Auf Tribenzotriquinacen und Fulleren basierende supramolekulare Aggregate: Baukastenprinzip funktioneller Nano-Module

Im Rahmen der vorliegenden Arbeit wurden zwei neuartige Rezeptoren synthetisiert, die eine optimierte Passform für C60 besitzen. Die anschließenden spektroskopischen Untersuchungen mit C60 haben Aufschluss über die Zusammensetzung und die jeweilige Stärke der Wirt-Gast-Komplexe in Lösung gegeben. Diese grundlegende Selbstorganisations-Strategie aufgreifend, konnte der variable Einsatz von Rezeptor-Bausteinen und funktionalisierten Fullerenen, ebenfalls mittels Komplexierungsstudien, gezeigt werden. Diese Ergebnisse geben das positive Signal, dass weitere Untersuchungen zu molekularen Ratschen und Motoren auf dieser Basis möglich und sinnvoll sind. Um elementare Erkenntnisse zur Fixierung von Tribenzotriquinacenen auf Oberflächen realisieren zu können, wurde abschließend ein am "Rückgrat" funktionalisiertes Tribenzotriquinacen synthetisiert. Dieses konnte in einer gemischten Monolage zusammen mit Hexan- bzw. Decanthiol auf Gold-(111) immobilisiert und mit einem Rastertunnelmikroskop detektiert und untersucht werden.In the present doctoral thesis two novel receptors have been synthesized that provide a structurally optimized fit for fullerene C60. The subsequent spectroscopic studies with C60 gave information about the composition and the respective strengths of the host-guest complexes in solution. By picking up this basic self-organization strategy, the variable use of receptorblock and functionalized fullerenes was demonstrated by using spectroscopic studies as well, whereby the possible feasibility of molecular ratchets and motors was confirmed. Finally, a backbone-functionalized tribenzotriquinacene was synthesized, immobilized as a mixed monolayer with hexane- or decanethiol on gold-(111) and detected and investigated with a scanning tunneling microscope to carry out basic studies on surfaces

The Effectiveness of Bilateral Cochlear Implants for Severe-to-Profound Deafness in Adults:A Systematic Review

<p>Objective: Assessment of the clinical effectiveness of bilateral cochlear implantation compared with unilateral cochlear implantation or bimodal stimulation, in adults with severe-to-profound hearing loss. In 2007, the National Institute for Health and Clinical Excellence (NICE) in the U. K. conducted a systematic review on cochlear implantation. This study forms an update of the adult part of the NICE review.</p><p>Data Sources: The electronic databases MEDLINE and Embase were searched for English language studies published between October 2006 and March 2011.</p><p>Study Selection: Studies were included that compared bilateral cochlear implantation with unilateral cochlear implantation and/or with bimodal stimulation, in adults with severe-to-profound sensorineural hearing loss. Speech perception in quiet and in noise, sound localization and lateralization, speech production, health-related quality of life, and functional outcomes were analyzed.</p><p>Data Extraction: Data extraction forms were used to describe study characteristics and the level of evidence.</p><p>Data Synthesis: The effect size was calculated to compare different outcome measures.</p><p>Conclusion: Pooling of data was not possible because of the heterogeneity of the studies. As in the NICE review, the level of evidence of the included studies was low, although some of the additional studies showed less risk of bias. All studies showed a significant bilateral benefit in localization over unilateral cochlear implantation. Bilateral cochlear implants were beneficial for speech perception in noise under certain conditions and several self-reported measures. Most speech perception in quiet outcomes did not show a bilateral benefit. The current review provides additional evidence in favor of bilateral cochlear implantation, even in complex listening situations.</p>