TY - GEN ED - Barton, Thomas ED - Erdlenbruch, Burkhard ED - Herrmann, Frank ED - Müller, Christian T1 - Logistische Anwendungen in der Wirtschaftsinformatik BT - Herausforderungen an die Wirtschaftsinformatik; Tagungsband zur AKWI-Fachtagung am 15.9.2010 an der Technische Hochschule Wildau (FH) N2 - Seit jeher zeichnet sich die Wirtschaftsinformatik durch eine große thematische Breite aus, da sie ihre Aufgabe in der Entwicklung und Anwendung von Theorien, Konzepten, Modellen, Methoden und Werkzeugen für die Analyse, Gestaltung und Nutzung von Informationssystemen sieht. Dabei greift die Wirtschaftsinformatik auch auf Ansätze der Betriebswirtschaftslehre sowie der Informatik zurück, die sie erweitert, integriert und um eigene spezifische Ansätze ergänzt. Es freut uns mit diesem Tagungsband Forschungs- und Entwicklungsarbeiten vorstellen zu dürfen, die belegen, dass und wie an Fachhochschulen an dieser Aufgabe der Wirtschaftsinformatik im Rahmen der Logistik gearbeitet wird. Eine grundlegende Aufgabe von Wirtschaftsinformatikern ist die Integration heterogener Softwaresysteme zur Unterstützung von Unternehmensprozessen. Ausgehend von einer Anforderungsspezifikation werden für Unternehmen geeignete Softwaresysteme beschafft. In dem Beitrag „Verknüpfung von Softwarelösungen in einem IT-Logistiknetzwerk“ wird quasi der umgekehrten Aufgabestellung nachgegangen, wie nämlich heterogene Systeme so verknüpft werden können, dass mit ihnen gemeinsam Unternehmensprozesse unterstützt werden können. Während in diesem Beitrag die technische Verknüpfung über eine dedizierte Architektur nicht im Detail vorgestellt wird, ist sie Gegenstand in dem Beitrag „Ein Informationssystem für das RFID-gestützte Behältermanagement“. Konkret handelt es sich um den Architekturstil REST (Representational State Transfer). Prozessverbesserungen lassen sich durch die Nutzung von Simulations- und Optimierungsmodellen erreichen. Typischerweise werden diese als „stand-alone“- Systeme betrieben, und sie erhalten ihre Daten von einem ERP-, PPS- oder allgemein von einem „Decision Support“-System. Dies erfordert eine Schnittstelle. Einen Vorschlag enthält der Beitrag „Konzeption einer Datenschnittstelle für Klassen von Simulations- und Optimierungsmodellen“. Beispiele für die Lösung von Optimierungsproblemen werden in den Beiträgen „Einfuhrzollmanagement – neue Chancen und Herausforderungen für die Standortoptimierung“ und „Gestaltung von Logistiknetzen mit der EDA-Heuristik“ beschrieben. Kern des ersten Beitrags ist die Formulierung eines geeigneten Optimierungsmodells, welches mit einem rechnergestützter Optimierungssystem gelöst wird. Im zweiten Beitrag wird die Lösung von einem sehr anspruchsvollen Optimierungsproblem durch ein heuristisches Verfahren angenähert. Ein wichtiges Themengebiet der Wirtschaftsinformatik ist die Verbindung von Geschäftsprozessmodellierung und Softwareentwicklung. Einen Ansatz dazu beschreibt der Beitrag „Modellgetriebene Softwareentwicklung auf der Grundlage realer Geschäftsprozessoptimierung“. Generell zunehmende Bedeutung in der Wirtschaftsinformatik hat das Wissensmanagement. In dem Beitrag „Konzept, Methoden und offene Fragen für einen Web-Service zur Analyse des Wissensmanagement-Reifegrades in Logistikunternehmen“ wird die Relevanz dieses Themas und sein Umsetzungsgrad bei Logistikunternehmen aus verschiedenen Ländern erläutert, und es wird ein Rahmenkonzept für ein Wissensmanagement in Logistikunternehmen in Form einer webbasierten Infrastruktur dargestellt. KW - Informationstechnik KW - Logistik Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-2448 SN - 978-3-936527-24-7 PB - Verlag News & Media CY - Berlin ER - TY - GEN ED - Barton, Thomas ED - Erdlenbruch, Burkhard ED - Herrmann, Frank ED - Müller, Christian ED - Schuler, Joachim T1 - Management und IT. Tagungsband zur AKWI-Fachtagung vom 16. bis 18.09.2012 an der Hochschule Pforzheim (FH) N2 - Wirtschaftsinformatik befasst sich mit allen Themen, die an der Schnittstelle zwischen Informatik und Betriebswirtschaft anzutreffen sind. So geht es in der Wirtschaftsinformatik – basierend auf dem Wissen und dem Verstehen der betriebswirtschaftlichen Konzepte und Anwendungen – insbesondere darum, IT-Systeme für die betriebliche Praxis zu entwickeln, einzuführen und zu betreiben. Eine wissenschaftliche Fachtagung, die den Titel „Management und IT“ trägt, setzt an einer solchen Beschreibung der Wirtschaftsinformatik an. KW - Wirtschaftsinformatik Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-2225 SN - 978-3-936527-30-8 PB - Verlag News & Media CY - Berlin ER - TY - GEN ED - Barton, Thomas ED - Erdlenbruch, Burkhard ED - Guckert, Michael ED - Herrmann, Frank ED - Müller, Christian T1 - Herausforderungen an die Wirtschaftsinformatik: Integration und Konnexion BT - Tagungsband zur 26. AKWI-Fachtagung am 16.9.2013 an der Hochschule Friedberg (FH) N2 - Das aufgerufene Thema „Herausforderungen an die Wirtschaftsinformatik: Integration und Konnexion“ provozierte Beiträge, die thematisch ein sehr breites Spektrum abdecken. Neben theoretischen Betrachtungen und Definitionen des sicher noch nicht final geprägten Begriffs der Konnexion gab es auch sehr praktische Beiträge wie die Darstellung von konkreten prototypischen Entwicklungsvorhaben. Auch das ist ein Indiz für die lebendige Landschaft der Wirtschaftsinformatik an den deutschsprachigen Hochschulen für Angewandte Wissenschaften. KW - Wirtschaftsinformatik Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-2165 SN - 978-3-936527-36-0 PB - Verlag News & Media CY - Berlin ER - TY - GEN ED - Barton, Thomas ED - Erdlenbruch, Burkhard ED - Herrmann, Frank ED - Müller, Christian T1 - Betriebliche Anwendungssysteme BT - Tagungsband zur AKWI-Fachtagung am 13.9.2011 an der Fachhochschule Worms (FH) N2 - In heutigen Unternehmen werden im Kern alle Aufgaben durch Anwendungssysteme direkt oder durch diese unterstützt erledigt. Folglich beschreiben betriebliche Anwendungssysteme heute im Grunde, welche Aufgaben in Unternehmen überhaupt zu lösen sind und welche davon automatisiert und somit durch Software erledigt bzw. unterstützt werden können. Die Arbeit an und mit Betrieblichen Anwendungssystemen ist gekennzeichnet durch eine große thematische Breite und demonstriert die für die Wirtschaftsinformatik charakteristische Nutzung von Ansätzen der Betriebswirtschaftslehre sowie der Informatik. Deswegen erwarteten die Herausgeber sehr heterogene Themenvorschläge und sie wurden nicht enttäuscht. Die letztlich ausgewählten Themen stellen aktuelle Entwicklungs- und anwendungsorientierte Forschungsprojekte zu Geschäftsprozessen, Standardsoftware, Softwareentwicklung und Betrieb von Anwendungssystemen vor. Dadurch beschreiben sie das heute existierende Berufsbild von Wirtschaftsinformatikern und -innen in der industriellen Praxis. Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-2333 SN - 978-3-936527-26-1 PB - Verlag News & Media CY - Berlin ER - TY - JOUR A1 - Richter, Stefanie T1 - Integrated Care for People with Dementia BT - Results of a Social-Scientific Evaluation of an Established Dementia Care Model JF - Geriatrics N2 - This article presents results of the social-scientific evaluation of an established care model for people with dementia developed by the professionals as a result of acute problems in care in north-east Germany. In addition to the central elements of the model, the conditions of intersectoral and interprofessional cooperation as well as the qualification profile requirements of the professional groups involved are presented in detail. The results can give suggestions for the organization of integrated care for people with dementia in other countries. Further, the author would hereby like to highlight the gain from the scientific examination of solutions to problems in the field. KW - Demenz KW - Managed Care KW - Dementia KW - Integrated Care Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-22091 VL - 2 IS - 1 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Pangerl, Jonas A1 - Sukul, Pritam A1 - Rück, Thomas A1 - Fuchs, Patricia A1 - Weigl, Stefan A1 - Miekisch, Wolfram A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone JF - Photoacoustics N2 - n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field. KW - Photoacoustic spectroscopy KW - Real-time mass-spectrometry KW - Breath analysis KW - Acetone KW - UV-LED Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71279 SN - 2213-5979 N1 - Corresponding author der OTH Regensburg: Jonas Pangerl VL - 38 PB - Elsevier ER - TY - JOUR A1 - Bauer, Franz A1 - Sterner, Michael T1 - Impacts of lifestyle changes on energy demand and greenhouse gas emissions in Germany JF - Renewable and Sustainable Energy Reviews N2 - Most energy scenario studies typically focus on technological options and fuel substitution for decarbonising future energy systems. Lifestyle changes are rarely considered, although they can significantly reduce energy demand and climate change mitigation efforts. By using an energy system model, this study shows that it is possible to reduce final energy demand in Germany by 61 % in 2050 relative to 2019 levels, resulting in an annual per capita energy demand of 44 GJ for a representative country of the Global North. This goal can be achieved through a combination of technological measures and lifestyle changes without sacrificing a decent standard of living. Societal chances can eliminate reliance on not-yet-established negative emission technologies, reduce energy dependency, and reduce the need for energy-intensive hydrogen and e-fuels. Downsizing the energy system provides an opportunity for strengthening climate change mitigation, decrease material demand and reduce land use. KW - Climate change mitigation KW - Energy system modelling KW - Sufficiency KW - Lifestyle changes KW - Climate neutrality KW - Low energy demand KW - German climate targets Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77682 SN - 1364-0321 N1 - Corresponding author der OTH Regensburg: Franz Bauer VL - 207 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Ruiken, Axel A1 - Landmann, Philipp A1 - Zöller, Ralf A1 - Wolff, Thomas T1 - Untersuchungen zum Tragverhalten von Einfach- und Mehrfachverbundankern im Zuge des BA 2/2 der A281 in Bremen T2 - Vorträge der 38. Baugrundtagung, 25. bis 27. September 2024, Bremen N2 - Im Vorfeld zum Neubau der A281 BA2/2 in Bremen wurden u.a. 14 Eignungsanker hergestellt und das Lastabtragsverhalten in den anstehenden Wesersanden ermittelt. Die Verpresskörper wurden in Sanden mit mitteldichter und dichter Lagerung angeordnet und dabei die Länge und Anzahl der Verpresskörper systematisch variiert. Neben der Messung von Kraft und Verschiebung am Ankerkopf wurde mithilfe hochauflösender faseroptischer Instrumentierung von Verpresskörpern und Ankerlitzen der Lastabtrag über den reinen Verpresskörper hinaus über die gesamte Verbundlänge ermittelt. Anhand der Ergebnisse wird die sukzessive Aktivierung der Baugrundwiderstände sichtbar. Die Ergebnisse zeigen einen näherungsweise linearen Zusammenhang zwischen den untersuchten 6 m bis 12 m langen Verpresskörpern und den ermittelten Herausziehwiderständen im Sand und somit ein deutlich günstigeres Lastabtragsverhalten, als es bisherige Erfahrungen gezeigt haben. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77662 SN - 978-3-932653-57-5 SP - 129 EP - 135 PB - Aktiv Druck & Verlag GmbH CY - Ebelsbach ER - TY - JOUR A1 - Albrecht, Sophie Viktoria A1 - Hellerbrand, Stefan A1 - Weininger, Florian A1 - Thiel, Charlotte T1 - Strategies for Minimizing Environmental Impact in Construction: A Case Study of a Cementitious 3D Printed Lost Formwork for a Staircase JF - materials N2 - The construction industry faces significant challenges, including environmental sustainability, rising material costs, and a shortage of skilled labor. Digital fabrication technologies offer innovative solutions to address these issues by reducing raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an Environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, this study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and abiotic depletion potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low-clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities KW - permanent formwork KW - selective cement activation (SCA) KW - 3D concrete printing (3DCP) KW - life cycle assessment (LCA) KW - additive manufacturing in construction (AMC) Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79236 N1 - Corresponding author der OTHR: Sophie Viktoria Albrecht VL - 18 PB - MDPI ER - TY - JOUR A1 - Westner, Markus A1 - Reicheneder, Matthias A1 - Matschi, Markus T1 - From Captive Centers to Global Integration BT - Organizational Models and Good Practices in Information Technology Nearshoring and Offshoring JF - Information Resources Management Journal N2 - Contemporary developments in virtual work and global talent management are transforming information technology (IT) nearshoring and offshoring practices, yet research on organizational responses remains limited. Through expert interviews with 33 IT executives (76% chief information officers) from Germany's top 500 companies, this article examines organizational models, strategies, and good practices in IT nearshoring and offshoring. It reveals a shift from traditional captive centers toward fully integrated global teams, enabling high-value task delivery and reflecting increased workforce maturity. Companies are expanding their operations driven by talent needs rather than cost savings, with success factors including employee integration and robust on-site management. This study contributes to theory and practice by providing a framework for understanding organizational models in global IT delivery and offering actionable insights for executives, emphasizing workforce integration over geographical separation. KW - Offshoring KW - Informationstechnik KW - Internationale Arbeitsteilung KW - Organisationsstruktur KW - IT-Nearshoring KW - IT-Offshoring KW - Global IT-Teams KW - Organizational Models KW - Distributed Work Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-80406 SN - 1533-7979 N1 - Corresponding author der OTH Regensburg: Markus Westner VL - 38 IS - 1 PB - IGI Global ER - TY - JOUR A1 - Hausler, Peter A1 - Holzner, Lukas A1 - Ehrnsperger, Matthias A1 - Bierl, Rudolf T1 - Evaluation of the creep strength of samples produced by fused deposition modeling JF - Open Engineering N2 - Data sheets for 3D printing materials typically include softening temperature, impact strength, tensile strength, and stiffness. However, creep strength, an important parameter for components used over an extended period, is usually not included. Nevertheless, this parameter is of significant importance for components that are used over an extended period of time.This study compares the long-term creep behavior of a selection of materials that are commonly used in fused deposition modeling 3D printing. The materials under investigation are acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid, and polycarbonate. In addition, the influence of fiber reinforcements on these materials is also examined. A simple, reproducible test procedure is proposed for users to determine and compare creep resistance of materials. This enables developers to select materials suitable for their own requirements on creep resistance and allows 3D-printing users to compare different materials. Results suggest that fiber reinforcement generally improves creep stability in 3D-printing materials, with GreenTEC Pro Carbon and add:north PC Blend HT LCF showing the most promise in this study. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79760 N1 - Corresponding author der OTH Regensburg: Peter Hausler VL - 14 IS - 1 PB - de Gruyter ER - TY - CHAP A1 - Leinweber, Juliane ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Digitale Versorgung in der Logopädie/Sprachtherapie Von der Präsenz- und Videotherapie zur Teletherapie T2 - Digitale Technik für ambulante Pflege und Therapie II - Impulse für die Praxis T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 3 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-65039 SP - 145 EP - 152 PB - transcript CY - Bielefeld ER - TY - GEN ED - Weber, Karsten ED - Haug, Sonja ED - Lauer, Norina ED - Mohr, Christa ED - Pfingsten, Andrea ED - Raptis, Georgios ED - Bahr, Gudrun T1 - Digitale Technik für ambulante Pflege und Therapie III BT - Nutzung, Akzeptanz, Wirkung und Lebensqualität N2 - Dieser Artikel untersucht die Machbarkeit und Wirksamkeit einer physiotherapeutischen Tele-Intervention bei Schlaganfallpatient*innen. Die prospektive, nicht kontrollierte Interventionsstudie basiert auf einem Mixed-Methods-Design und analysiert funktionelle Veränderungen sowie die Lebensqualität der Teilnehmenden vor und nach der Intervention. Eingeschlossen wurden postakute und chronische Schlaganfallpatient*innen mit stabilen Krankheitsbildern, die in ihrem häuslichen Umfeld lebten. Die Intervention bestand aus videobasierten Einzelsitzungen und einer optionalen Gruppenintervention, die Physiotherapie und Logopädie kombinierte. Die Ergebnisse zeigten signifikante Verbesserungen in der Arm-Hand-Funktion und der Teilhabefähigkeit. Die Teletherapie erwies sich als eine praktikable Ergänzung zur traditionellen Rehabilitation, insbesondere in ländlichen Regionen, und förderte die Autonomie und das aktive Engagement der Patient*innen in ihrem Genesungsprozess. Die Studie belegt das Potenzial teletherapeutischer Maßnahmen zur Überbrückung von Versorgungslücken und zur Sicherstellung einer kontinuierlichen, hochfrequenten Rehabilitation. T3 - Regensburger Beiträge zur Digitalisierung des Gesundheitswesens - 4 KW - AAL-Technik KW - Ambulanter Hilfs- und Pflegedienst Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-73914 SN - 978-3-8394-6728-2 N1 - Enthaltene Beiträge sind einzeln erfasst. PB - transcript CY - Bielefeld ET - 1. Aufl. ER - TY - JOUR A1 - Grad, Marius A1 - Zentgraf, Jan A1 - Schultheiss, Ulrich A1 - Esper, Lukas A1 - Diemar, Andreas A1 - Noster, Ulf A1 - Spiess, Lothar T1 - Effect of Carbon Content on the Phase Composition, Microstructure and Mechanical Properties of the TiC Layer Formed in Hot-Pressed Titanium-Steel Composites JF - Metals N2 - During the hot pressing of pure titanium and different carbon steels in a temperature range of ϑ = 950–1050 °C, a compound layer up to dL≈10 μm thick is formed at the titanium–steel interface. With a higher carbon content of the used steel, the layer thickness increases. The carbon concentration within the layer is in the range of stoichiometry for TiC. Apart from TiC, no other phases can be detected by X-ray diffraction (XRD) measurements inside the formed layer. The calculation of the activation energy for the TiC layer formation is Q = 126.5–136.7 kJ mol−1 and is independent of the carbon content of the steel. The resulting microstructure has a grain size gradient, wherein the mechanical properties, such as hardness and Young‘s modulus, are almost constant. Statistical analysis using Response Surface Methodology (RSM) indicates that the carbon content of the steel has the most significant influence on layer thickness, followed by annealing temperature and annealing time. By selecting the appropriate carbon steel and the subsequent removal of the steel, it is possible to produce targeted TiC layers on titanium substrates, which holds enormous potential for this material in wear-intensive applications. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-74617 SN - 2075-4701 N1 - Cooresponding author der OTH Regensburg: Marius Grad VL - 14 IS - 9 PB - MDPI AG ER - TY - JOUR A1 - Altmann, Matthias A1 - Schlegl, Peter A1 - Volbert, Klaus T1 - A low-power wireless system for energy consumption analysis at mains sockets JF - EURASIP Journal on Embedded Systems N2 - Introduction: Improving energy efficiency and reducing energy wastage is an important topic of our time. But it is quite difficult to figure out how much of our total electricity bill can be mapped to which device or at what time the device used it. We believe energy efficiency of normal households can be improved, if this kind of transparency would be available. In this article, we present a system for energy measurement at mains sockets to gain a transparent view of energy consumption for each device in a household. It consists of several smart energy measuring devices (SEMDs) that use a low-power radio protocol to dynamically build and connect to a radio network to transfer power usage date to a server. At the server, the data is stored and can be accessed via web interface. Results: Our primary goal was to build a back-end system for an energy metering platform with very low energy consumption. This platform can provide data for a variety of services that enables users (the consumers) to understand and improve their energy consumption behavior and increase overall energy efficiency of their households. KW - Low power KW - Smart grid KW - Smart home KW - Smart metering KW - Wireless system Y1 - 2017 U6 - https://doi.org/10.1186/s13639-016-0041-y N1 - Corresponding author: Peter Schlegl IS - 1 PB - Springer Nature ER - TY - JOUR A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Börner, Juliane A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Salgado, Josefina A1 - Han, Hong A1 - Böse, Holger A1 - Probst, Jörn A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Schlunck, Günther T1 - Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata JF - PLoS ONE N2 - Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young’s modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of α-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (≈40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0076196 VL - 8 IS - 10 PB - PLOS ER - TY - JOUR A1 - Reinker, Lukas A1 - Bläsing, Dominic A1 - Bierl, Rudolf A1 - Ulbricht, Sabina A1 - Dendorfer, Sebastian T1 - Correlation of Acceleration Curves in Gravitational Direction for Different Body Segments during High-Impact Jumping Exercises JF - sensors N2 - Osteoporosis is a common disease of old age. However, in many cases, it can be very well prevented and counteracted with physical activity, especially high-impact exercises. Wearables have the potential to provide data that can help with continuous monitoring of patients during therapy phases or preventive exercise programs in everyday life. This study aimed to determine the accuracy and reliability of measured acceleration data at different body positions compared to accelerations at the pelvis during different jumping exercises. Accelerations at the hips have been investigated in previous studies with regard to osteoporosis prevention. Data were collected using an IMU-based motion capture system (Xsens) consisting of 17 sensors. Forty-nine subjects were included in this study. The analysis shows the correlation between impacts and the corresponding drop height, which are dependent on the respective exercise. Very high correlations (0.83–0.94) were found between accelerations at the pelvis and the other measured segments at the upper body. The foot sensors provided very weak correlations (0.20–0.27). Accelerations measured at the pelvis during jumping exercises can be tracked very well on the upper body and upper extremities, including locations where smart devices are typically worn, which gives possibilities for remote and continuous monitoring of programs. KW - osteoporosis KW - inertial measurement units KW - wearable motion-tracking sensors KW - high-impact exercisess Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58217 N1 - Corresponding author: Lukas Reinker N1 - This work was supported by the Bavarian Academic Forum [BayWISS-Verbundkolleg Gesundheit] and the DHZK fond for behavioral cardiovascular diseases [Behaviorale kardiovaskuläre Erkrankungen; grand number: 81Z0400105]. VL - 23 IS - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Rusavy, Zdenek A1 - Cechova, Hana A1 - Dendorfer, Sebastian A1 - Kalis, Vladimir A1 - Ismail, Khaled M. T1 - Is the Finnish grip tight enough? A manometric study of two manual perineal protection techniques JF - Acta Obstetricia et Gynecologica Scandinavica Y1 - 2024 U6 - https://doi.org/10.1111/aogs.15033 PB - Wiley ET - Early view ER - TY - JOUR A1 - Schmitz, Paul A1 - Neumann, Christoph Cornelius A1 - Neumann, Carsten A1 - Nerlich, Michael A1 - Dendorfer, Sebastian T1 - Biomechanical analysis of iliac crest loading following cortico-cancellous bone harvesting JF - Journal of Orthopaedic Surgery and Research N2 - Background Iliac crest bone harvesting is a frequently performed surgical procedure widely used to treat bone defects. The objective of this study is to assess the biomechanical quantities related to risk for pelvic fracture after harvesting an autologous bone graft at the anterior iliac crest. Methods Finite element models with a simulated harvest site (sized 15 × 20 mm, 15 × 35 mm, 30 × 20 mm and 30 × 35 mm) in the iliac wing are created. The relevant loading case is when the ipsilateral leg is lifted off the ground. Musculoskeletal analysis is utilized to compute the muscle and joint forces involved in this motion. These forces are used as boundary conditions for the finite element analyses. Bone tissue stress is analyzed. Results Critical stress peaks are located between the anterior superior iliac spine (ASIS) and the anterior edge of the harvest site. Irrespective of the graft size, the iliac wing does not show any significant stress peaks with the harvest site being 20 to 25 mm posterior to the ASIS. The harvest area itself inhibits the distribution of the forces applied on the ASIS to extend to the posterior iliac wing. This leads to a lack of stress posterior to the harvest site. A balanced stress distribution with no stress peaks appears when the bone graft is taken below the iliac crest. Conclusion A harvest site located at least 20 to 25 mm posterior to the ASIS should be preferred to minimize the risk of iliac fatigue fracture. KW - Bone harvesting KW - Autologous bone graft KW - Iliac crest KW - Fatigue fracture KW - Pelvis KW - ASIS KW - FEA KW - Biomechanical investigation KW - Beckenkammknochen KW - Knochenentnahme KW - Spongiosa KW - Biomechanische Analyse Y1 - 2018 U6 - https://doi.org/10.1186/s13018-018-0822-1 VL - 13 IS - 108 SP - 1 EP - 8 PB - Springer Nature ER - TY - JOUR A1 - Völlner, Florian A1 - Weber, Tim A. A1 - Weber, Markus A1 - Renkawitz, Tobias A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Craiovan, Benjamin T1 - A simple method for determining ligament stiffness during total knee arthroplasty in vivo JF - Scientific Reports N2 - A key requirement in both native knee joints and total knee arthroplasty is a stable capsular ligament complex. However, knee stability is highly individual and ranges from clinically loose to tight. So far, hardly any in vivo data on the intrinsic mechanical of the knee are available. This study investigated if stiffness of the native ligament complex may be determined in vivo using a standard knee balancer. Measurements were obtained with a commercially available knee balancer, which was initially calibrated in vitro. 5 patients underwent reconstruction of the force-displacement curves of the ligament complex. Stiffness of the medial and lateral compartments were calculated to measure the stability of the capsular ligament complex. All force-displacement curves consisted of a non-linear section at the beginning and of a linear section from about 80 N onwards. The medial compartment showed values of 28.4 ± 1.2 N/mm for minimum stiffness and of 39.9 ± 1.1 N/mm for maximum stiffness; the respective values for the lateral compartment were 19.9 ± 0.9 N/mm and 46.6 ± 0.8 N/mm. A commercially available knee balancer may be calibrated for measuring stiffness of knee ligament complex in vivo, which may contribute to a better understanding of the intrinsic mechanical behaviour of knee joints. KW - Biomechanische Analyse KW - Kniegelenkband KW - Steifigkeit Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-41732-x VL - 9 SP - 1 EP - 8 PB - Nature ER - TY - JOUR A1 - Putzer, Michael A1 - Auer, Stefan A1 - Malpica, William A1 - Süß, Franz A1 - Dendorfer, Sebastian T1 - A numerical study to determine the effect of ligament stiffness on kinematics of the lumbar spine during flexion JF - BMC Musculoskeletal Disorders N2 - Background There is a wide range of mechanical properties of spinal ligaments documented in literature. Due to the fact that ligaments contribute in stabilizing the spine by limiting excessive intersegmental motion, those properties are of particular interest for the implementation in musculoskeletal models. The aim of this study was to investigate the effect of varying ligament stiffness on the kinematic behaviour of the lumbar spine. Methods A musculoskeletal model with a detailed lumbar spine was modified according to fluoroscopic recordings and corresponding data files of three different subjects. For flexion, inverse dynamics analysis with a variation of the ligament stiffness matrix were conducted. The influence of several degrees of ligament stiffness on the lumbar spine model were investigated by tracking ligament forces, disc forces and resulting moments generated by the ligaments. Additionally, the kinematics of the motion segments were evaluated. Results An increase of ligament stiffness resulted in an increase of ligament and disc forces, whereas the relative change of disc force increased at a higher rate at the L4/L5 level (19 %) than at the L3/L4 (10 %) level in a fully flexed posture. The same behaviour applied to measured moments with 67 % and 45 %. As a consequence, the motion deflected to the lower levels of the lumbar spine and the lower discs had to resist an increase in loading. Conclusions Higher values of ligament stiffness over all lumbar levels could lead to a shift of the loading and the motion between segments to the lower lumbar levels. This could lead to an increased risk for the lower lumbar parts. KW - Lumbar spine KW - Ligament stiffness KW - Musculoskeletal Modeling KW - Biomechanics Y1 - 2016 U6 - https://doi.org/10.1186/s12891-016-0942-x VL - 17 IS - 95 ER - TY - JOUR A1 - Weber, Tim A. A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Verkerke, Gijsbertus Jacob A1 - Renkawitz, Tobias ED - Takagi, Michiaki T1 - Does Computer-Assisted Femur First THR Improve Musculoskeletal Loading Conditions? JF - BioMed Research International N2 - We have developed a novel, computer-assisted operation method for minimal-invasive total hip replacement (THR) following the concept of “femur first/combined anteversion,” which incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position (CAS FF). The purpose of this study is to assess whether the hip joint reaction forces and patient’s gait parameters are being improved by CAS FF in relation to conventional THR (CON). We enrolled 60 patients (28 CAS FF/32 CON) and invited them for gait analysis at three time points (preoperatively, postop six months, and postop 12 months). Data retrieved from gait analysis was processed using patient-specific musculoskeletal models. The target parameters were hip reaction force magnitude (hrf), symmetries, and orientation with respect to the cup. Hrf in the CAS FF group were closer to a young healthy normal. Phase-shift symmetry showed an increase in the CAS FF group. Hrf orientation in the CAS FF group was closer to optimum, though no edge or rim-loading occurred in the CON group as well. The CAS FF group showed an improved hrf orientation in an early stage and a trend to an improved long-term outcome. KW - Hüftgelenkprothese KW - Operationstechnik KW - Computerunterstütztes Verfahren KW - Bewegungsapparat KW - Mechanische Belastung Y1 - 2015 U6 - https://doi.org/10.1155/2015/625317 VL - 2015 SP - ID 625317 ER -