0000000000297121
AUTHOR
U. Höhne
Dynamics of Structure Formation in Model Membranes and in Adsorbed Layers
Unconventional and new ways to prepare ultrathin films with defined lateral distribution of components are described. These methods make use of two different principles: (1) Films with two coexisting phases are prepared and an active component preferentially partitions into one of the phases. Domain formation and interdomain distance largely depend on the kinetics of nucleation and growth and can thus be controlled. This is demonstrated by fluorescence microscopy with monolayers on water surfaces as well as with monolayers formed by co-adsorption of a fatty acid and a dye on silicon. (2) The support is structured by conventional techniques, in our case by photolithography. Adsorption or des…
The influence of counterions and hydrophobic moieties on the thermostability of Langmuir-Blodgett multilayers
Abstract Langmuir-Blodgett (LB) multilayers with various counterions and different organic moieties (one- and two-chain fatty acids, polymeric acid) are prepared to investigate on line temperature-dependent structural changes and desorption by small-angle X-ray scattering (SAXS), interference-enhanced reflection and Nomarsky microscopy. On temperature increase a sequence of phase transitions can be observed. A crystalline LB film melts to a fluid phase and eventually desorbs either from droplets or from a homogeneous film. The phase sequence depends on the counterion: nickel stearate and magnesium stearate melt while the layered structure is conserved; SAXS measurements reveal a continuous,…
Low temperature plasma treatment of monomolecular Langmuir-Blodgett films
Abstract The structure of the surface layer of materials is usually quite different from the bulk. Detailed information about the surface structure is often not available. This, together with the complex nature of low temperature plasma treatment, hinders the investigations of plasma chemical processes on solid surfaces. Monomolecular Langmuir-Blodgett (LB) structures offer a unique opportunity to prepare model surfaces with known thickness and molecular architecture. From the data obtained, the depth of the Ar plasma influence on solid organic surfaces was estimated to be about 400–1000 A depending on the nature of the surface layer. An oxygen plasma penetrates deeper with a penetration li…
Radiologische Verlaufskontrolle der Thoraxorgane beim Intensivpflegepatienten
Correlation between chest radiographs and clinical indicators was studied in 212 patients in intensive care. 1. There was good correlation between raised pulmonary artery pressure and radiological signs of left heart insufficiency, but not with the value of central venous pressure. 2. Fever and leukocytosis nearly always precede radiological evidence of pneumonia; their persistence does not necessarily indicate persistent pneumonia. 3. Pneumonias, effusions, atelectases and emboli are more common on the right. 4. More than 70% of central venous catheters were incorrectly placed; most commonly, the catheter was placed too low. Life-threatening complications occurred in 1.3%.
Thermodesorption of LB-multilayers of metal stearates
Thermodesorption of stearate multilayers containing different metal ions was investigated by Interference-enhanced Reflection (IeR) and Nomarsky microscopy. Heating of samples in air leads to desorption of stearyl chains and to formation of metal oxide clusters. A new approach to build controlled structures was made by preparing a surface with neighbouring hydrophobic and hydrophilic areas. It is shown that arranging inorganic particles in a predetermined way is possible.
Perkutane Entfernung von Schrittmachersonden
The large number of pace-makers introduced transvenously has resulted in increasing the number of complications, amongst which infections and dislocations are prominent. It is usually necessary to remove the electrode, which can be attempted percutaneously by using a Dormia basket, a loop or forceps. Amongst the complications of this procedure are tears to the myocardium, with the risk of pericardial tamponade, or tears of the tricuspid valve leading to tricuspid insufficiency. Consequently, thoracic surgical intervention should be available if necessary. Four successful procedures are described.
Ultrathin metal films and inorganic clusters via thermodesorption of LB films
Langmuir-Blodgett multilayers of cadmium arachidate and ferric stearate were investigated during heating in order to derive information on processes involved in thermodesorption and on the inorganic microstructures left on the substrate after thermodesorption. We studied these processes by X-ray induced photoelectron spectroscopy (XPS), interference enhanced reflection (IeR), Nomarsky microscopy, electron microprobe analysis and in the case of Fe57-ions by conversion electron Mossbauer spectroscopy (CEMS). Two different mechanisms of desorption were observed. In the case of cadmium arachidate multilayers it is shown that before desorption the film ruptures laterally and then forms droplets.…