Formation of Dense Nanoparticle Monolayers Mediated by Alternating Current Electric Fields and Electrohydrodynamic Flows

2010 ◽  
Vol 114 (19) ◽  
pp. 8800-8805 ◽  
Author(s):  
Myung-Geun Song ◽  
Kyle J. M. Bishop ◽  
Anatoliy O. Pinchuk ◽  
Bartlomiej Kowalczyk ◽  
Bartosz A. Grzybowski
1997 ◽  
Author(s):  
John Obringer ◽  
Brandon Horne ◽  
Brian Kelchner

1994 ◽  
Vol 8 (10) ◽  
pp. 771-776 ◽  
Author(s):  
Michael R. Cho ◽  
Hemant S. Thatte ◽  
Raphael C. Lee ◽  
David E. Golan

2019 ◽  
Author(s):  
Ehsan Negahbani ◽  
Iain M. Stitt ◽  
Marshall Davey ◽  
Thien T. Doan ◽  
Moritz Dannhauer ◽  
...  

SummaryModeling studies predict that transcranial alternating current stimulation (tACS) entrains brain oscillations, yet direct examination has been lacking or potentially contaminated by stimulation artefact. Here we first demonstrate how the posterior parietal cortex drives primary visual cortex and thalamic LP in the alpha-band in head-fixed awake ferrets. The spike-field synchrony is maximum within alpha frequency, and more prominent for narrow-spiking neurons than broad-spiking ones. Guided by a validated model of electric field distribution, we produced electric fields comparable to those in humans and primates (< 0.5 mV/mm). We found evidence to support the model-driven predictions of how tACS entrains neural oscillations as explained by the triangular Arnold tongue pattern. In agreement with the stronger spike-field coupling of narrow-spiking cells, tACS more strongly entrained this cell population. Our findings provide the firstin vivoevidence of how tACS with electric field amplitudes used in human studies entrains neuronal oscillators.


2014 ◽  
Vol 16 (1) ◽  
pp. 93-102 ◽  

Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.


2020 ◽  
Vol 123 (1) ◽  
pp. 428-438 ◽  
Author(s):  
Kohitij Kar ◽  
Takuya Ito ◽  
Michael W. Cole ◽  
Bart Krekelberg

Transcranial alternating current stimulation (tACS) is used as a noninvasive tool for cognitive enhancement and clinical applications. The physiological effects of tACS, however, are complex and poorly understood. Most studies of tACS focus on its ability to entrain brain oscillations, but our behavioral results in humans and extracellular recordings in nonhuman primates support the view that tACS at 10 Hz also affects brain function by reducing sensory adaptation. Our primary goal in the present study is to test this hypothesis using blood oxygen level-dependent (BOLD) imaging in human subjects. Using concurrent functional magnetic resonance imaging (fMRI) and tACS, and a motion adaptation paradigm developed to quantify BOLD adaptation, we show that tACS significantly attenuates adaptation in the human motion area (hMT+). In addition, an exploratory analysis shows that tACS increases functional connectivity of the stimulated hMT+ with the rest of the brain and the dorsal attention network in particular. Based on field estimates from individualized head models, we relate these changes to the strength of tACS-induced electric fields. Specifically, we report that functional connectivity (between hMT+ and any other region of interest) increases in proportion to the field strength in the region of interest. These findings add support for the claim that weak 10-Hz currents applied to the scalp modulate both local and global measures of brain activity. NEW & NOTEWORTHY Concurrent transcranial alternating current stimulation (tACS) and functional MRI show that tACS affects the human brain by attenuating adaptation and increasing functional connectivity in a dose-dependent manner. This work is important for our basic understanding of what tACS does, but also for therapeutic applications, which need insight into the full range of ways in which tACS affects the brain.


2015 ◽  
Vol 29 (11) ◽  
pp. 7601-7611 ◽  
Author(s):  
Hao Duan ◽  
Xiaomin Wu ◽  
Cong Zhang ◽  
Yuchen Cui ◽  
Juncai Hou ◽  
...  

2012 ◽  
Vol 116 (45) ◽  
pp. 13516-13524 ◽  
Author(s):  
Erwan Paineau ◽  
Ivan Dozov ◽  
Adrian-Marie Philippe ◽  
Isabelle Bihannic ◽  
Florian Meneau ◽  
...  

Author(s):  
Yevgen Honcharov ◽  
Nataliya Kruykova ◽  
Vladyslav Markov ◽  
Igor Polyakov

A definition of the "reactive power" concept needs to be clarified, since in the literature it is often given extremely vaguely, which causes difficulties in students' perception and is not entirely clear to the general public. Analysis of numerous sources shows that the physical meaning of this concept almost escapes the definitions given in these sources. Moreover, the formula by which the reactive power is calculated raises no objections. However, it does not explain the physical meaning of the concept. The need for a capacious definition that reflects the physical meaning is long overdue. Analysis of literature sources allows us to conclude that reactive power corresponds to the energy that goes from the source to the consumer and returns back, moreover, the process of circulation of this energy proceeds without dissipation. This energy is stored in inductors, keeping the current constant, and in capacitors, because they charge and discharge, keeping the voltage constant. The inductance and capacitance of the circuit consume and return reactive power. The power transferred to the inductor is stored in the magnetic field when the field expands and returns to the source when the field collapses. The power supplied to the capacitor is stored in an electrostatic field when the capacitor is charged and returned to the source when the capacitor is discharged. This power supplied to the circuit by the source is not consumed. It all returns to the source. Thus, the active power, which is the consumed power, is zero. We know that alternating current is constantly changing; thus, cycles of expansion and collapse of magnetic and electrostatic fields constantly occur. The following definition is proposed: non-dissipated electrical energy of alternating current, which excites the magnetic or electric fields, respectively, in inductive and capacitive elements and, coming from them back to the network, is called reactive power.


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