842 research outputs found
Nitric oxide releasing plasma polymer coating with bacteriostatic properties and no cytotoxic side effects
No full textPublished on 19 March 2015We report a stable plasma polymer coating, using isopentyl nitrite as a volatile precursor, which releases nitric oxide at bacteriostatic concentrations when contacted with water, inhibiting bacterial growth without cytotoxic side effects to human mesenchymal stem/stromal cells.Thomas D. Michl, Bryan R. Coad, Michael Doran, Michael Osiecki, Morteza Hasanzadeh Kafshgari, Nicolas H. Voelcker, Amanda Hüsler, Krasimir Vasilev and Hans J. Griesse
Cell Wall Responses to Biotrophic Fungal Pathogen Invasion
No full textFirst published: 15 November 2019To a plant the surrounding environment is filled with microbial organisms looking to take advantage of the bountiful resources held within. In order for a pathogen to access the internal nutrients it must gain entry through the plant cell outer layers that consist of the cuticular wax and the plant cell wall. This barrier is a complex structure composed of diverse waxes, lipids, polysaccharides, proteins, lignin, and antimicrobial compounds and plays many crucial roles during plant defence, growth, and development. We now have more evidence than ever about the dynamic nature of the cell wall providing various interaction-dependent passive and active defence responses, hence justifying a necessity of evolving such a complex structure. Here we summarise the current understanding of this multi-layered defence system, using the biotrophic interaction between barley and the causal agent of powdery mildew, Blumeria graminis f. sp. hordei (Bgh).Jamil Chowdhury, Bryan R. Coad, Alan Littl
A substrate-independent method for surface grafting polymer layers by atom transfer radical polymerization: reduction of protein adsorption
No full textAvailable online 11 October 2011
Link to a related website: https://digital.library.adelaide.edu.au/dspace/bitstream/2440/111895/3/hdl_111895.pdf, Open Access via UnpaywallAbstract not availableBryan R. Coad, Yi Lu, Laurence Meaghe
Polyethyleneimine for copper absorption: kinetics, selectivity and efficiency in artificial seawater
No full textPublished on 29 May 2014.Polyethyleneimine (PEI) is known to bind copper ions effectively and selectively. However, this is the first report on PEI-based materials for copper scavenging from ultra-low concentrations in seawater matrixes. The findings are relevant for water purification and sensing applications as well as extraction of copper from oceans.Johan B. Lindén, Mikael Larsson, Bryan R. Coad, William M. Skinner and Magnus Nydé
A novel flash detection algorithm for single molecule counting with TIRF microscopy
No full textA novel algorithm, Adjacent Pixel Temporal Intensity Correlation (APTIC), was developed to detect single fluorescent molecules by their stochastic emission patterns; photoblinking and photobleaching. The algorithm was evaluated using simulated image data and Total Internal Reflection Fluorescence Microscopy (TIRF-M) to count the number fluorescently labelled protein molecules adsorbed onto glass substrates modified by Radio Frequency Glow Discharge (RFGD) deposition. By selecting an appropriate correlation threshold, the algorithm was capable of detecting synthetic flashes with a signal-to-noise ratio (SNR) as low as 2.0 with 90% sensitivity. The methodology holds great promise for mapping the amount and distribution of biomolecules on surfaces.Joseph Radford, Liyuan Wang, JingJing Li, Bryan R. Coad, Clive D. McFarland, Robert E. Nordo
ToF-SIMS multivariate analysis of surface-grafted small bioactive molecules
No full textLink to a related website: https://digital.library.adelaide.edu.au/dspace/bitstream/2440/113363/3/hdl_113363.pdf, Open Access via UnpaywallIn the development of bioactive coatings on biomaterials, it is essential to characterize the successful fabrication and the uniformity of intended coatings by sensitive surface analytical techniques, so as to ensure reliable interpretation of observed biointerfacial responses. This can, however, be challenging when small bioactive molecules are grafted onto biomaterials surfaces at sub- and near-monolayer densities. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides the required sensitivity, but ion signals from small grafted molecules may still be dominated by fragment ions from the underlying polymer. In such cases, multivariate analysis provides valuable enhancement of spectral data, as illustrated here by examples comprising the surface grafting of bioactive serrulatane molecules, the peptide GRGDSP, the oligonucleotide 15-thymidine, and the antifungal compound Amphotericin B. The authors also show how ToF-SIMS plus principal component analysis can distinguish between covalent grafting and physisorption of the antibiotics caspofungin and micafungin.Marek Jasieniak, Bryan R. Coad and Hans J. Griesser
Antifungal coatings by caspofungin immobilization onto biomaterials surfaces via a plasma polymer interlayer
No full textPublished Online: 14 October 2015
Link to a related website: https://digital.library.adelaide.edu.au/dspace/bitstream/2440/123749/2/hdl_123749.pdf, Open Access via UnpaywallNot only bacteria but also fungal pathogens, particularly Candida species, can lead to biofilm infections on biomedical devices. By covalent grafting of the antifungal drug caspofungin, which targets the fungal cell wall, onto solid biomaterials, a surface layer can be created that might be able to provide long-term protection against fungal biofilm formation. Plasma polymerization of propionaldehyde (propanal) was used to deposit a thin (∼20 nm) interfacial bonding layer bearing aldehyde surface groups that can react with amine groups of caspofungin to form covalent interfacial bonds for immobilization. Surface analyses by x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry confirmed the intended grafting and uniformity of the coatings, and durability upon extended washing. Testing for fungal cell attachment and ensuing biofilm formation showed that caspofungin retained activity when covalently bound onto surfaces, disrupting colonizing Candida cells. Mammalian cytotoxicity studies using human primary fibroblasts indicated that the caspofungin-grafted surfaces were selective in eliminating fungal cells while allowing attachment and spreading of mammalian cells. These in vitro data suggest promise for use as antifungal coatings, for example, on catheters, and the use of a plasma polymer interlayer enables facile transfer of the coating method onto a wide variety of biomaterials and biomedical devices.Stefani S. Griesser, Marek Jasieniak, Bryan R. Coad, and Hans J. Griesse
Individual and population quantitative analyses of calcium flux in T-cells activated on functionalized material surfaces
No full textWe have developed a novel method for activating T-cells on material surfaces that enable individual and population-based analyses of intracellular calcium flux, as a quantitative measure of T-cell receptor engagement. Functionalized material surfaces were created using a plasma-polymerized foundation layer to immobilize stimulatory T-cell ligands, which could induce T-cell receptor-dependent calcium flux in naive T-cells. Real-time confocal microscopic detection and quantification of calcium flux using paired fluorescent ratiometric probes facilitated the tracking and analysis of response profiles of individual T-cells, as well as population analyses using a combination of individual T-cell events. This type of combined analysis cannot be achieved using traditional population-based flow cytometric approaches, and thus provides a logical step towards developing the capacity to assess the magnitude and quality of inherently heterogeneous effector T-cell responses to antigenic challenge.Susan N. Christo, Ghafar. T. Sarvestani, Stefani S. Griesser, Bryan R. Coad, Hans J. Griesser, Krasimir Vasilev, Michael P. Brown, Kerrilyn R. Diener and John D. Haybal
The Re-Valuation of William Jennings Bryan In Woodrow Wilson\u27s Administration
No full textThe Re-evaluation of William Jennings Bryan in Woodrow Wilson’s Administration is a study of the relationships of William Jennings Bryan, Secretary of State, Edward M. House, uncommissioned agent of Woodrow Wilson, Walter Hines Page, United States. Ambassador to England, and Woodrow Wils0n, President of the United States. The author’s purpose in writing this thesis is to throw light upon the machinations that were carried on behind the back of William Jennings Bryan, as Secretary of State in Woodrow Wilson\u27s Administration. This investigation gives to Bryan a higher and more reputable position in American history than he is usually accorded. In order to accomplish this task it was necessary to re-evaluate The Intimate Papers of Colonel House which covers the Colonel\u27s early youth up to the end of World War I. The period 1912-1915 was given special attention. The author does not contend that Bryan should have been given the appointment, nor does he contend that there were not others who could have served in the capacity of Secretary of State with more ability than Bryan. The author does contend that with all the handicaps that Bryan faced, the Commoner performed his duty to the American people admirably
Professor Bryan Harris Remembered: Volez to a Pierce Law Friend
No full textBryan Harris, MA (Oxon), passed away recently in his beloved native England, after a brief illness. His wife Mary, two sons and a daughter survive him. Bryan Harris had a long and distinguished career as an author, educator, barrister, diplomat, publisher and lobbyist. He was a consultant on European Union policies and laws to commercial and professional firms and associations. For almost three decades he was a Member of the Board of Trustees and Adjunct Professor of European Union Law at Pierce Law. Pierce Law President and Dean, John Hutson summed up what many members of the Pierce Law community expressed to me as I prepared this tribute saying, I think of Bryan mostly in single words ... jovial, cheerful, humble, dignified, diplomatic, caring ... Dean Huston shared that Professor Harris will be recognized during the 2004 Commencement
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