1,720,985 research outputs found
A low-noise transimpedance amplifier for BLM-Based ion channel recording
No full textData for the paper "Crescentini, Marco, Bennati, Marco, Saha, Shimul C., Ivica, Josip, de Planque, Maurits R.R., Morgan, Hywel and Tartagni, Marco (2016) A low-noise transimpedance amplifier for BLM-based ion channel recording. Sensors, 16, (5, 709), 1-20. (doi:10.3390/s16050709)."</span
A distributed amplifier system for bilayer lipid membrane (BLM) arrays with noise and individual offset cancellation
Full text linkLipid bilayer membrane (BLM) arrays are required for high throughput analysis, for example drug screening or advanced DNA sequencing. Complex microfluidic devices are being developed but these are restricted in terms of array size and structure or have integrated electronic sensing with limited noise performance. We present a compact and scalable multichannel electrophysiology platform based on a hybrid approach that combines integrated state-of-the-art microelectronics with low-cost disposable fluidics providing a platform for high-quality parallel single ion channel recording. Specifically, we have developed a new integrated circuit amplifier based on a novel noise cancellation scheme that eliminates flicker noise derived from devices under test and amplifiers. The system is demonstrated through the simultaneous recording of ion channel activity from eight bilayer membranes. The platform is scalable and could be extended to much larger array sizes, limited only by electronic data decimation and communication capabilities
RF MEMS Switches and Switch Circuits: Modeling of RF MEMS switches and development of RF MEMS capacitive switches and MEMS tunable filters
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Scaleable micro-cavity bilayer lipid membrane array for parallel ion channel recording
No full textA compact, scalable and high-throughput bilayer ion channel recording platform capable of simultaneous data acquisition from multiple bilayers is presented. Microfluidic chips house micro-cavities over which bilayers are made; each connected to a custom-made compact electronic readout circuit based on ASICs (Application-Specific Integrated Circuits). The micro-cavities are fabricated using a simple dry-film resist process on a glass wafer. Single 15 mm × 15 mm glass chips contain four separately addressable bilayers, each with integrated Ag/AgCl electrodes. The number of bilayers is scaled by increasing the number of ASICs and four-cavity chips. Each chip can be cleaned and re-used many times and the cavity-suspended lipid bilayers are stable for up to 10 days. System performance is demonstrated with simultaneous electrical recordings of the ion channels gramicidin A and alpha-hemolysin in multiple bilayers
Micro-cavity array with shaped apertures for optically and electrically accessible suspended BLMs
No full textA low-noise transimpedance amplifier for BLM-based ion channel recording
Full text linkHigh-throughput screening (HTS) using ion channel recording is a powerful drug discovery technique in pharmacology. Ion channel recording with planar bilayer lipid membranes (BLM) is scalable and has very high sensitivity. A HTS system based on BLM ion channel recording faces three main challenges: (i) design of scalable microfluidic devices; (ii) design of compact ultra-low-noise transimpedance amplifiers able to detect currents in the pA range with bandwidth >10 kHz; (iii) design of compact, robust and scalable systems that integrate these two elements. This paper presents a low-noise transimpedance amplifier with integrated A/D conversion realized in CMOS 0.35 µm technology. The CMOS amplifier acquires currents in the range ±200 pA and ±20 nA, with 100 kHz bandwidth while dissipating 41 mW. An integrated digital offset compensation loop balances any voltage offsets from Ag/AgCl electrodes. The measured open-input input-referred noise current is as low as 4 fA/Root Hz at ±200 pA range. The current amplifier is embedded in an integrated platform, together with a microfluidic device, for current recording from ion channels. Gramicidin-A, alpha-haemolysin and KcsA potassium channels have been used to prove both the platform and the current-to-digital converter
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterization of the prokaryotic sodium channel NavSp pore with a microfluidic bilayer platform
No full textThis paper describes the use of a newly-developed micro-chip bilayer platform to examine the electrophysiological properties of the prokaryotic voltage-gated sodium channel pore (NavSp) from Silicibacter pomeroyi. The platform allows up to 6 bilayers to be analysed simultaneously. Proteoliposomes were incorporated into suspended lipid bilayers formed within the microfluidic bilayer chips. The chips provide access to bilayers from either side, enabling the fast and controlled titration of compounds. Dose-dependent modulation of the opening probability by the channel blocking drug nifedipine was measured and its IC50 determined
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