A rapid LC-MS/MS method for determination of urinary EtG and application to a cut-off limit study

Ethyl glucuronide (EtG) is a metabolite and a specific marker of alcohol consumption that can be detected days after the complete elimination of alcohol after drinking. A rapid, simple, and sensitive LC-ESI-MS/MS method for the determination of urinary ethyl glucuronide was developed and fully validated in accordance with analytical standards, using the C₁₈ column. The whole process including sample preparation and LC-MS/MS lasted 10 min. A comprehensive validation including HorRat, measurement uncertainty, system suitability and intermediate precision calculations among analysts, and a cut-off limit study was performed. The method was applied to real samples and a cutoff limit determination study. The LOD and LOQ (using the IUPAC and Eurachem methods) were determined as 104.21 ng mL^?1 and 165.00 ng mL^?1. A cut-off limit of ≈ 818 ng mg^?1 (normalised to creatinine) was found for urinary EtG. The results showed that the cut-off limits currently in use should be re-considered in further studies and standardised on a global scale. Normalisation to creatinine is important because of the risk of the dilution of urine intentionally or with a change of diet. The concentrations of real samples from subjects who had consumed alcohol were successfully predicted using this method, after zero HS-GC/MS results of urine alcohol concentration.     

Reversible Calcium(II)‐Ion Binding through an Apparent pKa Shift of Thermosensitive Block‐Copolymer Micelles

There is an increasing need for smart materials capable of removing multivalent ions from aqueous streams without the inconvenience of brine regeneration as in ion‐exchange processes. Herein, we present a thermoresponsive micellar system consisting of polystyrene–poly(methoxy diethyleneglycol acrylate) block copolymer surfactants modified with carboxylic acid end groups (PS‐PMDEGA‐COOH) that can be used to switch between the adsorption and desorption of divalent calcium(II) cations by a mild temperature trigger, thus providing a new type of thermoregenerable ion‐adsorbing materials. The switch of calcium(II)‐binding capacity is demonstrated to result from a shift in the pK_a value of the carboxylic acid groups by the collapse and redissolution of the PMDEGA block and the associated change in local polarity.     

Design of multiple-target chemoprobe: “naked-eye” colorimetric recognition of Fe3+ and off–on fluorogenic detection for Hg2+ and its on-site applications

A novel multiple-target chemoprobe (E)-N′-((9-pentyl-9H-carbazole-3-yl)methylene)thiophene-2-carbohydrazide (CTH) was designed, successfully synthesized and employed for the detection of Hg²⁺ and Fe³⁺ ions as off–on fluorometric and colorimetric responses, respectively, in H₂O/DMF (10/90, v/v, Britton–Robinson buffer, pH 7) medium. The chemoprobe CTH demonstrated high sensitivity towards Hg²⁺ and Fe³⁺, among wide range of competitive cations with low recognition limits of 5.1 nM and 5.89 µM, respectively. The complexes of the chemoprobe CTH were synthesized and characterized by ¹H-NMR titration, FT-IR and MALDI-TOF MS techniques, which confirmed the binding stoichiometries and the possible sensing mechanisms, were suggested based on the hydrolysis reaction of C=N group. The practical utility of the chemoprobe CTH was revealed in quantification of the trace amounts of Hg²⁺ and Fe³⁺ in water samples. Also, a silica-coated test paper was used for the fluorescent monitoring of Hg²⁺, providing a novel approach for the quantitative and on-site detection in real samples. More excitingly, a smartphone application was employed for the visual detection of Fe³⁺ by recognizing the RGB (red/green/blue) of the chemoprobe CTH solution.

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Effects of different formulation PEDOT:PSS hole transport layers on photovoltaic performance of organic solar cells

In this study, the effects of the various types of PEDOT:PSS with different conductivities on the photovoltaic parameters of organic solar cells were investigated. The performances of five various commercially available PEDOT:PSS with formulations such as FET, PT2, PH1000, PH500 and PH were compared. It was observed that the device employing PH1000 as an interlayer between ITO and the active layer exhibited the highest photovoltaic performance as compared to other devices with FET, PT2, PH500 and PH. Copyright © 2015 John Wiley & Sons, Ltd.     

Distinguished Connections on Finsler Algebroids

Considering the prolongation of a Lie algebroid,the authors introduce Finsler algebroids and present important geometric objects on these spaces.Important endomorphisms like conservative and Barthel,Cartan tensor and some distinguished connections like Berwald,Cartan,Chern-Rund and Hashiguchi are introduced and studied.     

One‐Component Bimolecular Photoinitiating Systems, 2

The compounds 2‐thioxanthone‐thioacetic acid and 2‐(carboxymethoxy)thioxanthone, bimolecular photoinitiators for free radical polymerization, are synthesized and characterized. Their capability to act as initiators for the polymerization of methyl methacrylate was examined. The postulated mechanism is based on the intermolecular electron‐transfer reaction of the excited photoinitiator with the sulfur or oxygen atom of the ground state of the respective photoinitiator followed by decarboxylation. The resulting alkyl radicals initiate the polymerization.

Structures of the photoinitiators.