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Self metathesis of oleochemicals offers a variety of bifunctional compounds, that can be used as monomer for polymer production. Many precursors are in huge scales available, like oleic acid ester (biodiesel), oleyl alcohol (tensides), oleyl amines (tensides, lubricants). We show several ways to produce and separate and purify C18-α,ω-bifunctional compounds, using Grubbs 2nd Generation catalysts, starting from technical grade educts.
Shakedown analysis of two dimensional structures by an edge-based smoothed finite element method
(2010)
Simultaneous detection of cyanide and heavy metals for environmental analysis by means of µISEs
(2010)
Objective
To investigate whether functional brain networks of epilepsy patients treated with antiepileptic medication differ from networks of healthy controls even during the seizure-free interval.
Methods
We applied different rules to construct binary and weighted networks from EEG and MEG data recorded under a resting-state eyes-open and eyes-closed condition from 21 epilepsy patients and 23 healthy controls. The average shortest path length and the clustering coefficient served as global statistical network characteristics.
Results
Independent on the behavioral condition, epileptic brains exhibited a more regular functional network structure. Similarly, the eyes-closed condition was characterized by a more regular functional network structure in both groups. The amount of network reorganization due to behavioral state changes was similar in both groups. Consistent findings could be achieved for networks derived from EEG but hardly from MEG recordings, and network construction rules had a rather strong impact on our findings.
Conclusions
Despite the locality of the investigated processes epileptic brain networks differ in their global characteristics from non-epileptic brain networks. Further methodological developments are necessary to improve the characterization of disturbed and normal functional networks.
Significance
An increased regularity and a diminished modulation capability appear characteristic of epileptic brain networks.
Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5%, first to third quartile 2.1% to 4.5% vs 3.6%, first to third quartile 2.2% to 4.3%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.
Following the success of PET/CT during the last decade and the recent increasing proliferation of SPECT/CT, another hybrid imaging instrument has been gaining more and more interest: MR-PET. First combined, simultaneous PET and MR studies carried out in small animals demonstrated the feasibility of the new approach. Concurrently, some prototypes of an MR-PET scanner for simultaneous human brain studies have been built, their performance is being tested and preliminary applications have already been shown. Through this pioneering work, it has become clear that advances in the detector design are necessary for further optimization.
Recently, the different issues related to the present state and future prospects of MR-PET were presented and discussed during an international 2-day workshop at the Forschungszentrum Jülich, Germany, held after, and in conjunction with, the 2008 IEEE Nuclear Science Symposium and Medical Imaging Conference in Dresden, Germany on October 27–28, 2008. The topics ranged from small animal MR-PET imaging to human MR-BrainPET imaging, new detector developments, challenges/opportunities for ultra-high field MR-PET imaging and considerations of possible future research and clinical applications. This report presents a critical summary of the contributions made to the workshop.