TY - GEN A1 - Bauer, J. A1 - Yamamoto, Yuji A1 - Zaumseil, Peter A1 - Fursenko, Oksana A1 - Schulz, K. A1 - Kozłowski, Grzegorz A1 - Schubert, Markus Andreas A1 - Schroeder, Thomas A1 - Tillack, Bernd T1 - Nanostructured Silicon for Ge Nanoheteroepitaxy T2 - Microelectronics Engineering Y1 - 2012 SN - 0167-9317 VL - 97 SP - 169 EP - 172 ER - TY - GEN A1 - Rese, Alexandra A1 - Baier, Daniel A1 - Geyer-Schulz, Andreas A1 - Schreiber, Stefanie T1 - How augmented reality apps are accepted by consumers: a comparative analysis using scales and opinions T2 - Technological Forecasting and Social Change N2 - Increasingly, retailers rely on interactive technologies to improve consumers' shopping experiences. On the one side, interactive kiosks and smart mirrors make use of dedicated devices and software to explain, configure, and recommend products. On the other side, computer programs – so-called apps – are installed on the consumer's own device for the same purpose. They can be used at home, or – if installed on a mobile device – in retail outlets or on the move. In all cases, augmented reality (AR) can support these purposes by placing virtual content (e.g. newfurniture) in a real environment (the consumer's home). The overall perception and acceptance toward such interactive technologies are discussed in this paper. Users' perceptions and experiences are measured by applying a modified technology acceptance model (TAM). Four experiments, two with marker-based and two with markerless AR apps are presented to support the generalization of the results, the measurement models and the measurement approach. The results are satisfactory with regard to the robustness of the TAM model. However, the relative importance of hedonic (enjoyment, pleasure, fun) and utilitarian (information) aspects varies for different kinds of AR apps and has to be considered for improvement to occur. From a measurement point of view the acquiescence bias has to be dealt with when developing scale items. Y1 - 2017 U6 - https://doi.org/10.1016/j.techfore.2016.10.010 SN - 0040-1625 VL - 124 SP - 306 EP - 319 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Jung, Friedrich A1 - Lendlein, Andreas T1 - Aptamer supported in vitro endothelialization of poly(ether imide) films T2 - Clinical Hemorheology and Microcirculation N2 - Implantation of synthetic small-diameter vascular bypass grafts is often associated with an increased risk of failure, due to thrombotic events or late intimal hyperplasia. As one of the causes an insufficient hemocompatibility of the artificial surface is discussed. Endothelialization of synthetic grafts is reported to be a promising strategy for creating a self-renewing and regulative anti-thrombotic graft surface. However, the establishment of a shear resistant cell monolayer is still challenging. In our study, cyto- and immuno-compatible poly(ether imide) (PEI) films were explored as potential biomaterial for cardiovascular applications. Recently, we reported that the initial adherence of primary human umbilical vein endothelial cells (HUVEC) was delayed on PEI-films and about 9 days were needed to establish a confluent and almost shear resistant HUVEC monolayer. To accelerate the initial adherence of HUVEC, the PEI-film surface was functionalized with an aptamer-cRGD peptide based endothelialization supporting system. With this functionalization the initial adherence as well as the shear resistance of HUVEC on PEI-films was considerable improved compared to the unmodified polymer surface. The in vitro results confirm the general applicability of aptamers for an efficient functionalization of substrate surfaces. KW - aptamer KW - endothelialization KW - physical functionalization KW - poly(ether imide) films KW - shear resistance Y1 - 2020 U6 - https://doi.org/10.3233/CH-190775 SN - 1875-8622 SN - 1386-0291 VL - 75 IS - 2 SP - 201 EP - 217 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Lendlein, Andreas A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Potential Effects of Nonadherent on Adherent Human Umbilical Venous Endothelial Cells in Cell Culture T2 - International Journal of Molecular Science N2 - The adherence and shear-resistance of human umbilical venous endothelial cells (HUVEC) on polymers is determined in vitro in order to qualify cardiovascular implant materials. In these tests, variable fractions of HUVEC do not adhere to the material but remain suspended in the culture medium. Nonadherent HUVEC usually stop growing, rapidly lose their viability and can release mediators able to influence the growth and function of the adherent HUVEC. The aim of this study was the investigation of the time dependent behaviour of HUVEC under controlled nonadherent conditions, in order to gain insights into potential influences of these cells on their surrounding environment in particular adherent HUVEC in the context of in vitro biofunctionality assessment of cardiovascular implant materials. Data from adherent or nonadherent HUVEC growing on polystyrene-based cell adhesive tissue culture plates (TCP) or nonadhesive low attachment plates (LAP) allow to calculate the number of mediators released into the culture medium either from adherent or nonadherent cells. Thus, the source of the inflammatory mediators can be identified. For nonadherent HUVEC, a time-dependent aggregation without further proliferation was observed. The rate of apoptotic/dead HUVEC progressively increased over 90% within two days. Concomitant with distinct blebbing and loss of membrane integrity over time, augmented releases of prostacyclin (PGI2, up to 2.91 ± 0.62 fg/cell) and platelet-derived growth factor BB (PDGF-BB, up to 1.46 ± 0.42 fg/cell) were detected. The study revealed that nonadherent, dying HUVEC released mediators, which can influence the surrounding microenvironment and thereby the results of in vitro biofunctionality assessment of cardiovascular implant materials. Neglecting nonadherent HUVEC bears the risk for under- or overestimation of the materials endothelialization potential, which could lead to the loss of relevant candidates or to uncertainty with regard to their suitability for cardiac applications. One approach to minimize the influence from nonadherent endothelial cells could be their removal shortly after observing initial cell adhesion. However, this would require an individual adaptation of the study design, depending on the properties of the biomaterial used. KW - human venous endothelial cells KW - adherent KW - non-adherent KW - viability KW - mediator release Y1 - 2021 UR - https://www.mdpi.com/1422-0067/22/3/1493 U6 - https://doi.org/10.3390/ijms22031493 VL - 22 IS - 3 ER -