Cyclodextrin-based polyrotaxanes

In the paper cyclodextrin-based (CD) polyrotaxanes are presented in the aspect of their syntheses and properties allowing various applications. The text consists of four parts, which describe CD-based polyrotaxanes with threads containing poly(ethylene oxide), poly (4,4′-diphenylenevinylene), polyfluorene and other chains. Conclusion shows new trends connected with this theme.     

New bounds in Balog-Szemerédi-Gowers theorem

We prove, in particular, that every finite subset A of an abelian group with the additive energy κ|A|³ contains a set A′ such that |A′|?κ|A| and |A′ ? A′|?κ ^?4|A′|.     

Optimization of capillary isotachophoretic method for determination of major macroelements in blue honeysuckle berries (Lonicera caerulea L.) and related products

A reliable and repeatable isotachophoretic method for the simultaneous determination of K⁺, Na⁺, Ca²⁺, Mg²⁺, and ammonium in berries of different blue honeysuckle cultivars was developed. The usefulness of the complex-forming equilibria in determining the cations mentioned above was studied. The addition of 7.5 mM 18-crown-6 and 2 mM α-hydroxyisobutyric acid to sulfuric acid enhanced the separation capacity of the leading electrolyte. The terminating electrolyte of 10 mM TRIS buffered to pH 4.30 was chosen as most appropriate for these studies. An ultrasound-assisted procedure for the extraction of macroelements from dried fruit of Lonicera caerulea L. was investigated using response surface methodology. The Box-Behnken experimental design showed the optimal extraction conditions as follows: temperature of 36 °C, extraction time of 42.3 min and solid-to-liquid ratio of 1:800 v/w. Detection limits for the method ranged from 0.030 to 0.097 mg/l with precision expressed by RSD ranging from 1.4 % for Mg to 4.4 % for Na. The results showed that blue honeysuckle berries are a good source of potassium, from 199 to 402 mg/100 g FW, especially ‘Zielona’ and ‘Zojka’ cultivars. The average content of other analytes in these berries was 5.2 mg Na, 24.8 mg Ca, 7.5 mg Mg and 52.0 mg ammonium per 100 g FW. The berry products contained lower amounts of minerals especially Mg and K. However, a glass of freshly squeezed juice can provide almost 20 % of the RDI of potassium. The results obtained using both the developed isotachophoretic method and ion chromatographic procedure did not differ significantly.

Promoted ternary CuO-ZrO2-Al2O3 catalysts for methanol synthesis

Ternary CuO-ZrO₂-Al₂O₃ catalysts promoted by palladium or gold were prepared and tested in CO hydrogenation reaction at 260°C under elevated pressure (4.8 MPa). The promotion effect of palladium or gold addition on the physicochemical and catalytical properties of CuO-ZrO₂-Al₂O₃ catalysts in methanol synthesis (MS) was studied. The catalysts were characterized by BET, XRD, TPR-H₂, TPD-NH₃ methods. The BET results showed that the ternary system CuO-ZrO₂-Al₂O₃ had the largest specific surface area, cumulative pore volume and average pore size in comparison with the promoted catalysts. The yield of methanol can be given through the following sequence: 5%Pd/CuO-ZrO₂-Al₂O₃ > CuO-ZrO₂-Al₂O₃ > 2%Au/CuO-ZrO₂-Al₂O₃. We also found that the presence of gold or palladium on catalyst surface has strong influence on the reaction selectivity. The high selectivity of gold doped ternary catalyst is explained by the gold-oxide interface sites created on the catalyst surface and the acidity of those systems. The higher selectivity to methanol in the case of the palladium catalyst is explained by the spillover effect between Pd and CuO.      

Multi-criteria optimisation of the vibro-isolation properties

The paper deals with a methodology of shaping the vibro-isolation properties of suspensions applied in automotive systems. The developed optimisation procedure allows to find the Pareto-optimal system configuration for the conflicted vibro-isolating criteria. The correctness of proposed methodology is evaluated using the semi active and active systems with optimal controller settings. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Simultaneous determination of mitotane,its metabolite,and five steroid hormones in urine samples by capillary electrophoresis using β-CD2SDS1 complexes as hydrophobic compounds solubilizers

Mitotane is a cytotoxic drug used in the treatment of inoperable adrenocortical carcinoma, it inhibits steroidogenesis as well, and therefore monitoring the level of steroid hormones in patients treated with mitotane is a crucial point of therapy. Hence, we have developed a simple, fast, and efficient electrophoretic method combined with reverse polarity sweeping as online preconcentration technique and dispersive liquid–liquid microextraction for the simultaneous determination of mitotane, its main metabolite DDA, and five steroid hormones (progesterone, testosterone, epitestosterone, cortisol, and corticosterone) in urine samples. In addition, a new sample matrix consisting of β-CD₂SDS₁ complexes for a high hydrophobic compounds solubilization was developed. Approach based on the application of β-cyclodextrin and SDS complex of a ratio 2:1 allowed for hydrodynamic injection into the capillary of a solution containing both mitotane and other analytes. The detection limits of the analytes for the reverse polarity sweeping-dispersive liquid–liquid microextraction method were found to be in the range of 1.5–3 ng/mL, which were approximately 1000 times lower than in the conventional hydrodynamic injection (5 s, 0.5 psi) without any preconcentration procedure. All analytes were completely resolved in less than 13 min by uncoated silica capillary with an inner diameter of 75 μm (ID) × 60 cm. Electrophoretic separation was performed in reverse polarity with a voltage of –25 kV with a background electrolyte (BGE) consisting of 100 mM SDS, 25% ACN, 25 mM phosphate buffer (pH 2.5), and 7 mM β-cyclodextrin.     

Amorphous alloys and differential scanning calorimetry (DSC)

Journal of Thermal Analysis and Calorimetry - A remarkable number of scientific papers are available in the literature about the bulk amorphous alloys and metallic glasses. Today, DSC is an...     

Blockade of NF-κB Translocation and of RANKL/RANK Interaction Decreases the Frequency of Th2 and Th17 Cells Capable of IL-4 and IL-17 Production,Respectively, in a Mouse Model of Allergic Asthma

The main purpose of this study was to investigate whether the blockade of the interaction between the receptor activator of nuclear factor-κB (NF-ĸB) ligand (RANKL) and its receptor RANK as well as the blockade of NF-κB inhibitor kinase (IKK) and of NF-κB translocation have the potential to suppress the pathogenesis of allergic asthma by inhibition and/or enhancement of the production by CD4⁺ and CD8⁺ T cells of important cytokines promoting (i.e., IL-4 and IL-17) and/or inhibiting (i.e., IL-10 and TGF-β), respectively, the development of allergic asthma. Studies using ovalbumin(OVA)-immunized mice have demonstrated that all the tested therapeutic strategies prevented the OVA-induced increase in the absolute number of IL-4- and IL-17-producing CD4⁺ T cells (i.e., Th2 and Th17 cells, respectively) indirectly, i.e., through the inhibition of the clonal expansion of these cells in the mediastinal lymph nodes. Additionally, the blockade of NF-κB translocation and RANKL/RANK interaction, but not IKK, prevented the OVA-induced increase in the percentage of IL-4-, IL-10- and IL-17-producing CD4⁺ T cells. These latter results strongly suggest that both therapeutic strategies can directly decrease IL-4 and IL-17 production by Th2 and Th17 cells, respectively. This action may constitute an important mechanism underlying the anti-asthmatic effect induced by the blockade of NF-κB translocation and of RANKL/RANK interaction. Thus, in this context, both these therapeutic strategies seem to have an advantage over the blockade of IKK. None of the tested therapeutic strategies increased both the absolute number and frequency of IL-10- and TGF-β-producing Treg cells, and hence they lacked the potential to inhibit the development of the disease via this mechanism.