Publications by authors named "Gunning R"

Background: Drug shortages are a complex global challenge, and few studies have analyzed quantitative data on their impacts. In September 2019, detection of a nitrosamine impurity in ranitidine led to recalls and shortages.

Aims: We investigated the extent of the ranitidine shortage and its impacts on acid suppression drug utilization in Canada and the United States (US).

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Objective: A shared care model was implemented in 2006 in Queensland to facilitate paediatric oncology, haematology and palliative care patients receiving care as close to home as possible. Following initial diagnosis, care planning and treatment at the tertiary children's hospital, appropriate local care was coordinated by Regional Case Managers (RCMs) established at each of 10 Shared Care Units (SCUs). This enabled safe and quality regional care supported by a statewide network providing clinical governance and education.

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Generally repressed by epigenetic mechanisms, retrotransposons represent around 40% of the murine genome. At the Agouti viable yellow (A) locus, an endogenous retrovirus (ERV) of the intracisternal A particle (IAP) class retrotransposed upstream of the agouti coat-color locus, providing an alternative promoter that is variably DNA methylated in genetically identical individuals. This results in variable expressivity of coat color that is inherited transgenerationally.

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Spinosad has been widely used in Australia to control western flower thrips Frankliniella occidentalis (Pergande) but spinosad usefulness is now compromised by resistance. Here we studied a highly spinosad resistant strain of F. occidentalis to explore if esterases had a role in spinosad resistance.

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We present an investigation on the optimisation of solid-state dye sensitized solar cells (SDSCs) comprising mesoporous tin oxide photoanodes infiltrated with poly(3-hexylthiophene-2,5-diyl) (P3HT) hole conductor and sensitized with an organic dye. We chose both the SnO(2) and P3HT for their high charge carrier mobilities and conductivities, but as a result preclude conventional device configurations because of high leakage current and low shunt-resistance. To minimize the "hole leakage current" through the FTO anode, we employed a double compact layer structure, and to minimize "electron leakage current" at the silver cathode, we developed a protocol for depositing an optimal P3HT "capping layer".

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According to geographical distribution, Nezara viridula (Heteroptera: Pentatomidae) can be found across tropical, subtropical, and temperate regions and this pattern is assumed to reflect differences in thermal adaptation, particularly in cold tolerance. Here the lethal temperature (LT) and critical thermal limits (CTL) (thermal tolerance) are examined for N. viridula.

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Nanothin sheets made of zinc sulfate hydroxide hydrate, ZnSO4[Zn(OH)2]3 x 5H2O, are easily and quickly prepared using an innovative electrochemical route onto polypyrrole-polystyrene sulfonate (PPy-PSS) films. The sheets are characterized using a range of experimental techniques. The deposits are formed on the film surface with instantaneous nucleation to grow into a network of entangled nanosheets.

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Background: The objective of this study was to describe the severity of oral/facial problems occurring in Navy and Marine Corps personnel deployed to Iraq.

Methods: Data documented by Navy Dental Officers deployed to Iraq were used to determine the number and type of oral/facial problems treated and to determine the percentages of severe, moderately severe, and pain/loss of function oral/facial problems treated in Iraq from March 2008 through February 2009.

Results: During the year of data collection, a total of 13,933 dental visits were documented for Navy and Marine Corps personnel.

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Background: A study was undertaken to determine the efficacy of seven natural compounds compared with piperonyl butoxide (PBO) in synergising pyrethrum, with the intention of formulating an effective natural synergist with pyrethrum for use in the organic crop market.

Results: Discriminating dose bioassays showed PBO to be significantly more effective at synergising pyrethrum in houseflies than the seven natural compounds tested, causing 100% mortality in insecticide-susceptible WHO and resistant 381zb strains of housefly. The most effective natural synergists against WHO houseflies were dillapiole oil, grapefruit oil and parsley seed oil, with 59, 50 and 41% mortality respectively, compared with 18% mortality with unsynergised pyrethrum.

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High yields of single-crystalline Ge nanowires (NWs) were synthesised in the vapour phase of a high boiling point organic solvent without the need for metal catalyst particles. High density, perpendicular arrays of Ge NWs were subsequently grown from ITO coated substrates. The approach represents a convenient route toward orientated arrays of catalyst-free Ge NWs.

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Coulomb repulsion due to the surface charge on semi-conductor nanorods works against the dipole-dipole attraction that tends to direct the nanorods to self-assemble; the nature of this self-assembly for CdSe nanorods can be thus altered by pyridine washing, which charges the rods surface--thereby allowing the Coulomb repulsion to tailor the alignment.

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A multi rate kinetic model to explain the spontaneous oriented attachment of CdS nanorods in the presence of an amine is presented. The model demonstrates the reasons that elongation is restricted to a maximum of quadruple, the starting rod length for rods of a certain aspect ratio (8 × 30 nm) with no elongation occurring for rods of a shorter aspect ratio. The rate constants for all possible attachment events are determined showing that elongation by attachment occurs sequentially by single rod addition alone.

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This paper presents a facile method for decreasing the size of water dispersible Ni nanoparticles from 30 to 3 nm by the incorporation of a passivating surfactant combination of pluronic triblock copolymer and oleic acid into a wet chemical reduction synthesis. A detailed study revealed that the size of the Ni nanoparticles is not only critically governed by the concentration of the triblock copolymers but also dependent on the hydrophobic nature of the micelle core formed. The synthesized Ni nanoparticles were thoroughly characterized by means of transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and temperature and field dependent magnetic measurements, along with a comprehensive Fourier transform infrared spectroscopy analysis, in order to predict a possible mechanism of formation.

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Spontaneous elongation from nanorod to nanowire in the presence of an amine is reported for nanocrystals of cadmium sulfide and silver sulfide (cation exchanged from CdS). Elongation occurs instantaneously where the final aspect ratio is a controllable multiple of the original nanorod length. Transmission electron microscopy (TEM) analysis reveals the influential factors on the attachment process are the concentration of amine, duration and temperature of the reaction.

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Background: Permethrin is the active component of topical creams widely used to treat human scabies. Recent evidence has demonstrated that scabies mites are becoming increasingly tolerant to topical permethrin and oral ivermectin. An effective approach to manage pesticide resistance is the addition of synergists to counteract metabolic resistance.

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Background: Previous work has demonstrated that piperonyl butoxide (PBO) not only inhibits microsomal oxidases but also resistance-associated esterases. The ability to inhibit both major metabolic resistance enzymes makes it an ideal synergist to enhance xenobiotics but negates the ability to differentiate which enzyme group is responsible for conferring resistance.

Results: This study examines an analogue that retains the ability to inhibit esterases but is restricted in its ability to act on microsomal oxidases, thus allowing an informed decision on resistance enzymes to be made when used in conjunction with the parent molecule.

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Background: Piperonyl butoxide (PBO) effectively synergises synthetic pyrethroids, rendering even very resistant insect pests susceptible, provided a temporal element is included between exposure to synergist and insecticide. This concept is now applied to carbamates and neonicotinoids.

Results: A microencapsulated formulation of PBO and pirimicarb reduced the resistance factor in a clone of Myzus persicae (Sulzer) from >19 000- to 100-fold and in Aphis gossypii (Glover) from >48 000- to 30-fold.

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It has been reported previously that the major resistance mechanism to pyrethroid insecticides by the cotton bollworm Helicoverpa armigera (Hübner) in Australia is a consequence of overproduction of esterase isoenzymes. This paper reports structure-activity relationships that support such a view, based on in vivo bioassays conducted with a range of pyrethroid structures containing a variety of acid and alcohol moieties and the correlation with in vitro esterase inhibition assays against the same structures, and identifies the critical regions of the molecule with regard to esterase inhibition, and hence resistance. The implications of this work in terms of possible resistance management are evaluated and discussed.

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A microencapsulated formulation that gives a burst release of piperonyl butoxide (PBO) several hours before a burst release of a conventional pyrethroid can effectively overcome metabolic resistance in Bemisia tabaci Gennadius, Helicoverpa armigera (Hübner), Aphis gossypii Glover and Myzus persicae Sulzer. This increase in efficacy against resistant pests was reflected in a field trial against B. tabaci on cotton, eliminating the need for two treatments.

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B-biotype Bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and horticultural industries. Control of this insect is hampered by resistance to many acetylcholinesterase (AChE)-inhibiting insecticides, such as organophosphates and carbamates. Consequently, insect growth regulators such as buprofezin, which act by inhibiting chitin synthesis, are being investigated for use against B-biotype B.

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The cotton bollworm, Helicoverpa armigera, is a cosmopolitan, insecticide-resistant insect pest of food and fiber (Gunning et al., 1992). Acetylcholinesterase (AChE) is the insect target site for carbamate insecticides, and H.

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Pyrethroid resistance in B-type Bemisia tabaci Gennadius and Australian Helicoverpa armigera Hübner field populations is primarily conferred by esterase isoenzymes which metabolise and sequester pyrethroid insecticides. It has been shown previously that pyrethroid resistance-associated esterases in H. armigera are inhibited by the insecticide synergist piperonyl butoxide (PBO) over a 22-h period.

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In Australia, the cotton bollworm, Helicoverpa armigera, has a long history of resistance to conventional insecticides. Transgenic cotton (expressing the Bacillus thuringiensis toxin Cry1Ac) has been grown for H. armigera control since 1996.

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Pyrethroid resistance in field populations of Australian Helicoverpa armigera (Hübner) is primarily a consequence of the overproduction of esterase isoenzymes which metabolise and sequester pyrethroid insecticides. Biochemical studies have shown that pyrethroid-resistance-associated esterases in H armigera are inhibited by the insecticide synergist piperonyl butoxide (PBO). Esterase inhibition by PBO did not occur immediately after dosing, but exhibited maximum inhibition 3-4 h after dosage.

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