Gevrey vectors in involutive tube structures and Gevrey regularity for the solutions of certain classes of semilinear systems

In this work, we introduce the notion of s-Gevrey vectors in locally integrable structures of tube type. Under the hypothesis of analytic hypoellipticity, we study the Gevrey regularity of such vectors and also show how this notion can be applied to the study of the Gevrey regularity of solutions of certain classes of semilinear equations.     

Preparation of cholesterol oxidase nanoparticles and their application in amperometric determination of cholesterol

Highly dispersed platinum nanoparticles were deposited on gram quantities of non-functionalized multiwalled carbon nanotubes (MWCNTs) by atomic layer deposition (ALD) in a fluidized bed reactor at 300 °C. (Methylcyclopentadienyl) trimethylplatinum and oxygen were used as precursors. The results of TEM analysis showed that ~1.3 nm Pt nanoparticles were highly dispersed on non-functionalized MWCNTs. The porous structures of MWCNTs did not change with the deposition of Pt nanoparticles. For comparison, the commercial 3 wt% Pt/C catalyst was also characterized. The ALD-prepared Pt/MWCNT was used for the hydrogenation of xylose to xylitol. The ALD-prepared Pt/MWCNT showed the best catalytic performance with 100 % conversion of xylose and 99.3 % selectivity to xylitol, compared to commercially available Pt/C, Ru/C, and Raney Ni catalysts. The stability of ALD produced Pt/MWCNT catalyst was higher than that of the commercial Pt/C, due to the presence of surface defects on the MWCNTs and the strong metal–support interaction for the ALD-prepared Pt/MWCNT catalyst.     

Smart,self-repair polymers based on acryloyl-6-aminocaproic acid and modified with magnetic nanoparticles—preparation and characterization

Capability of materials to self-repair is an innovative and unique property from a point of view both chemistry and physics. Moreover, such property could arouse special interests if such an ability could be caused by the selection of the environmental parameters. Such materials—polymers based on acryloyl-6-aminocaproic acid (A6ACA)—were synthesized in the present paper. In addition, mentioned polymers have been modified with different amount of magnetic nanoparticles solution. Subsequently, sorption capacity and behavior of synthesized polymers in simulated body fluids have been determined. What is also important, studies on cytotoxicity of prepared materials in relation to fibroblasts and cells of cancer origin have been conducted. Materials have also been analyzed by Fourier transform infrared spectroscopy and scanning electron microscopy method. Based on the research aiming at physicochemical characteristics of abovementioned materials it was proved that prepared hydrogels showed self-repair property in a low pH environment. Apart from this essential issue, these were characterized by high sorption capacity, high porosity which decreases with the introduced amount of nanoparticles and, what is important, cytotoxicity to cancer cells. Such combination is a very interesting from a point of view of many realms and due to its unique features may be widely applicable in the nearest future.     

Migration of perfluorinated compounds from paperbag to Tenax® and lyophilised milk at different temperatures

ABSTRACT

Migration tests of perfluoroalkyl substances (PFASs) from a grease-proof paperbag used for packaging of pet food have been carried out. No migration of perfluorocaboxylic acids (PFCAs), from PFBA to PFTeDA, to the simulant Tenax® was found after 10 days at 40°C. However, the increase of temperature in the range 80–160°C gave rise to the migration of the PFCAs. Finally, the migration to real foods such as lyophilised whole and low-fat milk samples at 80 and 120°C was studied. The results indicate that the migration percentages of the PFCASs into food samples are much higher than those obtained into Tenax®.