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In the fabrication of optical polymer-based components, such as diffractive gratings and waveguides, high throughput and high precision are required. The non-destructive evaluation of these complex polymer-based structures is a significant challenge. Different measurement techniques can measure the structure geometry directly or via its functionality indirectly. This study investigates various measurement techniques aimed at assessing these structures from 200 nm up to 20 µm. Environmental scanning electron microscopy (ESEM), white light interferometry (WLI), atomic force microscopy (AFM), micro computed tomography (µCT), optical coherence tomography (OCT), phase contrast microscopy (PCM), and Mueller matrix ellipsometry (MME) are investigated for their practical limits of lateral resolution and aspect ratio. The impact of the specimens’ complexity factors, including structure width and aspect ratio, on measurement quality is discussed. A particular focus of this study is on the suitability of different measurement systems for evaluating undercuts and enclosed structures while considering structure size, slant angle, and cover thickness. The aim is to discuss the specific advantages of the individual measurement systems and their application areas in order to be able to quickly select suitable measurement systems for a non-destructive evaluation of polymer-based micro and nanostructures.

Abstract Computer Vision (CV)-based human identification using orthopantomograms (OPGs) has the potential to identify unknown deceased individuals by comparing postmortem OPGs with a comprehensive antemortem CV database. However, the growing size of the CV database leads to longer processing times. This study aims to develop a standardized and reliable Convolutional Neural Network (CNN) for age estimation using OPGs and integrate it into the CV-based human identification process. The CNN was trained on 50,000 OPGs, each labeled with ages ranging from 2 to 89 years. Testing included three postmortem OPGs, 10,779 antemortem OPGs, and an additional set of 70 OPGs within the context of CV-based human identification. Integrating the CNN for age estimation into CV-based human identification process resulted in a substantial reduction of up to 96% in processing time for a CV database containing 105,251 entries. Age estimation accuracy varied between postmortem and antemortem OPGs, with a mean absolute error (MAE) of 2.76 ± 2.67 years and 3.26 ± 3.06 years across all ages, as well as 3.69 ± 3.14 years for an additional 70 OPGs. In conclusion, the incorporation of a CNN for age estimation in the CV-based human identification process significantly reduces processing time while delivering reliable results.

Deep learning image reconstruction (DLIR) has shown potential to enhance computed tomography (CT) image quality, but its impact on tumor visibility and adoption among radiologists with varying experience levels remains unclear. This study compared the performance of two deep learning-based image reconstruction methods, DLIR and Pixelshine, an adaptive statistical iterative reconstruction—volume (ASIR-V) method, and filtered back projection (FBP) across 33 contrast-enhanced CT staging examinations, evaluated by 20–24 radiologists. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for tumor and surrounding organ tissues across DLIR (Low, Medium, High), Pixelshine (Soft, Ultrasoft), ASIR-V (30–100%), and FBP. In two blinded surveys, radiologists ranked eight reconstructions and assessed four using a 5-point Likert scale in arterial and portal venous phases. DLIR consistently outperformed other methods in SNR, CNR, image quality, image interpretation, structural differentiability and diagnostic certainty. Pixelshine performed comparably only to ASIR-V 50%. No significant differences were observed between junior and senior radiologists. In conclusion, DLIR-based techniques have the potential to establish a new benchmark in clinical CT imaging, offering superior image quality for tumor staging, enhanced diagnostic capabilities, and seamless integration into existing workflows without requiring an extensive learning curve.

Abstract In a previous article a new algorithm for fully automatic ‘CT histogram based Fat Estimation and quasi-Segmentation’ (CFES) was validated on synthetic data, on a special CT phantom, and tested on one corpse. Usage of said data in FE-modelling for temperature-based death time estimation is the investigation’s number one long-term goal. The article presents CFES’s results on a human corpse sample of size R = 32, evaluating three different performance measures: the τ-value, measuring the ability to differentiate fat from muscle, the anatomical fat-muscle misclassification rate D, and the weighted distance S between the empirical and the theoretical grey-scale value histogram. CFES-performance on the sample was: D = 3.6% for weight exponent α = 1, slightly higher for α ≥ 2 and much higher for α ≤ 0. Investigating τ, S and D on the sample revealed some unexpected results: While large values of τ imply small D-values, rising S implies falling D and there is a positive linear relationship between τ and S. The latter two findings seem to be counter-intuitive. Our Monte Carlo analysis detected a general umbrella type relation between τ and S, which seems to stem from a pivotal problem in fitting Normal mixture distributions.

CT protocols that diagnose COVID-19 vary in regard to the associated radiation exposure and the desired image quality (IQ). This study aims to evaluate CT protocols of hospitals participating in the RACOON (Radiological Cooperative Network) project, consolidating CT protocols to provide recommendations and strategies for future pandemics. In this retrospective study, CT acquisitions of COVID-19 patients scanned between March 2020 and October 2020 (RACOON phase 1) were included, and all non-contrast protocols were evaluated. For this purpose, CT protocol parameters, IQ ratings, radiation exposure (CTDIvol), and central patient diameters were sampled. Eventually, the data from 14 sites and 534 CT acquisitions were analyzed. IQ was rated good for 81% of the evaluated examinations. Motion, beam-hardening artefacts, or image noise were reasons for a suboptimal IQ. The tube potential ranged between 80 and 140 kVp, with the majority between 100 and 120 kVp. CTDIvol was 3.7 ± 3.4 mGy. Most healthcare facilities included did not have a specific non-contrast CT protocol. Furthermore, CT protocols for chest imaging varied in their settings and radiation exposure. In future, it will be necessary to make recommendations regarding the required IQ and protocol parameters for the majority of CT scanners to enable comparable IQ as well as radiation exposure for different sites but identical diagnostic questions.

Abstract The study goal was to evaluate the distances from the radial (RN), the musculocutaneous (MN) and axillary nerves (AN) and the medial neurovascular bundle of the upper arm to a minimally invasive applied plate and to define its relation to the RN during different degrees of malrotation during MIPO. The sample involved ten upper extremities. Application of a PHILOS plate was performed through a Delta-split. Intervals between the AN, MN, RN and the medial vascular bundle were defined at various positions. The humeral shaft was artificially fractured at a height of about the mean of the plate. The distal fragment was brought into 15° and 30° internal (IR) as well as external rotation (ER) and here, the plate’s relation to the RN was evaluated. The medial neurovascular bundle intersected the plate at its distal part in two specimens. Regarding the distances from the RN to the plate during different rotation positions the distances became significantly longer during ER, respectively shorter during IR. The medial neurovascular bundle and the RN were identified as the main structures at risk. Care must be taken during distal screw placement and malrotation exceeding 15° must be avoided during MIPO.

Abstract Objectives To develop a goal-oriented indicator system based on the balanced scorecard (BSC) concept, which takes into account the perspectives of the referring physician and patient and emphasizes the focus on the internal processes of the radiology department. Methods Development of a BSC occurred in six steps: (Step 1) strengths/weaknesses and opportunities/risks (SWOT-) analysis of the radiology department, (Step 2) setting-specific objectives (model, core values, key objective) followed by the development of 4 perspectives, (Step 3) and definition of strategic issues oriented to the value-added chain of the processes of the radiology department. (Step 4) Creation of a “Strategy Map” with regard to the perspective and their cause–effect relationships. (Step 5) Development of an automated key performance indicator (KPI) cockpit for the monitoring, reporting, and management scorecard. Results A total of 10 success factors were identified using SWOT analysis. The core values include high quality in clinical, teaching, and research areas. The radiological value-added chain is composed of three processing steps. 1. registration, 2. examination, and 3. reading/X-ray demonstration. Three action programs were derived: 1. increase competency (e.g., specialist standard), 2. improve referring physician/patient satisfaction, 3. increase productivity. Daily process monitoring was added to the management cockpit as a monitoring scorecard. The scorecard comprises 18 KPIs and is automatically updated every month. The annual management scorecard comprises 10 KPIs. Conclusions The BSC makes it possible to implement a strategy for radiology that is strongly oriented toward the requirements of the referring physicians and the demands of patients.

Modern optical systems often require small, optically effective structures that have to be manufactured both precisely and cost-effectively. One option to do this is using nanoimprint lithography (NIL), in which the optical structures are replicated as masters using a stamping process. It would also be advantageous to manufacture the master structures quickly and easily. A master manufacturing process based on a photolithographic image of an inkjet-printed mask is presented and investigated in this paper. An essential element is that a deliberate blurring of the printed structure edge of the mask is used in the photolithographic process. Combined with the use of a non-linear photoresist, this allows for improved edge geometries of the master structure. We discuss the inkjet-printed photomask, the custom photolithography system to prevent imaging of the printing dot roughness and the manufacturing processes of NIL polymer masks as well as their subsequent stamp imprinting. Finally, it was shown that stamp geometries with a width of 1.7 µm could be realised using inkjet-printed photomasks in the master manufacturing process. This methodology opens up the potential of fast and simple master manufacturing for the development and manufacturing of optical elements.

Research on mass media in authoritarian regimes focuses more on state mechanisms of control than on actual media reporting and on moments of crises much more than on times of stable functioning of the regime. In order to shed more light on the role of journalistic mass media in authoritarian regimes, this article deals with the actual limits of pluralism in media reporting regarding policy issues in ‘ordinary’ authoritarian politics. Looking at pluralism in sources (i.e., actors being quoted) and pluralism in opinion, the article also deals with the often assumed increasing degree of pluralism from TV over print media to the Internet. This study is based on a qualitative content analysis of media reporting on export pipelines in three post-Soviet authoritarian regimes (Azerbaijan, Kazakhstan, and Turkmenistan). The text corpus comprises 3,618 media reports from 38 different journalistic media outlets published between 1998 and 2011. Two major results of the study are, first, that concerning the degree of pluralism, the differences between types of media are country specific, and, second, that ‘limited pluralism’ seems to be a misnomer, as the political opposition—at least in our cases—regularly does not have a voice at all.

Abstract Background The reconstruction of meta−/diaphyseal bone defects following bone tumour resection is challenging, and biological treatment options should be applied whenever possible, especially in benign lesions and early stage sarcomas. We aimed to evaluate the results of segmental (SR) and hemicortical reconstructions (HR) at the extremities using non-vascularised fibula grafts. Methods We retrospectively enrolled 36 patients who were treated with non-vascularised fibula reconstructions (15 SR, 21 HR) after bone tumour resection (15 malignant, 21 benign). All cases were evaluated regarding consolidation, hypertrophy at the graft-host junctions, and complications; moreover, the functional and oncological results were assessed. The mean follow-up was 8.3 years (2.1–26.6 years). Results Primary union was achieved in 94% (SR 87%, HR 100%) of patients, and 85% (SR 81%, HR 88%) showed hypertrophy at the graft-host junction. The overall complication rate was 36% with 4 patients (11%) developing local recurrence. There was a significant correlation between the development of mechanical complications (fracture, delayed-/non-union) and a defect size of ≥12 cm (p = 0.013), segmental defects (p = 0.013) and additional required treatment (p = 0.008). The functional outcome was highly satisfactory (mean MSTS score 86%). Conclusions Due to encouraging results and advantages (such as their remodelling capacity at the donor site), non-vascularised fibula reconstructions should be considered a valuable alternative treatment option for patients with hemicortical defects or segmental reconstructions of less than 12 cm in which no additional neo-/adjuvant treatment is necessary.

The social sciences are increasingly addressing the quality of research data and debating ways to improve data transparency, that is, the availability of original research data to corroborate claims made in academic publications. This article offers a systematic discussion of related problems and challenges with the example of post-Soviet area studies. It goes on to examine ways to improve data transparency. Although the Internet has a huge potential for linking research with resulting publications and underlying data as well as for organizing a collective discussion around the research, current data repositories do not truly go beyond basic upload and download functions for datasets. With the example of the Discuss Data project, this article gives an overview of more elaborated features that can easily be implemented to improve the visibility and quality assessment of data collections. Finally, it discusses ethical concerns about data transparency related to privacy protection and copyrights.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

As political elites in the Caspian countries see themselves as actors who determine the fate of their countries and not as mere objects of international power struggles or as managers of pipeline projects, this contribution examines how domestic elites assess different pipeline projects. Based on close to 1,500 TV reports from national TV stations, which are seen as the mouthpiece of the ruling elites, we analyze the arguments surrounding oil and gas pipeline debate and construction in Azerbaijan, Kazakhstan and Turkmenistan.

In order to reduce the tailpipe particulate matter emissions of Diesel engines, Diesel particulate filters (DPFs) are commonly used. Initial studies using a conductometric soot sensor to monitor their filtering efficiency, i.e., to detect a malfunction of the DPF, are presented. The sensors consist of a planar substrate equipped with electrodes on one side and with a heater on the other. It is shown that at constant speed-load points, the time until soot percolation occurs or the resistance itself are reproducible means that can be well correlated with the filtering efficiency of a DPF. It is suggested to use such a sensor setup for the detection of a DPF malfunction.

We report and classify the rich variety of patterns forming spontaneously in the oxide layer during the oscillatory photoelectrodissolution of n-type doped silicon electrodes under limited illumination. Remarkably, these patterns are often comprised of several dynamical states coexisting on the electrode, such as subharmonic phase clusters and spatio-temporal chaos, and include so-called ‘chimera states’. The experiments suggest that the subharmonic phase clusters emerge from a period doubling bifurcation that, upon further parameter changes, evolves into classical phase clusters. Experimentally the occurrence of the patterns is controlled via two coupling mechanisms: a linear global coupling by an external resistor and a nonlinear coupling imposed on the system by the limitation of the illumination.