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See detailComprehensive comparison of the chemical and structural characterization of landfill leachate and leonardite humic fractions
Tahiri, Abdelghani ULg; Richel, Aurore ULg; Destain, Jacqueline ULg et al

in Analytical and Bioanalytical Chemistry (2016), 408(7), 1917-1928

Humic substances (HS) are complex and heterogeneous mixtures of organic compounds that occur everywhere in the environment. They represent most of the dissolved organic matter in soils, sediments (fossil ... [more ▼]

Humic substances (HS) are complex and heterogeneous mixtures of organic compounds that occur everywhere in the environment. They represent most of the dissolved organic matter in soils, sediments (fossil), water, and landfills. The exact structure of HS macromolecules has not yet been determined because of their complexity and heterogeneity. Various descriptions of HS are used depending on specific environments of origin and research interests. In order to improve the understanding of the structure of HS extracted from landfill leachate (LHS) and commercial HS from leonardite (HHS), this study sought to compare the composition and characterization of the structure of LHS and HHS using elemental composition, chromatographic (high-performance liquid chromatography (HPLC)), and spectroscopic techniques (UV–vis, FTIR, NMR, and MALDI-TOF). The results showed that LHS molecules have a lower molecular weight and less aromatic structure than HHS molecules. The characteristics of functional groups of both LHS and HHS, however, were basically similar, but there was some differences in absorbance intensity. There were also less aliphatic and acidic functional groups and more aromatic and polyphenolic compounds in the humic acid (HA) fraction than in the fulvic acid (FA) and other molecules (OM) fractions of both origins. The differences between LHS and HHS might be due to the time course of humification. Combining the results obtained from these analytical techniques cold improve our understanding of the structure of HS of different origins and thus enhance their potential use. [less ▲]

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See detailA comprehensive density functional theory study of the key role of fluorination and dual hydrogen bonding in the activation of the epoxide/CO2 coupling by fluorinated alcohols
Alves, Margot ULg; Méreau, Raphaël; Grignard, Bruno ULg et al

in RSC Advances (2016), 6(43), 36327-36335

The activation mechanism of the CO2/propylene oxide coupling catalysed by a bicomponent organocatalyst combining the use of TBABr with (multi)phenolic or fluorinated hydrogen bond donors (HBDs) was ... [more ▼]

The activation mechanism of the CO2/propylene oxide coupling catalysed by a bicomponent organocatalyst combining the use of TBABr with (multi)phenolic or fluorinated hydrogen bond donors (HBDs) was investigated using the Density Functional Theory (DFT). Thus, it was shown that increasing the number of electron withdrawing trifluoromethyl substituents in HBDs strengthens their proton donor capability and allows a better stabilization by hydrogen bonding of the intermediates and transition states. In addition, the high efficiency of fluorinated monoalcohol activators is related to a dual hydrogen bonding mechanism by two fluorinated molecules that cooperatively contribute to the CO2/propylene oxide coupling. [less ▲]

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See detailComprehensive geriatric assessment : are the interRAI Acute care and the Minimum geriatric screening tool complements or substitutes ?
Wellens, N; Deschodt, M; Boman, X et al

Conference (2010)

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See detailThe Comprehensive Meaning of Life in Bergson
Caeymaex, Florence ULg

in Campbell, Scott M. (Ed.) The Science, Politics, and Ontology of Life-Philosophy (2013)

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See detailComprehensive plasma profiling for the characterization of graft-versus-host disease biomarkers
De Bock, Muriel; BEGUIN, Yves ULg; Leprince, Pierre ULg et al

in Talanta (2014), 125

Acute graft-versus-host disease (aGVHD) remains a life-threatening complication of hematopoietic stem cell transplantation (HSCT), limiting its application. To optimize management of aGVHD and reduce ... [more ▼]

Acute graft-versus-host disease (aGVHD) remains a life-threatening complication of hematopoietic stem cell transplantation (HSCT), limiting its application. To optimize management of aGVHD and reduce therapy-related toxicity, early specific markers are needed. The main objective of this study was thus to uncover diagnostic biomarkers comparing plasma protein profiles of patients at the time of acute GVHD diagnosis and of patients undergoing HSCT without aGVHD. Additional analysis of samples taken 15 days before aGVHD diagnosis was also performed to evaluate the potential of the newly discovered biomarkers for early diagnosis. To extract a maximum of information from plasma samples, we used three complementary proteomic approaches, namely 2D-DIGE, SELDI-TOF-MS and 2D-LC-MSE. We identified and confirmed by means of a independent techniques, the differential expression of several proteins indicating significantly increased inflammation response and disturbance in the coagulation cascade. The variation of these proteins was already observed 15 days before GVHD diagnosis, suggesting the potential early detection of the disease before symptoms appearance. Finally, logistic regression analysis determines a composite biomarker panel comprising fibrinogen, fragment of fibrinogen beta chain, SAA, prothrombin fragments, apolipoprotein A1 and hepcidin that optimally discriminated patients with and without GVHD. The area under the receiver operating characteristic curve distinguishing these 2 groups was 0.95. [less ▲]

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See detailA comprehensive pollen- and tephra- based chronostratigraphic model for the Late Glacial and Holocene Period in the French Massif Central.
Juvigné, Etienne ULg; Bastin, B; Delibrias, G et al

in Quaternary International (1996), 34-36

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See detailComprehensive study about the characteristics of 80 dopaminergic agonist resistants prolactinomas
Vroonen, Laurent ULg; Tamagno, G.; Naves, L. et al

in European Neuroendocrine Association - Liège, 22-25 septembre 2010 (2010, September)

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See detailComprehensive study of chemically cross-linked PCLs presenting one-way and two-way shape memory properties
Defize, Thomas ULg; Riva, Raphaël ULg; Thomassin, Jean-Michel ULg et al

Poster (2014, May 26)

Poly(ε-caprolactone) (PCL), a semi-crystalline polymer, is one of the most widely studied polymers for the development of shape memory materials when chemically cross-linked. PCL presents several ... [more ▼]

Poly(ε-caprolactone) (PCL), a semi-crystalline polymer, is one of the most widely studied polymers for the development of shape memory materials when chemically cross-linked. PCL presents several advantages such as a melting transition temperature close to human body temperature, a high biocompatibility and is (bio)degradable. So, this polymer is highly relevant for both biomedical devices such as stents or resorbable suture wires and also for degradable packaging. However, after cross-linking, the material can not be reprocessed, preventing any reuse/recycling of the material. One of the purposes of this work is to find a solution to this major drawback, which would then allow, for example, to reshape packaging films after use or to recycle trimmings remaining after fabrication. Amongst current trends in the design of new polymer and composite materials, the use of organic reactions that are able to create and reversibly disrupt chemical bonds upon an external stimulus (temperature, irradiation,…) is currently gaining more and more attention as it can lead to applications in various areas such as remendable materials, drug delivery systems, stimulus-degrading materials or recyclable materials. Amongst all the reversible links described in the literature, thermally (4+2) reversible cycloadditions present interesting features such as the creation of robust bonds and well defined reversibility conditions. As an example, the application of furan/maleimide adducts as covalent link, which cycloreversion is largely favored in the range of temperature (90-120°C), is widely reported. Typically, PCL-based shape memory materials have been prepared by mixing a stoichiometric amount of diene-bearing and maleimide-bearing PCLs in a twin-screw mini-extruder at a temperature at which DA cycloaddition is largely disfavored, followed by the curing of the blend above the melting temperature to improve the kinetic of DA adduct formation. The shape memory properties of the materials have been studied by cyclic tensile thermomechanical analysis. As cross-linked PCLs are knowned to exhibit one-way and two-way shape memory properties, a comprehensive study of the shape memory of these materials has been carried out. Unfortunately, creep from shape memory cycle to cycle was observed in DMA for the furan/maleimide sample, certainly due to the reversibility of the adduct. In order to limit this creep effect, the substitution of the furan/maleimide adduct by a more stable adduct is required. The anthracene/maleimide system was tested because this adduct is more stable under stress than the furan/maleimide one. This contribution aims at reporting a complete study of one-way and two-way shape memory properties of the PCL cross-linked by anthracene/maleimide adduct. The shape memory properties of this material have been assessed by DMA and DSC experiments. [less ▲]

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See detailComprehensive study of the thermo-reversibility of Diels-Alder based PCL polymer networks
Defize, Thomas ULg; Thomassin, Jean-Michel ULg; Alexandre, Michaël et al

in Polymer (2016), 84

Chemical crosslinking is an efficient tool to improve or impart new properties to conventional polymers. Especially, crosslinking imparts remarkable shapeememory properties to poly-ε-caprolactone (PCL ... [more ▼]

Chemical crosslinking is an efficient tool to improve or impart new properties to conventional polymers. Especially, crosslinking imparts remarkable shapeememory properties to poly-ε-caprolactone (PCL) materials. Nevertheless, the processing of networks is often tricky due to infusibility and insolubility of cross-linked chains. Therefore, the synthesis of PCL networks including thermo-reversible crosslinks based on (retro)-Diels-Alder (DA) reaction were developed to allowpreserving the melt-processing while keeping the required mechanical properties below the melting point. This paper aims at studying in depth, such thermo-dependent network formation and stability. Besides conventional swelling experi- ments, Raman spectroscopy was revealed as a powerful tool to follow the formation of the DA adduct during the crosslinking. In combination with rheological measurements, we were able to determine the most appropriate temperatures to form the network (DA crosslinking) and to process it (retro-DA re- action) without degradation of the material. [less ▲]

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See detailA comprehensive system of control characters for Ancient Egyptian hieroglyphic text in Unicode
Nederhof, Mark-Jan; Rajan, Vinodh; Lang, Johannes et al

Computer development (2016)

We propose a comprehensive system of control characters for encoding Ancient Egyptian hieroglyphs in Unicode.

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See detailComprehensive therapy in osteoporosis using a single drug: From ADFR to strontium ranelate
Manette, Christine ULg; Collette, Julien ULg; Sarlet, Nathalie ULg et al

in Current Medicinal Chemistry (2006), 13(13), 1585-1590

In vitro, strontium ranelate increases collagen and non-collagenic proteins synthesis by mature osteoblast enriched cells. The effects of strontium ranelate on bone formation were confirmed as the drug ... [more ▼]

In vitro, strontium ranelate increases collagen and non-collagenic proteins synthesis by mature osteoblast enriched cells. The effects of strontium ranelate on bone formation were confirmed as the drug enhanced preosteoblastic cell replication. In the isolated rat osteoclast, a preincubation of bone slices with strontium ranclate induced a dose-dependent inhibition of the bone resorbing activity of treated rat osteoclast. Strontium ranelate dose-dependently inhibited preosteoclast differentiation. In a phase 11 dose ranging trial Strontium ranclate (500 mg. 1000 mg, 2000 mg/day) or placebo were given to 353 postmenopausal women with prevalent vertebral osteoporosis. At the conclusion of this 2-year study. the annual increase in lumbar BMD of the group receiving 2000 mg of strontium ranclate was + 7.3%. a significant increase in bone alkaline phosphatase, over a 6-month period and a significant decrease in N-telopeptide crosslinks throughout the 2-year period were seen. During the second year of treatment, the dose of 2000 mg was associated with a 44% reduction in the number of patients experiencing a new vertebral deformity. The primary analysis of the SOTI study, evaluatine the effect of strontium ranelate 2000 mg on vertebral fracture rates, revealed a 41% reduction in the relative risk of patient experiencing a first new vertebral fracture with strontium ranelate throughout the 3-year study. The TROPOS study showed a significant reduction in the risk of experiencing a first non-vertebral fracture by 16% in the group treated with strontium ranclate throughout the 3-year study. A reduction in the risk of experiencing a hip fracture by 36% was also demonstrated in the patients at high risk of hip fracture (age >= 74 years and Femoral Neck T score <=-2.4 according to NHANES normative value). [less ▲]

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See detailComprehensive Two-Dimensional Gas Chromatography Time of Flight Mass Spectrometry (GCxGC-TOFMS) for Environmental Forensic Investigations in Developing Countries
de Vos, Jayne; Dixon, Roger; Vermeulen, Gerhard et al

in Chemosphere (2011), 82

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See detailComprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass
Patterson Jr; Focant, Jean-François ULg

Scientific conference (2003, June)

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See detailComprehensive two-dimensional gas chromatography with isotope dilution time-of-flight mass spectrometry for the measurement of dioxins and polychlorinated biphenyls in foodstuffs - Comparison with other methods
Focant, Jean-François ULg; Eppe, Gauthier ULg; Scippo, Marie-Louise ULg et al

in Journal of Chromatography. A (2005), 1086(1-2), 45-60

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo ... [more ▼]

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), ten 2,3,7,8-substituted polychlorinated dibenzofurans (PCDFs), four non-ortho-polychlorinated biphenyls (PCBs), eight mono-ortho-PCBs, and six indicator PCBs (Aroclor 1260) in foodstuff samples. A 40 m RTX-500 (0.18 mm I.D., 0.10 mu m df) was used as the first dimension (D-1) and a 1.5 nn BPX-50 (0.10 mm I.D., 0.10 mu m df) as the second dimension (2 D). The GC x GC chromatographic separation was completed in 45 min. Quantification was performed using C-13-label isotope dilution (11)). Isotope ratios of the selected quantification ions were checked against theoretical values prior to peak assignment and quantification. The dynamic working range spanned three orders of magnitude. The lowest detectable amount of 2,3,7,8-TCDD was 0.2 pg. Fish, pork, and milk samples were considered. On a congener basis, the GC x GC-ID-TOF-MS method was compared to the reference GC-ID high resolution mass spectrometry (HRMS) method and to the alternative GC-ID tandem-in-time quadrupole ion storage mass spectrometry (QIST-MS/MS). PCB levels ranged from low picogram (pg) to low nanogram (ng) per gram of sample and data compared very well between the different methods. For all matrices, PCDD/Fs were at a low pg level (0.05-3 pg) on a fresh weight basis. Although congener profiles were accurately described, RSDs of GC x GC-ID-TOF-MS and GC-QIST-MS/MS were much higher than for GC-ID-HRMS, especially for low level pork and milk. On a toxic equivalent (TEQ) basis, all methods, including the dioxin-responsive chemically activated luciferase gene expression (DR-CALUX) assay, produced similar responses. A cost comparison is also presented. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 129 (15 ULg)