The origin of life is one of humanity’s greatest mysteries. For centuries, scientists have sought to understand how the complex systems that govern our world emerged from the simple chemistry of the early Earth. A crucial step in this process is the replication of genetic material, which would have been carried by RNA (ribonucleic acid) molecules before DNA and proteins later took over.

Chemists at UCL and the MRC Laboratory of Molecular Biology have made a groundbreaking discovery that brings us closer to understanding how life began. They’ve successfully recreated the conditions under which RNA might have replicated itself on early Earth, a key process in the origin of life.

The researchers used three-letter “triplet” RNA building blocks in water and added acid and heat, which separated the double helix structure that normally prevents RNA strands from replicating. By neutralizing and freezing the solution, they created liquid gaps between the ice crystals where the triplet building blocks could coat the RNA strands and prevent them from zipping back together, allowing replication to occur.

By repeating this cycle of changes in pH and temperature, which could plausibly occur in nature, the researchers were able to replicate RNA over and over again. This process produced RNA strands long enough to have a biological function and play a role in the origin of life.

The study’s lead author, Dr James Attwater, emphasized that replication is fundamental to biology. “In one sense, it is why we are here,” he said. “But there’s no trace in biology of the first replicator.”

The researchers believe that early life was run by RNA molecules, and their findings provide a possible explanation for how this process could have occurred before life began several billion years ago.

While the study focuses solely on the chemistry, the conditions they created could plausibly mimic those in freshwater ponds or lakes, especially in geothermal environments where heat from inside the Earth has reached the surface. However, this replication of RNA could not occur in freezing and thawing saltwater, as the presence of salt interferes with the freezing process and prevents RNA building blocks from reaching the concentration required to replicate RNA strands.

The origin of life is likely to have emerged out of a combination of RNA, peptides, enzymes, and barrier-forming lipids that can protect these ingredients from their environment. The researchers are uncovering clues about how life began, and their findings bring us closer to understanding this fundamental mystery.
In recent years, teams led by Dr John Sutherland and Professor Matthew Powner have demonstrated how chemistry could create many of the key molecules of life’s origin, including nucleotides, amino acids and peptides, simple lipids and precursors to some of the vitamins, from simple molecular building blocks likely abundant on the early Earth.

The latest study was supported by the Medical Research Council (MRC), part of UK Research and Innovation (UKRI), as well as the Royal Society and the Volkswagen Foundation.

Rapid simulations of toxic particles could aid air pollution fight by providing more precise ways of monitoring air quality and predicting how these harmful substances move through the air. Researchers have developed a new computer modeling approach that significantly improves the accuracy and efficiency of simulating nanoparticles’ behavior in the air.

These tiny particles, found in exhaust fumes, wildfire smoke, and other airborne pollutants, are linked to serious health conditions such as stroke, heart disease, and cancer. Predicting how they move is notoriously difficult, making it challenging to develop effective strategies for mitigating their impact.

The new method allows researchers to calculate a key factor governing how particles travel – known as the drag force – up to 4,000 times faster than existing techniques. This breakthrough was made possible by creating a mathematical solution based on how air disturbances caused by nanoparticles fade with distance.

By applying this approach to simulations, researchers can zoom in much closer to particles without compromising accuracy. This differs from current methods, which involve simulating vast regions of surrounding air to mimic undisturbed airflow and require far more computing power.

The new approach could help better predict how these particles will behave inside the body, potentially aiding the development of improved air pollution monitoring tools. It could also inform the design of nanoparticle-based technologies, such as lab-made particles for targeted drug delivery.

The study, published in the Journal of Computational Physics, was supported by the Engineering and Physical Sciences Research Council (EPSRC). Lead author Dr Giorgos Tatsios, from the University of Edinburgh’s School of Engineering, said: “Our method allows us to simulate their behavior in complex flows far more efficiently, which is crucial for understanding where they go and how to mitigate their effects.”

Professor Duncan Lockerby, from the University of Warwick’s School of Engineering, added: “This approach could unlock new levels of accuracy in modeling how toxic particles move through the air – from city streets to human lungs – as well as how they behave in advanced sensors and cleanroom environments.”

The article reveals that personal care products can significantly suppress the human oxidation field, which is generated by people’s presence indoors. This field changes the indoor air chemistry around us, affecting our intake of chemicals and impacting human health.

Researchers from the Max Planck Institute for Chemistry conducted a study in 2022 that found high levels of OH radicals can be generated indoors due to the presence of people and ozone. A follow-up study showed that commonly used personal care products substantially suppress a person’s production of OH radicals, with implications for indoor chemistry, air quality, and human health.

The study involved an international research team, including scientists from the University of California (Irvine, USA) and the Pennsylvania State University. They developed a state-of-the-art chemical model to simulate concentrations of chemical compounds near humans in the indoor environment.

The researchers examined how body lotion and perfume affect the human oxidation field. When applied to the skin, they found that both products suppressed the production of OH radicals, with the primary component of perfume (ethanol) reacting with OH radicals. Body lotion also contributed to suppressing the human oxidation field by reacting with ozone on the skin.

The study suggests that fragrances impact the OH reactivity and concentration over shorter time periods, whereas lotions show more persistent effects consistent with the rate of emissions of organic compounds from these personal care products.

Implications for indoor chemistry include the suppression of the personal human oxidation field when applying a fragrance indoors. Lotions are expected to suppress the human oxidation field due to dilution of skin oil constituents and reduced interaction between O3 and the skin, as well as the presence of preservatives acting as antimicrobial agents.

The study was part of the ICHEAR project (Indoor Chemical Human Emissions and Reactivity Project), which brought together international scientists from Denmark, USA, and Germany. The modeling was part of the MOCCIE project based in University of California Irvine and the Pennsylvania State University, funded by grants from the A. P. Sloan foundation.

In conclusion, personal care products can have a significant impact on indoor air chemistry, suppressing the human oxidation field that affects our intake of chemicals and human health. As we spend up to 90% of our time indoors, it is essential to be aware of this phenomenon and consider the potential implications for our well-being.

The experiments were conducted in a climate-controlled chamber at the Technical University of Denmark (DTU) in Copenhagen, where four test subjects stayed under standardized conditions. Ozone was added to the chamber air inflow, and the team determined the OH concentrations indirectly by quantifying individual OH sources and overall loss rates of OH. By combining air measurements with model simulations, they calculated the effect of lotion and fragrance on the human oxidation field.

The findings have implications for indoor chemistry, highlighting the need for further research into the properties and effects of chemical compounds in our breathing zone.