Amplitude Of Electrical Signal Research Articles

Preliminary analysis of neuroprotective effects of capillary fascia preservation recurrent laryngeal nerve anatomical method in right level Ⅵ dissection

Objective: To investigate the application and effect of capillary fascia preservation between the recurrent laryngeal nerve (RLN) and common carotid artery (fascia preservation method) in nerve protection when dissecting right level Ⅵ lymph nodes for patients with papillary thyroid carcinoma. Methods: A retrospective cohort study enrolling 195 patients with papillary thyroid carcinoma undergoing right level Ⅵ lymph node dissection in Beijing Tongren Hospital from March 2021 to August 2022 was carried out. The RLN was dissected by fascia preservation method in study group and by routine method in control group. The intraoperative electrical signal amplitude of the RLN, the number of dissected lymph nodes, and the postoperative complications were recorded and analyzed. Results: A total of 195 patients (study group: 94 cases, control group: 101 cases) were collected. There were 71 males and 124 females, with the median age of 32 (39, 51) years. In the study group, the total number of right level Ⅵ lymph nodes was significantly larger than the number of right Ⅵa level lymph nodes [8 (6, 11) vs 6 (4, 8), P<0.001]. There were no significant differences between the two groups in the number of level Ⅵa or level Ⅵb lymph nodes [Ⅵa: 6 (4, 8) vs 5 (3, 7), P=0.373; Ⅵb: 3 (1, 4) vs 2 (1, 4), P=0.337] and metastasis rate [Ⅵa: 51.1% (48/94) vs 52.5% (53/101), P=0.844; Ⅵb: 12.8% (12/94) vs 15.8% (16/101), P=0.541]. The ratio of electromyography (EMG) amplitude R2 in lower level Ⅵ and entry into larynx (grouped as>90%, 50%~90%,<50%) in the study group was significantly higher than that in the control group (P<0.001). No significant differences were detected between the two groups in temporary RLN paralysis [1.1% (1/94) vs 2.0% (2/101), P=1.000]. Conclusions: Fascia preservation method can decrease the stimulus and traction to RLN and preserve the capillary network serving RLN. It can thoroughly dissect lymph nodes and decrease the injury of RLN.

Clinical advantages and neuroprotective effects of monitor guided fang's capillary fascia preservation right RLN dissection technique.

ObjectiveTo investigate the feasibility and advantages of Fang’s capillary fascia preservation right recurrent laryngeal nerve (RLN) dissection technique (F-R-RLN dissection) with preservation of the capillary network and fascia between the RLN and common carotid artery for greater neuroprotective efficiency compared with traditional techniques.MethodsWe retrospectively analyzed 102 patients with papillary thyroid carcinoma undergoing right level VI lymph node dissection in our department from March 2021 to January 2022. Sixty patients underwent F-R-RLN dissection (the experimental group) and 42 patients underwent standard dissection (the control group). The intraoperative electrical signal amplitude ratios of the RLN, the number of dissected lymph nodes, and the preservation rates of the parathyroid glands were recorded and compared between the two groups.ResultsThe electrical signal amplitude ratio of the lower neck part point of the RLN to the upper laryngeal inlet point in the experimental group was significantly lower than the ratio in the control group (p = 0.006, Z-score = -2.726). One patient suffered transient RLN paralysis in both groups, but this resolved within 1 month after operation. There were no significant differences between the two groups in terms of the number of level VIa or level VIb lymph nodes dissected, nor in the rate of preservation of the parathyroid glands.ConclusionsF-R-RLN dissection is a thorough dissection technique that is effective at preventing an electrical signal amplitude decrease in the RLN, and at preventing RLN paralysis by preserving its blood supply.

Assessment of the potential damaging effect of radiofrequency exposure in children in prospective follow-up (case report series)

Aim: To evaluate the electrical activity of the myocardium and the radiofrequency (RF) application zone resulting from radiofrequency ablation (RFA) performed at an early age.Material and Methods. A prospective follow-up study included three patients who underwent intracardiac electrophysiological study (EPS) and effective RFA of the tachycardia for the first time at an early age. A reintervention was required in one case 12 years after the procedure and in two cases six years after it due to recurrent and new-onset arrhythmias. During the reintervention, electroanatomical mapping was performed to assess the potential damaging effect of radiofrequency exposure in the area of the first ablation.Results. The intracardiac EPS and amplitude bipolar CARTO-reconstruction of primary ablation area were performed during repeated RFA procedure. The study showed that neither zones with a decrease in the amplitude of electrical signal from the myocardium nor silent electrical zones were present ruling out the cicatricial-sclerotic changes in the myocardium in children in the long-term period after RF exposure.Conclusion. The study showed that no increase in the coagulation necrosis zone in the area of primary ablation occurred during the growth of child when the sparing energy and temperature parameters of RFA and the limited number of RF applications were used. Further research in this area is required.

Evidence for the impact of BAG3 on electrophysiological activity of primary culture of neonatal cardiomyocytes.

Homeostasis of proteins involved in contractility of individual cardiomyocytes and those coupling adjacent cells is of critical importance as any abnormalities in cardiac electrical conduction may result in cardiac irregular activity and heart failure. Bcl2-associated athanogene 3 (BAG3) is a stress-induced protein whose role in stabilizing myofibril proteins as well as protein quality control pathways, especially in the cardiac tissue, has captured much attention. Mutations of BAG3 have been implicated in the pathogenesis of cardiac complications such as dilated cardiomyopathy. In this study, we have used an in vitro model of neonatal rat ventricular cardiomyocytes to investigate potential impacts of BAG3 on electrophysiological activity by employing the microelectrode array (MEA) technology. Our MEA data showed that BAG3 plays an important role in the cardiac signal generation as reduced levels of BAG3 led to lower signal frequency and amplitude. Our analysis also revealed that BAG3 is essential to the signal propagation throughout the myocardium, as the MEA data-based conduction velocity, connectivity degree, activation time, and synchrony were adversely affected by BAG3 knockdown. Moreover, BAG3 deficiency was demonstrated to be connected with the emergence of independently beating clusters of cardiomyocytes. On the other hand, BAG3 overexpression improved the activity of cardiomyocytes in terms of electrical signal amplitude and connectivity degree. Overall, by providing more in-depth analyses and characterization of electrophysiological parameters, this study reveals that BAG3 is of critical importance for electrical activity of neonatal cardiomyocytes.

Extremely High Frequency Electromagnetic Fields Facilitate Electrical Signal Propagation by Increasing Transmembrane Potassium Efflux in an Artificial Axon Model

Among the many biological effects caused by low intensity extremely high frequency electromagnetic fields (EHF-EMF) reported in the literature, those on the nervous system are a promising area for further research. The mechanisms by which these fields alter neural activity are still unclear and thus far there appears to be no frequency dependence regarding neuronal responses. Therefore, proper in vitro models for preliminary screening studies of the interaction between neural cells with EMF are needed. We designed an artificial axon model consisting of a series of parallel RC networks. Each RC network contained an aqueous solution of lipid vesicles with a gradient of potassium (K+) concentration as the functional element. We investigated the effects of EHF-EMF (53.37 GHz–39 mW) on the propagation of the electric impulse. We report that exposure to the EHF-EMF increases the amplitude of electrical signal by inducing a potassium efflux from lipid vesicles. Further, exposure to the EHF-EMF potentiates the action of valinomycin – a K+ carrier – increasing the extent of K+ transport across the lipid membrane. We conclude that exposure to the EHF-EMF facilitates the electrical signal propagation by increasing transmembrane potassium efflux, and that the model presented is promising for future screening studies of different EMF frequency spectrum bands.

Electrical Activity of the Bladder Is Attenuated by Intravesical Inhibition of P2X2/3 Receptors During Micturition in Female Rats.

PurposeTo simultaneously monitor electrical discharges in various bladder regions and the external urethral sphincter (EUS) during voiding contractions, and to assess the functional role of myogenic modulation of the lower urinary tract (LUT) by ionotropic purinergic receptors containing the P2X3 subunit.MethodsFemale Sprague-Dawley rats were anesthetized with urethane, and implanted with a suprapubic catheter for open cystometry. Flexible microelectrodes were placed ventrally in the bladder dome, upper bladder, lower bladder, and bladder base, along with the middle section of the exposed EUS. Intravesical P2X3-containing receptors were blocked with AF-323, a specific P2X3-P2X2/3 receptor antagonist. A digital electrophysiology amplifier was used to record electrical and cystometric signals throughout the LUT.ResultsElectrical activity in the LUT started before effective voiding contractions. Bladder pressure and electrical waveforms showed consistent out-of-phase activity when compared with the recordings made at the EUS. This pattern was also observed during voiding contractions in the presence of AF-353, supporting the hypothesis that during bladder distension, activation of P2X3-containing receptors is required for voiding contractions. Furthermore, the inhibition of P2X3-containing receptors significantly decreased the amplitude of electrical signals in the urinary bladder, but not the base or EUS.ConclusionsOur results provide novel information about the regulation of the micturition process by P2X3-containing receptors located in the inner layers of the bladder.

COBRA: a zero-deadtime camera based multiparticle detector

SynopsisA new time and position sensitive detector is described, which combines an MCP stack with a phosphor screen, a CMOS camera and a waveform digitizer. Particle identification relies on the correlation between brightness of phosphor screen spots and amplitude of electrical signals (COBRA).

X-ray diffraction on the X-cut of a Ca3TaGa3Si2O14 single crystal modulated by a surface acoustic wave

The result of X-ray diffraction study on a single crystal of the calcium-gallogermanate family Ca3TaGa3Si2O14 (CTGS) modulated by a surface acoustic wave (SAW) is presented. The power flow angle for SAW propagating along the X2 axis of the X-cut in CTGS was measured. The rocking curves for the CTGS crystal were recorded at different amplitudes of an input high frequency electric signal on interdigital transducer used to excite a SAW. Based on the data obtained, intensity dependence of diffraction satellites on the amplitude of electric signal exciting a SAW was built. Numerical simulation of the crystal rocking curves and dependence of diffraction satellite intensities on the SAW amplitude enabled the selection of a set of material constants at which the most complete coincidence of experimental and calculated results is observed.

Research on Characteristics of Plant Electrical Signal under High Voltage Pulse Stimulation

In order to further understand the Agave americana var. marginata electrical signals in High Voltage Pulse Stimulation conditions, a new method is provided in this paper by using wavelet soft threshold noise reduction and the power spectrum analysis. The results show that the level `of its electrical distribution in uV. The plant electrical signal amplitude arithmetic mean increases with the increase of pulse stimulation signal but for a little effect on the natural frequency of the plant, its frequency is mainly distributed in the 0.07813 Hz ~0.1953 Hz.

An induced current method for measuring zeta potential of electrolyte solution–air interface

This paper reports a novel and very simple method for measuring the zeta potential of electrolyte solution–air interface. When a measuring electrode contacts the electrolyte solution–air interface, an electrical current will be generated due to the potential difference between the electrode–air surface and the electrolyte solution–air interface. The amplitude of the measured electric signal is linearly proportional to this potential difference; and depends only on the zeta potential at the electrolyte solution–air interface, regardless of the types and concentrations of the electrolyte. A correlation between the zeta potential and the measured voltage signal is obtained based on the experimental data. Using this equation, the zeta potential of any electrolyte solution–air interface can be evaluated quickly and easily by inserting an electrode through the electrolyte solution–air interface and measuring the electrical signal amplitude. This method was verified by comparing the obtained results of NaCl, MgCl2 and CaCl2 solutions of different pH values and concentrations with the zeta potential data reported in the published journal papers.

Review of unprecedented ULF electromagnetic anomalous emissions possibly related to the Wenchuan &amp;lt;i&amp;gt;M&amp;lt;/i&amp;gt;&amp;lt;sub&amp;gt;S&amp;lt;/sub&amp;gt; = 8.0 earthquake, on 12 May 2008

Abstract. This work presents ground based ultra low frequency (ULF) electromagnetic field measurements in the frequency range 0.1–10 Hz from January 2007 to December 2008. In this time period a strong earthquake series hits the Wenchuan region with a main shock of magnitude MS = 8.0 on 12 May 2008. The Hebei ULF electromagnetic observation network includes eight observation stations in north China and the observation system named E-EM is employed to record the electric potential difference between two electrodes with an analog automatic real-time continuous pen recorder. First, weak electric signals appeared on 11 October 2007 at Ningjin station, most of which are with relative long periods ~0.4–3 s and unequal amplitudes ~0.5–20 mm. Then, similar signals appeared at Gaobeidian station at the end of October. Abnormal behavior with various time intervals appeared randomly and not every day. At the beginning of April 2008, one and a half months before the Wenchuan MS = 8.0 earthquake, the anomalies were gradually subject to an intensive increase mainly in Gaobeidian SN direction and Ningjin EW direction. The abnormal behavior appeared almost every day and the amplitudes of electric signals, with short periods of ~0.1–0.3 s, enhanced to ~3–30 mm. Qingxian station started to record marginally high frequency signals in SN and EW components in the middle of April. On 9 May, 3 days before the main shock, the amplitude of high frequency information increased sharply at the same time in two components at Gaobeidian station and the maximum amplitude was up to 70 mm, i.e. 1.3 mV m−1 for the electric field. This situation did not stop until 17 May, 5 days after the main event. However, this kind of climax phenomena did not happen at Ningjin station and Qingxian station. Then weak anomalous information lasted about four months again, and strong signals appeared again for a short time before several powerful aftershocks. It is the first time that an abnormity with so large an amplitude and so long a duration time in the observation history of this network though several strong earthquakes were recorded. Furthermore, no obvious interferences have been found during this period. So this event is possibly related to this shock although all these three stations are more than 1300 km away from the Wenchuan earthquake epicenter.

Functional Assessment of Crystallization-Optimized G Protein-Coupled Receptors using Ion Channel-Coupled Receptors

Ion Channel-Coupled Receptors (ICCRs) are artificial ligand-gated ion channels created by genetic fusion of G protein-coupled receptors (GPCRs) to a K+ inward rectifier channel (Kir6.2) such that the channel is a direct reporter of the receptor conformational changes. This concept has been validated with 4 prototypical GPCRs: the M2 muscarinic, the D2L dopaminergic, the β2 adrenergic and the opsin receptors (Moreau et al., Nature Nanotech 3:620 2008, Caro et al. PLoS ONE 6:e18226 2011, Caro et al. PLoS ONE 7:e43766 2012). Voltage-clamp recordings showed that ICCRs detect the agonist- and antagonist-bound states of the receptor via direct physical coupling. This GPCR-channel communication proceeds without any involvement of G proteins and the electrical signal amplitude is correlated with the ligand concentration.The intrinsic instability of the GPCRs has proved a challenge to crystallographic studies. A successful approach, introduced in 2007 by Cherezov et al (Science. 318:1258) and subsequently applied to obtain 12 GPCR structures, consists in the insertion of the T4 phage lysozyme domain in the 3rd intracellular loop of the receptors. However, this modification abolishes G protein binding and prohibits related functional assays. Current characterization of crystallization-optimized GPCR(T4L) is performed by radiolabeled ligand assays or localized FRET techniques. Requiring no biochemical steps, ICCRs are an alternative tool to functionally characterize modified GPCRs that are unable to bind or activate G proteins and not amenable to most GPCR functional assays. We demonstrate here the validity of this tool with 3 different GPCRs (M2-muscarinic, β2-adrenergic and oxytocin receptors). The final application of this study would be the integration of this technology in the current crystallographic platforms dedicated to GPCR structure determination or for structure-function studies independent of G protein interaction.

Mechanoelectrical transformations in heterogeneous materials with piezoelectric inclusions

Mechanoelectrical transformations are studied on models with different geometries and piezoelectric inclusion concentrations. The electrical signal intensity is found to decrease with increasing depth of a piezoelectric source relative to the position of an electrical signal detector. The electrical signal is the difference between signals from the unlikely charged surfaces of the piezoelectric source being deformed by an acoustic excitation wave. The spectral amplitudes of electrical signals coming from different regions of one sample and from identical (in composition) samples containing a large amount of piezoelectric inclusions differ considerably. This difference is due to the random orientation of the quartz piezoelectric axes relative to the electrical detector. Therefore, nondestructive mechanoelectrical techniques for inspection of heterogeneous materials with piezoelectric inclusions must use amplitude-independent criteria.

The Changes of Electrical Signals in Corn at Different Temperatures

Electrical signals in plants play the role of biological messages. It is significant to make them understood. In order to acquire the basic characteristics of the electrical signal in corn, wavelet soft-threshold de-noising method was introduced to reduce the noise for the acquisition signals. The amplitudes of electrical signals in corn were μV level, and the frequencies were below 1Hz, large parts of which were lower than 0.5Hz. The amplitudes were large, and the distribution of power spectrum was stable when the environment temperature between 20°C and 35°C. The ratio of signal below 0.1Hz gained when the temperature was above 35°C, while the amplitude reduced obviously. It can be considered that the disappearance of the high frequency and the reducing of the amplitudes were the signs of cell vital activity subsiding. Thus, it is possible to achieve the prediction life status according to the amplitudes and the frequencies of electrical signals in plants.

Ultrasonic Investigation of Field-Induced Piezoelectric Properties in Lead Free Materials

Ultrasonic method was applied for evaluation of piezoelectricity in layered crystals of CuInP2S6 family and of La(Mg1/2Ti1/2)O3-BaTiO3 (BT-LMT) electroceramics. Amplitude of electric signal appearing on the plate under ultrasonic excitation is proportional to appropriate piezoelectric constant. In CuInP2S6 family piezosensitivity was observed only in low temperature phase. In BT-LMT ceramics piezosensitivity had anomalies at low temperature phase transitions and had long tails in the high temperature paraelectric phase. Field-induced hysteresis loops of such ultrasonically detected piezoelectric signal amplitude in the ferroelectric phase were observed. In the paraelectric phase field-induced piezosensitivity due to electrostriction appeared in layered crystals and BT-LMT ceramics when DC bias electric field was applied. In centrosymetric AgInP2Se6 crystals comparatively large piezoelectric sensitivity was induced due to electrostriction by DC bias electric field applied along c-axis.

Generation of an electric signal in the interaction of HF-laser radiation with bottom surface of a water column

Generation of an electrical signal (ES) is experimentally investigated in the interaction of the pulse of a non-chain electric-discharge HF laser with the bottom surface of a water column. It was found that the ES amplitude is influenced by thin water layers (water contacts) present in the system under study, which undergo mechanical action in the process of water column movement initiated by the laser. Approximately ten-fold increase in the ES amplitude is observed if the water layer is present in the gap between the end of the water cell and surface of the quartz plate covering the cell and having a contact with the top water column boundary, as compared to the case of the free top boundary. Possible reasons for the thin water layer influence on ES characteristics and for the mechanism for the second ES peak origin in collapsing of the vapour cavity produced during water volume explosive boiling under the laser radiation are qualitatively discussed.

Unavoidable errors: A spatio-temporal analysis of time-course and neural sources of evoked potentials associated with error processing in a speeded task

The detection of errors is known to be associated with two successive neurophysiological components in EEG, with an early time-course following motor execution: the error-related negativity (ERN/Ne) and late positivity (Pe). The exact cognitive and physiological processes contributing to these two EEG components, as well as their functional independence, are still partly unclear. Furthermore, these components are typically obtained in conditions where errors are rare events relative to correct trials, and thus presumably implicate other cognitive and motivational processes besides error monitoring. Here, we investigated error processing using high-density scalp ERPs and advanced topographical analyses in healthy participants, during a new Go/noGo task that led to many errors within a relatively short period of time, yet without generating frustration or insufficient motivation. ERP results showed the presence of two distinct electrophysiological markers of error monitoring (ERN/Ne and Pe) during this task, even though errors were practically as frequent as correct responses. Topographic mapping analyses showed for the first time that both the ERN/Ne and Pe elicited a specific distribution of electrical activity relative to correct responses (not just a change in the amplitude of electric signals), suggesting the activation of a distinct configuration of intracranial generators during error detection. This was confirmed by additional analyses using dipole source localization, showing generators in anterior cingulate cortex contributing to the ERN/Ne, but in more posterior cingulate regions for Pe. Moreover, we found that, across all participants, the magnitude of the ERN/Ne correlated with the level of state anxiety, even in the subclinical range, whereas the Pe was correlated negatively with the total number of errors and positively with the improvement of response speed on correct trials. By contrast, no significant relation was found between error monitoring ERPs and individual measures of impulsivity. Taken together, these data suggest that these two successive EEG components associated with errors reflect different monitoring processes, with distinct neural substrates in cingulate cortex. While ERN/Ne processes in anterior cingulate might primarily mediate error detection, Pe processes in posterior cingulate might be more directly related to behavioral adjustment based on the outcome of current actions.

Sustained Rhythmic Activity in Gap-Junctionally Coupled Networks of Model Neurons Depends on the Diameter of Coupled Dendrites

Gap junctions are known to be important for many network functions such as synchronization of activity and the generation of waves and oscillations. Gap junctions have also been proposed to be essential for the generation of early embryonic activity. We have previously shown that the amplitude of electrical signals propagating across gap-junctionally coupled passive cables is maximized at a unique diameter. This suggests that threshold-dependent signals may propagate through gap junctions for a finite range of diameters around this optimal value. Here we examine the diameter dependence of action potential propagation across model networks of dendro-dendritically coupled neurons. The neurons in these models have passive soma and dendrites and an action potential-generating axon. We show that propagation of action potentials across gap junctions occurs only over a finite range of dendritic diameters and that propagation delay depends on this diameter. Additionally, in networks of gap-junctionally coupled neurons, rhythmic activity can emerge when closed loops (re-entrant paths) occur but again only for a finite range of dendrite diameters. The frequency of such rhythmic activity depends on the length of the path and the dendrite diameter. For large networks of randomly coupled neurons, we find that the re-entrant paths that underlie rhythmic activity also depend on dendrite diameter. These results underline the potential importance of dendrite diameter as a determinant of network activity in gap-junctionally coupled networks, such as network rhythms that are observed during early nervous system development.

Generation of an electrical signal upon the interaction of laser radiation with water surface

A new physical effect lying in the generation of an electrical signal (ES) upon the interaction of IR laser radiation with the water surface at a laser fluences lower than the plasma formation threshold is studied. An ES amplitude exceeding 15 V is detected. A one-to-one relationship between the observed effect and the bulk explosive boiling of water is established, and a qualitative interpretation is proposed. In the case of irradiation of an open surface, the ES is generated due to bulk explosive boiling accompanied by the evacuation and splashing of the surface layer, the destruction of the double electric layer on the surface, and the spread of an electrified vapor-drop mixture (balloelectric effect). When the surface is covered with a transparent plate, ES generation can be caused by the charge separation upon the detachment of the water surface from the plate by a vapor bubble resulting from boiling and the displacement of the charged water surface upon the expansion and contraction of the bubble.

The origin of the skewed amplitude distribution of spontaneous excitatory junction potentials in poorly coupled smooth muscle cells

The skewed amplitude distribution of spontaneous excitatory junction potentials (sEJPs) in the mouse vas deferens and other electrically-coupled smooth muscle syncytia has been attributed to electrically-attenuated depolarizations resulting from the spontaneous release of quantized packets of ATP acting on remote smooth muscle cells (SMCs). However, in the present investigation surface SMCs of the mouse isolated vas deferens were poorly electrically coupled, with input resistances (176±18 MΩ, range: 141–221 MΩ, n=4) similar to those of dissociated cells. Furthermore, the amplitude of evoked EJPs was more variable in surface compared with deeper SMCs (F test, F=17.4, P<0.0001). Using simultaneous electrophysiology and confocal microscopy to investigate these poorly-coupled cells, it is shown that α-latrotoxin-stimulated sEJPs correlate, in timing (median delay ranged from −30 to −57 ms, P<0.05 in all experiments, n=5) and amplitude (Pearson product moment correlation, ρ>0.55 and P<0.001), with purinergic neuroeffector Ca2+ transients (NCTs) in SMCs. The temporal correlation between sEJPs of widely ranging amplitude with NCTs in the impaled SMC demonstrates that all sEJPs could arise from neurotransmitter action on the impaled cell and that the skewed distribution of sEJPs can be explained by the variable effect of packets of ATP on a single SMC. The amplitude correlation of sEJPs and NCTs argues against the attenuation of electrical signal amplitude along the length of a single SMC. The skewed sEJP amplitude distribution arising from neurotransmitter release on single SMCs is consistent with a broad neurotransmitter packet size distribution at sympathetic neuroeffector junctions.