HTS Applications Research Articles

Application of Fluorescence- and Bioluminescence-Based Biosensors in Cancer Drug Discovery

Recent advances in drug discovery have established biosensors as indispensable tools, particularly valued for their precision, sensitivity, and real-time monitoring capabilities. The review begins with a brief overview of cancer drug discovery, underscoring the pivotal role of biosensors in advancing cancer research. Various types of biosensors employed in cancer drug discovery are then explored, with particular emphasis on fluorescence- and bioluminescence-based technologies such as FRET, TR-FRET, BRET, NanoBRET, and NanoBiT. These biosensors have enabled breakthrough discoveries, including the identification of Celastrol as a novel YAP-TEAD inhibitor through NanoBiT-based screening, and the development of TR-FRET assays that successfully identified Ro-31-8220 as a SMAD4R361H/SMAD3 interaction inducer. The integration of biosensors in high throughput screening and validation for cancer drug compounds is examined, highlighting successful applications such as the development of LATS biosensors that revealed VEGFR as an upstream regulator of the Hippo signaling pathway. Real-time monitoring of cellular responses through biosensors has yielded invaluable insights into cancer cell signaling pathways, as demonstrated by NanoBRET assays detecting RAF dimerization and HiBiT systems monitoring protein degradation dynamics. The review addresses challenges linked to biosensor applications, such as maintaining stability in complex tumor microenvironments and achieving consistent sensitivity in HTS applications. Emerging trends are discussed, including integrating artificial intelligence and advanced nanomaterials for enhanced biosensor performance. In conclusion, this review offers a comprehensive analysis of fluorescence- and bioluminescence-based biosensor applications in the dynamic cancer drug discovery field, presenting quantitative evidence of their impact and highlighting their potential to revolutionize targeted cancer treatments.

Characteristic Analysis of Electromagnetic Force in an HTS Field Coil Using a Performance Evaluation System

A performance evaluation system (PES) can experimentally test the structural stability and magnetic field effects of HTS coils against high magnetic fields and electromagnetic forces before mounting the HTS coils on a large-capacity rotating machine. This paper deals with the characteristic analysis of electromagnetic force in an HTS field coil for a 10 MW Class HTS Wind Power Generator using PES. Based on the designed 10 MW class HTS wind power generator, the HTS coils are manufactured and installed in the PES by a support structure, which is designed considering the electromagnetic force (torque) and heat loads in the HTS coil. To check the stress and deformation in the support structure caused by the electromagnetic force generated from the coil, strain gauge sensors were attached to the support structure and measured under full-load conditions. As a result, the maximum magnetic field and electromagnetic force are 2.8 T and 71 kN, respectively. Compared to the analysis results, the magnetic field and generated electromagnetic force in the HTS coil were the same under no-load and full-load conditions. These results will be effectively used to study and fabricate high magnetic field coils for HTS applications, as well as the PES being fabricated.

Development of a HTS application for the Colombian aircraft manufacturing industry

Development of a HTS application for the Colombian aircraft manufacturing industry

High Temperature Superconductivity Application Readiness Map - Energy Delivery - Transmission, Substation and Distribution

The International Energy Agency's High Temperature Superconductivity Technology Collaboration Program (IEA HTS TCP) analyzed energy delivery applications for HTS. The product was a Readiness Map that illustrates the Technology Readiness Levels (TRL) over time of HTS applications. Assessing these TRL levels is important since the electric power system that supplies our residential, commercial and industrial sectors is experiencing a transition to safer, more efficient and cleaner power supply. The international experts assessed the present degree of technological development of the main transmission, substation and distribution HTS applications in the energy delivery sector and estimated the pathway to commercialization phase. Instead of using a specific TRL number 1-9 for each of the applications, they are categorized into low, medium and high TRL levels. Superconducting fault current limiters and medium voltage AC cables to interconnect substations at the low side of the transformer are currently at a high TRL as they can be purchased in the market. High voltage AC and DC cables are at a medium TRL and could reach a high level TRL level in 2030-2035. Superconducting transformers are at a low TRL and they could reach a high TRL level by 2030-2035.

Development of a high capacity single stage GM cryocooler at 30 K range

Recently, there has been a demand for high-performance cryocoolers at the 30 K range to support emerging developments in high-temperature superconductors, green hydrogen power systems and circulating cooling system applications. The Low Pressure Cooler (LPC), a mobile circulating cooling system used to cool down superconducting magnets, mainly MRI’s, is currently a four cold head system running with four compressors. There is a strong demand to develop a more compact system to replace the LPC to cool down legacy and helium-free MRI magnets, which addresses ease of use, faster cool down, low power consumption, and simplifies handling and logistics. A more efficient large capacity cold head can replace multiple smaller cold heads and achieve these demands. Sumitomo (SHI) Cryogenics of America, Inc. has developed a high-capacity single-stage GM cryocooler, CH-160D2LT, for low temperature, circulating cooling and HTS applications. It has a capacity of 200 W around 30 K at 60 Hz, which is described in this paper. This cryocooler is part of the high-performance, low-noise, high capacity single-stage CH-160D2 Cryocooler family. This paper will discuss developments such as the cryocooler’s performance, heat exchanger efficiencies and regenerator designs.

Hammerhead ribozyme-based U-insertion and deletion RNA editing assays for multiplexing in HTS applications.

Untranslatable mitochondrial transcripts in kinetoplastids are decrypted post-transcriptionally through an RNA editing process that entails uridine insertion/deletion. This unique stepwise process is mediated by the editosome, a multiprotein complex that is a validated drug target of considerable interest in addressing the unmet medical needs for kinetoplastid diseases. With that objective, several in vitro RNA editing assays have been developed, albeit with limited success in discovering potent inhibitors. This manuscript describes the development of three hammerhead ribozyme (HHR) FRET reporter-based RNA editing assays for precleaved deletion, insertion, and ligation assays that bypass the rate-limiting endonucleolytic cleavage step, providing information on U-deletion, U-insertion, and ligation activities. These assays exhibit higher editing efficiencies in shorter incubation times while requiring significantly less purified editosome and 10,000-fold less ATP than the previously published full round of in vitro RNA editing assay. Moreover, modifications in the reporter ribozyme sequence enable the feasibility of multiplexing a ribozyme-based insertion/deletion editing (RIDE) assay that simultaneously surveils U-insertion and deletion editing suitable for HTS. These assays can be used to find novel chemical compounds with chemotherapeutic applications or as probes for studying the editosome machinery.

Abstract 220: Disease monitoring of mycosis fungoides via high throughput sequencing of CDR3

Abstract Background High-throughput T-cell receptor sequencing (HTS) has been shown to be both sensitive and specific at diagnosing Mycosis Fungoides (MF); a sensitivity of 85% was achieved with superiority to TCRγ; PCR in detecting monoclonality and a specificity of 99.89% was achieved in detecting minimal residual disease, specifically Sezary Syndrome cells with superiority to flow cytometry. In this study, we look at the potential application of HTS as a method for monitoring treatment response in patients with MF. Methods We sequenced the CDR3 region of the T-cell receptor (TCR) subunit of T cells in the skin lesional tissue, as well as in pre- and post-treatment blood samples of 7 patients with late stage Mycosis Fungoides (stage IIB-IV). DNA and RNA were extracted from peripheral blood and skin samples. Library preparation followed the manufacturer's instructions (Illumina). The template DNA fragments of the constructed libraries were hybridized to the surface of Nimblegen sequence Capture chip and detected with Hiseq2000 platform. Raw data was analyzed and verified to obtain aberrantly expressed genes. A multiplex PCR system was used to amplify the specific CDR3 region. Distinct TCR CDR3 sequences were plotted on the basis of their frequency of appearance to generate the TCR “repertoire”. The malignant clonal TCR signature was determined by the highest frequency CDR3 sequence of the tumor cells from skin biopsy specimens and confirmed by pathological diagnosis. This malignant sequence was identified in pre-treatment blood and monitored in post-treatment blood. Further analysis of each patient's TCR repertoire allowed us to calculate a diversity index (Simpson's diversity index) for each patient's skin sample. Results of diversity index calculation was analyzed with unpaired T-test using GraphPad Prism version 7 (GraphPad Software, La Jolla, CA). All p-values were two-tailed, with a p<0.05 considered statistically significant. Results Frequency of the identified malignant TCR clone remained high in the post-treatment blood samples of the patients with poor treatment response, while the number of TCR signature clones diminished in the post-treatment blood samples of the patients with good treatment response. Higher levels of diversity of TCR was also seen in the skin pre-treatment for good responders to treatment. Conclusion This study used HTS to identify malignant TCR signatures from skin biopsy specimens and to monitor the changes in blood samples in MF patients. The findings suggest that HTS is a potential ancillary blood test to monitor treatment response in MF patients by comparing the levels of the TCR signature before and after therapy. A greater diversity of T-cells in the skin may also predict a better treatment response in MF, as the presence of tumor infiltrating lymphocytes has been correlated with better outcomes in many different cancers. Citation Format: Kevin Y. Wang, Tao Wang, Yuehua Liu, Christine Lian. Disease monitoring of mycosis fungoides via high throughput sequencing of CDR3 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 220.

Performance characteristics map using exergy analysis of reverse Brayton cryocooler for HTS applications: Selection, Optimization, Design and Operational guidelines

In this paper, investigation has been carried out to find a guideline for selection of optimum process parameters such as the operating pressure and pressure ratio of an RBC for given loads at different temperature for HTS cables. Grid search method-based optimisation technique has been adopted where the exergetic efficiency has been considered as the objective function and the operating pressure and pressure ratio have been adopted as the primary variables. The effects of the change in the primary variables on the other process parameters such as mass flow rate, turbine power output, compressor power input, heat exchangers UA etc. have been investigated. Studies have been made to find out the effects of the design variables such as compressor efficiency, turbine efficiency, heat exchanger minimum approach etc. on the optimum values of the pressure ratio and operating pressure. The applications of the above findings have been elucidated with an example of selection of the process parameters of RBC for a given load conditions for HTS cables and utilized to develop a new simple and effective optimization approach. The findings and methodology may be adopted for RBC used in various other applications by researcher, process designer and operational engineer.

Exploiting asymmetric wire critical current for the reduction of AC loss in HTS coil windings

Critical current and AC loss in coil windings are two important factors for various HTS applications. Many coated conductors exhibit asymmetry in the variation of the critical current with magnetic field angle. This asymmetry results in different coil critical current values depending on the orientation of the conductors in the coil windings. We report critical current and AC loss results at 77 K and 65 K for three hybrid coil assemblies which have a common central winding and different arrangements of the end windings. We found a difference greater than 13% in both the critical current and the AC loss results for the different arrangements. The results imply that if we wind coil assemblies smartly even using the same materials and the same design, we can not only improve critical current but also reduce AC loss significantly.

Dynamic Resistance Measurement in a Four-Tape YBCO Stack With Various Applied Field Orientation

The dynamic resistance which occurs when a superconductor carrying DC current is exposed to alternating magnetic field plays an important role in HTS applications such as flux pumps and rotating machines. We report experimental results on dynamic resistance in a four-tape coated conductor stack when exposed to AC magnetic fields with different magnetic field angles (the angles between the magnetic field and normal vector component of the tape surface, θ) at 77 K. The conductors for the stack are 4-mm-wide SuperPower SC4050 wires. The field angle was varied from 0° to 120° at a resolution of 15° to study the field angle dependence of dynamic resistance on field angle as well as wire I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> (B, θ). We also varied the field frequency, the magnetic field amplitude, and the DC current level to study the dependence of dynamic resistance on these parameters. Finally, we compared the measured dynamic resistance results at perpendicular magnetic field with the analytical models for single wires. Our results show that the dynamic resistance of the stack was mainly, but not solely, determined by the perpendicular magnetic component. I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> (B, θ) influences dynamic resistance in the stack due to tilting of the crystal lattice of the superconductor layer with regard to buffer layers.

Active magnetic bearing for a liquid nitrogen pump

The development of a liquid nitrogen submerged pump for HTS applications is underway. A cryogenic active magnetic bearing is the main component of the pump. The bearing makes the maintenance interval of the pump longer than 3years such interval is essential for the pump in commercial use of HTS applications such as long HTS cable. The bearing will be set in a HTS motor shaft of the pump. In experiments, a shaft without an HTS motor is used and the bearing was immersed in liquid nitrogen. The rotation of the shaft is made by a high-speed motor at room temperature. The bearing consists of two radial bearings and one axial bearing. The shaft was floating by the bearing and was rotated by the motor at room temperature. The steady rotation speed of 2,000, 3,000, 4,000 and 5,000 rpm were achieved, and the rotation speed satisfied the design speed of the pump which is 5,000rpm.

Application of HTS for Routine Plant Virus Diagnostics: State of the Art and Challenges.

Application of HTS for Routine Plant Virus Diagnostics: State of the Art and Challenges.

Electrical Characteristics of Twisted Soldered-Stacked-Square (3S) Wires Consisting of HTS Narrow Tapes with 1mm Width

To reduce the effect of external magnetic field, we proposed a novel wire with a square cross section of 1 mm × 1 mm which is named Soldered-Stacked-Square (3S) HTS wire. 3S HTS wire has great advantages in HTS applications due to its small square dimension, but it is inevitable to endure twisting. To study the twist structure of 3S HTS wire, a series of twisted 3S HTS wire samples are prepared, and we evaluate the typical electrical characteristics: twist pitch, critical current, self-field AC loss and so on. It is shown that the critical current of twisted 3S wire is constant up to a twist pitch of 80 mm, and the minimum twist pitch is approximately 50 mm. Measured AC losses are independent of frequency and are in good agreement with the thin strip theoretical values. Specially, measured AC losses are a little smaller than the thin strip theoretical value when peak transport current is reaching critical current. Besides, the measured AC losses of twisted 3S wire and 3S wire are almost identical.

Abstract 3312: A novel plate-based assay for screening autophagic activity in 2D and 3D cell culture models

Abstract The critical importance of autophagy in cell health and its proposed role in disease-relevant biology, including cancer, inflammation, and immunology, has increased the need for more effective assays to screen for agents that modulate autophagic activity. Here we utilize NanoLuc Binary Technology (NanoBiT) to develop a homogeneous plate-based assay to measure autophagic flux in cell culture models. In this approach, an exogenous LC3B (Atg8) fusion protein was tagged on its N-terminus with an 11 amino acid peptide (HiBiT) and stably expressed in mammalian cells, including U2OS and HEK293. After exposure to various treatment conditions, cellular levels of this novel autophagy reporter were determined by addition of a lytic detection reagent containing Large BiT (LgBiT). LgBiT rapidly associates with HiBiT in the cell lysate, producing a bright, luminescent enzyme in the presence of the furimazine substrate. The bright signal allows low levels of expression of the reporter, maximizing the assay response, and the signal is stable, allowing assay of multiple 96- or 384-well plates in the same experiment. In response to autophagic stimuli, including nutrient deprivation and various mTORC inhibitors (e.g., PP242 and rapamycin), autophagic degradation of expressed LC3 reporter was evident by reduced assay signal. In contrast, in response to both upstream (e.g., 3-MA and wortmannin) and downstream (e.g., bafilomycin A1 and chloroquine) inhibitors of the autophagy pathway, degradation of the autophagic reporter was effectively blocked and assay signal was consistently increased as predicted. Compound effects were time dependent and stratified according to expected potency and efficacy of the test agents employed. The use of a mutant reporter based on LC3G120A further demonstrated the specificity of the wild-type LC3 reporter for the detection of autophagic activity. When assayed in 384-well plates with automation, HEK293 autophagy reporter cells produced Z’ values of ~0.7 in response to autophagy induction with PP242, while subsequent blockade of autophagy with bafilomycin A1 resulted in Z’ values of ~0.8. This data, and subsequent LOPAC library screening, indicates the potential utility of this assay method for HTS applications. In addition, the HEK293 autophagy reporter cells can be induced to form 3D cell spheroids, thus allowing investigation of assay performance in this more complex model. Autophagy reporter levels increased with increasing spheroid size (up to 650 μm diameter tested) in a manner proportional to a surrogate measure of viable cell number. Importantly, both induction and inhibition of autophagic activity was easily detected following PP242 and bafilomycin A1 treatment, respectively. Using this novel plate-based assay system for the determination of autophagic flux, it is possible to screen test agents and quantitatively determine both the potency and efficacy of autophagy modulation. Citation Format: Dan F. Lazar, Amani A. Gillette, Braeden L. Butler, Christopher T. Eggers, Brock F. Binkowski, Gediminas Vidugiris, Michael R. Slater, Dongping Ma, James J. Cali. A novel plate-based assay for screening autophagic activity in 2D and 3D cell culture models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3312. doi:10.1158/1538-7445.AM2017-3312

Trapped Flux Behavior in Melt-Growth GdBCO Bulk Superconductor Under Off-Axis Field Cooled Magnetization

The effective pinning of magnetic flux in high-temperature superconductor bulk plays a basic role in a variety of engineering applications as superior magnetic field sources. We have studied the trapped magnetic flux behavior of large single-grain GdBa 2 Cu 3 O 7-δ (GdBCO) bulk cryomagnet. Here, an off-axis field cooled magnetization is proposed, in which magnetic field was applied with an angle θ with respect to the crystallographic c-axis of the bulk, i.e., off-axis geometry. To verify the trapped flux performance, the flux density parallel to the c-axis was scanned with Hall sensor on the surface of the bulk after off-axis field cooled magnetization. It was found that the trapped flux component along the c-axis still remains strong with up to θ = 30°, and the total flux over the bulk surface reaches over 97% compared with that when θ = 0°. These results demonstrate GdBCO bulk can nearly maintain their full trapped flux potential along the c-axis under off-axis field cooled magnetization with finite inclination angle. Thus, the present off-axis magnetization can provide an alternative choice for the magnetization geometry design in HTS applications using bulks, when the magnetizing field cannot be applied perfectly aligned with the crystallographic c-axis of the bulk.

Modeling AC ripple currents in HTS coated conductors by integral equations

In several HTS applications, the superconducting tapes experience the simultaneous presence of DC and AC excitations. For example in high-current DC cables, where the transport current is not perfectly constant, but it exhibits some ripples at different frequencies introduced by the rectification process (AC–DC conversion). These ripples give rise to dissipation, whose magnitude and possible influence on the device’s cooling requirements need to be evaluated. Here we report a study of the AC losses in a HTS coated conductor subjected to DC currents and AC ripples simultaneously. The modeling approach is based on an integral equation method for thin superconductors: the superconducting tape is modeled as a 1-D object with a non-linear resistivity, which includes the dependence of the critical current density Jc on the magnetic field. The model, implemented in a commercial finite-element program, runs very fast (the simulation of one AC cycle typically takes a few seconds on standard desktop workstation): this allows simulating a large number of cycles and estimating when the AC ripple losses stabilize to a constant value. The model is used to study the influence of the flux creep power index n on the stabilization speed and on the AC loss values, as well as the effect of using a field-dependent Jc instead of a constant one. The simulations confirm that the dissipation level should not be a practical concern in HTS DC cables. At the same time, however, they reveal a strong dependence of the results upon the power index n and the form of Jc, which spurs the question whether the power-law is the most suitable description of the superconductor’s electrical behavior for this kind of analysis.

Fabrication and Characterization of Sintered Iron-Chalcogenide Superconductors

Iron-chalcogenide superconductors are appealing for high-magnetic-field applications due to their promising superconducting properties, i.e., extremely high upper critical and irreversibility field.In this paper, the first achievements obtained from sintering polycrystalline samples are presented. The sintering of FeSe polycrystalline powders and pellets was obtained in several steps starting from stoichiometric quantities of freshly polished powders shots; after grinding, powders were loaded into cleaned and dried silica tubes sealed under vacuum for subsequent heat treatments in order to obtain the superconducting phase. Samples were then characterized from the structural, transport, and magnetic points of view. From the structural characterization, it has been discovered that, in addition to the presence of the desired tetragonal FeSe phase, hexagonal phase and several impurities are present in the samples; the lack of homogeneity inside the samples is confirmed by the superconductive characterization: despite the small undeniable enhancement of the results with the application of subsequent HTs and, nearby, a resistive superconductive onset of 12 K, the transition is still broad after the third HT.

Transition to the Normal State Induced by High Current Densities in High-Tc Superconductor Microbridges Under Applied Magnetic Fields

We report some of our experimental results about the transition to the normal state of high-temperature superconductors subjected to high current densities and, simultaneously, under external magnetic fields up to 1 T. Our data analysis, which is based on a recently published instability model, show that the quenching may be explained in terms of thermal instabilities due to self-heating favored by the nonlinear nature of the current–voltage characteristics of high- $T_{c}$ superconductors (HTS). In fact, we predict the density current $J^{\ast}$ at which the samples quench, i.e., jump abrupt to the normal state, with an accuracy around 1%. Beyond its interest from a fundamental point of view, this thermal model opens a practical way to estimate the quenching point thus avoiding the damaging or even burning up of devices in high power applications of HTS.

Study of 2G HTS Superconducting Coils Using Line Front Track Approximation

This paper demonstrates an efficient method to calculate the ac losses in multipancake coils. We use the front track line to analyze stacked pancakes by assuming that the current fronts are straight lines and using the critical state model. The current distribution is solved by minimization of total magnetic energy. The calculated ac loss results are compared with the well-accepted H-formula in COMSOL. We further apply this model to the design of a SMES with 2 kJ, which is under construction. The object of the design is to maximize the stored energy and decrease the ac loss. We discuss the detailed geometry parameters and operation temperature with the validated numerical model. Our model provides a fast calculation method of ac loss in stacked (Re)BCO pancakes and is useful to HTS applications in high field magnets, energy storage devices, and electric machines.

Development of resazurin-based assay in 384-well format for high throughput whole cell screening of Trypanosoma brucei rhodesiense strain STIB 900 for the identification of potential anti-trypanosomal agents

To accelerate the discovery of novel leads for the treatment of Human African Trypanosomiasis (HAT), it is necessary to have a simple, robust and cost-effective assay to identify positive hits by high throughput whole cell screening. Most of the fluorescence assay was made in black plate however in this study the HTS assay developed in 384-well format using clear plate and black plate, for comparison. The HTS assay developed is simple, sensitive, reliable and reproducible in both types of plates. Assay robustness and reproducibility were determined under the optimized conditions in 384-well plate was well tolerated in the HTS assay, including percentage of coefficient of variation (% CV) of 4.68% and 4.74% in clear and black 384-well plate, signal-to-background ratio (S/B) of 12.75 in clear 384-well plate and 12.07 in black 384-well plate, Z′ factor of 0.79 and 0.82 in clear 384-well plate and black 384-well plate, respectively and final concentration of 0.30% dimethylsulfoxide (DMSO) in both types of plate. Drug sensitivity was found to be comparable to the reported anti-trypanosomal assay in 96-well format. The reproducibility and sensitivity of this assay make it compliant to automated liquid handler use in HTS applications.