Rational ligand design for metal ion recognition. Synthesis of a N-benzylated N2S3-donor macrocycle for enhanced silver(I) discrimination

Four previously documented ligand design strategies for achieving Ag(I) discrimination have been applied to the design of a new N-benzylated N2S3-donor macrocycle; the latter shows high selectivity for Ag(I) over Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) in log K and bulk membrane transport studies.     

Sensing lipid bilayer formation and expansion with a microfabricated cantilever array

We show that cantilever array sensors can sense the formation of supported phospholipid bilayers on their surface and that they can monitor changes in mechanical properties of lipid bilayers. Supported lipid bilayers were formed on top of microfabricated cantilevers by vesicle fusion. The formation of bilayers led to a bending of the cantilevers of 70-590 nm comparable to a surface stress of 27-224 mN/m. Physisorption of bilayers of DOPC and other bilayers on the silicon oxide surface of cantilevers led to a tensile bending of about 70 nm whereas formation of chemisorbed bilayers of mixed thiolated (DPPTE) and non-thiolated lipids (DOPC) on the gold side of cantilevers led to a compressive bending of nearly 600 nm which depended on the ratio of DPPTE to DOPC. First results on bending of bilayer-covered cantilevers due to their interaction with the pore-forming peptide melittin are shown. The results demonstrate that cantilever sensors with immobilized bilayers can be used as model systems to investigate mechanical properties of cellular membranes and may be used for screening of membrane processes involving modification, lateral expansion, or contraction of membranes.     

Convergence of invariant measures for singular stochastic diffusion equations

It is proved that the solutions to the singular stochastic p$p$-Laplace equation, p∈(1,2)$p\in (1,2)$ and the solutions to the stochastic fast diffusion equation with nonlinearity parameter r∈(0,1)$r\in (0,1)$ on a bounded open domain Λ⊂R^d$\Lambda \subset {\mathbb{R}}^d$ with Dirichlet boundary conditions are continuous in mean, uniformly in time, with respect to the parameters p$p$ and r$r$ respectively (in the Hilbert spaces L²(Λ)$L^2\left(\Lambda \right)$, H⁻¹(Λ)$H^{-1}\left(\Lambda \right)$ respectively). The highly singular limit case p=1$p=1$ is treated with the help of stochastic evolution variational inequalities, where P$\mathbb{P}$-a.s. convergence, uniformly in time, is established.     

Separation of nitrophenols. Equilibriums in bi- and tri-phasic systems

The paper presents experimental data obtained in the study of liquid–liquid partition equilibriums in biphasic system in order to optimize the process of transport through bulk liquid membranes (triphasic partition systems). The partition equilibriums of some nitrophenols using chloroform as extraction solvent and membranary solvent, respectively, were studied. The influence of the pH on the partition equilibriums was investigated. The repartition constants and the pK_a values of the studied nitrophenols were calculated. Nitrophenols were transferred in triphasic system from a feed phase with pH 2, through a chloroform liquid membrane, into a receiving phase with pH 12, with efficiencies over 90%.     

Surface Analysis of Inhibitor Film Formed by 4-Amino-N-(1,3-thiazol-2-yl) Benzene Sulfonamide on Carbon Steel Surface in Acidic Media

Inhibitive properties of the antibacterial sulfa drug sulfathiazole—IUPAC name being 4-amino-N-(1,3-thiazol-2-yl) benzene sulfonamide—on the corrosion of carbon steel in 1.0 M HCl solution were investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Sulfathiazole is a good adsorption inhibitor, and the inhibition efficiency increases with increasing concentration. Adsorption is spontaneous and is best described by Temkin isotherm. XPS analysis showed, at this stage, that the main product of corrosion is a nonstoichiometric Fe³⁺ oxide/oxyhydroxide consisting of a mixture of Fe₂O₃, α, and γ-FeO(OH) and/or Fe(OH)₃, where α, γ-FeO(OH) is the main phase.     

Some abstract maximal ideal-like spaces

Presented by R. S. Pierce.     

Sur les solutions fondamentales d'ordre fini de croissance

Sans résumé     

Application of phase correlation to the montage synthesis and three-dimensional reconstruction of large tissue volumes from confocal laser scanning microscopy.

We have implemented and tested a new automatic method for the montage synthesis and three-dimensional (3D) reconstruction of large tissue volumes from confocal laser scanning microscopy data (CLSM). This method relies on maximization of the phase correlation between adjacent images. It was tested on a large specimen (a murine heart) that was cut into a number of individual sections with thickness appropriate for CLSM. The sections were scanned horizontally (in-plane) and vertically (perpendicular to the optical planes) to produce "tiles" of a 3D volume. Phase correlation maximization was applied to the montage synthesis of in-plane tiles and 3D alignment of optical slices within a given physical section. The performance of the new method is evaluated.     

Food web model with detritus path

We present and study a lattice (Monte Carlo) model of a food web consisting of three levels. Agents on the lowest level produce food from dead agents (detritus) of the upper levels and are themselves eaten by the first level species, which in turn are prey for the top level species. Agents which do not find food in a given time, die with a given probability, while eating enables them to produce offspring in their neighborhood. This rule applies to species on all levels, including the lowest one. The dynamics is therefore nutrient limited. We are considering two pathways — grazers and detritus (using dead organic matter). We show that the emerging dynamics is more complex than the ordinary predator-prey systems in which bottom species are indestructible. We investigate the viability of our model and we construct appropriate (extinct-alive) phase diagrams. We demonstrate how the temporal fluctuations in the densities of the three populations are correlated. We show also that the density of the middle level agents plays the key role in the viability of the investigated food web.     

Efficient solver for swirling flow problems in ducts with variable radius

The paper presents preliminary results of a work in progress addressing the hydrodynamic stability of swirling flows problems in ducts with variable radius which imply mathematical modeling, dynamic and stability investigations. The proposed quasi-analytical method aims to obtain the velocity profiles with a low order approximation method of which the computation costs were neglijable and regain the central stagnation zone developed in the fluid. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)