Hybrid Inorganic-Organic Sol–Gel Coatings in the SiO2-TiO2 System

In the present work, the influence of substituted Si-alkoxides on the structural and optical properties of films obtained in the SiO₂-TiO₂ system was studied. Methyltriethoxysilane (MTEOS) and 3-(tri-methoxysilyl)propyl methacrylate (TSPM) were used as SiO₂ sources and Ti(OBu)₄ was used as TiO₂ source. Acetylacetone was added to the Ti(OBu)₄ as chelating agent and the synthesis was carried out in acid medium. The films were deposited on oxidized Si-wafers by spin-coating. The films were characterized by XRD, spectro-ellipsometry (SE), and atomic force microscopy (AFM). The results obtained have shown that in the case of hybrid films the desired thickness could be obtained in a single deposition step. The thickness of the films and the optical properties are controlled by the bulkiness of the organic substitute bounded to Si. Among other optical applications, the potential use of such films as optical waveguides is proposed.     

Monitoring Methylmalonic Aciduria by NMR Urinomics

The paper reports on monitoring methylmalonic aciduria (MMA)-specific and non-specific metabolites via NMR urinomics. Five patients have been monitored over periods of time; things involved were diet, medication and occasional episodes of failing to comply with prescribed diets. An extended dataset of targeted metabolites is presented, and correlations with the type of MMA are underlined. A survey of previous NMR studies on MMA is also presented.     

Bioanalysis of pentoxifylline and related metabolites in plasma samples through LC‐MS/MS

Analytical aspects related to the assay of pentoxifylline (PTX), lisofylline (M1) and carboxypropyl dimethylxanthine (M5) metabolites are discussed through comparison of two alternative analytical methods based on liquid chromatography separation and atmospheric pressure electrospray ionization tandem mass spectrometry detection. One method is based on a ‘pure’ reversed‐phase liquid chromatography mechanism, while the second one uses the additional polar interactions with embedded amide spacers linking octadecyl moieties to the silicagel surface (C‐18 Aqua stationary phase). In both cases, elution is isocratic. Both methods are equally selective and allows separation of unknowns (four species associated to PTX, two species associated to M1) detected through specific mass transitions of the parent compounds and owning respective structural confirmation. Plasma concentration–time patterns of these compounds follow typical metabolic profiles. It has been advanced that in‐vivo formation of conjugates of PTX and M1 is possible, such compounds being cleaved back to the parent ones within the ion source. The first method was associated with a sample preparation procedure based on plasma protein precipitation by strong organic acid addition. The second method used protein precipitation by addition of a water miscible organic solvent. Both analytical methods were fully validated and used to assess bioequivalence between a prolonged release generic formulation and the reference product, under multidose and single dose approaches. Copyright © 2009 John Wiley & Sons, Ltd.     

The visibility parameter for words and permutations

We investigate the visibility parameter, i.e., the number of visible pairs, first for words over a finite alphabet, then for permutations of the finite set {1, 2, …, n}, and finally for words over an infinite alphabet whose letters occur with geometric probabilities. The results obtained for permutations correct the formula for the expectation obtained in a recent paper by Gutin et al. [Gutin G., Mansour T., Severini S., A characterization of horizontal visibility graphs and combinatorics on words, Phys. A, 2011, 390 (12), 2421–2428], and for words over a finite alphabet the formula obtained in the present paper for the expectation is more precise than that obtained in the cited paper. More importantly, we also compute the variance for each case.     

Synthesis, spectroscopic, and X-ray structural characterization of pharmacologically active substituted pyrazolyl-acetanilides

Five new pyrazole acetanilides were synthesized by N-alkylation of pyrazole and its derivatives with 4′-propionyl-2-iodoacetanilide. Compounds 1–5 were characterized by ¹H NMR, ¹³C NMR, IR, UV–Vis, MS, and elemental analysis. X-ray structures of representative compounds 1, 3, and 5 established their conformations and solid-state hydrogen bonding preferences. Acute toxicity, local anesthetic, and antiarrhythmic activities were assessed for compounds 1–5 using established protocols. Lower potencies and lower acute toxicities were recorded relative to lidocaine. Enhanced anesthetic activity of compound 3 was attributed to the presence of the propionyl group in the molecule. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Connected generalised Sierpiński carpets

Generalised Sierpiński carpets are planar sets that generalise the well-known Sierpiński carpet and are defined by means of sequences of patterns. We present necessary and sufficient conditions, under which generalised Sierpiński carpets are connected, with respect to Euclidean topology.     

Effect of dopant on the physical properties of polymer films for microphotonics

This paper presents experimental results concerning the influence of the additives on the physical properties of polymer films. Metal oxides/inorganic salts were used as additives in vinyl-polymers solutions. The physical properties of the metal doped polymer films can be significantly modified by the composition of the doping elements and the curing conditions of the polymer. Morphologic, electronic, magnetic and optic properties of the doped polymers were analysed by AFM, SEM, Mössbauer spectroscopy and optical measurements. The film composition and the deposition processes were optimized to allow a better control of the optical parameters (refractive index, transmission), to reduce the processing temperatures and to improve the chemical sensitivity of the films for sensor applications. These compounds can be easily spin coated onto a variety of directly patterned semiconductor substrates.     

Beta‐lactoglobulin Electrochemical Detection Based with an Innovative Platform Based on Composite Polymer

In this work, we present a new electrochemical disposable platform based on poly(aniline‐co‐anthranilic acid) (PANI/PAA) composite polymer coupled with an aptamer for sensitive detection of β‐lactoglobulin. Firstly, PANI/PAA film was electrodeposited on the graphite screen‐printed electrode surface by cyclic voltammetry. The co‐polymer modified electrode was then employed as platform for the covalent immobilization of an amino‐modified aptamer. Various β‐lactoglobulin solutions, with a fixed amount of biotinylated oligonucleotide complementary sequence, were dropped onto the aptasensor surface. A streptavidin‐alkaline phosphatase conjugate was then employed to trace the affinity reaction. After the addition of 1‐naphthyl‐phosphate enzymatic substrate, 1‐naphthol electroactive product was detected by differential pulse voltammetry. A decrease in the signal was obtained when the target concentration was increased, in according to a signal‐off approach. After optimization of key experimental parameters, a dose‐response curve was obtained between 0.01–1.0 μg mL^?1 β‐lactoglobulin concentration range. The limit of detection of 0.053 μg L^?1 was obtained. Milk samples spiked with β‐lactoglobulin were analyzed.