A SiGe layer epitaxially grown on a silicon substrate is experimentally studied by convergent beam electron diffraction (CBED) experiments and used as a test sample to analyse the higher-order Laue zones (HOLZ) line splitting. The influence of surface strain relaxation on the broadening of HOLZ lines is confirmed. The quantitative fit of the observed HOLZ line profiles is successfully achieved using a formalism particularly well-adapted to the case of a z-dependent crystal potential (z being the zone axis). This formalism, based on a time-dependent perturbation theory approach, proves to be much more efficient than a classical Howie-Whelan approach, to reproduce the complex HOLZ lines profile in this heavily strained test sample.
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http://dx.doi.org/10.1016/j.ultramic.2006.04.011 | DOI Listing |
Ophthalmol Sci
October 2024
Genentech, Inc., South San Francisco, California.
Purpose: The region of growth (ROG) of geographic atrophy (GA) throughout the macular area has an impact on visual outcomes. Here, we developed multiple deep learning models to predict the 1-year ROG of GA lesions using fundus autofluorescence (FAF) images.
Design: In this retrospective analysis, 3 types of models were developed using FAF images collected 6 months after baseline to predict the GA lesion area (segmented lesion mask) at 1.
Ophthalmol Retina
March 2023
Roche Ophthalmology Personalized Healthcare, Genentech, Inc., South San Francisco, California; Data Science Imaging, Genentech, Inc., South San Francisco, California. Electronic address:
Objective: To develop deep learning models for annualized geographic atrophy (GA) growth rate prediction using fundus autofluorescence (FAF) images and spectral-domain OCT volumes from baseline visits, which can be used for prognostic covariate adjustment to increase power of clinical trials.
Design: This retrospective analysis estimated GA growth rate as the slope of a linear fit on all available measurements of lesion area over a 2-year period. Three multitask deep learning models-FAF-only, OCT-only, and multimodal (FAF and OCT)-were developed to predict concurrent GA area and annualized growth rate.
Transl Vis Sci Technol
January 2021
Department of Ophthalmology, University Hospital Bonn, Bonn, Germany.
Purpose: The purpose of this study was to design and evaluate an instrument for assessing vision-related quality of life appropriate for the specific visual impairment characteristic for all stages of age-related macular degeneration (AMD), with a focus on the low luminance deficit in early/intermediate stages.
Methods: A standardized questionnaire was developed in three steps with participants with early, intermediate, and late AMD: (1) based on in-depth interviews ( = 19) and two focus group discussions ( = 5 each), content was developed followed by 2. (2) The questionnaire development using cognitive debriefing interviews ( = 3) and leading to a preliminary version of the questionnaire.
J Comput Assist Tomogr
April 2020
From the Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Cologne, Germany.
Objective: The aim of the study was to evaluate the effect of slice thickness, iterative reconstruction (IR) algorithm, and kernel selection on measurement accuracy and interobserver variability for semiautomated renal cortex volumetry (RCV) with multislice computed tomography (CT).
Methods: Ten patients (62.4 ± 17.
Invest Ophthalmol Vis Sci
March 2018
Department of Ophthalmology, University of Bonn, Bonn, Germany.
Purpose: To assess the impact of distinct atrophy border characteristics based on spectral-domain optical coherence tomography (SD-OCT) imaging on local atrophy progression.
Methods: Patients with geographic atrophy (GA) secondary to AMD were recruited in the context of the Longitudinal Fundus Autofluorescence in Age-related Macular Degeneration and Directional Spread in Geographic Atrophy studies (NCT00393692, NCT02051998). Horizontal and vertical SD-OCT scans were acquired at sequential visits using a device allowing for anatomically accurate registration of follow-up to baseline scans.
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