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A 6.5 MVA/25 kV high temperature superconducting (HTS) transformer for the Chinese Fuxing high-speed train has been proposed to replace the oil-based transformers while achieving higher efficiency, lighter weight, and minimized volume. The high targeted efficiency (> 99%) makes AC loss reduction a vital issue. HTS coated conductors generally exhibit asymmetric critical current characteristics as a function of magnetic field angle Ic(B, θ), leading to a non-trivial influence on the AC loss of coil windings. The fast-computing T-A homogenization method is proposed to calculate the AC loss of the 6.5 MVA/25 kV traction transformer with large turn numbers. The variables, T and A, are the current and magnetic vector potentials, respectively. The AC loss of the transformer windings is analyzed for various coil configurations with and without flux diverters considering Ic(B, θ). At the rated current and 65 K, employing the flux diverters with a square-shape cross-section, the total AC loss is decreased by 73.7% and an extra 150 W loss reduction was also obtained. Moreover, an additional reduction of 37 W is realized upon utilizing the asymmetric Ic(B, θ) characteristic. The reduced 187 W in AC loss at 65 K corresponds to a reduction in ambient power requirement of over 5.6 kW. Therefore, considering asymmetric Ic(B, θ), can lead to a non-trivial reduction in AC loss, even incorporating flux diverters.

C-Met is a receptor tyrosine kinase that is overexpressed in a range of different cancer types, and has been identified as a potential biomarker for cancer imaging and therapy. Previously, a 68Ga-labelled peptide, [68Ga]Ga-EMP-100, has shown promise for imaging c-Met in renal cell carcinoma in humans. Herein, we report the synthesis and preliminary biological evaluation of an [18F]AlF-labelled analogue, [18F]AlF-EMP-105, for c-Met imaging by positron emission tomography. EMP-105 was radiolabelled using the aluminium-[18F]fluoride method with 46 ± 2% RCY and >95% RCP in 35–40 min. In vitro evaluation showed that [18F]AlF-EMP-105 has a high specificity for c-Met-expressing cells. Radioactive metabolite analysis at 5 and 30 min post-injection revealed that [18F]AlF-EMP-105 has good blood stability, but undergoes transformation—transchelation, defluorination or demetallation—in the liver and kidneys. PET imaging in non-tumour-bearing mice showed high radioactive accumulation in the kidneys, bladder and urine, demonstrating that the tracer is cleared predominantly as [18F]fluoride by the renal system. With its high specificity for c-Met expressing cells, [18F]AlF-EMP-105 shows promise as a potential diagnostic tool for imaging cancer.

N-Triphos derivatives (NP

In 2020, the government of Aotearoa New Zealand imposed some of the most stringent funerary restrictions in the world as part of its efforts to eliminate COVID-19. This article explores how people experienced this situation, asking why restrictions that some described as precipitating ‘the most difficult time of their lives’ were described by others as a ‘relief’, ‘blessing’, or ‘gift’. Much existing literature frames funerary restrictions as a distressing assault upon established ways of grieving to which mourners must try to adapt–and in Aotearoa, both the stringency of the restrictions and the means by which they had been imposed did lead to many people finding them challenging. However, for those with ambivalent pre-existing feelings regarding their funerary traditions–such as many in the Samoan diaspora–COVID-19 restrictions afforded both a reprieve from burdensome practices and a much-welcomed opportunity to reimagine their traditions. Funerary restrictions, though disruptive, are thereby shown to have generative potential.

The synthesis and characterisation of a series of Kryptofix 222-based chelators that can be radiolabelled with 201Tl(i) in high radiochemical yields at ambient temperature are described.

High-temperature superconductor (HTS) based devices have the potential to be useful technologies for space applications, allowing very high current transfer and magnetic field generation. However, HTS technology requires cryogenic temperatures (

Conjugated polymer nanoparticles have shown great promise in biological imaging due to their stable optical properties and inert composition but are usually polydispersed. By encapsulating conjugated polymer CN-PPV with a thin silica shell, it is possible to generate photo-stable, nearly monodispersed hollow nanoparticles with tuneable emission.

Rhenium-based metallodrugs have recently been highlighted as promising candidates for new antibiotics to combat multi-drug resistant (MDR) pathogens. A new class of rhenium(V) dioxo complexes were prepared from readily accessible diphosphine ligands, and have been shown to possess potent activity against

AC loss generated in Superferric magnets composed of high temperature superconducting (HTS) coil windings and iron cores is one of critical issues for rapid-cycling synchrotrons (RCSs) application. In this work, we carried out 3D FEM AC loss simulations in HTS coil assemblies coupled with an iron core using the T-A homogenization method. The HTS coil assemblies consist of a stack of double pancake coils (DPCs) wound with 4 mm - wide Shanghai Superconductor wires with an average self-field critical current of 192.6 A. The numerical and experimental AC loss results of a DPC (1 DPC) without the iron core were compared to validate the 3D T-A homogenization method. Then, 3D AC loss simulations were carried out on the DPC assemblies with different number of DPCs with/without the iron core to investigate the influence of the iron core and the coil number on AC loss. The iron core causes increase in AC loss values of the DPC assemblies. AC loss increases by a factor of five in the 4 DPC assembly with the iron core compared with that without the iron core. The simulation result in the 4 DPC assembly with the iron core reveals that strong perpendicular magnetic field penetration occurs even in the center DPCs and this explains the substantial AC loss increase in the 4 DPC assembly.

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Flux diverters (FDs) are used in High Temperature Superconducting (HTS) transformers for AC loss reduction and flux optimization. In this paper, a 2D axial symmetric superconducting winding model is proposed and two designs of flux diverters are applied to the windings. A homogenization approach is used to analyze the windings with large turn numbers. The key parameters including the number, width, height and the spatial positions of the FDs are adjusted for AC loss and magnetic flux analysis. The means of obtaining optimum designs of the FDs is provided and can be used to develop new winding designs with FDs, which contributes to better electromagnetic performance and higher efficiency of HTS transformers.

We have designed and built a small, conduction cooled, 1.5 T high-temperature superconductor (HTS) magnet. The magnet coils have been wet-wound with a novel conductive epoxy resin system to achieve a derivative of the no-insulation coil winding method. The epoxy is filled with copper powder to reliably set the turn-to-turn contact resistivity and diamond powder to accurately space the coil turns apart, as well as match the filled epoxy thermal contraction rate to that of the HTS. The magnet is designed to act as a test bed to measure sudden discharge rates and hence validate models of coil behaviour using the filled epoxy system we have developed. A lumped-element electrical model was used to predict the coil contact resistivity needed to bring the magnetic field of the 1.5 T magnet down to a near-zero level within 0.5 s. The conductive epoxy blend was tuned to give a contact resistivity of $1\times 10^{-6}\;\Omega {\rm m}^{2}$ , based on previous measurements of coil contact resistivity at 77 K. Once the magnet was wound and tested at 40 K, we found the magnet's sudden discharge time constant was 500 ms rather than 69 ms as was predicted from the 77 K measurements. The discrepancy was traced to the temperature dependence of the contact resistivity. With further testing of the individual coils this was accounted for and the model adjusted. The predicted discharge time was 2 s, in good agreement with the measured sudden discharge time of the magnet.

In honour of Eddie (Ed) Abel, past president of the Royal Society of Chemistry, who passed away on April 19, 2021, at 89.

A lanthanide-based peptide-directed bioprobe LnP19 (Ln = Eu or Yb) is designed as an impressive example of a small molecule-based dual-functional probe for the EBV oncoprotein LMP1. The peptide P19 (Pra-KAhx-K-LDLALK-FWLY-K-IVMSDKW-K-RrRK) is designed to selectively bind to LMP1 by mimicking its TM1 region during oligomerization in lipid rafts while signal transduction is significantly suppressed. Immunofluorescence imaging and Western blotting results reveal that P19 can effectively inactivate the oncogenic cellular pathway nuclear factor kappa B (NF-kappa B) and contribute to a selective cytotoxic effect on LMP1-positive cells. By conjugation with cyclen-based europium(III) and ytterbium(III) complexes, EuP19 and YbP19 were constructed to offer visible and near-infrared LMP1-targeted imaging and cancer monitoring. In addition to the ability to target and inhibit LMP1 and to selective inhibit LMP1-positive cells, selective growth inhibition toward the LMP1-positive tumor by LnP19 is also demonstrated.

Palladium-based catalysts are widely used in pharmaceutical industries, which can sometimes cause palladium contamination in pharmaceutical drug manufacture. It is important to separately quantify the different oxidation states of palladium (Pd0 and Pd2+) in pharmaceuticals as they react with scavengers differently. Although palladium sensors have been under intense investigation, oxidation state differentiators are very rare. Here, we report a simple porphyrin–coumarin conjugate, PPIX-L2, that can selectively discriminate between the oxidation states of palladium. The reaction of PPIX-L2 with Pd0 showed a 24-fold fluorescence increase of the coumarin emission, meanwhile, the presence of Pd2+ led to a 98% quenching of the porphyrin emission. Fluorescent responses of PPIX-L2 towards Pd0 and Pd2+ are specific, and its sensitivity towards both palladium species is significantly increased with a detection limit of 75 nM and 382 nM for Pd0 and Pd2+ respectively., A simple porphyrin–coumarin conjugate PPIX-L2 was developed for the discrimination of different oxidation states of palladium (Pd0 and Pd2+), and with a significantly improved sensitivity.

International media have praised Aotearoa New Zealand for its response to the coronavirus pandemic. While New Zealand Police played a fundamental role in enforcing pandemic control measures, the policing landscape remained plural. This article employs Loader [2000. Plural policing and democratic governance. Social and legal studies, 9 (3), 323–345] model of plural policing to understand responses to public health emergencies. It identifies two forms of policing which were evident in Aotearoa during the COVID-19 lockdown that should be added to Loader's model. First, we argue that contexts with colonial history require that the model not only includes by-government and below-government policing but also next-to-government policing by Indigenous peoples – such as the 'community checkpoints' run by Māori. Second, and further developing Loader's model, we argue that the category of below-government policing be expanded to include 'peer-to-peer policing' in which government responsibilizes members of the public to subject each other to large-scale surveillance and social control. Since plural forms of policing affect each other's functionality and legitimacy, we argue that what happens at the synapses between policing nodes has profound implications for the process of community building. Because community building is essential to fighting pandemics, we conclude that the policing of pandemic intervention measures may require an expanded understanding and practice of plural policing to support an optimal public health strategy.

Heme oxygenase-1 (HO-1) is a vital enzyme in humans that primarily regulates free heme concentrations. The overexpression of HO-1 is commonly associated with cardiovascular and neurodegenerative diseases including atherosclerosis and ischemic stroke. Currently, there are no known chemical probes to detect HO-1 activity, limiting its potential as an early diagnostic/prognostic marker in these serious diseases. Reported here are the design, synthesis, and photophysical and biological characterization of a coumarin–porphyrin FRET break-apart probe to detect HO-1 activity, Fe–L1. We designed Fe–L1 to “break-apart” upon HO-1-catalyzed porphyrin degradation, perturbing the efficient FRET mechanism from a coumarin donor to a porphyrin acceptor fluorophore. Analysis of HO-1 activity using Escherichia coli lysates overexpressing hHO-1 found that a 6-fold increase in emission intensity at 383 nm was observed following incubation with NADPH. The identities of the degradation products following catabolism were confirmed by MALDI-MS and LC–MS, showing that porphyrin catabolism was regioselective at the α-position. Finally, through the analysis of Fe–L2, we have shown that close structural analogues of heme are required to maintain HO-1 activity. It is anticipated that this work will act as a foundation to design and develop new probes for HO-1 activity in the future, moving toward applications of live fluorescent imaging.

Enzyme-activated probes enable complex biological processes to be studied in real-time. A wide range of enzymes are modulated in diseases, including cancer, inflammatory diseases and cardiovascular disease, and have the potential to act as vital diagnostic and prognostic biomarkers to monitor and report on disease progression. In this perspective article, we discuss suitable design characteristics of enzyme-activated fluorescent probes for ex vivo and in vivo optical imaging applications. With a particular focus on atherosclerosis imaging, we highlight recent approaches to report on the activity of cathepsins (K and B), matrix metalloproteinases (MMP-2 and MMP-9), thrombin, heme oxygenase-1 (HO-1) and myeloperoxidase (MPO)., This perspective provides an overview of the design requirements and fluorogenic mechanisms of enzyme-activatable probes in optical imaging, focusing particularly on detecting enzymatic targets overexpressed in vulnerable atherosclerotic plaque.

(RE)Ba2Cu3O7-d (REBCO) coated conductors are becoming a preferred wire choice for many potential high temperature superconducting (HTS) applications, where additional metal layers are usually attached to the REBCO conductors to improve reliability and stability. In such cases, the eddy current loss in the metal layers is affected by the magnetic field shielding by adjacent REBCO coated conductors. Here we present the ac loss measurement and simulation results in three copper-superconductor stacks comprising a 10-mm-wide Fujikura-coated conductor with one, two, and four 0.1-mm-thick, 10-mm-wide copper strips, under various applied magnetic field angles (defined by the angle between the applied magnetic field and the wide face of the superconductor) from 15° to 90° at 77 K. The amplitude of the magnetic field is up to 100 mT. The shielding effect, which reduces the eddy current loss in the metal layers stacked with a superconductor layer, increases with decreasing field angles, due to the change of the effective penetration field at the different field angles. The eddy current loss in the copper strips in the copper-superconductor stacks under the magnetic fields with various orientations is dominated by the perpendicular magnetic field component.

Radiolabelled lipophilic cations can be used to non-invasively report on mitochondrial dysfunction in diseases such as cardiovascular disease, cardiotoxicity and cancer. Several such lipophilic cations are currently used clinically to map myocardial perfusion using SPECT imaging. Since PET offers significant advantages over SPECT in terms of sensitivity, resolution and the capacity for dynamic imaging to allow pharmacokinetic modelling, we have synthesised and radiolabelled a series of NODAGA-based radiotracers, with triarylphosphonium-functionalisation, with gallium-68 to develop PET-compatible cationic complexes. To evaluate their capacity to report upon mitochondrial membrane potential, we assessed their pharmacokinetic profiles in isolated perfused rat hearts before and after mitochondrial depolarisation with the ionophore CCCP. All three tracers radiolabel with over 96% RCY, with log D7.4 values above −0.4 observed for the most lipophilic example of this family of radiotracers. The candidate tracer [68Ga]Ga4c exhibited non-preferential uptake in healthy cardiac tissue over CCCP-infused cardiac tissue. While this approach does show promise, the lipophilicity of this family of probes needs improving in order for them to be effective cardiac imaging agents.

Lanthanide-based luminescence resonance energy transfer (LRET) can be used as a tool to enhance lanthanide emission for time-resolved cellular imaging applications. By shortening lanthanide emission lifetimes whilst providing an alternative radiative pathway to the formally forbidden, weak lanthanide-only emission, the photon flux of such systems is increased. With this aim in mind, we investigated energy transfer in differently spaced donor–acceptor terbium–rhodamine pairs with the LRET “on” (low pH) and LRET “off” (high pH). Results informed the design, preparation and characterisation of a compound containing terbium, a spectrally-matched pH-responsive fluorophore and a receptor-targeting group. By combining these elements, we observed switchable LRET, where the targeting group sensitises lanthanide emission, resulting in an energy transfer to the rhodamine dye with an efficiency of E = 0.53. This strategy can be used to increase lanthanide emission rates for brighter optical probes. EPSRC Centre for Doctoral Training in Neurotechnology; Royal Society Wolfson Foundation