so boost productivity.

This problem is normally solved by genetic engineering, but researchers Dr Tim Overton from the university’s School of Chemical Engineering, and Dr Francisco Fernández Trillo from the School of Chemistry*, both of whom are members of the Institute of Microbiology and Infection, set out to create an alternative method to bypass this costly and time-consuming process.

The researchers identified a library of synthetic polymers and screened them for their ability to induce biofilm formation in E. coli, a bacterium that is one of the most widely studied micro-organisms, and commonly used in biocatalysis.

Black cardamom effective against lung cancer cells

NUS researchers embarked on a scientific study of black cardamom, a spice used in Indian Ayurvedic medicine, as a source of potent bioactive compounds that are effective against lung cancer cells. Source: National University of Singapore

The main challenges associated with existing lung cancer drugs are severe side effects and drug resistance. There is hence a constant need to explore new molecules for improving the survival rate and quality of life of lung cancer patients.

In Indian Ayurvedic medicine, black cardamom has been used in formulations to treat cancer and lung conditions. A team of researchers from the NUS Faculty of Science, NUS Yong Loo Lin School of Medicine, and NUS College of Design and Engineering studied the scientific basis behind this traditional medicinal practice and provided evidence of the cytotoxic effect of black cardamom on lung cancer cells. The research highlighted the spice as a source of potent bioactives, such as cardamonin and alpinetin, which could be used in the treatment or prevention of lung cancer. The study is the first to report the association of black cardamom extract with oxidative stress induction in lung cancer cells, and compare the spice’s effects on lung, breast and liver cancer cells.

The findings could potentially lead to the discovery of safe and effective new bioactives which can prevent or cure cancer formation. The research was first published in the Journal of Ethnopharmacology.

Wednesday, July 27, 2022

Scientists develop greener, more efficient method for producing next-generation antibiotics

With the addition of a murine-derived biocatalyst (green), this engineered protein can add a fluoride atom to create macrolide analogs (structure, right). This approach offers a greener, more efficient method for creating new antibiotics.
Credit: Martin Grininger and Rajani Arora

An international team of researchers has developed a method for altering one class of antibiotics, using microscopic organisms that produce these compounds naturally.

The findings, published in Nature Chemistry, could lead to more efficient production of antibiotics that are effective against drug-resistant bacteria.

The team started with a microorganism that is genetically programmed to produce the antibiotic erythromycin. Scientists from the Institute of Organic Chemistry and Chemical

Biology at Germany’s Goethe University wondered if the system could be genetically altered to assemble the antibiotic with one additional fluorine atom, which can often improve pharmaceutical properties.

“We had been analyzing fatty acid synthesis for several years when we identified a part of a mouse protein that we believed could be used for directed biosynthesis of these modified antibiotics, if added to a biological system that can already make the native compound,” said Martin Grininger, professor for biomolecular chemistry at Goethe University.

Towards High-Quality Manganese Oxide Catalysts with Large Surface Areas


The octahedral molecular sieve (OMS-1) is a very powerful manganese oxide-based catalyst, and researchers from Tokyo Tech have found a remarkably simple way to synthesize it. By using a low-crystallinity precursor and a straightforward solid-state transformation method, they managed to produce high-quality OMS-1 nanoparticles. Their unprecedented catalytic performance and durability prove the potential of this novel synthesis approach for developing efficient catalysts and functional materials.

Manganese oxides have received much attention from materials scientists due to their widespread applications including electrodes, catalysts, sensors, supercapacitors, and biomedicine. Further, manganese is widely abundant and has many oxidation states, which allows it to form various interesting crystalline structures.

One such structure is the "todorokite-type manganese oxide octahedral molecular sieve (OMS-1)," a crystal whose unit cells (simplest repeating units of the crystal) consist of three-by-three MnO6 octahedral chains. Though promising as a catalyst, the potential of OMS-1 is limited by two reasons. First, its conventional synthesis methods are complex multi-step crystallization processes involving hydrothermal or reflux treatment. Second, these processes tend to create crystals with a higher particle size and a lower surface area, features detrimental to catalytic performance.

Shape-Memory Polymers

Ilya Starodumov as a member of an international team, is developing a technology for creating "smart" polymers.
Credit: Ilya Safarov

Biocompatible polymers based on a "smart" material poly (ε-caprolactone) that keeps its shape may appear in Russia. An international team of scientists from Russia, Israel, and Japan, including physicists from Ural Federal University, work on the technology of its creation. The research is supported by the Russian Foundation for Basic Research.

Polymeric materials based on poly (ε-caprolactone) are suitable for biomedical purposes: for surgery, cell engineering, regenerative medicine. Such material can be used to make devices for minimally invasive surgery (with minimal incisions), self-tightening surgical sutures, etc. A description of this material was published in The Journal of Physical Chemistry B.

"A special feature of polymers with shape memory is the ability to return to the original shape when the temperature changes. It looks like this: a polymer product with a certain "programmed" shape is made. Then this product is deformed in any manner, for example, stretched or curled, like surgical sutures. When heated to a certain temperature, the memory mechanism in the polymer is activated at the molecular level, and the product restores its original shape," says Ilya Starodumov, Head of the Laboratory of Multiphase Physico-Biological Environment Simulation at UrFU.

Friday, July 1, 2022

Home Sweet Home: A Study of the ‘Chemical Soup’ in our Houses


Chances are very good that as you read this, you are seated somewhere indoors. The surfaces around you are covered in microbes and you are also covered in microbes. All those microbes are busy excreting molecules and responding to the rest of the molecules in the mix. What does all of this mean for your health?

“We are living in a soup of chemistry,” says UConn Department of Chemistry researcher Alexander Aksenov, who is working to understand this microbial and molecular soup in our indoor environments and how it could be impacting our health. He and a multidisciplinary team of researchers, including from the University of California, San Diego, Colorado State University, and the University of Colorado published a paper today in Science Advances exploring these under-studied questions, with some surprising findings that could help inform us how to live healthier lives indoors.

Accounting for our full day, including time spent in cars, on average we spend over 90% of our time indoors, says Aksenov, so the indoor environment is by far the most important for us.

Previous studies show human activities impact our indoor environments, through things like gas stoves, chemical off-gassing, and the type of cleaning solutions we use. These studies usually looked at a limited number of molecules. For this study, the researchers sought to explore the full suite of molecules and microbes within a household environment.

Researchers discover new leukemia-killing compounds

Natasha Kirienko (left) and Svetlana Panina in Kirienko’s Rice University laboratory in 2019. Kirienko, associate professor of biosciences, and Panina, a former postdoctoral research associate in Kirienko’s lab, collaborated with researchers at the University of Texas MD Anderson Cancer Center to study potential new mitophagy-inducing drugs that could be paired with other chemotherapies to deliver a potent one-two punch to leukemia.
Photo by Jeff Fitlow/Rice University

Researchers from Rice University and the University of Texas MD Anderson Cancer Center have discovered potential new drugs that work in concert with other drugs to deliver a deadly one-two punch to leukemia.

The potential drugs are still years away from being tested in cancer patients, but a recently published study in the journal Leukemia highlights their promise and the innovative methods that led to their discovery.

In previous studies, the research groups of Rice biochemist Natasha Kirienko and MD Anderson physician-scientist Marina Konopleva screened some 45,000 small-molecule compounds to find a few that targeted mitochondria. In the new study, they chose eight of the most promising compounds, identified between five and 30 closely related analogs for each and conducted tens of thousands of tests to systematically determine how toxic each analog was to leukemia cells, both when administered individually or in combination with existing chemotherapy drugs like doxorubicin.

“One of the big challenges was to establish optimal conditions and doses for testing on both cancer cells and healthy cells,” said study lead author Svetlana Panina , a researcher at the University of Texas at Austin who conducted the research during her postdoctoral studies at Rice. “The results from our previously published cytotoxicity assay were helpful, but very little is known about these small-molecule compounds. None of them had been thoroughly described in other studies, and we had to essentially start from scratch to determine how much to use, what they do in cells, everything. All the doses and treatment conditions had to be adjusted by multiple preliminary experiments.”

Thursday, June 30, 2022

Scientists find trigger that sets off metastasis in pancreatic cancer

Scientists have found that cancers in the pancreas (left) readily metastasize because these tumors suppress levels of an enzyme, MSRA, that pulls oxygen atoms off amino acids called methionine. As MSRA levels decrease, methionines on proteins become more oxidized. This causes one particular protein to rev up energy production in the tumor, promoting the migration of cancer cells to other organs. Metastatic tumors on the liver (right) lead to rapid death.
Image courtesy of Christopher Chang, UC Berkeley, and Christine Chio, Columbia

Pancreatic cancer, though rare, is one of the deadliest of cancers, killing nearly 50,000 people yearly and doing so quickly, primarily because it metastasizes rapidly through the body. Barely one in 10 people survive beyond five years.

But a discovery by chemists at the University of California, Berkeley, suggests a new way to slow or stop metastatic spread of pancreatic and perhaps other cancers.

In last week’s issue of the journal Molecular Cell, Christopher Chang and his group at UC Berkeley, collaborating with Christine Chio’s team at Columbia University in New York, report that metastasis is triggered by the loss of an enzyme that repairs oxygen damage to proteins.

Without this enzyme to erase the oxidative damage, one particular protein in cancer cells goes on to rev up energy production and seed new cancers around the body. The researchers confirmed this by knocking down levels of the “eraser” enzyme in mice and in cultured mouse and human cells, or organoids. In both cases, this promoted the migration of cancer cells and metastatic spread.

Wednesday, June 29, 2022

Shining some light on the obscure proteome

Group Leader in Chemical Proteomics, Dr. Guillaume Médard, and his research group in the lab.
 Credit: Uli Benz / TUM

Mass-spectrometry based proteomics is the big-data science of proteins that allows to monitor the abundances of thousands of proteins in a sample at once. It is therefore a particularly well suited readout to discover which proteins are targeted by any small molecule. An international research team has investigated this using chemical proteomics.

Histone deacetylase (HDAC) inhibitors are a class of drugs used in oncology. An international research team involving scientists at the Technical University of Munich (TUM), Cornell University in Ithaca (USA), the German Cancer Research Center (DKFZ) in Heidelberg and Martin Luther University of Halle-Wittenberg has now investigated the effects of some HDAC drugs in more detail. The scientists wanted to know whether those epidrugs engage proteins other than the HDACs which they are designed to inhibit.

“To do so, target deconvolution by chemical proteomics is the method of choice. Hence, we first made new chemical tools - the so called affinity matrices - that would allow us to systematically profile the HDACs,” explains Dr. Guillaume Médard, group leader for chemical proteomics at the TUM chair of Proteomics and Bioanalytics led by Prof. Bernhard Küster.

“I profiled 53 drugs”, details Severin Lechner, doctoral candidate at the TUM School of Life Sciences. “Most of them, but not all, hit their intended HDAC target. However there were some surprises. Drugs used in hundreds of scientific studies were not as selective as assumed. Many had additional targets that were not previously known.

Friday, June 24, 2022

Small molecules transport iron in mice, and human cells to treat some forms of anemia

University of Illinois chemistry professor Martin D. Burke and graduate student Stella Ekaputri were part of a team that found a small molecule, hinokitiol, ferries iron out of liver cells lacking the protein that normally does the job and restores hemoglobin and red blood cell production.   
Photo Credit: Michelle Hassel

A natural small molecule derived from a cypress tree can transport iron in live mice and human cells lacking the protein that normally does the job, easing a buildup of iron in the liver and restoring hemoglobin and red blood cell production, a new study found.

Stemming from a collaboration between researchers at the University of Illinois Urbana Champaign, the University of Michigan, Ann Arbor and the University of Modena in Italy, the study demonstrated that the small molecule hinokitiol potentially could function as a “molecular prosthetic” when the iron-transporting protein ferroportin is missing or defective, offering a potential treatment path for ferroportin disease and certain kinds of anemia.

“This is a really striking demonstration in a whole animal model that an imperfect mimic of a missing protein can reestablish physiology, acting as a prosthesis on a molecular scale,” said study co-leader Dr. Martin D. Burke, a professor of chemistry at Illinois and a member of the Carle Illinois College of Medicine, as well as a medical doctor. “The implications are really quite broad with respect to other diseases caused by loss of protein function.”

Ferroportin is a protein that forms a channel for transporting iron in and out of cells. Ferroportin deficiency can be due to a genetic mutation or caused by inflammation or infection. Patients without the protein have an excess buildup of iron in the liver, spleen and bone marrow, particularly in a type of cell called a macrophage. Macrophages in the liver chew up old red blood cells and transport the iron in them for recycling into new red blood cells. However, without ferroportin, the iron builds up inside the cells and can’t be recycled, Burke said.

Wednesday, June 22, 2022

Research Finds Repurposed Drug Inhibits Enzyme Related to COVID-19

With the end of the pandemic seemingly nowhere in sight, scientists are still very focused on finding new or alternative drugs to treat and stop the spread of COVID-19. In a first-of-its-kind study, researchers at the University of New Hampshire have found that using an already existing drug compound in a new way, known as drug repurposing, could be successful in blocking the activity of a key enzyme of the coronavirus, or SARS-CoV-2, which causes COVID-19.

“The goal was to slow or prevent the spread of the virus by using a strategic therapeutic that could possibly disrupt key steps in the viral life cycle at the molecular level, like the first contact with a healthy cell or the first step in replicating within an infected cell,” said Harish Vashisth, associate professor of chemical engineering.

In their study, recently published in the journal PROTEINS: Structure, Function, and Bioinformatics, researchers set out to target a key enzyme responsible for COVID-19, called the main protease enzyme Mpro, which has become a primary target of intense research and therapeutic development because it is essential for the virus to replicate. In this case, they explored the inhibiting properties of a derivative of the potent chemical compound known as Thiadiazolidinones, or TDZD, which are already being studied as a potential treatment for neurological disorders like Parkinson’s Disease. Researchers used a specific TDZD compound, known as CCG-50014, to target Mpro which acts like a molecular scissor by cutting up long chains of polypeptide proteins of the virus into smaller component proteins. These smaller segments can fold and mature to form new virus particles. Using molecular dynamics simulations combined with laboratory experiments, the researchers determined that TDZD compound was able to inhibit the Mpro enzyme.

Monday, June 20, 2022

New model offers potential solutions for next-generation battery challenges

A new mathematical model has brought together the physics and chemistry of highly promising lithium-metal batteries, providing researchers with plausible, fresh solutions to a problem known to cause degradation and failure.

A new study by Stanford University researchers lights a path forward for building better, safer lithium-metal batteries.

Close cousins of the rechargeable lithium-ion cells widely used in portable electronics and electric cars; lithium-metal batteries hold tremendous promise as next-generation energy storage devices. Compared to lithium-ion devices, lithium-metal batteries hold more energy, charge up faster, and weigh considerably less.

To date, though, the commercial use of rechargeable lithium-metal batteries has been limited. A chief reason is the formation of “dendrites” – thin, metallic, tree-like structures that grow as lithium metal accumulates on electrodes inside the battery. These dendrites degrade battery performance and ultimately lead to failure which, in some instances, can even dangerously ignite fires.

The new study approached this dendrite problem from a theoretical perspective. As described in the paper, published in the Journal of The Electrochemical Society, Stanford researchers developed a mathematical model that brings together the physics and chemistry involved in dendrite formation.

This model offered the insight that swapping in new electrolytes – the medium through which lithium ions travel between the two electrodes inside a battery – with certain properties could slow or even outright stop dendrite growth.

Thursday, June 16, 2022

Chemists Created a Sensor that Accurately Detects the Saliva pH Level

Timofey Moseev has been engaged in research work since 2015.
Credit: Regina Pidgaetskaya

Chemists at UrFU have created a sensor for determining the pH of human saliva. This is a fluorophore with strong and stable emission, which picks up the smallest fluctuations in the pH in biological fluids (tenths). The analysis is performed using microdoses of the substance and a spectrometer, in which the substance is irradiated with a special lamp (its lifetime is tens of thousands of hours). The pH data appears in 5-7 seconds. The first results of joint studies of saliva samples and the sensor, conducted by scientific groups of the Department of Organic and Biomolecular Chemistry and the Department of Analytical Chemistry of the Institute of Chemical Engineering, are described in the famous Dyes and Pigments journal.

"Modern fluorometric pH sensors are based on small organic molecules. Typically, they are very sensitive and are able to detect the desired analyte in very low concentrations, up to nanoconcentrations. Our sensor is based on a new compound. We introduced a fluorinated fragment, and this allowed us to get the photophysical and electrochemical properties we needed," explains Timofey Moseev, an engineer-researcher at the Department of Organic and Biomolecular Chemistry at UrFU.

Saliva pH analysis is an accessible and non-invasive method of clinical diagnosis. With its help at an early stage, you can detect diseases, in particular gastrointestinal diseases: gastritis, stomach ulcers, duodenitis, etc. The pH level also affects the teeth: even a slight increase in the acidity of saliva can cause tooth decay and other problems.

Tuesday, June 14, 2022

Real-time Imaging of Dynamic Atom-atom Interactions


In a breakthrough, Tokyo Tech researchers have managed to observe and characterize dynamic assembly of metallic atoms using an ingenious combination of scanning transmission electron microscopy and video-based tracking. By visualizing short-lived molecules, such as metallic dimers and trimers, that cannot be observed using traditional methods, the researchers open up the possibility of observing more such dynamic structures predicted by simulations.

Chemistry is the study of bond formation (or dissociation) between atoms. The knowledge of how chemical bonds form is, in fact, fundamental to not just all of chemistry but also fields like materials science. However, traditional chemistry has been largely limited to the study of stable compounds. The study of dynamic assembly between atoms during a chemical reaction has received little attention. With recent advances in computational chemistry, however, dynamic, short-lived structures are gaining importance. Experimental observation and characterization of dynamic bonding predicted between atoms, such as the formation of metallic dimers, could open up new research frontiers in chemistry and materials science.

However, observing this bond dynamics also requires the development of a new methodology. This is because conventional characterization techniques only provide time-averaged structural information and are, thus, inadequate for observing the bonds as they are formed.

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