@article{HuangWaadtNuhkatetal.2019, author = {Huang, Shouguang and Waadt, Rainer and Nuhkat, Maris and Kollist, Hannes and Hedrich, Rainer and Roelfsema, M. Rob G.}, title = {Calcium signals in guard cells enhance the efficiency by which abscisic acid triggers stomatal closure}, series = {New Phytologist}, volume = {224}, journal = {New Phytologist}, doi = {10.1111/nph.15985}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322716}, pages = {177-187}, year = {2019}, abstract = {During drought, abscisic acid (ABA) induces closure of stomata via a signaling pathway that involves the calcium (Ca2+)-independent protein kinase OST1, as well as Ca2+-dependent protein kinases. However, the interconnection between OST1 and Ca2+ signaling in ABA-induced stomatal closure has not been fully resolved. ABA-induced Ca2+ signals were monitored in intact Arabidopsis leaves, which express the ratiometric Ca2+ reporter R-GECO1-mTurquoise and the Ca2+-dependent activation of S-type anion channels was recorded with intracellular double-barreled microelectrodes. ABA triggered Ca2+ signals that occurred during the initiation period, as well as in the acceleration phase of stomatal closure. However, a subset of stomata closed in the absence of Ca2+ signals. On average, stomata closed faster if Ca2+ signals were elicited during the ABA response. Loss of OST1 prevented ABA-induced stomatal closure and repressed Ca2+ signals, whereas elevation of the cytosolic Ca2+ concentration caused a rapid activation of SLAC1 and SLAH3 anion channels. Our data show that the majority of Ca2+ signals are evoked during the acceleration phase of stomatal closure, which is initiated by OST1. These Ca2+ signals are likely to activate Ca2+-dependent protein kinases, which enhance the activity of S-type anion channels and boost stomatal closure.}, language = {en} } @article{LebedevStehnoRanaetal.2021, author = {Lebedev, N. and Stehno, M. and Rana, A. and Reith, P. and Gauquelin, N. and Verbeeck, J. and Hilgenkamp, H. and Brinkman, A. and Aarts, J.}, title = {Gate-tuned anomalous Hall effect driven by Rashba splitting in intermixed LaAlO3/GdTiO3/SrTiO3}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, doi = {10.1038/s41598-021-89767-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363244}, year = {2021}, abstract = {The Anomalous Hall Effect (AHE) is an important quantity in determining the properties and understanding the behaviour of the two-dimensional electron system forming at the interface of SrTiO3-based oxide heterostructures. The occurrence of AHE is often interpreted as a signature of ferromagnetism, but it is becoming more and more clear that also paramagnets may contribute to AHE. We studied the influence of magnetic ions by measuring intermixed LaAlO3/GdTiO3/SrTiO3 at temperatures below 10 K. We find that, as function of gate voltage, the system undergoes a Lifshitz transition while at the same time an onset of AHE is observed. However, we do not observe clear signs of ferromagnetism. We argue the AHE to be due to the change in Rashba spin-orbit coupling at the Lifshitz transition and conclude that also paramagnetic moments which are easily polarizable at low temperatures and high magnetic fields lead to the presence of AHE, which needs to be taken into account when extracting carrier densities and mobilities.}, language = {en} } @article{LeeChoiKimetal.2021, author = {Lee, Duk Hyun and Choi, Sang-Jun and Kim, Hakseong and Kim, Yong-Sung and Jung, Suyong}, title = {Direct probing of phonon mode specific electron-phonon scatterings in two-dimensional semiconductor transition metal dichalcogenides}, series = {Nature Communications}, volume = {12}, journal = {Nature Communications}, doi = {10.1038/s41467-021-24875-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363261}, year = {2021}, abstract = {Electron-phonon scatterings in solid-state systems are pivotal processes in determining many key physical quantities such as charge carrier mobilities and thermal conductivities. Here, we report direct probing of phonon mode specific electron-phonon scatterings in layered semiconducting transition metal dichalcogenides WSe2, MoSe2, WS2, and MoS2 through inelastic electron tunneling spectroscopy measurements, quantum transport simulations, and density functional calculation. We experimentally and theoretically characterize momentum-conserving single- and two-phonon electron-phonon scatterings involving up to as many as eight individual phonon modes in mono- and bilayer films, among which transverse, longitudinal acoustic and optical, and flexural optical phonons play significant roles in quantum charge flows. Moreover, the layer-number sensitive higher-order inelastic electron-phonon scatterings, which are confirmed to be generic in all four semiconducting layers, can be attributed to differing electronic structures, symmetry, and quantum interference effects during the scattering processes in the ultrathin semiconducting films.}, language = {en} } @article{LacknerDuselEgorovetal.2021, author = {Lackner, L. and Dusel, M. and Egorov, O. A. and Han, B. and Knopf, H. and Eilenberger, F. and Schr{\"o}der, S. and Watanabe, K. and Taniguchi, T. and Tongay, S. and Anton-Solanas, C. and H{\"o}fling, S. and Schneider, C.}, title = {Tunable exciton-polaritons emerging from WS2 monolayer excitons in a photonic lattice at room temperature}, series = {Nature Communications}, volume = {12}, journal = {Nature Communications}, doi = {10.1038/s41467-021-24925-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363080}, year = {2021}, abstract = {Engineering non-linear hybrid light-matter states in tailored lattices is a central research strategy for the simulation of complex Hamiltonians. Excitons in atomically thin crystals are an ideal active medium for such purposes, since they couple strongly with light and bear the potential to harness giant non-linearities and interactions while presenting a simple sample-processing and room temperature operability. We demonstrate lattice polaritons, based on an open, high-quality optical cavity, with an imprinted photonic lattice strongly coupled to excitons in a WS2 monolayer. We experimentally observe the emergence of the canonical band-structure of particles in a one-dimensional lattice at room temperature, and demonstrate frequency reconfigurability over a spectral window exceeding 85 meV, as well as the systematic variation of the nearest-neighbour coupling, reflected by a tunability in the bandwidth of the p-band polaritons by 7 meV. The technology presented in this work is a critical demonstration towards reconfigurable photonic emulators operated with non-linear photonic fluids, offering a simple experimental implementation and working at ambient conditions.}, language = {en} } @article{LauruschkatPageEtteretal.2021, author = {Lauruschkat, Chris D. and Page, Lukas and Etter, Sonja and Weis, Philipp and Gamon, Florian and Kraus, Sabrina and Einsele, Hermann and Wurster, Sebastian and Loeffler, Juergen}, title = {T-Cell Immune Surveillance in Allogenic Stem Cell Transplant Recipients: Are Whole Blood-Based Assays Ready to Challenge ELISPOT?}, series = {Open Forum Infectious Diseases}, volume = {8}, journal = {Open Forum Infectious Diseases}, doi = {10.1093/ofid/ofaa547}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363164}, year = {2021}, abstract = {We compared the feasibility of 4 cytomegalovirus (CMV)- and Aspergillus-reactive T-cell immunoassay protocols in allogenic stem cell transplant recipients. While enzyme-linked immunospot performed best overall, logistically advantageous whole blood-based assays performed comparably in patients with less severe lymphocytopenia. CMV-induced interferon-gamma responses correlated strongly across all protocols and showed high concordance with serology.}, language = {en} } @article{LobbezooAarabAhlersetal.2020, author = {Lobbezoo, Frank and Aarab, Ghizlane and Ahlers, M. Oliver and Baad-Hansen, Lene and Bernhardt, Olaf and Castrillon, Eduardo E. and Giannakopoulos, Nikolaos Nikitas and Gr{\o}nbeck, Anders and Hauschild, Justus and Holst-Knudsen, Marianne and Skovlund, Naja and Thymi, Magdalini and Svensson, Peter}, title = {Consensus-based clinical guidelines for ambulatory electromyography and contingent electrical stimulation in sleep bruxism}, series = {Journal of Oral Rehabilitation}, volume = {47}, journal = {Journal of Oral Rehabilitation}, doi = {10.1111/joor.12876}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237032}, pages = {164-169}, year = {2020}, abstract = {As yet, there are still no evidence-based clinical diagnostic and management guidelines for ambulatory single-channel EMG devices, like the BUTLER® GrindCare® (GrindCare), that are used in patients with sleep bruxism. Therefore, a consensus meeting was organised with GrindCare developers, researchers, and academic and non-academic clinicians experienced with the use of ambulatory EMG devices. The aim of the meeting was to discuss and develop recommendations for clinical guidelines for GrindCare usage, based on the existing clinical and research experience of the consensus meeting's participants. As an important outcome of the consensus meeting, clinical guidelines were proposed in which an initial 2-week baseline phase with the device in its inactive (non-stimulus) mode for habituation and assessment of the number of jaw-muscle activities is followed by a 4-week active phase with contingent electrical stimuli suppressing the jaw-muscle activities. As to avoid the commonly reported reduction in sensitivity to the stimuli, a 2-week inactive phase is subsequently installed, followed by a repetition of active and inactive phases until a lasting reduction in the number of jaw-muscle activities and/or associated complaints has been achieved. This proposal has the characteristics of a single-patient clinical trial. From a research point of view, adoption of this approach by large numbers of GrindCare users creates a great opportunity to recruit relatively large numbers of study participants that follow the same protocol.}, language = {en} } @article{LehnertPrausseHuennigeretal.2021, author = {Lehnert, Teresa and Prauße, Maria T. E. and H{\"u}nniger, Kerstin and Praetorius, Jan-Philipp and Kurzai, Oliver and Figge, Marc Thilo}, title = {Comparative assessment of immune evasion mechanisms in human whole-blood infection assays by a systems biology approach}, series = {PLOS ONE}, volume = {16}, journal = {PLOS ONE}, doi = {10.1371/journal.pone.0249372}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363343}, year = {2021}, abstract = {Computer simulations of mathematical models open up the possibility of assessing hypotheses generated by experiments on pathogen immune evasion in human whole-blood infection assays. We apply an interdisciplinary systems biology approach in which virtual infection models implemented for the dissection of specific immune mechanisms are combined with experimental studies to validate or falsify the respective hypotheses. Focusing on the assessment of mechanisms that enable pathogens to evade the immune response in the early time course of a whole-blood infection, the least-square error (LSE) as a measure for the quantitative agreement between the theoretical and experimental kinetics is combined with the Akaike information criterion (AIC) as a measure for the model quality depending on its complexity. In particular, we compare mathematical models with three different types of pathogen immune evasion as well as all their combinations: (i) spontaneous immune evasion, (ii) evasion mediated by immune cells, and (iii) pre-existence of an immune-evasive pathogen subpopulation. For example, by testing theoretical predictions in subsequent imaging experiments, we demonstrate that the simple hypothesis of having a subpopulation of pre-existing immune-evasive pathogens can be ruled out. Furthermore, in this study we extend our previous whole-blood infection assays for the two fungal pathogens Candida albicans and C. glabrata by the bacterial pathogen Staphylococcus aureus and calibrated the model predictions to the time-resolved experimental data for each pathogen. Our quantitative assessment generally reveals that models with a lower number of parameters are not only scored with better AIC values, but also exhibit lower values for the LSE. Furthermore, we describe in detail model-specific and pathogen-specific patterns in the kinetics of cell populations that may be measured in future experiments to distinguish and pinpoint the underlying immune mechanisms.}, language = {en} } @article{LehnertLeonhardtTimmeetal.2021, author = {Lehnert, Teresa and Leonhardt, Ines and Timme, Sandra and Thomas-R{\"u}ddel, Daniel and Bloos, Frank and Sponholz, Christoph and Kurzai, Oliver and Figge, Marc Thilo and H{\"u}nniger, Kerstin}, title = {Ex vivo immune profiling in patient blood enables quantification of innate immune effector functions}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, doi = {10.1038/s41598-021-91362-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363337}, year = {2021}, abstract = {The assessment of a patient's immune function is critical in many clinical situations. In complex clinical immune dysfunction like sepsis, which results from a loss of immune homeostasis due to microbial infection, a plethora of pro- and anti-inflammatory stimuli may occur consecutively or simultaneously. Thus, any immunomodulatory therapy would require in-depth knowledge of an individual patient's immune status at a given time. Whereas lab-based immune profiling often relies solely on quantification of cell numbers, we used an ex vivo whole-blood infection model in combination with biomathematical modeling to quantify functional parameters of innate immune cells in blood from patients undergoing cardiac surgery. These patients experience a well-characterized inflammatory insult, which results in mitigation of the pathogen-specific response patterns towards Staphylococcus aureus and Candida albicans that are characteristic of healthy people and our patients at baseline. This not only interferes with the elimination of these pathogens from blood, but also selectively augments the escape of C. albicans from phagocytosis. In summary, our model could serve as a valuable functional immune assay for recording and evaluating innate responses to infection.}, language = {en} }