Tissue factor pathway inhibitor in endothelial cells colocalizes with glycolipid microdomains/caveolae. Regulatory mechanism(s) of the anticoagulant properties of the endothelium

Tissue factor pathway inhibitor (TFPI), the main downregulator of the procoagulant activity of tissue factor.factor VIIa complex, locates in human endothelial cells (EC) in culture as well-defined clusters uniformly distributed both on the cell surface and intracellularly. We here demonstrate by immunofluorescence that TFPI colocalizes in EC with caveolin, urokinase-type plasminogen activator receptor, and glycosphingolipids. The localization of TFPI in caveolae in resting endothelium is proved by double immunogold electron microscopy for TFPI and caveolin. After ultracentrifugation of rat lung or EC homogenates through density gradients of Nycodenz, TFPI was highly enriched at densities of 1.05 to 1.08 g/mL, together with caveolin and alkaline phosphatase. By ELISA, more than half of the cellular TFPI was detected in Triton X-100-insoluble extracts of EC. TFPI incorporates [1-3H]ethanolamine and is cleaved from the cell surface by phosphatidylinositol-phospholipase C, indicating a specific glycosylphosphatidylinositol-anchorage mechanism for TFPI in the plasma membrane. Clustering of TFPI and its localization in caveolae are dependent on the presence of cholesterol in the membrane. Agonist-induced stimulation of EC caused marked changes of distribution for both TFPI and caveolin at subcellular level, with subsequent increase of the cell surface-associated inhibitory activity toward tissue factor.factor VIIa. Our findings suggest that, beside their function in transcytosis, potocytosis, cell surface proteolysis, and regulation of signal transduction, caveolae also play a direct role in the regulation of EC anticoagulant properties.     

High speed waveguide-integrated photodiodes grown by metal organic molecular beam epitaxy

Using InP/InGaAs layers grown by metal organic molecular beam epitaxy (MOMBE) on semi-insulating (SI) InP substrate the authors have fabricated waveguide-integrated pin-photodiodes working on the principle of evanescent field coupling. A 3 dB cutoff frequency of 9.6 GHz has been found in a 50 Omega system. The 100 mu m long diodes exhibit a capacitance of <0.1 pF at -5 V bias. In addition design criteria are given to improve the speed of the devices.<>     

Using fluffy layer material to study the fate of particle-bound organic pollutants in the southern Baltic Sea

This paper examines the utility of fluffy layer material for studying and monitoring the environmental levels, transport, and fate of particle-bound contaminants in coastal ecosystems. Fluffy layer material is the very young and mobile layer of particulate matter that accumulates on the sediment surface under quiescent conditions. We used this material to study the behavior of polycyclic aromatic hydrocarbons (PAHs) that are discharged by the Oder River into the Baltic Sea. With the fluffy layer material, it was possible to (i) do fingerprint analysis to trace the sources of PAHs in the river discharge, (ii) follow the modification of the PAHs from the mouth of the river to the depositional basin and identify the responsible processes, (iii) monitor the seasonal variation in the PAH input, (iv) study the influence of a major flood event on the PAH loading to the coastal ecosystem, and (v) conduct a PAH mass balance to estimate the contribution of the Oder River source to PAH accumulation in the depositional basin. The fluffy layer material integrated the particle-bound contaminant signal over a period ranging from several days to several months, depending on the sampling location. As such, fluffy layer material is a valuable addition to the matrixes commonly used for studying particle-associated chemicals: SPM and sediment, which reflect time scales of hours and years, respectively.     

Offshore wind farm wake recovery: Airborne measurements and its representation in engineering models

We present an analysis of wind measurements from a series of airborne campaigns conducted to sample the wakes from two North Sea wind farm clusters, with the aim of determining the dependence of the downstream wind speed recovery on the atmospheric stability. The consequences of the stability dependence of wake length on the expected annual energy yield of wind farms in the North Sea are assessed by an engineering model. Wakes are found to extend for significantly longer downstream distances (>50 km) in stable conditions than in neutral and unstable conditions (  15 km). The parameters of one common engineering model are modified to reproduce the observed wake decay at downstream distances  30 km. More significant effects on the energy yield are expected for wind farms separated by distances  30 km, which is generally the case in the North Sea, but additional data would be required to validate the suggested parameter modifications within the engineering model. A case study is accordingly performed to show reductions in the farm efficiency downstream of a wind farm. These results emphasize not only the importance of understanding the impact of atmospheric stability on offshore wind farms but also the need to update the representation of wakes in current industry models to properly include wake‐induced energy losses, especially in large offshore clusters.     

The dependence of offshore turbulence intensity on wind speed

Four years of 10 min mean wind data from the offshore measuring platform FINO1 (Forschung in Nord-und Ostsee 1) in the German Bight have been analyzed to obtain the dependence of turbulence intensity on the wind speed. The investigated dataset is unique in so far as no high quality long-term measurements with a height resolution of 10 m at heights between 33 and 103 m and a minimum distance to the coast of 45 km have been available so far.Wave height and therefore sea surface roughness and turbulence intensity increase with increasing wind speed. The influence of the surface roughness decreases with height. Results are compared to previous results and to the specifications given by the IEC wind turbine standards 61400-1 and 61400-3.     

A simple analytical wind park model considering atmospheric stability

The analytical top‐down wind park model by Emeis and Frandsen 1 is enhanced by consistently making both the downward momentum flux and the momentum loss at the rough surface dependent on atmospheric stability. Specifying the surface roughness underneath the turbines in a wind farm in the model gives the opportunity to investigate principal differences between onshore and offshore wind parks, because the roughness length of the sea surface is two to three orders of magnitude lower than the roughness length of land surfaces. Implications for the necessary distance between single turbines in offshore wind farms and the distance between neighbouring wind parks are computed. It turns out from the model simulations that over smooth surfaces offshore the wind speed reduction at hub height in a wind farm is larger than over rough onshore surfaces given the same density of turbines within the park. Mean wind profiles within the park are also calculated from this model. Offshore wind farms must have a larger distance between each other in order to avoid shadowing effects of the upstream farm. Copyright © 2009 John Wiley & Sons, Ltd.     

Analyse und Charakterisierung von Glucosesirup mit Hilfe der Gelchromatographie

Analysis and Characterization of Glucose Sirup by Means of Gel Chromatography. A series of glucose sirups have been investigated by gel chromatography technique with respect to their carbohydrate composition. It was possible to determine both qualitatively and quantitatively the carbohydrate components from 1 up to 15 glucose units. Several sirups which have been manufactured by acid, acid-enzyme and enzyme-enzyme hydrolysis have been analyzed. Characteristic differences occurred in dependence to the manufacturing techniques.     

A comparative study of the conformational mobility of octamethyltetrasiloxane and cyclododecane in the solid state

A crystalline mesophase state in which molecules show conformational mobility is discussed for cyclododecane and octamethyltetrasiloxane.¹³C and²⁹Si solid state NMR spectra show changes of the resonance signals which can be explained by changes of the conformation. The transition temperatures in the NMR spectra are correlated with the thermal transitions detected by DSC. Comparisons with the solution spectra give evidence that in case of octamethyltetrasiloxane, the conformational mobility is determined mainly by the molecular packing in the crystal, while packing effects are neglegibly small for cyclododecane. The data are discussed with concern to the corresponding linear chain molecules, i. e. poly(ethylene) and poly(dimethylsiloxane).Herrn Prof. Dr. H. Inagaki zu seinem 60. Geburtstag herzlich gewidmet     

Dietary sphingolipids lower plasma cholesterol and triacylglycerol and prevent liver steatosis

The prevalence of dyslipidemia and obesity resulting from excess energy intake and physical inactivity is increasing. The liver plays a pivotal role in the systemic lipid homeostasis. Effective, natural dietary interventions that lower plasma lipids and promote liver health are needed. APOE*3Leiden mice were fed a Western‐type diet, supplemented with different sphingolipids, to determine their effect on plasma lipids and liver steatosis. Hepatic lipid levels and lipid‐related gene expression were also determined. Dietary sphingolipids dose‐dependently lowered both plasma cholesterol (C) and triglycerides (TG) in APOE*3Leiden mice. 1% Phytosphingosine (PS) reduced C and TG by 57 and 58%, respectively. PS (a) decreased the absorption of dietary C and free fatty acid but did not affect the intestinal TG lipolysis, (b) increased hepatic VLDL‐TG production whereas plasma lipolysis was not affected; and (c) increased the hepatic uptake of VLDL remnants. Hepatic mRNA levels indicated enhanced hepatic lipid synthesis and VLDL and LDL uptake. Livers of PS (1%) fed mice were lighter (?22%), less pale, and contained less cholesteryl ester (?61%) and TG (?56%). Furthermore, markers for liver inflammation (SAA) and liver damage (ALAT) were decreased by 74% and 79%, respectively in PS‐fed mice. Sphingolipids lower plasma C and TG and protect the liver from fat‐ and cholesterol‐induced steatosis. In a preliminary small double‐blind cross‐over study with six middle‐aged slightly overweight male volunteers the daily supplementation of one gram of PS to the diet resulted in a ?9.8% (p = 0.0074) and – 13.2% (p = 0.0002) reduction of total C and LDL‐C, respectively. The C/HDL‐C ratio was not significantly affected (p = 0.0571). Due to the relatively low pre‐study levels of TG in the human volunteers, and the individual variability of TG levels, the TG lowering in humans was not significant in this first small study, but per individual there was a clear trend in TG lowering.