Probing Solvent Effects In Aromatic Interactions Using Molecular Balances

Aromatic interactions play a key role in many important processes, such as the formation and stability of biological and synthetic assemblies, facilitation of molecular recognition processes, and catalysis of chemical reactions. One of the key factors determining the strength of aromatic interaction is the solvent environment. Therefore, developing model systems that can accurately measure the influence or effects of solvents on non-polar interaction strengths is a task of great importance. Over the years, we have been approaching this challenge via designing and analyzing molecular devices that can quantitatively report aromatic interaction energies under various solvent and chemical environments. With this methodology, we have: 1) studied the ability of protic solvents to dissolve aromatic surfaces via solvent OH-π interactions, 2) determined the influence of anions on solvophobic interactions in organic solvent, 3) measured the strength of individual Ag-π interaction and its sensitivity to changes in solvent environment and interaction geometry, and 4) studied the CH-π interactions of fluorinated aromatic surfaces. The knowledge and experience gained in the studies of these small model systems contribute to the development of more effective predictive solvent models but also help guide further experimental research on aromatic interactions

Quantification of light-promoted conidiation of Neurospora crassa bd, al-2 using a video system and densitometry software

Quantification of conidia from Neurospora crassa mycelia grown on solid media by turbidity assay or weighing of conidia is difficult. We demonstrate here measurement of the intensity of light-promoted conidiation bands of Neurospora crassa strain albino-band (al-2, bd) using a video image system and densitometry software

Helga Ninnemann, 1938-2003

Helga Ninnemann, 1938-200

Arbeitssitzungen der Gruppe Datenerfassung in Garching und Greifswald

Verteilte Videokonferenz an 6 Standorten (Berlin, Dresden, Duisburg, Garching, Jena, Würzburg) Videokonferenztechnologien und ihre Anwendungsszenarien "Weit entfernt und doch so nah" Viktas 200

Flexible delivery of Er:YAG radiation at 2.94 µm with negative curvature silica glass fibers:a new solution for minimally invasive surgical procedures

We present the delivery of high energy microsecond pulses through a hollow-core negative-curvature fiber at 2.94 µm. The energy densities delivered far exceed those required for biological tissue manipulation and are of the order of 2300 J/cm(2). Tissue ablation was demonstrated on hard and soft tissue in dry and aqueous conditions with no detrimental effects to the fiber or catastrophic damage to the end facets. The energy is guided in a well confined single mode allowing for a small and controllable focused spot delivered flexibly to the point of operation. Hence, a mechanically and chemically robust alternative to the existing Er:YAG delivery systems is proposed which paves the way for new routes for minimally invasive surgical laser procedures

Vergleichende Untersuchung der endokrinen Ophthalmopathie mittels Ultrasonographie, Computertomographie und Fischbioassay

Bei 35 Patienten mit endokriner Ophthalmopathie (eO) wurde zu den Parametern der Schilddrüsenfunktion (T3, T4, TBI, TRH-Test), dem Szintigramm und der Bestimmung der Schilddrüsenantikörper ergänzend die Ultrasonographie (A-scan) und Computertomographie (CT) der Orbita, sowie der Nachweis exophthalmogener Serumaktivität im Fischbioassay durchgeführt. Charakteristische Sonogramme für eine eO fanden sich in 26 Fällen. Die CT ergab bei 24 von 33 Patienten die Verdickung der musculi recti mediales und/oder der musculi recti laterales, sowie bei 17 Patienten eine Verdichtung im Bereich der Orbitaspitze. Im retrobulbären Bindegewebe zeigte sich nach Kontrastmittelgabe keine signifikante Dichtezunahme. Mit beiden Verfahren zusammen waren nur bei 2 Patienten die Kriterien einer eO nicht erfüllt. Die exophthalmogene Serumaktivität wurde in der IgG-Fraktion im Fischbioassay nachgewiesen; die Trefferquote war mit 69% relativ hoch. Zur Diagnostik der eO kann jedoch der Fischbioassay nicht empfohlen werden