Faberself0845

The model demonstrated to have potential for use as a platform to investigate therapies and may help in the study of new drugs for bone diseases. Laser powder bed fusion (L-PBF) techniques have been increasingly adopted for the production of highly personalized and customized lightweight structures and bio-medical implants. L-PBF can be used with a multiplicity of materials including several grades of titanium. Due to its biocompatibility, corrosion resistance and low density-to-strength ratio, Ti-6Al-4V is one of the most widely used titanium alloys to be processed via L-PBF for the production of orthopedic implants and lightweight structures. Mechanical properties of L-PBF Ti-6Al-4V lattice structures have mostly been studied in uniaxial compression and lately, also in tension. However, in real-life applications, orthopedic implants or lightweight structures in general are subjected to more complex stress conditions and the load directions can be different from the principal axes of the unit cell. In this research, the mechanical behavior of Ti-6Al-4V diamond based lattice structures produced by L-PBF is investigated exploring the energy absorption and failure modes of these metamaterials when the loading directions are different from the principal axis of the unit cell. Moreover, the impact of a heat treatment (i.e. hot isostatic pressing) on the mechanical properties of the aforementioned lattice structures has been evaluated. Results indicate that the mechanical response of the lattice structures is significantly influenced by the direction of the applied load with respect to the unit cell reference system revealing the anisotropic behavior of the diamond unit cell. In order to solve the artifact problem in magnetic resonance images, a low magnetic Zr-1Mo(wt%) alloy with high mechanical performance was successfully fabricated by laser powder bed fusion (L-PBF) using gas-atomized Zr-1Mo alloy powder. The as-built Zr-1Mo alloy showed superior strength and elongation compared to the as-cast Zr-1Mo alloy due to grain refinement and the inexistence of large casting defects. The microstructure of L-PBF-processed Zr-1Mo alloy builds was not sensitive to process parameters. On the other hand, morphology and distribution of defects, interstitials concentration, and crystallographic orientation comprehensively influenced the mechanical properties of the builds. Increasing interstitials concentration caused by increasing energy density render to increasing strength. Large pores caused by balling effect lead to a severe decrease of both strength and ductility of builds using high energy density (over 70.3 J·mm-3) and high scanning speed (1050/1200 mm·s-1). On the contrary, spherical pores possessing several microns in size has much less effect on mechanical properties than the large-size pores. There are two kinds of texture(1 1 0α texture and 1 1 0α+1 0 2α bi-texture) were confirmed in this study. 1 1 0α texture contributed to the slight increase of elongation with increasing energy density in low scanning speed case (600/750 mm·s-1) and the superior elongation of low scanning speed specimens compare to that of high scanning speed specimens in medium energy density range (about 48 J·mm-3). From the viewpoints of the ultimate tensile strength(UTS) and elongation, it was found that an energy density of 84.4 mm·s-1 with a scanning speed of 600 mm·s-1 is preferable for the L-PBF-processed Zr-1Mo alloy in this study. These experimental results may provide direct guidelines regarding the applicability of Zr-1Mo alloy fabricated by L-PBF for biomedical applications. In this study, single filaments of acrylated epoxidized soybean oil (AESO)/polyethylene glycol diacrylate (PEGDA)/nanohydroxyapatite (nHA)-based nanocomposites intended for bone defect repair have displayed significant improvement of their mechanical properties when extruded through smaller needle gauges before UV curing. These nanocomposite inks can be deposited layer-by-layer during direct ink writing (DIW) - a form of additive manufacturing. Single filaments were prepared by extruding the nanocomposite ink through needles with varying diameters from 0.21 mm to 0.84 mm and then UV cured. Filaments and cast specimens were tensile tested to determine elastic modulus, strength and toughness. The cured nanocomposite filaments were further characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). SEM confirmed that the hydroxyapatite nanoparticles were well dispersed in the polymer matrices. The ultimate tensile strength and moduli increased as the diameter of the extrusion needle was decreased. These correlated with increased matrix crystallinity and fewer defects. For instance, filaments extruded through 0.84 mm diameter needles had ultimate tensile stress and modulus of 26.3 ± 2.8 MPa and 885 ± 100 MPa, respectively, whereas, filaments extruded through 0.21 mm needles had ultimate tensile stress and modulus of 48.9 ± 4.0 MPa and 1696 ± 172 MPa, respectively. This study has demonstrated enhanced mechanical properties resulting from extrusion-based direct ink writing of a new AESO-PEGDA-nHA nanocomposite biomaterial intended for biomedical applications. These enhanced properties are the result of fewer defects and increased crystallinity. A means of achieving mechanical properties suitable for repairing bone defects is apparent. AIM For the proper function of small diameter vascular grafts their mechanical properties are essential. A variety of testing methods and protocols exists to measure tensile strength, compliance and viscoelastic material behavior. In this study the impact of the measurement protocol in hoop tensile tests on the measured compliance and tensile strength was investigated. METHODS Vascular grafts made out of two different materials, a thermoplastic polyurethane (PUR) and polylactid acid (PLLA), with three different wall thicknesses were produced by electrospinning. Samples were tested with a measurement protocol that allowed the comparison of dynamic sample loading to a common quasistatic tensile test. Influence of measurement temperature, preconditioning cycles and the influence of a high number of loading cycles was also investigated. Compliance and tensile strength were evaluated and compared between the different samples and the different load cases. RESULTS In all samples a significant difference in the measeasurements at 37 °C are mandatory, as temperature has a significant influence on the mechanical properties. Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about the material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young's modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not only for PCU-Sil, but also for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters. Prophylactic treatment is advised for metastatic bone disease patients with a high risk for fracture. RMC-4550 research buy Femoroplasty provides a minimally invasive procedure to stabilize the femur by injecting bone cement into the lesion. However, uncertainty remains whether it provides sufficient mechanical strength to the weight-bearing femur. The goal of this study was to quantify the improvement in bone stiffness, failure load and energy to failure due to cement augmentation of metastatic lesions at varying locations in the proximal femur. Eight pairs of human cadaveric femurs were mechanically tested until failure in a single-leg stance configuration. In each pair, an identical defect was milled in the left and right femur using a programmable milling machine to simulate an osteolytic lesion. The location of the defects varied amongst the eight pairs. One femur of each pair was augmented with polymethylmethacrylate, while the contralateral femur was left untreated. Digital image correlation was applied to measure strains on the bone surface during mechanical testing. Only femurs with a critical lesion showed an improvement in failure load and energy to failure due to augmentation. In these femurs, bone strength improved with 28% (±17%) on average and energy to failure with 58% (±41%), while stiffness did not show a significant improvement. The strain measurements from digital image correlation showed that cement augmentation reinforced the lesion, resulting in reduced strain magnitudes in the bone tissue adjacent to the lesion. The results indicate that femoroplasty may be an effective treatment to prevent fractures in several metastatic bone disease patients. However, the large scatter in the data clarifies the need for developing strategies to identify those patients who will benefit the most from the procedure. OBJECTIVE To assess the influence of antioxidants (sodium ascorbate - SA, epigallocatechin-3-gallate (EGCG) from Camellia sinensis and punicalagin from Punica granatum) or lasers (ErYAG and diode) on bleached dentin. METHODS Four hundred and forty slabs of intracoronary dentin were prepared 224 for bond strength (debonding test) (n = 14), 96 for chemical analysis (EDS) and morphology (SEM) (n = 6), 96 for interface analysis (n = 6) and 24 for atomic force microscopy (AFM). The slabs were distributed according to the post-treatment after bleaching (35% hydrogen peroxide) GI- no bleaching and no post-treatment, GII- only bleached, GIII- 10-days delay in restorative procedure, GIV- 10% SA (10 min), GV- 0.5% EGCG (10 min), GVI- 0.5% punicalagin (10 min), GVII- ErYAG laser (0.80W, 20s) and GVIII- diode laser (1.5W, 20s). Restorative procedures were done. Half of the slabs were analyzed immediately and the others, after 12 months. Debonding and AFM data were analyzed by ANOVA and Tukey tests (α = 0.05). RESULTS All the post-treatments, except for punicalagin, reestablished the immediate bond strength, similar to those restored after 10 days (p > 0.