Chelating polymeric particles intended for the therapy of Wilson’s disease

Wilson’s disease is a genetic disorder that leads to a high accumulation of copper in multiple organs with subsequent toxic effects. In this paper, a gentle therapy to eliminate harmful copper concentrations in patients with Wilson’s disease is proposed using an oral administration of insoluble polymeric sorbents containing selective chelating groups for copper(II). The sorbents contained triethylenetetramine, N,N-di(2-pyridylmethyl)amine, 8-hydroxyquinoline or 8-hydroxyquinoline-5-sulfonic acid chelating groups bound to a methacrylate-based macroporous support. Nearly quantitative copper(II) uptake within minutes was achieved in buffers modeling the pH range present in the gastric environment (pH 2.0 and 4.0). The sorbents demonstrated chelating selectivity for copper(II) against zinc(II) with ratios of up to 1321. The sorbents demonstrated sufficient stability of the copper complexes against rechelation using studies in a model environment for the small intestine (the presence of chelating amino acids, pH 6.8).     

Synthetic Polyamine BPA‐C8 Inhibits TGF‐β1‐Mediated Conversion of Human Dermal Fibroblast to Myofibroblasts and Establishment of Galectin‐1‐Rich Extracellular Matrix in Vitro

Cancer‐associated fibroblasts (CAFs) play a role in the progression of malignant tumors. They are formed by conversion of fibroblasts to smooth muscle α‐actin‐positive (SMA‐positive) myofibroblasts. Polyamines are known to change the arrangement of the actin cytoskeleton by binding to the anionic actin. We tested the effect of the synthetic polyamine BPA‐C8 on the transition of human dermal fibroblasts to myofibroblasts induced either by TGF‐β1 alone or by TGF‐β1 together with adhesion/growth‐regulatory galectin‐1. Pre‐existing CAFs, myofibroblasts from pancreatitis, and rat smooth muscle cells were also exposed to BPA‐C8. BPA‐C8 impaired myofibroblast formation from activated fibroblasts, but it had no effect on cells already expressing SMA. BPA‐C8 also reduced the occurrence of an extracellular matrix around the activated fibroblasts. The reported data thus extend current insights into polyamine activity, adding interference with tumor progression to the tumor‐promoting processes warranting study.     

Kocuria Bacterial Isolates from Radioactive Springs of Jáchymov spa (Joachimsthal) as Sources of Polyunsaturated Fatty Acids

Four bacterial isolates, which produced polyunsaturated fatty acids (PUFA), were isolated from water samples of radioactive springs collected from Jáchymov spa. Jáchymov (Sankt Joachimsthal) is a city in northwestern Bohemia, where Marie and Pierre Curie isolated radium in 1898 from the mineral uraninite. To date, four springs (Agricola, Behounek, C1, and Curie) have been used for spa purposes, that is for the treatment of nervous and rheumatic disorders by constantly produced radioactive gas radon (²²²Rn) dissolved in the water. The radioactivity reaches 24 kBq/L. Using 16S rRNA gene sequence analysis, all four isolates were identified as members of the genus Kocuria, with two isolates designated 208 and 401 affiliated with Kocuria kristinae, while isolates 101 and 301 most likely with K. rhizophila. The content of fatty acids in polar lipids was determined by gas chromatography–mass spectrometry (GC–MS) and two PUFA, that is arachidonic and eicosapentaenoic, were identified. The position of double bonds was confirmed by GC–MS of 3-pyridylcarbinol (formerly picolinyl) esters. We assume that all four isolates of Kocuria produce PUFA to increase the stability of cell membranes, which may be impaired by the reaction of the reactive oxygen species. These can arise, for example, because of α radiation during ²²²Rn decay.     

Nano-functionalization of carbon-bonded alumina using graphene oxide and MWCNTs

This paper focused on the nano-functionalization of carbon-bonded alumina using graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs). GO was prepared according to the modified Tour's method. The rheology of suspensions containing GO, CNTs and both substances were analyzed and discussed. Xanthan proved to be a suitable stabilizer for the three systems. The spraying process of the suspensions was investigated with the aid of a high-speed camera. Al₂O₃-C filters and flat samples were spray coated, for investigations in contact with steel. The ceramic foam filters as well as the starting suspensions were analyzed by several analytic techniques to investigate the microstructure and other properties. Moreover, the hot stage microscope was used to study the steel/coating wetting behavior during operation at high temperatures. The results showed that the formulation containing both GO and CNTs delivered the best performance in contact with the melt. Similar coatings based on these nano-sized materials may offer an innovative route to improve purification of steel melts by filtration.     

Artificially perforated single-grain YBCO bulks: Dependence of superconducting properties on the bulk thickness

A high and homogenous trapped field, as well as the levitation force of YBCO parts are the key properties in regard to practical applications of high-temperature superconductors. Both of these parameters are often the determining factor in the bulk's performance. In this contribution, the impact of bulk thickness on the trapped field and levitation force was studied in detail. A number of significantly thicker samples both with and without artificial holes were prepared. The samples were manufactured using top-seeded melt growth with a diameter of 28 mm and a thickness of 18 mm. An additional source of “liquid phase” was placed underneath the YBCO bulks during the TSMG process in order to negate the leakage of “liquid phase.” Properties of these samples were compared and to most similar samples with and without artificial holes were chosen to be gradually ground down. SEM was employed in order to confirm the impact of artificial holes on the microstructure. The samples were characterized between each individual grinding step. Using this approach, the dependency of the trapped field and levitation force, as well as the addition of artificial holes, can be properly evaluated. The method described above has allowed us to determine the optimal bulk geometries for various applications depending on the desired properties. Such data are of the utmost importance in the field of applied high-temperature superconducting bulks.     

Boolean functions with long prime implicants

In this short note we introduce a hierarchy of classes of Boolean functions, where each class is defined by the minimum allowed length of prime implicants of the functions in the class. We show that for a given DNF and a given class in the hierarchy, it is possible to test in polynomial time whether the DNF represents a function from the given class. For the first class in the hierarchy we moreover present a polynomial time algorithm which for a given input DNF outputs a shortest logically equivalent DNF, i.e. a shortest DNF representation of the underlying function. This class is therefore a new member of a relatively small family of classes for which the Boolean minimization problem can be solved in polynomial time. For the second class and higher classes in the hierarchy we show that the Boolean minimization problem can be approximated within a constant factor.     

In Flight Properties of W Particles in an Ar-H<Subscript>2</Subscript> Plasma

An in-flight properties measurement performed on W particles, injected into thermal plasma generated by an inductively coupled RF plasma torch, is presented. The measured surface properties of the particles along the centerline of the plasma plume are expressed by means of temperature and velocity maps, within the domain formed by individual particle’s diameters and their distances from the torch exit. The influence of some of the processing parameters (plate power, carrier gas flow rate, spray chamber pressure) on particle properties is discussed for both individual particles and the resultant integral spray plume characteristics. The results so obtained appear to confirm the suitability of the RF plasma process for the deposition/production of W coatings/deposits.