Hochschule Bonn-Rhein-Sieg
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Vom Instagram-Account zum Instagram-Profil: Zur Variantenevolution einer Bewertungsgrundlage und ihren (Über)Forderungen
No full textSurface Characterization of Skin Substitute Materials
Full text linkBackground: Transdermal therapeutic systems use substance transport through the skin to provide an active pharmaceutical ingredient. To ensure a reliable supply, adhesion to skin must be guaranteed. In practice in vivo studies as well as in vitro studies on steel (ISO-standard for self-adhesive tapes) are used. As in vitro—in vivo correlation is poor, extensive in vivo studies are applied during industrial product performance tests. Hence, a specialized skin substitute material for in vitro adhesion testing is needed.
Materials and Methods: Synthetic leather (polyurethane), silicone (Dragon Skin), gelatines, and VitroSkin are used as skin substitute materials. For topographical analysis, reflected light microscopy and confocal light microscopy are applied. Infrared spectroscopy is performed for analysis of functional groups. Dermatological skin probe systems are used to analyze friction, surface pH, and elasticity. To bundle all data with regards to skin similarity, mid-level data fusion is applied.
Results: For all substitute materials, common topographic characteristics compared to human skin can be observed. However, all materials show limitations regarding their topography. Gelatine and VitroSkin feature comparable surface functionality compared to human skin. All materials show significant deficits in their mechanical properties. All characteristics can be summarized as the Skin Similarity Index to give a comprehensive overview regarding substitutes similarity to skin.
Conclusions: A comprehensive evaluation of topography, chemical functionality, and mechanical properties regarding a skin substitutes similarity to human skin was performed. This data should be considered as a baseline for further research in the field of adhesion to skin. By adding further characteristics and materials, it is a versatile approach that can be implemented in a variety of areas
Ordnung zur Regelung der Zugangsprüfung für im Ausland qualifizierte Studienbewerberinnen und Studienbewerber an der Hochschule Bonn-Rhein-Sieg (Zugangsprüfungsordnung) vom 19.10.2023 in der ersten Änderungsverordnung vom 17.07.2025
No full textRedirecting the Peptide Cleavage Causes Protease Inactivation
No full textCysteine and serine proteases cleave peptides through covalent catalysis by generating a transient adduct with the N-terminal part of the substrate after releasing its C-terminal part. We demonstrate the unique redirection of this event leading to strong enzyme inactivation. For targeting human cathepsin B, a cysteine protease of significant therapeutic importance, we designed tailored peptidomimetics with a variety of dipeptide fragments directed toward the occluding loop and equipped with numerous N-terminal carbamate warheads. The carbamate deprotonation catalyzed by the active site thiolate initiates the redirected cleavage. The C-terminal part of the inhibitors remains covalently attached to the protease. Hydrolysis of such carbamoyl-enzyme complexes is catalytically unsupported rendering inhibition irreversible. This novel mechanism of action comprises a significant extension of the covalent drug space. Cysteine and serine proteases cleave peptides through covalent catalysis by generating a transient adduct with the N-terminal part of the substrate after releasing its C-terminal part. We demonstrate the unique redirection of this event leading to strong enzyme inactivation. For targeting human cathepsin B, a cysteine protease of significant therapeutic importance, we designed tailored peptidomimetics with a variety of dipeptide fragments directed toward the occluding loop and equipped with numerous N-terminal carbamate warheads. The carbamate deprotonation catalyzed by the active site thiolate initiates the redirected cleavage. The C-terminal part of the inhibitors remains covalently attached to the protease. Hydrolysis of such carbamoyl-enzyme complexes is catalytically unsupported rendering inhibition irreversible. This novel mechanism of action comprises a significant extension of the covalent drug space
Antioxidant profiling by two-dimensional chromatography with post-column ABTS: example of lignin
No full textLignin as a natural antioxidant is currently gaining interest as a renewable substitute for fossil-based antioxidants. Here, two-dimensional liquid chromatography (size-exclusion and reversed-phase chromatography) coupled with a post-column radical scavenging assay (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS)) is used to profile the antioxidant activity of softwood Kraft lignin. This method can assign antioxidant activity to different molecular weight fractions (monomeric, oligomeric, polymeric) within the complex lignin matrix. Four guaiacyl-type monomeric compounds (guaiacol, acetovanillone, vanillic acid, and vanillin) were identified in the lignin sample, consistent with softwood lignin composition; however, antioxidant activity varies widely among them. Guaiacol shows the highest specific radical scavenging activity, whereas vanillin's activity is lower than the detection limit. Antioxidant activity was also detected for oligomeric and polymeric domains. For polymeric lignin higher specific antioxidant activity was detected with decreasing molecular weight. This approach provides a more detailed understanding of lignin's structure-property relationship regarding its antioxidant activity than conventional bulk-type assays or solvent fractionation experiments, thereby guiding the selection of lignin fractions for antioxidant applications
Structural dynamic effects of the freewheel-clutch in e-bike drive units using a hybrid measurement and simulation approach
No full textThe Political Economy of Building Up a Domestic Agricultural Value Chain: Exploring Success and Failure in Coffee Farming and Coffee-Processing in Post-2000 Rwanda
No full textArchitekturjournalismus: Über Bauen und Planen berichten
No full textKaum etwas prägt und beeinflusst Menschen so sehr wie die Gebäude, in denen sie leben, und der öffentliche Raum, der sie umgibt. Im medialen Diskurs spielen die Themen Architektur und Stadtplanung in der Lokalberichterstattung eine zunehmend wichtige Rolle – ein Genre »Architekturjournalismus«, das sich nicht nur mit künstlerisch-gestalterischen, sondern auch mit sozialen, politischen, ökonomischen und ökologischen Aspekten des Planens und Bauens auseinandersetzt, hat sich bislang jedoch nicht etabliert. Die Beiträger*innen greifen das Thema erstmals wissenschaftlich auf und fragen nach der Bedeutung der gebauten Umwelt für Gesellschaft und Medien
Ko-Kreation als Ansatz in Lehre, Curriculums- und Organisationsentwicklung: Implikationen für die Qualitätsentwicklung an Hochschulen
No full textDer Begriff Ko-Kreation ist im Hochschulkontext noch relativ neu, findet sich aber zunehmend dort, wo ko-kreative Ansätze konkret auf die Aufgaben von Hochschulen in Forschung, Lehre und Transfer angewendet werden.
Die Ursprünge gehen bis in die 70er und 80er Jahre zurück, als die Beteiligung von Mitarbeitenden an der Ausgestaltung ihrer Arbeitsplätze populär wurde. In den 1990er und 2000er Jahren vollzog sich ein Paradigmenwechsel in Marketingkonzepten und Innovationsprozessen, bei dem wiederum die Kund*innen und externe Partner*innen als wertvolle Mitwirkende in Wertschöpfungsprozessen angesehen wurden (Dahm & Heydenreich 2024). In der Folge wurden diese Ansätze auch auf den öffentlichen Sektor übertragen. Ko-Kreation wird hier zunehmend als Strategie gesehen, eine Wertschöpfung durch Zusammenarbeit zu erreichen. Bürger*innen und andere gesellschaftliche und private Akteur*innen sollen zusammengebracht werden, um gemeinschaftlich Innovation voranzutreiben, zur Lösung öffentlicher Aufgaben beizutragen und so die zunehmend komplexeren Herausforderungen gemeinsam zu bewältigen
