OPUS documents https://opus4.kobv.de/opus4-thd/index/index/ Thu, 03 Sep 2026 17:53:56 +0200 Thu, 03 Sep 2026 17:53:56 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/505 Significance Cochlear implants (CIs) are a proven intervention for severe hearing loss; however, outcomes vary widely among CI recipients. Emerging evidence suggests that cortical adaptation to the electric hearing provided by CIs play a crucial role. Aim We investigate cortical brain activation differences in CI users, comparing individuals with good speech understanding (good performers, GP) to those with poor outcomes (poor performers, PP) alongside a control group with normal hearing (NH). Approach We recruited 46 CI users and 26 NH participants to perform a clinically adapted audiovisual speech comprehension task while we measured their brain activity using functional near-infrared spectroscopy (fNIRS). We corroborated our findings with objective and behavioral data. Results Our findings showed distinct brain activation patterns associated with speech understanding. GP showed comparable brain activation patterns to NH in audio-only conditions, indicative of successful hearing rehabilitation. Further, both GP and PP participants showed an adaptive mechanism during visual speech processing. However, compared with GP, PP relied heavily on visual cues and showed altered neural resource allocation during audio-only conditions, potentially limiting their overall rehabilitation success. Conclusions fNIRS revealed significant differences in brain activation between GP and PP, highlighting the role of cortical factors in CI rehabilitation. Understanding these neural mechanisms has the potential to lead to better patient counseling, optimized postoperative management, and personalized therapeutic strategies to improve outcomes for CI users. András Bálint; Wilhelm Wimmer; Christian Rummel; Marco Caversaccio; Stefan Weder article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/505 Thu, 03 Sep 2026 17:53:56 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/503 Thermal propagation remains a safety challenge for lithium-ion traction batteries in the growing electric-vehicle market. While mitigation strategies have largely focused on limiting thermal interactions between cells, electrical coupling effects during and after cell failure have received comparatively less systematic attention. This study examines electrical cell-to-cell interactions during thermal runaway using a three-module assembly containing cylindrical 21700 cells. To characterize the electrical response, row voltages and selected cell surface temperatures were recorded during thermal runaway. The measured voltage response indicates internally driven electrical redistribution through the parallel network during thermal runaway, influenced by the effective short-circuit resistance established in the trigger cell. The three-module experiments further indicate temporary overcharge conditions in modules connected in series to the failing module, with the corresponding cell groups temporarily exceeding their normal operating window. Dedicated single-cell nail-penetration tests revealed substantial variation in the effective post-failure short-circuit resistance, resulting in a wide range of estimated short-circuit currents and electrical loading within the investigated assembly. A simplified electrical model of the three-module assembly reproduced the measured redistribution trends and provided insight into the electrical behavior of individual cells within the assembly. Overall, the results provide experimentally supported insight into topology-dependent electrical redistribution and temporary localized overcharge conditions during thermal runaway under representative local module-level boundary conditions. Denis Düzgün; Alexander Hahn; Michael Steckel; Michael Pfeiffer; Michael Sternad article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/503 Thu, 03 Sep 2026 17:45:04 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/501 Introduction Volunteer firefighters must assess scene hazards before initiating rescues; however, line-of-duty fatality data consistently identify failures of self-protection as a proximate cause of preventable casualties. Whether mnemonic-based training, specifically the GAMS schema ( Gefahr erkennen–Absperren–Menschenrettung–Spezialkräfte; identify hazard–cordon off the scene-rescue-request specialist units ), translates into reliable behavioral activation under operational pressure has not been empirically tested. Methods Using a convergent mixed-methods design, 21 active volunteer firefighters from a single department in northern Germany were randomly assigned to three groups and exposed to four sequential hazard scenarios: carbon monoxide poisoning, an unsecured aggressive dog, electrical shock in a wet environment, and a flooded basement with a missing person; the fourth was delivered as a theoretical briefing and excluded from quantitative scoring. Quantitative data were collected via standardized, structured observations across the three enacted scenarios, scored on a four-point severity scale (0–3). Results The qualitative data consisted of 130 transcribed speech sequences, which were analyzed using structured qualitative content analysis following Mayring's methodology, with all sequences independently double-coded. Six deductively derived main categories were differentiated into 30 inductively derived subcategories, each of which was operationalized with explicit definitions, coding rules, and anchor examples. Critical-action errors formed the single largest error category and were elevated across all enacted scenarios, with no significant between-group differences [Kruskal–Wallis H(2) = 0.633, p  = .729]. Qualitative analysis identified a systematic rescue impulse that overrode hazard assessment routines at the perception-to-action transition, despite participants demonstrating intact declarative knowledge of the correct procedures during post-scenario debriefings. Discussion This knowledge–action dissociation was invariant across hazard types. The GAMS mnemonic remains stored as declarative knowledge rather than functioning as a procedural-action trigger. Mnemonic-based didactic instruction alone is insufficient and must be supplemented by repeated scenario-based rehearsal to proceduralise self-protective behaviors. Andrea C. Baron; Cosmo Bulasikis; Laura Over-Müller; Ole Franzen; Michael Reppel; Kai Mortensen; Peer Franzen; Victoria Edwards; Bernhard Elsner; Philipp Dahlmann; Daniel Drömann; Klaas F. Franzen; Patrick Ristau article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/501 Thu, 27 Aug 2026 17:02:23 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/499 Background Partially ionized gas, also known as cold atmospheric plasma (CAP), is reported to have anti-tumor specific properties via reactive oxygen and nitrogen species (RONS) in different tumor entities. Many CAP effects have already been studied, but the exact influence on metabolism has yet to be defined. Methods Analyses of metabolic substrates, metabolic pathways, genes, mRNA and nitration were performed to investigate CAP-treated and untreated melanoma and non-malignant cells. Results We discovered a dose-dependent downregulation of oxidative phosphorylation and glycolysis in CAP-treated compared to untreated melanoma cells, whereas for non-malignant cells we saw no change in the oxidative phosphorylation and even an increase in the glycolysis. Gene set enrichment analyses demonstrated a downregulation of gene sets associated with metabolic processes in melanoma cells. These effects could be explained by posttranslational modification via tyrosine nitration, induced by RONS. A higher induction of protein nitration was found in CAP-treated melanoma cells opposed to non-malignant cells. This difference may contribute to the antitumor-specific effects of CAP. Conclusion This study shows different molecular and metabolic responses of melanoma and non-malignant cells in vitro. It thereby contributes to a better understanding of the antitumor-specific effects of CAP and facilitates the development of CAP-based treatments. Erika Rein; Tom Zimmermann; Stefan Fischer; Zubeir El Ahmad; R. Verena Taudte; Arne Gessner; Martin F. Fromm; Melanie Kappelmann-Fenzl; Anja Bosserhoff article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/499 Thu, 27 Aug 2026 16:43:46 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/502 This Editorial Commentary refers to: Al Riyami et al (2026) Clinical spectrum, genetic variants, and outcomes of autosomal recessive polycystic kidney disease in Omani children: two-center experience. Pediatr Nephrol. https://doi.org/10.1007/s00467-026-07418-z Kathrin Burgmaier; Max C. Liebau article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/502 Thu, 27 Aug 2026 16:21:23 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/493 This Editorial refers to: Gegenfurtner, A., Schmidt-Hertha, B., & Lewis, P. (Eds.). (2020). Digital technologies in training and adult education [Special issue]. International Journal of Training and Development, 24(1). https://doi.org/10.1111/ijtd.12153 Andreas Gegenfurtner; Bernhard Schmidt‐Hertha; Paul Lewis article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/493 Thu, 27 Aug 2026 16:06:21 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/498 Miniaturized and rechargeable energy storage systems, which easily power smart and (in vivo) sensors or the wirelessly networked transmitting devices of the so‐called internet of things, are expected to open unprecedented ways for how information can be shared autonomously. On the macroscale, such battery‐powered devices have already revolutionized our daily life by the use of mobile phones and portable computers. The eagerly‐awaited advent of sufficiently powerful and long‐living microbatteries will definitely make our lives more comfortable, especially in sectors such as medicine, security, autonomous driving or artificial intelligence in conjunction with fields where information need to be quickly shared, also including pandemic‐like situations. Here, a fully matured lithium‐ion microbattery with millimeter‐sized dimensions that can be manufactured by mass production methods well‐established in semiconductor industry is presented. The battery can directly be machined from wafer‐grade monocrystalline silicon which acts as both the electrochemically active anodic part and, at the same time, as the electrically insulating housing material of the accumulator. The high current output power (200 mW cm−2; 30 mA peak current) and the solid charge‐discharge stability of at least 100 cycles (10 mAh cm−2), combined with a high Coulombic efficiency near 100%, make the device ideally suited to be implemented in a large range of intelligent, self‐powered electric devices. Michael Sternad; Georg Hirtler; Michael Sorger; Daniel Knez; Kamil Karlovsky; Magdalena Forster; H. Martin R. Wilkening article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/498 Fri, 21 Aug 2026 14:41:55 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/494 The key property of monotone classifiers is that increasing (decreasing) input values lead to increasing (decreasing) the output value. Preserving monotonicity for a classifier typically requires many constraints to be respected by modelling approaches such as artificial intelligence techniques. The type of constraints strongly depends on the modelling assumptions. Of course, for sophisticated models, such conditions might be very complex. In this study, we present a new family of kernels that we call it Choquet kernels. Henceforth, it allows for employing popular kernel‐based methods, such as support vector machines. Instead of a naïve approach with exponential computational complexity, we propose an equivalent formulation with quadratic time in the number of attributes. Furthermore, because coefficients derived from kernel solutions are not necessarily monotone in the dual form, different approaches are proposed to monotonize coefficients. Finally, experiments illustrate beneficial properties of the Choquet kernels. Ali Fallah Tehrani; Marc Strickert; Diane Ahrens article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/494 Fri, 21 Aug 2026 14:09:28 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/496 Zeolitic imidazolate framework-8 (ZIF-8) is a widely studied metal–organic framework whose porous structure and gas adsorption behavior strongly influence its optical properties. In particular, variations in the refractive index caused by gas loading into the metal–organic frameworks (MOF) pores represent a viable signal-generating mechanism for optical gas sensors. In this study, we investigate the gas-dependent optical properties of ZIF-8 thin films using spectroscopic ellipsometry. ZIF-8 thin films were prepared via a liquid-phase deposition process comprising surface functionalization with triethoxy-3-(2-imidazolin-1-yl)propylsilane and successive growth cycles from aqueous solutions. The influence of the number of deposition cycles and the gas environment on the optical properties was systematically studied with a total of 108 individual ellipsometric measurements. The structural properties of the films were analyzed by grazing-incidence x-ray diffraction. The refractive index of the ZIF-8 films exhibited statistically significant, gas-dependent changes, with average values of 1.4242, 1.4246, and 1.4253 measured under vacuum, atmospheric-pressure nitrogen, and atmospheric-pressure methane, respectively. Film thickness increased from ∼630 nm after one deposition cycle to up to 1400 nm after three cycles, while no significant increase in surface roughness was observed with increasing thickness. This indicates homogeneous, densely packed film growth without the formation of voids or discontinuities, as further supported by scanning electron microscopy. This work provides a transparent and reproducible ellipsometric modeling strategy for MOF thin films that is applicable beyond the specific case of ZIF-8, addressing a key limitation in the current literature and improving inter-study comparability of optical constants under varying environmental conditions. Valerius Abb; Artur Samp; Benedikt Winter; Günther Ruhl; Jörg Franke; Martin Kammler article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/496 Fri, 21 Aug 2026 12:30:32 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/492 What are the reactions of training participants toward digital webinar‐based training programs? Webinars are digital tools to deliver training and education through synchronous audiovisual communication among remotely located training instructors and participants. A webinar is a special case of web conferencing that serves the educational function of learning and teaching. Because the previous literature underemphasized the webinar process and qualitative learner experiences, the present study aimed to explore the reactions of 419 trainees toward 48 webinars in the four content areas supply chain management, industrial management, early childhood education and mathematics, the present study used a sequential mixed methods research design. The quantitative part of the study employed a multi‐item online questionnaire to measure satisfaction and reactions toward the webinar trainer; survey responses were analyzed to estimate mean differences across webinars. The qualitative part of the study employed narrative interviews with 23 trainees; interview transcripts were analyzed with qualitative content analysis to identify how the instructional design, webinar content and implementation can be improved for future web conferences. The findings indicate that early childhood education trainees had the highest satisfaction levels. Trainees preferred greater levels of learner‐teacher interaction, less time spent on discussing task solutions collaboratively and digital webinar recordings as a follow‐up possibility at home or in the workplace. Trainees also liked the fact that webinars afforded the possibility to deepen the content, to prepare for upcoming exams and to have virtual consultation hours with the facilitator. Furthermore, trainees preferred webinars no longer than 90 min and webinars on weekdays after work rather than at weekends. Optimal internet/broadband connections were perceived as a requirement across web conferencing and virtual classroom programs for effective digital education. Implications of the findings for educational technology, human resource development and professional learning are discussed. Andreas Gegenfurtner; Alexander Zitt; Christian Ebner article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/492 Thu, 20 Aug 2026 16:49:39 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/491 Background Healthcare professionals are frequently exposed to serious work-related events that may adversely affect their psychological well-being, work ability, and professional retention. Peer support systems have been proposed as a low-threshold organizational approach to providing psychosocial support following such job-inherent events. This study examined the incidence of serious work-related events among healthcare workers, employees’ perceptions of an implemented peer support system, and the potential relevance of psychosocial support for employer attractiveness. Methods A multicenter cross-sectional survey was conducted following the implementation of peer support structures in three German hospitals in 2022. A total of 295 healthcare workers completed an anonymous questionnaire assessing experiences with serious work-related events, perceptions of the peer support system, preferred support services, and the potential influence of psychosocial support on employer choice. Descriptive statistics and bivariate correlations were performed. Results Overall, 46.4% of participants reported experiencing at least one serious work-related event within the previous two years. The peer support system was perceived as a valuable resource for supporting staff and managing psychosocial stress. Participants reported benefits not only from direct use of peer support but also from knowing that support was available when needed. Negative perceptions of the peer support system were uncommon. Approximately 27% of respondents indicated that the availability of psychosocial support could influence their choice of employer. Conclusions Peer support systems are perceived as an acceptable and beneficial approach to addressing psychosocial stress among healthcare professionals. Beyond their supportive function, such systems may be perceived as part of employer attractiveness and a feasible organizational strategy to support workforce well-being and workforce stability in healthcare settings. Susanne Katharina Heininger; Andrea Forster; Michael Frey; Dominik Hinzmann article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/491 Thu, 20 Aug 2026 11:46:24 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/490 Introduction Valid multidimensional instruments for assessing crisis preparedness at the municipal population level are largely unavailable. Nationally representative surveys cannot provide the subnational granularity required for locally targeted civil protection planning. We developed and validated KOMPAKT112, which is, to our knowledge, the first all-hazards, multidimensional preparedness questionnaire designed for German municipal civil protection research. Methods A three-round modified Delphi study (October-November 2025) was conducted with 26 interdisciplinary experts from eight domains: civil protection authorities, fire brigades, THW, aid organizations, the German Armed Forces, church communities, municipal administration, and academia. An initial 183-item pool was generated from seven preparedness frameworks, rated on a five-point Likert scale, with an a priori consensus threshold of ≥75%. Reporting followed the CREDES guidelines. External validation comprised a cognitive pre-test ( n  = 12, think-aloud protocol) and a population-based pretest ( n  = 50). Results Response rates were 100% (Rounds 1-2) and 92.3% (Round 3). The item pool decreased from 183 to 132 items across 14 themes. The mean block-level consensus increased monotonically from 78.9 to 91.2%, and the mean interquartile range converged from 1.60 to 0.77. The overall Content Validity Index was 0.91 (range, 0.85–0.94), exceeding the ≥0.80 threshold across all blocks. Cognitive pretesting prompted revisions to the six blocks. The population-based pre-test confirmed score differentiation, absence of floor/ceiling effects, and a knowledge–behavior gap of 7.3 percentage points (knowledge: 76.2% vs. behavior: 68.9%). Seventy percent of the pre-test participants reported increased crisis preparedness awareness following completion. Discussion KOMPAKT112 demonstrated robust content validity and is suitable for population-level municipal crisis preparedness research in Germany. Its 14-block architecture uniquely covers civil-military cooperation perception and volunteer engagement readiness, which are dimensions absent from existing instruments, including the HEPI. The instrument is freely available as Supplementary material and constitutes a promising, content-validated candidate instrument for comparative studies on municipal preparedness. Andrea C. Baron; Andreas Batsios; Laura Over-Müller; Cosmo Bulasikis; Ole Franzen; Michael Reppel; Peer Franzen; Kai Mortensen; Daniel Drömann; Patrick Ristau; Klaas F. Franzen article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/490 Wed, 19 Aug 2026 17:22:10 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/489 The use of inquiry-based laboratory instruction has been widely promoted as an effective alternative in science education, particularly due to its student-centered approach. However, chemistry teaching often still relies on verification-based practices, which restrict opportunities for deep conceptual learning of scientific principles. To assess the impact of inquiry-based instruction on conceptual understanding in chemistry, this meta-analysis synthesized empirical evidence from studies published between 2018 and 2024, following PRISMA 2020 guidelines. Ten empirical studies were incorporated following meticulous selection from prominent databases (ERIC, Scopus, Web of Science). Using a pooled model, the meta-analysis found that students participating in inquiry-based chemistry laboratory instruction had significantly higher conceptual knowledge, with a positive moderate effect size (Hedges’g = 0.71), compared to peers taught through traditional laboratory methods. Sensitivity analyses confirmed the reliability of this finding, and funnel plot inspection indicated a low risk of publication bias. In summary, the analysis provides strong evidence that adopting inquiry-based laboratory teaching in chemistry enhances students’ conceptual understanding and supports the implementation of student-centered experimental approaches in science education. Etienne Twizeyimana; Theophile Shyiramunda article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/489 Mon, 17 Aug 2026 13:43:17 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/487 † This paper is an extended version of our paper published in EEEIC/I&CPS Europe 2023—2023 IEEE International Conference on Environment and Electrical Engineering and 2023 IEEE Industrial and Commercial Power Systems Europe, Madrid, Spain, 6–9 June 2023. Accurate forecasting of power production and consumption is essential for the efficient operation of smart energy grids, enabling stable energy exchange and grid reliability. However, the growing integration of photovoltaics (PVs) and electric vehicles introduces significant uncertainty. This paper evaluates multiple Machine Learning (ML) models for single- and multi-step forecasts of PV generation and household consumption, incorporating uncertainty bounds to inform operator decisions. We use data from two Swedish sites and the CityLearn benchmark dataset to compare direct, recursive, and hybrid multi-step strategies. LightGBM with gradient-boosted quantile regression achieves the best single-step performance, with Mean Absolute Error (MAE) as low as 10.19 W in Halmstad and 16.12 W in Uppsala. For multi-step forecasts, the direct method outperforms others, reaching a 48 h consumption MAE of 71.08 W in Uppsala and 52.05 W in Halmstad, and achieving prediction interval coverage probabilities above 0.95. Moreover, personalized models trained on individual households outperform generalized ones, even with smaller datasets, highlighting the value of tailored approaches for improving forecast accuracy under uncertainty. Phil Aupke; Seema Seema; Andreas Theocharis; Andreas Kassler article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/487 Mon, 17 Aug 2026 10:00:11 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/488 Microwave heating of clay-based materials has the potential to make ceramic processing more energy efficient. However, the influence of mineralogical composition and bulk density of the clays on heating behavior is not yet fully understood. This study investigates the microwave response at 2.45 GHz of kaolinite-, illite-, and smectite-rich clays with and without additives, as well as brick clays. The heating behavior was evaluated in relation to mineralogical, thermal (experimental), and dielectric (literature) analyses. Smectite-rich systems exhibited the strongest initial microwave coupling, followed by illite-rich clays, while kaolinite-rich systems showed comparatively weak absorption. During dehydroxylation, the net heating rate decreased in all systems due to the endothermic nature of the reaction, which was most pronounced in kaolinite. Kaolinite-rich clays exhibited significant dielectric changes during phase transitions, shifting from weakly to strongly absorbing regions. This promoted local overheating and temperature inhomogeneities. In contrast, illite- and smectite-rich clays maintained a more stable absorption over several reaction intervals, resulting in more uniform energy distribution and homogeneous temperature profiles. Additional phases altered the overall microwave interaction: iron oxides and carbonaceous components enhanced absorption, while most carbonates had only a minor influence. Increased bulk density, especially in quartz-containing systems, contributed to more uniform temperature fields. Overall, the microwave heating response of the investigated clay systems was governed by the interplay between mineralogical composition, additive content, and sample density. This provides a framework for improving the evaluation of thermal treatment strategies for ceramic raw materials using microwave heating. Andreas Blüml; Markus Hainthaler; Karl-Christian Thienel article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/488 Mon, 17 Aug 2026 09:18:26 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/484 Purpose The purpose of this study was to evaluate whether Chat Generative Pre‐trained Transformer (ChatGPT; Version 5.1) can reproduce frequentist meta‐analytic calculations with an accuracy comparable to established statistical software in orthopaedic research. Methods In this methodological comparison study, data from two previously published orthopaedic meta‐analyses with identical statistical architectures as reference standards were used. Between‐study variance (τ²) was estimated using the Sidik–Jonkman method and uncertainty was quantified using the Hartung–Knapp adjustment for the random‐effects models, while common‐effect models assume τ²= 0. Original data extraction tables were provided to ChatGPT‐5.1, which was instructed to perform the same analyses. ChatGPT‐generated pooled mean differences, confidence intervals and heterogeneity statistics (I², τ², p values) were compared with verified reference results obtained using the meta and metafor packages in R. Results Across seven evaluated outcomes, ChatGPT‐5.1 reproduced the direction of effects in all cases. Deviations compared with reference meta‐analyses were classified as minor in three outcomes (43%), moderate in one outcome (14%) and major in three outcomes (43%). Agreement was highest in low‐heterogeneity settings, whereas substantial deviations occurred in outcomes with pronounced between‐study heterogeneity, particularly under random‐effects models. Conclusion ChatGPT‐5.1 demonstrates emerging capability to approximate frequentist meta‐analytic calculations, particularly in low‐heterogeneity settings. However, its tendency to underestimate between‐study variability and to deviate in complex random‐effects scenarios limits its reliability as a standalone tool. At present, large language models may support exploratory analyses but cannot fully replace dedicated statistical software for meta‐analyses in orthopaedic research. Level of Evidence Level III. Mikhail Salzmann; Nikolai Ramadanov; Robert Prill; Robert Hable; Roland Becker article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/484 Wed, 05 Aug 2026 15:52:20 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/482 Digital health technologies are increasingly used in healthcare, but their implementation in routine practice remains uneven. Many solutions are introduced as pilots but are not sustained, scaled up, or fully embedded in everyday organizational work. This study aimed to identify implementation determinants that recur across different real-world digital health settings and to organize them into a practical analytical framework for implementation planning and readiness assessment. We conducted a secondary qualitative multiple case study with cross-case synthesis. Thirteen digital health implementations from six European countries, developed within an Erasmus+ project, were analyzed using standardized implementation case reports. The cases covered a range of technologies, including telemonitoring, artificial intelligence, extended reality solutions, and digital platforms, implemented at different levels of healthcare systems. The reports described implementation context, technology type, stakeholders, barriers and facilitators, organizational conditions, and lessons learned. Because the material consisted of secondary standardized reports rather than primary qualitative data, the analysis focused on recurring reported determinants and did not aim to develop a fully inductive explanatory theory. Established implementation frameworks were used ex post to support interpretation. The analysis identified 20 implementation determinants. These were organized into four interdependent domains: technological, organizational, user-related, and system-level. Frequently reported issues included interoperability, usability, leadership and governance, workflow integration, staff competencies, user engagement, funding stability, and regulatory alignment. Across the cases, implementation challenges rarely concerned the technology alone. The resulting four-domain framework offers a concise way to structure implementation knowledge across heterogeneous digital health settings. It may support early identification of implementation risks, readiness assessment, and more systematic planning of digital health interventions. The framework is best understood as an analytical and planning tool, rather than as a model that predicts implementation success. Mariusz Jaworski; Petra Petrová; Thomas Spittler; Radu-George Ciorap; Agnieszka Wojtczuk-Turek; Ilona Cieslak article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/482 Mon, 03 Aug 2026 12:06:51 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/481 Extensive research exists on artificial intelligence (AI)-assisted fracture detection in various anatomical regions, but clavicle fractures remain comparatively understudied. This study aimed to compare the diagnostic performance of AI-guided clavicle fracture detection on plain radiographs with that of an experienced orthopedic surgeon. We retrospectively analyzed all clavicle radiographs obtained at our institution between September 11,2023 and October 31,2024 following the clinical implementation of AI-guided fracture detection. Radiological findings confirmed by a senior radiologist served as the reference standard. AI performance was additionally compared with the assessments of an experienced, blinded orthopedic surgeon. Diagnostic performance metrics included accuracy, sensitivity, specificity, Cohen kappa, F1 score, and Youden index. A total of 367 clavicle radiographs were included, comprising 186 anteroposterior (AP) and 181 second-plane views. The mean patient age was 44.6 ± 26.2 years, and 59.4% were male. According to the reference standard, clavicle fractures were present in 96 AP radiographs (51.6%) and 95 second-plane radiographs (52.5%). On AP radiographs, the AI system achieved an accuracy of 97.31%, sensitivity of 95.83%, specificity of 98.89%, Cohen kappa of 0.95, and F1 score of 0.97. Diagnostic performance on second-plane radiographs was similarly high and overall comparable to that of the experienced orthopedic surgeon. This retrospective diagnostic accuracy study shows that AI-guided clavicle fracture detection is highly accurate and reliable, with performance approaching that of an experienced orthopedic surgeon. These findings support the potential role of AI as a diagnostic support tool in clavicle fracture detection, while prospective and multicenter validation remains warranted. Nikolai Ramadanov; Robert Hable; Maximilian Voss; Roland Becker; Andreas G. Schreyer; Robert Prill; Mikhail Salzmann article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/481 Wed, 22 Jul 2026 15:27:16 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/480 Malignant melanoma is characterized by high metastatic potential and cellular plasticity. Its progression is driven not only by genetic alterations but also by epigenetic reprogramming and changes in the transcriptome, mediated by transcription factors. The AP-1 family favors an invasive cell state by facilitating processes such as angiogenesis and migration. However, the AP-1-driven regulatory landscape and its implications for melanoma plasticity remain poorly understood. Here, we further elucidate the role of the AP-1 members c-Jun and Fra-1 in enhancer-related gene regulation during melanoma development. Integrative ChIP-seq and RNA-seq analyses revealed extensive enhancer reprogramming during tumor formation and significant upregulation of genes annotated to enhancers gained in melanoma cells. On average, half of these regions are directly bound by c-Jun/Fra-1, given a high AP-1 motif rate (~80%) and chromatin accessibility. Genes associated with c-Jun/Fra-1-bound enhancer regions are functionally linked to an invasive phenotype and comprise well-known melanoma drivers involved in migration and EMT. Clinically, high c-Jun/Fra-1 and target gene expression correlate with poor survival in BRAF wild-type and NRAS mutant melanoma patients, highlighting c-Jun/Fra-1 as a potential biomarker and therapeutic target. Overall, our data identify c-Jun/Fra-1 as important contributors to melanoma development through enhancer-mediated transcriptional programs. Zubeir El Ahmad; Katrin Ludwig; Alexander O. Matthies; Anja Katrin Bosserhoff; Melanie Kappelmann-Fenzl article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/480 Wed, 22 Jul 2026 14:51:21 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/467 Sickle cell nephropathy (SCN) is a major determinant of morbidity and mortality in sickle cell disease (SCD), yet early injury remains difficult to recognize with conventional laboratory markers alone. Creatinine-based assessment is problematic in SCD because low muscle mass, increased tubular secretion, and glomerular hyperfiltration may keep serum creatinine (SCr) deceptively low even in the presence of evolving nephropathy. Cystatin C (Cys-C) is useful but can still remain within reference range in early disease, while albuminuria reflects predominantly glomerular injury and may miss an earlier phase of tubular damage. Serum uromodulin (sUmod), a circulating form of the kidney-specific glycoprotein produced by the epithelial cells of the thick ascending limb of Henle's loop, may therefore provide a tissue-specific marker of tubular integrity and an opportunity to detect SCN before conventional filtration markers become abnormal [1-8]. Ferras Alashkar; Robert Hable; Denise Zwanziger; Friederike Poppenborg; Raina Yamamoto; Hans Christian Reinhardt; Alexander Röth; Victor Herbst; Yara Bestmann; Marco Kai; Jürgen E. Scherberich article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/467 Mon, 13 Jul 2026 14:38:48 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/466 Background Amputation is still the most common therapy for patients suffering from osteosarcoma in Myanmar, despite the fact that limb salvage surgery e.g. Borggreve–Van Nes-Winkelmann rotationplasty for malignant tumors located within the distal femur or proximal tibia is the current state-of-the-art reconstructive procedure. A safe and reliable operation technique is crucial in order to perform a complex surgical procedure like the rotationplasty in lower-middle income economies with limited infrastructure and resources. The authors present seven cases of patients with osteosarcomas that received a Borggreve–Van Nes-Winkelmann rotationplasty with an evaluation of the procedures focusing on safety and sustainability. Methods From 2019 until 2020, seven young patients with osteosarcomas of the distal femur or proximal tibia were treated with Borggreve–Van Nes-Winkelmann rotationplasties in the Orthopaedic Hospital in Mandalay, Myanmar. As modification of the standard procedure the dissection and subsequent clamping of the femoral artery in order to minimize blood loss as well as the formation of an adipocutaneous flap that minimizes swelling and decreases the pressure on the vessels were successfully performed. This modified procedure resembles a safe and simplified surgical technique that is feasible under the circumstances of lower-middle income economies with good outcomes. Results All patients showed good functional and aesthetic results. One of the seven patients needed secondary wound closure due to wound dehiscence. Conclusions A simplified and safe operation technique for the performance of the Van Nes-Borggreve rotationplasty was adapted to the given constraints in lower-middle income economies and proved to be successful. Trial registration All patients approved to participate in the study and have given consent to publication. Laura Sommerauer; Aung Phyo; Eric Pion; Isabel Zucal; Eric Klingelhoefer; Si Thu; Than Win; Sopyay Khin; Thura Kyaw; Hein Htet Zaw; Maung Mg Htwe; Nicola Fabbri; Silke Haerteis; Thiha Aung article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/466 Mon, 13 Jul 2026 14:01:41 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/464 The purpose of this study was to investigate the hydrogen permeability of different tubular polymer membranes for the usage in a biological methanation (BM) membrane reactor. An extensive literature research was conducted to collect permeability data of various polymers. Furthermore, five polymers were chosen concerning commercial availability, chemical resistance and the capability to endure elevated temperatures up to 63°C and pressures up to 5 bar. The hydrogen permeability of these selected polymers was experimentally determined for different tube sizes. The permeability measurement was conducted with a highly reproducible and reliable measurement method for tubular polymer membranes. From these results, the most promising polymer (PTFE with 3 × 2 mm size) with a mean hydrogen permeability of 18.208 (10−15 mol m−1 s−1 Pa−1) at 63°C was chosen. This tube was further investigated by varying the size (outer and inner diameter) and the feed pressure. In addition, the gas permeability for carbon dioxide was determined. Finally, the hydrogen permeation characteristics were evaluated for a tubular polymer membrane immersed in deionized water to imitate the operating conditions of a BM membrane reactor. Maximilian Peter Mock; Maria Bieringer; Raimund Brotsack; Stephan Leyer article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/464 Mon, 13 Jul 2026 12:15:05 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/463 Aim To provide an overview of existing research on interventions addressing the needs and requirements of families after intrauterine or perinatal loss of a child. Design A scoping review Methods: We conducted a systematic literature search in Medline, Cochrane, and CINAHL without restrictions on the publication period. We only included original empirical studies that investigated interventions for families following intrauterine or perinatal child loss. After the title, abstract, and full-text screening, data was extracted and synthesized using an inductive approach. Results Of the 3,502 studies obtained, a total of 25 were included in the scoping review. The selected studies were divided into six clusters: "interaction with the baby" (n = 6), "comprehensive care" (n = 3), "psycho-social support services" (n = 11), "digital support services" (n = 7), "psycho-social support services for siblings" (n = 2), and "supportive interventions in subsequent pregnancies" (n = 1). Conclusion This scoping review identified key components of needs-based interventions when experiencing intrauterine or perinatal loss. The identified studies cover a wide range, from the period after birth to two years after the loss, and are primarily designed for parents. To enable needs-based care for parents and siblings, implementing care pathways to standardize continuous, safe care is recommended. Further interventions (e.g., lactation management) need to be developed, implemented, and evaluated in further research. Lydia Bauernfeind; Yvonne Spyra; Fritz Sterr; Julian Siepmann; Karsten Gensheimer; Christian Rester article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/463 Mon, 13 Jul 2026 10:56:04 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/462 Selecting suitable biological models remains one of the most challenging and least formalised steps in biomimetic design. Existing tools support searching for biological strategies and transferring principles into engineering concepts, but provide limited guidance on which organism to prioritise once multiple plausible candidates are identified. Here we present a phylogeny-informed, data-driven framework that structures model selection as an explicit comparison. The framework computes four module scores per candidate model: data sufficiency, innovativeness, phylogenetic characteristics, and an open-ended contextual module for project-specific constraints. Users assign weights to the modules to reflect resources, timelines, and design requirements, yielding an overall compatible score and a ranked shortlist. We demonstrate the framework in a microplastic-filtration case study using 35 suspension-feeding taxa and three archetypal user scenarios. Rankings reveal a compact set of candidates that remains competitive across scenarios, while a smaller subset shifts in response to changes in priorities, thereby distinguishing robust starting points from context-dependent opportunities. Overall, the framework fills an under-supported gap in current biomimetic workflows by providing a structured decision-support layer for biological model selection. Jindong Zhang; Kirsten Wommer; Kristina Wanieck article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/462 Mon, 13 Jul 2026 10:25:54 +0200 https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/461 Purpose Hip arthroscopy (HAS) is technically demanding, and surgeon's experience may influence outcomes. However, the magnitude and domain‐specific effects of the learning curve remain unclear. Methods A systematic review and meta‐analysis were conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) and registered in PROSPERO (CRD420251185937). PubMed/MEDLINE, Embase and Scopus were searched through 31 December 2025 for studies comparing early versus late experience phases in HAS. Random‐effects meta‐analyses (Sidik–Jonkman estimator with Hartung–Knapp adjustment) were performed for operative and traction time, patient‐reported outcomes, complications, revision arthroscopy and conversion to total hip arthroplasty (THA). Risk of bias was assessed using ROBINS‐I and certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Results Eighteen studies (2624 procedures; 1291 early and 1333 late cases) were included. Late cases showed significantly shorter operative time (−31.77 min; 95% confidence interval [CI] −51.40 to −12.14) and traction time (−15.67 min; 95% CI −25.42 to −5.92), with substantial heterogeneity. Functional outcomes favoured late experience, including higher improvement in minimal clinically important difference units (0.58; 95% CI 0.17 to 0.99) and modest gains in modified Harris Hip Score (2.78 points; 95% CI 0.16 to 5.41) and Non‐Arthritic Hip Score (8.41 points; 95% CI 1.99 to 14.83). Complication rates and revision arthroscopy did not differ significantly, whereas conversion to THA was lower in late cases (odds ratio [OR] 0.10; 95% CI 0.01 to 0.98). Most studies were at moderate to serious risk of bias, and certainty of evidence was low to very low. Conclusion Surgeon experience in HAS is associated with improved operative efficiency and modest functional gains, while safety outcomes remain largely unchanged. The lower THA conversion rate in late cases may reflect improved patient selection and decision‐making, although confidence is limited by study design and heterogeneity. Level of Evidence Level III systematic review and meta‐analysis of predominantly retrospective cohort studies. Nikolai Ramadanov; Maximilian Heinz; Robert Hable; Roland Becker; Ingo J. Banke article https://opus4.kobv.de/opus4-thd/frontdoor/index/index/docId/461 Fri, 10 Jul 2026 17:07:01 +0200