References of "De Pauw, Edwin"
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See detailIdentification of Potential Biomarkers of Human Peripheral Blood Mononuclear Cell intoxication by dioxins
Brenez, Cécile; Cellier, Nicolas; Gerkens, Pascal et al

in Organohalogen Compounds (2005), 67

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See detailRemoval of PCDD/Fs and DL-PCBs from fish oil by activated carbon: Compliance with European Legislation
Eppe, Gauthier ULg; Carbonnelle, Sophie; Hellebosch, Laeticia et al

in Organohalogen Compounds (2005), 67

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See detailDecrease of serum concentrations of dioxins and PCBs in Belgium between 2000 and 2003
Fierens, Sébastien; Heilier, Jean-François; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2005), 67

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See detailFast gas-phase hydrogen/deuterium exchange observed for a DNA G-quadruplex
Gabelica, Valérie ULg; Rosu, Frédéric ULg; Witt, Matthias et al

in Rapid Communications in Mass Spectrometry : RCM (2005), 19(2), 201-208

The gas-phase hydrogen/deuterium (H/D) exchange kinetics of DNA G-quadruplexes has been investigated using Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The quadruplex [(TGGGGT)(4 ... [more ▼]

The gas-phase hydrogen/deuterium (H/D) exchange kinetics of DNA G-quadruplexes has been investigated using Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The quadruplex [(TGGGGT)(4).3NH(4)(+)] undergoes very fast H/D exchange, in both the positive and in the negative ion modes, compared to DNA duplexes and other quadruplexes tested, and compared to the corresponding single-stranded TGGGGT. Substitution of NH4+ for K+ did not alter this fast H/D exchange, indicating that the hydrogens of the ammonium ions are not those exchanged. However, stripping of the interior cations of the quadruplex by source collision-induced dissociation (CID) in the positive ion mode showed that the presence of the inner cations is essential for the fast exchange to be possible. Molecular dynamics simulations show that the G-quadruplex is very rigid in the gas phase with NH4+ ions inside the tetrads. We suggest that the fast H/D exchange is favored by this rigid quadruplex conformation. This example illustrates that the concept that compact DNA structures exchange H for D slower than unfolded ones is a misconception. Copyright (C) 2004 John Wiley Sons, Ltd. [less ▲]

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See detailInternal energy and fragmentation of ions produced in electrospray sources
Gabelica, Valérie ULg; De Pauw, Edwin ULg

in Mass Spectrometry Reviews (2005), 24(4), 566-587

This review addresses the determination of the internal energy of ions produced by electrospray ionization (ESI) sources, and the influence of the internal energy on analyte fragmentation. A control of ... [more ▼]

This review addresses the determination of the internal energy of ions produced by electrospray ionization (ESI) sources, and the influence of the internal energy on analyte fragmentation. A control of the analyte internal energy is crucial for several applications of electrospray mass spectrometry, like structural studies, construction of reproducible and exportable spectral libraries, analysis of non-covalent complexes. Sections II and III summarize the Electrospray mechanisms and source design considerations which are relevant to the problem of internal energy, and Section IV gives an overview of the interrelationships between ion internal energy, reaction time scale, and analyte fragmentation. In these three sections we tried to make the most important theoretical elements understandable by all ESI users, and their understanding requires a minimal background in physical chemistry. We then present the different approaches used to experimentally determine the ion internal energy, as well as various attempts in modeling the internal energy uptake in electrospray sources. Finally, a tentative comparison between electrospray and other ionization sources is made. As the reader will see, although many reports appeared on the subject, the knowledge in the field of internal energy of ions produced by soft ionization sources is still scarce, because of the complexity of the system, and this is what makes this area of research so interesting. The last section presents some perspectives for future research. [less ▲]

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See detailSteatosis-induced proteomic changes in liver mitochondria evidenced by two-dimensional differential in-gel electrophoresis
Douette, Pierre ULg; Navet, Rachel ULg; Gerkens, Pascal et al

in Journal of Proteome Research (2005), 4(6), 2024-2031

Steatosis encompasses the accumulation of droplets of fats into hepatocytes. In this work, we performed a comparative analysis of mitochondrial protein patterns found in wild-type and steatosis-affected ... [more ▼]

Steatosis encompasses the accumulation of droplets of fats into hepatocytes. In this work, we performed a comparative analysis of mitochondrial protein patterns found in wild-type and steatosis-affected liver using the novel technique two-dimensional differential in-gel electrophoresis (2D-DIGE). A total of 56 proteins exhibiting significant difference in their abundances were unambiguously identified. Interestingly, major proteins that regulate generation and consumption of the acetyl-CoA pool were dramatically changed during steatosis. Many proteins involved in the response to oxidative stress were also affected. [less ▲]

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See detailProteomic approach to investigate plant – aphid interactions
Francis, Frédéric ULg; Gerkens, Pascal; De Pauw, Edwin ULg et al

Conference (2005)

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See detailFactors influencing the PCDD/F levels in plasma of Belgian blood donors
Debacker, Neomi; Van Wouwe, Nathalie; Sasse, André et al

in Organohalogen Compounds (2005)

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See detailRemoval of dioxins and PCBs in fish oils: comparison of CALUX and GC-HRMS results
Carbonnelle, Sophie; Eppe, Gauthier ULg; Hellebosch, Laeticia et al

in Organohalogen Compounds (2005)

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See detailMeasurement of Dioxins and WHO-PCBs in Foodstuffs using GCxGC-IDTOFMS
Focant, Jean-François ULg; De Pauw, Edwin ULg

Scientific conference (2004, December)

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See detailPerformances and limitations of the HRMS method for dioxins, furans and dioxin-like PCBs analysis in animal feedingstuffs Part I: Results of an inter-laboratory study
Eppe, Gauthier ULg; Cofino, W. P.; De Pauw, Edwin ULg

in Analytica Chimica Acta (2004), 519(2), 231-242

The European strategy for dioxin monitoring of the food chain has defined high-resolution gas chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) method as the confirmatory method that ... [more ▼]

The European strategy for dioxin monitoring of the food chain has defined high-resolution gas chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS) method as the confirmatory method that can provide reliable and comparable results at sub-parts per trillion (ppt) level. This paper describes the first inter-laboratory study on dioxins, furans and dioxin-like PCBs by HRGC/HRMS method in animal feedingstuffs. Two different statistical approaches (ISO 5725 and Cofino's statistics) were used for the statistical evaluation. For this particular study, the performances of the HRGC/HRMS method seem to be congener-independent in repeatability and reproducibility conditions over a concentration range covering more than four orders of magnitude. Results clearly show the effect of precision loss below 0.1 ppt level per congener in repeatability conditions and below 0.2 ppt level per congener in reproducibility conditions. LODs reported by the laboratories give median values of 0.02 ng/kg for most of the toxic congeners. Relative standard deviation between the laboratories' mean values using upper-bound approach for TEQ calculation is 6.2%, more than twice the maximum level set at 0.75 ng TEQ/kg of product. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailPerformances and limitations of the HRMS method for dioxins, furans and dioxin-like PCBs analysis in animal feedingstuffs Part II: Does it comply with the European pro-active approach?
Eppe, Gauthier ULg; Maghuin-Rogister, Guy ULg; De Pauw, Edwin ULg

in Analytica Chimica Acta (2004), 519(2), 243-253

Based on the results obtained from the inter-laboratory study in Part 1, different approaches for detection and quantification limits are evaluated and discussed. An overview of the most commonly used ... [more ▼]

Based on the results obtained from the inter-laboratory study in Part 1, different approaches for detection and quantification limits are evaluated and discussed. An overview of the most commonly used concepts and terminologies in analytical chemistry is presented with the aim of establishing a link between them. Whatever the method used by laboratories for detection limit assessment, the median LOD value reported for the less chlorinated PCDD/Fs (i.e. 0.02 ng/kg) is in good agreement with the values recalculated using the inter-laboratory data. For LOQ the Eurachem approach based on a pre-established percentage of repeatability RSD appears to be. suitable. The study shows that a pre-established RSDr of 20% is recommended in order to achieve an acceptable LOQ of 0.05 ng/kg per congener. The 20% value seems to be sufficiently low to act tolerable RSD close to maximum limits. Furthermore, the repeatability and the reproducibility standard deviation against parts-per-trillion congener levels has been modeled by inverse first order functions. This congener precision model provides an interesting tool to subsequently assess the performances of the method in TEQ close to regulatory limits. Finally, the paper discusses two different ways of reporting and interpreting the results to assess compliance against statutory limits. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailAutomated sample preparation-fractionation for the measurement of dioxins and related compounds in biological matrices: a review
Focant, Jean-François ULg; Pirard, Catherine ULg; De Pauw, Edwin ULg

in Talanta (2004), 63(5), 1101-1113

This article reviews some of the recent developments in the extraction and clean-up areas of biological samples dedicated to dioxin and related compound analysis. A brief introduction on the major dioxin ... [more ▼]

This article reviews some of the recent developments in the extraction and clean-up areas of biological samples dedicated to dioxin and related compound analysis. A brief introduction on the major dioxin contamination events, which have occurred in the food chain, is given to illustrate the need of fast high throughput methods in case of crises. The emphasis of this paper is the method development based upon reliable instrumental extraction techniques for rapid sample processing and automation such as; supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), pressurized liquid extraction (PLE) and, solid-phase extraction (SPE). The PLE and SPE are also discussed in conjunction with the use of a multi-column automated clean-up system that can accommodate up to 5 g of extracted lipids. The fractionation in sub-groups of analytes during the clean-up process allows the isolation of various types of toxicants from a single sample and illustrates the versatility of the system. An integrated extraction and clean-up instrument is finally presented in terms of feasibility and attainable sample turnover for the parallel processing of liquid and solid biological samples. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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