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ANSTO

Online
Michael James (Australian Synchrotron), Marta Krasowska
Description

Virtual User Meeting 2020 

The Australian Synchrotron's annual User Meeting showcases some of the best research and investigations undertaken at the facility, and provides our user community with updates on the latest developments and technical advances in synchrotron science, both at home and at our sister light sources overseas. Organised by the Australian Synchrotron User Advisory Committee, the 2020 meeting will be held as a 2-day online event due to COVID-19 restrictions.

 

Registration Fees

Two Day Student Registration (Thursday & Friday)            Free

Two Day Conference Registration (Thursday & Friday)      Free

One Day Conference Registration                                         Free

 

Important Dates

Abstract submissions open: August 2020
Abstract submissions for Oral presentations close: Closed
Abstract submissions for Posters close: Closed
Synchrotron Lifetime Award & Research Award submissions open: Closed
Synchrotron  Lifetime Award & Research Award submissions close: Closed
Registrations Open August 2020
Registrations Close  16 November 2020
AS_User_Meeting_2020_Combined_Program_ZoomLinks.pdf Book of Abstracts Final.pdf UM2020 - Poster Session Groups.pdf UM2020 - Poster Session Presentations.pdf
Bettina Richen, Events
  • Thursday, 19 November
    • 09:00 → 09:30
      Opening and Organisational Update 30m Zoom Webinar Room

      Zoom Webinar Room
      Speakers: Andrew Peele (Australian Synchrotron), Michael James (Australian Synchrotron)
    • 09:30 → 10:30
      Plenary 1: Prof. Esther Takeuchi, Stony Brook University Zoom Webinar Room

      Zoom Webinar Room
      • 09:30
        Peering into Batteries: Electrochemical Insight through Operando Methods 1h

        Esther S. Takeuchi
        William and Jane Knapp Chair of Energy and the Environment
        Stony Brook University
        Chief Scientist and Chair
        Brookhaven National Laboratory

        Abstract

        Emerging new applications such as electric vehicles and integration of renewable energy demand expanded function of batteries. However, complex phase transitions of electroactive materials, kinetics of ion transport, and electrode-electrolyte interfacial reactions, still limit the full understanding of functional and degradation mechanisms. To date, many interrogation approaches of batteries are static, unable to track mechanisms arising from dynamic battery (dis)charge behavior. Emerging in situ and operando characterization methodologies focused on multiple size domains and time scales are becoming a powerful approach to resolve existing limitations of material and battery design and provide insights for future directions. A series of illustrative examples of in situ and operando characterization over atomic, crystallite/particle, electrode, and battery system length scales will be provided for lithium based batteries as well as those beyond lithium ion. The use of multiple synergistic methods to gain further insight will also be highlighted.

        Speaker: Prof. Esther Takeuchi
    • 10:25 → 12:00
      Session 1 - Biomedicine & Health Zoom Meeting Room

      Zoom Meeting Room
      • 10:30
        USING SYNCHROTRON RADIATION TO MAP THE METALLO-MAZE TO MEMORY LOSS 30m

        Transition metals such as Fe, Cu, Zn are essential for brain function, because they enable energy production, metabolism, and neurotransmitter synthesis. Disturbed brain metal homeostasis has been observed in the ageing and degenerating brain (e.g., Alzheimer’s disease). Elevated levels of Fe, Cu, Zn are frequently observed in to spatially associate with markers of brain pathology (e.g. elevated metal content within amyloid plaques). Due to the redox active nature of Fe and Cu (e.g., classic Fenton Chemistry pathways) there is much interest in the role metal ion catalyzed free radical production and oxidative stress may hold in driving cognitive decline.
        There is extensive literature studying possible roles for Fe and Cu overload during natural ageing and neurodegeneration; yet in our studies at the XFM beamline of the Australian Synchrotron we have not observed any direct increase in Fe or Cu concentration within hippocampal neurons, in rodent models of natural ageing or dementia. Indeed, under certain conditions we have observed apparent decreases in neuronal metal ion concentration during ageing or neurodegeneration. This finding has led our research group to investigate differences in the sensitivity and specificity of direct elemental mapping techniques compared to histochemical methods to detect metal ions in brain tissue (e.g., Perl’s Fe stain). We have also examined at length, how multiple aspects of sample preparation may affect the metal ion concentration, distribution, and chemical form in brain tissue.
        Our findings appear to indicate that there are unique differences in the handling of metal ions by different brain cells. Specifically, brain cells of glial lineage (oligodendrocytes, macrophages, astrocytes) appear to be capable of accumulating Fe and Cu metal ions, while concomitantly neurons may become metal ion deficient. On the basis of our results, we suggest that neuronal metal ion deficiency may occur in the ageing and degenerating brain, possibly as a result of excessive metal ion accumulation in glia. If this is correct, metal ion deficiency would result in impaired energy metabolism and reduced neurotransmitter synthesis, which could be a potent driver of cognitive decline and memory loss. Our results suggest that future studies are needed to specifically investigate the mechanisms through which neuronal metal ion deficiency can occur, which may identify new opportunities for therapeutic intervention.

        Speaker: Dr Mark J. Hackett (School of Molecular and Life Sciences, Curtin University)
      • 11:00
        Spectroscopic Studies of Brain Zinc Homeostasis and Its Role During Cognitive Decline and Ageing 20m

        The greatest risk factor for dementia is ageing. With no cure or effective therapies to slow progression, and with an ageing population, dementia has reached crisis levels in Australia. The content and distribution of metals such as Fe, Cu, Zn is known to change in the ageing brain (metal dis-homeostasis)(1, 2), and thus, increased understanding of the mechanistic role of metal dis-homeostasis may illuminate new therapeutic strategies. Specifically, Zn homeostasis and dis-homeostasis appears to be a potent modulator of memory function (3-5), yet, the exact chemical form(s) of Zn that are vital to memory function are unknown (6,7). Development of new spectroscopic methods to image different chemical forms of Zn may help increase understanding of Zn-modulated memory function and dysfunction. There are currently no available imaging protocols to differentiate between different chemical forms of Zn, however, substantive evidence supports that X-ray absorption techniques could provide such capability (8-10). Recently, our group has utilised X-ray absorption spectroscopy (XAS) to build a spectroscopic library of Zn compounds that reflects the chemical forms of Zn likely to be present in the brain. Preliminary analysis has revealed that XAS is able to differentiate between multiple Zn compounds across anatomically separate brain regions (Figure 1). Future experiments hope to reveal which Zn compounds change, in which brain regions, during ageing or neuorodegenerative disease. Such insights into whether specific types of zinc are affected with ageing may reveal mechanisms contributing to cognitive decline, in turn presenting potential pathways for targeted therapeutic interventions.

        1. Zecca L, Zucca FA, Toscani M, Adorni F, Giaveri G, Rizzio E, et al. Iron, copper and their proteins in substantia nigra of human brain during aging. Journal of Radioanalytical and Nuclear Chemistry. 2005; 263(3):733-737.
        2. Ramos P, Santos A, Pinto NR, Mendes R, Magalhães T, Almeida A. Anatomical Region Differences and Age-Related Changes in Copper, Zinc, and Manganese Levels in the Human Brain. Biological Trace Element Research. 2014; 161(2):190-201.
        3. Takeda A. Significance of Zn2+ signaling in cognition: Insight from synaptic Zn2+ dyshomeostasis. Journal of Trace Elements in Medicine and Biology. 2014; 28(4):393-396.
        4. Huang EP. Metal ions and synaptic transmission: Think zinc. Proceedings of the National Academy of Sciences [10.1073/pnas.94.25.13386]. 1997; 94(25):13386. Available from: http://www.pnas.org/content/94/25/13386.abstract.
        5. Nakashima AS, Dyck RH. Enhanced Plasticity in Zincergic, Cortical Circuits after Exposure to Enriched Environments. The Journal of Neuroscience [10.1523/JNEUROSCI.4645-08.2008]. 2008; 28(51):13995. Available from: http://www.jneurosci.org/content/28/51/13995.abstract.
        6. Sato S, Frazier J, Goldberg A. The distribution and binding of zinc in the hippocampus. Journal of Neuroscience. 1984; 4(6):1662-1670.
        7. Frederickson C, Suh S, Silva D, Thompson R. Importance of Zinc in the Central Nervous System: The Zinc-Containing Neuron. Journal of Nutrition. 2000; 130(5):1471S-1483S.
        8. Hackett M, Paterson P, Pickering I, George G. Imaging Taurine in the Central Nervous System Using Chemically Specific X-ray Fluorescence Imaging at the Sulfur K-Edge. Analytical Chemistry 18(22):10916-10924.
        9. James SA, Roberts BR, Hare DJ, de Jonge MD, Birchall IE, Jenkins NL, et al. Direct in vivo imaging of ferrous iron dyshomeostasis in ageing Caenorhabditis elegans. Chemical Science [10.1039/C5SC00233H]. 2015; 6(5):2952-2962.
        10. Salt DE, Prince RC, Baker AJM, Raskin I, Pickering IJ. Zinc Ligands in the Metal Hyperaccumulator Thlaspi caerulescens As Determined Using X-ray Absorption Spectroscopy. Environmental Science & Technology. 1999; 33(5):713-717.
        Speaker: Ashley Hollings (Curtin University, Bentley Western Australia 6845, Australia)
      • 11:20
        Towards Personalized Microbeam Radiation Therapy for Brain Cancer Treatment 20m

        Brain cancer is a detrimental disease with poor long term prognosis. The most common type of brain cancer, glioblastoma, has an associated 5 year survival of only 5% in Australia [1]. New treatments are therefore highly sought after to overcome the glioblastoma resistance to radiation and chemotherapy. Microbeam Radiation Therapy (MRT) at the Imaging and Medical Beam Line (IMBL) of the Australian Synchrotron implements ultra-fast radiosurgical cancer treatment with 50 µm microbeams spaced 400 µm apart [2].
        This study reports the brain cancer treatment efficacy of individualized MRT at the IMBL delivered in a single fraction with results from the first long-term MRT pre-clinical trial in Australia. The personalized treatment approach used state of the art dosimetry, new image alignment systems, cell studies and preclinical treatments performed at the IMBL. A 9L gliosarcoma brain cancer model was investigated in vitro with MRT and synchrotron broad beam to understand the cell response to the ultra-fast X-ray treatment. Following this, juvenile (8-week old) male Fischer rats were injected with intracerebral 9L gliosarcoma cells. Twelve days later, the rats received MRT following individualized image alignment based on individual tumours imaged on day 11 performed at Monash Biomedical Imaging. Treatment efficacy was evaluated in terms of in vitro cell survival, long term preclinical survival, histological brain and tumour morphology, and a pioneering assessment of the individual MRT tumour dose-coverage (Figure 1).
        The results of our study reveal the relationships between the in vitro cell response, tumour dose-volume coverage and survival post MRT irradiation of a radioresistant brain cancer in a rodent model. The synchrotron radiation therapy (both MRT and broad beam) showed improvements over the conventional (low dose rate) treatment of 9L cells, providing evidence for an in vitro dose rate dependence and FLASH effect. Preclinical studies showed that MRT increased the mean lifespan of rats by 570% compared to unirradiated controls. Individuals responded to MRT based on their tumour dose coverage with depth and tumour size (Figure 1).
        This innovative and interdisciplinary approach provides an in-depth understanding of brain cancer treatment using MRT at the Australian Synchrotron. The developments made in this work are the first steps towards personalized clinical strategies using MRT. The extension of this work to larger animals is required, but may ultimately improve the outcome for young patients with brain cancer.

        We acknowledge time and access to the Illawarra Health and Medical Research Institute (IHMRI), Wollongong, Australia, the Australian Synchrotron, and Monash Biomedical Imaging, Melbourne, Australia, the Australian Nuclear Science and Technology Organisation (ANSTO), and the University of Wollongong (UOW) Animal House. We are grateful to all assisting personnel including IMBL staff, Beamline Veterinary Scientist Mitzi Klein, UOW animal research staff, and UOW Animal Welfare Officer Dr Sarah Toole. We acknowledge the support of the Monash, Australian Synchrotron and UOW Animal Ethics Committees. We acknowledge the financial support of the Australian Government Research Training Program Scholarship, and Australian National Health & Medical Research Council (APP1084994 and APP1093256).

        References
        [1] Australian Institute of Health and Welfare 2017. Brain and other central nervous system cancers. Cat. no. CAN 106. Canberra: AIHW.
        [2] Engels, E., Li, N., Davis, J. et al. Toward personalized synchrotron microbeam radiation therapy. Sci Rep 10, 8833 (2020).

        Speaker: Elette Engels (University of Wollongong)
      • 11:40
        A structural and functional investigation of the periplasmic arsenate-binding protein, ArrX from Chrysiogenes arsenatis 20m

        Arsenic is a toxic metalloid found both naturally in the environment and as a harmful pollutant generated from industrial waste waters and gold mines. Arsenic can exist in both organic and inorganic forms and in four oxidation states: arsines and methyl arsines (As3-), elemental arsenic (As0), arsenite (AsO33-) and arsenate (AsO43-). Although arsenic is toxic and hazardous to human health, some prokaryotes have developed unique mechanisms that utilise inorganic forms of arsenic, such as arsenite (AsO33-) and arsenate (AsO43-) for respiration [2].
        Such prokaryotes include Rhizobium NT-26 and Chrysiogenes arsenatis which utilise the arsenite oxidase enzyme (Aio) and the arsenate reductase enzyme (Arr), respectively for their crucial respiratory activities. In these bacteria, the periplasmic binding proteins (PBPs) AioX and ArrX bind to arsenite (AsO33-) and arsenate (AsO43-), respectively and trigger, through sensor histidine kinase signalling, the expression of their respective respiratory enzymes [3]. The structure of the AioX protein has been previously reported in the presence and absence of arsenite (AsO33-) [4]. In order to investigate the structural basis of arsenate (AsO43-) binding to the ArrX protein, we determined its crystal structure in the presence and absence of substrate. This presentation will describe the structure of ArrX and a structural comparison between it and that of the AioX protein, in order to determine the molecular mechanisms by which these proteins discriminate between the chemically similar substrates arsenate (AsO43-) and arsenite (AsO33-).
        Keywords: arsenate, Chrysiogenes arsenatis, periplasmic binding protein (PBP), X-ray crystallography.

        References:
        [1] Brinkel, K.K. et al. (2009). Int. Journal of Environmental Research and Public Health 6: 1609-1619.
        [2] Gadd et al. (2000). Current opinion in biotechnology 11: 271-279.
        [3] Stolz JF, Basu P, Oremland RS (2002) Microbial transformation of elements: the case of arsenic and selenium. Int Microbiol 5: 201-7
        [4] Badilla et al. (2018). Scientific reports 8: 6282.

        Speaker: Ms Nilakhi Poddar
    • 10:30 → 12:00
      Session 2 - Advanced Materials & Hard Matter Zoom Meeting Room

      Zoom Meeting Room
      • 10:30
        Soft x-ray studies of molecular nanoarchitectures 30m

        One of the goals of nanoscience is achieving precise control over the structure and function of nanoscale architectures at surfaces. Bottom-up approaches using molecular building blocks present a flexible and intuitive approach to this challenge. Combining the Lego-like modularity of molecules with the epitaxial and reactive influences of surfaces creates a range of opportunities to build exciting new nanoarchitectures.

        Our recent work has focused on studying the reactions of halogenated and carboxylated molecules at metal surfaces, where we investigate their adsorption, self-assembly, coupling reactions and the subsequent formation of oligomeric and polymeric structures. Understanding the on-surface behavior of the molecules is possible using a combination of scanning tunneling microscopy, photoelectron spectroscopy and near-edge x-ray absorption fine structure. We are particularly interested in looking at how the structure of these molecular systems affects their electronic properties, and I will discuss our progress in measuring both the filled and unfilled electronic states of these materials.

        Speaker: Jennifer MacLeod (QUT)
      • 11:00
        Quantification of Material Gradients in Nanocrystals 20m

        Core/shell nanocrystals in which the materials change gradually from core to shell are very very promising structures to optimise the opto-electronic properties and quantum efficiencies of nanoscale semiconductors. Gradients are able to minimise crystal defects, lattice mismatch, and can be used to engineer the envelope wave function of excitons in order to suppress non-radiative Auger processes. However, due to the small size of the particles, so far no reliable method exists to quantify the extent of such a gradient.

        In this work we have measured the material gradient of ZnSe/CdS core/shell nanocrystals, which were synthesised at elevated temperatures (260 and 290 °C), which controls the rate of radial ion migration. We used EXAFS spectroscopy to determine the average coordination of selenium ions, which were fitted to a continuum model for the radial distribution of cations and anions [2].

        It could be shown that for the 260 °C sample the data shows strong cation migration, which transports significant amounts (> 50%) of cadmium into the core, while the anion gradient is consistent with negligible ion migration beyond the interfacial monolayer. This is significant, because many shell growth protocols that are assumed to produce sharp interfaces are performed at similar temperatures. At higher temperatures of 290 °C the data deviates strongly from the model, with effectively less cation migration. This is explained by the formation of an ordered Zn0.5Cd0.5Se superlattice in the core in order to mitigate the lattice mismatch die to the increasing CdSe content of the core [3]. Raman spectroscopy shows selective resonant enhancement of the core LO phonon overtones, which indicates that the exciton is primarily localized in the core and at interfacial traps, and that the electronic structure flips from a type-II to a type-I system.

        Hence, the combination of X-ray and Raman spectroscopy is able to identify both the chemical and electronic structure of core/shell particles and produces an accurate gradient model that can be employed in more precise and predictive structural calculations. The high-temperature product sheds light on why some highly emissive nanocrystals still blink and struggle to reach unity quantum yield [4].

        References:
        [1] Boldt, K.; Bartlett, S.; Kirkwood, N.; Johannessen, B. Quantification of Material Gradients in Core/Shell Nanocrystals Using EXAFS Spectroscopy. Nano Lett. 2020, 20, 1009-1017.
        [2] Cragg, G. E.; Efros, A. L. Suppression of Auger Processes in Confined Structures. Nano Lett. 2010, 10, 313-317.
        [3] Wei, S. H.; Ferreira, L. G.; Zunger, A. First-Principlescalculation of Temperature-Composition Phase of Semiconductor Alloys. Phys. Rev. B 1990, 41, 8240-8269.
        [4] Boldt, K.; Kirkwood, N.; Beane, G. A.; Mulvaney, P. Synthesis of Highly Luminescent and Photo-Stable, Graded Shell CdSe/CdxZn1-xS Nanoparticles by In Situ Alloying. Chem. Mater. 2013, 25, 4731-4738.

        Speaker: Dr Boldt Klaus (University of Konstanz)
        ePoster.pdf
      • 11:20
        Resonant Tender X-ray Diffraction for Disclosing the Molecular Packing of Paracrystalline Conjugated Polymer Films 20m

        The performance of optoelectronic devices based on conjugated polymers is critically dependent upon molecular packing; however the paracrystalline nature of these materials limits the amount of information that can be extracted from conventional X-ray diffraction. Resonant diffraction (also known as anomalous diffraction) occurs when the X-ray energy used coincides with an X-ray absorption edge in one of the constituent elements in the sample. The rapid changes in diffraction intensity that occur as the X-ray energy is varied across an absorption edge provide additional information that is lost in a conventional nonresonant experiment. Taking advantage of the fact that many conjugated polymers contain sulfur as heteroatoms, this work reveals pronounced resonant diffraction effects at the sulfur K-edge with a particular focus on the well-studied electron transporting polymer poly([N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)), P(NDI2ODT2. The observed behavior is found to be consistent with the theory of resonant diffraction, and by simulating the energy-dependent peak intensity based on proposed crystal structures for P(NDI2OD-T2) it is shown that resonant diffraction can discriminate between different crystalline packing structures. The utilization of resonant diffraction opens up a new way to unlock important microstructural information about conjugated polymers for which only a handful of diffraction peaks are typically available.

        Speaker: Prof. Chris McNeill (Monash University)
      • 11:40
        The Structure and Air Stability of Calcium and Magnesium Intercalated Graphene on 6H-SiC(0001) 20m

        Calcium intercalated graphene has been shown to exhibit superconductivity below 2 K, yet its structure has remained elusive in the literature to date. Furthermore, the intercalation of Mg underneath epitaxial graphene on SiC(0001) has not been reported. In this talk, epitaxial monolayer graphene samples synthesised on 6H-SiC(0001) are utilised to investigate calcium and magnesium intercalated graphene. By making use of low energy electron diffraction, X-ray photoelectron spectroscopy and secondary electron cut-off photoemission techniques available at the Australian Synchrotron Soft X-ray Beamline, and the scanning tunnelling microscope at Monash University, we are able to elucidate the structure of these intercalated systems.

        We find that Ca intercalates underneath the buffer layer and bonds to the Si-terminated SiC surface,breaking the C−Si bonds of the buffer layer, i.e., “freestanding” the buffer layer to form Ca-intercalated quasi-freestanding bilayer graphene (Ca-QFSBLG). The situation is similar for the Mg-intercalation of epitaxial graphene on SiC(0001), where an ordered Mg-terminated reconstruction at the SiC surface is formed and Mg bonds to the Si-terminated SiC surface are found, resulting in Mg-intercalated quasi-freestanding bilayer graphene (Mg-QFSBLG). Ca-intercalation underneath the buffer layer has not been considered in previous studies of Ca-intercalated epitaxial graphene. Furthermore, we find no evidence that either Ca or Mg intercalates between graphene layers. However, we do find that both Ca-QFSBLG and Mg-QFSBLG exhibit very low work functions of 3.68 and 3.78 eV, respectively, indicating high n-type doping. Upon exposure to ambient conditions, we find Ca-QFSBLG degrades rapidly, whereas Mg-QFSBLG remains remarkably stable.

        Speaker: Jimmy Kotsakidis (Monash University)
    • 10:30 → 12:00
      Session 3 - Earth, Atmosphere & Environment Zoom Meeting Room

      Zoom Meeting Room
      • 10:30
        Light on the details: exploring the nano-silver behaviour at the plant-soil interface 30m

        Over the past decade, significant advances have been made towards understanding the fate and impact of engineered nanomaterials (ENMs) in the environment, driven by concerns over their unique nanoscale properties and their increasing abundance in the market [1]. Synchrotron-based X-ray Absorption Spectroscopy (XAS) has played a key role in these advances, giving insights to the chemical speciation of common ENMs in environmental matrices, a key determinant of the potential fate and effects in the environment. The speciation of commonly studied metal-based ENMs (Zn, Cu and Ag) determined by XAS in the environmental matrices to which they are likely to released, often resemble their non-nano (ionic) counterparts (for example [2-4]). In these cases, understanding the transformation from nanomaterial to dissolved form helped to predict impacts. However, this is not always the case, for example sulfidation of Ag in waste streams results in different speciation which have been shown to alter environmental fate and toxicity. XAS has been vital in demonstrating this and has consequently, together with an array of analytical and predictive tools on their behaviour, transport and fate, have greatly advanced our understanding of ENMs and their potential impact on the environment.

        However, while our general understanding has greatly advanced, the exponential rate at which nanotechnology is expanding precludes the case-by-case experimental assessment of every nano-enabled product. Therefore, there is a need for predictive tools that enable stakeholders, such as manufacturers, regulators and consumers, to assess the potential fate and impact of their ENM products in the environment. Furthermore, an understanding of how ENMs interact with the environment to which they are released (e.g. varying soil characteristics, interactions with biota) needs to be improved [5]. Recently, as part of a purposely designed experiment towards the development of such tools within the European NanoFASE project [6], we examined the speciation, kinetics and the distribution of silver nanomaterials (nano-Ag) in three different soils cropped with wheat. In particular, there was a focus on resolving the nano-Ag behaviour at the soil-plant interface via operationally defined regions of proximity and interplay with the plant roots. We will present the key results from these experiments, demonstrate how XAS was used at two different facilities to provide complementary insights, and finally give some consideration to how the results improve our understanding towards future exposure assessment tools.

        References: [1] The Nanodatabase. 2011-2019, https://nanodb.dk/. [2] Sekine, R. et al. 2014. Environ. Sci. Tech. 49: 897-905. [3] Wang P, et al. 2016. Environ. Sci. Tech. 50: 8274-8281. [4] R. Sekine et al. J. Environ. Qual. 46: 1198-1205 (2017). [5] Pradas del Real, A.E. et al. 2017. Environ Sci. Tech. 51: 5774-5782. [6] NanoFASE: Nanomaterial Fate and Speciation in the Environment, 2015-2019, http://nanofase.eu.

        Speaker: Dr Ryo Sekine (USC)
      • 11:00
        The use of synchrotron X-ray fluorescence microscopy to study the “battle for nutrients” between plant and pathogen 20m

        Metal homeostasis is essential to normal plant growth and development. The balance is potentially impacted during plant-pathogen interactions as the host and pathogen compete for the same nutrients. Our knowledge of outcome of the interaction in terms of metal homeostasis is still limited. Here, we visualise and analyse the fate of nutrients in wheat leaves infected with a devastating pathogen, by high-resolution X-ray fluorescence microscopy (XFM). We employed XFM, at the ANSTO Australian synchrotron, for a detailed time-course of nutrient re-distribution in wheat leaves infected with Pyrenophora tritici-repentis (Ptr) to (i) evaluate the utility of XFM for spatially mapping the essential mineral nutrients in wheat leaves at sub-micron level, and (ii) examine the spatiotemporal impact of a necrotrophic fungus on nutrient re-distribution in wheat leaves. The XFM maps of K, Ca, Fe, Cu, Mn, and Zn revealed substantial hyperaccumulation and depletion within and around the infected region relative to uninfected control leaf tissue. We were able to visualise fungal mycelia as threadlike structures in the Cu and Zn maps. The hyperaccumulation of Mn in the lesion and localised depletion in asymptomatic tissue surrounding the lesion was particularly striking. Interestingly, Ca accumulated within and closer to the periphery of symptomatic region, often observed as micro-accumulations aligning with fungal mycelia. These disruptions may reflect secondary strategies used by the fungus to induce cell death, localised defence mechanisms used by the plant or wound responses. Collectively, our results highlight that synchrotron-based XFM imaging provides capability for high resolution mapping of elements for probing nutrient distribution in hydrated diseased leaves in situ.

        Speaker: Dr Fatima Naim (Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia)
      • 11:20
        XFM analysis of marsupial teeth - insights into life, growth and reproduction 20m

        Mammal species vary in how much time and energy they invest in growth, reproduction and development throughout their lifetime, summarised collectively as their ‘life history’. Knowledge of such differences among species helps us understand how they trade off these factors of their life history, yet, due to variability between populations, the logistical challenge of multi-year observational studies and extinction these data can be very difficult or impossible to collect. Elemental indicators of life history, environment and diet are mineralised into an animal’s hard tissues as they develop incrementally. Our research, using the X-Ray Fluorescence Microscopy (XFM) beamline of the Australian Synchrotron, focuses on unlocking biological information from the teeth of Australian marsupials. We have analysed the sectioned teeth of a range of living (e.g. Macropus giganteus, Notamacropus eugenii & Vombatus ursinus) and extinct (e.g. Macropus giganteus titan & Diprotodon optatum) marsupials. Our novel results indicate that strontium is a particularly powerful indicator of life history in marsupials. A gradual rise in strontium concentration tracks the progression of weaning, with subsequent oscillations following a likely seasonal dietary signal. Furthermore, calcium reflects the varying degree of mineralisation of tooth enamel and dentine, while zinc is preferentially deposited in the outer enamel layers. These results, applicable to both living and extinct marsupials, indicate that trace element mapping can provide unique insights into the life history of Australia’s living marsupials and extinct marsupial megafauna.

        Speaker: William Parker (School Of Biological Sciences, Monash University, Melbourne, Victoria, Australia)
      • 11:40
        Probing the cell wall response of Sphagnum moss to a changing aqueous chemical environment. A synchrotron infrared microscopy study. 20m

        Sphagnum is an important species of moss in peatland ecosystems and subsequently plays a vital role in carbon sequestration. Understanding its physiology is essential for predicting the possible impacts of a changing climate. In particular, the cell wall tissue of Sphagnum is composed of a high proportion of carboxylated polysaccharides, acting as ion exchangers, and is therefore sensitive to changes such as pH and metal ion concentrations in the surrounding environment. Using synchrotron infrared microscopy coupled with a flow-through liquid cell, the influence of pH and metal ions (Na+ and Ca2+) on the cell wall chemistry of freshly sectioned Sphagnum cristatum stems was investigated. The carboxylate functional groups in the cell wall were shown to behave as a monoprotic aliphatic acid with an acid dissociation constant (pKa) of 4.97–6.04. Furthermore, the cell wall material showed a high affinity for calcium, with the binding constant (K) determined to be 103.9–104.7 for a 1:1 complex. These results allow for the prediction of environmental chemical conditions for which calcium uptake in Sphagnum can occur, and improves our ability to understand the patterns of distribution of Sphagnum in the environment.1

        1Silvester et al. (2018) Environ. Chem. 15, 513.

        Speaker: Dr Annaleise Klein (ANSTO)
    • 12:00 → 13:00
      Lunch Break 1h
    • 13:00 → 14:30
      Session 4 - Biomedicine & Health Zoom Meeting Room

      Zoom Meeting Room
      • 13:00
        Phase-contrast tomography for breast cancer imaging at Imaging and Medical Beamline of the Australian Synchrotron 30m

        T. E. Gureyev1,2,3,4, B. Arhatari5,6, A. Aminzadeh1, Ya. I. Nesterets7,4, S. T. Taba2, E. Vafa2, S. C. Mayo7, D. Thompson7,4, D. Lockie8, J. Fox3, B. Kumar3, Z. Prodanovic3, D. Hausermann5, A. Maksimenko5, C. Hall5, A. G. Peele5,6, M. Dimmock3, K. M. Pavlov9,3,4, S. Lewis2, G. Tromba10, H. M. Quiney1 and P. C. Brennan2
        1 The University of Melbourne, Parkville 3010, Australia
        2 The University of Sydney, Lidcombe 2141, Australia
        3 Monash University, Clayton 3800, Australia
        4 University of New England, Armidale 2351, Australia
        5 Australian Synchrotron, ANSTO, Clayton 3168, Australia
        6 La Trobe University, Bundoora 3086, Australia
        7 Commonwealth Scientific and Industrial Research Organisation, Clayton 3168, Australia
        8 Maroondah BreastScreen, Ringwood East 3135, Australia
        9 University of Canterbury, Christchurch 8041, New Zealand
        10 Elettra Sincrotrone, 34149 Basovizza, Trieste, Italy
        Electronic mail: timur.gureyev@unimelb.edu.au

        Abstract
        Breast cancer is one of the two leading causes of cancer fatalities among women in most industrialized countries. This type of cancer is very aggressive, with success of the treatment depending heavily on early detection. Health authorities in most countries recommend regular screening of women over a particular age, with 2D X-ray mammography being the main screening and diagnostic technique. Unfortunately, mammography produces a relatively high percentage of both false-positive and false-negative results. In this research, we aim at defining and developing a practical imaging setup for whole breast imaging using propagation-based phase-contrast computed tomography (PB-CT) in such a way that, compared to the best presently utilised medical X-ray imaging techniques: (a) the quality and the diagnostic value of the obtained 3D images are higher, (b) the delivered radiation dose is lower and (c) the need for painful breast compression is removed. To date, we have imaged 95 unfixed complete mastectomy samples with and without breast cancer lesions using absorption-only CT and PB-CT techniques at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron. The radiation doses delivered to the mastectomy samples during the scans were comparable to those approved for mammographic screening. Physical characteristics of the reconstructed images, such as spatial resolution and signal-to-noise ratio, and radiologic quality were assessed and compared to conventional absorption-based CT. Our results demonstrate that PB-CT holds a high potential for improving on the quality and diagnostic value of images obtained using existing medical X-ray technologies, such as mammography and digital breast tomosynthesis. When implemented at IMBL in 2021, PB-CT will be used to complement existing medical breast imaging modalities, leading to more accurate breast cancer diagnosis [1, 2].
        [1] S.T. Taba et al., Am.J.Roentgen., 211, 133-145 (2018).
        [2] T.E. Gureyev et al., Med.Phys., 46, 5478-5487 (2019).

        Speaker: Dr Timur Gureyev (the University of Melbourne)
      • 13:30
        Capturing lung health in animal models of ventilator-induced lung injury and cystic fibrosis using 4D X-ray imaging 20m

        Introduction:
        Lung disease, including chronic respiratory conditions and thoracic cancers, is Australia’s second leading cause of death [1]. Furthermore, the current COVID-19 pandemic has acutely highlighted the importance of understanding acute respiratory distress syndrome and mechanical ventilation. Lung health is typically measured in the clinic by functional measures such as spirometry and structural measures from CT images, but neither can identify regional changes in lung function. The regional manifestation of lung disease and the dynamic nature of the lung means that experimental in vivo 4D X-ray imaging is ideal for detailed analysis of the lung in health and disease. The imaging and medical beamline (IMBL) at the Australian Synchrotron provides a wide, monochromatic X-ray beam, with suitable flux for high-speed in vivo imaging of small animals such as mice and rats. Here, we demonstrate the methods and preliminary results from two studies of dynamic lung imaging and X-ray velocimetry (4DXV) [2] analysis of mouse models of ventilator-induced lung injury and rat models of cystic fibrosis-like lung disease.

        Methods:
        The X-ray beam was set to an energy of 25 - 30 keV, with exposure lengths of between 0.02 - 0.04 seconds, suitable for the imaging of lung tissue in either mice or rats (respectively). The sample-to-detector distance was 3 metres, for capturing propagation-based phase contrast images of the lungs. Animals were anaesthetised, surgically intubated (according to University of Tasmania and University of Adelaide animal ethics committee approvals), and attached to a small animal ventilator (4DMedical) to acquire breath-cycle gated images.

        A four-dimensional computed tomography image acquisition was conducted with 12133 projection images of the lungs captured over a 182 degree rotation for one 4DCT scan. This resulted in 15 phases (CT images) in the 4DCT sequence and took 3.5 - 11 minutes, depending on the mechanical ventilation rate. The Ruby X-ray detector was used with a pixel size of between 19 - 24 μm. The X-ray beam width (field-of-view) was set to either 2.4 cm (for mouse lungs) or 4 cm (for rat lungs).

        Projection images were captured as hierarchical data format version 5 (hdf5) and binned into the phases of the breath cycle on the Australian Synchrotron’s computing infrastructure environment (ASCI). Customised code provided integration of the projection images with the CSIRO X-TRACT CT reconstruction software [3], whereby images were reconstructed using the transport-of-intensity equation (TIE) phase retrieval algorithm [4]. The reconstructed CTs from both studies were transferred to MASSIVE, a dedicated computing cluster environment for image processing and visualisation [5], and the 4DXV analysis [2] was applied to the data.

        Results:
        An example of a resulting CT of a mouse lung is shown as a slice image in panel (c) of the figure. 4DXV results are shown in the figure from a normal rat (a) before, and (b) after delivery of sterile agar beads into a single lobe of the lung. The colour bar represents the lung tissue expansion (in voxels), whereby the dark blue region indicates a region of low expansion, due to the agar beads blocking the airways, in a similar manner to the mucus obstructions that are a hallmark of cystic fibrosis disease. Panel (c) shows the lung detail from a CT slice of mouse lungs from the ventilator-induced lung injury study, taken at the beginning of mechanical ventilation, with a peak inspiratory pressure of 12 cmH2O and zero positive end-expiratory pressure. The scale bar represents 2 mm. The anatomical detail of the lung can be seen as airways (1), blood vessels (2), lobe fissures (3) and fat and muscle layers (4).

        Conclusions:
        We have successfully performed dynamic in vivo CT imaging and 4DXV analysis of lungs on the Australian Synchrotron IMBL. We have investigated two pre-clinical models: a rat model of cystic fibrosis-like disease, and a mouse model of ventilator-induced lung injury. In addition to the on-going studies of ventilator-induced lung injury, new pre-clinical studies are planned for testing the efficacy of novel drugs for the treatment of antibiotic-resistant bacterial lung infections.

        Acknowledgements: MASSIVE HPC facility (www.massive.org.au), ARC DECRA (SD), ARC Future Fellowship (KM), NHMRC APP1160774 (GZ, KM, SD), NHMRC APP1160011 (DP, MD, KM), Australian Synchrotron beamtime grants (14690, 11727, 12061, 12926).

        Keywords: 4DCT, X-ray velocimetry, small animal imaging, lung imaging, mechanical ventilation, ventilator-induced lung injury, cystic fibrosis.

        References:

        [1] Australian Bureau of Statistics – Australia’s leading causes of death, 2016.

        [2] Dubsky S, Hooper S, Siu KKW, and Fouras A, “Synchrotron-based dynamic computed tomography of tissue motion for regional lung function measurement”. J. R. Soc. Interface 9, 2213-2224, 2012.

        [3] Gureyev TE, Nesterets Y, Ternovski D, Thompson D, Wilkins SW, Stevenson AW, Taylor JA, “Toolbox for advanced X-ray image processing. Advances in Computational Methods for X-Ray Optics II”, 8141, 1-14, 2011.

        [4] Paganin, D, Mayo SC, Gureyev TE, Miller PR, and Wilkins SW. "Simultaneous phase and amplitude extraction from a single defocused image of a homogeneous object." Journal of microscopy 206, no. 1: 33-40, 2002.

        [5] Goscinski, WJ, Hines C, McIntosh P, Bambery K, Felzmann U, Hall C, Maksimenko A, Panjikar S, Paterson D, and Tobin M. "MASSIVE: An HPC Collaboration To Underpin Synchrotron Science." 15th International Conference on Accelerator and Large Experimental Control Systems (ICALEPCS 2015), Melbourne, 2015.

        Speaker: Melissa Preissner (Monash University)
      • 13:50
        Assessment of bone microarchitecture and mineralisation changes in an animal model of inflammatory bowel disease using high-resolution synchrotron-based microCT 20m

        Background: The Winnie-muc2 mouse (C57BL/6 background) exhibits pathophysiology of inflammatory bowel disease and other organ system changes, providing an opportunity to study bone loss related to malabsorption and other factors. We hypothesised that both bone microstructure and mineralisation may differ in Winnie-muc2 mice so performed temporal studies using high-resolution synchrotron-based microCT (HR-S-uCT).

        Aim: To characterise cortical and trabecular metrics in Winnie-muc2 vs C57BL/6 mice including bone volume, bone mineral density (BMD) and other ultrastructural parameters.

        Methods: Male and female animals (4-7/group) were euthanised after cardiac perfusion (4% PFA) at 6, 14 and 24 wks and femurs harvested then stored in 10% formol saline. MicroCT images were acquired at the Australian Synchrotron (25keV beam, 1800 projections, 6.82 u3 isotropic volumes, at 2-3 mm below condyls). Volumes were reconstructed using X-TRACT (CSIRO), trimmed using Image-J and processed using the BMA module in Analyze14.0 (Mayo Clinic).

        Results:
        1. In Winnie-muc2 males (vs C57BL/6), whole Bone Volume (Ctx+Tb) was 26% lower at 24 wks (0.99 mm3, IQR 0.82-1.155 vs 1.34 mm3, IQR 1.28-1.39 p=0.021) and in Winnie-muc2 females (vs C57BL/6 females), whole BV was less at 14 and 24wks (21% p=0.011, and 9% p=0.021, respectively) with both female groups decreasing over time.
        2. Tb vBMD was sustained over time for all groups but Tb Tissue vBMD (Tb+IntraTb) was lower at 14 and 24wks in Winnie-muc2 males (vs C57BL/6 males p=0.047 and 0.021) and at 14 wks in females (vs C57BL/6 females; p=0.033).
        3. Tb Tissue BMD in Winnie-muc2 males (vs C57BL/6 males) was 21% less at 14 wks (155 mg/cc, IQR 131-173 vs 203 mg/cc, IQR 175-215 p=0.043) and 32% less at 24wks (116 mg/cc, IQR 105-128 vs 174 mg/cc, IQR 168-175, p=0.021). In females, both C57BL/6 and Winnie-muc2 showed similar temporal decreases over 6 to 24wks (both p=0.021).
        4. Whilst Tb BMD was sustained in Winnie-muc2 and C57BL/6 males, C57BL/6 females showed an increase from 6 to 24wks (p=0.021), however, the Winnie-muc2 group did not change over time (p>0.05), indicating compromised mineralisation of trabeculae in female Winnie-muc2.

        Conclusion: HR-S-uCT analysis reveals microarchitectural and BMD changes in the Winnie-muc2 that highlight the value of this model to study bone microarchitecture. This model exhibits severe bone loss and altered mineralisation and, through the capabilities of the Australian Synchrotron, will enable the study of mechanisms and potential treatments for diverse bone lytic diseases.

        Speaker: Prof. Damian Myers (The University of Melbourne and the Australian Institute for Musculoskeletal Science (AIMSS))
      • 14:10
        A Vδ3+ subset of MR1 reactive γδ T cells recognise the side of the MR1 molecule 20m

        T cells are broadly categorised by their expression of either an αβ or γδ T cell receptor (TCR). Whilst αβ T cells are comprehensively understood γδ T cells are ill-defined but are increasingly realised to be an important T cell subset that display both innate- and adaptive-like immune functions. The MHC class 1 related protein (MR1), presents bacterial vitamin B metabolites to αβ mucosal associated invariant T cells (MAIT). MAIT cell TCR’ bind atop MR1 in a conventional fashion, contacting the α1 and α2 helices which comprise the MR1 antigen presenting pocket, as well as contacting the ligand directly. Recently, published in Science we identified that γδ T cells recognised MR1 but did so irrespective of the ligand being presented. Analysis of a Vδ1+ γδ TCR in complex with MR1 revealed, an unusual docking mode binding underneath the MR1 antigen presenting groove. This was in stark contrast to the conventional MAIT TCR-MR1 interactions and all other TCR complex structures to date. Here, we present biochemical and structural analysis of a Vδ3+ MR1 restricted TCR which bound along the side of MR1, adopting another novel TCR docking topology and making no contacts with the presented antigen. Ultimately, our results expand the knowledge of MR1 restricted γδ TCR’s shedding further light on the unusual docking modes that γδ TCR’s likely employ more broadly.

        Speaker: Mr Michael Rice (Monash University)
    • 13:00 → 14:30
      Session 5 - Advanced Materials & Hard Matter Zoom Meeting Room

      Zoom Meeting Room
      • 13:00
        Understanding the Mechanisms Bending in Flexible Crystals 30m

        Amy J. Thompson, a Anna Worthy, b Arnaud Grosjeana Jason R. Price,c John C. McMurtrie, b and Jack K. Clegg*a
        aSchool of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane St Lucia, QLD, Australia, 4072
        bSchool of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4001, Australia
        cANSTO Melbourne, The Australian Synchrotron, 800 Blackburn Rd, Clayton, Vic 3168, Australia.

        E-mail: j.clegg@uq.edu.au
        A crystal is normally thought of as a homogenous solid formed by a periodically repeating, three-dimensional pattern of atoms, ions, or molecules. Indeed, the regular arrangement of molecules, in a single crystal lead to many useful characteristics (in addition to diffraction!) including unique optical and electrical properties, however, molecular crystals are not typically mechanically robust, particularly compared to crystals of network solids like diamond. Upon the application of stress or strain, these crystals generally irreversibly deform, crack or break resulting in the loss of single crystallinity.
        We have recently discovered a class of crystalline compounds that display the intriguing property of elastic flexibility – that is they are capable of reversibly bending without deforming, cracking or losing crystallinity. A number of these crystals are flexible enough to be tied into a knot! (See Figure 1). We have developed a unique approach to determine the atomic-scale mechanism that allows the bending to occur which employs mapping changes in crystal structure using micro-focused synchrotron radiation. We have applied this technique to understand the deformation in both elastically1 and plastically2 flexible crystals. Most recently we have used it to show that previous theories regarding the requirement of “interlocked” crystal packing for flexibility is incorrect.

        Figure 1: A crystal of [Cu(acac)2] showing elastic flexibility.

        A. Worthy, A. Grosjean, M. Pfrunder, Y. Xu, C. Yan, G. Edwards, J. K. Clegg and J. C. McMurtrie, “Atomic Resolution of Structural Changes in Elastic Crystals of Copper(II) acetylacetonate”, Nature Chemistry, 2018, 65-69.
        2 S. Bhandary, A. J. Thompson, J. C. McMurtrie, J. K. Clegg, P. Ghosh, S. R. N. K. Mangalampalli, S. Takamizawa, and D. Chopra, “The mechanism of bending in a plastically flexible crystal.” Chem. Commun., 2020, 12841-12844.

        Speaker: Jack Clegg (The University of Queensland)
      • 13:30
        Developing High Pressure Single Crystal Crystallography at MX 20m

        Pressure is an important thermodynamic variable, but its effects on chemical systems have been explored to a much smaller extent than that of temperature. High pressure has been shown to induce significant geometrical, configurational and conformation changes within chemical systems.

        The development of diamond anvil cells (DACs) in recent years has allowed the study of chemical systems under high pressure by single crystal X-ray crystallography. This has enabled the analysis of the molecular structure of materials at high pressure, which is invaluable for an increased understanding of their properties. Pressure has been shown to be an important tool in the characterisation of structure-property relationships in porous materials, such as metal organic frameworks (MOFs). High pressure has been used as a useful tool for investigating the stability of MOFs, as well as their mechanical properties such as elasticity, stiffness, and hardness.

        A diamond anvil cell contains two opposing diamonds which between them create a sample chamber which can reach pressures of up to 10 GPa. The macromolecular crystallography (MX) beamlines at the Synchrotron are a pair of dual-purpose beamlines serving the needs of the Australasian structural biology and chemical crystallography community. The development of small DACs which can be easily mounted on a goniometer has opened the possibility to conduct high pressure crystallography on the MX beamlines, without major changes to the beamline setup. This development of beamline capability will enable users to study chemical systems at high pressure in order to better understand their properties and study the geometric changes which occur at high pressure.

        Speaker: Stephanie Boer (Australian Synchrotron)
      • 13:50
        Chemical Crystallography at the Australian Synchrotron Macromolecular Beamlines 20m

        The macromolecular (MX) beamlines at the Australian Synchrotron are mixed use between the structural biology (PX) and chemical crystallography (CX) communities. Since commissioning the high throughput MX1 bending magnet and the MX2 microfocus undulator beamlines have proven very successful for both communities.

        With the deployment of upgrades to the optics, endstation and detectors, the beamlines are able to produce data at an astounding rate with high throughput crystallography the norm. For the calendar year of 2019, 51 million Eiger 16M frames were collected on MX2 equating to ~5 Petabytes of uncompressed data.

        This increase in throughput necessitates the development of tools to give rapid feedback on data quality. There has also been the opportunity to develop automated collection of multiple CX datasets. An overview of these new tools will be presented.

        Speaker: Jason Price
      • 14:10
        Investigation of a 3D-crosslinked nonconjugated Radical Polymer to Tune Electrical Conductivity 20m

        Organic-based high-performance semiconductor research has attracted significant attention not long ago because of their promising performance. Since the morphology of the solution-processed conductive polymers, used in organic semiconductors, affects the intrinsic charge transport characteristics and mechanical properties, several strategies have been searched to control molecular ordering and alignment enhancing performance. Also, improving performance requires using a measurement technique for molecular orientation and a molecular dynamics simulation approach to predict electrical and mechanical properties.
        Our work presents a protocol that adopts the four angles technique to provide an accurate measurement of molecular orientation and a Hamiltonian Monte Carlo simulation to investigate charge transport characteristics. The four angle technique offers precise information on the molecular orientation of selected molecules utilizing the alignment of the electric vector of the Polarised Infrared probing beam with the dipole oscillation corresponding to the absorbing frequency of a specific functional group. In contrast, the Monte Carlo simulation algorithm can generate polymeric molecular chains following a standard random walk controlled by Hamiltonian parametrized utilizing Ab Initio calculations. This simulation will depend on radical concentration, the distance between radicals, and radical orientation to the polymer backbone, allowing to investigate the effect of radical and defect densities on the formation of the percolation network, which supports designing conductive polymers with high conductivity.
        Key Words:
        Four Angle Approach, Organic-based high-performance semiconductor, Nonconjugated radical polymer, Monte Carlo Simulation, Hamiltonian parametrized utilizing Ab Initio calculations.

        Speaker: Mr Ahmed Al-Qatatsheh (Swinburne University of Technology)
        15112020User_Meeting_2020_Presentation.pdf
    • 13:00 → 14:30
      Session 6 - Chemistry, Catalysis & Soft Matter Zoom Meeting Room

      Zoom Meeting Room
      • 13:00
        Tracks, Pores, Cylinders and Cones: SAXS as a tool to study high-energy ion modified materials 30m

        Heavy ions with MeV to GeV energies (also termed ‘swift heavy ions’) interact predominately through inelastic interactions with the target electrons when penetrating a material. The resulting intense electronic excitation can produce narrow trails of permanent damage along the ion paths, so called ‘ion tracks’. Ion tracks are generally between 5-20 nm in diameter, tens of micrometers long and have been observed in many materials. They have numerous applications across a variety of scientific areas such as materials science and engineering, nanotechnology, geology, archaeology, nuclear physics, and interplanetary science. For example, nanopores in polymer membranes are commercially produced using ion tracks by preferential chemical etching of the damaged material in the tracks. Tracks also naturally occur in minerals such as apatite and are widely used to determine the age and thermal history of geological sites.

        Small angle x-ray scattering (SAXS) provides a powerful tool for characterizing both ion tracks and track etched nano-pores and enables in situ measurements in high-temperature, high-pressure and corrosive environments. Over the last decade we have developed a number of SAXS experiments and analytical methods to characterize ion tracks and track etched nano-pores with unprecedented precision. The presentation will give an overview over some of the developments including in situ nanopore etching in polymers, temperature induced track recovery in minerals under high-pressure and the temperature dependent elastic response of cylindrical tracks in silica.

        Speaker: Patrick Kluth (Australian National University)
      • 13:30
        Effect of surfactant ionicity on critical micelle concentration in aqueous ionic liquid mixtures 20m

        Protic ionic liquids are the largest known solvent class capable of promoting surfactant self-assembly. However, ILs are increasingly used as mixtures with molecular solvents, such as water, to reduce their cost, viscosity and melting point, and the self-assembly promoting properties of these mixtures are largely unknown. Here we investigated the critical micelle concentration (CMC) of ionic and non-ionic amphiphiles in ethylammonium nitrate (EAN)-water mixtures to gain insight into the role of solvent species, and effect of solvent ionicity on the self-assembly process. The amphiphiles used were the cationic cetyltrimethylammonium bromide (CTAB), anionic sodium octanoate sulfate (SOS), and the non-ionic surfactant tetraethylene glycol monododecyl ether (C12E4). Surface tensiometry was used to obtain the CMCs and free energy parameters of micelle formation, and Small angle x-ray scattering (SAXS) was used to characterise the micelle shape and size.

        The EAN-water solvents displayed self-assembly results consistent with a salt in water for EAN proportions below 5 mol% across all three surfactants, leading to CMC values lower than the CMC observed in water. A steep incline in the CMC was observed for concentrations between 5 mol% to 50 mol% of EAN for SOS and C12E4. However, CTAB displayed more complex behaviour where the CMC remained below the CMC of water until 33 mol% EAN. Across all surfactants, a plateau in CMC values were observed at very high EAN concentrations, which could indicate that there is a shift in the dominant solvent beyond EAN concentrations of 50 mol%. This study furthers our understanding of PIL solvent behaviour in ternary mixtures with amphiphiles.

        Speaker: Sachini Kadaoluwa Pathirannahalage (RMIT University)
      • 13:50
        Quantitative Determination of Protein Solubility in Ionic Liquids 20m

        Proteins are often utilised for a range of applications in the pharmaceutical, biological, chemical and food industries[1-2]. The ideal solvent for hydrophilic proteins is usually buffered water due to its minimal cost, and ability to mimic the native environment of proteins, however many proteins are hydrophobic and have poor solubility in water. Because of this, organic solvents have been investigated as an alternative solvent for biocatalysis[3] and protein extraction[4], but often have detrimental effects on the protein stability and structure. We propose to use ionic liquids (ILs) as an alternative solvent, or as an additive in aqueous solutions, to quantify the solubility and stability of proteins. Initially the model protein lysozyme will be tested in ILs from highly dilute to neat. A novel, high throughput method has been developed to quantitatively determine the solubility of lysozyme. The aim is to explore specific-ion effects and how these differ for concentrated IL solutions compared to conventional dilute salts. A variety of techniques including UV/vis spectroscopy, Fourier-transformation infrared spectroscopy, circular dichroism and small angle x-ray scattering will be used to describe the stability and structure of the protein, and to gain insight into its interactions with ILs. It is hoped that any solubility trends present for lysozyme or specific ions can then be extrapolated to other proteins. Further studies will be done to compare any variations in the specific ion effects on different proteins and to begin building a database of quantified protein solubility and stability in ILs.

        1. Egorova, K. S.; Gordeev, E. G.; Ananikov, V. P., Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine. Chemical Reviews 2017, 117 (10), 7132-7189.
        2. van Rantwijk, F.; Sheldon, R. A., Biocatalysis in Ionic Liquids. Chemical Reviews 2007, 107 (6), 2757-2785.
        3. Klibanov, A. M., Improving enzymes by using them in organic solvents. Nature 2001, 409 (6817), 241-246.
        4. Hyde, A. M.; Zultanski, S. L.; Waldman, J. H.; Zhong, Y.-L.; Shevlin, M.; Peng, F., General Principles and Strategies for Salting-Out Informed by the Hofmeister Series. Organic Process Research & Development 2017, 21 (9), 1355-1370.
        Speaker: Mr Stuart Brown (RMIT)
      • 14:10
        Solvent properties of protic ionic liquid-water mixtures, and their application to biological molecules 20m

        Protic ionic liquids (PILs) are cost efficient “designer” solvents which can be tailored to have properties suitable for a broad range of applications. PILs are also being combined with molecular solvents to enable more control over the solvent environment, driven by a need to reduce their cost and viscosity. However, there are relatively few structure-property studies which look at these more complex mixtures. We have explored the solvation properties of common PIL-molecular solvents using various techniques,[1] and have identified many interesting solvent properties of these solutions, and their interactions with solutes.
        In this presentation I will discuss how we are using our understanding of PIL-water solvent properties to design and characterise solvents for biological molecules. In particular, we are targeting being able to control protein solubility and stability, which are critical for applications in bioprocessing, biocatalysis, protein crystallography and cryopreservation. We have explored lysozyme as a model protein in various PIL-water systems, predominantly using spectroscopic techniques and small angle x-ray scattering (SAXS).[2-3] From this we have been able to identify which PILs are more biocompatible, and to identify specific conformational changes of lysozyme due to the presence of PILs.[4] More recently, we have used protein crystallography to identify specific binding sites of the PIL ions and water to lysozyme.[4]

        References
        1. Yalcin, D.; Drummond, C. J.; Greaves, T. L., High throughput approach to investigating ternary solvents of aqueous non-stoichiometric protic ionic liquids. Phys. Chem. Chem. Phys. 2019, 21, 6810-6827.
        2. Wijaya, E. C.; Separovic, F.; Drummond, C. J.; Greaves, T. L., Activity and conformation of lysozyme in molecular solvents, protic ionic liquids (PILs) and salt-water systems. Phys. Chem. Chem. Phys. 2016, 18, 25926-25936.
        3. Arunkumar, R.; Drummond, C. J.; Greaves, T. L., FTIR Spectroscopic Study of the Secondary Structure of Globular Proteins in Aqueous Protic Ionic Liquids. Frontiers in Chemistry 2019, 7, Article 74.
        4. Qi, H.; Smith, K. M.; Darmanin, C.; Ryan, T. M.; Drummond, C. J.; Greaves, T. L., Lysozyme conformational changes with ionic liquids: spectroscopic, small angle x-ray scattering and crystallographic study. Journal of Colloid and Interface Science, Accepted 8th October 2020.

        Speaker: Tamar Greaves (RMIT University)
    • 14:30 → 14:50
      Afternoon Tea 20m
    • 14:50 → 16:00
      Session 7 - Biomedicine & Health
      • 14:50
        Metal Nanoparticle Radiosensitization for Improving Radiotherapy 30m

        Ivan Kempson1, Douglass Howard1, Tyron Turnbull1
        1 Future Industries Institute, University of South Australia, SA, 5095
        Corresponding Author: Ivan.Kempson@unisa.edu.au
        Metal nanoparticles have gained market approval for enhancing the effects of ionizing radiation in radiotherapy treatment of cancer. However the mechanism of action of metal nanoparticles exerting their effect remain controversial and poorly elucidated. We have developed a methodology inspired by Quality-by-Design principals to investigate the structure-function relationship of nanoparticle parameters with radiobiological effect.
        A cross-correlative methodology was developed to measure biological parameters such as the number of DNA breaks in single cells after irradiation with clinical X-ray sources coupled with quantitative analysis of the number nanoparticles in the same individual cells with XRF. A major challenge in identifying mechanisms is the massive degree of heterogeneity between cells.1
        Sub-cellular populations were identified and radiobiological response was determined for individual cells as a function of the number of nanoparticles in the same cells. The data is continuing to reveal many insightful aspects of nanoparticle-cell interactions and the consequence these have on radiobiological response of cancer cells. Importantly, a number of biological mechanisms exist that not only sensitize cells but can actually de-sensitize cells. These mechanisms contravene the physical concepts of radiosensitization. Nanoparticle uptake is highly heterogeneous and the observations made in our research cannot be deduced by conventional bulk assays. Biological mechanisms, such as down regulating proteins involved in DNA damage repair, lead to preferential sensitization of the most radio-resistant S-phase cells which act as a negative prognostic factor for many indications.2 Despite metal nanoparticles entering clinical use, we highlight many questions that remain in how they exert their function. Our research is revealing these mechanisms and will enable optimization of radiosensitizer formulations.
        References
        1 – T Turnbull, B Thierry, I Kempson. A Quantitative Study of Intercellular Heterogeneity in Gold Nanoparticle Uptake across Multiple Cell Lines, Analytical Bioanalytical Chemistry, 411(28), 7529-7538, 2019.
        2 - T Turnbull, M Douglass, N Williamson, D Howard, R Bhardwaj, M Lawrence, D Paterson, E Bezak, B Thierry, I Kempson, Cross-Correlative Single-Cell Analysis Reveals Biological Mechanisms of Nanoparticle Radiosensitization, ACS Nano, 13(5), 5077-5090, 2019.

        Speaker: Ivan Kempson
      • 15:20
        Molecular insights into the specificity and potency of metabolite-mediated T-cell immunity 20m

        Mucosal associated invariant T (MAIT) cells are an abundant human T cells subset that are variably activated by small-molecule metabolites presented by the MHC class 1 related molecule, MR1. During infection with riboflavin-producing microorganisms, the microbial metabolite 5-amino-6-D-ribitylaminouracil (5-A-RU) reacts with glycolysis byproducts of glyoxal/methylglyoxal forming highly potent ribityl pyrimidine ligands. These pyrimidine intermediates are trapped by MR1 and presented on the surface of the antigen-presenting cells encountering the MAIT T cell receptor (TCR) leading to the activation of the MAIT cells. These riboflavin-based MAIT cell agonists are unique for a wide range of microbes and accordingly represent a molecular signature of microbial infection. The most potent MAIT agonist is 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU), but the mechanism that underpins this potency remains unclear.

        To explore the molecular basis for the high potency of 5-OP-RU as a MAIT agonist, we chemically synthesized and characterized a large panel of 5-OP-RU analogues, termed ‘’altered metabolite ligands’’ (AMLs), and investigated functionally and structurally their impact on MAIT TCR recognition. Here, modification of the 5-OP-RU ribityl moiety impacted differentially on MAIT TCR binding affinity, consistent with the ability of AMLs to stimulate MAIT cells. Through an analysis of 13 high-resolution (~ 1.9 Å) MAIT TCR-MR1-AML crystal structures, we show that the propensity of MR1 upregulation on the cell surface was related to the nature of MR1-AML interactions. Further, MR1-AML adaptability and a dynamic compensatory interplay at the MAIT TCR-AML-MR1 interface impacted on the affinity of the MAIT TCR-MR1-AML interaction, which ultimately underscored the ability of the AMLs to activate MAIT cells. Therefore, we determined the molecular basis underlying MR1 antigen capture, MAIT TCR recognition and thereby provide insights into MAIT cell antigen specificity and potency.

        1.Awad, W.#, Ler, G.J.M.# et al. (2020). The molecular basis underpinning the potency and specificity of MAIT cell antigens. Nature Immunology 21, 400-411.
        2.Salio, M.#, Awad, W.# et al. (2020). Ligand-dependent downregulation of MR1 cell surface expression. PNAS, 202003136.
        3.Awad W., et al. (2020). Atypical TRAV1-2- T cell receptor recognition of the antigen-presenting molecule MR1. J. Biol. Chem., in press.

        Speaker: Wael Awad (Monash University)
      • 15:40
        Characterization of SARS-CoV-2 peptides presented by Human Leukocyte Antigen molecules 20m

        To date, the COVID-19 pandemic has claimed 970,000 lives and afflicted more than 31 million individuals. Although a global effort has been enacted for vaccines and drug discovery, our rudimentary understanding of SARS-CoV-2 infection and our own immune defense against this infection remains unclear. Our immune system can naturally overcome viral infection through the presentation of viral protein fragments or peptides (p) via human leukocyte antigen (HLA) molecules. These peptide-HLA complexes (pHLAs) are recognized by cytotoxic T cells that can activate, proliferate, and kill infected cells. T cells also retain memory of their encounter with the virus, and will respond faster during re-infection. How peptides are presented on the cell surface by HLA molecules impact T cell recognition and influence the outcome of viral clearance, and therefore, outcome of the disease. Although SARS and SARS-CoV2 cause severe acute respiratory syndrome, other coronavirus strains (229E, OCE43, HKU1, and NL63) only cause the common cold. These coronaviruses share similar peptide sequences that can be presented by HLAs, meaning that prior exposure to a less severe strain of coronavirus may infer immunity via memory T cells if similar peptides are presented in the same structural fashion. Using protein crystallography and X-ray diffraction at the Australian Synchrotron, we have characterized the presentation of SARS-CoV-2 peptides, which could influence vaccine strategies and provide a basis for research in T cell therapy.

        Speaker: Dr Christopher Szeto (Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia)
    • 14:50 → 16:00
      Session 8 - Advanced Materials and Hard Matter
      • 14:50
        Mechanistic insights into functional Electrocatalysis from XAS: the story from Experimental Design to Insights into Electron Transfer Timescales important for Selectivity. 30m

        1Department of Chemistry and Biotechnology and Centre for Translational Atomaterials, Faculty of Science, Engineering and Technology, Swinburne University of Technology

        One of the greatest challenges of the 21st century will be securing cheap and renewable sources of energy. One of the most promising approaches to this challenge is to design catalysts from earth abundant materials capable of implementing key chemical reactions including splitting water into hydrogen and oxygen (H2O → 2H+ + O2); and both the oxidation (H2→ 2H+) and reduction (2H+→ H2) of hydrogen among many others. Structural type and disorder have become important questions in catalyst design- it is often noted in studies of functional materials that the most active catalysts are “disordered” or “amorphous” in nature. But the impact of this “disorder” on catalysis and other material properties has been hard to quantify- in part because of the challenges of characterising disordered materials. X-ray Absorption Spectroscopy offers an important solution to this problem enabling us to study materials in their “functional active state” even when highly disordered and amorphous. In this talk I will examine some of the things we have learnt about functional electro-catalysts from X-ray Absorption Spectroscopy- from catalyst identification to understanding timescale effects in electron transfer important for catalyst design.§

        Speaker: Rosalie Hocking (Swinburne University of Technology)
      • 15:20
        Highly Active Gas Phase Organometallic Catalysis Supported Within Metal-organic Framework Pores 20m

        Metal-organic Frameworks (MOFs) possess a set of unique attributes including permanent porosity, large internal surface areas and robust crystallinity which has motivated extensive interest in the field of gas-phase catalysis. In particular, MOFs can act as a platform for the heterogenization of molecular catalysts, allowing easy catalyst recovery and a route towards structural elucidation of the active centres immobilised in a crystalline host. We have developed a unique MOF, MnMOF-1 which features vacant N,N-chelation sites which are accessible via the porous channels that penetrate the structure1,2. In the present work, cationic Rhodium(I) norbornadiene (NBD), cyclooctadiene (COD) and bis(ethylene) complexes have been incorporated into the vacant N,N-chelation sites of MnMOF-1 via post-synthetic metalation and facile anion exchange. Exploiting the crystallinity of the host framework, the immobilised Rh(I) centres were structurally characterised using X-ray crystallography.
        The activity of the Rh(I) bisethylene complexes MnMOF-1·[Rh(C2H4)2]BF4 and MnMOF-1·[Rh(C2H4)2]Cl in gas phase butene isomerisation was studied using gas-phase NMR spectroscopy. Under one atmosphere of butene at 46˚C, MnMOF-1·[Rh(C2H4)2]BF4 rapidly catalyses the conversion of 1-butene to 2-butene with a TOF of ca. 2000hr-1. Notably, the chloride derivative, MnMOF-1 [Rh(C2H4)2]Cl displays negligible activity in comparison, suggesting that interactions between the chloride anion and the Rh centre impact the catalytic activity.

        References
        1. Peralta, R.A.; Huxley, M.; Young, R.; Linder-Patton, O. M.; Evans, J. D.; Doonan, C. J.; Sumby, C. J. Faraday Discussions 2020.
        2. Peralta R. A.; Huxley, M. T; Evans, J. D.; Fallon, T.; Cao, H.; He, M.; Zhao, X. S.; Agnoli, S.; Sumby, C. J.; Doonan, C. J. J. Am. Chem. Soc., 2020.

        Speaker: Mr Ricardo Peralta (University of Adelaide)
      • 15:40
        Probing phase transitions of metal-organic frameworks by THz/Far-IR 20m

        Current research on metal–organic frameworks (MOFs) has concentrated predominantly on the properties of ordered crystalline phases. However, there is growing recognition of the importance of the physical properties of MOFs. In particular, the role of disorder, defects, and structural flexibility in installing beneficial physical behaviour is now widely studied. We synthesised four novel crystalline zeolitic imidazolate framework (ZIF) structures using a mixed-ligand approach. The inclusion of both imidazolate and halogenated benzimidazolate-derived linkers leads to glass-forming behaviour by all four structures. Melting temperatures are observed to depend on both electronic and steric effects. In situ THz/far-IR spectroscopic techniques reveal the dynamic structural properties of crystal, glass, and liquid phases of the halogenated ZIFs, linking the melting behaviour of ZIFs to the propensity of the ZnN4 tetrahedra to undergo thermally induced deformation.

        Speaker: Dr JINGWEI HOU (Uni of Queensland)
    • 14:50 → 16:00
      Session 9 - Manufacturing, Engineering and Cultural Heritage
      • 14:50
        Dual sample analysis on the XFM beamline: a new approach to increase the throughput of analysis of large samples 30m

        Casey L. Doolette1, Daryl L. Howard2, David, J. Paterson2, Cameron M. Kewish2, Nader Afshar2, Peter M. Kopittke3, Enzo Lombi1
        1University of South Australia, Future Industries Institute, Mawson Lakes, South Australia 5095, Australia
        2Australian Synchrotron, ANSTO Clayton, Victoria, 3168, Australia
        3The University of Queensland, School of Agriculture and Food Sciences, St. Lucia,
        Queensland 4072, Australia

        X-ray fluorescence microscopy (XFM) is a powerful mapping technique that can be used to determine the distribution of elements and chemical species at a range of spatial resolutions. Synchrotron radiation is commonly used as the X-ray source over conventional benchtop XFM as the photon flux is orders of magnitude greater, meaning that speed of analysis is also orders of magnitude faster.1 However, there is extremely high demand for synchrotron-based X-ray fluorescence mapping due to its wide range of applications including biomedical, geological, environmental, agricultural and cultural heritage fields of reserach.2 Therefore, user access to the Australian Synchrotron XFM beamline is very competitive and the beamline is oversubscribed. In this study, we developed a dual scanning approach that allows for simultaneous data collection from two samples. More specifically, we performed milliprobe analysis of an upstream sample concurrently with microprobe analysis of a downstream sample. The motivation behind this work was driven by the need to map large samples (>100 cm2) without sacrificing the throughput of the XFM beamline. For this study, our upstream samples were large (10 cm x 17 cm) diffusive gradient in thin-film devices (DGT); a DGT is a hydrogel embedded with a binding agent that acts as a sink for labile soil nutrients. After deployment on the soil surface, the DGT can then be mapped to visualise the distribution of available soil nutrients. We investigated the effect of DGT composition on the quality of analysis of two contrasting highly heterogeneous downstream samples (mineral and wheat thin-sections). Overall, gel composition did not affect the quality of analysis of highly heterogeneous downstream. For the first time, we demonstrated that data collection from large DGT devices can be performed in the background of other experiments on the Kirkpatrick Baez mirror (KB) end-station. This dual-scanning approach has the potential to translate to an increased throughput of analysis for XFM, as large DGTs (or other gels e.g. those used for metalloprotein separation) can be scanned at virtually no beamtime cost.

        (1) Kopittke, P. M.; Punshon, T.; Paterson, D. J.; Tappero, R. V.; Wang, P.; Blamey, F. P. C.; van der Ent, A.; Lombi, E. Plant physiology 2018, 178, 507-523.
        (2) Paterson, D.; Jonge, M. D. d.; Howard, D. L.; Lewis, W.; McKinlay, J.; Starritt, A.; Kusel, M.; Ryan, C. G.; Kirkham, R.; Moorhead, G.; Siddons, D. P. AIP Conference Proceedings 2011, 1365, 219-222.

        Speaker: Casey Doolette (University of South Australia)
      • 15:20
        Fast-scanning X-ray Diffraction Microscopy (SXDM) at the XFM beamline 20m

        Scanning X-ray Diffraction Microscopy (SXDM, aka ptychography) produces phase and absorption contrast images at high spatial resolution, well below the incident beam size(1). The experimental conditions for SXDM are close enough to X-ray Fluorescence Microscopy (XFM) that they are readily combined into a single simultaneous measurement(2-5). However, SXDM has additional coherence and positioning precision requirements compared to XFM and therefore has tended to slow down the whole data collection process(3). Here we present recent advances in fast “flyscan” SXDM data collection, and processing strategies implemented at the XFM beamline that reduce the time taken to collect the data, and produce artefact-free images. These advances provide a pathway to nanoscale imaging of millimetre-sized samples, in the gigapixels per hour regime.

        Speaker: Dr Michael Jones (QUT)
      • 15:40
        Trace element distributions in Al-Zn based coating alloys on steel substrates investigated by synchrotron XFM 20m

        The 55Al-Zn-1.6Si alloy is widely used in hot-dip galvanizing to coat steel and displays a multilayered microstructure (steel substrate/intermetallic compound (IMC) layer/coating overlay) that offers protection from corrosion. Trace level (less than a few tens of ppm) V and Cr are hypothesized to influence the corrosion performance of the coated steel via localized segregation. This work investigates the distribution of trace V and Cr using synchrotron X-ray fluorescence microscopy (XFM) and scanning transmission electron microscopy (STEM), and discusses the mechanism of trace V and Cr distribution during coating formation.

        Speaker: Dongdong Qu (The University of Queensland)
    • 16:00 → 17:00
      Plenary 2: Prof. Serena DeBeer, Max Planck Institute for Chemical Energy Conversion Zoom Webinar Room

      Zoom Webinar Room
      • 16:00
        The Evolution of Electronic Complexity in Biology: 2p3d and 1s3p RIXS of Iron-Sulfur Clusters 1h

        The Evolution of Electronic Complexity in Biology: 2p3d and 1s3p RIXS of Iron-Sulfur Clusters
        Serena DeBeer*1
        1 Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, Mülheim an der Ruhr, D-45470, Germany

        *e-mail: serena.debeer@cec.mpg.de

        Iron sulfur proteins are ubiquitous in nature, performing essential roles in electron transfer processes, redox chemistry, regulatory sensing and catalysis. The metal active sites of these proteins range from simple single iron sites to complex eight iron clusters. Perhaps the most complex iron sulfur cluster that has been identified to date is the iron molybdenum cofactor (or FeMoco) of nitrogenase, which is capable of cleaving the strong triple bond of dinitrogen. The fundamental question that arises is how does nature evolve complexity in order to enable challenging transformations? In our view, a deeper understanding of the complex geometric and electronic structure of iron sulfur clusters requires the pursuit of novel experimental approaches for integrating their electronic structure in a detailed and quantitative fashion. To this end, we are applying both 2p3d and 1s3p resonant inelastic X-ray scattering (2p3d RIXS), in order to obtain deeper insights into the electronic structure of these important clusters. These data provide an experimental measure of the d-d transitions and allow for more detailed insights into the nature of the multiplet structure. The utility of these methods for understanding the electronic structure of nitrogenase will be highlighted. The challenges that RIXS spectroscopy presents for theoretical modeling will also be discussed.

        Speaker: Prof. Serena DeBeer
    • 17:00 → 19:00
      Poster Session & Online Welcome Function 2h Zoom Webinar Room ()

      Zoom Webinar Room
  • Friday, 20 November
    • 09:00 → 10:00
      Plenary 3: Australian Synchrotron Lifetime Contribution Award: Prof Peter Lay Zoom Webinar Room ()

      Zoom Webinar Room
      • 09:00
        Adventures in Biomedical Research Through Synchrotron Science 1h

        Peter A. Lay
        School of Chemistry and Sydney Analytical, the University of Sydney

        With each decade of my research in synchrotron science that began in the mid 1990’s came multiple new developments in beamline technologies that made experiments in biomedical research possible that could only be dreamed about a short time beforehand. This, in turn, opened up many new possibilities in groundbreaking biomedical research that have placed synchrotron science at the forefront of providing previously inaccessible information on mechanisms of both disease processes and drug treatments.
        In this lecture, I will discuss key developments and applications of synchrotron science in areas such as: (i) the use of multiple scattering analysis of EXAFS for 3D structural information on unstable proteins and species related to understanding protein structure, and mechanisms of disease processes; (ii) XANES for probing metallodrug speciation under biologically relevant conditions; (iii) XFM and micro-XANES for understanding the biodistributions and speciation of elements in cells and tissues related to the roles of metals in diseases and the development of new metallodrugs; and (iv) the use of infrared microscopy to understand changes in the biochemistry of cells and tissues to provide information on the mechanisms of disease processes (brain, cardiovascular, etc.) and their treatments.

        Speaker: Peter Lay (The University of Sydney)
    • 10:00 → 11:50
      Session 10 - Chemistry, Catalysis and Soft Matter Zoom Meeting Room

      Zoom Meeting Room
      • 10:00
        Protein-Lipid interactions and protein structures in multi-component systems 30m

        Understanding protein-lipid interactions and the resulting protein structures is crucial for evolving food technology, biological and biomedical applications of nanomaterials. Knowledge regarding the effect of the multiple components in the system on the nanostructure, within the context of the application, is needed. Lyotropic liquid crystal design rules1 were developed and the effect of protein encapsulation on lipid self-assembly materials was extensively studied by us in recent years. We used this to obtain a protein-eye view of the in meso crystallisation method of integral membrane proteins from the bicontinuous cubic phase over time.2 Recently there has been a shift towards using biomimetic cubic phases,1,3,4 and SAXS studies at the Australian Synchrotron were used to investigate encapsulation of biologically relevant proteins and peptides.

        Speaker: Leonie van 't Hag (Monash University)
      • 10:30
        Cubosomes for the Delivery of Biopharmaceuticals 20m

        Biopharmaceuticals, including therapeutic proteins and peptides, represent the fastest growing class of new pharmaceuticals with application as treatments for auto-immune disorders, cancer and cardiovascular disease. Significant efforts have converged towards the design and development of more sophisticated delivery systems for protein-based pharmaceuticals, able to ensure controlled release of these bioactive compounds as well as protect the encapsulated therapeutic from denaturing processes such as enzymatic or acidic hydrolysis. Lipid-based nanomaterials are particularly useful for the encapsulation of amphiphilic proteins and peptides, as their bilayer structure mimics the native cell membrane environment and may assist in retaining the protein in a functionally active form.1 The research presented aims to elucidate the fundamental physicochemical interactions between lipidic nanomaterials, encapsulated proteins and peptides, and cells. In order to screen the large compositional space associated with the design of such materials, we focus on high-throughput methodologies, and the use of large national and international synchrotron facilities such as the Australian Synchrotron, the Bragg Institute and ASTRID2 synchrotron, Denmark. Uptake of cubosomes into eukaryotic cells was shown to be driven by a process of membrane fusion between the lipid bilayer that makes up the nanoparticle and the external cell membrane.2 Synchrotron CD experiments demonstrated that the lipidic cubic phase was able to protect encapsulated insulin against enzymatic degradation by chymotrypsin, which is typically found in the small intestine, over a period of several hours. Finally, the use of lipid nanoparticles as effective delivery vehicles for anti-microbial compounds will be discussed.3
        1. Conn, C. E.; Drummond, C. J., Nanostructured Bicontinuous Cubic Lipid Self-Assembly Materials as Matrices for Protein Encapsulation. Soft Matter 2013, 9 (13), 3449-3464.
        2. Dyett, B. P.; Yu, H.; Strachan, J.; Drummond, C. J.; Conn, C. E., Fusion dynamics of cubosome nanocarriers with model cell membranes. Nat Commun 2019, 10 (1), 4492.
        3. Meikle, T.G.; Dyett, B.; Strachan, J.B.; White, J.; Drummond, C.J. and Conn, C.E. Preparation, Characterization, and antimicrobial activity of cubosome encapsulated metal nanocrystals. ACS Applied Materials & Interfaces 2020, 12 (6), 6944-6954

        Speaker: Charlotte Conn (RMIT)
      • 10:50
        Pulling Milk Lipids Apart and Putting Them Back Together Again – A Self-assembly Approach 20m

        Introduction: Digestion of the milk lipids in our intestines yields monoglycerides and fatty acids that self-assemble into a variety of liquid crystalline structures. This self-assembly process is species dependent,[1,2] suggesting an important role for these structures in infant nutrition. Our recent work on the SAXS/WAXS beamline has focussed on studying how the lipid compositions of different milks generates different self-assembled structures both by digesting milk and analysing the by-products and assembling lipid mixtures that replicate the milk of different species from readily available fats and oils.
        Methods: Small angle X-ray scattering (SAXS) with in situ lipolysis was used to measure the lipid self-assembly in various types of milk and infant formulae during digestion.[3] The structures observed were correlated with the resulting digestion products using a combination of liquid chromatography coupled to mass spectrometry (LCMS) and principle component analysis (PCA).[4] Lipid mixtures were prepared in the lab by mixing either homotriglycerides or natural fats and oils. These lipid mixtures were dispersed to form milk-like emulsions and their lipid self-assembly during digestion was compared with the milks and infant formulae.
        Results & Discussion: This presentation will discuss the lipid liquid crystalline structures formed in a variety of milks and milk-like emulsions during digestion and how they can be mimicked. The lipid self-assembly in cow and human milk was shown to be replicated when the right balance of emulsified lipids was prepared by mixing homotriglycerides or blending milk fat with natural oils.[5] These emulsions provide representative digestive colloid structures through which to analyse the impact of lipid composition on self-assembly and bioactive delivery.

        References

        [1] Clulow, A. J.; Salim, M.; Hawley, A.; Boyd, B. J. A closer look at the behaviour of milk lipids during digestion. Chem. Phys. Lipids 2018, 211, 107-116.
        [2] S. Salentinig, S. Phan, A. Hawley, B. J. Boyd, Angew. Chem. Int. Ed. 2015, 54, 1600-1603.
        [3] Warren, D. B.; Anby, M. U.; Hawley, A.; Boyd, B. J. Real Time Evolution of Liquid Crystalline Nanostructure during the Digestion of Formulation Lipids Using Synchrotron Small-Angle X-ray Scattering. Langmuir 2011, 27 (15), 9528-9534.
        [4] Pham, A. C.; Peng, K.-Y.; Salim, M.; Ramirez, G.; Hawley, A.; Clulow, A. J.; Boyd, B. J. Correlating Digestion-Driven Self-Assembly in Milk and Infant Formulas with Changes in Lipid Composition. ACS Appl. Bio Mater. 2020, 3 (5), 3087-3098.
        [5] Clulow, A. J.; Salim, M.; Hawley, A.; Boyd, B. J. Milk mimicry – Triglyceride mixtures that mimic lipid structuring during the digestion of bovine and human milk. Food Hydrocolloids 2021, 110, 106126.

        Speaker: Andrew Clulow (Monash University)
      • 11:10
        Fluctuation x-ray scattering of self-assembled lipids, colloidal particles and liquids 20m

        Fluctuation x-ray scattering studies how the x-ray diffraction pattern changes as a small x-ray beam is scanned relative to the sample. The ensemble of diffraction patterns from different sample positions can reveal information about the local 3D structure in disordered materials. We have developed a fluctuation scattering technique called the pair-angle distribution function (PADF) method that recovers three- and four-body correlations in the sample, including local angular structure[1,2]. This is a natural generalisation of the pair-distribution function obtained from small-angle x-ray scattering (SAXS). Here we present recent applications of the PADF technique to self-assembled lipids[3] to reveal distortions of the water channel shape with lipid composition. We discuss the potential application to disordered, dense packings of colloidal particles to distinguish dominant icosahedral, face-centred cubic, body-centred cubic or hexagaonal packings[4]. Looking further into future, we discuss the potential applications to liquid structure with x-ray free-electron lasers.

        [1] A.V. Martin, IUCrJ, 2017, 4, 24-36.
        [2] A.V. Martin, E.D. Bøjesen, T.C. Petersen, C. Hu, M.J. Biggs, M. Weyland, A.C.Y. Liu, Small 2020, 16, 2000828.
        [3] A.V. Martin, , A. Kozlov, P. Berntsen, F.G. Roque, L. Flueckiger, S. Saha, T.L. Greaves, C.E. Conn, A.M. Hawley, T.M. Ryan, B. Abbey, C. Darmanin, Commun. Mater. 2020, 1, 40.
        [4] E. Bojesen, T.C. Petersen, A.V. Martin, M. Weyland, A. Liu, Journal of Physics: Materials, 2020, 3 044002.

        Speaker: Andrew Martin (RMIT University)
      • 11:30
        Separating Macro- and Nano-structural Effects in Intensity Correlation Measurements of Self-assembled Lipid Materials 20m

        By correlating large ensembles of X-ray scattering data, fluctuation X-ray scattering can extract atomic and nanoscale structural information from a range of systems including colloidal glasses and crystals, liquid-crystal membranes, nanoparticles, and magnetic domains [1-4]. Real-space pair-angle distribution functions are higher order analogues of the basic pair-distribution functions and are rich in information about orientation and bond angles. This method maps fluctuations of scattered intensity into three- and four-atom correlation functions which encode two pairwise distances and one relative angle [5-7].

        Here we present results of fluctuation scattering experiments on the inverted hexagonal phase of a model self-assembled lipid system (cetyltrimethylammonium bromide-water). Using newly developed semiautomated algorithms for big datasets (>1000 patterns) we uncover a macroscopic preferred orientation effect which masks the nano-structural signal due to intensity fluctuations. Texture phenomena such as a preferred orientation, strain and peak broadening are commonly encountered throughout materials science. By simulating distorted datasets, we explore how correlation plots are altered by macroscale effects and present methods for disentangling structural information at these two length scales, broadening the range of materials and phase transitions amenable to fluctuation scattering analysis.

        [1] P. Wochner, C. Gutt, T. Autenrieth, T. Demmer, V. Bugaev, A. D. Ortiz, A. Duri, F. Zontone, G. Grübel, and H. Dosch, Proceedings of the National Academy of Sciences of the United States of America 106, 11511–11514 (2009).

        [2] I. A. Zaluzhnyy, R. P. Kurta, N. Mukharamova, Y. Y. Kim, R. M. Khubbutdinov, D. Dzhigaev, V. V. Lebedev, E. S. Pikina, E. I. Kats, N. A. Clark, M. Sprung, B. I. Ostrovskii, and I. A. Vartanyants, Physical Review E 98, 1–8 (2018).

        [3] R. P. Kurta, L. Wiegart, A. Fluerasu, and A. Madsen, IUCrJ 6, 635–648 (2019).

        [4] R. Su, K. A. Seu, D. Parks, J. J. Kan, E. E. Fullerton, S. Roy, and S. D. Kevan, Physical Review Letters 107, 16–19 (2011).

        [5] A. V. Martin, IUCrJ 4, 24–36 (2017)

        [6] Martin, A. V, et al., Communications Materials, 1(40), 1–8 (2020)

        [7] Martin, A. V., Bøjesen, E. D., Petersen, T. C., Hu, C., Biggs, M. J., Weyland, M., & Liu, A. C. Y., Small, 2000828, 1–6. (2020)

        Speaker: Dr Jack Binns (RMIT University)
    • 10:00 → 11:50
      Session 11 - Advanced Materials and Hard Matter Zoom Meeting Room

      Zoom Meeting Room
      • 10:00
        Energy Dispersive X-ray Diffraction for In-Situ and Operando Characterization of Electrochemical Energy Storage Systems 30m

        Electrochemical energy storage systems can be challenging to characterize as they function far from equilibrium, dominated by kinetics. Heterogeniety of the ion distribution and phase transformations within the electrode can have a significant impact on the electrochemistry of the system, but is not discernable by conventional methods. The benefits of energy dispersive x-ray diffraction diffraction as a tool for for in-situ and operando characterization of electrochemical energy storage systems will be highlighted in this presentation, including examples from both conversion and insertion based electrodes.

        Speaker: Amy Marschilok
      • 10:30
        Materials And Interfacial Design For Advanced Potassium Ion Storage 20m

        Developing new renewable energy storage devices is vital for regulating the energy output of intermittent solar and wind energy, which have been expected to occupy increasing proportions of energy sources in light of the environmental issues caused by fossil fuel energy. Amid staggering advances on grid-scale devices and electric vehicles, there has been great interest in exploring potassium ion batteries (PIBs). The motivations triggering the study of PIBs relate to the benefits of their relatively high energy density resulting from the low standard redox potential of potassium (-2.93 V vs. E0), which is close to that of lithium (-3.04 V vs. E0), their low cost, which is ascribed to the abundance of potassium (1.5 wt. %) in the Earth’s crust ), and also their fast ion transport kinetics in electrolyte. In terms of electrode materials, alloy-based materials have been considered as good candidates for high-energy-density devices due to their relatively high theoretical capacity. However, the huge volume variations and sluggish ionic diffusion hinder their cycle life and fast charge/discharge capability. Through the optimization of materials processing, the introduction of carbon matrix and the selection of electrolytes, the high-energy-density and long cycle life alloy-based anodes have been obtained. In addition, to further increase the energy density, we successfully fabricate the K-CO2 batteries by employing three-dimensional carbon-based metal-free electrocatalysts. We hope the relevant work will promote the developments of K ion chemistry in energy storage fields.

        Speaker: Wenchao Zhang (University of Wollongong)
      • 10:50
        Visualisation of the rapid Cu6Sn5 lithium-ion battery anode fabrication process via real-time X-ray imaging 20m

        Under the sponsorship of the Australian Synchrotron International Synchrotron Access Program (ISAP), real-time X-ray imaging was conducted at the SPring-8 synchrotron BL20XU beamline to visualise the rapid formation of Cu6Sn5 for lithium-ion battery anode applications. This presentation describes the experimental setup employed at the BL20XU beamline, and shares the results obtained. Lithium-ion batteries have found numerous applications in modern technologies, especially in portable devices, and increasingly in electric vehicles and renewable energy storage applications. Sn-based lithium-ion battery anodes have a higher theoretical storage capacity of 993 mAh g-1 vs. 372 mAh g-1 compared to commercial carbon-based anodes. Their better safety profile due to a lower risk of lithium dendrite formation compared to the carbon-based anodes is also desirable. However, Sn-based anodes suffer from inferior cycling performance due to the enormous stresses during the lithiation and delithiation process. Alloying Sn with Cu can reduce the reaction stresses in the anode, as Cu does not react with Li, and acts as a stress buffer. Cu6Sn5 is therefore a promising candidate material to replace carbon-based anodes. Traditionally, anode fabrication is a multi-step process where the active materials are first fabricated, and then mixed with binders and conductive materials, followed by slip casting the resultant slurry on to a current collector and dried. To simplify this fabrication process, a simple method involving direct growth of Cu6Sn5 on a Cu current collector is proposed. Yet, the growth rate of Cu6Sn5 is limited by the inter-diffusion of Cu and Sn, restricting the potential of this method for large scale production. This study proposes a method to accelerate the growth rate of Cu6Sn5 by alloying Ni to the Cu current collector. A maximum growth rate is found when 6 wt% of Ni is present in the Cu current collector, where a growth rate of up to 50x faster compared to the growth rate on a pure Cu current collector is observed. Visualisation of the fabrication process via real-time synchrotron X-ray imaging allowed the kinetics and mechanisms of the rapid Cu6Sn5 growth to be characterised.

        Speaker: Xin Fu Tan (University of Queensland)
      • 11:10
        Using the Pair Angle Distribution Function for Analysing Protein Structure. 20m

        X-Ray Free Electron Lasers provide a means of conducting crystallography experiments with remarkable time and spatial resolution. These methods can directly recover the electron density of the materials analysed, however, stringent requirements such as crystal size, number density per exposure, and the crystal order can compromise data quality. Membrane proteins, which do not readily crystallise or meet these requirements [1], are particularly interesting to study as they comprise up to 50% of drug targets [2], but less than 10% of the protein structures in the Protein Data Bank [3]. The Pair Angle Distribution Function (PADF) describes the three and four body correlations of the electron density in a sample, and can be recovered from X-ray angular cross-correlation analysis [4]. Although it does not recover the electron density directly, it still contains significant information about the local three dimensional structure of the material. PADF analysis also has the potential to relax the stringent crystal requirements imposed by current XFEL experiments. We discuss the sensitivity of the PADF to different protein structures [5], and the correlations generated at different length scales; from atomic bonding to tertiary structure. Our aim is to develop PADF analysis to be used complementarily with conventional crystallography analysis, and to use changing angular correlations to measure conformational changes in proteins.

        [1] Johansson, L.C. et al. Lipidic phase membrane protein serial femtosecond crystallography. Nat. Methods 2012, 9, 263–265.

        [2] Cournia, Z. et al. Membrane protein structure, function, and dynamics: A perspective from experiments and theory. J. Membr. Biol. 2015, 248, 611–640.

        [3] Berman, H.M. et al. The Protein Data Bank. Acta Crystallogr. Sect. D Biol. Crystallogr. 2002, 58, 899–907.

        [4] Martin, A.V. Orientational order of liquids and glasses via fluctuation diffraction. IUCrJ 2017, 4, 24–36.

        [5] Adams, Patrick, et al. "The Sensitivity of the Pair-Angle Distribution Function to Protein Structure." Crystals 10.9 (2020): 724.

        Speaker: Patrick Adams (RMIT University)
      • 11:30
        Data evaluation on the fly: Auto-Rickshaw at the MX beamlines of the Australian Synchrotron 20m

        Auto-Rickshaw [1,2] is a system for automated crystal structure determination. It provides computer coded decision-makers for successive and automated execution of a number of existing macromolecular crystallographic computer programs thus forming a software pipeline for automated and efficient crystal structure determination.

        Auto-Rickshaw (AR) is freely available to the crystallography community through the EMBL-Hamburg AR Server (http://www.embl-hamburg.de/Auto-Rickshaw).

        Recently, it has been installed at the ASCI cluster at the Australian Synchrotron. The AS-AR server is accessible from the MX beamline computers during the X-ray data collection.

        AR at the MX beamlines can be invoked through command line or a web-based graphical user interface (GUI) for data and parameter input and for monitoring the progress of structure determination. It can be also invoked via automatic data processing if the parameter inputs have been pre set at the GUI during X-ray diffraction experiment.

        A large number of possible structure solution paths are encoded in the system and the optimal path is selected by the decision-makers as the structure solution evolves. The platform can carry out experimental (SAD, SIRAS, RIP or various MAD) and MR phasing or combination of experimental and MR phasing. The system can be used in evaluation of multiple datasets for any phasing protocols as well as for evaluation of ligand binding or fragment screening.

        The new implementation and features will be discussed during the presentation.

        References
        [1] Panjikar, S., Parthasarathy, V., Lamzin, V. S., Weiss, M. S. & Tucker, P. A. (2005). Auto-Rickshaw - An automated crystal structure determination platform as an efficient tool for the validation of an X-ray diffraction experiment. Acta Cryst. D61, 449-457.
        [2] Panjikar, S., Parthasarathy, V., Lamzin, V. S., Weiss, M. S. & Tucker, P. A. (2009). On the combination of molecular replacement and single-wavelength anomalous diffraction phasing for automated structure determination Acta Cryst. D65,1089-1097.

        Speaker: Dr Santosh Panjikar (Australian Synchrotron)
    • 10:00 → 11:50
      Session 12 - Earth, Atmosphere and Environment Zoom Meeting Room

      Zoom Meeting Room
      • 10:00
        Non-invasive imaging of hydraulic function in leaves, stems and roots 30m

        Plants have evolved a water transport system that relies on water sustaining a tensile force. Counter intuitively, this means water moves through the plant as a liquid under negative absolute pressures. This mechanism is made possible by the intricate plumbing system that constitutes the xylem tissue of plants. However, water under tension is prone to cavitation, which results in the formation of a gas bubble (embolism). Embolism reduces the capacity of the xylem tissue to deliver water to the canopy, eventually causing dieback and whole plant mortality. Xylem embolism is exacerbated by environmental stresses and is now considered one of the leading causes of plant mortality resulting from drought stress. Non-invasive imaging techniques offer the potential to make direct observations on intact plants at high resolution and in real time. In this presentation, I discuss recent exciting developments in the application of non-invasive imaging technologies such as X-ray Micro Computed Tomography (microCT) and optical imaging to studies of plant vascular function. This includes visualisation of xylem networks during drought stress and recovery in leaves, stems and roots. MicroCT imaging of stems and roots indicated that significant embolism formation occurs at similar time points and levels of water stress in dehydrating plants. This result was observed in herbaceous and woody species, and is surprising given previous hydraulic measurements indicating that, within a plant, roots were more vulnerable to drought-induced embolism than stems. A newly developed optical technique indicates that leaf vasculature is also similar in vulnerability to stems and roots. The overlap in vulnerability suggests that induction of embolism occurs at the same time in different organs or is propagated rapidly through the plant. In examining recovery from drought stress, we saw little evidence of embolism refilling in the xylem of woody plants, except in cases where substantial root pressure is produced. These results suggest that embolism refilling is less widespread than previously thought.

        Speaker: Brendan Choat
      • 10:30
        Micro-Computed Tomography (MCT): A BRIGHT new beamline at ANSTO/Australian Synchrotron 20m

        Micro-Computed Tomography (MCT) has been announced as one of the first new beamlines to be constructed at the Australian Synchrotron as part of the BRIGHT program. MCT will complement the existing X-ray imaging/tomography capability provided by the Imaging and Medical Beamline (IMBL), and will target applications requiring higher (sub-micron) spatial resolution and involving smaller samples. MCT will be a bending-magnet beamline, operating in the 8 to 40 keV range, based on a double-multilayer monochromator. This monochromator will be able to be removed from the X-ray beam path, enabling studies with a filtered white beam when required. The photon-delivery system will also house a single-(vertical)bounce mirror, capable of suppressing harmonic contamination in low-energy monochromatic beams and providing the means to shape the spectrum of filtered white beams on the high-energy side. MCT will benefit from X-ray phase-contrast modalities (such as propagation-based, grating-based and speckle) in addition to conventional absorption contrast, and be equipped with a robotic stage for rapid sample exchange. A higher-resolution CT configuration based on the use of a Fresnel zone plate system will also be available. A number of sample environmental stages, such as for high temperature and the application of loads, are planned in collaboration with certain groups in the user community.

        Anticipated application areas for non-destructive 3D sample characterization include biomedical/ health science, food, materials science, and palaeontology. This presentation will provide an update on the progress of the MCT project, detailing the current design, planning and procurement effort.

        Speaker: Andrew Stevenson (Australian Synchrotron)
      • 10:50
        Soil carbon research from past, present and future using synchrotron-based techniques 20m

        Building and protecting soil carbon is critical to agricultural productivity, soil health and climate change mitigation. This study aims to answer new questions of the molecular scale mechanisms at the organo-mineral interfaces for building soil carbon in the past:Terra Preta Australis (ancient indigenous dark earth, dated back to 1600 years BP); present: the longest, continuous biochar field experiment in the world, located at Wollongbar, New Souths Wales (building new carbon over 14 years); future: the Australian Soil Free Air CO2 Enrichment (SoilFACE) field facility at Horsham, Victoria (mimicking elevated CO2 conditions in the field over 8.5 years in the Southern Hemisphere). Based upon synchrotron-based in situ spectromicroscopy, we reveal the functional complexity and spatial resolution of soil organic carbon under contrasting management practices, cropping histories and soil types over millennium. It will provide critical information to advance knowledge of building soil carbon for productive, sustainable and resilient cropping systems.

        Speaker: Dr Han Weng (The University of Queensland)
      • 11:10
        Latest developments and capabilities at the Infrared Microspectroscopy Beamline 20m

        The Infrared Microspectroscopy (IRM) beamline has been in operation for user experiments since 2007 and continues to provide access to cutting edge Fourier transform infrared (FTIR) microscope instrumentation with a bright, diffraction limited infrared beam for the analysis of diverse materials form single cells to cultural artefacts, and composite materials to food products. This presentation will provide an update on the current status and capabilities of the IRM beamline, illustrated with relevant case studies.
        Operation of the microscope in transmission mode provides a lateral resolution of between 4 μm and 10 μm, depending on wavelength, and is suitable for the analysis of thin films, single biological cells and microtomed thin sections of materials from biological tissues to polymer composites. The IRM beamline is equipped with a range of sample chambers for use in transmission mode, including a diamond compression cell for the flattening of materials, a Linkam heated stage for analysis at temperatures between -195°C and 600°C, and a set of custom liquid chambers for the analysis of live biological samples.
        Reflection and grazing incidence capabilities enable the analysis of certain materials that either have a polished surface, or are presented as a thin film coating on the surface of a reflective metal substrate.
        Enhanced lateral resolution, and the ability to map materials that are otherwise not suited to transmission IR microanalysis, are achieved by the Attenuated Total Reflection (ATR) method. The ATR approach has been developed as a key capability of the IRM beamline, and a separate presentation on this will be given at this meeting.
        The standard operating spectral range for the IRM microscope is from 4000 cm-1 to 750 cm-1, using a high sensitivity narrow band detector. This range can be extended on request using a wide band detector with a lower limit of around 500 cm-1, but with an overall loss of sensitivity across the full mid-IR range. A further extension of the range is possible through the use of a far-IR Si:B photodetector, or a Bolometer detector, with a lower limit of 250 cm-1 set by the IRM beamline infrared window. A focal plane array detector can be made available for certain experiments requiring snapshot images of small regions of around 30 × 30 μm.
        Rapid scan IR measurements at a microscopic scale are possible on the IRM beamline, with the ability to collect 65 spectra per second at 16 cm-1 spectral resolution.
        Future developments at the IRM beamline include the use of higher numerical aperture optics for improved beam collection in the reflection analysis of materials, a liquid ATR flow cell for the study of live biological samples at high spatial resolution, full piezo control of all adjustable mirrors and pinholes within the IR microscope, and improved capabilities for mail-in experiments.

        Speaker: Dr Mark Tobin (Australian Synchrotron)
      • 11:30
        “Wax On – Wax Off” Using Infrared Reflectance for minimally invasive in vivo monitoring of changes in leaf epicuticular waxes 20m

        With increasing global populations and rising temperatures associated with climate change it is important to monitor and mitigate the effects of environmental stress on both native flora and agricultural crops. Epicuticular waxes on the surface of plant leaves play essential roles in sustaining plant health. Such roles include; minimising water loss, protection against UV and diseases, as well as acting as an antifeedent. Studying the composition and distribution of epicuticular waxes on the surface of plant leaves can therefore, provide a valuable window-of-insight into plant fitness and the presence of environmental stressors.

        Current methods to study plant waxes require extraction of the wax from the leaf surface. This approach reveals substantial insight into chemical composition of plant waxes but, destroys valuable information relating to the spatial distribution of waxes on the leaf surface. Few methods exist that are capable of imaging the wax distribution in situ across anatomical components of the leaf surface, and a gap exists for non-destructive macro-scale imaging in vivo. In this presentation I will describe the development of FTIR micro-spectroscopy to non-destructively image in vivo wax distribution across the leaf surface of native flora and an important agriculture crop (wheat). The method is underpinned by apparent strong specular reflection that comes from the thin, highly ordered wax layers on leaf surfaces. To the best of our knowledge, this is the first report of in vivo monitoring of changes in leaf epicuticular waxes in response to environmental stressors. This new analytical capability could now enable in vivo studies of plants to provide insights into physiological responses of plants to environmental stresses such as disease, soil contamination, drought, soil acidity and/or climate change.

        Speaker: Ms Karina Khambatta (2School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia)
    • 11:50 → 12:50
      Lunch 1h
    • 12:50 → 13:35
      Plenary 4: Australian Synchrotron Research Award: Dr Wei Kong Pang Zoom Webinar Room ()

      Zoom Webinar Room
      • 12:50
        Synchrotron-based X-ray diffraction and spectroscopy for metal-ion battery material studies 45m

        Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2500, Australia.
        Email: wkpang@uow.edu.au

        The commercialisation of lithium-ion batteries (LIBs) has gained huge success and LIBs are taking an important part of our daily modern life, as confirmed by the prestigious award of the 2019 Nobel Prize in Chemistry. Owing to the limited abundance of lithium, other metal-ion batteries (MIBs), such as zinc-, sodium-, and potassium-ion batteries, with similar working mechanism, have also been studied and developed as alternatives. Compared with other energy storages, MIBs are relatively less predictable due to the complex reactions occurred on the bulk and surface of electrodes, as well as other battery components, such as electrolyte, during electrochemical processes. During charge and discharge, the intercalation and de-intercalation processes of metal ions (i.e. lithium ions) happening in the electrodes are very complex, involving the evolutions of phase, structure, composition, as well as morphology, with these processes underpinning electrochemical function and performance of the battery. Therefore, a mechanistic understanding of the reaction pathways, i.e. the atomistic and molecular-scale origin of battery performance, will enable the rational improvement of electrode materials and pave the way for entirely new battery systems, and in-situ in-operando synchrotron-based X-ray powder diffraction (XRPD) with high brightness and tuneable wavelength is an extremely powerful tool to obtain this crucial understanding.
        On the other hand, X-ray absorption spectroscopy (XAS) could be used to detect the electronic structure of certain ions within the active materials in the battery, especially helpful to investigate the elements with electrochemical activities. Transmission X-ray microscopy (TXM) can be employed to probe the electrode morphological changes during charge and discharge, linking to the electrochemical performance of the materials. Infra-red microscopy (IRM) is also found to be a powerful analytical method, allowing the characterisation of the chemical information and their distribution of solid-electrolyte interphase formed on the electrode surface. By correlating the chemical information with data obtained from other techniques, additional insights into their mechanism, which is critical for further development, can be gained.
        In this presentation, I will introduce the research work in our team and showcase some examples of these mechanistic and crystallographic research, demonstrating the important role of synchrotron-based X-ray scattering in battery research.

        Speaker: Dr Wei Kong Pang
    • 13:35 → 14:05
      Australian Synchrotron Stephen Wilkins Medal 30m Zoom Webinar Room ()

      Zoom Webinar Room
    • 14:05 → 14:35
      UAC Town Hall Meeting 30m
    • 14:35 → 15:05
      Afternoon Tea 30m
    • 15:05 → 17:15
      Session 13 - Chemistry, Catalysis and Soft Matter Zoom Meeting Room

      Zoom Meeting Room

      • 15:05
        Complex fluids and simple experiments - What could we do? 30m

        Structural studies often aim to overcome the shortcomings of a sample without compromising on signal or accuracy. One critical aspect of studying rheologically complex liquids is flow, and a sample's deformation history and characteristic time scales can complicate interpretation. In this talk I will discuss some simple (and cheap) methods of avoiding unwanted flow, but also adjusting fluid time scales when flow is desirable. We will also examine new (cheap and easy) methods of imposing flow on unsuspecting samples to benefit structural insights and enhance understanding of commercially relevant processes and materials.

        Speaker: Patrick Spicer
      • 15:35
        Experiments on the high-flux BioSAXS beamline: opportunities for dynamic studies of soft matter systems and advanced materials 20m

        The BioSAXS beamline is one of the new beamlines to be constructed at the Australian Synchrotron within the BRIGHT program. BioSAXS will be dedicated to perform solution small-angle X-ray scattering (SAXS) experiments, offering access to a variety of researchers from Australia and New Zealand. Solution SAXS experiments continue to be a growing area of the current Australian Synchrotron SAXS/WAXS operations, particularly in regard to protein and DNA/RNA structure, polymer solutions, nanoparticles and liquid crystal phases. Highly radiation-sensitive samples will be studied on the BioSAXS beamline with unprecedented levels of flux, using the CoFlow sample environment, a pioneering development of the Australian Synchrotron. A highly-automated end-station combined with a versatile detector system will allow the BioSAXS beamline to accommodate most solution SAXS experiments, covering a q-range of ~ 0.001 – 3 Å-1, with low instrument background. The optical design is optimized for high flux (>5×1014 ph/s) x-rays and a focused beam size of 0.3 mm (H) × 0.03 mm (V).

        Along with the CoFlow, a wide range of automated, in-situ sample environments are planned for users studying soft matter and nanoparticulate systems, with a focus on high throughput measurements and real-time dynamics to take advantage of the high flux beam and fast detector response time. These will include a stopped-flow and rheometer for dispersed polymer solutions, along with a novel, versatile magnetic-array system, optimized for small-angle scattering experiments on magnetic nanoparticles used in biomedical applications. The BioSAXS beamline will be developed as a highly-automated and versatile beamline that can accommodate a wide-range of solution scattering experiments, complementing the existing SAXS/WAXS beamline to ensure the world-leading capabilities of the SAXS offering at the Australian Synchrotron.

        Speaker: Lester Barnsley (ANSTO)
      • 15:55
        Internal liquid crystal structures in nanocarriers containing drug hydrophobic ion pairs dictate drug release 20m

        Hypothesis: Hydrophobic ion pairing (HIP), a solubility engineering technique in which ionic hydrophilic molecules are paired with a hydrophobic counterion, is an attractive strategy for encapsulating ionic water-soluble species into nanocarriers (NC). Drug release from NCs containing HIP complexes is sensitive to ionic strength, pH, and drug:counterion charge ratio, but the exact mechanism for this was unknown, as was the underlying microstructure inside the NC. We hypothesize that HIP complexes arrange into liquid crystalline structures in NC cores and that these structures are responsible for salt- and pH-dependent release.

        Experiment: A model hydrophobic ion pair from the cationic antimicrobial peptide polymyxin B sulfate and the anionic counterion sodium oleate is encapsulated into ~100nm NCs formed using Flash NanoPrecipitation (FNP) and stabilized with an amphiphilic diblock copolymer, poly(caprolactone)-b-poly(ethylene glycol). Internal structures are observed by synchrotron small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) following NC formulation and are found to vary with polymyxin:oleate charge ratio. In vitro drug release is also measured at two pHs and two charge ratios.

        Findings: For a formulation containing a four-fold charge excess of oleate relative to polymyxin, internal structures rearranged from a lamellar phase into an inverse hexagonal phase. The hexagonal phase formation corresponds to a greatly reduced rate of polymyxin release, suggesting that the polymyxin was incorporated into the center of hexagonally-packed rods. When release tests are repeated using phosphate-buffered saline (PBS) at pH 2.0 to ensure protonation of the oleic acid, all internal structures are eliminated and release occurs much faster than at neutral pH, regardless of charge ratio. These findings shed light on the mechanism behind stimulus-responsive drug release from systems containing hydrophobic ion pairs and enable the rational design of controlled-release formulations by manipulating the formation and dynamics of liquid crystalline phases inside NCs.

        Speaker: Kurt Ristroph
      • 16:15
        New insights into the self-assembly of amphiphilic poly(ethylene glycol-b-caprolactone) diblock copolymers in aqueous solution 20m

        The ability to self-assemble into nanostructures is a fundamental phenomenon is many living and non-living system. The design of polymeric systems that assemble into hierarchically structured nanomaterials requires careful consideration of the microstructure and molecular interactions. For many applications, such as micellar drug delivery systems, precise control over the self-assembly process are required. However, the relationship between molecular structural characteristics of block polymers and their micellar self-assembly mechanisms vary with different block types. In this study, the effect of polymer molecular weight and copolymer block ratio on the micellization of poly(ethylene glycol-b-caprolactone) (PEG-b-PCL) block copolymers was investigated. The stealth properties of PEG and biodegradable nature of PEG-b-PCL makes it a suitable choice for biomedical applications, including tissue engineering and drug delivery. Nuclear magnetic resonance (NMR) and dynamic light scattering (DLS) were used to measure the diffusion of block copolymers in water, from which the hydrodynamic diameters and dispersity of the polymer aggregates were determined; three aggregation scenarios were inferred from the data, including unimers (no self-assembly), large metastable aggregates, and monodisperse micelles. Small-angle x-ray scattering (SAXS) from polymer solutions provided morphological information on the shape of the micelles and their relationship to the polymers microstructure. The PEG molecular weight and PCL:PEG ratio was the primary factor affecting micelle shape. A clear transition from unimers to large aggregates to cylindrical and ellipsoid micelles was observed as the PEG molecular weight and PCL:PEG ratio increased, with an increase in the micelle hydrodynamic radii. We therefore propose a self-assembly phase diagram for the PEG-b-PCL system in aqueous media by combining NMR, DLS and SAXS data. Block copolymer composition with larger PEG molecular weights and larger PEG-b-PCL block ratios formed more monodisperse micelles, whereas copolymer compositions with smaller PEG molecular weights and smaller PEG-b-PCL block ratios formed large metastable aggregates.

        Speaker: Dr Khandokar Sadique Faisal (University of South Australia, Applied Chemistry and Translational Biomaterials Group)
      • 16:35
        Effect of Emulsifier Type on Interfacial Crystallisation 20m

        The study of interfacial crystallisation with SAXS/WAXS is commonly conducted using both water-in-oil and oil-in-water and emulsions. The former case can be compared to that of a continuous lipid system, where impurities in the bulk lipid catalyse the formation of a lipid crystal network. In the latter case, the dispersion of the lipid phase into emulsion droplets means the division of crystal-promoting impurities amongst these droplets, with the number of droplets likely to exceed the number of impurities, hence lowering the temperature required to form crystals. The inability to distinguish bulk lipid crystals from those at an interface is also made challenging in an emulsion system due to the size of the droplets relative to the size of the x-ray beam. We have used a different approach to study interfacial crystallisation, whereby a model lipid layer (medium-chain triglyceride, MCT) containing a mono-diglyceride mixture was added on top of a water layer inside a capillary. Synchrotron SAXS/WAXS was then used to study crystallisation occurring at the oil-water interface. Surfactant molecules are present in emulsions as stabilising agents and they may also influence crystallisation and the lipid crystal structure. The effect of stabilising agents on the structure and properties of lipid crystals was also investigated. The interfacial activity of fat crystals was also assessed in a complementary series of experiments using Profile Analysis Tensiometry by monitoring the kinetics of interfacial tension in response to temperature changes. Both the addition of stabiliser and the stabiliser type alter the interfacial tension profiles for heating and cooling cycles compared to the lipid-water system in the absence of stabiliser.

        Speaker: Ms Stephanie Macwilliams (University of South Australia)
      • 16:55
        The effect of surfactant type on the secondary crystallisation of milk fat at the oil-water interface 20m

        The crystallisation of lipids within a dispersed oil phase has the potential to stabilise or destabilise the system, depending on the size and position of the crystals. Interfacial crystallisation within dairy emulsions is of particular interest owing to the role of lipid crystals in partial coalescence, an essential process in the stabilisation of products such as whipped creams. Despite the critical importance of lipid crystallisation at droplet interfaces, little is known about this phenomenon. Our work utilises two complementary techniques to analyse the effect of thermal cycling on interfacial crystallisation within a simulated milk system. Profile analysis tensiometry (PAT) allows us to monitor the kinetics of interfacial lipid crystallisation by tracking the interfacial tension of a single droplet as a function of time and temperature. PAT analysis enabled determination of the temperature at which interfacially-active crystals affect the interfacial properties and highlighted the differences in behaviour of these lipid crystals due to the presence of an emulsifier. Additionally, the effect of emulsifier type was studied using both a protein and non-ionic emulsifier. We found that the presence of emulsifiers delays the effect of interfacial crystals on the interfacial tension, as well as altering the rates of change in interfacial tension. Synchrotron small angle X-ray scattering (SAXS) was conducted on emulsion systems (for the same composition as in PAT experiments) to study the formation, growth and structure of lipid crystals, following a similar temperature cycling regime to that of the PAT experiments. The SAXS results also indicated a suppression of interfacial crystallisation in the presence of emulsifiers, and a difference in the degree of suppression due to the type of emulsifier used.

        Speaker: Dr Damien Sebben (University of South Australia)
    • 15:05 → 17:15
      Session 14 - Life Science and Structural Biology Zoom Meeting Room

      Zoom Meeting Room

      • 15:05
        Structural studies of G protein-coupled receptors – implications for drug discovery 30m

        David Thal1
        1 Monash University

        Corresponding Author(s): david.thal@monash.edu
        G protein-coupled receptors (GPCRs) are key cell-surface proteins that transduce external environmental cues into biochemical signals across the cell membrane. They are the largest superfamily of cell-surface receptors encoded by the human genome and are also the largest class of FDA approved drug targets. The overarching goal of our lab is to understand the molecular basis of how GPCRs function and how this knowledge can be used to design new drug candidates. In particular, using lipidic cubic phase crystallography we have determined inactive state structures of the M4 and M5 muscarinic acetylcholine receptor (mAChR) subtypes, the A1 adenosine receptor (A1AR), and the neurokinin 1 receptor (NK1R). These GPCRs are important drug targets for neuropsychiatric diseases (mAChRs), cardiovascular disease (A1AR), and pain and inflammation (NK1R). In addition, using cryo-electron microscopy (cryo-EM) we have determined active state structures for several of these receptors. Collectively, the result of these structures has provided insight into how different classes of ligands bind to and modulate the structure and function of these receptors that we anticipate will aid future drug discovery efforts at these receptors.

        Speaker: David Thal (Monash Institute of Pharmaceutical Sciences)
      • 15:35
        An investigation of the T cell response against viruses through a structural lens 20m

        T cells are a critical part of the immune response, that would determine the fate of an infection and disease outcome. Our Lab is focused on understanding how T cell engage with viral particles, called peptide antigens, that are presented by highly polymorphic molecules called Human Leukocyte Antigens (HLA). T cells have receptors on their surface called T cell receptor (TCR) that allow them to recognise the composite surface of the peptide-HLA complex.
        Using X-ray crystallography we are seeking to understand both peptide antigens presentation as well as TCR recognition, both important to determine the quality of the subsequent immune response. This allow us to understand the response towards influenza and HIV viruses, and more recently SARS-cov-2 virus. The molecular and biophysical features of the peptide antigens help us map the regions of the virus that are recognised by T cells, as well as determining the most stable and potent antigens that represent attractive target for therapeutics.

        Speaker: Prof. Stephanie Gras (Monash University)
      • 15:55
        Structural plasticity between homo and heterodimeric IRF4-DNA Interactions 20m

        Interferon regulatory factor 4 (IRF4) is a transcription factor (TF) that regulates the gene expression of immune cells including T cells and B cells. Due to its critical role in B and T cell development, IRF4 is linked directly to numerous immune-related disease conditions including B cell-related chronic lymphocytic leukemia (CLL) and adult T cell leukemia (ATL) (1). Structurally, IRF4 consists of two conserved domains; an N-terminal DNA binding domain and the C-terminal IRF-association domain and binds the target DNA as either homo or heterodimer. Notably, it binds the canonical interferon-stimulated response elements (ISRE) DNA motif as a homodimer and regulates the expression of genes involved in interferon stimulation. Despite the significance of this association, the mechanistic basis underpinning this pivotal molecular interaction remains unknown. Through X-ray crystallography and surface plasmon resonance, we now provide the structural basis of this interaction. Our study has identified a head to tail orientation in IRF4-ISRE interaction, with each monomer docking the opposite face of the DNA. We also found a substantial bending in DNA to accommodate α3 recognition helix directly on the major groove with no observed intermolecular interaction between the bound monomers. This markedly contrasts heterodimeric form where DNA bound IRF4 is shown to physically interact with other TFs to regulate the target gene expression (2). Notably, we also identified that the disease-causing mutations (3,4) could bind directly to DNA as evidenced by their tighter binding affinities. Together, our study provides a structural snapshot of IRF4 homo and heterodimers and its role in regulating the target gene expression thereby providing insights into the basis of IRF4 mediated CLL and ATL pathogenesis.
        References
        1. Hagman, J. (2017) Critical Functions of IRF4 in B and T Lymphocytes. J Immunol 199, 3715-3716
        2. Escalante, C. R., Brass, A. L., Pongubala, J. M., Shatova, E., Shen, L., Singh, H., and Aggarwal, A. K. (2002) Crystal structure of PU.1/IRF-4/DNA ternary complex. Mol Cell 10, 1097-1105
        3. Havelange, V., Pekarsky, Y., Nakamura, T., Palamarchuk, A., Alder, H., Rassenti, L., Kipps, T., and Croce, C. M. (2011) IRF4 mutations in chronic lymphocytic leukemia. Blood 118, 2827-2829
        4. Cherian, M. A., Olson, S., Sundaramoorthi, H., Cates, K., Cheng, X., Harding, J., Martens, A., Challen, G. A., Tyagi, M., Ratner, L., and Rauch, D. (2018) An activating mutation of interferon regulatory factor 4 (IRF4) in adult T-cell leukemia. J Biol Chem 293, 6844-6858

        Speaker: Dr Srinivasan Sundararaj (Australian National University)
      • 16:15
        Molecular Interplay between SARS-CoV-2 and Human proteins for viral activation and entry, potential drugs and scope of new therapeutics 20m

        The pandemic Coronavirus Disease 2019 (COVID19) caused by SARS-CoV-2 is a serious public health concern with global mortality reaching 1 million. Whilst the search for a vaccine is underway, there a several antiviral and antibody treatments being clinically evaluated to fill the “therapeutic gap”. The development of potential drugs requires an understanding of SARS-CoV-2 pathogenicity and mechanism of action. Thus, it is essential to understand the full repertoire of viral proteins and their interplay with host factors. Here, we show how the SARS-CoV-2 spike protein undergoes 3 stages of processing to allow virion activation and host cell infection. We also conduct pre-clinical and cohort studies and found effective viral clearance by Arborol drug treatment inpatients. Our comprehensive structural studies reveal why COVID19 is hypervirulent and the reason for the failure of several antibody treatments to date. We demonstrate via molecular dynamics and functional studies how the host proteins CD26, Furin and TMPRSS2 process the viral spike glycoprotein and assist in the viral entry in addition to ACE2. These results cognize the detailed mechanism of spike glycoprotein and reveal new avenues for potential therapeutics to block different stages of viral entry and new pathways for vaccine development.

        Speaker: Naveen Vankadari (Monash University)
      • 16:35
        Structural characterisation of mitochondrial complex IV assembly factors 20m

        Cytochrome c oxidase or mitochondrial respiratory chain complex IV catalyses the transfer of electrons from cytochrome c in the intermembrane space, to molecular oxygen in the matrix and therefore contributes to the proton gradient that drives mitochondrial ATP synthesis. Complex IV dysfunction is a significant cause of human mitochondrial disease. Complex IV requires the incorporation of three copper ions, heme a and heme a3 cofactors for the assembly and activity of the complex. Complex IV assembly factors are required for subunit maturation, co-factor incorporation and stabilization of intermediate assemblies of complex IV in humans. Loss-of-function mutations in several genes encoding complex IV assembly factors have been shown to result in diminished complex IV activity and severe pathologic conditions in affected infants [1].

        Our study focuses on two mitochondrial complex IV assembly factors, Coa6 and Coa7, that are located in the intermembrane space of mitochondria and contain intramolecular disulfide bonds. Coa6 binds copper with femtomolar affinity and has been proposed to play a role in the biogenesis of the CuA site of complex IV [2,3]. The W59C pathogenic mutation in Coa6 does not affect copper binding or import of the protein into mitochondria but affects the maturation and stability of the protein [3,4]. The precise role of Coa7 in the biogenesis of complex IV is not completely understood. However, patients with Coa7 pathogenic mutations suffer from mitochondrial diseases owing to complex IV deficiency. This presentation will describe the crystal structures of the Coa7 and Coa6 (wild-type and the W59C mutant) proteins and implications for their roles in complex IV assembly and function. To elucidate the atomic structure of the WTCoa6, W59CCoa6 and WTCoa7 proteins, we crystallised and determined their structures to 1.65, 2.18 and 2.40 Å resolution, respectively by X-ray crystallography. Diffraction data were recorded at the Australian Synchrotron on beamline MX2. The crystal structure of WTCoa6 was determined by sulfur single- wavelength anomalous dispersion and the crystal structure of WTCoa7 and W59CCoa6 were solved by molecular replacement.

        References:

        [1] Timon-Gomez, A., Nyvltova, E., Abriata, L. A., Vila, A. J., Hosler, J., and Barrientos, A. (2018) Mitochondrial cytochrome c oxidase biogenesis: Recent developments, Seminars in cell & developmental biology 76, 163-178.
        [2] Stroud, D. A., Maher, M. J., Lindau, C., Vögtle, F. N., Frazier, A. E., Surgenor, E., … Ryan, M. T. (2015). COA6 is a mitochondrial complex IV assembly factor critical for biogenesis of mtDNA-encoded COX2. Human molecular genetics, 24(19), 5404–5415. doi:10.1093/hmg/ddv265
        [3] Maghool, S., Cooray, N., Stroud, D. A., Aragão, D., Ryan, M. T., & Maher, M. J. (2019). Structural and functional characterization of the mitochondrial complex IV assembly factor Coa6. Life science alliance, 2(5), e201900458. doi:10.26508/lsa.2019004583.
        [4] Maghool, S., Ryan, M. T., & Maher, M. J. (2020). What Role Does COA6 Play in Cytochrome C Oxidase Biogenesis: A Metallochaperone or Thiol Oxidoreductase, or Both?. International journal of molecular sciences, 21(19), E6983.

        Speaker: Dr Shadi Maghool (School of Chemistry and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Australia)
      • 16:55
        COVID-19 Research at the MX Beamlines 20m

        From March 2020, the Australian Synchrotron joined the rest of Victoria in COVID-19 lockdown, severely limiting the access to beamlines by staff and users. The MX beamlines stayed operational under a COVID-19 Rapid Access scheme, developed to facilitate research into the SARS-Cov-2 virus. A number of user groups pivoted their research interests to include SARS-Cov-2 proteins, and human proteins involved in the virus's progression and transmission. In this talk, we present a general overview of the COVID-19 Rapid Access program, some examples of research carried out using this beamtime, and the plans for supporting COVID-19 research in an ongoing capacity.

        Speaker: Dr Eleanor Campbell (ANSTO)
    • 15:05 → 17:15
      Session 15 - Manufacturing, Engineering and Cultural Heritage Zoom Meeting Room

      Zoom Meeting Room

      • 15:05
        Jumping molecular crystals: the role of molecular vibrations 30m

        Authors: A. Dowd, C. Ellis, A. Angeloski.
        Affiliations: Faculty of Science, University of Technology Sydney; Department of Chemistry, University of Otago.
        While we are familiar with the concept of the conversion of thermal energy to mechanical work, there is a little known class of materials known as thermosalient or jumping crystals which can spectacularly turn a small temperature change into a high speed leap, many times their own length.
        These materials might lead to some exciting new options for the creation of microscopic machines. The jumping and other movement is usually associated with a rapid single crystal-single crystal phase transition. Unfortunately the confusing mix of explanations in the literature shows that this phenomenon is poorly understood, which hinders the crystal engineering required to explore technical applications.
        The classic approach in studying such materials is to use diffraction to determine the crystal structure, however vibrational spectroscopy can be used to complement this information particularly from a dynamical aspect, revealing more about the nature of the phase transition.
        In this presentation I will present a case study on the newly discovered jumping crystal, nickel dithiocarbamate (Ni:DTC). I will briefly outline the current thinking on SCSC phase transitions in molecular crystals. Measurements of phonon and intramolecular vibrational modes from the THz – Far Infrared beamline using the variable temperature cryostat will be presented. Interpretation was guided with Crystal17 modelling using periodic density functional theory so lattice modes could be calculated. Calculations were based on structures determined by single crystal diffraction.

        Speaker: Annette Dowd
      • 15:35
        Using Synchrotron Sourced Microscopy to Explore Fingermark Chemistry 20m

        The successful detection of latent fingermarks is crucial to forensic investigations, however detection methods can be hindered by variation in response or lack of robustness. Despite ongoing research into fingermark development, many remain undetected(1). A fundamental understanding of fingermark chemistry can provide explanations for the effectiveness or lack thereof for current detection methods and drive development of improved techniques.
        We have combined synchrotron sourced Fourier Transform Infrared (FTIR) and X-ray Fluorescence Microscopy (XFM) to reveal the spatial distribution of the molecular and elemental components within latent fingermarks. FTIR showed that fingermarks have a complex heterogeneous distribution of organic material, our research focussing primarily on visualising the lipid and amino acid distribution at the sub-micron scale (2). Recent time-course studies have imaged the rate which freshly deposited fingermarks dry, with the results reinforcing the chemical heterogeneity of latent fingermarks and demonstrate how differences in composition appear to influence drying rates and redistribution of lipid material during drying.
        We used XFM to explore the inorganic components within fingermark residue. The distribution of trace metals including endogenous trace metals (Fe, Cu, Zn), diffusible ions (Cl−, K+, Ca2+), and exogeneous metals (Ni, Ti) have been imaged across multiple donors (see Figure 1) (3). Further experiments have explored the effects of the external environment on these metals post deposition, and the transfer of exogenous metals prior to deposition.
        With these techniques, we have begun to have a better understanding of the chemical complexity and transfer processes associated with latent fingermarks, thus providing the essential fundamental underpinning for the development of improved detection methods.

        1. S. Chadwick, S. Moret, N. Jayashanka, C. Lennard, X. Spindler and C. Roux, Forensic Science International, 2018, 289, 381-389.
        2. B. N. Dorakumbura, R. E. Boseley, T. Becker, D. E. Martin, A. Richter, M. J. Tobin, W. van Bronswjik, J. Vongsvivut, M. J. Hackett and S. W. Lewis, Analyst, 2018, 143, 4027-4039.
        3. R. E. Boseley, B. N. Dorakumbura, D. L. Howard, M. D. de Jonge, M. J. Tobin, J. Vongsvivut, T. T. M. Ho, W. van Bronswijk, M. J. Hackett and S. W. Lewis, Analytical Chemistry, 2019, 91, 10622-10630.
        Speaker: Rhiannon Boseley (Curtin University)
      • 15:55
        Synchrotron macro ATR-FTIR: where we are and what's next for live-cell measurement 20m

        Abstract
        This presentation aims to provide a summary on the recent applications of our synchrotron macro ATR-FTIR microspectroscopy, unique to the Australian Synchrotron’s Infrared Microspectroscopy (IRM) beamline. The technique provides molecular information with sub-cellular resolution down to 1-2 μm beyond the resolution limit allowed for standard synchrotron-FTIR setups and further simplifies otherwise complicated sample preparation [1]. Since the technique was made available for users in 2016, this high-resolution chemical mapping capability has facilitated diverse experiments on the beamline expanding its applications into many new areas. Some of the recent examples include novel environmental sustainable geopolymer concretes [2,3], archaeological bones [4] and spider silk cross-sections [5].
        The second part of the presentation will highlight further development of the macro ATR-FTIR technique specifically for live-cell measurement in an aqueous environment. Through the collaboration with the SMIS beamline at SOLEIL (France), we undertook a beamtime experiment using their inverted ATR-FTIR accessory to acquire spectra from live red blood cells. The experience and knowledge gained from this international beamtime experiment, together with the effort from our mechanical engineering team, have resulted in an optical design to be developed into the first prototype of ATR-FTIR setup for live-cell measurement.

        Acknowledgement
        We would like to acknowledge the financial support from International Synchrotron Access Program (ISAP No. AS/IA182/14167) to perform the live-cell ATR-FTIR experiment at SOLEIL’s SMIS beamline (Proposal ID. 20180157).

        References
        [1] J. Vongsvivut, D. Pérez-Guaita, B. R. Wood, P. Heraud, K. Khambatta, D. Hartnell, M. J. Hackett, and M. J. Tobin, “Synchrotron Macro ATR-FTIR Microspectroscopy for High-Resolution Chemical Mapping of Single Cells,” Analyst 144, 10, 3226-3238 (2019).
        [2] A. Hajimohammadi, T. Ngo, J. L. Provis, T. Kim, and J. Vongsvivut, “High Strength/Density Ratio in a Syntactic Foam Made from One-Part Mix Geopolymer and Cenospheres,” Composites Part B, 173, 106908 (2019).
        [3] A. Hajimohammadi, T. Ngo, and J. Vongsvivut, “Interfacial Chemistry of a Fly Ash Geopolymer and Aggregates,” Journal of Cleaner Production, 231, 980-989 (2019).
        [4] J. J. Miszkiewicz, C. Rider, S. Kealy, C. Vrahnas, N. A. Sims, J. Vongsvivut, M. J. Tobin, M. J. L. A. Bolunia, A. S. De Leon, A. L. Peñalosa, P. S. Pagulayan, A. V. Soriano, R. Page, and M. F. Oxenham, “Asymmetric Midshaft Femur Remodelling in an Adult Male with Left Sided Hip Joint Ankylosis, Metal Period Nagsabaran, Philippines,” International Journal of Palaeopathology, 31, 14 (2020).
        [5] C. Haynl, J. Vongsvivut, K. R. H. Mayer, H. Bargel, V. J. Neubauer, M. J. Tobin, M. A. Elgar, and T. Scheibel, “Dimensional Stability of a Remarkable Spider Foraging Web Achieved by Synergistic Arrangement of Silk Fibers,” accepted for publication in Scientific Reports (2020).

        Speaker: Dr Jitraporn (Pimm) Vongsvivut (ANSTO - Australian Synchrotron)
      • 16:15
        Macrocyclic peptides as the novel chemical probes for modulating the function of the Retromer endosomal trafficking complex 20m

        Maintenance of appropriate levels of endocytic trafficking and subsequent sorting in endosomes is essential for every aspect of cellular life. The evolutionarily conserved Retromer complex (composed of VPS35-VPS26-VPS29) is a central hub responsible for this process in endosomal compartments in all eukaryotes. It is known that mutations in Retromer complex can cause late-onset Parkinson’s disease, and can also be hijacked by viral and bacterial pathogens during cellular infection. Seeking tools to modulate Retromer function would provide new avenues in understanding Retromer function and the associated diseases. Here we employed the random nonstandard peptides integrated discovery (RaPID) approach to identify a group of macrocyclic peptides capable of binding to Retromer with high affinity and specificity. Our crystal structures show that five of the macrocyclic peptides bind to Vps29 via a di-peptide Pro-Leu sequence. Interestingly, these peptides structurally mimic known interacting proteins including TBC1D5, VARP, and the bacterial effector RidL, and potently inhibit their interaction with Retromer in vitro and in cells. Further analysis using cryo-electron microscopy (CryoEM) and mutagenesis showed that a unique macrocyclic peptide binds Retromer at the interface between Vps35 and Vps26 subunits and can act as a molecular chaperone to stabilise the complex with minimal disruptive effects on Retromer’s ability to interact with its accessory proteins. Finally, using reversible cell permeabilization approach, we demonstrate that both the Retromer inhibiting and stabilizing macrocyclic peptides can specifically co-label Vps35-positive endosomal structures, and can be used as baits for purifying Retromer from cells and subsequent proteomic analyses. We believe these macrocyclic peptides can be used as a novel toolbox for the study of Retromer-mediated endosomal trafficking, and sheds light on developing novel therapeutic modifiers of Retromer function.

        Speaker: Dr Kai-En Chen (The University of Queensland, Institute for Molecular Bioscience)
      • 16:35
        Full-field tomography with scattered X-rays 20m

        X-ray absorption imaging relies on transmitted photons being absorbed by the subject. As a natural consequence, X-rays are also scattered in significant quantities in all directions. This makes it potentially feasible to do tomography and obtain 3D volumetric information by capturing photons using detectors placed around the subject. Scatter tomography has previously been attempted with pencil and sheet beam illumination, in order to limit the multiple-scattering of photons, which generates an unwanted background signal. At energies suitable for preclinical imaging, multiple-scattering is less problematic, making it possible to imagine doing tomography even with full-field X-ray illumination. With the aim of augmenting our existing full-field 2D imaging experiments with additional scatter detectors, we pursued this possibility. Here we present what we believe are the first successful X-ray Scatter Tomography experiments using full-field illumination, performed in 2019 at the Imaging & Medical Beamline, of the chest of a juvenile rat, achieving sufficient resolution for segmentation of the lung and major airways.

        Speaker: Gary Ruben (Monash University)
      • 16:55
        Further insights into the effect of pH on the fluorescence and structure of green fluorescent protein (GFP) 20m

        The Enhanced Green Fluorescent Protein (EGFP) has intense and natural fluorescence, and is biocompatible with a diversity of biological systems, which makes it promising for use in the development of biosensors. However, this commercial application is limited, mainly due to the high cost and lack of knowledge about EGFP stability under stress conditions. Although studies have been done into EGFP stability at different pH, they mostly only show the presence or lack of fluorescence, with no in-depth structural evaluations or analysis of the reversibility of the process. Bridging this knowledge gap can allow the development of novel biocompatible pH-biosensors for medical use, which can help in monitoring different diseases that are known for altering the pH of the affected areas, such as certain tumors and synovial diseases. Hence, the objective of this work was to evaluate the effect of pH on the fluorescence activity and structure of EGFP to assist in the development of biosensors.
        In this study, EGFP was exposed to different pH for 30 min and evaluated by circular dichroism, fluorescence spectroscopy (2D and 3D), intrinsic fluorescence, small-angle X-ray scattering (SAXS) in well-plates, and with size-exclusion chromatography (SEC-SAXS). Then, the pH of each sample was adjusted until the solution reached neutrality (pH 7.4), and after 60 min, EGFP was again evaluated by the same techniques. It was determined that EGFP is highly stable at neutral-alkaline pH (7.4 to 13.0), has a small fluorescence quenching at slightly acidic pH (6.0 and 5.0) and total quenching at pH ≤ 4.0. At pH 6.0, the fluorescence was almost completely recovered with the return of the pH to neutral, however, from pH values of 5.0 to 2.0, the fluorescence was only partially recovered. In addition, at pH 6.0 there was no change in the secondary and tertiary structure of EGFP (as observed by CD, SAXS, and SEC-SAXS) because the fluorescence quenching was only the result of reversible changes caused by protonation, considering the isoelectric point of the protein is 6.2. Between pH 5.0 to 2.0, the results indicate that there were structural changes at tertiary and secondary levels, hence EGFP recovery was only partial. Therefore, it is possible to conclude EGFP fluorescence is highly dependent on pH, exhibiting reversible changes in conformation between pH 6.0 and 7.0, and irreversible structural changes at pH ≤ 5.0. These properties make EGFP a very promising biomolecule for the development of novel acidic-to-basic pH-biosensors.
        Keywords: Green Fluorescent Protein, pH Stability, Biosensors, Circular Dichroism, SAXS.
        Financial support: FAPESP (2014/16424-7; 2014/19793-3; 2018/50009-8; 2018/01858-2; 2016/07529-5; 2018/20833-0), CAPES 001, CNPq and RMIT University.

        Speaker: Ms Nathalia V. dos Santos (São Paulo State University, Brazil / RMIT University, Australia)
    • 17:15 → 17:45
      Final Remarks, Prizes and Close 30m Zoom Webinar Room ()

      Zoom Webinar Room
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