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- Eisenhauer, Klara, et al.
(författare)
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Scaling the Functional Nanopore (FuN) Screen: Systematic Evaluation of Self-Assembling Membrane Peptides and Extension with a K+-Responsive Fluorescent Protein Sensor
- 2023
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Ingår i: ACS Synthetic Biology. - 2161-5063. ; 13:4, s. 1382-1392
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Tidskriftsartikel (refereegranskat)abstract
- The functional analysis of protein nanopores is typically conducted in planar lipid bilayers or liposomes exploiting high-resolution but low-throughput electrical and optical read-outs. Yet, the reconstitution of protein nanopores in vitro still constitutes an empiric and low-throughput process. Addressing these limitations, nanopores can now be analyzed using the functional nanopore (FuN) screen exploiting genetically encoded fluorescent protein sensors that resolve distinct nanopore-dependent Ca2+ in- and efflux patterns across the inner membrane of Escherichia coli. With a primary proof-of-concept established for the S2168 holin, and thereof based recombinant nanopore assemblies, the question arises to what extent alternative nanopores can be analyzed with the FuN screen and to what extent alternative fluorescent protein sensors can be adapted. Focusing on self-assembling membrane peptides, three sets of 13 different nanopores are assessed for their capacity to form nanopores in the context of the FuN screen. Nanopores tested comprise both natural and computationally designed nanopores. Further, the FuN screen is extended to K+-specific fluorescent protein sensors and now provides a capacity to assess the specificity of a nanopore or ion channel. Finally, a comparison to high-resolution biophysical and electrophysiological studies in planar lipid bilayers provides an experimental benchmark for future studies.
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- Weingärtner, André, et al.
(författare)
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Parallel vortex body interaction enabled by active flow control
- 2020
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Ingår i: Experiments in Fluids. - : Springer. - 0723-4864 .- 1432-1114. ; 61:6
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Tidskriftsartikel (refereegranskat)abstract
- An experimental investigation has been conducted to demonstrate the utility of active flow control as a disturbance generator for vortex body interaction studies. The technique is used to explore the flow physics of parallel vortex body interaction between two NACA 0012 airfoils in series. Experiments were carried out at a chord-based Reynolds number of 740,000 relative to the first airfoil. Active flow control in the form of nanosecond pulse-driven dielectric barrier discharge plasma actuation, originating close to the leading edge, was used to produce vortex shedding from the upstream (disturbance) airfoil at various frequencies (0.038 <= F+ <= 0.762). These vortices were characterized, showing reduced circulation and diameter with increasing frequency, before examining the downstream wake-airfoil interactions. Time-resolved pressure and phase-locked PIV measurements were taken on the downstream (target) airfoil for multiple angles of attack. For F+ <= 0.5, the target airfoil is subject to strong oscillations from the wake of the disturbance airfoil that lead to large fluctuations in lift and pitching moment. However, a further increase in F+ reattaches the flow over the disturbance airfoil and no major vortex body interactions are observed on the target. Governing parameters for this type of vortex body interaction are explored, and differences between isolated and non-isolated encounters as well as the presence of a viscous response are examined. Finally, means to alleviate loads caused by the incident vortex are explored.
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