Development of integration mode proton imaging with a single CMOS detector for a small animal irradiation platform

A novel irradiation platform for preclinical proton therapy studies foresees proton imaging for accurate setup and treatment planning. Imaging at modern synchrocyclotron-based proton therapy centers with high instantaneous particle flux is possible with an integration mode setup. The aim of this work is to determine an object’s water-equivalent thickness (WET) with a commercially available large-area CMOS sensor. Image contrast is achieved by recording the proton energy deposition in detector pixels for several incoming beam energies (here, called probing energies) and applying a signal decomposition method that retrieves the water-equivalent thickness. A single planar 114 mm × 65 mm CMOS sensor (49.5 µm pixel pitch) was used for this study, aimed at small-animal imaging. In experimental campaigns, at two isochronous cyclotron-based facilities, probing energies suitable for small-animal-sized objects were produced once with built-in energy layer switching and the other time, using a custom degrader wheel. To assess water-equivalent thickness accuracy, a micro-CT calibration phantom with 10 inserts of tissue-mimicking materials was imaged at three phantom-to-detector distances: 3 mm, 13 mm, and 33 mm. For 3 mm and 13 mm phantom-to-detector distance, the average water-equivalent thickness error compared to the ground truth was about 1 and the spatial resolution was 0.16(3) mm and 0.47(2) mm, respectively. For the largest separation distance of 33 mm air gap, proton scattering had considerable impact and the water-equivalent thickness relative error increased to 30, and the spatial resolution was larger than 1.75 mm. We conclude that a pixelated CMOS detector with dedicated post-processing methods can enable fast proton radiographic imaging in a simple and compact setup for small-animal-sized objects with high water-equivalent thickness accuracy and spatial resolution for reasonable phantom-to-detector distances

High Precision Temperature Control of Normal-conducting RF GUN for a High Duty Cycle Free-Electron Laser

High precision temperature control of the RF GUN is necessary to optimally accelerate thousands of electrons within the injection part of the European X-ray free-electron laser XFEL and the Free Electron Laser FLASH. A difference of the RF GUN temperature from the reference value of only 0.01 K leads to detuning of the cavity and thus limits the performance of the whole facility. Especially in steady-state operation there are some undesired temperature oscillations when using classical standard control techniques like PID control. That is why a model based approach is applied here to design the RF GUN temperature controller for the free-electron lasers. A thermal model of the RF GUN and the cooling facility is derived based on heat balances, considering the heat dissipation of the Low-Level RF power. This results in a nonlinear model of the plant. The parameters are identified by fitting the model to data of temperature, pressure and control signal measurements of the FLASH facility, a pilot test facility for the European XFEL. The derived model is used for controller design. A linear model predictive controller was implemented in MATLAB/Simulink and tuned to stabilize the temperature of the RF GUN in steady-state operation. A test of the controller in simulation shows promising results

Long-Lived Individuals Show a Lower Burden of Variants Predisposing to Age-Related Diseases and a Higher Polygenic Longevity Score

Longevity is a complex phenotype influenced by both environmental and genetic factors. The genetic contribution is estimated at about 25%. Despite extensive research efforts, only a few longevity genes have been validated across populations. Long-lived individuals (LLI) reach extreme ages with a relative low prevalence of chronic disability and major age-related diseases (ARDs). We tested whether the protection from ARDs in LLI can partly be attributed to genetic factors by calculating polygenic risk scores (PRSs) for seven common late-life diseases (Alzheimer's disease (AD), atrial fibrillation (AF), coronary artery disease (CAD), colorectal cancer (CRC), ischemic stroke (ISS), Parkinson's disease (PD) and type 2 diabetes (T2D)). The examined sample comprised 1351 German LLI (≥94 years, including 643 centenarians) and 4680 German younger controls. For all ARD-PRSs tested, the LLI had significantly lower scores than the younger control individuals (areas under the curve (AUCs): ISS = 0.59, p = 2.84 × 10-35; AD = 0.59, p = 3.16 × 10-25; AF = 0.57, p = 1.07 × 10-16; CAD = 0.56, p = 1.88 × 10-12; CRC = 0.52, p = 5.85 × 10-3; PD = 0.52, p = 1.91 × 10-3; T2D = 0.51, p = 2.61 × 10-3). We combined the individual ARD-PRSs into a meta-PRS (AUC = 0.64, p = 6.45 × 10-15). Furthermore, the inclusion of nine markers from the excluded region (not in LD with each other) plus the APOE haplotype into the model raised the AUC from 0.55 to 0.61. Thus, our results highlight the importance of TOMM40/APOE/APOC1 as a longevity hub

Für Entmilitarisierung der Sicherheit: 25 Jahre Dresdener Studiengemeinschaft Sicherheitspolitik e. V.: Ein Resümee

Band zum 25. Jubiläum und Abschluss der Dresdener Studiengemeinschaft Sicherheitspolitik e.V.:Autorenbeiträge: - Wolfgang Scheler, Das Wirken der Studiengemeinschaft für einen Frieden in gemeinsamer Sicherheit. - Detlef Bald, Ost-West-Begegnungen nach der Einheit 1990 - Friedenshoffnung und Militärkritik. - Volker Bialas, Gedankenstürme über den globalen Frieden. - Endre Kiss, Persönlich über Nicht-Persönliches. - Rüdiger Wenzke, Brief an den Vorsitzenden der Dresdener Studiengemeinschaft Sicherheitspolitik e. V. - Heinrich Mund, Die Sächsische Friedensinitiative Dresden hätte ohne die Dresdener Studiengemeinschaft Sicherheitspolitik keinen Bestand gehabt. - Günter Glaser, Die Dresdener Studiengemeinschaft Sicherheitspolitik war auch für meine wissenschaftliche Arbeit von großer Bedeutung. - Rainer Böhme, Schlussakkord - meine Gedanken zur Dresdener Studiengemeinschaft Sicherheitspolitik. - Rolf Ziegenbein, Sieben Jahre als Grenzer in der Studiengemeinschaft. - Siegfried Schönherr, Friedenspolitisches Handeln erfordert militärökonomisches Denken. - Wilfried Schreiber, 25 Jahre Symbiose von Friedensforschung und Friedensbewegung. Anlagen (5): 1 Die Mitglieder der Dresdener Studiengemeinschaft Sicherheitspolitik e. V. 2 Chronik 3 Schriftenreihe der DSS-Arbeitspapiere. 4 Autoren der DSS-Arbeitspapiere. 5 Ständige Bezieher der DSS-Arbeitspapiere