Browsing by Author "Bambery, KR"
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- ItemFemtosecond laser fabrication of diffractive optics for spatial and spectral imaging at synchrotron infrared beamlines(Society of Photo-Optical Instrumentation Engineers (SPIE), 2021-03-06) Anand, V; Katkus, T; Ng, SH; Vongsvivut, JP; Maksimovic, J; Klein, AR; Bambery, KR; Lundgaard, S; Linklater, D; Ivanova, EP; Tobin, MJ; Juodkazis, SInfrared (IR) microspectroscopy is a powerful molecular fingerprinting tool widely used for the identification of structural and functional composition of biological and chemical samples. The IR microspectroscopy beamline at the Australian Synchrotron can be operated either with a single-point narrow-band mercury cadmium telluride (MCT) detector or a focal plane array (FPA) imaging detector with 64 × 64 pixels. For the implementation of indirect nonscanning imaging technology, the system was operated with the FPA detector. In this study, we propose an indirect IR imaging technique based on the principles of correlation optics using diffractive optical elements such as random pinhole array (RPA) and Fresnel zone plate (FZP). The spatial and spectral variations of point spread functions (PSFs) of the RPA and FZP were simulated for the synchrotron configuration. Intensity responses for 2D objects were simulated using the same simulation conditions and reconstructed using Lucy-Richardson algorithm. Fabrication of diffractive elements for IR wavelengths is often a challenging task as the IR transparent material substrates, such as barium fluoride and calcium fluoride, are highly susceptible to thermal shocks and brittle by nature. The diffractive elements were fabricated by ablating directly on a 100 nm thick gold coated substrate using femtosecond laser pulses. The simulation results and the fabrication outcomes demonstrate the feasibility of indirect imaging at the synchrotron IR beamline. © 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)
- ItemHigh-resolution macro ATR-FTIR chemical imaging capability at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline(Australian Nuclear Science and Technology Organisation, 2021-11-25) Vongsvivut, JP; Tobin, MJ; Klein, AR; Bambery, KRThis presentation aims to provide a summary on technical aspects and applications of our synchrotron macro ATR-FTIR microspectroscopy, unique to the Infrared Microspectroscopy (IRM) beamline at ANSTO–Australian Synchrotron.1 The device was developed by modifying the cantilever arm of a standard macro-ATR unit to accept Ge-ATR elements. Coupling synchrotron-IR beam to the Ge-ATR element (n=4), reduces the beam focus size by a factor of 4 (improving lateral resolution), and the mapping step size by 4 times relative to the stage step motion. As a result, the macro ATR-FTIR measurement at our IRM beamline can be performed at minimum projected aperture (sampling spot size) of 1-2 μm using a 20x objective, and minimum mapping step size of 250 nm, allowing high-resolution chemical imaging analysis with the resolution limit beyond those allowed for standard synchrotron-FTIR transmission and reflectance setups. The technique has facilitated many experiments in a diverse range of research disciplinary. Here, there will be presentations based on macro ATR-FTIR technique in archaeology, electrochemistry (battery), biomedical and forensic sciences. Apart from these, we will provide additional applications in the fields of food and pharmaceutical science,2-4 single-fibre analysis,5-6 and dentistry.7 References: [1] J. Vongsvivut, et al., Analyst 144, 10, 3226-323 (2019). [2] A.P. Pax, et al., Food Chemistry, 291, 214-222 (2019). [3] Y.P. Timilsena, et al., Food Chemistry, 275, 457-466 (2019). [4] D.M. Silva, et al., Journal of Colloid and Interface Science, 587, 499-509 (2021). [5] S. Nunna, et al., Journal of Materials Chemistry A, 5, 7372-7382 (2017). [6] C. Haynl, et al., Scientific Reports, 10, 17624 (2020). [7] P.V. Seredin, et al., International Journal of Molecular Sciences, 22, 6510 (2021). © 2021 The Authors
- ItemInvestigating the role of Zn in glucose regulation using x-ray fluorescence microscopy and x-ray absorption near-edge structure spectroscopy(Australian Nuclear Science and Technology Organisation, 2021-11-24) Ellison, G; Bambery, KR; Hackett, MJ; Hollings, A; Howard, DJ; Sharif, A; Takechi, RNZinc plays an important function in glucose regulation, particularly within pancreatic islets, the anatomical home of the glucose regulating hormones insulin and glucagon. Glucose dysregulation is a significant contributor to the epidemic of metabolic diseases, including diabetes, that affect an increasing number of people. Zn is found in very high (mM) concentrations in insulin-secreting β-cells, where it facilitates insulin synthesis and storage, and is co-secreted with insulin, subsequently acting as a signalling molecule. Zn dysregulation is often coincident with impairment of insulin secretion, but little is known about the nature of the changes. Since a subset of the pool of Zn in islets is labile, it is difficult to image in its in vivo situation using conventional techniques such as histochemistry. Not only do preparation steps such as washing displace Zn, but some forms in which it exists are not readily discernible using conventional microscopy techniques. X-ray fluorescence microscopy (XFM) and X-ray absorption near-edge structure spectroscopy (XANES) offer several advantages in that tissue preparation is minimal, facilitating the conservation of native states, and all forms of Zn are not only detectable, but are able to be discriminated by matching spectra against an existing library of Zn forms. Here we report the preliminary results from our study of Zn speciation and elemental mapping in murine islets from healthy or diabetes-prone animals in two age groups, 14 (denoted young) or 28 (old) weeks. This work uses a library of biologically relevant Zn forms created in our laboratory, and contributes to our understanding of the role of Zn in glucose regulation in health and disease, including aging. © The Authors
- ItemOpportunistic dose amplification for proton and carbon ion therapy via capture of internally generated thermal neutrons(Springer Nature, 2018-11-02) Safavi-Naeini, M; Chacon, A; Guatelli, S; Franklin, DR; Bambery, KR; Grégoire, MC; Rosenfeld, ABThis paper presents Neutron Capture Enhanced Particle Therapy (NCEPT), a method for enhancing the radiation dose delivered to a tumour relative to surrounding healthy tissues during proton and carbon ion therapy by capturing thermal neutrons produced inside the treatment volume during irradiation. NCEPT utilises extant and in-development boron-10 and gadolinium-157-based drugs from the related field of neutron capture therapy. Using Monte Carlo simulations, we demonstrate that a typical proton or carbon ion therapy treatment plan generates an approximately uniform thermal neutron field within the target volume, centred around the beam path. The tissue concentrations of neutron capture agents required to obtain an arbitrary 10% increase in biological effective dose are estimated for realistic treatment plans, and compared to concentrations previously reported in the literature. We conclude that the proposed method is theoretically feasible, and can provide a worthwhile improvement in the dose delivered to the tumour relative to healthy tissue with readily achievable concentrations of neutron capture enhancement drugs. © 2024 The Authors published by Springer Nature Limited. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
- ItemSingle-shot mid-infrared incoherent holography using Lucy-Richardson-Rosen algorithm(Institute of Optics and Electronics, Chinese Academy of Sciences, 2022-03-18) Anand, V; Han, Ml; Maksimovic, J; Ng, SH; Katkus, T; Klein, AR; Bambery, KR; Tobin, MJ; Vongsvivut, JP; Juodkazis, JIn recent years, there has been a significant transformation in the field of incoherent imaging with new possibilities of compressing three-dimensional (3D) information into a two-dimensional intensity distribution without two-beam interference (TBI). Most of the incoherent 3D imagers without TBI are based on scattering by a random phase mask exhibiting sharp autocorrelation and low cross-correlation along the depth. Consequently, during reconstruction, high lateral and axial resolutions are obtained. Imaging based on scattering requires an astronomical photon budget and is therefore precluded in many power-sensitive applications. In this study, a proof-of-concept 3D imaging method without TBI using deterministic fields has been demonstrated. A new reconstruction method called the Lucy-Richardson-Rosen algorithm has been developed for this imaging concept. We believe that the proposed approach will cause a paradigm-shift in the current state-of-the-art incoherent imaging, fluorescence microscopy, mid-infrared fingerprinting, astronomical imaging, and fast object recognition applications. © The Author(s) 2022. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License.
- ItemSynchrotron infrared micro-spectroscopy of single cells at the Australian Synchrotron(Australian Microscopy and Microanalysis Society, 2016-02-04) Bambery, KR; Tobin, MJ; Puskar, L; Martin, D; Vongsvivut, JPInfrared Microspectroscopy is increasingly revealing valuable bio-chemical information of biological and biomedical systems beyond the tissue level at the single cell level. At the Australian Synchrotron Infrared Microscopy beamline, FTIR spectroscopy provides sensitive molecular fingerprinting for tissues and cells without the need for sample pre-treatment with stains or external markers. Due to the brightness of a synchrotron source, good signal to noise at high spatial resolution (diffraction limited) can routinely be performed at the single cell level. In the study of live microbiological systems the principal restriction on the application of infrared microspectroscopy is the strong absorbance by water in the region of 1650 cm-1, overlaying the Amide I absorption band of proteins. The combination of a highly focused synchrotron beam with liquid cells constructed with microfabricated spacers of 6 to 8 microns in thickness have enabled complete mid-IR spectra to be obtained of single live cells under aqueous media within short scan times. Some applications include analysis of spectral changes in normal single living cells, diagnosing different disease states, discrimination of cell types and monitoring the effects of drug treatment at the single cell level. Details of these studies conducted at the infrared microscopy beamline at the Australian Synchrotron are presented.