Hemodialysis‐induced changes in the blood composition affect function of the endothelium

Hemodialysis induces oxidative stress causing intravascular inflammation, which may cause endothelial dysfunction. We evaluated how hemodialysis‐induced changes in blood affect the function of endothelial cells in in vitro culture. Serum samples were collected from 42 uremic patients treated with hemodialysis, one before the start of dialysis and the other one at the end of session. All patients were dialysed with polysulfone dialyzer. Concentrations of the inflammatory molecules carbonyl protein and metabolites of NO synthesis were measured in blood. Additionally, the effect of the serum obtained before and after dialysis on the function of endothelial cells in in vitro culture was studied. Hemodialysis caused increase of monocyte chemoattractant protein (MCP)‐1 (+17%), hepatocyte growth factor (+91%), and pentraxin‐3 (+30%) concentration in serum. Concentration of carbonyl protein was decreased by 30%. Decrease of blood level of asymmetric dimethylarginine (?25%) and nitrate/nitrites (?62%) was observed. Serum obtained after hemodialysis stimulated proliferation of endothelial cells (+10%) and synthesis of MCP‐1(+11%) in these cells. Hemodialysis‐induced intravascular inflammation changes the function of endothelial cells, which may lead to acceleration of atherosclerosis.     

Physicochemical and catalytic properties of palladium deposited on polyaniline-coated silica gel

The chemical incorporation of palladium into polyaniline (PANI) deposited onto the silica gel microparticles (15-μm in diameter) was studied. The as-prepared silica particles coated with PANI–hydrochloride (AC) were treated with aqueous ammonia solution (0.1 M) to transform polyaniline to its base (BA) form. Both AC and BA samples were reacted with PdCl₂ solutions (2.3×10⁻³ M) strongly differing in the concentration of HCl (0.1 M HCl, series K; 6.6×10⁻⁴ M HCl, series Z). Two series of samples with 0.43–2.14 wt.% Pd were obtained. Fourier-transform infra red (FTIR), UV-Vis, X-ray photoelectron spectroscopies (XPS) and scanning electron microscopy have been used to examine the nature of processes involved upon insertion of Pd and to characterize palladium species in the final samples. Very similar palladium species were found in the polymer matrix independently of the acidity of PdCl₂ solutions and the extent of PANI protonation (AC and BA samples). Pd²⁺ was the only form if no more than 0.86% Pd was introduced. Incorporation of higher content of palladium resulted in the partial reduction (14.6–28.7%) of Pd²⁺ to Pd⁰. The presence of Pd²⁺ species in the form of complexes in which besides Cl⁻ ligands also nitrogen groups of PANI participated has been postulated. The catalytic properties of Pd/PANI-SiO₂ have been studied in the liquid-phase hydrogenation of 2-ethylanthraquinone (EAQ) at 60 °C under 1 atm of hydrogen. Very low activity of the as-prepared catalysts significantly increased due to reduction of the samples with NaH₂PO₂ and subsequently with dihydrogen. The specific activities of reduced series K and Z samples were comparable and the maximum activity exhibited catalysts with 1–1.5% Pd.     

Thermal stability of polyurethanes with carbon-carbon crosslinks

Thermal properties of polyurethanes based on 4,4′-diphenylmethane diisocyanate and poly(ethylene adipate) crosslinked only by C? C linkages were studied by isothermal and non-isothermal thermogravimetry carried out in nitrogen atmosphere. Previously studied polyurethanes crosslinked only with allophanate groups were used for comparison. It was found that the structure of crosslinks determines the initial stage of degradation process.     

Designing and assessing everyday objects: Impact of externalisation tools and judges’ backgrounds

Professional designers increasingly rely on IT-based systems in the course of their work. It is therefore crucial to know how such systems, especially computer-aided design (CAD) systems, influence both the design process and the final design, compared with the use of manual design methods. The objective of this paper is twofold: to address this issue and to suggest ways of improving IT-based systems specifically developed to support designers’ activities. In the first phase of a two-phase study, we investigated how the use of different tools can affect the design process. In the second phase, we conducted two complementary analyses to determine how the use of different tools affects the assessment of final designs, as well as the effect of the judges’ backgrounds on their assessments. We began by comparing the activities of two groups of designers: one group working with a CAD system, the other carrying out manual modelling. The results of this first phase revealed significant differences in the designers’ activities (changing the viewpoint, switching tools, correcting errors) according to the design method they used. We then asked judges from four different backgrounds (professional designers, design teachers, retailers and users), to assess the final designs according to specific assessment criteria (aesthetics, originality, functionality, marketability). The results of this second phase revealed a significant preference for objects designed with a CAD system. Furthermore, the judges attributed different levels of importance to each of the assessment criteria, depending on their background. This last result underscored differences in the mental models constructed by different groups of audiences involved in product development and marketing. In addition, it allowed us to identify their specific expectations about final designs. Based on the results of our analyses, we suggest ways of improving IT-based systems with a view to integrating design assessment more fully into CAD environments.     

Comparison of furanocoumarin concentrations of greenhouse-grownRuta chalepensis with outdoor plants later transferred to a greenhouse

Ruta chalepensis contained concentrations of furanocoumarins 25–50% of those found inR. graveolens both in the whole leaf and on its surface. On the leaf surface of plants grown all year indoors in a greenhouse, they increased steadily between November 1 and December 14 on mature upper and lower leaves. New growth upper leaves on December 14 contained less than mature upper leaves. Plants transferred from outdoors to the greenhouse showed decreased concentrations after the first two weeks, followed by recovery both in the whole leaf and on the leaf surface. Proportions of xanthotoxin and bergapten to psoralen changed during the experiment. On the leaf surfaces and in the whole upper leaves of the indoor plants, the proportions were often similar, but in the transferred plants, in most cases, psoralen was less than bergapten or xanthotoxin in the upper leaves and markedly less in the lower leaves. Implications of these findings for possible effects of environmental changes on secondary plant metabolism are discussed.     

2D Intrinsic Ferromagnetic MnP Single Crystals

2D intrinsic ferromagnetic materials are highly anticipated in spintronic devices due to their coveted 2D limited magnetism. However, 2D non‐layered intrinsic ferromagnets have received sporadic attention, which is largely attributed to the fact that their synthesis is still a great challenge. Significantly, manganese phosphide (MnP) is a promising non‐layered intrinsic ferromagnet with excellent properties. Herein, high‐quality 2D MnP single crystals formed over liquid metal tin (Sn) is demonstrated through a facile chemical vapor deposition technique. The introduction of liquid metal Sn provides a fertile ground for the growth of 2D MnP single crystals. Interestingly, 2D MnP single crystals maintain their intrinsic ferromagnetism and exhibit a Curie temperature above room temperature. The research enriches the diversity of 2D intrinsic ferromagnetic materials, opening up opportunities for further exploration of their unique properties and rich applications.     

In Situ N‐Doped Graphene and Mo Nanoribbon Formation from Mo2Ti2C3 MXene Monolayers

Since the advent of monolayered 2D transition metal carbide and nitrides (MXenes) in 2011, the number of different monolayer systems and the study thereof have been on the rise. Mo₂Ti₂C₃ is one of the least studied MXenes and new insights to this material are of value to the field. Here, the stability of Mo₂Ti₂C₃ under electron irradiation is investigated. A transmission electron microscope (TEM) is used to study the structural and elemental changes in situ. It is found that Mo₂Ti₂C₃ is reasonably stable for the first 2 min of irradiation. However, structural changes occur thereafter, which trigger increasingly rapid and significant rearrangement. This results in the formation of pores and two new nanomaterials, namely, N‐doped graphene membranes and Mo nanoribbons. The study provides insight into the stability of Mo₂Ti₂C₃ monolayers against electron irradiation, which will allow for reliable future study of the material using TEM. Furthermore, these findings will facilitate further research in the rapidly growing field of electron beam driven chemistry and engineering of nanomaterials.     

Synthesis and Bioactivity of Reduced Graphene Oxide/Alumina‐Noble Metal Nanocomposite Flakes

The aim of this study was to describe the modification of the bioactivity of Al₂O₃‐noble metal (Me = Ag, Au, or Pd) composite nanoparticles by the addition of graphene oxide and the formation of a RGO/Al₂O₃‐Me nanocomposite system. The nanocomposite flakes and Al₂O₃‐Me composite nanoparticles were widely characterized. The antibacterial effect was observed only for Al₂O₃‐Ag composite nanoparticles and RGO/Al₂O₃‐Ag nanocomposite flakes, while, in the case of RGO/Al₂O₃‐Ag, a more evident antibacterial effect against Staphylococcus aureus bacteria was observed compared with Al₂O₃‐Ag. In the case of other noble metals (Au, Pd), a slight growth‐stimulating effect was revealed for particular bacterial strains.