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Organofunctional silanes, siloxanes, and polysiloxanes are widely applied in industry. One of the most popular and commonly used processes for the synthesis of these compounds is based on the catalytic hydrosilylation reaction. However, even though this reaction was widely investigated in homogeneous single-phase systems, there is still a large problem with later separation of the catalyst from the product after completion of the reaction. One of the solutions to this problem is use of ionic liquids to create a biphasic system with substrates, where the catalyst is dissolved in the ionic liquid phase, and this phase can be easily separated and reused. Moreover, optimization and intensification of the process can be improved by using continuous flow-through reactors on a microscale (microreactors) due to significantly larger surface-to-volume ratios and microstructured internal volumes of the reactors, allowing much more efficient heat exchange. In our studies, we have investigated, as a model, the reaction between 1,1,1,3,5,5,5-heptamethyltrisiloxane and 1-octene, using a series of platinum and rhodium catalysts dissolved in four different ionic liquids in batch and in the microreactor system. Studies have shown that the use of ionic liquids in general allows for catalyst recycling and reuse in subsequent reaction cycles. Moreover, the use of microreactors intensified the process, allowing a higher yield to be obtained than under conventional batch reaction conditions. [ABSTRACT FROM AUTHOR]

Epoxy resin-based composites, also those containing POSS compounds, have been the subject of extensive research because of their attractive properties and broad practical applications. However, in some applications they suffer from too long curing times or not strong enough adhesion to metals. A solution to this problem is the use of episulfide (thiirane) derivatives or their combination with epoxies. In this paper, the synthesis of new octakis[(3-(thiiran-2-yloxy)propyl)dimethylsiloxy]octasilesquioxane from its 3-glycidoxypropyldimethylsiloxy analog is described. Results of study of its influence on thermal properties as well as curing processes of modified with this compound epoxy resins hardened with maleic, phthalic, and pyromellitic anhydrides are also presented. It is shown that addition of this new thiirane functional POSS compound can significantly increase thermal stability of obtained epoxy resin composites and decrease its curing temperatures. [ABSTRACT FROM AUTHOR]

In the present work the usefulness of photoalignment as a nematic liquid crystal aligning technique has been evaluated. A photocrosslinking mechanism of photosensitive polymer material has been used to cause anisotropy in the layer. The influence of the UV dose on the LC alignment of liquid crystal material in the TN-type cell has been examined. [ABSTRACT FROM PUBLISHER]

The purpose of the present study was to test the hypothesis that large increases in blood lactate concentration ([La]b) and/or body temperature may occur during an endurance training on a rowing ergometer and disrupt training. The influence of an increase in air convection on the capacity to perform a prolonged exercise was also explored. Ten trained oarsmen were asked to undergo twice, in control (C) and increased air ventilation (AV) conditions, two 30-min trainings on a rowing ergometer at a work rate corresponding to 2.5 mmol·L-1 of [La]b determined during a previous incremental exercise (P2.5). Four subjects did not complete the training session in C despite a steady state in [La]b in two of them. In these four subjects, the end of the exercise was associated with the highest measured rectal temperatures (Tre, 39.4 ± 0.1 °C) and rate of perceived exertion (RPE, 17.8 ± 0.3). Regarding the six other subjects, their heart rate, oxygen uptake, RPE, Tre and water loss values were lower (p <0.05) in AV than in C. [La]b displayed the same profile in C and AV. This study suggests that i) high body temperature may constitute a significant factor of perceived exertion and disrupt indoor training session, and ii) capacity to perform an endurance training on a rowing ergometer was improved by increasing air convection. [ABSTRACT FROM AUTHOR]

According to X-ray diffraction data, the nickel complex [Ni(Bu3P)2(NCS)2] has a square-planar structure with the two phosphine ligands trans to each other and the thiocyanate ligand coordinated by the nitrogen atom. The IR and 1H, 13C, and 31P NMR data show that the same structure is preserved in solutions. The catalytic activity of the complex in hydrosilylation of 1-hexene with chlorohydrosilanes HSiMe3-nCln varies in the series HSiCl3 > HSiMeCl2 > HSiMe2Cl. The reactions of the complex with hydrosilanes involve substitution of the anionic ligand and formation of silyl complexes. [ABSTRACT FROM AUTHOR]

The article presents a study on the physical anaerobic assessment of young rowers.

Abstract Background It is supposed that fibroblasts present in tumour microenvironment increase cancer invasiveness and its ability to metastasize but the mechanisms have not been clearly defined yet. Thus, the current study was designed to assess changes in gene expression in five various cancer cell lines grown as a co-culture with the carcinoma-associated fibroblasts (CAFs) in vitro. Results A carcinoma-associated fibroblast cell line was isolated from a canine mammary cancer. Then, a co-culture of cancer cells with the CAFs was established and maintained for 72 hrs. Having sorted the cells, a global gene expression in cancer cells using DNA microarrays was examined. The analysis revealed an up-regulation of 100 genes and a down-regulation of 106 genes in the cancer cells grown as a co-culture with the CAFs in comparison to control conditions. The PANTHER binomial statistics tool was applied to determine statistically over-manifested pathways (p < 0.05). Bulk of the up-regulated genes are involved in the adhesion, the angiogenesis, the epithelial-mesenchymal transition (EMT) and generally take part in the developmental processes. These results were further confirmed using real-time qPCR. Moreover, a wound-healing assay and growth characteristics on Matrigel matrix showed that CAFs increase cancer cell migration and matrix invasion. Conclusion The results of the current study showed that the co-culturing of cancer cells and the CAFs caused significant changes to the cancer gene expression. The presence of the CAFs in a microenvironment of cancer cells promotes adhesion, angiogenesis and EMT.

Functionalized siloxanes, as one of the most important classes of organosilicon compounds, are widely applied in industry. In our studies, we have investigated, the reaction between 1,1,3,3-tetramethyldisiloxane (TMDSO) and 1-octene, using the rhodium catalyst immobilized in six phosphonium-based ionic liquids differing in the structure of cation and anion. Studies have shown high potential for using ionic liquids to create biphasic system with reactants, where IL/catalyst phase can be separated and reused in subsequent reaction cycles allowing, in this way, for efficient and highly selective monofunctionalization of TMDSO with reuse of the same portion of catalyst up to 20 times in comparison to conventional homogenous reaction. [ABSTRACT FROM AUTHOR]