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Bone substitutes are widely employed for applications in orthopedic surgery for the replacement of injured bone. Among the diverse methods that are used to design 3D bioceramic matrices, Freeze Foaming has gained attention, since it provides the ability to tune the shape of the created structures. One of the major problems related to these constructs is the lack of porosity at the outwards sides (holder) of the scaffold, thus reducing the cellular affinity and creating a rejection of the implant. In this research, we aimed to develop a bone scaffold with enhanced surface properties and improved cellular affinity. The main aim was to alter the biocompatibility characteristics of the 3D bioceramic constructs. We have produced three-dimensional, complex-shaped hollow shell structures, manufactured by Additive Manufacturing processes and as a second step, filled with a ceramic suspension by the Freeze-Foaming process. 3D constructs from HAP-derived TCP and TCP/ZrO2 were synthesized by freezefoaming method and subsequently irradiated with a fs-laser (λ = 800 nm) spanning a range of parameters for achievement of optimal surface processing conditions. The designed scaffolds demonstrated enhanced topographical properties with improved porosity examined by SEM, EDX, and 3D profilometry after laser treatment. Wettability and computer tomography (CT) evaluation was also performed. The results from X-ray diffraction (XRD) and micro-Raman analysis did not show photochemical and surface or volume defects and changes after laser processing of the ceramic samples. Preliminary results from MG-63 osteoblast-like cell tests showed good cell affinity on the processed surfaces and no cytotoxic effect on the cells. [ABSTRACT FROM AUTHOR]

A pilot study using a non-destructive imaging technique to detect the presence of microparticles of lead shot in earthworms Lumbricus terrestris was carried out. Earthworms play a crucial role as inhabitants of soil communities, constituting a substantial portion of their biomass. They are regarded as valuable indicators providing insights into the functional status of soils and the deposition of heavy metals. The differentiation of lead-shot microparticles from other metallic or organic particles was achieved using high-resolution X-ray computed microtomography. Applying this method allowed the reconstruction of the internal structure of the samples without compromising their integrity. [ABSTRACT FROM AUTHOR]

Dielectric glass-ceramic materials find various applications as parts of sensors, electronic components and even in biomedicine. The present work reports on the synthesis of glass-ceramic materials in the complex oxide system (23.1-z)Na2O/17.1BaO/6SrO/23TiO2/17.4SiO2/7.6B2O3/5.8Fe2O3/zAl2O3, z = 0 and 3 mol %. The melts show spontaneous crystallization during quenching. The phase composition is studied using X-ray diffraction and reveals crystallization of Ba1-xSrxTiO3 solid solutions with varying Ba/Sr ratio. The valence states and the local environments of the Ba, Ti and Fe ions of the prepared materials are investigated by utilizing X-ray photoelectron spectroscopy. It is shown that all the elements in the composition are present in their oxidized states and the formation of barium titanate based compounds is possible. The microstructure of the obtained samples is imaged by scanning electron microscopy and shows bright polygon-like crystalline structures embedded in a dark amorphous matrix. The further evaluation of the microstructure as average crystal size and volume fraction of the precipitated crystals is done by using microcomputed tomography. Thus, a relatively high crystalline volume fraction is observed for the samples without alumina. The samples with alumina possess comparable as size and volume fraction crystals. [ABSTRACT FROM AUTHOR]

Highly symmetrical protein cage architectures from three different iron storage proteins, heavy and light human ferritin chains (HuHFt and HuLFt) and ferritin from the hyperthemophilic bacterium Pyrococcus furiosus (PfFt) were used as models to better understand the molecular basis of silver ion deposition and metal core formation inside the protein cavity. The obtained AgNP endowed with a narrow size distribution, high stability in water solution, and high thermal stability could used for range of applications such as catalysts in water, for preparation of metamaterials, and in vivo diagnosis and antibacterial or tumor therapy.

ABSTRACT Observations of the interaction of poly(dimethylsiloxane) (PDMS) sheet (210 μm thick) with KrF excimer laser irradiation (λ = 248 nm), with low energy of 50 mJ/pulse are presented. The negative ablation or swelling of the material caused by low frequency pulse irradiation is characterized by optical microscopy, μ-Raman spectrometry and X-ray micro-tomography. The appearance of defected areas in the form of cones inside the sheet and changes of material chemistry are discussed. These phenomena are considered as a precursor of the ablation occurring after passing a threshold of absorbed laser irradiation energy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44541. [ABSTRACT FROM AUTHOR]

The two-phase approximation in small-angle scattering is well known and is still the dominant approach to data analysis. The intensity scattered at small angles is proportional to the second power of the difference between the scattering densities of the two phases. Nevertheless, scattering contrast variation techniques are widely used, and they are obviously suitable for multiphase systems or systems with gradually varying scattering density, since if no parasitic scattering contributions are present the scattering contrast variation would only change a proportionality coefficient. It is shown here that the scattered intensity at small angles of a multiphase system can be represented as a sum of the scattering of two-phase systems and terms describing interference between all pairs of phases. Extracting two-phase scattering patterns from multiphase samples by contrast variation is possible. These two-phase patterns can be treated with the usual small-angle scattering formalism. The case of gradually varying scattering density is also discussed. [ABSTRACT FROM AUTHOR]

A comparison between the resonant scattering curve obtained by anomalous small-angle X-ray scattering at the X-ray absorption edge of Ni and the complementary small-angle neutron scattering curve from an Al89Ni6La5 alloy sample is reported. The sample does not comply with the two-phase approximation. The two resulting scattering curves are approximately proportional to each other in this particular case. The anomalous small-angle X-ray scattering resonant curve at the Ni absorption edge equals the Ni-Ni partial structure factor and, owing to the favourable neutron scattering lengths of Ni, La and Al, the neutron scattering curve is also proportional to that partial structure factor. [ABSTRACT FROM AUTHOR]