TY - JOUR A1 - Brückner, Tobias A1 - Dewhurst, Rian D. A1 - Dellermann, Theresa A1 - Müller, Marcel A1 - Braunschweig, Holger T1 - Mild synthesis of diboryldiborenes by diboration of B–B triple bonds JF - Chemical Science N2 - A set of diboryldiborenes are prepared by the mild, catalyst-free, room-temperature diboration of the B–B triple bonds of doubly base-stabilized diborynes. Two of the product diboryldiborenes are found to be air- and water-stable in the solid state, an effect that is attributed to their high crystallinity and extreme insolubility in a wide range of solvents. KW - boron KW - diborenes KW - diboration KW - triple bonds KW - diborynes Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186306 VL - 10 ER - TY - INPR A1 - Brückner, Tobias A1 - Arrowsmith, Merle A1 - Heß, Merlin A1 - Hammond, Kai A1 - Müller, Marcel A1 - Braunschweig, Holger T1 - Synthesis of fused B,N-heterocycles by alkyne cleavage, NHC ring-expansion and C-H activation at a diboryne T2 - Chemical Communications N2 - The addition of alkynes to a staturated N-heterocyclic carbene (NHC)-supported diboryne results in spontaneous cycloaddition, with complete B≡B and C≡C triple bond cleavage, NHC ring- expansion and activation of a variety of C-H bonds, leading to the formation of complex mixtures of fused B,N-heterocycles. KW - heterocycles KW - alkynes KW - boron KW - carbenes Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-184899 N1 - This is the pre-peer reviewed version of the following article: Chem. Commun., 2019,55, 6700-6703, which has been published in final form at doi:10.1039/C9CC02657F ER - TY - THES A1 - Müller, Holger T1 - Gestaltungsanforderungen Internettechnologie-basierter Marktplätze aus Sicht der industriellen Beschaffung : Entwurf eines entscheidungsorientierten objektzentrierten Analyseschemas T1 - Industrial supply management requirements on internet-technology based marketplaces N2 - Internettechnologie-basierte Marktplätze standen von 1999 bis Mitte 2000 im Mittelpunkt euphorischer Prognosen. Schnell kehrte jedoch Ernüchterung ein, da die Nutzung der Marktplätze weitaus langsamer voranging als allgemein erwartet wurde. Dafür wird als ein Hauptgrund die mangelnde Erfahrungen sowohl auf Seiten der Marktplatzbetreiber als auch der nachfragenden Unternehmen hinsichtlich der ganzheitlichen Betrachtung und Restrukturierung der Beschaffungsprozesse unter Einsatz des „Hilfsmittels“ Internettechnologie-basierter Marktplatz angeführt. Mit der einhergehenden Versachlichung der Diskussion wurde aber auch deutlich, dass viele nachfragende Unternehmen mittlerweile in diesen Plattformen ein unentbehrliches Instrument zur Unterstützung des zwischenbetrieblichen Leistungsaustauschs sehen. Die steigende Akzeptanz der virtuellen Handelsplattformen darf nicht darüber hinweg täuschen, dass die Mehrzahl der nachfragenden Unternehmen erst seit kurzer Zeit und nur bei einigen der angebotenen Marktplatzdiensten Erfahrungen sammeln konnten. Ähnliches ist auf Seiten der Marktplatzbetreiber zu konstatieren, die zum Teil die Leistungen und Funktionen ihrer Systeme in den vergangenen Jahren mehrfach neu gestalteten, da sich bei vielen Plattformen der Fokus von konkurrenzorientierten hin zu kollaborativen Szenarien verschob. In der Konsequenz existiert nach wie vor eine hohe Unsicherheit, welche Gestaltungsanforderungen an die Plattformen zu stellen sind, um die Beschaffungsabläufe sicher, effizient und durchgängig zu unterstützen. Im Rahmen der Dissertation wird daher ein beschaffungsobjektzentrierter Anforderungskatalog an Internettechnologie-basierte Marktplätze systematisch erarbeitet, um eine betriebswirtschaftlich fundierte Bewertung dieser Plattformen aus Sicht der industriellen Beschaffung zu ermöglichen. Neben der Einleitung und der Schlussbetrachtung gliedert sich die Untersuchung in fünf Hauptteile. Im zweiten Kapitel werden zunächst die für die Arbeit relevanten Grundlagen der industriellen Beschaffung herausgearbeitet. Das dritte Kapitel dient der Einordnung elektronischer Marktplätze in den zwischenbetrieblichen Beschaffungsprozess. Dabei steht im ersten Teil der Markt als grundlegender ökonomischer Koordinationsmechanismus im Mittelpunkt. Ausgehend von der volks- und betriebswirtschaftlichen Definition werden die relevanten Faktoren herausgearbeitet, die einen Markt aus Beschaffungssicht fixieren. Darauf aufbauend erfolgt eine Analyse der marktmäßig organisierten Leistungskoordination, die in einem idealtypischen Phasenmodell einer Geschäftstransaktion mündet. Der im Anschluss skizzierte Aufbau elektronischer Marktplätze, in den das Phasenmodell integriert wird, stellt die strukturelle Grundlage zur Ableitung der Gestaltungsanforderungen dar. Die in der Arbeit fokussierte Teilmenge der elektronischen Marktplätze – die Internettechnologie-basierten Marktplätze – werden im zweiten Teil des dritten Kapitels aus Beschaffungssicht diskutiert und anderen interorganisationalen Systemen zur Unterstützung des Transaktionsprozesses gegenübergestellt. Abschließend wird veranschaulicht, auf welche dieser Systeme die Erkenntnisse dieser Arbeit übertragbar sind. Die Zielstellung des vierten Kapitels besteht im Entwurf eines Klassifizierungssystems für Beschaffungsobjekte, das zur Entwicklung des objektzentrierten Analyseschemas Internettechnologie-basierter Marktplätze geeignet ist. Durch eine Auswertung sowohl der wissenschaftlichen als auch praxisnahen Fachliteratur werden die für die Untersuchung einzubeziehenden Objektmerkmale ermittelt. Die nachfolgende Verdichtung und Verknüpfung der Eigenschaften resultiert in drei zu berücksichtigenden Objektmerkmalen – Spezifität, Komplexität und strategische Bedeutung – mit jeweils bipolaren Ausprägungen, die zusammen einen Würfel mit acht Beschaffungsobjektgruppen bilden. Im fünften Kapitel werden ausgehend vom Aufbau elektronischer Marktplätze die möglichen Funktionalitäten und Leistungen in den einzelnen Untersuchungsbereichen aufgezeigt. Im Mittelpunkt steht dabei neben der Unterstützung der einzelnen Phasen einer Geschäftstransaktion die übergeordnete Organisationsebene, welche die Ausrichtung und Positionierung des Marktplatzes sowie die durchführbaren Geschäftsvorfälle bzw. Prozessabläufe determiniert. Nachfolgend wird aus den gewonnenen Erkenntnissen für jede der acht Objektgruppen der spezifische Anforderungskatalog aus Beschaffungssicht abgeleitet. Inwieweit Internettechnologie-basierte Marktplätze für den deutschsprachigen Raum die abgeleiteten Gestaltungsanforderungen erfüllen, wird abschließend im sechsten Kapitel untersucht. Basierend auf Datenmaterial, das im Rahmen der seit Anfang 2000 am Lehrstuhl für Betriebswirtschaftslehre und Industriebetriebslehre der Bayerischen Julius-Maximilians-Universität laufenden Studie „b2b-Marktplatzführer“ erhoben wurde, konnten zum 15.07.2003 79 Marktplätze einbezogen werden. N2 - For years electronic marketplaces based on internet-technology have been considered as a promising tool to greatly improve the efficiency of business-to-business procurement transaction. Despite the considerable attention in this area there is still a substantial uncertainty about the services of marketplaces needed by the industrial supply management. The goal of this study is to analyse the requirements of supply management depending on types of demanded goods. Therefore a classification scheme for demanded goods is developed based on three identified attributes – the complexity, the specificity and the strategic importance of an item. In consequence this classification scheme consists of eight classes of objects to be procured. Subsequently the specific requirements for each class are determined founding on a detailed analysis of potential services of marketplaces. Finally a survey was carried out to investigate how marketplaces in German speaking countries meet the proposed requirements. KW - Internet KW - Beschaffung KW - Electronic Commerce KW - elektronischer Marktplatz KW - Beschaffung KW - Beschaffungsobjekte KW - Objektgruppenanalyse KW - Beschaffungsprozess KW - electronic marketplace KW - supply managament KW - demand goods KW - classsification scheme KW - procurement transaction Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-8353 ER - TY - JOUR A1 - Weber-Lassalle, Nana A1 - Hauke, Jan A1 - Ramser, Juliane A1 - Richters, Lisa A1 - Groß, Eva A1 - Blümcke, Britta A1 - Gehrig, Andrea A1 - Kahlert, Anne-Karin A1 - Müller, Clemens R. A1 - Hackmann, Karl A1 - Honisch, Ellen A1 - Weber-Lassalle, Konstantin A1 - Niederacher, Dieter A1 - Borde, Julika A1 - Thiele, Holger A1 - Ernst, Corinna A1 - Altmüller, Janine A1 - Neidhardt, Guido A1 - Nürnberg, Peter A1 - Klaschik, Kristina A1 - Schroeder, Christopher A1 - Platzer, Konrad A1 - Volk, Alexander E. A1 - Wang-Gohrke, Shan A1 - Just, Walter A1 - Auber, Bernd A1 - Kubisch, Christian A1 - Schmidt, Gunnar A1 - Horvath, Judit A1 - Wappenschmidt, Barbara A1 - Engel, Christoph A1 - Arnold, Norbert A1 - Dworniczak, Bernd A1 - Rhiem, Kerstin A1 - Meindl, Alfons A1 - Schmutzler, Rita K. A1 - Hahnen, Eric T1 - BRIP1 loss-of-function mutations confer high risk for familial ovarian cancer, but not familial breast cancer JF - Breast Cancer Research N2 - Background Germline mutations in the BRIP1 gene have been described as conferring a moderate risk for ovarian cancer (OC), while the role of BRIP1 in breast cancer (BC) pathogenesis remains controversial. Methods To assess the role of deleterious BRIP1 germline mutations in BC/OC predisposition, 6341 well-characterized index patients with BC, 706 index patients with OC, and 2189 geographically matched female controls were screened for loss-of-function (LoF) mutations and potentially damaging missense variants. All index patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germline testing and tested negative for pathogenic BRCA1/2 variants. Results BRIP1 LoF mutations confer a high OC risk in familial index patients (odds ratio (OR) = 20.97, 95% confidence interval (CI) = 12.02–36.57, P < 0.0001) and in the subgroup of index patients with late-onset OC (OR = 29.91, 95% CI = 14.99–59.66, P < 0.0001). No significant association of BRIP1 LoF mutations with familial BC was observed (OR = 1.81 95% CI = 1.00–3.30, P = 0.0623). In the subgroup of familial BC index patients without a family history of OC there was also no apparent association (OR = 1.42, 95% CI = 0.70–2.90, P = 0.3030). In 1027 familial BC index patients with a family history of OC, the BRIP1 mutation prevalence was significantly higher than that observed in controls (OR = 3.59, 95% CI = 1.43–9.01; P = 0.0168). Based on the negative association between BRIP1 LoF mutations and familial BC in the absence of an OC family history, we conclude that the elevated mutation prevalence in the latter cohort was driven by the occurrence of OC in these families. Compared with controls, predicted damaging rare missense variants were significantly more prevalent in OC (P = 0.0014) but not in BC (P = 0.0693) patients. Conclusions To avoid ambiguous results, studies aimed at assessing the impact of candidate predisposition gene mutations on BC risk might differentiate between BC index patients with an OC family history and those without. In familial cases, we suggest that BRIP1 is a high-risk gene for late-onset OC but not a BC predisposition gene, though minor effects cannot be excluded. KW - breast cancer KW - ovarian cancer KW - BRIP1 gene KW - germline mutations Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233433 VL - 20 ER - TY - JOUR A1 - Wilde, Anne-Christin Beatrice A1 - Lieb, Charlotte A1 - Leicht, Elise A1 - Greverath, Lena Maria A1 - Steinhagen, Lara Marleen A1 - Wald de Chamorro, Nina A1 - Petersen, Jörg A1 - Hofmann, Wolf Peter A1 - Hinrichsen, Holger A1 - Heyne, Renate A1 - Berg, Thomas A1 - Naumann, Uwe A1 - Schwenzer, Jeannette A1 - Vermehren, Johannes A1 - Geier, Andreas A1 - Tacke, Frank A1 - Müller, Tobias T1 - Real-world clinical management of patients with primary biliary cholangitis — a retrospective multicenter study from Germany JF - Journal of Clinical Medicine N2 - Background: Clinical practice guidelines for patients with primary biliary cholangitis (PBC) have been recently revised and implemented for well-established response criteria to standard first-line ursodeoxycholic acid (UDCA) therapy at 12 months after treatment initiation for the early identification of high-risk patients with inadequate treatment responses who may require treatment modification. However, there are only very limited data concerning the real-world clinical management of patients with PBC in Germany. Objective: The aim of this retrospective multicenter study was to evaluate response rates to standard first-line UDCA therapy and subsequent Second-line treatment regimens in a large cohort of well-characterized patients with PBC from 10 independent hepatological referral centers in Germany prior to the introduction of obeticholic acid as a licensed second-line treatment option. Methods: Diagnostic confirmation of PBC, standard first-line UDCA treatment regimens and response rates at 12 months according to Paris-I, Paris-II, and Barcelona criteria, the follow-up cut-off alkaline phosphatase (ALP) ≤ 1.67 × upper limit of normal (ULN) and the normalization of bilirubin (bilirubin ≤ 1 × ULN) were retrospectively examined between June 1986 and March 2017. The management and hitherto applied second-line treatment regimens in patients with an inadequate response to UDCA and subsequent response rates at 12 months were also evaluated. Results: Overall, 480 PBC patients were included in this study. The median UDCA dosage was 13.2 mg UDCA/kg bodyweight (BW)/d. Adequate UDCA treatment response rates according to Paris-I, Paris-II, and Barcelona criteria were observed in 91, 71.3, and 61.3% of patients, respectively. In 83.8% of patients, ALP ≤ 1.67 × ULN were achieved. A total of 116 patients (24.2%) showed an inadequate response to UDCA according to at least one criterion. The diverse second-line treatment regimens applied led to significantly higher response rates according to Paris-II (35 vs. 60%, p = 0.005), Barcelona (13 vs. 34%, p = 0.0005), ALP ≤ 1.67 × ULN and bilirubin ≤ 1 × ULN (52.1 vs. 75%, p = 0.002). The addition of bezafibrates appeared to induce the strongest beneficial effect in this cohort (Paris II: 24 vs. 74%, p = 0.004; Barcelona: 50 vs. 84%, p = 0.046; ALP < 1.67 × ULN and bilirubin ≤ 1 × ULN: 33 vs. 86%, p = 0.001). Conclusion: Our large retrospective multicenter study confirms high response rates following UDCA first-line standard treatment in patients with PBC and highlights the need for close monitoring and early treatment modification in high-risk patients with an insufficient response to UDCA since early treatment modification significantly increases subsequent response rates of these patients. KW - primary biliary cholangitis KW - autoantibodies KW - ursodeoxycholic acid KW - treatment response KW - second line therapy Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234003 SN - 2077-0383 VL - 10 IS - 5 ER - TY - JOUR A1 - Kole, Goutam Kumar A1 - Košćak, Marta A1 - Amar, Anissa A1 - Majhen, Dragomira A1 - Božinović, Ksenija A1 - Brkljaca, Zlatko A1 - Ferger, Matthias A1 - Michail, Evripidis A1 - Lorenzen, Sabine A1 - Friedrich, Alexandra A1 - Krummenacher, Ivo A1 - Moos, Michael A1 - Braunschweig, Holger A1 - Boucekkine, Abdou A1 - Lambert, Christoph A1 - Halet, Jean‐François A1 - Piantanida, Ivo A1 - Müller‐Buschbaum, Klaus A1 - Marder, Todd B. T1 - Methyl Viologens of Bis‐(4’‐Pyridylethynyl)Arenes – Structures, Photophysical and Electrochemical Studies, and their Potential Application in Biology JF - Chemistry – A European Journal N2 - A series of bis‐(4’‐pyridylethynyl)arenes (arene=benzene, tetrafluorobenzene, and anthracene) were synthesized and their bis‐N‐methylpyridinium compounds were investigated as a class of π‐extended methyl viologens. Their structures were determined by single crystal X‐ray diffraction, and their photophysical and electrochemical properties (cyclic voltammetry), as well as their interactions with DNA/RNA were investigated. The dications showed bathochromic shifts in emission compared to the neutral compounds. The neutral compounds showed very small Stokes shifts, which are a little larger for the dications. All of the compounds showed very short fluorescence lifetimes (<4 ns). The neutral compound with an anthracene core has a quantum yield of almost unity. With stronger acceptors, the analogous bis‐N‐methylpyridinium compound showed a larger two‐photon absorption cross‐section than its neutral precursor. All of the dicationic compounds interact with DNA/RNA; while the compounds with benzene and tetrafluorobenzene cores bind in the grooves, the one with an anthracene core intercalates as a consequence of its large, condensed aromatic linker moiety, and it aggregates within the polynucleotide when in excess over DNA/RNA. Moreover, all cationic compounds showed highly specific CD spectra upon binding to ds‐DNA/RNA, attributed to the rare case of forcing the planar, achiral molecule into a chiral rotamer, and negligible toxicity toward human cell lines at ≤10 μM concentrations. The anthracene‐analogue exhibited intracellular accumulation within lysosomes, preventing its interaction with cellular DNA/RNA. However, cytotoxicity was evident at 1 μM concentration upon exposure to light, due to singlet oxygen generation within cells. These multi‐faceted features, in combination with its two‐photon absorption properties, suggest it to be a promising lead compound for development of novel light‐activated theranostic agents. KW - cell imaging KW - DNA/RNA binding KW - methyl viologen KW - singlet oxygen KW - two-photon absorption Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287126 VL - 28 IS - 40 ER - TY - JOUR A1 - Kole, Goutam Kumar A1 - Merz, Julia A1 - Amar, Anissa A1 - Fontaine, Bruno A1 - Boucekkine, Abdou A1 - Nitsch, Jörn A1 - Lorenzen, Sabine A1 - Friedrich, Alexandra A1 - Krummenacher, Ivo A1 - Košćak, Marta A1 - Braunschweig, Holger A1 - Piantanida, Ivo A1 - Halet, Jean-François A1 - Müller-Buschbaum, Klaus A1 - Marder, Todd B. T1 - 2- and 2,7-substituted para-N-methylpyridinium pyrenes: syntheses, molecular and electronic structures, photophysical, electrochemical, and spectroelectrochemical properties and binding to double-stranded (ds) DNA JF - Chemistry - A European Journal N2 - Two N-methylpyridinium compounds and analogous N-protonated salts of 2- and 2,7-substituted 4-pyridyl-pyrene compounds were synthesised and their crystal structures, photophysical properties both in solution and in the solid state, electrochemical and spectroelectrochemical properties were studied. Upon methylation or protonation, the emission maxima are significantly bathochromically shifted compared to the neutral compounds, although the absorption maxima remain almost unchanged. As a result, the cationic compounds show very large apparent Stokes shifts of up to 7200 cm\(^{-1}\). The N-methylpyridinium compounds have a single reduction at ca. −1.5 V vs. Fc/Fc\(^+\) in MeCN. While the reduction process was reversible for the 2,7-disubstituted compound, it was irreversible for the mono-substituted one. Experimental findings are complemented by DFT and TD-DFT calculations. Furthermore, the N-methylpyridinium compounds show strong interactions with calf thymus (ct)-DNA, presumably by intercalation, which paves the way for further applications of these multi-functional compounds as potential DNA-bioactive agents. KW - inorganic chemistry KW - viologens KW - chromophores KW - luminescent KW - pyrenes KW - pyridinium Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256642 VL - 27 IS - 8 ER - TY - JOUR A1 - Hattori, Yohei A1 - Michail, Evripidis A1 - Schmiedel, Alexander A1 - Moos, Michael A1 - Holzapfel, Marco A1 - Krummenacher, Ivo A1 - Braunschweig, Holger A1 - Müller, Ulrich A1 - Pflaum, Jens A1 - Lambert, Christoph T1 - Luminescent Mono-, Di-, and Tri-radicals: Bridging Polychlorinated Triarylmethyl Radicals by Triarylamines and Triarylboranes JF - Chemistry - A European Journal N2 - Up to three polychlorinated pyridyldiphenylmethyl radicals bridged by a triphenylamine carrying electron withdrawing (CN), neutral (Me), or donating (OMe) groups were synthesized and analogous radicals bridged by tris(2,6‐dimethylphenyl)borane were prepared for comparison. All compounds were as stable as common closed‐shell organic compounds and showed significant fluorescence upon excitation. Electronic, magnetic, absorption, and emission properties were examined in detail, and experimental results were interpreted using DFT calculations. Oxidation potentials, absorption and emission energies could be tuned depending on the electron density of the bridges. The triphenylamine bridges mediated intramolecular weak antiferromagnetic interactions between the radical spins, and the energy difference between the high spin and low spin states was determined by temperature dependent ESR spectroscopy and DFT calculations. The fluorescent properties of all radicals were examined in detail and revealed no difference for high and low spin states which facilitates application of these dyes in two‐photon absorption spectroscopy and OLED devices. KW - density functional calculations KW - fluorescence KW - NIR OLED KW - radical KW - two-photon absorption Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208162 VL - 25 IS - 68 ER -