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21.
A simple, rapid and sensitive high-performance liquid chromatography method was developed for the analysis of the sesquiterpene lactone 15-deoxygoyazensolide (LAC15-D) in rat plasma samples. The chromatographic separation was achieved on a LiChrospher® RP18 column using methanol:water (50:50, v/v) containing 0.6% acetic acid as mobile phase, at a flow rate of 0.7 mL min−1. UV detection was carried out at 270 nm. Phenytoin was used as internal standard. Prior to the analysis, the rat plasma samples were submitted to liquid-liquid extraction with dichloromethane. The mean absolute recoveries were 73% with R.S.D. values lower than 3.5. The method was linear over the 6.0-2000 ng mL−1 concentration range and the quantification limit was 6.0 ng mL−1. Within-day and between-day assay precision and accuracy were studied at three concentration levels (15, 300 and 480 ng mL−1) and were lower than 15%. The validated method was used to measure the plasmatic concentration of LAC15-D in rats that received a single intraperitoneal dose of 30 mg kg−1. 相似文献
22.
Raja Ramamoorthy Govindaraj Maheswari Antony Maggie Dayana Krishnan Karthika Velusamy Eswaramoorthi Sambandam Anandan Subbaiah Manoharan Rayar Victor Williams 《Journal of Solid State Electrochemistry》2017,21(3):891-903
Journal of Solid State Electrochemistry - The objective of the present work was to study the change in efficiency of dye-sensitized solar cells due to introduction of a thin blocking composite... 相似文献
23.
Beer flavor stability is greatly influenced by external temperature, vibrations, and longer delivery times. The present study assessed the impact of transport and storage conditions on staling aldehyde evolution in lager beers across five sample groups (fresh, transport, and storage simulation, and their controls), which differed in their bottle opening system (either crown cap or ring pull cap). Maritime transport conditions (45 days of travel, vibrations of 1.7 Hz, and warm temperatures (21–30 °C)) were simulated, together with storage time in a distributor’s warehouse (up to 75 days). The results revealed that the concentration of Strecker aldehydes increased more quickly after transport and storage simulation in beer bottles with the ring pull cap opening system, and the contents of 2-methylpropanal and 3-methylbutanal, in particular, were up to three times higher. Benzaldehyde content also increased significantly, by 33% on average, in these samples. Hexanal was only found in beers with a ring pull cap that underwent transport simulation. Further storage after transport simulation significantly reduced the content of 2-methylpropanal, 3-methylbutanal, and hexanal, by 73%, 57%, and 43%, respectively, suggesting the formation of a bound state. 5-hydroxymethylfurfural was continuously increased by 78.5% and 40.5% after the Transport and Transport & Storage simulations, respectively. Transport conditions lead to a slight increase, of 0.6 EBC units, in beer color. 相似文献
24.
Hanying Zhao S. Dayana Argoti Brendan P. Farrell Devon A. Shipp 《Journal of polymer science. Part A, Polymer chemistry》2004,42(4):916-924
Polymer–silicate nanocomposites were synthesized with atom transfer radical polymerization (ATRP). An ATRP initiator, consisting of a quaternary ammonium salt moiety and a 2‐bromo‐2‐methyl propionate moiety, was intercalated into the interlayer spacings of the layered silicate. Subsequent ATRP of styrene, methyl methacrylate, or n‐butyl acrylate with Cu(I)X/N,N‐bis(2‐pyridiylmethyl) octadecylamine, Cu(I)X/N,N,N′,N′,N″‐pentamethyldiethylenetriamine, or Cu(I)X/1,1,4,7,10,10‐hexamethyltriethylenetetramine (X = Br or Cl) catalysts with the initiator‐modified silicate afforded homopolymers with predictable molecular weights and low polydispersities, both characteristics of living radical polymerization. The polystyrene nanocomposites contained both intercalated and exfoliated silicate structures, whereas the poly(methyl methacrylate) nanocomposites were significantly exfoliated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 916–924, 2004 相似文献
25.
Manuel Souto Dayana C. Morales Judith Guasch Imma Ratera Concepció Rovira Anna Painelli Jaume Veciana 《Journal of Physical Organic Chemistry》2014,27(6):465-469
A comparative analysis of the physicochemical properties of different donor–acceptor dyads, based on a perchlorotriphenylmethyl radical acceptor subunit linked through a vinylene π‐bridge to ferrocene derivatives (1–3) or a tetrathiafulvalene (4) donor subunit, is presented. Intramolecular electron transfer and charge delocalization of these donor–acceptor dyads are discussed on the basis of data obtained in solution by cyclic voltammetry, UV–Vis near‐infrared, and electron spin resonance spectroscopies. Bistability in the crystalline phase is also discussed on the basis of the results provided by X‐ray diffraction analysis and temperature‐dependent Mössbauer spectra. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
26.
Jhanis J. Gonzalez Alberto Fernandez Dayana Oropeza Xianglei Mao Richard E. Russo 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
This paper demonstrates the feasibility of performing bulk chemical analysis based on laser ablation for good lateral resolution with only nominal mass ablated per pulse. The influence of repetition rate (1–1000 Hz) and scan speed (1–200 µm/s) using a low energy (30 µJ) and a small spot size (~ 10 µm) UV-femtosecond laser beam was evaluated for chemical analysis of silica glass samples, based on laser ablation sampling and inductively coupled plasma mass spectrometry (ICP-MS). Accuracy to approximately 14% and precision of 6% relative standard deviation (RSD) were measured. 相似文献
27.
Briceño A Leal D Atencio R Díaz de Delgado G 《Chemical communications (Cambridge, England)》2006,(33):3534-3536
An unprecedented example of supramolecular isomerism based on 2D hydrogen-bonded multi-component networks that leads to the preparation of different photoproducts via a topochemical transformation is reported. 相似文献