Search results for "instability"

MR-Tomographie versus CT-Arthrographie bei glenohumeralen Instabilitäten

1992

In a prospective study the diagnostic value of MRI compared to CT arthrography (CT-A) was evaluated in 26 patients with 27 instable shoulder joints. Surgical and/or arthroscopic correlation was available in all cases. Both methods showed a high accuracy (96% CT-A, 94% MRI) in the evaluation of the glenoid labrum. CT-A was significantly superior to MRI in the detection of capsular lesions (sensitivity 96% vs. 44%, accuracy 96% vs. 72%, negative predictive value 96% vs. 67%). CT-A and MRI results regarding humeral head fractures were similar; fractures of the glenoid rim were better detected by CT-A, the difference, however, was statistically not significant. Overall, CT-A proved to be superi…

Treatment of Combined Medial and Lateral Collateral Ligament Insufficiency

2016

The medial and lateral collateral ligament complexes represent primary elbow ligament stabilizers. Injury to these structures may occur because of an elbow dislocation or due to a severe varus or valgus force. Most elbow dislocations are stable once reduced and may be treated conservatively. However, if the elbow remains unstable surgical treatment is recommended. Repair should be anatomical and should restore stability to the elbow in order to permit an early active range of motion. Reconstruction may be required in severe cases and where primary repair is not possible. Depending on the degree of instability, either one or both of the collateral ligament complexes may need to be repaired o…

Kinetic Analysis: A Sensitive Outcome Objective Measurement Method in Evaluating Lateral Patellar Instability

2011

There are many diagnostic clinical tests (e.g., apprehension patellar test or the moving patellar apprehension test), outcome measures (general health and knee scales [IKDC form, Kujala scale, Fulkerson scale, Lysholm knee scoring scale, Tegner activity level scale, short form-36]), and instrumented measurements of patellar mobility (static stability), to assess lateral patellar instability.7,10,15,16 However, according to Smith and colleagues,15 the sensitivity/specificity – reliability/validity of such tests and outcome tools remain unclear for this patient population. These authors conclude that further work is needed to assess the appropriateness of these tests and outcomes.15Moreover, …

Measurement of nonlinear and chromatic dispersion parameters of optical fibers using modulation instability

2006

International audience; We present a simple method for the measurement of Kerr, second- and third-order dispersion coefficients in optical fibers using power and dispersion dependences of modulation instability near the zero-dispersion wavelength. We also complete the analysis by the accurate determination of the zero-dispersion wavelength of the fiber using the phase-matched four wave mixing process which occurs near this specific wavelength.

Polarisation attraction and incoherent modulation instability in optical fibers

2006

This thesis, entitled « Polarisation attraction and incoherent modulation instability in optical fibers », presents a theoretical and experimental study of two new processes from the nonlinear optic in optical fibers domain. We introduce in the first chapter some theoretical notions useful for the comprehension of this work. Then, we demonstrate in the second chapter that it is possible to generate some modulation instability in optical fibers using a partially coherent optical beam. We highlight and observe the main properties of the phenomenon. We study the polarisation attraction in isotropic fibers process in the third chapter. Our work proves the existence of the phenomenon, and permit…

Pulsating B and Be stars in the Small Magellanic Cloud

2008

Context: Stellar pulsations in main-sequence B-type stars are driven by the kappa-mechanism due to the Fe-group opacity bump. The current models do not predict the presence of instability strips in the B spectral domain at very low metallicities. As the metallicity of the SMC is lower than Z=0.005, it constitutes a very suitable object to test these predictions. Aims: The main objective is to investigate the existence of B-type pulsators at low metallicities, searching for short-term periodic variability in absorption-line B and Be stars in the SMC. The analysis has been performed in a sample of 313 B and Be stars with fundamental astrophysical parameters accurately determined from high-res…

Refined instability estimates for some inverse problems

2022

Many inverse problems are known to be ill-posed. The ill-posedness can be manifested by an instability estimate of exponential type, first derived by Mandache [29]. In this work, based on Mandache's idea, we refine the instability estimates for two inverse problems, including the inverse inclusion problem and the inverse scattering problem. Our aim is to derive explicitly the dependence of the instability estimates on key parameters. The first result of this work is to show how the instability depends on the depth of the hidden inclusion and the conductivity of the background medium. This work can be regarded as a counterpart of the depth-dependent and conductivity-dependent stability estim…

FORMAZIONE DI PATTERN PER IL PROCESSO DELL'ELETTRODEPOSIZIONE IN MODELLI DI TIPO REAZIONE-DIFFUSIONE

2014

Testing for Lynch Syndrome in Endometrial Carcinoma: From Universal to Age-Selective MLH1 Methylation Analysis

2022

Simple Summary International guidelines recommend universal screening of endometrial carcinoma patients for Lynch syndrome, a hereditary cancer predisposition syndrome. Screening is based on mismatch repair protein immunohistochemistry and reflex MLH1 methylation analysis to exclude the likely sporadic cases of MMR deficiency. As sporadic MLH1 protein loss is common in endometrial carcinoma, the ability to target methylation testing would save efforts and costs. We discovered that limiting methylation testing to patients under 65 years would have significantly reduced the testing effort while maintaining a low false negative rate for MLH1-LS detection (0% and 3% in our clinic and registry-b…

Dynamic regimes of cyclotron instability in the afterglow mode of minimum-B electron cyclotron resonance ion source plasma

2016

The paper is concerned with the dynamic regimes of cyclotron instabilities in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source operated in pulsed mode. The instability appears in decaying ion source plasma shortly (1–10 ms) after switching off the microwave radiation of the klystron, and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high-energy electrons along the magnetic field lines. Recently it was shown that this plasma instability causes perturbations of the extracted ion current, which limits the performance of the ion source and generates strong bursts of bremsstrahlung emission. In this artic…