Neural network solution to an inverse problem associated with the eigenvalues of the Stokes operator

A numerical method, based on the design of two artificial neural networks, is presented in order to approximate the viscosity and density features of fluids from the eigenvalues of the Stokes operator. The finite element method is used to solve the direct problem by training a first artificial neural network. A nonlinear map of eigenvalues of the Stokes operator as a function of the viscosity and density of the fluid under study is then obtained. This relationship is later inverted and refined by training a second artificial neural network, solving the aforementioned inverse problem. Numerical examples are presented in order to show the effectiveness and the limitations of this methodology.     

Equal treatment without large numbers

We provide a necessary and sufficient condition under which core allocations of arbitrary TU-games treat substitute players equally. The core satisfies the equal treatment property if and only if no player needs the participation of all of her substitutes to attain her core payoffs. We show how, without the requirement of a large number of players, this condition generalizes and unifies other sufficient conditions proposed in the literature (in the context of large games and economies) and it helps derive new results for particular classes of games.     

4-Chlorophenol degradation by chloroperoxidase from Caldariomyces fumago

This study investigated the degradation of 4-chlorophenol (4-CP) by Caldariomyces fumago chloroperoxidase (CPO). Enzymatic oxidations were studied in reaction mixtures at pH 3.0, 4.0, and 6.0 in the presence and absence of Cl⁻ containing 3.5 IU of CPO and 4-CP and hydrogen peroxide concentrations within the range of 0.5–50 and 0.005–50 mM, respectively. Distinct patterns of products regarding color, concentration, and solubility were observed. Reaction mixtures at pH 6.0 containing 3.5 IU of CPO and 5.0 mM 4-CP and H₂O₂ (1:1 stoichiometry) showed the highest 4-CP removal of 95% and the highest formation of a dark precipitate.     

Towards the analysis of high molecular weight proteins and protein complexes using TIMS-MS

In the present work, we demonstrate the potential and versatility of TIMS for the analysis of proteins, DNA-protein complexes and protein-protein complexes in their native and denatured states. In addition, we show that accurate CCS measurement are possible using internal and external mobility calibration and in good agreement with previously reported CCS values using other IMS analyzers (<5 % difference). The main challenges for the TIMS-MS analysis of high mass proteins and protein complexes in the mobility and m/z domain are described. That is, the analysis of high molecular weight systems in their native state may require the use of higher electric fields or a small compromise in the TIMS mobility resolution by reducing the bath gas velocity in order to effectively trap at lower electric fields. This is the first report of CCS measurements of high molecular weight biomolecules and biomolecular complexes (~150 kDa) using TIMS-MS.     

Structure and stability of self-assembled actin-lysozyme complexes in salty water

Interactions between actin, an anionic polyelectrolyte, and lysozyme, a cationic globular protein, have been examined using a combination of synchrotron small-angle x-ray scattering and molecular dynamics simulations. Lysozyme initially bridges pairs of actin filaments, which relax into hexagonally coordinated columnar complexes comprised of actin held together by incommensurate one-dimensional close-packed arrays of lysozyme macroions. These complexes are found to be stable even in the presence of significant concentrations of monovalent salt, which is quantitatively explained from a redistribution of salt between the condensed and the aqueous phases.     

Highly functionalized pyranopyrazoles: synthesis,antimicrobial activity,simulation studies and their structure activity relationships (SARs)

Research on Chemical Intermediates - Development of potent antibacterial and antifungal agents is a permanently new and unremitting investigation in the therapeutic field. Still, medicinal research...     

Electrochemical Properties of a Conducting Film Derived from Iron(II) Tris(diaminopolypyridyl) Complex in the S(IV) Oxoanions Reduction

A new conducting film derived from the complex [Fe (diaphen)₃]²⁺, (diaphen=5,6‐diamino‐1,10‐phenanthroline) was electropolymerized by cyclic voltammetry onto a glassy carbon electrode. Poly‐[Fe^II (diaphen)₃] was studied by cyclic voltammetry, SEM, UV‐vis and micro‐Raman spectroscopy. Poly‐[Fe^II (diaphen)₃] shows electrocatalytic activity in HSO₃^? reduction in an ethanol/water solution. Electrocatalysis is centered at the π ring of phenanthroline. Rotating disk electrode studies showed a 0.117 V/dec Tafel slope, suggesting an EC process where the electrochemical process is the determining step. The chemical step was studied by UV‐vis spectroelectrochemistry. Amperometric behavior showed a linear range between 47.5 µM to 417 µM and the LOD was 19.5 µM.     

Implementation of a block-decomposition algorithm for solving large-scale conic semidefinite programming problems

In this paper, we consider block-decomposition first-order methods for solving large-scale conic semidefinite programming problems given in standard form. Several ingredients are introduced to speed-up the method in its pure form such as: an aggressive choice of stepsize for performing the extragradient step; use of scaled inner products; dynamic update of the scaled inner product for properly balancing the primal and dual relative residuals; and proper choices of the initial primal and dual iterates, as well as the initial parameter for the scaled inner product. Finally, we present computational results showing that our method outperforms the two most competitive codes for large-scale conic semidefinite programs, namely: the boundary-point method introduced by Povh et al. and the Newton-CG augmented Lagrangian method by Zhao et al.     

Characterization of PVC-Tetraruthenated Metalloporphyrins Modified Electrodes: Application as Electrocatalyst in the Nitrite Reduction

Summary: This paper describes the electrochemical reduction of nitrite ion in 0.1 M NaClO₄, on glassy carbon or ITO electrodes modified with mixtures PVC- tetraruthenated metalloporphyrins. This electrode is able to keep the extraordinary electrocatalytic properties of the macrocycle allowing multielectronic transfers and a great stability as a consequence of the inclusion of the macrocycles into a polymeric support such as PVC. On the other hand, the electrochemical reduction of nitrite ion on these modified electrodes studied by cyclic voltammetry shows an enhancement in the current values and lower overpotential compared with the activity of the bare glassy carbon electrode. Controlled potential electrolysis experiments verify the production of ammonia, hydrazine and hydroxylamine, showing the electrocatalytic character and the stability of this modified electrode.