Magneto-responsive hyaluronan hydrogel for hyperthermia and bioprinting: Magnetic, rheological properties and biocompatibility

Magneto-responsive soft hydrogels are used for a number of biomedical applications, e.g., magnetic hyperthermia, drug delivery, tissue engineering, and neuromodulation. In this work, this type of hydrogel has been fabricated from hyaluronan (HA) filled with a binary system of Al2O3 nanoparticles and multicore magnetic particles (MCPs), which were obtained by clustering of superparamagnetic iron oxide FeOx NPs. It was established that the presence of diamagnetic Al2O3 has several positive effects: it enhances the hydrogel storage modulus and long-term stability in the cell cultivation medium; prevents the magnetic interaction among the MCPs. The HA hydrogel provides rapid heating of 0.3 °C per min under exposure to low amplitude radio frequency alternating magnetic field. Furthermore, the magneto-responsive hydrogel was successfully used to encapsulate cells and extrusion-based 3D printing with 87±6% cell viability, thus providing a bio-ink. The combination of high heating efficiency, softness, cytocompatibility, and 3D printability of magnetic HA hydrogel leads to a material suitable for biomedical applications

Preparation of calcium-deficient hydroxyapatite particles on vermiculite by precipitation and sonication

Ca-deficient hydroxyapatite (CDH) is biocompatible, cheap material used in implants and non-biological applications. Due to similarity of CDH with human hard tissues, it is suitable for manufacturing of bone substituents. Clay minerals are suitable natural and non-toxic materials used as substrates for the growth of nanoparticles. Combination of nontoxic nature of the clay minerals with CDH is possible to achieve nanocomposites with properties advantageous for medical or catalytic applications. The aim of the study was to prepare CDH on the surface of a monoionic Na/Mg form of original vermiculites (Vs) from Brazil and Bulgaria. The CDH was prepared by precipitation under constant mixing or sonication conditions. XRD analysis confirmed that CDH was successfully prepared on the V surfaces, and the type of V did not influence CDH creation. Basal reflections of vermiculites do not show changes indicating an interaction between vermiculites and CDH. No interactions between V and CDH were observed in FTIR measurement and fitting analysis. Scanning electron microscopy shows creation of CDH particles and coherent layer on the V surface. The results showed that V serves as a support for CDH particles and probably does not influence the chemistry of CDH.Web of Science53278577

Widespread occurrence of expressed fungal secretory peroxidases in forest soils

Fungal secretory peroxidases mediate fundamental ecological functions in the conversion and degradation of plant biomass. Many of these enzymes have strong oxidizing activities towards aromatic compounds and are involved in the degradation of plant cell wall (lignin) and humus. They comprise three major groups: class II peroxidases (including lignin peroxidase, manganese peroxidase, versatile peroxidase and generic peroxidase), dye-decolorizing peroxidases, and hemethiolate peroxidases (e. g. unspecific/aromatic peroxygenase, chloroperoxidase). Here, we have repeatedly observed a widespread expression of all major peroxidase groups in leaf and needle litter across a range of forest ecosystems (e. g. Fagus, Picea, Acer, Quercus, and Populus spp.), which are widespread in Europe and North America. Manganese peroxidases and unspecific peroxygenases were found expressed in all nine investigated forest sites, and dye-decolorizing peroxidases were observed in five of the nine sites, thereby indicating biological significance of these enzymes for fungal physiology and ecosystem processes. Transcripts of selected secretory peroxidase genes were also analyzed in pure cultures of several litter-decomposing species and other fungi. Using this information, we were able to match, in environmental litter samples, two manganese peroxidase sequences to Mycena galopus and Mycena epipterygia and one unspecific peroxygenase transcript to Mycena galopus, suggesting an important role of this litter-and coarse woody debris-dwelling genus in the disintegration and transformation of litter aromatics and organic matter formation

Behavioural reactions of consumers to economic recession

The negative effects caused by the economic recession of the recent year, led to the necessity to recognize the changes in the consumer behaviour that may have a lasting impact, and they definitely will. The situation in the Slovak consumer market is described and characterized by the survey which was conduced in 2013. The article also raises three hypotheses considering the basic fact about consumers and their impact on the intensity of behavioural changes. In order to verify our results surveys and studies carried out by many companies in various countries are analyzed in the last chapter