Search results for " method"
showing 10 items of 10455 documents
Calibration of the underground muon detector of the Pierre Auger Observatory
2021
To obtain direct measurements of the muon content of extensive air showers with energy above $10^{16.5}$ eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 $\mathrm{m^2}$-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m$^2$ close to the intersection of the shower axis with the ground to much less than one per m$^2$ when far away, the necessary bro…
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…
Transdermal nitroglycerine treatment of shoulder tendinopathies in patients with spinal cord injuries.
2011
A clinical blind study was conducted to determine the efficacy of transdermal nitroglycerine treatment on the awareness of shoulder pain. This study aims to determine the effects of transdermal nitroglycerine on shoulder pain and on functional shoulder movement in patients with spinal cord injuries and shoulder tendinopathies. A second aim is to establish the side effects of the treatment. Hospital “La Fe” in Valencia, Spain. A total of 45 spinal cord injury patients, all of whom are wheelchair users with shoulder tendinopathy, were randomly divided into two groups: placebo (n=12) and experimental (n=33). The experimental group (EG) received transdermal treatment for 6 months in the form of…
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 …
Influence of the Screw Positioning on the Stability of Locking Plate for Proximal Tibial Fractures: A Numerical Approach
2020
Tibial fractures are common injuries in people. The proper treatment of these fractures is important in order to recover complete mobility. The aim of this work was to investigate if screw positioning in plates for proximal tibial fractures can affect the stability of the system, and if it can consequently influence the patient healing time. In fact, a more stable construct could allow the reduction of the non-weight-bearing period and consequently speed up the healing process. For that purpose, virtual models of fractured bone/plate assemblies were created, and numerical simulations were performed to evaluate the reaction forces and the maximum value of the contact pressure at the screw/bo…
Ritz Solution for Transient Analysis of Variable-Stiffness Shell Structures
2020
The dynamic response of thin-walled structures is driven by mass and stiffness distribution. As such, variable-stiffness (VS) composites offer opportunities to tune structural dynamic responses. To this extent, efficient analysis tools become increasingly important for structural analysis and design purposes. In this work, an efficient and versatile Ritz method for free vibrations and linear transient analysis of VS doubly curved shell structures is presented. VS shell structures are modeled as an assembly of shell-like domains. The shell kinematics is based on the first-order shear deformation theory, and no further assumption is made on the shallowness or on the thinness of the structure.…
Kinematic Parameters Following Pilon Fracture Treatment with the Ilizarov Method
2022
Background: The purpose of our study was to analyze kinematic parameters following pilon fracture treatment with the Ilizarov method. Methods: Our study assessed kinematic parameters of gait in 23 patients with pilon fractures treated with the Ilizarov method. Patients had completed their treatment 24–48 months prior to measurements. The range-of-motion values in the non-operated limb (NOL) and operated limb (OL) were compared. Kinematic parameters were measured using the Noraxon MyoMOTION System. Results: We observed no significant differences in hip flexion, hip abduction, or knee flection between the OLs and NOLs in patients after treatment with the Ilizarov method. We observed significa…
Patient-specific computational evaluation of stiffness distribution in ascending thoracic aortic aneurysm
2021
Quantifying local aortic stiffness properties in vivo is acknowledged as essential to assess the severity of an ascending thoracic aortic aneurysm (ATAA). Recently, the LESI (local extensional stiffness identification) methodology has been established to quantify non-invasively local stiffness properties of ATAAs using electrocardiographic-gated computed tomography (ECG-gated CT) scans. The aim of the current study was to determine the most sensitive markers of local ATAA stiffness estimation with the hypothesis that direct measures of local ATAA stiffness could better detect the high-risk patients. A cohort of 30 patients (12 BAV and 18 TAV) referred for aortic size evaluation by ECG-gated…