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See detailQuantitative analysis of the porous structure of a petroleum reservoir
Pirard, Eric ULg; Pierroux, Alain; Darimont, Anne ULg

in Microscopy Research and Technique (1993), 25(2), 173-174

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See detailQuantitative Analysis of the Stabilization by Substrate of Staphylococcus Aureus Pc1 Beta-Lactamase
Lejeune, Annabelle ULg; Vanhove, Marc; Lamotte-Brasseur, Josette et al

in Chemistry & Biology (2001), 8(8), 831-42

BACKGROUND: The stabilization of enzymes in the presence of substrates has been recognized for a long time. Quantitative information regarding this phenomenon is, however, rather scarce since the enzyme ... [more ▼]

BACKGROUND: The stabilization of enzymes in the presence of substrates has been recognized for a long time. Quantitative information regarding this phenomenon is, however, rather scarce since the enzyme destroys the potential stabilizing agent during the course of the experiments. In this work, enzyme unfolding was followed by monitoring the progressive decrease of the rate of substrate utilization by the Staphylococcus aureus PC1 beta-lactamase, at temperatures above the melting point of the enzyme. RESULTS: Enzyme inactivation was directly followed by spectrophotometric measurements. In the presence of substrate concentrations above the K(m) values, significant stabilization was observed with all tested compounds. A combination of unfolding kinetic measurements and enzymatic studies, both under steady-state and non-steady-state regimes, allowed most of the parameters characteristic of the two concurrent phenomena (i.e. substrate hydrolysis and enzyme denaturation) to be evaluated. In addition, molecular modelling studies show a good correlation between the extent of stabilization, and the magnitude of the energies of interaction with the enzyme. CONCLUSIONS: Our analysis indicates that the enzyme is substantially stabilized towards heat-induced denaturation, independently of the relative proportions of non-covalent Henri-Michaelis complex (ES) and acyl-enzyme adduct (ES*). Thus, for those substrates with which the two catalytic intermediates are expected to be significantly populated, both species (ES and ES*) appear to be similarly stabilized. This analysis contributes a new quantitative approach to the problem. [less ▲]

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See detailA quantitative analysis of the use of posture verbs by French-speaking learners of Dutch
Lemmens, Maarten; Perrez, Julien ULg

in CogniTextes (2012), 8

This article presents a study of the use of the Dutch cardinal posture verbs staan (‘stand’), liggen (‘lie) and zitten (‘sit’) by French-speaking learners of Dutch; the data is drawn from a corpus of semi ... [more ▼]

This article presents a study of the use of the Dutch cardinal posture verbs staan (‘stand’), liggen (‘lie) and zitten (‘sit’) by French-speaking learners of Dutch; the data is drawn from a corpus of semi-spontaneous oral picture descriptions. Due to the typological differences between French and Dutch in the spatial domain (see Talmy 2000; Lemmens & Slobin 2008), the use of posture verbs is a highly problematic subject for French-speaking learners of Dutch. As a result, their interlanguage is typically characterized by an overall underuse of posture verbs as well as a confusion of the different posture verbs. Our study evaluates how the use of the posture verbs by the learners aligns with their level of proficiency. Strikingly, the statistical tendencies in our data show that a higher proficiency does not correspond to a more accurate use of posture verbs. At first sight, this seems to suggest that advanced learners have become worse at the use of posture verbs. A more refined analysis, however, shows that despite the increase of errors, the learners adopt more native-like strategies as their level of foreign language proficiency increases, suggesting that they gradually become more aware of the strong locative character of Dutch. [less ▲]

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See detailQuantitative analysis of -solanine and -chaconine in potatoes by high performance thin layer chromatography
Bodart, P.; Hubert, Philippe ULg; Kabengera, Ch. et al

Conference (1999)

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See detailQuantitative analysis using near infrared spectroscopy, application to tablet content uniformity test, II
Ginot, Y.-M.; Bernard-Moulin, P.; Boiret, M. et al

in STP Pharma Pratiques (2014), 24(1), 3-36

The first part of this article [1] described the methodology to follow to develop a technique for the quantitative analysis of active substance in a solid tablet type formulation using near infrared ... [more ▼]

The first part of this article [1] described the methodology to follow to develop a technique for the quantitative analysis of active substance in a solid tablet type formulation using near infrared spectroscopy. It seems appropriate to complete this description by detailing the different steps involved through illustrated examples and by proposing useful guidelines for new users. The quantitative analysis example chosen is that of content uniformity (CU) of tablet type solid forms (cf. Ph. Eur. 2.9.6/2.9.40) [2], a test required in the pharmaceutical industry and for which this alternative quantitative analysis could offer substantial gains. It should be noted that the approach described applies to other types of quantitative analysis (mean assay, water content in raw materials, polymorph assay within a tablet, etc.). [less ▲]

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See detailQuantitative analysis using near infrared spectroscopy, Application to tablet content uniformity, I. Methodology
Ginot, Y. M.; Bernard-Moulin, P.; Cinier, R. et al

in STP PHARMA PRATIQUES (2010), 20(2), 117-135

This first document describes guidelines to develop a quantification method for active pharmaceutical ingredient content in solid dose formulation, using near-infrared spectroscopy. This new approach ... [more ▼]

This first document describes guidelines to develop a quantification method for active pharmaceutical ingredient content in solid dose formulation, using near-infrared spectroscopy. This new approach offers several advantages over classical techniques, in particular for tablets content uniformity determination. This document is intended to help users addressing the numerous questions pertaining to number and types of samples, usable spectral range for quantification, importance of the reference method, development of a model and potential pitfalls, use of chemometrics tools and method validation. It also offers a statistical support that used as an aid for decision for routine controls, when a sample falls near acceptance limits. The document gathers basic principles and will be complemented by a second article with practical examples to illustrate the methodology. [less ▲]

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See detailA quantitative and qualitative assessment of verbal short-term memory and phonological processing in 8-year-olds with a history of repetitive otitis media
Majerus, Steve ULg; Amand, Pierre; Boniver, Vincent et al

in Journal of Communication Disorders (2005), 38(6), 473-498

Language outcome in children experiencing fluctuant hearing loss due to otitis media (OME) remains highly equivocal. In the current study, we assessed performance on highly sensitive verbal short-term ... [more ▼]

Language outcome in children experiencing fluctuant hearing loss due to otitis media (OME) remains highly equivocal. In the current study, we assessed performance on highly sensitive verbal short-term memory (STM), new word learning and phonological processing tasks in 8-year-old children who had suffered from recurrent OME before the age of 3. Relative to a control group with no history of OME, we observed strictly normal performance for different STM and new word learning tasks. Performance on these tasks was also normally influenced by phonotactic, lexical and semantic variables. However, at the level of phonological processing, a small but significant decrease of performance was found in a speeded nonword identification task and a rhyme judgment task. The results of this study suggest that outcome of OME is characterized by subtle impairments at the level of perceptual-phonological analysis, but there is no significant impact on verbal STM and new word learning abilities. Learning outcomes: As a result of this activity, the participant will be able to (1) explain the outcome of recurrent OME before age 3 on later language and verbal STM development, (2) be aware of the complex relationships that link language development and verbal STM, (3) explain how fluctuant hearing loss during infancy and early childhood could affect verbal STM development and learning capacity for new phonological information, (4) describe different verbal STM measures that distinguish retention capacities for phonological and lexico-semantic information, and (5) explain the influence of phonotactic frequency on nonword processing in language and verbal STM tasks. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailQuantitative and qualitative estimation of bacteria in foodstuffs by genetic amplification
China, Bernard; Ghafir, Yasmine; Daube, Georges ULg

in Annales de Médecine Vétérinaire (2002), 146(2, APR-MAY),

Food quality is a major concern of our modern society. The sudden awareness that food is not sterile underlines the need of a rigorous microbiological analysis of foodstuffs. The techniques developed ... [more ▼]

Food quality is a major concern of our modern society. The sudden awareness that food is not sterile underlines the need of a rigorous microbiological analysis of foodstuffs. The techniques developed until now require the growth of the microorganism on a selective medium allowing to differentiate it from other bacteria. This procedure could be long and difficult for the analysis. To improve these classical methods, molecular biology techniques based on the specific amplification of a DNA sequence are in development. Moreover, the apparition of real time PCR allows new future prospects since it allows to quantify the number of bacteria present in a sample. This quantitative aspect is very important in food microbiology. In this way, the molecular biology tools should allow to develop fast, sensitive, specific and quantitative diagnosis tests to confirm the results obtained by classical methods but also to allow the diagnosis of fastidious bacteria. [less ▲]

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See detailQuantitative and qualitative hydrogeological study of the alluvial aquifer of Somes-Szamos (RO-HU) NATO SfP Project 973684 SQUASH
Dassargues, Alain ULg; Lenart, Laszlo; Drobot, Radu

in Hidrotehnica (2004), 49(9-10), 3-7

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See detailQuantitative and qualitative modifications of pyoverdines from Pseudomonas putida BTP16 induced by culture medium variations.
Ongena, Marc ULg; Jacques, P.; Delfosse, Ph. et al

Poster (1993, August)

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See detailQuantitative and qualitative study of spelt and wheat fibers in varying milling fractions
Escarnot, Emmanuelle ULg; Agneessens, Richard; Wathelet, Bernard ULg et al

in Food Chemistry (2010), 122

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See detailQuantitative and qualitative study of the production of broad-spectrum antifungal lipopeptides from Bacillus subtilis S499.
Jacques, Ph.; Hbid, Ch.; Vanhentenryck, F. et al

Poster (1993, June)

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See detailQuantitative and qualitative study of the production of broad-spectrum antifungal lipopeptides from Bacillus subtilis S499.
Jacques, Ph.; Hbid, Ch.; Vanhentenryck, F. et al

in Progress in biotechnology (1994), 9

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See detailA quantitative approach to ecotone creation for nature reserve design.
Bogaert, Jan ULg; Salvador-Van Eysenrode, D; Van Hecke, P et al

in The European dimension in ecology, perspectives and challenges for the 21th century (1999)

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See detailQuantitative approach to the conservation of a tropical seabird population in the western Indian Ocean
Monticelli, David; Ramos, J. A.; Doucet, Jean-Louis ULg et al

Poster (2006)

The roseate tern (Sterna dougalli) is an oceanic seabird species showing mainly a tropical distribution, with a relatively fragile status worldwide. It was still recently considered as a "near-threatened ... [more ▼]

The roseate tern (Sterna dougalli) is an oceanic seabird species showing mainly a tropical distribution, with a relatively fragile status worldwide. It was still recently considered as a "near-threatened" (IUCN red list) due to the strong decline in population trends over the last decades. For instance, the annual breeding population found on Aride Island, western Indian Ocean, has fluctuated between a high of 4,000 in the 1970's to a low of 60-1200 pairs from 2000 onwards. As a result, an intensive monitoring program was conducted on Aride between 1998 and 2006 in order to understand how environmental factors may affects this breeding population. This included the estimation of annual productivity (no of chicks fledged per pair), demographic parameters such as survival rate and recruitment (age-specific breeding probabilities), and their affecting co-factors (e.g. food availability, tick parasitism,...). We suggest that these three parameters (productivity, survival, recruitment) constitute the necessary basis to model the life-cycle of this population, and, ultimately, to provide local managers with conservations measures. [less ▲]

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See detailQuantitative approaches based on Surface-Enhanced Raman Scattering (SERS) and Surface-Enhanced Raman Chemical Imaging (SER-CI)
De Bleye, Charlotte ULg; Sacre, Pierre-Yves ULg; Dumont, Elodie ULg et al

Conference (2014, January 20)

Surface-enhanced Raman scattering (SERS), discovered in 1978, is a recent technique enabling to circumvent the main limitations of classical Raman spectroscopy by dramatically exalting the Raman ... [more ▼]

Surface-enhanced Raman scattering (SERS), discovered in 1978, is a recent technique enabling to circumvent the main limitations of classical Raman spectroscopy by dramatically exalting the Raman scattering of the target molecules which are adsorbed or very closed to metallic surfaces while reducing the fluorescence impact on spectra [1]. This technique combines the sensitivity of the fluorescence keeping the structural information of molecules obtained from the SERS spectrum [2]. This last point allows to implement multiplex analyses. Moreover, it is possible to perform Surface-enhanced Raman chemical imaging (SER-CI) analyses which enable to acquire a visual representation of samples combining spectral and spatial measurements. Therefore SERS could become an attractive technique in numerous fields such as pharmaceutical and biomedical research. In this context, the feasibility of developing quantitative approaches using SERS and SER-CI on a pharmaceutical model was studied. The aim was to develop methods allowing the quantification of 4-aminophenol (4-AP) in a pharmaceutical formulation based on paracetamol. 4-AP is the main impurity of paracetamol and is actively research because of its toxicity. This pharmaceutical model was first investigated using SERS and a quantitative method enabling to quantify 4-AP from 3 to15 µg/mL was developed and validated using the standard addition method as a calibration method [3]. From these results, the possibility of developing a quantitative approach using SER-CI was investigated. Tablets based on paracetamol comprising different concentrations of 4-AP were prepared. Different ways to cover the sample surface by the SERS substrate were tested and a homogeneity study was performed to improve the repeatability of SER-CI analyses. Different spectral intensity normalizations were also tested in order to optimize the SER-CI method. Finally, a quantitative approach using SER-CI was developed allowing the quantification of 4-AP from 0.025% to 0.2% (w/w) in paracetamol tablets [4]. This first quantitative approach could pave the way to quantitative analysis of small molecules using SER-CI in complex matrices. References [1] P.L. Stiles, J.A. Dieringer, N.C. Shah, R.P. Van Duyne, Annu. Rev. Anal. Chem. 1 (2008) 601-626. [2] R.F. Aroca, R.A. Alvarez-Puebla, N. Pieczonka, S. Sanchez-Cortez, J.V. Garcia-Ramos, Adv. Colloid Interface Sci. 116 (2005) 45-61. [3] C. De Bleye, E. Dumont, E. Rozet, P.-Y. Sacré, P.-F. Chavez, L. Netchacovitch, G. Piel, Ph. Hubert, E. Ziemons, Talanta 116 (2013) 899-905. [4] C. De Bleye, P.-Y. Sacré, E. Dumont, L. Netchacovitch, P.-F. Chavez, G. Piel, P. Lebrun, Ph. Hubert, E. Ziemons, J. Pharm. Biomed. Anal. (in Press) [less ▲]

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See detailQuantitative aspect of serum myoglobin changes in acute myocardial infarction
Chapelle, Jean-Paul ULg; Albert, Adelin ULg; Smeets, J. P. et al

in European Heart Journal (1981), 2(A), 213

Detailed reference viewed: 10 (1 ULg)
See detailQuantitative aspects of serum myoglobin changes in acute myocardial infarction
Chapelle, Jean-Paul ULg; Albert, Adelin ULg; Smeets, J. P. et al

Poster (1981, September)

Detailed reference viewed: 3 (0 ULg)