XPS investigation of thin SiOx and SiOxNy overlayers

Cataloged from PDF version of article.Angle-resolved XPS is used to determine the thickness and the uniformity of the chemical composition with respect to oxygen and nitrogen of the very thin silicon oxide and oxynitride overlayers grown on silicon. (C) 1999 Elsevier Science B.V. All rights reserved

Heart ablation using a planar rectangular high intensity ultrasound transducer and MRI guidance

The aim of this study was to evaluate a flat rectangular (3 × 10 mm2) MRI compatible transducer operating at 5 MHz. The main task was to explore the feasibility of creating deep lesions in heart at a depth of at least 15 mm. The size of thermal necrosis in heart tissue was estimated as a function of power and time using a simulation model. The system was then tested in an excised lamb heart. In this study, we were able to create lesions of 15 mm deep with acoustic power of 6 W for an exposure of approximately 1 min. The contrast to noise ratio (CNR) between lesion and heart tissue was evaluated using fast spin echo (FSE). The CNR value was approximately 22 using T1 W FSE. Maximum CNR was achieved with repetition time (TR) between 300 and 800 ms. Using T2W FSE, the corresponding CNR was approximately 13 for the 14 in vivo experiments. The average lesion depth was 11.93 mm with a standard deviation of 0.62 mm. In vivo irradiation conditions were 6 W for 60 s. The size of the lesion in the other two dimensions was close to 3 × 10 mm2 (size of the transducer element)

MESURE NON INVASIVE DU DÉBIT AORTIQUE PAR VOIE OESOPHAGIÈNNE

Depuis plusieurs années nous avons montré la faisabilité et l'intérêt clinique de la débitmétrie aortique par voie oesophagienne. Une amélioration importante de cette méthode a été apportée par le développement d'un nouveau type de débitmètre associant un imageur T.M. et un vélocimètre Doppler à émission pulsée. Afin de pouvoir mesurer simultanément et de façon continue le diamètre de l'aorte et la vitesse du flux sanguin aussi bien chez l'adulte que chez l'enfant (à l'aide d'une sonde oesophagienne simplifiée et miniaturisée). Les résultats obtenus chez l'animal lors de la validation expérimentale de cette méthode ont montré un coefficient de corrélation de 0,94 entre le débit mesuré au niveau de l'aorte descendante à la fois par voie oesophagienne et au moyen d'un débitmètre électromagnétique.For several years it has been shown the feasibility and clinical interest of non invasive aortic blood flow measurement in adult using an intraesophageal ultrasonic probe. In order to improve accuracy of this method a new flowmeter combining M-mode imaging system and pulsed Doppler was developped. The choice of such ultrasound techniques makes possible to measure simultaneously and continuously flow blood velocity and aortic diameter and allows more accurate aortic blood flow measurements as well in adult as in child patients (using a miniaturized oesophageal probe). In vivo experimental results show a 0.94 correlation coefficient between blood flow in descending aorta measured by this method and by means of electromagnetic flowmeter

TiO2-Al2O3 binary mixed oxide surfaces for photocatalytic Nox abatement

Cataloged from PDF version of article.TiO2-Al2O3 binary oxide surfaces were utilized in order to develop an alternative photocatalytic NOx abatement approach, where TiO2 sites were used for ambient photocatalytic oxidation of NO with O-2 and alumina sites were exploited for NOx storage. Chemical, crystallographic and electronic structure of the TiO2-Al2O3 binary oxide surfaces were characterized (via BET surface area measurements, XRD, Raman spectroscopy and DR-UV-Vis Spectroscopy) as a function of the TiO2 loading in the mixture as well as the calcination temperature used in the synthesis protocol. 0.5 Ti/Al-900 photocatalyst showed remarkable photocatalytic NOx oxidation and storage performance, which was found to be much superior to that of a Degussa P25 industrial benchmark photocatalyst (i.e. 160% higher NOx storage and 55% lower NO2(g) release to the atmosphere). Our results indicate that the onset of the photocatalytic NOx abatement activity is concomitant to the switch between amorphous to a crystalline phase with an electronic band gap within 3.05-3.10 eV; where the most active photocatalyst revealed predominantly rutile phase together and anatase as the minority phase. (C) 2014 Elsevier B.V. All rights reserved

IONS AS PROBES OF SUB-PS WATER NETWORK DYNAMICS

Author Institution: Department of Physical Chemistry II, Ruhr-University Bochum, D-44780 Bochum, Germany; Department of Chemistry, Koc University, 34450 Istanbul, Turkey; Department of Chemistry, University of Nevada, 89557 Reno, Nevada, USAWe present THz measurements of salt solutions which shed new light on the controversy of salts as kosmotropes (structure makers) or chaotropes (structure breakers). We performed concentration dependent narrow-band THz-absorption spectroscopy on fifteen alkali-halide salt solutions around 85~cm$^{-1}$ (2.5 THz) and wide-band (30-300~cm$^{-1}$) THz Fourier transform measurements on six alkali halide salt solutions. All solutions show an increased THz-absorption compared to pure water with a linear concentration dependence. Our comprehensive data set is well-described by a model including damped harmonic oscillations (rattling modes) of both anions and cations within the water network. This model well-predicts key features of THz spectra for a variety of salt solutions. Complementary molecular dynamics simulations using the TIP3P water model support experiments and show that the fast sub-ps ionic motions and their surroundings are almost decoupled. These findings provide a complete description of the solute-induced changes in the THz solvation dynamics for the investigated salts and suggests a treatment of the ions as simple defects in an H-bond network. Our results show that THz spectroscopy is a powerful experimental tool to establish a new insights on contributions to the structuring of water by anions and cations

Anti-TNF agents restrict adherent-invasive E. coli replication within macrophages through modulation of chitinase 3-like 1 in patients with Crohn’s disease.

International audienc

Heart ablation using a planar rectangular high intensity focused ultrasound transducer and MRI guidance

The aim of this study was to evaluate the performance of a flat rectangular (3×10 mm2) MRI compatible transducer operating at 5 MHz in creating deep lesions in heart at a depth of at least 15 mm. The size of thermal necrosis in heart tissue was estimated as a function of power and time using a simulation model. The system was then tested in freshly excised heart of pig and lamb. In this study we were able to create lesions 15 mm deep with an acoustic power of 6W for an exposure of approximately one minute. The contrast to noise ratio (CNR) between lesion and heart tissue was evaluated using Fast Spin Echo (FSE). With T1W FSE the CNR value was approximately 22. Maximum CNR was achieved with repetition times (TR) between 300 and 800 ms. With T2W FSE the corresponding CNR was approximately 13. The transducer was tested in rabbits in vivo and despite the motion of the heart; it was possible to create thermal lesions. © 2011 American Institute of Physics