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Synthetic High-Throughput Microarrays of Peptidoglycan Fragments as a Novel Sero-Diagnostic Tool for Patient Antibody Profiling
No full textPeptidoglycan (PGN) is a complex biopolymer crucial for cell wall integrity and function of all bacterial species. While the strong inflammatory properties of PGN and its derived muropeptides are well-documented in human innate immune responses, adaptive immunity, including antibody responses to PGN, remain inadequately characterized. Microarray technology represents a cost- and time-efficient method for studying such interactions. Our laser-based technology enables the high-throughput synthesis of biomolecules on functionalized glass slides. Here, this on-chip synthesis was developed for PGN fragments, to generate a variety of 216 stem peptides and attach six different glycan moieties that are major structural components of bacterial cell walls. Thereby, 864 PGN fragments from different Gram-negative and Gram-positive species were generated. The arrays were validated with four different monoclonal antibodies against PGN or poly-N-acetyl glucosamine and identified their epitopes. Finally, proof of concept for antibody profiling in patient samples was performed by comparing a panel of well-characterized plasma samples of epidermolysis bullosa (EB) patients suffering from (chronic) wounds with Staphylococcus aureus infection. EB patients show an increased response to the muramyl dipeptide. Therefore, this novel high-throughput PGN glycopeptide microarray technology promises to identify distinct antibody profiles against human microbiomes in diseases, notably in those involving the intestine
Routing cross-blockchain communication
No full textBlockchain Interoperability Solutions (BISs) enable seamless communication and transactions between two or more blockchains. These solutions form an additional heterogeneous set on top of the blockchain layer and impose new constraints on cross-blockchain communication. This new interconnected network of blockchains can provide different communication routes, resulting in the need to find an optimal route between the source and target blockchains. In this paper, we aim to foster discussion about the problems and opportunities that the widescale adoption of BISs brings. We define the problem of using multiple BISs to route cross-blockchain communication and develop theoretical foundations for cross-blockchain routing. Based on the formalization, we implement and evaluate an algorithm that returns an optimal route for a communication request, given a network of blockchains and user-defined objectives
Development of an oxygen-sensitive hydrogel for monitoring oxygen diffusion in tissue engineering
No full textAdditive manufacturing has revolutionized the development of biomaterials by enabling precise control over structural properties at the microscale. In tissue engineering, oxygen transport remains a major challenge, particularly in the development of vascularized artificial tissues. To address this, we present an oxygen-sensitive hydrogel fabricated using one-photon polymerization and two-photon polymerization (2PP), designed for real-time observation of oxygen diffusion characteristics. The hydrogel, based on polyethylene glycol diacrylate (PEGDA), incorporates oxygen-sensitive dyes to enable a colorimetric response to varying oxygen concentrations.
The hydrogel formulation and fabrication were optimized for biocompatibility, tunable permeability, and stable optical readout. Diffusion experiments were conducted to analyze the oxygen transport behavior under different conditions, including variations in hydrogel thickness and environmental oxygen levels. The results demonstrate that the hydrogel allows for controlled oxygen diffusion, provides a measurable response to oxygen gradients and that the hydrogel’s permeability can be tailored via additive manufacturing. This approach offers a valuable tool for studying oxygen supply in engineered tissues and could enhance the design of microfluidic organ-on-a-chip systems.
Our findings indicate that oxygen-sensitive hydrogels hold great potential for improving in vitro tissue models by enabling precise monitoring of oxygen distribution, which is essential for cell viability and function. Future research will focus on integrating these hydrogels into microfluidic systems to simulate vascularized environments more accurately
Die Strategic Challenge der ECIU University: Ein internationaler, multidisziplinärer Ansatz für die Förderung von Nachhaltigkeitsthemen in der Hochschulbildung
No full textDie Strategic Challenge der aus dem European Consortium of Innovative Universities (ECIU) hervorgegangenen ECIU University stellt einen innovativen Ansatz zur Vermittlung von Nachhaltigkeit in der Hochschulbildung dar. Im Vordergrund der aus 14 Allianzen bestehenden ECIU University steht basierend auf dem Ansatz des Challenge-Based Learning das Lösen realer, sozialer „Challenges“. Das Pilotprojekt Strategic Challenge verbindet das Verfassen individueller Masterarbeiten mit der Mitarbeit in einer solchen Team-Challenge, die wie alle Challenges aus der Pilotphase der ECIU University thematisch das Nachhaltigkeitsziel 11 “Sustainable Cities and Communities” der Vereinten Nationen fokussiert. Die Idee besteht darin, dass Masterstudierende der Mitgliedsuniversitäten der ECIU in internationalen, multidisziplinären Teams an einer fünfmonatigen Challenge zur Big Idea „Climate neutral Campus in Europe“ arbeiten, während sie gleichzeitig ihre Masterarbeit ebenfalls in Verbindung zu diesem Thema schreiben. Da die Team-Challenge und die Masterarbeitsthemen eng verknüpft sein sollten, wurde ein gegenseitiger Nutzen für Challenge und Masterarbeiten erwartet.
Dieser Beitrag stellt den Pilotdurchgang des Projektes vor und diskutiert anschließend die auf Evaluationsdaten basierenden Erkenntnisse. Die Studierenden wertschätzten den neuen Ansatz und bewerteten insbesondere die Kooperation in internationalen, multidisziplinären Teams und das Thema klimaneutraler Campus positiv. Zugleich sahen sie einen gegenseitigen Mehrwert für Challenge und Masterarbeit. Bezüglich ihrer Team-Challenge kamen die Studierenden zu innovativen Ideen und Lösungsansätzen und fassten ihre Ergebnisse in Projektberichten von beachtlicher Qualität zusammen
NMR relaxometry probes solvent-polarity-dependent molecular interactions in stimuli-responsive lyogels
No full textStimuli-responsive gels demonstrate macroscopic changes upon exposure to external stimuli, offering potential for the development of adaptive chemical reactors. Early investigations into hydrogels established that crosslinked polymer networks experience reversible volume phase transitions, with temperature, pH, and solvent composition governing swelling and shrinking dynamics. Although hydrogels behavior in aqueous environments has been extensively characterized, lyogels that incorporate organic solvents remain comparatively underexplored, despite their potential for enhanced chemical compatibility and functional versatility. Here, we investigate how solvent polarity and crosslinking density govern the swelling behavior, pore formation, and molecular-scale dynamics of poly(N-isopropylacrylamide)-based lyogels. Using a combination of swelling measurement, scanning electron microscopy, and multiscale NMR relaxometry and diffusometry, we demonstrate that solvent polarity fundamentally alters lyogel structure and dynamics. Lyogels swollen in a high-polarity solvent exhibits macroporous networks and slower solvent exchange rates, whereas a low-polarity solvent induces shrinkage, denser microstructures, faster solvent exchange rates, and stronger surface interactions. These results establish a mechanistic framework linking thermodynamic affinity, solvent dynamics, and microstructural confinement to macroscopic gel responsiveness. This framework provides guidance for tailoring lyogels in dynamic environments, with potential applications in adaptable and tunable chemical reactors
Fatigue assessment of welded joints using extreme value statistics and laser-based weld toe geometry analysis
No full textThis paper presents a novel approach for fatigue assessment of welded joints by employing extreme value statistics to predict the most critical weld toe geometry in welded structures. The methodology integrates advanced laser line sensor technology for precise weld geometry measurements, allowing the identification of geometrical features that are most likely to contribute to fatigue failure. By applying extreme value statistical techniques, the approach emphasizes the criticality of localized weld toe imperfections, providing a more accurate prediction of fatigue life compared to traditional methods. This technique offers improved reliability in fatigue life estimation for large welded structures, particularly in high-stress applications, and enhances the safety and durability of engineering designs
Boosting the mechanical strength and photocatalytic activity of 3D-printed titania aerogels by atomic layer deposition and heat treatment
No full textTitania aerogels are highly porous materials optimal for photocatalysis due to their high surface area. Further spatial structuring by 3D printing improves gas diffusion in the aerogel, leading to a higher photocatalytic activity. However, the aerogel’s mechanical properties are reduced in comparison to non-3D printed aerogels. We hereby present an approach based on atomic layer deposition (ALD) of subnanometer-thin TiO2 layers to compensate for that detrimental effect. The ALD-deposited TiO2 consists of amorphous and anatase phase, with the anatase phase likely crystallizing on the aerogel’s crystallites. Nanoindentation measurements confirm that the TiO2 ALD-coatings improve the aerogel’s mechanical properties. Additionally, it enhances the photocatalytic properties of the TiO2 aerogel, which we attribute to the increased interface area and improved interconnection of the nanoparticle network. By further thermal postprocessing, it is possible to fully crystallize the ALD-deposited TiO2, which shows a complementary effect on photocatalytic performance, improving hydrogen evolution rate by more than 1 order of magnitude from 6.35 to 125 μmol g−1 h−1. The combination of 3D structuring of aerogels with ALD coatings demonstrated in this work could be extended in the future to a wide range of materials where the interplay between mechanical and catalytic properties is vital
Deciphering alcohol dehydrogenase catalysis in glycerol-based deep eutectic solvents through experimental and computational insights
No full textDesigning enzyme-compatible deep eutectic solvents (DESs) may be challenging due to their compositional complexity and variable enzyme responses. For instance, glycerol is beneficial for enzyme catalysis, while choline chloride is detrimental. This study assesses, experimentally and computationally, the performance of horse liver alcohol dehydrogenase (HLADH) in two glycerol-based DESs: betaine–glycerol (Bet–Gly, choline–chloride-free) and choline acetate–glycerol (ChAc–Gly, only chloride-free). Bet–Gly enables superior HLADH stability and activity, while ChAc–Gly, despite improved thermostability, shows significantly lower activity. Molecular dynamics (MD) simulations revealed a critical solvation transition at ∼20 vol% water content, where water begins to dominate the enzyme's solvation shell, maximizing enzyme stability at 40–50 vol%. Hydrogen-bond analyses reveal that water preferentially fills internal cavities at low concentrations, while in excess, it disrupts the stabilizing glycerol shell. Free energy profiles, calculated with MD, demonstrate that Bet–Gly permits unimpeded substrate diffusion and optimal positioning near the catalytic zinc ion. In contrast, ChAc–Gly components infiltrate the active site, increasing energy barriers and impeding catalysis. These findings highlight the dual role of DES composition and hydration in modulating enzyme stability and function, offering design principles for future tailored biocatalytic environments in non-aqueous media
Analyzing the worst-case behavior of multi-level caches in concurrent real-time systems
No full textDiese Arbeit befasst sich mit der Analyse des Worst-Case Zeitverhaltens von harten Echtzeitsystemen mit mehrstufigen Cache-Hierarchien. Zunächst wird eine Analyse der Inter-Core Interferenz in Mehrkernsystemen vorgestellt. Desweiteren wird eine Analyse der Kontext-wechselkosten für nicht-inklusive Cache-Hierarchien präsentiert. Die Auswertungen beider Analysen zeigen, dass in vielen Fällen die Analysepräzision gegenüber dem State-of-the-Art verbessert wird. Abschließend wird eine Optimierung vorgestellt, die Cache-Umgehung verwendet, um die Planbarkeit des Systems zu verbessern.This thesis tackles the analysis of the worst-case timing behavior of hard real-time systems featuring multi-level cache hierarchies. First, an analysis of inter-core cache interference in multi-core systems is presented. Second, an analysis of context-switching costs for non-inclusive cache hierarchies is presented, and flaws in the previous state-of-the-art analysis are identified. The evaluations of both analyses show that, in many situations, analysis precision is significantly improved compared to the previous state-of-the-art. Finally, an optimization to improve schedulability using cache bypassing is presented
A combined chemo-enzymatic treatment for the oxidation of epoxy-based carbon fiber-reinforced polymers (CFRPs)
No full textCarbon fiber-reinforced polymers (CFRPs), particularly epoxy-based composites, have become essential in the aerospace, automotive, and wind energy industries due to their robust mechanical properties, and lightweight nature. However, there is a lack of recycling technologies that are environmentally sustainable while also ensuring the recovery of carbon fibers in their original state. Although certain bacterial and fungal strains can colonize epoxy polymers, enzymes capable of efficiently degrading these materials have not yet been reported. Consequently, there is an urgent need for an effective, sustainable, and biologically inspired solution for CFRP recycling. Here, a chemo-enzymatic two-step oxidation process was developed. A chemical pre-treatment with propionic acid and hydrogen peroxide was used to recover imbedded carbon fibers. Additionally, three novel bacterial laccases isolated from a European spruce bark beetle gut metagenome (Ips typographus) demonstrated the ability to oxidize three epoxy resin scaffolds derived from TGMDA-based epoxy resin system, a high-performance material commonly used in aerospace applications. The sequential combination of both oxidative steps enabled the retrieval of clean carbon fibers and showed the potential of the laccase to partially further modify the pre-treated cured epoxy. This bio-inspired approach marks an initial step toward developing a bio-based recycling method for epoxy CFRPs