https://ediss.sub.uni-hamburg.de:443 ediss captures, stores, indexes, preserves, and distributes digital research material. 2026-09-11T00:07:42Z https://ediss.sub.uni-hamburg.de:443/handle/ediss/12600 Title: Entwicklung hochsensitiver Pseudovirusassays für HIV-1 und SARS-CoV-2 auf Basis lentiviraler Vektoren Authors: Woens, Jannis Hendrik 2026-09-10T14:12:30Z https://ediss.sub.uni-hamburg.de:443/handle/ediss/12591 Title: Enhancing the Brain's Barrier: CD73 Gene Therapy for Stroke Protection in Mice Authors: Stamataki, Maria 2026-09-10T13:35:40Z https://ediss.sub.uni-hamburg.de:443/handle/ediss/12595 Title: The Role of Neural Replay in Shaping and Utilizing Neural Representations Supporting Learning, Memory, and Decision-Making Authors: Renz, Fabian Marvin Abstract: Flexible generalization depends on internal representations that capture the latent structure of the environment and can be dynamically updated as that structure changes. This thesis investigates the role of neural replay, the offline reactivation of sequential neural patterns, in building, refining, and leveraging such representations across wakefulness and sleep. The first empirical project combined functional magnetic resonance imaging (fMRI) with computational modelling to study how replay supports structure learning and generalization. Fifty-two participants performed a sequential decision task in which multiple options shared hidden reward sources. A latent cause inference model captured participants' discovery of this structure and outperformed standard reinforcement learning models. Backward replay in visual cortex selectively targeted unobserved sequences sharing the inferred latent reward structure, increased as participants discovered that structure, and tracked trial-by-trial non-local value updating from the computational model. When the latent structure changed on a second day, replay reorganised accordingly, including a directional shift for newly generalizable paths. The second empirical project examined how sleep transforms the neural basis of sequential memory retrieval. Participants learned hierarchically organized sequences and were tested before and after overnight sleep. Sequential reactivation during retrieval shifted in regional profile across consolidation: visual cortex dominated before sleep, whereas parietal cortex emerged as the primary locus after sleep, with replay strength predicting retrieval accuracy. This reorganisation is consistent with the systems consolidation hypothesis that sleep drives the redistribution of memory representations toward cortical networks. A methodological book chapter situated these findings within the broader landscape of tools for measuring neural plasticity in humans. Together, the three projects converge on a view of replay as an active computational mechanism sampling from an internal generative model supporting multiple functions including rapid value propagation over inferred structure during wakefulness, and driving cortical integration of memory representations during sleep. 2026-09-10T13:07:13Z https://ediss.sub.uni-hamburg.de:443/handle/ediss/12593 Title: Retrograde Schraubenosteosynthese für Frakturen des oberen Schambeinastes in schwierigen transpubischen Korridoren – eine Pilotstudie zu einer modifizierten Technik Authors: Seffert, Alena Maria Abstract: Die retrograde transpubische Schraubenosteosynthese kann bei anatomisch engen oder stark gekrümmten transpubischen Korridoren erschwert oder unmöglich sein. Zur Überwindung dieser anatomischen Schwierigkeiten wurde die in dieser Studie dargestellte modifizierte ESIN-ähnliche Technik mit vorgebogenem Führungsdraht entwickelt. Ziel der Studie, war die Bewertung der Nicht-Unterlegenheit gegenüber der klassischen Methode. Es handelt sich um eine retrospektive Pilotstudie, in die im Zeitraum von 01/2024 bis 04/2024 zehn Patienten eingeschlossen wurden. Dabei wurden demografische Daten, radiologische Ergebnisse (Matta-Kriterien), Komplikationen und funktionelle Ergebnisse (VAS-Schmerz und - Zufriedenheit, Majeed-Score) verglichen. Die modifizierte Technik zeigte keine höhere Komplikationsrate (p = 0,50). Auch die radiologischen Ergebnisse (Restdislokation modifiziert: 5,0 mm; klassisch 4,4 mm; p = 0,38) und die klinischen Ergebnisse (VAS-Schmerz: p = 0,47; VAS-Zufriedenheit: p = 0,42, Majeed-Score: p = 0,17) der modifizierten Technik waren der klassischen Technik nicht signifikant unterlegen. Die modifizierte, ESIN-ähnliche Technik mit vorgebogenem Führungsdraht ist somit eine sichere und praktische Alternative zur klassischen, retrograden Schraubenosteosynthese bei stark gebogenem oder engem transpubischen Korridor. Sie erweitert das minimalinvasive Spektrum, ohne die Komplikationsrate zu erhöhen.; Retrograde transpubic screw osteosynthesis can be difficult or even impossible due to narrow or severely curved transpubic corridors. To overcome these anatomic difficulties this modified ESIN-like with a pre-bent guidewire was developed. The aim of this study was to evaluate non-inferiority to the classical method. This is a retrospective pilot study including ten patients between 01/2024 and 04/2024. Demographic data, radiological outcome (Matta criteria), complications, and functional outcome (VAS pain and satisfaction, Majeed score) were compared. The complication rate of the modified technique was not significantly inferior to that of the classical technique (p = 0,50). Radiological outcomes (remaining dislocation modified: 5.0 mm; classical 4.4 mm; p = 0.38) and clinical outcomes (VAS pain: p = 0.47; VAS satisfaction: p = 0.42, Majeed score: p = 0.17) of the modified technique were not significantly inferior to those of the classical technique. Therefore, the modified technique was not significantly inferior to the classical technique in any aspect examined. The modified, ESIN-like technique using a pre-bent guidewire is therefore a safe and practical alternative to classical retrograde screw osteosynthesis in cases with a severely curved or narrow corridor. It expands the spectrum of minimally invasive techniques without increasing the rate of complications. 2026-09-10T12:37:54Z