Coercive boundary value problems for regular degenerate differential-operator equations

This study focuses on nonlocal boundary value problems (BVP) for degenerate elliptic differential-operator equations (DOE), that are defined in Banach-valued function spaces, where boundary conditions contain a degenerate function and a principal part of the equation possess varying coefficients. Several conditions obtained, that guarantee the maximal L_p regularity and Fredholmness. These results are also applied to nonlocal BVP for regular degenerate partial differential equations on cylindrical domain to obtain the algebraic conditions that ensure the same properties.     

Cystic fibrosis: a label-free detection approach based on thermally modulated electrochemical impedance spectroscopy

Cystic fibrosis is one of the most common genetically inherited diseases in northern Europe, with the DF508 mutation being the most common, and among the Caucasian population being responsible for almost 70% of cases. In this work, we report on the use of thermally modulated electrochemical impedance spectroscopy for the discrimination of the DF508 mutation from the wild-type sequence. DNA probes (15 and 21 bases long) were immobilised on the surface of gold electrodes and the variation of the charge-transfer resistance was monitored as a function of hybridisation. Two sets of targets were used in this work: synthetic 15-mer sequences and two single-stranded synthetic analogues of PCR products 82 (mutant) and 85 (wild type) bases long. Hybridisation with short targets resulted in very sequence specific charge-transfer-resistance variation with a discrimination factor at room temperature between fully complementary and mismatched sequences of approximately fivefold. However, in the case of the single-stranded synthetic PCR product analogues, a lower discrimination factor was recorded (1.5-fold). The effect of temperature was investigated to improve discrimination and the use of a posthybridisation wash at elevated temperature resulted in a fivefold improvement in the discrimination factor. Using an electrode array with probes immobilised against each of the mutant and wild-type sequences, we achieved an unequivocal detection of the DF508 mutation.     

Free Boundary Value Problems for Abstract Elliptic Equations and Applications

The free boundary value problems for elliptic differential-operator equations are studied. Several conditions for the uniform maximal regularity with respect to boundary parameters and the Fredholmness in abstract L _p -spaces are given. In application, the nonlocal free boundary problems for finite or infinite systems of elliptic and anisotropic type equations are studied.     

Planar Chromatography of Some 1-Arylpiperazines Behaving as Dopaminergic Ligands

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of fourteen 1-arylpiperazine derivatives has been studied by thin-layer chromatography on both silica...     

Synthesis, spectroscopy and electrochemical behaviors of nickel(II) complexes with tetradentate shiff bases derived from 3,5-Bu(2)(t)-salicylaldehyde

Nickel(II) complexes of a series of N,N'-polymethylenebis(3,5-Bu(2)(t)-salicylaldimine) ligands containing 2,4-di-Bu(2)(t)-phenol arms, NiL(x), were synthesized and their spectroscopic and redox properties were examined. The UV-vis, (1)H NMR spectroscopic and magnetic results indicate that complexes NiL(1)-NiL(4) unlike NiL(5) and NiL(6) have a square-planar structure in the solid state and in solution. Cyclic voltammograms of NiL(x) (x=1-4) complexes displayed two-step oxidation processes. The first oxidation peak potentials of all Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. The second oxidation peak of the complexes was assigned as the ligand based oxidation generating a coordinated phenoxyl radical species.     

Synthesis,Spectroscopic Characterization,and Oxidative C–C Coupling in New Copper(II) Salicylaldiminates Containing Sterically Hindered Phenol

New bis[N‐(2,6‐di‐tert‐butyl‐1‐hydroxyphenyl)salicylideneminato]copper(II) complexes bearing HO and CH₃O substituents on the salicyaldehyde moiety were prepared, and have been characterized by elemental analyses, IR, UV/Vis, ESR spectroscopy, and magnetic moments. It has been found that in the synthesis of CH₃O substituted complexes unlike HO bearing, the oxidative C–C coupling of coordinated salicylaldimine ligands take place. It has been suggested that the intermolecular H‐bonding is a dominant factor in controlling of oxidative C–C coupling conversion. The powder ESR spectra of CH₃O substituted compounds unlike of HO are typical of a triplet state Cu^II dimers with a half‐field forbidden (δM = ± 2) and the allowed (δM = ± 1) transitions at 300 and 113 K.     

Gold chloride cluster ions generated by vacuum laser ablation

In this work, a simple way for study the possibility of formation a vapor cluster species of tetrachloroauric acid (HAuCl₄), using the laser ablation in the absence of a buffer or reactive atmosphere, and without a postablation supersonic expansion on a commercial matrix assisted laser desorption/ionization time-of-flight mass spectrometer, is reported. Tetrachloroauric acid is known as precursor for the synthesis of gold nanostructures and the complex salts; therefore it is an important task to discover and quantify the species arising from HAuCl₄, in order to understand their role in the gold assisted reactions. Mass spectrum of HAuCl₄ in a reflector negative-ion mode contains the hydrated mono- and dinuclear gold clusters in the m/z range 286–436, and gold chloride clusters in the m/z range 447–795. In the first part of spectrum, m/z range 286–436, the hydrated gold cluster species of type Au _n ^? (H₂O)_m (n?=?1–2; m?=?1, 2, 5, 7, 8) and [Au_n(OH)_k]^?(H₂O)_m (n?=?1–2; k?=?1–2; m?=?1, 4–8) were found. Besides that, there are gold chloride clusters with general formula [AuH_r(HCl)₂]^?(H₂O)_m (m?=?1–5; 8–9; r?=?0–2) in this part of spectrum. In the second part of spectrum, the m/z range 447–795, only gold chloride clusters were obtained. Their general formulae can be written as [AuCl_t(HCl)_v]^?(H₂O)_m (t?=?1–4; v?=?5–8; m?=?2–4, 6–8) and [Au_n(HCl)_v]^?(H₂O)_m (n?=?1–2, v?=?4–5, m?=?1–2, 5, 7). The analysis of concentration effects on the LDI mass spectra of gold clusters reveals that the relative intensities of signals for the mono- and dinuclear Au clusters increase with decreasing the concentration of water HAuCl₄ solutions.