Search results for "Volt"
showing 10 items of 2187 documents
Effect of inhibition of the electrogenic Na+/K+ pump on the mechanical activity in the rat uterus.
1996
The effects of ouabain and K(+)-free solution were studied in estrogen-primed rat uterine strips under resting tone or repeatedly stimulated with KCl, acetylcholine or oxytocin applied for 20 minutes at 60 minute intervals. These effects were compared with those of the K+ channel opener cromakalim. In preparations under resting tone, ouabain (0.1 mM and 0.3 mM) induced rhythmic contractions which disappeared after 20-30 minutes whereas at a higher concentration (1 mM) it evoked a rapid, phasic response followed by a small tonic contraction. Exposure of the strip to a K(+)-free solution induced either rhythmic waves, which ceased after 8-10 minutes, or a single phasic contraction which was f…
The influence of Ca2+ antagonists on the ciliary activity of the guinea pig trachea.
1990
The ciliary activity of the guinea pig tracheal respiratory epithelium was measured using a photoelectric device. Fourteen animals were administered 75 mg diltiazem/kg body weight 2 days, 1 day and 4 h prior to the investigation. Thirteen animals served as controls. In the pretreated group, the mean ciliary stroke frequency (13.4 +/- 3.0 Hz) was significantly lower (P = 0.02) than in the control group (16.6 +/- 3.7 Hz). The application of aerosolized 0.3 mmol/l nifedipine solution on the tracheal preparations of the control animals also significantly reduced the stroke frequency (P = 0.02). The ciliary activity never dropped beyond a frequency of about 8 Hz. The most probable interpretation…
Differential blockade by nifedipine and ω-conotoxin GVIA of α1- and β1-adrenoceptor-controlled calcium channels on motor nerve terminals of the rat
1990
Electrically evoked release of [3H]acetylcholine ([3H]ACh) from the rat phrenic nerve and its facilitation by stimulation of presynaptic alpha 1- and beta 1-adrenoceptors were investigated in the absence and presence of nifedipine and omega-conotoxin GVIA. Both calcium channel antagonists did not modify electrically evoked [3H]ACh release, but selectively blocked the effect triggered by both facilitatory adrenergic receptors. The increase in [3H]ACh release mediated via beta 1-adrenoceptor activation was abolished by low concentrations (1 nM) of omega-conotoxin GVIA, whereas nifedipine (100 nM) abolished the facilitatory effect mediated via alpha 1-adrenoceptor stimulation. Therefore, the b…
Static Crow’s Feet Treated with Voltaic Arc Dermabrasion (Atmospheric Plasma): Post-Operative Pain Assessment by Thermal Infrared Imaging
2021
Background: In the literature, several strategies have been described for the treatment of unaesthetic marks on the face resulting from the aging processes. The atmospheric plasma procedure is a non-invasive, inexpensive technique proposed for the rejuvenation of facial tissues. The aim of this study was to evaluate the performance of voltaic arc dermabrasion (VAD) for the treatment of static crow’s feet of the periorbital area. Methods: The crow’s feet of 135 patients (127 female and 8 male) were treated using the VAD technique. The perioperative skin temperature measurement was assessed using an Infrared Temperature sensor. The pain was measured using the Visual Analogic Score (VAS) at 1 …
MECHANISMS OF TENSION DEVELOPMENT INDUCED BY MONENSIN IN GUINEA-PIG AORTA : EFFECTS OF VERAPAMIL, OUABAIN, PRAZOSIN AND GLIBENCLAMIDE
1993
The influence of monensin (10 µmol/L) alone and in the presence of verapamil (3 µmol/L) or ouabain (1 mmol) and prazosin (1 µmol/L) or glibenclamide (10 µmol/L) were studied on the muscle tension of guinea pig aorta. Changes in tissue sodium, potassium and calcium ion contents of the aortic muscle produced by monensin in the presence of prazosin were evaluated. Monensin in normal Tyrode's solution containing prazosin caused an increase in the resting tension followed by a decrease and returned to normal values. Verapamil reduced the muscle tension induced by monensin. After ouabain, monensin induced sustained increase in the resting tension. Glibenclamide partially reversed the relaxant pha…
Endothelin action on goat cerebral arteries.
1990
Abstract Cumulative application of endothelin-1 (human) markedly constricted goat isolated cerebral arteries in a concentration-dependent manner. Contractile responses were not affected by removal of endothelial cells. Removal of extracellular calcium or addition of the calcium channel blocker nicardipine (10−7 M) failed to abolish responses to endothelin. The results suggest that the endothelium-independent constriction of cerebral arteries produced by endothelin cannot be explained solely by voltage-dependent calcium channels. The contractile responses are likely to be mediated by stimulation of specific receptors for this peptide.
Evaluation of Flavonoid Derivative and Doxorubicin Effects in Lung Cancer Cells (A549) Using Differential Pulse Voltammetry Method.
2018
Purpose: Electrochemical measurements have prompted the progress as a consequence of their affectability, cost-affectivity and comparatively short examination time. The aim of this study was the fast evaluation of the effect of chemotherapy compounds on the viability of lung cancer cells (A549) via electrochemical methods. Methods: Cyclic voltammetry (CV) was used as a primary method to distinguish between electrochemical behavior of normal and lung cancer cells. Differential pulse voltammetry (DPV) was employed as a complementary analyses method for the impact of doxorubicin (DOX) and Flavonoid modified drug (FMD) (US patent Application number: 62548886) on Lung cancer cells. Results: Only…
A Cost-Effective Solution for Clearing High-Impedance Ground Faults in Overhead Low-Voltage Lines
2019
Downed distribution conductors in overhead distribution systems may not be a concern for equipment but greatly challenge the safety of persons, as well as the integrity of properties. Standard overcurrent protective devices may not be able to detect the magnitudes of currents resulting from high-impedance ground faults. Sophisticated relays able to detect high-impedance ground faults have been available to electric utilities. However, their implementation is rather uncommon, especially in developing countries, most likely due to their costs. In this paper, the authors formalize the problem, and propose a possible cost-effective solution for low-voltage overhead lines with neutral wire. This…
EFFECT OF IONIC STRENGTH AND MEDIUM COMPOSITION ON THE REMOVAL OF Pb2+ BY ALGINATE GEL BEADS. DPVASV AND ICP-OES MEASUREMENTS.
2012
The biosorption, i.e. a passive sequestering process by metabolically inactive biomass, shows a growing interest for toxic metal ions removal from contaminated aqueous solutions (1), such as municipal and industrial wastewaters. Since the sorption mechanism occurs mainly by ion exchange between the metal ion present in solution and the counter ion of the biopolymer (2), the efficiency of the sorption process largely depends on ionic strength and on the medium composition of solution containing the metal ion to be removed. In order to evaluate quantitatively the influence of ionic strength and medium on the metal removal process by the biomass, we report here results of a study on the sorpti…
Single Event Transients and Pulse Quenching Effects in Bandgap Reference Topologies for Space Applications
2016
An architectural performance comparison of bandgap voltage reference variants, designed in a $0.18~\mu \text {m}$ CMOS process, is performed with respect to single event transients. These are commonly induced in microelectronics in the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) are used to explore the analog single-event transients and have revealed pulse quenching mechanisms in analogue circuits. The different topologies are compared, in terms of cross-section, pulse duration and pulse amplitude. The measured results, and the explanations behind the findings, reveal important guidelines for designing analog integrated circuits, which are intended for space appli…