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Cranial reconstructions are essential for restoring both function and aesthetics in patients with craniofacial deformities or traumatic injuries. Titanium prostheses have gained popularity due to their biocompatibility, strength, and corrosion resistance. The use of Superplastic Forming (SPF) and Single Point Incremental Forming (SPIF) techniques to create titanium prostheses, specifically designed for cranial reconstructions was investigated in an ovine model through microtomographic and histomorphometric analyses. The results obtained from the explanted specimens revealed significant variations in bone volume, trabecular thickness, spacing, and number across different regions of interest (VOIs or ROIs). Those regions next to the center of the cranial defect exhibited the most immature bone, characterized by higher porosity, decreased trabecular thickness, and wider trabecular spacing. Dynamic histomorphometry demonstrated differences in the mineralizing surface to bone surface ratio (MS/BS) and mineral apposition rate (MAR) depending on the timing of fluorochrome administration. A layer of connective tissue separated the prosthesis and the bone tissue. Overall, the study provided validation for the use of cranial prostheses made using SPF and SPIF techniques, offering insights into the processes of bone formation and remodeling in the implanted ovine model.

Information on the flyer deformation during laser impact welding (LIW) is an important aspect to consider when high reliability of the welded components is required. For this reason, accurate numerical models simulating thermal and mechanical aspects are needed. In the present work, the cross-section morphology during LIW of Ti/Brass joints at varying laser pulse energies is modeled by a 2D finite element (FE) model. A hydrodynamic plasma pressure model able to describe the evolution of the pressure load step by step, taking into account the progressive deformation of the flyer, was implemented. Hence, this paper proposes an alternative method to the conventional node concentrated forces or predefined velocity as flyer boundary conditions. The levels of the equivalent plastic strain (PEEQ), shear stress, and critical flyer velocity at the collision point were used as reference parameters to predict the success of the welding bond, distinguishing the welded area from the unwelded area. The model was validated by comparison with the experimental data, which showed the effectiveness of the proposed FE code in predicting the cross-section morphology of the welded materials. Moreover, practical industrial information such as variation in the flyer impact velocity, collision angle, and process temperatures was predicted by varying the process laser pulse energy according to the basic principle of the process.

Introduction: We report the development and preliminary evaluation of a novel dynamic bioreactor to culture ovarian cortical tissue strips that leverages tissue response to enhanced oxygen transport and adequate mechanical stimulation. In vitro multistep ovarian tissue static culture followed by mature oocyte generation, fertilization, and embryo transfer promises to use the reserve of dormant follicles. Unfortunately, static in vitro culture of ovarian tissue does not promote development of primordial to secondary follicles or sustain follicle viability and thereby limits the number of obtainable mature oocytes. Enhancing oxygen transport to and exerting mechanical stimulation on ovarian tissue in a dynamic bioreactor may more closely mimic the physiological microenvironment and thus promote follicle activation, development, and viability. Materials and Methods: The most transport-effective dynamic bioreactor design was modified using 3D models of medium and oxygen transport to maximize strip perifusion and apply tissue fluid dynamic shear stresses and direct compressive strains to elicit tissue response. Prototypes of the final bioreactor design were manufactured with materials of varying cytocompatibility and assessed by testing the effect of leachables on sperm motility. Effectiveness of the bioreactor culture was characterized against static controls by culturing fresh bovine ovarian tissue strips for 7 days at 4.8 × 10 −5  m/s medium filtration flux in air at −15% maximal total compressive strain and by assessing follicle development, health, and viability. Results and Conclusions: Culture in dynamic bioreactors promoted effective oxygen transport to tissues and stimulated tissues with strains and fluid dynamic shear stresses that, although non-uniform, significantly influenced tissue metabolism. Tissue strip culture in bioreactors made of cytocompatible polypropylene preserved follicle viability and promoted follicle development better than static culture, less so in bioreactors made of cytotoxic ABS-like resin.

Currently, the growing need for highly customized implants has become one of the key aspects to increase the life expectancy and reduce time and costs for prolonged hospitalizations due to premature failures of implanted prostheses. According to the literature, several technological solutions are considered suitable to achieve the necessary geometrical complexity, from the conventional subtractive approaches to the more innovative additive solutions. In the case of cranial prostheses, which must guarantee a very good fitting of the region surrounding the implant in order to minimize micromotions and reduce infections, the need of a product characterized by high geometrical complexity combined with both strength and limited weight, has pushed the research towards the adoption of manufacturing processes able to improve the product’s quality but being fast and flexible enough. The attention has been thus focused in this paper on sheet metal forming processes and, namely on the Single Point Incremental Forming (SPIF) and the Superplastic Forming (SPF). In particular, the complete procedure to design and produce titanium cranial prostheses for in vivo tests is described: starting from Digital Imaging and COmmunications in Medicine (DICOM) images of the ovine animal, the design was conducted and the production process simulated to evaluate the process parameters and the production set up. The forming characteristics of the prostheses were finally evaluated in terms of thickness distributions and part’s geometry. The effectiveness of the proposed methodology has been finally assessed through the implantation of the manufactured prostheses in sheep.

Polymeric matrix composites (PMCs) have gained increasing relevance in different industrial applications and their employment results to be a necessity in the production of lightweight structures. The manufacturing solutions, which allow to properly shape PMC panels, need molds for shaping the material reducing the process flexibility. In this context, the single point incremental forming (SPIF) could be a valuable process solution if properly customized to the PMC properties. Herein, a possible process variant is introduced and its capability in forming long fiber–reinforced thermoplastics was evaluated. To achieve this aim, a numerical model was implemented focusing the attention, first, on the material properties that have to be considered for a proper model construction. The performed numerical simulations showed the applicability of SPIF to shape PMC sheets. Furthermore, the executed simulations pointed out the influences of some variables on the quality of the formed parts showing possible arising of defects, such as wrinkling and rippled surfaces, at different process conditions and providing a first proof of concept of the proposed working solution.

This work presents a novel 2D finite element (FE) model to investigate the bonding morphology and microstructural evolution during laser impact welding (LIW) of Ni/Ni joints, considering variations in flyer thickness and target impact angle. A key innovation is the introduction of a hydrodynamic plasma pressure model that captures the progressive deformation of the flyer, providing a physically accurate alternative to conventional methods that apply node-concentrated forces or predefined velocities. The model uses equivalent plastic strain (PEEQ), shear stress and critical flyer velocity at the collision point to assess bonding quality and identify welded regions. A user-defined subroutine was developed and implemented in commercial FE software to simulate the metallurgical changes induced by severe plastic deformation during welding. This subroutine incorporates a physically based plasticity model for Nickel 201 to predict dislocation density evolution, a Zener–Hollomon-based formulation for grain refinement and a dislocation-driven hardness model to estimate local mechanical property variations. The numerical results were validated against experimental data, demonstrating the model’s effectiveness in predicting key features such as grain refinement, dislocation density evolution, hardness changes, affected layer depth and overall bond integrity. This integrated and physics-informed modeling strategy provides new insights into the interplay between process parameters and microstructural transformations in LIW. It represents a significant scientific contribution by enabling predictive simulations that support process optimization and enhance understanding of weld quality in nickel-based materials.

Composite materials are widely used for their peculiar combination of excellent structural, mechanical, and damping properties. This work presents an experimental study on the dissipation properties of disk-shaped composite specimens exploiting vibration tests. Two different polymer matrix composites with the same number of identical laminae, but characterized by different stacking sequences, namely unidirectional and quasi-isotropic configurations, have been evaluated. An ad-hoc steel structure was designed and developed to reproduce an in-plane torsional excitation on the specimen. The main idea of the proposed approach relies on deriving the damping properties of the disks by focusing on the modal damping of the overall vibrating structure and, in particular, using just the first in-plane torsional deformation mode. Experimental torsional damping evaluations were conducted by performing vibrational hammer excitation on the presented setup. Two methods were proposed and compared, both relying on a single-degree-of-freedom (SDOF) approximation of the measured frequency response function (FRF).

Degradable and non-degradable biomaterials are two categories that can be used to classify the existing biomaterials, being a solution for eliminating a second surgical intervention of the implant when the tissue has properly recovered. In the present paper, the effect of deposition temperature on the structure, morphology, hardness, electrochemical evaluation, degradation properties and functional peptides adhesion of Mg and Si-doped hydroxyapatite was investigated. The coatings were obtained by RF magnetron sputtering technique at room temperature (RT) and 200 °C on AZ31B alloy substrate. Results showed that an increase in deposition temperature led to an improvement in hardness and reduced modulus of about 47%. From an electrochemical point of view, a comparative assessment of corrosion resistance was made as a function of the immersion medium used, highlighting the superior behaviour revealed by the coating deposited at elevated temperature when immersed in DMEM medium (icorr~12 µA/cm2, Rcoat = 705 Ω cm2, Rct = 7624 Ω cm2). By increasing the deposition temperature up to 200 °C, the degradation rate of the coatings was slowed, more visible in the case of DMEM, which had a less aggressive effect after 14 days of immersion. Both deposition temperatures are equally suitable for further bio-inspired coating with a mussel-derived peptide, to facilitate biointegration.

Background: Nurses experience high levels of distress due to the nature of their work and workplaces; Antonovsky’s salutogenic theory shows that individual and work-related factors can influence human health. The aim of this paper is to analyze the possible correlations with different work-related and individual variables, which influence or are influenced by Sense of Coherence (SOC) and verify the possible use of SOC scales to prevent negative health determinants in workplaces. Methods: Electronic databases were searched with selected studies compared for sample, sample size, study design and basic results. Cross-sectional studies were reviewed for correlations between individual physical and mental health, distress, burnout, job satisfaction and SOC, with intervention studies used to assess the possible impact of training on nurses’ SOC. Results: The review found several correlations between SOC and different work-related variables; but also with several individual characteristics. Conclusion: The review found that SOC was predictor of depressive state, burnout, job dissatisfaction among female nurses; therefore, SOC could be a health promoting resource.

The serine/threonine kinase Akt is crucial for cell physiology and can also contribute to pathology if its activation and regulation is disturbed. This kinase phosphorylates several substrates involved in mechanisms that are altered in human disease. AKT is regulated by several post-translational modifications (PTMs), including ubiquitination/deubiquitination. Ubiquitination can both target AKT to the proteasome and promote its activation. The interplay with the deubiquitination mechanism plays a crucial role in almost all biological activities of AKT. Information on the mechanisms of AKT deubiquitination and its key players has evolved rapidly in recent years along with the development of potential targeting strategies, although many of them are still unclear. Nevertheless, AKT in turn regulates various deubiquitinases (DUBs), suggesting further targeting strategies for human diseases. In this review, we aim to provide an up-to-date overview of the dual relationship between AKT and DUBs with respect to potential translational aim. Graphical Abstract Highlights The Ser/Thr kinase AKT is subject to both activating and inactivating deubiquitination. Deubiquitination mediated by CYLD, USP1, and OTUD5 inactivates AKT Deubiquitination mediated by USP7 activates AKT. OTUD1 inhibits AKT in a noncanonical manner. AKT phosphorylates USP4, USP14, USP35, and USP43, promoting cell growth and survival, cancer cell migration and invasion, and reducing autophagy.