Lebenswissenschaften und Ethik
Refine
Year of publication
Document Type
Language
- English (285) (remove)
Is part of the Bibliography
- no (285)
Keywords
- Deep Learning (13)
- Artificial Intelligence (12)
- Diagnose (11)
- Maschinelles Lernen (9)
- Bildgebendes Verfahren (8)
- Humans (8)
- Künstliche Intelligenz (7)
- Simulation (7)
- Speiseröhrenkrankheit (7)
- Biomechanics (6)
Institute
- Fakultät Informatik und Mathematik (105)
- Fakultät Maschinenbau (93)
- Regensburg Center of Biomedical Engineering - RCBE (88)
- Regensburg Medical Image Computing (ReMIC) (70)
- Regensburg Center of Health Sciences and Technology - RCHST (43)
- Fakultät Angewandte Sozial- und Gesundheitswissenschaften (42)
- Labor Biomechanik (LBM) (42)
- Fakultät Elektro- und Informationstechnik (19)
- Fakultät Betriebswirtschaft (15)
- Institut für Sozialforschung und Technikfolgenabschätzung (IST) (15)
Begutachtungsstatus
- peer-reviewed (285) (remove)
Objective
The risk of in-stent restenosis can be considerably reduced by stents eluting cytostatic compounds. We created a novel drug-eluting stent system that includes several new features in the rapidly evolving field of stent-based drug delivery.
Methods and Results
The aim of the present study was the preclinical evaluation of a stent-coating system permitting individual, on-site coating of stents with a unique microporous surface allowing for individualizable, dose-adjustable, and multiple coatings with identical or various compounds, designated ISAR (individualizable drug-eluting stent system to abrogate restenosis). Stents were coated with 0.75% rapamycin solution, and high-performance liquid chromatography (HPLC)-based determination of drug release profile indicated drug release for >21 days. Rapamycin-eluting microporous (REMP) stents implanted in porcine coronary arteries were safe. To determine the efficacy of REMP stents, this novel drug-eluting stent platform was compared with the standard sirolimus-eluting stent. At 30 days, in-stent neointima formation in porcine coronary arteries was similar in both groups, yielding a significant decrease of neointimal area and injury-dependent neointimal thickness compared with bare-metal stents.
Conclusion
The ISAR drug-eluting stent platform as a novel concept for stent coating allows for a safe, effective, on-site stent coating process, thus justifying further clinical evaluation to decrease in-stent restenosis in humans.
In-stent neointima formation can be successfully attenuated by drug-eluting stents. We introduce a novel conceptual approach for stent-coating that allows for dose-adjustable, on-site stent coating process if desired with multiple compounds. Microporous stents coated with rapamycin proved safe and effective for the limitation of neointima formation in a porcine coronary stent model.
The paper at hand describes how a regional university of applied sciences tried to internationalize its learning and teaching environment. It describes the challenges encountered, the managerial approach taken, illustrates the implemented initiatives, and how effective they turned out. The results might be relevant to faculty staff in managerial positions at regional universities all over the world that face the challenge to internationalize their teaching and learning environment for the benefit of their domestic students.
We conceptualize the new phenomenon of the Fractional Chief InformationOfficer (CIO) as a part-time executive who usually works for more than one pri-marily small- to medium-sized enterprise (SME) and develop promising avenuesfor future research on Fractional CIOs. We conduct an empirical study by drawingon semi-structured interviews with 40 individuals from 10 different countries whooccupy a Fractional CIO role. We derive a definition for the Fractional CIO, dis-tinguish it from other forms of employment, and compare it with existing researchon CIO roles. Further, we find four salient engagement types of Fractional CIOsoffering value for SMEs in various situations: Strategic IT management, Restruc-turing, Rapid scaling, and Hands-on support. The results reveal similarities withexisting CIO roles as well as novel insights concerning the different engagementtypes. Lastly, we propose a research agenda for the Fractional CIO field, based onfour research themes derived from existing CIO research and insights from theinterviews.
The University of Shanghai for Science and Technology (USST), the Coburg University of Applied Sciences and Arts (CUASA) and the OTH Regensburg, University of Applied Sciences (OTHR) established an English taught international cooperative bachelor program in the area of Engineering Physics/Optoelectronics. Students from China study their first four semesters at USST. They continue their studies in Germany for the last three semesters, including an internship and a bachelor thesis, graduating with a Chinese and a German bachelor degree. Students from Germany study their third and fourth semester at USST to gain international experience. While the first cohort of Chinese students is currently in Germany, the second cohort of German students is in Shanghai. Up to now the feedback regarding this study program is completely positive, thus it is planned to develop it further.
Aim of the study was to develop a standardized model system to investigate endodontic irrigation techniques and assess the efficiency of different activation methods on the removal of hard tissue debris in complex root canal systems. Mesial roots of mandibular molars were firstly scanned by micro-computed tomography (µCT) and allocated to three groups of irrigant activation: sonic activation (EDDY, VDW, Munich, Germany), laser activation (AutoSWEEPS, FOTONA, Ljubljana, Slovenia) and conventional needle irrigation (control). Roots were fixed in individual 3D-printed holders to facilitate root canal enlargement under constant irrigation with NaOCl (5%). To enable standardized quantification of remaining debris, BaSO4-enriched dentine powder was compacted into the canals, followed by another µCT-scan. The final irrigation was performed using 17% ethylenediaminetetraacetic acid (EDTA) and 5% sodium hypochlorite (NaOCl) with the respective activation method, and the volume of remaining artificial debris was quantified after a final µCT-scan. The newly developed model system allowed for reliable, reproducible and standardized assessment of irrigation methods. Activation of the irrigant proved to be significantly more effective than conventional needle irrigation regarding the removal of debris, which persisted particularly in the apical third of the root canal in the control group. The efficiency of irrigation was significantly enhanced with laser- and sonic-based activation, especially in the apical third.
In-stent restenosis remains a major problem of arteriosclerosis treatment by stenting. Expansion-optimized stents could reduce this problem. With numerical simulations, stent designs/ expansion behaviours can be effectively analyzed. For reasons of efficiency, simplified models of balloon-expandable stents are often used, but their accuracy must be challenged due to insufficient experimental validation. In this work, a realistic stent life-cycle simulation has been performed including balloon folding, stent crimping and free expansion of the balloon-stent-system. The successful simulation and validation of two stent designs with homogenous and heterogeneous stent stiffness and an asymmetrically positioned stent on the balloon catheter confirm the universal applicability of the simulation approach. Dogboning ratio, as well as the final dimensions of the folded balloon, the crimped and expanded stent, correspond well to the experimental dimensions with only slight deviations. In contrast to the detailed stent life-cycle simulation, a displacement-controlled simulation can not predict the transient stent expansion, but is suitable to reproduce the final expanded stent shape and the associated stress states. The detailed stent life-cycle simulation is thus essential for stent expansion analysis/optimization, whereas for reasons of computational efficiency, the displacement-controlled approach can be considered in the context of pure stress analysis.
Advances in additive manufacturing enable the production of tailored lattice structures and thus, in principle, coronary stents. This study investigates the effects of process-related irregularities, heat and surface treatment on the morphology, mechanical response, and expansion behavior of 316L stainless steel stents produced by laser powder bed fusion and provides a methodological approach for their numerical evaluation. A combined experimental and computational framework is used, based on both actual and computationally reconstructed laser powder bed fused stents. Process-related morphological deviations between the as-designed and actual laser powder bed fused stents were observed, resulting in a diameter increase by a factor of 2-2.6 for the stents without surface treatment and 1.3-2 for the electropolished stent compared to the as-designed stent. Thus, due to the increased geometrically induced stiffness, the laser powder bed fused stents in the as-built (7.11 ± 0.63 N) or the heat treated condition (5.87 ± 0.49 N) showed increased radial forces when compressed between two plates. After electropolishing, the heat treated stents exhibited radial forces (2.38 ± 0.23 N) comparable to conventional metallic stents. The laser powder bed fused stents were further affected by the size effect, resulting in a reduced yield strength by 41% in the as-built and by 59% in the heat treated condition compared to the bulk material obtained from tensile tests. The presented numerical approach was successful in predicting the macroscopic mechanical response of the stents under compression. During deformation, increased stiffness and local stress concentration were observed within the laser powder bed fused stents. Subsequent numerical expansion analysis of the derived stent models within a previously verified numerical model of stent expansion showed that electropolished and heat treated laser powder bed fused stents can exhibit comparable expansion behavior to conventional stents. The findings from this work motivate future experimental/numerical studies to quantify threshold values of critical geometric irregularities, which could be used to establish design guidelines for laser powder bed fused stents/lattice structures.
Customized additively manufactured (laser powder bed fused (L-PBF)) stents could improve the treatment of complex lesions by enhancing stent-artery conformity. However, geometric irregularities inherent for L-PBF stents are expected to influence not only their mechanical behavior but also their interaction with the artery. In this study, the influence of geometrical irregularities on stent-artery interaction is evaluated within a numerical framework. Thus, computed arterial stresses induced by a reconstructed L-PBF stent model are compared to those induced by the intended stent model (also representing a stent geometry obtained from conventional manufacturing processes) and a modified CAD stent model that accounts for the increased strut thickness inherent for L-PBF stents. It was found that, similar to conventionally manufactured stents, arterial stresses are initially related to the basic stent design/topology, with the highest stresses occurring at the indentations of the stent struts. Compared to the stent CAD model, the L-PBF stent induces distinctly higher and more maximum volume stresses within the plaque and the arterial wall. In return, the modified CAD model overestimates the arterial stresses induced by the L-PBF stent due to its homogeneously increased strut thickness and thus its homogeneously increased geometric stiffness compared with the L-PBF stent. Therefore, the L-PBF-induced geometric irregularities must be explicitly considered when evaluating the L-PBF stent-induced stresses because the intended stent CAD model underestimates the arterial stresses, whereas the modified CAD model overestimates them. The arterial stresses induced by the L-PBF stent were still within the range of values reported for conventional stents in literature, suggesting that the use of L-PBF stents is conceivable in principle. However, because geometric irregularities, such as protruding features from the stent surface, could potentially damage the artery or lead to premature stent failure, further improvement of L-PBF stents is essential.
This paper investigates DevOps adoption, emphasizing its cultural dimensions in the context of the information systems domain. Utilizing a robust systematic literature review methodology, we discerned nine salient success factors and delineated three stage models instrumental for a smooth transition into DevOps-centric projects. Despite the increasing breadth of research in the DevOps area, the absence of a consolidated definition remains a challenge, underscoring the importance of a unified interpretative framework. This research notably extends the current body of knowledge by focusing on the cultural dynamics of DevOps adoption. As a result, it offers a refined lens through which both practitioners involved in the adoption process and academic researchers can comprehend the nuances and implications of cultural shifts in the evolving landscape of DevOps within information systems.