Search results for "DOPPLER"
showing 10 items of 637 documents
Study of neurinomas with ultrasound contrast media: review of a case series to identify characteristic imaging patterns
2011
The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique.Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated co…
Changes in ultrasound-assessed carotid intima-media thickness and plaque with a Mediterranean diet: a substudy of the PREDIMED trial.
2014
OBJECTIVE - : The Prevención con Dieta Mediterránea (PREDIMED) trial showed that a Mediterranean diet (MedDiet) supplemented with either extra virgin olive oil or 30 g/d of mixed nuts reduced incident cardiovascular events compared with a control (low fat) diet. The mechanisms of cardiovascular protection afforded by MedDiets remain to be uncovered. We assessed the effect of both supplemented MedDiets on internal carotid intima-media thickness (ICA-IMT) and plaque height, the ultrasound features that best predict future cardiovascular events, in subjects at high cardiovascular risk. APPROACH AND RESULTS - : In a PREDIMED subcohort (n=175), plaque height and carotid IMT of 3 prespecified seg…
A refugee newborn with heart failure and initial hydrops: Diagnostic clues of spectral Doppler examinations
2022
A newnborn admitted to NICU showed a severe clinical profile
PREDICTION OF CEREBROVASCULAR AND CARDIOVASCULAR EVENTS IN PATIENTS WITH SUBLINICAL CAROTID ATHEROSCLEROSIS: THE ROLE OF C-REACTIVE PROTEIN
2008
Background Several studies have suggested that inflammation and infection may be important for accelerated progression of atherosclerosis, but few data are available on subjects with early stages of atherosclerosis. Methods and Results We included, in a prospective 5-year follow-up study, 150 patients with subclinical carotid atherosclerosis, evaluating at baseline all established traditional cardiovascular risk factors (eg, older age, male sex, obesity, hypertension, diabetes, smoking, family history of coronary artery disease, and dyslipidemia); 2 markers of inflammation, fibrinogen, and high-sensitivity C-reactive protein (CRP); and the seropositivity to Helicobacter pylori, Chlamydia pn…
First demonstration of Doppler-free 2-photon in-source laser spectroscopy at the ISOLDE-RILIS
2020
Abstract Collinear Doppler-free 2-photon resonance ionization has been applied inside a hot cavity laser ion source environment at CERN-ISOLDE. An injection-seeded Ti:sapphire ring laser was used to generate light pulses with a Fourier-limited linewidth for high-resolution spectroscopy. Using a molybdenum foil as a reflective surface positioned at the end of the target transfer line, rubidium was successfully ionized inside the hot cavity. The results are presented alongside previously obtained data from measurements performed at the RISIKO mass separator at Mainz University, where collinear and perpendicular ionization geometries were tested inside an RFQ ion guide. This work is a pre-curs…
Doppler-free two-photon spectrum of SF_6 for metrological purposes
1998
We report on our systematic investigation of strong Doppler-free two-photon absorption in the middle infrared. The absorption frequencies for two counterpropagating waves of identical frequencies are predicted. Five of these transitions were observed with sub-Doppler resolution with a sideband CO(2) laser and were measured with 10-kHz accuracy. Knowledge of these strong two-photon absorptions frequencies will allow the improvement of secondary frequency standards in the infrared.
Dietary phytoestrogens improve stroke outcome after transient focal cerebral ischemia in rats.
2006
As phytoestrogens are postulated as being neuroprotectants, we assessed the hypothesis that dietary isoflavone-type phytoestrogens are neuroprotective against ischemic stroke. Transient focal cerebral ischemia (90 min) was induced by middle cerebral artery occlusion (MCAO) following the intraluminal thread technique, both in rats fed with soy-based diet and in rats fed with isoflavone-free diet. Cerebro-cortical laser-Doppler flow (cortical perfusion, CP), arterial blood pressure, core temperature, PaO2, PaCO2, pH and glycemia were measured before, during and after MCAO. Neurological examination and infarct volume measurements were carried out 3 days after the ischemic insult. Dietary isofl…
Test of Time Dilation Using StoredLi+Ions as Clocks at Relativistic Speed
2014
We present the concluding result from an Ives-Stilwell-type time dilation experiment using 7Li+ ions confined at a velocity of β=v/c=0.338 in the storage ring ESR at Darmstadt. A Λ-type three-level system within the hyperfine structure of the 7Li+3S1 →3P2 line is driven by two laser beams aligned parallel and antiparallel relative to the ion beam. The lasers' Doppler shifted frequencies required for resonance are measured with an accuracy of <4×10(-9) using optical-optical double resonance spectroscopy. This allows us to verify the special relativity relation between the time dilation factor γ and the velocity β, γ√1-β2=1 to within ±2.3×10(-9) at this velocity. The result, which is singled …
Asymptomatic carotid lesions add to cardiovascular risk prediction.
2010
AIM To show that subclinical atherosclerosis (subclinical-ATS) of carotid arteries [intima-media thickness (IMT) or asymptomatic carotid plaque (ACP)], may provide additional information for risk stratification, in asymptomatic patients, aged greater than 45 years, with a cluster of risk factors (RFs). METHODS AND RESULTS We studied 558 asymptomatic patients (235 males). RFs for atherosclerosis were assessed and the 10-year-risk was calculated according to the Italian risk score. Doppler ultrasound of carotid arteries identified the presence of IMT greater than 0.9 mm in 183 patients and ACP in 147 patients. One hundred and fifty-three patients developed cerebrovascular or cardiovascular (C…
FLUMO: FLexible Underwater MOdem
2019
The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …