TY - JOUR A1 - Fischer, Dania A1 - Thies, Fabian A1 - Awad, Omar A1 - Brat, Camilla A1 - Meybohm, Patrick A1 - Baer, Patrick C. A1 - Müller, Markus M. A1 - Urbschat, Anja A1 - Maier, Thorsten J. A1 - Zacharowski, Kai A1 - Roos, Jessica T1 - Red blood cell-derived microparticles exert no cancer promoting effects on colorectal cancer cells in vitro JF - International Journal of Molecular Sciences N2 - The biomedical consequences of allogeneic blood transfusions and the possible pathomechanisms of transfusion-related morbidity and mortality are still not entirely understood. In retrospective studies, allogeneic transfusion was associated with increased rates of cancer recurrence, metastasis and death in patients with colorectal cancer. However, correlation does not imply causation. The purpose of this study was to elucidate this empirical observation further in order to address insecurity among patients and clinicians. We focused on the in vitro effect of microparticles derived from red blood cell units (RMPs). We incubated different colon carcinoma cells with RMPs and analyzed their effects on growth, invasion, migration and tumor marker expression. Furthermore, effects on Wnt, Akt and ERK signaling were explored. Our results show RMPs do not seem to affect functional and phenotypic characteristics of different colon carcinoma cells and did not induce or inhibit Wnt, Akt or ERK signaling, albeit in cell culture models lacking tumor microenvironment. Allogeneic blood transfusions are associated with poor prognosis, but RMPs do not seem to convey tumor-enhancing effects. Most likely, the circumstances that necessitate the transfusion, such as preoperative anemia, tumor stage, perioperative blood loss and extension of surgery, take center stage. KW - transfusion KW - red blood cells KW - microparticles KW - colorectal carcinoma Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286018 SN - 1422-0067 VL - 23 IS - 16 ER - TY - THES A1 - Maier, Patrick T1 - Memristanz und Memkapazität von Quantenpunkt-Speichertransistoren: Realisierung neuromorpher und arithmetischer Operationen T1 - Memristance and memcapacitance of quantum dot floating gate transistors: realization of neuromorphic and arithmetic operations N2 - In dieser Arbeit werden Quantenpunkt-Speichertransistoren basierend auf modulationsdotierten GaAs/AlGaAs Heterostrukturen mit vorpositionierten InAs Quantenpunkten vorgestellt, welche in Abhängigkeit der Ladung auf den Quantenpunkten unterschiedliche Widerstände und Kapazitäten aufweisen. Diese Ladungsabhängigkeiten führen beim Anlegen von periodischen Spannungen zu charakteristischen, durch den Ursprung gehenden Hysteresen in der Strom-Spannungs- und der Ladungs-Spannungs-Kennlinie. Die ladungsabhängigen Widerstände und Kapazitäten ermöglichen die Realisierung von neuromorphen Operationen durch Nachahmung von synaptischen Funktionalitäten und arithmetischen Operationen durch Integration von Spannungs- und Lichtpulsen. N2 - In this thesis, state-dependent resistances and capacitances in quantum dot floating gate transistors based on modulation doped GaAs/AlGaAs heterostructures with site-controlled InAs quantum dots are presented. The accumulation of electrons in the quantum dots simultaneously increases the resistance and decreases the capacitance, which leads to characteristic pinched hysteresis loops in the current-voltage- and the charge-voltage-characteristics when applying periodic input signals. The concurrent resistance and capacitance switching enables the realization of neuromorphic operations via mimicking of synaptic functionalities and arithmetic operations via the integration of voltage and light pulses. KW - Nichtflüchtiger Speicher KW - Memristor KW - Neuroinformatik KW - Quantenpunkt KW - Transportspektroskopie KW - Künstliche Synapsen KW - Speichertransistor KW - GaAs/AlGaAs Heterostruktur KW - transport spectroscopy KW - artificial synapse KW - floating gate transistor KW - GaAs/AlGaAs heterostructure KW - Elektronengas KW - Halbleiterphysik Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164234 ER -