References of "Bahri, Mohamed Ali"
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See detailTHE EFFECT OF BETA MICROPROBE IMPLANTATION ON THE BLOOD BRAIN BARRIER
Warnock, Geoffrey ULg; Dedeurwaardere, Stefanie; Bahri, Mohamed Ali ULg et al

Poster (2010, September)

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See detailDISPLACEMENT OF 18F-FALLYPRIDE BINDING WITH HALOPERIDOL IN A WITHIN-SUBJECT DESIGN USING A BETA MICROPROBE
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Cerebral Blood Flow & Metabolism (2009, October), 29(S1), 352-353

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See detailNEMA NU4-2008 Image Quality Performance Report for the microPET Focus 120 and for Various Transmission and Reconstruction Methods
Bahri, Mohamed Ali ULg; Plenevaux, Alain ULg; Warnock, Geoffrey ULg et al

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (2009), 50

This work aimed to evaluate the image quality and accuracy of attenuation and scatter corrections provided with the microPET Focus 120 scanner using the National Electrical Manufacturers Association NU4 ... [more ▼]

This work aimed to evaluate the image quality and accuracy of attenuation and scatter corrections provided with the microPET Focus 120 scanner using the National Electrical Manufacturers Association NU4-2008 image quality phantom. Methods: Attenuation correction was obtained from transmission measurements using either a 68Ge or a 57Copoint source. Fully correctedemission images were reconstructed using Fourier rebinning (FORE) and filtered backprojection (FBP). For attenuation data obtained with the 57Co source, fully corrected emission images were also reconstructed using FORE and 2-dimensional (2D) ordered-subset expectation maximization (OSEM), 3-dimensional (3D) filtered backprojection (3DRP), 3D OSEM, and 3D maximum a posteriori methods. The mean activity, the coefficients of variation (COVs) of the uniform slices, the recovery coefficients (RCs) for hot rods, and the spillover ratio (SOR) for nonemittingwater and air compartments were measured. Results: For 57Co-based attenuation correction, the mean activity value differed by less than 3% from the true activity.Measuring the attenuation with 68Ge resulted in lower reconstructed activity and higher COV. On the basis of 57Co measurements, the SORs for air and water nonemitting compartments were the closest to zero for attenuation correction. The RC measured on emission images corrected for attenuation but not for scatter did not show any significant difference linked to the transmissionmethod. However, higherRCswere noted for transmission measurement with 68Ge in coincidence with windowing when emission data were corrected for attenuation and scatter. This resulted from a lower mean value in the uniform area. 2D and 3DRP reconstructionmethods showed little effect on themean activity value, whereas iterative 3D methods gave 7%higher values. Higher RCs were found with iterative reconstruction than with FBP and 3DRP. However, the SOR seemed to be optimal with FBP. SORs were higher with iterative methods and decreased with the number of iterations. Conclusion: For studies of small rodents with the Focus 120, 57Co transmission seems to be the most suitable method for attenuation correction. FORE and 2D reconstruction methods appear to be a good compromise between overall image quality and reconstruction time: OSEM provides the largest contrasts, but FBP provides superior attenuation and scatter correction. [less ▲]

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See detailTIME-DEPENDENT PREFERENTIAL IN VIVO D2 OCCUPANCY BY AMISULPRIDE IN THE MEDIAL STRIATUM – CONTINUOUS MEASUREMENT USING A BETA MICROPROBE SYSTEM
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 105

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See detailUSE OF A BETA MICROPROBE SYSTEM AS AN AFFORDABLE TRANSLATIONAL TOOL COMPARED TO PET – EXAMPLES USING FDG AND 18F-FALLYPRIDE BINDING
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 55

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See detailTHE USEFULNESS OF AN ARTERIOVENOUS SHUNT COMBINED WITH A BETA MICROPROBE FOR THE MEASUREMENT OF INPUT FUNCTION IN RATS
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 106

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See detailThe CMC-like behaviour of bile salts as probed by photoexcited Rose Bengal
Seret, Alain ULg; Bahri, Mohamed Ali ULg

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2009), 339

The onset of the aggregation process in aqueous bile salt (BS) solutions remains a debated question. This study aimed at investigating this point through the detection of BS monomers and small aggregates ... [more ▼]

The onset of the aggregation process in aqueous bile salt (BS) solutions remains a debated question. This study aimed at investigating this point through the detection of BS monomers and small aggregates using the dye Rose Bengal. Results showed that a few small BS aggregates led to a red shift of the absorption spectrum, while the BS monomer reacted with the photo-induced semi-oxidized dye and decreased its decay rate constant. The dye was dissolved in aqueous solution (10 mmol dm-3 NaOH) of sodium cholate (NaC), deoxycholate (NaDC), chenodoxycholate (NaCDC), dehydrocholate (NaDHC), glycocholate (NaGC) glycodeoxycholate (NaGDC), taurocholate (NaTC), taurodeoxycholate (NaTDC) and the zwitterionic analogue of sodium cholate called CHAPS. BS aggregates were detected at concentrations well below the concentration above which any added bile salt molecules participate in the aggregation process for all trihydroxy bile salts and for CHAPS but not for the dihydroxy bile salts. No aggregation of NaDHC could be observed in the studied concentration range (≤ 10 mmol dm-3). The presence of 150 and 600 mmol dm-3 sodium ions lowered the concentration below which BS are mainly monomers for dihydroxy but not for trihydroxy bile salts. As already proposed by others, the use of the concept of Micellar Dissociation Concentration (MDC) is suggested here instead of the classical Critical Micelle Concentration (CMC). [less ▲]

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See detailQuantification of Randomly-methylated-b-cyclodextrin effect on liposome: An ESR study
Grammenos, Angeliki ULg; Bahri, Mohamed Ali ULg; Guelluy, Pierre-Henri ULg et al

in Biochemical and Biophysical Research Communications (2009), 390

In the present work, the effect of Randomly-methylated-b-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-a phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance ... [more ▼]

In the present work, the effect of Randomly-methylated-b-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-a phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance (ESR) technique. The ability of Rameb to extract membrane cholesterol was demonstrated. For the first time, the percentage of cholesterol extracted by Rameb from cholesterol doped DMPC bilayer was monitored and quantified throughout a wide Rameb concentration range. The effect of cholesterol on the inner part of the membrane was also investigated using 16-doxyl stearic acid spin label (16-DSA). 16-DSA seems to explore two different membrane domains and report their respective microviscosities. ESR experiments also establish that the presence of 30% of cholesterol in DMPC liposomes suppresses the jump in membrane fluidity at lipids phase-transition temperature (23.9°C). [less ▲]

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See detailImage Quality, Accuracy of Attenuation and Scatter Corrections of the microPET Focus 120 Using the NEMA NU4-2008 Phantom
Bahri, Mohamed Ali ULg; Plenevaux, Alain ULg; Seret, Alain ULg

Poster (2008, October)

This work aimed at evaluating the image quality and the accuracy of attenuation and scatter corrections methodologies provided with the microPET Focus 120 scanner. The protocol used here is described in ... [more ▼]

This work aimed at evaluating the image quality and the accuracy of attenuation and scatter corrections methodologies provided with the microPET Focus 120 scanner. The protocol used here is described in the forthcoming NEMA NU4-2008 document. This study included 1 h transmission experiments, with two sources (68Ge and 57Co, both one half-live old), in coincidence mode (Ge) with and without windowing, and singles mode (Ge and Co). Transmission data with Co were also collected for shorter acquisition times (515/1030/2060 s). Transmission with scatter correction, and emission with attenuation with or without scatter correction, slices were reconstructed using 2D-FBP (ramp filter). The uniformity, the recovery coefficients (RC) and the accuracy of corrections were evaluated as described in the NEMA document. We also determined the attenuation coefficient (AC) for water using the methodology applied to measure the mean pixel value for the emission slices of the uniform part of the phantom. The Co single mode measurements provided a mean AC for water closer to the theoretical value than the Ge measurements either in single or in coincidence mode even for the shortest acquisition time. Moreover, the lowest coefficients of variation per pixel of the uniform slices were measured for attenuation corrected data based on Co measurements. Also, spill-over ratio for non-emitting air and water compartments reflected a higher capability of this attenuation correction method for scatter correction. The RC measured on emission image corrected only for attenuation did not show any significant difference linked to the transmission measured methods. However, higher RC values were noted for Ge coincidence with windowing when emission data were corrected for both attenuation and scatter. Hence, Co singles transmission seems to be the most suitable method for attenuation correction on the microPET Focus 120 scanner. [less ▲]

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See detailEffect of statin on liposome and cell membranes fluidity. An ESR spin probe study
Ngendakamuna; Bahri, Mohamed Ali ULg; Hoebeke, Maryse ULg

Poster (2008, May 16)

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See detailAttenuation and scatter correction accuracy of the microPET Focus 120 assessed with the NEMA NU-4 2008 phantom.
Bahri, Mohamed Ali ULg; Plenevaux, Alain ULg; Seret, Alain ULg

in European Journal of Nuclear Medicine and Molecular Imaging (2008), 35(S2), 193

Detailed reference viewed: 76 (15 ULg)