Charge trapping and ac conductivity in Amorphous Silicon Oxide

AbstractIn this paper we have studied the effect of accelerated thermal ageing on the electrical properties of amorphous silicon oxide films a-SiO2. In order to study the charge trapping phenomenon in this material, we have performed the mirror method using a secondary Electron Microscope (SEM). This method consists to inject a negative space charge in the specimen with a high energy electron beam. Results show that trapped charges increase with thermal ageing time. Dielectric investigations performed in the frequency range between 20 Hz and 1 MHz, showed that the relative permittivity increases with thermal ageing time. The ac conductivity has been found to follow the Jonsher law σacαωn. The decrease of ac conductivity has been interpreted

7th International Workshop on Osteoarthritis Imaging report: “imaging in OA – now is the time to move ahead”

SummaryThe 7th Osteoarthritis Research Society International (OARSI) International Workshop on Osteoarthritis Imaging was held in Reykjavik, Iceland, from July 9–12, 2014; attracting attendees from academia, pharmaceutical and Magnetic resonance imaging (MRI) industries, as well as a large number of young investigators. The Workshop program consisted of six modules, including imaging in osteoarthritis (OA), imaging and pain in OA, new techniques in imaging, risk factors and structural outcomes, anti-nerve growth factor (a-NGF) therapy, and joint replacement. A wealth of data was presented from OA researchers from all over the world and participants gained insightful knowledge on up-to-date research work focusing on imaging of OA. This paper presents a summary of the salient points from the workshop.ConclusionsIdentifying the appropriate imaging modality and parameters will be critical for ensuring responsive, reproducible and reliable outcomes for clinical trials. Continued efforts from the OA research community are needed to establish the most effective use of imaging in OA clinical trials, including anti-NGF therapy and joint replacement trials, and to validate newer imaging techniques such as compositional MRI for use in the future clinical trials

Cathodoluminescence investigations of GaAs thin layers

AbstractIn this work, we report the theoretical results of cathodoluminescence (CL) for GaAs layer. The simulation of the CL excitation and intensity is developed using 2-D model based on the electron beam energy dissipation and taking into account the effects of carrier diffusion, internal absorption and the recombination process in the semiconductors.We have investigated the influence of the electron beam conditions (energy, current and beam diameter) and some physical parameters (absorption coefficient, gap energy) on the CL intensity. Results allow us particularly to predict the intensity evolution and shift of CL peak emitted near the fundamental energy gap as a function of the electron beam current and energy. A comparative study between simulated and experimental CL spectra at low temperature is realized

Imaging atlas for eligibility and on-study safety of potential knee adverse events in anti-NGF studies (Part 1)

SummaryMonoclonal antibodies that bind and inhibit nerve growth factor (NGF) have demonstrated both, good analgesic efficacy and improvement in function in patients with osteoarthritis (OA). Despite initial promising data, trials in OA had been suspended by the Federal Food and Drug Administration (FDA) due to concerns over accelerated rates of OA progression. Imaging will play a crucial role in future clinical trials to define eligibility of potential participants and to monitor safety during the course of these studies. This will require baseline and frequent follow-up radiographs of both, the index joints and other large weight bearing joints to identify subjects at risk prior inclusion and on study so treatment can be discontinued.This imaging overview in the form of an atlas describes and illustrates potential exclusionary joint imaging findings at eligibility and potential adverse joint events on radiography and magnetic resonance imaging (MRI) in studies investigating a-NGF compounds. The overarching goal of this atlas is to facilitate trial design and to promote a common language and understanding between potential expert readers. This first section of the atlas will focus on knee joint specific findings that are relevant to a-NGF studies

Translation into Arabic and validation of the ASES index in assessment of shoulder disabilities

AbstractObjectiveTo translate into Arabic and validate the “American Shoulder and Elbow Surgeons Evaluation Form” (ASES) for use in a Tunisian population presenting with periarticular pathologies of the shoulder.BackgroundNo functional index assessing the functional capacities of the shoulder is presently available in Arabic.Patients and methodsThe translation was achieved by means of forward/backward translation. Adaptations were carried out subsequent to a preliminary test involving 15 persons. Patients with periarticular shoulder disabilities were included. Clinical measurements evaluated pain and functional disability by means of the visual analogue scale (VAS). Interrater concordance (repeatability) was assessed using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Construct validity (convergent and discriminant validity) was investigated using the Spearman rank correlation coefficient and a factorial analysis followed by orthogonal rotation. The internal consistency of each factor was graded in terms of the Cronbach alpha coefficient.ResultsEighty (80) patients were included in the study. Interrater concordance was excellent (ICC=0.96). The Bland and Altman method showed a low-variability mean difference. Correlations of the index score with the pain VAS (r=−0.49) and functional disability (r=−0.58) suggested satisfactory convergent validity, and our index likewise showed good discriminant validity. Factorial analysis led to the extraction of two factors with a cumulative variance rate of 92.6% that could not be explained.ConclusionTranslated into Arabic, the ASES index was found to possess high metrological qualities. While the index has been satisfactorily validated with regard to a Tunisian population, additional studies are needed to verify its applicability to other Arab populations