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941.
Guetens G Prenen H De Boeck G Van Dongen W Esmans E Lemière F van Oosterom AT Schöffski P de Bruijn EA 《Journal of chromatography. A》2005,1082(1):2-5
The development of an on-column focusing gradient capillary LC method coupled to tandem mass spectrometry (quadrupole-linear ion trap) for the quantitative determination of the anticancer agent ZD1839 (Gefitinib, Iressa) in blood plasma is described. Plasma samples (0.2 ml) were extracted with methyl tert-butyl ether. The analytes of interest, ZD1839 and the internal standard [(2)H8]ZD1839 (ZD1839-d8) were eluted on a 50 mm x 1 mm, 5 microm particle size, capillary ODS Hypersil column using an aqueous ammonium acetate gradient at 40 microl/min. Mass spectrometric detection was performed by a Q-Trap tandem mass spectrometer with electrospray positive ionisation, and monitored in the multiple reaction monitoring transitions 447 >128 and 455 >136, respectively. The limit of quantification of ZD18395 was 0.1 ng/ml. The method proved to be robust, allowing quantification of ZD1839 with sufficient precision, accuracy and sensitivity. 相似文献
942.
Le Bihan T Pelletier D Tancrède P Heppell B Chauvet JP Gicquaud CR 《Journal of colloid and interface science》2005,288(1):88-96
It is generally admitted that actin filaments are anchored to a membrane by membranar actin-binding-proteins. However, we found that actin may also interact directly with membrane phospholipids. The actin-phospholipid complex has been investigated at the air-water interface using a film balance technique. In order to probe the effect of the phospholipid headgroup on the actin-phospholipid interaction, we focus mainly on phospholipids that have the same acyl chain length but different headgroups. For all the phospholipids, the apparent area per molecule (the total surface divided by the number of lipid molecules) increases after the injection of the protein into the subphase, which suggests an intercalation of actin between the phospholipid molecules. This effect seems to be more important for DMPE and DMPS than for DMPG, suggesting that the headgroup plays an important role in this intercalation. The critical surface pressure associated to the liquid expanded-liquid condensed (LE-LC) phospholipid transition increases with the concentration of G-actin and thus suggests that G-actin acts as an impurity, simply competing as a surfactant at the air-water interface. On the other hand, F-actin affects the LE to LC transition of phospholipids differently. In this case, the LE to LC transition is broader and F-actin slightly decreases the critical surface pressure, which suggests that electrostatic interactions are involved. 相似文献
943.
M.?L.?Di?VonaEmail author M.?Trombetta S.?Dirè P.?Egger C.?D’Ottavi S.?Licoccia 《Journal of Sol-Gel Science and Technology》2005,35(2):151-157
Diphenylsilanediol (DPDO) reacts with triethoxysilane (TREOS) in anhydrous conditions and in the presence of pyridine, to form complex mixtures of linear and cyclic condensation products which were identified by 29Si NMR and ATR/FTIR spectroscopies. The distribution of products can be varied by modifying the reaction conditions. Spectroscopic analysis allowed to identify the optimal reagents ratio and concentration for the production of hetero-condensation products minimizing the number of residual –OH groups whose presence would affect the performance of optical waveguides based on the synthesised nano building blocks. 相似文献
944.
Novikov A Caroff M Della-Negra S Depauw J Fallavier M Le Beyec Y Pautrat M Schultz JA Tempez A Woods AS 《Rapid communications in mass spectrometry : RCM》2005,19(13):1851-1857
A Au-Si liquid metal ion source which produces Au(n) clusters over a large range of sizes was used to study the dependence of both the molecular ion desorption yield and the damage cross-section on the size (n = 1 to 400) and on the kinetic energy (E = 10 to 500 keV) of the clusters used to bombard bioorganic surfaces. Three pure peptides with molecular masses between 750 and 1200 Da were used without matrix. [M+H](+) and [M+cation](+) ion emission yields were enhanced by as much as three orders of magnitude when bombarding with Au(400) (4+) instead of monatomic Au(+), yet very little damage was induced in the samples. A 100-fold increase in the molecular ion yield was observed when the incident energy of Au(9) (+) was varied from 10 to 180 keV. Values of emission yields and damage cross-sections are presented as a function of cluster size and energy. The possibility to adjust both cluster size and energy, depending on the application, makes the analysis of biomolecules by secondary ion mass spectrometry an extremely powerful and flexible technique, particularly when combined with orthogonal time-of-flight mass spectrometry that then allows fast measurements using small primary ion beam currents. 相似文献
945.
946.
Van den Driessche B Lemière F Witters E Van Dongen W Esmans EL 《Rapid communications in mass spectrometry : RCM》2005,19(4):449-454
Calf thymus DNA was treated with melphalan, a nitrogen mustard, and the formation of melphalan cross-linked DNA adducts was investigated. These cross-linked adducts could not be detected either in the enzymatically or in the thermally generated DNA hydrolysates. However, a search for DNA cross-linked adducts in the hydrolysates obtained under acidic conditions revealed the presence of different types of cross-links, mainly containing an adenine moiety. These results are very important because they show that the detection of cross-links is dependent on the hydrolytic procedure used and that these cross-linked adducts are formed under totally different reaction conditions from those in in vivo situations. This can explain the very low abundance or even the absence of cross-linked adducts in nitrogen mustard treated animals. The generally accepted theory that the anti-cancer activity of bifunctional mustards such as melphalan is due to cross-linking of DNA strands remains therefore from our point of view questionable. 相似文献
947.
Etienne M Grosso D Boissière C Sanchez C Walcarius A 《Chemical communications (Cambridge, England)》2005,(36):4566-4568
We provide the first electrochemical evidence of permeability changes in continuous mesoporous TiO2 thin film electrodes induced by nanocrystallisation. 相似文献
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