Carbon monoxide and carbon dioxide insertion chemistry of f-block <em>N</em>-heterocyclic carbene complexes

The reactions of f-block silylamido N-heterocyclic carbene (NHC) complexes ([M(L)(N{SiMe3}2)2], M = Y, Ce, and U, L = bidentate alkoxy-tethered NHC ligand) with CO and CO2 have been studied and compared to each other, to those of selected [M(L)2 (N{SiMe3}2)] complexes, and to those of [M(N{SiMe3}2)3] to identify the effect of the labile NHC group on the small molecule activation chemistry. The small molecules COS and N2CPh2 have also been studied.</p

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

Auswirkungen von Nutzung und Nicht-Nutzung einer vom Hausarzt vermittelten zugehenden Form der Angehörigenberatung bei zu Hause versorgten Patienten mit leichter und mittelschwerer Demenz

Backround and aims: In Germany more than two-thirds of patients with diagnosed Dementia are cared for at home by family members. Due to the progress of this disease family members have to take over all daily routine for the absolute helpless patient after a certain point. This extraordinary burden results for many in physical and psychological exhaustion. Aim of this study has been to determine the impact of a special form of counselling - the Counsellors Contact Caregivers (CCC) - mediated by general practitioners. Results and Observations: Bearing in mind that usage of counselling was on a voluntary basis only and not an inclusion criterion of this study, 45% of caregivers in group C made use of an extensive counselling during the 2-year period - defined as more than one personal contact of caregiver and counsellor. In contrast, analyzing group B und C together for one year, only 27% made use of extensive counselling. Prospectively observed the usage of Counsellors Contact Caregivers did not result in a significant reduction of subjective burden of caregivers comparing to caregivers who did not use the counselling. But acceptance of Counsellors Contact Caregivers could be increased several-fold by recommendation of general practitioners in comparison with the situation without systematic recommendation by general practitioners. Practical Conclusions: This extensive form of counselling (Counsellors Contact Caregivers), mediated by general practitioners, is a successful approach to establishing early contacts with family members of patients with dementia living at home. To make a valid investigation whether CCC can reduce the subjective burden of caregivers, the same average burden should be present in both the intervention and control group. Furthermore an attempt should be made to form a closer relationship between caregiver and counsellor, for example by agreeing on a minimum number of personal meetings.Hintergrund und Ziele: In Deutschland werden über zwei Drittel der Demenzpatienten von Familienangehörigen zu Hause versorgt. Durch die Progredienz des Krankheitsbildes müssen die Angehörigen ab einem gewissen Zeitpunkt jegliche Alltagsfunktionen für den völlig hilflosen Erkrankten übernehmen. Diese außerordentliche Belastung führt bei vielen zu physischer und psychischer Erschöpfung. Ziel der Studie war es, die Auswirkung einer vom Hausarzt vermittelten speziellen Form der Angehörigenberatung - der zugehenden Angehörigenberatung - zu untersuchen. Ergebnisse und Beobachtungen: Unter Berücksichtigung der Tatsache, dass die Inanspruchnahme der Angehörigenberatung auf freiwilliger Basis erfolgte und kein Einschlusskriterium der Studie darstellte, machten in Studienarm C in dem Zeitraum von zwei Jahren 45% der Angehörigen Gebrauch von einer intensiveren Beratung - das bedeutet mehr als ein persönlicher Kontakt zwischen Angehörigem und Berater. Hingegen wurde sie innerhalb eines Jahres in den gemeinsam betrachteten Studienarmen B und C nur von 27% angenommen. Prospektiv betrachtet, führte die zugehende Angehörigenberatung bei den Nutzern zu keiner signifikanten Reduktion der subjektiven Belastung unterstützender Angehöriger im Verlgiech zu den Nicht-Nutzern. Die Akzeptanz der zugehenden Angehörigenberatung konnte jedoch durch die Vermittlung des Hausarztes um ein Vielfaches gesteigert werden, verglichen mit der Situation ohne systematische hausärztliche Vermittlung. Praktische Schlussfolgerungen: Die vom Hausarzt vermittelte Form der zugehenden Angeörigenberautng stellt einen erfolgreichen Ansatz bezüglich der Herstellung eines frühen Kontaktes zu unterstützenden Angehörigen von zu Hause lebenden Demenzpatienten dar. Um valide untersuchen zu können, ob zugehende Angehörigenberatung die subjektive Belastung unterstützender Angehöriger reduzieren kann, sollte man innerhalb einer Folgestudie die gleiche durchschnittliche Ausgangsbelastung für die Interventions- und Kontrollgruppe vorliegen. Zudem sollte der Versuch unternommen werden, die Angehörigen enger an den Berater zu binden, zum Beispiel durch die Vereinbarung einer bestimmten Mindestanzahl persönlicher Treffen

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

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

Amplifying Indigenous Wellbeing: ‘Imi Pono Survey Development and Validation

The growth of indigenous research methodologies and calls for data sovereignty are reshaping the discourse around evidence-based policymaking. This article summarizes the development and validation of the ‘Imi Pono Hawai‘i Wellbeing Survey, which examines wellbeing from indigenous, holistic, and strengths-based perspectives. The survey is anchored to a Kanaka Maoli (Native Hawaiian) model of wellbeing created through a community-participatory process involving diverse stakeholders. Early results show Native Hawaiians to be major contributors to Hawai‘i’s wellbeing, consistently reporting higher rates than non-Hawaiians for civic engagement, family relationships, and spirituality, as well as connections to culture, ‘āina, and community. This project informs strategic planning, reporting, and advocacy efforts among research partners who are committed to assessing and improving Kanaka Maoli wellbeing

Hemodynamic and Monitoring Considerations in a Total Artificial Heart Recipient

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