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We have studied the effect of electroslag remelting on the content and composition of non-metallic inclusions. It was found that a decrease in the non-metallic inclusion content occurred during the electroslag remelting. A change in the chemical composition of the non-metallic inclusions was observed, while the aluminum and calcium contents were increased. The complexity of the inclusions also increased, as there were fewer single-phase inclusions after the electroslag remelting process. Based on the results and a thermodynamic assessment of the formation of the non-metallic inclusions, a mechanism for inclusion behavior during electroslag remelting has been proposed.

Barbara Drašler,1 Damjana Drobne,1–3 Sara Novak,1 Janez Valant,1 Sabina Boljte,1,4 Lado Otrin,1 Michael Rappolt,5,6 Barbara Sartori,5 Aleš Iglic,7 Veronika Kralj-Iglic,8 Vid Šuštar,9 Darko Makovec,3,10 Sašo Gyergyek,10 Matej Hocevar,11 Matjaž Godec,11 Jernej Zupanc11University of Ljubljana, Biotechnical Faculty, Department of Biology, Ljubljana, 2Centre of Excellence in Advanced Materials and Technologies for the Future, Ljubljana, 3Centre of Excellence in Nanoscience and Nanotechnology, Ljubljana, 4Institute of Microbial Sciences and Technologies, Ljubljana, Slovenia; 5Institute of Inorganic Chemistry, Graz University of Technology, Basovizza, Italy; 6School of Food Science and Nutrition, University of Leeds, Leeds, UK; 7Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, 8Faculty of Health Sciences, Laboratory of Clinical Biophysics, University of Ljubljana, Ljubljana 9Laboratory of Clinical Biophysics, Chair of Orthopaedics, Faculty of Medicine, University of Ljubljana, Ljubljana, 10Institute Jožef Stefan, Ljubljana, 11Institute of Metals and Technology, Ljubljana, SloveniaBackground: The purpose of this work is to provide experimental evidence on the interactions of suspended nanoparticles with artificial or biological membranes and to assess the possibility of suspended nanoparticles interacting with the lipid component of biological membranes.Methods: 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid vesicles and human red blood cells were incubated in suspensions of magnetic bare cobalt ferrite (CoFe2O4) or citric acid (CA)-adsorbed CoFe2O4 nanoparticles dispersed in phosphate-buffered saline and glucose solution. The stability of POPC giant unilamellar vesicles after incubation in the tested nanoparticle suspensions was assessed by phase-contrast light microscopy and analyzed with computer-aided imaging. Structural changes in the POPC multilamellar vesicles were assessed by small angle X-ray scattering, and the shape transformation of red blood cells after incubation in tested suspensions of nanoparticles was observed using scanning electron microscopy and sedimentation, agglutination, and hemolysis assays.Results: Artificial lipid membranes were disturbed more by CA-adsorbed CoFe2O4 nanoparticle suspensions than by bare CoFe2O4 nanoparticle suspensions. CA-adsorbed CoFe2O4-CA nanoparticles caused more significant shape transformation in red blood cells than bare CoFe2O4 nanoparticles.Conclusion: Consistent with their smaller sized agglomerates, CA-adsorbed CoFe2O4 nanoparticles demonstrate more pronounced effects on artificial and biological membranes. Larger agglomerates of nanoparticles were confirmed to be reactive against lipid membranes and thus not acceptable for use with red blood cells. This finding is significant with respect to the efficient and safe application of nanoparticles as medicinal agents.Keywords: CoFe2O4, nanoparticles, agglomerates, human red blood cells, lipid vesicles

Magnesium (Mg) alloys are used as biomaterials because of their biocompatibility and stiffness which is similar to that of human bone tissue. This reduces the stress shielding complications associated with bone resorption. Mg is one of the fundamental divalent ions that have an effect on bone-forming cells and also plays an important role in bone metabolism. This is supported by the results of in vivo studies, which indicate that Mg degradation does not damage surrounding tissue and promotes bone remodelling [1]. One of the main drawbacks limiting the wide use of Mg alloys in biomedicine is their low corrosion resistance, and associated high hydrogen release in the surrounding environment which causes pain in the area of implant placement [1-3]. Additive manufacturing is an attractive alternative to conventional manufacturing of Mg alloys, and researchers have so far studied the properties of the following Mg-based alloys:Mg-Al-Zn, Mg-Zn-Zr, and REE-containing alloys [4]. In this research, we propose to develop degradation of Mg-based alloys enriched with Li and Ca which will decrease the density of the alloys and simultaneously improve mechanical properties of the alloys. It is expected to create refined microstructure which should lead to the lowering of the intensity of the occurring corrosion mechanisms. We decided to focused on the Mg-4Li-0.5Ca with single a (Mg) phase. As a reference cast material with the same composition was used. Micro-computed tomography was used to check the porosity of the materials produced. The microstructure of alloys was analyzed through electron back scattered diffraction and phase composition was analyzed using X-ray. Corrosion resistance of both alloys were performed using various electrochemical techniques in phosphate-buffered saline solution (PBS). The materials corrosion rate was investigated by hydrogen evolution tests, and corroded specimens were characterized by SEM and optical profilometer. [ABSTRACT FROM AUTHOR]

We report on self-organized patterning of polycrystalline noble metal films, supported on dielectric substrates, by defocused Ar+ ion beam irradiation. The initial surface morphology affects the formation of nanostructures, forcing the growth of ripples with a lateral periodicity imposed by the pristine polycrystalline grain distribution. At the early stages, the self-organization process is dominated by the shadowing of taller grains, while a crossover to the conventional erosive regime, observed for single crystals, sets in at longer sputtering times. The grain boundaries, although providing an additional bias for diffusion of mobile defects, do not affect the propagation of nanoscale ripples across individual grains. [ABSTRACT FROM AUTHOR]