Search results for " Scanning"
showing 10 items of 988 documents
The boson peak of deeply cooled confined water reveals the existence of a low-temperature liquid-liquid crossover.
2014
International audience; The Boson peak of deeply cooled water confined in the pores of a silica xerogel is studied by inelastic neutron scattering at different hydration levels to separate the contributions from matrix, water on the pore surfaces and "internal" water. Our results reveal that at high hydration level, where the contribution from internal water is dominant, the temperature dependence of the Boson peak intensity shows an inflection point at about 225 K. The complementary use of differential scanning calorimetry to describe the thermodynamics of the system allows identifying the inflection point as the signature of a water liquid-liquid crossover.
Artificial cartilage bio-matrix formed of hyaluronic acid and Mg2+-polyphosphate.
2016
Here we show that inorganic polyphosphate (polyP), a polyanionic metabolic regulator consisting of multiple phosphate residues linked by energy-rich phosphoanhydride bonds, is present in the synovial fluid. In a biomimetic approach, to enhance cartilage synthesis and regeneration, we prepared amorphous polyP microparticles with Mg2+ as counterions. The particles were characterised by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and Fourier transformed infrared spectroscopic (FTIR) analyses. Similar particles were obtained after addition of Mg2+ ions to a solution containing hyaluronic acid, as a major component of the synovial fluid, and soluble Na-polyP. The viscous paste-like ma…
Myocardial blood flow quantification for evaluation of coronary artery disease by computed tomography
2017
During the last decade coronary computed tomography angiography (CTA) has become the preeminent non-invasive imaging modality to detect coronary artery disease (CAD) with high accuracy. However, CTA has a limited value in assessing the hemodynamic significance of a given stenosis due to a modest specificity and positive predictive value. In recent years, different CT techniques for detecting myocardial ischemia have emerged, such as CT-derived fractional flow reserve (FFR-CT), transluminal attenuation gradient (TAG), and myocardial CT perfusion (CTP) imaging. Myocardial CTP imaging can be performed with a single static scan during first pass of the contrast agent, with monoenergetic or dual…
Implementation of dosimetry equipment and phantoms at the MedAustron light ion beam therapy facility
2017
Purpose: To describe the implementation of dosimetry equipment and phantoms into clinical practice of light ion beam therapy facilities. This work covers standard dosimetry equipment such as computerized water scanners, films, 2D-array, thimble and plane parallel ionization chambers, but also dosimetry equipment specifically devoted to the pencil beam scanning delivery technique such as water columns, scintillating screens or multi-layer ionization chambers. Method: Advanced acceptance testing procedures developed at MedAustron and complementary to the standard acceptance procedures proposed by the manufacturer are presented. Detailed commissioning plans have been implemented for each piece…
Long-term prognostic implications of revascularization in patients with known or suspected chronic coronary syndromes without ischemia in vasodilator…
2021
In this study, we evaluated the association between symptoms-guided revascularization occurred within three months following a negative vasodilator stress cardiovascular magnetic resonance (negative stress-CMR) and long-term adverse events in patients with known or suspected chronic coronary syndrome (CCS).We retrospectively evaluated 3517 patients in which the stress first-pass perfusion imaging revealed no ischemia. The primary endpoint was the composite of death, spontaneous myocardial infarction, heart failure (HF), or stroke. The association between symptoms-guided revascularization after a negative stress-CMR and the endpoint was assessed using the multivariable Cox proportional hazar…
Surface Topographies of Glaucoma Drainage Devices and Their Influence on Human Tenon Fibroblast Adhesion
2010
PURPOSE. This study was performed to investigate the surface topography of different glaucoma drainage devices and to determine the effects of surface roughness on cell adhesion of cultured human tenon fibroblasts.METHODS. The surface topography of four widely used devices (Ahmed FP7 and Ahmed S-2; New World Medical, Inc., Rancho Cucamonga, CA; Baerveldt BG101-350; Advanced Medical Optics, Irvine, CA; and Molteno S1; Molteno Ophthalmic Ltd., Dunedin, New Zealand) was investigated by scanning electron microscopy, and roughness was quantified by white-light confocal microscopy. Cells were grown for 72 hours on the surfaces of implants affixed to standard culture dishes. The cells were labeled…
WITHDRAWN: Defining In Vivo Mucosal Inflammatory Activity Using Laser Scanning Confocal Endomicroscopy in Human Ulcerative Colitis
2008
This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.
Prognostic value of cardiac CT
2020
In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on corona…
Quantitative magnetic resonance imaging for focal liver lesions: bridging the gap between research and clinical practice
2021
Magnetic resonance imaging (MRI) is highly important for the detection, characterization, and follow-up of focal liver lesions. Several quantitative MRI-based methods have been proposed in addition to qualitative imaging interpretation to improve the diagnostic work-up and prognostics in patients with focal liver lesions. This includes DWI with apparent diffusion coefficient measurements, intravoxel incoherent motion, perfusion imaging, MR elastography, and radiomics. Multiple research studies have reported promising results with quantitative MRI methods in various clinical settings. Nevertheless, applications in everyday clinical practice are limited. This review describes the basic princ…
Vasodilator Stress CMR and All-Cause Mortality in Stable Ischemic Heart Disease
2020
Abstract Objectives This study explored the association of ischemic burden, as measured by vasodilator stress cardiovascular magnetic resonance (CMR), with all-cause mortality and the effect of revascularization on all-cause mortality in patients with stable ischemic heart disease (SIHD). Background In patients with SIHD, the association of ischemic burden, derived from vasodilator stress CMR, with all-cause mortality and its role for decision-making is unclear. Methods The registry consisted of 6,389 consecutive patients (mean age: 65 ± 12 years; 38% women) who underwent vasodilator stress CMR for known or suspected SIHD. The ischemic burden (at stress first-pass perfusion imaging) was com…