TY - CHAP A1 - Probst, Anne-Catherine A1 - Hitzinger, Hans A1 - Bochtler, Ulrich A1 - Wölfel, Maximilian A1 - Schmitt, Christoph ED - U.R.S.I. Landesausschuss in Deutschland e.V. 2021, T1 - High Frequency Power Amplifier for Wideband Wireless Communication Systems T2 - Proceedings of the 2021 Kleinheubach Conference N2 - Increasing data transmission rates and bandwidth both belong to the challenges of the development of high-performance wireless communication systems. Multi-channel communication systems commonly use several narrowband power amplifiers each one for a single communication channel. Lossy couplers are needed both to separate the different channels from each other at the amplifiers input and to combine the amplified signals on each channel at the output. This approach depicts a poor efficiency and is limited to a few number of channels since each channel duplication involves 3 dB losses due to couplers. Alternatively, broadband radio frequency power amplifiers ensuring the simultaneous transmission of several carriers on a wide frequency range contribute to increase the cost and resource efficiency of transceivers in wireless communication systems. Gain flatness, a high output power, and low power levels of second and third order harmonics are required on the whole operating frequency range of the power amplifier in multi-carrier communication systems since overtones will degrade the quality of the communication. The present work investigates the performances of a broadband push-pull power amplifier based on LDMOS transistors, the input matching network using a 8:1 transmission line transformer. For the first time investigations on harmonic distortions of the amplified signal when using a transformer with 8:1 impedance transformation ratio are presented. Characterisation of the power amplifiers performances is focused on gain flatness, output power, harmonic distortions and efficiency at 110 W. KW - LDMOS KW - broadband RF power amplifier KW - push-pull KW - transmission line transformer KW - harmonic distortion KW - Hochfrequenzverstärker KW - Leistungsverstärker KW - Kommunikationssystem Y1 - 2021 U6 - https://doi.org/10.23919/IEEECONF54431.2021.9598443 VL - 2021 ER - TY - JOUR A1 - Eryilmaz, Marion A1 - Schmitt, Eberhard A1 - Krufczik, Matthias A1 - Theda, Franziska A1 - Lee, Jin-Ho A1 - Cremer, Christoph A1 - Bestvater, Felix A1 - Schaufler, Wladimir A1 - Hausmann, Michael A1 - Hildenbrand, Georg T1 - Localization Microscopy Analyses of MRE11 Clusters in 3D-Conserved Cell Nuclei of Different Cell Lines JF - Cancers N2 - In radiation biophysics, it is a subject of nowadays research to investigate DNA strand break repair in detail after damage induction by ionizing radiation. It is a subject of debate as to what makes up the cell’s decision to use a certain repair pathway and how the repair machinery recruited in repair foci is spatially and temporarily organized. Single-molecule localization microscopy (SMLM) allows super-resolution analysis by precise localization of single fluorescent molecule tags, resulting in nuclear structure analysis with a spatial resolution in the 10 nm regime. Here, we used SMLM to study MRE11 foci. MRE11 is one of three proteins involved in the MRN-complex (MRE11-RAD50-NBS1 complex), a prominent DNA strand resection and broken end bridging component involved in homologous recombination repair (HRR) and alternative non-homologous end joining (a-NHEJ). We analyzed the spatial arrangements of antibody-labelled MRE11 proteins in the nuclei of a breast cancer and a skin fibroblast cell line along a time-course of repair (up to 48 h) after irradiation with a dose of 2 Gy. Different kinetics for cluster formation and relaxation were determined. Changes in the internal nano-scaled structure of the clusters were quantified and compared between the two cell types. The results indicate a cell type-dependent DNA damage response concerning MRE11 recruitment and cluster formation. The MRE11 data were compared to H2AX phosphorylation detected by γH2AX molecule distribution. These data suggested modulations of MRE11 signal frequencies that were not directly correlated to DNA damage induction. The application of SMLM in radiation biophysics offers new possibilities to investigate spatial foci organization after DNA damaging and during subsequent repair. KW - Krebs, Medizin KW - Strahlentherapie KW - Brustkrebs Y1 - 2018 U6 - https://doi.org/https://doi.org/10.3390/cancers10010025 SN - 2072-6694 VL - 10 IS - 1 PB - MDPI AG ER - TY - JOUR A1 - Bartosova, Maria A1 - Zhang, Conghui A1 - Schaefer, Betti A1 - Herzog, Rebecca A1 - Ridinger, David A1 - Damgov, Ivan A1 - Levai, Eszter A1 - Marinovic, Iva A1 - Eckert, Christoph A1 - Romero, Philipp A1 - Sallay, Peter A1 - Ujszaszi, Akos A1 - Unterwurzacher, Markus A1 - Wagner, Anja A1 - Hildenbrand, Georg A1 - Warady, Bradley A. A1 - Schaefer, Franz A1 - Zarogiannis, Sotirios G. A1 - Kratochwill, Klaus A1 - Schmitt, Claus Peter T1 - Glucose Derivative Induced Vasculopathy in Children on Chronic Peritoneal Dialysis JF - Circulation Research N2 - Rationale: Patients with chronic kidney disease (CKD) have an exceedingly high cardiovascular risk; which further increases in patients on peritoneal dialysis (PD). The pathophysiological role of reactive metabolites accumulating in CKD such as glucose degradation products (GDP) is uncertain. Objective: Delineating the impact of GDP present in PD fluids in accelerated vasculopathy development in patients with CKD. Methods and Results: Omental and parietal peritoneal tissues were obtained from 107 children with CKD before dialysis and 90 children on chronic PD with PD fluids containing very low or high concentrations of GDP. Omental arterioles, protected from local PD fluid exposure by surrounding fat, were microdissected for multiomics analyses. High-GDP exposed omental arterioles exhibited 3-fold higher advanced glycation endproduct concentrations and upregulated genes involved in cell death/apoptosis and suppressed genes related to cell viability/survival, cytoskeleton organization, and immune response biofunctions. Vasculopathy-associated canonical pathways concordantly regulated on gene and protein level with high-GDP exposure included cell death/proliferation, apoptosis, cytoskeleton organization, metabolism and detoxification, cell junction signaling, and immune response. Parietal peritoneal arterioles of patients exposed to high-GDP fluids exhibited lumen narrowing compared to patients with CKD stage 5 (end-stage kidney disease) and patients on low-GDP PD, intima thickness was increased. Protein quantification verified increased proapoptotic activity and cytoskeleton disintegration, single-molecule-localization microscopy demonstrated arteriolar endothelial ZO-1 (zonula occludens-1) disruption. Absolute and per endoluminal surface length, arteriolar endothelial cell counts inversely correlated with GDP exposure, caspase-3, TGF (transforming growth factor)-β–induced pSMAD2/3 (phosphorylated SMAD2/3), interleukin-6, ZO-1 abundance, and lumen narrowing. In vitro, 3,4-dideoxyglucosone-3-ene reduced lamin-A/C and membrane ZO-1 assembly, increased pSMAD2/3, and ionic and 4 and 10 kDa permeability of arterial endothelial cells. Conclusions: Our findings indicate a fundamental role of GDP in PD-associated vasculopathy, exerted by endothelial cell junction and cytoskeleton disruption, and induction of apoptosis. They should redirect the focus of research and intervention on targeting reactive metabolite overload in CKD and PD. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01893710. KW - Peritonealdialyse KW - Gefäßkrankheit KW - Kind Y1 - 2021 U6 - https://doi.org/https://doi.org/10.1161/CIRCRESAHA.121.319310 SN - 0009-7330 VL - 129 IS - 5 PB - Ovid Technologies (Wolters Kluwer Health) ER - TY - JOUR A1 - Bartosova, Maria A1 - Schaefer, Betti A1 - Zhang, Conghui A1 - Herzog, Rebecca A1 - Ridinger, David A1 - Damgov, Ivan A1 - Levai, Eszter A1 - Marinovic, Iva A1 - Eckert, Christoph A1 - Romero, Philipp A1 - Sallay, Peter A1 - Ujszaszi, Akos A1 - Unterwurzacher, Markus A1 - Wagner, Anja A1 - Hildenbrand, Georg A1 - Warady, Bradley A1 - Schaefer, Franz A1 - Zarogiannis, Sotirios G. A1 - Kratochwill, Klaus A1 - Schmitt, Claus Peter T1 - Glucose Derivative Induced Vasculopathy in Children on Chronic Peritoneal Dialysis JF - Nephrology Dialysis Transplantation N2 - Abstract Background and Aims Patients with chronic kidney disease patients (CKD) have an exceedingly high cardiovascular risk. While vasculopathy is further accelerated during peritoneal dialysis (PD), the pathophysiological role of reactive metabolites such as glucose degradation products (GDP) is uncertain. Method Omental and parietal peritoneal tissues from 100 non-CKD individuals, 107 children with CKD5, 60 children treated with neutral pH, low GDP, and 30 children treated with acidic pH, high GDP PD fluids underwent standardized digital histomorphometry. Omental arterioles localized within the fat tissue, protected from direct PD fluid exposure were microdissected for multi-omics analysis. Key regulated pathways were validated by quantitative immunostaining, with localization microscopy in peritoneal tissues of matched cohorts and in vitro in human umbilical vein endothelial cells. Results Arterioles from children with CKD5 exhibited reduced lumen to vessel ratio (L/V) and reduced endothelial telomere length compared to non-CKD individuals; gene ontology analysis identified enrichment of arteriolar genes associated with nuclear telomere cap complex and focal adhesion. Pathway analysis of arteriolar cross-omics identified top canonical pathways including telomere extension by telomerase, actin cytoskeleton, integrin and tight junction signalling. Peritoneal vasculopathy progressed with PD vintage and was more pronounced with high versus low GDP exposure (p<0.001). Compared to CKD5, low GDP-PD upregulated 145/110 and downregulated 38/34 arteriolar genes/proteins, high GDP-PD upregulated 684/137 and supressed 1560/55 genes/proteins (p<0.01). High GDP milieu induced upregulation of arteriolar genes involved in cell death/apoptosis and suppressed genes related to cell viability/survival, cytoskeleton organization and immune response biofunctions. Vasculopathy associated canonical pathways concordantly regulated on arteriolar gene and protein level with high GDP exposure included cell death/proliferation, apoptosis, cytoskeleton organization, metabolism and detoxification, cell junction signalling, and immune response. Quantitative validation in PD cohorts with similar PD vintage, dialytic glucose exposure and age (n=15 / group) verified increased proapoptotic activity and cytoskeleton disintegration with high-GDP exposure; single-molecule-localization microscopy demonstrated arteriolar endothelial zonula occludens-1 (ZO-1) disruption. Absolute and relative to endoluminal surface length, arteriolar endothelial cell counts were inversely correlated with GDP exposure, with apoptosis marker caspase-3, TGF-ß induced pSMAD2/3, interleukin-6, ZO-1 protein abundance and the degree of vasculopathy. In vitro, exposure to GDP 3,4-dideoxyglucosone-3-ene dose-dependently reduced nuclear endothelial lamin-A/C and membrane ZO-1 assembly. Transendothelial electrical resistance was decreased. ZO-1 and sealing tight junction claudin-5 protein abundance were decreased in cells after incubation with high GDP compared to low GDP PD fluid and culture media. On nanoscale level GDP reduced junction cluster formation in the membrane area. Conclusion Multi-omics analysis of omental arterioles from children without pre-existing vasculopathy and life-style related confounders identified key mechanisms of vascular aging in CKD5 and the major contribution of GDP to accelerated vasculopathy during PD, i.e. disruption of endothelial cell junctions and cytoskeleton and induction of apoptosis. KW - Peritonealdialyse KW - Gefäßkrankheit KW - Kind Y1 - 2021 U6 - https://doi.org/https://doi.org/10.1093/ndt/gfab126.004 SN - 0931-0509 VL - 36 IS - Supplement_1 PB - Oxford University Press (OUP) ER - TY - JOUR A1 - Hausmann, Michael A1 - Winkler, Ralph A1 - Hildenbrand, Georg A1 - Finsterle, Jutta A1 - Weisel, Andrea A1 - Rapp, Alexander A1 - Schmitt, Eberhard A1 - Janz, Siegfried A1 - Cremer, Christoph T1 - COMBO-FISH: specific labeling of nondenatured chromatin targets by computer-selected DNA oligonucleotide probe combinations JF - BioTechniques KW - Genom Y1 - 2003 U6 - https://doi.org/https://doi.org/10.2144/03353rr03 SN - 0736-6205 VL - 35 IS - 3 SP - 564 EP - 577 PB - Informa UK Limited ER - TY - CHAP A1 - Probst, Anne-Catherine A1 - Neumaier, Marcel A1 - Hufgard, Christopher A1 - Wölfel, Maximilian A1 - Schmitt, Christoph A1 - Bochtler, Ulrich T1 - Network Planning a Digital TETRA-Simulcast-System T2 - Kleinheubacher Tagung, Miltenberg, 23.09.2025 - 25.09.2025 KW - TETRA, Telekommunikation Y1 - 2025 ER -