Search results for "Sound"
showing 10 items of 1845 documents
The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma opt…
2009
A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte elements. Ultrasound-assisted two-step digestion with digestion solutions of 6 mL of HNO₃(Step 1) and 3 mL of HNO₃+ 3 mL of HF (Step 2) resulted in recovery rates of over 92% for all the analyte elemen…
An ultrasound-assisted digestion method for the determination of toxic element concentrations in ash samples by inductively coupled plasma optical em…
2007
method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of toxic element concentrations (arsenic, barium, cobalt, copper, lead, nickel, strontium, vanadium and zinc) in ash samples was developed. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg(II) 280.270 nm/Mg(I) 285.213 nm line intensity ratios. The highest line intensity ratios were observed when a nebulizer gas flow of 0.6 L minˉ¹, auxiliary gas flow of 0.2 L minˉ¹ and plasma power of 1400 W were used for radially viewed plasma. The analysis of SRM 1633b showed that the ultrasound-assisted metho…
The assessment of skeletal status in young patients with Turner syndrome by 2 densitometric techniques: Phalangeal quantitative ultrasound and dual e…
2018
Background. Studies using dual energy X-ray absorptiometry (DXA) demonstrate a reduction in bone mineral density (BMD) in children and adolescents with Turner syndrome (TS). However, these studies do not take into account changes in bone size, which influence BMD in the case of short-statured patients. Phalangeal quantitative ultrasound (phQUS) measurements have shown an ability to reveal changes due to skeletal growth, aging, and bone and mineral disorders. There is limited data on bone mineral status in girls with TS assessed by 2 different techniques, i.e., DXA and phQUS. Objectives. The aim of this study was to investigate the potential negative impact of TS on bone status and to assess…
Assessment of the tibia using ultrasonic guided waves in pubertal girls
2002
The purpose of this study was to compare low frequency ultrasonic guided wave measurements with established ultrasound and bone density measurements in terms of their ability to characterize the tibia in pubertal girls. Subjects were 12-14-year-old girls ( n=106) who were participating in a calcium and vitamin D intervention study. A prototype low frequency pulse transmission device consisting of a uniaxial scanning mechanism and low frequency transducers orientated perpendicularly to the limb was used to measure two ultrasound velocities in the tibia. The first velocity, V1, was that of the first arriving signal, similar to that measured by existing commercial tibial ultrasound devices. Th…
Hoffa’s fat pad thickness: a measurement method with sagittal MRI sequences
2021
Abstract Background Hoffa’s fat pad is a structure located within the fibrous joint capsule of the knee joint, but outside the synovial cavity. It plays an important biomechanical and metabolic role in knee joint, reducing the impact of forces generated by loading and producing cytokines. Changes in its size can induce modifications in the knee homeostasis. However, a great variability exists regarding its measurements. This work aims to evaluate the reliability of a measurement method of Hoffa’s fat pad dimensions through MRI. Methods 3T sagittal IW 2D TSE fat-suppressed MRI sequences, taken from the OAI (Osteoarthritis initiative) database, of 191 male and female patients, aged between 40…
Lower Limb Dominance, Morphology, and Sonographic Abnormalities of the Patellar Tendon in Elite Basketball Players: A Cross-Sectional Study.
2019
Context Patellar tendinopathy is common in basketball players, and structural ultrasound abnormalities can be found in symptomatic and asymptomatic tendons. Lower limb dominance may also be a critical load factor, potentially leading to overloading of the patellar tendon. Objective To describe and compare the prevalence by lower limb dominance of patellar tendons with structural and vascular abnormalities and to describe the morphologic measures of tendons without abnormalities among adult male elite basketball players. Design Cross-sectional study. Setting Medical center of a professional basketball team in the Spanish league. Patients or Other Participants A total of 73 adult male elite …
Ultrasound evaluation of joint damage and disease activity in adult patients with severe haemophilia A using the HEAD‐US system
2021
Introduction The Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) system and scoring scale has proven to be an accurate and time-efficient imaging method for identifying joint damage in patients with haemophilia. Aim Observational, multicentre, cross-sectional study conducted in 8 centres in Spain that assessed the joint status of adult patients with severe haemophilia A (SHA) using HEAD-US. Methods Joint status of the elbow, knee and ankle was evaluated in adults with SHA receiving on-demand (OD) treatment, or primary (PP), secondary (SP), tertiary (TP) or intermittent (IP) prophylaxis. Results Of the 95 patients enrolled, 87 received prophylaxis (6.3% PP, 38.9% SP, 43.2% …
In vitro comparison of the efficacy of two fractured implant-prosthesis screw extraction methods: Conventional versus mechanical.
2019
Abstract Statement of problem Implant-supported prostheses may be subject to esthetic, biological, or mechanical complications. Protocols for dealing with these mechanical problems are sparse. Purpose The purpose of this in vitro study was to compare the efficacy of a mechanical system for extracting fractured implant-prosthesis screws with the conventional method. Material and methods A total of 60 screws were divided into 2 groups according to their morphology (flat screws with a smooth shaft and threaded apical area and screws with a completely threaded body) and subjected to fatiguing and static load testing until fracture. The specimens were assigned to 3 operators with varying levels …
Safety of intra-articular hip injection of hyaluronic acid products by ultrasound guidance: an open study from ANTIAGE register.
2013
Abstract. – OBJECTIVE: We developed a standardized technique for ultrasound guided intra-articular injection of the hip joint with the purpose of extending routine intra-articular injection of hyaluronans and steroids to the hip, as commonly used in the knee. In this article we report the safety of this technique in an extended series of patients. PATIENTS AND METHODS: Patients were injected supine with an anterosuperior approach under ultrasound guidance. The Us probe is applied with a target device for biopsy. RESULTS: The standardised technique was used to inject 1906 patients with 4002 injections of hyaluronan products over a four-year period. The treatment was well tolerated with few, …
Ultrasound-guided percutaneous treatment of a calcific acromioclavicular joint
2020
Abstract Rationale: Calcific tendinopathy is one of the most frequent causes of nontraumatic shoulder pain. However, intra-articular calcifications appear to be an infrequent condition. We herein report a rare case study of an intra-articular calcification of the acromioclavicular joint. Patient concerns: A 46-year-old man presented with an acute pain in the anterior superior region of the left shoulder which also radiated to the left cervical region. The man during the physical evaluation also presented severe functional limitation of the shoulder movements in all planes of motion. Diagnoses: The diagnosis was carried out through a radiographic and an echotomographic examination, highlight…