Low-level Currents Research Articles

Novel electrical characteristic measurement system of semiconductor films for estimating device characteristics

We proposed a novel measurement method and system to measure the electrical characteristics of non-patterned semiconductor films to estimate the final device’s properties. The proposed method is based on measuring bottom-gate structure thin-film transistor (TFT) using the probe pins as source and drain electrodes. We carefully designed the array structure and material of the probe pin to effectively detect extremely low-level currents without patterned electrodes on the semiconductor film. The contact pressure was also carefully controlled through continuous monitoring using an implemented pressure sensor to ensure the reliability and reproducibility of the measured data. In addition, we developed a method of extracting device parameters, such as the threshold voltage and field-effect mobility, from the measured data, considering the geometric factor of the proposed method. Comparative analysis between the measurement results of the film sample using the proposed system and that of the final TFT sample exhibited similar results with slight deviations. Furthermore, the proposed system provided similar results under repetitive measurements. Consequently, the proposed method and system successfully demonstrated the estimation of the final TFT’s properties by measuring the electrical characteristics of the non-patterned semiconductor film with excellent reliability, highlighting the possibility of effectively reducing costs for development and fabrication.

High-Throughput Growth of Armored Perovskite Single Crystal Fibers for Pixelated Arrays.

The poor machinability of halide perovskite crystals severely hampered their practical applications. Here a high-throughput growth method is reported for armored perovskite single-crystal fibers (SCFs). The mold-embedded melt growth (MEG) method provides each SCF with a capillary quartz shell, thus guaranteeing their integrality when cutting and polishing. Hundreds of perovskite SCFs, exemplified by CsPbBr3, CsPbCl3, and CsPbBr2.5I0.5, with customized dimensions (inner diameters of 150-1000µm and length of several centimeters), are grown in one batch, with all the SCFs bearing homogeneity in shape, orientation, and optical/electronic properties. Versatile assembly protocols are proposed to directly integrate the SCFs into arrays. The assembled array detectors demonstrated low-level dark currents (< 1nA) with negligible drift, low detection limit (< 44.84nGys-1), and high sensitivity (61147µCGy-1cm-2). Moreover, the SCFs as isolated pixels are free of signal crosstalk while showing uniform X-ray photocurrents, which is in favor of high spatial resolution X-ray imaging. As both MEG and the assembly of SCFs involve none sophisticated processes limiting the scalable fabrication, the strategy is considered to meet the preconditions of high-throughput productions.

Harnessing tidal energy efficiency: A comprehensive analysis of tandem flapping hydrofoils for maximizing power generation from low-level currents

Harnessing natural water currents for renewable energy generation holds significant promise. Flapping foil hydrokinetic turbines (FHTs), inspired by aquatic organisms' propulsion mechanisms, leverage undulating motion to extract energy from flowing water. This study investigates the impact of hydrofoil shape and mechanical parameters on oscillating tandem hydrofoil systems' performance for energy harvesting, focusing on Persian Gulf tidal currents. Computational Fluid Dynamics (CFD) in a 2D domain is employed for analysis. Parameters include hydrofoil profiles (IFS, NACA 0015, HSVA, and flat plate), damping coefficient, and initial pitch angle optimized for low-level currents around 1 m/s, derived from HYCOM data. Numerical simulations highlight the superior hydrodynamic efficiency of the IFS hydrofoil. Through RANS equations in unsteady conditions, an optimal configuration with a 75-degree initial angle and damping coefficient of 4 achieves a maximum power efficiency of approximately 66.77%. Efforts have been made to ensure data accuracy, including rounding reported efficiencies appropriately and conducting thorough uncertainty analyses.

Longitudinal Retrospective Study of a Wearable NMES System to Determine the Effects on Arm Usage in Hemiparetic and Hemiplegic Patients

ABSTRACT Introduction Brain disorders such as traumatic brain injury (TBI), stroke, cerebral palsy (CP), and surgical interventions can result in aberrant motor function in the contralateral limbs, resulting in paralysis, weakness, and/or spasticity. It is known that, in the short term, neuromuscular electrical stimulation (NMES), the application of low-level electrical currents to motor nerves to induce muscle contractions in paralyzed muscles, can stimulate affected muscle groups and increase arm mobility. However, there remains a paucity of longitudinal evidence examining NMES-mediated improvements of arm usage. Objective The aim of this study was to determine the effectiveness of a long-term BioSleeve intervention on the recovery of arm mobility in hemiparetic patients. Study Design The design of this study is a retrospective cohort study. Methods We examined self-reported arm usage in patients with 1) TBI, 2) stroke, 3) hemispherectomy, or 4) CP who wore Axiobionics’ BioSleeve NMES device and compared this to arm usage achieved from years of conventional therapy. Results The device was well-tolerated. Patients reported an average increase in arm usage from 9.9% to 43.5%, with the TBI subcohort reporting a consistent increase in arm usage of 5.7% per year over the treatment period. Conclusions This study supports the literature suggesting that longitudinal NMES can be used to increase arm usage in hemiplegic patients. Clinical Relevance Statement This study supports the use of wearable NMES intervention in the treatment of arm hemiparesis.

Bioelectric medicine: unveiling the therapeutic potential of micro-current stimulation.

Bioelectric medicine (BEM) refers to the use of electrical signals to modulate the electrical activity of cells and tissues in the body for therapeutic purposes. In this review, we particularly focused on the microcurrent stimulation (MCS), because, this can take place at the cellular level with sub-sensory application unlike other stimuli. These extremely low-level currents mimic the body's natural electrical activity and are believed to promote various physiological processes. To date, MCS has limited use in the field of BEM with applications in several therapeutic purposes. However, recent studies provide hopeful signs that MCS is more scalable and widely applicable than what has been used so far. Therefore, this review delves into the landscape of MCS, shedding light on the multifaceted applications and untapped potential of MCS in the realm of healthcare. Particularly, we summarized the hierarchical mediation from cell to whole body responses by MCS including its physiological applications. Our final objective of this review is to contribute to the growing body of literature that unveils the captivating potential of BEM, with MCS poised at the intersection of technological innovation and the intricacies of the human body.

Microcurrent therapy as the nonpharmacological new protocol against Alzheimer's disease.

Alzheimer's disease (AD) poses an increasing global health challenge and is marked by gradual cognitive deterioration, memory impairment, and neuroinflammation. Innovative therapeutic approaches as non-pharmacological protocol are urgently needed with side effect risk of drugs. Microcurrent therapy, a non-invasive modality involving low-level electrical currents, has emerged as a potential solution to address AD's complex pathogenesis. This study investigates the optimal application of microcurrent therapy as a clinical protocol for AD, utilizing a comprehensive approach that integrates behavioral assessments and neuroinflammation evaluation in a mouse model of dementia. The results reveal that microcurrent therapy holds promise in ameliorating memory impairment and reducing neuroinflammation in AD. Behavioral assessments, including the Novel Object Recognition Test (NOR) and Radial Arm Maze Test (RAM), demonstrated improved cognitive function following microcurrent therapy. Furthermore, microcurrent therapy inhibited expression of neuroinflammatory proteins, including ionized calcium binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP) in current-treated group. Mechanistic insights suggest that microcurrent therapy may modulate neuroinflammation through the regulation of MAPK signaling pathways. This study emphasizes the prospect of microcurrent therapy as a safe and efficacious non-pharmacological strategy for Alzheimer's disease (AD), providing optimism to the countless individuals impacted by this debilitating ailment. These results contribute to the developments of an innovative clinical protocol for AD and recovery from neurological injury, underscoring the significance of investigating unconventional therapeutic approaches for addressing this complex condition.

Electrical stimulation: a novel therapeutic strategy to heal biological wounds.

Electrical stimulation (ES) has emerged as a powerful therapeutic modality for enhancing biological wound healing. This non-invasive technique utilizes low-level electrical currents to promote tissue regeneration and expedite the wound healing process. ES has been shown to accelerate wound closure, reduce inflammation, enhance angiogenesis, and modulate cell migration and proliferation through various mechanisms. The principle goal of wound management is the rapid recovery of the anatomical continuity of the skin, to prevent infections from the external environment and maintain homeostasis conditions inside. ES at the wound site is a compelling strategy for skin wound repair. Several ES applications are described in medical literature like AC, DC, and PC to improve cutaneous perfusion and accelerate wound healing. This review aimed to evaluate the primary factors and provides an overview of the potential benefits and mechanisms of ES in wound healing, and its ability to stimulate cellular responses, promote tissue regeneration, and improve overall healing outcomes. We also shed light on the application of ES which holds excellent promise as an adjunct therapy for various types of wounds, including chronic wounds, diabetic ulcers, and surgical incisions.

Facile Method for the Preperation of a Stable, and High Performance UV-Vis Photodetector with Poly(3-hexylthiophene-2,5-diyl):PCBM Composite Polymer

A high performance and stable UV-Vis hybrid photodetector with P3HT:PCBM composite polymer film encapsulated with a micro thin layer of Polydimethylsiloxane (PDMS) is reported. The hybrid P3HT:PCBM composite junction was chractarized with several tools. XRD revaled the presence of both P3HT and PCBM polymer in the The hybrid P3HT:PCBM composite junction. Furthermore, the ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectrometers reveal that the absorption and emission of the hybrid P3HT:PCBM composite junction have significantly enhanced compared with that of the pure P3HT film, and PCBM. In addition. the hybrid photodetector shows a low-level dark current (0.13 nA), a high-level light current (IL = 0.13 nA), an ON/OFF ratio (2.69×106), a responsivity (R = 7.11 A/W), and a specific detectivity (D* = 3.32×1013 J). The responsivity of the hybrid was improved by 4 times in magnitudes compared with that of the pure PCBM and the P3HT. this result pave the way for utlizing the hybrid P3HT:PCBM composite junction in enhncing performance of optolectronics.

Design and Fabrication of Optical Sensors Based on Neodymium (Nd) Doped Titanium Dioxide (TiO2) Layer Prepared by Sol–Gel Dip-Coating Method

A high performance and stable UV photodetector with a bsorbant layer of Neodymium (Nd) doped Titanium dioxide (TiO2) is reported. The Neodymium (Nd) doped Titanium dioxide (TiO2) layer was chractarized with several tools. XRD and FTIR revaled that the crsytal structure of Neodymium (Nd) doped Titanium dioxide (TiO2) has changed compared with that of the undoped anatase Titanium dioxide (TiO2). Furthermore, the ultraviolet-visibleand photoluminescence spectrometers reveal that the measured absorption and emission of the hybrid Nd doped TiO2 layer have significantly enhanced compared with that of the undoped Titanium dioxide (TiO2). In addition. The photodetector based on Neodymium (Nd) doped Titanium dioxide (TiO2) shows a low-level dark current (Idark = 0.13 nA), a high-level light current (Ilight = 15655.6 nA), an ON/OFF ratio (1.2×105), a responsivity (R = 0.32 A/W), and a specific detectivity (D* = 4.2×1012 J). The photoresponsivity (R) of Nd doped TiO2 layer was improved by nearly 3 times in magnitude in comparison with the photoresponsivity of the undoped TiO2 layer PD without the Nd. This result pave the way for utlizing the hybrid Nd doped TiO2 in enhncing performance of optolectronics.

Mechanisms of Action of Noninvasive Brain Stimulation with Weak Non-Constant Current Stimulation Approaches.

Objective: Non-constant current stimulation (NCCS) is a neuromodulatory method in which weak alternating, pulsed or random currents are delivered to the human head via scalp or earlobe electrodes. This approach is widely used in basic and translational studies. However, the underlying mechanisms of NCCS, which lead to biological and behavioral effects in the brain, remain largely unknown. In this review, we characterize NCCS techniques currently being utilized in neuroscience investigations, including transcranial alternating current stimulation (tACS), transcranial pulsed current stimulation (tPCS), transcranial random noise stimulation (tRNS), and cranial electrotherapy stimulation (CES). Method: We unsystematically searched all relevant conference papers, journal articles, chapters, and textbooks on the biological mechanisms of NCCS techniques. Results: The fundamental idea of NCCS is that these low-level currents can interact with neuronal activity, modulate neuroplasticity and entrain cortical networks, thus, modifying cognition and behavior. We elucidate the mechanisms of action for each NCCS technique. These techniques may cause microscopic effects (such as affecting ion channels and neurotransmission systems) and macroscopic effects (such as affecting brain oscillations and functional connectivity) on the brain through different mechanisms of action (such as neural entrainment and stochastic resonance). Conclusion: The appeal of NCCS is its potential to modulate neuroplasticity noninvasively, along with the ease of use and good tolerability. Promising and interesting evidence has been reported for the capacity of NCCS to affect neural circuits and the behaviors under their control. Today, the challenge is to utilize this advancement optimally. Continuing methodological advancements with NCCS approaches will enable researchers to better understand how NCCS can be utilized for the modulation of nervous system activity and subsequent behaviors, with possible applications to non-clinical and clinical practices.

Portable Spectroscopy System for Environmental Monitoring: An SO2 Case Study

In this work, a compact, portable, extended operating life, maintenance-free and remotely operable apparatus for optical absorbance measurements in the ultraviolet region is proposed. The system is useful for concentration measurement of chemical species or biological agents that exhibit ultraviolet light absorption. An apparatus prototype was developed using a commercial LED as photons source at the desired wavelength and a photo-detector with low noise, high sensitivity and visible blindness, opportunely fabricated using Silicon Carbide technology. A suitable electronic for handling the very low-level current of the detector has been designed and built to be robust, portable, low-power, low-cost and with a WiFi user interface. The ultraviolet spectroscopy apparatus application to which this work is aimed, is the low-level concentration measurement of SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in volcanic environment, while it can be easily adapted to other molecules detection and higher concentration level. While in previous Authors’ work the system feasibility has been explored using laboratory instrumentation, in this work the focus is to design a system that can be used in real harsh volcanic environment, where system lightweight, endurance and chemical strength against aggressive compounds are paramount. Resolution of approximately 1 ppm, compactness, robustness and insensitivity to humidity and temperature variations are required for this kind of environment. The performed laboratory tests and calibration for SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> monitoring, are reported and discussed. The system shows good sensitivity as high as 8 pA/ppm, a resolution < 1 ppm for SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> detection and low cross-sensitivity to main components usually present in volcanic gases.

Improving mechanical properties of welds through tailoring microstructure characteristics and fracture mechanism in multi-pulse resistance spot welding of Q&P980 steel

In the present research, the multi-pulse resistance spot welding involving three thermal cycles has been carried out on the Q&P980 steel sheet with the thickness of 1.8 mm. The influence of welding pulses on the microstructure evolution and mechanical properties of the welded specimens was analyzed through EPMA, SEM, TEM and tensile test, etc. It is found that there is a crack sensitive area in single and double-pulse samples, which is corresponding to the broadening of the partially melted zone with severe element segregation. Furthermore, the softened of nugget associated with microstructure coarsening on the outside of the re-melting zone can be observed during multi-pulse welding. As the nugget size increases, the enlarged connection/joint area between the sheets significantly enhances the ability of the nugget to resist tensile shear stress, leading to the increase of tensile-shear strength. Due to the crack propagating away from the partially melted zone into the softened nugget, where the tempered martensite provides a higher resistance to crack initiation and propagation, the cross-tension properties have been improved by applying the tempering pulse with low-level current. The multi-pulse welding samples show a better combination of tensile-shear and cross-tension properties, i.e. their peak load of cross tension (13.19 kN) is increased by 160% and 56% respectively, while the energy absorption (108.49 J) is raised by 390% and 107% respectively, compared with the single and double pulse samples.

Electrokinetic assisted anaerobic digestion of spent mushroom substrate supplemented with sugar mill wastewater for enhanced biogas production

This study investigated electrokinetic assisted anaerobic digestion of spent mushroom substrate supplemented with sugar mill wastewater for enhanced biogas production. Response surface method and artificial neural network tools were used to optimize the reactor performance. Findings showed that the best reactor performance was achieved at a temperature of 34.52 °C, a direct electric current of 1.61 V, and sugar mill wastewater loading of 59.61%, while the highest observed biogas yield and methane contents were 10344 mL and 63.05%, respectively. Moreover, amongst the different control parameters, sugar mill wastewater loading showed the most significant (P < 0.001) effect on bioenergy recovery from spent mushroom substrate followed by temperature (P < 0.0298) and electric current (P < 0.1783). Besides this, the artificial neural network (feed-forward-backpropagation configuration with logistic function) simulated the biogas/methane production more efficiently as compared to the quadratic model of response surface method as revealed from R2 (<0.9979 and 0.9987), root means-square error (>117.588 and 97.253), and model efficiency (<0.998) tools. Thus, supplementation of sugar mill wastewater along with low-level direct electric current can be useful for enhanced bioenergy recovery from the spent mushroom substrate.

Interaction between the pulmonary stretch receptor and pontine control of expiratory duration

Medial parabrachial nucleus (mPBN) neuronal activity plays a key role in controlling expiratory (E)-duration (TE). Pulmonary stretch receptor (PSR) activity during the E-phase prolongs TE. The aims of this study were to characterize the interaction between the PSR and mPBN control of TE and underlying mechanisms. Decerebrated mechanically ventilated dogs were studied. The mPBN subregion was activated by electrical stimulation via bipolar microelectrode. PSR afferents were activated by low-level currents applied to the transected central vagus nerve. Both stimulus-frequency patterns during the E-phase were synchronized to the phrenic neurogram; TE was measured. A functional mathematical model for the control of TE and extracellular recordings from neurons in the preBötzinger/Bötzinger complex (preBC/BC) were used to understand mechanisms. Findings show that the mPBN gain-modulates, via attenuation, the PSR-mediated reflex. The model suggested functional sites for attenuation and neuronal data suggested correlates. The PSR- and PB-inputs appear to interact on E-decrementing neurons, which synaptically inhibit pre-I neurons, delaying the onset of the next I-phase.

Optimal Protection Coordination Scheme for Radial Distribution Network Considering ON/OFF-Grid

Technology advancement for renewable energy resources and its integration to the distribution network (DN) has garnered substantial interest in the last few decades. Integrating such resources has proven to reduce power losses and improve the reliability of DN. However, the growing number of these resources in DN has imposed additional operational and control issues in voltage regulation, system stability, and protection coordination. Incorporation of various types of distributed generators (DG) into DN causes significant changes in the system. These including new fault current sources, new fault levels, a blinding effect in the protection scheme, reduction in the reach of relays, and decrement in the detection of low-level fault currents for existing relays. Such changes will jeopardize the effectiveness of the entire protection scheme in the DN. This research aims to propose a robust protection scheme in which the relay coordination settings are optimized based on the network layout. The potential impacts of DGs on the DN are mitigated by utilizing a user-defined overcurrent-based relay characteristic to obtain the minimum operating time while satisfying protection coordination constraints. A hybrid optimization algorithm based on Metaheuristic and Linear Programming that has the capability to attain the optimal solution and reduces computational time is proposed in this work. The performance of the proposed technique is tested on radial DN integrated with microgrid (MG). The results obtained show the proposed technique has successfully reduced the relay operating time while meeting the protection coordination requirements for dynamic operating modes of a network.

Non-Destructive Evaluation for Sectional Loss of External Tendon of Prestressed Concrete Structures Using Total Flux Leakage

A non-destructive evaluation method is proposed to identify the sectional loss of the external tendon of prestressed concrete structures by detecting the change of the magnetic flux in the external tendon exposed to a magnetic field. The method uses a solenoid-shaped device with two coils: a primary coil for producing magnetic field and secondary coil for damage detection, wrapping the external tendon. A current applied to the primary coil in the device causes the magnetic field. Then, the change in the magnetic flux by the damage in the external tendon is detected by the variation of the voltage in the secondary coil in the device as the device moves along the tendon. An alternating current is applied to the primary coil to minimize the effect of the moving speed of the device. As a result, the damaged area can be detected with a low-level energy current. In addition, a wrapping solenoid-shaped device that is easy to disassemble and assemble was developed for in situ inspection. The measured signal from the secondary coil has a sinusoidal form with the same frequency as the applied current to the primary coil, and the peak curve of the measured signal provides enough information to detect the damage. It is shown that the proposed method can quantitatively identify one or multiple damaged-tendon locations as well as damages of at least 2 cm.

Network-level mechanisms underlying effects of transcranial direct current stimulation (tDCS) on visuomotor learning

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation approach in which low level currents are administered over the scalp to influence underlying brain function. Prevailing theories of tDCS focus on modulation of excitation-inhibition balance at the local stimulation location. However, network level effects are reported as well, and appear to depend upon differential underlying mechanisms. Here, we evaluated potential network-level effects of tDCS during the Serial Reaction Time Task (SRTT) using convergent EEG- and fMRI-based connectivity approaches. Motor learning manifested as a significant (p<.0001) shift from slow to fast responses and corresponded to a significant increase in beta-coherence (p<.0001) and fMRI connectivity (p<.01) particularly within the visual-motor pathway. Differential patterns of tDCS effect were observed within different parametric task versions, consistent with network models. Overall, these findings demonstrate objective physiological effects of tDCS at the network level that result in effective behavioral modulation when tDCS parameters are matched to network-level requirements of the underlying task.

Isotropy and spurious currents in pseudo-potential multiphase lattice Boltzmann models

The spurious currents observed in multiphase flow simulations with pseudo-potential lattice Boltzmann (LB) models are usually understood to be the result of the lack of isotropy of the model-generated interaction force between phases. Remedies have been proposed to utilize larger stencils to compute the interaction force with higher orders of isotropy. In this document, we point out the incompleteness in the current understanding and propose a new consistent implementation to more effectively suppress the spurious currents. We also demonstrate theoretically that certain low-level spurious currents cannot be eliminated by increasing isotropy if the local hydrostatic balance inside the diffuse interface is not established in the LB models.

Response surface methodology based electro-kinetic modeling of biological and chemical oxygen demand removal from sugar mill effluent by water hyacinth (Eichhornia crassipes) in a Continuous Stirred Tank Reactor (CSTR)

Abstract This study investigated the biological and chemical oxygen demand (BOD and COD) removal from sugar mill effluent by water hyacinth (Eichhornia crassipes). The batch phytoremediation experiments were performed in a Continuous Stirred Tank Reactor (CSTR) assisted with low-level direct current (DC). Response surface methodology (RSM) based electro-kinetic modeling and optimization was done using a Central Composite Design (CCD) of 19 experimental runs. A total of three initial BOD/COD dose ( X 1 : 50, 475 and 900 mg/L) with stirring rates ( X 2 : 0, 15 and 30 rpm) and DC current ( X 3 : 0, 1 and 2 Volts) were chosen as independent variables to optimize percent BOD and COD removal by E. crassipes, separately. Results showed that the quadratic model was best fitted in the data and had high R2 value (0.98), low P value ( − 1 and 0.9069 mg/Lw−1 for BOD and COD, respectively. This study emphasized a novel method for effective approach to reduce BOD and COD load of sugar mill effluent using E. crassipes in CSTR assisted with low-level DC current.

A Chimeric NaV1.8 Channel Expression System Based on HEK293T Cell Line.

Among the nine voltage-gated sodium channel (NaV) subtypes, NaV1.8 is an attractive therapeutic target for pain. The heterologous expression of recombinant NaV1.8 currents is of particular importance for its electrophysiological and pharmacological studies. However, NaV1.8 expresses no or low-level functional currents when transiently transfected into non-neuronal cell lines. The present study aims to explore the molecular determinants limiting its functional expression and accordingly establish a functional NaV1.8 expression system. We conducted screening analysis of the NaV1.8 intracellular loops by constructing NaV chimeric channels and confirmed that the NaV1.8 C-terminus was the only limiting factor. Replacing this sequence with that of NaV1.4, NaV1.5, or NaV1.7 constructed functional channels (NaV1.8/1.4L5, NaV1.8/1.5L5, and NaV1.8/1.7L5, respectively), which expressed high-level NaV1.8-like currents in HEK293T cells. The chimeric channel NaV1.8/1.7L5 displayed much faster inactivation of its macroscopic currents than NaV1.8/1.4L5 and NaV1.8/1.5L5, and it was the most similar to wild-type NaV1.8 expressed in ND7/23 cells. Its currents were very stable during repetitive depolarizations, while its repriming kinetic was different from wild-type NaV1.8. Most importantly, NaV1.8/1.7L5 pharmacologically resembled wild-type NaV1.8 as revealed by testing their susceptibility to two NaV1.8 selective antagonists, APETx-2 and MrVIB. NaV chimeras study showed that at least the domain 2 and domain 4 of NaV1.8 were involved in binding with APETx-2. Our study provided new insights into the function of NaV1.8 intracellular loops, as well as a reliable and convenient expression system which could be useful in NaV1.8 studies.