Aqueous microgels based on poly(N-vinylcaprolactam) with reversible temperature-induced volume transition are promising "smart" materials for various applications. In this work, the microgels are modified via acid-base interaction by wedge-shaped amphiphilic sulfonic acid molecules with alkyl chains of different lengths and an azobenzene group. In contrast to the pristine microgel the modified microgels retain colloidal stability in water and show different responses to the change of temperature and pH.
View Article and Find Full Text PDFIn supramolecular assemblies, absorption of water can assist the channel formation, similarly to biological systems and Nafion-like commercial ion-selective membranes. In this work, we investigate humidity-induced formation of water channels in wedge-shaped amphiphilic molecules, namely sodium 4'-[3'',4'',5''-tris(alkyloxy)benzoyloxy]azobenzene-4-sulfonates. The studied molecules contain a polar sulfonate group at the tip and a hydrophobic periphery composed of alkyl chains of two different lengths.
View Article and Find Full Text PDFFirst measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.
View Article and Find Full Text PDFThe convergence of corticofugal impulses in reticular and grisea pontis nuclei evoked by stimulation of the neocortex frontobasal regions (proreal, posterior orbital, basal temporal) as well as of the dorsal hippocampus was studied in cats narcotized by a mixture of nembutale and chloralose. Three foci of corticofugal impulse convergence were determined in the structures of pons varolii: one in the reticular formation and two in grisea pontis nuclei -- in their medial and lateral regions. Neurons with excitatory reactions are shown to dominate in the pons varolii reticular formation and those with inhibitory and mixed reactions -- in the grisea pontis.
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