The synthesis and characterization of two biphenyl phosphates of different structures, as substrates for preparation of two series of functionalized addition silicone rubbers of different crosslink ...density and amount of pendant functional groups, is presented. Obtained materials were applied as flame retardant protective coatings for cotton fabric and characterized by TG and MMC techniques. The relationship between thermal stability, flame-retardant properties, and structure of prepared silicone rubbers is discussed.
•The synthesis and characterization of two new biphenyl phosphates•One-pot synthesis of phosphate functionalized, crosslinked silicone rubbers•TG and MMC characterization of flame retardant protective coatings for cotton fabric
Many methods of gene set analysis developed in recent years have been compared empirically in a number of comprehensive review articles. Although it is recognized that different methods tend to ...identify different gene sets as significant, no consensus has been worked out as to which method is preferable, as the recommendations are often contradictory. In this article, we want to group and compare different methods in terms of the methodological assumptions pertaining to definition of a sample and formulation of the actual null hypothesis. We discuss four models of statistical experiment explicitly or implicitly assumed by most if not all currently available methods of gene set analysis. We analyse validity of the models in the context of the actual biological experiment. Based on this, we recommend a group of methods that provide biologically interpretable results in statistically sound way. Finally, we demonstrate how correlated or low signal-to-noise data affects performance of different methods, observed in terms of the false-positive rate and power.
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.
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•Developing a strategy for high-yield and selective synthesis of TMDSO derivatives•Immobilization of catalyst in phosphonium ionic liquids•Reusing ionic liquid/catalyst up to 20 times using biphasic catalysis•Synthesis of monofunctionalized TMDSO derivatives with reducing amount of catalyst
Continuous flow-through reactors on a micro scale (microreactors) are being investigated as a new approach to chemical synthesis, due to significantly larger surface-to-volume ratios and ...micro-structured internal volumes, which allow for much more efficient heat exchange. Functionalized siloxanes, as one of the most important classes of organosilicon compounds, are widely applied in industry. Many of their synthetic methods are based on the catalytic process of hydrosilylation. In our studies, we investigated, as a model, the reaction between 1,1,1,3,5,5,5-heptamethyltrisiloxane and 1-octene, using the Karstedt catalyst dissolved in seven different ionic liquids. The reaction was carried out 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 when using conventional batch reactions.
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)dimethylsiloxyoctasilesquioxan e 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.
In recent years fluorinated polyhedral oligomeric silsesquioxanes (POSS) have been established as useful for the fabrication of superhydrophobic surfaces, however little attention has been paid to ...their use for making ultrathin coatings by the Langmuir-Blodgett method. On the other hand, recently POSS compounds have been recognized as a new group of film-forming materials. In this study the interfacial behavior of fluorinated polyhedral oligomeric silsesquioxanes (POSS) mixed with silica nanoparticles was studied at the air/water interface. Surface pressure-area isotherms and Brewster angle microscopy revealed the formation of a mixed film. Incorporation of nanoparticles in a POSS monolayer caused formation or more condensed and rigid film as shown by analysis of compressibility and dilatational viscoelasticity. On the other hand POSS molecules act as an excellent dispersant which prevents silica nanoparticles from aggregation. Deposition of the Langmuir-Blodgett film composed of POSS and silica nanoparticles allowed a hydrophobic surface showing water contact angles reaching 135° to be obtained, which suggests possible application of our approach in the fabrication of ultrathin, water-repellent coatings.
Fluorinated polyhedral oligomeric silsesquioxanes (POSS) have been established as useful for the fabrication of superhydrophobic coatings, however little attention has been paid to their use for making ultrathin film by the Langmuir-Blodgett method.
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)dimethylsiloxyoctasilesquioxane 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.
The aim of this study was to test (a) three methods to estimate the quantity of lactate accumulated (QLaA) in response to supramaximal exercise and (b) correlations between QLaA and the nonoxidative ...energy supply assessed by the accumulated oxygen deficit (AOD). Nine rowers performed a 3‐min all‐out test on a rowing ergometer to estimate AOD and lactate accumulation in response to exercise. Peak blood lactate concentration (La)peak during recovery was assessed, allowing QLaA(m1) to be estimated by the method of Margaria et al. Application of a bicompartmental model of lactate distribution space to the blood lactate recovery curves allowed estimation of (a) the net amount of lactate released during recovery from the active muscles (NALRmax), and (b) QLaA according to two methods (QLaA(m2) and QLaA(m3)). (La)peak did not correlate with AOD. QLaA(m1), QLaA(m2) and QLaA(m3) correlated with AOD (r = 0.70, r = 0.85 and r = 0.92, respectively). These results confirm that (La)peak does not provide reliable information on nonoxidative energy supply during supramaximal exercise. The correlations between AOD and QLaA(m2) and QLaA(m3) support the concept of studying blood lactate recovery curves to estimate lactate accumulation and thus the contribution of nonoxidative pathway to energy supply during supramaximal exercise.
Studies identifying specific pathologically expressed genes have been performed on diseased myocardial tissue samples, however less invasive studies on gene expression of peripheral blood ...mononucleated cells give promising results. This study assessed transcriptomic data that may be used to evaluate Dachshunds with chronic mitral valve disease. Dachshunds with different stages of heart disease were compared to a control, healthy group. Microarray data analysis revealed clusters of patients with similar expression profiles. The clusters were compared to the clinical classification scheme. Unsupervised classification of the studied groups showed three clusters. Clinical and laboratory parameters of patients from the cluster 1 were in accordance with those found in patients without heart disease. Data obtained from patients from the cluster 3 were typical of advanced heart failure patients. Comparison of the cluster 1 and 3 groups revealed 1133 differentially expressed probes, 7 significantly regulated process pathways and 2 significantly regulated Ariadne Metabolic Pathways. This study may serve as a guideline for directing future research on gene expression in chronic mitral valve disease.
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