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Peer Reviewed
See detailComparing deviancy training in three groups of adolescents : qualitative and quantitative data
Mathys, Cécile ULg; Born, Michel; Shaw, Daniel

Poster (2010, March)

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See detailComparing duration of response and duration of clinical benefit between fulvestrant treatment groups in the CONFIRM trial: application of new methodology.
Garnett, Sally Anne; Martin, Miguel; JERUSALEM, Guy ULg et al

in Breast Cancer Research and Treatment (2013), 138(1), 149-55

Comparisons of duration of response (DoR) and duration of clinical benefit (DoCB) within clinical trials are prone to biases. To address these biases, we used new methodology to prospectively analyze ... [more ▼]

Comparisons of duration of response (DoR) and duration of clinical benefit (DoCB) within clinical trials are prone to biases. To address these biases, we used new methodology to prospectively analyze expected DoR and expected DoCB. Objective response rate and clinical benefit rate were calculated for fulvestrant 500 and 250 mg, and used to calculate expected DoR and expected DoCB for each dose group. The ratios for expected DoR and expected DoCB (expected DoR500/expected DoR250 and expected DoCB500/expected DoCB250) were then calculated, thereby allowing statistical comparisons of these endpoints between each arm of the COmparisoN of Faslodex In Recurrent or Metastatic breast cancer (CONFIRM) trial. Expected DoRs for fulvestrant 500 and 250 mg were 3.2 and 3.6 months, respectively. The expected DoR ratio between fulvestrant 500 and 250 mg was not statistically significant (0.89; 95 % CI, 0.48-1.67, P = 0.724). The expected DoCBs for fulvestrant 500 and 250 mg were 9.8 and 7.2 months, respectively. The expected DoCB ratio showed that the expected DoCB for fulvestrant 500 mg was significantly improved compared with the expected DoCB for fulvestrant 250 mg (1.36; 95 % CI, 1.07-1.73, P = 0.013). Analysis of the expected DoR and expected DoCB showed fulvestrant 500 mg significantly increased expected DoCB compared with fulvestrant 250 mg in the CONFIRM trial. [less ▲]

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See detailComparing Farmer-to-Farmer Video with Workshops to Train Rural Women in Improved Rice Parboiling in Central Benin
Zossou, Enangnon ULg; Van Mele, Paul; Vodouhe, Davo Simplice et al

in Journal of Agricultural Education & Extension (2009), 15(4), 329-339

This article deals with the comparison of the conventional training based on two day community workshops and farmer-to-farmer video used as methodologies for the dissemination of improved rice parboiling ... [more ▼]

This article deals with the comparison of the conventional training based on two day community workshops and farmer-to-farmer video used as methodologies for the dissemination of improved rice parboiling process in Benin. From November 2007 to May 2008, we interviewed 160 women and 17 women groups who had been exposed to both, one or other of the methodologies. Data were analysed using ANOVA and logistic binomial regressions. Video reached more women (74%) than conventional training (27%). The conventional training was biased by participant selection, stakes in per diem payment and monopoly by the elite class. Video helped to overcome local power structures and reduced conflict at the community level. More than 95% of those who watched the video adopted drying their rice on tarpaulins and removed their shoes before stirring the rice, compared to about 50% of those who received traditional training and did not watch the video. Group use of the improved equipment was significantly higher for those who watched the video (pB0.05). By 2009, the various rice videos had been translated into over 30 African languages by Africa Rice Centre (Africa Rice) partners and involved 500 organizations and over 130,000 farmers. This study helps to give a better understanding of the role that farmer-to-farmer video could play in agricultural extension. This comparative analysis is an opportunity for a better understanding of how farmer-to-farmer video improves farmers’ practices and attitudes in agricultural technology dissemination. [less ▲]

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See detailComparing global models of terrestrial net primary productivity (NPP): analysis of the seasonal atmospheric CO2 signal
Nemry, B.; François, Louis ULg; Gérard, Jean-Claude ULg et al

in Global Change Biology (1999), 5(Suppl. 1), 65-76

Eight terrestrial biospheric models (TBMs) calculating the monthly distributions of both net primary productivity (NPP) and soil heterotrophic respiration (R-H) in the Potsdam NPP Model Intercomparison ... [more ▼]

Eight terrestrial biospheric models (TBMs) calculating the monthly distributions of both net primary productivity (NPP) and soil heterotrophic respiration (R-H) in the Potsdam NPP Model Intercomparison workshop are used to simulate seasonal patterns of atmospheric CO2 concentration. For each model, we used net ecosystem productivity (NEP=NPP-R-H) as the source function in the TM2 atmospheric transport model from the Max-Planck Institute for Meteorology. Comparing the simulated concentration fields with detrended measurements from 25 monitoring stations spread over the world, we found that the decreasing seasonal amplitude from north to south is rather well reproduced by all the models, though the amplitudes are slightly too low in the north. The agreement between the simulated and observed seasonality is good in the northern hemisphere, but poor in the southern hemisphere, even when the ocean is accounted for. Based on a Fourier analysis of the calculated zonal atmospheric signals, tropical NEP plays a key role in the seasonal cycle of the atmospheric CO2 in the whole southern hemisphere. The relatively poor match between measured and predicted atmospheric CO2 in this hemisphere suggests problems with all the models. The simulation of water relations, a dominant regulator of NEP in the tropics, is a leading candidate for the source of these problems. [less ▲]

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See detailComparing measures of poverty and relative deprivation: an example for Belgium
Delhausse, Bernard; Luttgens, Axel; Perelman, Sergio ULg

in Journal of Population Economics (1993), 6

This paper presents three different poverty standards. A first approach takes the disposable income as an indicator of poverty. A second approach uses the Leyden approach. Finally an aggregate index of ... [more ▼]

This paper presents three different poverty standards. A first approach takes the disposable income as an indicator of poverty. A second approach uses the Leyden approach. Finally an aggregate index of deprivation, based on the observation of consumption events, is constructed through a particular econometric procedure proposed by Desai and Shah (1988). These alternative measures are then compared on a sample composed of 6380 Belgian households. Such an analysis can be expected to provide some further insight into the problem of measuring poverty, which has been the subject of a recent controversial debate. [less ▲]

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See detailComparing monoterpenoid emissions and net photosynthesis of beech (Fagus sylvatica L.) in controlled and natural conditions
Šimpraga; Verbeeck, H.; Demarcke, M. et al

in Atmospheric Environment (2011), 45(17), 2922-2928

Although biogenic volatile organic compounds (BVOCs) only represent a very limited fraction of the plant's carbon (C) budget, they play an important role in atmospheric chemistry for example as a ... [more ▼]

Although biogenic volatile organic compounds (BVOCs) only represent a very limited fraction of the plant's carbon (C) budget, they play an important role in atmospheric chemistry for example as a precursor of tropospheric ozone. We performed a study comparing BVOC emissions of European beech (Fagus sylvatica L.) in controlled and natural environmental conditions. A young and adult beech tree was exposed to short-term temperature variations in growth room conditions and in an experimental forest, respectively. This study attempts to clarify how short-term temperature variations between days influenced the ratio between monoterpenoid (MT) emissions and net photosynthesis (Pn). Within a temperature range of 17-27 °C and 13-23 °C, the MT/Pn carbon ratio increased 10-30 fold for the growth room and forest, respectively. An exponential increasing trend between MT/Pn C ratio and air temperature was observed in both conditions. Beech trees re-emitted a low fraction of the assimilated C back into the atmosphere as MT: 0.01-0.12% and 0.01-0.30% with a temperature rise from 17 to 27 °C and 13-23 °C in growth room and forest conditions, respectively. However, the data showed that the MT/Pn C ratio of young and adult beech trees responded significantly to changes in temperature. [less ▲]

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See detailComparing Radical rights
Jamin, Jérôme ULg

Conference (2002, August 05)

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See detailComparing Simulations and Measurements of Prestressed MEMS
Hannot, Stephan; Rochus, Véronique ULg; Rixen, Daniel

in ECCOMAS (2008)

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See detailComparing sky shape skeletons for the analysis of the visual dynamics along routes
Sarradin, François; Siret, Daniel; Couprie, Michel et al

in Environment & Planning B : Planning & Design (2007), 34/5

The motion of an observer in a given space produces a particular perception called motion perception. This has been defined by Gibson as the gradual changes in the rate of displacements of contour lines ... [more ▼]

The motion of an observer in a given space produces a particular perception called motion perception. This has been defined by Gibson as the gradual changes in the rate of displacements of contour lines in the visual field of the observer. This paper describes a new approach intended for analysing the motion perspective in order to quantify the morphology of urban open spaces along routes. It is based on spherical projections, which provide the shape of the sky boundary around the observer. The projections are studied through their skeletons, which are continuous sets of curves obtained by a progressive thinning down of the shapes around their main saliencies. The proposed method uses these skeletons to follow the variations in the shape of the sky boundary between the successive views. Measures of these variations have been developed and applied in a range of simplified theoretical examples and a real field example in order to show that they succeeded in capturing significant variations in spherical projections. [less ▲]

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See detailComparing technologies for municipal solid waste management using life cycle assessment methodology: a Belgian case study
Belboom, Sandra ULg; Digneffe, Jean-Marc; Renzoni, Roberto ULg et al

in International Journal of Life Cycle Assessment (2013), 18(8), 1513-1523

Purpose The present study aims at identifying the best practice in residual municipal solid waste management using specific data from Liège, a highly industrialized and densely populated region of Belgium ... [more ▼]

Purpose The present study aims at identifying the best practice in residual municipal solid waste management using specific data from Liège, a highly industrialized and densely populated region of Belgium. We also illustrate the importance of assumptions relative to energy through sensitivity analyses and checking uncertainties regarding the results using a Monte Carlo analysis. Methods We consider four distinct household waste management scenarios. A life cycle assessment is made for each of them using the ReCiPe method. The first scenario is sanitary landfill, which is considered as the base case. In the second scenario, the refuse-derived fuel fraction is incinerated and a sanitary landfill is used for the remaining shredded organic and inert waste only. The third scenario consists in incinerating the whole fraction of municipal solid waste. In the fourth scenario, the biodegradable fraction is collected and the remaining waste is incinerated. The extracted biodegradable fraction is then treated in an anaerobic digestion plant. Results and discussion The present study shows that various scenarios have significantly different environmental impact. Compared to sanitary landfill, scenario 4 has a highly reduced environmental impact in terms of climate change and particulate matter formation. An environmental gain, equal to 10, 37, or 1.3 times the impact of scenario 1 is obtained for, respectively, human toxicity, mineral depletion, and fossil fuel depletion categories. These environmental gains are due to energetic valorization via the incineration and anaerobic digestion. Considering specific categories, greenhouse gas emissions are reduced by 17 % in scenario 2 and by 46 % in scenarios 3 and 4. For the particulate matter formation category, a 71 % reduction is achieved by scenario 3. The figures are slightly modified by the Monte Carlo analysis but the ranking of the scenarios is left unchanged. Conclusions The present study shows that replacing a sanitary landfill by efficient incineration significantly reduces both emissions of pollutants and energy depletion, thanks to electricity recovery. [less ▲]

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See detailComparing the effectiveness of alternative investigation methods for library environmental evaluation
Durieux, Nancy ULg; Pasleau, Françoise ULg

Conference (2010, June 16)

The use of new technologies and the merging of our libraries have led us to think about marketing our library services. At the same time, Belgian universities in the French Community decided to conduct ... [more ▼]

The use of new technologies and the merging of our libraries have led us to think about marketing our library services. At the same time, Belgian universities in the French Community decided to conduct the LibQual+ survey. We participated in the working group responsible for data analysis of this survey regarding our institution. This gave us an initial assessment of the level of user satisfaction in our library, pointing to general library strengths and weaknesses and highlighting several questions to be investigated further. We searched for alternative evaluation methods that could help us to validate the LibQual+ conclusions and to explore further certain issues regarding different library user groups (students / researchers / clinicians / academic professors). Methodologies for conducting focus groups, semi-structured interviews and participant observations are largely described in the literature. We propose to test and compare these methodologies in order to discover which method is the most appropriate for each type of user and how far these approaches may be complementary. We also want to verify whether these investigation strategies will lead to reproducible conclusions able to support strategic planning for the library. Lastly, we need to decide whether these methods could also be used to measure the impact of future marketing activities. It may be useful to share our working procedures, conclusions and experiences with colleagues involved in similar marketing challenge. [less ▲]

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See detailComparing the EthoVision 2.3 system and a new computerized multitracking prototype system to measure the swimming behavior in fry fish
Delcourt, Johann ULg; Becco, Christophe ULg; Ylieff, Marc ULg et al

in Behavior Research Methods (2006), 38

Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The ... [more ▼]

Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The EthoVision system has proved to be impressive for tracking a fry using the detection by gray scaling. Detection by subtraction has given less accurate results. Our video multitracking system is able to detect and track more than 100 unmarked fish by gray scaling technique. It permits an analysis at the group level as well as at the individual level. The multitracking program is able to attribute a number to each fish and to follow each one for the whole duration of the track. Our system permits the analysis of the movement of each individual, even if the trajectories of two fish cross each other. This is possible thanks to the theoretical estimation of the trajectory of each fish, which can be compared with the real trajectory (analysis with feedback). However, the period of the track is limited for our system (about 1 min), whereas EthoVision is able to track for numerous hours. In spite of these limitations, these two systems allow an almost continuous automatic sampling of the movement behaviors during the track. [less ▲]

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See detailComparing the neural bases of self-referential processing in typically developing and 22q11.2 adolescents
Schneider, Maude; Debbané, Martin; Lagioia, Anna Laura et al

in Developmental Cognitive Neuroscience (2012), 2

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See detailComparing the paleoseismic record obtained by coring a sag-pond and by classical trenching along the eastern segment of the North Anatolian Fault
Hubert, Aurelia ULg; Avsar, Ulas; Fraser, Jeef et al

Conference (2012, October)

Shallow lakes along minor structural bends or discontinuities of strike-slip fault are not usually paleoseismological target sites. In the present talk we show that a 2m deep, 700m long lake crosscut by ... [more ▼]

Shallow lakes along minor structural bends or discontinuities of strike-slip fault are not usually paleoseismological target sites. In the present talk we show that a 2m deep, 700m long lake crosscut by the eastern segment of the North Anatolian Fault contains a reliable paleoseimological record obtained through coring. The North Anatolian Fault, a major strike-slip fault in Turkey, last ruptured across the Aşağıtepecik Lake in 1939 with a slip of about 6 m. Seismic lines still show remains of the fault rupture forming minor scarps across the lake. Collected short cores display a set of sedimentary sequences. Each sequence is composed of similar organic rich sedimentary units. The lower unit is dark and fibrous, and is similar to the present sedimentation at the top of the core. The upper unit is disturbed and has anomalous organic matter content, grain size and mineralogy. It is interpreted as an earthquake induced sedimentary event. The 2.5 m long AT2007LG core comprises four sequences, and four sedimentary events. Radiogenic 210Pb and 137Cs data obtained in Boes et al. (2009) imply that the shallowest event 1 was triggered by the 1939 M=7.9 Erzincan earthquake. Radiocarbon dating suggest that events 2 and 4 were initiated by the 1668 and 1254 historical earthquakes. The event 3 does not correspond to a large historical earthquake on the NAF. The record can be compared to a classical paleoseismological study located about 2.5 km more to the east. The investigation comprised three paleoseismic trenches located along about 2km of the principal fault strand. Trench T1 revealed clear evidence for one earthquake interpreted to be the 1939 Erzincan earthquake. Trench T2 revealed evidence of three earthquakes. Trench T3 revealed a record of colluvial wedges that interfinger with fine-grained inter-fan deposits. We interpreted a sequence of six earthquake event horizons including the 1939 Erzincan earthquake. The first three earthquakes are correlated to historical earthquakes in A.D. 1668, 1254, 499 and two further events were identified at 881 – 673 B.C. and 1406 – 1291 B.C. (2σ age ranges). By comparing all available earthquake timing studies,we conclude that the 1939 earthquake segment does not always rupture in unison. [less ▲]

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See detailComparing traffic engineering objective functions
Balon, Simon ULg; Skivée, Fabian; Leduc, Guy ULg

in CoNext 2005 - Student Workshop (2005, October)

We compare and evaluate how well-known and novel network-wide objective functions for Traffic Engineering (TE) algorithms fulfil TE requirements. To compare the objective functions we model the TE problem ... [more ▼]

We compare and evaluate how well-known and novel network-wide objective functions for Traffic Engineering (TE) algorithms fulfil TE requirements. To compare the objective functions we model the TE problem as a linear program and solve it to optimality, thus finding for each objective function the best possible target of any heuristic TE algorithm. Our first results suggest that they can give quite different results. [less ▲]

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See detailComparing vertical ground heat exchanger models
Bertagnolio, Stéphane ULg; Bernier, Michel; Kummert, Michaël

in Journal of Building Performance Simulation [=JBPS] (2012)

The main objective of this article is to establish a set of test cases for analytical verification and inter-model comparison of vertical ground heat exchanger (GHX) models used in building simulation ... [more ▼]

The main objective of this article is to establish a set of test cases for analytical verification and inter-model comparison of vertical ground heat exchanger (GHX) models used in building simulation programs. Several test cases are suggested. They range from steady-state heat rejection in a single borehole to varying hourly loads with relatively large yearly thermal imbalance in multiple borehole configurations. The usefulness of the proposed test cases is illustrated with different GHX models. This comparison exercise has shown that analytical one-dimensional (1D) models compare favourably well with three-dimensional (3D) models for relatively short-simulation periods, where axial effects are not significant. Cyclic heat rejection/collection tests proved to be useful to characterize the accuracy and the computational performance of different load aggregation algorithms. Finally, different spatial superposition methods have been compared for various bore field sizes and configurations and various loads. [less ▲]

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See detailA comparison study of image appraisal tools for electrical resistivity tomography
Caterina, David ULg; Beaujean, Jean ULg; Robert, Tanguy ULg et al

in Near Surface Geophysics (2013)

To date, few studies offer a quantitative comparison of the performance of image appraisal tools. Moreover, there is no commonly accepted methodology to handle them even though it is a crucial aspect for ... [more ▼]

To date, few studies offer a quantitative comparison of the performance of image appraisal tools. Moreover, there is no commonly accepted methodology to handle them even though it is a crucial aspect for reliable interpretation of geophysical images. In this study, we compare quantitatively different image appraisal indicators to detect artefacts, estimate depth of investigation, address parameters resolution and appraise ERT-derived geometry. Among existing image appraisal tools, we focus on the model resolution matrix (R), the cumulative sensitivity matrix (S) and the depth of investigation index (DOI) that are regularly used in the literature. They are first compared with numerical models representing different geological situations in terms of heterogeneity and scale and then used on field data sets. The numerical benchmark shows that indicators based on R and S are the most appropriate to appraise ERT images in terms of the exactitude of inverted parameters, DOI providing mainly qualitative information. In parallel, we test two different edge detection algorithms – Watershed’s and Canny’s algorithms – on the numerical models to identify the geom-etry of electrical structures in ERT images. From the results obtained, Canny’s algorithm seems to be the most reliable to help practitioners in the interpretation of buried structures. On this basis, we propose a methodology to appraise field ERT images. First, numerical bench¬mark models representing simplified cases of field ERT images are built using available a priori information. Then, ERT images are produced for these benchmark models (all simulated acquisition and inversion parameters being the same). The comparison between the numerical benchmark mod¬els and their corresponding ERT images gives the errors on inverted parameters. These discrepan¬cies are then evaluated against the appraisal indicators (R and S) allowing the definition of threshold values. The final step consists in applying the threshold values on the field ERT images and to validate the results with a posteriori knowledge. The developed approach is tested successfully on two field data sets providing important information on the reliability of the location of a contamina¬tion source and on the geometry of a fractured zone. However, quantitative use of these indicators remains a difficult task depending mainly on the confidence level desired by the user. Further research is thus needed to develop new appraisal indicators more suited for a quantitative use and to improve the quality of inversion itself. [less ▲]

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See detailA comparison among portal lactate, intramucosal sigmoid pH, and Delta CO2 (Paco(2) regional Pco(2)) as indices of complications in patients undergoing abdominal aortic aneurysm surgery
Donati, A.; Cornacchini, O.; Loggi, S. et al

in Anesthesia and Analgesia (2004), 99(4), 1024-1031

Our aim in this observational, prospective, noncontrolled study was to detect, in 29 patients who underwent abdominal aortic aneurysm (AAA) surgery, correlations between the incidence of postoperative ... [more ▼]

Our aim in this observational, prospective, noncontrolled study was to detect, in 29 patients who underwent abdominal aortic aneurysm (AAA) surgery, correlations between the incidence of postoperative organ failure and intraoperative changes in arterial and portal blood lactate; changes in intramucosal sigmoid pH (pHi); differences between sigmoid P-CO2 and arterial P-CO2 (DeltaCO(2)); and hemoglobin (Hb). Hb, arterial blood lactate concentrations, pHi, and DeltaCO(2) (air tonometry) were recorded at the start of anesthesia (T0), before aorta clamping (T1), 30 minutes after clamping (T2), and at the end of surgery (T3). Portal venous lactate concentrations were recorded at T1 and T2. Patients were stratified into two groups: group A patients had no postoperative organ failure, and group B patients had one or more organ failures. As compared with group A (n = 16), group B patients (n = 13) had a lower pHi value at T2 and T3 and a higher DeltaCO(2) at T3. A pHi value of <7.15 was a predictor of organ failure, with a sensitivity of 92.3%, a specificity of 68.8%, and positive and negative predictive values of 70.6% and 91.7%, respectively, whereas a DeltaCO(2) value of >28 mm Hg predicted later organ failure with a sensitivity of 92.3%, a specificity of 62.5%, and positive and negative predictive values of 66.6% and 90.9%, respectively. Portal venous lactate concentrations were larger in group B at T2 (P<0.001), and an increase greater than or equal to5 g/dL predicted later postoperative organ failure with a sensitivity of 92.3%, a specificity of 100%, and positive and negative predictive values of 100% and 94.1%, respectively. The comparison of the receiving operator characteristic curves to test the discrimination of each variable and the logistic regression analysis revealed that the increase in portal lactate was the best predictor for the development of postoperative organ failure. Hb concentration was significantly smaller in group B at T0 (13.8 +/- 1.0 g/dL versus 12.2 +/- 2.2 g/dL) and T2 (10.9 +/- 1.2 g/dL versus 9.1 +/- 1.9 g/dL). In conclusion, both pHi and DeltaCO(2) are reasonably sensitive prognostic indices of organ failures after AAA surgery, but they are less specific and accurate than portal venous lactate. [less ▲]

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See detailComparison and combination of spectroscopic techniques for the detection of counterfeit medicines
Sacré, Pierre-Yves ULg; Deconinck, Eric; De Beer, Thomas et al

Poster (2010, September 23)

During this study, Fourier transform infrared spectroscopy (FT-IR), near infrared spectroscopy (NIR) and Raman spectroscopy were applied to 55 samples of counterfeit and imitations of Viagra® and 39 ... [more ▼]

During this study, Fourier transform infrared spectroscopy (FT-IR), near infrared spectroscopy (NIR) and Raman spectroscopy were applied to 55 samples of counterfeit and imitations of Viagra® and 39 samples of counterfeit and imitations of Cialis®. The aim of the study was to investigate which of these techniques and associations of them were the best for discriminating genuine from counterfeit and imitation samples. Only the regions between 1800-400 cm-1 and 7000-4000 cm-1 were used for FT-IR and NIR spectroscopy respectively. Partial Least Square analysis has been used to allow the detection of counterfeit and imitation tablets. It is shown that for the Viagra® samples, the best results were provided by a combination of FT-IR and NIR spectroscopy. On the other hand, the best results for the Cialis® samples were provided by the combination of NIR and Raman spectroscopy (1400-1190 cm-1). These techniques permitted a clear discrimination between genuine and counterfeit or imitation samples but also the distinction of clusters among illegal samples. This might be interesting for forensic investigations by authorities. [less ▲]

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See detailComparison and combination of spectroscopic techniques for the detection of counterfeit medicines
Sacré, Pierre-Yves ULg; Deconinck, Eric; De Beer, Thomas et al

in Journal of Pharmaceutical & Biomedical Analysis (2010), 53

During this study, Fourier transform infrared spectroscopy (FT-IR), near infrared spectroscopy (NIR) and Raman spectroscopy were applied to 55 samples of counterfeit and imitations of Viagra® and 39 ... [more ▼]

During this study, Fourier transform infrared spectroscopy (FT-IR), near infrared spectroscopy (NIR) and Raman spectroscopy were applied to 55 samples of counterfeit and imitations of Viagra® and 39 samples of counterfeit and imitations of Cialis®. The aim of the study was to investigate which of these techniques and associations of them were the best for discriminating genuine from counterfeit and imitation samples. Only the regions between 1800-400 cm-1 and 7000-4000 cm-1 were used for FT-IR and NIR spectroscopy respectively. Partial Least Square analysis has been used to allow the detection of counterfeit and imitation tablets. It is shown that for the Viagra® samples, the best results were provided by a combination of FT-IR and NIR spectroscopy. On the other hand, the best results for the Cialis® samples were provided by the combination of NIR and Raman spectroscopy (1400-1190 cm-1). These techniques permitted a clear discrimination between genuine and counterfeit or imitation samples but also the distinction of clusters among illegal samples. This might be interesting for forensic investigations by authorities. [less ▲]

Detailed reference viewed: 60 (14 ULg)