TY - JOUR A1 - Hoche, Joscha A1 - Schulz, Alexander A1 - Dietrich, Lysanne Monika A1 - Humeniuk, Alexander A1 - Stolte, Matthias A1 - Schmidt, David A1 - Brixner, Tobias A1 - Würthner, Frank A1 - Mitric, Roland T1 - The origin of the solvent dependence of fluorescence quantum yields in dipolar merocyanine dyes JF - Chemical Science N2 - Fluorophores with high quantum yields are desired for a variety of applications. Optimization of promising chromophores requires an understanding of the non-radiative decay channels that compete with the emission of photons. We synthesized a new derivative of the famous laser dye 4-dicyanomethylen-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM),i.e., merocyanine 4-(dicyanomethylene)-2-tert-butyl-6-[3-(3-butyl-benzothiazol-2-ylidene)1-propenyl]-4H-pyran (DCBT). We measured fluorescence lifetimes and quantum yields in a variety of solvents and found a trend opposite to the energy gap law.This motivated a theoretical investigation into the possible non-radiative decay channels. We propose that a barrier to a conical intersection exists that is very sensitive to the solvent polarity. The conical intersection is characterized by a twisted geometry which allows a subsequent photoisomerization. Transient absorption measurements confirmed the formation of a photoisomer in unpolar solvents, while the measurements of fluorescence quantum yields at low temperature demonstrated the existence of an activation energy barrier. KW - solvent-dependent fluorescence yield Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-198707 UR - https://doi.org/10.1039/C9SC05012D VL - 10 ER - TY - THES A1 - Schulz, Robert Frank T1 - A radio view of high-energy emitting AGNs T1 - Eine radioastronomische Betrachtung von hochenergetisch emittierenden AGNs N2 - The most energetic versions of active galactic nuclei (AGNs) feature two highly-relativistic plasma outflows, so-called jets, that are created in the vicinity of the central supermassive black hole and evolve in opposite directions. In blazars, which dominate the extragalactic gamma-ray sky, the jets are aligned close to the observer's line of sight leading to strong relativistic beaming effects of the jet emission. Radio observations especially using very long baseline interferometry (VLBI) provide the best way to gain direct information on the intrinsic properties of jets down to sub-parsec scales, close to their formation region. In this thesis, I focus on the properties of three AGNs, IC 310, PKS 2004-447, and 3C 111 that belong to the small non-blazar population of gamma-ray-loud AGNs. In these kinds of AGNs, the jets are less strongly aligned with respect to the observer than in blazars. I study them in detail with a variety of radio astronomical instruments with respect to their high-energy emission and in the context of the large samples in the monitoring programmes MOJAVE and TANAMI. My analysis of radio interferometric observations and flux density monitoring data reveal very different characteristics of the jet emission in these sources. The work presented in this thesis illustrates the diversity of the radio properties of gamma-ray-loud AGNs that do not belong to the dominating class of blazars. N2 - Die energetischsten Versionen von aktiven Galaxienkernen (AGNs) weisen zwei hoch-relativistische Plasmaausflüsse, sogenannte Jets auf, welche in der Nähe des zentralen supermassiven schwarzen Lochs entstehen und sich in entgegengesetzte Richtungen ausbreiten. In Blazaren, die die extragalaktische Gamma-Strahlung dominieren, sind diese Jets nahe zur Sichtlinie des Beobachters orientiert, das zu starkem relativistischen Beaming der Jetemission führt. Radiobeobachtungen vor allem mit Very Long Baseline Interferometry (VLBI) bieten die beste Möglichkeit direkt Informationen über die intrinsischen Eigenschaften von Jets in der Nähe ihrer Entstehungsregion auf sub-parsec Skalen zu sammeln. Der Fokus dieser Dissertation liegt auf den Eigenschaften von drei AGNs, IC 310, PKS 2004-447, and 3C 111, die zur kleinen Population von gamma-lauten AGNs abseits von Blazaren gehören. Diese Jets weisen einen etwas größeren Winkel zur Sichtlinie des Beobachters auf als Blazare. Ich untersuche diese AGNs im Detail mit Hilfe verschiedener radioastronomischer Instrumente in Bezug auf deren hochenergetischer Emission und im Vergleich der großen Samples der Langzeitbeobachtungsprogramme MOJAVE und TANAMI. Meine Analyse von Radiointerferometrie-Beobachtungen und Flussdichte-Messungen zeigen sehr unterschiedliche Eigenschaften der Jets. Damit verdeutlicht diese Arbeit anschaulich die vielfältigen Radioeigenschaften von gamma-lauten AGNs, die nicht zur dominierenden Klasse von Blazaren gehören. KW - Aktiver galaktischer Kern KW - Radioastronomie KW - Very long baseline interferometry KW - High-energy emission KW - Astrophysical Jet KW - Active galactic nucleus KW - Radio astronomy Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137358 ER - TY - JOUR A1 - Hebestreit, Helge A1 - Zeidler, Cornelia A1 - Schippers, Christopher A1 - de Zwaan, Martina A1 - Deckert, Jürgen A1 - Heuschmann, Peter A1 - Krauth, Christian A1 - Bullinger, Monika A1 - Berger, Alexandra A1 - Berneburg, Mark A1 - Brandstetter, Lilly A1 - Deibele, Anna A1 - Dieris-Hirche, Jan A1 - Graessner, Holm A1 - Gündel, Harald A1 - Herpertz, Stephan A1 - Heuft, Gereon A1 - Lapstich, Anne-Marie A1 - Lücke, Thomas A1 - Maisch, Tim A1 - Mundlos, Christine A1 - Petermann-Meyer, Andrea A1 - Müller, Susanne A1 - Ott, Stephan A1 - Pfister, Lisa A1 - Quitmann, Julia A1 - Romanos, Marcel A1 - Rutsch, Frank A1 - Schaubert, Kristina A1 - Schubert, Katharina A1 - Schulz, Jörg B. A1 - Schweiger, Susann A1 - Tüscher, Oliver A1 - Ungethüm, Kathrin A1 - Wagner, Thomas O. F. A1 - Haas, Kirsten T1 - Dual guidance structure for evaluation of patients with unclear diagnosis in centers for rare diseases (ZSE-DUO): study protocol for a controlled multi-center cohort study JF - Orphanet Journal of Rare Diseases N2 - Background In individuals suffering from a rare disease the diagnostic process and the confirmation of a final diagnosis often extends over many years. Factors contributing to delayed diagnosis include health care professionals' limited knowledge of rare diseases and frequent (co-)occurrence of mental disorders that may complicate and delay the diagnostic process. The ZSE-DUO study aims to assess the benefits of a combination of a physician focusing on somatic aspects with a mental health expert working side by side as a tandem in the diagnostic process. Study design This multi-center, prospective controlled study has a two-phase cohort design. Methods Two cohorts of 682 patients each are sequentially recruited from 11 university-based German Centers for Rare Diseases (CRD): the standard care cohort (control, somatic expertise only) and the innovative care cohort (experimental, combined somatic and mental health expertise). Individuals aged 12 years and older presenting with symptoms and signs which are not explained by current diagnoses will be included. Data will be collected prior to the first visit to the CRD’s outpatient clinic (T0), at the first visit (T1) and 12 months thereafter (T2). Outcomes Primary outcome is the percentage of patients with one or more confirmed diagnoses covering the symptomatic spectrum presented. Sample size is calculated to detect a 10 percent increase from 30% in standard care to 40% in the innovative dual expert cohort. Secondary outcomes are (a) time to diagnosis/diagnoses explaining the symptomatology; (b) proportion of patients successfully referred from CRD to standard care; (c) costs of diagnosis including incremental cost effectiveness ratios; (d) predictive value of screening instruments administered at T0 to identify patients with mental disorders; (e) patients’ quality of life and evaluation of care; and f) physicians’ satisfaction with the innovative care approach. Conclusions This is the first multi-center study to investigate the effects of a mental health specialist working in tandem with a somatic expert physician in CRDs. If this innovative approach proves successful, it will be made available on a larger scale nationally and promoted internationally. In the best case, ZSE-DUO can significantly shorten the time to diagnosis for a suspected rare disease. KW - rare diseases KW - multi‑center cohort study KW - dual guidance Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300440 VL - 17 IS - 1 ER - TY - JOUR A1 - Liu, Bin A1 - Vonhausen, Yvonne A1 - Schulz, Alexander A1 - Höbartner, Claudia A1 - Würthner, Frank T1 - Peptide Backbone Directed Self-Assembly of Merocyanine Oligomers into Duplex Structures JF - Angewandte Chemie International Edition N2 - The pseudopeptide backbone provided by N-(2-aminoethyl)-glycine oligomers with attached nucleobases has been widely utilized in peptide nucleic acids (PNAs) as DNA mimics. Here we demonstrate the suitability of this backbone for the formation of structurally defined dye stacks. Toward this goal a series of peptide merocyanine (PMC) dye oligomers connected to a N-(2-aminoethyl)-glycine backbone were prepared through peptide synthesis. Our concentration-, temperature- and solvent-dependent UV/Vis absorption studies show that under the control of dipole–dipole interactions, smaller-sized oligomers consisting of one, two or three dyes self-assemble into defined duplex structures containing two up to six chromophores. In contrast, upon further extension of the oligomer, the chosen peptide backbone cannot direct the formation of a defined duplex architecture anymore due to intramolecular aggregation between the dyes. For all aggregate species a moderate aggregation-induced emission enhancement is observed. KW - dipole-dipole interaction KW - peptide backbone KW - merocyanine KW - dye assembly KW - duplex structure Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318797 VL - 61 IS - 21 ER - TY - JOUR A1 - Schulz, Alexander A1 - Würthner, Frank T1 - Folding-induced fluorescence enhancement in a series of merocyanine hetero-folda-trimers JF - Angewandte Chemie International Edition N2 - Many dyes suffer from fast non-radiative decay pathways, thereby showing only short-lived excited states and weak photoluminescence. Here we show a pronounced fluorescence enhancement for a weakly fluorescent merocyanine (MC) dye by being co-facially stacked to other dyes in hetero-folda-trimer architectures. By means of fluorescence spectroscopy (lifetime, quantum yield) the fluorescence enhancement was explained by the rigidification of the emitting chromophore in the defined foldamer architecture and the presence of a non-forbidden lowest exciton state in H-coupled hetero-aggregates. This folding-induced fluorescence enhancement (FIFE) for specific sequences of π-stacked dyes points at a viable strategy toward improved fluorophores that relates to the approach used by nature in the green fluorescent protein (GFP). KW - organic chemistry KW - merocyanines KW - aggregation KW - dyes/pigments KW - fluorescence KW - folding Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256582 VL - 61 IS - 2 ER - TY - JOUR A1 - Kaireit, Till F. A1 - Sorrentino, Sajoscha A. A1 - Renne, Julius A1 - Schoenfeld, Christian A1 - Voskrebenzev, Andreas A1 - Gutberlet, Marcel A1 - Schulz, Angela A1 - Jakob, Peter M. A1 - Hansen, Gesine A1 - Wacker, Frank A1 - Welte, Tobias A1 - Tümmler, Burkhard A1 - Vogel-Claussen, Jens T1 - Functional lung MRI for regional monitoring of patients with cystic fibrosis JF - PLoS ONE N2 - Purpose To test quantitative functional lung MRI techniques in young adults with cystic fibrosis (CF) compared to healthy volunteers and to monitor immediate treatment effects of a single inhalation of hypertonic saline in comparison to clinical routine pulmonary function tests. Materials and methods Sixteen clinically stable CF patients and 12 healthy volunteers prospectively underwent two functional lung MRI scans and pulmonary function tests before and 2h after a single treatment of inhaled hypertonic saline or without any treatment. MRI-derived oxygen enhanced T1 relaxation measurements, fractional ventilation, first-pass perfusion parameters and a morpho-functional CF-MRI score were acquired. Results Compared to healthy controls functional lung MRI detected and quantified significantly increased ventilation heterogeneity in CF patients. Regional functional lung MRI measures of ventilation and perfusion as well as the CF-MRI score and pulmonary function tests could not detect a significant treatment effect two hours after a single treatment with hypertonic saline in young adults with CF (p>0.05). Conclusion This study shows the feasibility of functional lung MRI as a non-invasive, radiation-free tool for monitoring patients with CF. KW - Physics KW - Magnetic resonance imaging KW - Functional magnetic resonance imaging KW - Cystic fibrosis KW - Oxygen KW - Pulmonary imaging KW - Hypertonic KW - Pulmonary function KW - Quantum chronodynamics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172457 VL - 12 IS - 12 ER - TY - JOUR A1 - Sitter, Magdalena A1 - Schlesinger, Tobias A1 - Reinhold, Ann-Kristin A1 - Scholler, Axel A1 - Heymann, Christian von A1 - Welfle, Sabine A1 - Bartmann, Catharina A1 - Wöckel, Achim A1 - Kleinschmidt, Stefan A1 - Schneider, Sven A1 - Gottschalk, André A1 - Greve, Susanne A1 - Wermelt, Julius Z. A1 - Wiener, Roland A1 - Schulz, Frank A1 - Chappell, Daniel A1 - Brunner, Maya A1 - Neumann, Claudia A1 - Meybohm, Patrick A1 - Kranke, Peter T1 - COVID-19 in der geburtshilflichen Anästhesie: Prospektive Erfassung von SARS-CoV-2-Infektionen zum Zeitpunkt der Geburt sowie des peripartalen Verlaufs SARS-CoV-2-positiver Schwangerer JF - Der Anaesthesist N2 - Hintergrund Im Rahmen der Pandemie des SARS-CoV-2-Virus erlangte das Patientenkollektiv der Schwangeren früh Aufmerksamkeit. Initial wurde angesichts sich früh abzeichnender Krankheitsfälle bei jüngeren Patienten mit einem erheblichen Aufkommen peripartal zu betreuender, COVID-19-positiver Schwangerer gerechnet. Ziel der Arbeit Diese Arbeit vermittelt einen Einblick in die SARS-CoV-2-Infektionszahlen im Rahmen der geburtshilflichen Anästhesie zu Beginn der Pandemie sowie während der zweiten Infektionswelle in Deutschland. Methoden Über das COALA-Register (COVID-19 related Obstetric Anaesthesia Longitudinal Assessment-Registry) wurden sowohl von März bis Mai 2020 als auch von Oktober 2020 bis Februar 2021 in Deutschland und der Schweiz wöchentlich prospektiv Daten zu Verdachts- und bestätigten SARS-CoV-2-Fällen bei Schwangeren zum Zeitpunkt der Geburt erhoben. Betrachtet wurden die Verteilung dieser auf die Anzahl der Geburten, Zentren und Erhebungswochen sowie mütterliche Charakteristika und Krankheitsverläufe. Ergebnisse Neun Zentren haben im Verlauf 44 SARS-CoV-2-positive Schwangere zum Zeitpunkt der Geburt bei 7167 Geburten (0,6 %) gemeldet (3 Fälle auf 2270 Geburten (0,4 %) und 41 Fälle auf 4897 Geburten (0,8 %)). Berichtet wurden 2 schwere COVID-19-Verläufe (n = 1 mit Todesfolge nach ECMO, n = 1 mit ECMO überlebt). Bei 28 (68 %) Patientinnen verlief die Infektion asymptomatisch. Ein Neugeborenes wurde im Verlauf positiv auf SARS-CoV‑2 getestet. Schlussfolgerung Mithilfe des Registers konnte das Auftreten von Fällen zu Beginn der Pandemie zeitnah eingeschätzt werden. Es traten sporadisch Verdachtsfälle bzw. bestätigte Fälle auf. Aufgrund fehlender flächendeckender Testung muss aber von einer Dunkelziffer asymptomatischer Fälle ausgegangen werden. Während der zweiten Infektionswelle wurden 68 % asymptomatische Fälle gemeldet. Jedoch kann es bei jungen, gesunden Patientinnen ohne das Vorliegen typischer Risikofaktoren zu schwerwiegenden Verläufen kommen. KW - ECMO-Therapie KW - Geburtshilfe KW - Geburtshilfliche Intensivmedizin KW - COVID-19-Pademie KW - Infektionswellen Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264878 SN - 1432-055X VL - 71 IS - 6 ER -