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961.
Azadeh Kermanshahi Pour Orval A. Mamer David G. Cooper Milan Maric Jim A. Nicell 《Journal of mass spectrometry : JMS》2009,44(5):662-671
Metabolites from the biodegradation of a potential plasticizer 1,6‐hexanediol dibenzoate in the presence of n‐hexadecane as a co‐substrate by the common soil organism Rhodococcus rhodochrous were identified using GC/MS and Fourier transform mass spectroscopy (FTMS) techniques. Trimethylsilylation of compounds from the biodegradation broth permitted detection of the following metabolites: 1‐hexadecyl benzoate, 6‐benzoyloxyhexanoic acid, 4‐benzoyloxybutanoic acid, 6‐benzoyloxyhexan‐1‐ol and benzoic acid. The presence of these metabolites was confirmed by repeating the biodegradation with 1,6‐hexanediol di[2H5]benzoate, by measurement of their exact masses in FTMS and by comparison with available authentic materials. The results show that biodegradation of 1,6‐hexanediol dibenzoate by R. rhodochrous does not lead to the accumulation of persistent metabolites as has been reported for commercial dibenzoate plasticizers. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
962.
963.
964.
E Sola F Torres M V Jiménez J A López S E Ruiz F J Lahoz A Elduque L A Oro 《Journal of the American Chemical Society》2001,123(48):11925-11932
The substitution of a terminal hydride ligand in the complexes [Ir(2)(mu-H)(mu-Pz)(2)H(3)(L)P(i)Pr(3))(2)] (L = NCCH(3) (1) or pyrazole (3)) by chloride provokes a significant change in the lability of the L ligand, despite the fact that the substituted hydride and the L ligand lie in opposite extremes of the diiridium(III) complexes. Detailed structural studies of complex 3 and its chloro-trihydride analogue [Ir(2)(mu-H)(mu-Pz)(2)H(2)Cl(HPz)(P(i)Pr(3))(2)] (4) have shown that this behavior is a consequence of the transmission of ligand trans effects from one extreme of the molecule to the other, with the participation of the bridging hydride. Extended Hückel calculations on model diiridium complexes have suggested that such trans effect transmissions are due to the formation of molecular orbitals of sigma symmetry extended along the backbones of the complexes. This is also an expected feature for metal-metal bonded complexes. The feasibility of the transmission of ligand trans effects and trans influences through metal-metal bonds and its relevance to the understanding of both the reactivity and structures of metal-metal bonded dinuclear compounds have been substantiated through structural studies and selected reactions of the diiridium(II) complexes [Ir(2)(mu-1,8-(NH)(2)naphth)I(CH(3))(CO)(2)(P(i)Pr(3))(2)] (isomers 6 and 7) and their cationic derivatives [Ir(2)(mu-1,8-(NH)(2)naphth)(CH(3))(CO)(2)(P(i)Pr(3))(2)](CF(3)SO(3)) (isomers 8 and 9). 相似文献
965.
Amber L. Broadbent Jim M. Mullin Sarah L. Codd Jack D. Dockery Joseph D. Seymour 《Applied magnetic resonance》2012,42(1):137-152
Magnetic resonance microscopy and Ansys Fluent? computational fluid dynamics simulation have been used to classify Taylor vortex flows (TVF) for several single fluid and
axially stratified two-fluid systems in a vertically oriented Taylor–Couette device. A Rheo-NMR (nuclear magnetic resonance)
Couette system (Magritek Ltd, New Zealand) with a 1.05-mm gap was used to evaluate the transition from Couette flow to TVF
in 1.65 cSt silicone oil, 1 cSt deionized water, and 0.65 cSt silicone oil. The rotation rate at which instability onset occurred
agreed between experiment and simulation, as did the critical wavelength. Velocities were mapped for axially stratified two-fluid
systems. The vortex containing the two-fluid interface was found to form with a significantly longer wavelength than that
observed in the pure fluids. For experiments and simulations in the TVF regime, a region with no secondary flows was found
at the interface, indicating interface stabilization by surface tension forces. 相似文献
966.
967.
Richard M. Gauld Dr. Ross McLellan Dr. Alan R. Kennedy Dr. Jim Barker Dr. Jacqueline Reid Prof. Dr. Robert E. Mulvey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(64):14728-14734
Though alkali metal NacNac (β-diketiminate) complexes have been utilised in synthesis as NacNac-transfer agents, studies of them in their own right with small molecules are exceptionally rare. Here, the lithium compound of the common 2,6-diisopropylphenyl-β-methyldiketiminate [NacNac(Dipp, Me)] ligand is investigated with carbon dioxide and isocyanates. In all four cases reaction occurs at the backbone γ-C atom of the NacNac ligand, which redistributes electronically into a diimine. Insertion of CO2 gives an eight-atom carboxylate (Li2O4C2) ring at the γ-C site in a dimer. Insertion of tBuNCO gives a secondary amide at the γ-C site in a monomer with TMEDA chelating lithium. Double insertion of tBuNCO and (adventitious) oxygen gives a dimer with a (LiO)2 central core involving the latter source. Insertion of less bulky (iPrNCO) gives a dimer with dimerisation through the C=O bonds of the emergent secondary amide function. 相似文献
968.
969.
Nicolas Villarino Sherry Cox Jason Yarbrough Tomás Martín‐Jiménez 《Biomedical chromatography : BMC》2010,24(8):908-913
Carboplatin is an antineoplastic drug administered to treat different tumoral conditions in canine oncology. The objective of this study was to validate a high‐performance chromatographic (HPLC) method which could be applied in canine pharmacokinetic studies. Following ultrafiltration using a Centrifree device, standards, quality controls and plasma samples were separated by isocratic reversed‐phase HPLC on an Inertsil ODS‐2 (250 × 4.6 mm i.d.) analytical column and quantified using UV detection at 220 nm. The mobile phase was potassium phosphate (pH 4.5), with a flow‐rate of 1.0 mL/min. The procedure produced a linear curve (r2 > 0.999) over the concentration range 1–200 μg/mL. The lower limit of quantification was 1 μg/mL. The intra‐assay and inter‐assay precision was ~90%. The overall recovery was ~90%. The method was illustrated with a preliminary pharmacokinetic analysis on nine dogs treated with carboplatin at our hospital. Carboplatin disposition followed a monocompartmental structure in dogs and was characterized by a short half‐life (50 min). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
970.
P. Jiménez Guerra M. A. Melguizo M. J. Muñoz-Bouzo 《Journal of Optimization Theory and Applications》2009,142(2):343-354
In the context of vector optimization, several results are stated mainly about the continuity and the derivability of a conic
set-valued map (the polar conic function) having a close relation with the positive efficient points, the ideal points and
other distinguished elements of the efficient line. The contingent cone to the set of the general positive quasiefficient
points at a point x
0 is also related with the frontier of the dual cone of the image at x
0 of the polar conic function.
This work was partially supported by Grant SEJ2006–15401–C04–02 of Spanish Ministerio de Ciencia y Tecnología and Grant S-0505/tic/0230-D3
of Comunidad Autónoma de Madrid. The authors are grateful to the referees for suggestions which led to improving the paper. 相似文献