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Standing modes of light in front of the reflecting surface of silicon modulate the excitation and emission of fluorescent dyes. This effect was used to determine the distance of a biomembrane from an oxidized silicon chip. The membrane of a red blood cell (ghost) was stained with a cya-nine dye and attached with poly-lysine to a surface structured with(More)
Protein interactions inside the human body are expected to differ from the situation in vitro. This is crucial when investigating protein functions or developing new drugs. In this study, we present a sample-efficient, free-solution method, termed microscale thermophoresis, that is capable of analysing interactions of proteins or small molecules in(More)
Molecules drift along temperature gradients, an effect called thermophoresis, the Soret effect, or thermodiffusion. In liquids, its theoretical foundation is the subject of a long-standing debate. By using an all-optical microfluidic fluorescence method, we present experimental results for DNA and polystyrene beads over a large range of particle sizes, salt(More)
Two experiments measured listeners' abilities to detect facial expression in unfamiliar speech in normal and whisper registers. Acoustic differences between speech produced with neutral or marked facial expression were also assessed. Experiment 1 showed that in a forced-choice identification task, listeners could accurately select frowned speech as such,(More)
The hallmark of living matter is the replication of genetic molecules and their active storage against diffusion. We implement both in the simple nonequilibrium environment of a temperature gradient. Convective flow both drives the DNA replicating polymerase chain reaction while concurrent thermophoresis accumulates the replicated 143 base pair DNA in bulk(More)
The manipulation and analysis of biomolecules in native bulk solution is highly desired; however, few methods are available. In thermophoresis, the thermal analog to electrophoresis, molecules are moved along a microscopic temperature gradient. Its theoretical foundation is still under debate, but practical applications for analytics in biology show(More)
For the emergence of early life, the formation of biopolymers such as RNA is essential. However, the addition of nucleotide monomers to existing oligonucleotides requires millimolar concentrations. Even in such optimistic settings, no polymerization of RNA longer than about 20 bases could be demonstrated. How then could self-replicating ribozymes appear,(More)
The capacitive stimulation of nerve cells from semiconductor chips is a prerequisite for the development of neuroelectronic devices. We report on the primary response of a cell membrane to a voltage step applied to oxidized silicon. It is observed with a luminescent voltage-sensitive dye. We find exponential voltage transients with a time constant of 1-5(More)
Evolving systems rely on the storage and replication of genetic information. Here we present an autonomous, purely thermally driven replication mechanism. A pool of hairpin molecules, derived from transfer RNA replicates the succession of a two-letter code. Energy is first stored thermally in metastable hairpins. Thereafter, energy is released by a highly(More)