A 4-D dataset for validation of crystal growth in a complex three-phase material, ice cream

Four dimensional (4D, or 3D plus time) X-ray tomographic imaging of phase changes in materials is quickly becoming an accepted tool for quantifying the development of microstructures to both inform and validate models. However, most of the systems studied have been relatively simple binary compositions with only two phases. In this study we present a quantitative dataset of the phase evolution in a complex three-phase material, ice cream. The microstructure of ice cream is an important parameter in terms of sensorial perception, and therefore quantification and modelling of the evolution of the microstructure with time and temperature is key to understanding its fabrication and storage. The microstructure consists of three phases, air cells, ice crystals, and unfrozen matrix. We perform in situ synchrotron X-ray imaging of ice cream samples using in-line phase contrast tomography, housed within a purpose built cold-stage (-40 to +20oC) with finely controlled variation in specimen temperature. The size and distribution of ice crystals and air cells during programmed temperature cycling are determined using 3D quantification. The microstructural evolution of three-phase materials has many other important applications ranging from biological to structural and functional material, hence this dataset can act as a validation case for numerical investigations on faceted and non-faceted crystal growth in a range of materials

Two predominant molecular subtypes of spinal meningioma: thoracic NF2‑mutant tumors strongly associated with female sex, and cervical AKT1‑mutant tumors originating ventral to the spinal cord

Spinal meningiomas (SM) comprise 5–10% of primary meningiomas and up to 30% of spinal intradural tumors. SMs are usually sporadic, but rarely, they can develop in association with genetic diseases like neurofibromatosis type 2 or schwannomatosis [2, 4, 6]. While the mutational landscape of intracranial meningiomas has been extensively studied [3, 5, 11, 14], our understanding of the molecular profile of SM remains incomplete. To date, genomic studies in SMs have been underpowered to make significant conclusions about the correlations between main genomic driver alterations and clinical features of these tumors. Here, we sought to assess the mutational profile of WHO grade 1 SM and to investigate the clinical characteristics that correlate with the genomic status

Present and Future X-ray Tomographic Microscopy at TOMCAT

During its first four years of life, the TOMCAT beamline [1] at the Swiss Light Source has established itself as a state‐of‐the art hard x‐ray tomographic microscopy endstation for experiments on a large variety of samples, ranging from the fields of biology to materials science. It routinely performs absorption as well as phase‐contrast imaging with an isotropic voxel size ranging from 0.360 up to 14.8 microns. Phase contrast is obtained either with simple edge‐enhancement, a modified transport of intensity approach [2] or grating interferometry [3]. Typical acquisition times are on the order of a few minutes, depending on energy and resolution. A recently implemented automatic sample exchanger is now available for high‐throughput studies [4]. In addition to further developments in phase‐contrast imaging, current scientific activities at the beamline focus on pushing spatial and temporal resolution by a few orders of magnitude, aiming at nano‐ [5] and “real‐time” [6] tomography