TY - GEN A1 - Li, Chouyang A1 - Rezania, Simin A1 - Kammerer, Sarah A1 - Sokolowski, Armin Andreas A1 - Devaney, Trevor Thomas Joseph A1 - Gorischek, Astrid A1 - Jahn, Stephan Wenzel A1 - Hackl, Hubert A1 - Groschner, Klaus A1 - Windpassinger, Christian A1 - Malle, Ernst A1 - Bauernhofer, Thomas A1 - Schreibmayer, Wolfgang T1 - Piezo1 forms mechanosensitive ion channels in the human MCF-7 breast cancer cell line T2 - Scientific Reports N2 - Mechanical interaction between cells - specifically distortion of tensional homeostasis-emerged as an important aspect of breast cancer genesis and progression. We investigated the biophysical characteristics of mechanosensitive ion channels (MSCs) in the malignant MCF-7 breast cancer cell line. MSCs turned out to be the most abundant ion channel species and could be activated by negative pressure at the outer side of the cell membrane in a saturable manner. Assessing single channel conductance (GΛ) for different monovalent cations revealed an increase in the succession: Li⁺ < Na⁺ < K⁺ ≈Rb⁺ ≈ Cs⁺. Divalent cations permeated also with the order: Ca²⁺ < Ba²⁺. Comparison of biophysical properties enabled us to identify MSCs in MCF-7 as ion channels formed by the Piezo1 protein. Using patch clamp technique no functional MSCs were observed in the benign MCF-10A mammary epithelial cell line. Blocking of MSCs by GsMTx-4 resulted in decreased motility of MCF-7, but not of MCF-10A cells, underscoring a possible role of Piezo1 in invasion and metastatic propagation. The role of Piezo1 in biology and progression of breast cancer is further substantiated by markedly reduced overall survival in patients with increased Piezo1 mRNA levels in the primary tumor. Y1 - 2015 U6 - https://doi.org/10.1038/srep08364 SN - 2045-2322 VL - 5 ER - TY - GEN A1 - Rezania, Simin A1 - Kammerer, Sarah A1 - Li, Chouyang A1 - Steinecker-Frohnwieser, Bibiane A1 - Gorischek, Astrid A1 - Devaney, Trevor Thomas Joseph A1 - Verheyen, Sarah A1 - Passegger, Christina A1 - Ghaffari Tabrizi-Wizsy, Nassim A1 - Hackl, Hubert A1 - Platzer, Dieter A1 - Zarnani, A.H. A1 - Malle, Ernst A1 - Jahn, Stephan Wenzel A1 - Bauernhofer, Thomas A1 - Schreibmayer, Wolfgang T1 - Overexpression of KCNJ3 gene splice variants affects vital parameters of the malignant breast cancer cell line MCF-7 in an opposing manner T2 - BMC Cancer N2 - Background Overexpression the KCNJ3, a gene that encodes subunit 1 of G-protein activated inwardly rectifying K+ channel (GIRK1) in the primary tumor has been found to be associated with reduced survival times and increased lymph node metastasis in breast cancer patients. Methods In order to survey possible tumorigenic properties of GIRK1 overexpression, a range of malignant mammary epithelial cells, based on the MCF-7 cell line that permanently overexpress different splice variants of the KCNJ3 gene (GIRK1a, GIRK1c, GIRK1d and as a control, eYFP) were produced. Subsequently, selected cardinal neoplasia associated cellular parameters were assessed and compared. ResultsAdhesion to fibronectin coated surface as well as cell proliferation remained unaffected. Other vital parameters intimately linked to malignancy, i.e. wound healing, chemoinvasion, cellular velocities / motilities and angiogenesis were massively affected by GIRK1 overexpression. Overexpression of different GIRK1 splice variants exerted differential actions. While GIRK1a and GIRK1c overexpression reinforced the affected parameters towards malignancy, overexpression of GIRK1d resulted in the opposite. Single channel recording using the patch clamp technique revealed functional GIRK channels in the plasma membrane of MCF-7 cells albeit at very low frequency. DiscussionWe conclude that GIRK1d acts as a dominant negative constituent of functional GIRK complexes present in the plasma membrane of MCF-7 cells, while overexpression of GIRK1a and GIRK1c augmented their activity. The core component responsible for the cancerogenic action of GIRK1 is apparently presented by a segment comprising aminoacids 235–402, that is present exclusively in GIRK1a and GIRK1c, but not GIRK1d (positions according to GIRK1a primary structure). Conclusions The current study provides insight into the cellular and molecular consequences of KCNJ3 overexpression in breast cancer cells and the mechanism upon clinical outcome in patients suffering from breast cancer. Y1 - 2016 U6 - https://doi.org/10.1186/s12885-016-2664-8 SN - 1471-2407 VL - 16 ER - TY - GEN A1 - Herrmann, Ludger A1 - Jahn, Reinhold A1 - Maurer, Thomas T1 - Mineral dust around Sahara - from source to sink. A review with emphasis on contributions of the German soil science community in the last twenty years T2 - Journal of Plant Nutrition and Soil Science Y1 - 2010 SN - 1522-2624 VL - 173 IS - 6 SP - 811 EP - 821 ER - TY - GEN A1 - Brinkmann, Nicole A1 - Hodač, Ladislav A1 - Mohr, Kathrin I. A1 - Hodačova, Alena A1 - Jahn, Regine A1 - Ramm, Jessica A1 - Hallmann, Christine A1 - Arp, Gernot A1 - Friedl, Thomas T1 - Cyanobacteria and diatoms in biofilms of two karstic streams in Germany and changes of their communities along calcite saturation gradients T2 - Geomicrobiology Journal KW - cyanobacteria KW - diatoms Y1 - 2015 U6 - https://doi.org/10.1080/01490451.2014.901438 SN - 0149-0451 SN - 1521-0529 VL - 32 IS - 3-4 SP - 255 EP - 274 ER - TY - GEN A1 - Jahn, Stephan F. A1 - Blaudeck, Thomas A1 - Baumann, Reinhard R. A1 - Jakob, Alexander A1 - Ecorchard, Petra A1 - Rüffer, Tobias A1 - Lang, Heinrich A1 - Schmidt, Peer T1 - Inkjet Printing of Conductive Silver Patterns by Using the First Aqueous Particle-Free MOD Ink without Additional Stabilizing Ligands T2 - Chemistry of Materials N2 - The chemical and physical properties of [AgO2C(CH2OCH2)3H] (3) and its use as an aqueous, ligand-free MOD ink (MOD = metal−organic decomposition) for piezo inkjet printing is discussed. The printed, thermal, or photochemical sintered silver features are electrically conductive on glass (2.7 × 107 S m−1) and PET (PET = polyethylene terephthalate) substrates (1.1 × 107 S m−1) corresponding to 43% and 18% of the bulk silver conductivity. Conducted tape tests show the suitability of the ink for particularly polymer substrates. TG-MS studies demonstrate a two-step decomposition for the conversion of 3 to elemental silver. The structure of 3 in the solid state was determined by single X-ray structure determination. Y1 - 2010 UR - http://pubs.acs.org/doi/abs/10.1021/cm9036428 U6 - https://doi.org/10.1021/cm9036428 SN - 1520-5002 VL - 22 IS - 10 SP - 3067 EP - 3071 ER - TY - GEN A1 - Jahn, Stephan F. A1 - Jakob, Alexander A1 - Blaudeck, Thomas A1 - Schmidt, Peer A1 - Lang, Heinrich A1 - Baumann, Reinhard R. T1 - Inkjet printing of conductive patterns with an aqueous solution of [AgO2C(CH2OCH2)3H] without any additional stabilizing ligands T2 - Thin Solid Films N2 - The use of silver(I)-2-[2-(2-methoxyethoxy)ethoxy]acetate, [AgO2C(CH2OCH2)3H], and its application as an aqueous metal-organic decomposition (MOD) inkjet ink is reported. The chemical and physical properties of the silver carboxylate and the ink formulated thereof are discussed. The ink meets all requirements of piezo driven inkjet printing. The printed features were converted into electrically conducting silver patterns by thermal or photo-thermal treatment. The conversion of [AgO2C(CH2OCH2)3H] to elemental silver follows a two-step decomposition as demonstrated by thermogravimetry–mass spectrometry (TG–MS) measurements. The measured conductivities of the printed features on glass and polyethylene-terephthalate (PET) are 2.7 × 107 S m−1 and 1.1 × 107 S m−1, respectively, which correspond to 43% (glass) and 18% (PET) of the bulk silver conductivity. KW - Inkjet printing KW - Silver KW - Carboxylate KW - Ethyleneglycol KW - Flexible electronics Y1 - 2010 UR - http://www.sciencedirect.com/science/article/pii/S0040609010000866 U6 - https://doi.org/10.1016/j.tsf.2010.01.030 SN - 0040-6090 VL - 518 IS - 12 SP - 3218 EP - 3222 ER - TY - BOOK A1 - Hirschl, Bernd A1 - Grießhammer, Rainer A1 - Jahn, Thomas A1 - Hosang, Maik A1 - Keil, Florian A1 - Schröder, Winfried A1 - Walk, Heike T1 - Klimaschutz erfordert Handeln – Beiträge der sozial-ökologischen Forschung N2 - Der Klimawandel hat Auswirkungen auf die Umwelt, die Menschen und ihre Lebensbedingungen, aber auch auf ihre Gestaltungsmöglichkeiten für die Zukunft. Die Bundesregierung hat deshalb klare und weit reichende Ziele für den Klimaschutz vorgegeben. Die Forschung mit ihren naturwissenschaftlich-technischen Lösungen und ihren gesellschaftswissenschaftlichen Erkenntnissen trägt zur Umsetzung dieser Ziele bei. Eine kohlenstofffreie Energiegewinnung und -nutzung zu fördern und weiterzuentwickeln sowie die vorhandenen Potenziale von energieeffizienten Techniken zu erschließen, kann einen entscheidenden Beitrag zur Senkung von Treibhausgasemissionen leisten. Verdeutlicht man sich jedoch die Herausforderungen, die mit dem Ziel einer Begrenzung des Temperaturanstiegs auf maximal zwei Grad verbunden sind, so ist unabweisbar, dass durch technologische Innovationen allein die Probleme des Klimawandels nicht gelöst werden können. Die Broschüre "Klimaschutz erfordert Handeln" des Bundesministeriums für Bildung und Forschung zeigt Ergebnisse aus Forschungsvorhaben des Förderschwerpunktes "Sozial-ökologische Forschung", die eine lösungsorientierte Wissensbasis der dynamischen Wechselwirkungen zwischen Gesellschaften und ihrer natürlichen Umwelt geschaffen haben. Y1 - 2008 UR - https://www.ioew.de/fileadmin/_migrated/tx_ukioewdb/klimaschutz_erfordert_handeln.pdf PB - BMBF CY - Bonn [u.a.] ER - TY - GEN A1 - Schneider, Erich A1 - Jahn, Klaus A1 - Dieterich, Marianne A1 - Brandt, Thomas A1 - Strupp, Michael T1 - Gait deviations induced by visual stimulation in roll T2 - Experimental Brain Research Y1 - 2008 U6 - https://doi.org/10.1007/s00221-007-1134-6 SN - 0014-4819 SN - 1432-1106 VL - 185 IS - 1 SP - 21 EP - 26 ER - TY - GEN A1 - Jahn, Klaus A1 - Naeßl, Andrea A1 - Schneider, Erich A1 - Strupp, Michael A1 - Brandt, Thomas A1 - Dieterich, Marianne T1 - Inverse u-shaped curve for age dependency of torsional eye movement responses to galvanic vestibular stimulation T2 - Brain Y1 - 2003 U6 - https://doi.org/10.1093/brain/awg163 SN - 1460-2156 SN - 0006-8950 VL - 126 IS - 7 SP - 1579 EP - 1589 ER - TY - GEN A1 - Jahn, Klaus A1 - Naeßl, Andrea A1 - Strupp, Michael A1 - Schneider, Erich A1 - Brandt, Thomas A1 - Dieterich, Marianne T1 - Torsional eye movement responses to monaural and binaural galvanic vestibular stimulation: side-to-side asymmetries. T2 - Annals of the New York Academy of Sciences Y1 - 2003 U6 - https://doi.org/10.1111/j.1749-6632.2003.tb00265.x SN - 0077-8923 SN - 1749-6632 VL - 1004 SP - 485 EP - 489 ER - TY - GEN A1 - Jahn, Klaus A1 - Strupp, Michael A1 - Schneider, Erich A1 - Dieterich, Marianne A1 - Brandt, Thomas T1 - Visually induced gait deviations during different locomotion speeds T2 - Experimental Brain Research Y1 - 2001 U6 - https://doi.org/10.1007/s002210100884 SN - 0014-4819 SN - 1432-1106 VL - 141 IS - 3 SP - 370 EP - 374 ER - TY - GEN A1 - Jahn, Klaus A1 - Strupp, Michael A1 - Schneider, Erich A1 - Dieterich, Marianne A1 - Brandt, Thomas T1 - Differential effects of vestibular stimulation on walking and running T2 - Neuroreport Y1 - 2000 SN - 1473-558X SN - 0959-4965 VL - 11 IS - 8 SP - 1745 EP - 1748 ER - TY - GEN A1 - Strupp, Michael A1 - Glasauer, Stefan A1 - Jahn, Klaus A1 - Schneider, Erich A1 - Krafczyk, Siegbert A1 - Brandt, Thomas T1 - Eye movements and balance T2 - Annals of the New York Academy of Sciences Y1 - 2003 SN - 1749-6632 VL - 1004 SP - 352 EP - 358 ER - TY - GEN A1 - Kammerer, Sarah A1 - Jahn, Stephan Wenzel A1 - Winter, Elke A1 - Eidenhammer, Sylvia A1 - Rezania, Simin A1 - Regitnig, Peter A1 - Pichler, Martin A1 - Schreibmayer, Wolfgang A1 - Bauernhofer, Thomas T1 - Critical evaluation of KCNJ3 gene product detection in human breast cancer: MRNA in situ hybridisation is superior to immunohistochemistry T2 - Journal of Clinical Pathology N2 - Increased expression levels of KCNJ3 have been correlated with lymph node metastases and poor prognosis in patients with breast cancer, suggesting a prognostic role of KCNJ3. We aimed to establish protocols for the detection of KCNJ3 in formalin-fixed, paraffin-embedded (FFPE) breast cancer tissue. Several antibodies were tested for sensitivity and specificity by western blot, followed by optimisation of the immunohistochemistry (IHC) procedure and establishment of KCNJ3 mRNA in situ hybridisation (ISH). Methods were validated by processing 15 FFPE breast cancer samples for which microarray data were available. Spearman's rank correlation analysis resulted in borderline significant correlation for IHC versus ISH (rS: 0.625; p<0.05) and IHC versus microarray (rS: 0.668; p<0.01), but in significant correlation for ISH versus microarray (rS: 0.861; p<0.001). The ISH method was superior to IHC, regarding robustness, sensitivity and specificity and will aid to further study expression levels of KCNJ3 in both malignant and physiological conditions. Y1 - 2016 U6 - https://doi.org/10.1136/jclinpath-2016-203798 SN - 1472-4146 SN - 0021-9746 VL - 69 IS - 12 SP - 1116 EP - 1121 ER - TY - GEN A1 - Kammerer, Sarah A1 - Sokolowski, Armin Andreas A1 - Hackl, Hubert A1 - Platzer, Dieter A1 - Jahn, Stephan Wenzel A1 - El-Heliebi, Amin A1 - Schwarzenbacher, Daniela A1 - Stiegelbauer, Verena A1 - Pichler, Martin A1 - Rezania, Simin A1 - Fiegl, Heidelinde A1 - Peintinger, Florentia A1 - Regitnig, Peter A1 - Höfler, Gerald A1 - Schreibmayer, Wolfgang A1 - Bauernhofer, Thomas T1 - KCNJ3 is a new independent prognostic marker for estrogen receptor positive breast cancer patients T2 - OncoTarget : open access impact journal N2 - Numerous studies showed abnormal expression of ion channels in different cancer types. Amongst these, the potassium channel gene KCNJ3 (encoding for GIRK1 proteins) has been reported to be upregulated in tumors of patients with breast cancer and to correlate with positive lymph node status. We aimed to study KCNJ3 levels in different breast cancer subtypes using gene expression data from the TCGA, to validate our findings using RNA in situ hybridization in a validation cohort (GEO ID GSE17705), and to study the prognostic value of KCNJ3using survival analysis. In a total of > 1000 breast cancer patients of two independent data sets we showed a) that KCNJ3 expression is upregulated in tumor tissue compared to corresponding normal tissue (p < 0.001), b) that KCNJ3 expression is associated with estrogen receptor (ER) positive tumors (p < 0.001), but that KCNJ3 expression is variable within this group, and c) that ER positive patients with high KCNJ3 levels have worse overall (p < 0.05) and disease free survival probabilities (p < 0.01), whereby KCNJ3 is an independent prognostic factor (p <0.05). In conclusion, our data suggest that patients with ER positive breast cancer might be stratified into high risk and low risk groups based on the KCNJ3 levels in the tumor. Y1 - 2016 U6 - https://doi.org/10.18632/oncotarget.13224 VL - 7 IS - 51 SP - 84705 EP - 84717 ER - TY - GEN A1 - Heuser, Fabian A1 - Schulz, Christian A1 - Sağlam, Murat A1 - Ramaioli, Cecilia A1 - Heuberger, Maria A1 - Wagner, Klaus J. A1 - Jahn, Klaus A1 - Schneider, Erich A1 - Brandt, Thomas A1 - Glasauer, Stefan A1 - Lehnen, Nadine T1 - Preventing opioid-induced nausea and vomiting: Rest your head and close your eyes? T2 - PloS one Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0173925 SN - 1932-6203 VL - 12 IS - 3 SP - e0173925 ER - TY - GEN A1 - Spiegel, Rainer A1 - Claassen, Jens A1 - Teufel, Julian A1 - Bardins, Stanislav A1 - Schneider, Erich A1 - Lehrer, Nicole A1 - Jahn, Klaus A1 - Anciaes da Silva, Fábio A1 - Hahn, Ales A1 - Farahmand, Parvis A1 - Brandt, Thomas A1 - Strupp, Michael A1 - Kalla, Roger T1 - Resting in darkness improves downbeat nystagmus: evidence from an observational study T2 - Annals of the New York Academy of Sciences N2 - Resting in an upright position during daytime decreases downbeat nystagmus (DBN). When measured in brightness only, that is, without intermitting exposure to darkness, it does not make a significant difference whether patients have previously rested in brightness or in darkness. In real-world scenarios, people are often exposed to brightness and darkness intermittently. The aim of this study was to analyze whether resting in brightness or resting in darkness was associated with a lower post-resting DBN after intermitting exposures to brightness and darkness. Eight patients were recorded with three-dimensional video-oculography in brightness and darkness conditions, each following two 2-h resting intervals under either brightness or darkness resting conditions. The dependent variable was DBN intensity, measured in mean slow phase velocity. A repeated measures ANOVA with the factors measurement condition (brightness vs. darkness), resting condition (brightness vs. darkness), and time (after first vs. second resting interval) showed a significant effect for the factor resting condition, where previous resting in darkness was associated with a significantly lower DBN relative to previous resting in brightness (P < 0.01). The clinical relevance is to advise patients with DBN to rest in darkness. KW - downbeat nystagmus KW - symptom relief KW - resting KW - oscillopsia KW - video-oculographic measurement (VOG) Y1 - 2016 U6 - https://doi.org/10.1111/nyas.13172 SN - 1749-6632 SN - 0077-8923 VL - 1375 IS - 1 SP - 66 EP - 73 ER - TY - GEN A1 - Aubele, Maria A1 - Grill, Eva A1 - Eggert, Thomas A1 - Schneider, Erich A1 - Strobl, Ralf A1 - Jahn, Klaus A1 - Müller, Martin A1 - Holle, Rolf A1 - Linkohr, Birgit A1 - Heier, Margit A1 - Ladwig, Karl-Heinz A1 - Lehnen, Nadine T1 - Symptoms in unilatral vestibular hypofunction are associated with number of catch-up saccades and retinal errors: results from the population-based KORA FF4study T2 - Frontiers in Neurology N2 - Objective: The presence and intensity of symptoms vary in patients with unilateral vestibular hypofunction. We aimed to determine which saccadic and vestibulo-ocular reflex parameters best predict the presence of symptoms in unilateral vestibular hypofunction in order to better understand vestibular compensation and its implications for rehabilitation therapy. Methods: Video head impulse test data were analyzed from a subpopulation of 23 symptomatic and 10 currently symptom-free participants with unilateral vestibular hypofunction, embedded in the KORA (Cooperative Health Research in the Region of Augsburg) FF4 study, the second follow-up of the KORA S4 population-based health survey (2,279 participants). Results: A higher number of catch-up saccades, a higher percentage of covert saccades, and a larger retinal error at 200 ms after the onset of the head impulse were associated with relevant symptoms in participants with unilateral vestibular hypofunction (p = 0.028, p = 0.046, and p = 0.038, respectively). After stepwise selection, the number of catch-up saccades and retinal error at 200 ms remained in the final logistic regression model, which was significantly better than a null model (p = 0.014). Age, gender, saccade amplitude, saccade latency, and VOR gain were not predictive of the presence of symptoms. Conclusion: The accuracy of saccadic compensation seems to be crucial for the presence of symptoms in unilateral vestibular hypofunction, highlighting the role of specific gaze stabilization exercises in rehabilitation. Early saccades, mainly triggered by the vestibular system, do not seem to compensate accurately enough, resulting in a relevant retinal error and the need for more as well as more accurate catch-up saccades, probably triggered by the visual system. KW - video head impulse test, vHIT, catch-up saccades, unilateral vestibular hypofunction, retinal error, vestibulo-ocular reflex, VOR, population-based survey Y1 - 2023 UR - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10715252/ SN - 1664-2295 VL - 2023 IS - 14 ER - TY - GEN A1 - Schöberl, Florian A1 - Pradhan, Cauchy A1 - Irving, Stephanie A1 - Buerger, Katharina A1 - Xiong, Guoming A1 - Kugler, Günter A1 - Kohlbecher, Stefan A1 - Engmann, Julia A1 - Werner, Philipp A1 - Brendel, Matthias A1 - Schneider, Erich A1 - Perneczky, Robert A1 - Jahn, Klaus A1 - Fougère, Christian la A1 - Bartenstein, Peter A1 - Brandt, Thomas A1 - Dietrich, Marianne A1 - Zwergal, Andreas T1 - Real-space navigation testing differentiates between amyloid-positive and -negative aMCI T2 - Neurology : official journal of the American Academy of Neurology Y1 - 2020 UR - https://n.neurology.org/content/94/8/e861 U6 - https://doi.org/10.1212/WNL.0000000000008758 SN - 1526-632X VL - 94 IS - 8 SP - e861 EP - e873 ER - TY - GEN A1 - González Merino, Bernardo A1 - Jahn, Thomas A1 - Polyanskii, Alexander A1 - Wachsmuth, Gerd T1 - Hunting for Reduced Polytopes T2 - Discrete & Computational Geometry N2 - We show that there exist reduced polytopes in three-dimensional Euclidean space. This partially answers the question posed by Lassak (Israel J Math 70(3):365–379, 1990) on the existence of reduced polytopes in d-dimensional Euclidean space for d≥3. KW - Minimum width KW - Polytope KW - Reducedness Y1 - 2018 U6 - https://doi.org/10.1007/s00454-018-9982-3 SN - 0179-5376 SN - 1432-0444 VL - 60 IS - 3 SP - 801 EP - 808 ER - TY - BOOK A1 - Hirschl, Bernd A1 - Grießhammer, Rainer A1 - Jahn, Thomas A1 - Hosang, Maik A1 - Keil, Florian A1 - Schröder, Winfried A1 - Walk, Heike T1 - Climate protection demands action - Contributions Made by Social-Ecological Research N2 - Climate change impacts on the environment, people and their living conditions but also for on their possibilities for shaping their future. The Federal Government has therefore set clear and far-reaching targets for combating climate change. With its scientific technical solutions and sociological knowledge, research contributes to the implementation of these goals. Promoting and developing the carbon-free generation and use of energy as well as tapping existing potentials of energy-efficient technologies can make a decisive contribution to reducing greenhouse gas emissions. But if one looks at the challenges linked to the goal of limiting the rise in temperature to a maximum of two degrees, it is quite obvious that the problems of climate change cannot be solved through technological innovation alone. The brochure “Climate protection needs action”, published by the Federal Ministry for Education and Research, shows results from research projects conducted under the support measure “socio-ecological research” which have created a solution-oriented knowledge base about the dynamic interactions between societies and their natural environment. Y1 - 2009 UR - https://www.ioew.de/fileadmin/_migrated/tx_ukioewdb/climate_protection_demands_action.pdf PB - BMBF CY - Bonn [u.a.] ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Völkel, Sandra A1 - Jahn, Andreas A1 - Hiess, Andre A1 - Knaut, Martin A1 - Albert, Matthias A1 - Wenger, Christian A1 - Steinke, Olaff A1 - Stephan, Ulf A1 - Röhlecke, Sören A1 - Mikolajick, Thomas T1 - Enhanced Electrical Properties of Optimized Vertical Graphene-Base Hot Electron Transistors T2 - ACS Applied Electronic Materials N2 - The arrival of high-mobility two-dimensional materials like graphene leads to the renaissance of former vertical semiconductor–metal–semiconductor (SMS) hot electron transistors. Because of the monolayer thickness of graphene, improved SMS transistors with a semimetallic graphene-base electrode are now feasible for high-frequency applications. In this study we report about a device that consists of amorphous silicon, graphene, and crystalline silicon. For the first time, this device is fabricated by a four-mask lithography process which leads to significant improvements in the device performance. A strongly increased common-emitter current gain of 2% could be achieved while the on–off ratio improved to 1.6 × 105, which is already higher than predicted theoretically. This could be mainly attributed to better interface characteristics and decreased lateral dimensions of the devices. A cutoff frequency of approximately 26 MHz could be forecasted based on the DC measurements of the device. KW - Graphene KW - Transistor Y1 - 2023 U6 - https://doi.org/10.1021/acsaelm.2c01725 SN - 2637-6113 VL - 5 IS - 3 SP - 1670 EP - 1675 ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Richter, Karola A1 - Knaut, Martin A1 - Reif, Johanna A1 - Völkel, Sandra A1 - Jahn, Andreas A1 - Albert, Matthias A1 - Wenger, Christian A1 - Kirchner, Robert A1 - Bartha, Johann Wolfgang A1 - Mikolajick, Thomas T1 - Novel Graphene Adjustable-Barrier Transistor with Ultra-High Current Gain T2 - ACS Applied Materials & Interfaces N2 - A graphene-based three terminal barristor device was proposed to overcome the low on/off ratios and insufficient current saturation of conventional graphene field effect transistors. In this study, we fabricated and analyzed a novel graphene-based transistor, which resembles the structure of the barristor but uses a different operating condition. This new device, termed graphene adjustable-barriers transistor (GABT), utilizes a semiconductor-based gate rather than a metal−insulator gate structure to modulate the device currents. The key feature of the device is the two graphene-semiconductor Schottky barriers with different heights that are controlled simultaneously by the gate voltage. Due to the asymmetry of the barriers, the drain current exceeds the gate current by several orders of magnitude. Thus, the GABT can be considered an amplifier with an alterable current gain. In this work, a silicon−graphene−germanium GABT with an ultra-high current gain (ID/IG up to 8 × 106) was fabricated, and the device functionality was demonstrated. Additionally, a capacitance model is applied to predict the theoretical device performance resulting in an on−off ratio above 106, a swing of 87 mV/dec, and a drivecurrent of about 1 × 106 A/cm2. KW - Graphene KW - Transistor Y1 - 2022 U6 - https://doi.org/10.1021/acsami.2c10634 SN - 1944-8244 SN - 1944-8252 VL - 14 IS - 34 SP - 39249 EP - 39254 ER -