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91.
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94.
Hu Zhou Weimin Hou Jean-Philippe Lambert Daniel Figeys 《Analytical and bioanalytical chemistry》2010,397(8):3421-3430
The enrichment and processing of proteomic samples prior to multi-dimensional chromatography remain a challenge in ‘gel-free’
proteomics. We previously reported the development of a microfluidic device called the “proteomic reactor” that relied on
enriching proteins by using strong cation exchange (SCX) followed by trypsin digestion in an interstitial volume as little as 50 nL. Here, we report a novel proteomic reactor
that is based on polymeric strong anion exchange (SAX) material to analyse proteomic samples. We also compare the performance of the SAX proteomic reactor to our previously
reported SCX proteomic reactor for analysing complex yeast proteomes. Our results indicate that the SAX protein reactor preferentially
identifies more acidic peptides and proteins compared to the SCX reactor. We show that the SAX and SCX reactors are complementary
and that their combination increases the number of unique peptides and proteins identified by 50%. Furthermore, we show that
the number of protein identified can be increased further by up to 40% using different proteolytic enzymes on the proteomic
reactor. 相似文献
95.
Fanny Kieken Gaud Pinel Jean-Philippe Antignac Fabrice Monteau Anne Christelle Paris Marie-Agnès Popot Yves Bonnaire Bruno Le Bizec 《Analytical and bioanalytical chemistry》2009,394(8):2119-2128
Despite the worldwide existing regulation banning the use of the recombinant equine growth hormone (reGH) as growth promoter,
it is suspected to be used in horseracing to improve performances. Various analytical methods previously developed to screen
for its misuse have encountered some limitations in terms of detection timeframes, in particular during the first days following
reGH administration. A novel strategy involving the characterization of global metabolomic fingerprints in urine samples of
non-treated and reGH-treated horses by liquid chromatography–electrospray–high-resolution mass spectrometry (LC-ESI-HRMS)
is described and assessed in this paper in order to develop a new screening tool for growth hormone abuse in horseracing.
The strategy involves a limited sample preparation of the urine samples and the use of appropriate software for data processing
and analysis. As preliminary work, reproducibility of both sample preparation and mass spectrometry (MS) measurements was
evaluated in order to demonstrate the reliability of the method. Application of the developed protocol on two horses demonstrated
the suitability of the developed strategy and preliminary results showed significant modifications of the metabolome after
treatment with reGH.
相似文献
96.
In this paper we study iterative algorithms for finding a common element of the set of fixed points of κ-strict pseudocontractions or finding a solution of a variational inequality problem for a monotone, Lipschitz continuous mapping. The last problem being related to finding fixed points of pseudocontractions. These algorithms were already studied in [G.L. Acedo, H.-K. Xu, Iterative methods for strict pseudo-contractions in hilbert spaces, Nonlinear Analysis 67 (2007) 2258–2271] and [N. Nadezhkina, W. Takahashi, Strong convergence theorem by a hybrid method for nonexpansive mappings and lipschitz-continuous monotone mappings, SIAM Journal on Optimization 16 (4) (2006) 1230–1241] but our aim here is to provide the links between these known algorithms and the general framework of -class algorithms studied in [H.H. Bauschke, P.L. Combettes, A weak-to-strong convergence principle for fejér-monotone methods in hilbert spaces, Mathematics of Operations Research 26 (2) (2001) 248–264]. 相似文献
97.
98.
Cariou R Antignac JP Debrauwer L Maume D Monteau F Zalko D le Bizec B Andre F 《Journal of chromatographic science》2006,44(8):489-497
The chromatographic and mass spectrometric (MS) behaviors of 49 polybrominated diphenylether (PBDE) homologues toward various techniques is investigated. Special attention is paid to chromatographic separation, ionization processes, and signal acquisition modes. Different liquid chromatographic (LC) separation systems and gas chromatographic (GC) temperature program parameters are studied. For LC-MS experiments, the ionization efficiencies of electrospray, atmospheric pressure chemical ionization, and atmospheric pressure photoionization (APPI) are evaluated. For GC-MS experiments, negative chemical ionization with ammonia as reagent gas as well as negative and positive electron impact (EI) ionization are studied. Thus, fragmentation pathways of PBDEs are investigated, with the main objective being to determine the sensitivity/specificity balance of each tested technique with respect to their potential respective application (parent compound focusing, metabolite identification, and screening of analogue compounds). Finally, performances of the different tested techniques are compared and evaluated in terms of detection limits on standard solutions for each homologue group. In terms of ionization, EI remains the best compromise between sensitivity and specificity with possible complementary applications in MS-MS and high-resolution MS. Nevertheless, APPI appears to be a promising alternative. 相似文献
99.
Palladium-catalyzed tandem multifunctional reactions leading to the synthesis of substituted biaryl molecules have been developed including tandem Heck-direct arylation and tandem-sequential Heck-direct arylation-hydrogenation. These reactions occur in good yield and have been employed in the synthesis of a cytotoxic biaryl compound. 相似文献
100.
Sub-ppm multi-gas photoacoustic sensor 总被引:1,自引:0,他引:1
Besson JP Schilt S Thévenaz L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(5):899-904
A photoacoustic multi-gas sensor using tuneable laser diodes in the near-infrared region is reported. An optimized resonant configuration based on an acoustic longitudinal mode is described. Automatic tracking of the acoustic resonance frequency using a piezo-electric transducer and a servo electronics is demonstrated. Water vapour, methane and hydrogen chloride have been measured at sub-ppm level in different buffer gas mixtures. The importance of the system calibration in presence of several diluting gases is discussed. Finally, trace gas measurements have been assessed and detection limits (signal-to-noise ratio=3) of 80 ppb at 1651.0 nm for CH(4), 24 ppb at 1368.6 nm for H(2)O and 30 ppb at 1737.9 for HCl have been demonstrated. 相似文献