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Detailed characterization of the tooth and jaw structure and development among shark ancestors by synchrotron based X-ray tomographic microscopy at TOMCAT led an international team of researchers from the Naturalis Biodiversity Center in Leiden and the University of Bristol to the discovery that while teeth evolved once, complex dentitions have been gained and lost many times in evolutionary history.

The very large number of coherent photons produced by free-electron lasers is one of the key qualities of such facilities, attracting users from numerous research fields including chemistry, biology and materials science. Recently, the two branches of PSI's free-electron laser SwissFEL each have reached new record pulse energies, packing more photons than ever before into ultrashort X-ray pulses delivered at rates of 100 Hz to the users of both beamlines.

The compounds known as ‘pyrazinacenes’ are simple, stable compounds that consist of a series of connected nitrogen-containing carbon rings. They are suitable for applications in electrochemistry or synthesis, as the researchers describe in the science journal Communications Chemistry. They were first designed, synthesized and chemically characterized in solution by the Hill team and carefully investigated by Scanning Tunneling Microscopy and Surface Chemical Analysis. The compounds have been shown to reversibly release and accept electrons and arrange themselves differently depending on the oxidation state. Interestingly, the oxidation and reduction reactions of the pyrazinacenes are not only affected by a chemical impulse, but can also be stimulated by light so they can be considered photo-redox active.