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See detailDetermination of urinary metanephrine, normetanephrine and methoxymetanephrine by liquid chromatography-electrospray tandem mass spectrometry.
LE GOFF, Caroline ULg; PEETERS, Stéphanie ULg; NETCHACOVITCH, Matthieu ULg et al

in Biochimica Clinica (2013, May), 37(SS), 316

Background: The aim of this work was to develop and validate a method for the determination of metanephrine (M), normetanephrine (NM) and methoxymetanephrine (METHO) in urine by liquid chromatography ... [more ▼]

Background: The aim of this work was to develop and validate a method for the determination of metanephrine (M), normetanephrine (NM) and methoxymetanephrine (METHO) in urine by liquid chromatography-tandem mass spectrometry (LCMS-MS) on the Triple Quad TQ 5500 from AB SCIEX. In fact, the determination of M and NM concentrations is used in clinical diagnosis of pheochromocytoma, a rare but potentially fatal tumor arising primarily from the chromaffin cells of the adrenal medulla. Methods: The samples were made of 24 hours acidified urines after centrifugation. Sample preparation was performed by hydrolysing and purifying by extraction column. After that, labeled M, NM and METHO were added as internal standard. Samples were analysed by liquid chromatography-electrospray tandem mass spectrometry. We determined the repeatability, reproducibility, accuracy profile and recovery on pooling urines samples from 9 volunteers analysed in triple run. Results: The results of the precision evaluation are shown in table. The repeatability did not exceed 8.4 % for M, 6.8% for NM and 10.8% for METHO. The concentration range was 71-781 µg/24h, 71-853 µg/24h and 20-854µg/24h for the M, NM and METHO respectively. The total precision did not exceed 12.5%, 11.8% and 8.8% for M, NM and METHO. The limit of quantification (LOQ) were 33.77µg/24h, 14.49µg/24H and 19.81 µg/24H for M, NM and METHO respectively. The accuracy varied from 99.69 to 100.2% for a range of 71 to 781 µg/24h, from 93.32 to 100.2% for a range of 71-853 µg/24h and from 99.85 to 100.6% for the range 20-854µg/24h for M, NM and METHO respectively. The recovery were 99.96% (95% CI for the mean: 96.5-103.4), 99.75% (96.5-102.9) and 100.08 (95.97-104.2) for the M, NM and METHO respectively. Conclusions: We have successfully developed and validated an LCMS-MS method to determine urinary M, NM and METHO on the TQ 5500 from AB SCIEX. It represents a convincing alternative to the HPLC method for a faster and reliable measurement of urinary M, NM and METHO. [less ▲]

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See detailDetermination of verapamil and norverapamil in human plasma by liquid chromatography: comparison between a liquid-liquid extraction procedure and an automated liquid-solid extraction method for sample preparation.
Hubert, Philippe ULg; Chiap, Patrice ULg; Ceccato, Attilio ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (1992), 10(10-12), 937-42

A conventional liquid-liquid extraction (LLE) procedure with high-performance liquid chromatography (HPLC) has been developed for the determination of verapamil and its main metabolite, norverapamil, in ... [more ▼]

A conventional liquid-liquid extraction (LLE) procedure with high-performance liquid chromatography (HPLC) has been developed for the determination of verapamil and its main metabolite, norverapamil, in plasma. After addition of the internal standard, plasma samples were basified with phosphate buffer (pH 9.0) and extracted with a mixture of cyclohexane-dichloromethane. After centrifugation, the organic layer was separated and the analytes were extracted back into a 0.1 N sulphuric acid solution containing 2-aminoheptane. An aliquot of this aqueous phase was then injected directly onto the HPLC column. This LLE procedure has been compared with an automated liquid-solid extraction (LSE) method that has been developed in parallel. Good linearity was obtained using both extraction methods. The absolute recoveries for the two analytes were ca 95% with the automated LSE procedure and slightly lower (ca 84%) for the LLE method. The automated method gives better results with respect to detectability and precision, but the LLE procedure is simpler to develop, requires much less expensive equipment, and remains a useful alternative when the number of samples to be analysed is limited. [less ▲]

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See detailDetermination of Vs-models for the Basel region: Comparison between Array measurements, SASW and S-wave reflection
Havenith, Hans-Balder ULg; Polom, Ulrich; Fäh, Donat et al

in Geophysical Research Abstracts (2006)

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See detailDetermination of water-soluble vitamins by capillary zone electrophoresis
Fotsing, Lucas ULg; Bechet, I.; Fillet, Marianne ULg et al

in Journal de Pharmacie de Belgique (1996), 51

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See detailDetermination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry
Hurdebise, Quentin ULg; Tarayre, Cédric ULg; Fischer, Christophe ULg et al

in Sensors (2015)

Zinc, lead and cadmium are metallic trace elements (MTEs) that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this ... [more ▼]

Zinc, lead and cadmium are metallic trace elements (MTEs) that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this work is to evaluate the applicability of biosensors as tools able to provide data about the bioavailability of such MTEs in contaminated soils. Here, we tested the genetically-engineered strain Escherichia coli pPZntAgfp as a biosensor applicable to the detection of zinc, lead and cadmium by the biosynthesis of green fluorescent protein (GFP) accumulating inside the cells. Flow cytometry was used to investigate the fluorescence induced by the MTEs. A curvilinear response to zinc between 0 and 25 mg/L and another curvilinear response to cadmium between 0 and 1.5 mg/L were highlighted in liquid media, while lead did not produce exploitable results. The response relating to a Zn2+/Cd2+ ratio of 10 was further investigated. In these conditions, E. coli pPZntAgfp responded to cadmium only. Several contaminated soils with a Zn2+/Cd2+ ratio of 10 were analyzed with the biosensor, and the metallic concentrations were also measured by atomic absorption spectroscopy. Our results showed that E. coli pPZntAgfp could be used as a monitoring tool for contaminated soils being processed. [less ▲]

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See detailDétermination par analyse palynologique de l'âge Crétacé Inférieur de la mise en place du gisement de Barite de Fleurus. (Synclinorium de Namur, Belgique).
Dejonghe, L; Fairon-Demaret, M; Gauthier, B. et al

in Comptes rendus Académie des Sciences Paris (1987), 304(11/6), 227-232

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See detailDétermination provisoire des constantes de la nutation diurne et de la nutation initiale
Folie, François ULg

in Annuaire de l'Observatoire Royal de Belgique (1890), 57

The author shows the necessary to consider the diurnal nutation in the writing of their astronomical observations.

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See detailDetermination rapide par immunodosage de l'hemoglobine glyquee sur sang capillaire comparee a une methode d'affinite pour le boronate et capture d'ions sur sang veineux.
Bozet, Marie-Claire ULg; Gerard, Pascale ULg; Scheen, André ULg et al

in Annales de Biologie Clinique (1997), 55(2), 139-44

Measurement of glycosylated haemoglobin has become an essential tool in the management of diabetic patients. A recently developed device allows the rapid immuno-assay of HbA1c in 1 microliter capillary ... [more ▼]

Measurement of glycosylated haemoglobin has become an essential tool in the management of diabetic patients. A recently developed device allows the rapid immuno-assay of HbA1c in 1 microliter capillary blood obtained by a finger prick. In 100 ambulatory diabetic patients, we compared the results obtained with this method to those obtained in venous blood using a standard affinity chromatography laboratory method. Although both methods correlated (r = 0.88, p < 0.001), the mean +/- SD levels respectively obtained differed slightly (7.6 +/- 1.5 vs 79 +/- 1.4% p < 0.001). The 95% confidence interval of the difference was [-0.41. -0.14]. Considering a cut-off HbA1c value of 8%, as indicative of the need for treatment adjustment, 33 patients with the capillary blood immuno-assay method and 42 with the venous-blood affinity chromatography method were above that limit (Mc Nemar test, p < 0.05). In conclusion, the rapid assay of HbA1c in capillary blood can be useful for the management of some diabetic patients but the results are not readily exchangeable with those obtained from other standardized laboratory methods. Consequently, specific ranges and clinical decision limits must be determined. [less ▲]

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See detailThe determinations of household agricultural land use strategies in Red River Delta, Vietnam
Nguyen Thi, Dien; Vu Dinh, Ton; Lebailly, Philippe ULg et al

Conference (2014)

This research presents the determinations of household land use strategy in the context of the rapid rural changes due to the industrialization and urbanization in Vietnam. The mechanism that turns land ... [more ▼]

This research presents the determinations of household land use strategy in the context of the rapid rural changes due to the industrialization and urbanization in Vietnam. The mechanism that turns land to livelihood from both productive and non-productive processes is investigated to understand the different land use strategies of smallholders in Red River Delta region. Based on the presence of migrating members, the total selected 191 households in Hai Duong province were divided into 3 different groups to do the surveys. The research results show that local land use strategies are various in which 79.06% of surveyed households maintain the allocated land for agricultural production while 65.97% of households leave land idly at least once a year. The factors from productive process such as small landholding, high production cost and overall downward income from agricultural production meantime the greater opportunities from non-farm jobs are the main socio-economical determinations of agricultural land abandonment or less effective use. The security questions of shifting livelihood between farming and non – farming sectors, the inter-household arrangements, the social supports and the institutional constraints are non-productive elements that make the exchange and other forms of commercializing agricultural land are less prominent. The complexity of household land use strategy and its determinations not only reflects the dynamism and flexibility of peasant’s livelihood adaptation but also explain why the land concentration does not proceed faster in Red River Delta region of Vietnam. [less ▲]

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See detailDetermining Appropriate Amount of Redworm Meal Supplemented in the Diet of Broiler (Ho x Luong Phuong) in the Open Air Production System
Vu, Dinh Ton; Han Quang, Hanh ULg

in Journal of Science and development (2010), 8(6), 949-958

A study was carried out on 168 heads of broiler chicken (Ho x Luong Phuong) from 5 to 12 weeks of age to measure the effect of red worm meal (Perionyx excavatus) used as a rich protein feed in the diet on ... [more ▼]

A study was carried out on 168 heads of broiler chicken (Ho x Luong Phuong) from 5 to 12 weeks of age to measure the effect of red worm meal (Perionyx excavatus) used as a rich protein feed in the diet on growth performance, feed conversion and meat quality. Based on a completely randomized design, chickens were divided into four groups, involving a control group and three experimental groups corresponding to three levels of red worm meal, viz 8 and 6g/kg of feed (level 1), 13 and 10g/kg of feed (level 2), 18 and 14 g/kg of feed (level 3) according to two respectively growth periods of chicken (from 5 to 8 weeks of age and from 9 to 12 weeks of age. The results showed that supplementation of redworm meal with level 3 in the diets resulted in higher growth rate (P<0.05), lower feed consumption (reducing by 0.53 kg of feed/kg of weight gain, equal to 13.8%) and more improved of yellowness value (P<0.05) than those of control group. Adding redworm to chicken’s diets didn’t affect significantly other characteristics of meat quality (pH, drip and cooking loss, L* and a* values). If cost of worm is not calculated, feed price and feed cost per each kilogram of weight gain in group 3 will be reduced by 287 VND/kg and 4278 VND/kg, corresponding to 4.51% and 17.47% as compared with those of control one. [less ▲]

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See detailDetermining prevalence of chronic kidney disease using estimated glomerular filtration rate.
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Krzesinski, Jean-Marie ULg

in JAMA : Journal of the American Medical Association (2008), 299(6), 631

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See detailDetermining the competence of mountainous Mediterranean streams using lichenometric techniques
Gob, F.; Jacob, N.; Bravard, J. P. et al

in International Association of Hydrological Sciences : “River Catchment Dynamics : Natural Processes and Human Impacts (2005)

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See detailDetermining the Geographical Origin of a Serial Offender Considering the Temporal Uncertainty of the Recorded Crime Data
Trotta, Marie ULg; Bidaine, Benoît ULg; Donnay, Jean-Paul ULg

in GEOProcessing 2011 : The Third International Conference on Advanced Geographic Information Systems, Applications, and Services (2011, February)

Since the days the investigating officers used ”pin maps” to locate and to think about crime events, crime mapping has become widespread thanks to spatial analysis mainly supplied by GIS-like software. In ... [more ▼]

Since the days the investigating officers used ”pin maps” to locate and to think about crime events, crime mapping has become widespread thanks to spatial analysis mainly supplied by GIS-like software. In particular these methods suit well to geographic profiling devoted to crime series characterised by a single offender and hence limited space and time variability. Although spatial techniques are now regularly performed to delineate an offender’s area of residence, the temporal dimension is underemployed due to the wider uncertainty of time records. This paper proposes a methodology based on a least-squares adjustment in order to cope with this temporal issue for determining the most probable offender’s residence. Moreover, a chi-square test is described to check the significance of the solutions suggested by the method. The process is carried out on the real road network which has been discretised (rasterised) for computing convenience. Three simulations show the validity of the reasoning. Finally the main time and speed assumptions introduced in the model are discussed paving the way for further research. [less ▲]

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See detailDeterminism in tropical forest biomass distribution due to forest spatial structure, highlighted by the study of the edge effect.
Bastin, Jean-François ULg; Bogaert, Jan; De Cannière, Charles

in Islands in land- and seascape: the challenges of fragmentation, Erlangen February 2012 (2012, February)

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See detailDeterminisme de la derive lente de la frequence cardiaque pendant l'exercise musculaire.
Cornet, Françoise ULg; Scheen, André ULg; Juchmes, J. et al

in Comptes Rendus des Séances de la Société de Biologie et de ses Filiales (1978), 172(3), 569-74

The slow increase in heart rate which is observed in normal man submitted to heavy muscular exercise is due for a part to an activation of orthosympathetic cardiac activity which is blocked by beta ... [more ▼]

The slow increase in heart rate which is observed in normal man submitted to heavy muscular exercise is due for a part to an activation of orthosympathetic cardiac activity which is blocked by beta antagonists. It is also explained by direct action of hyperthermia on the heart. [less ▲]

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See detailLe determinisme genetique de la differenciation sexuelle humaine.
Ectors, Fabien ULg

in Revue Médicale de Bruxelles (1995), 16(6), 404-10

The genetic mechanism controlling sexual differentiation had remained unknown for a long time. Karyotype analysis of sex-inverted patients or individuals with ambiguous sexual differentiation has enabled ... [more ▼]

The genetic mechanism controlling sexual differentiation had remained unknown for a long time. Karyotype analysis of sex-inverted patients or individuals with ambiguous sexual differentiation has enabled the localization and identification of genes involved. It is currently known that the SRY gene is responsible for the initiation of a cascade reaction leading to male differentiation of the primitive gonad. SRY is a +/- 820 base pairs gene located on the small arm of the Y chromosome, more precisely within the 1A1 alpha sub-segment. Although a few other genes are known to be involved in the downstream regulation of SRY, their precise mode of action is yet unknown. [less ▲]

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