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The Development of Functionally Tunable Hierarchical Nanomaterials
Superatomic crystals (SACs) with tunable physical properties offer a new approach to the design of inorganic nanomaterials. Very little is known about how these systems function, or how their properties can be transformed. Here I describe work that helps to develop an understanding of how functional properties behave in SACs, and how they can be altered through superatomic intercalation or with phase transitions.
Chapter 1 describes work characterizing the thermal transport behavior of SACs. We find that heat transfer is dominated by coherent inter-cluster phonons with vibrational frequencies determined by the periodicity of the SAC superstructure. We also demonstrate a transformation from amorphous to crystalline thermal transport behavior through manipulation of the vibrational landscape and orientational order of the superatoms.
Chapters 2 and 3 describe the intercalation of a porous superatomic host, [Co₆Te₈(PⁿPr₃)₆][C₆₀]₃. We find that guests can be inserted into the superstructure through single-crystal-to-single-crystal transformations, dramatically transforming the electronic properties of the SAC. Using electronic absorption spectroscopy, electrical transport measurements and electronic structure calculations, we demonstrate that the intercalation is driven by the exchange of charge between the host, establishing an exciting design space for the preparation of superatomic materials.
Chapter 4 describes a hierarchical solid, [Co₆Te₈(PEt₃)₆][C₇₀]₂, in which the delicate balance of interactions between constituent building blocks produces two separate phase transitions: one affecting thermal transport properties, the other transforming the electronic and magnetic behavior of the SAC. We use a wide range of structural and spectroscopic characterization tools to understand the mechanism of each transformation. This work establishes a new ability to program functional phase transitions into cluster-assembled materials.
In a completely different area of study, chapter 5 describes a new covalent organic framework (COF) whose unique structure enables a post-synthetic topochemical polymerization of the framework’s linker fragments. The polymerization of the 1-3 butadiyne into a polydiacetylene backbone covalently crosslinks the material without compromising its original crystallinity. This work not only enables the preparation of more structurally resilient COFs, but also diversifies the design space for this emerging class of materials
Safety and efficacy of midline catheters versus peripheral intravenous catheters: A pilot randomized controlled trial
Background: Despite pervasive need for peripheral intravenous catheters, insertion is often difficult, and approximately two thirds fail prematurely. Midline catheters are an alternative long peripheral catheter, inserted in the upper arm, ideal for patients with difficult access.
Aim: The aim of this study is to test feasibility of the protocol and compare the efficacy and safety of midline catheters to peripheral intravenous catheters.
Design: A parallel-group, pilot randomized controlled trial of adult medical/surgical hospitalized patients, from a single Australian referral hospital.
Methods: Participants with difficult vascular access (≤2 palpable veins) and/or anticipated ≥5 days of peripherally compatible intravenous therapy were recruited between May 2019 and March 2020. Participants were randomized to (1) peripheral intravenous catheter or (2) midline catheter. Primary feasibility outcome measured eligibility, recruitment, protocol adherence, retention and attrition. Primary clinical outcomes measured device insertion failure and post-insertion failure.
Results: In total, n = 143 participants (71 peripheral intravenous catheters and 72 midline catheters) were recruited; n = 139 were analysed. Most feasibility criteria were met. Peripheral intravenous catheters had shorter functional dwell time, with higher incidence of post-insertion failure compared to midline catheters.
Conclusion: Midline catheters appear to be superior for patients with difficult vascular access or receiving prolonged intravenous therapy; a large, multi-centre trial to confirm findings is feasible
Discovery of a pulsar-powered bow shock nebula in the Small Magellanic Cloud supernova remnant DEMS5
We report the discovery of a new Small Magellanic Cloud pulsar wind nebula (PWN) at the edge of the supernova remnant (SNR) DEMS5. The pulsar powered object has a cometary morphology similar to the Galactic PWN analogues PSR B1951+32 and ´the mouse´. It is travelling supersonically through the interstellar medium.We estimate the pulsar kick velocity to be in the range of 700-2000 km s-1 for an age between 28 and 10 kyr. The radio spectral index for this SNR-PWN-pulsar system is flat (-0.29 ± 0.01) consistent with other similar objects. We infer that the putative pulsar has a radio spectral index of -1.8, which is typical for Galactic pulsars. We searched for dispersion measures up to 1000 cm-3 pc but found no convincing candidates with an S/N greater than 8. We produce a polarization map for this PWN at 5500 MHz and find a mean fractional polarization of P ∼ 23 per cent. The X-ray power-law spectrum (τ ∼ 2) is indicative of non-thermal synchrotron emission as is expected from PWN-pulsar system. Finally, we detect DEMS5 in infrared (IR) bands. Our IR photometric measurements strongly indicate the presence of shocked gas that is expected for SNRs. However, it is unusual to detect such IR emission in an SNR with a supersonic bow shock PWN.We also find a low-velocity HI cloud of ∼107 km s-1 that is possibly interacting with DEMS5. SNR DEMS5 is the first confirmed detection of a pulsar-powered bow shock nebula found outside the Galaxy.Fil: Alsaberi, Rami Z. E.. Western Sydney University; AustraliaFil: Maitra, C.. Max Planck Institut Für Extraterrestrische Physik; AlemaniaFil: Filipovic, M. D.. Western Sydney University; AustraliaFil: Bozzetto, L.M.. Western Sydney University; AustraliaFil: Haberl, F.. Max Planck Institut Für Extraterrestrische Physik; AlemaniaFil: Maggi, P.. Université de Strasbourg; FranciaFil: Sasaki, M.. Universitat Erlangen-Nuremberg; AlemaniaFil: Manjolovic, P.. Western Sydney University; AustraliaFil: Velovic, V.. University Of Belgrade; SerbiaFil: Kavanagh, P.. Dublin Institute For Advanced Studies; IrlandaFil: Maxted, N. I.. University Of New South Wales (unsw) Australia; AustraliaFil: Urosevic, D.. Isaac Newton Institute Of Chile; ChileFil: Rowell, G. P.. University of Adelaide; AustraliaFil: Wong, G. F.. University Of New South Wales (unsw) Australia; AustraliaFil: For, B. Q.. The University Ofwestern Australia; AustraliaFil: O'Brien, A. N.. Western Sydney University; AustraliaFil: Galvin, T. J.. Western Sydney University; AustraliaFil: Staveley-Smith, L.. The University Ofwestern Australia; AustraliaFil: Norris, R. P.. Western Sydney University; AustraliaFil: Jarrett, T.. University Of Cape Town; SudáfricaFil: Kothes, R.. National Research Council Canada; CanadáFil: Luken, K. J.. Western Sydney University; AustraliaFil: Hurley-Walker, N.. Curtin University; AustraliaFil: Sano, H.. Nagoya University; JapónFil: Onic, D.. University Of Belgrade; SerbiaFil: Dai, S. T.. Australia Telescope National Facility; AustraliaFil: Pannuti, G.. Morehead State University; Estados UnidosFil: Tothill, N. F. H.. Western Sydney University; AustraliaFil: Crawford, Evan. Western Sydney University; AustraliaFil: Yew, M.. Western Sydney University; AustraliaFil: Bojicic, I.. Western Sydney University; AustraliaFil: Dénes, H.. Netherlands Foundation For Research In Astronomy; BélgicaFil: McClure-Griffiths, N.. Australian National University; AustraliaFil: Gurovich, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Fukui, Y.. Nagoya University; Japó
Characterization of the apoptotic response of human leukemia cells to organosulfur compounds
Background: Novel therapeutic agents that selectively induce tumor cell death are urgently needed in the clinical management of cancers. Such agents would constitute effective adjuvant approaches to traditional chemotherapy regimens. Organosulfur compounds (OSCs), such as diallyl disulfide, have demonstrated anti-proliferative effects on cancer cells. We have previously shown that synthesized relatives of dysoxysulfone, a natural OSC derived from the Fijian medicinal plant, Dysoxylum richi, possess tumor-specific antiproliferative effects and are thus promising lead candidates.
Methods: Because our structure-activity analyses showed that regions flanking the disulfide bond mediated specificity, we synthesized 18 novel OSCs by structural modification of the most promising dysoxysulfone derivatives. These compounds were tested for anti-proliferative and apoptotic activity in both normal and leukemic cells.
Results: Six OSCs exhibited tumor-specific killing, having no effect on normal bone marrow, and are thus candidates for future toxicity studies. We then employed mRNA expression profiling to characterize the mechanisms by which different OSCs induce apoptosis. Using Gene Ontology analysis we show that each OSC altered a unique set of pathways, and that these differences could be partially rationalized from a transcription factor binding site analysis. For example, five compounds altered genes with a large enrichment of p53 binding sites in their promoter regions (p < 0.0001).
Conclusions: Taken together, these data establish OSCs derivatized from dysoxysulfone as a novel group of compounds for development as anti-cancer agents
The Evolutionary Map of the Universe Pilot Survey
We present the data and initial results from the first pilot survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The survey covers 270 deg2 of an area covered by the Dark Energy Survey, reaching a depth of 25–30 μJy beam−1 rms at a spatial resolution of ∼11–18 arcsec, resulting in a catalogue of ∼220 000 sources, of which ∼180 000 are single-component sources. Here we present the catalogue of single-component sources, together with (where available) optical and infrared cross-identifications, classifications, and redshifts. This survey explores a new region of parameter space compared to
previous surveys. Specifically, the EMU Pilot Survey has a high density of sources, and also a high sensitivity to low surface brightness emission. These properties result in the detection of types of sources that were rarely seen in or absent from previous surveys. We present some of these new results here
Time course study of oxidative and nitrosative stress and antioxidant enzymes in K(2)Cr(2)O(7)-induced nephrotoxicity
BACKGROUND: Potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity is associated with oxidative and nitrosative stress. In this study we investigated the relation between the time course of the oxidative and nitrosative stress with kidney damage and alterations in the following antioxidant enzymes: Cu, Zn superoxide dismutase (Cu, Zn-SOD), Mn-SOD, glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT). METHODS: Nephrotoxicity was induced in rats by a single injection of K(2)Cr(2)O(7). Groups of animals were sacrificed on days 1,2,3,4,6,8,10, and 12. Nephrotoxicity was evaluated by histological studies and by measuring creatinine clearance, serum creatinine, blood urea nitrogen (BUN), and urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) and total protein. Oxidative and nitrosative stress were measured by immunohistochemical localization of protein carbonyls and 3-nitrotyrosine, respectively. Cu, Zn-SOD, Mn-SOD, and CAT were studied by immunohistochemical localization. The activity of total SOD, CAT, GPx, and GR was also measured as well as serum and kidney content of chromium and urinary excretion of NO(2 )(-)/NO(3)(-). Data were compared by two-way analysis of variance followed by a post hoc test. RESULTS: Serum and kidney chromium content increased reaching the highest value on day 1. Nephrotoxicity was made evident by the decrease in creatinine clearance (days 1–4) and by the increase in serum creatinine (days 1–4), BUN (days 1–6), urinary excretion of NAG (days 1–4), and total protein (day 1–6) and by the structural damage to the proximal tubules (days 1–6). Oxidative and nitrosative stress were clearly evident on days 1–8. Urinary excretion of NO(2)(-)/NO(3)(- )decreased on days 2–6. Mn-SOD and Cu, Zn-SOD, estimated by immunohistochemistry, and total SOD activity remained unchanged. Activity of GPx decreased on days 3–12 and those of GR and CAT on days 2–10. Similar findings were observed by immunohistochemistry of CAT. CONCLUSION: These data show the association between oxidative and nitrosative stress with functional and structural renal damage induced by K(2)Cr(2)O(7). Renal antioxidant enzymes were regulated differentially and were not closely associated with oxidative or nitrosative stress or with kidney damage. In addition, the decrease in the urinary excretion of NO(2)(-)/NO(3)(- )was associated with the renal nitrosative stress suggesting that nitric oxide was derived to the formation of reactive nitrogen species involved in protein nitration
The NORMAN Suspect List Exchange (NORMAN-SLE): facilitating European and worldwide collaboration on suspect screening in high resolution mass spectrometry
Background: The NORMAN Association (https://www.norman-.network.com/) initiated the NORMAN Suspect List Exchange (NORMAN-SLE; https://www.norman-.network.com/nds/SLE/) in 2015, following the NORMAN collaborative trial on non-target screening of environmental water samples by mass spectrometry. Since then, this exchange of information on chemicals that are expected to occur in the environment, along with the accompanying expert knowledge and references, has become a valuable knowledge base for "suspect screening" lists. The NORMAN-SLE now serves as a FAIR (Findable, Accessible, Interoperable, Reusable) chemical information resource worldwide.Results: The NORMAN-SLE contains 99 separate suspect list collections (as of May 2022) from over 70 contributors around the world, totalling over 100,000 unique substances. The substance classes include per- and polyfluoroalkyl substances (PFAS), pharmaceuticals, pesticides, natural toxins, high production volume substances covered under the European REACH regulation (EC: 1272/2008), priority contaminants of emerging concern (CECs) and regulatory lists from NORMAN partners. Several lists focus on transformation products (TPs) and complex features detected in the environment with various levels of provenance and structural information. Each list is available for separate download. The merged, curated collection is also available as the NORMAN Substance Database (NORMAN SusDat). Both the NORMAN-SLE and NORMAN SusDat are integrated within the NORMAN Database System (NDS). The individual NORMAN-SLE lists receive digital object identifiers (DOIs) and traceable versioning via a Zenodo community (https:// zenodo.org/communities/norman-.sle), with a total of > 40,000 unique views, > 50,000 unique downloads and 40 citations (May 2022). NORMAN-SLE content is progressively integrated into large open chemical databases such as PubChem (https://pubchem.ncbi.nlm.nih.gov/) and the US EPA's CompTox Chemicals Dashboard (https://comptox. epa.gov/dashboard/), enabling further access to these lists, along with the additional functionality and calculated properties these resources offer. PubChem has also integrated significant annotation content from the NORMAN-SLE, including a classification browser (https://pubchem.ncbi.nlm.nih.gov/classification/#hid=101).Conclusions: The NORMAN-SLE offers a specialized service for hosting suspect screening lists of relevance for the environmental community in an open, FAIR manner that allows integration with other major chemical resources. These efforts foster the exchange of information between scientists and regulators, supporting the paradigm shift to the "one substance, one assessment" approach. New submissions are welcome via the contacts provided on the NORMAN-SLE website (https://www.norman-.network.com/nds/SLE/)
In Support of a Patient-Driven Initiative and Petition to Lower the High Price of Cancer Drugs
Comment in
Lowering the High Cost of Cancer Drugs--III. [Mayo Clin Proc. 2016]
Lowering the High Cost of Cancer Drugs--I. [Mayo Clin Proc. 2016]
Lowering the High Cost of Cancer Drugs--IV. [Mayo Clin Proc. 2016]
In Reply--Lowering the High Cost of Cancer Drugs. [Mayo Clin Proc. 2016]
US oncologists call for government regulation to curb drug price rises. [BMJ. 2015
Measurement-induced entanglement and teleportation on a noisy quantum processor
Measurement has a special role in quantum theory: by collapsing the
wavefunction it can enable phenomena such as teleportation and thereby alter
the "arrow of time" that constrains unitary evolution. When integrated in
many-body dynamics, measurements can lead to emergent patterns of quantum
information in space-time that go beyond established paradigms for
characterizing phases, either in or out of equilibrium. On present-day NISQ
processors, the experimental realization of this physics is challenging due to
noise, hardware limitations, and the stochastic nature of quantum measurement.
Here we address each of these experimental challenges and investigate
measurement-induced quantum information phases on up to 70 superconducting
qubits. By leveraging the interchangeability of space and time, we use a
duality mapping, to avoid mid-circuit measurement and access different
manifestations of the underlying phases -- from entanglement scaling to
measurement-induced teleportation -- in a unified way. We obtain finite-size
signatures of a phase transition with a decoding protocol that correlates the
experimental measurement record with classical simulation data. The phases
display sharply different sensitivity to noise, which we exploit to turn an
inherent hardware limitation into a useful diagnostic. Our work demonstrates an
approach to realize measurement-induced physics at scales that are at the
limits of current NISQ processors
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