Effect of closed and permanent stoma on disease course, psychological well-being and working capacity in Swiss IBD cohort study patients.

Background: Little is known about the impact of ostomy formation in inflammatory bowel disease patients on course of disease, psychological well-being, quality of life and working capacity.

Methods: We analyzed patients over a follow-up of up to 16 years in the Swiss inflammatory bowel disease cohort study (SIBDCS) with prospective data collection. We compared Ulcerative colitis and Crohn's disease patients with and without ostomy as well as permanent and closed stoma formation before and after surgery, investigating disease activity, psychological wellbeing and working capacity in a case-control design.

From time-resolved atomic-scale imaging of individual donors to their cooperative dynamics.

The key elements in the steady miniaturization process of cutting-edge semiconductor devices are the understanding and controlling of charge dynamics on the atomic scale. In detail, we address the study of charging processes of individual doping atoms and, especially, the interaction of those atoms with their surroundings. We use pulsed optical excitation in combination with scanning tunneling microscopy at the n-doped gallium arsenide [GaAs(110)] surface to investigate single donor dynamics within a nanoscaled, localized space charge region.

A versatile implementation of pulsed optical excitation in scanning tunneling microscopy.

We present a combination of pulsed optical excitation and scanning tunneling microscopy with a highly flexible pulse generation method. A high frequency arbitrary wave generator drives a gigahertz electro-optical modulator, which processes a continuous-wave laser beam of a low-noise laser diode into the desired wave shape. For pump-probe excitation we generate optical pulse series in an all-electronic way.

Controlling the screening process of a nanoscaled space charge region by minority carriers.

The miniaturization of future electronic devices is intimately connected to the ability to control electric fields on the atomic scale. In a nanoscopic system defined by a limited number of charges, the combined dynamics of bound and free charges become important. Here we present a model system based on the electrostatic interaction between a metallic tip of a scanning tunnelling microscope and a GaAs(110) semiconductor surface.

Sesquiterpenes of the liverwort Scapania undulata.

The essential oil of the liverwort Scapania undulata, collected in the Harz mountains, Northern Germany, was analysed by gas chromatography (GC), GC-mass spectrometry (MS) and several new components were isolated and investigated by various NMR techniques. As new natural compounds the sesquiterpene hydrocarbons (+)-helminthogermacrene (1) [the 4Z-isomer of germacrene A (9)], (-)-cis-beta-elemene (2) as a Cope-rearrangement product of 1, (+)-beta-isolongibornene (3) and (-)-perfora-1,7-diene (4) could be identified. 1 has an identical mass spectrum and identical GC retention time on a non-polar stationary phase as germacrene A (9) but is considerably more stable than the latter.