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In the present work the results of an extensive experimental campaign in which laser-shocks were used to assess the mechanical strength of graphitic materials are presented. The aim of the project was to study innovative advanced materials used in high energy particle accelerators for beam intercepting devices (BIDs), such as collimators, absorber blocks and dumps. In this framework, thin targets of graphitic materials relevant for the use as particle accelerator BIDs were submitted to high-power laser driven shocks at the PHELIX laser facility in GSI. Online diagnostics such as shadowgraphy and laser velocimetry were deployed together with post-mortem analysis on collected debris and shocked specimens.The experimental results were compared with results obtained in literature. In this work the data acquired for the performed shots are presented with a focus on graphite samples. The testing campaign provided large amount of information to cross-check and validate the models implemented for laser-matter interaction, shockwave propagation and spall strength concerning a wide range of materials, all relevant for the use in beam intercepting devices of particle accelerators.

Objective. Phrenic nerve stimulation reduces ventilator-induced-diaphragmatic-dysfunction, which is a potential complication of mechanical ventilation. Electromagnetic simulations provide valuable information about the effects of the stimulation and are used to determine appropriate stimulation parameters and evaluate possible co-activation. Approach. Using a multiscale approach, we built a novel detailed anatomical model of the neck and the phrenic nerve. The model consisted of a macroscale volume conduction model of the neck with 13 tissues, a mesoscale volume conduction model of the phrenic nerve with three tissues, and a microscale biophysiological model of axons with diameters ranging from 5 to 14  µ m based on the McIntyre-Richardson-Grill-model for myelinated axons. This multiscale model was used to quantify activation thresholds of phrenic nerve fibers using different stimulation pulse parameters (pulse width, interphase delay, asymmetry of biphasic pulses, pulse polarity, and rise time) during non-invasive electrical stimulation. Electric field strength was used to evaluate co-activation of the other nerves in the neck. Main results. For monophasic pulses with a pulse width of 150  µ s, the activation threshold depended on the fiber diameter and ranged from 20 to 156 mA, with highest activation threshold for the smallest fiber diameter. The relationship was approximated using a power fit function x -3 . Biphasic (symmetric) pulses increased the activation threshold by 25 to 30 %. The use of asymmetric biphasic pulses or an interphase delay lowered the threshold close to the monophasic threshold. Possible co-activated nerves were the more superficial nerves and included the transverse cervical nerve, the supraclavicular nerve, the great auricular nerve, the cervical plexus, the brachial plexus, and the long thoracic nerve. Significance. Our multiscale model and electromagnetic simulations provided insight into phrenic nerve activation and possible co-activation by non-invasive electrical stimulation and provided guidance on the use of stimulation pulse types with minimal activation threshold., (Creative Commons Attribution license.)

Purpose: Morphological changes to the optic nerve head (ONH) can be detected at the early stages of glaucoma. Three-dimensional imaging and analysis may aid in the diagnosis. Light field (LF) fundus cameras can generate three-dimensional (3D) images of optic disc topography from a single shot and are less susceptible to motion artifacts. Here, we introduce a processing method to determine diagnostically relevant ONH parameters automatically and present the results of a subject study performed to validate this method., Methods: The ONHs of 17 healthy subjects were examined and images were acquired with both an LF fundus camera and by optical coherence tomography (OCT). The LF data were analyzed with a novel algorithm and compared with the results of the OCT study. Depth information was reconstructed, and a model with radial basis functions was used for processing of the 3D point cloud and to provide a finite surface. The peripapillary rising and falling edges were evaluated to determine optic disc and cup contours and finally calculate the parameters., Results: Nine of the 17 subjects exhibited prominent optic cups. The contours and ONH parameters determined by an analysis of LF 3D imaging largely agreed with the data obtained from OCT. The median disc areas, cup areas, and cup depths differed by 0.17 mm², -0.04 mm², and -0.07 mm, respectively., Conclusions: The findings presented here suggest the possibility of using LF data to evaluate the ONH., Translational Relevance: LF data can be used to determine geometric parameters of the ONH and thus may be suitable for future use in glaucoma diagnostics.

Laser-driven x-ray backlighting can be used to image fast dynamic processes like the propagation of laser-driven shock waves in matter. We demonstrate and evaluate the feasibility of operating the JUNGFRAU detector designed by PSI, a direct detecting x-ray detector, in environments with extreme electromagnetic pulses. The electromagnetic pulse-protective housing is specifically designed for this detector and optimized for pump-probe experiments at the Petawatt High-Energy Laser for Heavy Ion EXperiments (PHELIX) facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH. The beryllium x-ray entrance window of the protective housing has a high x-ray transmission of 94% at 8 keV. Measurements have shown that the housing simultaneously provides a relative damping of the electromagnetic field on average higher than 1000 in the frequency range of 100 MHz to 5 GHz. The results demonstrate the feasibility of operating digital detectors in experiments where strong electromagnetic pulses are present., (© 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)

Purpose/objective: Patients with squamous cell carcinoma of the head and neck undergoing (chemo-)radiotherapy are at high risk of malnutrition. Nevertheless, there is still a lack of prospective, randomized trials investigating the influence of nutritional status on therapy-related toxicity and patients' outcome., Materials and Methods: Between October 2018 and October 2020, 61 patients were randomized into an intervention and control group. Questionnaires (MUST, NRS-2002, and Nutriscore), clinical examinations, laboratory analyses, and bioelectrical impedance analysis (BIA) were used to assess nutritional status for all patients at the beginning and end of therapy as well as every 2 weeks during therapy. The intervention consisted of an individualized nutritional counseling every 2 weeks during therapy., Results: Median baseline BMI for all participants was 23.8 (14.5-37.2) kg/m 2 and dropped to 22.9 (16.8-33) kg/m 2 after therapy (p < 0.001). In all patients, median baseline fat-free mass index (FFMI) was 18.1 (14-24.7) kg/m 2 and decreased to 17.8 (13.4-21.6) kg/m 2 till the end of therapy (p < 0.001). Compliant patients with a BMI < 22 kg/m 2 presented with less weight loss in the intervention group compared to the control (p = 0.015, CI: 0.33-2.95). At baseline, MUST was the only screening-test which showed both good sensitivity (86%) and specificity (88%) in detecting malnutrition. Median follow-up was 15 (1-26) months and is still ongoing. 2-year overall survival rate was 70% in the control and 79% in the intervention group (log-rank p = 0.79). Pretherapeutic phase angle, posttherapeutic FFMI and albumin level were prognostic indicators for overall survival (log-rank p = 0.002, p = 0.008 and p = 0.016)., Conclusions: Malnutrition negatively impacts patients' outcome under (chemo-)radiotherapy. Baseline phase angle, posttherapeutic FFMI and albumin level are proposed as reliable indicators for overall survival. This study was registered within the German Clinical Trials Register (DRKS00016862)., (Copyright © 2021 Elsevier B.V. All rights reserved.)