Antithrombotic properties of trillium coated connectors

Trillium coating (Medtronic Inc., Minneapolis, MN) offers, in addition to the presence of heparin, endothelium-like properties of its negatively charged surface. Its thromboresistant properties on coated connectors are tested here and compared with uncoated standard connectors, as well as with the Carmeda BioActive surface (CBAS) heparin surface coating. A partial cardiopulmonary bypass bovine model (body weight 68 +/- 5 kg) was selected, and the surfaces were exposed to the blood stream (pump flow 3.5 L/min) for up to 350 minutes without systemic heparinization. Thereafter, another set of samples was exposed to stagnant blood for 20 minutes. Besides hemodynamic, hematologic, and biochemical analyses, the macroscopic appearance of 45 blood exposed surface samples were graded semiquantitatively on a scale of 0 to 10: no macroscopic deposits = grade 0, one spot (1 mm diameter) = grade 1, two spots = grade 2, five or more spots = grade 5, 10% of the surface covered with clots = grade 6, 100% covered = grade 10. When exposed to blood flow, Trillium and CBAS coatings showed a statistically significant (p = 0.03) better thromboresistance (score: 0 +/- 0 for both) than uncoated connectors (score: 0.8 +/- 1.5) in this nonheparinized model. The same holds true when the connectors were exposed to stagnant blood (score: 0 +/- 0 for both coatings vs 4.3 +/- 2.8 for controls; p = 0.03). Therefore, Trillium coating exhibits significant antithrombotic properties that outperform standards for connectors used in clinical perfusion

Beam induced heating

In 2011, the rapid increase of the luminosity performance of LHC came at the expense of increased temperature and pressure readings on several near-beam LHC equipments. In some cases, this beam induced heating was suspected to cause beam dumps and even degradation of the equipment. This contribution aims at gathering the observations of beam induced heating due to beam coupling impedance, their current level of understanding and possible actions that could be implemented during the winter stop 2011-2012

Computational Model-Based Development of Novel Stimulation Algorithms

In the context of this entry, the model-based development of stimulation algorithms designatesa process of creation and computational testing of new techniques for control and modulation ofundesirable (pathological) neuronal dynamics. Abnormal brain activity has been observed in severalneurological disorders including Parkinson’s disease, essential tremor, epilepsy, tinnitus, and others.Brain stimulation is used for the therapy of patients suffering, for example, from Parkinson’s disease,epilepsy, or mental disorders. Brain stimulation is called deep brain stimulation (DBS) if structuresdeeply inside the brain are targeted, cortical stimulation (intracortical or epicortical) if the electricalcontacts of the stimulator are positioned within the cortex or on its surface, or noninvasivetranscranial stimulation if the neurons are stimulated by electrical currents induced across scalp byeither external magnetic field (transcranial magnetic stimulation, TMS) or electrical current admin-istered via scalp electrodes (transcranial direct-current stimulation, tDCS). Apart from direct brainstimulation, other stimulation forms and targets may also be used, such as spinal cord stimulation(e.g., for the treatment of pain), vagus nerve stimulation (for the treatment of epilepsy), or acousticstimulation (for the treatment of tinnitus). Novel, model-based approaches, which use methods fromsynergetics, nonlinear dynamics, and statistical physics to specifically restore brain function andconnectivity, demonstrate how insights into the dynamics of complex systems contribute to thedevelopment of novel therapies