麻豆淫院

When high-energy radiation interacts with water in living organisms, it generates particles and slow-moving electrons that can subsequently damage critical molecules like DNA. Now, Professor Petr Slav铆膷ek and his bachelor's student Jakub Dubsk媒 from UCT Prague (University of Chemistry and Technology, Prague) have described in detail one of the key mechanisms for the creation of these slow electrons in water, a process known as Intermolecular Coulombic Decay (ICD). Their powerful mathematical model successfully explains all the data from complex laser experiments conducted at ETH Zurich (Hans-Jakob Woerner team).

The work, which deepens the fundamental understanding of radiation chemistry, has been in the journal Nature Communications.

A detailed knowledge of the processes in aqueous solutions, combined with advances in research technologies using high-energy radiation, is transforming the field of radiation chemistry. In the future, these insights could lead to significant changes in various fields, including medicine, particularly in developing more sensitive and controllable applications for devices based on ionizing radiation.

Intermolecular Coulombic Decay (ICD) was first experimentally proven in water about 15 years ago, but until recently, all experiments have been conducted on isolated molecules or very small water clusters. The new research from the Prague-Zurich collaboration is the first to quantify the competition of ICD with proton transfer and nonadiabatic relaxation in liquid water and to establish the isotope dependence.

The study shows that after an inner-valence electron is ejected from a water molecule by radiation, the ICD process is not 100% efficient. It is in a race against other phenomena, primarily ultrafast proton transfer between neighboring water molecules and nonadiabatic relaxation. By performing experiments on both regular (H鈧侽) and heavy water (D鈧侽), the researchers showed that ICD is more efficient in heavy water. This isotope effect confirms that the slower movement of deuterium nuclei gives the electronic decay process more time to occur, providing clear evidence of the competition.

"Our model predicts all the data that the instruments in these challenging experiments can measure," says Professor Slav铆膷ek. "Therefore, we can also trust it in areas where instruments cannot yet see, and we can explain what happens in a solution after exposure to high-energy radiation."

The stochastic model is based on inputs from quantum mechanics, which are typically only feasible to calculate for limited systems like single water molecules or small clusters. These inputs, combined with the experimental results, were developed into a probabilistic model that provides a complete picture of ICD in a realistic environment.

Remarkably, the author of the published stochastic model is Jakub Dubsk媒, who recently completed his bachelor's degree at UCT Prague and is preparing to continue his master's studies at the University of Oxford.

"It is extraordinary when an undergraduate student delivers work at the level of a doctoral candidate, resulting in a real, functional product that brings entirely new knowledge," adds Professor Slav铆膷ek in praise of his student's contribution.