Influence of Nature of Functional Groups on Interaction of Tetrasubstituted at Lower Rim p-tert-Butyl Thiacalix[4]arenes in 1,3-Alternate Configuration with Model Lipid Membranes

The influence of p-tert-butyl thiacalix[4]arenes (1,3-alternate) functionalized by N-propyl morpholine, N,N-dipropyliden-amine and aminodiacetate fragments on dynamic structure of liposomal membranes prepared from dipalmitoyl phosphatidylcholine was investigated by means of electron spin resonance spin-probe technique and Fourier transform infrared spectroscopy. Nuclear magnetic resonance and transmission electron microscopy techniques were applied to characterize the interacting systems. The obtained results have shown that all studied calixarenes interact with polar domains of bilayer. Depending on functional groups and hydrophobic/hydrophilic properties of calixarenes they can dip into bilayer, locate close to the surface of bilayer or form bridges between positively charged groups of adjacent lipid molecules, thus assisting to disordering or putting in order the lipid molecules. © 2011 Springer-Verlag

International Law and Protection of the Caspian Ecosystem

An overwhelming international legal act on the status of the Caspian is developed now by the Caspian States. One of the provisions already agreed upon provides for the responsibility of these States for conservation of all the values of the sea for the present and future generations. Main approaches for protection of the sea are formulated in the Frame Convention on the protection of the Caspian environment, developed by States, mostly commercially interested in exploitation of the oil and gas resources of the Caspian Sea. However, it is the oil and gas activity that makes the gravest negative impact on the environment in general, as well as on the sea bottom itself, provoking intensification of the tectonics. This is the factor that makes the adverse influence on the oil and gas facilities increasing the geoecological risks. Integrated management of Caspian resources, taking into consideration all geo and ecological particularities of the region, seems a perspective field of cooperation of the Caspian States

Effect of Phase Heterogeneity on the Properties of Poly(vinyl alcohol)-Based Composite Pervaporation Membranes

The structure, thermophysical characteristics, and pervaporation properties of composite membranes based on poly(vinyl alcohol) (PVA) are studied in dependence of the film preparation conditions. It is shown that the nature of the supramolecular organization of the composite polymer film determines which of the components of the separated mixtures of toluene and heptane predominantly penetrate through the corresponding pervaporation membrane. The observed structural effects can become more pronounced if the second component of a polymer mixture is purposefully selected (in this case, poly(N,N-dimethylaminoethyl methacrylate) instead of poly(acrylic acid)) or a nano-sized filler that can be well dispersed in the polymer matrix is introduced. Multi-wall carbon nanotubes are introduced into binary PVA-containing polymer blends. The influence of these fillers on the structure and transport properties of the obtained membranes is studied

Modification of secondary disease mortality. Abstr.

The influence of p-tert-butyl thiacalix[4]arenes (1,3-alternate) functionalized by N-propyl morpholine, N,N-dipropyliden-amine and aminodiacetate fragments on dynamic structure of liposomal membranes prepared from dipalmitoyl phosphatidylcholine was investigated by means of electron spin resonance spin-probe technique and Fourier transform infrared spectroscopy. Nuclear magnetic resonance and transmission electron microscopy techniques were applied to characterize the interacting systems. The obtained results have shown that all studied calixarenes interact with polar domains of bilayer. Depending on functional groups and hydrophobic/hydrophilic properties of calixarenes they can dip into bilayer, locate close to the surface of bilayer or form bridges between positively charged groups of adjacent lipid molecules, thus assisting to disordering or putting in order the lipid molecules. © 2011 Springer-Verlag

Influence of Nature of Functional Groups on Interaction of Tetrasubstituted at Lower Rim p-tert-Butyl Thiacalix[4]arenes in 1,3-Alternate Configuration with Model Lipid Membranes

The influence of p-tert-butyl thiacalix[4]arenes (1,3-alternate) functionalized by N-propyl morpholine, N,N-dipropyliden-amine and aminodiacetate fragments on dynamic structure of liposomal membranes prepared from dipalmitoyl phosphatidylcholine was investigated by means of electron spin resonance spin-probe technique and Fourier transform infrared spectroscopy. Nuclear magnetic resonance and transmission electron microscopy techniques were applied to characterize the interacting systems. The obtained results have shown that all studied calixarenes interact with polar domains of bilayer. Depending on functional groups and hydrophobic/hydrophilic properties of calixarenes they can dip into bilayer, locate close to the surface of bilayer or form bridges between positively charged groups of adjacent lipid molecules, thus assisting to disordering or putting in order the lipid molecules. © 2011 Springer-Verlag

New Membrane-Forming Aromatic Co-Poly(amide-imide)s: Influence of the Chemical Structure on the Morphological, Thermal and Transport Properties

Polymer film membranes are used to solve specific separation problems that dictate structural requirements. Structural and morphological parameters of film membranes based on glassy polyheteroarylenes can be controlled in the process of preparation from solutions that opens up prospects for obtaining structured membranes required for targeted separation. In the case of aromatic poly(amide-imide)s, the possibility of controlling film formation and structure virtually has not been studied. In the present work, a series of homologous co-poly(amide-imide)s differing in the number of repeating units with carboxyl-substituted aromatic fragments was synthesized by polycondensation. Comparative analysis of the processes of formation of membranes with different morphologies based on these polymers under equal conditions was performed. New information was obtained about the influence of the amounts of carboxyl groups and the residual solvent on structural properties of asymmetric membranes. The influence of these factors on transport properties of dense membranes under pervaporation conditions was studied. It was demonstrated that in the case of carboxyl-containing poly(amide-imide)s, the domains formed during film preparation had a significant effect on membrane properties