Multiple levels of native cardiac Na+ channels at elevated temperature measured with high-bandwidth/low-noise patch clamp

1993 ◽  
Vol 422 (5) ◽  
pp. 506-515 ◽  
Author(s):  
K. Benndorf
Keyword(s):  
Elevated Temperature ◽  
Patch Clamp ◽  
Low Noise ◽  
Na Channels ◽  
High Bandwidth ◽  
Multiple Levels

Design and modeling of an ultra-wideband low-noise distributed amplifier in InP DHBT technology

2019 ◽  
Vol 11 (7) ◽  
pp. 635-644 ◽  
Author(s):  
T. Shivan ◽  
E. Kaule ◽  
M. Hossain ◽  
R. Doerner ◽  
T. Johansen ◽  
...  
Keyword(s):  
Noise Figure ◽  
Impedance Matching ◽  
Low Noise ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Collector Current ◽  
Noise Sources ◽  
Distributed Amplifier ◽  
Double Heterojunction ◽  
High Bandwidth

AbstractThis paper reports on an ultra-wideband low-noise distributed amplifier (LNDA) in a transferred-substrate InP double heterojunction bipolar transistor (DHBT) technology which exhibits a uniform low-noise characteristic over a large frequency range. To obtain very high bandwidth, a distributed architecture has been chosen with cascode unit gain cells. Each unit cell consists of two cascode-connected transistors with 500 nm emitter length and ft/fmax of ~360/492 GHz, respectively. Due to optimum line-impedance matching, low common-base transistor capacitance, and low collector-current operation, the circuit exhibits a low-noise figure (NF) over a broad frequency range. A 3-dB bandwidth from 40 to 185 GHz is measured, with an NF of 8 dB within the frequency range between 75 and 105 GHz. Moreover, this circuit demonstrates the widest 3-dB bandwidth operation among all reported single-stage amplifiers with a cascode configuration. Additionally, this work has proposed that the noise sources of the InP DHBTs are largely uncorrelated. As a result, a reliable prediction can be done for the NF of ultra-wideband circuits beyond the frequency range of the measurement equipment.

A low-noise miniaturized patch-clamp amplifier

2007 ◽  
Author(s):  
Pujitha Weerakoon ◽  
Kate Klemic ◽  
Fred J. Sigworth ◽  
Eugenio Culurciello
Keyword(s):  
Patch Clamp ◽  
Low Noise

LOW-NOISE AND HIGH-BANDWIDTH 0.8 μm CMOS TRANSIMPEDANCE AMPLIFIER FOR OPTICAL RECEIVER CIRCUIT

2005 ◽  
Vol 14 (02) ◽  
pp. 267-279 ◽  
Author(s):  
M. B. GUERMAZ ◽  
L. BOUZERARA ◽  
H. ESCID ◽  
M. T. BELAROUSSI
Keyword(s):  
Dynamic Range ◽  
Supply Voltage ◽  
High Sensitivity ◽  
Low Noise ◽  
Transimpedance Amplifier ◽  
Power Supply Voltage ◽  
Stability Performance ◽  
High Bandwidth ◽  
The Stability ◽  
Transmission Speed

This paper describes and analyzes a low-noise and high-bandwidth transimpedance amplifier featuring a large dynamic range. The designed amplifier is configured on three identical stages that use an active load compensated by an active resistor to improve the stability performance of the amplifier. This topology displays a transimpedance gain of 150 kΩ, which is necessary to obtain a high sensitivity. This structure operates at 5 V power supply voltage, exhibits a gain bandwidth product of 18 THzΩ and a low-noise level of about [Formula: see text]. This transimpedance amplifier can reach a transmission speed of 240 Mb/s for a photocurrent of 0.5 μA. For a photocurrent of 9.5 μA, a transmission speed of 622 Mb/s can be achieved by using an optical fiber connection containing four channels. The predicted performance is verified by simulations using PSPICE and MAGIC tools with 0.8 μm CMOS AMS parameters.

A low-noise, two-stage DC SQUID amplifier with high bandwidth and dynamic range

1997 ◽  
Vol 7 (2) ◽  
pp. 3033-3036 ◽  
Author(s):  
R. Cantor ◽  
L.P. Lee ◽  
A. Matlashov ◽  
V. Vinetskiy
Keyword(s):  
Dynamic Range ◽  
Low Noise ◽  
Two Stage ◽  
High Bandwidth

Abstract 16820: CaMKIIδc Transgenic Mice Develop Spontaneous Ventricular Arrhythmias Which Can Be Suppressed by Inhibition of Late Na+ Current

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Maria Arolfo ◽  
Liguo Chi ◽  
Aliya Zeng ◽  
Nesrine El-Bizri ◽  
Joan Brown ◽  
...  
Keyword(s):  
Single Dose ◽  
Patch Clamp ◽  
Transgenic Mice ◽  
Ventricular Arrhythmias ◽  
Ventricular Myocytes ◽  
Na Channels ◽  
Wild Type ◽  
Na Current ◽  
Patch Clamp Technique ◽  
Post Surgery

Introduction: It has been shown that activated CaMKII can phosphorylate cardiac Na+ channels that leads to an enhanced late Na current (INaL). We hypothesized that enhanced INaL plays an important role in arrhythmogenesis linked to increased CaMKII activity. To test this hypothesis we determined the effect of a selective INaL inhibitor GS-967 on spontaneously occurring ventricular arrhythmias in mice overexpressing CaMKIIδc (TG). Methods: TG (n=6) and wild type (WT, n=3) mice at age 8 week (wk) were instrumented with telemetry transmitters to record ECG. ECG were recorded continuously starting 1 wk post- surgery (age 9 wk) until age 19 wk. Incidence and burden of arrhythmias were evaluated at ages 9, 11, 13, 15, 17 and 19 wks using DSI ECG Pro software. At age 17 wk, when arrhythmia burden was relatively stable, mice were treated with a single dose of GS-967 (1 mg/kg, i.p.) or vehicle. After 4 days of washout, the treatment was repeated in a cross-over manner. Arrhythmia burden was quantified over a duration of 15-hours post-treatment. Using patch clamp technique, INaL was measured in ventricular myocytes isolated from both TG and WT mice at 17 wk age. Results: Incidence and burden of spontaneous ventricular arrhythmias increased progressively with age in TG mice. Between age 9 and 11 wks, 50% of TG mice had an arrhythmia burden ≥ 5 minutes/24 hours. The incidence increased to 83% at wk 13, 15, 17 and to 100% at 19 wks and the burden increased to 71 ± 35 min/24 hr at 17 wk. A single dose of GS-967 significantly decreased arrhythmia burden from 42.5 ± 9.6 min (treated with vehicle) to 9.4 ± 4.3 min (p<0.05) during a 15-hr period. No arrhythmias were observed in WT mice during the course of the study. INaL was enhanced by more than 2-fold in myocytes isolated from TG mice compared to WT (0.2±0.03 vs. 0.08±0.02 pA/pF, n=16 each, p<0.05). GS-967 caused a concentration-dependent reduction of INaL (50.5±3.4% at 0.3 μM, n=7; and 91±5.2% at 1 μM, n=4). Conclusions: This is the first report to show a reduction of spontaneously occurring ventricular arrhythmias by inhibition of INaL indicating a key role for INaL in CaMKII associated arrhythmogenesis.

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