Last 7 days     Results 1601-1620 of 72977.   76 77 78 79 80 81 82 83 84 85 86   Raman Chemical Imaging in Kidney Stone AnalysisCastiglione, Vincent ; Sacre, Pierre-Yves ; CAVALIER, Etienne et alPoster (2017, November 02)Background: The structure of kidney stones might provide clinical useful information in addition to the stone composition. The Raman chemical imaging (RCI) is a new technology used for the production of ... [more ▼]Background: The structure of kidney stones might provide clinical useful information in addition to the stone composition. The Raman chemical imaging (RCI) is a new technology used for the production of two-dimensions maps of the constituents' distribution in samples. We aimed at determining the use of RCI in urinary stone analysis. Methods: Twelve calculi were analyzed by RCI using a confocal Raman microspectrophotometer. They were selected according to their heterogeneous composition and morphology. Prior to the analysis, samples were sliced and milled in order to detect the nucleus of the stones and having a smooth surface. RCI was performed on the whole section of stones. Once acquired, the data were baseline corrected and analyzed by MCR-ALS. Results were then compared to the spectra obtained by Fourier Transform Infrared spectroscopy, the gold standard method for the determination of urolithiasis composition. Results: RCI succeeded in identifying all the chemical components contained in each sample, including monohydrate and dihydrate calcium oxalate, anhydrous and dihydrate uric acid, apatite, struvite, brushite, whitlockite and ammonium urate. However, proteins couldn't be detected because of the huge autofluorescence background and the small concentration of these poor Raman scatterers. Carbapatite and calcium oxalate were correctly detected even when they represented less than 5 percent of the whole stones, allowing the detection of very small structures like Randall's plaques. Moreover, RCI provided the distribution of components within the stones. The nuclei were accurately identified, as well as thin layers of other components. Conversion of dihydrate to monohydrate calcium oxalate was correctly observed in the center of one sample. Conclusion: RCI showed a good accuracy in comparison with infrared spectroscopy in identifying components of kidney stones. In addition, RCI is nondestructive enabling the storage of samples. This analysis was also useful in determining the organization of components within stones, which help locating constituents in low quantity, such as nuclei. However, this analysis is time-consuming, which makes it more suitable for research studies rather than routine analysis. [less ▲]Detailed reference viewed: 43 (1 ULiège) Effects of Transcranial Direct Current Stimulation, Transcranial Pulsed Current Stimulation, and Their Combination on Brain Oscillations in Patients with Chronic Visceral Pain: A Pilot Crossover Randomized Controlled Study.Thibaut, Aurore ; Russo, Cristina; Hurtado-Puerto, Aura-Maria et alin Frontiers in Neurology (2017)Objective: Chronic visceral pain (CVP) syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different ... [more ▼]Objective: Chronic visceral pain (CVP) syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different neuromodulation techniques in patients with CVP on cortical activity, through electreocephalography (EEG) and on pain perception, through clinical tests. Design:A pilot crossover randomized controlled study. Settings: Out-patient. Subjects: Adults with CVP (>3 months). Methods: Participants received four interventions in a randomized order: (1) transcranial pulsed current stimulation (tPCS) and active transcranial direct current stimulation (tDCS) combined, (2) tPCS alone, (3) tDCS alone, and (4) sham condition. Resting state quantitative electroencephalography (qEEG) and pain assessments were performed before and after each intervention. Results were compared with a cohort of 47 healthy controls. Results: We enrolled six patients with CVP for a total of 21 visits completed. Compared with healthy participants, patients with CVP showed altered cortical activity characterized by increased power in theta, alpha and beta bands, and a significant reduction in the alpha/beta ratio. Regarding tES, the combination of tDCS with tPCS had no effect on power in any of the bandwidths, nor brain regions. Comparing tPCS with tDCS alone, we found that tPCS induced higher increase in power within the theta and alpha bandwidths. Conclusion: This study confirms that patients with CVP present abnormal EEG-indexed cortical activity compared with healthy controls. Moreover, we showed that combining two types of neurostimulation techniques had no effect, whereas the two interventions, when applied individually, have different neural signatures. [less ▲]Detailed reference viewed: 22 (0 ULiège) An X-ray view of HD 166734, a massive supergiant systemNazé, Yaël ; Gosset, Eric ; Mahy, Laurent et alin Astronomy and Astrophysics (2017), 607(A97), 1-10The X-ray emission of the O+O binary HD 166734 was monitored using Swift and XMM-Newton observatories, leading to the discovery of phase-locked variations. The presence of an f line in the He-like ... [more ▼]The X-ray emission of the O+O binary HD 166734 was monitored using Swift and XMM-Newton observatories, leading to the discovery of phase-locked variations. The presence of an f line in the He-like triplets further supports a wind-wind collision as the main source of the X-rays in HD 166734. While temperature and absorption do not vary significantly along the orbit, the X-ray emission strength varies by one order of magnitude, with a long minimum state (Δ(φ) 0.1) occurring after a steep decrease. The flux at minimum is compatible with the intrinsic emission of the O-stars in the system, suggesting a possible disappearance of colliding wind emission. While this minimum cannot be explained by eclipse or occultation effects, a shock collapse may occur at periastron in view of the wind properties. Afterwards, the recovery is long, with an X-ray flux proportional to the separation d (in hard band) or to d[SUP]2[/SUP] (in soft band). This is incompatible with an adiabatic nature for the collision (which would instead lead to F[SUB]X[/SUB] ∝ 1 /d), but could be reconciled with a radiative character of the collision, though predicted temperatures are lower and more variable than in observations. An increase in flux around φ 0.65 and the global asymmetry of the light curve remain unexplained, however. Based on observations collected with Swift and the ESA science mission XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). [less ▲]Detailed reference viewed: 16 (3 ULiège) High-precision multi-wavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 bDelrez, L.; Madhusudhan, N.; Lendl, M. et alin Monthly Notices of the Royal Astronomical Society (2017), 474(2), 2334-2351We present sixteen occultation and three transit light curves for the ultra-short period hot Jupiter WASP-103 b, in addition to five new radial velocity measurements. We combine these observations with ... [more ▼]We present sixteen occultation and three transit light curves for the ultra-short period hot Jupiter WASP-103 b, in addition to five new radial velocity measurements. We combine these observations with archival data and perform a global analysis of the resulting extensive dataset, accounting for the contamination from a nearby star. We detect the thermal emission of the planet in both the $z'$ and $K_{\mathrm{S}}$-bands, the measured occultation depths being 699$\pm$110 ppm (6.4-$\sigma$) and $3567_{-350}^{+400}$ ppm (10.2-$\sigma$), respectively. We use these two measurements together with recently published HST/WFC3 data to derive joint constraints on the properties of WASP-103 b's dayside atmosphere. On one hand, we find that the $z'$-band and WFC3 data are best fit by an isothermal atmosphere at 2900 K or an atmosphere with a low H$_2$O abundance. On the other hand, we find an unexpected excess in the $K_{\mathrm{S}}$-band measured flux compared to these models, which requires confirmation with additional observations before any interpretation can be given. From our global data analysis, we also derive a broad-band optical transmission spectrum that shows a minimum around 700 nm and increasing values towards both shorter and longer wavelengths. This is in agreement with a previous study based on a large fraction of the archival transit light curves used in our analysis. The unusual profile of this transmission spectrum is poorly matched by theoretical spectra and is not confirmed by more recent observations at higher spectral resolution. Additional data, both in emission and transmission, are required to better constrain the atmospheric properties of WASP-103 b. [less ▲]Detailed reference viewed: 15 (1 ULiège) Le droit de propriété et le droit au logement font-ils bon ménage ? De quelques réflexions politologiques à partir des libertés fondamentalesGrandjean, Geoffrey in Le Cri (2017), (418), 10-13Detailed reference viewed: 32 (5 ULiège) Seismic inversion of the solar entropy. A case for improving the standard solar modelBuldgen, Gaël ; Salmon, Sébastien ; Noels-Grötsch, Arlette et alin Astronomy and Astrophysics (2017), 607Context. The Sun is the most constrained and well-studied of all stars. As a consequence, the physical ingredients entering solar models are used as a reference to study all other stars observed in the ... [more ▼]Context. The Sun is the most constrained and well-studied of all stars. As a consequence, the physical ingredients entering solar models are used as a reference to study all other stars observed in the Universe. However, our understanding of the solar structure is still imperfect, as illustrated by the current debate on the heavy element abundances in the Sun.