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See detailDetermination of a Suitable Protocol for Indigenous Oilseed Cucurbits Plant Regeneration
Gnamien, Yah Gwladys; Zoro Bi, I. A.; Djè, Y. et al

in Tropicultura (2010), 28(4), 217-225

The present work was carried out to establish rapid in vitro propagation of the indigenous oilseed Citrullus lanatus. Efficiency of 3 protocols for seed decontamination was investigated. High level of ... [more ▼]

The present work was carried out to establish rapid in vitro propagation of the indigenous oilseed Citrullus lanatus. Efficiency of 3 protocols for seed decontamination was investigated. High level of seed sterilization was obtained after removing seed coat and soaking the seeds in 1.6 % sodium hypochlorite with a drop of Tween 20. Shoot tips, single node and cotyledon explants of 3 morphotypes have been screened for adventitious shoot formation in tissue culture. Best response in termis of multiple shoot induction was obtained from cotyledon proximal part with hypocotyl segmenet on Murashige and Skoog medium supplemented with 1 mg/l 6-Benzylaminopurine, 30 g/l sucrose and 8 g/l agar. After 3 weeks of culture, 90% of cotyledon proximal parts induced shoot. An average of 12.6 shoots per explants and a mean shoot length of 8 mm were obtained after multiplication stage. Shoot induction appeared to be strongly influenced by genotype and explant type. The percentage of shoot induction from cotyledon proximal parts ranged from 23.3% to 64.0% according to the genotype. Efficient rooting was achieved on half-solid MS medium containing 0.1 mg/l 1-Naphthaleneactic acid or without growth regulator. Acclimatised plantlets were transferred to greenhouse where they grew and flowered like seeded plantlets. [less ▲]

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See detailDetermination of absolute molecular weight of bioactive polycations
Plotnikova, Evgeniya ULg; Sevrin, Chantal ULg; Claes, Nicolas et al

Poster (2015)

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See detailDetermination of Absolute Strengths of N2 Quadrupole Lines From High-Resolution Ground-based IR Solar Observations
Demoulin, Philippe ULg; Farmer, C.B.; Rinsland, C.P. et al

in Journal of Geophysical Research (1991), 96(D7), 13003-13008

High-resolution, high signal-to-noise ratio, solar absorption spectra recorded with a Fourier transform spectrometer at the International Scientific Station of the Jungfraujoch, Switzerland, have been ... [more ▼]

High-resolution, high signal-to-noise ratio, solar absorption spectra recorded with a Fourier transform spectrometer at the International Scientific Station of the Jungfraujoch, Switzerland, have been analyzed to determine the strengths of several lines belonging to the S branch of the N2 (1-0) electric quadrupole vibration-rotation band centered at 2329.9168 cm-1. The method which was applied here was based on equivalent width measurements of lines observed over a broad range of air masses; extrapolation of these measurements to zero air mass gave the line strengths for the transitions S7 to S10, independent of half widths, an ambiguity unavoidable with the use of curve-fitting techniques. The resulting absolute accuracies of the line strengths derived here, estimated to be better than +-2.5% for S8, +-2.6% for S10, +-3.4% for S9, and +-5.1% for S7, are due largely to the high quality and quantity of the spectra retained in this analysis and the accuracy with which the observation conditions are known. An important application of the improved values for these N2 transitions, which have low initial ground state energies, is the direct determination of the line-of-sight atmospheric air masses associated with remotely sensed infrared spectroscopic observations. Positions of the N2 transitions studied here have further been redetermined with an absolute accuracy better than 0.0002 cm-1. [less ▲]

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See detailDetermination of acidic and basic drugs by capillary zone electrophoresis
Crommen, Jacques ULg; Bechet, I.; Fillet, Marianne ULg et al

Conference (1994)

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See detailDetermination of activation yield curves for fusion escaping particle diagnostics
Strivay, David ULg; Bonheure, George; Delvigne, Thierry et al

Conference (2013, June)

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See detailDetermination of activation yields for fusion plasma escaping charged particles diagnostics
Chene, Grégoire ULg; Bonheure, George; Delvigne, Thierry et al

Conference (2013, June)

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See detailDetermination of affinity, stoichiometry and sequence selectivity of minor groove binder complexes with double-stranded oligodeoxynucleotides by electrospray ionization mass spectrometry
Rosu, Frédéric ULg; Gabelica, Valérie ULg; Houssier, Claude ULg et al

in Nucleic Acids Research (2002), 30(16), 82

Electrospray mass spectrometry was evaluated regarding the reliability of the determination of the stoichiometries and equilibrium association constants from single spectra. Complexes between minor groove ... [more ▼]

Electrospray mass spectrometry was evaluated regarding the reliability of the determination of the stoichiometries and equilibrium association constants from single spectra. Complexes between minor groove binders (Hoechst 33258, Hoechst 33342, DAPI, netropsin and berenil) and 12mer oligonucleotide duplexes with a central sequence (A/T)(4) flanked by G/C base pairs were chosen as model systems. To validate the electrospray ionization mass spectrometry (ESI-MS) method, comparisons were made with circular dichroism and fluorescence spectroscopy measurements. ESI-MS allowed the detection of minor (2 drug + DNA) species for Hoechst 33258, Hoechst 33342, DAPI and berenil with duplex d(GGGG(A/T)(4)GGGG). d(CCCC(A/T)(4)CCCC), which were undetectable with the other techniques. Assuming that the duplexes and the complexes have the same electrospray response factors, the equilbrium association constants of the 1:1 and 2:1 complexes were determined by ESI-MS, and the values show a good quantitative agreement with fluorescence determined constants for Hoechst 33258 and Hoechst 33342. It is also shown that ESI-MS can quickly give reliable information on the A/T sequence selectivity of a drug: the signal of a complex is directly related to the affinity of the drug for that particular duplex. The potential of ESI-MS as a qualitative and quantitative affinity screening method is emphasized. [less ▲]

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See detailDetermination of air‐sea ice transfer coefficient for CO2: Significant contribution of gas bubble transport during sea ice growth
Kotovitch, Marie ULg; Moreau, S.; Zhou, Jiayun et al

Poster (2015, September)

Air‐ice CO2 fluxes were measured continuously from the freezing of a young sea‐ice cover until its decay. Cooling seawater was as a sink for atmospheric CO2 but asthe ice crystalsformed,sea ice shifted to ... [more ▼]

Air‐ice CO2 fluxes were measured continuously from the freezing of a young sea‐ice cover until its decay. Cooling seawater was as a sink for atmospheric CO2 but asthe ice crystalsformed,sea ice shifted to a source releasing CO2 to the atmosphere throughout the whole ice growth. Atmospheric warming initiated the decay, re‐shifting sea‐ice to a CO2 sink. Combining these CO2 fluxes with the partial pressure of CO2 within sea ice, we determined gas transfer coefficients for CO2 at air‐ice interface for growth and decay. We hypothesize that this difference originates from the transport of gas bubbles during ice growth, while only diffusion occurs during ice melt. In parallel, we used a 1D biogeochemical model to mimic the observed CO2 fluxes. The formation of gas bubbles was crucial to reproduce fluxes during ice growth where gas bubbles may account for up to 92 % of the upward CO2 fluxes. [less ▲]

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See detailDetermination of Albendazole and Its Main Metabolites in Ovine Plasma by Liquid Chromatography with Dialysis as an Integrated Sample Preparation Technique
Chiap, Patrice ULg; Evrard, Brigitte ULg; Bimazubute, M. A. et al

in Journal of Chromatography. A (2000), 870(1-2), 121-34

Albendazole is a benzimidazole derivative with a broad-spectrum activity against human and animal helminth parasites. In order to determine the main pharmacokinetic parameters in sheep after oral and ... [more ▼]

Albendazole is a benzimidazole derivative with a broad-spectrum activity against human and animal helminth parasites. In order to determine the main pharmacokinetic parameters in sheep after oral and intravenous administration of a new formulation of albendazole (an aqueous solution), a fully automated method was developed for the determination of this drug and its main metabolites, albendazole sulfoxide (active metabolite) and sulfone in ovine plasma. This method involves dialysis as purification step, followed by enrichment of the dialysate on a precolumn and liquid chromatography (LC). All sample handling operations were executed automatically by means of an ASTED XL system. After conditioning of the trace enrichment column (TEC) packed with octadecyl silica with pH 6.0 phosphate buffer containing sodium azide, the plasma sample, in which a protein releasing reagent (1 M HCl) containing Triton X-100 was automatically added, was loaded in the donor channel and dialysed on a cellulose acetate membrane in the static-pulsed mode. The dialysis liquid consisted of pH 2.5 phosphate buffer. By rotation of a switching valve, the analytes were eluted from the TEC in the back-flush mode by the LC mobile phase and transferred to the analytical column, packed with octyl silica. The chromatographic separation was performed at 35 degrees C and the analytes were monitored photometrically at 295 nm. Due to the differences in hydrophobic character between albendazole and its metabolites, a gradient elution was applied. The mobile phase consisted of a mixture of acetonitrile and pH 6.0 phosphate buffer. The proportion of organic modifier was increased from 10.0 to 50.1% in 12.30 min, then from 50.1 to 66.9% in 1.70 min. First, the gradient conditions and the temperature were optimised for the LC separation using the DryLab software. Then, the influence of some parameters of the dialysis process on analyte recovery was investigated. Finally, the method developed was validated. The mean recoveries for albendazole and its metabolites were about 70 and 65%, respectively. The limits of quantification for albendazole and its metabolites were 10 and 7.5 ng/ml, respectively. [less ▲]

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See detailDetermination of Alpha-Solanine and Alpha-Chaconine in Potatoes by High-Performance Thin-Layer Chromatography/Densitometry
Bodart, P.; Kabengera, C.; Noirfalise, Alfred ULg et al

in Journal of AOAC International (2000), 83(6, Nov-Dec), 1468-73

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from ... [more ▼]

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied. [less ▲]

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See detailDetermination of Ambiant Air quality Guidelines
CHARLIER, Corinne ULg

Conference (2013, July 15)

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See detailDetermination of arsenic (III) at a nano gold modified solid carbon paste electrode
Sakira, Abdoul Karim; Somé, Issa Touridomon; Ziemons, Eric ULg et al

in Electroanalysis (2015), 27

A selective and sensitive electroanalytical method was developed for arsenic determination based on a nanogold (AuNP) modified solid carbon paste work- ing electrode (SCPE) modified in two steps (i ... [more ▼]

A selective and sensitive electroanalytical method was developed for arsenic determination based on a nanogold (AuNP) modified solid carbon paste work- ing electrode (SCPE) modified in two steps (i) physisorp- tion and (ii) additional electrodeposition of nanogold par- ticles in the presence of iodide. Copper(II) interference was solved by covering the gold layer by a self assembled mono layer (SAM) of glutathione. Using DPASV a linear response of the signal was obtained as a function of As(III) in the concentration range 0.05–20mM (4– 1498 ppb) with a limit of detection of 0.01 mM (0.9 ppb). Sample stirring and degassing were not needed. Applica- tion to the determination of arsenic(III) and (V) in un- derground water samples from Burkina Faso was success- fully achieved. [less ▲]

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See detailDetermination of As in Industrial Wastewater by Laser-Induced Breakdown Spectroscopy
Lin, Zhaoxiang; Chang, Liang; Li, Jie ULg et al

in Spectroscopy and Spectral Analysis (2009), 29(6), 1675-1677

The wastewater from industrial smelting process contains heavy metals such as arsenic(As)that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to ... [more ▼]

The wastewater from industrial smelting process contains heavy metals such as arsenic(As)that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to control the pollution at the source and achieve a real-time and online monitoring.The 1aser-induced breakdown spectroscopy(LIBS)iS a new elemental analysis technique,and has the advantage of rapid detection.An LIBs setup has been established.The Nd:YAG Iaser beam is focused onto the sample,then the plasmas are produced.The emission spectra of plasmas are dispersed by an Echelle spectrograph and detected by an intensified charge-coupled device(ICCD).Experiments have been carried out on the industrial wastewarer collected from the scene.The spectral lines of As element were obtained.The calibration curve of the line intensities versus the concentrations of the As element was acquired by the experiment.The calibration curve can be used for the quantitative analysis of arsenic element with an unknown concentration in the industrial wastewater.The results showed that the LIBS technique can be applied in the rapid detection of As element in industrial wastewater,and has wide range of applications [less ▲]

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See detailDetermination of Benzodiazepines by Micellar Electrokinetic Chromatography
Bechet, I.; Fillet, Marianne ULg; Hubert, Philippe ULg et al

in Electrophoresis (1994), 15(10), 1316-21

A method for the separation and determination of benzodiazepines by micellar electrokinetic chromatography (MEKC) has been developed. Separation buffers consisted of aqueous solutions of glycine and ... [more ▼]

A method for the separation and determination of benzodiazepines by micellar electrokinetic chromatography (MEKC) has been developed. Separation buffers consisted of aqueous solutions of glycine and triethanolamine (pH 9.0), containing sodium dodecyl sulfate (SDS) as surfactant and methanol as organic modifier. The effect of the concentration of SDS, methanol, glycine and triethanolamine on migration times and resolution was studied. Ten benzodiazepines were baseline separated at a 25 mM SDS concentration and 20% v/v methanol in a 75 mM glycine-250 mM triethanolamine buffer. Under these conditions, the within-day reproducibilities were 0.3-0.5% for migration times and 1.7-1.9% for peak areas at a concentration of 10 micrograms/mL. The limits of detection and quantification for oxazepam were 0.2 and 0.7 micrograms/mL, respectively, using an injection time of 5 s. [less ▲]

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See detailDetermination of binary polymorphic mixtures of fluconazole using near infrared spectroscopy and X-ray powder diffraction: A comparative study based on the pre-validation stage results
Ziemons, Eric ULg; Bourichi, H.; Mantanus, Jérôme ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 55

The aim of the present study was to develop near infrared (NIR) and X-ray powder diffraction methods (XRPD) able to determine pure crystalline form II of fluconazole in a binary polymorphic mixtures ... [more ▼]

The aim of the present study was to develop near infrared (NIR) and X-ray powder diffraction methods (XRPD) able to determine pure crystalline form II of fluconazole in a binary polymorphic mixtures containing form II and III. In order to give a first performance estimation of both methods, these latters were pre-validated using accuracy profiles, a statistical approach based on β-expectation tolerance intervals. Both methods showed a good trueness, precision and accuracy and their β-expectation tolerance intervals were fully included within the acceptance limits. The comparative study was carried out using statistical analysis based on the work of Bland and Altman. A good agreement between the two methods was demonstrated indicating the interchangeability of NIR method with XRPD method. [less ▲]

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See detailDetermination of blood concentration levels of psychotrope medications in Rwandan patients
Hahirwa, Innocent; DENOOZ, Raphael ULg; Karangwa, Charles et al

in Acta Clinica Belgica (2015)

OBJECTIVES: In Rwanda, no therapeutic monitoring of psychotropic drugs is done. This results in difficult treatment optimisation and exposition to a high risk of toxicity and drug ineffectiveness for ... [more ▼]

OBJECTIVES: In Rwanda, no therapeutic monitoring of psychotropic drugs is done. This results in difficult treatment optimisation and exposition to a high risk of toxicity and drug ineffectiveness for patients under treatment. This study aimed to determine blood concentration levels of psychotropic drugs in Rwandan patients and identify problems associated with the lack of therapeutic drug monitoring (TDM) of these drugs. METHODS: The analysis was performed on 1 ml of serum sample using prazepam as internal standard. Regarding the step of sample preparation, we used a liquid-liquid extraction with a mixture of organic solvents: diethyl ether/dichloromethane/hexane/n-amyl alcohol (50/30/20/0.5:V/V). A Waters Alliance 2695 was used for analysis. The chromatography was run on a Symmetry C8 column and as mobile phase acetonitrile and phosphate buffer (pH 3.8) were used. RESULTS: Concerning the results, serum samples from 128 patients were analysed. Twenty-one different psychotropic drugs belonging to various pharmacological classes were detected and quantified. Analytical results were put into three categories based upon therapeutic reference ranges (TRR) of various drugs: subtherapeutic, therapeutic and supratherapeutic. For a total of 237 analyses, results within TRR represented 46% while 47 and 8% of results were, respectively, below and above TRR. CONCLUSION: It was therefore concluded that patients under psychotropic treatment in Rwanda are exposed to both the risk of drug ineffectiveness and the risk of toxicity (54%) with only 46% of results within the TRR. Consequently, TDM is needed to optimise psychotropic treatment in Rwandan patients. [less ▲]

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See detailDetermination of cardiac performance in healthy dogs during maximal inotropic stimulation with dobutamine.
Mc Entee, Kathleen ULg; Clercx, Cécile ULg; Pypendop, Bruno et al

in Proceedings of the 4th Annual Congress of the ESVIM (1994)

Detailed reference viewed: 6 (2 ULg)