Current-clamp Research Articles

Robotized Mobile Platform for Non-Destructive Inspection of Aircraft Structures

The robotization of the non-destructive inspection of aircraft is essential for improving the accuracy and duration of performed inspections, being an integral part of inspection and data management systems within the currently developed NDT 4.0 concept. In this paper, the authors presented the design and testing of a universal mobile platform with interchangeable sensing systems for the non-destructive inspection of aircraft structures with various angles of inclination. As a result of the performed studies, a low-cost approach of automation of existing measurement devices used for inspection was proposed. The constructed prototype of the mobile platform was equipped with eddy current testing probe and successfully passed both laboratory and environmental tests, demonstrating its performance in various conditions. The presented approach confirms the effectiveness of the automation of the inspection process using climbing robots and defining the directions of possible development of automation in non-destructive testing in aviation.

Causal relationship between inflammatory cytokines and polycystic ovary syndrome: a bidirectional mendelian randomization study.

Polycystic ovary syndrome (PCOS) is defined as a chronic low-grade inflammatory reproductive endocrine disorder. PCOS can induce various metabolic disorders, which are associated with a state of mild and slow-acting inflammation. Nevertheless, the causal relationship between polycystic ovary syndrome and inflammatory factors is uncertain. The causality between inflammatory cytokines and PCOS was analyzed by bidirectional Mendelian randomization (MR) in this current probe. We performed an interactive MR study to assess the causal relationships between 91 inflammatory cytokines and PCOS using Genome Wide Association Study (GWAS) data. We underwent dual-sample MR analysis with inverse variance weights (IVW) as the predominant MR methodology with multiple validity and heterogeneity analyses. MR-Egger, weighted median, simple mode, weighted mode and MR-PRESSO were analyzed as multiple likelihood sensitivity analyses to enhance the final results.The results came out interleukin-1-alpha (IL-1A) levels (odds ratio [OR] = 1.051, 95% fiducial interval [95% CI] = 1.009-1.095, P = 0.02) and oncostatin-M (OSM) levels ( [OR] = 1.041, [95% CI] = 1.001-1.082, P = 0.04) were positively associated with the development of PCOS. Moreover, interleukin-7 (IL-7) levels ([OR] = 0.935, [95% CI] = 0.884-0.989, P = 0.02); interleukin-15 receptor subunit alpha (IL15RA) levels ([OR] = 0.959, [95% CI] = 0.929-0.99, P = 0.01); and C-X-C motif chemokine 11 (CXCL11) levels ([OR] = 0.959, [95% CI] = 0.922-0.996. P = 0.03) were strongly negatively associated with PCOS. However, we did not find any strong positive results in the reverse analysis, suggesting that although inflammatory factors contribute to the pathogenesis of PCOS, PCOS itself does not trigger inflammatory factor production.Our study provides genetic evidence for the connection between systemic inflammatory regulators and PCOS. Treatments targeting specific inflammatory factors may help to mitigate the risk of PCOS. The levels of five of the 91 inflammatory factors included in this study, namely, IL1A and OSM, were associated with PCOS. IL1A and OSM contribute to the progression of PCOS while IL-7, IL15RA, and CXCL11 levels are negatively correlated with the development of PCOS.

Correlation of thyroid function and sensitivity to thyroid hormone with spinal bone mineral content, bone mineral density, and osteoporotic vertebral fracture: A cross-sectional study based on NHANES.

Previous studies have demonstrated that thyroid hormone plays an important role in normal bone development, bone metabolism, and establishment of peak bone mass. However, the correlation of thyroid status with bone mineral content (BMC), bone mineral density (BMD), and osteoporotic vertebral fracture (OVF) is rarely discussed. The current study probes into the potential association between thyroid status and spinal BMC, BMD, and OVF from a novel perspective of thyroid function (TF) and sensitivity to thyroid hormone based on the National Health and Nutrition Examination Survey database. A total of 1844 participants were included in this study. The association of thyroid status with outcome variables, like spinal BMC, BMD, and OVF, was analyzed using thyroid function indices and sensitivity to thyroid hormone indices as influence factors. The correlation of them were assessed using univariate and multivariable weighted linear regression, weighted logistic regression models, restricted cubic spline model, and subgroup analyses. The results of this study showed that the association of free triiodothyronine (FT3)/free thyroxine (FT4) with BMC remained negatively associated after adjustment for all covariates. Higher thyroid peroxidase antibody (TPOAb) was significantly associated with an increased risk of developing OVF in both unadjusted and adjusted models. In addition, the results of the restricted cubic spline model were consistent with the weighted multivariate regression analysis after adjustment. The results of this cross-sectional study showed that higher FT3/FT4 and TPOAb were associated with decreased spinal BMC and the increased risk of OVF, indicating a complex link between thyroid status and bone health. Therefore, patients with hyperthyroidism, hypothyroidism, autoimmune thyroid disease, or abnormal peripheral thyroid sensitivity, especially who with elevated TPOAb or FT3/FT4, should focus on the prevention of vertebral osteopenia, osteoporosis, and OVF.

Mapping of β3-Adrenergic Receptor in Living Cells with a Ligand-Guided Fluorescent Probe.

Tracking the dynamic distribution of native proteins in living cells or tissues in real time is essential for understanding the functional mechanisms involved in their physiological or pathological processes. The β3-adrenergic receptor (β3-AR) has important biological functions. It is expected to be a diagnostic indicator for aging, yet current probes for β-ARs are unable to dynamically monitor β3-AR in real time, which impedes the progress of β3-AR research. Here, we developed a ligand-directed anchoring probe, β3-ARP, that precisely covalently anchors with native β3-AR in living cells, for the diagnosis of senescence. The ligand-directed anchoring probe selectively recognizes and traces β3-AR and can achieve dynamic observation and monitoring of β3-AR in living cells, including the interaction between lipid droplets and mitochondria. Moreover, we were able to directly probe the distribution of β3-AR in various organs of aging mice in situ and track the location of native β3-AR in different types of primary neuronal cells using β3-ARP and two-photon imaging, which revealed the aberrant accumulation of lipid droplets and the distribution of β3-AR in neurological diseases. This research has resulted in a new covalently anchoring fluorescent probe, β3-ARP, which could serve as a powerful tool to explore the link between β3-AR and age-related diseases.

Quantitative molecular imaging of cardiac fibrosis and response to treatment using a novel collagen III-specific MR imaging probe

Abstract Background Heart failure (HF) remains a major cause of morbidity and death affecting 64 million people globally[1]. Myocardial fibrosis, characterised by changes in type I (COL1) and III (COL3) collagen levels, may lead to HF [2,3]. Cardiac magnetic resonance (CMR) is a preferred method to detect fibrosis non-invasively, however it provides only indirect measures of fibrosis. Molecular imaging can directly visualise fibrosis, but current imaging probes target COL1. Purpose Here, we developed a COL3-specific probe and used molecular CMR imaging to directly quantify, previously undetectable, COL3 remodelling following myocardial infarction and to monitor treatment response. Methods Myocardial infarction (MI) was induced in mice by permanent ligation of the left anterior descending artery (LAD). Functional and molecular CMR images were acquired at days 10 and 21 post-MI in untreated and mice treated with Enalapril (20mg/kg/day) (n=6/group) using a 3T clinical MRI scanner. A subgroup of untreated mice was also imaged using a negative control probe and Gadovist (n=3). Cardiac function was assessed using 2D short-axis cine images of the left ventricle, and late gadolinium enhancement (LGE) images were obtained using T1-weighted 3D inversion recovery (IR) imaging. T1 mapping was performed using a 2D Look-Locker sequence with thirty inversion recovery images. Results Molecular CMR enabled selective profiling of the natural turnover of COL3 after MI with strong signal enhancement at day 10, and decreased enhancement at day 21 when COL3 is replaced by COL1 (Fig. 1A). Quantitative T1 maps discriminated between infarcted and remote myocardium with lower T1 values in the infarct and higher in the remote myocardium. Importantly, there was no enhancement using the scrambled probe or the clinical agent Gadovist. The imaging data were validated by histology (Fig.1B). Mice treated with Enalapril showed similar enhancement at day 10 compared to untreated mice (Fig. 2A). However, at day 21 mice treated with Enalapril showed higher signal enhancement compared to untreated mice, suggesting that Enalapril may prolong the presence of COL3 in the infarcted myocardium. Quantification of signal enhancement showed the increase in LGE volume and R1 relaxation rates within the infarcted myocardium at day 10, the subsequent decrease at day 21 and the prolongation of the COL3 signal at day 21 in enalapril treated mice (Fig.2B-C) Despite changes in cardiac fibrosis detected with molecular imaging, cardiac function was similar between the groups (Fig. 2D), suggesting that molecular change may precede functional changes. Conclusion(s) Quantitative molecular CMR imaging of COL3 enabled visualisation of changes in COL3 after MI and in response to treatment for the first time. This approach may provide insights into the role of COL3 in cardiac fibrosis and provide an non-invasive method to detect fibrosis early, stage fibrosis and monitor therapeutic response.

Towards Advancing Real-Time Railroad Inspection Using a Directional Eddy Current Probe

In the field of railroad safety, the effective detection of surface cracks is critical, necessitating reliable, high-speed, non-destructive testing (NDT) methods. This study introduces a hybrid Eddy Current Testing (ECT) probe, specifically engineered for railroad inspection, to address the common issue of “lift-off noise” due to varying distances between the probe and the test material. Unlike traditional ECT methods, this probe integrates transmit and differential receiver (Tx-dRx) coils, aiming to enhance detection sensitivity and minimise the lift-off impact. The study optimises ECT probes employing different transmitter coils, emphasising three main objectives: (a) quantitatively evaluating each probe using signal-to-noise ratio (SNR) and outlining a real-time data-processing algorithm based on SNR methodology; (b) exploring the frequency range proximal to the electrical resonance of the receiver coil; and (c) examining sensitivity variations across varying lift-off distances. The experimental outcomes indicate that the newly designed probe with a figure-8 shaped transmitter coil significantly improves sensitivity in detecting surface cracks on railroads. It achieves an impressive SNR exceeding 100 for defects with minimal dimensions of 1 mm in width and depth. The simulation results closely align with experimental findings, validating the investigation of the optimal operational frequency and lift-off distance for selected probe performance, which are determined to be 0.3 MHz and 1 mm, respectively. The realisation of this project would lead to notable advancements in enhancing railroad safety by improving the efficiency of crack detection.

Measurement of Hydraulic Fracture Aperture by Electromagnetic Induction.

We present a new method for accurately measuring the aperture of a fluid-driven fracture. This method uses an eddy current probe located within a completion tool specifically designed to obtain the fracture aperture in the wellbore at the location where the fluid is injected into the fracture. The probe induces an eddy current in a target object, producing a magnetic field that affects the overall magnetic field. It does not have any limitations with respect to fluid pressure and temperature within a large range, making it unlike other methods. We demonstrate the accuracy and performance of the sensor under laboratory conditions. A hydraulic fracture experiment in a porous sandstone is conducted and discussed. The obtained measurement of the evolution of the fracture inlet aperture by the eddy current probe during the multiple injection cycles performed provided robust information. The residual fracture aperture (after the test) measured by the probe is in line with estimations from image processing of X-ray CT scan images as well as a thin-section analysis of sub-parts of the fractured specimen. The robustness and accuracy of this electromagnetic induction probe demonstrated herein under laboratory conditions indicate an interesting potential for field deployment.

Performance Investigation of Multi-Turn Pickup for Circular Fractal Flexible Planar Eddy Current Probe

ABSTRACT This paper aims to compare and analyze the performance differences between a single-coil and multi-coil pickup coil layout in a flexible circular fractal planar eddy current probe. Flexible planar eddy current probes offer flexibility and adaptability, making them widely used in the detection of complex structures. The circular fractal flexible planar eddy current probe is a new type of probe that has a lower miss rate in detecting cracks at specific angles compared to traditional circular and rectangular coil eddy current probes. However, the single-coil structure of the probe’s pickup coil has the drawback of being less sensitive to weak signals. This paper investigates the detection performance of the flexible circular fractal probe by varying the number of turns in the original pickup coil. Experimental comparisons were conducted by preparing and installing single-coil and multi-coil circular fractal planar eddy current probes. The performance differences between single-coil and multi-coil configurations were compared and analyzed under various excitation frequencies, liftoff distances, and internal crack depths. The results showed that, compared to the single-coil probe, the multi-coil probe exhibited significantly improved detection signal values and sensitivity.

Circumferential Crack Detection in Ultra-High-Pressure Tubular Reactors with Pulsed Eddy Current Testing.

Ultra-high-pressure tubular reactors are crucial pieces of equipment for polyethylene production. Long-term operation under high temperature, high pressure, and other extremely harsh conditions can lead to various defects, with circumferential cracks posing a major safety risk. Detecting cracks is challenging, particularly when they are under a protective layer of a certain thickness. This study designed a pulsed eddy current differential probe to detect circumferential cracks in ultra-high-pressure tubular reactors, with the lift-off distance acting as a protective layer. Detection models for traditional cylindrical and semi-circular excitation differential probes were established using finite element simulations. Corresponding experiments under different lift-off conditions were carried out, and the model's accuracy was verified by the consistency between the simulation results and experimental data. The distribution of the eddy current field under different conditions and the disturbances caused by cracks at various positions to the detection signal were then calculated in the simulations. The simulation results showed that the cracks significantly disturbed the eddy current field of the semi-circular excitation differential probe compared with that of the traditional cylindrical probe. The designed differential probe effectively detected circumferential cracks of specific lengths and depths using the difference in the voltage signals. The experimental results were in agreement with the simulation results, showing that the designed probe could effectively detect 20 mm-long circumferential cracks at a lift-off of 60 mm. The experimental results also show that the probe's detection coverage area in the axial direction varied with the lift-off height. The probe design and findings are valuable for detecting cracks in ultra-high-pressure tubular reactors with protective layers.

Development of Clinically Viable Non-Muscle Myosin II Small Molecule Inhibitors with Broad Therapeutic Potential.

Research suggests numerous indications, from axon regeneration and cancer, would benefit from a small molecule inhibitor of non-muscle myosin II, a molecular motor that regulates the actin cytoskeleton. Current chemical probe options are very limited and lack sufficient safety for in vivo studies, which we show is primarily due to potent inhibition of cardiac myosin II.Rational design that focused on improving target selectivity over the pan-myosin II inhibitor, blebbistatin, led to the identification of MT-228, a small molecule inhibitor with a wide therapeutic window.High-resolution structure of MT-228 bound to myosin II reveals that selectivity results from a different positioning compared to blebbistatin and an important sequence difference between cardiac and non-muscle myosin II in the inhibitor binding pocket.A single administration of MT-228 shows long-lasting efficacy in animal models of stimulant use disorder, a current unmet and rapidly escalating need with no FDA-approved treatments.

Synthesis and Application of a Versatile Immunoproteasome Activity Probe.

The immunoproteasome (iCP) has gained significant interest in recent years as it has been discovered to be significantly expressed under inflammatory conditions, as well as playing significant roles in several diseases, such as autoimmune disorders, viral infection, and cancer. Selective inhibitors have been generated as a method to overcome the off-target effects of current proteasome inhibitor therapeutics. However, selective probes that allow for monitoring this protein complex remain limited, hindering our understanding of the iCP. Current probes are non-selective, not commercially available, or require difficult synthesis. Here, we describe the modular synthesis and application of an iCP-selective probe. The modular nature of the synthetic strategy can enable the incorporation of different fluorophores and covalent warheads, demonstrating the versatility of this probe.

Research of EDDY current probes for inspection of aluminum alloy structure welds using smartphone-based flaw detector

Research of EDDY current probes for inspection of aluminum alloy structure welds using smartphone-based flaw detector

BOS-318 treatment enhances elexacaftor-tezacaftor-ivacaftor (ETI)-mediated improvements in airways hydration and mucociliary transport

BackgroundCFTR triple modulator therapy, elexacaftor-tezacaftor-ivacaftor (ETI) has transformed care for people with cystic fibrosis (pwCF) who have eligible mutations. It is, however, not curative. Response to treatment also varies and lung disease although slowed, remains progressive. We have previously demonstrated that inhibition of the epithelial sodium channel (ENaC) by selective furin inhibition offers an alternative, mutation-agnostic approach to enhance airways hydration and restore mucociliary transport (MCT) in CF. Inhibition of furin therefore, offers a potential therapeutic strategy for those ineligible, intolerant or non-responsive to ETI and may provide a further opportunity for clinical benefit for those currently treated with ETI. The aim of this study was to determine the impact of furin inhibition on ETI responses to assess its utility as an adjunct therapy.MethodsDifferentiated primary human CF bronchial epithelial cells (CF HBECs) were treated with the highly selective furin inhibitor, BOS-318 and ETI. Ion channel function was measured using a 24-channel Transepithelial Current Clamp (TECC-24) system and airways surface hydration was investigated by measuring airway surface liquid (ASL) height and MCT rate.ResultsThe presence of BOS-318 had no effect on the ability of ETI to stimulate CFTR-mediated Cl−secretion but contributed a reduced Na+transportviarobust inhibition of ENaC. This altered ion transport profile effected an improved ASL height and MCT rate which were significantly greater than improvements observed with ETI alone, demonstrating the benefits of the dual approach.ConclusionsSelective furin inhibition has potential to further improve clinical outcomes for all pwCF and offers opportunity as an adjunct to improve responses to currently available CFTR modulator therapies.

A near-infrared fluorescent probe with assembly/aggregation-induced retention effect for specific diagnosis of metastasis and image-guided surgery in breast cancer

Image-guided surgery is crucial for achieving complete tumor resection, reducing postoperative recurrence and improving patient survival. However, current clinical near-infrared fluorescent probes, such as indocyanine green (ICG), face two main limitations: 1) lack of active tumor targeting, and 2) short retention time in tumors, which restricts real-time imaging during surgery. To address these issues, we developed a near-infrared fluorescent probe capable of in situ nanofiber formation within tumor lesions. This probe actively targets the integrin αvβ3 receptors overexpressed on breast cancer cells and exhibits assembly/aggregation-induced retention effects at the tumor site, significantly extending the imaging time window. Additionally, we found that the probe's fluorescence intensity can be enhanced under receptor induction. Due to its excellent tumor specificity and sensitivity, 1FCG-FFGRGD not only identifies primary breast cancer but also precisely locates smaller lymph node metastases and detects sub-millimeter peritoneal metastases. In summary, this near-infrared probe, leveraging assembly/aggregation-induced retention effects, holds substantial potential for various biomedical applications.

Computational Modeling of Sodium-Ion-Channel-Based Glucose Sensing Biophysics to Study Cardiac Pacemaker Action Potential

Elevated blood glucose levels, known as hyperglycemia, play a significant role in sudden cardiac arrest, often resulting in sudden cardiac death, particularly among those with diabetes. Understanding the internal mechanisms has been a challenge for healthcare professionals, leading many research groups to investigate the relationship between blood glucose levels and cardiac electrical activity. Our hypothesis suggests that glucose-sensing biophysics mechanisms in cardiac tissue could clarify this connection. To explore this, we adapted a single-compartment computational model of the human pacemaker action potential. We incorporated glucose-sensing mechanisms with voltage-gated sodium ion channels using ordinary differential equations. Parameters for the model were based on existing experimental studies to mimic the impact of glucose levels on pacemaker action potential firing. Simulations using voltage clamp and current clamp techniques showed that elevated glucose levels decreased sodium ion channel currents, leading to a reduction in the pacemaker action potential frequency. In summary, our mathematical model provides a cellular-level understanding of how high glucose levels can lead to bradycardia and sudden cardiac death.

Modeling of two-element tangential eddy current probe with active shielding for soldered joints inspection

The paper is devoted to designing a finite-element model of the eddy current probe for testing the degree of soldering of lap soldered joints of conductive busbars. The method for finite-element model designing is developed, which parameters provide calculations error of signals of finite-element model of eddy current probe below 1.5%. The test results confirm the performance of the eddy current probe, the measurement range for soldered joints defect size from 0 to 100 % and provision of the declared basic absolute error of the degree of soldering measurement of 5 %.

Effect of current probe location on response law of shielded multi-core wire

Abstract Bulk current injection (BCI) is a commonly used method in electromagnetic compatibility testing. In order to enhance the injection efficiency of the current probe, the interference process into the internal core wire is analyzed. Theoretical calculations indicate that the shielded multi-core wire exhibits a frequency selective response under BCI conditions. The-peak of the terminal load response voltage occurs at frequencies corresponding to the integral multiples of half the relative length of the cable. The position of the current probe along the cable only affects the amplitude of the distributed current on the shielding layer, but not its distribution pattern. The response of the internal core wire at the resonant frequencies is positively correlated with the distribution pattern of the distributed current on the shielding layer. The probe position has a significant effect on the magnitude of the wire-to-terminal response. Placing the current probe at both ends of the cable results in high injection efficiency and significant power savings.

A Nanosecond level current pulse capture taper optical fiber probe based on micron level NV color center diamond

Abstract This work demonstrates a micron-sized nanosecond current pulse probe using a quantum diamond magnetometer. A micron-sized diamond crystal affixed to a fiber tip is integrated on the end of a conical waveguide. We demonstrate real-time visualization of a single 100 nanosecond pulse and discrimination of two pulse trains of different frequencies with a coplanar waveguide and a home-made PCB circuits. This technique finds promising applications in the display of electronic stream and to be used as a pulse discriminator to Simultaneously receive and demodulate multiple pulse frequencies. This method of detecting pulse current is expected to provide further detailed analysis of the internal working state of the chip.

Eddy Currents Probe Design for NDT Applications: A Review.

Eddy current testing (ECT) is a crucial non-destructive testing (NDT) technique extensively used across various industries to detect surface and sub-surface defects in conductive materials. This review explores the latest advancements and methodologies in the design of eddy current probes, emphasizing their application in diverse industrial contexts such as aerospace, automotive, energy, and electronics. It explores the fundamental principles of ECT, examining how eddy currents interact with material defects to provide valuable insights into material integrity. The integration of numerical simulations, particularly through the Finite Element Method (FEM), has emerged as a transformative approach, enabling the precise modeling of electromagnetic interactions and optimizing probe configurations. Innovative probe designs, including multiple coil configurations, have significantly enhanced defect detection capabilities. Despite these advancements, challenges remain, particularly in calibration and sensitivity to environmental conditions. This comprehensive overview highlights the evolving landscape of ECT probe design, aiming to provide researchers and practitioners with a detailed understanding of current trends in this dynamic field.

Large area kidney imaging for pre-transplant evaluation using real-time robotic optical coherence tomography

Optical coherence tomography (OCT) can be used to image microstructures of human kidneys. However, current OCT probes exhibit inadequate field-of-view, leading to potentially biased kidney assessment. Here we present a robotic OCT system where the probe is integrated to a robot manipulator, enabling wider area (covers an area of 106.39 mm by 37.70 mm) spatially-resolved imaging. Our system comprehensively scans the kidney surface at the optimal altitude with preoperative path planning and OCT image-based feedback control scheme. It further parameterizes and visualizes microstructures of large area. We verified the system positioning accuracy on a phantom as 0.0762 ± 0.0727 mm and showed the clinical feasibility by scanning ex vivo kidneys. The parameterization reveals vasculatures beneath the kidney surface. Quantification on the proximal convoluted tubule of a human kidney yields clinical-relevant information. The system promises to assess kidney viability for transplantation after collecting a vast amount of whole-organ parameterization and patient outcomes data.