Paul Scherrer Institut PSI

Polystyrene is made from styrene building blocks and is the most widely used plastic in terms of volume, for example in packaging. Unlike PET, which can now be produced and recycled using biotechnological methods, the production of polystyrene has so far been a purely chemical process. The plastic can't be broken down by biotechnological means, either. Researchers are looking for ways to rectify this: An international team decoded a bacterial enzyme that plays a key role in styrene degradation. This paves the way for biotechnological application. Understanding the function of a specific bacterial enzyme has paved the way for the biotechnological degradation of styrene. Polystyrene is made from styrene building blocks and is the most widely used plastic in terms of volume, for example in packaging. Unlike PET, which can now be produced and recycled using biotechnological methods, the production of polystyrene has so far been a purely chemical process. The plastic can't be broken down by biotechnological means, either. Researchers are looking for ways to rectify this: An international team headed by Dr. Xiaodan Li from the Paul Scherrer Institute, Switzerland, in collaboration with Professor Dirk Tischler, head of the Microbial Biotechnology research group at Ruhr University Bochum, Germany, has decoded a bacterial enzyme that plays a key role in styrene degradation. This paves the way for biotechnological application. The researchers published their findings in the journal Nature Chemistry on May, 14, 2024. Styrene in the environment "Several million tons of styrene are produced and transported every year," says Dirk Tischler. "In the process, some of it also gets released unintentionally into the environment." This is not the only source of styrene in the environment, however: It occurs naturally in coal tar and lignite tar, can occur in traces in essential oils from some plants and is formed during the decomposition of plant material. "It is therefore not surprising that microorganisms have learned to handle or even to metabolize it," says the researcher. Fast, but complex: microbial styrene degradation Bacteria and fungi, as well as the human body, activate styrene with the help of oxygen and form styrene oxide. While styrene itself is toxic, styrene oxide is even more harmful. Rapid metabolization is therefore crucial. "In some microorganisms as well as in the human body, the epoxide formed by this process usually undergoes glutathione conjugation, which makes it both more water-soluble and easier to break down and excrete," explains Dirk Tischler. "This process is very fast, but also very expensive for the cells. A glutathione molecule has to be sacrificed for every molecule of styrene oxide." The formation of the glutathione conjugate and whether, or rather how, glutathione can be recovered is part of current research at the MiCon Graduate School at Ruhr University Bochum, funded by the German Research Foundation (DFG). Some microorganisms have developed a more efficient variant. They use a small membrane protein, namely styrene oxide isomerase, to break down the epoxide. Styrene oxide isomerases are more efficient "Even after the first enrichment of styrene oxide isomerase from the soil bacterium Rhodococcus, we observed its reddish color and showed that this enzyme is bound in the membrane," explains Dirk Tischler. Over the years, he and his team have studied various enzymes of the family and used them primarily in biocatalysis. All of these styrene oxide isomerases have a high catalytic efficiency, are very fast and don't require any additional substances (co-substrates). They therefore allow rapid detoxification of the toxic styrene oxide in the organism and also a potent biotechnological application in the field of fine chemical synthesis. "In order to optimize the latter, we do need to understand their function," points out Dirk Tischler. "We made considerable progress in this area in our international collaboration between researchers from Switzerland, Singapore, the Netherlands and Germany." The team showed that the enzyme exists in nature as a trimer with three identical units. The structural analyses revealed that there is a heme cofactor between each subunit and that this is loaded with an iron ion. The heme forms an essential part of the so-called active pocket and is relevant for the fixation and conversion of the substrate. The iron ion of the heme cofactor activates the substrate by coordinating the oxygen atom of the styrene oxide. "This means that a new biological function of heme in proteins has been comprehensively described," concludes Dirk Tischler.

STOCKHOLM, Feb. 23, 2024 /PRNewswire/ -- FOURTH QUARTER (OCTOBER - DECEMBER 2023) Order intake SEK 317.7 M (514.4) Net sales SEK 299.6 M (264.4) Operating profit SEK 44.4 M (20.7) Profit after tax SEK 31.5 M (14.1) Earnings per share before/after dilution SEK 0.92 (0.41) Cash flow SEK 45.5 M (42.8) Order backlog SEK 1,864.4 M (1,940.1) at the end of the period TWELVE MONTHS (JANUARY - DECEMBER 2023) Order intake SEK 1,004.2 M (1,218.5) Net sales SEK 1,022.2 M (843.6) Operating profit SEK 114.9 M (42.7) Profit after tax SEK 81.6 M (23.8) Earnings per share before/after dilution SEK 2.38 (0.69) Cash flow SEK 190.3 M (46.8) The Board of Directors proposes an ordinary dividend of SEK 0.70 (0) per share which corresponds to 30 percent of the group profit for the period in accordance with the dividend policy. Additionally, the Board of Directors proposes an extra dividend of SEK 1.30 (0) per share. SIGNIFICANT EVENTS DURING THE FOURTH QUARTER RaySearch secured an order from Israel-based P-Cure and expanded collaboration focusing on advanced proton therapy solutions. Paul Scherrer Institute in Switzerland placed an order for RayStation. The Mass General Cancer Center in the US placed an order and thereby expanded its installation of RayStation to also include proton treatment planning. Vejle Hospital in Denmark became the first center in the world to use RayStation for an online adaptive treatment with augmented CBCT. The hospital chain Froedtert & Medical College of Wisconsin, US, placed an order for RayStation. SIGNIFICANT EVENTS AFTER THE END OF THE REPORTING PERIOD The number of radiation therapy centers that have chosen RayStation for treatment planning now exceeds 1,000. The Royal Marsden in the UK will be the first center in the world to implement online adaptive radiation therapy utilizing ARTemis from RaySearch. RaySearch acquired the product DrugLog from Pharmacolog. FOR FURTHER INFORMATION, PLEASE CONTACT: Johan Löf, CEO Telephone: +46 (0)8 510 530 00, [email protected] Annika Blondeau Henriksson, Interim CFO Telephone: +46 (0)8 510 530 00, [email protected] The information contained in this interim report is such that RaySearch Laboratories AB (publ) is obliged to disclose under the EU Market Abuse Regulation and the Swedish Securities Market Act. The information was submitted for publication on February 23, 2024 at 7:45 a.m. CET. WEBCAST CEO Johan Löf and Interim CFO Annika Blondeau Henriksson will present RaySearch's year-end report for January-December 2023 at a webcast to be held in English on Friday, February 23, 2024 at 10:00-10:30 a.m. CET. Link to webcast: RaySearch Q4, 2023 You can also join the webcast by phone: Sverige: +46 (0) 8 505 100 31 UK: +44 (0) 207 107 06 13 US: +1 (1) 631 570 56 13 The following files are available for download: SOURCE RaySearch Laboratories

New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, a new paper shows. New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, shows paper in Nature Physics. Clean lines and minimalism, or vintage shabby chic? It turns out that the same trends that occupy the world of interior design are important when it comes to designing the building blocks of quantum computers. How to make qubits that retain their quantum information long enough to be useful is one of the major barriers to practical quantum computing. It's widely accepted that the key to qubits with long lifetimes, or 'coherences', is cleanliness. Qubits lose quantum information through a process known as decoherence when they start to interact with their environment. So, conventional wisdom goes, keep them away from each other and from other disturbing influences and they'll hopefully survive a little longer. In practice such a 'minimalistic' approach to qubit design is problematic. Finding suitable ultra-pure materials is not easy. Furthermore, diluting qubits to the extreme makes scale-up of any resulting technology challenging. Now, surprising results from researchers at the Paul Scherrer Institute PSI, ETH Zurich and EPFL show how qubits with long lifetimes can exist in a cluttered environment. "In the long run, how to make it onto a chip is a question that's universally discussed for all types of qubits. Instead of diluting more and more, we've demonstrated a new pathway by which we can squeeze qubits closer together," states Gabriel Aeppli, head of the Photon Science Division at PSI and professor at ETH Zürich and EPFL, who led the study. Picking the gems from the junk The researchers created solid-state qubits from the rare-earth metal terbium, doped into crystals of yttrium lithium fluoride. They showed that within a crystal jam-packed with rare-earth ions were qubit gems with much longer coherences than would typically be expected in such a dense system. "For a given density of qubits, we show that it's a much more effective strategy to throw in the rare-earth ions and pick the gems from the junk, rather than trying to separate the individual ions from each other by dilution," explains Markus Müller, whose theoretical explanations were essential to understand bamboozling observations. Like classical bits that use 0 or 1 to store and process information, qubits also use systems that can exist in two states, albeit with the possibility of superpositions. When qubits are created from rare-earth ions, typically a property of the individual ions -- such as the nuclear spin, which can point up or down -- is used as this two-state system. Pairing up offers protection The reason the team could have such success with a radically different approach is that, rather than being formed from single ions, their qubits are formed from strongly interacting pairs of ions. Instead of using the nuclear spin of single ions, the pairs form qubits based on superpositions of different electron shell states. Within the matrix of the crystal, only a few of the terbium ions form pairs. "If you throw a lot of terbium into the crystal, by chance there are pairs of ions -- our qubits. These are relatively rare, so the qubits themselves are quite dilute," explains Adrian Beckert, lead author of the study. So why aren't these qubits disturbed by their messy environment? It turns out that these gems, by their physical properties are shielded from the junk. Because they have a different characteristic energy at which they operate, they cannot exchange energy with the single terbium ions -- in essence, they are blind to them. "If you make an excitation on a single terbium, it can easily hop over to another terbium, causing decoherence," says Müller. "However, if the excitation is on a terbium pair, its state is entangled, so it lives at a different energy and cannot hop over to the single terbiums. It'd have to find another pair, but it can't because the next one is a long distance away." Shining light on qubits The researchers stumbled upon the phenomenon of qubit pairs when probing terbium doped yttrium lithium fluoride with microwave spectroscopy. The team also uses light to manipulate and measure quantum effects in materials, and the same kind of qubits are expected to operate at the higher frequencies of optical laser light. This is of interest as rare-earth metals possess optical transitions, which give an easy way in with light. "Eventually, our goal is to also use light from the X-ray Free Electron Laser SwissFEL or Swiss Light Source SLS to witness quantum information processing," says Aeppli. This approach could be used to read out entire qubit ensembles with X-ray light. In the meantime, terbium is an attractive choice of dopant: it can be easily excited by frequencies in the microwave range used for telecommunications. It was during spin echo tests -- a well-established technique to measure coherence times -- that the team noticed funny peaks, corresponding to much longer coherences than those on the single ions. "There was something unexpected lurking," remembers Beckert. With further microwave spectroscopy experiments and careful theoretical analysis, they could unpick these as pair states. "With the right material, the coherence could be even longer." As the researchers delved into the nature of these qubits, they could understand the different ways in which they were protected from their environment and seek to optimise them. Although the excitations of the terbium pairs might be well shielded from the influence of other terbium ions, the nuclear spins on other atoms in the material could still interact with the qubits and cause them to decohere. To protect the qubits further from their environment, the researchers applied a magnetic field to the material that was tuned to exactly cancel out the effect of the nuclear spin of the terbium in the pairs. This resulted in essentially non-magnetic qubit states, which were only minimally sensitive to noise from the nuclear spins of surrounding 'junk' atoms. Once this level of protection was included, the qubit pairs had lifetimes of up to one hundred times longer than single ions in the same material. "If we'd set out to look for qubits based on terbium pairs, we wouldn't have taken a material with so many nuclear spins," says Aeppli. "What this shows is how powerful this approach can be. With the right material, the coherence could be even longer." Armed with knowledge of this phenomenon, optimising the matrix is what the researchers will now do.