Comparing GIPAW with numerically exact chemical shieldings: the role of two-centre contributions to the induced current

2021 ◽  
Author(s):  
Gilles A de Wijs ◽  
Georg Kresse ◽  
Remco Havenith ◽  
Martijn Marsman
Keyword(s):  
Induced Current ◽  
Chemical Shieldings

The role of induced current density in Steroelectronic effects: Perlin effect

2015 ◽  
Vol 36 (21) ◽  
pp. 1573-1578 ◽  
Author(s):  
Joseelyne G. Hernández-Lima ◽  
Jose E. Barquera-Lozada ◽  
Gabriel Cuevas ◽  
Fernando Cortés-Guzmán
Keyword(s):  
Current Density ◽  
Induced Current

Role of hole trapping by deep acceptors in electron-beam-induced current measurements in β-Ga2O3 vertical rectifiers

2020 ◽  
Vol 53 (49) ◽  
pp. 495108 ◽  
Author(s):  
E B Yakimov ◽  
A Y Polyakov ◽  
N B Smirnov ◽  
I V Shchemerov ◽  
P S Vergeles ◽  
...  
Keyword(s):  
Electron Beam ◽  
Induced Current ◽  
Hole Trapping ◽  
Electron Beam Induced Current

Molecular Diamagnetism: Uncoupled Calculations for Two Center Systems

1970 ◽  
Vol 25 (6) ◽  
pp. 867-877
Author(s):  
B. M. Ludwig ◽  
J. Voitländer
Keyword(s):  
Diamagnetic Susceptibility ◽  
Induced Current ◽  
Fermi Theory ◽  
Nodal Structure ◽  
Hartree Fock ◽  
Invariant Approximation ◽  
Shielding Constants ◽  
The Mean ◽  
Methodological Aspects

Abstract For Σ1 molecules constructed from first row elements of the Periodic Table computations of the diamagnetic susceptibility and the nuclear magnetic shielding constants are reported. The method used is a gauge invariant approximation to the gauge dependent “uncoupled” perturbation theory in the Hartree-Fock scheme; the groundstate description considered is provided by the best limited MO functions. Some emphysis is placed on methodological aspects and the role of π-electrons in this context; acceptable overall agreement with experiment is achieved, especially for the mean diamagnetic susceptibility. The phenomenon of antishielding occurring for fluorine and nitrogen nuclei is shown to depend critically upon the nodal structure of the state. A similar behaviour of the induced current density is not predicted by the semiclassical Thomas-Fermi theory, for which results are obtained too. This theory fails for principle reasons to explain the linear magnetic response of nonspherical systems.

Selected Contribution: Effect of the aldehyde acrolein on acetylcholine-induced membrane current in airway smooth muscle cells

2001 ◽  
Vol 90 (2) ◽  
pp. 750-754 ◽  
Author(s):  
Jean-Marc Hyvelin ◽  
Jean-Pierre Savineau ◽  
Roger Marthan
Keyword(s):  
Protective Role ◽  
Air Pollutant ◽  
Membrane Currents ◽  
Airway Smooth Muscle Cells ◽  
Induced Current ◽  
High Concentration ◽  
Induced Membrane ◽  
Rat Trachea ◽  
In Cells

Acrolein administered to isolated airways has been shown to alter airway responsiveness as a consequence of its effect on Ca2+ signaling. To examine the mechanisms involved, we studied the effect of acrolein on ACh- and caffeine-induced membrane currents (patch-clamp) in myocytes freshly isolated from rat trachea. In cells clamped at −60 mV, ACh (0.1–10 μM) induced a concentration-dependent inward current, which, in ∼50% of the cells, was followed by current oscillations in response to high concentration of ACh (10 μM). Exposure to acrolein (0.2 μM) for 10 min significantly enhanced the amplitude of the low-ACh (0.1 μM) concentration-induced initial peak of current (318.8 ± 28.3 vs. 251.2 ± 40.3 pA; n = 25, P < 0.05). At a high-ACh concentration (10 μM), the frequency at which subsequent peaks occurred was significantly increased (13.2 ± 1.1 vs. 8.7 ± 2 min−1; n = 20, P < 0.05). ACh-induced current was identified as a Ca2+-activated Cl− current. In contrast, similar exposure to acrolein, which does not alter caffeine-induced Ca2+ release, did not alter caffeine-induced transient membrane currents (595 ± 45 and 640 ± 45 pA in control cells and in cells exposed to acrolein, respectively; n = 15). It is concluded that acrolein alters ACh-induced current as a consequence of its effect on the cytosolic Ca2+ concentration response and that the protective role of inhibitors of Cl− channels in air pollutant-induced airway hyperresponsiveness should be examined.

scholarly journals The role of pulmonary ORCC and CLC-2 channels in the response to oxidative stress

2021 ◽  
Author(s):  
Rita Canella ◽  
Mascia Benedusi ◽  
Marta Martini ◽  
Anna Guiotto ◽  
Franco Cervellati ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Human Lung ◽  
Lung Epithelial Cells ◽  
Pharmacological Intervention ◽  
Mathematical Approach ◽  
Induced Current ◽  
Voltage Range ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

Abstract Background Exposure of human lung epithelial cells to the oxidant pollutant ozone (O3) alters cell Cl− currents inducing an outward rectifier effect. Among the various Cl− channels, ClC-2 and ORCC seemed to be involved in this response. Objectives To identify the channel related to O3 induced current changes. Results Down regulating the expression of ORCC and ClC-2 genes and analyzing the membrane current show that the enhancement of the current disappeared when ORCC was silenced. The contribution of ORCC and ClC-2 channels in control and O3 treated cells was obtained by a mathematical approach. Conclusion We suggest that O3 activates ORCC channels and slightly inhibited ClC-2 channels in the negative voltage range. These findings open the possibility of identifying the biomolecular changes induced by O3 allowing a possible pharmacological intervention towards chloride current due to oxidative stress.

Enhancement of Potency and Efficacy of NADA by PKC-Mediated Phosphorylation of Vanilloid Receptor

2004 ◽  
Vol 91 (3) ◽  
pp. 1442-1449 ◽  
Author(s):  
Louis S. Premkumar ◽  
Zhan-Heng Qi ◽  
Jeremy Van Buren ◽  
Manish Raisinghani
Keyword(s):  
Action Potentials ◽  
Vanilloid Receptor ◽  
Dependent Manner ◽  
Induced Current ◽  
Repeated Application ◽  
Drg Neurons ◽  
Kinase C ◽  
Potent Agonist ◽  
Intracellular Binding

The search for an endogenous ligand for the vanilloid receptor (VR or TRPV1) has led to the identification of N-arachidonyl dopamine (NADA). This study investigates the role of protein kinase C (PKC)-mediated phosphorylation on NADA-induced membrane currents in Xenopus oocytes heterologously expressing TRPV1 and in dorsal root ganglion (DRG) neurons. In basal state, current induced by 10 μM NADA is 5-10% of the current induced by 1 μM capsaicin or protons at pH 5. However, PKC activator, phorbol 12,13-dibutyrate (PDBu) strongly potentiated (∼15-fold) the NADA-induced current. Repeated application of NADA at short intervals potentiated its own response approximately fivefold in a PKC-dependent manner. PKC inhibitor, bisindolylmaleimide (BIM, 500 nM), a mutant TRPV1 (S800A/S502A), and maximal activation of PKC abolished the potentiation induced by repeated application of NADA. As a further confirmation that NADA could stimulate PKC, pretreatment with NADA potentiated the response of protons at pH 5 (∼20 fold), which was dramatically reduced in the mutant TRPV1. In DRG neurons, capsaicin (100 nM) induced a ∼15 mV depolarization and initiated a train of action potentials compared with 1 μM NADA that produced a ∼5 mV response. Pretreatment with PDBu induced significantly larger depolarization and potentiated NADA-induced current. Furthermore, exposure of NADA to the intracellular surface of the membrane-induced larger currents suggesting inaccessibility to the intracellular binding site might contribute to its weaker action. These results indicate that NADA is a potent agonist of VR when the receptor is in the PKC-mediated phosphorylation state.

The role of interfaces in thin-film CdTe solar cells

2002 ◽  
Vol 719 ◽  
Author(s):  
M. J. Romero ◽  
T. A. Gessert ◽  
M. M. Al-Jassim ◽  
R. G. Dhere ◽  
D.S. Albin ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Photovoltaic Effect ◽  
Cost Effective ◽  
External Circuit ◽  
Future Cost ◽  
Induced Current ◽  
Cdte Solar Cells ◽  
Electron Beam Induced Current

AbstractThin-film CdTe solar cells are very promising for future cost-effective photovoltaics. The photovoltaic effect in these cells is based on the extraction of photoexcited carriers by the field provided by the CdTe/CdS heterojunction. An additional interface with non-rectifying characteristics is needed to close the external circuit on the other side of the CdTe thin film. Finally, the transport of photoexcited carriers is influenced by the presence of grain boundaries (GBs). In this contribution, we investigate several aspects of these interfaces and their effects on the operation of CdTe solar cells by electron-beam-induced current (EBIC) and cathodoluminescence (CL) measurements.

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