Silyl Modification of Biologically Active Compounds. 14. Organosilicon Lipid-like Derivatives of Hydroxyethyl Tetrahydro(iso)quinoline and Thiazole with Antitumour,Antibacterial and Antifungal Properties

Silicon - A series of novel lipid-like O- and N-(3-trimethylsilyl)propyl derivatives of N-(2-hydroxyethyl)-1,2,3,4-tetrahydroquinoline, -tetrahydroisoquinoline and...     

Structural and physicochemical studies of hydration of crosslinked TBA polyacrylates with different substitution degrees of H+ ions with TBA+ ions

X‐ray powder diffraction studies and physicochemical studies have been carried out of the hydrate phases formed in binary water systems with crosslinked tetrabutylammonium (TBA) polyacrylates (n = 1%) in mixed [x(C₄H₉)₄N + (100?x)H] form with low degrees of substitution of proton ions of the carboxylic groups in poly(acrylic acid) for TBA cations x = 40%, 30%, and 20%. As was shown by structural studies, the clathrate hydrate is formed in the water system with the polyacrylate in the mixed form with x = 40%. The structure is analogous to that of earlier studied hydrates formed by crosslinked polyacrylates in mixed [x(C₄H₉)₄N + (100?x)H] form with higher values of x = ～100%, 80%, and 60% and can be related to the tetragonal structure I, characteristic of the ionic clathrate hydrates of TBA salts with monomeric anions. Decomposition temperature and fusion enthalpy of the studied hydrate were determined using differential thermal analysis and calorimetric methods. It was revealed that the further decrease of x led to the destruction of clathrate hydrate framework. According to the results of X‐ray powder diffraction research, the phase of ice is crystallized instead of the hydrate phase in water systems with the polyacrylates with x = 30% and 20%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46209.     

Nanometallocarbosilanes： Synthesis,Physicochemical Properties and Structure

Highly efficient synthesis methods have been developed and characteristics of nanometallocarbosilanes molecular structure were studied by the research team of GNIIChTEOS （State Research Institute for Chemistry and Technology of Organoelement Compounds）. Nanometallocarbosilanes were synthesized by thermal co-condensation of oligocarbosilanes and alkyl amides of refractory metals. Initial, intermediate and final products of side reactions were characterized by 1H, 13C, 29Si NMR （nuclear magnetic resonance）, IR （infra-red） spectroscopy, GPC （gel-penetrating chromatography）, TGA （thermal gravimetric analysis）, TEM （transmission electron microscopy）, SEM （scanning electron microscopy）, RES （X-ray phase analysis） and elemental analysis. The proposed synthesis method of nanometallocarbosilanes was lbund to produce fusable soluble organosilicon oligomers with homogeneous distribution of nanoscale （10-20 nm） metal particles in the oligomer matrix. A computational model of the group and elemental composition of nanometallocarbosilanes was developed; it was shown that they are molecular globules of near-spherical shape and rigid polycyclic structure. Thermochemical treatment of nanometallocarbosilanes leads to SiC-nanoceramics （a high yield of up to 75-80 mass%） modified by metal nanoparticles （20-30 nm） contributing to its stabilization. The application of preceramic oxygen-free nanometallocarbosilanes will make it possible to advance in solving the problem of ceramic composite materials with long-term resistance at temperatures above 1,500 ℃ in oxidizing environments.     

Long-term field and laboratory leaching tests of cemented radioactive wastes

Experiments with real and simulated radioactive cementitious wasteforms were set up to compare the leaching behaviour of cementitious wasteforms containing nuclear power plant operational waste in field and laboratory test conditions. Experiments revealed that the average annual (137)Cs leach rate in deionised water was about thirty-five times greater compared with the measured average value for the 1st year of the field test. Cumulative leached fraction of (137)Cs for 1st year (3.74%) was close to values reported in literature for similar laboratory experiments in deionised water, however more than two orders of magnitude higher than the 1st year leached fraction of (137)Cs in the repository test (0.01%). Therefore, to compare field and laboratory test results, a scaling factor is required in order to account for surface to volume factor difference, multiplied by a temperature factor and a leach rate decrease coefficient related to the ground water composition.     

Test systems and a method for express detection of synthetic food dyes in drinks

In this study, new test systems and express method were developed for the rapid detection of synthetic food dyes in drinks including alcoholic drinks, fruit juices, soft drinks and other non-alcoholic drinks. The detection is based on selective adsorption of synthetic food dyes from a drink by the specific adsorbent contained in the developed test system. The method allows screening of samples for synthetic food dyes in the presence of natural colors by differential spectrophotometry following adsorption. The said adsorbent provides adsorption of synthetic food dyes and substantially does not interact with natural dyes of drinks. Therefore, when a drink contains synthetic dyes, the color of the sample changes, whereas the color of a drink having only natural dyes stays substantially the same. This test can be used as a first step analysis for screening. So, only in a case when the test showed the presence of synthetic dyes in a drink, further laborious identification and quantitative determination of the revealed dyes could be performed. The use of such an approach reduces the time and costs required to perform the analysis.     

Cationic Surfactants as Disinfectants against SARS-CoV-2

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.     

Constructive texturing based on hypervolume modeling

The concept of solid texturing is extended in two directions: constructive modeling of space partitions for texturing and modeling of multidimensional textured objects called hypervolumes. A hypervolume is considered as a point set with attributes of both physical (density, temperature, etc.) and photometric (color, transparency, diffuse and specular reflections, etc.) nature. The point set geometry and attributes are modeled independently using real‐valued scalar functions of several variables. Each real‐valued function defining geometry or an attribute is evaluated at the given point by a procedure traversing a constructive tree structure with primitives in the leaves and operations in the nodes of the tree. This approach provides a framework for modeling, texturing and visualization of 3D solids, time‐dependent and multidimensional objects in a completely uniform manner. We introduced a special modeling language and implemented software tools supporting the proposed approach. The concept of constructive hypervolume textures is independent of the geometry representation. We provide examples of textured Frep and BRep objects as illustrations. Copyright © 2002 John Wiley & Sons, Ltd.