Einen neuen Sparbrenner

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Beitr?ge zum Nachweis von Eisen

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Über einen Inhaltsstoff der Pertusaria dealbata Ach., Nyl.

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Chord-length distribution functions and Rice formulae. Application to random media

We consider a stationary and isotropic bi-phasic (pore and solid) medium, draw many lines through it, and see each line as a one-dimensional level-cut process with value 0 or 1 according to whether a regular stationary process X is less or greater than a given level. The intervals corresponding to the points at which X is in a given phase are named chords. We are interested in obtaining information on the chord-length distribution functions. Working with the Palm probability measure and using level crossings techniques, in particular Rice methods, we can obtain not only the exact analytical formula of the chord-length distribution function but also the joint distribution function of the lengths of two successive chords. Finally, we indicate some concrete applications for the computation of usual stereological parameters.     

Development and validation of a sensitive,simple, and rapid method for simultaneous quantitation of atorvastatin and its acid and lactone metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

The aim of the proposed work was to develop and validate a simple and sensitive assay for the analysis of atorvastatin (ATV) acid, ortho- and para-hydroxy-ATV, ATV lactone, and ortho- and para-hydroxy-ATV lactone in human plasma using liquid chromatography-tandem mass spectrometry. All six analytes and corresponding deuterium (d5)-labeled internal standards were extracted from 50 μL of human plasma by protein precipitation. The chromatographic separation of analytes was achieved using a Zorbax-SB Phenyl column (2.1 mm × 100 mm, 3.5 μm). The mobile phase consisted of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). All analytes including ortho- and para-hydroxy metabolites were baseline-separated within 7.0 min using a flow rate of 0.35 mL/min. Mass spectrometry detection was carried out in positive electrospray ionization mode, with multiple-reaction monitoring scan. The calibration curves for all analytes were linear (R ² ≥ 0.9975, n = 3) over the concentration range of 0.05–100 ng/mL and with lower limit of quantitation of 0.05 ng/mL. Mean extraction recoveries ranged between 88.6–111%. Intra- and inter-run mean percent accuracy were between 85–115% and percent imprecision was ≤ 15%. Stability studies revealed that ATV acid and lactone forms were stable in plasma during bench top (6 h on ice-water slurry), at the end of three successive freeze and thaw cycles and at −80 °C for 3 months. The method was successfully applied in a clinical study to determine concentrations of ATV and its metabolites over 12 h post-dose in patients receiving atorvastatin.     

Synthesis and characterization of coordination polymers prepared from Cu<Superscript>II</Superscript> and Ni<Superscript>II</Superscript> cyclam perchlorate and carmosine

Reaction of [Cu^II(cyclam)](ClO₄)₂ or [Ni^II(cyclam)](ClO₄)₂ in DMF with aqueous 4-hydroxy-3-(4-sulfonato-1-naphthylazo)naphthalen-1-sulfonate disodium salt (carmoisine) yielded coordination polymers {[Cu^II(cyclam)](carmoisine dianion)(H₂O)₅}n and powder {[Ni^II(cyclam)](carmoisine dianion)}_n, respectively (cyclam = 1,4,8,11-tetrazacyclotetradecane). They were characterized by powder X-ray diffraction, IR, Raman spectrometry and TGA.     

Synthesis, optical characterization, and electrochemical properties of isomeric tetraphenylbenzodifurans containing electron acceptor groups

Isomeric tetraphenylbenzodifuran systems, benzo[1,2-b:5,4]difuran and benzo[1,2-b:4,5]difuran, containing electron acceptor groups (CF(3), CN, and NO(2)) have been synthesized and studied. Their electronic absorption, fluorescence, two-photon absorption cross sections, and electrochemical properties were investigated. The absorption and emission maxima are red-shifted for the linear-conjugated systems in comparison with the corresponding isomer. Dual fluorescence was observed and the existence of a twisted intramolecular charge transfer state was confirmed by low-temperature emission experiments. Wide HOMO-LUMO energy gaps were obtained ranging from 2.53 to 3.28 eV. HOMO levels were found in the energy range of -6.03 to -6.63 eV while LUMO are within -2.55 to -3.52 eV.     

Convergence rate for Rényi-type continued fraction expansions

Periodica Mathematica Hungarica - This paper continues our investigation of Rényi-type continued fractions studied in Lascu and Sebe (A dependence with complete connections approach to...