Wissenschaftliche Integration des Kamera-Spektrographen LUCI und Galaxienhaufenumgebungen um aktive Galaxienkerne

Die vorliegende Arbeit gibt einen kleinen technischen Überblick über das Large Binocular Telescope in den USA. Der Fokus verschiebt sich dann weiter auf die Instrumente dieses Großteleskops. Es werden die wichtigsten physikalischen Eigenschaften dieser Geräte der ersten Generation kurz erläutert, bevor LUCI – ein Kamera-Multiobjekt-Spektrograph für das nahe Infrarot – genauer betrachtet wird. Nach der Vorstellung des eigentlichen Instrumentes werden mit ihm durchgeführte Ergebnisse aus Labortests und Effizienzmessungen am Nachthimmel dargelegt. Als ein wichtiges Werkzeug zum Planen von Beobachtungen mit LUCI hat sich der im Rahmen dieser Arbeit entwickelte Belichtungszeitrechner erwiesen. Er ist in der Lage, das Signal-Rausch Verhältnis oder die benötigte Belichtungszeit für alle Beobachtungsmodi von LUCI zu berechnen. Zusammen mit Aufnahmen der beiden Weitfeldkameras des Large Binocular Telescopes lieferte LUCI für diese Arbeit einen Beitrag zur Erforschung der nahen Umgebung von aktiven Galaxienkernen. Gibt es wirklich einen Unterschied zwischen radiolauten und radioleisen aktiven Galaxienkernen in Bezug auf die Einbettung in einen Galaxienhaufen, oder waren die Messungen zuvor nur ein Auswahleffekt? Um dieser Frage nachzugehen, wurden die Umgebungen von 23 fast ausschließlich radioleisen aktiven Galaxienkernen untersucht. Für eine Untergruppe erfolgte eine Untersuchung über einen Zusammenhang zwischen der Masse des schwarzen Loches und der Anzahl der Haufengalaxien

Reactivity of electropositive f-block metal N-heterocyclic carbene complexes

The combination of Lewis acidic f-block metals and a labile nucleophilic carbene can be an excellent means to activate small molecules such as silanes, CO2 and other traditionally inert substrates. Furthermore, bidentate alkoxy-NHC ligands have shown promise in the support of unusual high oxidation state organometallic complexes, including examples of CeIV, PdIV and UVI. In this thesis the synthesis and reactivity of a series of f-block metal NHC complexes is described. Chapter One introduces N-heterocyclic carbenes and their f-block metal complexes, in particular of cerium, praseodymium and uranium. Furthermore, it will give an overview of small molecule activation by NHCs, lanthanides and specifically [Ce(LAr)N"], (L = OC(CH3)2CH2(CNCH2CH2NMes) the magnetic properties and use of lanthanides e.g. as single molecule magnets and oxo-functionalisation of the uranyl moiety. Chapter Two describes the addition-elimination reaction chemistry of CeIII and UIV NHC complexes in which polar reagents add in a heterocyclic fashion across the MNHC bond. It also describes the synthesis of the lithium salt of the alkoxycarbene proligand [LiLAr]4 and its reactivity towards f-element halide and aryloxide salts. A series of reactions to target the formation of metal-metal bonds is described. Chapter Three focuses on the synthesis of novel cerium and praseodymium complexes [Pr(LAr)N"2], [Pr(LAr)2N"], [Pr(OAr2,6-tBu)3] and [Ce(OAr2,6-tBu)3] and their reactivity towards oxidants. A series of alkoxide bridged lanthanide dimers [(Cl)Ce(μ- LAr)2Ce(Cl)2], [N"(LAr)Ce(μ-OAr2,6-tBu)OAr2,6- 2Ce(LAr)N"] and [N"(Cl)Pr(μ LAr)2Pr(Cl)N"] have been made and characterised including by SQUID variable temperature magnetometry. Chapter Four evaluates the synthesis and reactivity of uranyl complexes [UO2(LAr)2], [UO2N"2(py)2] and [UO2(OAr2,6-tBu)2(py)2], specifically their reactivity towards haloboranes in different solvents. Additionally, the oxo-functionalisation of uranyl compounds with haloboranes is discussed. Chapter Five draws conclusions and provides a summary of the work presented. Chapter Six comprises the experimental details and analytical data

Interaction of human heat shock protein 70 with tumor-associated peptides

Molecular chaperones of the heat shock protein 70 (Hsp70) family play a crucial role in the presentation of exogenous antigenic peptides by antigen-presenting cells (APCs). In a combined biochemical and immunological approach, we characterize the biochemical interaction of tumor-associated peptides with human Hsp70 and show that the strength of this interaction determines the efficacy of immunological cross-presentation of the antigenic sequences by APCs. A fluorescein-labeled cytosolic mammalian Hsc70 binding peptide is shown to interact with human Hsp70 molecules with high affinity (K(d)=0.58 mu M at 25 degrees C). Competition experiments demonstrate weaker binding by Hsp70 of antigenic peptides derived from the tumor-associated proteins tyrosinase (K(d)=32 mu M) and melanoma antigen recognized by T cells (MART-1) (K(d)=2.4 mu M). Adding a peptide sequence (pep70) with high Hsp70 binding affinity (K(d)=0.04 mu M) to the tumor-associated peptides enables them to strongly interact with Hsp70. Presentation of tumor-associated peptides by B cells resulting in T cell activation in vitro is enhanced by Hsp70 when the tumor-associated peptides contain the Hsp70 binding sequence. This observation has relevance for vaccine design, as augmented transfer of tumor-associated antigens to APCs is closely linked to the vaccine's efficacy of T cell stimulation

Hemodynamic and Monitoring Considerations in a Total Artificial Heart Recipient

Presented as a poster at Indiana Society of Anesthesiologists Annual Meeting 2021

Expamers: a new technology to control T cell activation

T cell activation is a cornerstone in manufacturing of T cell-based therapies, and precise control over T cell activation is important in the development of the next generation T-cell based therapeutics. This need cannot be fulfilled by currently available methods for T cell stimulation, in particular not in a time dependent manner. Here, we describe a modular activation reagent called Expamers, which addresses these limitations. Expamers are versatile stimuli that are intended for research and clinical use. They are readily soluble and can be rapidly bound and removed from the cell surface, allowing nearly instantaneous initiation and termination of activation signal, respectively. Hence, Expamers enable precise regulation of T cell stimulation duration and provide promise of control over T cell profiles in future products. Expamers can be easily adopted to different T cell production formats and have the potential to increase efficacy of T cell immunotherapeutics

Black Hole Mass Estimates Based on CIV are Consistent with Those Based on the Balmer Lines

Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on the CIV, Halpha and Hbeta broad emission lines. Our sample is based upon that of Greene, Peng & Ludwig, expanded with new near-IR spectroscopic observations, consistently analyzed high S/N optical spectra, and consistent continuum luminosity estimates at 5100A. We find that BH mass estimates based on the FWHM of CIV show a systematic offset with respect to those obtained from the line dispersion, sigma_l, of the same emission line, but not with those obtained from the FWHM of Halpha and Hbeta. The magnitude of the offset depends on the treatment of the HeII and FeII emission blended with CIV, but there is little scatter for any fixed measurement prescription. While we otherwise find no systematic offsets between CIV and Balmer line mass estimates, we do find that the residuals between them are strongly correlated with the ratio of the UV and optical continuum luminosities. Removing this dependency reduces the scatter between the UV- and optical-based BH mass estimates by a factor of approximately 2, from roughly 0.35 to 0.18 dex. The dispersion is smallest when comparing the CIV sigma_l mass estimate, after removing the offset from the FWHM estimates, and either Balmer line mass estimate. The correlation with the continuum slope is likely due to a combination of reddening, host contamination and object-dependent SED shapes. When we add additional heterogeneous measurements from the literature, the results are unchanged.Comment: Accepted for publication in The Astrophysical Journal. 37 text pages + 8 tables + 23 figures. Updated with comments by the referee and with a expanded discussion on literature data including new observation