The discovery of rich, well preserved skull material in the latest Middle Pleistocene deposits of Mishin Kamik cave (N-W Bulgaria) presents an opportunity for a new analysis of the taxonomy and the phylogeny of the so called “small cave bears”. Not all the small cave bears known would have necessarily had a common origin, the size decrease could be related in a number of cases to a parallelism. The bear from Mishin Kamik is identical with “Ursus rossicus” Borissiak from Krasnodar (S. Russia). Both these samples must be referred to U. savini Andrews from Bacton near Cromer (England). The specimens from Krasnodar and Mishin Kamik could be classified as U. sa. rossicus, a late form of the species. This species may have affinities with some Middle Pleistocene Siberian forms. U. savini is a small but very robust spelaeoid bear which is more advanced in a number of features than U. deningeri. In several aspects it attained the evolutional adaptations of the cave bears of the U. spelaeus-U. ingressus group and represents an independent lineage of spelaeoid bears. The Mishin Kamik population was adapted to a mosaic landscape of forests and open areas in hilly terrain. This bear had well developed grazing adaptations but had weak motor abilities.

This study presents a methodology for developing and validating digital models of tooth-inlay systems, aiming to trace the complete workflow from clinical procedures to simulation by involving dental professionals—dentists for manual cavity preparation and dental technicians for restoration modelling—while integrating micro-computed tomography (micro-CT) imaging with finite element analysis (FEA). The proposed workflow includes (1) the acquisition of high-resolution 3D micro-CT scans of a non-restored tooth, (2) image segmentation and reconstruction to create anatomically accurate digital twins and mesh generation, (3) the selection of proper resin and the 3D printing of four typodonts, (4) the manual preparation of cavities on the typodonts, (5) the acquisition of high-resolution 3D micro-CT scans of the typodonts, (6) mesh generation, digital inlay and onlay modelling and material property assignment, and (7) nonlinear FEA simulations under representative masticatory loading. The approach enables the visualisation of stress and deformation patterns, with preliminary results indicating stress concentrations at the tooth-restoration interface integrating different cavity alternatives and restorations on the same tooth. Quantitative outputs include von Mises stress, strain energy density, and displacement distribution. This study demonstrates the feasibility of using image-based, tooth-specific digital twins for biomechanical modelling in dentistry. The developed framework lays the groundwork for future investigations into the optimisation of restoration design and material selection in clinical applications.

The materials used for the synthesis of parent glass are 70% wt. metallurgical slag and 30% wt. industrial quartz sand. The initial batch is melted at and then quenched in water. The resulting glass frit is milled bellow 75 microns and pressed 1400 °C into “green” samples. In a next stage, they are heat treated at different temperatures with various heating rates and holding times. As a result, it is demonstrated the possibility for production variations, allowing the manufacture of three types of new materials by using the same pressed glass powders. We highlight the flexibility of the synthesis obtaining namely well densified glass-ceramics at about 950 °C, self-glazed glass-ceramics at about 1000 °C or glass-ceramic foams at approximately 1100 °C. The first set of materials is characterized by very well sintered structure combined with reasonable crystallinity; the second one—by smooth self-glazed surface with an attractive appearance and good properties and the third one—by 80–90% closed porosity and very good thermal stability above 1000 °C.

The frontal bone develops as two halves, which further unite in a single bone by the closure of the mid-sagittal metopic suture, typically by the end of the first postnatal year. The frontal sinus begins to expand into the orbital and vertical plates of the frontal bone postnatally and reaches the level of the nasion by the fourth year of age. At this time, the metopic suture is usually entirely closed. However, in the cases of failed closure of the metopic suture, its relationship to the frontal sinus development is still obscure. Here, we review the relevant literature and discuss the frontal bone development and maturation, from the viewpoint of the frontal sinus pneumatization in relation to the metopic craniosynostosis and failed closure of the metopic suture. The peculiar to the metopic skulls frontal bone configuration is rather an expression of the underlying neural mass demands than a consequence of the metopic suture persistence. Furthermore, the persistent metopic suture is frequently associated with a frontal sinus underdevelopment. It seems that the metopic suture does not inhibit the frontal sinus pneumatization itself, but rather both traits are an expression or an aftereffect of a certain condition during the early development.

Sinter-crystallization is a specific method of producing glass-ceramics that allows the manufacture of complexly shaped products, composites and solder. However, it usually is limited when the glass powders used are characterized by a high crystallization trend. This study proposes a new opportunity to improve the sinter-crystallization and demonstrates the benefits of microwave processing using diopside (CaMg(Si₂O₆)) glass-ceramics with an enhanced crystallinity of ~70%. The advantages of microwave processing are shown by comparing the results obtained with scanning electron microscopy, X-ray computed tomography and gas pycnometry for two glass-ceramic specimens. The first sample is obtained in the heat resistant furnace of an optical dilatometer, while the second is obtained by heating it with high-power microwave irradiation at 2.45 GHz, 1kW. Intense crystallization was observed in the sample sintered in an electric furnace, which blocked the sintering process and resulted in significant open porosity (7.1%). In addition, closed pores caused by the crystallization are observed in the centers of the sintered particles (5.2%). At the same time, the overall porosity of the microwave-sintered glass-ceramic is reduced by about two times, and the open porosity is practically eliminated (0.5%). In this sample, together with the crystallization-induced pores, some residual closed spherical pores, typical for a well-sintered sample, are also observed.