Real-time Impedance Research Articles

Adaptive Cooperative Control Strategy for a Wrist Exoskeleton Using Model-Based Joint Impedance Estimation

Wrist rehabilitation exoskeletons have gained much attention over the last decades, striving to restore motor functions for patients with neuromuscular disorders. Electromyography signal has been employed to estimate the motion intention to achieve interactive training schemes. However, it is a challenging task to estimate the joint impedance in real time, as it is a crucial parameter for control of exoskeletons. This article proposes an adaptive cooperative control strategy for a wrist exoskeleton based on a real-time joint impedance estimation approach. By explicitly interpreting the underlying transformation in the muscular and skeletal systems, the proposed approach estimates the motion intention and the joint impedance of a human subject simultaneously without additional calibration procedures and regulates the training trajectories and assistance accordingly. Results indicate the proposed method outperforms other training protocols, including the trajectory tracking control and the fixed cooperative control. The proposed control strategy provides an additional 66.25% motion deviation when estimated joint torque increases 12.36%, which enhances the training effectiveness and the interaction safety and promotes subjects' active engagement.

Fast electrochemical impedance spectroscopy of lithium-ion batteries based on the large square wave excitation signal

Electrochemical impedance spectroscopy (EIS) is a technique for electrochemical characterization that is sensitive to the battery state and can uncover multidimensional electrochemical evolution information within the battery. Lithium-ion batteries usually need to be used in conjunction with power conversion circuits, while conventional EIS testing is conducted offline and is time-consuming, which cannot effectively monitor the battery characteristics during use. To match the characteristics of the square wave signal during power switching, a rapid EIS measurement method for lithium-ion batteries based on the large square wave excitation signal is proposed in this paper, and develops a testing device with a response time of microseconds. The proposed method and device are applied to estimate the state of health (SOH) of the battery. In conclusion, we proposed method enhances the capabilities of EIS testing technology and has a good application prospect in real-time online impedance monitoring.

Targeting Glioblastoma-Associated Macrophages for Photodynamic Therapy Using AGuIX®-Design Nanoparticles.

Glioblastoma (GBM) is the most difficult brain cancer to treat, and photodynamic therapy (PDT) is emerging as a complementary approach to improve tumor eradication. Neuropilin-1 (NRP-1) protein expression plays a critical role in GBM progression and immune response. Moreover, various clinical databases highlight a relationship between NRP-1 and M2 macrophage infiltration. In order to induce a photodynamic effect, multifunctional AGuIX®-design nanoparticles were used in combination with a magnetic resonance imaging (MRI) contrast agent, as well as a porphyrin as the photosensitizer molecule and KDKPPR peptide ligand for targeting the NRP-1 receptor. The main objective of this study was to characterize the impact of macrophage NRP-1 protein expression on the uptake of functionalized AGuIX®-design nanoparticles in vitro and to describe the influence of GBM cell secretome post-PDT on the polarization of macrophages into M1 or M2 phenotypes. By using THP-1 human monocytes, successful polarization into the macrophage phenotypes was argued via specific morphological traits, discriminant nucleocytoplasmic ratio values, and different adhesion abilities based on real-time cell impedance measurements. In addition, macrophage polarization was confirmed via the transcript-level expression of TNFα, CXCL10, CD-80, CD-163, CD-206, and CCL22 markers. In relation to NRP-1 protein over-expression, we demonstrated a three-fold increase in functionalized nanoparticle uptake for the M2 macrophages compared to the M1 phenotype. The secretome of the post-PDT GBM cells led to nearly a three-fold increase in the over-expression of TNFα transcripts, confirming the polarization to the M1 phenotype. The in vivo relationship between post-PDT efficiency and the inflammatory effects points to the extensive involvement of macrophages in the tumor zone.

Monitoring biofilm growth and dispersal in real-time with impedance biosensors.

Microbial biofilm contamination is a widespread problem that requires precise and prompt detection techniques to effectively control its growth. Microfabricated electrochemical impedance spectroscopy (EIS) biosensors offer promise as a tool for early biofilm detection and monitoring of elimination. This study utilized a custom flow cell system with integrated sensors to make real-time impedance measurements of biofilm growth under flow conditions, which were correlated with confocal laser scanning microscopy (CLSM) imaging. Biofilm growth on EIS biosensors in basic aqueous growth media (tryptic soy broth; TSB) and an oil-water emulsion (metalworking fluid; MWF) attenuated in a sigmoidal decay pattern, which lead to an ∼22 to 25% decrease in impedance after 24 hours. Subsequent treatment of established biofilms increased impedance by ∼14% and ∼41% in TSB and MWF, respectively. In the presence of Furanone C-30, a quorum sensing inhibitor (QSI), impedance remained unchanged from the initial time point for 18 hours in TSB and 72 hours in MWF. Biofilm changes enumerated from CLSM imaging corroborated impedance measurements, with treatment significantly reducing biofilm. Overall, these results support the application of microfabricated EIS biosensors for evaluating the growth and dispersal of biofilm in situ and demonstrate potential for use in industrial settings.

Online Grid Impedance Estimation-Based Adaptive Control of Virtual Synchronous Generators Considering Strong and Weak Grid Conditions

The conventional virtual synchronous generator (VSG) is typically designed to meet certain operational and control requirements in the islanded mode. However, once the VSG is switched to grid-connected mode (GCM), the robust operation cannot be guaranteed under different grid conditions. It can lead to poor dynamic performance, especially in strong grids, such as significant oscillation, long settling time, and large overshoot. To improve the VSG performance in the GCM, this article first analyzes in depth the inherent coupling between the active and reactive power and its dependence on grid conditions, such as the short circuit ratio and the grid impedance ratio. Subsequently, an adaptive VSG (AVSG) control strategy based on online grid impedance estimation is proposed to ensure robust operation of the VSG considering both strong and weak grid conditions. This technique allows the operator to specify the desired settling time of the output power and damping ratio. To estimate the grid impedance in real time without additional hardware and reduce the associated impacts on power quality, an online event-based grid impedance estimation algorithm is embedded in the control loop of the AVSG. The simulation and experimental results indicate that, compared with the conventional fixed-parameters-based controller design method, the AVSG exhibits desired performance such as no oscillation, specified time duration for the settling time, and minimal overshoot regardless of the grid conditions.

Waveform Correlation Based Harmonic Voltage Contribution Determination of Iron and Steel Plants Supplied From PCC

This paper presents a new waveform correlation based method which determines the individual harmonic voltage contributions of Electric Arc Furnace (EAF) plants supplied from a point of common coupling (PCC). The method is based on the waveform correlation computations between the PCC voltage and the feeder current at the individual harmonic frequency. PCCs supplying multiple EAF plants usually suffer from high voltage harmonic components due to their operation principles. A relationship between the correlation coefficient of the PCC voltage and the feeder current waveforms, and the harmonic voltage contribution of each plant is derived and this relationship is used to derive the individual contributions to the PCC voltage. The main idea of the method is based on the fact that harmonic voltage at the PCC is a result of the additive effect of voltage drops on the source side impedance of the power system caused by the individual feeder currents. No real-time impedance measurements are required in the proposed method and no need for the measurements of the other feeders to compute the contribution of a specific feeder in contrast to some previously proposed methods for the same problem. The proposed method is further expanded in order to reveal the effects of the compensation systems of the EAF plants, which identifies the harmonic current sinking problem of a victim plant with a powerful compensation system using further correlation computations between the feeder currents and in-plant current measurements. The proposed method can be easily adapted as a real time harmonic contribution detection tool for the already-installed power quality analyzers, most of which employ synchronized voltage and feeder current waveform measurements.

Vertebral Body Bone Ablation with and without a Saline-Infused System in a Porcine Model

The purpose of this study was to evaluate the effect of bone radiofrequency (RF) ablation in the spine with and without controlled saline infusion. RF ablation with and without controlled saline infusion was performed in the vertebral bodies of 2 swine with real-time temperature and impedance recordings. Histology and magnetic resonance (MR) imaging results were reviewed to evaluate the ablation zone size, breach of spinal canal, and damage to the spinal cord and nerves. There was no difference in maximum and mean temperatures between controlled saline and noninfusion groups. The impedance and power output were not significantly different between the groups. MR imaging and histopathology demonstrated ablation zones confined within the vertebral bodies. Ablation zone size correlated on MR imaging and histopathology by groups. No ablation effect, breach of posterior cortex, spinal cord injury, or nerve or ganglion injury was observed at any level using MR imaging or histology. Controlled saline infusion does not appear to impact bone RF ablation and, specifically, does not increase the ablation zone size.

PMA-Treatment of Human Monocytes Induces a M1 Phenotype in Adherent Macrophages

Background: Human monocyte lines are widely used in basic research as model of inflammation, mostly following adherence with phorbol 12-myristate 13-acetate (PMA). However, the SC line, of normal human monocytes is not well documented, unlike tumour-derived cell lines, such as THP-1. Aim: The purpose of this study was to determine the phenotype of adherent macrophages, induced after the treatment with PMA in three different concentrations, starting from the most widely reported concentration in the literature. Methods: Normal human monocytes SC (ATCC CRL-9855) were routinely maintained according to manufacturer’s instructions. Cells were treated with Phorbol 12-myristate 13-acetate (PMA Sigma Aldrich P1585), in concentrations of 200 ng/mL, 100 ng/mL, 25 ng/mL and adhesion was documented using an Evos phase-contrast inverted microscope. Cell behaviour was validated by real-time impedance readings. The adhered cells were treated with bacterial lipopolysaccharide (LPS) in concentrations of 50 ng/mL (mimicking chronic inflammation) and 1 μg/mL (mimicking acute inflammation). The supernatant was collected twice, after 4 hours, respectively after 18 hours of treatment with LPS. A screening of pro- and anti-inflammatory cytokines was performed using the multiplexing platform Luminex 200. ELISA tests were performed to validate the cytokines secretion: IL-6, IL-8, IL-10, IL-23 and TNF-ɑ, using a LEGEND MAX Human ELISA kit specific to each cytokine. Results: Cell adhesion was studied by time-lapse microscopy for 48 hrs. The lowest concentration of PMA which induced cell adherence was 25 ng/mL. Multiplex screening of cytokines showed a pro-inflammatory phenotype of macrophages stimulated with LPS. This finding was validated by ELISA tests for IL-6, IL-8, IL-23 and TNF-ɑ (as pro-inflammatory cytokine) and IL-10 (an anti-inflammatory molecule). For the first category, we noticed a time-dependent response, present in adherent macrophages, but not in circulating monocytes. Regarding the second category of cytokines, the secretion is present only for the adhered and LPS treated cells. It is also present in a time-dependent manner (a higher concentration can be noticed in the collected supernatant after 18 hours of treatment compared with the one collected after 4 hours of treatment). Conclusion: The macrophages obtained from normal human monocytes with PMA are M1 type, regardless of the concentration used for differentiation.

A method to measure the electric parameters of the driver in a fusion-relevant RF ion source

RF ion sources for the neutral beam injection application contain a part called the driver where the plasma is generated. Measurement of the driver's external electrical parameters, such as coil current Icoil and driver equivalent impedance ZD, is useful for assessing the RF power coupling process and estimating the internal plasma parameters. The direct measuring method using RF I-V sensors at the driver's input terminal is inconvenient since it requires the installation of I-V sensors with very high phase (difference) accuracy near the driver. Thus, an indirect measuring method is developed for the RF ion sources equipped with the transformer-isolated Γ-type matching network in this paper. The method uses the electric parameters measured before the matching network and an impedance matching model of the real-world matching network. In the matching model, the matching transformer is treated as a mutual inductance circuit, and the parasitic impedance of the matching network is considered. Then the method is applied to an RF ion source, HINT. With the real-time impedance and power measured before the matching network as inputs, the driver's electric parameters and the RF power transfer efficiency η of HINT are monitored. Without plasma discharge, Icoil and ZD measured indirectly are consistent with those measured directly. With discharges (at transmitted power of 5∼12 kW and filling pressure of 0.45∼0.7 Pa), the deviations of indirect measurements from direct measurements are below 10% in Icoil, and then below 0.06 (absolute) in η. The comparisons show that the indirect measuring method can be used as an alternative to evaluate the driver's electric parameters and η in HINT.

Robotic pullback technique of a precurved cochlear-implant electrode array using real-time impedance sensing feedback.

During traditional insertion of cochlear implant (CI) electrode arrays (EAs), surgeons rely on limited tactile feedback and visualization of the EA entering the cochlea to control the insertion. One insertion approach for precurved EAs involves slightly overinserting the EA and then retracting it slightly to achieve closer hugging of the modiolus. In this work, we investigate whether electrical impedance sensing could be a valuable real-time feedback tool to advise this pullback technique. Using a to-scale 3D-printed scala tympani model, a robotic insertion tool, and a custom impedance sensing system, we performed experiments to assess the bipolar insertion impedance profiles for a cochlear CI532/632 precurved EA. Four pairs of contacts from the 22 electrode contacts were chosen based on preliminary testing and monitored in real time to halt the robotic insertion once the closest modiolar position had been achieved but prior to when the angular insertion depth (AID) would be reduced. In this setting, the open-loop robotic insertion impedance profiles were very consistent between trials. The exit of each contact from the external stylet of this EA was clearly discernible on the impedance profile. In closed-loop experiments using the pullback technique, the average distance from the electrode contacts to the modiolus was reduced without greatly affecting the AID by using impedance feedback in real time to determine when to stop EA retraction. Impedance sensing, and specifically the access resistance component of impedance, could be a valuable real-time feedback tool in the operating room during CI EA insertion. Future work should more thoroughly analyze the effects of more realistic operating room conditions and inter-patient variability on this technique.

Quantitative study of tumor angiogenesis in three-dimensional matrigel barrier using electric impedance measurement technique

Tumor angiogenesis refers to the development of new blood vessels in tumors and is a vital indicator of cancer metastasis which is the major cause of cancer-related deaths. Study of tumor angiogenesis is critical for the development of potential therapeutic strategies of suppressing cancer metastasis. In the current work, a microfluidic device has been developed and was composed of 2 reservoirs connecting with a Matrigel-filled microchannel. The microchannel was mimicked as a biological barrier and embedded with measurement microelectrodes. New blood vessels were successfully induced to extend along the microchannel. Meanwhile, real-time impedance measurement was conducted to quantitatively monitor the tumor angiogenesis process. The results revealed the extension speed of new blood vessels was proportional to chemical induction level, i.e., VEGF165 concentration. Moreover, tumor angiogenesis was shown to be induced by the VEGF released from cancer cells and significantly correlated to the number of cancer cells. In addition, anti-VEGF suppressor was quantitatively evaluated to study the suppression efficacy of tumor angiogenesis. The current microfluidic device provides a promising tool to study tumor angiogenesis in 3D biological barrier. The impedance technique offers reliable and quantitative evidences for evaluating drug efficacy. Development of tumor angiogenesis analytical platform can potentially lead to develop novel therapeutic strategies of suppressing cancer metastasis.

Real-time traffic impedance and priority based cooperative path planning mechanism for SOC-ITS: Efficiency and equilibrium

With the support of new information technologies such as the Internet of Vehicles (IoV) and cloud computing, the Intelligent Transportation System (ITS) has begun a new stage role as Cooperative ITS (C-ITS). Moreover, featuring the collaboration of vehicles, roads, clouds and humans, it becomes possible to scientifically mitigate several serious phenomena in the traditional ITS, including traffic congestion, blocked emergency vehicles, etc. While focusing on optimizing the Quality of Transportation Service (QoTS) requirements from vehicles with different types of tasks, covering emergency vehicles (fire engine, police vehicle and ambulance), shuttle buses, and others, this paper studies and proposes a new service-oriented and cloud-based cooperative path planning mechanism for such heterogeneous vehicles. First, the architecture of service-oriented cooperative path planning is established, where the types and QoTS of traffic tasks are illustrated. Then, a hybrid traffic impedance model is put forward, in which three influencing factors of traffic impedance are concluded and combined through the entropy weight method. On this basis, a service-oriented cooperative path planning mechanism with load balancing strategies named SoCPPLB is designed. The main principle of SoCPPLB is to provide different levels of path planning service for vehicles according to their QoTS requirements per the constraint of the QoTS of vehicles and traffic equilibrium. Finally, all these proposed models and algorithms have been implemented within the Simulation of Urban MObility (SUMO), and further verified under several typical traffic scenarios. The experimental results show that, this new mechanism can effectively improve the QoTS of emergency vehicles and traffic equilibrium performance obviously.

Real-Time Temperature Rise Estimation during Irreversible Electroporation Treatment through State-Space Modeling

To evaluate the feasibility of real-time temperature monitoring during an electroporation-based therapy procedure, a data-driven state-space model was developed. Agar phantoms mimicking low conductivity (LC) and high conductivity (HC) tissues were tested under the influences of high (HV) and low (LV) applied voltages. Real-time changes in impedance, measured by Fourier Analysis SpecTroscopy (FAST) along with the known tissue conductivity and applied voltages, were used to train the model. A theoretical finite element model was used for external validation of the model, producing model fits of 95.8, 88.4, 90.7, and 93.7% at 4 mm and 93.2, 58.9, 90.0, and 90.1% at 10 mm for the HV-HC, LV-LC, HV-LC, and LV-HC groups, respectively. The proposed model suggests that real-time temperature monitoring may be achieved with good accuracy through the use of real-time impedance monitoring.

Rail Sample Laboratory Evaluation of Eddy Current Rail Inspection Sustainable System

Increasing the efficiency, frequency, and speed of rail defect detection can reduce maintenance costs and improve the sustainability of railways. The non-contact eddy current (EC) system can be operated along with a railcar for detecting rail flaws. Even if the EC can be utilized for rail defect identification and characterization, current commercial devices are not sufficient for defect classification on rails by providing highly sensitive signals for post-processing. In this study, we established an efficient and expandable eddy current rail inspection system and verified its capability for classification of different defect signals. The integrated hardware and software EC measurement system was firstly applied to detect notched cracks in steel samples with different crack depths and angles. The measured voltage and current analog inputs from the eddy current sensor were acquired and processed with a fast Fourier transformation (FFT) algorithm in the LabVIEW platform. The real-time impedance was then obtained by transferring signals to a normalized impedance plane plot. The processed EC signals showed adequate sensitivity and efficiency with changes of notched crack depths and angles during the sensor movement. A comparative case study on field rail samples was then conducted to examine the feasibility and capability of the established system on different types of actual rail defects. The experimental analysis and case study results demonstrate that the integrated eddy current system could possibly be used for non-destructive rail crack inspection and classification. The enhanced detection capability (especially on subsurface cracks) and real-time post-processing technique could further contribute to improving rail-life sustainability.

Epstein-Barr viral product-containing exosomes promote fibrosis and nasopharyngeal carcinoma progression through activation of YAP1/FAPα signaling in fibroblasts

BackgroundThe progression of nasopharyngeal carcinoma (NPC) is profoundly affected by Epstein-Barr virus (EBV) infection. However, the role of EBV in the intercommunication between NPC and surrounding stromal cells has yet to be explored.MethodsNPC biopsies were obtained for immunohistochemical (IHC) analyses. Clinical correlations between the expression of active YAP1/FAPα and the fibrotic response and between YAP1/FAPα and the density of cytotoxic CD8a+ T lymphocytes were determined. Survival times based on IHC scores were compared between groups using Kaplan-Meier survival and log-rank tests. Independent prognostic factors for metastasis/recurrence-free survival and overall survival were identified using univariate and multivariate Cox regression models. Fibroblasts were isolated from human nasopharyngeal biopsies. Exosomes were purified from culture supernatants of EBV+-positive NPC cells. The effects of EBV product-containing exosomes on fibroblast activation, fibrotic response, tumor growth, immune response, and correlations between the expression of featured genes were investigated using gel contraction assays, ELISAs, EdU incorporation assays, real-time impedance assays, RNA sequencing, immunostaining, 3D cancer spheroid coculture systems, and an NPC xenograft model.ResultsNPC patients who developed metastasis had significantly higher levels of active YAP1 and FAPα in their tumor stroma, which was further correlated with tumor fibrosis and poorer metastasis-free survival. Exosomes released from EBV+-NPC cells contained abundant FAPα protein and EBV-encoded latent membrane protein 1. Viral product-containing exosomes markedly enhanced the fibrotic response and tumor growth in a mouse xenograft model. IHC analyses of human NPC and NPC xenografts revealed positive correlations between levels of active YAP1 and FAPα, YAP1 and the fibrotic response, and FAPα and the fibrotic response. Mechanistic studies showed that treatment of fibroblasts with viral product-containing exosomes promoted the characteristics of cancer-associated fibroblasts by stimulating YAP1 signaling and the production of the immunosuppressive cytokines IL8, CCL2, and IL6. Inhibition of YAP1 activation markedly reversed these exosome-mediated protumoral effects, resulting in reduced contractility, inactivation of YAP1 signaling, and decreased production of immunosuppressive cytokines in fibroblasts. Furthermore, fibroblasts stimulated with these viral product-containing exosomes promoted NPC resistance to T cell-mediated cytotoxicity within tumor spheroids. In NPC tissues, a significant negative correlation was found between YAP1/FAPα and the density of CD8a+ T lymphocytes with a granzyme B signature.ConclusionEBV orchestrates interactions with the host and surrounding stroma by stimulating the functions of YAP1 and FAPα in fibroblasts through exosome cargos to create a more immunosuppressive, proinvasive microenvironment.

Abstract 5184: Real-time cytotoxicity assays as a pre-clinical screening tool for LGR5-targeting CAR-T cells for treatment of solid tumors

Abstract Current challenges for CAR-T therapies in solid tumors relate to target specificity and T cell penetration of the tumor. A key determinant in CAR-T selection for clinical trials is the potency and persistence of the selected CAR-T to kill cancerous cells. This is often difficult to determine across different donors and batches. Additionally, these characteristics can be difficult to determine in vitro in a rapid, high-throughput manner. In this study we have utilized real-time impedance cytotoxicity assays to screen LGR5-targeting CAR-T cells. LGR5 is a well described cancer stem cell antigen implicated in tumor initiation and metastasis, and prognosis of colon, ovarian and neuroblastoma cancers. Impedance measurements are taken continuously, providing comprehensive real-time information about CAR-T cell efficiency over time, which is not achievable with single timepoint cytotoxicity assays. Through this validation process we have been able to concurrently test different Effector to Target (E:T) ratios and different CAR constructs to accurately and directly compare CAR-T killing efficiency. This readout is a key indicator of CAR-T potency. Similar to inhibitory concentration 50 (IC50) or lethal dose 50 (LD50) data, CAR-T potency can be expressed in a measure as kill time 50 (KT50), and represents the time required for the CAR-T to stimulate cytolysis in 50% of the target cancer cells. KT50 data was key to the selection of our lead clinical candidate; CNA3103. In addition to selection of our lead candidate, real-time impedance technology has allowed us to screen a broad range of LGR5-expressing cancer types. Our data indicates that CNA3103 can effectively target colon, neuroblastoma, and ovarian cancer cells in vitro. Real-time impedance assay has allowed us to analyze cancer cells with different levels of LGR5 expression to confirm the specificity of our CAR-T cells and to develop an understanding of how LGR5 expression levels might impact cancer cell killing. The data also indicates that our LGR5 targeting CAR-T cells have the potential to repeatedly kill, i.e. the same CAR-T cell is able to move on from one cancer cell to another and remain cytotoxic. Taken together, real-time cytotoxicity assays provide valuable pre-clinical data, enabling the selection of CNA3103 as our LRG5-CAR-T clinical candidate. This technology may also assist in patient and dose selection within a clinical trial. Citation Format: Emma J. Thompson, Veronika Bandara, Timothy Sadlon, Batjargal Gundsambuu, Lih Yin Tan, Carmela Ricciardelli, Simon C. Barry, Claudine S. Bonder. Real-time cytotoxicity assays as a pre-clinical screening tool for LGR5-targeting CAR-T cells for treatment of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5184.

Kinase Inhibition by PKC412 Prevents Epithelial Sheet Damage in Autosomal Dominant Epidermolysis Bullosa Simplex through Keratin and Cell Contact Stabilization

Epidermolysis bullosa simplex (EBS) is a severe and potentially life-threatening disorder for which no adequate therapy exists. Most cases are caused by dominant sequence variations in keratin genes K5 or K14, leading to the formation of cytoplasmic keratin aggregates, profound keratinocyte fragility, and cytolysis. We hypothesized that pharmacological reduction of keratin aggregates, which compromise keratinocyte integrity, represents a viable strategy for the treatment of EBS. In this study, we show that the multikinase inhibitor PKC412, which is currently in clinical use for acute myeloid leukemia and advanced systemic mastocytosis, reduced keratin aggregation by 40% in patient-derived K14.R125C EBS-associated keratinocytes. Using a combination of epithelial shear stress assay and real-time impedance spectroscopy, we show that PKC412 restored intercellular adhesion. Molecularly, global phosphoproteomic analysis together with immunoblots using phosphoepitope-specific antibodies revealed that PKC412 treatment altered phosphorylated sites on keratins and desmoplakin. Thus, our data provide a proof of concept to repurpose existing drugs for the targeted treatment of EBS and showcase how one broad-range kinase inhibitor reduced keratin filament aggregation in patient-derived EBS keratinocytes and the fragility of EBS cell monolayers. Our study paves the way for a clinical trial using PKC412 for systemic or local application in patients with EBS.

Effects of fasudil on blood–brain barrier integrity

BackgroundCerebral infarction accounts for 85% of all stroke cases. Even in an era of rapid and effective recanalization using an intravascular approach, the majority of patients have poor functional outcomes. Thus, there is an urgent need for the development of therapeutic agents to treat acute ischemic stroke. We evaluated the effect of fasudil, a Rho kinase inhibitor, on blood brain barrier (BBB) functions under normoxia or oxygen–glucose deprivation (OGD) conditions using a primary cell-based in vitro BBB model.MethodsBBB models from rat primary cultures (brain capillary endothelial cells, astrocytes, and pericytes) were subjected to either normoxia or 6 h OGD/24 h reoxygenation. To assess the effects of fasudil on BBB functions, we evaluated real time impedance, transendothelial electrical resistance (TEER), sodium fluorescein permeability, and tight junction protein expression using western blotting. Lastly, to understand the observed protective mechanism on BBB functions by fasudil we examined the role of cyclooxygenase-2 and thromboxane A2 receptor agonist U-46619 in BBB-forming cells.ResultsWe found that treatment with 0.3–30 µM of fasudil increased cellular impedance. Fasudil enhanced barrier properties in a concentration-dependent manner, as measured by an increased (TEER) and decreased permeability. Fasudil also increased the expression of tight junction protein claudin-5. Reductions in TEER and increased permeability were observed after OGD/reoxygenation exposure in mono- and co-culture models. The improvement in BBB integrity by fasudil was confirmed in both of the models, but was significantly higher in the co-culture than in the monoculture model. Treatment with U-46619 did not show significant changes in TEER in the monoculture model, whereas it showed a significant reduction in TEER in the co-culture model. Fasudil significantly improved the U-46619-induced TEER reduction in the co-culture models. Pericytes and astrocytes have opposite effects on endothelial cells and may contribute to endothelial injury in hyperacute ischemic stroke. Overall, fasudil protects the integrity of BBB both by a direct protective effect on endothelial cells and by a pathway mediated via pericytes and astrocytes.ConclusionsOur findings suggest that fasudil is a BBB-protective agent against acute ischemic stroke.

Research on the evolution law of incidental traffic congestion based on CTM

This paper takes the urban road network as the research object to study the temporal and spatial characteristics and evolution mechanism of incidental traffic congestion. Firstly, the improved cell transmission model (CTM) is proposed considering the traffic flow delay phenomenon and the boundary conditions of the cell at the intersection. Secondly, considering the delay time of vehicles at the intersection, the A * path-finding algorithm is proposed, and a dynamic path selection model based on real-time road impedance is established. Finally, combined with the improved CTM and dynamic path selection model, starting from the severity of the incident and the frequency of information induction and update, the traffic flow is simulated by MATLAB software to simulate the traffic flow in the road network under different conditions and analyze the diffusion characteristics of congestion under sudden events. The simulation results show that during the simulation time period, when the traffic capacity caused by the severity of the incident is only 1/2, 1/4 and 1/8 of the original, the maximum number of congestion cells in the network is 9, 26 and 35, and the maximum delay per unit time stepping is 290, 1.31*103 and 2.41*103 vehicles, and the total delay in the road network is 2.73*105, 7.19*105, and 1.50*106 vehicles, after 320δ, 578δ and 588δ the congestion cells in the road network completely disappear. At the information induced update time of 30s, 120s and 600s, the maximum number of congestion cells in the road network is 5, 10 and 23, the maximum number of delayed vehicles is 162, 254 and 985 vehicles - time stepping, the total delay is 1.25*105, 1.68*105 and 5.84*105 vehicles. The findings of the study can provide reference for urban road network design and traffic management.

Study on Na2V0.67Mn0.33Ti(PO4)3 electrodes with ultralow voltage hysteresis for high performance sodium-ion batteries

The Na superionic conductor (NASICON) is one of the promising electrode materials used in advanced Na-based secondary batteries, but designing a low-overpotential structure is crucial for developing NASICON-type electrodes to repress voltage hysteresis and reduce energy loss. In this study, the integration of Mn3+ into a NASICON-type material (Na2VTi(PO4)3) decreases the voltage hysteresis of the redox couples due to the enlarged migration pathway for mobile Na+ ions. When using Na2V0.67Mn0.33Ti(PO4)3 as cathode material, two Na+ ions can be extracted from the structure, leading to the specific capacity of 110 mAh g−1 at the current density of 0.1 C. In operando synchrotron radiation diffraction elucidates that there is a combination of mono- and biphasic mechanisms for reversible Na+ insertion/extraction within initial two cycles. Moreover, fast sodium diffusion in the NMVTP electrode has been measured and analysed via first-principles calculation and real-time impedance spectroscopy. The results of this work indicate that Na2V0.67Mn0.33Ti(PO4)3 is a promising material for sodium-ion batteries.