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  • Journal article
    Wilson LE, Jian X, White AJP, Long NJet al., 2018,

    Synthesis and characterisation of linear and towards cyclic diferrocenes with alkynyl spacers

    , Inorganics, Vol: 6, ISSN: 2304-6740

    Ferrocenediyl systems offer a motif that incorporates multiple functionality and redox-active centers, enabling these units to be used as molecular scaffolds in linear and cyclic compounds. Herein, we discuss a new modular methodology for the synthesis and incorporation of ferrocenediyl motifs within extended conjugated systems. We have synthesized a family of compounds featuring ferrocenediyl-ethynyl units with various para-substituted aromatic linkages. Extended linear, open-chain species have been isolated and understanding towards the analogous cyclic compounds gained. The new compounds have been probed using NMR, mass spectrometry, cyclic voltammetry and X-ray crystallography to gain further understanding of their structural and electronic properties.

  • Journal article
    Apps SL, White AJP, Miller PW, Long NJet al., 2018,

    Synthesis and reactivity of an N-triphos Mo(0) dinitrogen complex

    , Dalton Transactions, Vol: 47, Pages: 11386-11396, ISSN: 1477-9234

    The preparation and reactivity of a novel molybdenum dinitrogen complex supported by a nitrogen-centred tripodal phosphine ligand (N-triphos, N(CH2PPh2)3, NP3Ph) are reported. Reaction of N-triphos with [MoX3(THF)3] (X = Cl, Br, I) gave the Mo(III) complex [MoX3(κ2-NP3Ph)(THF)] (1), where bidentate N-triphos coordination was observed. Reduction of this complex in the presence of dppm (bis(diphenylphosphino)methane) gave the dinitrogen complex [Mo(N2)(dppm)(κ3-NP3Ph)] (2), which exhibits moderate dinitrogen activation. An additional hydride complex, [Mo(H)2(dppm)(κ3-NP3Ph)] (4), was produced either as a minor side product during the reduction step, or as a major product by direct hydrogenation of the dinitrogen complex 2. The reactivity of the dinitrogen complex 2 with a range of Lewis acids was also investigated. At low temperatures, protic or borane Lewis acids (H+, BBr3 and tris(pentafluorophenyl)borane (BCF)) were found to coordinate to the apical nitrogen atom of the N-triphos ligand, with no conclusive evidence of any functionalisation of the dinitrogen ligand. Alkali metal Lewis acid addition to 2 resulted in the unexpected rearrangement of the N-triphos ligand to form [Mo(dppm)(PMePh2)(PCP)][B(C6F5)4] (7), where PCP, [Ph2PCNHCH2PPh2] is the carbenic ligand formed upon rearrangement from the reaction of 2 with M[B(C6F5)4] (M = Li, Na or K). Single crystal X-ray diffraction of complexes 1, 2, 4 and 7 provided structural confirmation of the N-triphos molybdenum complexes described.

  • Conference paper
    Evans RJ, Hernandez-Gil J, Mohri Z, Chooi KY, Lavin-Plaza B, Phinikaridou A, Pease JE, Krams R, Botnar R, Long NJet al., 2018,

    DEVELOPING NEW TARGETED MOLECULAR CONTRAST AGENTS FOR IMAGING INFLAMMATION OF VULNERABLE PLAQUES

    , Annual Meeting of the British-Atherosclerosis-Society (BAS), Publisher: OXFORD UNIV PRESS, Pages: S3-S4, ISSN: 0008-6363
  • Journal article
    Gawne P, Man F, Fonslet J, Radia R, Bordoloi J, Cleveland M, Jimenez-Royo P, Gabizon A, Blower PJ, Long N, de Rosales RTMet al., 2018,

    Manganese-52: applications in cell radiolabelling and liposomal nanomedicine PET imaging using oxine (8-hydroxyquinoline) as an ionophore

    , DALTON TRANSACTIONS, Vol: 47, Pages: 9283-9293, ISSN: 1477-9226
  • Journal article
    Wang L, Long NJ, Li L, Lu Y, Li M, Cao J, Zhang Y, Zhang Q, Xu S, Yang Z, Mao C, Peng Met al., 2018,

    Multi-functional bismuth-doped bioglasses: combining bioactivity and photothermal response for bone tumor treatment and tissue repair

    , LIGHT-SCIENCE & APPLICATIONS, Vol: 7, ISSN: 2047-7538
  • Journal article
    Zeng F, Wu Y, Li X, Ge X, Guo Q, Lou X, Cao Z, Hu B, Long NJ, Mao Y, Li Cet al., 2018,

    Custom-made ceria nanoparticles show a neuroprotective effect by modulating phenotypic polarization of the microglia

    , Angewandte Chemie International Edition, Vol: 57, Pages: 5808-5812, ISSN: 1521-3757

    The neuroprotective effect of ceria nanoparticles in the context of brain disorders has been explained by their antioxidant effect. However, the in-depth mechanism remains unknown. As resident immune cells in the brain, microglia exert a variety of functional reprogramming termed as polarization in response to stress stimuli. Herein, custom-made ceria nanoparticles were developed and found to scavenge multiple reactive oxygen species with extremely high efficiency. These nanoparticles drove microglial polarization from a pro-inflammatory phenotype to an anti-inflammatory phenotype under pathological conditions. Pretreatment of these nanoparticles changed the microglial function from detrimental to protective for the neuronal cells by blocking the pro-inflammatory signaling. This work not only helps to elucidate the mechanism of ceria-nanoparticle-mediated neuroprotection but also provides a new strategy to rebalance the immuno-environment by switching the equilibrium of the phenotypic activation of microglia.

  • Journal article
    Price TW, Firth G, Eling CJ, Kinnon M, Long NJ, Sturge J, Stasiuk GJet al., 2018,

    A F-18 radiolabelled Zn(II) sensing fluorescent probe

    , CHEMICAL COMMUNICATIONS, Vol: 54, Pages: 3227-3230, ISSN: 1359-7345
  • Conference paper
    Milan DC, Al-owaedi O, Bock S, Oerthel M, Inkpen M, Yufit D, Sobolev A, Long N, Albrecht T, Higgins S, Bryce M, Nichols R, Lambert C, Low Pet al., 2018,

    Insulated molecular wires: Inhibiting orthogonal contacts in metal complex

    , 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
  • Conference paper
    Bamber J, Shah A, Bush N, Costa M, Harris-Birtill D, Lin S, Singh M, Scienti O, Darabara D, Elson D, ter Haar G, Rivens I, Long N, Tang Met al., 2018,

    Photoacoustic imaging and contrast agents in cancer research

    , Leeds Microbubble Symposium
  • Conference paper
    Leow CH, Marta B, Stanziola A, Hernandez-Gil J, Long NJ, Aboagye EO, Tang M-Xet al., 2017,

    Multi-Frame Rate Plane Wave Contrast-Enhance Ultrasound Imaging for Tumour Vasculature Imaging and Perfusion Quantification

    , IEEE International Ultrasonics Symposium (IUS), Publisher: IEEE, ISSN: 1948-5719

    A multi-frame rate plane wave imaging strategy is developed to simultaneously image tumor vasculature and quantify tumor perfusion. Customised imaging sequences interleaving a short but high frame rate (HFR) plane wave imaging sequence with a long but low frame rate imaging (LFR) sequence were implemented using a programmable ultrasound research platform. The results from a spatio-temporal coherence processing technique of ours demonstrated a significant improvement in the SNR and vasculature contrast when compared with the existing ultrafast Power Doppler (PD) using the same data. Initial perfusion quantification using LFR imaging was also demonstrated. Mean time intensity curve and some parametric measures were generated. Combining both structural and functional perfusion imaging using the multiframe rate sequences, a better evaluation of the tumour angiogenesis can be assessed.

  • Conference paper
    Morse SV, Pouliopoulos AN, Chan T, Lin J, Copping M, Long NJ, Choi JJet al., 2017,

    Rapid short-pulse (RaSP) sequences improve the distribution of drug delivery to the brain in vivo

    , IEEE UFFC, Publisher: IEEE, ISSN: 1948-5719

    Focused ultrasound and microbubbles have been shown to locally and noninvasively open the blood-brain barrier. Despite encouraging results in human patients, several performance and safety features, such as poor drug distribution, high drug accumulation along vessels and small sites of red blood cell extravasation, have been unavoidable. We have recently developed a new ultrasound sequence - rapid short-pulse (RaSP) sequence - designed to suppress these adverse features by promoting safer modes of cavitation activity throughout capillaries. In our RaSP sequences, low-pressure short ultrasonic pulses are emitted at kHz pulse repetition frequencies (PRF) and grouped into bursts. We have shown in vitro that RaSP sequences prolong microbubble lifetime and increase their mobility, enhancing the distribution of acoustic cavitation activity. Here we evaluate the ability of RaSP sequences to improve the in vivo performance and safety of ultrasound-mediated drug delivery to the brain.

  • Conference paper
    Leow CH, Braga M, Hernandez-Gil J, Long NJ, Aboagye EO, Tang MXet al., 2017,

    Multi-frame rate plane wave contrast-enhanced ultrasound imaging for tumour vascular imaging and perfusion quantification

    , IEEE International Ultrasonics Symposium, IUS, Publisher: IEEE, ISSN: 1948-5719

    Angiogenesis and blood flow dynamics play an important role in the development of malignant tumours and their response to treatment. While contrast enhanced ultrasound (CEUS) imaging with microbubble contrast agents as a tool for imaging angiogenesis and flow dynamics has shown great potential [1], recent development of plane wave high frame-rate (HFR) CEUS has offered new opportunities in such applications. In this study, we demonstrate an interleaved multi-frame rate plane wave CEUS imaging to quantify perfusion and to image vascular structure with improved resolution and contrast.

  • Conference paper
    Lin S, Shah A, Hernandez-Gil J, Stanziola A, Harriss B, Matsunaga T, Long N, Bamber J, Tang MXet al., 2017,

    Notice of Removal: Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging

    , ISSN: 1948-5719

    To explore the extravascular space, sub-micron phase-change droplets show widespread interest in medical imaging and therapy with various modalities, such as ultrasound and photoacoustic. Existing studies (Wilson 2012, Wei 2014) on such dual-modality contrast agents have demonstrated the generation of both optical and ultrasound contrast after optical activation. However these studies did not explore the option of acoustic activation. Furthermore, high boiling point perfluorocarbons were used in these studies. A low boiling point may be preferred, to minimise un-wanted bioeffects, especially when activating in deeper tissues. In this study, we demonstrate a versatile phase-change sub-micron contrast agent that can provide three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This would add versatility of vaporisation triggering, offering new possibilities in dual mode imaging, molecular imaging and drug delivery.

  • Journal article
    Du S, Hernandez-Gil J, Dong H, Zheng X, Lyu G, Banobre-Lopez M, Gallo J, Sun L-D, Yan C-H, Long NJet al., 2017,

    Design and validation of a new ratiometric intracellular pH imaging probe using lanthanide-doped upconverting nanoparticles

    , Dalton Transactions, Vol: 46, Pages: 13957-13965, ISSN: 1477-9234

    pH homeostasis is strictly controlled at a subcellular level. A deregulation of the intra/extra/subcellular pH environment is associated with a number of diseases and as such, the monitoring of the pH state of cells and tissues is a valuable diagnostic tool. To date, only a few tools have been developed to measure the pH in living cells with the spatial resolution needed for intracellular imaging. Among the techniques available, only optical imaging offers enough resolution and biocompatibility to be proposed for subcellular pH monitoring. We present herein a ratiometric probe based on upconversion nanoparticles modified with a pH sensitive moiety for the quantitative imaging of pH at the subcellular level in living cells. This system provides the properties required for live cell quantitative imaging i.e. positive cellular uptake, biocompatibility, long wavelength excitation, sensitive response to pH within a biologically relevant range, and self-referenced signal.

  • Journal article
    Parker D, Long NJ, Faulkner S, 2017,

    Challenges for chemistry in molecular imaging

    , Philosophical Transactions of the Royal Society A. Mathematical, Physical and Engineering Sciences, Vol: 375, ISSN: 1364-503X

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