Search results for "Sound"
showing 10 items of 1845 documents
RECOVERY OF THE SOUND SPEED FOR THE ACOUSTIC WAVE EQUATION FROM PHASELESS MEASUREMENTS
2018
We recover the higher order terms for the acoustic wave equation from measurements of the modulus of the solution. The recovery of these coefficients is reduced to a question of stability for inverting a Hamiltonian flow transform, not the geodesic X-ray transform encountered in other inverse boundary problems like the determination of conformal factors. We obtain new stability results for the Hamiltonian flow transform, which allow to recover the higher order terms.
Effect of Different Green Extraction Methods and Solvents on Bioactive Components of Chamomile (Matricaria chamomilla L.) Flowers
2020
Chamomile (Matricaria chamomilla L.) dried flowers contain a group of interesting biologically active compounds such as sesquiterpenes, flavonoids, coumarins, vitamins, phenolic acids and glucosides. Therefore, the aim of the present study was to characterize the composition in bioactive compounds (specialized metabolites) present in water and ethanol extracts of chamomile flowers, together with monitoring the impact of different extraction techniques (conventional vs. ultrasound-assisted extraction (UAE)) on the parameters under investigation. UAE treatment significantly decreased the extraction time of bioactive compounds from herbal material. Polyphenolic compounds content and antioxidan…
Structural and Functional Characterization of Chronic Obstructive Lung Disease and Emphysema Using 3He- MRI: Comparison with CT and Pulmonary Functio…
2005
mor types. For these reasons, Matrigel impregnated with angiogenic hormone, basic-Fibroblast Growth Factor (bFGF), in a mouse model has been extensively used in fundamental angiogenesis research to induce endothelial cell differentiation and successfully allow the study of different phases of the angiogenesis process. The objective of this study was to evaluate the ability of functional ultrasound imaging (fUSI) to provide data allowing the quantification of the angiogenic process, using the Matrigel model.
Hydrodynamic ultrasonic maxillary sinus lift : review of a new technique and presentation of a clinical case
2010
Objectives: Placing implants in the posterior maxillary area has the drawback of working with scarce, poor quality bone in a significant percentage of cases. Numerous advanced surgical techniques have been developed to overcome the difficulties associated with these limitations. Subsequent to reports on the elevation of the maxillary sinus through the lateral approach, there were reports on the use of the crestal approach, which is less aggressive but requires a minimal amount of bone. Furthermore, it is more sensitive to operator technique, as the integrity of the sinus membrane is checked indirectly. The aim of this paper is to review the technical literature on minimally invasive sinus l…
Analogy experience of sound and speech : from perception to meaning
2018
Like any human experience, the relationship to sound calls for language, which contributes to engaging it in the lives of individuals and communities. Speakers, though, often claim to encounter special difficulties when talking about acoustic phenomena. Should this situation be attributed to the essential irreductibility of percept to speech, to possible deficiencies of language in the field of auditory experience or to the specificity of a situation in which speech, bound both by signans and signatum to sound, has to reactivate the semiotic process at its source? Highlighting the fact that talking about soundsalways means talking about our relation to acoustic phenomena, this study is base…
Prenatal diagnosis of sacrococcygeal teratomas by two- and three-dimensional ultrasound
2002
We suspected two fetuses of having sacrococcygeal teratomas following initial two-dimensional ultrasound scanning at 18 and 22 weeks' gestation. The fetuses were then scanned with three-dimensional multiplanar surface and three-dimensional orthogonal planar ultrasound to establish a definitive diagnosis. Although we made a presumptive diagnosis in both cases after initial two-dimensional scanning, with three-dimensional ultrasound we were better able to define the degree of involvement of the sacrum and other pelvic structures of prognostic importance. Copyright © 2002 ISUOG
Italian Society of Anesthesia, Analgesia, Resuscitation, and Intensive Care expert consensus statement on the use of lung ultrasound in critically il…
2021
Abstract Background To produce statements based on the available evidence and an expert consensus (as members of the Lung Ultrasound Working Group of the Italian Society of Analgesia, Anesthesia, Resuscitation, and Intensive Care, SIAARTI) on the use of lung ultrasound for the management of patients with COVID-19 admitted to the intensive care unit. Methods A modified Delphi method was applied by a panel of anesthesiologists and intensive care physicians expert in the use of lung ultrasound in COVID-19 intensive critically ill patients to reach a consensus on ten clinical questions concerning the role of lung ultrasound in the following: COVID-19 diagnosis and monitoring (with and without i…
Contrast-Enhanced Ultrasound Qualitative and Quantitative Characteristics of Parathyroid Gland Lesions
2021
Background and Objectives: preoperative differentiation of enlarged parathyroid glands may be challenging in conventional B-mode ultrasound. The aim of our study was to analyse qualitative and quantitative characteristics of parathyroid gland lesions, using multiparametric ultrasound protocol—B-mode, Colour Doppler (CD), and contrast-enhanced ultrasound (CEUS)—and to evaluate correlation with morphology in patients with hyperparathyroidism (HPT). Materials and Methods: consecutive 75 patients with 88 parathyroid lesions and biochemically confirmed HPT prior to parathyroidectomy were enrolled in the prospective study. B-mode ultrasound, CD, and CEUS were performed with the subsequent qualita…
Does Function Determine the Structure? Changes in Flexor Hallucis Longus Muscle and the Associated Performance Related to Dance Modality: A Cross-Sec…
2020
Background and Objectives: Flexor hallucis longus pathology is one of the most common conditions of the ankle and foot in dancers, due to the high demand of dance movements performed in an extreme plantar flexion and dorsiflexion range of motion. The objectives of this study were to determine the bilateral differences between the thickness and cross-sectional area of the flexor hallucis longus muscle in dancers, to establish possible differences between dance modalities, and to analyze whether there is a correlation between ultrasonographic parameters or performance variables and the dance modality. Material and Methods: A sample of 50 (29 classical and 21 contemporary) full-time pre-profes…
Focal Pancreatic Lesions: Role of Contrast-Enhanced Ultrasonography.
2021
The introduction of contrast-enhanced ultrasonography (CEUS) has led to a significant improvement in the diagnostic accuracy of ultrasound in the characterization of a pancreatic mass. CEUS, by using a blood pool contrast agent, can provide dynamic information concerning macro- and micro-circulation of focal lesions and of normal parenchyma, without the use of ionizing radiation. On the basis of personal experience and literature data, the purpose of this article is to describe and discuss CEUS imaging findings of the main solid and cystic pancreatic lesions with varying prevalence.