Peripheral interactions of relativistic 14N nuclei with emulsion nuclei

The results of investigation of the dissociation of the 2.86-A-GeV/c ¹⁴N nucleus in an emulsion are presented. The cross sections for various fragmentation channels are given. The invariant approach to analysis of fragmentation is used. The momentum and correlation characteristics of the α particles for the ¹⁴N → 3α + X channel in the laboratory system and c.m.s. of three α particles are examined. The results obtained for the ¹⁴N nucleus are compared with similar data for the ¹²C and ¹⁶O nuclei.     

Features of the 9Be → 2He fragmentation in an emulsion for an energy of 1.2 GeV per nucleon

The results of investigation of the fragmentation of relativistic nuclei ⁹Be in an emulsion, which is accompanied by the formation of two 1.2-A-GeV He fragments, are presented. The angular measurements of the ⁹Be → 2He events are analyzed. The ⁹Be → ⁸Be + n fragmentation channel with the decay of ⁸Be from the ground (0⁺) and first excited (2⁺) states into a pair of α particles appears to be dominant.     

Mica surfaces stabilize pentavalent uranium

High-resolution X-ray photoelectron spectroscopy was used to demonstrate that reduction of aqueous U6+ at ferrous mica surfaces at 25 degrees C preserves U5+ as the dominant sorbed species over a broad range of solution compositions. Polymerization of sorbed U5+ with sorbed U6+ and U4+ is identified as a possible mechanism for how mineral surfaces circumvent the rapid disproportionation of aqueous U5+. The general nature of this mechanism suggests that U5+ could play an important, but previously unidentified, role in the low-temperature chemistry of uranium in reducing, heterogeneous aqueous systems.     

Phenols monitoring and Hill coefficient evaluation using tyrosinase-based amperometric biosensors

Sensitive amperometric biosensors for phenols compounds, based on tyrosinase (polyphenoloxidase, PPO) immobilized on a Pt electrode in an electropolymerized poly-amphiphilic pyrrole matrix or cross-linked with glutaraldehyde, were constructed and compared. Steady-state amperometric measurements, performed at -50 mV vs. SCE in aqueous phosphate buffer containing LiClO(4) 0.1 M (pH 7) as well as in a chloroform solution containing 0.1 M C(6)H(5)CH(2)N(CH(3))(3)Cl, were used in order to compare the electroanalytical and kinetic parameters of the investigated amperometric biosensors in aqueous and nonaqueous media. It was established that the polypyrrole matrix has a higher efficiency for enzyme retention resulting in higher bioelectrode sensitivity, both in aqueous buffer (690 microA M(-1)) and in chloroform (149 microA M(-1)).     

Continuous permeation of analytes through a thin poly(dimethylsiloxane) membrane followed by sorbent trapping for their gas chromatographic monitoring

Omeprazole is a benzimidazole compound that acts as a proton-pump inhibitor. Because the metabolism of omeprazole is mainly catalyzed by cytochrome P-450 (CYP) 3A4 and CYP2C19. the genetic polymorphism of CYP2C19 could be of clinical concern in the treatment of acid-related diseases with omeprazole. Therefore, a reliable method for omeprazole phenotyping is desirable in clinical situations. This study has demonstrated the determination of omeprazole and its metabolites in human plasma by liquid chromatography-three-dimensional quadrupole mass spectrometry with a sonic spray ionization interface. The analytical column was YMC-Pack Pro C18(50x2.0 mm I.D.) using acetonitrile-50 mM ammonium acetate (pH 7.25) (1:4) at a flow-rate of 0.2 ml/min. The drift voltage was 30 V. The sampling aperture was heated at 110 degrees C and Shield temperature was 230 degrees C. In the mass spectrum, the molecular ions of omeprazole, hydroxyomeprazole and omeprazole sulfone were clearly observed as base peaks. This method is sufficiently sensitive and accurate for pharmacokinetic studies of omeprazol.     

An approach of majorization in spaces with a curved geometry

The Hardy–Littlewood–Pólya majorization theorem is extended to the framework of some spaces with a curved geometry (such as the global NPC spaces and the Wasserstein spaces). We also discuss the connection between our concept of majorization and the subject of Schur convexity. Several applications are included.     

Self-assembled architecture based on triiron-substituted polyoxomolybdate anion and positively charged polymer

A new self-assembled multilayer architecture was constructed by successive deposition of poly(4-vinylpyridine) partially quaternized with ethylamine (B) and Keggin trilacunary polyoxomolybdate [Aα-PFe₃^III(H₂O)₃Mo₉O₃₇]⁶⁻ (PFe₃Mo₉) on the Au electrode surface, covered with 3-mercapto-1-propanesulfonic acid (MPS). Surface plasmon resonance and cyclic voltammetry measurements were performed at Au/MPS/B/PFe₃Mo₉/B interface in order to investigate the structure and the electrochemical behavior of this electrode. Due to the presence of PFe₃Mo₉, the Au/MPS/B/PFe₃Mo₉/B-modified electrode showed electrocatalytic activity towards H₂O₂ amperometric detection. Additionally, when GOx was deposited as the outermost layer on the abovementioned multilayer structure, the Au/MPS/B/PFe₃Mo₉/B/GOx-modified electrode was able to detect glucose.     

Small Time Uniform Controllability of the Linear One-Dimensional Schrödinger Equation with Vanishing Viscosity

This paper addresses the exact controllability problem of the linear one-dimensional Schrödinger equation perturbed by a vanishing viscosity term depending on a strictly positive parameter. It is shown that, for any time and for each initial datum in a suitable space, there exists a uniformly bounded family of boundary controls. Any weak limit of this family is a control for the linear Schrödinger equation.