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  • Working paper
    Open Access
    talking back: junge Muslim*innen in Deutschland im Kontext eines (konstruierten) Bedrohungsszenarios
    EZIRE Working Paper : 2023/1, (2023-09-28) Löble, Nike; Müssig, Stephanie; Thielmann, Jörn
    People marked and racialised as Muslims are often portrayed as danger-ous subjects because of the – sometimes supposedly – attributed cultur-al, religious, or ethnic affiliations. At the same time, their own experienc-es of racism go largely unnoticed. In addition, they face difficulties in ad-dressing these experiences. On the basis of four interviews with young Muslim adults, I examined different possibilities of response and speech of young Muslims in the context of a (constructed) threat scenario. Stu-art Hall’s and Judith Butler's reflections on the concept of interpellation form the theoretical framework. Based on analytic categories according to bell hooks, I conceptualised different forms of talking back. This ap-proach allows the perception of the interview partner’s subject positions and their agency and, at the same time, the consideration of their situat-edness and conditionality within the security dispositive.
  • Article
    Open Access
    Comparative Characterization of Iron and Silver Nanoparticles: Extract-Stabilized and Classical Synthesis Methods
    (MDPI, 2023-06-12) Akhatova, Farida; Konnova, Svetlana; Kryuchkova, Marina; Batasheva, Svetlana; Mazurova, Kristina; Vikulina, Anna; Volodkin, Dmitry; Rozhina, Elvira
    Synthesis of silver nanoparticles using extracts from plants is an advantageous technological alternative to the traditional colloidal synthesis due to its simplicity, low cost, and the inclusion of environmentally friendly processes to obtain a new generation of antimicrobial compounds. The work describes the production of silver and iron nanoparticles using sphagnum extract as well as traditional synthesis. Dynamic light scattering (DLS) and laser doppler velocimetry methods, UV-visible spectroscopy, transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), dark-field hyperspectral microscopy, and Fourier-transform infrared spectroscopy (FT-IR) were used to study the structure and properties of synthesized nanoparticles. Our studies demonstrated a high antibacterial activity of the obtained nanoparticles, including the formation of biofilms. Nanoparticles synthesized using sphagnum moss extracts likely have high potential for further research.
  • Doctoral thesis
    Open Access
    Perfusable microvascular networks for biofabrication of three-dimensional tissue models: Channel endothelialization and biofunctional characterization of constructs
    (2023-06-05) Genc, Hatice; Reim, Ingolf
    Functionality of the native tissue is a result of complex interaction between cells and extracellular matrix (ECM) and depends on the composition, architecture and mechanical properties of the ECM, as well as the adequate supply of oxygen and nutrients. Advanced biofabrication techniques offer a great possibility to recapitulate these functional features in the laboratory. However, creating functional tissue models with appropriate ECM characteristics and adequate support of tissue specific cell types remains challenging. The presented work aimed at developing physiologically-relevant, endothelialized microvacular networks embedded within an engineered matrix. To achieve this, analyses related to microchannel endothelialization and cell-matrix interactions were conducted. Completing the thesis within the SFB-TRR225 consortium enabled me to perform collaborative studies at the interface of biology, chemistry and engineering. In the first part of my thesis, sacrificial scaffolds produced from thermoresponsive polymer poly(2-oxazoline) (POx) using melt electro writing (MEW) technique were used. Bifurcated sacrificial scaffolds were either directly seeded with primary human endothelial cells (ECs) for endothelial layer formation on their surface, or were embedded in bulk hydrogels placed in a customized bioreactor. In the latter approach, POx was removed by temperature lowering to create bifurcating microchannels, which were subsequently endothelialized and exposed to bidirectional perfusion. The second approach enabled a rapid formation of a tight and biologically functional endothelial layer. In the second part of my thesis, different hydrogels were evaluated with regard to their suitability as matrices for microvascularized models and tissue engineering. Extensive analyses were done to determine their biocompatibility with ECs and primary fibroblasts. Within those, oxidized alginate-based hydrogels (ADA and ADA-GEL), as well as allyl-modified gelatin (gelAGE), were casted with primary cells and investigated using flow cytometric, spectrometric, as well as imaging techniques. Molecular studies with ADA and ADA-GEL demonstrated the mechanisms of their toxicity towards ECs and of fibroblast survival. GelAGE hydrogels were tailored to improve the response of ECs and fibroblasts and were shown to support cell viability, motility, and biological functions. The results obtained within this thesis are of high importance for the progress of the SFB-TRR225 within the cross-cutting topics of vascularization and tumor models, as well as for the field of biofabrication. The developed endothelialized microvascular networks, together with the suitable 7 ECM candidates will be in the future tailored to the needs of specific tissue models for the purpose of disease modelling and drug screening studies.
  • Article
    Open Access
    The Post-Pandemic World: between Constitutionalized and Authoritarian Orders – China’s Narrative-Power Play in the Pandemic Era
    (Springer Netherlands, 2023-05-24) Chang, Yung-Yung
    Abstract The paper aims to address the development of China’s narrative power during the COVID-19 pandemic and its impact on world order. It argues that in the post-pandemic world, the emergence of the authoritarian sub-order would be prompted by China’s more proactive narrative power, given that the climate of opinion is ambiguous when faced with the uncertainty of the pandemic. (This does not imply the end of the existing liberal order; instead, it features the coexistence of both orders.) To understand how China’s narrative power has encouraged the emergence of the authoritarian sub-order to coexist in parallel with the dominant constitutional order, the article first reviews the existing literature concerning the changing world order. In this section, it also briefly defines and differentiates between the constitutional and authoritarian orders, what defines world order, and what distinguishes authoritarian from constitutional liberal order. Second it looks at the theoretical grounding. The nature, role and power of narratives are explored. Ideas about strategic narratives and the economics of attention are discussed. This theoretical background paves the way to examine China’s narrative power during a pandemic. Lastly, it switches to the Chinese perspective to address its support for the plurality of orders and its awareness of the strength of narrative in influencing dominant ideas. It looks at how China’s narrative power has been exercised from three perspectives (formation, projection and reception). Here, it mainly tackles how China has used its narrative power to spin the pandemic to its advantage in the reorganization of world order: improving its international image and advocating the authoritarian order as an alternative. China has been building its narrative along with its changing strategic diplomacy – from restrained and low-profile to proactive and assertive. In the conclusion, some reflections on China’s narrative power and the implications for world order are considered.
  • Article
    Open Access
    Device Performance of Emerging Photovoltaic Materials (Version 3)
    (Wiley-VCH GmbH, 2023-04-21) Almora, Osbel; Baran, Derya; Bazan, Guillermo C.; Cabrera, Carlos I.; Erten‐Ela, Sule; Forberich, Karen; Guo, Fei; Hauch, Jens; Ho‐Baillie, Anita W. Y.; Jacobsson, T. Jesper; Janssen, Rene A. J.; Kirchartz, Thomas; Kopidakis, Nikos; Loi, Maria A.; Lunt, Richard R.; Mathew, Xavier; McGehee, Michael D.; Min, Jie; Mitzi, David B.; Nazeeruddin, Mohammad K.; Nelson, Jenny; Nogueira, Ana F.; Paetzold, Ulrich W.; Rand, Barry P.; Rau, Uwe; Snaith, Henry J.; Unger, Eva; Vaillant‐Roca, Lídice; Yang, Chenchen; Yip, Hin‐Lap; Brabec, Christoph J.
    Abstract Following the 2nd release of the “Emerging PV reports,” the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer‐reviewed articles in academic journals since August 2021. Updated graphs, tables, and analyses are provided with several performance parameters, e.g., power conversion efficiency, open‐circuit voltage, short‐circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application, and are put into perspective using, e.g., the detailed balance efficiency limit. The 3rd installment of the “Emerging PV reports” extends the scope toward triple junction solar cells.
  • Doctoral thesis
    Open Access
    Das Extramedulläre Plasmozytom - Recherche zu Tumorcharakteristika und Therapieprinzipien anhand von Literatur (1998-2018) und eigenem Patientenkollektiv -
    (2023-04-12) Holler, Adrian; Cicha, Iwona
    1. Zusammenfassung 1.1. Hintergrund und Ziele Das Extramedulläre Plasmozytom (EMP) ist ein Plasmazelltumor, der formal zu den plasmozy-tischen Non-Hodgkin-Lymphomen zählt und eine lokale Manifestation außerhalb des Knochens zeigt. Das EMP gehört zu den niedrig-malignen Tumoren und kann mit einer Inzidenz von 4/100.000 als seltener Tumor bezeichnet werden. Die Therapie des EMP stellt eine Herausfor-derung dar, da es keine Leitlinien oder Ähnliches gibt, worauf sich Behandler stützen könnten. In dieser Arbeit soll durch eine umfangreich angelegte Literaturrecherche und eigene Patienten-untersuchungen eine möglichst repräsentative Fallzahl erreicht werden, um eine Empfehlung für eine Therapie hinsichtlich dieser Tumorentität zu formulieren. 1.1. Methoden (Patienten, Material, Untersuchungsmethoden) Diese retrospektive Literaturrecherche untersucht wichtige Charakteristika (Alter, Geschlecht, Lokalisation, Immunhistochemie, Leichtketten im Serum) des EMP sowie dessen Therapiemög-lichkeiten und deren Behandlungserfolg. Das Material, das für diese Arbeit analysiert wurde, setzt sich aus den Patientenfällen zusammen, die in der Uniklinik Erlangen an einem EMP be-handelt wurden, sowie dem Patientengut, welches über eine Literaturrecherche der Datenbank PubMed für den Zeitraum vom 01.01.1998 bis zum 31.12.2018 mit den Suchbegriffen „Extramedullary Plasmocytoma“ und „Extramedullary Plasmacytoma“ generiert werden konn-ten; wobei nur Artikel in deutsch und englisch berücksichtigt wurden. Die PubMed-Suche ergab 929 Artikel die darauf geprüft wurden, ob sie für die Auswertung relevant sind. Den Kri-terien dieses Auswahlprozesses entsprachen 408 Veröffentlichungen. Die Daten waren haupt-sächlich deskriptiver Natur. Die Überlebenszeitanalyse der vier untersuchten Therapiegruppen wurde anhand von Kaplan-Meier-Kurven durchgeführt. 1.2. Ergebnisse und Beobachtungen Aus der Literaturrecherche und dem eigenen Patientengut wurden 1.050 Fälle von EMPs ge-sammelt. Der Hauptteil der diagnostizierten EMPs befand sich mit 655 (62,38%) im oberen Aerodigestivtrakt (OAD), wohingegen 395 (37,62%) außerhalb des oberen Aerodigestivtrakts (AOAD) auftraten. Im OAD wurde für die rein chirurgische Therapie (OP) ein 5-Jahres-Überleben von 89,6% festgestellt. Die Radiotherapie (RT) zeigte ein 5-Jahres-Überleben von 91%. Bei der Kombina-tion Operation und Bestrahlung (OPRT) wurde ein 5-Jahres-Überleben von 96,5% beobachtet, während die sonstigen Therapieformen ein 5-Jahres-Überleben von lediglich 72,7% erzielten. Für den AOAD wurde für die rein chirurgische Therapie ein 5-Jahres-Überleben von 82,8% festgestellt. Die Radiotherapie zeigte ein 5-Jahres-Überleben von 90,6%. Bei der Kombination Operation und Bestrahlung wurde ein 5-Jahres-Überleben von 96,2% beobachtet, wobei mit 82,6% für die sonstigen Therapieformen ebenfalls hohe Werte erzielt wurden. 1.3. Schlussfolgerung Diese Arbeit stellt eine detaillierte Analyse von EMP-Fällen, die zwischen 1998 und 2018 ver-öffentlicht wurden, hinsichtlich der Charakteristika, Diagnostik und Therapie dieses seltenen Tumors dar. Es wird deutlich, dass das EMP vornehmlich im OAD auftritt und dass es sich für gewöhnlich an Stellen des Körpers manifestiert, an denen die Schleimhaut äußeren Einflüssen ausgesetzt ist. Basierend auf den Therapieangaben stellen die chirurgische Behandlung, die Strahlentherapie und die Kombination aus beiden die häufigsten Behandlungsstrategien der EMP dar, sowohl bei OAD als auch bei AOAD. Schlussendlich kann diese Arbeit keine definitive Aussage darüber treffen, welche der drei The-rapiemodalitäten die am besten geeignete zur Behandlung des EMP ist. Allerdings kann abgelei-tet werden, dass hohe Tumorkontrolle und lange Nachbeobachtungszeiten mit allen drei haupt-sächlich angewandten Therapien möglich ist und diese sich im Outcome nur geringfügig unter-scheiden. Weiterhin zeigt diese Untersuchung des EMP, dass weitere Studien, bestenfalls pros-pektive randomisierte Multicenterstudien, nötig sind, um die Frage nach der optimalen Behand-lung des EMP klären zu können.
  • Article
    Open Access
    Viscosity and Surface Tension of Benzene at Saturation Conditions from Surface Light Scattering
    (Springer US, 2023-04-11) Kerscher, Manuel; Fröba, Andreas P.; Koller, Thomas M.
    In the present study, the liquid viscosity and surface tension of benzene was determined at saturation conditions from surface light scattering (SLS) experiments between (283 and 393) K. Based on the application of the hydrodynamic theory for surface fluctuations at the vapor–liquid phase boundary which was successfully validated by the measurements, a simultaneous determination of liquid viscosity and surface tension with average relative expanded uncertainties (k = 2) of (1.0 and 0.8)% was achieved. Agreement between the measurement data and reference values available in the literature was found for the viscosity and in general also for the surface tension, where benzene constitutes a recommended reference material of relatively moderate surface tension values. All these findings demonstrate for a repeated time that SLS is a suitable method for the investigation of fluids including reference fluids such as benzene, which enables a sound representation of its surface tension, presumably as a result of a rather random molecular orientation at the surface. Overall, the experimental results from this work could contribute to an improved data situation for benzene, in particular with respect to providing viscosities and surface tensions at true saturation conditions.
  • Working paper
    Open Access
    Identitätsstiftende Praktiken in Gangsta-Rap-, Türsteher:in-, Kraft- und Kampfsport- sowie Shisha-Bar-Szene: Methodische und theoretische Annäherung an die Szenenfelder
    EZIRE Working Paper : 2022/1, (2023-03-31) Elliesie, Hatem; Rosin, Jacqueline; Soliman, Eslam; Reinold, Luca; Müssig, Stephanie; Thielmann, Jörn
    In öffentlichen Debatten taucht immer häufiger der Begriff „Clan“ auf. Dabei wird der Begriff gegenwärtig meist mit „Clankriminalität“ in unmittelbare Verbindung gesetzt. Hierdurch wird ein Zusammenhang zur (organisierten) Kriminalität vermittelt. Häufig entsteht auch eine Verknüpfung zur sogenannten Paralleljustiz. Mangelnde Integrationsbereitschaft sticht in diesem Zusammenhang ebenfalls als Schlagwort hervor. In der medialen Berichterstattung und behördlichen Berichten werden dabei die Begriffe „Clan“ und „Clankriminalität“ weitgehend undifferenziert verwendet. Was einen „Clan“ und dessen Kriminalität ausmacht, bleibt in den gesellschaftspolitischen Debatten vage. Sozialwissenschaftliche Erkenntnisse zur Struktur und Funktionsweise der im Fokus stehenden Gemeinschaften bzw. Solidarverbände, häufig nahöstlicher Herkunft, stellen ein Desiderat dar. Eine sozialwissenschaftliche Betrachtungsweise ist jedoch unerlässlich. Insbesondere auch eine, die die bisherigen, spärlichen Kenntnisse in den Blick nimmt. Dieser wird in erster Linie durch die Linse der ermittlungsbehördlichen Wahrnehmung geprägt. „Clans“ werden demnach weitgehend als eine aus Familienangehörigen bestehende kriminelle Vereinigung verstanden. Qua Familienzugehörigkeit erfolgt also eine Zuschreibung, der ein kriminelles oder deviantes Handeln innewohne. Ausschlaggebendes Kriterium sei dabei der Familienname. Das vorliegende Working Paper leistet einen sozialwissenschaftlichen Beitrag zur Versachlichung der Debatte. Es zeigt die Grundstruktur eines vom Bundesministerium für Bildung und Forschung geförderte Forschungsvorhabens auf, welches gegenwärtig von den Autor:innen gemeinsam durchgeführt wird. Ziel ist es, wissenschaftlich fundierte Einblicke in den Alltag von Angehörigen der Familien zu erhalten, denen die Zuschreibung zuteilwird. Auf Empirie gestützter Basis sollen wissenschaftlich fundierte Erkenntnisse über Lebenswelten einschlägiger großfamiliärer Strukturen und ihrer Umwelt, insbesondere der Gesamtgesellschaft, gewonnen werden. Hierbei wird die Methodologie der Grounded Theory (GT) angewendet. Im Sinne des nachfolgend näher beschriebenen GT-Ansatzes wird der Fokusgruppe möglichst offen begegnet. Dabei wird vor dem Feldeinstieg auf die Formulierung eng zugeschnittener Forschungsfragen verzichtet. Was den Alltag der Fokusgruppen in welcher Weise prägt, wird nicht vorab durch eine feste Fragestellung antizipiert, sondern aus der qualitativen Forschung im Feld herausgearbeitet. Eine praxeologische Sichtweise soll demgemäß bei der Generierung von Einblicken in die Lebenswelt(en) der Akteur:innen helfen. Zu identifizierende Praktiken der Fokusgruppe dienen dabei als Analyseeinheit. Ziel ist es, den Blick auf Alltägliches zu schärfen und mit dem der öffentlichen Wahrnehmung abzugleichen. In der durch Medien geprägten Öffentlichkeit werden mit dem Begriff der „Clankriminalität“ – und somit mit den der „Clankriminalität“ zugeordneten Familienangehörigen – häufig auch bestimmte Szenenfelder genannt. So beispielsweise die Gangsta-Rap-, Shisha-Bar-, Kampfsport- und Türsteher:innenszene. Auffällig ist hierbei, dass die Lebensrealitäten derjenigen, die sich in eben jenen Feldern aufhalten, kaum Beachtung erfährt und, wie bereits erwähnt, sozialwissenschaftlich kaum erforscht ist. Aus diesem Grund fokussiert die hier dargestellte Forschung diese vier Szenen, um gängige Narrative konzeptionell zu durchdringen und die Lebenswelten derjenigen, die sich in den genannten vier Szenenfelder aufhalten, möglichst präzise abzubilden. Zu betonen ist hierbei auch, dass das Forschungsprojekt eine Analyse der Szenen vornehmen und somit die Frage beantworten möchte, ob und wo sich das Konstrukt „Clan“ überhaupt als relevant zeigt. Das vorliegende Working Paper ist entlang der Logik der GT strukturiert. Ausgangspunkt ist eine kurze Einführung in den Themenkomplex „Clankriminalität“. Danach erfolgt eine kritische Auseinandersetzung mit Begriffsbestimmungen der „Clan-“ und organisierte Kriminalität. Darauf aufbauend stellen wir unser Erkenntnisinteresse dar, artikulieren unsere Forschungsfragen mit Blick auf die ausgewählten Szenenfelder und deren Akteur:innen. Da unser Vorhaben sich an der GTM orientiert, messen wir insbesondere den Methoden rund um die GT und ihrer Methodologie ein nicht unerhebliches Gewicht bei. Unsere Daten generieren wir im Feld, wobei im sprichwörtlichen Vorfeld möglichst wenig konzeptionelle Vorannahmen für das Feld getroffen werden sollen. Aus diesem Grund verstehen wir unser sozialwissenschaftliches Vorwissen als sensibilisierende Konzepte, die erst am Ende dieses Working Papers ihren Raum finden. Abschließend versuchen wir uns an einem Ausblick. In diesem Ausblick werfen wir Fragen auf, derer Beantwortung wir im Rahmen des Projektes anstreben. Wie für einen „Ausblick“ typisch dürften dabei auch Gesichtspunkte aufkommen, die es über die Projektlaufzeit (2020–2023) hinaus noch weiter aufzuarbeiten lohnt.
  • Doctoral thesis
    Open Access
    Effekte eines optimierten 18-monatigen körperlichen Trainings auf postmenopausale Risikofaktoren bei Frauen mit einer Osteopenie und Osteoporose
    (2023-03-06) Hettchen, Michael; Kemmler, Wolfgang
    Zusammenfassung Hintergrund und Ziele Das Promotionsvorhaben sollte Effekte eines optimierten 18-monatigen körperlichen Trainings auf postmenopausale Risikofaktoren bei Frauen mit einer Osteopenie und Osteoporose eruieren. Innerhalb der ACTLIFE-ER Studie wurde ein evidenzbasiertes Übungsprotokoll entwickelt und auf seine Wirksamkeit kontrolliert. Die erste Publikation erfasste Veränderungen kardiometabolischer Größen nach 16 Wochen Intervention. Die zweite Publikation mit den Abschlussdaten der Intervention beinhaltete mehrere Endpunkte mit Hauptaugenmerk auf muskuloskelettaler Parameter. Studien mit längeren Interventionsdauern zeigen meist positive Effekte auf Knochen und Muskulatur. So kommen einige Untersuchungen zu dem Ergebnis, dass sich die Anpassungsprozesse insbesondere ossärer Parameter deutlich später manifestieren als bei kardiometabolischen Parametern und erst nach längeren Studiendauern valide nachweisbar sind. Methoden und Material 54 Frauen zwischen 48 und 60 Jahren mit einer Osteopenie oder Osteoporose wurden randomisiert einer Trainingsgruppe mit hochintensivem Kraft- und Aerobic-Training und in einer aktiven Kontrollgruppe mit niederschwelligem nicht/wenig knochenanabolen Übungsprotokoll zugeordnet. Primärer Endpunkt nach 16 Wochen war ein kardiometabolisches Risikocluster für das Metabolische Syndrom, der über einen Z-Score zusammengefasst wurde. Der primäre Studienendpunkt in der zweiten Publikation war die Knochendichte (BMD) an der Lendenwirbelsäule (LS) und der Hüfte, sekundäre Endpunkte waren die fettfreie Körpermasse (LBM), der Gesamt- und abdominale Körperfettanteil, der Metabolische Syndrom Z-Score (MetS-Z), Wechseljahresbeschwerden sowie Muskelkraft und -leistung. Wir verwendeten das Intention-to-Treat (ITT) Prinzip mit multipler Imputation sowie Per-Protokoll-Analyse (PPA) und berechneten neben Signifikanzwerten auch Effektgrößen (SMD). Aufgrund von COVID-19 und dem angeordneten Lockdown musste die Studie nach 13 Monaten im März 2019 verfrüht beendet werden. Ergebnisse Nach 16 Wochen Intervention konnten zwei Teilnehmerinnen (EG: n=1; CG: n=1) nicht an der Kontrollmessung teilnehmen (EG: n=26; CG: n=26). Die Effekte auf den Endpunkt MetS Z-Score waren moderat hoch (EG: -0,36±1,36 vs. CG: 0,51±2,28; SMD: 0,47), aber grenzwertig nicht signifikant (ITT: p=.089; PPA: p=.060). Bei den sekundären Endpunkten verbesserte sich der Gesamtkörperfett-Anteil in der EG signifikant (p=.017) und verschlechterte sich in der CG nicht signifikant (p=.215). Die Unterschiede zwischen beiden Gruppen waren signifikant (p=.006, SMD: 0,62) Die fettfreie Körpermasse verbesserte sich in beiden Gruppen. Allerdings waren die Veränderungen nur in der EG signifikant (EG: p=.001), während die Zunahme der fettfreien Körpermasse in der CG vernachlässigbar war (p=.604). Die Unterschiede zwischen den beiden Gruppen waren signifikant (p=.022, SMD: 0,47). Über die 13 Monate Interventionszeitraum sind in der CG und EG jeweils eine Probandin verloren gegangen. Die Ursache für den Abbruch waren Zeitmangel (EG) oder Interessenverlust (CG). Die durchschnittliche Teilnahme an den Trainingseinheiten lag bei 78 ± 12% in der EG und 75 ± 20% in der CG. Nach 13 Monaten Intervention beobachteten wir in der „finalen“ (13 Monats-) Abschlussuntersuchung signifikante Effekte für die BMD-LS (EG: 0,002±0,018 versus CG: -0,009±0,018 mg/cm2, p=.027), aber nicht für die BMD-Gesamthüfte (EG: -0,01±0,016 versus CG: -0,009±0,020 mg/cm2, p=.129). Die LBM verbesserte sich signifikant in der EG und nahm in der CG ab (0,39±1,08 vs -0,37±1,34 kg, p=.026). Das gesamte und abdominale Körperfett verbesserte sich signifikant in der EG und blieb in der CG konstant (-1,44±1,49 vs -0,02±1,55 kg, p=.002 und -1,50±2,33 vs 0,08±2,07 kg, p=.011). Signifikante Effekte zu Gunsten der EG wurden auch für Wechseljahresbeschwerden (CG: -0,01±0,54 vs EG: -0,32±0,51, p=.029), Hüft-/Beinstreckkraft (CG: 46±187 vs EG: 607±285 N, p<.001) und Kraft (CG: 0,55±1,82 vs EG: 4,10±2,41 cm, p<.001) festgestellt. Die Veränderungen des MetS-Z unterschieden sich jedoch nicht signifikant (CG: 0,77±2,07 vs EG: 0,08±1,29, p=.149) zwischen EG und CG. Schlussfolgerung Das vorliegende multimodale Übungsprotokoll zeigte nach 16 Wochen Intervention weder signifikante Effekte auf den MetS Z-Score noch auf dessen zugrundeliegenden kardiometabolischen Größen. Inwieweit dieses Ergebnis einschlägig für dieses Frauenkollektiv ist oder auf die zu Studienbeginn lediglich moderat hohe Belastungsintensität bei vergleichsweise kurzer Interventionsdauer zurückgeführt werden kann, ist noch zu evaluieren. Im Gegensatz dazu zeigen die Abschlussdaten, dass ein adäquates Übungsprogramm Risikofaktoren und Beschwerden die in engem Zusammenhang mit den Klimakterium gesehen werden, überwiegend positiv beeinflussen kann. Inwieweit die Lockdown-bedingte Verkürzung des Übungsprogrammes von 18 Monate auf 13 Monaten eine Verwässerung unserer Ergebnisse verursachte, ist schwer zu beurteilen. Es lässt sich allerdings vermuten, dass die volle Wirkung des Trainingsprotokolls nicht zur Geltung kam, da initial eine verhältnismäßig lange Konditionierungsphase mit möglicherwiese unterschwelligen Reizen erfolgte und zum anderen knochenanabole Auswirkungen eher nach länger andauernder Intervention und somit in dem letzten Drittel der Intervention berichtet werden.
  • Article
    Open Access
    Characterization of Fluorescence Tracers for Thermometry and Film Thickness Measurements in Liquid Coolants Relevant for Thermal Management of Electric and Electronic Components
    (MDPI, 2022-12-13) Koegl, Matthias; Delwig, Moritz; Zigan, Lars
    This study investigated a novel two-color LIF (laser-induced fluorescence) technique for thermometry in coolants relevant for electric components. In principle, this diagnostic enables thermometry in liquid flows but also a simultaneous determination of film thickness and film temperature, which is relevant, e.g., for jet impingement cooled electric components. Temperature measurements are based on a temperature-sensitive intensity ratio of special tracers realized by suitable band pass filters within the respective emission spectra. For this purpose, the heat transfer fluids Fragoltherm F12, Marlotherm LH, and a water–glycol mixture WG20 (80 vol.% water, 20 vol.% glycol) and its individual components were doped with suitable tracers. The tracer Eosin-Y was utilized for polar coolants (water, WG20, and glycol) and Nile red was utilized for non-polar solvents (Fragoltherm F12 and Marlotherm LH). The spectral LIF intensities were recorded for a wide range of temperatures (253–393 K), which are relevant for cooling of electric motors, batteries, and power electronics. Furthermore, absorption spectra were analyzed as well. The temperature-dependent fluorescence measurements revealed different behavior for the polar and non-polar solvents. A temperature increase in the polar solvents (water, WG20, glycol) led to a spectral shift of the emission peaks of Eosin-Y towards longer wavelengths (red-shifted), while the peaks of Nile red in the non-polar solvents (Fragoltherm F12 and Marlotherm LH) showed an opposite behavior and were blue-shifted. The highest average temperature sensitivity was achieved for Marlotherm LH (4.22%/K), followed by glycol (1.99%/K), WG20 (1.80%/K), water (1.62%/K), and Fragoltherm F12 (1.12%/K). These sensitivities are similar to or even much higher than the literature data of other LIF tracers, which were, however, not determined in those coolants. Consequently, the two novel proposed dyes for the studied heat transfer liquids enable a reliable temperature determination.
  • Article
    Open Access
    Dextran and Its Derivatives: Biopolymer Additives for the Modulation of Vaterite CaCO3 Crystal Morphology and Adhesion to Cells
    (2022-11-25) Campbell, Jack; Ferreira, Ana M.; Bowker, Laura; Hunt, John; Volodkin, Dmitry; Vikulina, Anna
    Abstract Nowadays, a great demand for the development of novel drug delivery systems with high potential for bench‐to‐market transition attracts scientific attention toward materials that are already approved for biomedical use. Here, controlled fabrication of hybrid organic inorganic mesoporous crystals is realized in physiologically relevant conditions by co‐synthesis of vaterite CaCO3 in the presence of dextran (DEX) or its functional derivatives. The effects of DEX molecular weight and chemical structure on morphology, porosity, and stability of the hybrids are investigated. Molecular weight of DEX does not affect the crystal growth but leads to the partial blocking of crystal pores. Co‐synthesis of DEX functionalized with either carboxymethyl (CM) or diethylaminoethyl (DEAE) groups drastically increased crystal porosity without influencing crystal size. pH‐dependent vaterite‐to‐calcite recrystallization is significantly suppressed by inclusion of carboxymethyl‐dextran (CM‐DEX), making vaterite crystals stable in acidic medium, whereas the incorporation of diethylaminoethyl‐dextran (DEAE‐DEX) has no effect. The hybrids prepared with charged DEX derivatives possess stronger adhesion to normal human dermal fibroblasts: three times higher crystal adherence compared to pristine crystals. These results provide fundamental physical–chemical insights into the crystallization of DEX/vaterite hybrids and are discussed in view of the potential of these functional delivery carriers for biomedical and other applications.
  • Article
    Open Access
    Immobilization of Antioxidant Enzyme Catalase on Porous Hybrid Microparticles of Vaterite with Mucin
    (2022-11-24) Balabushevich, Nadezhda G.; Kovalenko, Ekaterina A.; Maltseva, Liliya N.; Filatova, Lyubov Yu; Moysenovich, Anastasia M.; Mikhalchik, Elena V.; Volodkin, Dmitry; Vikulina, Anna S.
    Catalase is one of the crucial antioxidant enzymes with diverse applications in textile, food industries, wastewater treatment, cosmetics, and pharmaceutics, which, however, is highly sensitive to environmental challenges. Resisting the loss of activity and prolongation of formulation storage can be achieved via the catalase entrapment into insoluble carriers. Affordable and degradable vaterite is proposed as amicable material for catalase immobilization. To improve the carrier properties of the vaterite, it was co‐precipitated with mucin from the pig's stomach producing ca 5 μm hybrid mucin/vaterite microparticles. Catalase is impregnated into the crystals by means of adsorption without chemical modifications. The presence of mucin matrix partially hinders catalase penetration into the crystals and reduces the adsorption capacity (for 0.1 mg mL−1 catalase, ca 2.3 vs ca 1.5 mg g−1 for pristine and hybrid microparticles, respectively) but significantly promotes the protection of antioxidant activity upon storage and under the action of temperature, organic solvent (acetonitrile), and proteolytic enzyme (trypsin). Hybrid microcrystals are pH‐sensitive and better retain the enzyme at pH 3–5 due to catalase‐mucin complexation. Immobilized catalase can be used for 5–6 consecutive cycles until it loses catalytic activity. Altogether, these findings indicate promises of hybrid mucin/vaterite microparticles for immobilization of antioxidant enzymes.
  • Doctoral thesis
    Open Access
    Quantum Optics with Molecules
    (2022-09-12) Reitz, Michael; Genes, Claudiu
    Molecules constitute compact hybrid quantum optical systems that can efficiently interface mechanical degrees of freedom with optical or infrared transitions. However, the coupling of molecules to the environment typically limits their coherence times which hampers their wider use in quantum optical applications. The aim of this thesis is to understand the properties of light-coupled molecules interacting with their environment and with each other and to investigate platforms where molecular degrees of freedom can be harnessed and collective effects can be observed. To this end, for the description of molecules interacting with light, we develop an open system approach based on quantum Langevin equations. The method considers the time evolution of a polaron operator, i.e., a vibrationally-dressed electronic dipole operator and can account for all coherent and incoherent interactions. In a first step, we apply the method to Floquet engineering of infraredactive molecules and show how one can make use of strong driving of molecular vibrations to control the amplitude and coherence of vibronic sidebands. In a next step, we investigate molecules encased in crystalline host environments and coupled to optical cavities and illustrate how the coupling to the phonons of the host matrix imprints itself onto the molecular absorption and the transmission spectrum of the cavity. We also discuss the vibrationally-induced cross-talk between upper and lower polaritonic states and derive rate equations for the population transfer. We then move on to regularly spaced ensembles of dipole-dipole coupled molecules, especially in ring configurations, and discuss how the vibronic coupling affects the dispersion relation and cooperative radiative properties of the ring. In particular, by moving to a collective basis, we show molecular vibrations can be used to address collective subradiant states of the ensemble. Finally, for mesoscopic disordered ensembles of molecules strongly coupled to optical cavites, we quantitatively describe the loss mechanism from polaritonic states into the dark state manifold, providing an analytical scaling of the vacuum Rabi splitting on frequency disorder.
  • Article
    Open Access
    Porous Alginate Scaffolds Designed by Calcium Carbonate Leaching Technique
    (Wiley-VCH GmbH, 2022-06-15) Wulf, Alena; Mendgaziev, Rais I.; Fakhrullin, Rawil; Vinokurov, Vladimir; Volodkin, Dmitry; Vikulina, Anna S.
    Abstract One of the main challenges in modern tissue engineering is to design biocompatible scaffolds with finely tuned porous architecture and capacity to load bioactive molecules that guide the growth and differentiation of the cells during tissue reconstruction. This work proposes a strategy to design porous alginate scaffolds (PAS) with well‐tuned architecture by leaching of sacrificial vaterite CaCO3 microspheres packed in alginate. Pore size and interconnectivity depend on CaCO3 sphere dimensions and packing as well as alginate concentration. Varying of these parameters, almost hundred percent pore interconnectivity (or, by contrast, a zero pore interconnectivity) can be achieved. Junctions between interconnected pores are about 50–70% of the pore dimensions that provides molecular transport through the PASs potentially ensuring diffusion of nutrition, oxygen and metabolic products when cell seeding. An opportunity to fabricate a multifunctional scaffold is demonstrated by encapsulation of desired macromolecules into the individual pores of a scaffold (is illustrated by dextran loading). Mechanical properties of PASs are found typical for soft and hydrated structures (Young's modulus of 19 ± 15 kPa) which is appropriate for cell seeding. The three cell lines (HeLa, HEK293, and L929) are cultured on different alginate scaffolds to examine cell viability and adhesiveness.
  • Article
    Open Access
    The structure dilemma in biological and artificial neural networks
    (Springer Nature Limited, 2022-05-23) Pircher, Thomas; Pircher, Bianca; Schlücker, Eberhard; Feigenspan, Andreas
    Brain research up to date has revealed that structure and function are highly related. Thus, for example, studies have repeatedly shown that the brains of patients suffering from schizophrenia or other diseases have a different connectome compared to healthy people. Apart from stochastic processes, however, an inherent logic describing how neurons connect to each other has not yet been identified. We revisited this structural dilemma by comparing and analyzing artificial and biological-based neural networks. Namely, we used feed-forward and recurrent artificial neural networks as well as networks based on the structure of the micro-connectome of C. elegans and of the human macro-connectome. We trained these diverse networks, which markedly differ in their architecture, initialization and pruning technique, and we found remarkable parallels between biological-based and artificial neural networks, as we were additionally able to show that the dilemma is also present in artificial neural networks. Our findings show that structure contains all the information, but that this structure is not exclusive. Indeed, the same structure was able to solve completely different problems with only minimal adjustments. We particularly put interest on the influence of weights and the neuron offset value, as they show a different adaption behaviour. Our findings open up new questions in the fields of artificial and biological information processing research.
  • Article
    Open Access
    Predictors of the one-year-change in depressiveness in informal caregivers of community-dwelling people with dementia
    (Springer Nature Limited, 2021-12-17) Kürten, Lara; Dietzel, Nikolas; Kolominsky-Rabas, Peter L.; Graessel, Elmar
    Background The care of people with dementia is usually carried out by their family members, which can cause objective und subjective burden and raise their risk of depressiveness. Thus, the aim of this study is to identify predictors of the change in depressiveness of informal caregivers over 1 year in order to be able to derive hypotheses for interventions that promise success. Methods The Bavarian Dementia Survey (BayDem) is a multi-center, longitudinal study conducted at three different sites in Bavaria, Germany. Participants were people with dementia and their informal caregivers. Data was collected at baseline and after 12 months by standardized face-to-face interviews in cooperation with local players. The informal caregivers’ depressiveness was assessed with the WHO-5. Data was also collected on the people with dementia’s cognition (MMSE), behavioral symptoms (NPI) and comorbidities (Charlson Comorbidity Index) as well as caregivers’ social inclusion (LSNS), time spent on care and care contribution (RUD). For statistical analysis, a multiple regression model was used. Results The data of 166 people with dementia and their informal caregivers was analyzed. Of the latter, 46% were categorized as “likely depressed”. The change in depressiveness over a year was significantly predicted by baseline depressiveness as well as an increase in the time informal caregivers spent supervising the person with dementia. Conclusions Informal caregivers of people with dementia are at high risk of depression. The time spent supervising the person with dementia has a significant impact on increasing depressiveness. This highlights the importance of support services to provide the informal caregiver with relief and possibly reduce depressiveness.
  • Doctoral thesis
    Open Access
    Development and Investigation of a Printed Multi-Ion-Selective Sensor System Towards Healthcare Applications
    (2021-06-07) Zörner, Alicia; Virtanen, Sannakaisa
    Wearable devices offer an important enrichment to the healthcare and fitness sector as they allow for continuous monitoring of body parameters. In particular, the application of wearables in the field of sweat analysis becomes of high interest due to its non-invasive character, which minimizes discomfort and is easily accessible. Within this work, the technical base for a screen-printed multi-ion-selective sensor system for healthcare and fitness applications is presented. This sensor system combines for the first time the advantages of printing technology and the simultaneous measurement of primary and interfering ions. Printing technology enables flexibility, low-cost fabrication, miniaturization, and portability. Moreover, a simultaneous measurement of primary and interfering ions facilitates the exclusion of the impact of the interfering potentials reducing an overestimation during the determination of the primary ion concentration. The electrodes are developed with focusing on an application of sweat analysis, in detail the detection of physical stress. However, due to the generic design of the sensor system, it can be adapted to a wide range of applications, where concentrations of ions in fluids are of interest, e.g. in the environmental, food, as well as industrial sector. With a focus on the detection of physical stress, sport performance tests are carried out and compared to conventional measurements and published results. The results of the performance tests reveal the importance of sweat-rate measurements and motivate the simultaneous measurement of multiple ions to correct the impact of interfering ions on the potential measurement. Correspondingly, for the determination of ammonium, sodium, potassium, and chloride ions in sweat, the respective all-solid-state ion-selective electrodes are developed in this work according to the requirements for the intended sweat analysis. Evaluating the performance of each single-ion sensor reveals response times of only a few seconds, detection limits of less than 10^(-4.5) M, and sensitivities close to the ideal Nernstian slope. Besides the four developed all-solid-state ion-selective electrodes, the multi-ion-selective sensor system consists of a single joint all-solid-state reference electrode. For a proper sensor performance, an insensitive reference electrode with a stable reference potential is crucial. Within this work, the chloride insensitivity of the reference electrode is improved successfully by reducing the membrane porosity and the leaching of sodium chloride from the membrane. This results in an excellent potential stability of the all-solid-state reference electrode with a standard deviation of about ± 10mV regardless of the measured solution and over a wide range of concentrations corresponding to the typical ion concentration ranges in sweat (10^-5 M to 10^-1 M). The improvement of the all-solid-state reference electrode and the fully functional all-solid-state ion-selective electrodes facilitate the development of the multi-ion-selective sensor system. Additionally, for the first time, a novel short-circuiting method is proposed and investigated for the developed sensor system. Only by this method, it is possible to calibrate each ion-selective electrode independently without influencing the other ion-selective electrodes. Hence, this treatment is essential to prevent any influence of the calibration sequence. Moreover, this short-circuiting method enhances the sensor-to-sensor reproducibility of the standard potential of each electrode and their mid-term repeatability. For the investigation of the short-circuiting treatment of the proposed sensor system, a theoretical model is developed describing the processes during short circuiting within the solid electrode contacts made of printed carbon. Based on the investigations and developments mentioned above, the selectivities of the sensor system are analyzed using a new data pre-processing and curve-fitting algorithm. Furthermore, a visualization model is generated to evaluate the change in the detectable concentration range due to the interdependence of the primary and interfering ions. This model facilitates the determination of the required selectivity for an application with assumed concentration ranges. Finally, the benefit of the proposed multi-ion-selective sensor system is demonstrated by experiments. This sensor system successfully simultaneously determines the concentration of all four primary ions, ammonium,sodium, potassium, and chloride. Moreover, it effectively proves the benefit of the co-determination of the concentration of the interfering ions to exclude their impact on the measurement of the primary ions, which reduces an overestimation of the primary ion concentration. This successfully validates the usefulness of the developed sensor device for the simultaneous and continuous concentration measurement of real sweat samples and other potential fluids consisting of a mixture of different ions. In conclusion, this work presents the development and investigation of a printed multi-ion-selective sensor system. It was demonstrated how the interdependency of primary and interfering ions in mixed solutions can be overcome. The developed concept was validated by experiments. Essential characteristics, such as possible ion concentrations in sweat, for the described application of a sweat-based analysis for the determination of physical stress were considered. Above all, due to the generic design of the sensor system, its benefits are available not only for healthcare and fitness applications but also for environmental and industrial applications. Therefore, this work provides an essential contribution to the current research and development field of printed sensors.
  • Doctoral thesis
    Open Access
    Characterization of odor-active compounds in post-consumer polyolefins
    (2021-03-08) Strangl, Miriam; Büttner, Andrea
    Various political measures as well as social and economic rethinking in the use of natural resources call for the establishment of circular economy concepts for post-consumer plastics. The aim of these sustainability strategies is, in particular, to increase the content of recycled polyolefins in consumer goods. However, the unwanted odor of the secondary raw material constitutes a major impediment to its reuse in high-value applications and thus adversely affects its competitiveness compared to virgin plastics. In view of the urgent need for targeted odor minimization and avoidance strategies, knowledge of the underlying odor-active constituents is required. Therefore, the main objective of this thesis was to characterize the odors of post-consumer polyolefin wastes and recyclates by a combinatory chemo-analytical approach based on human-sensory evaluations and multi-dimensional gas chromatographic and mass spectrometric techniques. To gain detailed insights into possible formation pathways and odor sources, post-consumer polyolefins of different polymer types and applications were investigated. In addition, various recycling process stages were systematically evaluated for their odor reduction potential. Odor extract dilution analyses of the solvent extracts obtained from the sample materials revealed that the most potent odorants in recycled high-density polyethylene (HDPE) from the packaging sector are flowery- and fruity-smelling fragrances. These odor-active compounds typically derive from migration processes of constituents from washing or cleaning agents which are commonly packed in HDPE. On the other hand, several known metabolites of microorganisms with cheesy, sulphurous, fecal or moldy smells were detected among the most intense perceived odorants in recycled low-density polyethylene (LDPE). As LDPE is frequently used in food packaging, the decomposition of organic residues is likely to be responsible for their presence. While the odor composition of recycled polypropylene (PP) packaging showed great similarities to the one of recycled HDPE packaging, some application-specific odorants were elucidated in recycled PP from the automotive industry. These include an array of benzene and phenolic structured compounds, which may be attributed to the degradation of additives or copolymers commonly applied in this sector. In addition, odor-active compounds were identified which indicate the decomposition of the polyolefins itself. This particularly applies to several carbonyl compounds that were reported in all sample materials regardless of polymer and application type. v It was further demonstrated that a specifically developed post-hoc thermal decontamination leads to an odor minimization of recycled HDPE pellets. However, the limited profitability and sustainability of this deodorization process highlights the need for odor reduction in other recycling stages. Accordingly, the waste collection strategy and some defined sorting and washing procedures were identified as key process steps affecting the odor properties of post-consumer polyolefins.
  • Doctoral thesis
    Open Access
    Hydrotreatment von Öl aus der thermo-katalytischen Reformierung von biogenen Reststoffen
    (2021-01-18) Schmitt, Nina; Hornung, Andreas
    Since the European Union has been drawing up guidelines for reducing CO2 and adding biogenic pendants to fossil fuels, new approaches for reaching these climate targets need to be developed. The Thermo-Catalytic Reforming (TCR) process offers the opportunity to generate renewable fuels and chemicals. Therefore, biological residues are thermo-chemically converted into bio-oil, hydrogen rich gases, and coal. Due to included sulfur, nitrogen, and oxygen, catalytic hydrotreatment is the chosen process to upgrade the bio-oil and produce renewable fuels. Process parameters and various catalysts like Ru/C and nickel, molybdenum, cobalt, and tungsten on Al2O3, H-ZSM-5, activated carbon and TCR-coal as support materials are tested. The highest heteroatom conversion rate is determined with Ru/C catalyst. However, the high activity also results in high mass loss. The combination of cobalt or nickel and molybdenum on alumina in sulfured form show similar conversion results, but lower mass loss than the Ru/C catalyst. The support material itself does not reveal any activity. Except for TCR-coal, which removes 1/3 of the heteroatoms. Vice versa, the impregnation with metal salts leads to a significant increase of the heteroatom turnover except for the TCR-catalyst. The utilization of the TCR-gas instead of hydrogen leads to 40 % heteroatom turnover and a minimal mass loss. In conclusion, the economic analysis results in the application of TCR-gas for a first hydrotreatment step, as it is the most profitable approach.
  • Article
    Open Access
    ‘This is (not) Entertainment!’: media constructions of political scandal discourses in the 2016 US presidential election
    (SAGE Publications, 2020-07-09) Vorberg, Laura; Zeitler, Anna
    The phenomenon of scandal(ization) has become omnipresent in contemporary political media discourses – at the latest since the 2016 US presidential election. Our article addresses causes and effects of this recent prevalence of scandal narratives. By connecting concepts from social systems theory and media theory, we consider crucial practices and processes of scandal construction in the 2016 US presidential election, focusing on the much-noticed emailgate and trumptape scandals. Both examples serve to illustrate how the emergence of partial public spheres in social media may lead to a fight for sovereignty over scandal discourse, political attitudes, and the negotiation of social norms, morals, and values.