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See detailDevelopment and validation of a questionnaire assessing volitional competencies to enhance the performance of physical activities in chronic low back pain patients.
Mathy, Céline ULg; Broonen, Jean-Paul ULg; Henrotin, Yves ULg et al

in BMC Musculoskeletal Disorders (2011), 12

BACKGROUND: Motivation has long been emphasized as the most important determinant of action. However, there is a substantial gap between people's goals and their attainment. Patients may be motivated and ... [more ▼]

BACKGROUND: Motivation has long been emphasized as the most important determinant of action. However, there is a substantial gap between people's goals and their attainment. Patients may be motivated and yet unable to take action if their volitional competencies are insufficient. One of the important tasks of volition is goal-maintenance. Research has stressed the importance of a volitional tool, the implementation intentions. Implementation intentions indicate where, when, and how the action leading to the goal will be performed. Forming implementation intentions favours the execution of goal-directed efforts, and reinforces the relationship between intentions and behaviours. Results from various studies clearly suggest that volitional competencies and implementation intentions could play a role in low back pain (LBP) patients. However, there is at present no questionnaire allowing assessing the capacity of implementation intentions of physical activities in LBP patients. METHODS/DESIGN: This study will develop such a questionnaire, using a 3-step approach. A first qualitative step to build categories and generate items; 30 patients suffering chronic LBP will be invited to participate in semi-structured interviews; verbatim and derived items will then be submitted to a panel of experts, using a Delphi method; a second quantitative step to examine the properties of items, and determine the factorial structure of the questionnaire; 100 patients suffering chronic LBP will be recruited to respond to this phase; and third, preliminary psychometric analyses (item-scale correlations, construct validity, reliability); 180 chronic LBP patients will be recruited for this phase of the study. The relationships between implementation intentions and variables affecting physical activity on chronic LBP patients, i.e. pain, physical capacities, fear-avoidance beliefs, kinesiophobia, work status, and level of physical activity will be considered. DISCUSSION: Developing a questionnaire to assess implementation intentions would allow investigating the role of these intentions in the transition from acute to chronic LBP. The results of this study should contribute to the understanding of the psychological processes at stake in the development of chronic LBP, and in particular to the identification of factors eventually favouring patients' participation in and adherence to active physical treatments. [less ▲]

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See detailDevelopment and validation of a radioimmunoassay for thyrotropin in cattle
Guyot, Hugues ULg; Sulon, Joseph ULg; Beckers, Jean-François ULg et al

in Journal of Veterinary Diagnostic Investigation (2007), 19(6), 643-651

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of ... [more ▼]

In mammals, thyrotropin, or thyroid-stimulating hormone (TSH), assay is used for the diagnosis of primary hypothyroidism. Hypothyroidism is the most common type of thyroid disorder in cattle. The aim of this study was to develop and validate, under physiologic and pathologic conditions, a radioimmunoassay (RIA) for bovine TSH (bTSH). Double RIA was performed with purified bTSH and specific bovine antiserum. Laboratory validation included research of minimal detection limit, accuracy, and reproducibility. The physiologic validation included a thyrotropin-releasing hormone (TRH) challenge performed on euthyroid cows and a follow-up of bTSH concentration over a 24-hour period. Furthermore, bTSH concentration was assayed in a large population of healthy dairy and beef cows to define reference interval. The pathologic validation was made by assaying bTSH and thyroid hormones on healthy and goitrous newborn calves. The minimum detection limit (MDL) for bTSH assay was 1.3 microU/ml. The recovery was 101% to 106%. The intra- and interassay coefficients of variation (CVs) ranged from 5% to 11% and 11% to 15%, respectively. The RIA covered the whole range of physiologic bTSH values, as shown by bTSH values induced by TRH-challenge. A pulsatile secretion of bTSH was observed, accompanied by a diurnal variation with lower night values than day values. Reference intervals of bTSH ranged from 1.3 to 13.0 microU/ml for beef and dairy breeds. Finally, bTSH easily discriminated goitrous newborn calves from healthy ones, leading to the definition of a cutoff value of 35 microU/ml. The bTSH assay positively reacted to physiologic and pathologic conditions. The accuracy and precision of the RIA were satisfying. [less ▲]

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See detailDevelopment and validation of a reference material for food microbiology using Bacillus cereus spores
Abel Massih, Marleen; Debast, Laurent; Planchon, Viviane et al

in Proceedings of the Thirteenth Conference on Food Microbiology (2008, September)

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See detailDevelopment and validation of a self-administrated quality of life questionnaire specific to sarcopenia: the SarQol
Beaudart, Charlotte ULg; Reginster, Jean-Yves ULg; Rizzoli, R. et al

in European Geriatric Medicine (2015, September), 6S1

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See detailDevelopment and validation of a sensitive solid phase extraction/hydrophilic interaction liquid chromatography/mass spectrometry method for the accurate determination of glucosamine in dog plasma.
Hubert, Cédric ULg; Houari, Sabah ULg; Lecomte, Frédéric ULg et al

in Journal of Chromatography. A (2010), 1217

A sensitive and accurate LC/MS method was developed for the monitoring of glucosamine (GLcN) dog plasmatic concentration. In this scope, relatively low plasmatic concentrations of GLcN were expected ... [more ▼]

A sensitive and accurate LC/MS method was developed for the monitoring of glucosamine (GLcN) dog plasmatic concentration. In this scope, relatively low plasmatic concentrations of GLcN were expected, ranging from 50 to 1000ng/mL. Liquid chromatography coupled to simple quadrupole mass spectrometry detection (LC/MS) was selected bringing the selectivity and the sensitivity needed for this application. Additionally, a solid phase extraction (SPE) step was performed to reduce matrix and ion suppression effects. Due to the ionisable character of the compound of interest, a mixed-mode strong cation exchange (Plexa PCX) disposable extraction cartridge (DEC) was selected. The separation was carried out on a Zorbax SB-CN column (5mum, 4.6mm i.d.x250mm), considering hydrophilic interaction liquid chromatography (HILIC). Indeed, the mobile phase was made of methanol and 5mM ammonium hydrogen carbonate buffer at pH 7.5 (95/5, v/v). The detection was led at m/z ratios of 180.0 and 417.0, for GLcN and IS, respectively. Reliability of the results was demonstrated through the validation of the method using an approach based on the accuracy profile allowing managing the risk associated to the use of these methods in routine analysis: it is thus guaranteed that each future result will fall in the +/-30% acceptance limits with a probability of at least 90%. Successful application of the method to a preliminary pharmacokinetic study illustrated the usefulness of the method for pre-clinical studies. [less ▲]

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See detailDevelopment and validation of a short Italian UPPS-P Impulsive Behavior Scale
D'Orta, Isabella; Burnay, Jonathan ULg; Aiello, Daniela et al

in Addictive Behaviors Reports (2015), 2

Impulsivity is a multidimensional construct that plays a prominent role in the development, maintenance, and relapse of addictive disorders. The UPPS-P model of impulsivity, which distinguishes between ... [more ▼]

Impulsivity is a multidimensional construct that plays a prominent role in the development, maintenance, and relapse of addictive disorders. The UPPS-P model of impulsivity, which distinguishes between five impulsivity components (positive urgency, negative urgency, lack of perseverance, lack of premeditation, sensation seeking), has been increasingly investigated during the last decade in relation to addictive and risky behaviors. Unfortunately, it currently lacks a validated scale that allows Italian researchers and clinicians to measure impulsivity based on the UPPS-P model. The current study fills this gap by testing the psychometric properties of a short 20-item Italian scale used to assess the five dimensions of the UPPS-P model in 188 volunteer participants from the community. Confirmatory factor analysis supported a model of five distinct, but interrelated, impulsivity components. The results indicated good internal consistency (Cronbach's α ranges from .73 to .84). Construct validity was evidenced by specific relations with measures of addictive behaviors and depressive symptoms. On the whole, this study demonstrated that the Italian short UPPS-P has good psychometric properties. [less ▲]

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See detailDevelopment and validation of a specific radioimmunoassay for equine osteocalcin
Carstanjen, Bianca; Sulon, Joseph ULg; Banga-Mboko, H. et al

in Domestic Animal Endocrinology (2003), 24(1), 31-41

This study describes for the first time the development and validation of a sensitive and specific radioimmunoassay (RIA) for equine osteocalcin (OC) quantification using purified equine OC as standard ... [more ▼]

This study describes for the first time the development and validation of a sensitive and specific radioimmunoassay (RIA) for equine osteocalcin (OC) quantification using purified equine OC as standard, tracer, and immunogen for antibody formation in rabbits. The assay allowed to measure equine serum OC levels with a sensitivity of 0.2 ng/mL. Immunoreactive serum OC values of clinically normal, different-aged horses ranged from 3.68 to 127.31 ng/mL. Intra- and inter-assay coefficients of variation (CV) were 6.2 and 8.2%, respectively. Serial equine scrum sample dilutions were linear. The recovery of equine OC from equine serum samples ranged from 93.88 to 107.9%. There was a tight correlation between OC values measured with the equine- specific OC RIA and two commercially available bovine-specific OC RIA kits. However, highest serum OC values were obtained with the equine-specific OC RIA. In conclusion, our equine-specific OC RIA is sensitive, linear, accurate, precise, and reproducible. The assay allowed to quantify OC in equine serum samples and might, therefore, be used to monitor equine osteoblast activity associated with bone diseases, exercise, therapy forms or diet. [less ▲]

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See detailDevelopment and validation of a UHPLC−LTQ−Orbitrap MS method for non-anthocyanin flavonoids quantification in Euterpe oleracea juice
Dias, A.L.; Rozet, Eric ULg; Larondelle, Y. et al

in Analytical and Bioanalytical Chemistry (2013)

Euterpe oleracea fruits have gained much attention because of their phenolic constituents that have shown potential beneficial effects for health. The aim of this work was to identify and quantify major ... [more ▼]

Euterpe oleracea fruits have gained much attention because of their phenolic constituents that have shown potential beneficial effects for health. The aim of this work was to identify and quantify major non-anthocyanin flavonoids in fruit juice by an accurate UHPLC−LTQ−Orbitrap MS method. Fruits were processed to juice, lyophilized and defatted. The residue was then extracted with methanol by sonication and the extraction time optimized giving recovery rates > 90%. Solubilization of dried extract was realized using 40% MeOH which showed the best compromise for MS detection. For the UHPLC quantification, a HSS C18 column (1.8µm) was used with a gradient elution of methanol and water both with 0.1% formic acid. Total error and accuracy profiles were used as validation criteria. Seven compounds and their isomers were successfully separated, including the major non-anthocyanin flavonoids. Calibration in the matrix was found to be more accurate than calibration without matrix. Trueness (< 15% relative bias), repeatability and intermediate precision (<13% RSD), selectivity, response function, linearity, LOD (ranged from 0.04 to 0.81 µg/mL) and LOQ (0.15 - 5.78 µg/mL) for 12 compounds were evaluated and the quantification method validated. Its applicability was demonstrated on real samples from different suppliers. Their qualitative and quantitative profiles were similar and some compounds were for the first time quantified. In addition eriodictyol was identified for the first time in this fruit along with 5 other flavonoids for which we proposed a possible structure. [less ▲]

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See detailDevelopment and validation of a ultra-high-performance liquid chromatography-UV method for the detection and quantification of erectile dysfunction drugs and some of their analogues found in counterfeit medicines
Sacré, Pierre-Yves ULg; Deconinck, Eric; Chiap, Patrice ULg et al

in Journal of Chromatography. A (2011), 1218

Pharmaceutical counterfeiting is a permanently growing problem. Control laboratories are constantly analysing counterfeit medicines. In industrialised countries, one of the main counterfeited class of ... [more ▼]

Pharmaceutical counterfeiting is a permanently growing problem. Control laboratories are constantly analysing counterfeit medicines. In industrialised countries, one of the main counterfeited class of medicines are erectile dysfunction drugs. This paper describes the development and validation of a fast method to detect and quantify the three authorised phosphodiesterase type 5 inhibitors and five analogues. The method is based on the use of a sub-2 microns polar-embedded column with a gradient using acetonitrile as organic modifier and 10 mM ammonium formate buffer (pH 3.5) as aqueous component of the mobile phase. The separation was achieved in less than 4.5 min. The method has also been compared to the registered HPLC method for the assay of Viagra® which was considered as the reference method. The method is also compatible with on-line coupling mass spectrometry and will significantly reduce analysis times and solvent consumption. [less ▲]

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See detailDevelopment and validation of an accelerometer-based method for quantifying gait events
Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg; Stamatakis, Julien et al

in Medical Engineering & Physics (2015)

An original signal processing algorithm is presented to automatically extract, on a stride-by-stride basis, four consecutive fundamental events of walking, heel strike (HS), toe strike (TS), heel-off (HO ... [more ▼]

An original signal processing algorithm is presented to automatically extract, on a stride-by-stride basis, four consecutive fundamental events of walking, heel strike (HS), toe strike (TS), heel-off (HO), and toe-off (TO), from wireless accelerometers applied to the right and left foot. First, the signals recorded from heel and toe three-axis accelerometers are segmented providing heel and toe flat phases. Then, the four gait events are defined from these flat phases. The accelerometer-based event identification was validated in seven healthy volunteers and a total of 247 trials against reference data provided by a force plate, a kinematic 3D analysis system, and video camera. HS, TS, HO, and TO were detected with a temporal accuracy ± precision of 1.3 ms ± 7.2 ms, ‒4.2 ms ± 10.9 ms, ‒3.7 ms ± 14.5 ms, and ‒1.8 ms ± 11.8 ms, respectively, with the associated 95% confidence intervals ranging from ‒6.3 ms to 2.2 ms. It is concluded that the developed accelerometer-based method can accurately and precisely detect HS, TS, HO, and TO, and could thus be used for the ambulatory monitoring of gait features computed from these events when measured concurrently in both feet. [less ▲]

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See detailDevelopment and Validation of an Automated Method for the Liquid Chromatographic Determination of Sotalol in Plasma Using Dialysis and Trace Enrichment on a Cation-Exchange Pre-Column as on-Line Sample Preparation
Chiap, Patrice ULg; Ceccato, Attilio ULg; Miralles Buraglia, B. et al

in Journal of Pharmaceutical & Biomedical Analysis (2001), 24(5-6), 801-14

A fully automated method for the determination of sotalol in human plasma was developed, involving dialysis through a cellulose acetate membrane, clean-up and enrichment of the dialysate on a strong ... [more ▼]

A fully automated method for the determination of sotalol in human plasma was developed, involving dialysis through a cellulose acetate membrane, clean-up and enrichment of the dialysate on a strong cation-exchange pre-column and subsequent liquid chromatographic (LC) analysis with UV detection. All sample handling operations were carried out by means of an ASTED system. Before starting dialysis, the trace enrichment column (TEC) was conditioned. The plasma sample, to which the internal standard (atenolol) was automatically added, was then loaded in the donor channel and was kept static while the dialysis liquid, consisting of 0.017 M acetic acid, was passed through the acceptor channel in successive pulses. After each pulse, the dialysate was dispensed onto the TEC. When dialysis was discontinued, the analytes were eluted from the TEC by the LC mobile phase by rotation of a switching valve and transferred to the analytical column packed with octyl silica. The LC mobile phase was a mixture of methanol and pH 7.0 phosphate buffer containing 1-octanesulfonate at a concentration of 7.5 x 10(-4) M (19:81; v/v). The UV detection was performed at 230 nm. The influence of several parameters of the dialysis and trace enrichment processes on analyte recovery and method selectivity was investigated. The method was then validated. The mean absolute recovery for sotalol was about 60%. The limit of quantitation was 25 ng/ml and R.S.D. for repeatability and intermediate precision obtained at a concentration level of 50 ng/ml were 4.3 and 5.8%, respectively. [less ▲]

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See detailDevelopment and validation of analytical methods based on GC-MS/MC Triple Quadrupole instrument for the analysis of POPs in food and feed matrices
Calaprice, Chiara ULg

Doctoral thesis (2016)

This thesis focused on the development and validation of analytical methods for the de-tection and quantification of Persistent Organic Pollutants (POPs) in biological matrices, namely food and feed ... [more ▼]

This thesis focused on the development and validation of analytical methods for the de-tection and quantification of Persistent Organic Pollutants (POPs) in biological matrices, namely food and feed samples. POPs are a group of chemical compounds listed after the Stockholm Convention in 2001, with demonstrated toxicity and dangerousness for envi-ronment, animals and humans. In this work of thesis, special attention was reserved to some selected POPs: polychlo-rodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), usually referred to as “dioxins”, and polychlorinated biphenyls (PCBs), as there is a big concern about these contaminants in Taranto, a city in the Southern Italy very close to Bari, my home town. Taranto, indeed, is characterized by a large industrial area with a steel mill, several incin-erators and a refinery in few kilometre radius (Di Leo et al., 2014). This work has been done in collaboration with the University of Liège (Belgium) where a consolidated exper-tise in the field of POP measurements was available, especially in terms of dioxin anal-yses. In Chapter 1 the main steps, from sample preparation to data elaboration, of a validated confirmatory method for dioxin and PCB detection in food and feed using gas chromatog-raphy coupled to tandem mass spectrometry Triple Quad instrument (GC-MS/MS Triple Quad) have been described. This method was developed at the University of Liège in the framework of the last updates of the EU Regulation that in 2014 allowed confirmatory quantitative analysis of dioxins with Triple Quad. This method was the starting point of this work of thesis, because it was used for all dioxin and PCB quantifications. In Chapter 2 and chapter 3 alternative clean-up approaches for dioxin analysis in fatty food matrices have been developed using different automated systems. These works have been done in the framework of solvent and time saving for high throughput analytical methods in dioxin analysis. In chapter 2, an already existing automated system, DEXTechTM from LCTech GmbH (LCTech GmbH, Bahnweg 41, 84405 Dorfen, Germany) was used for sample clean-up, but a completely new clean-up approach was developed with this. GC-MS/MS Triple Quad instrument, as well as Magnetic Sector High Resolution Mass Spectrometry (HRMS) instrument were employed for final quantification, to demonstrate the suitability of our newly developed clean-up approaches whatever the instrumental detection. In Chapter 3 PowerPrepTM automated system from Fluid Management System (FMS Inc., 580 Pleasant Street, Watertown, MA 02472, USA) was used and our routine sample clean-up approach was modified in order to enhance the efficiency and to reduce cost and solvent consumption of the analysis. In Chapter 4 the main method for dioxin analysis was adapted for the integration of Dechloranes in the list of the analytes targeted in the regular control for dioxins in food and feed. Dechloranes are a family of 6 organo-chlorinated compounds with structure similar to Mirex, also called Dechlorane, a POP listed in the Stockholm convention. Dechloranes have been found in human blood of people from Europe (Brasseur et al., 2014) and in this work an analytical method for Dechlorane detection was developed and validated to investigate food as a possible route of exposure for humans in Europe, where no production plant has been identified so far. The analytical method was used to analyse 88 food and feed real sample and to give an idea of Dechlorane daily dietary intake. [less ▲]

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See detailDevelopment and Validation of LC Method for the Diclofenac Sodium Release Determination Using Accuracy Profile Concept
Al-Kamarany, M.A.; El Karbane, M; Belomaria, M et al

in Asian Journal of Chemistry (2012), 24(10), 4393-4400

The article presents a rapid and sensitive RP-HPLC method with UV detection, using the diclofenac sodium release determination in solid pharmaceutical formulations. A novel validation strategy based on ... [more ▼]

The article presents a rapid and sensitive RP-HPLC method with UV detection, using the diclofenac sodium release determination in solid pharmaceutical formulations. A novel validation strategy based on accuracy profiles was used to select the most appropriate regression model with highest accuracy within well defined acceptance limits. Furthermore, the strategy was used to determine the limits of quantification as well as the suitable concentration range. The validation phase was completed by investigating of the risk profiles of various acceptable regression models in order to avoid obtaining measurements outside the acceptance limits fixed a priori. On the other hand, the present study shows how the LC method can be used more accurately to assess the kinetic dissolution profiles, instead the UV-visible method required by monographs of the USP. Robustness study was also performed in order to demonstrate the capability of this method to remain unaffected by a small and deliberate variation in method parameters. The LC method was validated using the total error approach, as a decision tool, guarantees that each of the future results that will be within the acceptance limits settled at ± 5 %. The UV spectrophotometric method based on the USP monograph, gives rise of impurities from diclofenac sodium in acidic condition (HCl 0.1 N). These impurities absorb at the same wave length (276 nm) as the active principal ingredient, which will yield some significant error in the per cent release during the dissolution test study. Described analytical method is a simple, sensitive, specific and more accurate indicating that this LC method is useful for manufacturing and quality control assay. [less ▲]

Detailed reference viewed: 103 (3 ULg)