BCI Integration: Application Interfaces

Natural disaster

Chapter BCI Integration: Application Interfaces

Natural disaster

Design of stimuli-responsive OmpF-conjugates as biovalves for nano-reactors

Without compartmentalisation, there would be no life, as cells require spatial organization to perform all metabolic processes to sustain it. Compartmentalisation, or physical separation of biological reactions requires defined reaction spaces and active control over all molecules that enters or leaves them. Nature utilises for this purpose cell membranes and a plethora of different membrane proteins, which act as tunnels allowing and controlling molecular flow across the membrane. In a similar manner mimicking nature, by molecular self-assembly, allows us to produce artificial cells as simplified models for better understanding specific parts of cells. Our knowledge allows us today to go a step further, as we can use natural or artificial enzymes and trans-membrane channel proteins to create artificial organelles (nanoreactors) capable of supporting selective reactions and replacement the deficient structures or organelles. That is why the nanoreactors are gaining more and more interest for specific applications in the field of nano-medicine, analytics and advanced functional materials. To achieve the desired compartmentalization, it was needed to advance from the artificial assemblies, with passive membrane transport, based on permanently open pores. First attempts in this direction are represented by the design of single stimuli triggered transport via structures capable of opening upon acidification or reduction. The second step will be to have reversible triggered transport structures, like cells have. To have reliable artificial replacements of the dysfunctional cell structures is needed. This thesis, is achieving this necessary step by the development of a biovalve which can open and close on demand in a similar manner that the trans-membrane proteins work. This is a significant advance in the design of new cell-like polymeric compartmentalised structures with sustainable specific function. This new system can be switched on and off by demand, theoretically endlessly, opening new ways in the development of artificial structures to replace the non-functional ones in living cells. This biovalve was obtained by modifying trans-membrane proteins (Omp F) capable of passive transport of a range of molecules, with selected pH sensitive peptides capable of opening and closing its pore. This new biovalve functionality was tested by reconstituting it in an artificial membrane of a nanoreactor that delimits an inner empty space in which selected enzymes were entrapped. The specific substrate for the entrapped enzyme was added on top of the assembled nanoreactors mixture, outside of the closed polymeric compartments. At physiological pH the biovalve opens, and the substrate molecules diffuse passively in the inner space of the nanoreactor entrapping the enzyme molecules. The enzymatic reaction takes place and the (fluorescent) product formation is monitored. At low pH the biovalve closed blocking the access of the substrate molecules and no fluorescent product can be detected

Brain Computer Interface for Virtual Reality Control

A brain-computer interface (BCI) is a new communication channel between the human brain and a computer. Applications of BCI systems comprise the restoration of movements, communication and environmental control. In this study experiments were made that used the BCI system to control or to navigate in virtual environments (VE) just by thoughts. BCI experiments for navigation in VR were conducted so far with synchronous BCI and asynchronous BCI systems. The synchronous BCI analyzes the EEG patterns in a predefined time window and has 2 to 3 degrees of freedom

Biomimetic Strategy To Reversibly Trigger Functionality of Catalytic Nanocompartments by the Insertion of pH-Responsive Biovalves

We describe an innovative strategy to generate catalytic compartments with triggered functionality at the nanoscale level by combining pH-reversible biovalves and enzyme-loaded synthetic compartments. The biovalve has been engineered by the attachment of stimuli-responsive peptides to a genetically modified channel porin, enabling a reversible change of the molecular flow through the pores of the porin in response to a pH change in the local environment. The biovalve functionality triggers the reaction inside the cavity of the enzyme-loaded compartments by switching the in situ activity of the enzymes on/off based on a reversible change of the permeability of the membrane, which blocks or allows the passage of substrates and products. The complex functionality of our catalytic compartments is based on the preservation of the integrity of the compartments to protect encapsulated enzymes. An increase of the in situ activity compared to that of the free enzyme and a reversible on/off switch of the activity upon the presence of a specific stimulus is achieved. This strategy provides straightforward solutions for the development of catalytic nanocompartments efficiently producing desired molecules in a controlled, stimuli-responsive manner with high potential in areas, such as medicine, analytical chemistry, and catalysis

Direct Flow Medical vs. Edwards Sapien 3 Prosthesis: A Propensity Matched Comparison on Intermediate Safety and Mortality

Aims: To compare intermediate performance and mortality rates in patients, who underwent transcatheter aortic valve implantation (TAVI) with two different types of prostheses: Edwards Sapien 3 (ES3) and Direct Flow Medical (DFM).Methods and Results: 42 consecutive patients implanted with a DFM prosthesis for severe aortic stenosis were matched 1:1 with an equal number of patients, who received an ES3 during the same period. Primary endpoint was mortality. MACE, as a composite of all-cause death, stroke, and re-do-procedure (valve-in-valve), was defined as secondary endpoint. Moreover, we compared NYHA class, NT-proBNP-levels and the extent of restenosis. Patients were followed for 2 years. DFM patients showed echocardiographic elevated mean pressure gradients compared to ES3 patients before discharge (11.2 mmHg ± 5.3 vs. 3.5 mmHg ± 2.7; p < 0.001) and upon 6-months follow-up (20.3 mmHg ± 8.8 vs. 12.3 mmHg ± 4.4; p < 0.001). ES3 candidates showed superior NYHA class at follow-up (p = 0.001). Kaplan-Meier analysis revealed significantly worse survival in patients receiving a DFM prosthesis compared to ES3 (Breslow p = 0.020). MACE occurred more often in DFM patients compared to ES3 (Breslow p = 0.006).Conclusions: Patients receiving DFM valve prostheses showed worse survival and higher rates in MACE compared to ES3. Prosthesis performance regarding mean pressure gradients and patients' NYHA class also favored ES3

Real-Time Position Reconstruction with Hippocampal Place Cells

Brain–computer interfaces (BCI) are using the electroencephalogram, the electrocorticogram and trains of action potentials as inputs to analyze brain activity for communication purposes and/or the control of external devices. Thus far it is not known whether a BCI system can be developed that utilizes the states of brain structures that are situated well below the cortical surface, such as the hippocampus. In order to address this question we used the activity of hippocampal place cells (PCs) to predict the position of an rodent in real-time. First, spike activity was recorded from the hippocampus during foraging and analyzed off-line to optimize the spike sorting and position reconstruction algorithm of rats. Then the spike activity was recorded and analyzed in real-time. The rat was running in a box of 80 cm × 80 cm and its locomotor movement was captured with a video tracking system. Data were acquired to calculate the rat's trajectories and to identify place fields. Then a Bayesian classifier was trained to predict the position of the rat given its neural activity. This information was used in subsequent trials to predict the rat's position in real-time. The real-time experiments were successfully performed and yielded an error between 12.2 and 17.4% using 5–6 neurons. It must be noted here that the encoding step was done with data recorded before the real-time experiment and comparable accuracies between off-line (mean error of 15.9% for three rats) and real-time experiments (mean error of 14.7%) were achieved. The experiment shows proof of principle that position reconstruction can be done in real-time, that PCs were stable and spike sorting was robust enough to generalize from the training run to the real-time reconstruction phase of the experiment. Real-time reconstruction may be used for a variety of purposes, including creating behavioral–neuronal feedback loops or for implementing neuroprosthetic control