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In the present work, the state of the art of the most common additive manufacturing (AM) technologies used for the manufacturing of complex shape structures of graphene-based ceramic nanocomposites, ceramic and graphene-based parts is explained. A brief overview of the AM processes for ceramic, which are grouped by the type of feedstock used in each technology, is presented. The main technical factors that affect the quality of the final product were reviewed. The AM processes used for 3D printing of graphene-based materials are described in more detail; moreover, some studies in a wide range of applications related to these AM techniques are cited. Furthermore, different feedstock formulations and their corresponding rheological behavior were explained. Additionally, the most important works about the fabrication of composites using graphene-based ceramic pastes by Direct Ink Writing (DIW) are disclosed in detail and illustrated with representative examples. Various examples of the most relevant approaches for the manufacturing of graphene-based ceramic nanocomposites by DIW are provided.

SiC-TiB2-TiC composites with matrices consisting of semiconductor material (SiC), conductive materials (TiB2-TiC), or their combination were fabricated by spark plasma sintering (SPS) at 2000 °C in a vacuum under a pressure of 80 MPa for 3 min. The composition and microstructure of the obtained composites were studied by X-ray diffraction and a scanning electron microscope equipped with an energy-dispersive detector. The flexural strength, Vickers hardness, and fracture toughness of SPSed samples were determined. Based on the observations in this work, three variations of the sintering process were proposed with different matrix compositions. The dense (99.7%) 60SiC-25TiB2-15TiC vol.% sintered ceramic composites exhibited the highest strength and hardness values of the studied composites, as well as a fracture toughness of 6.2 MPa·m1/2.

In this work, we report an available technique for the effective reduction of graphene oxide (GO) and the fabrication of nanostructured zirconia reduced graphene oxide powder via a hydrothermal method. Characterization of the obtained nano-hybrid structure materials was carried out using a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The confirmation that GO was reduced and the uniform distribution of zirconia nanoparticles on graphene oxide sheets during synthesis was obtained due to these techniques. This has presented new opportunities and prospects to use this uncomplicated and inexpensive technique for the development of zirconia/graphene nanocomposite powders.

The spatiotemporal proteome of the intervertebral disc (IVD) underpins its integrity and function. We present DIPPER, a deep and comprehensive IVD proteomic resource comprising 94 genome-wide profiles from 17 individuals. To begin with, protein modules defining key directional trends spanning the lateral and anteroposterior axes were derived from high-resolution spatial proteomes of intact young cadaveric lumbar IVDs. They revealed novel region-specific profiles of regulatory activities and displayed potential paths of deconstruction in the level- and location-matched aged cadaveric discs. Machine learning methods predicted a ‘hydration matrisome’ that connects extracellular matrix with MRI intensity. Importantly, the static proteome used as point-references can be integrated with dynamic proteome (SILAC/degradome) and transcriptome data from multiple clinical samples, enhancing robustness and clinical relevance. The data, findings, and methodology, available on a web interface ( http://www.sbms.hku.hk/dclab/DIPPER/ ), will be valuable references in the field of IVD biology and proteomic analytics. The backbone of vertebrate animals consists of a series of bones called vertebrae that are joined together by disc-like structures that allow the back to move and distribute forces to protect it during daily activities. It is common for these intervertebral discs to degenerate with age, resulting in back pain and severely reducing quality of life. The mechanical features of intervertebral discs are the result of their proteins. These include extracellular matrix proteins, which form the external scaffolding that binds cells together in a tissue, and signaling proteins, which allow cells to communicate. However, how the levels of different proteins in each region of the disc vary with time has not been fully examined. To establish how protein composition changes with age, Tam, Chen et al. quantified the protein levels and gene activity (which leads to protein production) of intervertebral discs from young and old deceased individuals. They found that the position of different mixtures of proteins in the intervertebral disc changes with age, and that young people have high levels of extracellular matrix proteins and signaling proteins. Levels of these proteins decreased as people got older, as did the amount of proteins produced. To determine which region of the intervertebral disc different proteins were in, Tam, Chen et al. also performed magnetic resonance imaging (MRI) of the samples to correlate image intensity (which represents water content) with the corresponding protein signature. The data obtained provides a high-quality map of how the location of different proteins changes with age, and is available online under the name DIPPER. This database is an informative resource for research into skeletal biology, and it will likely advance the understanding of intervertebral disc degeneration in humans and animals, potentially leading to the development of new treatment strategies for this condition.

The materials used in dentistry for the fabrication of all-ceramic restorations have undergone great and rapid developments over the last two decades. Among the most common ceramic materials in dentistry are those based on zirconium and lithium disilicate. Due to the properties of these materials, they are in great demand in the field of dental restoration production. Thus, dental restorations that will use those materials are commonly machined in CAD/CAM systems, which offer the possibility of manufacturing all-ceramic dental restorations in a very short period of time. This article reviews the modern materials in the field of all-ceramic dental restorations, their manufacturing processes, as well as what determines which ceramic materials are used for the production of CAD/CAM blanks and their production technology.

Using spark plasma sintering technology, SiC-TiB2-TiC ceramic composites with various graphene oxide content (0.15, 0.25, 0.5 vol.%) were manufactured, and their microstructure as well as physico-mechanical and tribological properties were studied. Ceramic composite with 0.25 vol.% of graphene oxide showed a relative density of 99.9%, fracture toughness of 6.3 MPa·m1/2, flexural strength of 583 MPa and Vickers hardness of 22.2 GPa. Moreover, this composite showed a coefficient of friction and wear rate of 0.53 and 1.92 × 10−6 mm3/N·m, respectively, under a load of 10 N. Similarly, under a load of 30 N, this composite showed a coefficient of friction and wear rate of 0.6 and 4.05 × 10−5 mm3/N·m, respectively. This research demonstrated that the addition of 0.25 vol.% of graphene oxide improved the physical–mechanical and tribological properties of ceramic composites based in the SiC-TiB2-TiC ternary system, which in turn makes this composite more promising for use, for example, as a cutting tool material.

Niobium–graphene oxide–zirconia-toughened alumina (ZTA) composites were produced by wet mixing and spark plasma sintering. The microstructure and mechanical properties of this novel composite have been studied. The results show that niobium particles are homogeneously dispersed in the ZTA matrix. Raman spectroscopy confirmed the thermal reduction in graphene oxide during sintering. The presence of ductile metal and graphene flakes leads to an increase in the crack resistance value of the ZTA matrix. The developed composites demonstrate a fracture toughness of 16 MPa∙m1/2, which is three times higher than ZTA ceramic composites. The high toughness values found in this new composite are a consequence of the strong interaction between the simultaneous action of several toughening mechanisms, specifically involving crack trapping, crack blunting, crack renucleation, and the bridging mechanisms of the metallic and graphene particles. Moreover, this increase has also occurred due to the enhancement of the transformability of zirconia in ceramic–metal composites.

In healthy skin, epidermis and dermis are anchored together at the dermal-epidermal junction (DEJ), a specialized basement membrane pivotal for skin integrity and function. However, increased inflammation in the DEJ is associated with the disruption and separation of this junction and sub-epidermal blistering. Granzyme B (GzmB) is a serine protease secreted by immune cells. Dysregulated inflammation may lead to increased GzmB accumulation and proteolysis in the extracellular milieu. Although elevated GzmB is observed at the level of the DEJ in inflammatory and blistering skin conditions, the present study is the first to explore GzmB in the context of DEJ degradation in autoimmune sub-epidermal blistering. In the present study, GzmB induced separation of the DEJ in healthy human skin. Subsequently, α6/β4 integrin, collagen VII, and collagen XVII were identified as extracellular substrates for GzmB through western blot, and specific cleavage sites were identified by mass spectrometry. In human bullous pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita, GzmB was elevated at the DEJ when compared to healthy samples, while α6/β4 integrin, collagen VII, and collagen XVII were reduced or absent in the area of blistering. In summary, our results suggest that regardless of the initial causation of sub-epidermal blistering, GzmB activity is a common final pathway that could be amenable to a single targeted treatment approach.

This paper deals with the application of statistical analysis in the study of the dependence of the flexural strength of sintered alumina (Al2O3) disks on the parameters (nozzle diameter of the printer print head, layer height, and filling pattern) of the fused deposition method (FDM) printing of ceramic–polymer filament containing 60 vol.% alumina and 40 vol.% polylactide. By means of a correlation analysis applied to the results of flexural tests, a linear relationship was found between the thickness of the printed layer and the strength of the sintered specimens. A statistically significant linear relationship was found between the geometric parameters and the weight of both printed ceramic–polymer and sintered ceramic samples, as well as the diameter of the nozzle used in the printing of the workpiece. It was found that the highest strength is achieved with a layer thickness equal to 0.4 mm, and the smallest scatter of mass values and geometric dimensions of ceramic samples is achieved using a nozzle diameter of 0.6 mm. As a result of the conducted research, linear equations allowing the prediction of changes in the geometry and mass of samples after sintering, as well as the strength properties of sintered samples, taking into account the geometry and mass of FDMed samples, were obtained.

Wire Electrical Discharge Machining (WEDM) is a technology for processing electrically conductive materials that enables localized material removal through high-temperature plasma generated by continuous spark discharges between the tool electrode and the workpiece electrode. In recent years, researchers have focused particularly on enhancing the productivity of WEDM processes. Unlike other intensification methods, vibrational assistance represents a universal and technologically efficient solution. This review systematizes studies on WEDM involving the application of vibration, whether exerted on the wire electrode or the workpiece. It has been demonstrated that vibration significantly improves machining productivity and quality. The key mechanisms include enhanced dielectric fluid circulation and more efficient debris removal, often facilitated by cavitation effects that prevent material resolidification. This ensures discharge stability, reduces short circuits and wire breakage, and promotes a more uniform distribution of discharge points. As a result, the material removal rate (MRR) is increased, while surface roughness (Ra) is substantially reduced. Additionally, geometric accuracy is improved, residual stresses are minimized, and workpiece burning is prevented. Thus, vibration-assisted WEDM presents a promising solution for enhancing the efficiency and quality of machining difficult-to-cut materials.