capacitance
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A variety of techniques of cell capacitance measurement have been proposed and applied in cellular electrophysiology. They are mostly based on the evaluation of membrane current responses to small changes in the membrane voltage. One of the currently used approaches applies the least-squares fit of an exponential current decay in response to voltage clamped rectangular pulses. In this study, we propose an alternative simpler approach to evaluation of the exponential parts in the current responses to square wave stimulation and present preliminary results of membrane capacitance evaluation. It is based on the property of the exponential function that has not yet been used to measure membrane capacitance. The time constant and the asymptote of the exponential waveform are unambiguously determined by the values read at three points separated by a constant time interval. In order to minimize the effect of noise and deviations from the exponential waveform, the triplet of points is designed to slide along the time axis. The results of the proposed approach and those previously evaluated by the least squares method are comparable. The method described may be advantageous for continuously recording changes in membrane capacitance.
- MeSH
- algoritmy MeSH
- elektrická kapacitance MeSH
- elektrická vodivost MeSH
- elektrofyziologie MeSH
- krysa rodu rattus MeSH
- membránové potenciály fyziologie MeSH
- metoda nejmenších čtverců MeSH
- metoda terčíkového zámku metody MeSH
- modely neurologické MeSH
- neurony MeSH
- počítačová simulace MeSH
- reprodukovatelnost výsledků MeSH
- software MeSH
- srdeční síně patologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Acta physiologica Scandinavica, ISSN 0302-2994 vol. 124, suppl. 541, 1985
34 s. : grafy ; 24 cm
- MeSH
- adrenergní receptory MeSH
- adrenergní vlákna MeSH
- cévy MeSH
- krysa rodu rattus MeSH
- noradrenalin MeSH
- Check Tag
- krysa rodu rattus MeSH
- Konspekt
- Fyziologie člověka a srovnávací fyziologie
- NLK Obory
- fyziologie
- neurovědy
- MeSH
- buněčná membrána fyziologie MeSH
- elektrická kapacitance MeSH
- elektrofyziologie MeSH
- membránové potenciály MeSH
- Publikační typ
- kongresy MeSH
Platinum is the most widespread electrode material used for implantable biomedical and neuroelectronic devices, motivating exploring ways to improve its performance and understand its fundamental properties. Using reactive magnetron sputtering, PtOx is prepared, which upon partial reduction yields a porous thin-film form of platinum with favorable properties, notably record-low impedance values outcompeting other reports for platinum-based electrodes. It is established that its high electrochemical capacitance scales with thickness, in the way of volumetric capacitor materials like IrOx and poly(3,4-ethylenedioxythiophene), PEDOT. Unlike these two well-known analogs, however, it is found that PtOx capacitance is not caused by reversible pseudofaradaic reactions but rather due to high surface area. In contrast to IrOx, PtOx is not a reversible valence-change oxide, but rather a porous form of platinum. The findings show that this oxygen-containing form of Pt can place Pt electrodes on a level competitive with IrOx and PEDOT. Due to its relatively low cost and ease of preparation, PtOx can be a good choice for microfabricated bioelectronic devices.
- MeSH
- diagnostické techniky a postupy přístrojové vybavení trendy využití MeSH
- elektrická impedance diagnostické užití MeSH
- elektrická kapacitance diagnostické užití MeSH
- elektroencefalografie metody přístrojové vybavení využití MeSH
- lidé MeSH
- neurologie metody přístrojové vybavení trendy MeSH
- pohyb fyziologie MeSH
- prsty ruky fyziologie MeSH
- Check Tag
- lidé MeSH
738 s. : il.
Nonsense mediated RNA decay (NMD) is well-known as an RNA quality control mechanism that sequesters a substantial portion of RNA from expression by targeting it for degradation. However, a number of recent studies across a range of organisms indicate a broader role for NMD in gene regulation and transcriptome homeostasis. Here we propose a novel role for NMD as a buffering system with the capability of accumulating and subsequently releasing a wide spectrum of cryptic genetic variation in response to environmental stimuli, and hence facilitating adaptive evolution. We discuss this role for NMD in the context of evolution of plant pathogen defense, whereby NMD may promote rapid diversification of intracellular immune receptors by mitigating the potentially harmful impact of their newly formed variants on plant fitness.
