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Paleoarchean stromatolites are among the oldest compelling evidence for life. We present advanced two- and three-dimensional (2-D and 3-D) reconstructions of the morphology, mineralogy, trace element geochemistry, and taphonomy of permineralized stromatolites from the lowermost horizons of the ca. 3.5 Ga Dresser Formation, Pilbara, Western Australia. Rare earth element plus yttrium compositions suggest a restricted paleodepositional setting influenced by marine influxes; this contrasts with other Dresser stromatolites, which developed around terrestrial hot springs. Mineral phase relationships and positive Eu anomalies denote syndepositional hydrothermal influence and silicification promoting high-fidelity microstructural preservation. Although no primary kerogen is preserved, numerous 2-D and 3-D morphological characteristics denote a biogenic origin, including the onlap of sedimentary layers onto stromatolitic topography, fine-scale undulatory laminations, non-isopachous laminations with crestal thickening, laminoid fenestrae, and subvertical pillar-like fabrics interpreted as microbial palisade structure; these features suggest that the stromatolite ecosystem was dominantly phototrophic. The deep iron-rich weathering profile of the Dresser stromatolites makes them pertinent analogues for potential microbialites in altered carbonates on Mars. Were similar putative biogenic macro-, meso- and micromorphologies identified in habitable Martian settings by rover imaging systems, such materials would be compelling targets for sample return. [ABSTRACT FROM AUTHOR]

Background: Histopathological analysis represents the gold standard in clinical practice for diagnosing skin neoplasms. While the current diagnostic workflow has specialized in producing robust and accurate results, interpreting tissue architecture and malignant cellular morphology correctly remains one of the greatest challenges for pathologists. This paper aims to explore the prospect of applying x-ray virtual histology to human skin tumor excisions and correlating it with the histological validation., Materials and Methods: Seven skin biopsies containing intriguing melanoma types and pigmented skin lesions were scanned using x-ray Computed micro-Tomography (μCT) and then sectioned for conventional histology assessment., Results: The tissue microarchitecture reconstructed by μCT offers detailed insights into diagnosing the malignancy or benignity of the skin lesions. Three-dimensional reconstruction via x-ray virtual histology reveals infiltrative patterns in basal cell carcinoma and evaluated invasiveness in melanoma. The technology enables the identification of pagetoid distributions of neoplastic cells and the assessment of melanoma depth in three dimensions., Conclusion: Although the proposed approach is not intended to replace conventional histology, the non-destructive nature of the sample and the clarity provided by virtual inspection demonstrate the promising impact of μCT as a valid support method prior to conventional histological sectioning. Indeed, μCT images can suggest the optimal sectioning position before using a microtome, as is commonly performed in histological practice. Moreover, the three-dimensional nature of the proposed approach paves the way for a more accurate assessment of significant prognostic factors in melanoma, such as Breslow thickness, by considering the whole micro-volume rather than a two-dimensional observation., (© 2024 The Author(s). Skin Research and Technology published by John Wiley & Sons Ltd.)

Pulmonary fibrosis (PF) is a severe and progressive condition in which the lung becomes scarred over time resulting in pulmonary function impairment. Classical histopathology remains an important tool for micro-structural tissue assessment in the diagnosis of PF. A novel workflow based on spatial correlated propagation-based phase-contrast micro computed tomography (PBI-microCT), atomic force microscopy (AFM) and histopathology was developed and applied to two different preclinical mouse models of PF - the commonly used and well characterized Bleomycin-induced PF and a novel mouse model for progressive PF caused by conditional Nedd4-2 KO. The aim was to integrate structural and mechanical features from hallmarks of fibrotic lung tissue remodeling. PBI-microCT was used to assess structural alteration in whole fixed and paraffin embedded lungs, allowing for identification of fibrotic foci within the 3D context of the entire organ and facilitating targeted microtome sectioning of planes of interest for subsequent histopathology. Subsequently, these sections of interest were subjected to AFM to assess changes in the local tissue stiffness of previously identified structures of interest. 3D whole organ analysis showed clear morphological differences in 3D tissue porosity between transient and progressive PF and control lungs. By integrating the results obtained from targeted AFM analysis, it was possible to discriminate between the Bleomycin model and the novel conditional Nedd4-2 KO model using agglomerative cluster analysis. As our workflow for 3D spatial correlation of PBI, targeted histopathology and subsequent AFM is tailored around the standard procedure of formalin-fixed paraffin-embedded (FFPE) tissue specimens, it may be a powerful tool for the comprehensive tissue assessment beyond the scope of PF and preclinical research., Competing Interests: Declaration of competing interest Conflict of interest statement for the manuscript: None Declared, (Copyright © 2024. Published by Elsevier Ltd.)

Hydroxyapatite is one of the materials of choice for tissue engineering bone scaffolds manufacturing. Vat photopolymerization (VPP) is a promising Additive Manufacturing (AM) technology capable of producing scaffolds with high resolution micro-architecture and complex shapes. However, mechanical reliability of ceramic scaffolds can be achieved if a high fidelity printing process is obtained and if knowledge of the intrinsic mechanical properties of the constituent material is available. As the hydroxyapatite (HAP) obtained from VPP is subjected to a sintering process, the mechanical properties of the material should be assessed with specific reference to the process parameters (e.g. sintering temperature) and to the specific characteristic size of the microscopic features in the scaffolds. In order to tackle this challenge the HAP solid matrix of the scaffold was mimicked in the form of miniaturized samples suitable for ad hoc mechanical characterization, which is an unprecedented approach. To this purpose small scale HAP samples, having a simple geometry and size similar to that of the scaffolds, were produced through VPP. The samples were subjected to geometric characterization and to mechanical laboratory tests. Confocal laser scanning and Computed micro-Tomography (micro-CT) were used for geometric characterization; while, micro-bending and nanoindentation were used for mechanical testing. Micro-CT analyses have shown a highly dense material with negligible intrinsic micro-porosity. The imaging process allowed quantifying the variation of geometry with respect to the nominal size showing high accuracy of the printing process and identifying printing defects on one specific sample type, depending on the printing direction. The mechanical tests have shown that the VPP produces HAP with an elastic modulus as high as approximately 100GPa and flexural strength of approximately 100MPa. The results of this study have shown that vat photopolymerization is a promising technology capable of producing high quality HAP with reliable geometric fidelity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This work introduces a novel setup for computed tomography of heavy and bulky specimens at the SYRMEP beamline of the Italian synchrotron Elettra. All the key features of the setup are described and the first application to off-center computed tomography scanning of a human chest phantom (approximately 45 kg) as well as the first results for vertical helical acquisitions are discussed., (open access.)

In this work, polyvinylidene fluoride (PVDF) aerogels with a tailorable phase composition were prepared by following the crystallization-induced gelation principle. A series of PVDF wet gels (5 to 12 wt.%) were prepared from either PVDF−DMF solutions or a mixture of DMF and ethanol as non-solvent. The effects of the non-solvent concentration on the crystalline composition of the PVDF aerogels were thoroughly investigated. It was found that the nucleating role of ethanol can be adjusted to produce low-density PVDF aerogels, whereas the changes in composition by the addition of small amounts of water to the solution promote the stabilization of the valuable β and γ phases. These phases of the aerogels were monitored by FTIR and Raman spectroscopies. Furthermore, the crystallization process was followed by in-time and in situ ATR−FTIR spectroscopy. The obtained aerogels displayed specific surface areas > 150 m2 g−1, with variable particle morphologies that are dependent on the non-solvent composition, as observed by using SEM and Synchrotron Radiation Computed micro-Tomography (SR-μCT).

Frey syndrome (gustatory sweating, auricolotemporal syndrome) is a complication of parotidectomy, probably caused by misdirection of regenerating fibers in the auricolotemporal nerve. The authors review the pathophysiology and describe the treatment used in this entity.

The concentrations of natural alpha-emitting isotopes of thorium (228Th, 230Th and 232Th) have been determined in 22 sets of human tissue samples obtained at autopsy from Grand Junction, CO and in 10 sets from Washington, DC. Tissues included lung, pulmonary lymph nodes, liver, kidney, bone, a few gonads, spleen and thyroid. Personal data on each individual's age, sex, smoking history and occupation were obtained whenever possible. The concentrations of 228Th, 230Th and 232Th were highest in lymph nodes for both populations with 2.6 and 5.1 pCi/kg of 228Th, 4.60 and 11.10 pCi/kg of 230Th, and 2.8 and 7.8 pCi/kg of 232Th in Washington, DC and Grand Junction, CO, respectively. The order of concentrations of all three isotopes in all other organs for both populations was as follows: (formula; see text) The data suggest that the non-mining residents who lived in the vicinity of uranium mine tailings do not have elevated 230Th concentrations in their lungs, when compared to the residents of Washington, DC who are not exposed to such tailings. However, 230Th concentration in bone of Grand Junction subjects was just significantly higher (at p less than 0.1) than that for Washington, DC subjects after suitable age adjustments. The data also suggest that 230Th is more available for accumulation in skeleton than would be supposed from its relative geochemical abundance.

Three patients with condylomata acuminata of the urinary bladder are reported. Two of the patients were immunosuppressed, and one had longstanding extensive condylomata acuminata of the external genitalia and adjacent areas. All lesions recurred at least once and were difficult to treat. The diagnosis was confirmed by in situ hybridization on archival material with human papillomavirus (HPV) DNA probes under stringent conditions. In two of the patients, probes for HPV types 6 and 11 were positive; HPV 11 only was identified in one patient. Probes for HPV types 16 and 18 and pBR322 vector controls were negative. In one patient with a strong hybridization signal, the lesion was also positive for common papillomavirus antigen. DNA content measured by cytophotometry of Feulgen-stained whole nuclei isolated from lesions in two patients revealed a markedly aneuploid DNA pattern. Whether this is a factor in the behavior of the lesions is not known at this time. Although rare, HPV infection of the urinary bladder may result in widespread condylomatosis and may mimic giant condylomas of Buschke-Löwenstein or even verrucous carcinomas, sometimes necessitating radical treatment. Nevertheless, until there is proof to the contrary, the lesions must be considered benign and should not be confused with squamous cancer of the bladder.